KR20220038762A

KR20220038762A - Method of making silver nanowire dispersion

Info

Publication number: KR20220038762A
Application number: KR1020227006522A
Authority: KR
Inventors: 마사나오 하라; 히데키 오하타; 시게루 야마키; 마사히코 토바
Original assignee: 쇼와 덴코 가부시키가이샤
Priority date: 2019-12-27
Filing date: 2020-12-18
Publication date: 2022-03-29
Also published as: JPWO2021132095A1; WO2021132095A1; CN114302778A; TW202138043A

Abstract

(과제) 은 나노와이어 및 구조 규정제를 포함하고, 은 농도가 1.0질량% 이상인 은 나노와이어 조분산액을 크로스 플로우 여과법을 이용하여 정제하여, 고수율로 고순도의 은 나노와이어 분산액을 제조한다.
(해결 수단) 은 나노와이어의 수/전체 입자의 수 > 90%인 은 나노와이어와 구조 규정제를 포함하고, 은 농도가 1.0질량% 이상인 은 나노와이어 조분산액을 준비하는 공정(S1∼S6)과, 상기 은 나노와이어 조분산액을 순환식의 크로스 플로우 여과법에 의해 정제하는 크로스 플로우 여과 공정(S7)을 포함하는 은 나노와이어 분산액의 제조 방법.(Project) Purifying a coarse dispersion of silver nanowires containing silver nanowires and a structure defining agent and having a silver concentration of 1.0% by mass or more using cross flow filtration to prepare a high-purity silver nanowire dispersion in high yield.
(Solution) A step of preparing a coarse dispersion of silver nanowires containing silver nanowires having a number of silver nanowires/total number of particles > 90% and a structure defining agent, and having a silver concentration of 1.0% by mass or more (S1 to S6) and a cross flow filtration step (S7) of purifying the silver nanowire coarse dispersion by a circulating cross flow filtration method.

Description

은 나노와이어 분산액의 제조 방법Method of making silver nanowire dispersion

본 발명은 은 나노와이어 분산액의 제조 방법에 관한 것이다.The present invention relates to a method for preparing a dispersion of silver nanowires.

은 나노와이어는 지름이 나노미터 오더의 와이어 형상(선상)의 은으로 이루어지는 도전성 재료이다. 은 나노와이어에 의해 형성된 도전층(박막)은 도전성 및 광투과성이 높으므로, 예를 들면 터치패널의 투명 전극 재료 등에 사용되고 있다. The silver nanowire is a conductive material made of silver having a wire shape (linear shape) with a diameter on the order of nanometers. A conductive layer (thin film) formed of silver nanowires has high conductivity and light transmittance, and is therefore used, for example, as a material for a transparent electrode of a touch panel.

이러한 은 나노와이어의 제조 방법으로서는, 예를 들면 하기 비특허문헌 1에 기재된 바와 같이, 폴리올(글리콜 용매) 중에서 은염을 환원하는 방법(폴리올 환원법)이 있다. As a manufacturing method of such a silver nanowire, as described in the following nonpatent literature 1, there exists a method (polyol reduction method) of reducing a silver salt in polyol (glycol solvent), for example.

폴리올 환원법으로 은 나노와이어를 제조했을 경우, 합성액 중에는 은 나노와이어 이외에, 폴리올(글리콜) 용매, 보호제로서 사용하는 폴리머, 부생하는 은 나노입자 등이 혼재하기 때문에, 은 나노와이어의 분산액을 여과(전량 여과)나 원심 침강함으로써 불필요한 물질을 제거하여, 은 나노와이어만을 단리할 필요가 있다. 그러나, 이 방법에서는 단리 시에 은 나노와이어에 응력이 가해지기 때문에, 대 스케일로의 제조로 이루어질수록 은 나노와이어가 응집하기 쉬워서 재분산이 곤란해진다고 하는 문제가 있었다.When silver nanowires are produced by the polyol reduction method, in addition to the silver nanowires, polyol (glycol) solvent, a polymer used as a protective agent, silver nanoparticles, etc. are mixed in the synthesis solution, so the dispersion of silver nanowires is filtered ( It is necessary to remove unnecessary substances by filtration) or centrifugal sedimentation to isolate only silver nanowires. However, in this method, since stress is applied to silver nanowires at the time of isolation|separation, there existed a problem that silver nanowires aggregate easily, and redispersion becomes difficult, so that manufacture on a large scale was made.

그래서, 하기 특허문헌 1∼7에는, 크로스 플로우 여과를 사용해서 배치식으로 은 나노와이어가 분산된 분산액을 여과, 정제하는 기술이 개시되어 있다. 크로스 플로우 여과를 사용했을 경우, 은 나노와이어의 응집을 억제할 수 있다. Then, to the following patent documents 1-7, the technique of filtration and refinement|purification of the dispersion liquid in which silver nanowires were disperse|distributed in batch type using cross flow filtration is disclosed. When cross-flow filtration is used, aggregation of silver nanowires can be suppressed.

특허문헌 1에는 한외여과막을 사용한 막 분리법에 의해 은 나노와이어 분산액으로부터 친수성 고분자 또는 양친매성 분자인 형태 제어제를 제거하는 방법이 개시되어 있다. 특허문헌 2∼5에는 0.4% 이하의 희박한 은 농도의 분산액을 크로스 플로우 여과를 이용하여 정제하는 방법이 개시되어 있다. 특허문헌 6, 7에는 반응 액에 아세톤을 20배량 첨가하고, 정치 후 디캔테이션하는 방법(세정 공정)을 반복함으로써, 과잉의 유기 보호제나 은 나노입자를 어느 정도 제거한 후, 크로스 플로우 여과를 행함으로써 길이 1∼5㎛ 정도의 와이어를 더욱 제거하는 방법이 개시되어 있다.Patent Document 1 discloses a method for removing a shape controlling agent, which is a hydrophilic polymer or an amphiphilic molecule, from a silver nanowire dispersion by a membrane separation method using an ultrafiltration membrane. Patent Documents 2 to 5 disclose a method for purifying a dispersion having a thin silver concentration of 0.4% or less by using cross flow filtration. In Patent Documents 6 and 7, 20 times the amount of acetone is added to the reaction solution and the method (washing step) of decantation after standing is repeated to remove excess organic protective agent and silver nanoparticles to some extent, and then cross flow filtration is performed. A method of further removing a wire having a length of about 1 to 5 μm is disclosed.

일본 특허공개 2009-129732호 공보Japanese Patent Laid-Open No. 2009-129732 국제공개 제 WO2009/107694호 공보International Publication No. WO2009/107694 일본 특허공개 2010-84173호 공보Japanese Patent Laid-Open No. 2010-84173 일본 특허공개 2013-199690호 공보Japanese Patent Laid-Open No. 2013-199690 US 공개 2018-354039호 공보US Publication No. 2018-354039 일본 특허공개 2017-220453호 공보Japanese Patent Laid-Open No. 2017-220453 일본 특허공개 2016-55283호 공보Japanese Patent Laid-Open No. 2016-55283

Ducamp-Sanguesa, et al., J. Solid State Chem., 1992, 100, 272 Ducamp-Sanguesa, et al., J. Solid State Chem., 1992, 100, 272

특허문헌 1에 기재된 방법은 은 농도가 희박한 합성액(약 0.35%)을 액량이 15%가 될 때까지 농축(은 농도 약 2.3%)하고, 에탄올을 첨가해서 초기량으로 되돌리는 방법이며, 1 배치로 정제 가능한 은량은 약 1g으로 매우 적다. 그 때문에, 은 나노와이어의 수량을 증가시키기 위해서는 일련의 배치를 복수회 반복할 필요가 있어서, 효율이 나쁘다고 하는 과제가 있었다. 특허문헌 2∼7도 마찬가지로, 0.4% 이하의 희박한 은 농도의 분산액을 크로스 플로우 여과를 이용하여 정제하는 방법이며, 배치당 생산량이 적다고 하는 과제가 있었다.The method described in Patent Document 1 is a method of concentrating a synthetic liquid (about 0.35%) with a thin silver concentration until the liquid amount becomes 15% (a silver concentration of about 2.3%), and adding ethanol to return the initial amount, 1 The amount of silver that can be purified in a batch is very small, about 1 g. Therefore, in order to increase the quantity of silver nanowires, it was necessary to repeat a series of arrangement|positioning several times, and there existed a subject that efficiency was bad. Patent Documents 2 to 7 are also methods of purifying a dispersion having a thin silver concentration of 0.4% or less by using cross flow filtration, and there is a problem that the production amount per batch is small.

배치당 생산량을 향상시키기 위해서는, 크로스 플로우 여과에 투입하는 은 나노와이어 분산액의 은 농도를 높게 해서 수량을 증가시키는 방법이 고려된다. 그러나, 높은 은 농도의 은 나노와이어 분산액을 연속적으로 크로스 플로우 여과에 의해 정제했을 경우, 필터 상에 퇴적되는 은 나노와이어의 양이 증가하기 때문에, 크로스 플로우 여과법을 이용해도 와이어의 응집을 방지하는 것은 어렵다. 그 때문에, 수율이 낮아지기 쉽다고 하는 문제가 존재했다.In order to improve the yield per batch, a method of increasing the amount of silver by increasing the silver concentration of the silver nanowire dispersion to be subjected to cross flow filtration is considered. However, when the silver nanowire dispersion with a high silver concentration is continuously purified by cross flow filtration, the amount of silver nanowires deposited on the filter increases. it's difficult. Therefore, there existed a problem that a yield tends to become low.

특허문헌 6, 7에서는, 세정 공정 후의 농축물로서는 은 농도가 0.8질량%인 분산액이 얻어지고 있음에도 불구하고, 크로스 플로우 정제 시에 은 농도가 0.08질량%가 되도록 순수로 희석하고 있다. 이것은 0.8질량%의 분산액을 크로스 플로우 여과한 경우, 0.08질량%의 희박 조건과 비교하여 수율이 저하하기 때문이라고 생각된다. 더욱이, 희박 조건에서 크로스 플로우 여과를 실시했다고 해도, 합성시의 투입 은량으로부터 산출한 단리 수율은 34%로 제조 공정으로서는 충분한 값은 아니다.In patent documents 6 and 7, although the dispersion liquid whose silver concentration is 0.8 mass % is obtained as a concentrate after a washing|cleaning process, it is diluted with pure water so that the silver concentration may become 0.08 mass % at the time of cross-flow refinement|purification. This is considered to be because a yield falls compared with a 0.08 mass % dilution condition, when cross-flow filtration of this 0.8 mass % dispersion liquid is carried out. Moreover, even if cross-flow filtration was performed under lean conditions, the isolation yield calculated from the amount of silver charged at the time of synthesis was 34%, which is not a sufficient value as a manufacturing process.

이상에 나타낸 바와 같이, 크로스 플로우 여과법을 이용하여 높은 은 농도의 분산액을 고수율로 정제하는 것은 매우 곤란하며, 지금까지 달성된 전례가 전혀 존재하지 않는다.As shown above, it is very difficult to purify a dispersion having a high silver concentration in a high yield using a cross flow filtration method, and there is no precedent achieved so far.

본 발명의 목적은 은 나노와이어 및 구조 규정제를 포함하고, 은 농도가 1.0질량% 이상인 은 나노와이어 조분산액을 크로스 플로우 여과법을 이용하여 정제하여, 고수율로 고순도의 은 나노와이어 분산액을 제조하는 방법을 제공하는 것에 있다.It is an object of the present invention to purify a coarse dispersion of silver nanowires containing silver nanowires and a structure defining agent, and having a silver concentration of 1.0% by mass or more, using cross flow filtration, to prepare a high-purity silver nanowire dispersion in high yield. It's about providing a way.

본 발명자는 상기 과제를 해결하기 위해 예의 연구를 거듭한 결과, 은 농도가 1.0질량% 이상인 은 나노와이어의 조분산액을 크로스 플로우 여과법을 이용하여 정제했을 경우, 구조 규정제 및 은 나노입자의 제거가 진행되지 않는 것을 밝혔다. 그 원인을 검토한 바, 은 나노와이어의 부생물인 은 나노입자에 의해 여과 필터가 폐색되어 있기 때문인 것을 발견했다.As a result of repeated intensive studies to solve the above problems, the present inventors found that when a crude dispersion of silver nanowires having a silver concentration of 1.0% by mass or more was purified using cross-flow filtration, the removal of the structure-regulating agent and silver nanoparticles was stated that it did not proceed. When the cause was examined, it was discovered that it was because the filtration filter was blocked by the silver nanoparticles which are by-products of silver nanowires.

이들 지견을 근거로 더욱 검토를 진행시킨 결과, 크로스 플로우 여과 공정에 투입하는 분산액으로서, 구조 규정제를 포함하고 은 나노와이어의 수/전체 입자의 수(나노와이어의 수 + 나노입자의 수) > 90%인 은 나노와이어 분산액을 사용함으로써, 은 나노와이어 및 구조 규정제를 포함하고 은 농도가 1.0질량% 이상인 은 나노와이어 조분산액으로부터 구조 규정제를 효율적으로 제거할 수 있어서, 고수율로 은 나노와이어를 단리할 수 있는 것을 발견하고, 본 발명에 이르렀다.As a result of further investigation based on these findings, the number of silver nanowires/total number of particles (the number of nanowires + the number of nanoparticles) including a structure-regulating agent as a dispersion to be injected into the cross-flow filtration process > By using the silver nanowire dispersion of 90%, it is possible to efficiently remove the structure-defining agent from the coarse dispersion of silver nanowires containing silver nanowires and the structure-regulating agent and having a silver concentration of 1.0 mass % or more, so that the silver nanowires can be efficiently removed in high yield. It discovered that a wire could isolate|separate, and came to this invention.

본 발명은 이하의 실시형태를 포함한다.The present invention includes the following embodiments.

[1] 은 나노와이어의 수/전체 입자의 수 > 90%인 은 나노와이어와 구조 규정제를 포함하고, 은 농도가 1.0질량% 이상인 은 나노와이어 조분산액을 준비하는 공정과, 상기 은 나노와이어 조분산액을 순환식의 크로스 플로우 여과법에 의해 정제하는 크로스 플로우 여과 공정을 포함하는, 은 나노와이어 분산액의 제조 방법.[1] A step of preparing a coarse dispersion of silver nanowires containing silver nanowires having a number of silver nanowires/total number of particles > 90% and a structure defining agent, and having a silver concentration of 1.0% by mass or more, and the silver nanowires A method for producing a silver nanowire dispersion comprising a cross-flow filtration step of purifying the crude dispersion by a circulating cross-flow filtration method.

[2] 상기 크로스 플로우 여과 공정에 있어서, 단위 필터 면적·단위 시간당 여과 속도를 16.0kg/㎡·h 이하로 제어하는, [1]에 기재된 은 나노와이어 분산액의 제조 방법.[2] The method for producing a silver nanowire dispersion according to [1], wherein in the cross-flow filtration step, the filtration rate per unit filter area/unit time is controlled to 16.0 kg/m 2 ·h or less.

[3] 상기 여과 속도가 1.0kg/㎡·h 이상인, [2]에 기재된 은 나노와이어 분산액의 제조 방법.[3] The method for producing a silver nanowire dispersion according to [2], wherein the filtration rate is 1.0 kg/m 2 ·h or more.

[4] 은 나노와이어 조분산액 중에 구조 규정제를 0.5질량% 이상 포함하는, [1]∼[3] 중 어느 하나에 기재된 은 나노와이어 분산액의 제조 방법.[4] The method for producing a dispersion of silver nanowires according to any one of [1] to [3], wherein the coarse dispersion of silver nanowires contains 0.5% by mass or more of a structure-regulating agent.

[5] 상기 은 나노와이어 조분산액을 준비하는 공정은 은 나노와이어가 합성에 의해 반응 용매에 분산된 은 나노와이어 조분산액을 제조하는 은 나노와이어 조분산액 제조 공정을 포함하는, [1]∼[4] 중 어느 하나에 기재된 은 나노와이어 분산액의 제조 방법.[5] The step of preparing the silver nanowire coarse dispersion includes a silver nanowire coarse dispersion preparation step of preparing a silver nanowire coarse dispersion in which silver nanowires are synthesized and dispersed in a reaction solvent, [1] to [ 4] The manufacturing method of the silver nanowire dispersion liquid in any one of.

[6] 상기 은 나노와이어 조분산액을 준비하는 공정은 상기 은 나노와이어가 상기 반응 용매에 분산된 은 나노와이어 조분산액에 침강 용매를 첨가해서 은 나노와이어를 침강시키는 침강 공정과, 부생 나노입자를 포함하는 상기 반응 용매와 침강 용매의 혼합물의 상청액의 일부를 제거하는 상청액 제거 공정과, 침강 공정을 복수회 반복함으로써 부생 나노입자를 제거하여 분산액 중의 은 나노와이어의 수/전체 입자의 수 > 90%인 분산액을 얻는 재침 세정 공정을 은 나노와이어 조분산액 제조 공정 후에 추가로 포함하는, [5]에 기재된 은 나노와이어 분산액의 제조 방법.[6] The step of preparing the silver nanowire coarse dispersion is a sedimentation step of adding a precipitation solvent to the silver nanowire coarse dispersion in which the silver nanowires are dispersed in the reaction solvent to settle the silver nanowires; The supernatant removal process of removing a part of the supernatant of the mixture of the reaction solvent and the precipitation solvent, including the removal of the supernatant, and the number of silver nanowires in the dispersion/total number of particles > 90% by removing by-product nanoparticles by repeating the precipitation process a plurality of times The method for producing a silver nanowire dispersion according to [5], further comprising a reprecipitation washing step of obtaining a phosphorus dispersion after the silver nanowire coarse dispersion production step.

[7] 상기 크로스 플로우 여과 공정에 있어서, 은 나노와이어 조분산액의 농축 중 또는 농축 후에, 여액으로서 배출된 용매를 보충하도록 세정 용매를 첨가함으로써, 은 나노와이어 조분산액량을 여과 전의 조분산액량의 60% 이상으로 유지하는, [1]∼[6] 중 어느 하나에 기재된 은 나노와이어 분산액의 제조 방법.[7] In the cross flow filtration step, during or after the concentration of the silver nanowire coarse dispersion, a washing solvent is added to replenish the solvent discharged as the filtrate, whereby the amount of the coarse silver nanowire dispersion is equal to the amount of the coarse dispersion before filtration. The method for producing a silver nanowire dispersion according to any one of [1] to [6], which is maintained at 60% or more.

본 발명에 의하면, 은 나노와이어 및 구조 규정제를 포함하고, 은 농도가 1.0질량% 이상인 은 나노와이어 조분산액을 크로스 플로우 여과법을 이용하여 정제 함으로써, 고수율로 고순도의 은 나노와이어 분산액을 제조할 수 있다.According to the present invention, a silver nanowire dispersion containing silver nanowires and a structure defining agent and having a silver concentration of 1.0% by mass or more is purified using cross flow filtration to prepare a high-purity silver nanowire dispersion in high yield. can

도 1은 본 발명의 실시형태에 관한 은 나노와이어 분산액의 제조 방법의 공정도이다.BRIEF DESCRIPTION OF THE DRAWINGS It is a process diagram of the manufacturing method of the silver nanowire dispersion liquid which concerns on embodiment of this invention.

이하, 본 발명을 실시하기 위한 형태(이하, 실시형태라고 함)를 도면에 따라서 설명한다.EMBODIMENT OF THE INVENTION Hereinafter, the form (henceforth an embodiment) for implementing this invention is demonstrated according to drawing.

도 1에는 본 발명의 실시형태에 관한 은 나노와이어 분산액의 제조 방법의 공정도가 표시된다. 우선, 은 나노와이어가 합성에 의해 반응 용매에 분산된 그대로의 은 나노와이어 조분산액을 준비한다(S1: 은 나노와이어 조분산액 제조 공정). 본 공정으로서는 종래 공지의 방법에 의한 은 나노와이어의 합성 등을 적용할 수 있다. 은 나노와이어의 합성에 의해 얻어지는 조분산액 중에는 합성에 의해 생성된 은 나노와이어, 합성에 사용된 이온성 유도체, 구조 규정제, 용매 이외에, 부생된 은 나노입자가 포함된다. 또한, 구조 규정제는 합성 용매 중에 포함됨과 아울러 생성된 은 나노와이어의 표면에도 부착되어 있어, 후술하는 침강 공정에서 부생된 은 나노입자의 제거가, 또한 크로스 플로우 여과 공정에서 은 나노와이어 표면에 부착된 구조 규정제의 세정이 행해진다.1 shows a flowchart of a method for producing a silver nanowire dispersion according to an embodiment of the present invention. First, a coarse dispersion of silver nanowires in which silver nanowires are synthesized and dispersed in a reaction solvent is prepared (S1: coarse dispersion of silver nanowires). As this process, the synthesis|combination of silver nanowire by a conventionally well-known method, etc. are applicable. In the crude dispersion obtained by the synthesis of silver nanowires, silver nanoparticles produced by the synthesis are contained in addition to the silver nanowires produced by the synthesis, the ionic derivatives used for the synthesis, the structure defining agent, and the solvent. In addition, the structure-regulating agent is included in the synthesis solvent and adheres to the surface of the produced silver nanowires, so that the removal of silver nanoparticles generated by the sedimentation process described below is also attached to the surface of the silver nanowires in the cross-flow filtration process. The structure-regulating agent that has been used is washed.

여기에서 사용되는 합성에서 얻어지는 은 나노와이어는 지름이 나노미터 오더의 사이즈를 갖는 금속 은이며, 선상(중공의 튜브 형상인 은 나노튜브를 포함함)의 형상을 갖는 도전성 재료이다. 또한, 은 나노와이어의 금속 은은 도전 성능의 점에서는 금속 산화물을 포함하지 않는 편이 바람직하지만, 공기 산화가 회피되지 않을 경우에는 일부(표면의 적어도 일부)에 은 산화물을 포함해도 좋다.The silver nanowire obtained in the synthesis used herein is metallic silver having a size on the order of nanometers in diameter, and is a conductive material having a linear shape (including silver nanotubes having a hollow tube shape). In addition, although it is preferable not to contain a metal oxide from the point of the silver metallic silver electroconductive performance of silver nanowire, when air oxidation is not avoided, you may contain silver oxide in a part (at least a part of surface).

상기 은 나노와이어의 단축 방향의 길이(지름)는 평균 10nm 이상 90nm 이하, 바람직하게는 평균 10nm 이상 85nm 이하, 또한 장축 방향의 길이는 평균 1㎛ 이상 100㎛ 이하, 바람직하게는 평균 5㎛ 이상 100㎛ 이하, 보다 바람직하게는 평균 10㎛ 이상 80㎛ 이하이다. 즉, 본 명세서에 있어서 「은 나노와이어」란, 장축 방향의 길이를 a, 단축 방향의 길이(지름)를 b라고 할 때, a/b로 나타내지는 애스펙트비가 5를 초과하는 것을 의미한다. 또한, 본 명세서에 있어서 「은 나노입자」란, 애스펙트비가 5 이하이고 합성에 의해 부생하는 상기 「은 나노와이어」를 제외한 입자상의 것을 의미한다.The length (diameter) in the minor axis direction of the silver nanowire is an average of 10 nm or more and 90 nm or less, preferably an average of 10 nm or more and 85 nm or less, and the length in the long axis direction is an average of 1 µm or more and 100 µm or less, preferably an average of 5 µm or more and 100 Micrometer or less, More preferably, it is 10 micrometers or more and 80 micrometers or less on average. That is, in the present specification, "silver nanowire" means that the aspect ratio represented by a/b exceeds 5 when a is the length in the major axis direction and b is the length (diameter) in the minor axis direction. In addition, in this specification, a "silver nanoparticle" has an aspect-ratio 5 or less, and means the particulate-form thing except the said "silver nanowire" produced by synthesis.

상기 이온성 유도체는 은의 와이어의 생장에 기여하는 성분이며, 용매에 용해해서 할로겐 이온을 해리할 수 있는 화합물이면 적용할 수 있고, 금속 할로겐화물이 적합하다. 할로겐 이온으로서는 염소 이온, 브롬 이온, 요오드 이온 중 적어도 하나인 것이 바람직하고, 염소 이온을 해리할 수 있는 화합물을 포함하는 것이 보다 바람직하다.The ionic derivative is a component contributing to the growth of the silver wire, and can be applied as long as it is a compound capable of dissociating halogen ions by dissolving in a solvent, and a metal halide is preferable. The halogen ion is preferably at least one of a chlorine ion, a bromine ion, and an iodine ion, and more preferably contains a compound capable of dissociating a chlorine ion.

금속 할로겐 화합물로서는 알칼리 금속 할로겐화물, 알칼리 토류금속 할로겐화물, 장주기율표의 제 3 족∼제 12 족의 금속 할로겐화물을 들 수 있다.Examples of the metal halide include alkali metal halides, alkaline earth metal halides, and metal halides of Groups 3 to 12 of the Long Periodic Table.

알칼리 금속 할로겐화물로서는 염화 리튬, 염화 나트륨, 염화 칼륨 등의 알칼리 금속 염화물, 브롬화 리튬, 브롬화 나트륨, 브롬화 칼륨 등의 알칼리 금속 브롬화물, 요오드화 리튬, 요오드화 나트륨, 요오드화 칼륨 등의 알칼리 금속 요오드화물 등을 들 수 있다. 알칼리 토류금속 할로겐화물로서는 염화 마그네슘, 염화 칼슘을 들 수 있다. 장주기율표의 제 3 족∼제 12 족의 금속 할로겐화물로서는 염화 제 2 철, 염화 제 2 구리, 브롬화 제 2 철, 브롬화 제 2 구리를 들 수 있다. 이들 중 어느 하나를 단독으로 사용해도 2종류 이상을 조합해서 사용해도 좋다.Examples of the alkali metal halide include alkali metal chlorides such as lithium chloride, sodium chloride and potassium chloride, alkali metal bromides such as lithium bromide, sodium bromide and potassium bromide, and alkali metal iodides such as lithium iodide, sodium iodide and potassium iodide. can be heard Examples of the alkaline earth metal halide include magnesium chloride and calcium chloride. Examples of the metal halide of Groups 3 to 12 of the Long Periodic Table include ferric chloride, cupric chloride, ferric bromide, and cupric bromide. Any one of these may be used independently, or may be used in combination of 2 or more types.

이들 중에서도 염소 이온을 해리하는 화합물을 포함하는 것이 특히 와이어의 생성에 바람직하다. 또한, 가는 지름의 와이어를 얻기 위해서는 염소 이온을 해리하는 화합물과, 브롬 이온을 해리하는 화합물 및 요오드 이온을 해리하는 화합물 중 적어도 일방을 병용하는 것이 바람직하다. 염소 이온을 해리하는 화합물의 염소원자의 총 몰수를 (A), 브롬 이온을 해리하는 화합물의 브롬 원자 및 요오드 이온을 해리하는 화합물의 요오드 원자의 총 몰수를 (B)라고 했을 경우, (A)/(B)의 몰비가 커지면 와이어 지름이 굵어지고, 작아지면 와이어 지름은 가늘어지지만, 지나치게 작아지면 구상 분말의 부생률이 높아지는 경향이 있다. 따라서, (A)/(B)의 몰비는 2∼8이 바람직하고, 3∼6이 보다 바람직하다.Among these, those containing a compound that dissociates chlorine ions are particularly preferred for the production of wires. Moreover, in order to obtain a wire of a thin diameter, it is preferable to use together at least one of the compound which dissociates a chlorine ion, the compound which dissociates a bromine ion, and the compound which dissociates an iodine ion. If (A) is the total number of moles of chlorine atoms in the compound that dissociates chlorine ions, (A) When the molar ratio of /(B) becomes large, the wire diameter becomes thick, and when it becomes small, the wire diameter becomes thin, but when it becomes small too much, there exists a tendency for the by-product rate of a spherical powder to become high. Therefore, 2-8 are preferable and, as for the molar ratio of (A)/(B), 3-6 are more preferable.

합성에 사용되는 구조 규정제는 합성시에 은 입자의 성장 방위를 일차원으로 규정하는 기능을 갖는 화합물이며, 구조 규정제를 사용함으로써 입자 형성 공정에 있어서 형성되는 은 나노와이어의 비율을 높일 수 있다. 많은 경우, 구조 규정제는 대상이 되는 입자의 특정 결정면에 우선적 또는 선택적으로 흡착하여, 흡착면의 성장을 억제함으로써 성장 방위를 제어한다. 이 성장 방위의 제어는 후술하는 폴리올류 중에 구조 규정제를 첨가해 두고, 생성되는 은 나노와이어의 표면에 흡착시킴으로써 행할 수 있다. 이 구조 규정제로서는 중량 평균 분자량이 1000보다 큰 구조 규정제가 바람직하고, 2000 이상의 구조 규정제가 보다 바람직하고, 10000 이상의 구조 규정제가 더욱 바람직하다. 한편, 구조 규정제의 중량 평균 분자량이 지나치게 크면, 은 나노와이어가 응집할 가능성이 높아진다. 따라서, 상기 구조 규정제의 중량 평균 분자량은 150만 이하가 바람직하고, 100만 이하가 보다 바람직하고, 50만 이하가 더욱 바람직하다. 상기 구조 규정제의 종류로서는, 예를 들면 폴리-N-비닐피롤리돈(PVP), 폴리-N-비닐아세트아미드(PNVA), 젤라틴, 폴리비닐알콜(PVA), 폴리아크릴산의 부분 알킬에스테르, 메틸셀룰로오스, 히드록시프로필 메틸셀룰로오스, 폴리알킬렌아민, 셀룰로오스아세테이트, 아세탈 수지 등을 들 수 있다.The structure-regulating agent used for synthesis is a compound having a function of one-dimensionally defining the growth direction of silver particles at the time of synthesis, and by using the structure-regulating agent, the proportion of silver nanowires formed in the particle-forming step can be increased. In many cases, the structure-regulating agent preferentially or selectively adsorbs to a specific crystal plane of a target particle, thereby suppressing the growth of the adsorption plane, thereby controlling the growth direction. Control of this growth direction can be performed by adding a structure-regulating agent to the polyol mentioned later, and making it adsorb|suck to the surface of the silver nanowire produced|generated. As this structure-defining agent, a structure-defining agent having a weight average molecular weight of more than 1000 is preferable, a structure-defining agent of 2000 or more is more preferable, and a structure-defining agent of 10000 or more is still more preferable. On the other hand, when the weight average molecular weight of a structure defining agent is too large, the possibility that silver nanowires will aggregate will become high. Therefore, 1.5 million or less are preferable, as for the weight average molecular weight of the said structure-regulating agent, 1 million or less are more preferable, 500,000 or less are still more preferable. Examples of the structure-regulating agent include poly-N-vinylpyrrolidone (PVP), poly-N-vinylacetamide (PNVA), gelatin, polyvinyl alcohol (PVA), partial alkyl esters of polyacrylic acid, Methyl cellulose, hydroxypropyl methyl cellulose, polyalkyleneamine, cellulose acetate, acetal resin, etc. are mentioned.

구조 규정제는 상기한 바와 같이 은 나노와이어 합성시의 은 나노와이어의 와이어 형상의 성장을 제어함과 아울러, 생성된 은 나노와이어끼리의 응집을 방지하는 작용도 갖는다.The structure-regulating agent controls the wire-shaped growth of silver nanowires during silver nanowire synthesis as described above, and also has an action of preventing aggregation of the generated silver nanowires.

구조 규정제는 은 나노와이어 조분산액 중에 0.5질량% 이상 포함하는 것이 바람직하고, 보다 바람직하게는 0.7∼7질량%, 더욱 바람직하게는 1.0∼5질량%이다. 0.5질량% 이상으로 함으로써, 은 농도 1.0% 이상과 같은 고농도 분산액을 취급해도 응집되는 경우가 없다. 또한, 구조 규정제의 농도가 지나치게 높으면, 후의 정제 공정이 길어져서 생산성이 저하된다.It is preferable to contain 0.5 mass % or more of a structure-regulating agent in silver nanowire coarse dispersion liquid, More preferably, it is 0.7-7 mass %, More preferably, it is 1.0-5 mass %. By setting it as 0.5 mass % or more, even if it handles a high-concentration dispersion liquid like a silver concentration of 1.0 % or more, aggregation does not occur. Moreover, when the density|concentration of a structure defining agent is too high, a subsequent refinement|purification process will become long and productivity will fall.

은 나노와이어(또는 은 나노튜브)의 합성 방법으로서는 공지의 합성 방법을 사용할 수 있다. 예를 들면 은 나노와이어는 폴리올(Poly-ol)법을 이용하여, 폴리-N-비닐피롤리돈 존재하에서 질산은을 환원함으로써 합성할 수 있다(Chem. Mater., 2002, 14, 4736 참조).As a method for synthesizing silver nanowires (or silver nanotubes), a known synthesis method can be used. For example, silver nanowires can be synthesized by reducing silver nitrate in the presence of poly-N-vinylpyrrolidone using the poly-ol method (see Chem. Mater., 2002, 14, 4736).

상기 폴리올법으로 사용되는 반응 용매는 환원제로서 사용되는 폴리올류, 예를 들면 에틸렌글리콜, 1,2-프로필렌글리콜, 1,3-프로필렌글리콜, 디에틸렌글리콜, 트리에틸렌글리콜, 디프로필렌글리콜, 1,2-부탄디올, 1,3-부탄디올, 1,4-부탄디올, 2-메틸-1,3-프로판디올, 글리세린 등을 들 수 있고, 이들로 이루어지는 군에서 선택되는 적어도 1종인 것이 바람직하다. 합성 반응 후에는 목적으로 하는 은 나노와이어와 함께 합성시에 생성된 은 나노입자 등의 불순물도 포함하는 은 나노와이어 조분산액으로 되어 있다.The reaction solvent used in the polyol method is a polyol used as a reducing agent, for example, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, 1, 2-butanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, glycerin, etc. are mentioned, It is preferable that it is at least 1 type selected from the group which consists of these. After the synthesis reaction, it becomes a coarse dispersion of silver nanowires containing impurities such as silver nanoparticles generated during synthesis together with the target silver nanowires.

은 나노와이어 조분산액 중의 폴리올이 지나치게 많으면, 후술하는 빈용매의 사용량이 많아지므로, 필요에 따라서 폴리올을 증류에 의해 증류제거하여, 은 나노와이어를 어느 정도 농축해도 좋다(S2: 농축 공정). 단, 지나치게 고온에서 증류제거하면 응집될 우려가 있으므로, 100mmHg 이하의 압력에서 150℃ 이하의 온도에서 증류시키는 것이 바람직하다. 이 경우, 은 나노와이어 조분산액의 양을 본래의 양의 20질량%∼80질량%의 범위까지 감용을 행하는 것이 바람직하다. 또한, S2의 공정은 필수가 아니고 생략해도 좋다.If the amount of the polyol in the silver nanowire coarse dispersion is too large, the amount of the poor solvent to be described later increases. If necessary, the polyol may be distilled off by distillation to concentrate the silver nanowires to some extent (S2: concentration step). However, since there is a risk of agglomeration when distilled at too high a temperature, it is preferable to distill at a pressure of 100 mmHg or less and a temperature of 150° C. or less. In this case, it is preferable to reduce the volume of the silver nanowire coarse dispersion to the range of 20 mass % - 80 mass % of the original quantity. In addition, the process of S2 is not essential and may be omitted.

다음에, 상기 은 나노와이어 조분산액(필요에 따라서 상기 S2에서 농축 후의 은 나노와이어 조분산액)에 침강 용매를 첨가해서 은 나노와이어를 침강시킨다(S3: 침강 공정).Next, a precipitation solvent is added to the silver nanowire coarse dispersion (the silver nanowire coarse dispersion after concentration in S2 as necessary) to precipitate silver nanowires (S3: sedimentation step).

침강 용매는 구조 규정제의 용해성이 낮은 빈용매이며, 예를 들면 케톤계 용매 또는 에스테르계 용매를 들 수 있다. 케톤계 용매로서는 아세톤, 메틸에틸케톤, 메틸이소부틸케톤, 시클로헥사논, 벤조페논 등을 들 수 있다. 에스테르계 용매로서는 아세트산 에틸, 아세트산-n-프로필, 아세트산 이소프로필, 아세트산 알릴, 아세트산-n-부틸, 프로피온산 에틸, 아세트산 프로필렌글리콜 모노메틸에테르 등을 들 수 있고, 이 중에서도 은 나노와이어의 침강성과 폴리올류에 대한 용해성의 관점으로부터 아세톤, 아세트산 에틸, 아세트산-n-프로필, 아세트산 이소프로필, 아세트산-n-부틸, 아세트산 프로필렌글리콜 모노메틸에테르가 바람직하다. 사용량으로서는 사용한 폴리올류(상기 S2에서 농축한 경우에는 농축 후) 100질량부에 대하여 50질량부∼2000질량부인 것이 바람직하고, 보다 바람직하게는 70질량부∼600질량부이다.A precipitation solvent is a poor solvent with low solubility of a structure-regulating agent, For example, a ketone type solvent or an ester type solvent is mentioned. Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and benzophenone. Examples of the ester solvent include ethyl acetate, n-propyl acetate, isopropyl acetate, allyl acetate, n-butyl acetate, ethyl propionate, and propylene glycol monomethyl ether. Among them, silver nanowire sedimentation properties and polyol Acetone, ethyl acetate, acetate-n-propyl, isopropyl acetate, acetate-n-butyl, and propylene glycol monomethyl ether are preferable from a solubility viewpoint with respect to solvent. As a usage-amount, it is preferable that they are 50 mass parts - 2000 mass parts with respect to 100 mass parts of polyols used (after concentration when concentrating in said S2), More preferably, they are 70 mass parts - 600 mass parts.

빈용매에는 분산제(고분자 분산제 중 빈용매에 용해하는 분산제)를 첨가해도 좋다. 이것에 의해, 당초의 은 나노와이어 분산액뿐만 아니라 빈용매에도 분산제를 첨가하는 것으로 되므로, 은 나노와이어의 응집을 보다 억제할 수 있다.You may add a dispersing agent (a dispersing agent which melt|dissolves in the poor solvent among polymer dispersing agents) to a poor solvent. Thereby, since a dispersing agent is added not only to the original silver nanowire dispersion liquid but to a poor solvent, aggregation of silver nanowires can be suppressed more.

빈용매 첨가에 의해 은 나노와이어를 침강(S3)시킨 후, 은 나노와이어 합성시에 부생된 은 나노입자를 포함하는 상청액인 반응 용매 및 침강 용매의 혼합물을 제거한다(S4: 상청액 제거 공정). 상청액 제거 방법은 특별히 한정되지 않는다. 예를 들면 디캔테이션 처리에 의해 제거할 수도 있고, 펌프에 의해 흡인 제거할 수도 있다.After the silver nanowires are precipitated (S3) by the addition of the poor solvent, a mixture of the reaction solvent and the precipitation solvent, which is a supernatant containing silver nanoparticles generated by the synthesis of silver nanowires, is removed (S4: supernatant removal process). The method for removing the supernatant is not particularly limited. For example, it can also be removed by a decantation process, and can also be suction-removed with a pump.

이상과 같이 하여, 반응 용매 및 침강 용매를 상청액으로서 제거한 은 나노와이어의 침강 물을 포함하는 잔액에, 반응 용매와는 다른 분산 용매를 첨가한 후, 재차 침강 용매를 첨가해서 은 나노와이어를 침강시킨다(S5: 재침 세정 공정). 이때, 구조 규정제가 역치 이하가 되면, 침강 용매를 첨가한 후에도 은 나노입자는 상청액 중에 양호하게 분산되게 되기 때문에, 은 나노입자와 은 나노와이어를 분리할 수 있다.A dispersion solvent different from the reaction solvent is added to the residue containing the precipitate of silver nanowires from which the reaction solvent and the precipitation solvent have been removed as a supernatant as described above, and then a precipitation solvent is added again to precipitate the silver nanowires. (S5: re-immersion cleaning process). At this time, when the structure-regulating agent is below the threshold, silver nanoparticles are well dispersed in the supernatant even after the addition of the precipitation solvent, so that the silver nanoparticles and the silver nanowires can be separated.

재침 세정 공정에서 사용하는 분산 용매는 구조 규정제의 용해성이 있는 양용매이며, 예를 들면 물, 알콜계 용매, 니트릴계 용매, 락톤계 용매 등을 들 수 있다. 이 중에서도 은 나노와이어의 침강성과 은 나노입자의 분산성의 관점으로부터 물, 아세토니트릴, γ-부티로락톤이 바람직하다. 사용량으로서는 침강된 은 나노와이어를 포함하는 잔액 중의 은 1질량부에 대하여 25∼400질량부이며, 30∼300질량부인 것이 바람직하고, 50∼200질량부인 것이 보다 바람직하다. 25질량부 미만이면 은 나노와이어의 농도가 지나치게 높기 때문에 균일하게 재분산시키는 것이 어렵고, 400질량부를 초과하면 침강에 필요한 용매량이 매우 많아지기 때문에, 재침 세정에 엄청난 노동력이 필요로 된다.The dispersion solvent used in the reprecipitation washing step is a good solvent soluble in the structure defining agent, and examples thereof include water, an alcohol solvent, a nitrile solvent, and a lactone solvent. Among them, water, acetonitrile, and γ-butyrolactone are preferable from the viewpoint of sedimentation of silver nanowires and dispersibility of silver nanoparticles. As usage-amount, it is 25-400 mass parts with respect to 1 mass part of silver in the residual liquid containing the settled silver nanowire, It is preferable that it is 30-300 mass parts, It is more preferable that it is 50-200 mass parts. If it is less than 25 parts by mass, it is difficult to uniformly redisperse the silver nanowires because the concentration is too high, and if it exceeds 400 parts by mass, the amount of solvent required for sedimentation becomes very large, so re-precipitation cleaning requires tremendous labor.

침강 용매는 침강 공정(S3)에서 열거한 빈용매이면 어느 것이어도 좋다. 사용량으로서는 사용한 양용매 100질량부에 대하여 50질량부∼500질량부인 것이 바람직하고, 보다 바람직하게는 70질량부∼300질량부이다.The precipitation solvent may be any of the poor solvents enumerated in the precipitation step (S3). As usage-amount, it is preferable that they are 50 mass parts - 500 mass parts with respect to 100 mass parts of used good solvents, More preferably, they are 70 mass parts - 300 mass parts.

재침 세정 공정(S5)은 복수회 반복함으로써, 보다 효과적으로 은 나노입자와 은 나노와이어를 분리하는 것이 가능하다. 후술하는 정제 공정에 유리하게 되도록, 분산액 중에 포함되는 은 나노와이어비, 즉 은 나노와이어의 수/(전체 입자의 수(= 은 나노와이어의 수 + 은 나노입자의 수)) > 90%가 될 때까지 반복한다.By repeating the re-precipitation cleaning process (S5) a plurality of times, it is possible to more effectively separate the silver nanoparticles and the silver nanowires. In order to be advantageous for the purification process to be described later, the ratio of silver nanowires contained in the dispersion, that is, the number of silver nanowires/(the number of total particles (= the number of silver nanowires + the number of silver nanoparticles)) > 90% Repeat until

이상과 같이 하여, 은 나노입자 및 침강 용매를 상청액으로서 제거한 은 나노와이어의 침강물을 포함하는 잔액에 다음 공정의 크로스 플로우 여과에 사용하는 여과 용매를 첨가해서 은 나노와이어를 재분산시킨다(S6: 재분산 공정). 여과 용매의 첨가량은 침강된 은 나노와이어를 포함하는 잔액 중의 은 1질량부에 대하여 10∼100질량부이며, 25∼100질량부인 것이 바람직하고, 50∼100질량부인 것이 보다 바람직하다. 10질량부 미만이면 은 나노와이어의 농도가 지나치게 높기 때문에 균일하게 재분산시키는 것이 어렵고, 100질량부를 초과하면 은 나노와이어 농도가 낮기 때문에, 생산량을 높이기 위해서는 다음 공정의 크로스 플로우 여과를 복수회 행하게 되어 엄청난 노동력이 필요로 된다.As described above, silver nanowires are redispersed by adding a filtration solvent used for cross-flow filtration in the next step to the remaining liquid containing the precipitate of silver nanowires from which the silver nanoparticles and the sedimentation solvent have been removed as a supernatant (S6: re-dispersion) dispersion process). It is 10-100 mass parts with respect to 1 mass part of silver in the residual liquid containing the silver nanowire which settled, and, as for the addition amount of a filtration solvent, it is preferable that it is 25-100 mass parts, It is more preferable that it is 50-100 mass parts. If it is less than 10 parts by mass, it is difficult to redisperse uniformly because the concentration of silver nanowires is too high, and if it exceeds 100 parts by mass, the concentration of silver nanowires is low. It requires an enormous amount of labor.

여과 용매로서는 은 나노와이어가 응집하지 않으면 특별히 제한 없이 사용할 수 있다. 특히, 제거하고자 하는 은 나노입자, 무기계 불순물, 구조 규정제, 은 나노와이어의 제조 공정, 침강 공정에서 첨가한 잉여의 분산제가 용해되는 용매인 것이 바람직하다. 여과 용매로서는 물 이외에 메탄올, 에탄올, 이소프로필알콜이나 n-프로필알콜과 같은 알콜류나 물과 알콜의 혼합물도 사용 가능하지만, 취급성(안전성)의 점으로부터 물을 사용하는 것이 바람직하다.As a filtration solvent, it can be used without a restriction|limiting in particular as long as silver nanowires do not agglomerate. In particular, it is preferable that the silver nanoparticles to be removed, the inorganic impurities, the structure defining agent, the surplus dispersing agent added in the manufacturing process of silver nanowires, and the precipitation process are dissolved in a solvent. As the filtration solvent, in addition to water, alcohols such as methanol, ethanol, isopropyl alcohol and n-propyl alcohol or a mixture of water and alcohol can be used, but water is preferably used from the viewpoint of handling (safety).

상기 S1∼S6의 공정에 의해, 후술하는 정제 공정(S7)에 있어서 크로스 플로우 여과되는 은 나노와이어 조분산액이 준비된다.According to the steps of S1 to S6, a coarse dispersion of silver nanowires subjected to cross flow filtration in a purification step (S7) described later is prepared.

다음에, S6에서 얻은 은 나노와이어 재분산액(조분산액)을 필터에 유입하여 크로스 플로우 여과를 행하고, 상기 재침 세정 공정(S5)에서 제거되지 않고 공존하는 은 나노입자, 침강 용매, 은 나노와이어의 합성액에 존재하는 폴리올이나 무기계 불순물, 은 나노와이어를 생성시키기 위해서 사용한 구조 규정제를 제거하여, 상기 은 나노와이어를 정제해서 정제 은 나노와이어 수분산액을 얻는다(S7: 정제 공정). 여기에서, 크로스 플로우 여과를 행하는 재분산액(조분산액) 중의 은(은 나노와이어, 은 나노입자를 포함함) 농도로서는 1.0질량% 이상이며, 1.1∼10.0질량%인 것이 바람직하고, 보다 바람직하게는 1.2질량%∼5.0질량%이다. 또한, 재분산액(조분산액) 중에 포함되는 은 나노와이어비, 즉 은 나노와이어의 수/(전체 입자의 수(= 은 나노와이어의 수 + 은 나노입자의 수)) > 90%인 은 나노와이어 분산액을 사용한다. 은 나노와이어비는 바람직하게는 92% 이상, 보다 바람직하게는 95% 이상, 더욱 바람직하게는 97% 이상이다. 또한, 크로스 플로우 여과 공정에 있어서, 단위 필터 면적·단위 시간당 여과 속도(조분산액의 공급 속도)를 16.0kg/㎡·h 이하로 제어하는 것이 바람직하다. 은 나노와이어의 조분산액을 크로스 플로우 여과법을 이용하여 정제할 경우, 조분산액 중의 은 농도가 고농도일수록 은 나노와이어의 부생물인 은 나노입자에 의해 여과 필터가 폐색되어, 은 나노입자의 제거가 진행되지 않게 되는 불량이 발생하기 쉬워진다. 또한, 여과 속도를 빠르게 했을 경우, 은 나노와이어의 응집에 의해 필터 상에 금속 은막이 형성되어, 폴리머(구조 규정제)의 제거가 진행되지 않게 될 불량이 발생하기 쉽다. 상기 여과 속도에 제어함으로써 이들 불량의 발생을 현저하게 억제할 수 있다. 또한, 여과 속도가 느리면 생산성이 낮기 때문에, 보다 바람직한 여과 속도는 1.0∼16.0kg/㎡·h이며, 더욱 바람직한 여과 속도는 2.0∼15.0kg/㎡·h이다. 또한, 필터의 전후에 가하는 압력차는 0.01MPa∼1.0MPa의 범위인 것이 바람직하고, 보다 바람직하게는 0.015∼0.9MPa, 더욱 바람직하게는 0.02∼0.8MPa이다. 상기 조건하에서 크로스 플로우 여과함으로써, 여과 중의 와이어 응집을 억제하면서 구조 규정제를 효율 좋게 제거할 수 있어서, 고수율로 은 나노와이어를 단리할 수 있다.Next, the silver nanowire re-dispersion (coarse dispersion) obtained in S6 is introduced into the filter, cross-flow filtration is performed, and the silver nanoparticles, sedimentation solvent, and silver nanowires coexisting without being removed in the reprecipitation cleaning step (S5) are The polyol or inorganic impurities present in the synthesis solution, and the structure-regulating agent used to generate the silver nanowires are removed to purify the silver nanowires to obtain a purified silver nanowire aqueous dispersion (S7: purification process). Here, the concentration of silver (including silver nanowires and silver nanoparticles) in the redispersion liquid (coarse dispersion) subjected to cross flow filtration is 1.0 mass % or more, preferably 1.1 to 10.0 mass %, more preferably It is 1.2 mass % - 5.0 mass %. In addition, the silver nanowire ratio contained in the redispersion (coarse dispersion), that is, the number of silver nanowires/(the total number of particles (= the number of silver nanowires + the number of silver nanoparticles)) > 90% of silver nanowires use dispersion. The silver nanowire ratio is preferably 92% or more, more preferably 95% or more, still more preferably 97% or more. Moreover, in a cross-flow filtration process, it is preferable to control the filtration rate per unit filter area and unit time (supply rate of a crude dispersion liquid) to 16.0 kg/m<2>*h or less. When the coarse dispersion of silver nanowires is purified using cross flow filtration, the higher the concentration of silver in the coarse dispersion, the more the filtration filter is blocked by silver nanoparticles, which are by-products of silver nanowires, and the removal of silver nanoparticles proceeds. It becomes easy to generate|occur|produce the defect which does not do it. Moreover, when a filtration rate is made fast, a metallic silver film is formed on a filter by aggregation of silver nanowires, and it is easy to generate|occur|produce the defect in which the removal of a polymer (structural-regulating agent) does not progress. By controlling the said filtration rate, generation|occurrence|production of these defects can be suppressed remarkably. Moreover, since productivity is low when a filtration rate is slow, a more preferable filtration rate is 1.0-16.0 kg/m<2>*h, and a more preferable filtration rate is 2.0-15.0 kg/m<2>*h. Moreover, it is preferable that the range of the pressure difference applied before and behind a filter is 0.01 MPa - 1.0 MPa, More preferably, it is 0.015-0.9 MPa, More preferably, it is 0.02-0.8 MPa. By cross-flow filtration under the said conditions, a structure-regulating agent can be removed efficiently, suppressing wire aggregation during filtration, and a silver nanowire can be isolated with a high yield.

상기 정제 공정에서는 은 나노와이어 재분산액을 농축한 후에, 필터 외에 여액으로서 배출된 용매(재분산액)의 합계량과 동등량의 세정 용매를 추가 라인으로부터 저장조에 첨가함으로써, 은 나노와이어 조분산액량을 여과 전의 조분산액량의 60% 이상으로 유지하고, 은 나노와이어 재분산액의 정제를 실시해도 좋다. 세정 용매로서는 은 나노와이어가 응집되지 않으면 특별히 제한 없이 사용할 수 있다. 특히, 제거하고자 하는 은 나노입자, 무기계 불순물, 구조 규정제, 은 나노와이어의 제조공정, 침강 공정에서 첨가한 잉여의 분산제가 용해되는 세정 용매인 것이 바람직하다. 세정 용매로서는 물 이외에 메탄올, 에탄올, 이소프로필알콜이나 n-프로필알콜과 같은 알콜류나 물과 알콜의 혼합물도 사용 가능하지만, 취급성(안전성)의 점으로부터 물을 사용하는 것이 바람직하다. 크로스 플로우 온도에 특별히 제한은 없지만, 높은 온도에서 실시한 편이 용매의 점도가 저하되기 때문에 여과에 걸리는 시간을 짧게 할 수 있다. 통상 10∼80℃의 범위이며, 바람직하게는 15∼70℃, 보다 바람직하게는 20∼60℃이다.In the purification process, after concentrating the silver nanowire redispersion, a washing solvent equivalent to the total amount of solvent (redispersion) discharged as a filtrate other than the filter is added to the storage tank from the additional line, whereby the amount of the silver nanowire coarse dispersion is filtered You may refine|purify silver nanowire re-dispersion liquid while maintaining at 60% or more of the amount of the previous coarse dispersion liquid. As a washing solvent, it can be used without a restriction|limiting in particular as long as silver nanowires do not agglomerate. In particular, it is preferable that the silver nanoparticles to be removed, inorganic impurities, structure regulating agent, and the surplus dispersant added in the manufacturing process of silver nanowires and the precipitation process are dissolved in a washing solvent. As the washing solvent, in addition to water, alcohols such as methanol, ethanol, isopropyl alcohol and n-propyl alcohol or a mixture of water and alcohol can be used, but water is preferably used from the viewpoint of handling (safety). Although there is no restriction|limiting in particular in the crossflow temperature, Since the viscosity of a solvent falls when it carries out at high temperature, the time taken for filtration can be shortened. Usually, it is the range of 10-80 degreeC, Preferably it is 15-70 degreeC, More preferably, it is 20-60 degreeC.

필터의 재료로서는 크로스 플로우 여과를 할 수 있는 것이면 한정되지 않지만, 예를 들면 세라믹막, 중공사막 등을 사용할 수 있다. 중공사막으로서는 셀룰로오스계, 폴리에테르술폰산계, PTFE(폴리테트라플루오로에틸렌) 등에서 선택되는 고분자 재료를 사용할 수 있다. 또한, 세라믹막으로서는 다공질의 세라믹스 재료를 사용할 수 있다. 세라믹막의 평균 구멍 지름은 용매와 은 나노와이어의 분리 효율을 향상시키기 위해서 0.01∼5.0㎛인 것이 적합하다. 세라믹막의 구멍 지름은 너무 지나치게 가늘면 여과 시간이 너무 오래 걸리고, 또한 너무 지나치게 크면 은 나노입자뿐만 아니라 은 나노와이어의 일부까지도 통과해버린다. 보다 바람직하게는 평균 1.0∼3.0㎛이다.The material of the filter is not limited as long as it can perform cross-flow filtration, and for example, a ceramic membrane, a hollow fiber membrane, or the like can be used. As the hollow fiber membrane, a polymer material selected from cellulose, polyethersulfonic acid, PTFE (polytetrafluoroethylene) and the like can be used. Further, as the ceramic film, a porous ceramic material can be used. The average pore diameter of the ceramic membrane is preferably 0.01 to 5.0 µm in order to improve the separation efficiency between the solvent and the silver nanowires. If the pore diameter of the ceramic membrane is too thin, the filtration time is too long, and if it is too large, not only the silver nanoparticles but also a part of the silver nanowires pass through. More preferably, it is 1.0-3.0 micrometers on average.

상기 정제 공정(S7)에 있어서의 정제의 종료 타이밍은 특별히 제한 없이 결정할 수 있다. 예를 들면 은 나노와이어와 구조 규정제의 농도비(은 나노와이어/구조 규정제 (질량비))는 10 이상, 바람직하게는 15 이상, 보다 바람직하게는 20 이상이 되었을 때나, 순환 여액 중의 세정 용매 농도가 95% 이상, 바람직하게는 98% 이상이 되었을 때 등을 종점으로 하면 좋다. 종점의 판단에는 열중량 분석이나 가스크로마토그래피 등의 분석 방법을 이용하여 구조 규정제, 은 나노와이어, 용매의 질량을 간이적으로 측정하면 좋다.The timing of the end of the purification in the purification step (S7) can be determined without particular limitation. For example, when the concentration ratio of the silver nanowires and the structure-regulating agent (silver nanowires/structure-defining agent (mass ratio)) is 10 or more, preferably 15 or more, more preferably 20 or more, the concentration of the washing solvent in the circulating filtrate is What is necessary is just to set it as an end point when it becomes 95 % or more, Preferably it becomes 98 % or more. What is necessary is just to simply measure the mass of a structure defining agent, a silver nanowire, and a solvent using analytical methods, such as thermogravimetry and gas chromatography, for judgment of an end point.

상술한 방법에 의해 얻어진 은 나노와이어 분산액의 분산매는 그대로 또는 필요에 따라서 인쇄에 적합한 용매로의 용매 치환을 행한 후, 필요에 따라서 바인더 수지 등을 더 첨가함으로써 은 나노와이어 잉크(이하, 잉크라고 하는 경우가 있음)를 제조할 수 있다. 본 실시형태에서는, 응집이 없는 상태에서 용매 치환 은 나노와이어 분산액을 얻을 수 있으므로, 후공정으로서 용이하게 바인더 성분을 첨가할 수 있어서, 은 나노와이어 잉크의 제조를 용이하게 행할 수 있다.The dispersion medium of the silver nanowire dispersion obtained by the above-mentioned method is as it is, or after solvent substitution with a solvent suitable for printing if necessary, a binder resin or the like is further added as necessary to a silver nanowire ink (hereinafter referred to as an ink). in some cases) can be prepared. In this embodiment, since the solvent-substituted silver nanowire dispersion liquid can be obtained in the state without aggregation, a binder component can be easily added as a post process, and manufacture of silver nanowire ink can be performed easily.

은 나노와이어 잉크에는 점도를 조정하기 위한 점도 조정 용매를 새로이 첨가해도 좋다. 점도 조정 용매의 예로서는 물, 알콜, 케톤, 에스테르, 에테르, 지방족계 탄화수소 용제 및 방향족계 탄화수소 용제를 들 수 있다. 은 나노와이어 잉크중의 각 성분이 양호하게 분산되는 관점으로부터, 물, 에탄올, 이소프로필알콜, 1-메톡시-2-프로판올(PGME), 에틸렌글리콜, 디에틸렌글리콜, 트리에틸렌글리콜, 디프로필렌글리콜, 에틸렌글리콜 모노메틸에테르, 에틸렌글리콜 모노에틸에테르, 에틸렌글리콜 모노프로필에테르, 디아세톤 알콜, 에틸렌글리콜 모노부틸에테르, 프로필렌글리콜, 디에틸렌글리콜 모노메틸에테르, 디에틸렌글리콜 모노에틸에테르, 디프로필렌글리콜 모노프로필에테르, 디에틸렌글리콜 모노부틸에테르, 트리프로필렌글리콜, 트리에틸렌글리콜 모노에틸에테르, 터피네올, 디히드로터피네올, 디히드로터피닐 모노아세테이트, 메틸에틸케톤, 시클로헥사논, 에틸락테이트, 프로필렌글리콜 모노메틸에테르 아세테이트, 디에틸렌글리콜 모노메틸에테르 아세테이트, 디에틸렌글리콜 모노부틸에테르 아세테이트, 에틸렌글리콜 모노메틸에테르 아세테이트, 에틸렌글리콜 모노부틸에테르 아세테이트, 디부틸에테르, 옥탄, 톨루엔이 바람직하다. 이들 용매는 단독으로 사용해도, 2종 이상을 혼합해서 사용해도 좋다.A viscosity-adjusting solvent for adjusting the viscosity may be newly added to the silver nanowire ink. Examples of the viscosity-adjusting solvent include water, alcohols, ketones, esters, ethers, aliphatic hydrocarbon solvents and aromatic hydrocarbon solvents. From the viewpoint of good dispersion of each component in the silver nanowire ink, water, ethanol, isopropyl alcohol, 1-methoxy-2-propanol (PGME), ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol , ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, diacetone alcohol, ethylene glycol monobutyl ether, propylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, dipropylene glycol mono Propyl ether, diethylene glycol monobutyl ether, tripropylene glycol, triethylene glycol monoethyl ether, terpineol, dihydroterpineol, dihydroterpinyl monoacetate, methyl ethyl ketone, cyclohexanone, ethyl lactate, Propylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monobutyl ether acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monobutyl ether acetate, dibutyl ether, octane and toluene are preferable. These solvents may be used independently, or 2 or more types may be mixed and used for them.

은 나노와이어 잉크 중에는 바인더 수지를 더 첨가할 수 있다. 바인더 수지로서는 폴리메틸메타크릴레이트, 폴리아크릴레이트, 폴리아크릴로니트릴 등의 폴리 아크릴로일 화합물; 폴리비닐알콜; 폴리에틸렌테레프탈레이트, 폴리에틸렌나프탈레이트 등의 폴리에스테르; 폴리카보네이트; 노볼락 등의 고공역성 폴리머; 폴리이미드, 폴리아미드이미드, 폴리에테르이미드 등의 이미드류; 폴리술피드; 폴리술폰; 폴리페닐렌; 폴리페닐에테르; 폴리우레탄; 에폭시; 폴리스티렌, 폴리비닐톨루엔, 폴리비닐크실렌 등의 방향족 폴리올레핀; 폴리프로필렌, 폴리메틸펜텐 등의 지방족 폴리올레핀; 폴리노르보르넨 등의 지환식 올레핀, 폴리-N-비닐피롤리돈, 폴리-N-비닐카프로락탐, 폴리-N-비닐아세트아미드 등의 폴리-N-비닐 화합물; 아크릴로니트릴-부타디엔-스티렌 공중합 폴리머(ABS); 히드록시프로필 메틸셀룰로오스(HPMC), 니트로셀룰로오스 등의 셀룰로오스류; 실리콘 수지; 폴리아세테이트; 합성 고무; 폴리염화비닐, 염소화 폴리에틸렌, 염소화 폴리프로필렌 등의 염소 함유 폴리머; 폴리플루오로비닐리덴, 폴리테트라플루오로에틸렌, 폴리헥사플루오로프로필렌, 플루오로올레핀-히드로카본올레핀의 공중합 폴리머 등의 불소 함유 폴리머 등을 들 수 있다.A binder resin may be further added to the silver nanowire ink. Examples of the binder resin include polyacryloyl compounds such as polymethyl methacrylate, polyacrylate, and polyacrylonitrile; polyvinyl alcohol; polyesters such as polyethylene terephthalate and polyethylene naphthalate; polycarbonate; high conjugated polymers such as novolac; imides such as polyimide, polyamideimide, and polyetherimide; polysulfide; polysulfone; polyphenylene; polyphenyl ether; Polyurethane; epoxy; aromatic polyolefins such as polystyrene, polyvinyltoluene, and polyvinylxylene; aliphatic polyolefins such as polypropylene and polymethylpentene; alicyclic olefins such as polynorbornene, poly-N-vinyl compounds such as poly-N-vinylpyrrolidone, poly-N-vinylcaprolactam, and poly-N-vinylacetamide; acrylonitrile-butadiene-styrene copolymer (ABS); celluloses such as hydroxypropyl methyl cellulose (HPMC) and nitrocellulose; silicone resin; polyacetate; synthetic rubber; chlorine-containing polymers such as polyvinyl chloride, chlorinated polyethylene, and chlorinated polypropylene; and fluorine-containing polymers such as polyfluorovinylidene, polytetrafluoroethylene, polyhexafluoropropylene, and a copolymer of fluoroolefin-hydrocarbon olefin.

상기 성분 이외에도 도전성 잉크에 배합되어 있는 공지의 임의 성분, 예를 들면 부식 방지제, 밀착 촉진제, 계면활성제 등을 함유시켜도 좋다. 부식 방지제로서는 벤조트리아졸 등, 밀착 촉진제로서는 2-히드록시메틸셀룰로오스 등, 계면활성제로서는 상품명 F-472SF(DIC Corporation 제) 등을 들 수 있다. 투명 도전성 잉크는 상술한 성분을 공지의 방법으로 교반, 혼합, 가열, 냉각, 용해, 분산 등을 적당히 선택해서 행함으로써 제조할 수 있다.In addition to the above components, a known optional component incorporated in the conductive ink, for example, a corrosion inhibitor, an adhesion promoter, a surfactant, and the like may be contained. As a corrosion inhibitor, such as benzotriazole, as an adhesion promoter, such as 2-hydroxymethylcellulose, brand name F-472SF (made by DIC Corporation) etc. are mentioned as a surfactant. The transparent conductive ink can be produced by appropriately selecting the above-mentioned components for stirring, mixing, heating, cooling, dissolving, dispersing, and the like by a known method.

실시예Example

이하, 본 발명의 실시예를 구체적으로 설명한다. 또한, 이하의 실시예는 본 발명의 이해를 용이하게 하기 위한 것이고, 본 발명은 이들 실시예에 제한되는 것은 아니다.Hereinafter, embodiments of the present invention will be described in detail. In addition, the following examples are provided to facilitate understanding of the present invention, and the present invention is not limited to these examples.

실시예 1Example 1

<은 나노와이어 조분산액의 제조><Preparation of silver nanowire coarse dispersion>

1L 폴리 용기에 프로필렌글리콜 667g(AGC Inc. 제품)을 칭량하고, 은염으로서 질산은 22.5g (0.13mol)(Toyo Chemical Industrial Co., Ltd. 제품)을 첨가하고 실온 차광 하에서 2시간 교반함으로써 질산은 용액(제 2 용액)을 조제했다.In a 1 L poly container, 667 g of propylene glycol (manufactured by AGC Inc.) is weighed, and silver nitrate solution (silver nitrate solution ( 2nd solution) was prepared.

메커니컬 스터러, 정량 펌프, 환류관, 온도계, 질소 가스 도입관을 구비한 5L 4개구 세퍼러블 플라스크에, 질소 가스 분위기 하, 프로필렌글리콜 3000g, 이온성 유도체로서의 염화 나트륨 0.28g(4.8mmol)(Manac Incorporated 제품) 및 브롬화 나트륨 0.12g(1.2mmol)(Manac Incorporated 제품), 구조 규정제로서 폴리비닐피롤리돈 K-90(PVP) 72.1g(BASF Corporation 제품, Sokalan K90)을 투입하고, 200rpm의 회전수로 150℃에서 1시간 교반함으로써 완전하게 용해시켜 제 1 용액을 얻었다. 먼저 조제한 질산은 용액(제 2 용액)을 정량 펌프에 접속하고, 상기 제 1 용액에 온도 150℃에서 2.5시간에 걸쳐서 적하함으로써 은 나노와이어를 합성하고, 적하 종료 후 30분 가열 교반을 추가로 계속해서 반응을 완결시켜 은 나노와이어 조분산액을 얻었다. In a 5L 4-neck separable flask equipped with a mechanical stirrer, metering pump, reflux tube, thermometer, and nitrogen gas inlet tube, 3000 g of propylene glycol, 0.28 g (4.8 mmol) of sodium chloride as an ionic derivative (Manac) Incorporated) and 0.12 g (1.2 mmol) of sodium bromide (manac Incorporated), 72.1 g of polyvinylpyrrolidone K-90 (PVP) as a structure regulator (BASF Corporation, Sokalan K90) were added, and the rotation was at 200 rpm. It was completely dissolved by stirring with water at 150 DEG C for 1 hour to obtain a first solution. Silver nanowires are synthesized by connecting the previously prepared silver nitrate solution (second solution) to a metering pump, and dropping the first solution at a temperature of 150° C. over 2.5 hours, and after completion of the dropping, heating and stirring are further continued for 30 minutes Upon completion of the reaction, a coarse dispersion of silver nanowires was obtained.

얻어진 은 나노와이어 조분산액의 은 농도를 적정법을 이용하여 측정한 바 0.4질량%이었다. 또한, 포함되는 은 나노와이어의 형상을 SEM(JEOL Ltd. 제품 JSM-7000F)을 이용하여 임의로 100점 관찰하고 계측한 바 평균 지름: 26nm, 평균 길이: 13㎛이었다.It was 0.4 mass % when the silver concentration of the obtained silver nanowire coarse dispersion was measured using the titration method. In addition, when the shape of the silver nanowire contained was observed and measured at 100 points arbitrarily using SEM (JEOL Ltd. JSM-7000F), it was average diameter: 26 nm, and average length: 13 micrometers.

<고농도 은 나노와이어 분산액의 제조><Preparation of high concentration silver nanowire dispersion>

상기 조작을 2회 반복해서 은 나노와이어를 0.4질량% 포함하는 조분산액 7.2kg을 얻었다. Said operation was repeated twice, and 7.2 kg of crude dispersions containing 0.4 mass % of silver nanowires were obtained.

얻어진 조분산액 중 6.3kg을 15L의 PFA(퍼플루오로알콕시에틸렌-테트라플루오로에틸렌 공중합체) 코트 SUS 용기에 넣고, 메커니컬 스터러를 이용하여 150rpm로 교반하면서 아세트산 부틸(FUJIFILM Wako Pure Chemical Corporation 제품) 6.6kg을 10분에 걸쳐서 첨가했다. 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 9.0kg 제거했다.6.3 kg of the obtained crude dispersion was placed in a 15 L PFA (perfluoroalkoxyethylene-tetrafluoroethylene copolymer) coated SUS container, and stirred at 150 rpm using a mechanical stirrer while stirring at 150 rpm, butyl acetate (manufactured by FUJIFILM Wako Pure Chemical Corporation) 6.6 kg was added over 10 minutes. After continuing stirring for 10 minutes, stirring was stopped and the supernatant and the precipitate were separated by allowing to stand for 10 minutes. Then, 9.0 kg of supernatant liquids were removed by decantation operation.

침전을 포함하는 잔액에 아세토니트릴(FUJIFILM Wako Pure Chemical Corporation 제품) 2.3kg을 첨가하고, 10분간 교반을 계속해서 침전을 재분산시킨 후, 아세트산 부틸 4.5kg을 10분에 걸쳐서 첨가했다. 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 전체 액량의 70%(7.5kg) 제거했다. 아세토니트릴(FUJIFILM Wako Pure Chemical Corporation 제품) 2.3kg 첨가 이후의 조작을 11회 반복함으로써 부생된 나노입자를 제거했다.After adding 2.3 kg of acetonitrile (manufactured by FUJIFILM Wako Pure Chemical Corporation) to the residue containing the precipitate, stirring was continued for 10 minutes to redisperse the precipitate, 4.5 kg of butyl acetate was added over 10 minutes. After continuing stirring for 10 minutes, stirring was stopped and the supernatant and the precipitate were separated by allowing to stand for 10 minutes. Then, 70% (7.5 kg) of the supernatant liquid was removed by decantation operation. By-product nanoparticles were removed by repeating the operation after addition of 2.3 kg of acetonitrile (manufactured by FUJIFILM Wako Pure Chemical Corporation) 11 times.

침전을 포함하는 잔액 2.9kg에 아세톤 3.0kg (FUJIFILM Wako Pure Chemical Corporation 제품)을 첨가하고, 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 전체 액량의 80%(4.7kg) 제거했다. 침전을 포함하는 잔액을 3L 폴리 용기로 이액하고, 이온 교환수를 내액이 2.1kg이 될 때까지 첨가하고 진탕교반함으로써 완전히 분산시켰다.To 2.9 kg of the residue containing the precipitate, 3.0 kg of acetone (manufactured by FUJIFILM Wako Pure Chemical Corporation) was added, stirring was continued for 10 minutes, stirring was stopped and the mixture was left still for 10 minutes to separate the supernatant and the precipitate. Then, 80% (4.7 kg) of the supernatant liquid was removed by decantation operation. The remaining liquid containing the precipitation was transferred to a 3L poly container, and ion-exchanged water was added until the inner liquid became 2.1 kg, and then completely dispersed by shaking and stirring.

얻어진 은 나노와이어/수분산액(은 나노와이어 재분산액)의 은 농도를 적정법을 이용하여 측정한 바 1.2질량%이었다. 또한, GPC에 의해 PVP의 농도를 측정한 바 1.8질량%이었다.It was 1.2 mass % when the silver concentration of the obtained silver nanowire/water dispersion (silver nanowire redispersion liquid) was measured using the titration method. Moreover, when the density|concentration of PVP was measured by GPC, it was 1.8 mass %.

은 농도의 측정 방법은 이하와 같다.The measuring method of silver concentration is as follows.

은 농도는 폴하르트법을 이용하여 결정한다. 시료를 비이커에 약 1g 칭량하고, 질산(1+1) 4mL 및 순수 20mL를 첨가한다. 비이커를 시계 접시로 덮고, 핫플레이트 상에서 150℃로 가열해서 고형분을 용해시킨다. 용해를 확인한 후, 가열을 멈추고 방냉하고, 시계 접시 내면과 비이커 벽면을 순수로 씻어내는 액량을 약 50mL로 한다. 이 용액에 질산(1+1) 5mL과 황산 암모늄철(III)(3% 질산 산성) 3mL를 첨가하고, 0.01mol/L 티오시안산 암모늄 수용액으로 적정한다. 이때, 용액이 무색으로부터 담차색으로 착색된 점을 종점으로 한다.The silver concentration is determined using the Folhardt method. Approximately 1 g of the sample is weighed into a beaker, and 4 mL of nitric acid (1+1) and 20 mL of pure water are added. Cover the beaker with a watch glass and heat to 150° C. on a hot plate to dissolve the solids. After confirming the dissolution, stop heating, allow to cool, and wash the inner surface of the watch face and the wall surface of the beaker with pure water to approximately 50 mL. To this solution, 5 mL of nitric acid (1+1) and 3 mL of ammonium iron (III) sulfate (3% nitric acid) are added, and titrated with 0.01 mol/L aqueous ammonium thiocyanate. At this time, the point where the solution is colored from colorless to pale green is taken as the end point.

적정 결과에 의거하여 하기식에 따라 은 농도를 구한다.Based on the titration result, the silver concentration is calculated according to the following formula.

은 농도(wt%) = {(V×c)×107.9/1000}/mSilver concentration (wt%) = {(V×c)×107.9/1000}/m

m: 시료의 중량(g)m: weight of sample (g)

V: 종점까지의 적정에 소비한 티오시안산 암모늄 수용액의 양(mL)V: Amount of ammonium thiocyanate aqueous solution consumed for titration to the end point (mL)

c: 티오시안산 암모늄 수용액의 농도(0.01mol/L)c: concentration of ammonium thiocyanate aqueous solution (0.01 mol/L)

질산(1+1), 황산 암모늄철(III), 티오시안산 암모늄(FUJIFILM Wako Pure Chemical Corporation 제품)은 모두 FUJIFILM Wako Pure Chemical Corporation 제품의 시약을 사용했다. 황산 암모늄철(III)(3% 질산 산성)은 황산 암모늄철(III) 5.17g, 순수 170g 및 질산 2.00g을 혼합해서 조제한 것을 사용했다. 0.01mol/L 티오시안산 암모늄 수용액은 티오시안산 암모늄 38.06mg에 순수를 첨가하여 전량 50mL으로 조제한 것을 사용했다.Nitric acid (1+1), ammonium iron (III) sulfate, and ammonium thiocyanate (manufactured by FUJIFILM Wako Pure Chemical Corporation) were all used as reagents manufactured by FUJIFILM Wako Pure Chemical Corporation. Ferrous ammonium sulfate (III) (3% nitric acid acid) was prepared by mixing 5.17 g of ammonium iron (III) sulfate, 170 g of pure water, and 2.00 g of nitric acid. The 0.01 mol/L aqueous solution of ammonium thiocyanate was prepared by adding pure water to 38.06 mg of ammonium thiocyanate to make a total amount of 50 mL.

GPC에 의해 PVP의 농도 측정은 이하와 같다.The concentration measurement of PVP by GPC is as follows.

폴리비닐피롤리돈(PVP) 농도의 측정에는 겔투과 크로마토그래피(이하 GPC로 생략한다.)를 사용하여, PVP 표준 수용액(0.05%, 0.10%, 0.25%, 0.50%, 1.00%)을 측정해서 작성한 검량선으로부터 구했다.For the measurement of polyvinylpyrrolidone (PVP) concentration, gel permeation chromatography (hereinafter abbreviated as GPC) was used to measure PVP standard aqueous solutions (0.05%, 0.10%, 0.25%, 0.50%, 1.00%). It calculated|required from the prepared calibration curve.

또한, GPC의 측정 조건은 이하와 같다.In addition, the measurement conditions of GPC are as follows.

장치명: JASCO Corporation 제품 HPLC 유닛Device name: JASCO Corporation product HPLC unit

컬럼: Shodex 컬럼 OHPAK SB-806M HQColumn: Shodex column OHPAK SB-806M HQ

이동상: 0.01M NaCl 수용액/메탄올=90:10Mobile phase: 0.01M NaCl aqueous solution/methanol=90:10

유속: 1.0mL/minFlow rate: 1.0 mL/min

검출기: JASCO Corporation 제품 RI-2031PlusDetector: RI-2031Plus from JASCO Corporation

온도: 40.0℃Temperature: 40.0℃

시료량: 샘플 루프 100μL Sample volume: 100 μL sample loop

시료 농도: 원액∼3배 희석액을 원심분리 후, 상청액을 0.22㎛ 필터에 통과시켜서 조제Sample concentration: After centrifugation of the stock solution to a 3-fold dilution, the supernatant is passed through a 0.22 μm filter to prepare

상기 얻어진 은 나노와이어/수분산액을 메탄올로 300배로 희석하여 은 나노와이어 희박 용액을 제작했다. 청정한 유리판 상에 이전의 은 나노와이어 희박 용액을 한 방울 드롭하고, 90℃의 핫플레이트에서 건조시켰다. 유리판을 레이저 현미경(Keyence VK-X200)을 사용해서 3000배의 배율로 관찰(측정 시야: 260㎛×200㎛)하고, 은 나노와이어의 수와 은 나노입자의 수를 계측했다. 분산액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 97%이었다.The silver nanowire/water dispersion obtained above was diluted 300 times with methanol to prepare a silver nanowire dilute solution. A drop of the old silver nanowire dilute solution was dropped on a clean glass plate and dried on a hot plate at 90°C. The glass plate was observed at a magnification of 3000 times using a laser microscope (Keyence VK-X200) (measurement field: 260 µm × 200 µm), and the number of silver nanowires and the number of silver nanoparticles were measured. The silver nanowire ratio in the dispersion (the number of silver nanowires/(the number of silver nanowires + the number of silver nanoparticles)) was calculated to be 97%.

<크로스 플로우 여과><Cross Flow Filtration>

상기 얻어진 은 나노와이어/수분산액 2.1kg을 탁상 소형 시험기(NGK Insulators, Ltd. 제품, 세라믹막 필터 Cefilt 사용, 막 면적 0.06㎡, 구멍 지름 2.0㎛, 치수 Φ 30mm×250mm)에 유입하고, 순환 유속 4L/min, 분산액 온도 25℃, 여과 차압 0.02MPa로 크로스 플로우 여과(제 2 여과까지 실시하는 실시예 6, 11, 12, 15, 16에 있어서의 제 1 여과에 상당)를 실시했다. 여액의 투과 속도가 10g/min이 되도록 투과 밸브의 개폐를 조정하고, 여액이 100g 얻어질 때(용매 유지율 95%) 마다 이온 교환수 100g을 역세에 의해 계에 첨가했다(역세 압력 0.15MPa). 여액이 합계 8400g 얻어진 단계에서 크로스 플로우 여과를 종료했다. 여과 시간은 합계로 18.6시간이며, 단위 시간·단위 여과 면적당 여과 속도를 산출하면 7.5kg/㎡·h이었다. 2.1 kg of the silver nanowire/water dispersion obtained above was introduced into a tabletop small tester (NGK Insulators, Ltd., using a ceramic membrane filter Cefilt, membrane area 0.06 m 2, pore diameter 2.0 μm, dimensions Φ 30 mm×250 mm), and the circulation flow rate Cross-flow filtration (corresponding to the 1st filtration in Examples 6, 11, 12, 15, 16 performed up to the 2nd filtration) was implemented by 4 L/min, the dispersion liquid temperature of 25 degreeC, and filtration differential pressure|pressure 0.02 MPa. The opening and closing of the permeation valve was adjusted so that the permeation rate of the filtrate was 10 g/min, and 100 g of ion-exchanged water was added to the system by backwashing each time 100 g of the filtrate was obtained (solvent retention rate of 95%) (backwashing pressure 0.15 MPa). Cross-flow filtration was complete|finished at the stage in which 8400g of filtrates were obtained in total. The filtration time was 18.6 hours in total, and when the filtration rate per unit time and unit filtration area was computed, it was 7.5 kg/m<2>*h.

크로스 플로우 여과 후의 분산액을 355메쉬의 나일론 필터에 통과시켜 응집물을 제거함으로써 은 나노와이어 정제액을 1.6kg 취득했다. 분산액이 통과하기 전후에 있어서, 나일론 필터의 중량 변화를 측정한 바 0.1g 증가하고, 크로스 플로우 여과에 의해 발생한 응집물은 매우 적었다.The dispersion liquid after cross flow filtration was passed through a 355 mesh nylon filter, and 1.6 kg of silver nanowire purification liquid was acquired by removing aggregates. Before and after the dispersion liquid passed, the weight change of the nylon filter was measured to increase 0.1 g, and the aggregates generated by cross flow filtration were very small.

나일론 필터를 통과한 은 나노와이어 정제액의 은 농도를 적정법을 이용하여 측정한 바 1.2질량%이었다(수율 76%). 또한, GPC에 의해 PVP의 농도를 측정한 바 0.07질량%이었다.The silver concentration of the silver nanowire purification solution that passed through the nylon filter was measured using a titration method, and it was 1.2 mass % (yield 76%). Moreover, when the density|concentration of PVP was measured by GPC, it was 0.07 mass %.

이전과 같은 방법으로, 나일론 필터를 통과한 은 나노와이어 정제액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 97%이었다.In the same way as before, the silver nanowire ratio (number of silver nanowires/(number of silver nanowires + number of silver nanoparticles)) in the silver nanowire purification solution that passed through the nylon filter was calculated, and it was 97%. .

실시예 2Example 2

실시예 1과 같은 합성 방법을 3회 반복해서 은 나노와이어를 0.4질량% 포함하는 조분산액 9.7kg을 얻었다. 얻어진 조분산액을 25L의 PFA 코트 SUS 용기에 넣고, 메커니컬 스터러를 이용하여 150rpm로 교반하면서 아세트산 부틸 10.2kg을 10분에 걸쳐서 첨가했다. 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 13.9kg 제거했다. The synthesis method similar to Example 1 was repeated 3 times, and 9.7 kg of crude dispersions containing 0.4 mass % of silver nanowires were obtained. The obtained crude dispersion liquid was put into a 25 L PFA-coated SUS container, and 10.2 kg of butyl acetate was added over 10 minutes while stirring at 150 rpm using a mechanical stirrer. After continuing stirring for 10 minutes, stirring was stopped and the supernatant and the precipitate were separated by allowing to stand for 10 minutes. Then, 13.9 kg of supernatant liquids were removed by decantation operation.

침전을 포함하는 잔액에 아세토니트릴 3.3kg을 재첨가하고, 10분간 교반을 계속해서 침전을 재분산시킨 후, 아세트산 부틸 6.6kg을 10분에 걸쳐서 첨가했다. 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 전체 액량의 70%(11.1kg) 제거했다. 이 조작을 11회 반복함으로써 부생된 나노입자를 제거했다.3.3 kg of acetonitrile was re-added to the residue containing the precipitation, stirring was continued for 10 minutes to redisperse the precipitate, and then 6.6 kg of butyl acetate was added over 10 minutes. After continuing stirring for 10 minutes, stirring was stopped and the supernatant and the precipitate were separated by allowing to stand for 10 minutes. After that, 70% (11.1 kg) of the total amount of the supernatant was removed by decantation. By repeating this operation 11 times, the nanoparticles by-produced were removed.

침전을 포함하는 잔액 4.3kg에 아세톤 3.0kg을 첨가하고, 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 전체 액량의 80%(5.8kg) 제거했다. 이 조작을 한번 더 반복한 후, 침전을 포함하는 잔액을 3L 폴리 용기로 이액하고, 이온 교환수를 내액이 2.1kg이 될 때까지 첨가하고 진탕교반함으로써 완전히 분산시켰다.After adding 3.0 kg of acetone to 4.3 kg of the residual liquid containing precipitation, stirring was continued for 10 minutes, stirring was stopped, and the supernatant and the precipitate were separated by standing still for 10 minutes. Then, 80% (5.8 kg) of the supernatant liquid was removed by decantation operation. After repeating this operation once more, the remaining liquid containing the precipitation was transferred to a 3 L poly container, and ion-exchanged water was added until the inner liquid became 2.1 kg, followed by shaking and stirring to disperse completely.

얻어진 은 나노와이어/수분산액의 은 농도를 적정법을 이용하여 측정한 바 1.8질량%이었다. 또한, GPC에 의해 PVP의 농도를 측정한 바 2.7질량%이었다.It was 1.8 mass % when the silver concentration of the obtained silver nanowire/water dispersion was measured using the titration method. Moreover, when the density|concentration of PVP was measured by GPC, it was 2.7 mass %.

얻어진 은 나노와이어/수분산액을 메탄올로 500배로 희석하여 은 나노와이어 희박 용액을 제작했다. 청정한 유리판 상에 이전의 은 나노와이어 희박 용액을 한 방울 드롭하고, 90℃의 핫플레이트에서 건조시켰다. 유리판을 레이저 현미경(Keyence Corporation 제품, VK-X200)을 사용해서 3000배의 배율로 관찰하고, 은 나노와이어의 수와 은 나노입자의 수를 계측했다. 분산액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 97%이었다.The obtained silver nanowire/water dispersion was diluted 500-fold with methanol to prepare a silver nanowire dilute solution. A drop of the old silver nanowire dilute solution was dropped on a clean glass plate and dried on a hot plate at 90°C. The glass plate was observed at a magnification of 3000 times using a laser microscope (manufactured by Keyence Corporation, VK-X200), and the number of silver nanowires and the number of silver nanoparticles were measured. The silver nanowire ratio in the dispersion (the number of silver nanowires/(the number of silver nanowires + the number of silver nanoparticles)) was calculated to be 97%.

얻어진 은 나노와이어/수분산액을 실시예 1과 같은 방법으로 크로스 플로우 여과에 의해 정제했다. 여과 시간은 합계로 29.1시간이며, 단위 시간·단위 여과 면적당 여과 속도를 산출하면 4.8kg/㎡·h이었다. 크로스 플로우 여과 후의 분산액을 355메쉬의 나일론 필터에 통과시켜 응집물을 제거함으로써 은 나노와이어 정제액을 1.4kg 취득했다. 분산액이 통과하기 전후에 있어서, 나일론 필터의 중량 변화를 측정한 바 0.02g 증가하고, 크로스 플로우 여과에 의해 발생한 응집물은 거의 없었다. The obtained silver nanowire/water dispersion was purified by cross flow filtration in the same manner as in Example 1. The filtration time was 29.1 hours in total, and when the filtration rate per unit time and unit filtration area was computed, it was 4.8 kg/m<2>*h. The dispersion liquid after cross flow filtration was passed through a 355 mesh nylon filter, and 1.4 kg of silver nanowire purification liquid was acquired by removing aggregates. Before and after the dispersion liquid passed, the weight change of the nylon filter was measured, and as a result, it increased by 0.02 g, and there was almost no aggregate generated by cross flow filtration.

나일론 필터를 통과한 은 나노와이어 정제액의 은 농도를 적정법을 이용하여 측정한 바 1.8질량%이었다(수율 69%). 또한, GPC에 의해 PVP의 농도를 측정한 바 0.09질량%이었다.The silver concentration of the silver nanowire purification solution passing through the nylon filter was measured using a titration method, and it was 1.8% by mass (yield 69%). Moreover, when the density|concentration of PVP was measured by GPC, it was 0.09 mass %.

이전과 같은 방법으로, 나일론 필터를 통과한 은 나노와이어 정제액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 98%이었다.In the same manner as before, the silver nanowire ratio (number of silver nanowires/(number of silver nanowires + number of silver nanoparticles)) in the silver nanowire purification solution that passed through the nylon filter was calculated, and it was 98%. .

실시예 3Example 3

실시예 2와 같은 방법으로 은 나노와이어/수분산액 2.1kg을 얻었다. 얻어진 은 나노와이어/수분산액의 은 농도를 적정법을 이용하여 측정한 바 1.8질량%이었다. 또한, GPC에 의해 PVP의 농도를 측정한 바 2.7질량%이었다.In the same manner as in Example 2, 2.1 kg of silver nanowires/water dispersion was obtained. It was 1.8 mass % when the silver concentration of the obtained silver nanowire/water dispersion was measured using the titration method. Moreover, when the density|concentration of PVP was measured by GPC, it was 2.7 mass %.

실시예 2와 같은 방법으로 분산액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 97%이었다.The silver nanowire ratio (the number of silver nanowires/(the number of silver nanowires + the number of silver nanoparticles)) in the dispersion was calculated in the same manner as in Example 2, and was 97%.

얻어진 은 나노와이어/수분산액 2.1kg을 탁상 소형 시험기(NGK Insulators, Ltd. 제품, 세라믹막 필터 Cefilt 사용, 막 면적 0.06㎡, 구멍 지름 2.0㎛, 치수 Φ 30mm×250mm)에 유입하고, 순환 유속 4L/min, 분산액 온도 25℃, 여과 차압 0.02MPa로 크로스 플로우 여과를 실시했다. 여액의 투과 속도가 대략 10g/min이 되도록 투과 밸브의 개폐를 조정하고, 여액이 200g 얻어질 때(용매 유지율 90%) 마다 이온 교환수 200g을 역세에 의해 계에 첨가했다(역세 압력 0.15MPa). 여액이 합계 8400g 얻어진 단계에서 크로스 플로우 여과를 종료했다. 여과 시간은 합계로 24.7시간이며, 단위 시간·단위 여과 면적당 여과 속도를 산출하면 5.7kg/㎡·h이었다.2.1 kg of the obtained silver nanowire/water dispersion was introduced into a tabletop small tester (NGK Insulators, Ltd., using a ceramic membrane filter Cefilt, membrane area 0.06 m 2, pore diameter 2.0 μm, dimensions Φ 30 mm×250 mm), and a circulation flow rate of 4 L Cross-flow filtration was performed at /min, the dispersion liquid temperature of 25 degreeC, and the filtration differential pressure|voltage of 0.02 MPa. The opening and closing of the permeation valve was adjusted so that the permeation rate of the filtrate was approximately 10 g/min, and 200 g of ion-exchanged water was added to the system by backwashing each time 200 g of the filtrate was obtained (solvent retention rate 90%) (backwash pressure 0.15 MPa) . Cross-flow filtration was complete|finished at the stage in which 8400g of filtrates were obtained in total. The filtration time was 24.7 hours in total, and when the filtration rate per unit time and unit filtration area was computed, it was 5.7 kg/m<2>*h.

크로스 플로우 여과 후의 분산액을 355메쉬의 나일론 필터에 통과시켜 응집물을 제거함으로써 은 나노와이어 정제액을 1.4kg 취득했다. 분산액이 통과하기 전후에 있어서, 나일론 필터의 중량 변화를 측정한 바 0.01g 증가하고, 크로스 플로우 여과에 의해 발생한 응집물은 거의 없었다.The dispersion liquid after cross flow filtration was passed through a 355 mesh nylon filter, and 1.4 kg of silver nanowire purification liquid was acquired by removing aggregates. Before and after the dispersion liquid passed, the weight change of the nylon filter was measured, and as a result, it increased by 0.01 g, and there was almost no aggregate generated by cross flow filtration.

나일론 필터를 통과한 은 나노와이어 정제액의 은 농도를 적정법을 이용하여 측정한 바 1.7질량%이었다(수율 66%). 또한, GPC에 의해 PVP의 농도를 측정한 바 0.07질량%이었다.When the silver concentration of the silver nanowire purification solution that passed through the nylon filter was measured using a titration method, it was 1.7% by mass (yield 66%). Moreover, when the density|concentration of PVP was measured by GPC, it was 0.07 mass %.

실시예 4Example 4

실시예 2와 같은 방법으로 은 나노와이어/수분산액 2.1kg을 얻었다. 얻어진 은 나노와이어/수분산액의 은 농도를 적정법을 이용하여 측정한 바 1.8질량%이었다. 또한, GPC에 의해 PVP의 농도를 측정한 바 2.2질량%이었다.In the same manner as in Example 2, 2.1 kg of silver nanowires/water dispersion was obtained. It was 1.8 mass % when the silver concentration of the obtained silver nanowire/water dispersion was measured using the titration method. Moreover, when the density|concentration of PVP was measured by GPC, it was 2.2 mass %.

실시예 2와 같은 방법으로 분산액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 95%이었다.The silver nanowire ratio (number of silver nanowires/(number of silver nanowires + number of silver nanoparticles)) in the dispersion was calculated in the same manner as in Example 2, and was 95%.

얻어진 은 나노와이어/수분산액 2.1kg을 탁상 소형 시험기(NGK Insulators, Ltd. 제품, 세라믹막 필터 Cefilt 사용, 막 면적 0.06㎡, 구멍 지름 2.0㎛, 치수 Φ 30mm×250mm)에 유입하고, 순환 유속 4L/min, 분산액 온도 25℃, 여과 차압 0.02MPa로 크로스 플로우 여과를 실시했다. 여액의 투과 속도가 대략 10g/min이 되도록 투과 밸브의 개폐를 조정하고, 여액이 400g 얻어질 때(용매 유지율 80%) 마다 이온 교환수 400g을 역세에 의해 계에 첨가했다(역세 압력 0.15MPa). 여액이 합계 8400g 얻어진 단계에서 크로스 플로우 여과를 종료했다. 여과 시간은 합계로 24.2시간이며, 단위 시간·단위 여과 면적당 여과 속도를 산출하면 5.8kg/㎡·h이었다.2.1 kg of the obtained silver nanowire/water dispersion was introduced into a tabletop small tester (NGK Insulators, Ltd., using a ceramic membrane filter Cefilt, membrane area 0.06 m 2, pore diameter 2.0 μm, dimensions Φ 30 mm×250 mm), and a circulation flow rate of 4 L Cross-flow filtration was performed at /min, the dispersion liquid temperature of 25 degreeC, and the filtration differential pressure|voltage of 0.02 MPa. The opening and closing of the permeation valve was adjusted so that the permeation rate of the filtrate was approximately 10 g/min, and 400 g of ion-exchanged water was added to the system by backwashing each time 400 g of the filtrate was obtained (solvent retention rate 80%) (backwash pressure 0.15 MPa) . Cross-flow filtration was complete|finished at the stage in which 8400g of filtrates were obtained in total. The filtration time was 24.2 hours in total, and when the filtration rate per unit time and unit filtration area was computed, it was 5.8 kg/m<2>*h.

크로스 플로우 여과 후의 분산액을 355메쉬의 나일론 필터에 통과시켜 응집물을 제거함으로써 은 나노와이어 정제액을 1.5kg 취득했다. 분산액이 통과하기 전후에 있어서, 나일론 필터의 중량 변화를 측정한 바 0.01g 증가하고, 크로스 플로우 여과에 의해 발생한 응집물은 거의 없었다.1.5 kg of silver nanowire purification liquid was acquired by making the dispersion liquid after cross flow filtration pass through a 355 mesh nylon filter, and removing aggregates. Before and after the dispersion liquid passed, the weight change of the nylon filter was measured, and as a result, it increased by 0.01 g, and there was almost no aggregate generated by cross flow filtration.

나일론 필터를 통과한 은 나노와이어 정제액의 은 농도를 적정법을 이용하여 측정한 바 1.8질량%이었다(수율 72%). 또한, GPC에 의해 PVP의 농도를 측정한 바 0.06질량%이었다.The silver concentration of the silver nanowire purification solution that passed through the nylon filter was measured using a titration method, and was found to be 1.8% by mass (yield 72%). Moreover, when the density|concentration of PVP was measured by GPC, it was 0.06 mass %.

실시예 5Example 5

실시예 2와 같은 방법으로 은 나노와이어/수분산액 2.1kg을 얻었다. 얻어진 은 나노와이어/수분산액의 은 농도를 적정법을 이용하여 측정한 바 1.8질량%이었다. 또한, GPC에 의해 PVP의 농도를 측정한 바 2.0질량%이었다.In the same manner as in Example 2, 2.1 kg of silver nanowires/water dispersion was obtained. It was 1.8 mass % when the silver concentration of the obtained silver nanowire/water dispersion was measured using the titration method. Moreover, when the density|concentration of PVP was measured by GPC, it was 2.0 mass %.

얻어진 은 나노와이어/수분산액 2.1kg을 탁상 소형 시험기(NGK Insulators, Ltd. 제품, 세라믹막 필터 Cefilt 사용, 막 면적 0.06㎡, 구멍 지름 2.0㎛, 치수 Φ 30mm×250mm)에 유입하고, 순환 유속 4L/min, 분산액 온도 25℃, 여과 차압 0.02MPa로 크로스 플로우 여과를 실시했다. 여액의 투과 속도가 대략 10g/min이 되도록 투과 밸브의 개폐를 조정하고, 여액이 700g 얻어질 때(용매 유지율 67%) 마다 이온 교환수 700g을 역세에 의해 계에 첨가했다(역세 압력 0.15MPa). 여액이 합계 8400g 얻어진 단계에서 크로스 플로우 여과를 종료했다. 여과 시간은 합계로 24.8시간이며, 단위 시간·단위 여과 면적당 여과 속도를 산출하면 5.7kg/㎡·h이었다.2.1 kg of the obtained silver nanowire/water dispersion was introduced into a tabletop small tester (NGK Insulators, Ltd., using a ceramic membrane filter Cefilt, membrane area 0.06 m 2, pore diameter 2.0 μm, dimensions Φ 30 mm×250 mm), and a circulation flow rate of 4 L Cross-flow filtration was performed at /min, the dispersion liquid temperature of 25 degreeC, and the filtration differential pressure|voltage of 0.02 MPa. The opening and closing of the permeation valve was adjusted so that the permeation rate of the filtrate was approximately 10 g/min, and whenever 700 g of the filtrate was obtained (solvent retention rate 67%), 700 g of ion-exchanged water was added to the system by backwashing (backwash pressure 0.15 MPa) . Cross-flow filtration was complete|finished at the stage in which 8400g of filtrates were obtained in total. The filtration time was 24.8 hours in total, and when the filtration rate per unit time and unit filtration area was computed, it was 5.7 kg/m<2>*h.

크로스 플로우 여과 후의 분산액을 355메쉬의 나일론 필터에 통과시켜 응집물을 제거함으로써 은 나노와이어 정제액을 1.9kg 취득했다. 분산액이 통과하기 전후에 있어서, 나일론 필터의 중량 변화를 측정한 바 0.02g 증가하고, 크로스 플로우 여과에 의해 발생한 응집물은 거의 없었다.1.9 kg of silver nanowire purification liquid was acquired by making the dispersion liquid after cross flow filtration pass through a 355 mesh nylon filter, and removing aggregates. Before and after the dispersion liquid passed, the weight change of the nylon filter was measured, and as a result, it increased by 0.02 g, and there was almost no aggregate generated by cross flow filtration.

나일론 필터를 통과한 은 나노와이어 정제액의 은 농도를 적정법을 이용하여 측정한 바 1.8질량%이었다(수율 88%). 또한, GPC에 의해 PVP의 농도를 측정한 바 0.04질량%이었다.The silver concentration of the silver nanowire purification solution passing through the nylon filter was measured using a titration method, and it was 1.8% by mass (yield 88%). Moreover, when the density|concentration of PVP was measured by GPC, it was 0.04 mass %.

실시예 6Example 6

얻어진 은 나노와이어/수분산액 2.1kg을 탁상 소형 시험기(NGK Insulators, Ltd. 제품, 세라믹막 필터 Cefilt 사용, 막 면적 0.06㎡, 구멍 지름 2.0㎛, 치수 Φ 30mm×250mm)에 유입하고, 순환 유속 4L/min, 분산액 온도 25℃, 여과 차압 0.02MPa로 크로스 플로우 여과(제 1 여과)를 실시했다. 여액의 투과 속도가 대략10g/min이 되도록 투과 밸브의 개폐를 조정하고, 여액이 100g 얻어질 때(용매 유지율 95%) 마다 이온 교환수 100g을 역세에 의해 계에 첨가했다(역세 압력 0.15MPa). 여액이 합계 5600g 얻어진 단계에서, 역세에 의해 계에 첨가하는 용매를 이온 교환수로부터 에탄올로 변경하고, 여과 차압 0.03MPa로 크로스 플로우 여과(제 2 여과)를 계속했다. 여액이 2800g 추가로 얻어진 단계에서 크로스 플로우 여과를 종료했다. 이온 교환수를 사용한 제 1 여과 시간은 합계로 20.9시간이며, 단위 시간·단위 여과 면적당 여과 속도를 산출하면 4.6kg/㎡·h이었다. 또한, 에탄올을 사용한 제 2 여과 시간은 합계로 11.7시간이며, 단위 시간·단위 여과 면적당 여과 속도를 산출하면 4.0kg/㎡·h이었다.2.1 kg of the obtained silver nanowire/water dispersion was introduced into a tabletop small tester (NGK Insulators, Ltd., using a ceramic membrane filter Cefilt, membrane area 0.06 m 2, pore diameter 2.0 μm, dimensions Φ 30 mm×250 mm), and a circulation flow rate of 4 L Crossflow filtration (first filtration) was performed at /min, a dispersion temperature of 25°C, and a filtration differential pressure of 0.02 MPa. The opening and closing of the permeation valve was adjusted so that the permeation rate of the filtrate was approximately 10 g/min, and 100 g of ion-exchanged water was added to the system by backwashing each time 100 g of the filtrate was obtained (solvent retention rate of 95%) (backwash pressure 0.15 MPa) . At the stage where a total of 5600 g of the filtrate was obtained, the solvent added to the system was changed from ion-exchanged water to ethanol by backwashing, and cross-flow filtration (second filtration) was continued at a filtration differential pressure of 0.03 MPa. Cross-flow filtration was completed at the stage in which 2800 g of the filtrate was additionally obtained. The first filtration time using ion-exchanged water was 20.9 hours in total, and when the filtration rate per unit time and unit filtration area was calculated, it was 4.6 kg/m 2 ·h. In addition, the 2nd filtration time using ethanol was 11.7 hours in total, Computing the filtration rate per unit time and unit filtration area, it was 4.0 kg/m<2>*h.

나일론 필터를 통과한 은 나노와이어 정제액의 은 농도를 적정법을 이용하여 측정한 바 1.8질량%이었다(수율 70%). 또한, GPC에 의해 PVP의 농도를 측정한 바 0.12질량%이었다.The silver concentration of the silver nanowire purification solution that passed through the nylon filter was measured using a titration method, and it was 1.8% by mass (yield 70%). Moreover, when the density|concentration of PVP was measured by GPC, it was 0.12 mass %.

가스크로마토그래피를 이용하여 은 나노와이어 정제액 중의 용매 비율을 측정한 바, 에탄올이 72.0%이며, 물의 비율은 28.0%로 산출되었다.When the ratio of the solvent in the silver nanowire purification solution was measured using gas chromatography, ethanol was 72.0% and the ratio of water was calculated to be 28.0%.

실시예 7Example 7

실시예 1과 같은 합성 방법을 4회 반복해서 은 나노와이어 조분산액 14.4kg을 얻었다. 얻어진 조분산액 중 13.2kg을 35L의 ETFE(에틸렌-테트라플루오로에틸렌 공중합체) 코트 SUS 용기에 넣고, 메커니컬 스터러를 이용하여 150rpm으로 교반하면서 아세트산 부틸 13.8kg을 10분에 걸쳐서 첨가했다. 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 18.8kg 제거했다.The same synthesis method as in Example 1 was repeated 4 times to obtain 14.4 kg of a coarse silver nanowire dispersion. 13.2 kg of the obtained crude dispersion was put into a 35 L ETFE (ethylene-tetrafluoroethylene copolymer) coated SUS container, and 13.8 kg of butyl acetate was added over 10 minutes while stirring at 150 rpm using a mechanical stirrer. After continuing stirring for 10 minutes, stirring was stopped and the supernatant and the precipitate were separated by allowing to stand for 10 minutes. Then, 18.8 kg of supernatant liquids were removed by decantation operation.

침전을 포함하는 잔액에 아세토니트릴 4.5kg을 첨가하고, 10분간 교반을 계속해서 침전을 재분산시킨 후, 아세트산 부틸 9.0kg을 10분에 걸쳐서 첨가했다. 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 전체 액량의 70%(15.1kg) 제거했다. 이 조작을 11회 반복함으로써 부생된 나노입자를 제거했다.After adding 4.5 kg of acetonitrile to the residual liquid containing a precipitation, stirring was continued for 10 minutes, and precipitation was redispersed, 9.0 kg of butyl acetate was added over 10 minutes. After continuing stirring for 10 minutes, stirring was stopped and the supernatant and the precipitate were separated by allowing to stand for 10 minutes. Then, 70% (15.1 kg) of the supernatant liquid was removed by decantation operation. By repeating this operation 11 times, the nanoparticles by-produced were removed.

침전을 포함하는 잔액에 아세톤 5.0kg을 첨가하고, 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 전체 액량의 80%(8.6kg) 제거했다. 이 조작을 한번 더 반복한 후, 침전을 포함하는 잔액을 3L 폴리 용기로 이액하고, 이온 교환수를 내액이 2.1kg이 될 때까지 첨가하고 진탕교반함으로써 완전히 분산시켰다.After adding 5.0 kg of acetone to the residue containing the precipitation, stirring was continued for 10 minutes, the stirring was stopped, and the supernatant and the precipitate were separated by standing still for 10 minutes. Then, 80% (8.6 kg) of the supernatant liquid was removed by decantation operation. After repeating this operation once more, the remaining liquid containing the precipitation was transferred to a 3 L poly container, and ion-exchanged water was added until the inner liquid became 2.1 kg, followed by shaking and stirring to disperse completely.

얻어진 은 나노와이어/수분산액의 은 농도를 적정법을 이용하여 측정한 바 2.5질량%이었다. 또한, GPC에 의해 PVP의 농도를 측정한 바 3.8질량%이었다.It was 2.5 mass % when the silver concentration of the obtained silver nanowire/water dispersion was measured using the titration method. Moreover, when the density|concentration of PVP was measured by GPC, it was 3.8 mass %.

얻어진 은 나노와이어/수분산액을 메탄올로 700배로 희석하여 은 나노와이어 희박 용액을 제작했다. 청정한 유리판 상에 이전의 은 나노와이어 희박 용액을 한 방울 드롭하고, 90℃의 핫플레이트에서 건조시켰다. 유리판을 레이저 현미경(Keyence VK-X200)을 사용해서 3000배의 배율로 관찰하고, 은 나노와이어의 수와 은 나노입자의 수를 계측했다. 분산액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 95%이었다.The silver nanowire/water dispersion obtained was diluted 700-fold with methanol to prepare a silver nanowire dilute solution. A drop of the old silver nanowire dilute solution was dropped on a clean glass plate and dried on a hot plate at 90°C. The glass plate was observed at a magnification of 3000 times using a laser microscope (Keyence VK-X200), and the number of silver nanowires and the number of silver nanoparticles were measured. The ratio of silver nanowires in the dispersion (the number of silver nanowires/(the number of silver nanowires + the number of silver nanoparticles)) was calculated to be 95%.

은 나노와이어/수분산액을 여과 차압이 0.04MPa인 것 이외에는 실시예 1과 같은 방법으로 크로스 플로우 여과에 의해 정제했다. 여과 시간은 합계로 35.0시간이며, 단위 시간·단위 여과 면적당 여과 속도를 산출하면 4.0kg/㎡·h이었다. 크로스 플로우 여과 후의 분산액을 355메쉬의 나일론 필터에 통과시켜 응집물을 제거함으로써 은 나노와이어 정제액을 1.4kg 취득했다. 분산액이 통과하기 전후에 있어서, 나일론 필터의 중량 변화를 측정한 바 0.1g 증가하고, 크로스 플로우 여과에 의해 발생한 응집물은 거의 없었다.The silver nanowire/water dispersion was purified by cross flow filtration in the same manner as in Example 1 except that the filtration differential pressure was 0.04 MPa. The filtration time was 35.0 hours in total, and when the filtration rate per unit time and unit filtration area was computed, it was 4.0 kg/m<2>*h. The dispersion liquid after cross flow filtration was passed through a 355 mesh nylon filter, and 1.4 kg of silver nanowire purification liquid was acquired by removing aggregates. Before and after the dispersion liquid passed, the weight change of the nylon filter was measured to increase by 0.1 g, and there was almost no aggregate generated by cross flow filtration.

나일론 필터를 통과한 은 나노와이어 정제액의 은 농도를 적정법을 이용하여 측정한 바 2.5질량%이었다(수율 72%). 또한, GPC에 의해 PVP의 농도를 측정한 바 0.18질량%이었다.The silver concentration of the silver nanowire purification solution that passed through the nylon filter was measured using a titration method, and it was 2.5 mass % (yield 72%). Moreover, when the density|concentration of PVP was measured by GPC, it was 0.18 mass %.

이전과 같은 방법으로, 나일론 필터를 통과한 은 나노와이어 정제액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 96%이었다.In the same manner as before, the silver nanowire ratio (number of silver nanowires/(number of silver nanowires + number of silver nanoparticles)) in the silver nanowire purification solution that passed through the nylon filter was calculated, and it was 96%. .

실시예 8Example 8

실시예 1과 같은 합성 방법을 2회 반복해서 은 나노와이어 조분산액 7.2kg을 얻었다. 얻어진 조분산액 중 5.3kg을 15L의 PFA 코트 SUS 용기에 넣고, 메커니컬 스터러를 이용하여 150rpm으로 교반하면서 아세트산 부틸 5.6kg을 10분에 걸쳐서 첨가했다. 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 7.6kg 제거했다.The same synthesis method as in Example 1 was repeated twice to obtain 7.2 kg of a coarse silver nanowire dispersion. 5.3 kg of the obtained crude dispersion was put into a 15 L PFA-coated SUS container, and 5.6 kg of butyl acetate was added over 10 minutes while stirring at 150 rpm using a mechanical stirrer. After continuing stirring for 10 minutes, stirring was stopped and the supernatant and the precipitate were separated by allowing to stand for 10 minutes. Then, 7.6 kg of supernatant liquids were removed by decantation operation.

침전을 포함하는 잔액에 아세토니트릴 2.3kg을 첨가하고, 10분간 교반을 계속해서 침전을 재분산시킨 후, 아세트산 부틸 4.5kg을 10분에 걸쳐서 첨가했다. 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 전체 액량의 70%(7.0kg) 제거했다. 이 조작을 11회 반복함으로써 부생된 나노입자를 제거했다.After adding 2.3 kg of acetonitrile to the residue containing a precipitation, stirring was continued for 10 minutes, and precipitation was redispersed, 4.5 kg of butyl acetate was added over 10 minutes. After continuing stirring for 10 minutes, stirring was stopped and the supernatant and the precipitate were separated by allowing to stand for 10 minutes. Then, 70% (7.0 kg) of the supernatant liquid was removed by decantation operation. By repeating this operation 11 times, the nanoparticles by-produced were removed.

침전을 포함하는 잔액에 아세톤 3.0kg을 첨가하고, 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 전체 액량의 80%(4.7kg) 제거했다. 이 조작을 한번 더 반복한 후, 침전을 포함하는 잔액을 3L 폴리 용기로 이액하고, 메탄올을 내액이 2.1kg이 될 때까지 첨가하고 진탕교반함으로써 완전히 분산시켰다.3.0 kg of acetone was added to the residue containing precipitation, stirring was continued for 10 minutes, stirring was stopped, and the supernatant and the precipitate were separated by standing still for 10 minutes. Then, 80% (4.7 kg) of the supernatant liquid was removed by decantation operation. After repeating this operation once more, the remaining liquid containing precipitation was transferred to a 3 L poly container, methanol was added until the inner liquid became 2.1 kg, and the mixture was completely dispersed by shaking and stirring.

얻어진 은 나노와이어/메탄올 분산액의 은 농도를 적정법을 이용하여 측정한 바 1.0질량%이었다. 또한, GPC에 의해 PVP의 농도를 측정한 바 1.4질량%이었다.It was 1.0 mass % when the silver concentration of the obtained silver nanowire/methanol dispersion liquid was measured using the titration method. Moreover, when the density|concentration of PVP was measured by GPC, it was 1.4 mass %.

얻어진 은 나노와이어/메탄올 분산액을 메탄올로 300배로 희석하여 은 나노와이어 희박 용액을 제작했다. 청정한 유리판 상에 이전의 은 나노와이어 희박 용액을 한 방울 드롭하고, 90℃의 핫플레이트에서 건조시켰다. 유리판을 레이저 현미경(Keyence VK-X200)을 사용해서 3000배의 배율로 관찰하고, 은 나노와이어의 수와 은 나노입자의 수를 계측했다. 분산액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 92%이었다.The silver nanowire/methanol dispersion obtained was diluted 300-fold with methanol to prepare a silver nanowire dilute solution. A drop of the old silver nanowire dilute solution was dropped on a clean glass plate and dried on a hot plate at 90°C. The glass plate was observed at a magnification of 3000 times using a laser microscope (Keyence VK-X200), and the number of silver nanowires and the number of silver nanoparticles were measured. The ratio of silver nanowires in the dispersion (the number of silver nanowires/(the number of silver nanowires + the number of silver nanoparticles)) was calculated to be 92%.

얻어진 은 나노와이어/메탄올 분산액 2.1kg을 탁상 소형 시험기(NGK Insulators, Ltd. 제품, 세라믹막 필터 Cefilt 사용, 막 면적 0.06㎡, 구멍 지름 2.0㎛, 치수 Φ 30mm×250mm)에 유입하고, 순환 유속 10L/min, 분산액 온도 25℃, 여과 차압 0.06MPa로 크로스 플로우 여과를 실시했다. 여액의 투과 속도가 12g/min이 되도록 투과 밸브의 개폐를 조정하고, 여액이 100g 얻어질 때(용매 유지율 95%) 마다 메탄올 100g을 역세에 의해 계에 첨가했다(역세 압력 0.15MPa). 여액이 합계 8400g 얻어진 단계에서 크로스 플로우 여과를 종료했다. 여과 시간은 합계로 12.7시간이며, 단위 시간·단위 여과 면적당 여과 속도를 산출하면 11.0kg/㎡·h이었다.2.1 kg of the obtained silver nanowire/methanol dispersion was introduced into a small tabletop tester (NGK Insulators, Ltd., using a ceramic membrane filter Cefilt, membrane area 0.06 m2, pore diameter 2.0 μm, dimensions Φ 30 mm×250 mm), and circulating flow rate 10 L Cross-flow filtration was performed at /min, the dispersion liquid temperature of 25 degreeC, and the filtration differential pressure|pressure of 0.06 Mpa. The opening and closing of the permeation valve was adjusted so that the permeation rate of the filtrate was 12 g/min, and 100 g of methanol was added to the system by backwashing each time 100 g of the filtrate was obtained (solvent retention rate of 95%) (backwash pressure 0.15 MPa). Cross-flow filtration was complete|finished at the stage in which 8400g of filtrates were obtained in total. The filtration time was 12.7 hours in total, and when the filtration rate per unit time and unit filtration area was computed, it was 11.0 kg/m<2>*h.

크로스 플로우 여과 후의 분산액을 355메쉬의 나일론 필터에 통과시켜 응집물을 제거함으로써 은 나노와이어 정제액을 1.5kg 취득했다. 분산액이 통과하기 전후에 있어서, 나일론 필터의 중량 변화를 측정한 바 0.04g 증가하고, 크로스 플로우 여과에 의해 발생한 응집물은 거의 없었다.1.5 kg of silver nanowire purification liquid was acquired by making the dispersion liquid after cross flow filtration pass through a 355 mesh nylon filter, and removing aggregates. Before and after the dispersion liquid passed, the weight change of the nylon filter was measured, and as a result, it increased by 0.04 g, and there was almost no aggregate generated by cross flow filtration.

나일론 필터를 통과한 은 나노와이어 정제액의 은 농도를 적정법을 이용하여 측정한 바 1.0질량%이었다(수율 75%). 또한, GPC에 의해 PVP의 농도를 측정한 바 0.07질량%이었다.The silver concentration of the silver nanowire purification solution passing through the nylon filter was measured using a titration method, and it was 1.0 mass % (yield 75%). Moreover, when the density|concentration of PVP was measured by GPC, it was 0.07 mass %.

가스크로마토그래피를 이용하여 은 나노와이어 정제액 중의 용매 비율을 측정한 바, 메탄올이 88.1%이며, 물의 비율은 11.9%로 산출되었다.When the solvent ratio in the silver nanowire purification solution was measured using gas chromatography, methanol was 88.1% and the water ratio was calculated to be 11.9%.

실시예 9Example 9

실시예 8과 같은 방법으로 은 나노와이어/메탄올 분산액 2.1kg을 얻었다. 얻어진 은 나노와이어/메탄올 분산액의 은 농도를 적정법을 이용하여 측정한 바 1.0질량%이었다. 또한, GPC에 의해 PVP의 농도를 측정한 바 1.2질량%이었다.2.1 kg of a silver nanowire/methanol dispersion was obtained in the same manner as in Example 8. It was 1.0 mass % when the silver concentration of the obtained silver nanowire/methanol dispersion liquid was measured using the titration method. Moreover, when the density|concentration of PVP was measured by GPC, it was 1.2 mass %.

실시예 8과 같은 방법으로 분산액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 95%이었다.The silver nanowire ratio (the number of silver nanowires/(the number of silver nanowires + the number of silver nanoparticles)) in the dispersion was calculated in the same manner as in Example 8, and was 95%.

얻어진 은 나노와이어/메탄올 분산액 2.1kg을 탁상 소형 시험기(NGK Insulators, Ltd. 제품, 세라믹막 필터 Cefilt 사용, 막 면적 0.06㎡, 구멍 지름 2.0㎛, 치수 Φ 30mm×250mm)에 유입하고, 순환 유속 14L/min, 분산액 온도 25℃, 여과 차압 0.07MPa로 크로스 플로우 여과를 실시했다. 여액의 투과 속도가 17g/min이 되도록 투과 밸브의 개폐를 조정하고, 여액이 100g 얻어질 때(용매 유지율 95%) 마다 메탄올 100g을 역세에 의해 계에 첨가했다(역세 압력 0.15MPa). 여액이 합계 8400g 얻어진 단계에서 크로스 플로우 여과를 종료했다. 여과 시간은 합계로 8.8시간이며, 단위 시간·단위 여과 면적당 여과 속도를 산출하면 16.0kg/㎡·h이었다.2.1 kg of the obtained silver nanowire/methanol dispersion was introduced into a small tabletop tester (NGK Insulators, Ltd., using a ceramic membrane filter Cefilt, membrane area 0.06 m2, pore diameter 2.0 µm, dimensions Φ 30 mm×250 mm), and a circulation flow rate of 14 L Cross-flow filtration was performed at /min, the dispersion liquid temperature of 25 degreeC, and the filtration differential pressure|voltage of 0.07 MPa. The opening and closing of the permeation valve was adjusted so that the permeation rate of the filtrate was 17 g/min, and 100 g of methanol was added to the system by backwashing each time 100 g of the filtrate was obtained (solvent retention rate of 95%) (backwash pressure 0.15 MPa). Cross-flow filtration was complete|finished at the stage in which 8400g of filtrates were obtained in total. The filtration time was 8.8 hours in total, and when the filtration rate per unit time and unit filtration area was computed, it was 16.0 kg/m<2>*h.

크로스 플로우 여과 후의 분산액을 355메쉬의 나일론 필터에 통과시켜 응집물을 제거함으로써 은 나노와이어 정제액을 1.3kg 취득했다. 분산액이 통과하기 전후에 있어서, 나일론 필터의 중량 변화를 측정한 바 0.25g 증가하고, 크로스 플로우 여과에 의해 발생한 응집물은 적었다.1.3 kg of silver nanowire purification liquid was acquired by making the dispersion liquid after cross flow filtration pass through a 355 mesh nylon filter, and removing aggregates. Before and after the dispersion liquid passed, the weight change of the nylon filter was measured. As a result, 0.25 g was increased, and the amount of aggregates generated by cross flow filtration was small.

나일론 필터를 통과한 은 나노와이어 정제액의 은 농도를 적정법을 이용하여 측정한 바 1.0질량%이었다(수율 65%). 또한, GPC에 의해 PVP의 농도를 측정한 바 0.09질량%이었다.The silver concentration of the silver nanowire purification solution passing through the nylon filter was measured using a titration method, and it was 1.0 mass % (yield 65%). Moreover, when the density|concentration of PVP was measured by GPC, it was 0.09 mass %.

이전과 같은 방법으로, 나일론 필터를 통과한 은 나노와이어 정제액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 92%이었다.In the same way as before, the silver nanowire ratio (number of silver nanowires/(number of silver nanowires + number of silver nanoparticles)) in the silver nanowire purification solution that passed through the nylon filter was calculated, and it was 92%. .

가스크로마토그래피를 이용하여 은 나노와이어 정제액 중의 용매 비율을 측정한 바, 메탄올이 85.6%이며, 물의 비율은 14.4%로 산출되었다.When the solvent ratio in the silver nanowire purification solution was measured using gas chromatography, methanol was 85.6%, and the water ratio was calculated to be 14.4%.

실시예 10Example 10

실시예 8과 같은 방법으로 은 나노와이어/메탄올 분산액 2.1kg을 얻었다. 얻어진 은 나노와이어/메탄올 분산액의 은 농도를 적정법을 이용하여 측정한 바 1.0질량%이었다. 또한, GPC에 의해 PVP의 농도를 측정한 바 1.5질량%이었다.2.1 kg of a silver nanowire/methanol dispersion was obtained in the same manner as in Example 8. It was 1.0 mass % when the silver concentration of the obtained silver nanowire/methanol dispersion liquid was measured using the titration method. Moreover, when the density|concentration of PVP was measured by GPC, it was 1.5 mass %.

실시예 8과 같은 방법으로 분산액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 97%이었다.The silver nanowire ratio (the number of silver nanowires/(the number of silver nanowires + the number of silver nanoparticles)) in the dispersion was calculated in the same manner as in Example 8, and was 97%.

얻어진 은 나노와이어/메탄올 분산액 2.1kg을 탁상 소형 시험기(NGK Insulators, Ltd. 제품, 세라믹막 필터 Cefilt 사용, 막 면적 0.06㎡, 구멍 지름 2.0㎛, 치수 Φ 30mm×250mm)에 유입하고, 순환 유속 14L/min, 분산액 온도 25℃, 여과 차압 0.07MPa로 크로스 플로우 여과를 실시했다. 여액의 투과 속도가 17g/min이 되도록 투과 밸브의 개폐를 조정하고, 여액이 100g 얻어질 때(용매 유지율 95%) 마다 메탄올 100g을 역세에 의해 계에 첨가했다(역세 압력 0.15MPa). 여액이 합계 8400g 얻어진 단계에서 크로스 플로우 여과를 종료했다. 여과 시간은 합계로 7.0시간이며, 단위 시간·단위 여과 면적당 여과 속도를 산출하면 20.0kg/㎡·h이었다.2.1 kg of the obtained silver nanowire/methanol dispersion was introduced into a small tabletop tester (NGK Insulators, Ltd., using a ceramic membrane filter Cefilt, membrane area 0.06 m2, pore diameter 2.0 µm, dimensions Φ 30 mm×250 mm), and a circulation flow rate of 14 L Cross-flow filtration was performed at /min, the dispersion liquid temperature of 25 degreeC, and the filtration differential pressure|voltage of 0.07 MPa. The opening and closing of the permeation valve was adjusted so that the permeation rate of the filtrate was 17 g/min, and 100 g of methanol was added to the system by backwashing each time 100 g of the filtrate was obtained (solvent retention rate of 95%) (backwash pressure 0.15 MPa). Cross-flow filtration was complete|finished at the stage in which 8400g of filtrates were obtained in total. The filtration time was 7.0 hours in total, and when the filtration rate per unit time and unit filtration area was computed, it was 20.0 kg/m<2>*h.

크로스 플로우 여과 후의 분산액을 30㎛의 데프스 필터에 통과시켜 응집물을 제거함으로써 은 나노와이어 정제액을 1.4kg 취득했다. 분산액이 통과하기 전후에 있어서, 데프스 필터의 중량 변화를 측정한 바 0.9g 증가하고, 크로스 플로우 여과에 의해 발생한 응집물은 적었다.1.4 kg of silver nanowire purification liquid was acquired by making the dispersion liquid after cross flow filtration pass through a 30-micrometer defs filter, and removing aggregates. Before and after the dispersion liquid passed, the weight change of the def filter increased by 0.9 g, and the amount of aggregates generated by cross flow filtration was small.

나일론 필터를 통과한 은 나노와이어 정제액의 은 농도를 적정법을 이용하여 측정한 바 0.9질량%이었다(수율 61%). 또한, GPC에 의해 PVP의 농도를 측정한 바 0.18질량%이었다.The silver concentration of the silver nanowire purification solution that passed through the nylon filter was measured using a titration method, and it was 0.9 mass % (yield 61%). Moreover, when the density|concentration of PVP was measured by GPC, it was 0.18 mass %.

가스크로마토그래피를 이용하여 은 나노와이어 정제액 중의 용매 비율을 측정한 바, 메탄올이 86.9%이며, 물의 비율은 13.1%로 산출되었다.When the ratio of the solvent in the silver nanowire purification solution was measured using gas chromatography, methanol was 86.9%, and the ratio of water was calculated to be 13.1%.

실시예 11Example 11

실시예 1과 같은 조작을 2회 반복해서 은 나노와이어 조분산액 7.2kg을 얻었다. 얻어진 조분산액 중 6.3kg을 15L의 PFA 코트 SUS 용기에 넣고, 메커니컬 스터러를 이용하여 150rpm으로 교반하면서 아세트산 부틸 6.6kg을 10분에 걸쳐서 첨가했다. 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 9.0kg 제거했다.The same operation as in Example 1 was repeated twice to obtain 7.2 kg of a coarse silver nanowire dispersion. 6.3 kg of the obtained crude dispersion was put into a 15 L PFA-coated SUS container, and 6.6 kg of butyl acetate was added over 10 minutes while stirring at 150 rpm using a mechanical stirrer. After continuing stirring for 10 minutes, stirring was stopped and the supernatant and the precipitate were separated by allowing to stand for 10 minutes. Then, 9.0 kg of supernatant liquids were removed by decantation operation.

침전을 포함하는 잔액에 아세토니트릴 2.3kg을 첨가하고, 10분간 교반을 계속해서 침전을 재분산시킨 후, 아세트산 부틸 4.5kg을 10분에 걸쳐서 첨가했다. 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 전체 액량의 70%(7.5kg) 제거했다. 이 조작을 11회 반복함으로써 부생된 나노입자를 제거했다.After adding 2.3 kg of acetonitrile to the residue containing a precipitation, stirring was continued for 10 minutes, and precipitation was redispersed, 4.5 kg of butyl acetate was added over 10 minutes. After continuing stirring for 10 minutes, stirring was stopped and the supernatant and the precipitate were separated by allowing to stand for 10 minutes. Then, 70% (7.5 kg) of the supernatant liquid was removed by decantation operation. By repeating this operation 11 times, the nanoparticles by-produced were removed.

침전을 포함하는 잔액에 아세톤 3.0kg을 첨가하고, 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 전체 액량의 80%(4.7kg) 제거했다. 침전을 포함하는 잔액을 3L 폴리 용기로 이액하고, 메탄올을 내액이 2.1kg이 될 때까지 첨가하고 진탕교반함으로써 완전히 분산시켰다.3.0 kg of acetone was added to the residue containing precipitation, stirring was continued for 10 minutes, stirring was stopped, and the supernatant and the precipitate were separated by standing still for 10 minutes. Then, 80% (4.7 kg) of the supernatant liquid was removed by decantation operation. The remaining liquid containing the precipitation was transferred to a 3 L poly container, methanol was added until the inner liquid became 2.1 kg, and the mixture was completely dispersed by shaking and stirring.

얻어진 은 나노와이어/메탄올 분산액의 은 농도를 적정법을 이용하여 측정한 바 1.2질량%이었다. 또한, GPC에 의해 PVP의 농도를 측정한 바 1.1질량%이었다.It was 1.2 mass % when the silver concentration of the obtained silver nanowire/methanol dispersion liquid was measured using the titration method. Moreover, when the density|concentration of PVP was measured by GPC, it was 1.1 mass %.

실시예와 같은 방법으로 분산액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 96%이었다.The silver nanowire ratio (the number of silver nanowires/(the number of silver nanowires + the number of silver nanoparticles)) in the dispersion was calculated in the same manner as in the example, and it was 96%.

얻어진 은 나노와이어/메탄올 분산액 2.1kg을 탁상 소형 시험기(NGK Insulators, Ltd. 제품, 세라믹막 필터 Cefilt 사용, 막 면적 0.06㎡, 구멍 지름 2.0㎛, 치수 Φ 30mm×250mm)에 유입하고, 순환 유속 10L/min, 분산액 온도 25℃, 여과 차압 0.02MPa로 크로스 플로우 여과(제 1 여과)를 실시했다. 여액의 투과 속도가 10g/min이 되도록 투과 밸브의 개폐를 조정하고, 여액이 100g 얻어질 때(용매 유지율 95%) 마다 메탄올 100g을 역세에 의해 계에 첨가했다(역세 압력 0.15MPa). 여액이 합계 7000g 얻어진 단계에서, 역세에 의해 계에 첨가하는 용매를 메탄올로부터 에탄올로 변경하고, 여과 차압 0.02MPa로 크로스 플로우 여과(제 2 여과)를 계속했다. 여액이 1400g 추가로 얻어진 단계에서 크로스 플로우 여과를 종료했다. 메탄올을 사용한 제 1 여과 시간은 합계로 16.7시간이며, 단위 시간·단위 여과 면적당 여과 속도를 산출하면 7.0kg/㎡·h이었다. 또한, 에탄올을 사용한 제 2 여과 시간은 합계로 3.0시간이며, 단위 시간·단위 여과 면적당 여과 속도를 산출하면 7.8g/㎡·h이었다.2.1 kg of the obtained silver nanowire/methanol dispersion was introduced into a small tabletop tester (NGK Insulators, Ltd., using a ceramic membrane filter Cefilt, membrane area 0.06 m2, pore diameter 2.0 μm, dimensions Φ 30 mm×250 mm), and circulating flow rate 10 L Crossflow filtration (first filtration) was performed at /min, a dispersion temperature of 25°C, and a filtration differential pressure of 0.02 MPa. The opening and closing of the permeation valve was adjusted so that the permeation rate of the filtrate was 10 g/min, and 100 g of methanol was added to the system by backwashing whenever 100 g of the filtrate was obtained (solvent retention rate of 95%) (backwash pressure 0.15 MPa). At the stage in which a total of 7000 g of the filtrate was obtained, the solvent added to the system was changed from methanol to ethanol by backwashing, and cross flow filtration (second filtration) was continued at a filtration differential pressure of 0.02 MPa. Cross-flow filtration was completed at the stage in which 1400 g of the filtrate was additionally obtained. The 1st filtration time using methanol was 16.7 hours in total, Computing the filtration rate per unit time and unit filtration area, it was 7.0 kg/m<2>*h. In addition, the 2nd filtration time using ethanol was 3.0 hours in total, Computing the filtration rate per unit time and unit filtration area, it was 7.8 g/m<2>*h.

크로스 플로우 여과 후의 분산액을 355메쉬의 나일론 필터에 통과시켜 응집물을 제거함으로써 은 나노와이어 정제액을 1.5kg 취득했다. 분산액이 통과하기 전후에 있어서, 나일론 필터의 중량 변화를 측정한 바 0.17g 증가하고, 크로스 플로우 여과에 의해 발생한 응집물은 매우 적었다.1.5 kg of silver nanowire purification liquid was acquired by making the dispersion liquid after cross flow filtration pass through a 355 mesh nylon filter, and removing aggregates. Before and after the dispersion liquid passed, the weight change of the nylon filter was measured to increase by 0.17 g, and the aggregates generated by cross flow filtration were very small.

나일론 필터를 통과한 은 나노와이어 정제액의 은 농도를 적정법을 이용하여 측정한 바 1.2질량%이었다(수율 76%). 또한, GPC에 의해 PVP의 농도를 측정한 바 0.10질량%이었다.The silver concentration of the silver nanowire purification solution that passed through the nylon filter was measured using a titration method, and it was 1.2 mass % (yield 76%). Moreover, when the density|concentration of PVP was measured by GPC, it was 0.10 mass %.

가스크로마토그래피를 이용하여 은 나노와이어 정제액 중의 용매 비율을 측정한 바, 메탄올이 46.5%, 에탄올이 38.0%이며, 물의 비율은 15.5%로 산출되었다.When the solvent ratio in the silver nanowire purification solution was measured using gas chromatography, methanol was 46.5%, ethanol was 38.0%, and the ratio of water was calculated to be 15.5%.

실시예 12Example 12

실시예 11과 같은 방법으로 은 나노와이어/메탄올 분산액 2.1kg을 얻었다. 얻어진 은 나노와이어 분산액의 은 농도를 적정법을 이용하여 측정한 바 1.2질량%이었다. 또한, GPC에 의해 PVP의 농도를 측정한 바 1.4질량%이었다.In the same manner as in Example 11, 2.1 kg of a silver nanowire/methanol dispersion was obtained. It was 1.2 mass % when the silver concentration of the obtained silver nanowire dispersion liquid was measured using the titration method. Moreover, when the density|concentration of PVP was measured by GPC, it was 1.4 mass %.

실시예 11과 같은 방법으로 분산액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 96%이었다.The silver nanowire ratio (number of silver nanowires/(number of silver nanowires + number of silver nanoparticles)) in the dispersion was calculated in the same manner as in Example 11, and it was 96%.

얻어진 은 나노와이어/메탄올 분산액 2.1kg을 탁상 소형 시험기(NGK Insulators, Ltd. 제품, 세라믹막 필터 Cefilt 사용, 막 면적 0.06㎡, 구멍 지름 2.0㎛, 치수 Φ 30mm×250mm)에 유입하고, 순환 유속 10L/min, 분산액 온도 25℃, 여과 차압 0.02MPa로 크로스 플로우 여과(제 1 여과)를 실시했다. 여액의 투과 속도가 10g/min이 되도록 투과 밸브의 개폐를 조정하고, 여액이 100g 얻어질 때(용매 유지율 95%) 마다 메탄올 100g을 역세에 의해 계에 첨가했다(역세 압력 0.15MPa). 여액이 합계 6300g 얻어진 단계에서, 역세에 의해 계에 첨가하는 용매를 메탄올로부터 에탄올로 변경하고, 여과 차압 0.02MPa로 크로스 플로우 여과(제 2 여과)를 계속했다. 여액이 2100g 추가로 얻어진 단계에서 크로스 플로우 여과를 종료했다. 메탄올을 사용한 제 1 여과 시간은 합계로 21.2시간이며, 단위 시간·단위 여과 면적당 여과 속도를 산출하면 5.0kg/㎡·h이었다. 또한, 에탄올을 사용한 제 2 여과 시간은 합계로 4.2시간이며, 단위 시간·단위 여과 면적당 여과 속도를 산출하면 8.3kg/㎡·h이었다.2.1 kg of the obtained silver nanowire/methanol dispersion was introduced into a small tabletop tester (NGK Insulators, Ltd., using a ceramic membrane filter Cefilt, membrane area 0.06 m2, pore diameter 2.0 μm, dimensions Φ 30 mm×250 mm), and circulating flow rate 10 L Crossflow filtration (first filtration) was performed at /min, a dispersion temperature of 25°C, and a filtration differential pressure of 0.02 MPa. The opening and closing of the permeation valve was adjusted so that the permeation rate of the filtrate was 10 g/min, and 100 g of methanol was added to the system by backwashing whenever 100 g of the filtrate was obtained (solvent retention rate of 95%) (backwash pressure 0.15 MPa). At the stage in which a total of 6300 g of the filtrate was obtained, the solvent added to the system was changed from methanol to ethanol by backwashing, and cross flow filtration (second filtration) was continued with a filtration differential pressure of 0.02 MPa. Cross-flow filtration was completed at the stage in which 2100 g of the filtrate was additionally obtained. The first filtration time using methanol was 21.2 hours in total, and when the filtration rate per unit time and unit filtration area was calculated, it was 5.0 kg/m 2 ·h. In addition, the 2nd filtration time using ethanol was 4.2 hours in total, and when the filtration rate per unit time and unit filtration area was computed, it was 8.3 kg/m<2>*h.

크로스 플로우 여과 후의 분산액을 355메쉬의 나일론 필터에 통과시켜 응집물을 제거함으로써 은 나노와이어 정제액을 1.4kg 취득했다. 분산액이 통과하기 전후에 있어서, 나일론 필터의 중량 변화를 측정한 바 0.18g 증가하고, 크로스 플로우 여과에 의해 발생한 응집물은 매우 적었다.The dispersion liquid after cross flow filtration was passed through a 355 mesh nylon filter, and 1.4 kg of silver nanowire purification liquid was acquired by removing aggregates. Before and after the dispersion liquid passed, the weight change of the nylon filter was measured to increase by 0.18 g, and the aggregates generated by cross flow filtration were very small.

나일론 필터를 통과한 은 나노와이어 정제액의 은 농도를 적정법을 이용하여 측정한 바 1.2질량%이었다(수율 71%). 또한, GPC에 의해 PVP의 농도를 측정한 바 0.11질량%이었다.The silver concentration of the silver nanowire purification solution passing through the nylon filter was measured using a titration method, and it was 1.2 mass % (yield 71%). Moreover, when the density|concentration of PVP was measured by GPC, it was 0.11 mass %.

가스크로마토그래피를 이용하여 은 나노와이어 정제액 중의 용매 비율을 측정한 바, 메탄올이 38.1%, 에탄올이 50.0%이며, 물의 비율은 11.9%로 산출되었다.When the solvent ratio in the silver nanowire purification solution was measured using gas chromatography, methanol was 38.1%, ethanol was 50.0%, and the ratio of water was calculated to be 11.9%.

실시예 13Example 13

이온 교환수 대신에 메탄올을 사용하는 것 이외에는 실시예 2와 같은 방법으로, 은 나노와이어/메탄올 분산액 2.1kg을 얻었다. 얻어진 은 나노와이어/메탄올 분산액의 은 농도를 적정법을 이용하여 측정한 바 1.8질량%이었다. 또한, GPC에 의해 PVP의 농도를 측정한 바 2.6질량%이었다.In the same manner as in Example 2 except for using methanol instead of ion-exchanged water, 2.1 kg of a silver nanowire/methanol dispersion was obtained. It was 1.8 mass % when the silver concentration of the obtained silver nanowire/methanol dispersion liquid was measured using the titration method. Moreover, when the density|concentration of PVP was measured by GPC, it was 2.6 mass %.

얻어진 은 나노와이어/메탄올 분산액 2.1kg을 탁상 소형 시험기(NGK Insulators, Ltd. 제품, 세라믹막 필터 Cefilt 사용, 막 면적 0.06㎡, 구멍 지름 2.0㎛, 치수 Φ 30mm×250mm)에 유입하고, 순환 유속 10L/min, 분산액 온도 25℃, 여과 차압 0.06MPa로 크로스 플로우 여과를 실시했다. 여액의 투과 속도가 10g/min이 되도록 투과 밸브의 개폐를 조정하고, 여액이 100g 얻어질 때(용매 유지율 95%) 마다 메탄올 100g을 역세에 의해 계에 첨가했다(역세 압력 0.15MPa). 여액이 합계 8400g 얻어진 단계에서 크로스 플로우 여과를 종료했다. 여과 시간은 합계로 15.4시간이며, 단위 시간·단위 여과 면적당 여과 속도를 산출하면 9.1kg/㎡·h이었다.2.1 kg of the obtained silver nanowire/methanol dispersion was introduced into a small tabletop tester (NGK Insulators, Ltd., using a ceramic membrane filter Cefilt, membrane area 0.06 m2, pore diameter 2.0 μm, dimensions Φ 30 mm×250 mm), and circulating flow rate 10 L Cross-flow filtration was performed at /min, the dispersion liquid temperature of 25 degreeC, and the filtration differential pressure|pressure of 0.06 Mpa. The opening and closing of the permeation valve was adjusted so that the permeation rate of the filtrate was 10 g/min, and 100 g of methanol was added to the system by backwashing whenever 100 g of the filtrate was obtained (solvent retention rate of 95%) (backwash pressure 0.15 MPa). Cross-flow filtration was complete|finished at the stage in which 8400g of filtrates were obtained in total. The filtration time was 15.4 hours in total, and when the filtration rate per unit time and unit filtration area was computed, it was 9.1 kg/m<2>*h.

크로스 플로우 여과 후의 분산액을 355메쉬의 나일론 필터에 통과시켜 응집물을 제거함으로써 은 나노와이어 정제액을 1.5kg 취득했다. 분산액이 통과하기 전후에 있어서, 나일론 필터의 중량 변화를 측정한 바 0.2g 증가하고, 크로스 플로우 여과에 의해 발생한 응집물은 매우 적었다.1.5 kg of silver nanowire purification liquid was acquired by making the dispersion liquid after cross flow filtration pass through a 355 mesh nylon filter, and removing aggregates. Before and after the dispersion liquid passed, the weight change of the nylon filter was measured to increase 0.2 g, and the aggregate generated by cross flow filtration was very small.

나일론 필터를 통과한 은 나노와이어 정제액의 은 농도를 적정법을 이용하여 측정한 바 1.8질량%이었다(수율 75%). 또한, GPC에 의해 PVP의 농도를 측정한 바 0.06질량%이었다.The silver concentration of the silver nanowire purification solution that passed through the nylon filter was measured using a titration method, and it was 1.8% by mass (yield 75%). Moreover, when the density|concentration of PVP was measured by GPC, it was 0.06 mass %.

가스크로마토그래피를 이용하여 은 나노와이어 정제액 중의 용매 비율을 측정한 바, 메탄올이 79.1%이며, 물의 비율은 20.9%로 산출되었다.When the solvent ratio in the silver nanowire purification solution was measured using gas chromatography, methanol was 79.1%, and the water ratio was calculated to be 20.9%.

실시예 14Example 14

이온 교환수 대신에 에탄올을 사용하는 것 이외에는 실시예 2와 같은 방법으로 은 나노와이어/에탄올 분산액 2.1kg을 얻었다. 얻어진 은 나노와이어/에탄올 분산액의 은 농도를 적정법을 이용하여 측정한 바 1.8질량%이었다. 또한, GPC에 의해 PVP의 농도를 측정한 바 2.7질량%이었다.2.1 kg of a silver nanowire/ethanol dispersion was obtained in the same manner as in Example 2, except that ethanol was used instead of ion-exchanged water. It was 1.8 mass % when the silver concentration of the obtained silver nanowire/ethanol dispersion liquid was measured using the titration method. Moreover, when the density|concentration of PVP was measured by GPC, it was 2.7 mass %.

실시예 13과 같은 방법으로 분산액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 92%이었다.The silver nanowire ratio (the number of silver nanowires/(the number of silver nanowires + the number of silver nanoparticles)) in the dispersion was calculated in the same manner as in Example 13, and was found to be 92%.

얻어진 은 나노와이어/에탄올 분산액 2.1kg을 탁상 소형 시험기(NGK Insulators, Ltd. 제품, 세라믹막 필터 Cefilt 사용, 막 면적 0.06㎡, 구멍 지름 2.0㎛, 치수 Φ 30mm×250mm)에 유입하고, 순환 유속 12L/min, 분산액 온도 25℃, 여과 차압 0.03MPa로 크로스 플로우 여과를 실시했다. 여액의 투과 속도가 대략 5g/min이 되도록 투과 밸브의 개폐를 조정하고, 여액이 100g 얻어질 때(용매 유지율 95%) 마다 에탄올 100g을 역세에 의해 계에 첨가했다(역세 압력 0.15MPa). 여액이 합계 8400g 얻어진 단계에서 크로스 플로우 여과를 종료했다. 여과 시간은 합계로 40.1시간이며, 여과 속도를 산출하면 3.5kg/㎡·h이었다.2.1 kg of the obtained silver nanowire/ethanol dispersion was introduced into a tabletop small tester (NGK Insulators, Ltd., using a ceramic membrane filter Cefilt, membrane area 0.06 m 2, pore diameter 2.0 μm, dimensions Φ 30 mm × 250 mm), and a circulation flow rate of 12 L Cross-flow filtration was performed at /min, the dispersion liquid temperature of 25 degreeC, and the filtration differential pressure|pressure of 0.03 MPa. The opening and closing of the permeation valve was adjusted so that the permeation rate of the filtrate was approximately 5 g/min, and 100 g of ethanol was added to the system by backwashing whenever 100 g of the filtrate was obtained (solvent retention rate of 95%) (backwashing pressure 0.15 MPa). Cross-flow filtration was complete|finished at the stage in which 8400g of filtrates were obtained in total. The filtration time was 40.1 hours in total, and when the filtration rate was computed, it was 3.5 kg/m<2>*h.

크로스 플로우 여과 후의 분산액을 355메쉬의 나일론 필터에 통과시켜 응집물을 제거함으로써 은 나노와이어 정제액을 1.4kg 취득했다. 분산액이 통과하기 전후에 있어서, 나일론 필터의 중량 변화를 측정한 바 0.2g 증가하고, 크로스 플로우 여과에 의해 발생한 응집물은 매우 적었다.The dispersion liquid after cross flow filtration was passed through a 355 mesh nylon filter, and 1.4 kg of silver nanowire purification liquid was acquired by removing aggregates. Before and after the dispersion liquid passed, the weight change of the nylon filter was measured to increase 0.2 g, and the aggregate generated by cross flow filtration was very small.

나일론 필터를 통과한 은 나노와이어 정제액의 은 농도를 적정법을 이용하여 측정한 바 1.8질량%이었다(수율 71%). 또한, GPC에 의해 PVP의 농도를 측정한 바 0.11질량%이었다.The silver concentration of the silver nanowire purification solution that passed through the nylon filter was measured using a titration method, and it was 1.8% by mass (yield 71%). Moreover, when the density|concentration of PVP was measured by GPC, it was 0.11 mass %.

가스크로마토그래피를 이용하여 은 나노와이어 정제액 중의 용매 비율을 측정한 바, 에탄올이 89.8%이며, 물의 비율은 10.2%로 산출되었다.When the solvent ratio in the silver nanowire purification solution was measured using gas chromatography, ethanol was 89.8%, and the water ratio was calculated to be 10.2%.

실시예 15Example 15

실시예 1과 같은 합성 방법을 27회 반복해서 은 나노와이어 조분산액 97.2kg을 얻었다.The same synthesis method as in Example 1 was repeated 27 times to obtain 97.2 kg of a coarse dispersion of silver nanowires.

상기 은 나노와이어 조분산액 중 15.4kg을 65L의 PFA 코트 SUS 용기에 넣고, 메커니컬 스터러를 이용하여 150rpm으로 교반하면서 아세트산 부틸 16.1kg을 10분에 걸쳐서 첨가했다. 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 22.1kg 제거했다. 은 나노와이어 조분산액을 16.9kg 더 첨가하고, 150rpm으로 10분간 교반을 계속해서 분산시켰다. 아세트산 부틸 17.8kg을 10분에 걸쳐서 첨가하고, 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 31.0kg 제거했다.15.4 kg of the silver nanowire coarse dispersion was placed in a 65 L PFA-coated SUS container, and 16.1 kg of butyl acetate was added over 10 minutes while stirring at 150 rpm using a mechanical stirrer. After continuing stirring for 10 minutes, stirring was stopped and the supernatant and the precipitate were separated by allowing to stand for 10 minutes. Then, 22.1 kg of supernatant liquids were removed by decantation operation. 16.9 kg of the silver nanowire coarse dispersion was further added, and stirring was continued at 150 rpm for 10 minutes to disperse. After adding 17.8 kg of butyl acetate over 10 minutes, stirring was continued for 10 minutes, stirring was stopped, and the supernatant and the precipitate were separated by allowing the mixture to stand for 10 minutes. Then, 31.0 kg of supernatant liquids were removed by decantation operation.

침전을 포함하는 잔액에 아세토니트릴 7.6kg을 첨가하고, 10분간 교반을 계속해서 침전을 재분산시킨 후, 아세트산 부틸 16.0kg을 10분에 걸쳐서 첨가했다. 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 전체 액량의 70%(23.0kg) 제거했다. 이 조작을 11회 반복함으로써 부생된 나노입자를 제거했다.7.6 kg of acetonitrile was added to the residue containing the precipitation, stirring was continued for 10 minutes to redisperse the precipitate, and then 16.0 kg of butyl acetate was added over 10 minutes. After continuing stirring for 10 minutes, stirring was stopped and the supernatant and the precipitate were separated by allowing to stand for 10 minutes. Thereafter, 70% (23.0 kg) of the total amount of the supernatant was removed by decantation operation. By repeating this operation 11 times, the nanoparticles by-produced were removed.

침전을 포함하는 잔액에 아세톤 7.0kg을 첨가하고, 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 전체 액량의 70%(11.9kg) 제거했다. 이 조작을 한번 더 반복한 후, 침전을 포함하는 잔액을 10L폴리 용기로 이액하고, 이온 교환수를 내액이 7.0kg이 될 때까지 첨가하고 진탕교반함으로써 완전히 분산시켰다.After adding 7.0 kg of acetone to the residue containing the precipitation, stirring was continued for 10 minutes, the stirring was stopped, and the supernatant and the precipitate were separated by allowing the mixture to stand for 10 minutes. Thereafter, 70% (11.9 kg) of the total amount of the supernatant was removed by decantation operation. After repeating this operation once more, the remaining liquid containing the precipitation was transferred to a 10 L poly container, and ion-exchanged water was added until the inner liquid became 7.0 kg, followed by shaking and stirring to disperse completely.

상기 재침전 조작을 2회 더 반복하고, 은 나노와이어/수분산액을 합계로 21.0kg 취득했다.The said reprecipitation operation was repeated 2 more times, and 21.0 kg of silver nanowires/water dispersion was acquired in total.

실시예 2와 같은 방법으로 분산액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 93%이었다.The silver nanowire ratio (number of silver nanowires/(number of silver nanowires + number of silver nanoparticles)) in the dispersion was calculated in the same manner as in Example 2, and was found to be 93%.

<크로스 플로우 여과><Cross Flow Filtration>

얻어진 은 나노와이어/수분산액 21.0kg을 표준시험기(NGK Insulators, Ltd. 제품, 세라믹막 필터 Cefilt 사용, 막 면적 0.24㎡, 구멍 지름 2.0㎛, 치수 Φ 30mm×1000mm)에 유입하고, 순환 유속 7L/min, 분산액 온도 25℃, 여과 차압 0.07MPa로 크로스 플로우 여과(제 1 여과)를 실시했다. 여액의 투과 속도가 대략40g/min이 되도록 투과 밸브의 개폐를 조정하고, 여액이 1.0kg 얻어질 때(용매 유지율 95%) 마다 이온 교환수 1.0kg을 역세에 의해 계에 첨가했다(역세 압력 0.15MPa). 여액이 합계 140kg 얻어진 단계에서, 역세에 의해 계에 첨가하는 용매를 이온 교환수로부터 에탄올로 변경하고, 여과 차압 0.07MPa로 크로스 플로우 여과(제 2 여과)를 계속했다. 여액이 10kg 추가로 얻어진 단계에서 크로스 플로우 여과를 종료했다. 이온 교환수를 사용한 제 1 여과 시간은 합계로 82.9시간이며, 단위 시간·단위 여과 면적당 여과 속도를 산출하면 7.0kg/㎡·h이었다. 또한, 에탄올을 사용한 제 2 여과 시간은 합계로 7.1시간이며, 단위 시간·단위 여과 면적당 여과 속도를 산출하면 5.9kg/㎡·h이었다.21.0 kg of the obtained silver nanowire/water dispersion was introduced into a standard testing machine (NGK Insulators, Ltd., using a ceramic membrane filter Cefilt, membrane area 0.24 m 2, pore diameter 2.0 μm, dimensions Φ 30 mm×1000 mm), and the circulation flow rate 7 L/ min, the dispersion liquid temperature of 25 degreeC, and cross-flow filtration (1st filtration) were implemented by 0.07 MPa of filtration differential pressures. The opening and closing of the permeation valve was adjusted so that the permeation rate of the filtrate was approximately 40 g/min, and each time 1.0 kg of the filtrate was obtained (solvent retention rate of 95%), 1.0 kg of ion-exchanged water was added to the system by backwashing (backwashing pressure 0.15) MPa). At the stage in which a total of 140 kg of the filtrate was obtained, the solvent added to the system by backwashing was changed from ion-exchanged water to ethanol, and cross-flow filtration (second filtration) was continued at a filtration differential pressure of 0.07 MPa. Cross-flow filtration was completed at the stage in which 10 kg of the filtrate was additionally obtained. The first filtration time using ion-exchanged water was 82.9 hours in total, and when the filtration rate per unit time and unit filtration area was calculated, it was 7.0 kg/m 2 ·h. In addition, the 2nd filtration time using ethanol was 7.1 hours in total, and when the filtration rate per unit time and unit filtration area was computed, it was 5.9 kg/m<2>*h.

크로스 플로우 여과 후의 분산액을 30㎛의 데프스 필터에 통과시켜 응집물을 제거함으로써 은 나노와이어 정제액을 16.4kg 취득했다. 분산액이 통과하기 전후에 있어서, 데프스 필터의 중량 변화를 측정한 바 1.6g 증가하고, 크로스 플로우 여과에 의해 발생한 응집물은 은 나노와이어의 이론 수량(378g)에 비하여 매우 적었다.16.4 kg of silver nanowire purification liquid was acquired by making the dispersion liquid after cross-flow filtration pass through a 30-micrometer defs filter, and removing aggregates. Before and after the dispersion liquid passed, the weight change of the DEF filter increased by 1.6 g, and the agglomerates generated by cross flow filtration were very small compared to the theoretical quantity (378 g) of silver nanowires.

데프스 필터를 통과한 은 나노와이어 정제액의 은 농도를 적정법을 이용하여 측정한 바 1.8질량%이었다(수율 78%). 또한, GPC에 의해 PVP의 농도를 측정한 바 0.09질량%이었다.The silver concentration of the silver nanowire purification solution that had passed through the DEF filter was measured using a titration method, and it was found to be 1.8% by mass (yield 78%). Moreover, when the density|concentration of PVP was measured by GPC, it was 0.09 mass %.

이전과 같은 방법으로, 데프스 필터를 통과한 은 나노와이어 정제액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 97%이었다.In the same manner as before, the silver nanowire ratio (number of silver nanowires/(number of silver nanowires + number of silver nanoparticles)) in the silver nanowire purification solution that passed through the def filter was calculated, 97% it was

가스크로마토그래피를 이용하여 은 나노와이어 정제액 중의 용매 비율을 측정한 바, 에탄올은 43.3%이며, 물의 비율은 56.7%로 산출되었다.As a result of measuring the solvent ratio in the silver nanowire purification solution using gas chromatography, ethanol was 43.3%, and the water ratio was calculated to be 56.7%.

실시예 16Example 16

실시예 1과 같은 합성 방법을 27회 반복해서 은 나노와이어를 0.4질량% 포함하는 조분산액 97.2kg을 얻었다.The synthesis method similar to Example 1 was repeated 27 times, and 97.2 kg of crude dispersions containing 0.4 mass % of silver nanowires were obtained.

얻어진 조분산액 중 29.0kg을 65L의 PFA 코트 SUS 용기에 넣고, 메커니컬 스터러를 이용하여 200rpm으로 교반하면서 아세트산 부틸 30.5kg을 20분에 걸쳐서 첨가했다. 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 41.6kg 제거했다.29.0 kg of the obtained crude dispersion was put into a 65 L PFA-coated SUS container, and 30.5 kg of butyl acetate was added over 20 minutes while stirring at 200 rpm using a mechanical stirrer. After continuing stirring for 10 minutes, stirring was stopped and the supernatant and the precipitate were separated by allowing to stand for 10 minutes. Then, 41.6 kg of supernatant liquids were removed by decantation operation.

침전을 포함하는 잔액에 조분산액을 23.0kg 재차 더 첨가하고, 20분간 교반을 계속해서 침전을 재분산시킨 후, 아세트산 부틸 24.2kg을 20분에 걸쳐서 첨가했다. 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 45.5kg 제거했다. 조분산액을 23.0kg 재차 더 첨가하고, 20분간 교반을 계속해서 침전을 재분산시킨 후, 아세트산 부틸 24.2kg을 20분에 걸쳐서 첨가했다. 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 46.7kg 제거했다. 조분산액을 21.9kg 재차 더 첨가하고, 20분간 교반을 계속해서 침전을 재분산시킨 후, 아세트산 부틸 23.0kg을 20분에 걸쳐서 첨가했다. 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 45.4kg 제거했다.After further adding 23.0 kg of crude dispersion to the residual liquid containing precipitation, stirring continued for 20 minutes, and re-dispersing a precipitate, 24.2 kg of butyl acetate was added over 20 minutes. After continuing stirring for 10 minutes, stirring was stopped and the supernatant and the precipitate were separated by allowing to stand for 10 minutes. Then, 45.5 kg of supernatant liquids were removed by decantation operation. After further adding 23.0 kg of crude dispersion liquid again, stirring was continued for 20 minutes and precipitation was redispersed, 24.2 kg of butyl acetate was added over 20 minutes. After continuing stirring for 10 minutes, stirring was stopped and the supernatant and the precipitate were separated by allowing to stand for 10 minutes. Then, 46.7 kg of supernatant liquids were removed by decantation operation. After further adding 21.9 kg of coarse dispersion liquid again, stirring was continued for 20 minutes, and precipitation was redispersed, 23.0 kg of butyl acetate was added over 20 minutes. After continuing stirring for 10 minutes, stirring was stopped and the supernatant and the precipitate were separated by allowing to stand for 10 minutes. Then, 45.4 kg of supernatant liquids were removed by decantation operation.

침전을 포함하는 잔액에 이온 교환수 9.0kg을 첨가하고, 20분간 교반을 계속해서 침전을 재분산시킨 후, 아세톤 20.1kg을 20분에 걸쳐서 첨가했다. 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 전체 액량의 70%(29.1kg) 제거했다. 이온 교환수 9.0kg 첨가 이후의 조작을 30회 반복함으로써 부생된 나노입자를 제거했다.After adding 9.0 kg of ion-exchanged water to the residue containing precipitation, stirring continued for 20 minutes, and redispersing a precipitate, 20.1 kg of acetone was added over 20 minutes. After continuing stirring for 10 minutes, stirring was stopped and the supernatant and the precipitate were separated by allowing to stand for 10 minutes. After that, 70% (29.1 kg) of the total amount of the supernatant was removed by decantation. By repeating the operation after the addition of 9.0 kg of ion-exchanged water 30 times, nanoparticles generated by-products were removed.

침전을 포함하는 잔액 19.4kg에 아세톤 7.0kg을 첨가하고, 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 전체 액량의 70%(13.7kg) 제거했다. 침전을 포함하는 잔액에 이온 교환수를 액량이 21.0kg이 될 때까지 첨가하고 교반함으로써 완전히 분산시켰다.After adding 7.0 kg of acetone to 19.4 kg of the residue containing precipitation, stirring was continued for 10 minutes, stirring was stopped, and the supernatant and the precipitate were separated by standing for 10 minutes. After that, 70% (13.7 kg) of the total amount of the supernatant was removed by decantation operation. Ion-exchanged water was added to the residual liquid containing precipitation until the liquid amount reached 21.0 kg, followed by stirring to disperse it completely.

얻어진 은 나노와이어/수분산액의 은 농도를 적정법을 이용하여 측정한 바 1.8질량%이었다. 또한, GPC에 의해 PVP의 농도를 측정한 바 2.5질량%이었다.It was 1.8 mass % when the silver concentration of the obtained silver nanowire/water dispersion was measured using the titration method. Moreover, when the density|concentration of PVP was measured by GPC, it was 2.5 mass %.

<크로스 플로우 여과><Cross Flow Filtration>

얻어진 은 나노와이어/수분산액 21.0kg을 표준시험기(NGK Insulators, Ltd. 제품, 세라믹막 필터 Cefilt 사용, 막 면적 0.24㎡, 구멍 지름 2.0㎛, 치수 Φ 30mm×1000mm)에 유입하고, 순환 유속 7L/min, 분산액 온도 25℃, 여과 차압 0.08MPa로 크로스 플로우 여과(제 1 여과)를 실시했다. 여액의 투과 속도가 대략40g/min이 되도록 투과 밸브의 개폐를 조정하고, 여액이 2.0kg 얻어질 때(용매 유지율 90%) 마다 이온 교환수 2.0kg을 역세에 의해 계에 첨가했다(역세 압력 0.15MPa). 여액이 합계 168kg 얻어진 단계에서, 역세에 의해 계에 첨가하는 용매를 이온 교환수로부터 에탄올로 변경하고, 여과 차압 0.08MPa로 크로스 플로우 여과(제 2 여과)를 계속했다. 여액이 14kg 추가로 얻어진 단계에서 크로스 플로우 여과를 종료했다. 이온 교환수를 사용한 제 1 여과 시간은 합계로 96.4시간이며, 단위 시간·단위 여과 면적당 여과 속도를 산출하면 7.3kg/㎡·h이었다. 또한, 에탄올을 사용한 제 2 여과 시간은 합계로 8.3시간이며, 단위 시간·단위 여과 면적당 여과 속도를 산출하면 5.0kg/㎡·h이었다.21.0 kg of the obtained silver nanowire/water dispersion was introduced into a standard testing machine (NGK Insulators, Ltd., using a ceramic membrane filter Cefilt, membrane area 0.24 m 2, pore diameter 2.0 μm, dimensions Φ 30 mm×1000 mm), and the circulation flow rate 7 L/ Min, the dispersion liquid temperature of 25 degreeC, and cross-flow filtration (1st filtration) were implemented with 0.08 MPa of filtration differential pressure|pressure. The opening and closing of the permeation valve was adjusted so that the permeation rate of the filtrate was approximately 40 g/min, and 2.0 kg of ion-exchanged water was added to the system by backwashing whenever 2.0 kg of the filtrate was obtained (solvent retention rate of 90%) (backwash pressure 0.15) MPa). At the stage in which a total of 168 kg of the filtrate was obtained, the solvent added to the system was changed from ion-exchanged water to ethanol by backwashing, and cross-flow filtration (second filtration) was continued at a filtration differential pressure of 0.08 MPa. Cross-flow filtration was completed at the stage in which 14 kg of the filtrate was additionally obtained. The 1st filtration time using ion-exchange water was 96.4 hours in total, Computing the filtration rate per unit time and unit filtration area, it was 7.3 kg/m<2>*h. In addition, the 2nd filtration time using ethanol was 8.3 hours in total, and when the filtration rate per unit time and unit filtration area was computed, it was 5.0 kg/m<2>*h.

크로스 플로우 여과 후의 분산액을 30㎛의 데프스 필터에 통과시켜 응집물을 제거함으로써 은 나노와이어 정제액을 14.7kg 취득했다. 분산액이 통과하기 전후에 있어서, 데프스 필터의 중량 변화를 측정한 바 1.3g 증가하고, 크로스 플로우 여과에 의해 발생한 응집물은 은 나노와이어의 이론 수량(378g)에 비하여 매우 적었다.14.7 kg of silver nanowire purification liquid was acquired by making the dispersion liquid after cross flow filtration pass through a 30-micrometer defs filter, and removing aggregates. Before and after the dispersion was passed, the weight change of the DEF filter increased by 1.3 g, and the agglomerates generated by cross flow filtration were very small compared to the theoretical quantity (378 g) of silver nanowires.

데프스 필터를 통과한 은 나노와이어 정제액의 은 농도를 적정법을 이용하여 측정한 바 1.8질량%이었다(수율 70%). 또한, GPC에 의해 PVP의 농도를 측정한 바 0.15질량%이었다.The silver concentration of the silver nanowire purification solution passing through the def filter was measured using a titration method, and it was 1.8% by mass (yield 70%). Moreover, when the density|concentration of PVP was measured by GPC, it was 0.15 mass %.

이전과 같은 방법으로, 데프스 필터를 통과한 은 나노와이어 정제액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 96%이었다.In the same manner as before, the silver nanowire ratio (number of silver nanowires/(number of silver nanowires + number of silver nanoparticles)) in the silver nanowire purification solution that passed through the def filter was calculated, and 96% it was

가스크로마토그래피를 이용하여 은 나노와이어 정제액 중의 용매 비율을 측정한 바, 에탄올은 48.7%이며, 물의 비율은 51.3%로 산출되었다.As a result of measuring the solvent ratio in the silver nanowire purification solution using gas chromatography, ethanol was 48.7%, and the water ratio was calculated to be 51.3%.

실시예 17Example 17

실시예 1과 같은 합성 방법을 3회 반복해서 은 나노와이어를 0.4질량% 포함하는 조분산액 9.7kg을 얻었다. 얻어진 조분산액을 25L의 PFA 코트 SUS 용기에 넣고, 메커니컬 스터러를 이용하여 150rpm으로 교반하면서 아세트산 부틸 10.2kg을 10분에 걸쳐서 첨가했다. 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 13.9kg 제거했다.The synthesis method similar to Example 1 was repeated 3 times, and 9.7 kg of crude dispersions containing 0.4 mass % of silver nanowires were obtained. The obtained crude dispersion was put into a 25 L PFA-coated SUS container, and 10.2 kg of butyl acetate was added over 10 minutes while stirring at 150 rpm using a mechanical stirrer. After continuing stirring for 10 minutes, stirring was stopped and the supernatant and the precipitate were separated by allowing to stand for 10 minutes. Then, 13.9 kg of supernatant liquids were removed by decantation operation.

침전을 포함하는 잔액에 아세토니트릴 5.0kg을 첨가하고, 30분간 교반을 계속해서 침전을 재분산시켰다. Hitachi Koki Co., Ltd. 제품의 고속 냉각 원심기(CR22N, 1.5L×4개)를 이용하여 2000rpm으로 30분 원심 침강시킴으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 전체 액량의 80% 제거했다. 아세토니트릴 5.0kg 첨가 이후의 조작을 3회 반복함으로써 부생된 나노입자를 제거했다.5.0 kg of acetonitrile was added to the residue containing the precipitate, and stirring was continued for 30 minutes to redisperse the precipitate. Hitachi Koki Co., Ltd. The supernatant and the precipitate were separated by centrifugal sedimentation at 2000 rpm for 30 minutes using a high-speed cooling centrifuge (CR22N, 1.5L×4) of the product. Then, 80% of the supernatant liquid was removed by decantation operation. By repeating the operation after the addition of 5.0 kg of acetonitrile three times, nanoparticles generated by-product were removed.

침전을 포함하는 잔액 1.3kg에 아세톤 3.0kg을 첨가하고, 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 전체 액량의 80%(3.4kg) 제거했다. 침전을 포함하는 잔액을 3L 폴리 용기로 이액하고, 이온 교환수를 내액이 2.1kg이 될 때까지 첨가하고 진탕교반함으로써 완전히 분산시켰다.3.0 kg of acetone was added to 1.3 kg of the residue containing precipitation, and stirring was continued for 10 minutes, and then the stirring was stopped and the supernatant and the precipitate were separated by standing for 10 minutes. After that, 80% (3.4 kg) of the total amount of the supernatant was removed by decantation. The remaining liquid containing the precipitation was transferred to a 3L poly container, and ion-exchanged water was added until the inner liquid became 2.1 kg, and then completely dispersed by shaking and stirring.

얻어진 은 나노와이어/수분산액의 은 농도를 적정법을 이용하여 측정한 바 1.7질량%이었다. 또한, GPC에 의해 PVP의 농도를 측정한 바 1.8질량%이었다.It was 1.7 mass % when the silver concentration of the obtained silver nanowire/water dispersion was measured using the titration method. Moreover, when the density|concentration of PVP was measured by GPC, it was 1.8 mass %.

얻어진 은 나노와이어/수분산액을 메탄올로 500배로 희석하여 은 나노와이어 희박 용액을 제작했다. 청정한 유리판 상에 이전의 은 나노와이어 희박 용액을 한 방울 드롭하고, 90℃의 핫플레이트에서 건조시켰다. 유리판을 레이저 현미경(Keyence VK-X200)을 사용해서 3000배의 배율로 관찰하고, 은 나노와이어의 수와 은 나노입자의 수를 계측했다. 분산액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 92%이었다.The obtained silver nanowire/water dispersion was diluted 500-fold with methanol to prepare a silver nanowire dilute solution. A drop of the old silver nanowire dilute solution was dropped on a clean glass plate and dried on a hot plate at 90°C. The glass plate was observed at a magnification of 3000 times using a laser microscope (Keyence VK-X200), and the number of silver nanowires and the number of silver nanoparticles were measured. The ratio of silver nanowires in the dispersion (the number of silver nanowires/(the number of silver nanowires + the number of silver nanoparticles)) was calculated to be 92%.

얻어진 은 나노와이어/수분산액을 실시예 1과 같은 방법으로 크로스 플로우 여과에 의해 정제했다. 여과 시간은 합계로 18.8시간이며, 단위 시간·단위 여과 면적당 여과 속도를 산출하면 7.4kg/㎡·h이었다. 크로스 플로우 여과 후의 분산액을 355메쉬의 나일론 필터에 통과시켜 응집물을 제거함으로써 은 나노와이어 정제액을 1.4kg 취득했다. 분산액이 통과하기 전후에 있어서, 나일론 필터의 중량 변화를 측정한 바 0.15g 증가하고, 크로스 플로우 여과에 의해 발생한 응집물은 거의 없었다.The obtained silver nanowire/water dispersion was purified by cross flow filtration in the same manner as in Example 1. The filtration time was 18.8 hours in total, and when the filtration rate per unit time and unit filtration area was computed, it was 7.4 kg/m<2>*h. The dispersion liquid after cross flow filtration was passed through a 355 mesh nylon filter, and 1.4 kg of silver nanowire purification liquid was acquired by removing aggregates. Before and after the dispersion liquid passed, the weight change of the nylon filter was measured to increase by 0.15 g, and there was almost no aggregate generated by cross flow filtration.

나일론 필터를 통과한 은 나노와이어 정제액의 은 농도를 적정법을 이용하여 측정한 바 1.7질량%이었다(수율 68%). 또한, GPC에 의해 PVP의 농도를 측정한 바 0.06질량%이었다.The silver concentration of the silver nanowire purification solution passing through the nylon filter was measured using a titration method, and it was 1.7% by mass (yield 68%). Moreover, when the density|concentration of PVP was measured by GPC, it was 0.06 mass %.

이전과 같은 방법으로, 나일론 필터를 통과한 은 나노와이어 정제액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 95%이었다.In the same manner as before, the silver nanowire ratio (number of silver nanowires/(number of silver nanowires + number of silver nanoparticles)) in the silver nanowire purification solution that passed through the nylon filter was calculated, and it was 95%. .

비교예 1Comparative Example 1

실시예 1과 같은 합성 방법을 3회 반복해서 은 나노와이어 조분산액 9.7kg을 얻었다. 얻어진 조분산액을 25L의 PFA 코트 SUS 용기에 넣고, 메커니컬 스터러를 이용하여 150rpm으로 교반하면서 아세트산 부틸 10.2kg을 10분에 걸쳐서 첨가했다. 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 13.9kg 제거했다.The same synthesis method as in Example 1 was repeated three times to obtain 9.7 kg of a coarse dispersion of silver nanowires. The obtained crude dispersion was put into a 25 L PFA-coated SUS container, and 10.2 kg of butyl acetate was added over 10 minutes while stirring at 150 rpm using a mechanical stirrer. After continuing stirring for 10 minutes, stirring was stopped and the supernatant and the precipitate were separated by allowing to stand for 10 minutes. Then, 13.9 kg of supernatant liquids were removed by decantation operation.

침전을 포함하는 잔액에 아세톤 3.0kg을 첨가하고, 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 전체 액량의 80%(7.2kg) 제거했다. 이 조작을 한번 더 반복한 후, 침전을 포함하는 잔액을 3L 폴리 용기로 이액하고, 이온 교환수를 내액이 2.1kg이 될 때까지 첨가하고 진탕교반함으로써 완전히 분산시켰다.3.0 kg of acetone was added to the residue containing precipitation, stirring was continued for 10 minutes, stirring was stopped, and the supernatant and the precipitate were separated by standing still for 10 minutes. After that, 80% (7.2 kg) of the total amount of the supernatant was removed by decantation. After repeating this operation once more, the remaining liquid containing the precipitation was transferred to a 3 L poly container, and ion-exchanged water was added until the inner liquid became 2.1 kg, followed by shaking and stirring to disperse completely.

얻어진 은 나노와이어/수분산액의 은 농도를 적정법을 이용하여 측정한 바 1.8질량%이었다. 또한, GPC에 의해 PVP의 농도를 측정한 바 5.9질량%이었다.It was 1.8 mass % when the silver concentration of the obtained silver nanowire/water dispersion was measured using the titration method. Moreover, when the density|concentration of PVP was measured by GPC, it was 5.9 mass %.

실시예 2와 같은 방법으로 분산액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 26%이었다.The silver nanowire ratio (the number of silver nanowires/(the number of silver nanowires + the number of silver nanoparticles)) in the dispersion was calculated in the same manner as in Example 2, and was 26%.

은 나노와이어 농축액을 실시예 2와 같은 방법으로 크로스 플로우 여과에 의해 정제했다. 여과 시간은 합계로 40.0시간이며, 단위 시간·단위 여과 면적당 여과 속도를 산출하면 3.5kg/㎡·h이었다. 크로스 플로우 여과 후의 분산액을 355메쉬의 나일론 필터에 통과시켜 응집물을 제거함으로써 은 나노와이어 정제액을 1.5kg 취득했다. 분산액이 통과하기 전후에 있어서, 나일론 필터의 중량 변화를 측정한 바 0.1g 증가하고, 크로스 플로우 여과에 의해 발생한 응집물은 매우 적었다.The silver nanowire concentrate was purified by cross flow filtration in the same manner as in Example 2. The filtration time was 40.0 hours in total, and when the filtration rate per unit time and unit filtration area was computed, it was 3.5 kg/m<2>*h. 1.5 kg of silver nanowire purification liquid was acquired by making the dispersion liquid after cross flow filtration pass through a 355 mesh nylon filter, and removing aggregates. Before and after the dispersion liquid passed, the weight change of the nylon filter was measured to increase 0.1 g, and the aggregates generated by cross flow filtration were very small.

나일론 필터를 통과한 은 나노와이어 정제액의 은 농도를 적정법을 이용하여 측정한 바 1.8질량%이었다(수율 74%). 또한, GPC에 의해 PVP의 농도를 측정한 바 0.22질량%이었다.The silver concentration of the silver nanowire purification solution passing through the nylon filter was measured using a titration method, and it was 1.8% by mass (yield 74%). Moreover, when the density|concentration of PVP was measured by GPC, it was 0.22 mass %.

이전과 같은 방법으로, 나일론 필터를 통과한 은 나노와이어 정제액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 33%이며, 나노입자의 제거는 거의 진행되어 있지 않았다.In the same way as before, the silver nanowire ratio (the number of silver nanowires/(the number of silver nanowires + the number of silver nanoparticles)) in the silver nanowire purification solution that passed through the nylon filter was calculated, and it was 33%. , the removal of nanoparticles was hardly progressed.

비교예 2Comparative Example 2

실시예 1과 같은 합성 방법을 3회 반복해서 은 나노와이어 조분산액 9.7kg을 얻었다. 얻어진 조분산액을 25L의 PFA 코트 SUS 용기에 넣고, 메커니컬 스터러를 이용하여 150rpm으로 교반하면서 아세트산 부틸 10.2kg을 10분에 걸쳐서 첨가했다. 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 13.9kg 제거했다.The same synthesis method as in Example 1 was repeated three times to obtain 9.7 kg of a coarse dispersion of silver nanowires. The obtained crude dispersion liquid was put into a 25 L PFA-coated SUS container, and 10.2 kg of butyl acetate was added over 10 minutes while stirring at 150 rpm using a mechanical stirrer. After stirring was continued for 10 minutes, the stirring was stopped and the supernatant and the precipitate were separated by allowing the mixture to stand for 10 minutes. Then, 13.9 kg of supernatant liquids were removed by decantation operation.

침전을 포함하는 잔액에 아세토니트릴 3.3kg을 첨가하고, 10분간 교반을 계속해서 침전을 재분산시킨 후, 아세트산 부틸 6.6kg을 10분에 걸쳐서 첨가했다. 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 전체 액량의 70%(11.1kg) 제거했다. 이 조작을 6회 반복함으로써 부생된 나노입자의 일부를 제거했다.3.3 kg of acetonitrile was added to the residue containing precipitation, stirring was continued for 10 minutes, and after redispersing a precipitate, 6.6 kg of butyl acetate was added over 10 minutes. After continuing stirring for 10 minutes, stirring was stopped and the supernatant and the precipitate were separated by allowing to stand for 10 minutes. Thereafter, 70% (11.1 kg) of the total amount of the supernatant was removed by decantation. By repeating this operation 6 times, a part of by-produced nanoparticles was removed.

침전을 포함하는 잔액에 아세톤 3.0kg을 첨가하고, 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 전체 액량의 80%(5.8kg) 제거했다. 이 조작을 한번 더 반복한 후, 침전을 포함하는 잔액을 3L 폴리 용기로 이액하고, 이온 교환수를 내액이 2.1kg이 될 때까지 첨가하고 진탕교반함으로써 완전히 분산시켰다.3.0 kg of acetone was added to the residue containing precipitation, stirring was continued for 10 minutes, stirring was stopped, and the supernatant and the precipitate were separated by standing still for 10 minutes. Thereafter, 80% (5.8 kg) of the total amount of the supernatant was removed by decantation. After repeating this operation once more, the remaining liquid containing the precipitation was transferred to a 3L poly container, and ion-exchanged water was added until the inner liquid became 2.1 kg, followed by shaking and stirring to disperse completely.

실시예 2와 같은 방법으로 분산액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 78%이었다.The silver nanowire ratio (the number of silver nanowires/(the number of silver nanowires + the number of silver nanoparticles)) in the dispersion was calculated in the same manner as in Example 2, and was found to be 78%.

은 나노와이어 농축액을 여액이 합계 14kg 얻어질 때까지 크로스 플로우 여과를 계속한 것을 제외하고, 실시예 2와 같은 방법으로 정제했다. 여과 시간은 합계로 38.4시간이며, 단위 시간·단위 여과 면적당 여과 속도를 산출하면 6.1kg/㎡·h이었다. 크로스 플로우 여과 후의 분산액을 355메쉬의 나일론 필터에 통과시켜 응집물을 제거함으로써 은 나노와이어 정제액을 1.4kg 취득했다. 분산액이 통과하기 전후에 있어서, 나일론 필터의 중량 변화를 측정한 바 0.2g 증가하고, 크로스 플로우 여과에 의해 발생한 응집물은 매우 적었다.The silver nanowire concentrate was purified in the same manner as in Example 2, except that cross-flow filtration was continued until a total of 14 kg of the filtrate was obtained. The filtration time was 38.4 hours in total, and when the filtration rate per unit time and unit filtration area was computed, it was 6.1 kg/m<2>*h. The dispersion liquid after cross flow filtration was passed through a 355 mesh nylon filter, and 1.4 kg of silver nanowire purification liquids were acquired by removing aggregates. Before and after the dispersion liquid passed, the weight change of the nylon filter was measured to increase 0.2 g, and the aggregate generated by cross flow filtration was very small.

나일론 필터를 통과한 은 나노와이어 정제액의 은 농도를 적정법을 이용하여 측정한 바 1.8질량%이었다(수율 67%). 또한, GPC에 의해 PVP의 농도를 측정한 바 0.15질량%이었다.The silver concentration of the silver nanowire purification solution passing through the nylon filter was measured using a titration method, and it was 1.8% by mass (yield 67%). Moreover, when the density|concentration of PVP was measured by GPC, it was 0.15 mass %.

이전과 같은 방법으로, 나일론 필터를 통과한 은 나노와이어 정제액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 88%이며, 크로스 플로우 여과 횟수를 실시예 2와 비교해서 증가시켰음에도 불구하고, 나노입자의 제거는 거의 진행되어 있지 않았다.In the same way as before, the silver nanowire ratio (the number of silver nanowires/(the number of silver nanowires + the number of silver nanoparticles)) in the silver nanowire purification solution that passed through the nylon filter was calculated, and it was 88%. , although the number of cross-flow filtration was increased compared to Example 2, the removal of nanoparticles was hardly progressed.

비교예 3Comparative Example 3

침전을 포함하는 잔액에 이온 교환수 2.1kg을 첨가하고, 10분간 교반을 계속해서 침전을 재분산시킨 후, 아세톤 4.4kg을 10분에 걸쳐서 첨가했다. 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 그 후, 디캔테이션 조작에 의해 상청액을 전체 액량의 70%(8.7kg) 제거했다. 이 조작을 8회 반복함으로써 부생된 나노입자의 일부를 제거했다.After adding 2.1 kg of ion-exchanged water to the residue containing precipitation, stirring was continued for 10 minutes, and precipitation was redispersed, 4.4 kg of acetone was added over 10 minutes. After stirring was continued for 10 minutes, the stirring was stopped and the supernatant and the precipitate were separated by allowing the mixture to stand for 10 minutes. Then, 70% (8.7 kg) of the supernatant liquid was removed by decantation operation. By repeating this operation eight times, a part of the by-produced nanoparticles was removed.

침전을 포함하는 잔액에 아세톤 3.0kg을 첨가하고, 10분간 교반을 계속한 후, 교반을 멈추고 10분 정치함으로써 상청액과 침전물을 분리시켰다. 디캔테이션 조작에 의해 상청액을 전체 액량의 80%(4.6kg) 제거한 후, 침전을 포함하는 잔액을 3L 폴리 용기로 이액하고, 이온 교환수를 내액이 2.1kg이 될 때까지 첨가하고 진탕교반함으로써 완전히 분산시켰다.3.0 kg of acetone was added to the residue containing precipitation, stirring was continued for 10 minutes, stirring was stopped, and the supernatant and the precipitate were separated by standing still for 10 minutes. After removing 80% (4.6 kg) of the supernatant by the decantation operation, the remaining liquid containing the precipitation is transferred to a 3L poly container, ion-exchanged water is added until the inner liquid becomes 2.1 kg, and completely by shaking and stirring dispersed.

실시예 2와 같은 방법으로 분산액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 85%이었다.The silver nanowire ratio (the number of silver nanowires/(the number of silver nanowires + the number of silver nanoparticles)) in the dispersion was calculated in the same manner as in Example 2, and was found to be 85%.

은 나노와이어 농축액을 여액이 합계 14kg 얻어질 때까지 크로스 플로우 여과를 계속한 것을 제외하고는 실시예 2와 같은 방법으로 정제했다. 여과 시간은 합계로 35.0시간이며, 단위 시간·단위 여과 면적당 여과 속도를 산출하면 5.0kg/㎡·h이었다. 크로스 플로우 여과 후의 분산액을 355메쉬의 나일론 필터에 통과시켜 응집물을 제거함으로써 은 나노와이어 정제액을 1.3kg 취득했다. 분산액이 통과하기 전후에 있어서, 나일론 필터의 중량 변화를 측정한 바 0.2g 증가하고, 크로스 플로우 여과에 의해 발생한 응집물은 매우 적었다.The silver nanowire concentrate was purified in the same manner as in Example 2, except that cross-flow filtration was continued until a total of 14 kg of the filtrate was obtained. The filtration time was 35.0 hours in total, and when the filtration rate per unit time and unit filtration area was computed, it was 5.0 kg/m<2>*h. 1.3 kg of silver nanowire purification liquid was acquired by making the dispersion liquid after cross flow filtration pass through a 355 mesh nylon filter, and removing aggregates. Before and after the dispersion liquid passed, the weight change of the nylon filter was measured to increase 0.2 g, and the aggregate generated by cross flow filtration was very small.

나일론 필터를 통과한 은 나노와이어 정제액의 은 농도를 적정법을 이용하여 측정한 바 1.8질량%이었다(수율 65%). 또한, GPC에 의해 PVP의 농도를 측정한 바 0.18질량%이었다.The silver concentration of the silver nanowire purification solution that passed through the nylon filter was measured using a titration method, and it was 1.8% by mass (yield 65%). Moreover, when the density|concentration of PVP was measured by GPC, it was 0.18 mass %.

이전과 같은 방법으로, 나일론 필터를 통과한 은 나노와이어 정제액 중의 은 나노와이어비(은 나노와이어의 수/(은 나노와이어의 수 + 은 나노입자의 수))를 산출한 바, 88%이며, 나노입자의 제거는 거의 진행되어 있지 않았다.In the same way as before, the silver nanowire ratio (the number of silver nanowires/(the number of silver nanowires + the number of silver nanoparticles)) in the silver nanowire purification solution that passed through the nylon filter was calculated, and it was 88%. , the removal of nanoparticles was hardly progressed.

이상의 결과를 표 1에 나타낸다. 은 농도가 1.0질량% 이상인 은 나노와이어 조분산액을 크로스 플로우 여과법을 이용하여 정제함으로써, 고수율로 고순도의 은 나노와이어 분산액을 제조할 수 있다.Table 1 shows the above results. By purifying the silver nanowire coarse dispersion having a silver concentration of 1.0% by mass or more using a cross flow filtration method, a high-purity silver nanowire dispersion can be prepared in a high yield.

비교예 1∼3의 결과로부터, 은 농도 1.0% 이상 또한 은 나노와이어비가 90%이하인 분산액을 크로스 플로우 여과에 의해 정제했을 경우, 크로스 플로우 여과 횟수를 증가시켜도 은 나노와이어비는 그다지 개선되지 않은 것을 알 수 있다. 이것은 나노입자에 의해 필터가 폐색되기 때문이라고 생각된다. 은 나노와이어비 90% 이하의 분산액은 나노입자 유래의 흡수에 의해 황색도가 크기 때문에, 이것을 이용하여 잉크화하여 도포, 투명 도전 필름을 제작하면, 광학특성이 불충분해진다.From the results of Comparative Examples 1 to 3, when a dispersion having a silver concentration of 1.0% or more and a silver nanowire ratio of 90% or less was purified by cross flow filtration, the silver nanowire ratio did not improve much even if the number of times of cross flow filtration was increased. Able to know. This is thought to be because the filter is blocked by the nanoparticles. Since a dispersion having a silver nanowire ratio of 90% or less has a large yellowness due to absorption from nanoparticles, if it is used to make an ink, coating, and producing a transparent conductive film, the optical properties will be insufficient.

한편으로, 은 나노와이어비가 90%를 초과하는 분산액을 크로스 플로우 여과에 의해 정제한 실시예 1∼17에서는 필터의 폐색이 없이 효율적으로 구조 규정제를 제거할 수 있는데다가, 용매 유지율을 낮게 해도 응집이 적다.On the other hand, in Examples 1 to 17, in which a dispersion having a silver nanowire ratio of more than 90% was purified by cross flow filtration, the structure defining agent can be efficiently removed without clogging the filter, and agglomeration even when the solvent retention rate is low this is less

Claims

은 나노와이어의 수/전체 입자의 수 > 90%인 은 나노와이어와 구조 규정제를 포함하고, 은 농도가 1.0질량% 이상인 은 나노와이어 조분산액을 준비하는 공정과,
상기 은 나노와이어 조분산액을 순환식의 크로스 플로우 여과법에 의해 정제하는 크로스 플로우 여과 공정을 포함하는 은 나노와이어 분산액의 제조 방법.A step of preparing a coarse dispersion of silver nanowires containing silver nanowires having a number of silver nanowires/total number of particles > 90% and a structure defining agent, and having a silver concentration of 1.0 mass% or more;
A method for producing a silver nanowire dispersion comprising a cross-flow filtration step of purifying the silver nanowire coarse dispersion by a circulating cross-flow filtration method.

제 1 항에 있어서,
상기 크로스 플로우 여과 공정에 있어서, 단위 필터 면적·단위 시간당 여과 속도를 16.0kg/㎡·h 이하로 제어하는 은 나노와이어 분산액의 제조 방법.The method of claim 1,
The said cross flow filtration process WHEREIN: The manufacturing method of the silver nanowire dispersion liquid which controls the filtration rate per unit filter area/unit time to 16.0 kg/m<2>*h or less.

제 2 항에 있어서,
상기 여과 속도는 1.0kg/㎡·h 이상인 은 나노와이어 분산액의 제조 방법.3. The method of claim 2,
The filtration rate is 1.0 kg / m 2 ·h or more method for producing a silver nanowire dispersion.

제 1 항 내지 제 3 항 중 어느 한 항에 있어서,
은 나노와이어 조분산액 중에 구조 규정제를 0.5질량% 이상 포함하는 은 나노와이어 분산액의 제조 방법.4. The method according to any one of claims 1 to 3,
The manufacturing method of the silver nanowire dispersion liquid containing 0.5 mass % or more of a structure-regulating agent in silver nanowire coarse dispersion liquid.

제 1 항 내지 제 4 항 중 어느 한 항에 있어서,
상기 은 나노와이어 조분산액을 준비하는 공정은 은 나노와이어가 합성에 의해 반응 용매에 분산된 은 나노와이어 조분산액을 제조하는 은 나노와이어 조분산액 제조 공정을 포함하는 은 나노와이어 분산액의 제조 방법.5. The method according to any one of claims 1 to 4,
The process of preparing the silver nanowire coarse dispersion includes a silver nanowire coarse dispersion preparation process of preparing a silver nanowire coarse dispersion in which silver nanowires are synthesized and dispersed in a reaction solvent.

제 5 항에 있어서,
상기 은 나노와이어 조분산액을 준비하는 공정은,
상기 은 나노와이어가 상기 반응 용매에 분산된 은 나노와이어 조분산액에 침강 용매를 첨가해서 은 나노와이어를 침강시키는 침강 공정과,
부생 나노입자를 포함하는 상기 반응 용매와 침강 용매의 혼합물의 상청액의 일부를 제거하는 상청액 제거 공정과,
침강 공정을 복수회 반복함으로써 부생 나노입자를 제거하여, 분산액 중의 은 나노와이어의 수/전체 입자의 수 > 90%인 분산액을 얻는 재침 세정 공정을 은 나노와이어 조분산액 제조 공정 후에 추가로 포함하는 은 나노와이어 분산액의 제조 방법.6. The method of claim 5,
The process of preparing the silver nanowire coarse dispersion is,
a precipitation process of adding a precipitation solvent to a coarse dispersion of silver nanowires in which the silver nanowires are dispersed in the reaction solvent to precipitate the silver nanowires;
A supernatant removal process of removing a part of the supernatant of the mixture of the reaction solvent and the precipitation solvent containing by-product nanoparticles;
Silver further comprising a reprecipitation cleaning process to remove by-product nanoparticles by repeating the sedimentation process a plurality of times to obtain a dispersion having a number of silver nanowires/total number of particles > 90% in the dispersion liquid after the silver nanowire coarse dispersion preparation process A method for preparing a nanowire dispersion.

제 1 항 내지 제 6 항 중 어느 한 항에 있어서,
상기 크로스 플로우 여과 공정에 있어서, 은 나노와이어 조분산액의 농축 중 또는 농축 후에, 여액으로서 배출된 용매를 보충하도록 세정 용매를 첨가함으로써, 은 나노와이어 조분산액량을 여과 전의 조분산액량의 60% 이상으로 유지하는 은 나노와이어 분산액의 제조 방법.7. The method according to any one of claims 1 to 6,
In the cross flow filtration step, during or after the concentration of the silver nanowire coarse dispersion, a washing solvent is added to replenish the solvent discharged as the filtrate, whereby the amount of the silver nanowire coarse dispersion before filtration is 60% or more A method for producing a silver nanowire dispersion to be maintained.