JPH01167343A - Polyolefin based finely porous film - Google Patents

Polyolefin based finely porous film

Info

Publication number
JPH01167343A
JPH01167343A JP62326438A JP32643887A JPH01167343A JP H01167343 A JPH01167343 A JP H01167343A JP 62326438 A JP62326438 A JP 62326438A JP 32643887 A JP32643887 A JP 32643887A JP H01167343 A JPH01167343 A JP H01167343A
Authority
JP
Japan
Prior art keywords
film
strength
longitudinal
polyolefin
elongation
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.)
Granted
Application number
JP62326438A
Other languages
Japanese (ja)
Other versions
JP2674625B2 (en
Inventor
Tatsuya Ito
達也 伊藤
Shigeru Tanaka
茂 田中
Kenji Yabe
矢部　健次
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.)
Toray Industries Inc
Original Assignee
Toray Industries Inc
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 Toray Industries Inc filed Critical Toray Industries Inc
Publication of JPH01167343A publication Critical patent/JPH01167343A/en
Application granted granted Critical
Publication of JP2674625B2 publication Critical patent/JP2674625B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G9/00—Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
    • H01G9/004—Details
    • H01G9/02—Diaphragms; Separators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • H01M50/491—Porosity
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/411—Organic material
    • H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
    • H01M50/417—Polyolefins
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
  • Cell Separators (AREA)

Abstract

PURPOSE:To obtain the title film having a definite average pore size and porosity as well as each specific value in longitudinal strength, longitudinal Young's modulus, widthwise strength and widthwise elongation and useful as electrolytic separator, various kind of films and separating membrane. CONSTITUTION:For example, in the production of the title film by blending 100 pts.wt. polyolefin resin with 100-200 pts.wt. organic solid such as phthalic acid ester, the blend is molded so that average pore size porosity, longitudinal strength, longitudinal Young's modulus, widthwise strength and widthwise elongation of the film are each 0.05-5mum, 50-85%, >=4kg/mm<2>, >=20kg/mm<2>, <=3kg/mm<2> and >=100% to provide the aimed film. Furthermore, thickness of the film is preferably 10-50mum.

Description

【発明の詳細な説明】 ［産業上の利用分野］ この発明は、新規なポリオレフィン系微孔性フィルムに
関する。この発明のポリオレフィン微孔性フィルムは電
解液セパレータや各種フィルム、分離膜としての用途を
有する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] This invention relates to a novel polyolefin microporous film. The polyolefin microporous film of the present invention has uses as an electrolyte separator, various films, and separation membranes.

［従来の技術］ 電解コンデンサ、リチウム電池、バッテリー等に用いら
れる電解液セパレータとして、古くからクラフト紙、マ
ニラ紙等の電解紙が用いられているが、最近、例えば実
開昭５９−１４０４２９号、特開昭６１−１３６１４号
、時開１Ｉ１１ａｚ−ｚｏｏｙ１ｓ号に記載されている
ように、電解紙よりも強度が高く、ショート（極間短絡
）発生率が低い多孔質ポリオレフィンフィルムを用いる
ことが提案されている。[Prior Art] Electrolytic paper such as kraft paper and Manila paper has been used for a long time as an electrolyte separator for electrolytic capacitors, lithium batteries, batteries, etc., but recently, for example, electrolytic paper such as kraft paper and Manila paper As described in JP-A No. 61-13614 and Jikai No. 1I11az-zooy1s, it has been proposed to use a porous polyolefin film that has higher strength than electrolytic paper and has a lower incidence of short circuits (short circuits between electrodes). ing.

［発明が解決しようとする問題点］ ポリオレフィン微孔性フィルムを電解セパレータとして
用いる場合には、フィルムを幅１０ｍｍ程度の短冊状に
切断（スリット）した後、素子巻きする。従来より提案
されているポリオレフィン微孔性フィルムは、短冊状に
切断する際の操作性が悪い、すなわちスリット性が悪い
。すなわち、フィルムをスリットする際、切断のエツジ
部が変形しやすく、また片伸びが生じやすい。さらに、
素子巻き時に伸びやすい。スリット性及び素子巻き性が
悪いと、電気特性に再現性が得られないので現実に電解
液セパレータとして使用することが困難である。[Problems to be Solved by the Invention] When a polyolefin microporous film is used as an electrolytic separator, the film is cut (slit) into strips with a width of about 10 mm and then wound into elements. Conventionally proposed microporous polyolefin films have poor operability when cut into strips, that is, poor slitting performance. That is, when the film is slit, the edges of the cut tend to be deformed and one-sided elongation tends to occur. moreover,
Easy to stretch when winding the element. If the slitting properties and element winding properties are poor, reproducibility of electrical properties cannot be obtained, making it difficult to actually use the material as an electrolyte separator.

この発明の目的は、電解液セパレータとして用いた場合
のスリット性を改善し、かつ素子巻き時にセパレータが
巻き張力により伸びることを極力小さくし、作業性、長
期信頼性を向上することができる新規なポリオレフィン
微孔性フィルムを提供することである。The purpose of this invention is to improve the slitting performance when used as an electrolyte separator, minimize the elongation of the separator due to winding tension during element winding, and improve workability and long-term reliability. An object of the present invention is to provide a polyolefin microporous film.

［問題点を解決するための手段］ 本願発明者らは、鋭意研究の結果、ポリオレフィン微孔
性フィルムの長手方向（ＭＤ）及び幅方向（ＴＤ）の強
度及びヤング率を最適化することによって、スリット性
及び素子巻き性の両方が改善されたポリオレフィン微孔
性フィルムを得ることができることを見出しこの発明を
完成した。[Means for Solving the Problems] As a result of intensive research, the inventors of the present application have optimized the strength and Young's modulus in the longitudinal direction (MD) and transverse direction (TD) of a polyolefin microporous film. The present invention was completed by discovering that it is possible to obtain a polyolefin microporous film with improved both slitting properties and element winding properties.

すなわち、この発明は、０．０５μｍから５μｍの平均
空孔径と５０％から８５％の空孔率を有し、長手方向強
度が４ｋＭｍｌｌ１２以上であり、長手方向ヤング率が
２０ｋｉｌｌ／ｍｍ２以上であり、幅方向強度が３ｋＱ
／１１１１１１２以下であり、幅方向伸度が１００％以
上であるポリオレフィン系微孔性フィルムを提供する。That is, the present invention has an average pore diameter of 0.05 μm to 5 μm, a porosity of 50% to 85%, a longitudinal strength of 4 kmMml12 or more, a longitudinal Young's modulus of 20 kill/mm2 or more, Width direction strength is 3kQ
/1111112 or less and has a width direction elongation of 100% or more.

この発明のポリオレフィン系微孔性フィルムの平均空孔
径は０．０５μｍから５μｍ、好ましくは０．０７μｍ
から２μｍ１更に好ましくは０゜６μｍから２μｍであ
る。平均空孔径が０．０５μｍ未満では電解液セパレー
タとして用いた場合の等価直列抵抗が大きくなり、５μ
ｍを超えるとショート発生率が大きくなる。また、フィ
ルムの空孔率は５０％から８５％、好ましくは５５％か
ら７０％である。空孔率が５０％未満であると電解液セ
パレータとして用いた場合に電解液保持率が低くドライ
アップする確立が高くなり、８５％を超えると機械特性
が悪化する。The average pore diameter of the polyolefin microporous film of the present invention is from 0.05 μm to 5 μm, preferably 0.07 μm.
to 2 μm1, more preferably from 0.6 μm to 2 μm. If the average pore diameter is less than 0.05 μm, the equivalent series resistance becomes large when used as an electrolyte separator;
If it exceeds m, the short circuit occurrence rate increases. Further, the porosity of the film is from 50% to 85%, preferably from 55% to 70%. If the porosity is less than 50%, when used as an electrolyte separator, the electrolyte retention rate will be low and the probability of dry-up will be high, and if it exceeds 85%, the mechanical properties will deteriorate.

この発明のポリオレフィン系微孔性フィルムの長手方向
（ＭＤ）の強度は４ｋｇ／ｍｍ２以上、好ましくは４．
５ｋａ／ｍｍ２以上である。長手方向の強度が４ｋＭｍ
ｍ２未満であるとスリット性及び素子巻き性に劣る。ま
た、長手方向のヤング率は２０ｋＭｌｌ１ｍ２　、好ま
しくは３０ｋＭｍｍ２である。長手方向のヤング率が２
０ｋＬ／ａ＋ｍ２未満であるとスリット時にシワが入り
、また伸びてスリットすることが困難になる。The strength of the polyolefin microporous film of the present invention in the longitudinal direction (MD) is 4 kg/mm2 or more, preferably 4.0 kg/mm2 or more.
It is 5ka/mm2 or more. Longitudinal strength is 4kmM
If it is less than m2, slitting properties and element winding properties will be poor. Further, the Young's modulus in the longitudinal direction is 20 kmMll1m2, preferably 30 kmMmm2. Young's modulus in the longitudinal direction is 2
If it is less than 0 kL/a+m2, wrinkles will appear during slitting, and it will also stretch, making slitting difficult.

この発明のポリオレフィン系微孔性フィルムの幅方向（
ＴＤ）の強度は３ｋＭｍｍ２以下、好ましくは０．６ｋ
ｇ／ｍｍ２から２．５ｋｇ／ｍｌｌ１２テアル。The width direction of the polyolefin microporous film of this invention (
TD) strength is 3kMmm2 or less, preferably 0.6k
g/mm2 to 2.5kg/ml12theal.

幅方向の強度が３ｋＭｍｍ２を超えるとスリット時に端
面の均一性が不良となり、良好なスリットを得ることが
困難になる。幅方向の強度の下限は特に制限はないが、
あまりにも強度が低いと取扱い性が悪化するので０．６
ｋＭｍｍ２以上であることが望ましい。また、幅方向の
伸度は１００％以上、好ましくは１５０％以上である。If the strength in the width direction exceeds 3 kmMmm2, the uniformity of the end face during slitting becomes poor, making it difficult to obtain good slits. There is no particular restriction on the lower limit of the strength in the width direction, but
If the strength is too low, handling will deteriorate, so 0.6
It is desirable that it is kmMmm2 or more. Further, the elongation in the width direction is 100% or more, preferably 150% or more.

幅方向の伸度が１００％未満の場合にはスリット時にク
ラックを生じやすくなる。If the elongation in the width direction is less than 100%, cracks are likely to occur during slitting.

また、フィルムの厚みは、電解液セパレータとして用い
た際の素子のコンパクト性及び取扱い性の観点から１０
μｍから５０μｍ１特に２０μｍから４０μｍが好まし
い。In addition, the thickness of the film is set to 10 mm from the viewpoint of compactness and handling of the device when used as an electrolyte separator.
From 1 to 50 μm is particularly preferred, from 20 to 40 μm.

この発明のポリオレフィン系微孔性フィルムを構成する
ポリオレフィン樹脂としては、ポリエチレン、ポリプロ
ピレン、ポリブテン、ポリメチルペンテン等のαオレフ
インポリマー及びこれらのコポリマーが好ましく、特に
融点が１２０℃以上でガラス転移点が１０℃未満のポリ
エチレン及びポリプロピレンが好ましく、とりわけ極限
粘度が１．８ｄｌ／ａから３．３ｄ１１０．より好まし
くは２゜７〜３．１ｄｌ／ａ、アイソタクチックインデ
ックスが９３％以上のポリプロピレンが好ましい。この
中でも、溶融結晶化温度が１０６℃以上、好ましくは１
０８℃以上、さらに好ましくは１１０℃以上のポリプロ
ピレンは、γブチロラクトン、プロピレンカーボネート
等の有機電解液に対する安定性に優れ好ましい。As the polyolefin resin constituting the polyolefin microporous film of the present invention, α-olefin polymers such as polyethylene, polypropylene, polybutene, polymethylpentene, and copolymers thereof are preferable, and in particular, those having a melting point of 120° C. or higher and a glass transition point of 10 Polyethylene and polypropylene are preferred, especially those with intrinsic viscosities below 1.8 dl/a to 3.3 dl/a. More preferably, polypropylene is 2.7 to 3.1 dl/a and has an isotactic index of 93% or more. Among these, the melt crystallization temperature is 106°C or higher, preferably 1
Polypropylene having a temperature of 08° C. or higher, more preferably 110° C. or higher is preferred because it has excellent stability against organic electrolytes such as γ-butyrolactone and propylene carbonate.

この発明のポリオレフィン系微孔性フィルムは以下のよ
うにして製造することができる。ポリオレフィン樹脂１
００重量部に、ジシクロへキシルフタレート（ＤＣＨＰ
）又はトリフェニルフォスフエイト（ＴＰＰ）のような
塩化ビニル等の可塑剤として使用されているフタル酸エ
ステル又はリン酸エステル等の有機固体８０重量部から
２４０重量部、好ましくは１００重量部から２００重量
部を配合し、溶融押出しした後、トリクロルメタン、ト
リクロルエタン、アセトン、メチルエチルケトン、酢酸
エチル、メタノール、トルエン、キシレン等の有機固体
の良溶媒を用いて、上記有機固体の添加聞の９５％以上
、好ましくは９８％以上を抽出する。The polyolefin microporous film of this invention can be produced as follows. Polyolefin resin 1
00 parts by weight, dicyclohexyl phthalate (DCHP)
) or organic solids such as phthalates or phosphates used as plasticizers such as vinyl chloride such as triphenyl phosphate (TPP), preferably 100 to 200 parts by weight. After blending parts by weight and melt-extruding, use a good organic solid solvent such as trichloromethane, trichloroethane, acetone, methyl ethyl ketone, ethyl acetate, methanol, toluene, xylene, etc. to add 95% or more of the above organic solid. , preferably 98% or more.

次に、ポリオレフィンのガラス転移点以上で融点−１０
℃の温度下でロール延伸を行なう。上記強度、ヤング率
及び伸度を得るため（延伸倍率は１゜５倍から６倍が好
ましい。延伸摸、ポリオレフィンの溶融結晶化温度以上
で融点−５℃の温度範囲で熱固定することが好ましい。Next, the melting point is -10 at or above the glass transition point of polyolefin.
Roll stretching is carried out at a temperature of °C. In order to obtain the above-mentioned strength, Young's modulus and elongation (stretching ratio is preferably 1°5 to 6 times), it is preferable to stretch and heat set at a temperature higher than the melt crystallization temperature of the polyolefin and a melting point of -5°C. .

この発明のポリオレフィン系微孔性フィルムを電解コン
デンサー用の電解セパレータとして用いる場合には、電
解液との親和性を良くするために親水化処理を施してお
くことが好ましい。親水化処理は、非イオン系界面活性
剤、アニオン若しくはカチオン系界面活性剤等のコーテ
ィング、コロナ若しくはプラズマ処理、グラフト処理、
紫外線処理又はこれらの組合せによって行なうことがで
きる。When the polyolefin-based microporous film of the present invention is used as an electrolytic separator for an electrolytic capacitor, it is preferable to perform a hydrophilic treatment in order to improve the affinity with the electrolytic solution. Hydrophilization treatment includes coating with nonionic surfactant, anionic or cationic surfactant, corona or plasma treatment, grafting treatment,
This can be done by ultraviolet treatment or a combination thereof.

この発明のポリオレフィン微孔性膜は、性能の観点から
ポリオレフィンのみから成っていることが好ましいが、
上記した平均空孔径、空孔率、並びに強度、ヤング率及
び伸度がこの発明の範囲内に入るならば、微量の不純物
を含んでいても差支えなく、また、例えば熱安定剤、酸
化防止剤、滑り剤、帯電防止剤等の添加剤やオレフィン
以外のモノマーを微量配合しても差支えない。特許請求
の範囲でいう「ポリオレフィン系微孔性フィルム」とは
このような不純物、添加剤等を含んだポリオレフィン微
孔性フィルムをも包含する意味で用いている。The polyolefin microporous membrane of the present invention is preferably composed only of polyolefin from the viewpoint of performance, but
As long as the average pore diameter, porosity, strength, Young's modulus, and elongation described above are within the scope of this invention, there is no problem even if it contains trace amounts of impurities, such as heat stabilizers, antioxidants, etc. There is no problem even if small amounts of additives such as , slip agents, antistatic agents, and monomers other than olefins are blended. In the claims, the term "polyolefin microporous film" is used to include polyolefin microporous films containing such impurities, additives, and the like.

この発明のポリオレフィン系微孔性フィルムは電解液セ
パレータとしての用途を有する。この場合、フィルムを
長手方向に沿ってスリットし素子巻きする。The polyolefin microporous film of the present invention has use as an electrolyte separator. In this case, the film is slit along the longitudinal direction and wound into elements.

［発明の効果］ この発明のポリオレフィン微孔性フィルムは電解セパレ
ータとして用いるのに最適化された平均空孔径及び空孔
率を有し、かつ、電解コンデンサやリチウム電池等を［
造する際のフィルムのスリット性及び素子巻き性の観点
から最適化された長手方向強度、長手方向ヤング率、幅
方向強度及び幅方向伸度を有する。この発明のポリオレ
フィン系微孔性フィルムでは長手方向の強度が大きいの
で素子巻き時に破断しにくい。また、長手方向のヤング
率が大きいのでスリット時に伸びが生じにくい。また、
幅方向の強度が小さいのでスリットしやすく、幅方向の
伸度が大きいのでスリット時にクラックが生じにくい。[Effects of the Invention] The polyolefin microporous film of the present invention has an average pore diameter and porosity optimized for use as an electrolytic separator, and is suitable for use in electrolytic capacitors, lithium batteries, etc.
It has longitudinal strength, longitudinal Young's modulus, width direction strength, and width direction elongation that are optimized from the viewpoint of film slitting properties and element winding properties during manufacturing. The polyolefin microporous film of the present invention has high strength in the longitudinal direction, so it is difficult to break when winding an element. Furthermore, since the Young's modulus in the longitudinal direction is large, elongation is less likely to occur during slitting. Also,
Its low strength in the width direction makes it easy to slit, and its high elongation in the width direction makes it difficult to crack during slitting.

これらの結果、作業性が良好となるばかりか電解コンデ
ンサやリチウム電池等としての長期信頼性が向上した。As a result, not only workability was improved, but also long-term reliability as an electrolytic capacitor, lithium battery, etc. was improved.

さらに、フィルムの厚みを１０μｍから５０μｍとする
と、素子のコンパクト性、電解液保持性及び内部抵抗特
性が良好にバランスされる。Furthermore, when the thickness of the film is 10 μm to 50 μm, the compactness, electrolyte retention, and internal resistance characteristics of the device are well balanced.

［特性の測定方法及び効果の評価方法１次にこの発明に
関する特性の測定方法及び効果の評価方法をまとめて示
す。[Method for Measuring Characteristics and Method for Evaluating Effects 1] Next, methods for measuring characteristics and evaluating effects relating to the present invention will be summarized.

（１）　　極限粘度（［η］） ＡＳＴＭ　　Ｄ　　１６０１に準拠し、試料０．１ｑを
１３５℃のテトラリン１００Ｗｄｌに完全溶解させ、こ
の溶液を粘度計で１３５℃の恒温槽中で、測定した比粘
度Ｓより次式に従って極限粘度を求めた。(1) Intrinsic viscosity ([η]) Based on ASTM D 1601, 0.1q of sample was completely dissolved in 100 Wdl of tetralin at 135°C, and the specific viscosity was measured using a viscometer in a constant temperature bath at 135°C. The intrinsic viscosity was determined from S according to the following formula.

［η］−８／（０，ＩＸ　（１＋０．２２ｘＳ））（２
）　　アイソタクチックインデックス（Ｉ　Ｉ）試料を
１３０℃で２時間真空乾燥する。これから重量Ｗ　（Ｊ
ｌｙ）の試料をとり、ソックスレー抽出器に入れ、沸ｌ
１ｎ−へブタンで１２時間抽出する。[η]-8/(0,IX (1+0.22xS))(2
) Vacuum dry the Isotactic Index (II) sample at 130° C. for 2 hours. From now on, the weight W (J
Take a sample of ly), put it in a Soxhlet extractor, and boil it.
Extract with 1n-hebutane for 12 hours.

次に、この試料を取り出し、アセトンで十分洗浄した模
、１３０℃で６時間真空乾燥し、その後重量Ｗ’　　（
＃）を測定し、次式で求める。Next, this sample was taken out, washed thoroughly with acetone, vacuum dried at 130°C for 6 hours, and then weighed W' (
#) is measured and calculated using the following formula.

ＩＩ（％）＝　（Ｗ’　／Ｗ）ｘｌｏｏ（３）　　ポリ
オレフィンの融点溶融結晶化温度及びガラス転移点 走査型熱量計ＤＳＣ−２型（パーキン・エルマ−社製）
を用い、試料５Ｉｒｔｇを窒素気流下で、昇温速度２０
℃／分にて室温より測定し、融解に伴う吸熱ピーク温度
を融点とする。II (%) = (W' /W)
sample 5Irtg under a nitrogen stream at a heating rate of 20
It is measured from room temperature at ℃/min, and the endothermic peak temperature associated with melting is defined as the melting point.

さらに、２８０℃まで昇温し、５分間その温度で保持し
た後に降下速度２０℃／分で冷却していく際に、ポリオ
レフィンの結晶化に伴う潜熱のピーク温度を溶融結晶化
温度とする。Furthermore, when the temperature is raised to 280° C., maintained at that temperature for 5 minutes, and then cooled at a rate of decrease of 20° C./min, the peak temperature of latent heat accompanying crystallization of the polyolefin is defined as the melt crystallization temperature.

同様に、液体窒素温度より昇温し、ポリオレフィンのガ
ラス転移（２次転移）に伴う比熱変化を読取りこれをガ
ラス転移温度とする。Similarly, the temperature is raised above the liquid nitrogen temperature, and the change in specific heat accompanying the glass transition (secondary transition) of the polyolefin is read and taken as the glass transition temperature.

（４）　　機械特性 サンプル長手方向（ＭＤ）及び幅方向（ＴＤ）について
、判断強度、引っ張り弾性率、伸度をＪＩＳに６７８２
に従い測定する。(4) Mechanical properties Judgment strength, tensile modulus, and elongation of sample longitudinal direction (MD) and transverse direction (TD) were determined according to JIS 6782.
Measure according to the following.

（５）　　平均空孔径 サンプル表面の走査型電子顕微鏡（ＳＥＭ）観察により
孔径の長袖及び短軸を測定し、平均長軸及び平均短軸の
相乗平均を平均孔径とする。(5) Average pore diameter The long axis and short axis of the pore diameter are measured by scanning electron microscopy (SEM) observation of the sample surface, and the geometric mean of the average long axis and the average short axis is defined as the average pore diameter.

（６）　　空孔率（Ｐｒ） 試料（１０ｃｍｘ　１０ｃｍ）を流動パラフィンに２４
時間浸漬し、表層の流動パラフィンを十分に拭き取った
俊の重ｆｆｉ　（Ｗ２　）を測定し、該試料の浸漬前の
重量（Ｗｌ）及び流動パラフィンの密度（ρ）より空孔
体積（Ｖｏ　）を次式により求める。(6) Porosity (Pr) A sample (10cm x 10cm) was soaked in liquid paraffin for 24 hours.
After immersing the sample for a period of time and thoroughly wiping off the surface liquid paraffin, the weight ffi (W2) of the sample was measured, and the pore volume (Vo) was calculated from the weight (Wl) of the sample before immersion and the density (ρ) of the liquid paraffin. It is calculated using the following formula.

Ｖｏ　＝　（Ｗ２−Ｗｌ）／ρ 空孔率（Ｐｒ）は、見掛は体積（厚み、寸法より計算さ
れる値）■と空孔体積Ｖｏより次の式により計算される
。Vo = (W2-Wl)/ρ The porosity (Pr) is calculated by the following formula from the apparent volume (value calculated from thickness and dimensions) and the pore volume Vo.

Ｐｒ＝Ｖｏ　／Ｖｘ１００　（％） （７）　　等価直列抵抗（ＥＳＲ） 特開昭６１−１８７２２１号に記載された方法に基づき
、γブチロラクトンにトリエチルアミンと７タル酸を溶
解し、３．１ｍＳ／ｃｍの電解液を用意した。この電解
液中での微孔性フィルムの１　ＫＨｚでの直流抵抗成分
をＥＳＲ（Ω）とした。Pr=Vo /Vx100 (%) (7) Equivalent series resistance (ESR) Based on the method described in JP-A-61-187221, triethylamine and 7-talic acid were dissolved in γ-butyrolactone, and a resistance of 3.1 mS/cm was obtained. An electrolyte solution was prepared. The direct current resistance component of the microporous film in this electrolytic solution at 1 KHz was defined as ESR (Ω).

ここで、比較サンプルとして、電解コンデンサ紙（マニ
ラ紙）ＩＥＲ２，５５０）の値（２，０Ω）を基準とし
、１．７Ω以下を○、１．８〜２．２Ωを△、２．３Ω
以上をＸとした。Here, as a comparison sample, based on the value (2.0Ω) of electrolytic capacitor paper (Manila paper) (IER2,550), 1.7Ω or less is ○, 1.8 to 2.2Ω is △, 2.3Ω
The above was defined as X.

なお、測定条件は次の通りであった。Note that the measurement conditions were as follows.

（ａ）電極：白金電極（２５ｍｍ角） 測定荷重　２４０ｇ （ｂ）インピーダンス測定機： ＡＧ−４３１１ＬＣＲＭＥＴＥＲ（安藤電気■製）測定
条件：１ｋＨ１５ｖレンジ （８）　　電解コンデンサテスト Ａ、スリット性 電解コンデンサ紙用小幅スリッタにて、サンプル１００
ｍを幅１０ｍｍにスリットするテストを行ない、以下の
ようにランク分けした。(a) Electrode: Platinum electrode (25mm square) Measuring load: 240g (b) Impedance measuring device: AG-4311LCRMETER (manufactured by Ando Electric) Measuring conditions: 1kHz, 15v range (8) Electrolytic capacitor test A, small width for slit electrolytic capacitor paper 100 samples with slitter
A test was conducted by slitting m into a width of 10 mm, and the results were ranked as follows.

（ａ）スリット性の良好なもの　　　　：○（ｂ）スリ
ットはできたもののエツジの乱れ等があったもの　　　
　　　　　：△ （Ｃ）サンプルの伸び等によりスリットできなかったも
の　　　　　　　　　　：Ｘ ８、素子巻性、寿命テスト ２２０　ｕ　Ｆ　−６、３ＷＶ（７）ｉｉｊｊ’ｉ’ｌ
　ン７　ンサｍ子を３０個作製し、素子巻性、寿命テス
トを行なった。製造直接の不良個数及び８５℃、５００
時間経過後の不良個数を評価した。(a) Items with good slitting properties: ○ (b) Items with slits but irregular edges, etc.
:△ (C) Samples that could not be slit due to elongation of the sample, etc.: X 8, element winding property, life test 220 u F -6, 3WV (7) iijj'i'l
7. Thirty pieces of M-shaped coils were manufactured, and element windability and life tests were conducted. Number of defective pieces directly from manufacturing and 85℃, 500
The number of defective pieces after time elapsed was evaluated.

［実施例］ 実施例１ ポリオレフィン樹脂としてポリプロピレンパウダー（三
井東圧化学■製、ＥＢタイプ［η］＝２゜８ｄｌ／（Ｊ
、ＩＩ＝９７．５％＞１００重量部とジシクロへキシル
フタレート（ＤＣＨＰ、大阪有機化学工業■製）１５６
重量部とを二軸押出機を用いて溶融ブレンドし、ペレッ
ト化した。次に、これを４Ωｍｍ押出機を用いてＴダイ
より溶融押出しし、水槽に導き冷却固化した。[Example] Example 1 Polypropylene powder (manufactured by Mitsui Toatsu Chemical Co., Ltd., EB type [η] = 2° 8 dl/(J
, II=97.5%>100 parts by weight and dicyclohexyl phthalate (DCHP, manufactured by Osaka Organic Chemical Industry ■) 156
parts by weight were melt-blended using a twin-screw extruder and pelletized. Next, this was melt-extruded from a T-die using a 4Ωmm extruder, introduced into a water tank, and cooled and solidified.

次に、このキャストフィルムを１−１−１−トリクロル
エタン抽出槽に導いて抽出を行ない、引き続き、ロール
延伸装置を用いて１３０℃にて４倍に延伸し、引き続き
、長手方向に５％のリラックスを許しながら１５０℃に
て熱固定を行なった。Next, this cast film is introduced into a 1-1-1-trichloroethane extraction tank for extraction, and then stretched 4 times at 130°C using a roll stretching device. Heat fixation was performed at 150°C while allowing relaxation.

このようにして得られたフィルムは厚みが３３μｍ１溶
融結晶化温度が１１７℃でありこの特性を表に示す。表
から明らかなように、このフィルムは長手方向と幅方向
の機械特性がバランスしており、スリット性が良好であ
り、素子巻性も良好であるので製造直後の不良もなく、
また、経時変化もなく、さらに内部抵抗特性も良好であ
った。The film thus obtained had a thickness of 33 μm and a melt crystallization temperature of 117° C., and its properties are shown in the table. As is clear from the table, this film has well-balanced mechanical properties in the longitudinal and width directions, good slitting properties, and good element winding properties, so there are no defects immediately after production.
Moreover, there was no change over time, and the internal resistance characteristics were also good.

比較例１ 実施例１において、抽出したフィルムを１３５℃にて長
手方向に３倍に延伸した後、引き続きステンタ式延伸装
置により１３８℃にて横方向に３倍延伸し、微孔性フィ
ルムを得た。Comparative Example 1 In Example 1, the extracted film was stretched 3 times in the longitudinal direction at 135°C, and then stretched 3 times in the transverse direction at 138°C using a stenter type stretching device to obtain a microporous film. Ta.

このようにして得られたフィルムの特性を表に示すが、
長手方向強度に比しての幅方向強度が大きいために、ス
リットはできたものの、エツジ部に乱れを生じ電解コン
デンサとした時に不良確立が高かった。また、寿命テス
トでも破壊個数が多く問題があることがわかる。The properties of the film thus obtained are shown in the table.
Since the strength in the width direction was greater than the strength in the longitudinal direction, although slits could be formed, the edges were disturbed and there was a high probability of failure when used as an electrolytic capacitor. Furthermore, it can be seen that there is a problem with the large number of broken pieces in the life test.

比較例２ 微粉ダイＭ１１５重量部、ジオクチルフタレート２７５
重量部をヘンシェルミキサーで混合し、これに重量平均
分子量８５０００　、数平均分子１２１０００のポリエ
チレン樹脂１００重量部を添加し、再度ヘンシェルミキ
サーで混合した。この混合物を直径３Ｑｍｓの二軸押出
機に４５０１１１１幅のＴダイを取付けたフィルム製造
装置にて膜状に成形した。Comparative Example 2 Fine powder die M115 parts by weight, dioctyl phthalate 275
Parts by weight were mixed using a Henschel mixer, 100 parts by weight of a polyethylene resin having a weight average molecular weight of 85,000 and a number average molecular weight of 121,000 were added thereto, and the mixture was mixed again using a Henschel mixer. This mixture was molded into a film using a film manufacturing device equipped with a twin-screw extruder having a diameter of 3 Qms and a T-die having a width of 4501111 mm.

成形された膜を１−ｉ−ｉ−トリクロロエタン中に５分
間浸漬し、ジオクチルフタレートを抽出した後乾燥した
。次いで、５０℃の４０％ＮａＯＨ中に３０分間浸漬し
、微粉ケイ酸を抽出した後乾燥し、厚さ１９０μｍのポ
リエチレンフィルムを得た。このフィルムを実施例１で
用いたロール式延伸機により、１１５℃にて長手方向に
３．５倍に延伸し、１１５℃にて５％のリラックスを許
して熱固定し巻きとった。The formed membrane was immersed in 1-i-i-trichloroethane for 5 minutes to extract dioctyl phthalate and then dried. Next, it was immersed in 40% NaOH at 50° C. for 30 minutes to extract fine powder silicic acid, and then dried to obtain a polyethylene film with a thickness of 190 μm. This film was stretched 3.5 times in the longitudinal direction at 115° C. using the roll-type stretching machine used in Example 1, heat-set at 115° C. with 5% relaxation, and then wound.

このようにして得られた微孔性膜の特性及び評価結果を
表にまとめて示すが、スリッ、ト時の延びが大きく安定
したスリットができず、コンデンサでの試験は中止した
。The characteristics and evaluation results of the microporous membrane thus obtained are summarized in a table. However, the elongation during slitting was large and stable slits could not be made, so tests on capacitors were discontinued.

Claims (3)

【特許請求の範囲】[Claims] （１）０．０５μｍから５μｍの平均空孔径と５０％か
ら８５％の空孔率を有し、長手方向強度が４ｋｇ／ｍｍ
＾２以上であり、長手方向ヤング率が２０ｋｇ／ｍｍ＾
２以上であり、幅方向強度が３ｋｇ／ｍｍ＾２以下であ
り、幅方向伸度が１００％以上であるポリオレフィン系
微孔性フィルム。(1) It has an average pore diameter of 0.05 μm to 5 μm, a porosity of 50% to 85%, and a longitudinal strength of 4 kg/mm.
^2 or more, and the longitudinal Young's modulus is 20 kg/mm^
2 or more, a width direction strength of 3 kg/mm^2 or less, and a width direction elongation of 100% or more. （２）厚みが１０μｍから５０μｍである特許請求の範
囲第１項記載のポリオレフィン系微孔性フィルム。(2) The polyolefin microporous film according to claim 1, having a thickness of 10 μm to 50 μm. （３）ポリオレフィンが溶融結晶化温度が１０６℃以上
であるポリプロピレンである特許請求の範囲第１項記載
のポリオレフィン系微孔性フィルム。(3) The polyolefin microporous film according to claim 1, wherein the polyolefin is polypropylene having a melt crystallization temperature of 106° C. or higher.
JP62326438A 1987-07-04 1987-12-23 Polyolefin microporous film Expired - Lifetime JP2674625B2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP62-167455 1987-07-04
JP16745587 1987-07-04

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JPH01167343A true JPH01167343A (en) 1989-07-03
JP2674625B2 JP2674625B2 (en) 1997-11-12

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001229971A (en) * 2000-02-14 2001-08-24 At Battery:Kk Nonaqueous electrolyte secondary battery
KR100760303B1 (en) * 2005-10-28 2007-09-19 더블유에이블(주) Fine porous polyolefin separator having property of 3 dimensional elongation and its manufacturing method
WO2013035381A1 (en) * 2011-09-07 2013-03-14 Jnc株式会社 Separator for lithium-ion battery

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57162214A (en) * 1981-03-30 1982-10-06 Sanyo Kokusaku Pulp Co Method of producing coating paper for wire
JPS60219080A (en) * 1984-04-16 1985-11-01 Mitsui Toatsu Chem Inc Production of film for typing ribbon
JPS60242035A (en) * 1984-04-27 1985-12-02 Toa Nenryo Kogyo Kk Microporous polyethylene film and production thereof
JPS60255107A (en) * 1984-05-31 1985-12-16 Mitsubishi Chem Ind Ltd Porous permeable polyethylene film

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57162214A (en) * 1981-03-30 1982-10-06 Sanyo Kokusaku Pulp Co Method of producing coating paper for wire
JPS60219080A (en) * 1984-04-16 1985-11-01 Mitsui Toatsu Chem Inc Production of film for typing ribbon
JPS60242035A (en) * 1984-04-27 1985-12-02 Toa Nenryo Kogyo Kk Microporous polyethylene film and production thereof
JPS60255107A (en) * 1984-05-31 1985-12-16 Mitsubishi Chem Ind Ltd Porous permeable polyethylene film

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001229971A (en) * 2000-02-14 2001-08-24 At Battery:Kk Nonaqueous electrolyte secondary battery
KR100760303B1 (en) * 2005-10-28 2007-09-19 더블유에이블(주) Fine porous polyolefin separator having property of 3 dimensional elongation and its manufacturing method
WO2013035381A1 (en) * 2011-09-07 2013-03-14 Jnc株式会社 Separator for lithium-ion battery

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