JPH10316793A - Porous film prepared from vinylidene fluoride resin - Google Patents
Porous film prepared from vinylidene fluoride resinInfo
- Publication number
- JPH10316793A JPH10316793A JP9128791A JP12879197A JPH10316793A JP H10316793 A JPH10316793 A JP H10316793A JP 9128791 A JP9128791 A JP 9128791A JP 12879197 A JP12879197 A JP 12879197A JP H10316793 A JPH10316793 A JP H10316793A
- Authority
- JP
- Japan
- Prior art keywords
- vinylidene fluoride
- film
- porous membrane
- porous
- membrane
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- 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
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、耐薬品性に優れた
多孔質膜、特に、リチウムイオン電池等で電極間の短絡
を防ぐために用いられる隔膜として使用される多孔質膜
に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a porous film having excellent chemical resistance, and more particularly to a porous film used as a diaphragm for preventing a short circuit between electrodes in a lithium ion battery or the like.
【０００２】[0002]
【従来の技術】一般にフッ化ビニリデン系樹脂は耐薬品
性が高いことから、有機溶媒中の懸濁物を濾過する目的
でフッ化ビニリデン系樹脂製多孔質膜が使用されること
があった。しかしながら、４０℃以上の高温での使用に
おいては、膜の強度低下や成分の溶解が起こることがあ
り、高温での使用に耐える多孔質膜が望まれていた。2. Description of the Related Art In general, a vinylidene fluoride resin-based porous membrane has been used for the purpose of filtering a suspension in an organic solvent because of its high chemical resistance. However, when used at a high temperature of 40 ° C. or higher, the strength of the film may be reduced or components may be dissolved, and a porous film that can withstand use at a high temperature has been desired.
【０００３】一方、近年、携帯電話やパソコン等の小型
化、軽量化のために高エネルギー密度の電池が要求さ
れ、これに対応する電池として非水系のリチウムイオン
電池が開発されている。この電池の正極および負極の電
極間には電解液に膨潤することのない、ポリオレフィン
製多孔質隔膜が配置されている。該ポリオレフィン製隔
膜を用いた場合には、電解液の漏出が起こりやすいた
め、電池構造体全体を重厚な金属容器でパッケージして
電解液の漏出を防止している。On the other hand, in recent years, batteries of high energy density have been required to reduce the size and weight of mobile phones and personal computers, and non-aqueous lithium ion batteries have been developed as corresponding batteries. A polyolefin porous diaphragm that does not swell in the electrolytic solution is disposed between the positive electrode and the negative electrode of this battery. When the polyolefin diaphragm is used, leakage of the electrolyte is likely to occur. Therefore, the entire battery structure is packaged in a heavy metal container to prevent leakage of the electrolyte.
【０００４】これに対して最近、電解液の漏出がなく、
非金属製パッケージの採用が可能で電池の薄型化や軽量
化の点で優れた、いわゆる『ポリマー電池』の開発が行
われている。このような電池として、ポリオレフィン性
隔膜の代わりにフッ化ビニリデン系樹脂製膜を用いたポ
リマー電池が提案されており、特に、特開平８−２５０
１２７号公報では、フッ化ビニリデン系樹脂から成る多
孔膜に電解液を含浸させ、該電解液含浸多孔膜を隔膜部
分に用いることによって、充放電可能な電池が実現でき
ることが開示されている。On the other hand, recently, there has been no leakage of electrolyte,
A so-called “polymer battery” has been developed which can adopt a non-metallic package and is excellent in terms of reducing the thickness and weight of the battery. As such a battery, a polymer battery using a vinylidene fluoride resin membrane instead of a polyolefinic membrane has been proposed.
No. 127 discloses that a battery capable of charging and discharging can be realized by impregnating a porous film made of a vinylidene fluoride resin with an electrolytic solution and using the electrolytic solution-impregnated porous film for a diaphragm portion.
【０００５】しかしながら、ここで開示された手段にお
いては、大きな電流密度では高い電池性能が得られない
欠点を有していた。また、高温では電解液に溶解し、内
部短絡を起こしてしまう欠点があった。したがって、急
速な充放電が可能な優れた電池性能を与え、且つ、高温
になっても溶解せず内部短絡を起こさない隔膜材料は、
未だ知られていない。[0005] However, the means disclosed herein has a disadvantage that high battery performance cannot be obtained with a large current density. Further, at a high temperature, there is a disadvantage that it is dissolved in the electrolytic solution to cause an internal short circuit. Therefore, a diaphragm material that provides excellent battery performance capable of rapid charge and discharge, and does not dissolve even at high temperatures and does not cause internal short circuit,
Not yet known.
【０００６】[0006]
【発明が解決しようとする課題】本発明は、高温での有
機溶媒環境下で固液分離膜として使用でき、且つ、隔膜
として電池を構成した時に、大きな電流密度でも高い電
池性能を示すことができるフッ化ビニリデン系樹脂製多
孔質膜を提供することを目的とする。SUMMARY OF THE INVENTION The present invention can be used as a solid-liquid separation membrane in an organic solvent environment at a high temperature, and exhibits high battery performance even at a large current density when the battery is configured as a diaphragm. It is an object of the present invention to provide a porous membrane made of vinylidene fluoride resin.
【０００７】[0007]
【課題を解決するための手段】本発明者らは上記の従来
技術の問題点に鑑み、検討を重ね本発明に至った。本発
明とその好ましい態様は、以下のとおりである。 １）多孔質膜が、架橋されたポリフッ化ビニリデンまた
は架橋されたフッ化ビニリデンを含む共重合体からな
り、膜の最小孔径層の平均孔径が０．０５〜５μｍであ
ることを特徴とするフッ化ビニリデン系樹脂製多孔質
膜。Means for Solving the Problems In view of the above-mentioned problems of the prior art, the present inventors have conducted various studies and reached the present invention. The present invention and preferred embodiments thereof are as follows. 1) A porous membrane comprising a crosslinked polyvinylidene fluoride or a copolymer containing crosslinked vinylidene fluoride, wherein the membrane has a minimum pore size layer having an average pore size of 0.05 to 5 μm. A porous membrane made of vinylidene fluoride resin.
【０００８】２）フッ化ビニリデン系樹脂製多孔質膜
が、電子線またはγ線照射により架橋されている上記１
記載のフッ化ビニリデン系樹脂製多孔質膜。 ３）フッ化ビニリデン系樹脂製多孔質膜中のゲル分率が
１０〜８０ｗｔ％である上記１記載のフッ化ビニリデン
系樹脂製多孔質膜。 ４）フッ化ビニリデン系樹脂製多孔質膜が、フッ化ビニ
リデン−ヘキサフロロプロピレン共重合体であって、ヘ
キサフルオロプロピレンの含有量が２０ｗｔ％以下であ
る上記１記載のフッ化ビニリデン系樹脂製多孔質膜。2) The above-mentioned 1 wherein the porous membrane made of a vinylidene fluoride resin is cross-linked by irradiation with an electron beam or γ-ray.
The porous membrane made of the vinylidene fluoride resin according to the above. 3) The vinylidene fluoride resin porous membrane according to 1 above, wherein the gel fraction in the vinylidene fluoride resin porous membrane is 10 to 80 wt%. 4) The vinylidene fluoride resin porous film according to 1 above, wherein the vinylidene fluoride resin porous membrane is a vinylidene fluoride-hexafluoropropylene copolymer having a hexafluoropropylene content of 20 wt% or less. Membrane.
【０００９】５）フッ化ビニリデン系樹脂製多孔質膜
が、フッ化ビニリデン−ヘキサフロロプロピレン共重合
体であって、ヘキサフルオロプロピレンの含有量が２０
ｗｔ％以下である共重合体からなり、ゲル分率が１０〜
８０ｗｔ％である上記１記載のフッ化ビニリデン系樹脂
製多孔質膜。 ６）フッ化ビニリデン系樹脂製多孔質膜が、少なくとも
一方の表面層が他の部分より緻密であり、内部に巨大空
孔及び三次元網目構造を有している上記１記載のフッ化
ビニリデン系樹脂製多孔質膜。5) The porous membrane made of vinylidene fluoride resin is a vinylidene fluoride-hexafluoropropylene copolymer having a hexafluoropropylene content of 20%.
wt% or less, and the gel fraction is 10 to 10.
2. The porous membrane made of a vinylidene fluoride-based resin according to the above 1, which is 80% by weight. 6) The vinylidene fluoride-based porous membrane according to 1 above, wherein the porous membrane made of a vinylidene fluoride-based resin has at least one surface layer that is denser than other portions, and has a huge pore and a three-dimensional network structure therein. Resin porous membrane.
【００１０】７）フッ化ビニリデン系樹脂製多孔質膜
が、少なくとも一方の表面層が他の部分より緻密であ
り、内部が三次元網目構造である上記１記載のフッ化ビ
ニリデン系樹脂製多孔質膜。 ８）フッ化ビニリデン系樹脂製多孔質膜が、表面及び内
部とも三次元網目構造である上記１記載のフッ化ビニリ
デン系樹脂製多孔質膜。[0010] 7) The vinylidene fluoride resin-based porous membrane according to the above item 1, wherein at least one surface layer of the porous membrane made of vinylidene fluoride-based resin is denser than other portions, and the inside has a three-dimensional network structure. film. 8) The vinylidene fluoride resin porous membrane according to 1 above, wherein the vinylidene fluoride resin porous membrane has a three-dimensional network structure on both the surface and the inside.
【００１１】９）１ａｔｍの静水圧をかけたときの２５
℃における透水量が１０００リットル／ｈｒ・ｍ2 ・ａ
ｔｍ以上である上記１記載のフッ化ビニリデン系樹脂製
多孔質膜。 以下、本発明を詳細に説明する。一般に、電池では出力
の電流密度を大きくすると、内部抵抗や濃度過電圧等が
原因で容量が低下することがある。特に、内部抵抗の大
きな隔膜部を有する非水系電池においてはその傾向が著
しい。9) 25 when a hydrostatic pressure of 1 atm is applied
1000 liter / hr · m 2 · a at ℃
2. The porous membrane made of a vinylidene fluoride-based resin according to the above 1, which has a tm or more. Hereinafter, the present invention will be described in detail. In general, when the output current density of a battery is increased, the capacity may decrease due to internal resistance, concentration overvoltage, or the like. In particular, the tendency is remarkable in a non-aqueous battery having a diaphragm having a large internal resistance.
【００１２】本発明の多孔質膜では、これを隔膜として
水系電池に用いたときに大きな電流密度でも容量が低下
しにくいことが特長である。例えば、充放電可能なリチ
ウムイオン二次電池において、１ｍＡ／ｃｍ2のような
低い電流密度と、３ｍＡ／ｃｍ2のような高い電流密度
とで放電容量に大きな差がないことを意味する。本発明
者らは、この特性が、単に隔膜部のイオン伝導度を高め
るだけでは得られず、多孔度が大きい構造を有する膜を
用いることによってはじめて達成できることを見いだし
た。The porous membrane of the present invention is characterized in that when it is used as a diaphragm in an aqueous battery, the capacity is not easily reduced even at a large current density. For example, in a chargeable / dischargeable lithium ion secondary battery, it means that there is no large difference in discharge capacity between a low current density such as 1 mA / cm 2 and a high current density such as 3 mA / cm 2 . The present inventors have found that this property cannot be obtained simply by increasing the ionic conductivity of the membrane portion, but can be achieved only by using a membrane having a structure with large porosity.
【００１３】即ち、膜の最小孔径層の平均孔径が０．０
５〜５μｍであることが要件である。さらに、０．０８
〜３μｍが好ましく、０．１〜３μｍの範囲であること
が特に好ましい。０．０５未満では、電池用隔膜として
用いる場合には、高い電流密度のときに充放電特性が低
くなるし、分離用として用いる場合には、透水性が低下
する。一方、５μｍを超える場合、電池用隔膜として用
いる場合には、内部短絡しやすくなるし、分離用として
用いる場合には、分画性が低下する。That is, the average pore size of the smallest pore size layer of the membrane is 0.0
The requirement is 5 to 5 μm. In addition, 0.08
To 3 μm, particularly preferably 0.1 to 3 μm. If it is less than 0.05, when used as a battery membrane, the charge / discharge characteristics are reduced at a high current density, and when used for separation, the water permeability is reduced. On the other hand, if it exceeds 5 μm, internal short-circuit is likely to occur when it is used as a battery diaphragm, and when it is used for separation, the fractionability decreases.
【００１４】本発明において、膜の最小孔径層は、電子
顕微鏡によって膜断面に存在する空孔径の分布を観測す
ることによって特定できる。更に、平均孔径とは、最小
孔径層が最表面にある場合には、表面層の電子顕微鏡写
真によって計測される平均孔径をいい、また、最小孔径
層が膜内部に存在する場合には、ＡＳＴＭ Ｆ ３１６
−８６に準じて測定される平均流量細孔径をいう。な
お、平均流量細孔径の測定においては、測定溶媒として
エタノールを用いる。In the present invention, the minimum pore size layer of the membrane can be specified by observing the distribution of pore sizes existing in the cross section of the membrane by an electron microscope. Furthermore, the average pore size refers to the average pore size measured by an electron micrograph of the surface layer when the minimum pore size layer is on the outermost surface, and is the ASTM when the minimum pore size layer exists inside the film. F 316
It refers to the average flow pore diameter measured according to -86. In measuring the average flow pore diameter, ethanol is used as a measurement solvent.
【００１５】本発明における平均孔径を有する多孔質膜
においては、１ａｔｍの静水圧をかけたときの２５℃に
おける透水量が１０００リットル／ｈｒ・ｍ2 ・ａｔｍ
以上であることが好ましい。特に好ましくは１５００リ
ットル／ｈｒ・ｍ2 ・ａｔｍ以上である。一方、高い電
池性能を得る上では透水量に上限はないが、透水量が大
きすぎると漏液性が大きくなったり、デンドライトと呼
ばれる樹枝状の金属の電析物による短絡の恐れがあるの
で、１０００００リットル／ｈｒ・ｍ2 ・ａｔｍ以下が
好ましく、５００００リットル／ｈｒ・ｍ2 ・ａｔｍ以
下がさらに好ましい。In the porous membrane having an average pore diameter according to the present invention, the water permeability at 25 ° C. when a hydrostatic pressure of 1 atm is applied is 1,000 liter / hr · m 2 · atm.
It is preferable that it is above. Particularly preferably, it is at least 1500 liter / hr · m 2 · atm. On the other hand, in order to obtain high battery performance, there is no upper limit to the amount of water permeation, but if the amount of water permeation is too large, liquid leakage increases, or there is a risk of short-circuiting due to dendritic metal deposits called dendrites, It is preferably at most 100,000 liter / hr · m 2 · atm, more preferably at most 50,000 liter / hr · m 2 · atm.
【００１６】本発明のフッ化ビニリデン系樹脂製多孔質
膜を形成するポリマー種としては、フッ化ビニリデンの
単独重合体の他、フッ化ビニリデン−ヘキサフルオロプ
ロピレン共重合体、フッ化ビニリデン−トリフルオロプ
ロピレン共重合体、フッ化ビニリデン−テトラフルオロ
エチレン共重合体、フッ化ビニリデン−トリフルオロエ
チレン共重合体、フッ化ビニリデン−フルオロエチレン
共重合体、フッ化ビニリデン−プロピレン共重合体、フ
ッ化ビニリデン−エチレン共重合体、フッ化ビニリデン
−ヘキサフルオロアセトン共重合体、フッ化ビニリデン
−パーフルオロビニルエーテル共重合体、フッ化ビニリ
デン−エチレン−テトラフルオロエチレン共重合体、フ
ッ化ビニリデン−テトラフルオロエチレン−ヘキサフル
オロプロピレン共重合体等を例示することができる。こ
れら単独あるいはこれらの重合体の混合物を用いること
もできる。また、フッ化ビニリデンを含まない他の重合
体との混合物を用いることもできる。これらのポリマー
種の中では、フッ化ビニリデン−ヘキサフルオロプロピ
レン共重合体が、機械的強度が良好であるので特に好ま
しい。The polymer species forming the porous membrane made of vinylidene fluoride resin of the present invention include vinylidene fluoride homopolymer, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-trifluoro Propylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, vinylidene fluoride-trifluoroethylene copolymer, vinylidene fluoride-fluoroethylene copolymer, vinylidene fluoride-propylene copolymer, vinylidene fluoride- Ethylene copolymer, vinylidene fluoride-hexafluoroacetone copolymer, vinylidene fluoride-perfluorovinyl ether copolymer, vinylidene fluoride-ethylene-tetrafluoroethylene copolymer, vinylidene fluoride-tetrafluoroethylene-hexafluoro Propylene It can be exemplified coalescence like. These can be used alone or a mixture of these polymers can be used. Further, a mixture with another polymer not containing vinylidene fluoride can also be used. Among these polymer types, vinylidene fluoride-hexafluoropropylene copolymer is particularly preferred because of its good mechanical strength.
【００１７】上記の共重合体、あるいは混合物の場合に
おいては、フッ化ビニリデン成分を５０ｗｔ％以上含有
することが好ましく、７５重量％以上含有することが特
に好ましい。フッ化ビニリデン成分が５０ｗｔ％未満で
は、電池用隔膜として用いる場合、隔膜部分のイオン伝
導性が低下する場合がある。さらに、フッ化ビニリデン
−ヘキサフルオロプロピレン共重合体の場合では、ヘキ
サフロロプロピレン含有量が２０ｗｔ％以下であること
が好ましい。２０ｗｔ％を越える範囲では、機械的強度
が必ずしも十分ではない。In the case of the above copolymer or mixture, the vinylidene fluoride component is preferably contained in an amount of 50% by weight or more, particularly preferably 75% by weight or more. When the vinylidene fluoride component is less than 50 wt%, when used as a battery diaphragm, the ion conductivity of the diaphragm portion may be reduced. Furthermore, in the case of a vinylidene fluoride-hexafluoropropylene copolymer, the hexafluoropropylene content is preferably 20% by weight or less. If it exceeds 20 wt%, the mechanical strength is not always sufficient.
【００１８】これらのフッ化ビニリデン系樹脂製多孔質
膜は架橋されている必要がある。一般にフッ化ビニリデ
ン系樹脂は、高温においてリチウムイオン二次電池で用
いられる電解液のような有機溶媒によって著しく膨潤し
たり、溶解してまう。架橋構造を有することで、高い高
温安定性が得られる。この架橋構造は、重合時、多孔質
薄膜の形成前、形成後のどの段階でも導入することがで
きる。These porous membranes made of vinylidene fluoride resin must be crosslinked. In general, a vinylidene fluoride resin is significantly swelled or dissolved at high temperature by an organic solvent such as an electrolyte used in a lithium ion secondary battery. By having a crosslinked structure, high high-temperature stability is obtained. This crosslinked structure can be introduced at any stage during polymerization, before or after formation of the porous thin film.
【００１９】架橋の方法としては、重合時に多官能のモ
ノマーを用いる方法、重合後に電子線、γ線、Ｘ線、紫
外線等の輻射エネルギーを照射する方法、また、重合後
にラジカル開始剤を含有させて熱や輻射エネルギー照射
により反応させる方法等を用いることができる。重合後
に架橋構造を導入する場合、新たに単官能または／およ
び多官能のモノマー成分を共存させておくこともでき
る。これらの方法の中でも、夾雑物や未反応官能基が残
存しにくいので、重合後に電子線、γ線、Ｘ線、紫外線
等の輻射エネルギーを照射する方法が好ましい。As a method of crosslinking, a method of using a polyfunctional monomer during polymerization, a method of irradiating radiation energy such as an electron beam, a γ-ray, an X-ray, or an ultraviolet ray after polymerization, or a method of incorporating a radical initiator after polymerization. For example, a method of reacting by irradiation of heat or radiation energy can be used. When a crosslinked structure is introduced after the polymerization, a monofunctional or / and polyfunctional monomer component may be newly allowed to coexist. Among these methods, a method in which radiation energy such as an electron beam, γ-ray, X-ray, or ultraviolet ray is irradiated after polymerization is preferable since impurities and unreacted functional groups hardly remain.
【００２０】なかでも、多孔質膜の膜厚が１００μｍ以
下の場合には、電子線照射による架橋が経済的であり、
特に好ましい。電子線照射により架橋を行う場合には、
照射量は５〜１００Ｍｒａｄの範囲であることが好まし
く、さらに好ましくは８〜５０Ｍｒａｄの範囲である。
５Ｍｒａｄ未満では架橋の効果が必ずしも十分でなく、
１００Ｍｒａｄを超えるとポリマーの崩壊が顕著になる
傾向が生じる。In particular, when the thickness of the porous film is 100 μm or less, crosslinking by electron beam irradiation is economical,
Particularly preferred. When crosslinking by electron beam irradiation,
The irradiation amount is preferably in the range of 5 to 100 Mrad, and more preferably in the range of 8 to 50 Mrad.
If it is less than 5 Mrad, the effect of crosslinking is not always sufficient,
If it exceeds 100 Mrad, the polymer tends to be significantly disintegrated.
【００２１】この架橋構造形成の確認は、未架橋ポリマ
ーが可溶な溶剤への溶解性により確認することができ
る。即ち、架橋構造を有する重合体は可溶性溶剤に溶解
しない成分を有し、均一溶解しないことから架橋構造形
成を判別することができる。この可溶性溶剤は、ポリマ
ーの種類によって異なるため、特に限定されないが、通
常、Ｎ−メチルピロリドン、ジメチルホルムアミド、ジ
メチルアセトアミド、ジメチルスルホキシド、クロロホ
ルム、ジクロロメタン、ジクロロエタン、アセトン、テ
トラヒドロフラン、エチレンカーボネート、プロピレン
カーボネートなどが使用できる。溶解に際しては、加温
して促進することもできる。The formation of the crosslinked structure can be confirmed by the solubility in a solvent in which the uncrosslinked polymer is soluble. That is, since the polymer having a crosslinked structure has a component that is insoluble in a soluble solvent and does not dissolve uniformly, formation of a crosslinked structure can be determined. The soluble solvent varies depending on the type of the polymer, and is not particularly limited.Normal N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethylsulfoxide, chloroform, dichloromethane, dichloroethane, acetone, tetrahydrofuran, ethylene carbonate, propylene carbonate, and the like are usually used. Can be used. The dissolution can be promoted by heating.
【００２２】上記の溶剤を用いて未架橋部を溶解した後
の残分の重量分率（以下、ゲル分率という）が１０〜８
０ｗｔ％の範囲であることが好ましい。さらに、２０〜
７０ｗｔ％の範囲であることが特に好ましい。ゲル分率
が１０ｗｔ％未満では、高温時に強度が著しく低下して
破損しやすくなったり、内部短絡が起こりやすくなる。
また、８０ｗｔ％を超えると多孔質膜が脆くなるため、
取り扱い時に破断したり、内部短絡が起こりやすくな
る。The weight fraction (hereinafter, referred to as gel fraction) of the residue after dissolving the uncrosslinked portion using the above-mentioned solvent is 10-8.
It is preferably in the range of 0 wt%. In addition, 20
It is particularly preferred that the content be in the range of 70 wt%. When the gel fraction is less than 10% by weight, the strength is remarkably reduced at a high temperature, and the gel is easily broken, and an internal short circuit is easily generated.
On the other hand, if it exceeds 80 wt%, the porous film becomes brittle.
Breakage during handling and internal short circuit are likely to occur.
【００２３】本発明のフッ化ビニリデン系樹脂製多孔質
膜は、連通孔を有する多孔質材料であって、上記のよう
な透水性を有する構造であるが、これによって、電池用
隔膜として使用する場合、電解液の含浸速度が非常に優
れている利点と、電解液を含浸したときのイオン伝導度
が高い利点がもたらされる。該多孔質膜の空隙率は１０
〜９５％の範囲にあることが好ましく、さらに好ましく
は２０〜９０％、さらに好ましくは４０〜８５％であ
る。１０％未満では電解液を含浸したときのイオン伝導
度が充分には高くなく、また、９５％を超えると充分な
強度が得られにくい。The porous membrane made of vinylidene fluoride resin of the present invention is a porous material having communication holes and has a structure having water permeability as described above. In this case, an advantage that the impregnation rate of the electrolytic solution is very excellent and an advantage that the ionic conductivity when the electrolytic solution is impregnated is high are provided. The porosity of the porous membrane is 10
It is preferably in the range of 95%, more preferably 20% to 90%, even more preferably 40% to 85%. If it is less than 10%, the ionic conductivity when impregnated with the electrolytic solution is not sufficiently high, and if it exceeds 95%, it is difficult to obtain sufficient strength.
【００２４】該多孔質膜の膜厚は、用途によって異なる
が、一般的には１〜５００μｍ程度のものが用いられ、
好ましくは１０〜３００μｍである。特に、電池用隔膜
としては、２０〜１００μｍの範囲が最も好ましい。１
μｍ未満では強度が必ずしも十分とはいえない。５００
μｍを越える膜厚では、分離膜用としては分離効率が低
下し、また、電池用隔膜としては実効電気抵抗が高くな
りすぎるうえ、電池の体積当たりのエネルギー密度が低
くなる傾向が生じる。The thickness of the porous film varies depending on the application, but is generally about 1 to 500 μm.
Preferably it is 10 to 300 μm. In particular, the range for the battery diaphragm is most preferably in the range of 20 to 100 μm. 1
If it is less than μm, the strength is not always sufficient. 500
If the film thickness exceeds μm, the separation efficiency is reduced for a separation membrane, the effective electric resistance is too high for a battery membrane, and the energy density per unit volume of the battery tends to be low.
【００２５】本発明のフッ化ビニリデン系樹脂製多孔質
膜においては、その構造は特に限定されるものではな
い。例えば、（１）少なくとも一方の表面に内部よりも
緻密な層を有し、内部に巨大空孔及び三次元網目構造を
有している膜、（２）少なくとも一方の表面に内部より
も緻密な層を有し、内部が三次元網目構造である膜、
（３）表面及び内部とも三次元網目構造である膜、
（４）片側表面に緻密な層を有し、該表面層の下部に巨
大空孔からなる層とから構成される２層構造である膜、
（５）少なくとも両表面に緻密な層を有し、内部に巨大
空孔からなる層とから構成される３層若しくは５層構造
の膜等が挙げられる。これらの構造の中でも、（１）、
（２）及び（３）の膜が、機械的強度が良好であるので
特に好ましい。The structure of the vinylidene fluoride resin porous membrane of the present invention is not particularly limited. For example, (1) a film having a denser layer than the inside on at least one surface and having a huge hole and a three-dimensional network structure inside, and (2) a film having a denser than the inside on at least one surface. A membrane having a layer and an interior having a three-dimensional network structure,
(3) a membrane having a three-dimensional network structure on both the surface and the inside;
(4) a film having a two-layer structure comprising a dense layer on one surface and a layer comprising huge holes below the surface layer;
(5) A film having a three-layer or five-layer structure including a dense layer on at least both surfaces, and a layer having huge holes inside. Among these structures, (1),
The films (2) and (3) are particularly preferred because of their good mechanical strength.
【００２６】このような本発明のフッ化ビニリデン系樹
脂製多孔質膜の製造法は特に限定されるものではなく、
公知の溶融法や湿式法による方法が適用できる。例え
ば、特開平３−２１５５３５号公報に記載の方法や、特
公昭６１−３８２０７号公報に記載の方法、特開昭５４
−１６３８２号公報に記載の方法、特開昭５８−９１７
３２号公報記載の方法、特開昭６３−２９６９４０号公
報に記載の方法等を利用することができる。The method for producing such a porous membrane made of vinylidene fluoride resin of the present invention is not particularly limited.
Known methods such as a melting method and a wet method can be applied. For example, the method described in JP-A-3-215535, the method described in JP-B-61-38207,
No. 16382, JP-A-58-917.
No. 32, the method described in JP-A-63-296940, and the like can be used.
【００２７】溶融法は、重合体を可塑剤や無機粉体等と
共に溶融後、平膜状に成形し、その後に可塑剤や無機粉
体等を抽出除去するものである。また湿式法は、重合体
を界面活性剤や添加剤等と共に溶媒に溶解しておき、こ
の溶液を薄膜状で非溶媒中に浸漬することで凝固させ、
溶媒や界面活性剤や添加剤等を洗浄除去するものであ
る。後者の場合、非溶媒中に直接平膜状に押し出して浸
漬することにより、膜の両面に緻密な層を有する膜が製
造でき、また、ガラスのような基板上に流延したものを
基板ごと非溶媒中に浸漬することによって、片面に緻密
な層を有するものが製造できる。さらに、原液組成や非
溶媒液組成やそれらの温度などの条件を適宜選択するこ
とによって、緻密な層を全く有さないものを製造するこ
ともできる。In the melting method, a polymer is melted together with a plasticizer, an inorganic powder and the like, formed into a flat film, and thereafter the plasticizer and the inorganic powder are extracted and removed. In the wet method, the polymer is dissolved in a solvent together with a surfactant and additives, and the solution is coagulated by immersing the solution in a thin film in a non-solvent.
The solvent, the surfactant, the additive and the like are washed and removed. In the latter case, a film having a dense layer on both sides of the film can be manufactured by directly extruding and immersing in a non-solvent in the form of a flat film. By immersing in a non-solvent, one having a dense layer on one side can be manufactured. Further, by appropriately selecting conditions such as the composition of the stock solution, the composition of the non-solvent solution, and the temperature thereof, a product having no dense layer can be produced.
【００２８】[0028]
【発明の実施の形態】以下、実施例によって本発明をさ
らに詳細に説明する。なお、測定は必要に応じて、測定
サンプルを以下の前処理を行った後、下記のとおりに行
った。 前処理：サンプル約２０ｃｍ2 を５０ｍｌのエタノール
（特級試薬）中に浸漬して洗浄する操作を３回行った。
その後、６０℃で真空乾燥を４時間行った。DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail by way of examples. In addition, the measurement was performed as follows, after performing the following pretreatment of the measurement sample as needed. Pretreatment: An operation of immersing about 20 cm 2 of the sample in 50 ml of ethanol (special grade reagent) to wash the sample was performed three times.
Thereafter, vacuum drying was performed at 60 ° C. for 4 hours.
【００２９】（１）断面構造と表面層の平均孔径 断面構造は、隔膜サンプルを液体窒素を用いて凍結させ
た後に割断し、その断面をＳＥＭ（日立製作所製ＳＥ
Ｍ；Ｓ−８００型）を用いて観察して、最小孔径層が表
面にあることを確認し、また、膜表面を上記のＳＥＭを
用いて観察して、その平均孔径を求めた。(1) Cross-sectional Structure and Average Pore Diameter of Surface Layer The cross-sectional structure was obtained by freezing a diaphragm sample using liquid nitrogen, cutting the sample, and then cutting the cross-section with an SEM (SE manufactured by Hitachi, Ltd.).
M: S-800) to confirm that the minimum pore size layer was on the surface, and to observe the membrane surface using the above SEM to determine the average pore size.
【００３０】（２）ゲル分率の測定 多孔質膜サンプル約１ｇを５０℃で真空乾燥した後、重
量を測定して溶解前重量（Ｗｘ）を求めた。該サンプル
を約１ｃｍ角の大きさにカットしてガラス製サンプル瓶
に入れ、Ｎ−メチルピロリドン１００ｍｌを添加した。
次いで、８０℃に加温しながら２４時間攪拌した後、粒
子保持能０．７μｍのガラス繊維濾紙を用いて濾過し
た。続いて２０ｍｌのＮ−メチルピロリドンで洗浄した
後濾過する操作を２回行い、さらに２０ｍｌのエタノー
ル２回洗浄した後、５０℃で真空乾燥した。その重量を
濾過器ごと測定し、予め測定した濾過器のみの重量から
差し引いて、溶解残差重量（Ｗｚ）を求めた。次式から
ゲル分率を計算した。(2) Measurement of Gel Fraction About 1 g of the porous membrane sample was vacuum-dried at 50 ° C., and the weight was measured to determine the weight before dissolution (Wx). The sample was cut into a size of about 1 cm square, placed in a glass sample bottle, and 100 ml of N-methylpyrrolidone was added.
Next, the mixture was stirred for 24 hours while being heated to 80 ° C., and then filtered using a glass fiber filter paper having a particle holding capacity of 0.7 μm. Subsequently, the operation of washing with 20 ml of N-methylpyrrolidone and then filtering was performed twice, further washing with 20 ml of ethanol twice, followed by vacuum drying at 50 ° C. The weight was measured for each filter and subtracted from the previously measured weight of only the filter to determine the residual weight of dissolution (Wz). The gel fraction was calculated from the following equation.
【００３１】ゲル分率（％）＝１００×Ｗｚ／Ｗｘ （３）厚みの測定 多孔質膜サンプルを表面が平滑なガラス板（厚み１ｍ
ｍ）２枚で挟み、その厚みをデジタルマイクロメーター
で測定した。上記ガラス板２枚の厚みを別途測定し、前
期測定値からガラス板分の値を差し引いて求めた。Gel fraction (%) = 100 × Wz / Wx (3) Measurement of thickness The porous membrane sample was placed on a glass plate having a smooth surface (1 m thick).
m) The sheet was sandwiched between two sheets, and the thickness was measured with a digital micrometer. The thickness of the two glass plates was separately measured, and the thickness was determined by subtracting the value of the glass plate from the previous measurement value.
【００３２】（４）空隙率の測定 多孔質膜サンプルをエタノール（特級試薬）に浸漬して
親水化処理を行った後、室温で２時間以上純水に浸漬し
て空隙内を完全に純水で置換した。次いで、膜表面の水
を拭き取った後、空隙に純水を含む多孔質膜の重量
（Ａ）を測定した。続いて、該多孔質膜サンプルを真空
中で６０℃で４時間以上乾燥して、空隙内の水を除去
し、ポリマー部のみの重量（Ｂ）を測定した。これらの
重量と膜の構成ポリマー及び水の真比重（ｄｐ、ｄｗ）
とから、次式によって計算で求めた。(4) Measurement of porosity The porous membrane sample was immersed in ethanol (special grade reagent) to perform hydrophilization treatment, and then immersed in pure water at room temperature for 2 hours or more to completely remove pure water in the void. Was replaced. Next, after the water on the membrane surface was wiped off, the weight (A) of the porous membrane containing pure water in the voids was measured. Subsequently, the porous membrane sample was dried in a vacuum at 60 ° C. for 4 hours or more to remove water in the voids, and the weight (B) of only the polymer portion was measured. These weights and the true specific gravity of the constituent polymer of the membrane and water (dp, dw)
From this, it was calculated by the following equation.
【００３３】空隙率（％）＝１００×（（Ａ−Ｂ）／ｄ
ｗ）／（Ｂ／ｄｐ＋（Ａ−Ｂ）／ｄｗ） なお、水の真比重（ｄｗ）は１．０とした。 （５）透水量の測定 多孔質膜サンプルを直径２５ｍｍに打ち抜いた後、エタ
ノール（特級試薬）中に浸漬して親水化した。次いで、
超純水中に浸漬して純水に置換し、該膜を有効面積３．
５ｃｍ2のメンブランフィルターホルダーに組み込んで
超純水を充たした。５分間１ａｔｍの静水圧をかけ、透
過した水の重量を測定した。この時の超純水の温度を測
定し、その温度での純水の真密度と粘度から、２５℃に
おける１時間当たり且つ１ｍ2 当たりの透水量（リット
ル／ｍ2 ／ｈｒ／ａｔｍ、２５℃）を計算した。Porosity (%) = 100 × ((A−B) / d)
w) / (B / dp + (AB) / dw) The true specific gravity (dw) of water was 1.0. (5) Measurement of Water Permeability After punching out a porous membrane sample to a diameter of 25 mm, it was immersed in ethanol (special grade reagent) to make it hydrophilic. Then
2. The membrane is immersed in ultrapure water and replaced with pure water.
It was incorporated into a 5 cm 2 membrane filter holder and filled with ultrapure water. The hydrostatic pressure of 1 atm was applied for 5 minutes, and the weight of the permeated water was measured. At this time, the temperature of the ultrapure water was measured, and from the true density and the viscosity of the pure water at that temperature, the amount of water per hour and per m 2 at 25 ° C. (liter / m 2 / hr / atm, 25 ° C.) ) Was calculated.
【００３４】（６）イオン伝導度 多孔質膜サンプルを室温で電解液（エチレンカーボネー
ト／プロピレンカーボネート／γ−ブチロラクトンの
１：１：２混合溶媒にＬｉＢＦ4を１．５ｍｏｌ／リッ
トルの濃度で溶かした溶液）中に浸漬して、電解液を含
浸した。この電解液含浸隔膜をステンレス製電極で挟み
込むことで電気化学セルを構成した。通常の交流インピ
ーダンス法に基づいて、この電極間に交流を印可して抵
抗成分を測定し、コールコールプロットの実数インピー
ダンス切片からイオン伝導度を計算した。なお、インピ
ーダンスの測定は、ＥＧ＆Ｇ社、３８９型インピーダン
スメーターを用い、周波数１ｋＨｚで行った。電解液の
含浸と測定操作は、露点−６０℃以下のドライ環境下で
行った。(6) Ion conductivity LiBF 4 was dissolved at a concentration of 1.5 mol / L in an electrolyte solution (1: 1: 2 mixed solvent of ethylene carbonate / propylene carbonate / γ-butyrolactone) at room temperature. Solution) to impregnate the electrolyte. An electrochemical cell was constructed by sandwiching the electrolyte impregnated diaphragm between stainless steel electrodes. Based on the normal AC impedance method, an AC was applied between the electrodes to measure the resistance component, and the ionic conductivity was calculated from the real impedance intercept of the Cole-Cole plot. The impedance was measured at a frequency of 1 kHz using a 389 type impedance meter manufactured by EG & G. The impregnation of the electrolyte solution and the measurement operation were performed in a dry environment with a dew point of -60 ° C or less.
【００３５】（７）高温安定性 上記（６）と同様にして電気化学セルを構成し、さらに
熱電対を埋め込んだアルミナ板でそのセルの両面を押さ
え、加熱可能な油圧プレス機で保持した。交流インピー
ダンス測定を行いながら、プレスダイを加熱し、室温か
ら２２０℃まで昇温させたときのインピーダンス変化を
測定した。(7) High Temperature Stability An electrochemical cell was constructed in the same manner as in (6) above, and both sides of the cell were pressed with an alumina plate in which a thermocouple was embedded, and held by a heatable hydraulic press. While performing the AC impedance measurement, the press die was heated and the impedance change when the temperature was raised from room temperature to 220 ° C. was measured.
【００３６】（８）電池性能（電流密度依存性） 次のような電極を用いた２次電池を構成し、その充放電
特性から評価した。まず、平均粒径１０μｍのＬｉＣｏ
Ｏ2粉末とカーボンブラックを、ポリフッ化ビニリデン
（呉羽化学工業製、ＫＦ＃１１００）のＮ−メチルピロ
リドン溶液（５重量％）に混合分散してスラリーを作製
した。尚、スラリー中の固形分重量組成は、ＬｉＣｏＯ
2（８９％）、カーボンブラック（８％）、ポリマー
（３％）とした。このスラリーをアルミ箔上にドクター
ブレード法で塗布、乾燥した後、プレスして膜厚１１０
μｍの正極シートを作製した。(8) Battery Performance (Current Density Dependence) A secondary battery using the following electrodes was constructed and evaluated from its charge / discharge characteristics. First, LiCo having an average particle size of 10 μm
O 2 powder and carbon black, polyvinylidene fluoride (Kureha Chemical Industry Ltd., KF # 1100) were mixed dispersed in the N- methylpyrrolidone solution (5 wt%) to prepare a slurry. The solid content by weight of the slurry was LiCoO
2 (89%), carbon black (8%) and polymer (3%). This slurry was applied to an aluminum foil by a doctor blade method, dried, and then pressed to a thickness of 110 mm.
A μm positive electrode sheet was prepared.
【００３７】次に、平均粒径１０μｍのニードルコーク
ス粉末をカルボキシメチルセルロース溶液とスチレンブ
タジエンラテックス（旭化成工業製、Ｌ１５７１）分散
液混合体に分散してスラリーを作製した。尚、スラリー
中の固形分重量組成は、ニードルコークス／カルボキシ
メチルセルロース／スチレンブタジエン＝１００／０．
８／２とした。該スラリーを金属銅シートにドクターブ
レード法で塗布、乾燥した後、プレスして膜厚１２０μ
ｍの負極シートを作製した。Next, a needle coke powder having an average particle diameter of 10 μm was dispersed in a carboxymethyl cellulose solution and a styrene-butadiene latex (L1571 manufactured by Asahi Kasei Kogyo Co., Ltd.) mixture to prepare a slurry. The weight composition of the solid content in the slurry was as follows: needle coke / carboxymethyl cellulose / styrene butadiene = 100/0.
8/2. The slurry was applied to a metal copper sheet by a doctor blade method, dried, and then pressed to a thickness of 120 μm.
m of the negative electrode sheet was produced.
【００３８】イオン伝導度の測定の場合と同様にして、
電解液を含浸した隔膜（電解液含浸隔膜）を調製した。
正極シート、負極シートはそれぞれ２ｃｍ角に切断し、
電解液含浸隔膜は２．３ｃｍ角に切断した。２枚の電極
シートが該電解液含浸隔膜を挟んで対向した状態に積層
した。このとき、正負極シートの対向しない部分ができ
ないようにした。さらに、該正極及び負極の外側からガ
ラス板で挟んで密着させて電池を形成した。次いで、該
電池の正極、負極にステンレス端子を取り付け、ガラス
製容器内に封入した。上記の電池の組立操作は、露点−
６０℃以下のドライ環境下で行った。As in the case of the measurement of ionic conductivity,
A diaphragm impregnated with an electrolyte (electrolyte-impregnated diaphragm) was prepared.
The positive electrode sheet and the negative electrode sheet are each cut into 2 cm square,
The electrolyte impregnated diaphragm was cut into 2.3 cm squares. Two electrode sheets were laminated so as to face each other with the electrolytic solution-impregnated diaphragm interposed therebetween. At this time, the non-opposing portions of the positive and negative electrode sheets were not formed. Further, a battery was formed by sandwiching and adhering a glass plate from the outside of the positive electrode and the negative electrode. Next, stainless terminals were attached to the positive electrode and the negative electrode of the battery, and sealed in a glass container. The above battery assembly operation is performed with the dew point-
The test was performed in a dry environment of 60 ° C. or less.
【００３９】該電池について充放電機（北斗電工製、１
０１ＳＭ６）を用い、充放電を繰り返し行った。充電は
定電流充電後４．２Ｖ定電位充電で行い、放電はカット
オフ電圧２．７Ｖ定電流放電で行った。まず、１ｍＡ／
ｃｍ2の電流密度で１０回充放電を繰り返し、続いて３
ｍＡ／ｃｍ2の電流密度で充放電を１０回繰り返した。
このときの１０回目（１ｍＡ／ｃｍ2）の放電容量に対
する２０回目（３ｍＡ／ｃｍ2）の放電容量の比を求め
た。The battery was charged / discharged (Hokuto Denko, 1
01SM6), and charging and discharging were repeatedly performed. Charging was performed at 4.2V constant potential charging after constant current charging, and discharging was performed at 2.7V constant current discharging with a cutoff voltage of 2.7V. First, 1mA /
Charge and discharge were repeated 10 times at a current density of 2 cm 2 ,
Charge / discharge was repeated 10 times at a current density of mA / cm 2 .
At this time, the ratio of the discharge capacity at the 20th (3 mA / cm 2 ) to the discharge capacity at the 10th (1 mA / cm 2 ) was obtained.
【００４０】[0040]
【実施例１】フッ化ビニリデン−ヘキサフルオロプロピ
レン共重合体（エルフ アトケム製、Ｋｙｎａｒ２８０
１：ヘキサフルオロプロピレン１２ｗｔ％含有品）１７
重量部、ポリビニルピロリドン（ＢＡＳＦ製Ｋ−３０）
１５重量部、Ｎ−メチルピロリドン（東京化成社製特級
試薬）６８重量部からなる溶液を調製し、５０℃でガラ
ス板上にキャストした。直ちに３０℃の７５ｗｔ％Ｎ−
メチルピロリドン水溶液中に浸漬して凝固させ、水、エ
タノールで洗浄後乾燥した。次いで、該多孔質膜に電子
線照射（照射量３０Ｍｒａｄ）し、架橋した多孔質膜を
作成した。Example 1 Vinylidene fluoride-hexafluoropropylene copolymer (manufactured by Elf Atochem, Kynar 280)
1: product containing 12% by weight of hexafluoropropylene) 17
Parts by weight, polyvinylpyrrolidone (K-30 manufactured by BASF)
A solution consisting of 15 parts by weight and 68 parts by weight of N-methylpyrrolidone (special grade reagent manufactured by Tokyo Chemical Industry Co., Ltd.) was prepared and cast at 50 ° C. on a glass plate. Immediately at 30 ° C, 75 wt% N-
The solid was immersed in an aqueous methylpyrrolidone solution for coagulation, washed with water and ethanol, and dried. Next, the porous film was irradiated with an electron beam (irradiation amount: 30 Mrad) to prepare a crosslinked porous film.
【００４１】この架橋した多孔質膜の断面を観察する
と、両表面に比較的緻密な層を有していて、内部は三次
元網目構造をとっていた。該多孔質膜は、膜厚６１μ
ｍ、空隙率５８％、ゲル分率７０％であり、最小孔径層
の平均孔径が２．０μｍ、透水量が１１０００（リット
ル／ｍ2 ／ｈｒ／ａｔｍ、２５℃）であった。該多孔質
膜を室温で電解液中に浸漬したところ、数秒以内に含浸
し、完全に透明になった。この電解液含浸隔膜の室温に
おけるイオン伝導度は１．３ｍＳ／ｃｍであり、２２０
℃までの昇温過程において大きな抵抗値の低下が無く、
短絡する現象は起こらなかった。さらに、その電池性能
は９５％で優れた性能を示した。Observation of the cross section of this crosslinked porous membrane revealed that both surfaces had relatively dense layers, and the inside had a three-dimensional network structure. The porous membrane has a thickness of 61 μm.
m, the porosity was 58%, and the gel fraction was 70%. The average pore size of the minimum pore size layer was 2.0 μm, and the water permeability was 11,000 (liter / m 2 / hr / atm, 25 ° C.). When the porous membrane was immersed in an electrolytic solution at room temperature, the porous membrane was impregnated within several seconds and became completely transparent. The ionic conductivity at room temperature of this electrolyte impregnated membrane was 1.3 mS / cm,
There is no large decrease in resistance value during the temperature rise process up to ℃.
The phenomenon of short circuit did not occur. Further, the battery performance was excellent at 95%.
【００４２】[0042]
【実施例２】凝固液を７０ｗｔ％Ｎ−メチルピロリドン
水溶液に変えた他は、実施例１と同様にして架橋した多
孔質膜を得た。この架橋した多孔質膜の断面を観察する
と、両表面に比較的緻密な層を有していて、内部は三次
元網目構造をとっていた。該多孔質膜は、膜厚７０μ
ｍ、空隙率６７％、ゲル分率７２％であり、最小孔径層
の平均径が０．２μｍ、透水量が５２００（リットル／
ｍ2 ／ｈｒ／ａｔｍ、２５℃）であった。Example 2 A crosslinked porous membrane was obtained in the same manner as in Example 1 except that the coagulating solution was changed to a 70 wt% aqueous solution of N-methylpyrrolidone. Observation of the cross section of the crosslinked porous film revealed that both surfaces had relatively dense layers, and the inside had a three-dimensional network structure. The porous membrane has a thickness of 70 μm.
m, porosity 67%, gel fraction 72%, average diameter of the smallest pore size layer is 0.2 μm, and water permeability is 5200 (liter / liter).
m 2 / hr / atm, 25 ° C.).
【００４３】該多孔質膜を室温で電解液中に浸漬したと
ころ、数秒以内に含浸し、完全に透明になった。この電
解液含浸隔膜の室温におけるイオン伝導度は１．２ｍＳ
／ｃｍであり、２２０℃までの昇温過程において大きな
抵抗値の低下が無く、短絡する現象は起こらなかった。
さらに、その電池性能は９３％で優れた性能を示した。When the porous film was immersed in an electrolytic solution at room temperature, it was impregnated within several seconds and became completely transparent. The ionic conductivity of this electrolyte impregnated membrane at room temperature is 1.2 mS.
/ Cm, and there was no large decrease in the resistance value during the temperature rise process up to 220 ° C, and the phenomenon of short-circuiting did not occur.
Further, the battery performance was excellent at 93%.
【００４４】[0044]
【実施例３】ポリマーをフッ化ビニリデン−ヘキサフル
オロプロピレン共重合体（エルフアトケム製、Ｋｙｎａ
ｒ２８５０：ヘキサフルオロプロピレン３ｗｔ％含有
品）とし、凝固液を８５ｗｔ％Ｎ−メチルピロリドン水
溶液中に変えた他は、実施例１と同様にして多孔質膜を
得た。次いで、該多孔質膜に電子線照射（照射量１０Ｍ
ｒａｄ）し、架橋した多孔質膜を作成した。Example 3 The polymer was a vinylidene fluoride-hexafluoropropylene copolymer (manufactured by Elphatochem, Kyna
r2850: a product containing 3% by weight of hexafluoropropylene), and a porous membrane was obtained in the same manner as in Example 1 except that the coagulating solution was changed to an aqueous solution of 85% by weight of N-methylpyrrolidone. Next, the porous film is irradiated with an electron beam (irradiation amount 10 M).
rad) to form a crosslinked porous membrane.
【００４５】この架橋した多孔質膜の断面を観察する
と、両表面に比較的緻密な層を有していて、内部は三次
元網目構造をとっていた。該多孔質膜は、膜厚４２μ
ｍ、空隙率７４％、ゲル分率５３％であり、最小孔径層
の平均孔径が０．９μｍ、透水量が７５００（リットル
／ｍ2 ／ｈｒ／ａｔｍ、２５℃）であった。該多孔質膜
を室温で電解液中に浸漬したところ、数秒以内に含浸
し、完全に透明になった。この電解液含浸隔膜の室温に
おけるイオン伝導度は１．３ｍＳ／ｃｍであり、２２０
℃までの昇温過程において大きな抵抗値の低下が無く、
短絡する現象は起こらなかった。さらに、その電池性能
は９５％であった。Observation of the cross section of this crosslinked porous membrane revealed that both surfaces had relatively dense layers, and the inside had a three-dimensional network structure. The porous film has a thickness of 42 μm.
m, the porosity was 74%, and the gel fraction was 53%. The average pore size of the minimum pore size layer was 0.9 μm, and the water permeability was 7,500 (liter / m 2 / hr / atm, 25 ° C.). When the porous membrane was immersed in an electrolytic solution at room temperature, the porous membrane was impregnated within several seconds and became completely transparent. The ionic conductivity at room temperature of this electrolyte impregnated membrane was 1.3 mS / cm,
There is no large decrease in resistance value during the temperature rise process up to ℃.
The phenomenon of short circuit did not occur. Further, the battery performance was 95%.
【００４６】[0046]
【実施例４】フッ化ビニリデン重合体（呉羽化学製、Ｋ
Ｆ＃１０００：ホモポリマー）１７．２重量部、ポリエ
チレングリコール＃２００（和光純薬工業製）１１．５
重量部、ポリオキシエチレン（２０）ソルビタンモノオ
レート（和光純薬工業製、試薬）０．８重量部、ジメチ
ルアセトアミド（東京化成社製特級試薬）７０．５重量
部からなる溶液を調製し、室温でガラス板上にキャスト
した。直ちに７０℃の水中に浸漬して凝固させ、水、エ
タノールで洗浄後乾燥した。次いで、該多孔質膜に電子
線照射（照射量３０Ｍｒａｄ）し、架橋した多孔質膜を
作成した。Example 4 Vinylidene fluoride polymer (Kureha Chemical, K
F # 1000: homopolymer) 17.2 parts by weight, polyethylene glycol # 200 (manufactured by Wako Pure Chemical Industries) 11.5
A solution consisting of 0.8 parts by weight of polyoxyethylene (20) sorbitan monooleate (manufactured by Wako Pure Chemical Industries, reagent) and 70.5 parts by weight of dimethylacetamide (special grade reagent manufactured by Tokyo Chemical Industry Co., Ltd.) was prepared at room temperature. And cast on a glass plate. Immediately, it was immersed in water at 70 ° C. to solidify, washed with water and ethanol, and dried. Next, the porous film was irradiated with an electron beam (irradiation amount: 30 Mrad) to prepare a crosslinked porous film.
【００４７】この架橋した多孔質膜の断面を観察する
と、両表面に比較的緻密な層を有していて、内部には巨
大空孔部と三次元網目構造部を有していた。該多孔質膜
は、膜厚４８μｍ、空隙率８０％、ゲル分率４９％であ
り、最小孔径層の平均孔径が０．１μｍ、透水量が１０
３０（リットル／ｍ2／ｈｒ／ａｔｍ、２５℃）であっ
た。Observation of the cross section of the crosslinked porous film revealed that both surfaces had a relatively dense layer, and had a huge void portion and a three-dimensional network structure inside. The porous membrane has a thickness of 48 μm, a porosity of 80%, a gel fraction of 49%, an average pore diameter of the minimum pore diameter layer of 0.1 μm, and a water permeability of 10 μm.
30 (liter / m 2 / hr / atm, 25 ° C.).
【００４８】該多孔質膜を室温で電解液中に浸漬したと
ころ、数秒以内に含浸し、完全に透明になった。この電
解液含浸隔膜の室温におけるイオン伝導度は１．１ｍＳ
／ｃｍであり、２２０℃までの昇温過程において大きな
抵抗値の低下が無く、短絡する現象は起こらなかった。
さらに、その電池性能は９２％であった。When the porous film was immersed in an electrolytic solution at room temperature, it was impregnated within a few seconds and became completely transparent. The ionic conductivity of the electrolyte-impregnated membrane at room temperature is 1.1 mS.
/ Cm, and there was no large decrease in the resistance value during the temperature rise process up to 220 ° C, and the phenomenon of short-circuiting did not occur.
Further, the battery performance was 92%.
【００４９】[0049]
【実施例５】平均一次粒子系１６μｍ、比表面積１１０
ｍ2 ／ｇの疎水性シリカ（アエロジルＲ−９７２）２９
重量部、フタル酸ジオクチル３５重量部、フタル酸ジブ
チル３重量部をヘンシェルミキサーで混合し、これにフ
ッ化ビニリデン重合体（呉羽化学製、ＫＦ＃１０００：
ホモポリマー）３３重量部を添加し、再度ヘンシェルミ
キサーで混合した。該混合物を３０ｍｍ二軸押出機（東
芝機械製）で混合してペレットにした。次いで、このペ
レットを３０ｍｍ二軸押出機にＴダイと冷却ロールを取
り付けた平膜製造装置を用いて薄膜を得た。Example 5 Average primary particle system 16 μm, specific surface area 110
m 2 / g hydrophobic silica (Aerosil R-972) 29
Parts by weight, 35 parts by weight of dioctyl phthalate, and 3 parts by weight of dibutyl phthalate were mixed with a Henschel mixer, and the mixture was mixed with a vinylidene fluoride polymer (KF # 1000: manufactured by Kureha Chemical Co., Ltd.).
(Homopolymer) 33 parts by weight were added and mixed again with a Henschel mixer. The mixture was mixed into pellets using a 30 mm twin screw extruder (manufactured by Toshiba Machine Co., Ltd.). Next, a thin film was obtained from the pellets using a flat film production apparatus in which a T die and a cooling roll were attached to a 30 mm twin screw extruder.
【００５０】該薄膜を１，１，１−トリクロロエタン中
に浸漬して、フタル酸ジオクチルとフタル酸ジブチルを
抽出した後、乾燥した。次いで、５０％エチルアルコー
ル水溶液に浸漬し、更に水中に浸漬して親水化した後、
７０℃、２０％苛性ソーダ水溶液中に浸漬して疎水性シ
リカを抽出した。次いで、十分水洗し、乾燥して多孔質
膜を得た。次いで、該多孔質膜に電子線照射（照射量３
０Ｍｒａｄ）し、架橋した多孔質膜を作成した。The thin film was immersed in 1,1,1-trichloroethane to extract dioctyl phthalate and dibutyl phthalate, and then dried. Then, after immersing in 50% ethyl alcohol aqueous solution and further immersing in water to make it hydrophilic,
It was immersed in a 20% aqueous solution of sodium hydroxide at 70 ° C. to extract hydrophobic silica. Next, it was sufficiently washed with water and dried to obtain a porous membrane. Next, the porous film was irradiated with an electron beam (irradiation amount 3
0 Mrad) to form a crosslinked porous membrane.
【００５１】この架橋した多孔質膜の表面と断面を観察
したところ、表面及び内部とも三次元網目構造であっ
た。該多孔質膜は、膜厚９０μｍ、空隙率７０％、ゲル
分率５０％であり、最小孔径層の平均孔径が０．７μ
ｍ、透水量が３５００（リットル／ｍ2 ／ｈｒ／ａｔ
ｍ、２５℃）であった。該多孔質膜を室温で電解液中に
浸漬したところ、数秒以内に含浸し、完全に透明になっ
た。この電解液含浸隔膜の室温におけるイオン伝導度は
１．２ｍＳ／ｃｍであり、２２０℃までの昇温過程にお
いて大きな抵抗値の低下が無く、短絡する現象は起こら
なかった。さらに、その電池性能は９２％であった。Observation of the surface and cross section of the crosslinked porous membrane revealed that both the surface and the inside had a three-dimensional network structure. The porous membrane has a thickness of 90 μm, a porosity of 70%, a gel fraction of 50%, and an average pore size of the minimum pore size layer of 0.7 μm.
m, water permeability is 3500 (liter / m 2 / hr / at
m, 25 ° C). When the porous membrane was immersed in an electrolytic solution at room temperature, the porous membrane was impregnated within several seconds and became completely transparent. The ionic conductivity at room temperature of this electrolyte-impregnated membrane was 1.2 mS / cm, and there was no large decrease in resistance value during the temperature rise process up to 220 ° C., and no short-circuit phenomenon occurred. Further, the battery performance was 92%.
【００５２】[0052]
【比較例１】架橋処理を行わなかった他は、実施例１と
同様にして多孔質膜を作成した。この多孔質膜の構造や
最小孔径層の平均孔径、膜厚、空隙率は実施例１の膜と
同様であった。また、透水量は９９００（リットル／ｍ
2／ｈｒ／ａｔｍ、２５℃）であり、実施例１の膜と同
等であった。しかしながら、ゲル分率は０％であり、完
全に溶解してしまった。Comparative Example 1 A porous membrane was prepared in the same manner as in Example 1 except that no crosslinking treatment was performed. The structure of the porous membrane, the average pore diameter, the film thickness, and the porosity of the minimum pore diameter layer were the same as those of the membrane of Example 1. The water permeability is 9900 (liter / m
2 / hr / atm, 25 ° C.), which is equivalent to the film of Example 1. However, the gel fraction was 0% and it was completely dissolved.
【００５３】該多孔質膜を室温で電解液中に浸漬したと
ころ、数秒以内に含浸し、完全に透明になった。この電
解液含浸隔膜の室温におけるイオン伝導度は１．３ｍＳ
／ｃｍであったが、２２０℃までの昇温過程において大
きな抵抗値の低下が起こり、遂には短絡して測定不能に
なった。When the porous membrane was immersed in an electrolytic solution at room temperature, it was impregnated within a few seconds and became completely transparent. The ionic conductivity at room temperature of this electrolyte impregnated membrane is 1.3 mS.
/ Cm, but a large decrease in the resistance value occurred during the temperature rise process up to 220 ° C., and eventually a short circuit occurred, making measurement impossible.
【００５４】[0054]
【比較例２】フッ化ビニリデン−ヘキサフルオロプロピ
レン共重合体（エルフ アトケム製、Ｋｙｎａｒ２８０
１：ヘキサフルオロプロピレン１２ｗｔ％含有品）１７
重量部、ポリエチレングリコール＃２００（和光純薬製
一級試薬）１０重量部、Ｎ−メチルピロリドン（東京化
成社製特級試薬）７３重量部からなる溶液を調製した他
は、実施例１と同様にして架橋した多孔質膜を作成し
た。Comparative Example 2 Vinylidene fluoride-hexafluoropropylene copolymer (Kynar 280, manufactured by Elf Atochem)
1: product containing 12% by weight of hexafluoropropylene) 17
Except that a solution consisting of 10 parts by weight of polyethylene glycol # 200 (a first-class reagent manufactured by Wako Pure Chemical Industries, Ltd.) and 73 parts by weight of N-methylpyrrolidone (a special-grade reagent manufactured by Tokyo Chemical Industry Co., Ltd.) was prepared in the same manner as in Example 1 A crosslinked porous membrane was made.
【００５５】この架橋した多孔質膜の断面を観察する
と、両表面に比較的緻密な層を有していて、内部は三次
元網目構造をとっていた。該多孔質膜は、膜厚６７μ
ｍ、空隙率７２％、ゲル分率７１％であり、最小孔径層
の平均孔径が０．０３μｍ、透水量が７０（リットル／
ｍ2 ／ｈｒ／ａｔｍ、２５℃）であった。この多孔質膜
に室温で電解液を含浸させた電解液含浸隔膜の室温にお
けるイオン伝導度は１．２ｍＳ／ｃｍであり、２２０℃
までの昇温過程において大きな抵抗値の低下が無く、短
絡する現象は起こらなかった。しかしながら、その電池
性能は３５％と極めて低いものであった。When the cross section of the crosslinked porous membrane was observed, it had a relatively dense layer on both surfaces, and the inside had a three-dimensional network structure. The porous membrane has a thickness of 67 μm.
m, porosity 72%, gel fraction 71%, average pore size of the minimum pore size layer is 0.03 μm, and water permeability is 70 (liter / liter).
m 2 / hr / atm, 25 ° C.). The ionic conductivity at room temperature of the electrolyte-impregnated membrane obtained by impregnating the electrolyte with the porous membrane at room temperature was 1.2 mS / cm, and was 220 ° C.
There was no large decrease in the resistance value during the heating process up to and no short-circuit phenomenon occurred. However, the battery performance was extremely low at 35%.
【００５６】[0056]
【比較例３】フッ化ビニリデン重合体（呉羽化学製、Ｋ
Ｆ＃１０００：ホモポリマー）１７重量部、Ｎ−メチル
ピロリドン（東京化成社製特級試薬）８３重量部からな
る溶液を調製し、凝固液に純水を用いた他は、実施例１
と同様にして架橋した多孔質膜を作成した。Comparative Example 3 Vinylidene fluoride polymer (Kureha Chemical, K
Example 1 except that a solution consisting of 17 parts by weight of F # 1000: homopolymer) and 83 parts by weight of N-methylpyrrolidone (special grade reagent manufactured by Tokyo Chemical Industry Co., Ltd.) was prepared, and pure water was used as a coagulating liquid.
In the same manner as in the above, a crosslinked porous membrane was prepared.
【００５７】この架橋した多孔質膜の断面を観察する
と、両表面に比較的緻密な層を有していて、内部には巨
大空孔部と三次元網目構造部を有していた。１５０００
倍に拡大しても両表面には孔が観察されなかった。おそ
らく０．０１μｍ以下の孔が存在していると推測され
る。該多孔質膜は、膜厚４０μｍ、空隙率７９％、ゲル
分率５０％であり、透水量が３７（リットル／ｍ2 ／ｈ
ｒ／ａｔｍ、２５℃）であった。Observation of the cross section of the crosslinked porous film revealed that both surfaces had a relatively dense layer, and had a huge pore and a three-dimensional network structure inside. 15000
No pores were observed on both surfaces even when magnified twice. It is presumed that there is probably a hole of 0.01 μm or less. The porous membrane had a thickness of 40 μm, a porosity of 79%, a gel fraction of 50%, and a water permeability of 37 (liter / m 2 / h).
r / atm, 25 ° C).
【００５８】この多孔質膜に室温で電解液を含浸させた
電解液含浸隔膜の室温におけるイオン伝導度は１．１ｍ
Ｓ／ｃｍであり、２２０℃までの昇温過程において大き
な抵抗値の低下が無く、短絡する現象は起こらなかっ
た。しかしながら、その電池性能は２５％と極めて低い
ものであった。The ionic conductivity at room temperature of the electrolyte-impregnated membrane obtained by impregnating the porous membrane with the electrolyte at room temperature is 1.1 m.
S / cm, and there was no large decrease in resistance value during the temperature rise process up to 220 ° C., and no short-circuit phenomenon occurred. However, the battery performance was extremely low at 25%.
【００５９】[0059]
【発明の効果】本発明のフッ化ビニリデン系樹脂製多孔
質膜は、電池用隔膜として使用される場合、大きな電流
密度でも高い電池性能を示す上、高温における安定性が
高く安全性の優れた電池を実現できる。また、分離膜と
して使用される場合には、高温においても良好な分離性
能を発揮することができる。When the porous membrane made of vinylidene fluoride resin of the present invention is used as a battery diaphragm, it exhibits high battery performance even at a large current density, and has high stability at high temperatures and excellent safety. A battery can be realized. When used as a separation membrane, good separation performance can be exhibited even at high temperatures.
【００６０】従って、本発明のフッ化ビニリデン系樹脂
製多孔質膜は、リチウム電池等の電池用の構成材料とし
て有用であるとともに、固液分離用膜としても有用なも
のである。Accordingly, the vinylidene fluoride resin porous membrane of the present invention is useful not only as a constituent material for batteries such as lithium batteries, but also as a solid-liquid separation membrane.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 ＦＩ // Ｃ０８Ｌ 27:16 ──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 6 Identification symbol FI // C08L 27:16
Claims (1)
リデンまたは架橋されたフッ化ビニリデンを含む共重合
体からなり、膜の最小孔径層の平均孔径が０．０５〜５
μｍであることを特徴とするフッ化ビニリデン系樹脂製
多孔質膜。1. A porous membrane comprising a crosslinked polyvinylidene fluoride or a copolymer containing crosslinked vinylidene fluoride, wherein the membrane has a minimum pore size layer having an average pore size of 0.05 to 5
A porous membrane made of a vinylidene fluoride-based resin having a thickness of μm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9128791A JPH10316793A (en) | 1997-05-19 | 1997-05-19 | Porous film prepared from vinylidene fluoride resin |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9128791A JPH10316793A (en) | 1997-05-19 | 1997-05-19 | Porous film prepared from vinylidene fluoride resin |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH10316793A true JPH10316793A (en) | 1998-12-02 |
Family
ID=14993549
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9128791A Pending JPH10316793A (en) | 1997-05-19 | 1997-05-19 | Porous film prepared from vinylidene fluoride resin |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH10316793A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000052774A1 (en) * | 1999-03-04 | 2000-09-08 | Japan Storage Battery Co., Ltd. | Composite active material and method for preparing active material, electrode and method for preparing electrode, and non-aqueous electrolyte cell |
| JP2001102089A (en) * | 1999-09-29 | 2001-04-13 | Tdk Corp | Solid electrolyte, electrolyte chemical device, lithium secondary cell and electricity double-layer capacitor |
| JP2002216734A (en) * | 2001-01-16 | 2002-08-02 | Asahi Kasei Corp | Separator for lithium battery |
| JP2004500686A (en) * | 1999-12-09 | 2004-01-08 | 日本特殊陶業株式会社 | Lithium ion battery separator and / or lithium ion polymer battery |
| WO2007119850A1 (en) * | 2006-04-19 | 2007-10-25 | Asahi Kasei Chemicals Corporation | Highly durable porous pvdf film, method of producing the same and washing method and filtration method using the same |
| WO2008034295A1 (en) * | 2006-09-19 | 2008-03-27 | Shenzhen Bak Battery Co., Ltd | A lithium ion battery electrode plate,a lithium ion battery electrode core and the preparation method of the same |
| JP2009518809A (en) * | 2005-12-06 | 2009-05-07 | エルジー・ケム・リミテッド | Organic / inorganic composite separation membrane having morphological gradient, method for producing the same, and electrochemical device including the same |
| EP3903914A4 (en) * | 2018-12-26 | 2022-11-23 | Toray Industries, Inc. | Porous film, composite film, and method for producing porous film |
-
1997
- 1997-05-19 JP JP9128791A patent/JPH10316793A/en active Pending
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6730404B1 (en) | 1999-03-04 | 2004-05-04 | Japan Storage Battery Co., Ltd. | Composite active material and process for the production thereof, electrode and process for the production thereof, and non-aqueous electrolyte battery |
| WO2000052774A1 (en) * | 1999-03-04 | 2000-09-08 | Japan Storage Battery Co., Ltd. | Composite active material and method for preparing active material, electrode and method for preparing electrode, and non-aqueous electrolyte cell |
| JP2001102089A (en) * | 1999-09-29 | 2001-04-13 | Tdk Corp | Solid electrolyte, electrolyte chemical device, lithium secondary cell and electricity double-layer capacitor |
| JP2004500686A (en) * | 1999-12-09 | 2004-01-08 | 日本特殊陶業株式会社 | Lithium ion battery separator and / or lithium ion polymer battery |
| JP2002216734A (en) * | 2001-01-16 | 2002-08-02 | Asahi Kasei Corp | Separator for lithium battery |
| JP2009518809A (en) * | 2005-12-06 | 2009-05-07 | エルジー・ケム・リミテッド | Organic / inorganic composite separation membrane having morphological gradient, method for producing the same, and electrochemical device including the same |
| JP5436854B2 (en) * | 2006-04-19 | 2014-03-05 | 旭化成ケミカルズ株式会社 | High durability PVDF porous membrane, method for producing the same, and cleaning method and filtration method using the same |
| JP2013075294A (en) * | 2006-04-19 | 2013-04-25 | Asahi Kasei Chemicals Corp | Highly durable pvdf porous membrane, method for manufacturing the same, and washing method and filtering method using the membrane |
| WO2007119850A1 (en) * | 2006-04-19 | 2007-10-25 | Asahi Kasei Chemicals Corporation | Highly durable porous pvdf film, method of producing the same and washing method and filtration method using the same |
| JP2014076446A (en) * | 2006-04-19 | 2014-05-01 | Asahi Kasei Chemicals Corp | Highly durable pvdf porous membrane and method of producing the same, and washing method and filtration method using the same |
| US8931647B2 (en) | 2006-04-19 | 2015-01-13 | Asahi Kasei Chemicals Corporation | Highly durable porous PVDF film, method of producing the same and washing method and filtration method using the same |
| WO2008034295A1 (en) * | 2006-09-19 | 2008-03-27 | Shenzhen Bak Battery Co., Ltd | A lithium ion battery electrode plate,a lithium ion battery electrode core and the preparation method of the same |
| EP3903914A4 (en) * | 2018-12-26 | 2022-11-23 | Toray Industries, Inc. | Porous film, composite film, and method for producing porous film |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR101110264B1 (en) | Composite microporous film, and production method and use thereof | |
| KR101965915B1 (en) | Separator and method for producing same | |
| JP3497569B2 (en) | Polyethylene microporous membrane for non-aqueous battery separator | |
| JP4705334B2 (en) | Separator for electronic parts and method for manufacturing the same | |
| WO1997048106A1 (en) | Hybrid electrolyte, method for manufacturing the same, and method for manufacturing electrochemical element using the same | |
| JP2992598B2 (en) | Lithium ion battery | |
| JP6543291B2 (en) | Separator for non-aqueous electrolyte secondary battery | |
| JP4964565B2 (en) | Polyethylene microporous membrane | |
| KR19990071903A (en) | Microporous Polyethylene Membrane with Low Fusing Temperature | |
| EP0577387A1 (en) | Separator for electrochemical cell and method of preparation | |
| JP2018147885A (en) | Nonaqueous electrolyte secondary battery separator | |
| JP4303355B2 (en) | Polyvinylidene fluoride resin, porous membrane comprising the same, and battery using the porous membrane | |
| JPH10316793A (en) | Porous film prepared from vinylidene fluoride resin | |
| JP3195120B2 (en) | Non-aqueous electrolyte battery separator | |
| JPH11152366A (en) | Porous membrane of vinylidene fluoride-based resin | |
| JP3486785B2 (en) | Battery separator and method of manufacturing the same | |
| JP3942277B2 (en) | Composite polymer electrolyte membrane and method for producing the same | |
| JP6598911B2 (en) | Manufacturing method of polyolefin microporous membrane, battery separator, and non-aqueous electrolyte secondary battery | |
| JPH09306462A (en) | Battery separator | |
| JPH1186828A (en) | Battery separator and its manufacture | |
| JP4090539B2 (en) | Lithium ion conductive polymer substrate film | |
| JP4227209B2 (en) | Non-aqueous secondary battery | |
| JP2000021233A (en) | Fluorine resin porous film, gel type polymer electrolyte film using it, and manufacture thereof | |
| JPH1186909A (en) | Electrolyte impregnated film | |
| JP2016188374A (en) | Method for producing polyolefin microporous film, battery separator, and nonaqueous electrolyte secondary battery |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20040510 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20060228 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20060314 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20060502 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20061114 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20070112 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20070508 |