JP2023027848A - Semi-conductive polyamide-based resin composition, semi-conductive belt using the same, image formation device, and method for manufacturing conductive belt - Google Patents

Semi-conductive polyamide-based resin composition, semi-conductive belt using the same, image formation device, and method for manufacturing conductive belt Download PDF

Info

Publication number
JP2023027848A
JP2023027848A JP2021133169A JP2021133169A JP2023027848A JP 2023027848 A JP2023027848 A JP 2023027848A JP 2021133169 A JP2021133169 A JP 2021133169A JP 2021133169 A JP2021133169 A JP 2021133169A JP 2023027848 A JP2023027848 A JP 2023027848A
Authority
JP
Japan
Prior art keywords
semiconductive
polyamide
parts
resin composition
weight
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2021133169A
Other languages
Japanese (ja)
Inventor
重利 武智
Shigetoshi Takechi
直樹 中村
Naoki Nakamura
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Okura Industrial Co Ltd
Original Assignee
Okura Industrial Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Okura Industrial Co Ltd filed Critical Okura Industrial Co Ltd
Priority to JP2021133169A priority Critical patent/JP2023027848A/en
Publication of JP2023027848A publication Critical patent/JP2023027848A/en
Pending legal-status Critical Current

Links

Images

Abstract

To provide a semi-conductive resin composition for obtaining a semi-conductive belt in which a polyamide-based resin composition exhibits semi-conductivity, uniformity of volume resistivity is good (small in-plane variation), variation in the volume resistivity is small even when a high voltage is continuously applied, and surface glossiness is high.SOLUTION: A semi-conductive polyamide-based resin composition contains a polyamide-based resin and a conductive agent, wherein the conductive agent contains both a fine carbon fiber and carbon black, and 0.3-2.5 pts.wt. of the fine carbon fiber and 7-25 pts.wt. of the carbon black are blended with respect to 100 pts.wt. of the polyamide-based resin.SELECTED DRAWING: Figure 1

Description

本発明は、半導電性ポリアミド系樹脂組成物、それを用いた半導電性ベルト、画像形成装置、および半導電性ベルトの製造方法に関する。 TECHNICAL FIELD The present invention relates to a semiconductive polyamide-based resin composition, a semiconductive belt using the same, an image forming apparatus, and a method for producing a semiconductive belt.

従来、電子写真方式のプリンター、複写機、ファクシミリ等の画像形成装置には、体積抵抗率が10~1012Ω・cmの半導電性を有するシームレス形状の半導電性ベルトが用いられている。しかしながら、熱可塑性樹脂へ電子伝導性材料(例えば、カーボンブラック)を配合した半導電性樹脂組成物から得られた成形体は、カーボンブラックのわずかな濃度変化や、カーボンブラックの分散状態によって電気抵抗が大きくばらついたり、導電性が経時で変化したりするという問題が生じ、半導電性領域の電気抵抗を安定的に発現させることが困難であった。 Conventionally, seamless semiconductive belts having semiconductive volume resistivity of 10 6 to 10 12 Ω·cm are used in image forming apparatuses such as electrophotographic printers, copiers, and facsimiles. . However, a molded article obtained from a semiconductive resin composition in which an electronically conductive material (for example, carbon black) is blended into a thermoplastic resin has an electrical resistance that varies depending on slight changes in the concentration of carbon black and the state of dispersion of carbon black. It has been difficult to stably develop the electrical resistance of the semiconductive region because of the problem that the conductivity varies greatly and the conductivity changes with time.

この課題に対し、特許文献1には、ポリアミド樹脂と微細炭素繊維とを含む半導電性ポリアミド樹脂組成物をダイスより溶融押出した後、冷却手段により冷却固化することにより、電気抵抗が均一で連続通電時における電気抵抗の変化が小さい半導電性ポリアミド樹脂からなる電子写真用シームレスベルトの製造方法が記載されている。 In response to this problem, Patent Document 1 discloses that a semiconductive polyamide resin composition containing a polyamide resin and fine carbon fibers is melt-extruded from a die and then cooled and solidified by a cooling means, whereby the electric resistance is uniform and continuous. A method for producing an electrophotographic seamless belt made of a semi-conductive polyamide resin that exhibits a small change in electrical resistance when energized is disclosed.

一方、電子写真用シームレスベルトには、濃度センサーによるトナー検知を行うため、高い表面光沢度が求められており、特許文献2には、数平均分子量が1000以上のポリアルキレンオキサイド構造を含む添加剤と導電剤を配合したポリフッ化ビニリデン系樹脂からなる表面光沢度が40以上の中間転写体が開示されている。 On the other hand, seamless belts for electrophotography are required to have a high surface glossiness in order to detect toner by a density sensor. disclosed is an intermediate transfer member having a surface glossiness of 40 or more, which is made of a polyvinylidene fluoride resin containing a conductive agent and a conductive agent.

また、特許文献3には、ポリイミド樹脂100重量部に対し、カーボンナノチューブを0.1~40重量部を含有したポリイミド管状物は、サンプル間、添加量変化、電圧変化、環境変化による抵抗値の変動が少なく、実施例3には、ポリアミド酸100重量部を溶解したDMF溶液にカーボンナノチューブとカーボンブラックとを配合し筒状SUSにキャストして得られたポリイミド管状物(ポリイミド固形分100重量部に対して、カーボンナノチューブ10重量部、カーボンブラック4重量部)が例示されているが、光沢度に関する記載はない。 In addition, in Patent Document 3, a polyimide tubular material containing 0.1 to 40 parts by weight of carbon nanotubes with respect to 100 parts by weight of polyimide resin has a resistance value between samples, changes in the amount of addition, changes in voltage, and changes in the environment. There was little variation, and in Example 3, a polyimide tubular product (polyimide solid content of 100 parts by weight , 10 parts by weight of carbon nanotubes and 4 parts by weight of carbon black), but there is no description of glossiness.

特開2017-101157号公報JP 2017-101157 A 特開2015-14744号公報JP 2015-14744 A 特開2003-246927号公報JP 2003-246927 A

本発明者らは、ポリアミド系樹脂に導電剤を配合した半導電性ベルトの表面光沢度に着目した。ポリアミド系樹脂組成物が、半導電性を示し、体積抵抗率の均一性が良好で(面内バラつきが小さく)、表面光沢度が高く、連続して印刷しても体積抵抗率の変化が小さい半導電性ベルトを得るための半導電性樹脂組成物を提供することが目的である。 The present inventors paid attention to the surface glossiness of a semiconductive belt in which a conductive agent is mixed with a polyamide resin. Polyamide-based resin composition exhibits semi-conductivity, good uniformity of volume resistivity (small in-plane variation), high surface glossiness, and small change in volume resistivity even after continuous printing. It is an object of the present invention to provide a semiconductive resin composition for obtaining a semiconductive belt.

本発明によれば、
(1)ポリアミド系樹脂と導電剤とを含有し、前記導電剤は、微細炭素繊維とカーボンブラックの両方を含有し、かつ前記ポリアミド系樹脂100重量部に対して、前記微細炭素繊維を0.3~2.5重量部と前記カーボンブラックを7~25重量部とを配合することを特徴とする半導電性ポリアミド系樹脂組成物;
(2)前記ポリアミド系樹脂が、ナイロン6、ナイロン12、ナイロン6,12から選ばれた1種以上であることを特徴とする(1)記載の半導電性ポリアミド系樹脂組成物;
(3)前記微細炭素繊維が、単層カーボンナノチューブ、多層カーボンナノチューブ、釣鐘状構造単位集合体から選ばれる少なくとも一種を含有することを特徴とする(1)または(2)記載の半導電性ポリアミド系樹脂組成物;
(4)(1)乃至(3)のいずれか記載の半導電性ポリアミド系樹脂組成物から形成された半導電性ベルト;
(5)(4)記載の半導電性ベルトを有することを特徴とする画像形成装置;
(6)ポリアミド系樹脂を100重量部と、微細炭素繊維を0.3~2.5重量部とカーボンブラックを7~25重量部とを配合した半導電性ポリアミド系樹脂組成物を押出機に供給し、前記半導電ポリアミド系樹脂組成物を環状ダイスより押出し、冷却固化することを特徴とする半導電性ベルトの製造方法;
(7)入射角60°での表面光沢度が50以上であることを特徴とする請求項6記載の半導電性ベルトの製造方法;
が提供される。
According to the invention,
(1) A polyamide resin and a conductive agent are contained, the conductive agent contains both fine carbon fibers and carbon black, and 0.00 of the fine carbon fibers is added to 100 parts by weight of the polyamide resin. A semiconductive polyamide-based resin composition characterized by blending 3 to 2.5 parts by weight and 7 to 25 parts by weight of the carbon black;
(2) The semiconductive polyamide resin composition according to (1), wherein the polyamide resin is one or more selected from nylon 6, nylon 12, and nylon 6,12;
(3) The semiconductive polyamide according to (1) or (2), wherein the fine carbon fibers contain at least one selected from single-walled carbon nanotubes, multi-walled carbon nanotubes, and bell-shaped structural unit aggregates. system resin composition;
(4) A semiconductive belt formed from the semiconductive polyamide resin composition according to any one of (1) to (3);
(5) An image forming apparatus comprising the semiconductive belt described in (4);
(6) A semiconductive polyamide resin composition containing 100 parts by weight of a polyamide resin, 0.3 to 2.5 parts by weight of fine carbon fibers and 7 to 25 parts by weight of carbon black is added to an extruder. A method for producing a semiconductive belt, characterized in that the semiconductive polyamide-based resin composition is extruded through an annular die and cooled to solidify;
(7) The method for producing a semiconductive belt according to (6), wherein the surface glossiness at an incident angle of 60° is 50 or more;
is provided.

本発明の半導電性ポリアミド系樹脂組成物は、ポリアミド系樹脂と導電剤を含有し、前記導電剤は、微細炭素繊維(以下、CNTと略記することがある)とカーボンブラックの両方を含有し、かつ前記ポリアミド系樹脂100重量部に対して、前記微細炭素繊維を0.3~2.5重量部と前記カーボンブラックを7~25重量部とを配合したものであり、前記半導電性ポリアミド系樹脂組成物から成形された半導電性ベルトは、半導電性を示し、体積抵抗率の均一性が良好で(面内バラつきが小さく)、連続して印刷しても体積抵抗率の変化が小さく、さらに表面光沢度が高い半導電性ベルトを得ることができる。 The semiconductive polyamide-based resin composition of the present invention contains a polyamide-based resin and a conductive agent, and the conductive agent contains both fine carbon fibers (hereinafter sometimes abbreviated as CNT) and carbon black. , and 0.3 to 2.5 parts by weight of the fine carbon fiber and 7 to 25 parts by weight of the carbon black are blended with 100 parts by weight of the polyamide resin, and the semiconductive polyamide The semiconductive belt molded from the resin composition exhibits semiconductivity, has good uniformity in volume resistivity (small in-plane variation), and does not change in volume resistivity even after continuous printing. A semiconductive belt that is small and has a high surface gloss can be obtained.

CNT配合量と光沢度との関係を示す図である。It is a figure which shows the relationship between CNT compounding quantity and glossiness. CNT配合量と連続通電試験における体積低効率の変動桁数との関係を示す図である。FIG. 4 is a diagram showing the relationship between the amount of CNT compounded and the number of digits of fluctuation of volumetric efficiency in a continuous current test. 連続通電試験における電圧印加装置を示す模式的断面図である。FIG. 4 is a schematic cross-sectional view showing a voltage application device in a continuous energization test;

以下、本発明を詳細に説明する。なお、ここでいう半導電性とは、温度23℃、相対湿度50%RH、印加電圧250Vにおける体積抵抗率が1×10~1×1012Ω・cmの範囲内であることを意味する。 The present invention will be described in detail below. The term “semiconductive” as used herein means that the volume resistivity is within the range of 1×10 6 to 1×10 12 Ω·cm at a temperature of 23° C., a relative humidity of 50% RH, and an applied voltage of 250 V. .

[ポリアミド系樹脂]
ポリアミド系樹脂は、ジアミンとジカルボン酸との重縮合、α,ω-アミノカルボン酸の重縮合、ラクタム類の開環重合などによって得られ、十分な分子量を有する熱可塑性樹脂である。ポリアミド系樹脂としては、例えば、ナイロン6、ナイロン4、ナイロン6,6、ナイロン11、ナイロン12、ナイロン6,10、ナイロン6,12、ナイロン6/6,6、ナイロン6/6,6/12、ナイロン6,MXD(MXDはm-キシリレンジアミン成分を表す)、ナイロン6,6T(Tはテレフタル酸成分を表す)、ナイロン6,6I(Iはイソフタル酸成分を表す)などが挙げられる。これらの中でも、吸水率が低いポリアミド系樹脂が好ましく、吸水率が低いポリアミド系樹脂は、カーボンブラックの分散性に優れるとともに、高湿度環境における電気抵抗の安定性に優れる。ポリアミド系樹脂の吸水率は、1.5%以下であることが好ましく、1.0%以下であることがより好ましい。吸水率が1.5%以下のポリアミド系樹脂としては、ナイロン11、ナイロン12、ナイロン6,10、ナイロン6,12などが挙げられ、吸水率が1.0%以下のポリアミド系樹脂としては、ナイロン11、ナイロン12が挙げられる。なお、これらのポリアミド系樹脂は、単独或は2種以上を組み合わせて用いても良い。
[Polyamide resin]
A polyamide-based resin is a thermoplastic resin having a sufficient molecular weight obtained by polycondensation of diamine and dicarboxylic acid, polycondensation of α,ω-aminocarboxylic acid, ring-opening polymerization of lactams, or the like. Examples of polyamide resins include nylon 6, nylon 4, nylon 6,6, nylon 11, nylon 12, nylon 6,10, nylon 6,12, nylon 6/6,6, nylon 6/6, 6/12. , nylon 6,MXD (MXD represents an m-xylylenediamine component), nylon 6,6T (T represents a terephthalic acid component), nylon 6,6I (I represents an isophthalic acid component), and the like. Among these, polyamide-based resins with low water absorption are preferable, and polyamide-based resins with low water absorption are excellent in dispersibility of carbon black and excellent in stability of electrical resistance in a high-humidity environment. The water absorption of the polyamide-based resin is preferably 1.5% or less, more preferably 1.0% or less. Polyamide resins with a water absorption of 1.5% or less include nylon 11, nylon 12, nylon 6,10, nylon 6,12, etc. Polyamide resins with a water absorption of 1.0% or less include: Examples include nylon 11 and nylon 12. These polyamide-based resins may be used alone or in combination of two or more.

[導電剤]
本発明の導電剤は、微細炭素繊維とカーボンブラックの両方を併用することが特徴である。本発明者らは表面光沢度の高い半導電性ベルトを開発すべく種々検討を行った結果、導電剤として微細炭素繊維のみを配合した半導電性ポリアミド系樹脂組成物から成形した半導電性ベルトは表面粗さが大きくなり、表面光沢度が小さくなることが明らかとなった。この現象は、微細炭素繊維の平均繊維径は小さいが平均繊維長が長いため、その影響で半導電性ベルトの表面粗さが大きくなり、表面光沢度が小さくなったものと推察した。一方、カーボンブラックは一次粒子径が小さいため、表面粗さへの影響は小さいものと考えられる。また、導電剤としてカーボンブラックのみを配合した半導電性ポリアミド系樹脂組成物から成形した半導電性ベルトは、大量にカーボンブラックを配合する必要があり、連続して電圧をかけると体積抵抗率の上昇が大きい事も明らかとなった。
[Conductive agent]
The conductive agent of the present invention is characterized by the combined use of both fine carbon fibers and carbon black. The present inventors conducted various studies to develop a semiconductive belt with a high surface glossiness, and as a result, a semiconductive belt molded from a semiconductive polyamide resin composition containing only fine carbon fibers as a conductive agent. It was found that the surface roughness increased and the surface glossiness decreased. It was speculated that this phenomenon was caused by the fact that the fine carbon fibers had a small average fiber diameter but a long average fiber length, which increased the surface roughness of the semiconductive belt and reduced the surface glossiness. On the other hand, since carbon black has a small primary particle size, it is thought that the effect on surface roughness is small. In addition, a semi-conductive belt molded from a semi-conductive polyamide-based resin composition containing only carbon black as a conductive agent requires a large amount of carbon black to be blended. A large increase was also found.

本発明に用いる微細炭素繊維とは、繊維の芯部に中空空間を有するものであり、繊維径が小さく、アスペクト比の大きい繊維状のものが好ましく、カーボンナノチューブと通称されるものも含まれる。具体的には、平均繊維径が1nm~200nm、平均繊維長が0.1μm~100μm、アスペクト比が10~10000の範囲内であることが好ましい。 The fine carbon fiber used in the present invention has a hollow space in the core of the fiber, and is preferably fibrous with a small fiber diameter and a large aspect ratio, and includes what is commonly called a carbon nanotube. Specifically, it is preferable that the average fiber diameter is 1 nm to 200 nm, the average fiber length is 0.1 μm to 100 μm, and the aspect ratio is 10 to 10,000.

微細炭素繊維としては、単層カーボンナノチューブ、多層カーボンナノチューブ(特開平1-270543、特公平3-64606、特公平3-77288、特開2004-299986)、カップ積層型カーボンナノチューブ(特開2003-73928、特開2004-360099)、プレートレット型カーボンナノファイバー(特開2004-300631)、釣鐘状構造単位集合体(特開2012-46864、特開2011-47081、特開2011-46852)などが挙げられる。これらの中でも、単層カーボンナノチューブ、多層カーボンナノチューブ、釣鐘状構造単位集合体が好ましい。特に、釣鐘状構造単位集合体は、ファンデルワールス力の弱い力で結合している釣鐘状構造単位の集合体の連結部が、混練や押出による剪断力により容易に切断され、微炭素繊維同士が絡まり合った凝集物となりにくく、分散性に優れることから好ましい。 As fine carbon fibers, single-walled carbon nanotubes, multi-walled carbon nanotubes (JP-A-1-270543, JP-B-3-64606, JP-B-3-77288, JP-A-2004-299986), cup-layered carbon nanotubes (JP-A-2003- 73928, JP-A-2004-360099), platelet-type carbon nanofibers (JP-A-2004-300631), bell-shaped structural unit assemblies (JP-A-2012-46864, JP-A-2011-47081, JP-A-2011-46852), etc. mentioned. Among these, single-walled carbon nanotubes, multi-walled carbon nanotubes, and bell-shaped structural unit aggregates are preferred. In particular, in the assembly of bell-shaped structural units, the joints of the assembly of bell-shaped structural units, which are joined by weak van der Waals forces, are easily cut by the shearing force due to kneading or extrusion, and fine carbon fibers are separated from each other. are less likely to form entangled aggregates and are excellent in dispersibility.

本発明に用いるカーボンブラックとしては、ファーネスブラック、チャンネルブラック、ケッチェンブラックおよびアセチレンブラック等の導電性カーボンブラックを挙げることができ、特に平均粒子径が50nm以下のカーボンブラックが少量の配合で電気抵抗を下げることができるので好ましい。また、カーボンブラックのストラクチャー構造が発達し、導電パスを形成する観点からDBP(Dibutyl phthalate)吸油量が100~500ml/100gが好ましく、100~300ml/100gであることが好ましく、150~250ml/100gであることがより好ましい。また導電性の観点から30~1500m/gの範囲のBET表面積であるカーボンブラックが好ましい。また、本発明においては、カルボキシル基、水酸基、エポキシ基、アミノ基、オキサゾリン基、から選ばれる1種以上の官能基を有するポリマーがグラフト付加されたグラフト化カーボンブラック、或いは低分子量化合物で表面処理したカーボンブラックも用いることができる。 Examples of the carbon black used in the present invention include conductive carbon black such as furnace black, channel black, ketjen black and acetylene black. can be lowered. In addition, from the viewpoint of developing the structural structure of carbon black and forming a conductive path, the DBP (Dibutyl phthalate) oil absorption is preferably 100 to 500 ml/100 g, preferably 100 to 300 ml/100 g, and 150 to 250 ml/100 g. is more preferable. Carbon black having a BET surface area in the range of 30 to 1500 m 2 /g is preferred from the viewpoint of conductivity. In the present invention, the surface is treated with a grafted carbon black in which a polymer having one or more functional groups selected from a carboxyl group, a hydroxyl group, an epoxy group, an amino group, and an oxazoline group is grafted, or a low molecular weight compound. Carbon blacks containing carbon black can also be used.

次に、本発明の半導電性ポリアミド系樹脂組成物の組成比については、ポリアミド系樹脂100重量部に対して、微細炭素繊維を0.3~2.5重量部及びカーボンブラックを7~25重量部配合することが必要である。ポリアミド系樹脂100重量部に対して、微細炭素繊維を0.4~2.0重量部を配合することがより好ましく、0.4~1.5重量部がさらに好ましい。微細炭素繊維を上記範囲とすることにより、半導電性ベルトに成形した際の表面粗さの値を小さくでき、その結果表面光沢度を高くすることができる。また、ポリアミド系樹脂組成物100重量部に対して、カーボンブラックを7~25重量部の割合で含有することが好ましく、8~23重量部がより好ましく、10~20重量部がさらに好ましい。カーボンブラックを上記範囲とすることにより、所望の半導電性領域に調整することが可能となる。カーボンブラックの配合が7重量部未満であると、前記微細炭素繊維の配合量と合わせても所定の半導電性を示す組成物が得られない可能性があり、25重量部を超えると、溶融粘度が高くなり、溶融押出が難しくなる。上記のように、微細炭素繊維の配合量は所定の表面光沢度となるように減らすが、微細炭素繊維の配合量を減少させると電気抵抗が高くなるため、所定の半導電性の電気抵抗を示すようにカーボンブラックの配合量を適宜決定することができる。 Next, regarding the composition ratio of the semiconductive polyamide resin composition of the present invention, 0.3 to 2.5 parts by weight of fine carbon fiber and 7 to 25 parts by weight of carbon black are added to 100 parts by weight of polyamide resin. It is necessary to mix parts by weight. It is more preferable to blend 0.4 to 2.0 parts by weight, more preferably 0.4 to 1.5 parts by weight, of the fine carbon fibers with respect to 100 parts by weight of the polyamide-based resin. By setting the fine carbon fibers within the above range, it is possible to reduce the surface roughness of the semiconductive belt when formed, and as a result, to increase the surface glossiness. Carbon black is preferably contained in an amount of 7 to 25 parts by weight, more preferably 8 to 23 parts by weight, and even more preferably 10 to 20 parts by weight, based on 100 parts by weight of the polyamide resin composition. By setting the amount of carbon black within the above range, it is possible to adjust the semiconductive region to a desired level. If the amount of carbon black is less than 7 parts by weight, it may not be possible to obtain a composition exhibiting the desired semi-conductivity even when combined with the amount of the fine carbon fibers. Viscosity increases and melt extrusion becomes difficult. As described above, the blending amount of the fine carbon fibers is reduced so as to achieve a predetermined surface glossiness. As shown, the blending amount of carbon black can be appropriately determined.

本発明のポリアミド系樹脂組成物には、必要に応じてその特性を損なわない範囲で添加剤を配合しても良い。添加剤としては、酸化防止剤、熱安定剤、有機フィラーや無機フィラー、アンチブロッキング剤、可塑剤、滑剤、加工助剤等が挙げられる。これらの樹脂や添加剤は、目的に応じて適量を使用することができる。 Additives may be blended into the polyamide resin composition of the present invention, if necessary, as long as the properties are not impaired. Examples of additives include antioxidants, heat stabilizers, organic fillers and inorganic fillers, antiblocking agents, plasticizers, lubricants, processing aids, and the like. These resins and additives can be used in appropriate amounts depending on the purpose.

[ポリアミド系樹脂組成物の製造方法]
本発明のポリアミド系樹脂組成物の製造方法は特に制限はないが、例えばポリアミド系樹脂、導電剤、必要に応じて用いられる添加剤を配合してドライブレンドした後、溶融混練する方法、ポリアミド系樹脂に導電剤を予め溶融混練してマスターバッチを作製し、これに必要に応じてポリアミド系樹脂や添加剤を配合して溶融混練する方法等が挙げられる。
[Method for producing polyamide resin composition]
The method for producing the polyamide-based resin composition of the present invention is not particularly limited, but for example, a polyamide-based resin, a conductive agent, a method of blending and dry-blending additives used as necessary, and then melt-kneading, a polyamide-based For example, a masterbatch is prepared by previously melt-kneading a conductive agent into a resin, and if necessary, a polyamide-based resin and additives are blended into the masterbatch and melt-kneaded.

溶融混練するための装置としては、バッチ式混練機、ニーダー、コニーダー、バンバリーミキサー、ロールミル、単軸もしくは二軸押出機等、公知の種々の混練機が挙げられる。これらの中でも、混練能力や生産性に優れる点から単軸押出機や二軸押出機が好ましく用いられる。 Apparatuses for melt-kneading include various known kneaders such as batch-type kneaders, kneaders, co-kneaders, Banbury mixers, roll mills, and single-screw or twin-screw extruders. Among these, single-screw extruders and twin-screw extruders are preferably used from the viewpoint of excellent kneading ability and productivity.

溶融混練時の温度は、使用するポリアミド系樹脂の種類や溶融粘度等により適宜選択できるが、通常、150~300℃の範囲であり、樹脂の劣化防止の観点から、好ましくは170~280℃である。 The temperature during melt-kneading can be appropriately selected depending on the type and melt viscosity of the polyamide resin to be used, but it is usually in the range of 150 to 300 ° C., and from the viewpoint of preventing deterioration of the resin, preferably 170 to 280 ° C. be.

[半導電性ベルト]
本発明の半導電性ベルトは、半導電性ポリアミド系樹脂組成物からなる層を少なくとも一層有するシームレスベルトである。多層の場合は、目的に応じて本発明の半導電性ポリアミド系樹脂組成物からなる基材層の上に弾性層や表面コート層を設けても良い。
[Semi-conductive belt]
The semiconductive belt of the present invention is a seamless belt having at least one layer made of a semiconductive polyamide resin composition. In the case of multiple layers, depending on the purpose, an elastic layer or a surface coating layer may be provided on the substrate layer comprising the semiconductive polyamide resin composition of the present invention.

本発明の半導電性ベルトは、押出成形法、遠心成形法、ディッピング法などで製造することができる。押出成形法、特に環状ダイスを用いた押出成形法は、継ぎ目のないベルトが得られるので好ましい。環状ダイスを用いた押出成形法としては、例えば押出機と、該押出機の下方に該押出機に連通して環状ダイスが配置され、該環状ダイスの下方には、該環状ダイスから下向きに押し出される溶融樹脂をその外周に担持させて冷却固化するマンドレルが配設された押出成形装置を用いることができる。半導電性樹脂組成物を押出機に供給して、環状ダイスからチューブ状に共押出し、マンドレルの外周に沿わせて冷却固化することによりチューブ状の成形体を得て、チューブ状の該成形体を所望の幅に切断することでベルトとすることができる。また、得られたベルトは金型に挿入し、ポリアミド系樹脂の融点以下の温度に設定したオーブン中でアニール処理することにより、さらに周長精度が向上した半導電性ベルトを得ることができる。なお、これらの説明は単層の場合であったが、複数層の場合は、層数に応じた押出機及びダイスを準備すればよい。
また、環状ダイスを用いた押出成形法の他の例としては、押出機と、該押出機の上方に該押出機に連通して環状ダイスが配置され、該環状ダイスの上方には、該環状ダイスから上向きに押し出される溶融樹脂をその外周に担持させて冷却固化するマンドレルが配設された押出成形装置を用いることができる。
The semiconductive belt of the present invention can be produced by an extrusion method, a centrifugal method, a dipping method, or the like. Extrusion molding, particularly extrusion molding using an annular die, is preferred because it yields a seamless belt. As an extrusion molding method using an annular die, for example, an extruder and an annular die are arranged below the extruder in communication with the extruder, and below the annular die, the resin is extruded downward from the annular die. It is possible to use an extrusion molding apparatus provided with a mandrel for cooling and solidifying the molten resin carried on its outer periphery. A semiconductive resin composition is supplied to an extruder, co-extruded into a tube from an annular die, cooled and solidified along the outer periphery of a mandrel to obtain a tubular molded body, and the tubular molded body is obtained. can be cut into a desired width to form a belt. In addition, the obtained belt is inserted into a mold and annealed in an oven set at a temperature below the melting point of the polyamide resin to obtain a semiconductive belt with improved circumferential length accuracy. In addition, although these explanations are for a single layer, in the case of a plurality of layers, an extruder and a die corresponding to the number of layers may be prepared.
Another example of an extrusion molding method using an annular die includes an extruder, an annular die arranged above the extruder in communication with the extruder, and an annular die above the annular die. An extrusion molding apparatus provided with a mandrel for cooling and solidifying a molten resin extruded upward from a die can be used.

本発明の半導電性ポリアミド系樹脂組成物は、中間転写ベルト、転写搬送ベルト、紙搬送ベルト等の半導電性ベルトや、自動車関連部品、電子・電気部品、機械部品、半導体包装用フィルム等として好適に用いることができる。 The semiconductive polyamide-based resin composition of the present invention can be used as semiconductive belts such as intermediate transfer belts, transfer transfer belts, and paper transfer belts, automotive parts, electronic/electrical parts, machine parts, semiconductor packaging films, and the like. It can be used preferably.

本発明の半導電性ベルトの入射角60°での表面光沢度は50以上が好ましく、さらに60以上が好ましく、70以上がより好ましい。ポリアミド系樹脂100重量部に対して、微細炭素繊維が2.5重量部以下配合することで、上記性能を達成することができる。
また、本発明の導電性ベルトの表面粗さRzは、1.00μm以下が好ましく、さらに0.80μm以下が好ましく、0.60μm以下がより好ましい。ポリアミド系樹脂100重量部に対して、微細炭素繊維が2.5重量部以下を配合することで、上記記載の表面粗さRzの性能を満足することができる。
さらに、本発明の導電性ベルトの後述する連続通電試験における体積抵抗率の変動桁は、1.00桁未満が好ましく、さらに0.50桁未満が好ましく、0.35桁未満が最も好ましい。ポリアミド系樹脂100重量部に対して、微細炭素繊維を0.3重量部以上配合することで、後述する連続通電試験における体積抵抗率の変動桁を満足することができる。
The surface glossiness of the semiconductive belt of the present invention at an incident angle of 60° is preferably 50 or more, more preferably 60 or more, and more preferably 70 or more. By blending 2.5 parts by weight or less of the fine carbon fibers with respect to 100 parts by weight of the polyamide-based resin, the above performance can be achieved.
The surface roughness Rz of the conductive belt of the present invention is preferably 1.00 μm or less, more preferably 0.80 μm or less, and more preferably 0.60 μm or less. By blending 2.5 parts by weight or less of the fine carbon fibers with respect to 100 parts by weight of the polyamide-based resin, the performance of the surface roughness Rz described above can be satisfied.
Furthermore, the fluctuation digit of the volume resistivity in the continuous energization test described later of the conductive belt of the present invention is preferably less than 1.00 digit, more preferably less than 0.50 digit, and most preferably less than 0.35 digit. By blending 0.3 parts by weight or more of the fine carbon fibers with respect to 100 parts by weight of the polyamide-based resin, it is possible to satisfy the fluctuation digit of the volume resistivity in the continuous current test described later.

以下、本発明について、実施例によりさらに詳しく説明するが、本発明は以下の実施例に限定されるものではない。なお、実施例における物性の測定方法は次の通りである。
(1)溶融粘度
溶融粘度は、長さ10mm×直径1mmの穴を有するダイを取り付けた島津製作所製高化式フローテスターを用いて測定した。
(2)表面抵抗率及び体積抵抗率
表面抵抗率及び体積抵抗率は、URSプローブ(荷重2kg)を取り付けたハイレスタUX(MCP-HT800、ダイヤインスツルメンツ社製)を用い、460mm×400mmに切出したサンプルについて、印加電圧250Vでランダムに10点測定した。
また、体積抵抗率の均一性(バラつき)は以下の式で求めた。
体積抵抗率の均一性[桁]=log10(体積抵抗率の最大値/体積抵抗率の最小値)
(3)表面粗さ
サーフコム580A(東京精密社製)を用い、JIS B0601-1982に準拠し、触針先端半径2μm、カットオフ値0.8mm、測定長さ2.5mm、速度0.3mm/secで表面粗さRzを測定した。
(4)表面光沢度
ハンディ光沢計グロスチェッカIG-320(堀場製作所製)を用いて、入射角60°で表面光沢度を測定した。
(5)連続通電試験
図3に示す電圧印加装置を用い、表面に銅板を張り付けた試料用ロール(3)上に粘着テープで半導電性ベルト(2)を貼付けた。半導電性ベルトの体積抵抗率の変動桁数は、導電ゴムロール(1)と試料用ロールとの間に1000Vの電圧を印加しながら試料用ロールを5回転/分で4000回転させた後に半導電性ベルトを取り外し、23℃中に24時間放置後の体積抵抗率を測定し、次式を用いて体積抵抗率の変動桁数を求めた。
体積抵抗率の変動桁数[桁]=log10(連続通電試験後の体積抵抗率/連続通電試験前の体積抵抗率)
EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples. Methods for measuring physical properties in Examples are as follows.
(1) Melt Viscosity Melt viscosity was measured using a Koka flow tester manufactured by Shimadzu Corporation equipped with a die having a hole of length 10 mm×diameter 1 mm.
(2) Surface resistivity and volume resistivity Surface resistivity and volume resistivity were measured using a Hiresta UX (MCP-HT800, manufactured by Dia Instruments) equipped with a URS probe (load 2 kg), and a sample cut to 460 mm x 400 mm. was randomly measured at 10 points with an applied voltage of 250V.
Further, the uniformity (variation) of the volume resistivity was determined by the following formula.
Uniformity of volume resistivity [digit] = log10 (maximum value of volume resistivity/minimum value of volume resistivity)
(3) Surface roughness Using Surfcom 580A (manufactured by Tokyo Seimitsu Co., Ltd.), conforming to JIS B0601-1982, stylus tip radius 2 μm, cutoff value 0.8 mm, measurement length 2.5 mm, speed 0.3 mm / The surface roughness Rz was measured in sec.
(4) Surface Glossiness Surface glossiness was measured at an incident angle of 60° using a gloss checker IG-320 (manufactured by Horiba, Ltd.).
(5) Continuous Current Test Using the voltage application device shown in FIG. 3, a semiconductive belt (2) was attached with an adhesive tape onto a sample roll (3) having a copper plate attached to its surface. The number of digits of variation in the volume resistivity of the semiconductive belt is obtained by applying a voltage of 1000 V between the conductive rubber roll (1) and the sample roll and rotating the sample roll 4000 times at 5 rotations/minute. After removing the elastic belt and leaving it at 23° C. for 24 hours, the volume resistivity was measured.
Number of digits of change in volume resistivity [digit] = log10 (volume resistivity after continuous energization test/volume resistivity before continuous energization test)

原料としては、下記のものを用いた。
<ポリアミド系樹脂(A)>
・ポリアミド12(A-1)[融点:178℃、溶融粘度:5950poise(測定温度200℃、荷重100kg)]
<導電剤(B)>
・カーボンナノチューブ(B-1)[平均直径:10~15nm、長さ:10μm以下、比表面積:180~250m/g]
・カーボンブラック(B-2)[DBP吸油量:190ml/100g、BET表面積:70m/g]
The following materials were used as raw materials.
<Polyamide resin (A)>
・Polyamide 12 (A-1) [melting point: 178°C, melt viscosity: 5950 poise (measurement temperature: 200°C, load: 100 kg)]
<Conductive agent (B)>
・Carbon nanotubes (B-1) [average diameter: 10 to 15 nm, length: 10 μm or less, specific surface area: 180 to 250 m 2 /g]
・Carbon black (B-2) [DBP oil absorption: 190 ml/100 g, BET surface area: 70 m 2 /g]

表1に示した配合比となるように、ポリアミド系樹脂と導電剤とをスクリュー径38mmの二軸混練押出機を用いて溶融混練し、コンパウンドを得た。次いで、得られたコンパウンドを、環状ダイスを備えた単軸押出機(押出径:50mm)に供給し、溶融状態でチューブ状に成形後、長さ350mmにカットし、周長800mm、幅350mm、厚み140μmの半導電性ベルトを得た。
実施例及び比較例で作成した半導電性ベルトの評価結果を表1、図1および図2に示す。
A polyamide resin and a conductive agent were melt-kneaded using a twin-screw kneading extruder with a screw diameter of 38 mm so as to obtain a compounding ratio shown in Table 1, to obtain a compound. Next, the obtained compound is supplied to a single screw extruder (extrusion diameter: 50 mm) equipped with an annular die, molded into a tubular shape in a molten state, cut into a length of 350 mm, a circumference of 800 mm, a width of 350 mm, A semiconductive belt having a thickness of 140 μm was obtained.
Table 1, FIGS. 1 and 2 show the evaluation results of the semiconductive belts produced in Examples and Comparative Examples.

Figure 2023027848000002
Figure 2023027848000002

表1、図1および図2に示すように、ポリアミド系樹脂100重量部に対して、微細炭素繊維を0.3~2.5重量部配合した半導電性ベルトである実施例1乃至4は、体積抵抗率の均一性に優れ、表面光沢度は50以上の高い値を示し、さらに連続通電試験における体積抵抗率の変動桁は0.5桁以下であり、半導電性ベルトとして優れた特性を示した。 As shown in Table 1, FIGS. 1 and 2, Examples 1 to 4, which are semiconductive belts in which 0.3 to 2.5 parts by weight of fine carbon fibers are blended with 100 parts by weight of polyamide resin, Excellent uniformity of volume resistivity, high surface glossiness of 50 or more, and fluctuation of volume resistivity of 0.5 digit or less in a continuous current test, excellent characteristics as a semiconductive belt showed that.

それに対し、ポリアミド系樹脂100重量部に対して微細炭素繊維の配合量が0.3重量部未満の比較例1および比較例2は体積抵抗率の均一性が良好で高い表面光沢度を示すものの、連続通電試験における体積抵抗率の変動が大きく、半導電性ベルトとして不適であった。一方、ポリアミド系樹脂100重量部に対して微細炭素繊維の配合量が2.5重量部を超えた比較例3および4は、体積抵抗率の均一性が良好で、連続通電試験における体積抵抗率の変動が小さいものの、表面光沢度が50以下と低い値を示した。 On the other hand, Comparative Examples 1 and 2, in which the amount of the fine carbon fibers is less than 0.3 parts by weight with respect to 100 parts by weight of the polyamide resin, have good uniformity of volume resistivity and high surface glossiness. , the fluctuation of the volume resistivity in the continuous current test was large, and it was not suitable as a semi-conductive belt. On the other hand, Comparative Examples 3 and 4, in which the amount of the fine carbon fiber was more than 2.5 parts by weight with respect to 100 parts by weight of the polyamide resin, had good uniformity of volume resistivity, and the volume resistivity in the continuous current test was Although the fluctuation of the surface glossiness was small, the surface glossiness showed a low value of 50 or less.

1 導電ゴムロール
2 半導電性ベルト
3 試料用ロール
4 電源








1 conductive rubber roll 2 semi-conductive belt 3 sample roll 4 power supply








Claims (7)

ポリアミド系樹脂と導電剤とを含有し、前記導電剤は、微細炭素繊維とカーボンブラックの両方を含有し、かつ前記ポリアミド系樹脂100重量部に対して、前記微細炭素繊維を0.3~2.5重量部と前記カーボンブラックを7~25重量部とを配合することを特徴とする半導電性ポリアミド系樹脂組成物。 It contains a polyamide resin and a conductive agent, the conductive agent contains both fine carbon fibers and carbon black, and the fine carbon fibers are added in an amount of 0.3 to 2 parts per 100 parts by weight of the polyamide resin. .5 parts by weight of the carbon black and 7 to 25 parts by weight of the carbon black are blended. 前記ポリアミド系樹脂が、ナイロン6、ナイロン12、ナイロン6,12から選ばれた1種以上であることを特徴とする請求項1記載の半導電性ポリアミド系樹脂組成物。 2. The semiconductive polyamide resin composition according to claim 1, wherein said polyamide resin is one or more selected from nylon 6, nylon 12 and nylon 6,12. 前記微細炭素繊維が、単層カーボンナノチューブ、多層カーボンナノチューブ、釣鐘状構造単位集合体から選ばれる少なくとも一種を含有することを特徴とする請求項1または2記載の半導電性ポリアミド系樹脂組成物。 3. The semiconductive polyamide resin composition according to claim 1, wherein said fine carbon fibers contain at least one selected from single-walled carbon nanotubes, multi-walled carbon nanotubes, and bell-shaped structural unit aggregates. 請求項1乃至3のいずれか記載の半導電性ポリアミド系樹脂組成物から形成された半導電性ベルト。 A semiconductive belt formed from the semiconductive polyamide resin composition according to any one of claims 1 to 3. 請求項4記載の半導電性ベルトを有することを特徴とする画像形成装置。 An image forming apparatus comprising the semiconductive belt according to claim 4 . ポリアミド系樹脂を100重量部と、微細炭素繊維を0.3~2.5重量部とカーボンブラックを7~25重量部とを配合した半導電性ポリアミド系樹脂組成物を押出機に供給し、前記半導電ポリアミド系樹脂組成物を環状ダイスより押出し、冷却固化することを特徴とする半導電性ベルトの製造方法。 A semiconductive polyamide resin composition containing 100 parts by weight of a polyamide resin, 0.3 to 2.5 parts by weight of fine carbon fibers and 7 to 25 parts by weight of carbon black is supplied to an extruder, A method for producing a semiconductive belt, wherein the semiconductive polyamide resin composition is extruded through an annular die and cooled to solidify. 入射角60°での表面光沢度が50以上であることを特徴とする請求項6記載の半導電性ベルトの製造方法。

7. The method of manufacturing a semiconductive belt according to claim 6, wherein the surface glossiness at an incident angle of 60[deg.] is 50 or more.

JP2021133169A 2021-08-18 2021-08-18 Semi-conductive polyamide-based resin composition, semi-conductive belt using the same, image formation device, and method for manufacturing conductive belt Pending JP2023027848A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2021133169A JP2023027848A (en) 2021-08-18 2021-08-18 Semi-conductive polyamide-based resin composition, semi-conductive belt using the same, image formation device, and method for manufacturing conductive belt

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2021133169A JP2023027848A (en) 2021-08-18 2021-08-18 Semi-conductive polyamide-based resin composition, semi-conductive belt using the same, image formation device, and method for manufacturing conductive belt

Publications (1)

Publication Number Publication Date
JP2023027848A true JP2023027848A (en) 2023-03-03

Family

ID=85331216

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2021133169A Pending JP2023027848A (en) 2021-08-18 2021-08-18 Semi-conductive polyamide-based resin composition, semi-conductive belt using the same, image formation device, and method for manufacturing conductive belt

Country Status (1)

Country Link
JP (1) JP2023027848A (en)

Similar Documents

Publication Publication Date Title
KR100941487B1 (en) Intermediate Transfer Belt Having Multilayered Structure
WO2006041186A1 (en) Resin composition containing vapor grown carbon fiber and use thereof
JP2003156902A (en) Image forming apparatus belt, sleeve or tube
JP3948227B2 (en) Endless belt, belt for image forming apparatus, and image forming apparatus
JP3891160B2 (en) Belt for image forming apparatus and image forming apparatus
JP4195285B2 (en) Polyamide-based electrophotographic member
JP2023027848A (en) Semi-conductive polyamide-based resin composition, semi-conductive belt using the same, image formation device, and method for manufacturing conductive belt
JP2021009400A (en) Sheet-like member for image forming apparatus
JP6808418B2 (en) Semi-conductive polyamide resin composition, molded article using it, and seamless belt for electrophotographic
JP6632352B2 (en) Method for producing semiconductive polyamide resin molded article
JP4740566B2 (en) Semiconductive film, method for producing the same, and charge control member
JP2008044179A (en) Conductive belt, manufacturing method of the same and image forming device having the same
KR100926967B1 (en) Semiconductive resin composition for transfer belt and transfer belt for image forming apparatus using same
JP5618718B2 (en) Semiconductive polyamide-based seamless belt
JP6590708B2 (en) Method for producing semiconductive resin composition
JP7463144B2 (en) Semiconductive polyethylene resin composition, and molded article and seamless belt using the same
JP7167563B2 (en) CONDUCTIVE SEAMLESS BELT AND IMAGE FORMING APPARATUS
JP2015055740A (en) Conductive resin belt, manufacturing method thereof, intermediate transfer belt using the conductive resin belt, and image forming apparatus
JP5724950B2 (en) Method for producing conductive resin molding
JP6752137B2 (en) Method for manufacturing transfer belt for image forming apparatus and transfer belt for image forming apparatus
JP6800023B2 (en) Method for manufacturing transfer belt for image forming apparatus and transfer belt for image forming apparatus
JP5052146B2 (en) Polyarylene thioether semiconductive film, charge control member formed from the film, endless belt, and transfer belt for image forming apparatus using the endless belt
JP6918597B2 (en) Semi-conductive resin composition and seamless belt for electrophotographic using it
JP2001302812A (en) Endless belt, belt for image-forming device, and device for forming image
JP6598669B2 (en) Semiconductive resin composition and electrophotographic seamless belt using the same