JPH0594812A - Polyolefine microporous membrane and its manufacture, and separator using such membrane - Google Patents
Polyolefine microporous membrane and its manufacture, and separator using such membraneInfo
- Publication number
- JPH0594812A JPH0594812A JP3283499A JP28349991A JPH0594812A JP H0594812 A JPH0594812 A JP H0594812A JP 3283499 A JP3283499 A JP 3283499A JP 28349991 A JP28349991 A JP 28349991A JP H0594812 A JPH0594812 A JP H0594812A
- Authority
- JP
- Japan
- Prior art keywords
- molecular weight
- weight
- polyolefin
- average molecular
- solution
- 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.)
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Classifications
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- 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
Landscapes
- Cell Separators (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
- Treatments Of Macromolecular Shaped Articles (AREA)
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
- Shaping By String And By Release Of Stress In Plastics And The Like (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、超高分子量成分を含有
するポリオレフィンからなる微多孔膜、それを製造する
方法及びそれを用いた電池用セパレータに関し、特に
水、各種の有機溶媒等との親和性に優れたポリオレフィ
ン微多孔膜、それを製造する方法、及びそれを用いた電
池用セパレータに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microporous membrane composed of a polyolefin containing an ultrahigh molecular weight component, a method for producing the same and a battery separator using the same, and particularly to water, various organic solvents and the like. The present invention relates to a polyolefin microporous membrane having excellent affinity, a method for producing the same, and a battery separator using the same.
【０００２】[0002]
【従来の技術及び発明が解決しようとする課題】ポリオ
レフィン微多孔膜は、孔径分布が比較的シャープで、適
度な孔径を有し、しかもある程度の薄膜化が容易である
ので、電池用セパレータ、電解コンデンサ等への適用が
広く行われている。このような電池用セパレータ等は、
電解質溶液に対する濡れ性、保液性に優れているのが好
ましい。2. Description of the Related Art Microporous polyolefin membranes have a relatively sharp pore size distribution, have an appropriate pore size, and can be easily thinned to a certain extent. Widely applied to capacitors. Such battery separators, etc.
It is preferable that the wettability with respect to the electrolyte solution and the liquid retaining property are excellent.
【０００３】しかしながら、リチウム電池、電解コンデ
ンサ等の電解質溶液は、プロピレンカーボネート、ジメ
トキシエタン5-ブチロラクトン、スルフォラン等の高沸
点の溶媒が用いられることが多い。高沸点溶媒は一般に
表面張力が高く、このため通常のポリオレフィン微多孔
膜は、電解液に対する濡れ性が悪く、電池として組み上
げた際に電気抵抗値が大きくなるという問題がある。However, a high boiling point solvent such as propylene carbonate, dimethoxyethane 5-butyrolactone or sulfolane is often used as the electrolyte solution for lithium batteries, electrolytic capacitors and the like. A high boiling point solvent generally has a high surface tension, and therefore a normal polyolefin microporous membrane has a problem that the wettability with an electrolytic solution is poor and an electric resistance value becomes large when assembled into a battery.
【０００４】そこで、ポリオレフィン微多孔膜に親水化
処理、親溶媒処理等を施すことが行われている。このよ
うな処理としては、微多孔膜の細孔の内部表面の一部又
は全部をポリエチレングリコールで被覆する方法、プロ
ピレングリコールモノ脂肪酸エステル等の界面活性剤で
細孔内を被覆する方法、有機溶剤湿潤・水置換法、物理
的吸着法、親水性、親溶媒性等のモノマー等をグラフト
する化学的表面変性法等が挙げられる。Therefore, the polyolefin microporous membrane is subjected to hydrophilic treatment, hydrophilic treatment, and the like. As such treatment, a method of coating a part or all of the inner surface of the pores of the microporous membrane with polyethylene glycol, a method of coating the inside of the pores with a surfactant such as propylene glycol monofatty acid ester, an organic solvent Examples thereof include a wetting / water substitution method, a physical adsorption method, a chemical surface modification method of grafting a hydrophilic or solvophilic monomer and the like.
【０００５】一方、ポリオレフィン微多孔膜の製造方法
としては、例えば異種ポリマー等の微粉体からなる孔形
成剤をポリオレフィンに混合してミクロ分散させた後、
孔形成剤を抽出する混合抽出法、ポリオレフィン相を溶
媒でミクロ相分離することにより多孔構造とする相分離
法、異種固体がミクロ分散しているポリオレフィン成形
体に延伸などの歪を与えることにより、異種固体間を界
面破壊して多孔化する延伸法などが、従来から用いられ
ている。しかし、これらの方法では通常分子量が50万未
満程度のポリオレフィンが用いられるため、延伸による
薄膜化及び高強度化には限界があった。On the other hand, as a method for producing a microporous polyolefin membrane, for example, a pore-forming agent consisting of fine powder of a different polymer is mixed with polyolefin and microdispersed.
A mixed extraction method of extracting a pore-forming agent, a phase separation method of forming a porous structure by microphase-separating a polyolefin phase with a solvent, and imparting strain such as stretching to a polyolefin molded body in which a heterogeneous solid is microdispersed, A stretching method and the like in which interfaces between different kinds of solids are destroyed to make them porous are conventionally used. However, since polyolefins having a molecular weight of less than 500,000 are usually used in these methods, there is a limit to thinning and strengthening by stretching.
【０００６】また高強度及び高弾性のフィルムに成形し
得る超高分子量ポリオレフィンが開発され、これによる
高強度の微多孔膜の製造が種々提案された。しかしなが
ら、この方法では、高倍率の延伸ができないという欠点
があった。このように従来のポリオレフィン微多孔膜で
は、電池用セパレータとして十分な強度を有し、かつ薄
膜化されたものとするのが困難である。Further, an ultrahigh molecular weight polyolefin which can be formed into a film having high strength and high elasticity has been developed, and various methods for producing a microporous membrane having high strength have been proposed. However, this method has a drawback that it cannot be stretched at a high magnification. As described above, it is difficult for the conventional polyolefin microporous film to have sufficient strength as a battery separator and to be thinned.
【０００７】したがって、本発明の目的は、十分な強度
を有し、薄膜とすることができ、しかも水、各種有機溶
媒等の溶媒に対する親和性に優れたポリオレフィン微多
孔膜、及びそれを製造する方法を提供することである。Therefore, an object of the present invention is to provide a polyolefin microporous film which has sufficient strength and can be formed into a thin film, and which has an excellent affinity for water and various organic solvents and the like, and a microporous film thereof. It is to provide a method.
【０００８】また、本発明のもう一つの目的は、上記ポ
リオレフィン微多孔膜を用いた電池用セパレータを提供
することである。[0008] Another object of the present invention is to provide a battery separator using the above-mentioned polyolefin microporous membrane.
【０００９】[0009]
【課題を解決するための手段】上記目的に鑑み鋭意研究
の結果、本発明者らは、超高分子量成分を含有し、分子
量分布（重量平均分子量／数平均分子量）が所定の範囲
内にあるポリオレフィンの溶液をシート状に成形し、急
冷して得られるゲル状シートに所定の温度で少なくとも
１軸方向に延伸を施すことにより得られる微多孔膜は、
薄膜で十分な強度を有しており、それに界面活性剤によ
る処理を施したものは、水、各種有機溶媒に対する親和
性に優れており、電池用セパレータとして優れた性能を
発揮することを見出し、本発明に想到した。As a result of earnest research in view of the above object, the present inventors have found that the present invention contains an ultrahigh molecular weight component and has a molecular weight distribution (weight average molecular weight / number average molecular weight) within a predetermined range. A microporous membrane obtained by forming a solution of polyolefin into a sheet and then rapidly cooling the resulting gel-like sheet in at least a uniaxial direction at a predetermined temperature is:
It has a sufficient strength in a thin film, those treated with a surfactant, water, excellent affinity for various organic solvents, found to exhibit excellent performance as a battery separator, The present invention was conceived.
【００１０】すなわち、本発明のポリオレフィン微多孔
膜は、重量平均分子量７×105 以上の成分を１重量％以
上含有し、分子量分布（重量平均分子量／数平均分子
量）が10〜300 のポリオレフィンからなり、厚さが0.1
〜50μｍで、空孔率が35〜95％で、平均貫通孔径が0.00
1 〜0.2 μｍであり、15mm幅の破断強度が0.2 kg以上で
あるポリオレフィン微多孔膜において、細孔の内部表面
及び膜表面に界面活性剤による処理が施されていること
を特徴とする。That is, the polyolefin microporous membrane of the present invention contains 1% by weight or more of a component having a weight average molecular weight of 7 × 10 5 or more, and has a molecular weight distribution (weight average molecular weight / number average molecular weight) of 10 to 300. And the thickness is 0.1
~ 50μm, porosity 35 ~ 95%, average through hole diameter 0.00
A polyolefin microporous membrane having a breaking strength of 1 to 0.2 μm and a breaking strength of 15 mm width of 0.2 kg or more is characterized in that the inner surface of the pores and the membrane surface are treated with a surfactant.
【００１１】また、上記ポリオレフィン微多孔膜を製造
する本発明の方法は、重量平均分子量７×105 以上の成
分を１重量％以上含有し、分子量分布（重量平均分子量
／数平均分子量）が10〜300 のポリオレフィン10〜50重
量％と、溶媒50〜90重量％とからなる溶液を調製し、前
記溶液をダイより押出し、冷却してゲル状組成物を形成
し、前記ゲル状組成物を前記ポリオレフィンの融点＋10
℃以下の温度で延伸し、しかる後残存溶媒を除去するこ
とにより、基材となるポリオレフィン微多孔膜を製造
し、得られたポリオレフィン微多孔膜の細孔の内部表面
及び膜表面を界面活性剤溶液で被覆し、続いて溶液を乾
燥することを特徴とする。The method of the present invention for producing the above-mentioned polyolefin microporous membrane contains 1% by weight or more of a component having a weight average molecular weight of 7 × 10 5 or more and a molecular weight distribution (weight average molecular weight / number average molecular weight) of 10 ~ 300 polyolefins 10 to 50% by weight and a solvent 50 to 90% by weight to prepare a solution, the solution is extruded through a die, cooled to form a gel composition, the gel composition Melting point of polyolefin +10
By stretching at a temperature of ℃ or less, and then removing the residual solvent, to produce a polyolefin microporous membrane as a substrate, the inner surface of the pores of the obtained polyolefin microporous membrane and the membrane surface is a surfactant. It is characterized in that it is coated with the solution and subsequently the solution is dried.
【００１２】さらに、本発明の電池用セパレータは、重
量平均分子量７×105 以上の成分を１重量％以上含有
し、分子量分布（重量平均分子量／数平均分子量）が10
〜300のポリオレフィンからなり、厚さが0.1 〜50μｍ
で、空孔率が35〜95％で、平均貫通孔径が0.001 〜0.2
μｍであり、15mm幅の破断強度が0.2 kg以上であるポリ
オレフィン微多孔膜により形成され、その細孔の内部表
面及び膜表面に界面活性剤による処理が施されているこ
とを特徴とする。Further, the battery separator of the present invention contains 1% by weight or more of a component having a weight average molecular weight of 7 × 10 5 or more, and has a molecular weight distribution (weight average molecular weight / number average molecular weight) of 10%.
〜300 polyolefin, thickness 0.1〜50μm
With a porosity of 35-95% and an average through-hole diameter of 0.001-0.2.
It is characterized in that it is formed by a polyolefin microporous film having a breaking strength of 0.2 kg or more in a width of 15 mm and a width of 15 mm, and that the inner surface of the pores and the film surface are treated with a surfactant.
【００１３】本発明を以下詳細に説明する。まず、本発
明のポリオレフィン微多孔膜について説明する。本発明
のポリオレフィン微多孔膜は、重量平均分子量７×105
以上の超高分子量成分を１重量％以上含有し、分子量分
布（重量平均分子量／数平均分子量）が特定の範囲内に
あるポリオレフィンからなる。The present invention is described in detail below. First, the polyolefin microporous membrane of the present invention will be described. The polyolefin microporous membrane of the present invention has a weight average molecular weight of 7 × 10 5
It comprises a polyolefin containing 1% by weight or more of the above ultrahigh molecular weight component and having a molecular weight distribution (weight average molecular weight / number average molecular weight) within a specific range.
【００１４】上記ポリオレフィンの重量平均分子量／数
平均分子量は10〜300 、好ましくは12〜 250である。重
量平均分子量／数平均分子量が10未満では、平均分子鎖
長が大きく、溶解時の分子鎖同志の絡み合い密度が高く
なるため、高濃度溶液の調製が困難である。また300 を
超えると、延伸時に低分子量成分の破断が起こりやす
く、得られる膜の強度が低い。The above polyolefin has a weight average molecular weight / number average molecular weight of 10 to 300, preferably 12 to 250. When the weight average molecular weight / number average molecular weight is less than 10, the average molecular chain length is large and the entanglement density of the molecular chains becomes high during dissolution, so that it is difficult to prepare a high-concentration solution. On the other hand, when it exceeds 300, the low molecular weight component is likely to break during stretching, and the strength of the obtained film is low.
【００１５】なお、分子量分布の尺度として用いられる
重量平均分子量／数平均分子量の比は、大きいほど分子
量分布の幅が広いことを意味する。The larger the weight average molecular weight / number average molecular weight ratio used as a measure of the molecular weight distribution, the wider the molecular weight distribution.
【００１６】本発明においては、ポリオレフィンの重量
平均分子量／数平均分子量を10〜300 と、通常の超高分
子量ポリオレフィン自身の重量平均分子量／数平均分子
量（通常６程度）よりも大きく設定している。この結
果、分子量分布は低分子量側へと広がりをみせるため、
高濃度のポリオレフィン溶液の調製が可能となる。In the present invention, the weight average molecular weight / number average molecular weight of the polyolefin is set to 10 to 300, which is larger than the weight average molecular weight / number average molecular weight of ordinary ultrahigh molecular weight polyolefin itself (usually about 6). .. As a result, the molecular weight distribution spreads toward the lower molecular weight side,
It is possible to prepare a high-concentration polyolefin solution.
【００１７】また上記ポリオレフィン中に重量平均分子
量７×105以上の成分が１重量％未満では、延伸性の向
上に寄与する超高分子量ポリオレフィンの分子鎖の絡み
合いがほとんど形成されず、高強度の微多孔膜を得るこ
とができない。一方、超高分子量成分の含有率の上限は
特に限定的ではないが、90重量％を超えると目的とする
ポリオレフィン溶液の高濃度化が困難となるため好まし
くない。When the content of the component having a weight average molecular weight of 7 × 10 5 or more in the above polyolefin is less than 1% by weight, the entanglement of the molecular chains of the ultrahigh molecular weight polyolefin, which contributes to the improvement of the stretchability, is hardly formed, resulting in high strength. A microporous membrane cannot be obtained. On the other hand, the upper limit of the content of the ultrahigh molecular weight component is not particularly limited, but if it exceeds 90% by weight, it becomes difficult to increase the concentration of the intended polyolefin solution, which is not preferable.
【００１８】このポリオレフィンは、上記分子量及び分
子量分布を有していれば、単独のポリオレフィンか、２
種以上のポリオレフィンからなる組成物のどちらでもよ
い。This polyolefin may be either a single polyolefin or 2 if it has the above-mentioned molecular weight and molecular weight distribution.
It may be either a composition of one or more polyolefins.
【００１９】単独のポリオレフィンの場合、例えば重量
平均分子量７×105 以上の超高分子量成分を１重量％以
上含有し、分子量分布（重量平均分子量／数平均分子
量）が10〜300 となるように多段重合することにより製
造することができる。多段重合としては、二段重合によ
り超高分子量部分と低分子量部分を製造するのが好まし
い。In the case of a single polyolefin, for example, it contains 1% by weight or more of an ultrahigh molecular weight component having a weight average molecular weight of 7 × 10 5 or more, and has a molecular weight distribution (weight average molecular weight / number average molecular weight) of 10 to 300. It can be produced by multistage polymerization. As the multistage polymerization, it is preferable to produce the ultrahigh molecular weight portion and the low molecular weight portion by two-stage polymerization.
【００２０】またポリオレフィン組成物（混合物）の場
合、重量平均分子量が７×105 以上の超高分子量ポリオ
レフィンと、重量平均分子量が７×105 未満のポリオレ
フィンとを重量平均分子量／数平均分子量が上記範囲と
なるように適量混合することによって得ることができ
る。Further, in the case of a polyolefin composition (mixture), an ultrahigh molecular weight polyolefin having a weight average molecular weight of 7 × 10 5 or more and a polyolefin having a weight average molecular weight of less than 7 × 10 5 have a weight average molecular weight / number average molecular weight of It can be obtained by mixing an appropriate amount within the above range.
【００２１】組成物の場合、超高分子量ポリオレフィン
は、重量平均分子量が７×105 以上、好ましくは１×10
6 〜15×106 のものである。重量平均分子量が７×105
未満では、最大延伸倍率が低く、目的の微多孔膜が得ら
れない。一方、上限は特に限定的ではないが15×106 を
超えるものは、ゲル状成形物の形成において、成形性に
劣る。In the case of the composition, the ultrahigh molecular weight polyolefin has a weight average molecular weight of 7 × 10 5 or more, preferably 1 × 10 5.
6 to 15 × 10 6 . Weight average molecular weight is 7 × 10 5
If it is less than the above, the maximum draw ratio is low, and the desired microporous membrane cannot be obtained. On the other hand, the upper limit is not particularly limited, but if it exceeds 15 × 10 6 , the moldability is poor in the formation of a gel-like molded product.
【００２２】このような超高分子量ポリオレフィンとし
ては、エチレン、プロピレン、1-ブテン、4-メチル-1-
ペンテン、1-ヘキセンなどを重合した結晶性の単独重合
体、２段重合体、又は共重合体及びこれらのブレンド物
等が挙げられる。これらのうち超高分子量ポリエチレ
ン、特に高密度の超高分子量ポリエチレンが好ましい。Such ultra high molecular weight polyolefins include ethylene, propylene, 1-butene, 4-methyl-1-
Examples thereof include crystalline homopolymers obtained by polymerizing pentene, 1-hexene and the like, two-stage polymers, copolymers and blends thereof. Of these, ultra high molecular weight polyethylene, particularly high density ultra high molecular weight polyethylene is preferred.
【００２３】また上記超高分子量ポリオレフィンのポリ
オレフィン組成物中の含有量は、ポリオレフィン組成物
全体を100 重量％として、１重量％以上である。超高分
子量ポリオレフィンの含有量が１重量％未満では、延伸
性の向上に寄与する超高分子量ポリオレフィンの分子鎖
の絡み合いがほとんど形成されず、高強度の微多孔膜を
得ることができない。一方、上限は特に限定的ではない
が、90重量％を超えると目的とするポリオレフィン溶液
の高濃度化が困難となるため好ましくない。The content of the ultrahigh molecular weight polyolefin in the polyolefin composition is 1% by weight or more, based on 100% by weight of the entire polyolefin composition. When the content of the ultra-high molecular weight polyolefin is less than 1% by weight, the entanglement of the molecular chains of the ultra-high molecular weight polyolefin that contributes to the improvement of the stretchability is hardly formed, and a high-strength microporous membrane cannot be obtained. On the other hand, the upper limit is not particularly limited, but if it exceeds 90% by weight, it becomes difficult to increase the concentration of the intended polyolefin solution, which is not preferable.
【００２４】またポリオレフィン組成物中の超高分子量
ポリオレフィン以外のポリオレフィンは、重量平均分子
量が７×105 未満のものであるが、重量平均分子量の下
限としては１×104 である。重量平均分子量が１×104
未満のポリオレフィンを用いると、延伸時に破断が起こ
りやすく、目的の微多孔膜が得られない。特に重量平均
分子量が１×105 以上７×105 未満のポリオレフィンを
超高分子量ポリオレフィンに配合するのが好ましい。The polyolefin other than the ultra-high molecular weight polyolefin in the polyolefin composition has a weight average molecular weight of less than 7 × 10 5 , but the lower limit of the weight average molecular weight is 1 × 10 4 . Weight average molecular weight is 1 × 10 4
If the amount of the polyolefin used is less than the range, breakage easily occurs during stretching, and the desired microporous membrane cannot be obtained. In particular, it is preferable to add a polyolefin having a weight average molecular weight of 1 × 10 5 or more and less than 7 × 10 5 to the ultrahigh molecular weight polyolefin.
【００２５】このようなポリオレフィンとしては、エチ
レン、プロピレン、1-ブテン、4-メチル-1- ペンテン、
1-ヘキセンなどを重合した結晶性の単独重合体、２段重
合体、又は共重合体、及びこれらのブレンド物等が挙げ
られる。特にエチレンを主体とする重合体である高密度
ポリエチレンが好ましい。Examples of such polyolefin include ethylene, propylene, 1-butene, 4-methyl-1-pentene,
Examples thereof include crystalline homopolymers obtained by polymerizing 1-hexene and the like, two-stage polymers, copolymers, and blends thereof. High density polyethylene, which is a polymer mainly composed of ethylene, is particularly preferable.
【００２６】なお、上述したようなポリオレフィンに
は、必要に応じて、酸化防止剤、紫外線吸収剤、滑剤、
アンチブロッキング剤、顔料、染料、無機充填剤などの
各種添加剤を、本発明の目的を損なわない範囲で添加す
ることができる。In addition, if necessary, the above-mentioned polyolefin may include an antioxidant, an ultraviolet absorber, a lubricant,
Various additives such as anti-blocking agents, pigments, dyes, and inorganic fillers can be added within a range that does not impair the object of the present invention.
【００２７】次に、本発明のポリオレフィン微多孔膜の
製造方法について説明する。Next, the method for producing the polyolefin microporous membrane of the present invention will be described.
【００２８】原料となるポリオレフィンの高濃度溶液
は、上述のポリオレフィンを溶媒に加熱溶解することに
より調製する。この溶媒としては、ポリオレフィンを十
分に溶解できるものであれば特に限定されない。例え
ば、ノナン、デカン、ウンデカン、ドデカン、パラフィ
ン油などの脂肪族または環式の炭化水素、あるいは沸点
がこれらに対応する鉱油留分などが挙げられるが、溶媒
含有量が安定なゲル状成形物を得るためには、パラフィ
ン油のような不揮発性の溶媒が好ましい。A high-concentration solution of the starting polyolefin is prepared by heating and dissolving the above-mentioned polyolefin in a solvent. The solvent is not particularly limited as long as it can sufficiently dissolve the polyolefin. For example, nonane, decane, undecane, dodecane, paraffin oil and other aliphatic or cyclic hydrocarbons, or a mineral oil fraction having a boiling point corresponding to these, etc. To obtain it, a non-volatile solvent such as paraffin oil is preferable.
【００２９】加熱溶解は、ポリオレフィンが溶媒中で完
全に溶解する温度で撹拌しながら行う。その温度は使用
する重合体及び溶媒により異なるが、例えばポリエチレ
ンの場合には140 〜250 ℃の範囲である。また、ポリオ
レフィン溶液の濃度は、10〜50重量％、好ましくは10〜
40重量％である。濃度が10重量％未満では、使用する溶
媒量が多く経済的でないばかりか、シート状に成形する
際に、ダイス出口で、スウェルやネックインが大きくシ
ートの成形が困難となる。一方、濃度が50重量％を超え
ると、均一な溶液の調製が困難となる。なお、加熱溶解
にあたってはポリオレフィンの酸化を防止するために酸
化防止剤を添加するのが好ましい。The heating dissolution is carried out with stirring at a temperature at which the polyolefin is completely dissolved in the solvent. The temperature varies depending on the polymer and solvent used, but in the case of polyethylene, for example, it is in the range of 140 to 250 ° C. The concentration of the polyolefin solution is 10 to 50% by weight, preferably 10 to
40% by weight. If the concentration is less than 10% by weight, not only is the amount of solvent used large and it is not economical, but also when forming into a sheet, the swell and neck-in are large at the die outlet, making it difficult to form the sheet. On the other hand, if the concentration exceeds 50% by weight, it becomes difficult to prepare a uniform solution. In addition, it is preferable to add an antioxidant in order to prevent the polyolefin from being oxidized during heating and melting.
【００３０】次にこのポリオレフィンの加熱溶液をダイ
スから押し出して成形する。ダイスは、通常長方形の口
金形状をしたシートダイスが用いられるが、２重円筒状
の中空系ダイス、インフレーションダイス等も用いるこ
とができる。シートダイスを用いた場合のダイスギャッ
プは通常0.1 〜５mmであり、押出し成形時には140 〜25
0 ℃に加熱される。この際押し出し速度は、通常20〜30
cm／分乃至２〜３ｍ／分である。Next, this heated solution of polyolefin is extruded from a die to be molded. As the die, a sheet die having a rectangular die shape is usually used, but a double cylindrical hollow die, an inflation die or the like can also be used. When using sheet dies, the die gap is usually 0.1 to 5 mm, and it is 140 to 25 mm during extrusion molding.
Heat to 0 ° C. At this time, the extrusion speed is usually 20 to 30.
cm / min to 2-3 m / min.
【００３１】このようにしてダイスから押し出された溶
液は、冷却することによりゲル状物に成形される。冷却
は少なくともゲル化温度以下までは50℃/ 分以上の速度
で行うのが好ましい。冷却速度が遅いと結晶化度が上昇
し、延伸に適したゲル状物となりにくい。冷却方法とし
ては、冷風、冷却水、その他の冷却媒体に直接接触させ
る方法、冷媒で冷却したロールに接触させる方法等を用
いることができる。なおダイスから押し出された溶液
は、冷却前あるいは冷却中に、１〜10、好ましくは１〜
５の引取比で引き取るのが好ましい。引取比が10以上に
なるとネックインが大きくなり、また延伸時に破断を起
こしやすくなり好ましくない。The solution thus extruded from the die is cooled to be formed into a gel. Cooling is preferably performed at a rate of 50 ° C./min or more at least up to the gelation temperature. When the cooling rate is slow, the degree of crystallinity increases, and it is difficult to form a gel-like material suitable for stretching. As a cooling method, a method of directly contacting with cold air, cooling water, or other cooling medium, a method of contacting with a roll cooled with a refrigerant, or the like can be used. The solution extruded from the die is 1 to 10, preferably 1 to 10 before or during cooling.
It is preferable to collect at a collection ratio of 5. When the take-up ratio is 10 or more, neck-in becomes large, and breakage easily occurs during stretching, which is not preferable.
【００３２】次にこのゲル状成形物を延伸する。延伸
は、ゲル状成形物を加熱し、通常のテンター法、ロール
法、インフレーション法、圧延法もしくはこれらの方法
の組合せによって所定の倍率で行う。２軸延伸が好まし
く、縦横同時延伸または逐次延伸のいずれでもよいが、
特に同時２軸延伸が好ましい。Next, this gel-like molded product is stretched. The stretching is carried out by heating the gel-like molded product and using a normal tenter method, roll method, inflation method, rolling method or a combination of these methods at a predetermined magnification. Biaxial stretching is preferable, and either longitudinal / transverse simultaneous stretching or sequential stretching may be used.
Simultaneous biaxial stretching is particularly preferable.
【００３３】延伸温度は、使用するポリオレフィンの融
点＋10℃以下、好ましくは結晶分散温度から結晶融点未
満の範囲である。例えば、多段重合ポリエチレンの場合
は90〜140 ℃で、より好ましくは100 〜130 ℃の範囲で
ある。延伸温度が融点＋10℃を超える場合は、樹脂の溶
融により分子鎖の配向ができない。また、延伸温度が結
晶分散温度未満では、樹脂の軟化が不十分で、延伸中破
断し易く、高倍率の延伸ができない。The stretching temperature is not more than the melting point of the polyolefin to be used + 10 ° C., preferably in the range from the crystal dispersion temperature to less than the crystal melting point. For example, in the case of multi-stage polymerized polyethylene, the temperature is 90 to 140 ° C, more preferably 100 to 130 ° C. If the stretching temperature exceeds the melting point + 10 ° C, the molecular chains cannot be oriented due to the melting of the resin. Further, if the stretching temperature is lower than the crystal dispersion temperature, the softening of the resin is insufficient, the resin is easily broken during stretching, and high-stretching cannot be performed.
【００３４】また、延伸倍率は原反の厚さによって異な
るが、１軸方向で少なくとも２倍以上、好ましくは３〜
30倍であり、面倍率で10倍以上、好ましくは15〜400 倍
である。面倍率が10倍未満では延伸が不十分で高弾性、
高強度の微多孔膜が得られない。一方、面倍率が400倍
を超えると、延伸装置、延伸操作などの点で制約が生じ
る。The stretching ratio varies depending on the thickness of the raw fabric, but at least 2 times or more, preferably 3 to 1 in the uniaxial direction.
It is 30 times, and the surface magnification is 10 times or more, preferably 15 to 400 times. If the surface magnification is less than 10 times, stretching is insufficient and high elasticity,
A high-strength microporous membrane cannot be obtained. On the other hand, when the surface magnification exceeds 400 times, there are restrictions on the stretching device, stretching operation, and the like.
【００３５】得られた延伸成形物は、溶剤で洗浄するこ
とにより残留する溶媒を除去する。洗浄溶剤としては、
ペンタン、ヘキサン、ヘプタンなどの炭化水素、塩化メ
チレン、四塩化炭素などの塩素化炭化水素、三フッ化エ
タンなどのフッ化炭化水素、ジエチルエーテル、ジオキ
サンなどのエーテル類などの易揮発性のものを用いるこ
とができる。これらの溶剤は、ポリオレフィンの溶解に
用いた溶媒に応じて適宜選択し、単独でもしくは混合し
て用いる。溶媒除去方法としては、洗浄溶剤に浸漬して
抽出する方法、洗浄溶剤をシャワーする方法、またはこ
れらの組合せなどがある。The stretched molded product thus obtained is washed with a solvent to remove the residual solvent. As a cleaning solvent,
Hydrocarbons such as pentane, hexane and heptane, chlorinated hydrocarbons such as methylene chloride and carbon tetrachloride, fluorinated hydrocarbons such as trifluoroethane, ethers such as diethyl ether and dioxane, and other easily volatile substances. Can be used. These solvents are appropriately selected according to the solvent used for dissolving the polyolefin, and are used alone or as a mixture. Examples of the solvent removal method include a method of immersing in a cleaning solvent for extraction, a method of showering the cleaning solvent, and a combination thereof.
【００３６】上述のような洗浄は、延伸成形物中の残留
溶媒が１重量％未満になるまで行う。その後洗浄溶剤を
乾燥するが、洗浄溶剤の乾燥方法は加熱乾燥、風乾など
の方法で行うことができる。乾燥した延伸成形物は、結
晶分散温度〜融点の温度範囲で熱固定することが望まし
い。The above-mentioned washing is carried out until the residual solvent in the stretch-molded product is less than 1% by weight. After that, the washing solvent is dried, and the washing solvent can be dried by heating or air drying. It is desirable that the dried stretched molded product be heat-set in the temperature range of the crystal dispersion temperature to the melting point.
【００３７】このようにして得られたポリオレフィン微
多孔膜に対して、界面活性剤による処理を施す。上記界
面活性剤としては、例えば電池用セパレータとして使用
する場合には、イオンの移動を妨げず、粘性が低い方が
良いことから、ノニオン系界面活性剤を用いるのが好ま
しい。ノニオン系界面活性剤としては、ポリオキシエチ
レンアルキルエーテル類、ポリオキシエチレンアルキル
フェニルエーテル類、ポリオキシエチレンアルキルアリ
ルエーテル類、脂肪酸モノグリセリド、ソルビタン脂肪
酸エステル等が挙げられる。これらのうちでは、特にポ
リオキシエチレンアルキルエーテル類が好ましい。The polyolefin microporous membrane thus obtained is treated with a surfactant. As the above-mentioned surfactant, when used as, for example, a battery separator, it is preferable to use a nonionic surfactant because it does not hinder the movement of ions and has a low viscosity. Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl allyl ethers, fatty acid monoglycerides, sorbitan fatty acid esters, and the like. Of these, polyoxyethylene alkyl ethers are particularly preferable.
【００３８】上述したような界面活性剤による表面処理
（界面活性剤による被覆）は、細孔の内部表面及び膜表
面の両方に対して行う。表面処理方法としては、界面
活性剤溶液に微多孔膜を浸漬した後、乾燥させる方法、
界面活性剤溶液を微多孔膜に噴霧した後、乾燥させる
方法、界面活性剤の溶液をコーティングする方法等が
挙げられる。The surface treatment with a surfactant (coating with a surfactant) as described above is performed on both the inner surface of the pores and the membrane surface. As the surface treatment method, a method of immersing the microporous film in a surfactant solution and then drying it,
Examples include a method of spraying a surfactant solution on a microporous membrane and then drying, a method of coating a solution of a surfactant, and the like.
【００３９】界面活性剤の溶液は、溶液全体を100 重量
％として0.1 〜10重量％の濃度とするのが好ましい。界
面活性剤の濃度が0.1 重量％未満では、微多孔膜を十分
に親水化、親溶媒化するのが困難であり、また10重量％
を超えると、細孔への界面活性剤の導入量が過剰となり
好ましくない。なお、上記界面活性剤溶液の溶媒として
は、界面活性剤を溶解しうるものであれば特に制限はな
いが、揮発性を有するものが好ましく、メタノール、エ
タノール、イソプロパノール等のアルコール類、脱イオ
ン水、あるいは適当な濃度に調整したアルコール水溶液
等が好ましい。The solution of the surfactant preferably has a concentration of 0.1 to 10% by weight based on 100% by weight of the entire solution. If the concentration of the surfactant is less than 0.1% by weight, it is difficult to make the microporous membrane sufficiently hydrophilic and hydrophilic, and 10% by weight.
If it exceeds, the amount of the surfactant introduced into the pores becomes excessive, which is not preferable. The solvent of the surfactant solution is not particularly limited as long as it can dissolve the surfactant, but a solvent having volatility is preferable, and alcohols such as methanol, ethanol and isopropanol, deionized water. Alternatively, an aqueous alcohol solution adjusted to an appropriate concentration or the like is preferable.
【００４０】また、乾燥はテンター式熱風乾燥機、ロー
ル式加熱乾燥機、風乾法等により、使用するポリオレフ
ィンの融点以下で溶媒の沸点以上の温度で行うのが好ま
しい。Further, the drying is preferably carried out by a tenter hot air dryer, a roll heating dryer, an air drying method or the like at a temperature not higher than the melting point of the polyolefin used and not lower than the boiling point of the solvent.
【００４１】なお、界面活性剤溶液を乾燥する際に、少
なくとも１軸方向延伸し、その後若干のリラックスをか
けながら熱セットを行ってもよい。このように、乾燥時
に延伸し、熱セットを行えば、孔径及び孔径分布を調節
することができるため、透気性能、透水性能、空孔率等
を適宜制御することができる。When the surfactant solution is dried, it may be stretched at least uniaxially, and then heat set with some relaxation. In this way, the pore size and the pore size distribution can be adjusted by stretching and heat setting during drying, so that the air permeation performance, the water permeation performance, the porosity, etc. can be appropriately controlled.
【００４２】この場合の延伸は、使用するポリオレフィ
ンの結晶分散温度以下で室温以上の温度で行うのが好ま
しい。延伸温度が結晶分散温度を超えると、局部延伸を
起こし、膜厚が不均一になりやすい。また室温以下で
は、延伸効率が著しく低下するため好ましくない。また
延伸倍率については、面倍率で1.1 〜５倍程度が好まし
い。延伸倍率が５倍を超えると、延伸に伴い微細なクラ
ックが生じ、得られる微多孔膜の膜強度が低下するため
好ましくない。The stretching in this case is preferably carried out at a temperature below the crystal dispersion temperature of the polyolefin used and above room temperature. If the stretching temperature exceeds the crystal dispersion temperature, local stretching occurs, and the film thickness tends to be non-uniform. Further, at room temperature or lower, the stretching efficiency is significantly reduced, which is not preferable. The stretching ratio is preferably about 1.1 to 5 times in terms of surface magnification. When the stretching ratio exceeds 5 times, fine cracks are generated during stretching, and the film strength of the obtained microporous film is reduced, which is not preferable.
【００４３】また熱セット温度は、使用するポリオレフ
ィンの結晶分散温度〜融点＋10℃とするのが好ましい。
熱セット温度が結晶分散温度未満では、熱セットによる
効果が発現せず、また融点＋10℃を超えると、膜の溶融
により細孔が閉塞してしまうため好ましくない。熱セッ
トの時間は、延伸倍率により、適宜設計すればよいが、
30秒以上行うのが好ましい。熱セットの時間が、30秒未
満では微多孔膜に十分な熱量を付与することができず、
熱収縮を生じやすいため好ましくない。さらにリラック
スの程度は、約30％以下であればよい。30％を超える
と、収縮が過剰となり、透気性能が著しく低下するた
め、好ましくない。The heat setting temperature is preferably from the crystal dispersion temperature of the polyolefin used to the melting point + 10 ° C.
If the heat-setting temperature is lower than the crystal dispersion temperature, the effect of heat-setting is not exhibited, and if it is higher than the melting point + 10 ° C, the pores are clogged due to the melting of the film, which is not preferable. The heat setting time may be appropriately designed according to the draw ratio,
It is preferable to carry out for 30 seconds or more. When the heat setting time is less than 30 seconds, a sufficient amount of heat cannot be applied to the microporous membrane,
It is not preferable because heat shrinkage is likely to occur. Furthermore, the degree of relaxation may be about 30% or less. If it exceeds 30%, the shrinkage becomes excessive and the air permeation performance remarkably decreases, which is not preferable.
【００４４】以上のようにして製造したポリオレフィン
微多孔膜は、空孔率が35〜95％で、平均貫通孔径が0.00
1 〜0.2 μｍで、かつ15mm幅の破断強度が0.2 kg以上で
ある。さらに界面活性剤による処理により、濡れ指数
(JIS 6768により測定) が55dyn/cm以上であり、未処理
のポリオレフィン微多孔膜のそれ(濡れ指数30dyn/cm程
度) と比較して大幅に向上したものとすることができ
る。またポリオレフィン微多孔膜の厚さは、適宜選択し
うるが、一般に0.1 〜50μｍであり、好ましくは２〜40
μｍにすることができる。The polyolefin microporous membrane produced as described above has a porosity of 35 to 95% and an average through-pore diameter of 0.005%.
It has a breaking strength of 1 to 0.2 μm and a width of 15 mm of 0.2 kg or more. Furthermore, by treatment with a surfactant, wetting index
(Measured by JIS 6768) is 55 dyn / cm or more, which can be greatly improved as compared with that of an untreated polyolefin microporous membrane (wetting index of about 30 dyn / cm). The thickness of the polyolefin microporous film may be appropriately selected, but is generally 0.1 to 50 μm, preferably 2 to 40 μm.
It can be μm.
【００４５】[0045]
【作用】本発明のポリオレフィン微多孔膜は、超高分子
量成分を含有し、分子量分布（重量平均分子量／数平均
分子量）が所定の範囲内にあるポリオレフィンの溶液を
シート状に成形し、急冷して得られるゲル状シートに所
定の温度で少なくとも１軸方向に延伸を施すことにより
微多孔膜を形成し、それに界面活性剤による処理を施し
てなるので、薄膜で十分な膜強度を有するとともに、
水、各種有機溶媒等に対する親和性に優れており、電池
用セパレータとして優れた性能を発揮する。The polyolefin microporous membrane of the present invention contains an ultrahigh molecular weight component, and a polyolefin solution having a molecular weight distribution (weight average molecular weight / number average molecular weight) within a predetermined range is formed into a sheet and rapidly cooled. The gel-like sheet thus obtained is stretched at least uniaxially at a predetermined temperature to form a microporous membrane, which is then treated with a surfactant, so that the thin membrane has sufficient membrane strength and
It has excellent affinity for water, various organic solvents, etc., and exhibits excellent performance as a battery separator.
【００４６】このような効果が得られる理由については
必ずしも明らかではないが、基材となる微多孔膜とし
て、強度的に極めて優れた薄膜を使用するとともに、こ
れに界面活性剤 (特にノニオン系界面活性剤) による処
理を施すことにより、膜強度が低下せず、水、各種有機
溶媒に対する親和性が向上するためであると考えられ
る。Although the reason why such an effect is obtained is not necessarily clear, a thin film having extremely excellent strength is used as a microporous film as a base material, and a surfactant (particularly a nonionic interface) is used. It is considered that the treatment with an activator does not reduce the film strength and improves the affinity for water and various organic solvents.
【００４７】[0047]
【実施例】以下に本発明の実施例を示す。なお、実施例
における試験方法は次の通りである。 (1) 分子量及び分子量分布：ウォーターズ（社）製のGP
C 装置を用い、カラムに東ソー（株）製GMH-6 、溶媒に
O-ジクロルベンゼンを使用し、温度135 ℃、流量1.0 ml
/ 分にて、ゲルパーミエーションクロマトグラフィー
（GPC)法により測定。 (2) 破断荷重：幅10mmの短冊状試験片の破断荷重をASTM
D882 に準拠して測定。 (3) フィルムの厚さ：断面を走査型電子顕微鏡により測
定。 (4) 透気度：JIS P8117 に準拠。 (5) 透水度：微多孔膜を平膜モジュールに組み込み、蒸
留水／エタノール混合液（容積比 50/50) により親水化
処理を行い、蒸留水で十分に洗浄した後、380mmHgの水
圧をかけたときの濾液の透過量を測定して求めた。 (6) 溶媒親和性評価： 濡れ指数：JIS 6768に準拠して測定。 水に対する濡れ性：サンプルを水平面上に置き、上か
ら蒸留水を滴下して、この際に、蒸留水がセンプルの反
対側の面（下面）に到達するまでの時間 (秒）を測定
し、以下の基準により評価した。 ◎：瞬時 (0.5 秒未満) △：0.5 〜２秒 ×：２秒を超えるもの γ−ブチロラクトンに対する濡れ性：蒸留水の代わり
にγ−ブチロラクトンを使用した以外は上記の評価試
験と同様の方法により、評価を行った。 (7) 平均孔径：上記(5) で記載したモジュールを用い
て、380 mmHgの差圧下で0.05重量％のプルラン（昭和電
工（株）製) の水溶液を循環させ、濾液中に含まれるプ
ルランの濃度を示差屈折率測定から求め、下記の式(1)
により阻止率が50％になるプルランの分子量を計算し、
その値から、下記Flory の式(2) 〜(3) により、孔径を
算出した。 プルランの阻止率＝｛１−（濾液中のプルラン濃度 /原
液中のプルラン濃度）｝×100 ・・・(1) 溶液状態にある鎖状高分子は球状の糸まり状で、その直
径d は、分子鎖の両末端の２乗平均距離〈γ2 〉に対し
て、近似的に 〔d/2 〕2 ＝〈γ2 〉・・・(2) の関係にあると考えられる。高分子溶液における粘性と
分子鎖の広がりに関するFlory の理論によると、高分子
の種類に無関係に 〔η〕Ｍ＝2.1 ×1021〈γ2 〉3/2 ・・・(3) が成立するので、式(2) 及び(3) により、固有粘度
〔η〕の測定値と、阻止率が50％になる分子量Ｍとか
ら、鎖状高分子の直径d を算出することができる。この
ｄをポリエチレン微多孔膜の平均孔径とした。 (8) 孔径分布：上記(7) と同じ方法により、阻止率が90
％となるプルランの分子量の値から同様に孔径を算出し
て最大孔径とし、この最大孔径の値を用いて、最大孔径
÷平均孔径の値により算出した。 (9) 空孔率：水銀ポロシメータで測定。EXAMPLES Examples of the present invention will be shown below. The test method in the examples is as follows. (1) Molecular weight and molecular weight distribution: Waters GP
Using C instrument, GOH-6 manufactured by Tosoh Corporation as a column and as a solvent
Using O-dichlorobenzene, temperature 135 ℃, flow rate 1.0 ml
/ Min, measured by gel permeation chromatography (GPC) method. (2) Breaking load: The breaking load of a 10 mm wide strip test piece
Measured according to D882. (3) Film thickness: The cross section was measured with a scanning electron microscope. (4) Air permeability: Conforms to JIS P8117. (5) Water permeability: A microporous membrane was installed in a flat membrane module, hydrophilized with distilled water / ethanol mixture (volume ratio 50/50), thoroughly washed with distilled water, and then water pressure of 380 mmHg was applied. It was determined by measuring the permeation amount of the filtrate at that time. (6) Solvent affinity evaluation: Wetting index: measured according to JIS 6768. Wettability with water: Place the sample on a horizontal surface, drop distilled water from above, and at this time, measure the time (seconds) until the distilled water reaches the opposite surface (lower surface) of the semple, The following criteria evaluated. ⊚: Instantaneous (less than 0.5 seconds) Δ: 0.5 to 2 seconds ×: More than 2 seconds Wettability with γ-butyrolactone: By the same method as the above evaluation test except that γ-butyrolactone was used instead of distilled water. , Evaluated. (7) Average pore size: Using the module described in (5) above, an aqueous solution of 0.05 wt% pullulan (manufactured by Showa Denko KK) was circulated under a differential pressure of 380 mmHg to remove pullulan contained in the filtrate. Obtain the concentration from the differential refractive index measurement, the following formula (1)
Calculate the molecular weight of pullulan with a rejection of 50% by
From the value, the pore size was calculated by the following Flory equations (2) to (3). Rejection rate of pullulan = {1- (pullulan concentration in filtrate / pullulan concentration in undiluted solution)} × 100 (1) The chain polymer in solution has a spherical thread shape and its diameter d is , And the root-mean-square distance <γ 2 > at both ends of the molecular chain is approximately [d / 2] 2 = <γ 2 > ... (2). According to Flory's theory of viscosity and spread of molecular chains in polymer solution, [η] M = 2.1 × 10 21 <γ 2 > 3/2 (3) holds regardless of the type of polymer. From equations (2) and (3), the diameter d of the chain polymer can be calculated from the measured value of the intrinsic viscosity [η] and the molecular weight M at which the rejection is 50%. This d was taken as the average pore diameter of the polyethylene microporous membrane. (8) Pore size distribution: 90% rejection by the same method as (7) above.
Similarly, the pore diameter was calculated from the value of the molecular weight of pullulan to be the maximum pore diameter, and the value of the maximum pore diameter was used to calculate the value of maximum pore diameter / average pore diameter. (9) Porosity: Measured with a mercury porosimeter.
【００４８】実施例１ 重量平均分子量（Ｍｗ）が 9.0×105 で、分子量分布
(重量平均分子量／数平均分子量）＝195 で、分子量７
×105 以上の成分の割合が21重量％の２段重合ポリエチ
レン15重量部と、流動パラフィン (64cst/40℃)85 重量
部とを混合し、２段重合ポリエチレンの溶液を調製し
た。次にこのポリエチレンの溶液100 重量部に、2,6-ジ
-t- ブチル-p- クレゾール (「BHT 」、住友化学工業
（株）製)0.125重量部と、テトラキス〔メチレン-3-(3,
5-ジ-t- ブチル-4- ヒドロキシルフェニル)-プロピオネ
ート〕メタン (「イルガノックス1010」、チバガイギー
製)0.25重量部とを酸化防止剤として加えて混合した。
この混合液を撹拌機付のオートクレーブに充填して、20
0 ℃で90分間撹拌し、均一な溶液を得た。 Example 1 Weight average molecular weight (Mw) was 9.0 × 10 5 , molecular weight distribution
(Weight average molecular weight / number average molecular weight) = 195, molecular weight 7
15 parts by weight of two-stage polymerized polyethylene having a proportion of x10 5 or more of 21% by weight was mixed with 85 parts by weight of liquid paraffin (64 cst / 40 ° C) to prepare a solution of two-stage polymerized polyethylene. Next, 100 parts by weight of this polyethylene solution was added to 2,6-diene.
0.125 parts by weight of -t-butyl-p-cresol ("BHT", manufactured by Sumitomo Chemical Co., Ltd.) and tetrakis [methylene-3- (3,
5-di-t-butyl-4-hydroxylphenyl) -propionate] methane (“Irganox 1010”, manufactured by Ciba Geigy) was added as an antioxidant and mixed.
Fill this mixture into an autoclave with a stirrer and
The mixture was stirred at 0 ° C for 90 minutes to obtain a uniform solution.
【００４９】この溶液を直径45mmの押出機のＴダイから
押出し、冷却ロールで引取りながらゲル状シートを成形
した。This solution was extruded from a T die of an extruder having a diameter of 45 mm, and a gel-like sheet was formed by taking it out with a cooling roll.
【００５０】得られたシートを２軸延伸機にセットし
て、温度115 ℃、延伸速度0.5 ｍ/ 分で５×５倍に同時
２軸延伸を行った。得られた延伸膜を塩化メチレンで洗
浄して、残留する流動パラフィンを抽出除去した後、乾
燥してポリエチレン微多孔膜を得た。The obtained sheet was set in a biaxial stretching machine and simultaneously biaxially stretched 5 × 5 times at a temperature of 115 ° C. and a stretching speed of 0.5 m / min. The stretched film thus obtained was washed with methylene chloride to extract and remove residual liquid paraffin, and then dried to obtain a polyethylene microporous film.
【００５１】このポリエチレン微多孔膜を、界面活性剤
溶液（ポリオキシエチレンラウリルエーテル (エマルゲ
ン108 花王（株）製）４重量％溶液（溶媒、エタノー
ル：水＝４：１））に３秒間浸漬し、テンター式の乾燥
機を用いて90℃で３分間、膜の収縮を防止しながら乾燥
し、親水化ポリエチレン微多孔膜を製造した。The polyethylene microporous membrane was dipped in a surfactant solution (polyoxyethylene lauryl ether (Emulgen 108 Kao Co., Ltd.) 4% by weight solution (solvent, ethanol: water = 4: 1)) for 3 seconds. Using a tenter drier, the membrane was dried at 90 ° C. for 3 minutes while preventing the membrane from shrinking, to produce a hydrophilic polyethylene microporous membrane.
【００５２】得られたポリエチレン微多孔膜の破断荷
重、膜厚、透気度、平均孔径の測定、濡れ指数、水に対
する濡れ性、γ−ブチロラクトンに対する濡れ性の評価
を行った。結果を第１表に示す。The polyethylene microporous film obtained was evaluated for breaking load, film thickness, air permeability, average pore size, wetting index, wettability with water, and wettability with γ-butyrolactone. The results are shown in Table 1.
【００５３】実施例２ 重量平均分子量 2.0×106 の超高分子量ポリエチレン13
重量％と、重量平均分子量（Ｍｗ）3.9 ×105 の高密度
ポリエチレン87重量％とからなるＭｗ／Ｍｎ＝12の原料
樹脂組成物（組成物の重量平均分子量4.9 ×105 、分子
量7.0 ×105 以上の割合57重量％) 15重量部と、流動パ
ラフィン (64cst/40℃)85 重量部とを混合し、ポリエチ
レン組成物の溶液を調製した。次にこのポリエチレン組
成物の溶液100 重量部に、2,6-ジ-t- ブチル-p- クレゾ
ール (「BHT 」、住友化学工業（株）製)0.125重量部
と、テトラキス〔メチレン-3-(3,5-ジ-t- ブチル-4- ヒ
ドロキシルフェニル)-プロピオネート〕メタン (「イル
ガノックス1010」、チバガイギー製)0.25 重量部とを酸
化防止剤として加えて混合した。この混合液を撹拌機付
のオートクレーブに充填して、200 ℃で90分間撹拌し、
均一な溶液を得た。 Example 2 Ultrahigh molecular weight polyethylene 13 having a weight average molecular weight of 2.0 × 10 6
A raw material resin composition of Mw / Mn = 12 (weight-average molecular weight of the composition of 4.9 × 10 5 , molecular weight of 7.0 × 10 5) , which comprises 87% by weight of high-density polyethylene having a weight-average molecular weight (Mw) of 3.9 × 10 5. 15 parts by weight of a ratio of 5 or more (57% by weight) and 85 parts by weight of liquid paraffin (64 cst / 40 ° C.) were mixed to prepare a solution of a polyethylene composition. Next, to 100 parts by weight of this polyethylene composition solution, 0.125 parts by weight of 2,6-di-t-butyl-p-cresol (“BHT”, manufactured by Sumitomo Chemical Co., Ltd.) and tetrakis [methylene-3- 0.25 parts by weight of (3,5-di-t-butyl-4-hydroxylphenyl) -propionate] methane (“Irganox 1010”, manufactured by Ciba Geigy) were added as an antioxidant and mixed. This mixture was charged into an autoclave equipped with a stirrer and stirred at 200 ° C for 90 minutes,
A homogeneous solution was obtained.
【００５４】この溶液を直径45mmの押出機のＴダイから
押出し、冷却ロールで引取りながらゲル状シートを成形
した。This solution was extruded from a T-die of an extruder having a diameter of 45 mm, and a gel-like sheet was formed by taking it with a cooling roll.
【００５５】得られたシートを２軸延伸機にセットし
て、温度115 ℃、延伸速度0.5 ｍ/ 分で５×５倍に同時
２軸延伸を行った。得られた延伸膜を塩化メチレンで洗
浄して、残留する流動パラフィンを抽出除去した後、乾
燥してポリエチレン微多孔膜を得た。The obtained sheet was set in a biaxial stretching machine and simultaneously biaxially stretched 5 × 5 times at a temperature of 115 ° C. and a stretching speed of 0.5 m / min. The stretched film thus obtained was washed with methylene chloride to extract and remove residual liquid paraffin, and then dried to obtain a polyethylene microporous film.
【００５６】このポリエチレン微多孔膜を、界面活性剤
溶液（ポリオキシエチレンラウリルエーテル (エマルゲ
ン108 花王（株）製）４重量％エタノール溶液) に３秒
間浸漬し、テンター式の乾燥機を用いて90℃で、１軸方
向に1.5 倍に延伸しながら乾燥した。乾燥後、120 ℃で
１分間熱セットすることにより、微多孔膜の平均孔径を
拡大し、空孔率及び透気性能の向上した親水化ポリエチ
レン微多孔膜を製造した。This polyethylene microporous membrane was dipped in a surfactant solution (polyoxyethylene lauryl ether (Emulgen 108 Kao Co., Ltd.) 4% by weight ethanol solution) for 3 seconds, and dried with a tenter type drier for 90 seconds. It was dried while being uniaxially stretched 1.5 times at ℃. After drying, heat setting was carried out at 120 ° C. for 1 minute to expand the average pore diameter of the microporous membrane to produce a hydrophilic polyethylene microporous membrane having improved porosity and air permeability.
【００５７】得られたポリエチレン微多孔膜の破断荷
重、膜厚、透気度、平均孔径の測定、濡れ指数、水に対
する濡れ性、γ−ブチロラクトンに対する濡れ性の評価
を行った。結果を第１表に示す。The polyethylene microporous film obtained was evaluated for breaking load, film thickness, air permeability, average pore size, wetting index, wettability with water, and wettability with γ-butyrolactone. The results are shown in Table 1.
【００５８】実施例３ 実施例２で得られたポリエチレン微多孔膜（未処理のも
の）を、界面活性剤溶液（ポリオキシエチレンラウリル
エーテル (エマルゲン108 花王（株）製）２重量部と、
ソルビタンモノラウレート（エマゾールL10F 花王
（株）製) １重量部との混合液の３重量％エタノール溶
液) に３秒間浸漬し、テンター式の乾燥機を用いて、90
℃で１軸方向に2.0 倍に延伸しながら乾燥した。乾燥
後、120 ℃で１分間熱セットすることにより、微多孔膜
の平均孔径を拡大し、空孔率及び透気性能の向上した親
水化ポリエチレン微多孔膜を製造した。 Example 3 The polyethylene microporous membrane (untreated) obtained in Example 2 was mixed with 2 parts by weight of a surfactant solution (polyoxyethylene lauryl ether (Emulgen 108, Kao Corporation)).
Immerse in 3% by weight of sorbitan monolaurate (Emazole L10F Kao Co., Ltd.) 1 part by weight for 3 seconds, and use a tenter type drier for 90 seconds.
It was dried while being drawn uniaxially 2.0 times at ℃. After drying, by heat setting at 120 ° C. for 1 minute, the average pore diameter of the microporous membrane was expanded to produce a hydrophilic polyethylene microporous membrane having improved porosity and air permeability.
【００５９】得られたポリエチレン微多孔膜の破断荷
重、膜厚、透気度、平均孔径の測定、濡れ指数、水に対
する濡れ性、γ−ブチロラクトンに対する濡れ性の評価
を行った。結果を第１表に示す。The polyethylene microporous film obtained was evaluated for breaking load, film thickness, air permeability, average pore diameter, wetting index, wettability with water, and wettability with γ-butyrolactone. The results are shown in Table 1.
【００６０】実施例４ 重量平均分子量（Ｍｗ）が 9.0×105 で、分子量分布
(重量平均分子量／数平均分子量）＝78.2で、分子量７
×105 以上の成分の割合が32重量％の２段重合ポリエチ
レン15重量部と、流動パラフィン (64cst/40℃)85 重量
部とを混合し、２段重合ポリエチレンの溶液を調製し
た。次にこのポリエチレンの溶液100 重量部に、2,6-ジ
-t- ブチル-p- クレゾール (「BHT 」、住友化学工業
（株）製)0.125重量部と、テトラキス〔メチレン-3-(3,
5-ジ-t- ブチル-4- ヒドロキシルフェニル)-プロピオネ
ート〕メタン (「イルガノックス1010」、チバガイギー
製)0.25重量部とを酸化防止剤として加えて混合した。
この混合液を撹拌機付のオートクレーブに充填して、20
0 ℃で90分間撹拌し、均一な溶液を得た。 Example 4 Weight average molecular weight (Mw) of 9.0 × 10 5 , molecular weight distribution
(Weight average molecular weight / number average molecular weight) = 78.2, molecular weight 7
15 parts by weight of two-stage polymerized polyethylene containing 32% by weight of a component of 10 5 or more and 85 parts by weight of liquid paraffin (64 cst / 40 ° C.) were mixed to prepare a solution of two-stage polymerized polyethylene. Next, 100 parts by weight of this polyethylene solution was added to 2,6-diene.
0.125 parts by weight of -t-butyl-p-cresol ("BHT", manufactured by Sumitomo Chemical Co., Ltd.) and tetrakis [methylene-3- (3,
5-di-t-butyl-4-hydroxylphenyl) -propionate] methane (“Irganox 1010”, manufactured by Ciba Geigy) was added as an antioxidant and mixed.
Fill this mixture into an autoclave with a stirrer and
The mixture was stirred at 0 ° C for 90 minutes to obtain a uniform solution.
【００６１】この溶液を直径45mmの押出機のＴダイから
押出し、冷却ロールで引取りながらゲル状シートを成形
した。This solution was extruded from a T-die of an extruder having a diameter of 45 mm, and a gel-like sheet was formed by taking it out with a cooling roll.
【００６２】得られたシートを２軸延伸機にセットし
て、温度115 ℃、延伸速度0.5 ｍ/ 分で５×５倍に同時
２軸延伸を行った。得られた延伸膜を塩化メチレンで洗
浄して、残留する流動パラフィンを抽出除去した後、乾
燥してポリエチレン微多孔膜を得た。The obtained sheet was set in a biaxial stretching machine and simultaneously biaxially stretched 5 × 5 times at a temperature of 115 ° C. and a stretching speed of 0.5 m / min. The stretched film thus obtained was washed with methylene chloride to extract and remove residual liquid paraffin, and then dried to obtain a polyethylene microporous film.
【００６３】このポリエチレン微多孔膜を、界面活性剤
溶液（ポリオキシエチレンラウリルエーテル (エマルゲ
ン108 花王（株）製）４重量％水溶液に３秒間浸漬し、
テンター式の乾燥機を用いて90℃で３分間、膜の収縮を
防止しながら乾燥し、親水化ポリエチレン微多孔膜を製
造した。The polyethylene microporous membrane was dipped in a 4% by weight aqueous solution of a surfactant solution (polyoxyethylene lauryl ether (Emulgen 108 Kao Corporation) for 3 seconds,
Using a tenter type dryer, the membrane was dried at 90 ° C. for 3 minutes while preventing the membrane from shrinking to produce a hydrophilic polyethylene microporous membrane.
【００６４】得られたポリエチレン微多孔膜の破断荷
重、膜厚、透気度、平均孔径の測定、濡れ指数、水に対
する濡れ性、γ−ブチロラクトンに対する濡れ性の評価
を行った。結果を第１表に示す。The polyethylene microporous film obtained was evaluated for breaking load, film thickness, air permeability, average pore size, wetting index, wettability with water, and wettability with γ-butyrolactone. The results are shown in Table 1.
【００６５】実施例５ 重量平均分子量 2.0×106 の超高分子量ポリエチレン13
重量％と、重量平均分子量（Ｍｗ）2.9 ×105 の高密度
ポリエチレン87重量％とからなるＭｗ／Ｍｎ＝32.4の原
料樹脂組成物（組成物の重量平均分子量4.5 ×105 、分
子量7.0 ×105 以上の割合52重量％) 15重量部と、流動
パラフィン (64cst/40℃)85 重量部とを混合し、ポリエ
チレン組成物の溶液を調製した。次にこのポリエチレン
組成物の溶液100 重量部に、2,6-ジ-t- ブチル-p- クレ
ゾール (「BHT 」、住友化学工業（株）製)0.125重量部
と、テトラキス〔メチレン-3-(3,5-ジ-t- ブチル-4- ヒ
ドロキシルフェニル)-プロピオネート〕メタン (「イル
ガノックス1010」、チバガイギー製)0.25 重量部とを酸
化防止剤として加えて混合した。この混合液を撹拌機付
のオートクレーブに充填して、200 ℃で90分間撹拌し、
均一な溶液を得た。 Example 5 Ultrahigh molecular weight polyethylene 13 having a weight average molecular weight of 2.0 × 10 6
A raw material resin composition of Mw / Mn = 32.4 consisting of 87% by weight of high-density polyethylene having a weight average molecular weight (Mw) of 2.9 × 10 5 (weight average molecular weight of the composition of 4.5 × 10 5 , molecular weight of 7.0 × 10 5) . 15 parts by weight of a ratio of 5 or more (52% by weight) and 85 parts by weight of liquid paraffin (64 cst / 40 ° C.) were mixed to prepare a solution of a polyethylene composition. Next, to 100 parts by weight of this polyethylene composition solution, 0.125 parts by weight of 2,6-di-t-butyl-p-cresol (“BHT”, manufactured by Sumitomo Chemical Co., Ltd.) and tetrakis [methylene-3- 0.25 parts by weight of (3,5-di-t-butyl-4-hydroxylphenyl) -propionate] methane (“Irganox 1010”, manufactured by Ciba Geigy) were added as an antioxidant and mixed. This mixture was charged into an autoclave equipped with a stirrer and stirred at 200 ° C for 90 minutes,
A homogeneous solution was obtained.
【００６６】この溶液を直径45mmの押出機のＴダイから
押出し、冷却ロールで引取りながらゲル状シートを成形
した。This solution was extruded from a T die of an extruder having a diameter of 45 mm, and a gel-like sheet was formed by taking it out with a cooling roll.
【００６７】得られたシートを２軸延伸機にセットし
て、温度115 ℃、延伸速度0.5 ｍ/ 分で５×５倍に同時
２軸延伸を行った。得られた延伸膜を塩化メチレンで洗
浄して、残留する流動パラフィンを抽出除去した後、乾
燥してポリエチレン微多孔膜を得た。The obtained sheet was set in a biaxial stretching machine and simultaneously biaxially stretched 5 × 5 times at a temperature of 115 ° C. and a stretching speed of 0.5 m / min. The stretched film thus obtained was washed with methylene chloride to extract and remove residual liquid paraffin, and then dried to obtain a polyethylene microporous film.
【００６８】このポリエチレン微多孔膜を、界面活性剤
溶液（ポリオキシエチレンラウリルエーテル (エマルゲ
ン108 花王（株）製）５重量％エタノール溶液) に３秒
間浸漬し、テンター式の乾燥機を用いて90℃で、１軸方
向に1.5 倍に延伸しながら乾燥した。乾燥後、120 ℃で
１分間熱セットすることにより、微多孔膜の平均孔径を
拡大し、空孔率及び透気性能の向上した親水化ポリエチ
レン微多孔膜を製造した。The polyethylene microporous membrane was dipped in a surfactant solution (polyoxyethylene lauryl ether (Emulgen 108 Kao Co., Ltd.) 5% by weight ethanol solution) for 3 seconds, and dried with a tenter drier for 90 seconds. It was dried while being uniaxially stretched 1.5 times at ℃. After drying, heat setting was carried out at 120 ° C. for 1 minute to expand the average pore diameter of the microporous membrane to produce a hydrophilic polyethylene microporous membrane having improved porosity and air permeability.
【００６９】得られたポリエチレン微多孔膜の破断荷
重、膜厚、透気度、平均孔径の測定、濡れ指数、水に対
する濡れ性、γ−ブチロラクトンに対する濡れ性の評価
を行った。結果を第１表に示す。The polyethylene microporous membranes obtained were evaluated for breaking load, membrane thickness, air permeability, average pore diameter, wetting index, wettability with water, and wettability with γ-butyrolactone. The results are shown in Table 1.
【００７０】実施例６ 重量平均分子量 2.0×106 の超高分子量ポリエチレン13
重量％と、重量平均分子量（Ｍｗ）1.2 ×105 の高密度
ポリエチレン87重量％とからなるＭｗ／Ｍｎ＝127.5 の
原料樹脂組成物（組成物の重量平均分子量2.7 ×105 、
分子量7.0 ×105 以上の割合42重量％) 15重量部と、流
動パラフィン (64cst/40℃)85 重量部とを混合し、ポリ
エチレン組成物の溶液を調製した。次にこのポリエチレ
ン組成物の溶液100 重量部に、2,6-ジ-t- ブチル-p-ク
レゾール (「BHT 」、住友化学工業（株）製)0.125重量
部と、テトラキス〔メチレン-3-(3,5-ジ-t- ブチル-4-
ヒドロキシルフェニル)-プロピオネート〕メタン (「イ
ルガノックス1010」、チバガイギー製)0.25 重量部とを
酸化防止剤として加えて混合した。この混合液を撹拌機
付のオートクレーブに充填して、200 ℃で90分間撹拌
し、均一な溶液を得た。 Example 6 Ultrahigh molecular weight polyethylene 13 having a weight average molecular weight of 2.0 × 10 6
A raw material resin composition having a weight average molecular weight (Mw) of 1.2 × 10 5 and a high-density polyethylene of 87% by weight having a Mw / Mn = 127.5 (weight average molecular weight of the composition: 2.7 × 10 5 ,
15 parts by weight of a mixture having a molecular weight of 7.0 × 10 5 or more (42% by weight) and 85 parts by weight of liquid paraffin (64 cst / 40 ° C.) were mixed to prepare a polyethylene composition solution. Next, to 100 parts by weight of this polyethylene composition solution, 0.125 parts by weight of 2,6-di-t-butyl-p-cresol (“BHT”, manufactured by Sumitomo Chemical Co., Ltd.) and tetrakis [methylene-3- (3,5-di-t-butyl-4-
0.25 parts by weight of (hydroxylphenyl) -propionate] methane (“Irganox 1010”, manufactured by Ciba-Geigy) were added as an antioxidant and mixed. This mixed solution was filled in an autoclave equipped with a stirrer and stirred at 200 ° C. for 90 minutes to obtain a uniform solution.
【００７１】この溶液を直径45mmの押出機のＴダイから
押出し、冷却ロールで引取りながらゲル状シートを成形
した。This solution was extruded from a T die of an extruder having a diameter of 45 mm, and a gel-like sheet was formed by taking it out with a cooling roll.
【００７２】得られたシートを２軸延伸機にセットし
て、温度115 ℃、延伸速度0.5 ｍ/ 分で５×５倍に同時
２軸延伸を行った。得られた延伸膜を塩化メチレンで洗
浄して、残留する流動パラフィンを抽出除去した後、乾
燥してポリエチレン微多孔膜を得た。The obtained sheet was set in a biaxial stretching machine and simultaneously biaxially stretched 5 × 5 times at a temperature of 115 ° C. and a stretching speed of 0.5 m / min. The stretched film thus obtained was washed with methylene chloride to extract and remove residual liquid paraffin, and then dried to obtain a polyethylene microporous film.
【００７３】このポリエチレン微多孔膜を、界面活性剤
溶液（ポリオキシエチレンラウリルエーテル (エマルゲ
ン108 花王（株）製）１重量％エタノール溶液) に３秒
間浸漬し、テンター式の乾燥機を用いて90℃で、１軸方
向に1.5 倍に延伸しながら乾燥した。乾燥後、120 ℃で
１分間熱セットすることにより、微多孔膜の平均孔径を
拡大し、空孔率及び透気性能の向上した親水化ポリエチ
レン微多孔膜を製造した。This polyethylene microporous membrane was dipped in a surfactant solution (polyoxyethylene lauryl ether (Emulgen 108 Kao Co., Ltd.) 1% by weight ethanol solution) for 3 seconds, and dried with a tenter dryer for 90 seconds. It was dried while being uniaxially stretched 1.5 times at ℃. After drying, heat setting was carried out at 120 ° C. for 1 minute to expand the average pore diameter of the microporous membrane to produce a hydrophilic polyethylene microporous membrane having improved porosity and air permeability.
【００７４】得られたポリエチレン微多孔膜の破断荷
重、膜厚、透気度、平均孔径の測定、濡れ指数、水に対
する濡れ性、γ−ブチロラクトンに対する濡れ性の評価
を行った。結果を第１表に示す。The breaking load, film thickness, air permeability, and average pore size of the obtained polyethylene microporous membrane were measured, and the wetting index, wettability with water, and wettability with γ-butyrolactone were evaluated. The results are shown in Table 1.
【００７５】比較例１ 実施例２で得られた未処理のポリエチレン微多孔膜につ
いて、破断荷重、膜厚、透気度、平均孔径の測定、濡れ
指数、水に対する濡れ性、γ−ブチロラクトンに対する
濡れ性の測定を行った。結果を第１表に示す。 Comparative Example 1 With respect to the untreated polyethylene microporous membrane obtained in Example 2, breaking load, film thickness, air permeability, measurement of average pore diameter, wetting index, wettability with water, wetting with γ-butyrolactone. The sex was measured. The results are shown in Table 1.
【００７６】 第 １ 表 物 性 実施例１ 実施例２ 実施例３ 実施例４ 破断荷重 （kgf/10mm幅) 2.3 2.7 3.0 2.2 膜厚 (μｍ) 25 25 25 25 透気度* 500 200 58 500 (秒/100cc) 平均孔径 (μｍ) 0.03 0.04 0.05 0.03 空孔率 (％) 50 60 70 50 濡れ指数(dyn/cm) 56 56 56 56 濡れ性の評価 水 ◎ ◎ ◎ ◎ γ−ブチロラクトン ◎ ◎ ◎ ◎ 注）＊：界面活性剤をエタノールで洗浄した後の膜に対して試験を行った。Table 1 Physical Properties Example 1 Example 2 Example 3 Example 4 Breaking load (kgf / 10mm width) 2.3 2.7 3.0 2.2 Film thickness (μm) 25 25 25 25 Air permeability * 500 200 58 500 ( Second / 100cc) Average pore size (μm) 0.03 0.04 0.05 0.03 Porosity (%) 50 60 70 50 Wetting index (dyn / cm) 56 56 56 56 Wettability evaluation water ◎ ◎ ◎ ◎ γ-butyrolactone ◎ ◎ ◎ ◎ ◎ Note) *: Tests were performed on the membrane after washing the surfactant with ethanol.
【００７７】 [0077]
【００７８】第１表から明らかなように、本発明のポリ
エチレン微多孔膜は、濡れ指数が55dyn/cm以上であり、
水及びγ−ブチロラクトンに対する濡れ性に著しく優れ
ており、かつ十分な大きさの破断荷重を有するのもので
あった。しかも、製造条件により、透気度の調整が自在
であり、電池用セパレータとして極めて優れた特性を有
していることがわかる。As is clear from Table 1, the polyethylene microporous membrane of the present invention has a wetting index of 55 dyn / cm or more,
The wettability to water and γ-butyrolactone was remarkably excellent, and the breaking load was sufficiently large. Moreover, it can be seen that the air permeability can be freely adjusted depending on the manufacturing conditions, and that it has extremely excellent characteristics as a battery separator.
【００７９】[0079]
【発明の効果】以上詳述したように、本発明のポリオレ
フィン微多孔膜は、超高分子量成分を含有し、分子量分
布（重量平均分子量／数平均分子量）が所定の範囲内に
あるポリオレフィンの溶液をシート状に成形し、急冷し
て得られるゲル状シートに特定の温度で少なくとも１軸
方向に延伸を施し、得られた微多孔膜に界面活性剤によ
る処理を施してなるので、薄膜で十分な膜強度を有する
とともに水、各種有機溶媒等に対する親和性に優れてお
り、電池用セパレータとして優れた性能を発揮する。As described in detail above, the microporous polyolefin membrane of the present invention contains a solution of a polyolefin containing an ultrahigh molecular weight component and having a molecular weight distribution (weight average molecular weight / number average molecular weight) within a predetermined range. Is formed into a sheet, and the gel-like sheet obtained by quenching is stretched at least uniaxially at a specific temperature, and the obtained microporous membrane is treated with a surfactant. It has excellent film strength and excellent affinity to water, various organic solvents, etc., and exhibits excellent performance as a battery separator.
【００８０】このような本発明のポリオレフィン微多孔
膜は、電池用セパレータの他、電解コンデンサー用隔
膜、超精密濾過膜、限外濾過膜、各種フィルター、透湿
防水衣料用多孔質膜等の各種用途にも好適である。The polyolefin microporous membrane of the present invention as described above includes various kinds of separators for batteries, diaphragms for electrolytic capacitors, ultra-precision filtration membranes, ultrafiltration membranes, various filters, porous membranes for moisture-permeable waterproof clothing, etc. It is also suitable for applications.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.5 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｃ０８Ｊ 9/36 ＣＥＳ 7148−4Ｆ // Ｃ０８Ｌ 23:00 (72)発明者 恒吉 衛 埼玉県入間郡大井町西鶴ケ岡１−３−１ 東燃株式会社総合研究所内─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 5 Identification number Internal reference number FI Technical display location C08J 9/36 CES 7148-4F // C08L 23:00 (72) Inventor Tsuneyoshi Mamoru Iruma-gun, Saitama Prefecture 1-3-1 Nishitsurugaoka, Oimachi Tonen Co., Ltd.
Claims (3)
重量％以上含有し、分子量分布（重量平均分子量／数平
均分子量）が10〜300のポリオレフィンからなり、厚さ
が0.1 〜50μｍで、空孔率が35〜95％で、平均貫通孔径
が0.001 〜0.2 μｍであり、15mm幅の破断強度が0.2 kg
以上であるポリオレフィン微多孔膜において、細孔の内
部表面及び膜表面に界面活性剤による処理が施されてい
ることを特徴とするポリオレフィン微多孔膜。1. A component having a weight average molecular weight of 7 × 10 5 or more
Made of polyolefin with a content of more than weight% and a molecular weight distribution (weight average molecular weight / number average molecular weight) of 10 to 300, thickness of 0.1 to 50 μm, porosity of 35 to 95%, average through pore diameter of 0.001 to 0.2 μm, breaking strength of 15 mm width is 0.2 kg
In the polyolefin microporous membrane described above, a treatment with a surfactant is applied to the inner surface of the pores and the membrane surface.
重量％以上含有し、分子量分布（重量平均分子量／数平
均分子量）が10〜300のポリオレフィン10〜50重量％
と、溶媒50〜90重量％とからなる溶液を調製し、前記溶
液をダイより押出し、冷却してゲル状組成物を形成し、
前記ゲル状組成物を前記ポリオレフィンの融点＋10℃以
下の温度で延伸し、しかる後残存溶媒を除去することに
より、基材となるポリオレフィン微多孔膜を製造し、得
られたポリオレフィン微多孔膜の細孔の内部表面及び膜
表面を界面活性剤溶液で被覆し、続いて溶液を乾燥する
ことを特徴とするポリオレフィン微多孔膜の製造方法。2. A component having a weight average molecular weight of 7 × 10 5 or more
10 to 50% by weight of polyolefin containing 10% to 300% by weight and having a molecular weight distribution (weight average molecular weight / number average molecular weight) of 10 to 300
A solution of 50 to 90% by weight of a solvent is prepared, the solution is extruded from a die and cooled to form a gel composition,
The gel composition is stretched at a temperature not higher than the melting point of the polyolefin + 10 ° C., and then the residual solvent is removed to produce a polyolefin microporous membrane as a base material, and the resulting polyolefin microporous membrane is finely divided. A method for producing a microporous polyolefin membrane, which comprises coating the inner surface of pores and the membrane surface with a surfactant solution and subsequently drying the solution.
重量％以上含有し、分子量分布（重量平均分子量／数平
均分子量）が10〜300のポリオレフィンからなり、厚さ
が0.1 〜50μｍで、空孔率が35〜95％で、平均貫通孔径
が0.001 〜0.2 μｍであり、15mm幅の破断強度が0.2 kg
以上であるポリオレフィン微多孔膜により形成され、そ
の細孔の内部表面及び膜表面に界面活性剤による処理が
施されていることを特徴とする電池用セパレータ。3. A component having a weight average molecular weight of 7 × 10 5 or more is 1
Made of polyolefin with a content of more than weight% and a molecular weight distribution (weight average molecular weight / number average molecular weight) of 10 to 300, thickness of 0.1 to 50 μm, porosity of 35 to 95%, average through pore diameter of 0.001 to 0.2 μm, breaking strength of 15 mm width is 0.2 kg
A battery separator, characterized in that it is formed of the polyolefin microporous film as described above, and the surface of the pores and the film surface are treated with a surfactant.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3283499A JP3072163B2 (en) | 1991-10-03 | 1991-10-03 | Polyolefin microporous membrane, method for producing the same, and battery separator using the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3283499A JP3072163B2 (en) | 1991-10-03 | 1991-10-03 | Polyolefin microporous membrane, method for producing the same, and battery separator using the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0594812A true JPH0594812A (en) | 1993-04-16 |
| JP3072163B2 JP3072163B2 (en) | 2000-07-31 |
Family
ID=17666339
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3283499A Expired - Lifetime JP3072163B2 (en) | 1991-10-03 | 1991-10-03 | Polyolefin microporous membrane, method for producing the same, and battery separator using the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3072163B2 (en) |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09326250A (en) * | 1996-06-04 | 1997-12-16 | Tonen Chem Corp | Composite film for battery separator |
| JPH11300180A (en) * | 1998-02-20 | 1999-11-02 | Mitsubishi Chemical Corp | Porous resin membrane |
| WO2002003486A1 (en) * | 2000-06-30 | 2002-01-10 | Matsushita Electric Industrial Co., Ltd. | Cell electrode plate, method for manufacturing it, and non-aqueous electrolyte secondary cell using them |
| JP2002367590A (en) * | 2001-06-11 | 2002-12-20 | Nitto Denko Corp | Porous film |
| JP2006136768A (en) * | 2004-11-10 | 2006-06-01 | Mitsubishi Rayon Eng Co Ltd | Hydrophilizing agent for hydrophobic porous membrane, hydrophilization method for hydrophobic porous membrane using this and inspection method |
| JP2008045077A (en) * | 2006-08-21 | 2008-02-28 | Univ Of Fukui | Method for controlling hydrophilic and hydrophobic property of surface of synthetic resin molded article |
| JP2011012242A (en) * | 2009-06-01 | 2011-01-20 | Kureha Corp | Manufacturing method of drawn resin porous membrane |
| KR101010463B1 (en) * | 2009-01-15 | 2011-01-21 | 도레이첨단소재 주식회사 | Lithium Secondary Battery Using Multi-Component Separator Film with Surfactant |
| JPWO2011129169A1 (en) * | 2010-04-16 | 2013-07-11 | 日立マクセル株式会社 | Electrochemical element separator, electrochemical element using the same, and method for producing the electrochemical element separator |
| JP2013194153A (en) * | 2012-03-21 | 2013-09-30 | Sumitomo Chemical Co Ltd | Method for producing modified polyolefin microporous membrane |
| CN103827185A (en) * | 2011-09-26 | 2014-05-28 | 旭化成电子材料株式会社 | Microporous membrane |
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1991
- 1991-10-03 JP JP3283499A patent/JP3072163B2/en not_active Expired - Lifetime
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09326250A (en) * | 1996-06-04 | 1997-12-16 | Tonen Chem Corp | Composite film for battery separator |
| JPH11300180A (en) * | 1998-02-20 | 1999-11-02 | Mitsubishi Chemical Corp | Porous resin membrane |
| WO2002003486A1 (en) * | 2000-06-30 | 2002-01-10 | Matsushita Electric Industrial Co., Ltd. | Cell electrode plate, method for manufacturing it, and non-aqueous electrolyte secondary cell using them |
| JP2002083590A (en) * | 2000-06-30 | 2002-03-22 | Matsushita Electric Ind Co Ltd | Battery electrode, its manufacturing method and nonaqueous electrolyte secondary battery using them |
| US6811577B2 (en) | 2000-06-30 | 2004-11-02 | Matsushita Electric Industrial Co., Ltd. | Cell electrode plate, method for manufacturing it, and non-aqueous electrolyte secondary cell using them |
| KR100708498B1 (en) * | 2000-06-30 | 2007-04-16 | 마츠시타 덴끼 산교 가부시키가이샤 | Cell electrode plate, method for manufacturing it, and non-aqueous electrolyte secondary cell using them |
| JP2002367590A (en) * | 2001-06-11 | 2002-12-20 | Nitto Denko Corp | Porous film |
| JP2006136768A (en) * | 2004-11-10 | 2006-06-01 | Mitsubishi Rayon Eng Co Ltd | Hydrophilizing agent for hydrophobic porous membrane, hydrophilization method for hydrophobic porous membrane using this and inspection method |
| JP2008045077A (en) * | 2006-08-21 | 2008-02-28 | Univ Of Fukui | Method for controlling hydrophilic and hydrophobic property of surface of synthetic resin molded article |
| KR101010463B1 (en) * | 2009-01-15 | 2011-01-21 | 도레이첨단소재 주식회사 | Lithium Secondary Battery Using Multi-Component Separator Film with Surfactant |
| JP2011012242A (en) * | 2009-06-01 | 2011-01-20 | Kureha Corp | Manufacturing method of drawn resin porous membrane |
| JPWO2011129169A1 (en) * | 2010-04-16 | 2013-07-11 | 日立マクセル株式会社 | Electrochemical element separator, electrochemical element using the same, and method for producing the electrochemical element separator |
| KR101485387B1 (en) * | 2010-04-16 | 2015-01-23 | 히다치 막셀 가부시키가이샤 | Separator for electrochemical device, electrochemical device using same, and method for producing the separator for electrochemical device |
| JP5681703B2 (en) * | 2010-04-16 | 2015-03-11 | 日立マクセル株式会社 | Electrochemical element separator, electrochemical element using the same, and method for producing the electrochemical element separator |
| CN103827185A (en) * | 2011-09-26 | 2014-05-28 | 旭化成电子材料株式会社 | Microporous membrane |
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| JP2014179519A (en) * | 2013-03-15 | 2014-09-25 | Nippon Sheet Glass Co Ltd | Separator for electricity storage device, and electricity storage device |
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