JP2013144442A - Porous film including both high heat resistance and high transmittance, and method for manufacturing the same - Google Patents
Porous film including both high heat resistance and high transmittance, and method for manufacturing the same Download PDFInfo
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- JP2013144442A JP2013144442A JP2013036560A JP2013036560A JP2013144442A JP 2013144442 A JP2013144442 A JP 2013144442A JP 2013036560 A JP2013036560 A JP 2013036560A JP 2013036560 A JP2013036560 A JP 2013036560A JP 2013144442 A JP2013144442 A JP 2013144442A
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- JP
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- Prior art keywords
- polyolefin resin
- porous membrane
- inorganic filler
- battery
- porous
- 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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- 238000000034 method Methods 0.000 title abstract description 52
- 238000002834 transmittance Methods 0.000 title abstract 2
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- 239000011256 inorganic filler Substances 0.000 claims abstract description 53
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- 229920002451 polyvinyl alcohol Polymers 0.000 claims abstract description 21
- 238000007127 saponification reaction Methods 0.000 claims abstract description 18
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- 239000011255 nonaqueous electrolyte Substances 0.000 claims description 23
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- 208000028659 discharge Diseases 0.000 description 13
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- 239000011148 porous material Substances 0.000 description 1
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- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 description 1
- 239000008213 purified water Substances 0.000 description 1
- 229920005604 random copolymer Polymers 0.000 description 1
- 238000007788 roughening Methods 0.000 description 1
- 238000007650 screen-printing Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 229920002379 silicone rubber Polymers 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 229920003048 styrene butadiene rubber Polymers 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- 239000002562 thickening agent Substances 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 229920000785 ultra high molecular weight polyethylene Polymers 0.000 description 1
- 238000001132 ultrasonic dispersion Methods 0.000 description 1
- PXXNTAGJWPJAGM-UHFFFAOYSA-N vertaline Natural products C1C2C=3C=C(OC)C(OC)=CC=3OC(C=C3)=CC=C3CCC(=O)OC1CC1N2CCCC1 PXXNTAGJWPJAGM-UHFFFAOYSA-N 0.000 description 1
- 239000000080 wetting agent Substances 0.000 description 1
- 239000008096 xylene Substances 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- XOOUIPVCVHRTMJ-UHFFFAOYSA-L zinc stearate Chemical compound [Zn+2].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O XOOUIPVCVHRTMJ-UHFFFAOYSA-L 0.000 description 1
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
Landscapes
- Laminated Bodies (AREA)
- Cell Separators (AREA)
- Secondary Cells (AREA)
Abstract
Description
本発明は、電池やコンデンサー等における隔離材や物質の分離等に好適に用いられる多孔膜およびその製造方法に関する。さらに、それを用いた非水電解液電池用セパレータおよび非水電解液電池に関する。 The present invention relates to a porous membrane suitably used for separation of separators and substances in batteries, capacitors and the like, and a method for producing the same. Furthermore, the present invention relates to a separator for a non-aqueous electrolyte battery and a non-aqueous electrolyte battery using the same.
ポリオレフィン多孔膜は優れた電気絶縁性、イオン透過性を示すことから電池やコンデンサー等におけるセパレータとして広く利用されている。特に近年では携帯機器の多機能化、軽量化に伴いその電源として高出力密度、高容量密度のリチウムイオン二次電池が使用されており、このような電池用セパレータにも主としてポリオレフィン多孔膜が用いられている。
リチウムイオン二次電池は高い出力密度、容量密度を持つ反面、電解液に有機溶媒を用いているために短絡や過充電などの異常事態に伴う発熱によって電解液が分解し、最悪の場合には発火に至ることがある。このような事態を防ぐためリチウムイオン二次電池にはいくつかの安全機能が組み込まれており、その中の一つにセパレータのシャットダウン機能がある。シャットダウン機能とは電池が異常発熱を起こした際、セパレータの微多孔が熱溶融等により閉塞して電解液内のイオン伝導を抑制し電気化学反応の進行をストップさせる機能のことである。一般的にシャットダウン温度が低いほど安全性が高いとされ、ポリエチレンがセパレータの成分として用いられている理由の一つに適度なシャットダウン温度を持つという点が挙げられる。しかし、高いエネルギーを有する電池においては熱暴走時の発熱量が大きく、シャットダウン温度を超えても温度が上昇し続けた場合、セパレータの熱収縮に伴う破膜により両極が短絡し、さらなる発熱を引き起こす危険性がある。
Polyolefin porous membranes are widely used as separators in batteries, capacitors and the like because they exhibit excellent electrical insulation and ion permeability. In recent years, lithium ion secondary batteries with a high output density and a high capacity density have been used as power sources in connection with the increasing functionality and weight of portable devices in recent years. Polyolefin porous membranes are mainly used for such battery separators. It has been.
Lithium ion secondary batteries have high output density and capacity density, but because the electrolyte uses an organic solvent, the electrolyte decomposes due to heat generated by abnormal situations such as short circuit and overcharge. May cause fire. In order to prevent such a situation, some safety functions are incorporated in the lithium ion secondary battery, and one of them is a shutdown function of the separator. The shutdown function is a function that stops the progress of the electrochemical reaction by suppressing the ionic conduction in the electrolytic solution by blocking the micropores of the separator by heat melting or the like when the battery generates abnormal heat. Generally, the lower the shutdown temperature, the higher the safety. One of the reasons why polyethylene is used as a component of the separator is that it has an appropriate shutdown temperature. However, in a battery with high energy, the amount of heat generated during thermal runaway is large, and if the temperature continues to rise even after exceeding the shutdown temperature, both electrodes are short-circuited due to the film breakage due to the thermal contraction of the separator, causing further heat generation There is a risk.
このような問題を解決するために、セパレータと電極の間に絶縁性無機フィラーを主成分とする層を形成する方法が提案されている。（特許文献１、２、３、４、５、６、７）この方法ではシャットダウン温度を超えて温度が上昇し続けてセパレータが破膜しても、無機フィラー層が絶縁層として存在するために両極の短絡を防止できるため、非常に安全性に優れていると記載されている。
ポリビニルアルコールは、接着剤や水系電解液電池用の電極用バインダとして広く用いられている樹脂である。非水電解液電池においても、上記絶縁性無機フィラーを主成分とする層中のバインダとして使用する方法（特許文献１、３、４）や、電極層とセパレータの間を接着する接着剤として使用する方法（特許文献８、９、１０）が提案されている。
In order to solve such a problem, a method of forming a layer mainly composed of an insulating inorganic filler between a separator and an electrode has been proposed. (Patent Documents 1, 2, 3, 4, 5, 6, 7) In this method, even if the temperature continues to rise beyond the shutdown temperature and the separator breaks down, the inorganic filler layer exists as an insulating layer. It is described that it is extremely safe because it can prevent a short circuit between the two electrodes.
Polyvinyl alcohol is a resin that is widely used as an electrode binder for adhesives and aqueous electrolyte batteries. Also in non-aqueous electrolyte batteries, it is used as a binder in a layer mainly composed of the above-mentioned insulating inorganic filler (Patent Documents 1, 3, and 4) and used as an adhesive for bonding between an electrode layer and a separator. (Patent Documents 8, 9, and 10) have been proposed.
セパレータであるポリオレフィン樹脂多孔膜の表面に無機フィラー層を形成させた場合、樹脂製バインダとしてポリビニルアルコールを用いると、シャットダウン温度を超えて温度が上昇し続けた場合、破膜等によって両極の短絡が発生する温度（ショート温度）に大きなばらつきが発生するという現象が生じていた。
本発明は、耐熱性と透過性に優れた多孔膜、特に非水電解液電池用セパレータとして有用な多孔膜を提供することを目的とする。また、そのような多孔膜を高い生産性にて提供できる製造方法、高い安全性と実用性を備えた非水電解液電池用セパレータおよび非水電解液電池を提供することを目的とする。
When an inorganic filler layer is formed on the surface of a polyolefin resin porous membrane as a separator, if polyvinyl alcohol is used as a resin binder, if the temperature continues to rise above the shutdown temperature, short-circuiting of both electrodes may occur due to membrane breakage, etc. There has been a phenomenon in which large variations occur in the generated temperature (short circuit temperature).
An object of the present invention is to provide a porous membrane excellent in heat resistance and permeability, particularly a porous membrane useful as a separator for a nonaqueous electrolyte battery. Moreover, it aims at providing the manufacturing method which can provide such a porous membrane with high productivity, the separator for nonaqueous electrolyte batteries and the nonaqueous electrolyte battery provided with high safety | security and practicality.
本発明者は、前記課題を解決するため鋭意検討した結果、本発明に到達した。
すなわち、本発明は下記の通りである。
［１］ポリオレフィン樹脂多孔膜の少なくとも片面に、無機フィラーとケン化度８５％以上のポリビニルアルコールからなる多孔層を備えた多層多孔膜。
［２］［１］に記載の多層多孔膜を用いた非水電解液電池用セパレータ。
［３］［２］に記載の電池用セパレータを用いた非水電解液電池。
［４］ポリオレフィン樹脂多孔膜の少なくとも片面に、無機フィラーとケン化度８５％以上のポリビニルアルコールとを含有する分散液を塗布することで、ポリオレフィン樹脂多孔膜表面に多孔層を形成することを特徴とする多層多孔膜の製造方法。
The inventor of the present invention has arrived at the present invention as a result of intensive studies to solve the above-mentioned problems.
That is, the present invention is as follows.
[1] A multilayer porous membrane comprising a porous layer composed of an inorganic filler and polyvinyl alcohol having a saponification degree of 85% or more on at least one surface of the polyolefin resin porous membrane.
[2] A separator for a non-aqueous electrolyte battery using the multilayer porous membrane according to [1].
[3] A nonaqueous electrolyte battery using the battery separator according to [2].
[4] A porous layer is formed on the surface of the polyolefin resin porous membrane by applying a dispersion containing an inorganic filler and polyvinyl alcohol having a saponification degree of 85% or more to at least one surface of the polyolefin resin porous membrane. A method for producing a multilayer porous membrane.
本発明によれば、優れた耐熱性と透過性を示し、リチウムイオン二次電池などの非水電解液二次電池および電気二重層キャパシタ等の蓄電池用セパレータ等として有用な多層多孔膜、その製造方法、それを用いた非水電解液電池用セパレータおよび非水電解液電池を提供できる。 According to the present invention, a multilayer porous membrane that exhibits excellent heat resistance and permeability and is useful as a separator for storage batteries such as non-aqueous electrolyte secondary batteries such as lithium ion secondary batteries and electric double layer capacitors, and the production thereof A method, a separator for a nonaqueous electrolyte battery using the method, and a nonaqueous electrolyte battery can be provided.
以下に、本発明について詳細に説明する。
本発明の多層多孔膜は、ポリオレフィン樹脂多孔膜の少なくとも片面に、無機フィラーとケン化度８５％以上のポリビニルアルコールからなる多孔層を有している。
ポリオレフィン樹脂多孔膜は、電池用セパレータとして用いた場合のシャットダウン性能などの点から、多孔膜を構成する樹脂成分の質量分率の５０％以上１００％以下をポリオレフィン樹脂が占める多孔膜であることが好ましく、さらには５５％以上１００％以下がより好ましく、６０％以上１００％以下であることが最も好ましい。
The present invention is described in detail below.
The multilayer porous membrane of the present invention has a porous layer made of an inorganic filler and polyvinyl alcohol having a saponification degree of 85% or more on at least one surface of the polyolefin resin porous membrane.
The polyolefin resin porous membrane is a porous membrane in which the polyolefin resin occupies 50% or more and 100% or less of the mass fraction of the resin component constituting the porous membrane from the viewpoint of shutdown performance when used as a battery separator. Preferably, it is more preferably 55% or more and 100% or less, and most preferably 60% or more and 100% or less.
ポリオレフィン樹脂とは、通常の押出、射出、インフレーション、及びブロー成形等に使用するポリオレフィン樹脂をいい、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、及び１−オクテン等のホモ重合体及び共重合体、多段重合体等を使用することができる。また、これらのホモ重合体及び共重合体、多段重合体の群から選んだポリオレフィンを単独、もしくは混合して使用することもできる。前記重合体の代表例としては、低密度ポリエチレン、線状低密度ポリエチレン、中密度ポリエチレン、高密度ポリエチレン、超高分子量ポリエチレン、アイソタクティックポリプロピレン、アタクティックポリプロピレン、エチレン−プロピレンランダム共重合体、ポリブテン、エチレンプロピレンラバー等が挙げられる。本発明の微多孔膜を電池セパレータとして使用する場合、低融点であり、かつ高強度の要求性能から、特に高密度ポリエチレンを主成分とする樹脂を使用することが好ましい。 The polyolefin resin refers to a polyolefin resin used for normal extrusion, injection, inflation, blow molding and the like, such as ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-octene. Homopolymers and copolymers, multistage polymers, and the like can be used. In addition, polyolefins selected from the group of these homopolymers, copolymers, and multistage polymers can be used alone or in combination. Representative examples of the polymer include low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, ultrahigh molecular weight polyethylene, isotactic polypropylene, atactic polypropylene, ethylene-propylene random copolymer, polybutene. And ethylene propylene rubber. When the microporous membrane of the present invention is used as a battery separator, it is preferable to use a resin mainly composed of high-density polyethylene because of its low melting point and high strength required performance.
ポリオレフィン樹脂の粘度平均分子量は、３万以上１２００万以下が好ましく、さらに好ましくは５万以上２００万未満、最も好ましくは１０万以上１００万未満である。粘度
平均分子量が３万以上であれば、溶融成形の際のメルトテンションが大きくなり成形性が向上しやすい上に、十分な絡み合いを付与しやすく高強度となりやすいので好ましい。粘度平均分子量が１２００万以下であれば、均一な溶融混練を得やすい傾向があり、シートの成形性、特に厚み安定性に優れる傾向があるので好ましい。さらに粘度平均分子量が１００万未満であれば、電池用セパレータとして使用した場合に、温度上昇時に孔を閉塞しやすく良好なシャットダウン機能が得られやすいので好ましい。使用するポリオレフィン樹脂は、例えば、単独で粘度平均分子量１００万未満のポリオレフィンを使用する代わりに、粘度平均分子量が２００万のポリエチレンと２７万の混合物とし、混合物の粘度平均分子量を１００万未満としてもよい。
The viscosity average molecular weight of the polyolefin resin is preferably from 30,000 to 12 million, more preferably from 50,000 to less than 2 million, and most preferably from 100,000 to less than 1 million. A viscosity average molecular weight of 30,000 or more is preferable because the melt tension at the time of melt molding becomes large and the moldability is easily improved and sufficient entanglement is easily imparted and the strength is easily increased. If the viscosity average molecular weight is 12 million or less, it tends to be easy to obtain uniform melt-kneading and is preferable because it tends to be excellent in sheet formability, particularly thickness stability. Further, when the viscosity average molecular weight is less than 1,000,000, it is preferable that when used as a battery separator, it is easy to close a hole when the temperature rises and a good shutdown function is easily obtained. For example, instead of using a polyolefin having a viscosity average molecular weight of less than 1 million alone, the polyolefin resin to be used is a mixture of polyethylene having a viscosity average molecular weight of 2 million and 270,000, and the viscosity average molecular weight of the mixture is less than 1 million. Good.
ポリオレフィン樹脂は、後述の無機充填材を含有することも可能であり、本発明の利点を損なわない範囲で必要に応じて、フェノール系やリン系やイオウ系等の酸化防止剤、ステアリン酸カルシウムやステアリン酸亜鉛等の金属石鹸類、紫外線吸収剤、光安定剤、帯電防止剤、防曇剤、着色顔料等の添加剤を混合して使用できる。
本発明の多層多孔膜は、上記ポリオレフィン樹脂多孔膜の少なくとも片面に、無機フィラーとケン化度８５％以上のポリビニルアルコールからなる多孔層を備えており、これにより優れた耐熱性を示す。
多孔層の層厚は耐熱性向上の点から０．５μｍ以上が好ましく、透過性や電池の高容量化の点から１００μｍ以下が好ましく、より好ましくは２μｍ以上５０μｍ以下、より好ましくは３μｍ以上３０μｍ以下、最も好ましくは４μｍ以上２０μｍ以下である。
The polyolefin resin can also contain an inorganic filler described later, and, as necessary, within the range not impairing the advantages of the present invention, an antioxidant such as phenol, phosphorus or sulfur, calcium stearate or stearin. Metal soaps such as zinc acid, ultraviolet absorbers, light stabilizers, antistatic agents, antifogging agents, and coloring pigments can be mixed and used.
The multilayer porous membrane of the present invention comprises a porous layer composed of an inorganic filler and polyvinyl alcohol having a saponification degree of 85% or more on at least one surface of the polyolefin resin porous membrane, thereby exhibiting excellent heat resistance.
The layer thickness of the porous layer is preferably 0.5 μm or more from the viewpoint of improving heat resistance, preferably 100 μm or less, more preferably 2 μm or more and 50 μm or less, and more preferably 3 μm or more and 30 μm or less from the viewpoint of permeability or high capacity of the battery. Most preferably, it is 4 μm or more and 20 μm or less.
多孔層に使用するポリビニルアルコールは、ケン化度８５％以上１００％以下である。ケン化度８５％以上だと、ショート温度が大幅に向上するため、良好な安全性能が得られる傾向にあるので好ましい。ケン化度は９０％以上１００％以下が好ましく、９５％以上１００％以下がより好ましく、９９％以上１００％以下が最も好ましい。ポリビニルアルコールの重合度は、２００以上５０００以下が好ましく、３００以上４０００以下がより好ましく、５００以上３５００以下が最も好ましい。重合度が２００以上のポリビニルアルコールでは、少量で無機フィラーを強固に結着できるため、多孔層の力学的強度を維持しながら多層多孔膜の透気度上昇を抑えることができるので好ましい。また、重合度５０００以下のポリビニルアルコールでは、無機フィラーとの分散液を調製する場合、ゲル化等を防止できるので好ましい。
多孔層中の無機フィラーの占める質量分率は、耐熱性の点から、５０％以上１００％未満であることが好ましく、５５％以上９９．９９％以下であることがより好ましく、６０％以上９９．９％以下であることがさらに好ましく、６５％以上９９％以下であることが特に好ましい。
Polyvinyl alcohol used for the porous layer has a saponification degree of 85% or more and 100% or less. A saponification degree of 85% or more is preferable because the short-circuit temperature is greatly improved and good safety performance tends to be obtained. The saponification degree is preferably 90% to 100%, more preferably 95% to 100%, and most preferably 99% to 100%. The polymerization degree of polyvinyl alcohol is preferably 200 or more and 5000 or less, more preferably 300 or more and 4000 or less, and most preferably 500 or more and 3500 or less. Polyvinyl alcohol having a degree of polymerization of 200 or more is preferable because the inorganic filler can be firmly bound in a small amount, and thus the increase in the air permeability of the multilayer porous membrane can be suppressed while maintaining the mechanical strength of the porous layer. Polyvinyl alcohol having a degree of polymerization of 5000 or less is preferable when preparing a dispersion with an inorganic filler because gelation can be prevented.
The mass fraction occupied by the inorganic filler in the porous layer is preferably from 50% to less than 100%, more preferably from 55% to 99.99%, more preferably from 60% to 99, from the viewpoint of heat resistance. Is more preferably 9% or less, and particularly preferably 65% or more and 99% or less.
多孔層に使用する無機フィラーとしては、２００℃以上の融点をもち、電気絶縁性が高く、かつリチウムイオン二次電池の使用範囲で電気化学的に安定であるものが好ましい。例えば、アルミナ、シリカ、チタニア、ジルコニア、マグネシア、セリア、イットリア、酸化亜鉛、酸化鉄などの酸化物系セラミックス、窒化ケイ素、窒化チタン、窒化ホウ素等の窒化物系セラミックス、シリコンカーバイド、炭酸カルシウム、硫酸アルミニウム、水酸化アルミニウム、チタン酸カリウム、タルク、カオリンクレー、カオリナイト、ハロイサイト、パイロフィライト、モンモリロナイト、セリサイト、マイカ、アメサイト、ベントナイト、アスベスト、ゼオライト、ケイ酸カルシウム、ケイ酸マグネシウム、ケイ藻土、ケイ砂等のセラミックス、ガラス繊維などが挙げられ、これらを単独で用いてもよいし、複数を混合して用いてもよい。電気化学的安定性の点から、アルミナ、チタニアがより好ましい。無機フィラーの平均粒径は、０．１μｍ以上２．０μｍ以下が好ましく、０．２μｍ以上１．０μｍ以下がより好ましい。０．１μｍ未満だとショート温度が低くなる傾向がある。また２．０μｍ超だと層厚の薄い多孔層を形成することが困難となる。 As the inorganic filler used for the porous layer, a filler having a melting point of 200 ° C. or higher, high electrical insulation, and electrochemically stable within the use range of the lithium ion secondary battery is preferable. For example, oxide ceramics such as alumina, silica, titania, zirconia, magnesia, ceria, yttria, zinc oxide, iron oxide, nitride ceramics such as silicon nitride, titanium nitride, boron nitride, silicon carbide, calcium carbonate, sulfuric acid Aluminum, aluminum hydroxide, potassium titanate, talc, kaolin clay, kaolinite, halloysite, pyrophyllite, montmorillonite, sericite, mica, amicite, bentonite, asbestos, zeolite, calcium silicate, magnesium silicate, diatom Examples thereof include ceramics such as soil and silica sand, glass fibers, and the like, and these may be used alone or in combination. From the viewpoint of electrochemical stability, alumina and titania are more preferable. The average particle size of the inorganic filler is preferably 0.1 μm or more and 2.0 μm or less, and more preferably 0.2 μm or more and 1.0 μm or less. If it is less than 0.1 μm, the short circuit temperature tends to be low. On the other hand, if it exceeds 2.0 μm, it becomes difficult to form a thin porous layer.
本発明により、優れた耐熱性と透過性を同時に達成する多層多孔膜を得ることができるのであるが、基材であるポリオレフィン樹脂多孔膜の透気度に対して、多孔層を形成した後の多層多孔膜の透気度の増加率は０％以上１００％以下であることが好ましく、０％以上７０％以下であることがより好ましく、０％以上５０％以下であることが特に好ましい。ただし、基材であるポリオレフィン樹脂多孔膜の透気度が１００秒／１００ｃｃ未満の場合は、多孔層を形成した後の多層多孔膜の透気度増加率は０％以上５００％以下であれば好ましく用いることが出来る。
多層多孔膜の透気度は１０秒／１００ｃｃ以上６５０秒／１００ｃｃ以下、好ましくは２０秒／１００ｃｃ以上５００秒／１００ｃｃ以下、より好ましくは３０秒／１００ｃｃ以上４５０秒／１００ｃｃ以下、特に好ましくは５０秒／１００ｃｃ以上４００秒／１００ｃｃ以下の範囲である。透気度が１０秒／１００ｃｃ以上では電池用セパレータとして使用した際に自己放電が少なく、６５０秒／１００ｃｃ以下では良好な充放電特性が得られる。
According to the present invention, it is possible to obtain a multilayer porous membrane that simultaneously achieves excellent heat resistance and permeability, but after forming a porous layer with respect to the air permeability of the polyolefin resin porous membrane as a substrate. The rate of increase in air permeability of the multilayer porous membrane is preferably 0% or more and 100% or less, more preferably 0% or more and 70% or less, and particularly preferably 0% or more and 50% or less. However, if the air permeability of the polyolefin resin porous membrane as the substrate is less than 100 seconds / 100 cc, the rate of increase in air permeability of the multilayer porous membrane after forming the porous layer is from 0% to 500% It can be preferably used.
The air permeability of the multilayer porous membrane is 10 seconds / 100 cc or more and 650 seconds / 100 cc or less, preferably 20 seconds / 100 cc or more and 500 seconds / 100 cc or less, more preferably 30 seconds / 100 cc or more and 450 seconds / 100 cc or less, particularly preferably 50 The range is from second / 100 cc to 400 second / 100 cc. When the air permeability is 10 seconds / 100 cc or more, self-discharge is small when used as a battery separator, and when 650 seconds / 100 cc or less, good charge / discharge characteristics are obtained.
多層多孔膜の最終的な膜厚は、２μｍ以上２００μｍ以下の範囲が好ましく、５μｍ以上１００μｍ以下の範囲がより好ましく、７μｍ以上５０μｍ以下の範囲がさらに好ましい。膜厚が２μｍ以上であれば機械強度が十分であり、また、２００μｍ以下であればセパレータの占有体積が減るため、電池の高容量化の点において有利となる傾向があるので好ましい。
多層多孔膜の１５０℃での熱収縮率は、ＭＤ方向、ＴＤ方向ともに０％以上１５％以下であることが好ましく、０％以上１０％以下であることがより好ましく、０％以上５％以下であることが特に好ましい。ＭＤ方向、ＴＤ方向ともに１５％以下であれば電池の異常発熱時においてもセパレータの破膜を防ぐことが出来るので、正負極間の接触を抑制し得るため、より良好な安全性能が得られる傾向があるので好ましい。
The final film thickness of the multilayer porous membrane is preferably in the range of 2 μm to 200 μm, more preferably in the range of 5 μm to 100 μm, and still more preferably in the range of 7 μm to 50 μm. If the film thickness is 2 μm or more, the mechanical strength is sufficient, and if the film thickness is 200 μm or less, the occupied volume of the separator is reduced, and this tends to be advantageous in terms of increasing the capacity of the battery.
The thermal shrinkage rate at 150 ° C. of the multilayer porous membrane is preferably 0% or more and 15% or less in both the MD direction and the TD direction, more preferably 0% or more and 10% or less, and more preferably 0% or more and 5% or less. It is particularly preferred that If the MD direction and the TD direction are 15% or less, it is possible to prevent the separator from breaking even when the battery is abnormally heated. Therefore, it is possible to suppress contact between the positive and negative electrodes, and thus better safety performance tends to be obtained. This is preferable.
多層多孔膜のシャットダウン温度は、１２０℃以上１６０℃以下が好ましく、より好ましくは１２０℃以上１５０℃以下の範囲である。１６０℃以下であると、電池が発熱した場合などにおいても、電流遮断を速やかに促進し、より良好な安全性能が得られる傾向にあるので好ましい。一方、１２０℃以上であると例えば１００℃前後での高温化の使用、熱処理等を実施できるので好ましい。
多層多孔膜のショート温度は、１８０℃以上１０００℃以下が好ましく、２００℃以上１０００℃以下がより好ましい。１８０℃以上であると電池異常発熱においても放熱するまで正負極間の接触を抑制し得るため、より良好な安全性能が得られる傾向があるので好ましい。
The shutdown temperature of the multilayer porous membrane is preferably 120 ° C. or higher and 160 ° C. or lower, more preferably 120 ° C. or higher and 150 ° C. or lower. When the temperature is 160 ° C. or lower, even when the battery generates heat, current interruption is promptly promoted, and better safety performance tends to be obtained, which is preferable. On the other hand, it is preferable that the temperature is 120 ° C. or higher because, for example, use of a high temperature around 100 ° C., heat treatment, and the like can be performed.
The short-circuit temperature of the multilayer porous membrane is preferably 180 ° C. or higher and 1000 ° C. or lower, and more preferably 200 ° C. or higher and 1000 ° C. or lower. When the temperature is 180 ° C. or higher, contact between the positive and negative electrodes can be suppressed until the heat is dissipated even in abnormal battery heat generation.
本発明の多層多孔膜は、ポリオレフィン樹脂多孔膜の少なくとも片面に、無機フィラーとケン化度８５％以上のポリビニルアルコールとを含有する分散液を塗布することで、ポリオレフィン樹脂多孔膜表面に多孔層を形成する方法により、好適に製造できる。
ポリオレフィン樹脂としては前述のものが好適に使用できる。ポリオレフィン樹脂には、本発明の利点を損なわない範囲で必要に応じて、フェノール系やリン系やイオウ系等の酸化防止剤、ステアリン酸カルシウムやステアリン酸亜鉛等の金属石鹸類、紫外線吸収剤、光安定剤、帯電防止剤、防曇剤、着色顔料等の添加剤を混合して使用できる。
In the multilayer porous membrane of the present invention, a porous layer is formed on the surface of the polyolefin resin porous membrane by applying a dispersion containing an inorganic filler and polyvinyl alcohol having a saponification degree of 85% or more to at least one surface of the polyolefin resin porous membrane. It can manufacture suitably by the method of forming.
As the polyolefin resin, those described above can be preferably used. Polyolefin resins include phenolic, phosphorus and sulfur-based antioxidants, metal soaps such as calcium stearate and zinc stearate, ultraviolet absorbers, light as necessary, as long as the advantages of the present invention are not impaired. Additives such as stabilizers, antistatic agents, antifogging agents, and coloring pigments can be mixed and used.
ポリオレフィン樹脂多孔膜の製造方法としては、特に制限することなく一般的な製造方法を採用することができる。例えば、一般的な製造方法として、ポリオレフィン樹脂と可塑剤とを溶融混練してシート状に成形後、可塑剤を抽出することで多孔化させる方法、ポリオレフィン樹脂を溶融混練して高ドロー比で押出した後、熱処理と延伸によってポリオレフィン結晶界面を剥離させることで多孔化させる方法、ポリオレフィン樹脂と無機充填材とを溶融混練してシート上に成形後、延伸によってポリオレフィン樹脂と無機充填材との界面を剥離させることで多孔化させる方法、ポリオレフィン樹脂を溶解後、ポリオレフ
ィン樹脂に対する貧溶媒に浸漬させポリオレフィン樹脂を凝固させると同時に溶剤を除去することで多孔化させる方法などが挙げられる。
As a manufacturing method of a polyolefin resin porous membrane, a general manufacturing method can be adopted without particular limitation. For example, as a general manufacturing method, a polyolefin resin and a plasticizer are melt-kneaded and formed into a sheet shape, and then made porous by extracting the plasticizer. A polyolefin resin is melt-kneaded and extruded at a high draw ratio. After that, the method is made porous by exfoliating the polyolefin crystal interface by heat treatment and stretching, melt-kneading the polyolefin resin and the inorganic filler and forming on the sheet, and then stretching the interface between the polyolefin resin and the inorganic filler. Examples thereof include a method of making it porous by peeling, a method of dissolving a polyolefin resin and then immersing it in a poor solvent for the polyolefin resin to solidify the polyolefin resin and simultaneously making it porous by removing the solvent.
以下、ポリオレフィン樹脂と可塑剤とを溶融混練してシート状に成形後、可塑剤を抽出することで多孔化させる方法について説明する。
可塑剤としては、ポリオレフィン樹脂と混合した際にポリオレフィン樹脂の融点以上において均一溶液を形成しうる不揮発性溶媒であれば良い。例えば、流動パラフィンやパラフィンワックス等の炭化水素類、フタル酸ジオクチルやフタル酸ジブチル等のエステル類、オレイルアルコールやステアリルアルコール等の高級アルコール等が挙げられる。特にポリオレフィン樹脂がポリエチレンの場合、流動パラフィンは、ポリエチレンと相溶性が高く延伸時に樹脂と可塑剤の界面剥離が起こりにくいために均一な延伸を実施しやすく好ましい。
Hereinafter, a method of making a porous structure by extracting a plasticizer after melt-kneading a polyolefin resin and a plasticizer to form a sheet and then forming the sheet will be described.
The plasticizer may be any non-volatile solvent that can form a uniform solution above the melting point of the polyolefin resin when mixed with the polyolefin resin. Examples thereof include hydrocarbons such as liquid paraffin and paraffin wax, esters such as dioctyl phthalate and dibutyl phthalate, and higher alcohols such as oleyl alcohol and stearyl alcohol. In particular, when the polyolefin resin is polyethylene, liquid paraffin is preferable because it is highly compatible with polyethylene and is difficult to cause interface peeling between the resin and the plasticizer during stretching.
本発明において、ポリオレフィン樹脂および可塑剤と一緒に無機充填材を溶融混練することが出来る。この際に使用する無機充填材は、２００℃以上の融点をもち、電気絶縁性が高く、かつリチウムイオン二次電池の使用範囲で電気化学的に安定であるものならば、特に限定することなく使用することが出来る。この条件を満たすものであれば単独で用いてもよいし、複数を混合して用いてもよい。無機充填材としては、例えば、アルミナ、シリカ、チタニア、ジルコニア、マグネシア、セリア、イットリア、酸化亜鉛、酸化鉄などの酸化物系セラミックスや窒化ケイ素、窒化チタン、窒化ホウ素等の窒化物系セラミックス、シリコンカーバイド、炭酸カルシウム、硫酸アルミニウム、チタン酸カリウム、タルク、カオリンクレー、カオリナイト、ハロイサイト、パイロフィライト、モンモリロナイト、セリサイト、マイカ、アメサイト、ベントナイト、アスベスト、ゼオライト、ケイ酸カルシウム、ケイ酸マグネシウム、ケイ藻土、ケイ砂等のセラミックス、ガラス繊維等のセラミックスなどが挙げられ、これらを単独で用いてもよいし、複数を混合して用いてもよい。 In the present invention, the inorganic filler can be melt-kneaded together with the polyolefin resin and the plasticizer. The inorganic filler used in this case is not particularly limited as long as it has a melting point of 200 ° C. or higher, has high electrical insulation, and is electrochemically stable within the usage range of the lithium ion secondary battery. Can be used. As long as these conditions are satisfied, they may be used alone or in combination. Examples of the inorganic filler include oxide ceramics such as alumina, silica, titania, zirconia, magnesia, ceria, yttria, zinc oxide and iron oxide, and nitride ceramics such as silicon nitride, titanium nitride and boron nitride, silicon Carbide, calcium carbonate, aluminum sulfate, potassium titanate, talc, kaolin clay, kaolinite, halloysite, pyrophyllite, montmorillonite, sericite, mica, amicite, bentonite, asbestos, zeolite, calcium silicate, magnesium silicate, Examples thereof include ceramics such as diatomaceous earth and silica sand, ceramics such as glass fiber, etc., and these may be used alone or in combination.
ポリオレフィン樹脂に対する無機充填材の含有量は、可塑剤を加えた状態で、均一な溶融製膜が可能であり、シート状の多孔膜前駆体を形成でき、かつ生産性を損なわない程度であることが好ましく、ポリオレフィン樹脂と無機充填材とからなる組成物中に占める無機充填材の質量分率で０％以上９０％以下であることが好ましく、１％以上８０％以下がより好ましく、３％以上７０％以下が特に好ましく、５％以上６０％以下が最も好ましい。無機充填材を添加すると、電解液との親和性が向上するため、電解液の含浸性を向上出来るので好ましい。また無機充填材の質量分率が９０％以下であれば、生産性を損なわずに、均一かつシート状の多孔膜前駆体を溶融製膜にて形成することが可能であるので好ましい。 The content of the inorganic filler relative to the polyolefin resin is such that uniform melt film formation is possible with the addition of a plasticizer, a sheet-like porous film precursor can be formed, and productivity is not impaired. The mass fraction of the inorganic filler in the composition comprising the polyolefin resin and the inorganic filler is preferably 0% or more and 90% or less, more preferably 1% or more and 80% or less, and more preferably 3% or more. It is particularly preferably 70% or less, and most preferably 5% or more and 60% or less. The addition of an inorganic filler is preferable because the affinity with the electrolytic solution is improved and the impregnation property of the electrolytic solution can be improved. A mass fraction of the inorganic filler of 90% or less is preferable because a uniform and sheet-like porous film precursor can be formed by melt film formation without impairing productivity.
ポリオレフィン樹脂と可塑剤、あるいはポリオレフィン樹脂と無機充填材と可塑剤との比率については、均一な溶融混練が可能な比率であり、シート状の微多孔膜前駆体を成形しうるのに充分な比率であり、かつ生産性を損なわない程度とするのが好ましく、ポリオレフィン樹脂と可塑剤からなる組成物、あるいはポリオレフィン樹脂と無機充填材と可塑剤とからなる組成物中に占める可塑剤の質量分率は、好ましくは３０〜８０質量％、更に好ましくは４０〜７０質量％である。可塑剤の質量分率が８０質量％以下の場合、溶融成形時のメルトテンションが不足しにくく成形性が向上する傾向があるので好ましい。一方、質量分率が３０質量％以上の場合は、延伸倍率の増大に伴い厚み方向に薄くなり、薄膜を得ることが可能であるので好ましい。また可塑化効果が十分なために結晶状の折り畳まれたラメラ晶を効率よく引き伸ばすことができ、高倍率の延伸ではポリオレフィン鎖の切断が起こらず均一かつ微細な孔構造となり強度も増加しやすい。さらに押出し負荷が低減され、生産性が向上する。 The ratio between the polyolefin resin and the plasticizer or between the polyolefin resin, the inorganic filler, and the plasticizer is a ratio that enables uniform melt-kneading and is a ratio sufficient to form a sheet-like microporous membrane precursor. The mass fraction of the plasticizer in the composition comprising the polyolefin resin and the plasticizer or the composition comprising the polyolefin resin, the inorganic filler and the plasticizer is preferable. Is preferably 30 to 80% by mass, more preferably 40 to 70% by mass. When the plasticizer has a mass fraction of 80% by mass or less, the melt tension at the time of melt molding is hardly insufficient and the moldability tends to be improved, which is preferable. On the other hand, when the mass fraction is 30% by mass or more, it is preferable because the film becomes thinner in the thickness direction as the draw ratio increases and a thin film can be obtained. In addition, since the plasticizing effect is sufficient, the crystalline folded lamellar crystal can be efficiently stretched, and when stretched at a high magnification, the polyolefin chain is not broken and a uniform and fine pore structure is obtained and the strength is easily increased. Furthermore, the extrusion load is reduced and productivity is improved.
ポリオレフィン樹脂と可塑剤、あるいはポリオレフィン樹脂と無機充填材と可塑剤を溶融混練する方法としては、ポリオレフィン樹脂単独、あるいはポリオレフィン樹脂と無機充填材を押出機、ニーダー、ラボプラストミル、混練ロール、バンバリーミキサー等の樹脂混練装置に投入し、樹脂を加熱溶融させながら任意の比率で可塑剤を導入し、更にポリオレフィン樹脂と可塑剤、あるいはポリオレフィン樹脂と無機充填材と可塑剤よりなる組成物を混練することにより、均一溶液を得る方法が好ましい。さらに好ましい方法としては予めポリオレフィン樹脂と可塑剤、あるいはポリオレフィン樹脂と無機充填材と可塑剤とをヘンシェルミキサー等を用い所定の割合で事前混練する工程を経て、該混練物を押出機に投入し、加熱溶融させながら任意の比率で可塑剤を導入し更に混練することが挙げられる。具体的には、ポリオレフィン樹脂と可塑剤、あるいはポリオレフィン樹脂と無機充填材と可塑剤とをヘンシェルミキサー等で事前混練したものを二軸押出機に投入し、所定可塑剤添加量の残り分をサイドフィードすることで、より分散性が良好なシートを得ることができ、高倍率の延伸を破膜することなく実施することができる。 As a method of melt-kneading polyolefin resin and plasticizer, or polyolefin resin, inorganic filler and plasticizer, polyolefin resin alone, or polyolefin resin and inorganic filler, extruder, kneader, lab plast mill, kneading roll, Banbury mixer Into a resin kneading apparatus such as a plasticizer, introducing a plasticizer at an arbitrary ratio while heating and melting the resin, and kneading a composition comprising a polyolefin resin and a plasticizer or a polyolefin resin, an inorganic filler and a plasticizer. Thus, a method of obtaining a uniform solution is preferable. As a more preferable method, a polyolefin resin and a plasticizer, or a polyolefin resin, an inorganic filler, and a plasticizer are previously kneaded at a predetermined ratio using a Henschel mixer or the like, and the kneaded product is put into an extruder. Examples of the method include introducing a plasticizer at an arbitrary ratio while heating and melting and further kneading. Specifically, polyolefin resin and plasticizer, or polyolefin resin, inorganic filler and plasticizer pre-kneaded with a Henschel mixer etc. are put into a twin screw extruder and the remaining amount of the specified plasticizer added is side By feeding, a sheet with better dispersibility can be obtained, and stretching at a high magnification can be performed without breaking the membrane.
上記溶融混練物はシート状に成形される。溶融物を押出して冷却固化させシート状成形体を製造する方法は、ポリオレフィン樹脂と可塑剤、あるいはポリオレフィン樹脂と無機充填材と可塑剤の均一溶融物を、Ｔダイ等を介してシート状に押出し、熱伝導体に接触させて樹脂の結晶化温度より充分に低い温度まで冷却することにより行うことが好ましい。冷却固化に用いられる熱伝導体としては、金属、水、空気、あるいは可塑剤自身等が使用できるが、特に金属製のロールに接触させて冷却する方法が最も熱伝導の効率が高く好ましい。また、金属製のロールに接触させる際に、ロール間で挟み込むと、更に熱伝導の効率が高まり、またシートが配向して膜強度が増し、シートの表面平滑性も向上するためより好ましい。Ｔダイよりシート状に押出す際のダイリップ間隔は４００μｍ以上３０００μｍ以下が好ましく、５００μｍ以上２５００μｍ以下がさらに好ましい。ダイリップ間隔が４００μｍ以上の場合には、メヤニ等が低減され、スジや欠点など膜品位への影響が少なく、その後の延伸工程に於いて膜破断などを防げる。３０００μｍ以下の場合は、冷却速度が速く冷却ムラを防げるほか、厚みの安定性を維持できる。 The melt-kneaded product is formed into a sheet shape. The method of producing a sheet-like molded body by extruding the melt and cooling and solidifying is to extrude a uniform melt of polyolefin resin and plasticizer or polyolefin resin, inorganic filler and plasticizer into a sheet form via a T-die or the like. It is preferably carried out by contacting with a heat conductor and cooling to a temperature sufficiently lower than the crystallization temperature of the resin. As the heat conductor used for cooling and solidification, metal, water, air, plasticizer itself, or the like can be used. In particular, a method of cooling by contacting with a metal roll has the highest heat conduction efficiency and is preferable. Further, it is more preferable that the metal roll is sandwiched between the rolls because the heat conduction efficiency is further increased, the sheet is oriented and the film strength is increased, and the surface smoothness of the sheet is also improved. The die lip interval when extruding into a sheet form from a T die is preferably 400 μm or more and 3000 μm or less, and more preferably 500 μm or more and 2500 μm or less. When the die lip interval is 400 μm or more, the mess and the like are reduced, and there is little influence on the film quality such as streaks and defects, and film breakage and the like can be prevented in the subsequent stretching process. When the thickness is 3000 μm or less, the cooling rate is high and uneven cooling can be prevented, and the thickness stability can be maintained.
延伸処理としては、一軸延伸または二軸延伸のいずれも好適に用いることが出来るが、得られる膜強度等の観点から二軸延伸がより好ましい。二軸方向に高倍率延伸した場合、面方向に分子配向するため裂けにくく安定な構造となり高い突刺強度が得られる。延伸方法は同時二軸延伸、逐次二軸延、多段延伸、多数回延伸等のいずれの方法を単独もしくは併用することも構わないが、延伸方法が同時二軸延伸であることが突刺強度の増加や均一延伸、シャットダウン性の観点から最も好ましい。ここでいう同時二軸延伸とはＭＤ方向の延伸とＴＤ方向の延伸が同時に施される手法であり、各方向の変形率は異なっても良い。逐次二軸延伸とは、ＭＤ方向、またはＴＤ方向の延伸が独立して施される手法であり、ＭＤ方向、またはＴＤ方向に延伸がなされている際は、他方向が非拘束状態、または定長に固定されている状態にある。延伸倍率は、面倍率で２０倍以上１００倍以下の範囲が好ましく、２５倍以上５０倍以下の範囲がさらに好ましい。各軸方向の延伸倍率はＭＤ方向に４倍以上１０倍以下、ＴＤ方向に４倍以上１０倍以下の範囲が好ましく、ＭＤ方向に５倍以上８倍以下、ＴＤ方向に５倍以上８倍以下の範囲がさらに好ましい。総面積倍率が２０倍以上の場合は、膜に十分な強度を付与でき、１００倍以下では膜破断を防ぎ、高い生産性が得られる。 As the stretching treatment, either uniaxial stretching or biaxial stretching can be suitably used, but biaxial stretching is more preferable from the viewpoint of the obtained film strength and the like. When the film is stretched at a high magnification in the biaxial direction, it has a stable structure that is difficult to tear because of molecular orientation in the plane direction, and a high puncture strength is obtained. The stretching method may be simultaneous biaxial stretching, sequential biaxial stretching, multi-stage stretching, multi-stretching, etc., either alone or in combination. And is most preferable from the viewpoints of uniform stretching and shutdown properties. Here, the simultaneous biaxial stretching is a method in which stretching in the MD direction and stretching in the TD direction are performed simultaneously, and the deformation rate in each direction may be different. Sequential biaxial stretching is a technique in which stretching in the MD direction or TD direction is performed independently. When stretching is performed in the MD direction or TD direction, the other direction is unconstrained or fixed. It is in a state of being fixed to the length. The draw ratio is preferably in the range of 20 times to 100 times, more preferably in the range of 25 times to 50 times in terms of surface magnification. The stretching ratio in each axial direction is preferably 4 to 10 times in the MD direction, preferably 4 to 10 times in the TD direction, 5 to 8 times in the MD direction, and 5 to 8 times in the TD direction. The range of is more preferable. When the total area magnification is 20 times or more, sufficient strength can be imparted to the film, and when it is 100 times or less, film breakage is prevented and high productivity is obtained.
圧延工程を二軸延伸工程と併用しても構わない。圧延はダブルベルトプレス機等を使用したプレス法にて実施できる。圧延は特に表層部分の配向を増すことが出来る。圧延面倍率は１倍より大きく３倍以下が好ましく、１倍より大きく２倍以下がさらに好ましい。１倍より大きければ、面配向が増加し膜強度が増加する。３倍以下では、表層部分と中心内部の配向差が小さく、延伸工程で表層部と内部で均一な多孔構造を発現するために好ましいし、また工業生産上も好ましい。
可塑剤を抽出する方法はバッチ式、連続式のいずれでもよいが、抽出溶剤に多孔膜前駆体を浸漬することにより可塑剤を抽出し、充分に乾燥させ、可塑剤を多孔膜から実質的に除去することが好ましい。多孔膜の収縮を抑えるために、浸漬、乾燥の一連の工程中に多孔膜の端部を拘束することは好ましい。また、抽出後の多孔膜中の可塑剤残存量は１質量％未満にすることが好ましい。
The rolling process may be used in combination with the biaxial stretching process. Rolling can be performed by a press method using a double belt press or the like. Rolling can particularly increase the orientation of the surface layer portion. The rolling surface magnification is greater than 1 and preferably 3 or less, more preferably greater than 1 and 2 or less. If it is larger than 1 time, the plane orientation increases and the film strength increases. If it is 3 times or less, the difference in orientation between the surface layer portion and the center is small, and it is preferable for expressing a uniform porous structure in the surface layer portion and inside in the stretching step, and also preferable for industrial production.
The method of extracting the plasticizer may be either a batch type or a continuous type. However, the plasticizer is extracted by immersing the porous membrane precursor in an extraction solvent and sufficiently dried, so that the plasticizer is substantially removed from the porous membrane. It is preferable to remove. In order to suppress the shrinkage of the porous film, it is preferable to constrain the end of the porous film during a series of steps of immersion and drying. Moreover, it is preferable that the plasticizer residual amount in the porous membrane after extraction is less than 1% by mass.
抽出溶剤は、ポリオレフィン樹脂に対して貧溶媒であり、かつ可塑剤に対して良溶媒であり、沸点がポリオレフィン多孔膜の融点より低いことが望ましい。このような抽出溶剤としては、例えば、ｎ−ヘキサンやシクロヘキサン等の炭化水素類、塩化メチレンや１，１，１−トリクロロエタン等のハロゲン化炭化水素類、ハイドロフルオロエーテルやハイドロフルオロカーボン等の非塩素系ハロゲン化溶剤、エタノールやイソプロパノール等のアルコール類、ジエチルエーテルやテトラヒドロフラン等のエーテル類、アセトンやメチルエチルケトン等のケトン類が挙げられる。またこれらの蒸留等の操作により、回収した抽出溶剤も使用してよいのは言うまでもない。
なお、可塑剤と共に無機充填材を溶融混練した場合は、必要に応じて無機充填材を抽出してもよい。この場合の抽出溶剤は、ポリオレフィン樹脂に対して貧溶媒であり、かつ無機充填材に対して良溶媒であり、沸点がポリオレフィン多孔膜の融点より低いことが望ましい。
It is desirable that the extraction solvent is a poor solvent for the polyolefin resin and a good solvent for the plasticizer, and has a boiling point lower than the melting point of the polyolefin porous membrane. Examples of such extraction solvents include hydrocarbons such as n-hexane and cyclohexane, halogenated hydrocarbons such as methylene chloride and 1,1,1-trichloroethane, and non-chlorine-based solvents such as hydrofluoroether and hydrofluorocarbon. Examples thereof include halogenated solvents, alcohols such as ethanol and isopropanol, ethers such as diethyl ether and tetrahydrofuran, and ketones such as acetone and methyl ethyl ketone. Needless to say, the recovered extraction solvent may be used by operations such as distillation.
When the inorganic filler is melt-kneaded with the plasticizer, the inorganic filler may be extracted as necessary. The extraction solvent in this case is preferably a poor solvent for the polyolefin resin and a good solvent for the inorganic filler, and has a boiling point lower than the melting point of the polyolefin porous membrane.
本発明の利点を損なわない範囲で各延伸過程に引き続いて、または後に熱固定及び熱緩和等の熱処理工程を加えることは、ポリオレフィン樹脂多孔膜の収縮をさらに抑制する効果があり好ましい。
また、本発明の利点を損なわない範囲で後処理を行っても良い。後処理としては、例えば、界面活性剤等による親水化処理、及び電離性放射線等による架橋処理等が挙げられる。
本発明の多層多孔膜は、無機フィラーと樹脂製バインダを溶媒に溶解または分散させた無機フィラー含有樹脂溶液を、上記ポリオレフィン樹脂多孔膜の少なくとも片面に塗布することによってポリオレフィン樹脂多孔膜表面に多孔層を形成することによって製造することが好ましい。
It is preferable to add a heat treatment step such as heat setting and heat relaxation subsequent to each stretching step within a range not impairing the advantages of the present invention, since it has an effect of further suppressing shrinkage of the polyolefin resin porous membrane.
Moreover, you may post-process in the range which does not impair the advantage of this invention. Examples of the post-treatment include a hydrophilic treatment with a surfactant and the like, and a crosslinking treatment with ionizing radiation.
The multilayer porous membrane of the present invention is a porous layer on the surface of a polyolefin resin porous membrane by applying an inorganic filler-containing resin solution in which an inorganic filler and a resin binder are dissolved or dispersed in a solvent to at least one surface of the polyolefin resin porous membrane. It is preferable to manufacture by forming.
無機フィラーおよび樹脂製バインダとしては、いずれも前述のものが好適に使用できる。溶媒としては、無機フィラーと樹脂製バインダが均一かつ安定に溶解または分散できるものが好ましく、例えば、Ｎ−メチルピロリドンやＮ，Ｎ−ジメチルホルムアミド、Ｎ，Ｎ−ジメチルアセトアミド、水、エタノール、トルエン、熱キシレン、ヘキサンなどを挙げることができる。また、無機フィラー含有樹脂溶液を安定化させるため、あるいはポリオレフィン樹脂多孔膜への塗工性を向上させるために、界面活性剤等の分散剤、増粘剤、湿潤剤、消泡剤、酸やアルカリを含めたＰＨ調製剤等の各種添加剤を加えてもよい。これらの添加剤は、溶媒除去や可塑剤抽出の際に除去できるものが好ましいが、リチウムイオン二次電池の使用範囲において電気化学的に安定で、電池反応を阻害せず、かつ２００℃程度まで安定ならば、電池内に残存してもよい。 As the inorganic filler and the resin binder, the above-mentioned ones can be preferably used. As the solvent, those in which the inorganic filler and the resin binder can be dissolved or dispersed uniformly and stably are preferable. For example, N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, water, ethanol, toluene, Examples include hot xylene and hexane. Further, in order to stabilize the inorganic filler-containing resin solution or to improve the coating property to the polyolefin resin porous membrane, a dispersant such as a surfactant, a thickener, a wetting agent, an antifoaming agent, an acid, Various additives such as a pH adjusting agent including an alkali may be added. These additives are preferably those that can be removed upon solvent removal or plasticizer extraction, but are electrochemically stable in the range of use of the lithium ion secondary battery, do not inhibit the battery reaction, and are up to about 200 ° C. If stable, it may remain in the battery.
無機フィラーと樹脂製バインダを溶媒に溶解または分散させる方法は、後述する塗布工程に必要な溶液または分散液特性を実現できる方法であれば特に限定しない。例えば、ボールミル、ビーズミル、遊星ボールミル、振動ボールミル、サンドミル、コロイドミル、アトライター、ロールミル、高速インペラー分散、ディスパーザー、ホモジナイザー、高速衝撃ミル、超音波分散、撹拌羽根等による機械撹拌等が挙げられる。
無機フィラー含有樹脂溶液をポリオレフィン樹脂多孔膜に塗布する方法については、必要とする層厚や塗布面積を実現できる方法であれば特に限定しない。例えば、グラビアコーター法、小径グラビアコーター法、リバースロールコーター法、トランスファロールコーター法、キスコーター法、ディップコーター法、ナイフコーター法、エアドクタコーター法、ブレードコーター法、ロッドコーター法、スクイズコーター法、キャストコーター法、ダイコーター法、スクリーン印刷法、スプレー塗布法等が挙げられる。また、用途に応じて無機フィラー含有樹脂溶液をポリオレフィン樹脂多孔膜の片面だけに塗布してもよいし、両面に塗布してもよい。
The method for dissolving or dispersing the inorganic filler and the resin binder in the solvent is not particularly limited as long as it can realize the solution or dispersion characteristics necessary for the coating process described later. Examples thereof include a ball mill, a bead mill, a planetary ball mill, a vibrating ball mill, a sand mill, a colloid mill, an attritor, a roll mill, a high-speed impeller dispersion, a disperser, a homogenizer, a high-speed impact mill, ultrasonic dispersion, and mechanical stirring using a stirring blade.
The method for applying the inorganic filler-containing resin solution to the polyolefin resin porous membrane is not particularly limited as long as it can realize the required layer thickness and application area. For example, gravure coater method, small diameter gravure coater method, reverse roll coater method, transfer roll coater method, kiss coater method, dip coater method, knife coater method, air doctor coater method, blade coater method, rod coater method, squeeze coater method, cast Examples include a coater method, a die coater method, a screen printing method, and a spray coating method. Moreover, according to a use, you may apply | coat an inorganic filler containing resin solution only to the single side | surface of a polyolefin resin porous film, and may apply | coat to both surfaces.
さらに、塗布に先立ち、ポリオレフィン樹脂多孔膜表面を積極的に表面処理すると、無機フィラー含有樹脂溶液がより均一に塗布し易くなる上に、塗布後の無機フィラー含有樹脂層とポリオレフィン樹脂多孔膜表面との接着性が向上するため、より好ましい。表面処理の方法は、ポリオレフィン樹脂多孔膜の多孔質構造が著しく損なわれなければ特に限定しないが、例えばコロナ放電処理法、機械的粗面化法、溶剤処理法、酸処理法、紫外線酸化法などが挙げられる。 Furthermore, if the surface of the polyolefin resin porous membrane is positively treated prior to application, the inorganic filler-containing resin solution can be more uniformly applied, and the inorganic filler-containing resin layer after application and the polyolefin resin porous membrane surface This is more preferable because of improving the adhesiveness. The surface treatment method is not particularly limited as long as the porous structure of the polyolefin resin porous membrane is not significantly impaired. For example, corona discharge treatment method, mechanical surface roughening method, solvent treatment method, acid treatment method, ultraviolet oxidation method, etc. Is mentioned.
ポリオレフィン樹脂多孔膜に塗布した無機フィラー含有樹脂溶液から溶媒を除去することで無機フィラーと樹脂製バインダからなる多孔層が形成されるのだが、溶媒を除去する方法としては、ポリオレフィン樹脂多孔膜に悪影響を及ぼさない方法であれば、特に限定することなく採用することが出来る。例えば、ポリオレフィン樹脂多孔膜を固定しながらその融点以下の温度にて乾燥する方法、低温で減圧乾燥する方法、樹脂製バインダに対する貧溶媒に浸漬して樹脂製バインダを凝固させると同時に溶媒を抽出する方法などが挙げられる。
本発明の多層多孔膜は、耐熱性、透過性に優れるため、非水電解液電池用セパレータとして用いた場合に特に有用であり、本発明の多層多孔膜をセパレータとして使用することで、良好な安全性能を持つ非水電解液電池を得ることができる。
By removing the solvent from the inorganic filler-containing resin solution applied to the polyolefin resin porous membrane, a porous layer consisting of an inorganic filler and a resin binder is formed. As a method for removing the solvent, the polyolefin resin porous membrane is adversely affected. If it is a method which does not affect, it can employ | adopt without specifically limiting. For example, a method of drying a polyolefin resin porous membrane while fixing it at a temperature below its melting point, a method of drying under reduced pressure at a low temperature, and dipping in a poor solvent for a resin binder to solidify the resin binder and simultaneously extract the solvent The method etc. are mentioned.
Since the multilayer porous membrane of the present invention is excellent in heat resistance and permeability, it is particularly useful when used as a separator for non-aqueous electrolyte batteries, and it is preferable that the multilayer porous membrane of the present invention is used as a separator. A nonaqueous electrolyte battery having safety performance can be obtained.
次に、実施例によって本発明をさらに詳細に説明するが、これらは本発明の範囲を制限するものではない。実施例における試験方法は次の通りである。
＜ポリビニルアルコールのケン化度評価＞
ＪＩＳ Ｋ−００７０に準拠する方法で算出した。
＜微多孔膜の評価＞
（１）粘度平均分子量Ｍｖ
ＡＳＴＭ−Ｄ４０２０に基づき、デカリン溶媒における１３５℃での極限粘度［η］（ｄｌ／ｇ）を求める。ポリエチレンのＭｖは次式により算出した。
［η］＝６．７７×１０-4Ｍｖ0.67
ポリプロピレンについては、次式によりＭｖを算出した。
［η］＝１．１０×１０-4Ｍｖ0.80
EXAMPLES Next, although an Example demonstrates this invention further in detail, these do not restrict | limit the scope of the present invention. The test methods in the examples are as follows.
<Evaluation of saponification degree of polyvinyl alcohol>
It calculated by the method based on JISK-0070.
<Evaluation of microporous membrane>
(1) Viscosity average molecular weight Mv
Based on ASTM-D4020, the intrinsic viscosity [η] (dl / g) at 135 ° C. in a decalin solvent is determined. Mv of polyethylene was calculated by the following formula.
[Η] = 6.77 × 10 −4 Mv 0.67
For polypropylene, Mv was calculated by the following formula.
[Η] = 1.10 × 10 −4 Mv 0.80
（２）膜厚
ダイヤルゲージ（尾崎製作所製ＰＥＡＣＯＣＫ Ｎｏ．２５（商標））にて測定した。ＭＤ１０ｍｍ×ＴＤ１０ｍｍのサンプルを多孔膜から切り出し、格子状に９箇所（３点×３点）の膜厚を測定した。得られた平均値を膜厚（μｍ）とした。
（３）透気度（秒／１００ｃｃ）
ＪＩＳ Ｐ−８１１７準拠のガーレー式透気度計（東洋精機製Ｇ−Ｂ２（商標））を用いた。内筒重量は５６７ｇで、直径２８．６ｍｍ、６４５ｍｍ2の面積を空気１００ｍｌが通過する時間を測定した。多孔層を形成させたことによる透気度増加率を、以下の式にて算出する。
透気度増加率（％）＝（多孔多層膜の透気度−ポリオレフィン樹脂多孔膜の透気度）／ポリオレフィン樹脂多孔膜の透気度×１００
(2) Film thickness Measured with a dial gauge (PEACOCK No. 25 (trademark) manufactured by Ozaki Seisakusho). A sample of MD 10 mm × TD 10 mm was cut out from the porous film, and the film thickness was measured at nine locations (3 points × 3 points) in a lattice shape. The average value obtained was defined as the film thickness (μm).
(3) Air permeability (sec / 100cc)
A Gurley type air permeability meter (G-B2 (trademark) manufactured by Toyo Seiki Co.) conforming to JIS P-8117 was used. The inner cylinder weight was 567 g, and the time required for 100 ml of air to pass through an area of 28.6 mm in diameter and 645 mm 2 was measured. The air permeability increase rate due to the formation of the porous layer is calculated by the following formula.
Permeability increase rate (%) = (Air permeability of porous multilayer film−Air permeability of polyolefin resin porous film) / Air permeability of polyolefin resin porous film × 100
（４）シャットダウン温度、ショート温度
ａ．正極の作製
正極活物質としてリチウムコバルト複合酸化物（ＬｉＣｏＯ2）を９２．２質量％、導電材としてリン片状グラファイトとアセチレンブラックをそれぞれ２．３質量％、バインダーとしてポリフッ化ビニリデン（ＰＶＤＦ）３．２質量％をＮ−メチルピロリドン（ＮＭＰ）中に分散させてスラリーを調製する。このスラリーを正極集電体となる厚さ２０μｍのアルミニウム箔の片面にダイコーターで塗布し、１３０℃で３分間乾燥後、ロールプレス機で圧縮成形する。この時、正極の活物質塗布量は２５０ｇ／ｍ2、活物質かさ密度は３．００ｇ／ｃｍ3になるようにする。
(4) Shutdown temperature, short-circuit temperature a. Production of positive electrode 92.2% by mass of lithium cobalt composite oxide (LiCoO 2 ) as a positive electrode active material, 2.3% by mass of flake graphite and acetylene black as a conductive material, and polyvinylidene fluoride (PVDF) 3 as a binder A slurry is prepared by dispersing 2% by mass in N-methylpyrrolidone (NMP). This slurry is applied to one side of a 20 μm thick aluminum foil serving as a positive electrode current collector with a die coater, dried at 130 ° C. for 3 minutes, and then compression molded with a roll press. At this time, the active material coating amount of the positive electrode is 250 g / m 2 , and the bulk density of the active material is 3.00 g / cm 3 .
ｂ．負極の作製
負極活物質として人造グラファイト９６．６質量％、バインダーとしてカルボキシメチルセルロースのアンモニウム塩１．４質量％とスチレン−ブタジエン共重合体ラテックス１．７質量％を精製水中に分散させてスラリーを調製する。このスラリーを負極集電体となる厚さ１２μｍの銅箔の片面にダイコーターで塗布し、１２０℃で３分間乾燥後、ロールプレス機で圧縮成形する。この時、負極の活物質塗布量は１０６ｇ／ｍ2、活物質かさ密度は１．３５ｇ／ｃｍ3になるようにする。
ｃ．非水電解液
プロピレンカーボネート：エチレンカーボネート：γ−ブチルラクトン＝１：１：２（体積比）の混合溶媒に、溶質としてＬｉＢＦ4を濃度１．０ｍｏｌ／Ｌとなるように溶解させて調製する。
b. Preparation of negative electrode A slurry was prepared by dispersing 96.6% by mass of artificial graphite as a negative electrode active material, 1.4% by mass of ammonium salt of carboxymethyl cellulose and 1.7% by mass of styrene-butadiene copolymer latex as a binder in purified water. To do. This slurry is applied to one side of a 12 μm-thick copper foil serving as a negative electrode current collector with a die coater, dried at 120 ° C. for 3 minutes, and then compression molded with a roll press. At this time, the active material coating amount of the negative electrode is set to 106 g / m 2 and the bulk density of the active material is set to 1.35 g / cm 3 .
c. Nonaqueous electrolyte solution Prepared by dissolving LiBF 4 as a solute in a mixed solvent of propylene carbonate: ethylene carbonate: γ-butyllactone = 1: 1: 2 (volume ratio) to a concentration of 1.0 mol / L.
ｄ．評価
熱電対を繋いだセラミックスプレート上に、６５ｍｍ×２０ｍｍに切り出し非水電解液に１分以上浸漬した負極を載せ、この上に中央部に直径１６ｍｍの穴をあけた５０ｍｍ×５０ｍｍに切り出した厚さ９μｍのアラミドフィルムを載せ、この上に４０ｍｍ×４０ｍｍに切り出し非水電解液に１時間以上浸漬した試料の多孔膜をアラミドフィルムの穴部を覆うように載せ、この上に６５ｍｍ×２０ｍｍに切り出し非水電解液に１分以上浸漬した正極を負極に接触しないように載せ、その上にカプトンフィルム、更に厚さ約４ｍｍのシリコンゴムを載せる。
これをホットプレート上にセットした後、油圧プレス機にて４．１ＭＰａの圧力をかけた状態で、１５℃／ｍｉｎの速度で昇温し、この際の正負極間のインピーダンス変化を交流１Ｖ、１ｋＨｚの条件下で２００℃まで測定した。この測定において、インピーダンスが１０００Ωに達した時点の温度をシャットダウン温度とし、孔閉塞状態に達した後、再びインピーダンスが１０００Ωを下回った時点の温度をショート温度とした。
d. Evaluation On a ceramic plate connected with a thermocouple, a negative electrode cut into 65 mm × 20 mm and immersed in a non-aqueous electrolyte for 1 minute or more is placed, and a thickness cut into 50 mm × 50 mm with a hole having a diameter of 16 mm is formed on the negative electrode. Place a 9 μm thick aramid film, cut it into 40 mm × 40 mm, place a porous film of the sample soaked in non-aqueous electrolyte for 1 hour or more so as to cover the hole of the aramid film, and cut it into 65 mm × 20 mm A positive electrode immersed in a non-aqueous electrolyte for 1 minute or longer is placed so as not to contact the negative electrode, and a Kapton film and a silicon rubber having a thickness of about 4 mm are placed thereon.
After this was set on a hot plate, the temperature was raised at a rate of 15 ° C./min with a pressure of 4.1 MPa applied by a hydraulic press machine, and the impedance change between the positive and negative electrodes at this time was AC 1V, Measurement was performed up to 200 ° C. under the condition of 1 kHz. In this measurement, the temperature at which the impedance reached 1000Ω was taken as the shutdown temperature, and the temperature at which the impedance again fell below 1000Ω after reaching the hole closed state was taken as the short-circuit temperature.
（５）電池評価
ａ．正極の作製
（４）のａで作製した正極を面積２．００ｃｍ2の円形に打ち抜いた。
ｂ．負極の作製
（４）のｂで作製した負極を面積２．０５ｃｍ2の円形に打ち抜いた。
ｃ．非水電解液
エチレンカーボネート：エチルメチルカーボネート＝１：２（体積比）の混合溶媒に、溶質としてＬｉＰＦ6を濃度１．０ｍｌ／Ｌとなるように溶解させて調製した。
ｄ．電池組立と評価
正極と負極の活物質面が対向するように、下から負極、セパレータ、正極の順に重ね、蓋付きステンレス金属製容器に収納する。容器と蓋とは絶縁されており、容器は負極の銅箔と、蓋は正極のアルミ箔と接している。この容器内に前記した非水電解液を注入して密閉する。
(5) Battery evaluation a. Production of positive electrode The positive electrode produced in (4) a was punched into a circle having an area of 2.00 cm 2 .
b. Production of Negative Electrode The negative electrode produced in (4) b was punched into a circle having an area of 2.05 cm 2 .
c. Nonaqueous Electrolytic Solution Prepared by dissolving LiPF 6 as a solute in a mixed solvent of ethylene carbonate: ethyl methyl carbonate = 1: 2 (volume ratio) to a concentration of 1.0 ml / L.
d. Battery assembly and evaluation The negative electrode, the separator, and the positive electrode are stacked in this order from the bottom so that the active material surfaces of the positive electrode and the negative electrode face each other, and stored in a stainless steel container with a lid. The container and the lid are insulated, the container is in contact with the negative electrode copper foil, and the lid is in contact with the positive electrode aluminum foil. The non-aqueous electrolyte described above is injected into this container and sealed.
上記のようにして組み立てた簡易電池を２５℃雰囲気下、電流値３ｍＡ（約０．５Ｃ）で電池電圧４．２Ｖまで充電し、さらに４．２Ｖを保持するようにして電流値を３ｍＡか
ら絞り始めるという方法で、合計約６時間、電池作成後の最初の充電を行い、そして 電流値３ｍＡで電池電圧３．０Ｖまで放電した。
次に、２５℃雰囲気下、電流値６ｍＡ（約１．０Ｃ）で電池電圧４．２Ｖまで充電し、さらに４．２Ｖを保持するようにして電流値を６ｍＡから絞り始めるという方法で、合計約３時間充電を行い、そして電流値６ｍＡで電池電圧３．０Ｖまで放電して、その時の放電容量を１Ｃ放電容量（ｍＡｈ）とした。
The simple battery assembled as described above is charged to a battery voltage of 4.2 V at a current value of 3 mA (about 0.5 C) in a 25 ° C. atmosphere, and the current value is reduced from 3 mA so as to maintain 4.2 V. In the method of starting, the first charge after battery preparation was performed for a total of about 6 hours, and then discharged to a battery voltage of 3.0 V at a current value of 3 mA.
Next, in a 25 ° C. atmosphere, the battery is charged to a battery voltage of 4.2 V at a current value of 6 mA (about 1.0 C), and the current value starts to be reduced from 6 mA so as to hold 4.2 V. The battery was charged for 3 hours and discharged at a current value of 6 mA to a battery voltage of 3.0 V. The discharge capacity at that time was set to 1 C discharge capacity (mAh).
次に、２５℃雰囲気下、電流値６ｍＡ（約１．０Ｃ）で電池電圧４．２Ｖまで充電し、さらに４．２Ｖを保持するようにして電流値を６ｍＡから絞り始めるという方法で、合計約３時間充電を行い、そして電流値１２ｍＡ（約２．０Ｃ）で電池電圧３．０Ｖまで放電して、その時の放電容量を２Ｃ放電容量（ｍＡｈ）とした。
１Ｃ放電容量に対する２Ｃ放電容量の割合を算出し、この値をレート特性とした。
レート特性（％）＝２Ｃ放電容量／１Ｃ放電容量 ×１００
さらに、６０℃雰囲気下、電流値６ｍＡ（約１．０Ｃ）で電池電圧４．２Ｖまで充電し、さらに４．２Ｖを保持するようにして電流値を６ｍＡから絞り始めるという方法で、合計約３時間充電を行い、そして電流値６ｍＡで電池電圧３．０Ｖまで放電するというサイクルを繰り返した。
このサイクルにおける１サイクル目の放電容量に対する所定サイクル後の放電容量の割合を容量維持率（％）として求め、サイクル特性を判断した。
Next, in a 25 ° C. atmosphere, the battery is charged to a battery voltage of 4.2 V at a current value of 6 mA (about 1.0 C), and the current value starts to be reduced from 6 mA so as to hold 4.2 V. The battery was charged for 3 hours, and discharged at a current value of 12 mA (about 2.0 C) to a battery voltage of 3.0 V. The discharge capacity at that time was 2 C discharge capacity (mAh).
The ratio of the 2C discharge capacity to the 1C discharge capacity was calculated, and this value was used as the rate characteristic.
Rate characteristics (%) = 2C discharge capacity / 1C discharge capacity × 100
Furthermore, in a 60 ° C. atmosphere, the battery is charged to a battery voltage of 4.2 V at a current value of 6 mA (about 1.0 C), and further, the current value starts to be reduced from 6 mA so as to maintain 4.2 V. The cycle of charging for a time and discharging to a battery voltage of 3.0 V at a current value of 6 mA was repeated.
The ratio of the discharge capacity after a predetermined cycle to the discharge capacity at the first cycle in this cycle was determined as the capacity retention rate (%), and the cycle characteristics were judged.
［実施例１］
粘度平均分子量（Ｍｖ）７０万のポリエチレン１６．６重量部とＭｖ２５万のポリエチレン１６．６重量部とＭｖ４０万のポリプロピレン１．８重量部、可塑剤として流動パラフィン（ＬＰ）を４０重量部、酸化防止剤としてペンタエリスリチル−テトラキス−［３−（３，５−ジ−ｔ−ブチル−４−ヒドロキシフェニル）プロピオネート］を０．３重量部添加したものをヘンシェルミキサーにて予備混合した。得られた混合物をフィーダーにより二軸同方向スクリュー式押出機フィード口へ供給した。また溶融混練し押し出される全混合物（１００重量部）中に占める流動パラフィン量比が６５重量部となるように、流動パラフィンを二軸押出機シリンダーへサイドフィードした。溶融混練条件は、設定温度２００℃、スクリュー回転数２４０ｒｐｍ、吐出量１２ｋｇ／ｈで行った。続いて、溶融混練物をＴダイを経て表面温度２５℃に制御された冷却ロール間に押出し、厚さ１３００μｍのシート状のポリオレフィン組成物を得た。次に連続して同時二軸テンター延伸機へ導き、ＭＤ方向に７倍、ＴＤ方向に６．４倍に同時二軸延伸を行った。この時同時二軸テンターの設定温度は１１８℃であった。次にメチルエチルケトン槽に導き可塑剤を除去した後、メチルエチルケトンを乾燥除去した。さらにＴＤテンター熱固定機に導き、熱固定を行った。熱固定温度は１２２℃、ＴＤ緩和率０．８０とした。その結果、膜厚１６μｍ、気孔率４８％、透気度１６５秒／１００ｃｃのポリオレフィン樹脂多孔膜を得た。
[Example 1]
16.6 parts by weight of polyethylene with a viscosity average molecular weight (Mv) of 700,000, 16.6 parts by weight of polyethylene with an Mv of 250,000 and 1.8 parts by weight of polypropylene with an Mv of 400,000, 40 parts by weight of liquid paraffin (LP) as a plasticizer, oxidized What added 0.3 weight part of pentaerythrityl-tetrakis- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] as an inhibitor was premixed with a Henschel mixer. The obtained mixture was supplied to the feed port of the twin-screw co-directional screw extruder by a feeder. Further, the liquid paraffin was side-fed to the twin-screw extruder cylinder so that the liquid paraffin content ratio in the total mixture (100 parts by weight) melt-kneaded and extruded was 65 parts by weight. The melt-kneading conditions were set at a preset temperature of 200 ° C., a screw rotation speed of 240 rpm, and a discharge rate of 12 kg / h. Subsequently, the melt-kneaded product was extruded through a T-die between cooling rolls controlled at a surface temperature of 25 ° C. to obtain a sheet-like polyolefin composition having a thickness of 1300 μm. Next, it was continuously led to a simultaneous biaxial tenter stretching machine, and simultaneous biaxial stretching was performed 7 times in the MD direction and 6.4 times in the TD direction. At this time, the set temperature of the simultaneous biaxial tenter was 118 ° C. Next, the plasticizer was removed by being led to a methyl ethyl ketone bath, and then methyl ethyl ketone was removed by drying. Furthermore, it was led to a TD tenter heat fixing machine and heat fixed. The heat setting temperature was 122 ° C. and the TD relaxation rate was 0.80. As a result, a polyolefin resin porous film having a film thickness of 16 μm, a porosity of 48%, and an air permeability of 165 seconds / 100 cc was obtained.
ポリビニルアルコール（平均重合度１７００、ケン化度９９％以上）５重量部とチタニア粒子（平均粒径０．４μｍ）９５重量部を１５０重量部の水にそれぞれ均一に分散させた水溶液を、上記ポリオレフィン樹脂多孔膜の表面にグラビアコーターを用いて塗布した後、６０℃にて乾燥して水を除去し、多孔膜上に厚さ４μｍの多孔層が形成した、総膜厚２０μｍの多層多孔膜を得た。
得られた多層多孔膜は、透気度１７５秒／１００ｃｃで、多孔層を形成させたことによる透気度増加率は６％と低く、優れた透過性を維持していた。また、シャットダウン温度は１４８℃に観測され、ショートは２００℃以上になっても観察されず、非常に高い耐熱性を示した。
この多層多孔膜をセパレータとして用いて電池評価を実施したところ、レート特性は９０％以上と高く、１００サイクル後の容量維持率は９０％以上でサイクル特性も良好であった。
An aqueous solution in which 5 parts by weight of polyvinyl alcohol (average degree of polymerization 1700, saponification degree 99% or more) and 95 parts by weight of titania particles (average particle size 0.4 μm) are uniformly dispersed in 150 parts by weight of water is used as the polyolefin. After applying the surface of the resin porous film using a gravure coater, the multilayer porous film having a total film thickness of 20 μm is formed by drying at 60 ° C. to remove water and forming a porous layer having a thickness of 4 μm on the porous film. Obtained.
The obtained multilayer porous membrane had an air permeability of 175 seconds / 100 cc, and the rate of increase in air permeability due to the formation of the porous layer was as low as 6%, thus maintaining excellent permeability. Further, the shutdown temperature was observed at 148 ° C., and the short circuit was not observed even when the temperature exceeded 200 ° C., indicating very high heat resistance.
When the battery was evaluated using this multilayer porous membrane as a separator, the rate characteristics were as high as 90% or more, the capacity retention after 100 cycles was 90% or more, and the cycle characteristics were also good.
［実施例２］
実施例１で、多孔膜上に厚さ６μｍの多孔層を形成させた以外は、実施例１と同様の方法で総膜厚２２μｍの多層多孔膜を得た。
得られた多層多孔膜は、透気度１８０秒／１００ｃｃで、多孔層を形成させたことによる透気度増加率は９％と低く、優れた透過性を維持していた。また、シャットダウン温度は１４６℃に観測され、ショートは２００℃以上になっても観察されず、非常に高い耐熱性を示した。
この多層多孔膜をセパレータとして用いて電池評価を実施したところ、レート特性は９０％以上と高く、１００サイクル後の容量維持率は９０％以上でサイクル特性も良好であった。
[Example 2]
A multilayer porous film having a total film thickness of 22 μm was obtained in the same manner as in Example 1 except that a porous layer having a thickness of 6 μm was formed on the porous film in Example 1.
The resulting multilayer porous membrane had an air permeability of 180 seconds / 100 cc, and the rate of increase in air permeability due to the formation of the porous layer was as low as 9%, maintaining excellent permeability. Further, the shutdown temperature was observed at 146 ° C., and the short circuit was not observed even when the temperature exceeded 200 ° C., indicating very high heat resistance.
When the battery was evaluated using this multilayer porous membrane as a separator, the rate characteristics were as high as 90% or more, the capacity retention after 100 cycles was 90% or more, and the cycle characteristics were also good.
［実施例３］
実施例１で基材に用いたポリオレフィン樹脂多孔膜の表面に、ポリビニルアルコール（平均重合度１７００、ケン化度８７％）５重量部とチタニア粒子（平均粒径０．４μｍ）９５重量部を１５０重量部の水にそれぞれ均一に分散させた水溶液を、上記ポリオレフィン樹脂多孔膜の表面にバーコーターを用いて塗布した後、６０℃にて乾燥して水を除去し、多孔膜上に厚さ３μｍの多孔層が形成した、総膜厚１９μｍの多層多孔膜を得た。
得られた多層多孔膜は、透気度１７１秒／１００ｃｃで、多孔層を形成させたことによる透気度増加率は４％と低く、優れた透過性を維持していた。また、シャットダウン温度は１４５℃に観測され、ショートは２００℃以上になっても観察されず、非常に高い耐熱性を示した。
この多層多孔膜をセパレータとして用いて電池評価を実施したところ、レート特性は９０％以上と高く、１００サイクル後の容量維持率は９０％以上でサイクル特性も良好であった。
[Example 3]
150 parts by weight of 5 parts by weight of polyvinyl alcohol (average degree of polymerization 1700, saponification degree 87%) and 95 parts by weight of titania particles (average particle size 0.4 μm) are formed on the surface of the polyolefin resin porous film used as the base material in Example 1. An aqueous solution uniformly dispersed in each part by weight of water was applied to the surface of the polyolefin resin porous film using a bar coater, and then dried at 60 ° C. to remove water, and the thickness of the porous film was 3 μm. A multilayer porous film having a total film thickness of 19 μm was obtained.
The obtained multilayer porous membrane had an air permeability of 171 sec / 100 cc, and the rate of increase in air permeability due to the formation of the porous layer was as low as 4%, maintaining excellent permeability. Further, the shutdown temperature was observed at 145 ° C., and the short circuit was not observed even when the temperature exceeded 200 ° C., indicating very high heat resistance.
When the battery was evaluated using this multilayer porous membrane as a separator, the rate characteristics were as high as 90% or more, the capacity retention after 100 cycles was 90% or more, and the cycle characteristics were also good.
［実施例４］
実施例３で、多孔膜上に厚さ６μｍの多孔層を形成させた以外は、実施例３と同様の方法で総膜厚２２μｍの多層多孔膜を得た。
得られた多層多孔膜は、透気度１７８秒／１００ｃｃで、多孔層を形成させたことによる透気度増加率は８％と低く、優れた透過性を維持していた。また、シャットダウン温度は１４６℃に観測され、ショートは２００℃以上になっても観察されず、非常に高い耐熱性を示した。
この多層多孔膜をセパレータとして用いて電池評価を実施したところ、レート特性は９０％以上と高く、１００サイクル後の容量維持率は９０％以上でサイクル特性も良好であった。
[Example 4]
A multilayer porous film having a total film thickness of 22 μm was obtained in the same manner as in Example 3 except that a porous layer having a thickness of 6 μm was formed on the porous film in Example 3.
The resulting multilayer porous membrane had an air permeability of 178 seconds / 100 cc, and the rate of increase in air permeability due to the formation of the porous layer was as low as 8%, maintaining excellent permeability. Further, the shutdown temperature was observed at 146 ° C., and the short circuit was not observed even when the temperature exceeded 200 ° C., indicating very high heat resistance.
When the battery was evaluated using this multilayer porous membrane as a separator, the rate characteristics were as high as 90% or more, the capacity retention after 100 cycles was 90% or more, and the cycle characteristics were also good.
［比較例１］
実施例１で基材に用いたポリオレフィン樹脂多孔膜の表面に、多孔層を形成させずに同様の評価を行ったところ、シャットダウン温度は１４８℃に観測されたが、ショート温度が１５２℃と低かった。なお、この多層多孔膜をセパレータとして用いて電池評価を実施したところ、レート特性は９０％以上と高く、１００サイクル後の容量維持率は９０％以上でサイクル特性も良好であった。
[Comparative Example 1]
When the same evaluation was performed without forming a porous layer on the surface of the polyolefin resin porous film used as the base material in Example 1, the shutdown temperature was observed at 148 ° C., but the short-circuit temperature was as low as 152 ° C. It was. When the battery was evaluated using this multilayer porous membrane as a separator, the rate characteristics were as high as 90% or more, the capacity retention after 100 cycles was 90% or more, and the cycle characteristics were also good.
［比較例２］
実施例１で基材に用いたポリオレフィン樹脂多孔膜の表面に、ポリビニルアルコール（平均重合度１７００、ケン化度８１％）５重量部とチタニア粒子（平均粒径０．４μｍ）９５重量部を１５０重量部の水にそれぞれ均一に分散させた水溶液を、上記ポリオレフィン樹脂多孔膜の表面にバーコーターを用いて塗布した後、６０℃にて乾燥して水を除去し、多孔膜上に厚さ４μｍの多孔層が形成した、総膜厚２０μｍの多層多孔膜を得た。
得られた多層多孔膜は、透気度１７４秒／１００ｃｃで、多孔層を形成させたことによる透気度増加率は５％と低く、優れた透過性を維持していた。シャットダウン温度は１４５℃に観測されたが、ショート温度は１６３℃と低かった。
[Comparative Example 2]
150 parts by weight of 5 parts by weight of polyvinyl alcohol (average polymerization degree 1700, saponification degree 81%) and 95 parts by weight of titania particles (average particle diameter 0.4 μm) are formed on the surface of the polyolefin resin porous film used as the substrate in Example 1. An aqueous solution uniformly dispersed in parts by weight of water was applied to the surface of the polyolefin resin porous membrane using a bar coater, and then dried at 60 ° C. to remove water, and the thickness of the porous membrane was 4 μm. A multilayer porous film having a total film thickness of 20 μm was obtained.
The obtained multilayer porous membrane had an air permeability of 174 sec / 100 cc, and the rate of increase in air permeability due to the formation of the porous layer was as low as 5%, maintaining excellent permeability. The shutdown temperature was observed at 145 ° C, but the short circuit temperature was as low as 163 ° C.
［比較例３］
比較例２で、多孔膜上に厚さ６μｍの多孔層を形成させた以外は、比較例２と同様の方法で総膜厚２２μｍの多層多孔膜を得た。
得られた多層多孔膜は、透気度１７８秒／１００ｃｃで、多孔層を形成させたことによる透気度増加率は８％と低く、優れた透過性を維持していた。シャットダウン温度は１４５℃に観測されたが、ショート温度は１６７℃と低かった。
[Comparative Example 3]
A multilayer porous film having a total film thickness of 22 μm was obtained in the same manner as in Comparative Example 2, except that a porous layer having a thickness of 6 μm was formed on the porous film in Comparative Example 2.
The resulting multilayer porous membrane had an air permeability of 178 seconds / 100 cc, and the rate of increase in air permeability due to the formation of the porous layer was as low as 8%, maintaining excellent permeability. The shutdown temperature was observed at 145 ° C, but the short circuit temperature was as low as 167 ° C.
［比較例４］
実施例１で基材に用いたポリオレフィン樹脂多孔膜の表面に、ポリビニルアルコール（平均重合度１７００、ケン化度７２％）５重量部とチタニア粒子（平均粒径０．４μｍ）９５重量部を１５０重量部の水にそれぞれ均一に分散させた水溶液を、上記ポリオレフィン樹脂多孔膜の表面にバーコーターを用いて塗布した後、６０℃にて乾燥して水を除去し、多孔膜上に厚さ６μｍの多孔層が形成した、総膜厚２２μｍの多層多孔膜を得た。
得られた多層多孔膜は、透気度１７７秒／１００ｃｃで、多孔層を形成させたことによる透気度増加率は７％と低く、優れた透過性を維持していた。シャットダウン温度は１４６℃に観測されたが、ショート温度は１６２℃と低かった。
以上の実施例、比較例における物性を表１にまとめて示した。
[Comparative Example 4]
150 parts by weight of polyvinyl alcohol (average polymerization degree 1700, saponification degree 72%) 5 parts by weight and titania particles (average particle diameter 0.4 μm) 150 parts on the surface of the polyolefin resin porous film used as the substrate in Example 1. An aqueous solution uniformly dispersed in each part by weight of water was applied to the surface of the polyolefin resin porous film using a bar coater, and then dried at 60 ° C. to remove water, and the thickness of the porous film was 6 μm. A multilayer porous film having a total film thickness of 22 μm was obtained.
The obtained multilayer porous membrane had an air permeability of 177 seconds / 100 cc, and the rate of increase in air permeability due to the formation of the porous layer was as low as 7%, maintaining excellent permeability. The shutdown temperature was observed at 146 ° C, but the short circuit temperature was as low as 162 ° C.
The physical properties in the above Examples and Comparative Examples are summarized in Table 1.
本発明の多層多孔膜は、優れた耐熱性と透過性を示すため、安全性および信頼性に優れることが要求される非水電解液二次電池および電機二重層キャパシタ等の蓄電池用セパレータとして特に有用である。 Since the multilayer porous membrane of the present invention exhibits excellent heat resistance and permeability, it is particularly useful as a separator for storage batteries such as non-aqueous electrolyte secondary batteries and electric double layer capacitors that are required to have excellent safety and reliability. Useful.
本発明者は、前記課題を解決するため鋭意検討した結果、本発明に到達した。
すなわち、本発明は下記の通りである。
［１］ポリオレフィン樹脂多孔膜の少なくとも片面に、無機フィラーとケン化度８５％以上のポリビニルアルコールからなる多孔層を備えた多層多孔膜。
［２］前記多孔層の層厚が０．５μｍ以上１００μｍ以下である［１］に記載の多層多孔膜。
［３］［１］または［２］に記載の多層多孔膜を用いた非水電解液電池用セパレータ。
［４］［３］に記載の電池用セパレータを用いた非水電解液電池。
［５］ポリオレフィン樹脂多孔膜の少なくとも片面に、無機フィラーとケン化度８５％以上のポリビニルアルコールとを含有する分散液を塗布することで、ポリオレフィン樹脂多孔膜表面に多孔層を形成することを特徴とする多層多孔膜の製造方法。
The inventor of the present invention has arrived at the present invention as a result of intensive studies to solve the above-mentioned problems.
That is, the present invention is as follows.
[1] A multilayer porous membrane comprising a porous layer composed of an inorganic filler and polyvinyl alcohol having a saponification degree of 85% or more on at least one surface of the polyolefin resin porous membrane.
[2] The multilayer porous membrane according to [1], wherein the porous layer has a thickness of 0.5 μm to 100 μm.
[ 3 ] A separator for a non-aqueous electrolyte battery using the multilayer porous membrane according to [1] or [2] .
[ 4 ] A non-aqueous electrolyte battery using the battery separator according to [ 3 ].
[ 5 ] A porous layer is formed on the surface of the polyolefin resin porous membrane by applying a dispersion containing an inorganic filler and polyvinyl alcohol having a saponification degree of 85% or more to at least one surface of the polyolefin resin porous membrane. A method for producing a multilayer porous membrane.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3435441A4 (en) * | 2016-03-23 | 2019-10-09 | Shanghai Energy New Materials Technology Co., Ltd. | Isolation membrane for electrochemical apparatus, and preparation method and application thereof |
| JP2020087791A (en) * | 2018-11-28 | 2020-06-04 | トヨタ自動車株式会社 | Method for manufacturing secondary battery separator |
| JP2022542567A (en) * | 2019-07-30 | 2022-10-05 | エルジー・ケム・リミテッド | Composite separation membrane for electrochemical device and electrochemical device including the same |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999031746A1 (en) * | 1997-12-18 | 1999-06-24 | Mitsubishi Denki Kabushiki Kaisha | Nonaqueous battery electrode and battery using the electrode |
| JP2004227972A (en) * | 2003-01-24 | 2004-08-12 | Sumitomo Chem Co Ltd | Separator for non-aqueous electrolytic solution secondary battery |
| JP2006248826A (en) * | 2005-03-09 | 2006-09-21 | Sekisui Chem Co Ltd | Thermoplastic resin sheet and laminate |
-
2013
- 2013-02-27 JP JP2013036560A patent/JP2013144442A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999031746A1 (en) * | 1997-12-18 | 1999-06-24 | Mitsubishi Denki Kabushiki Kaisha | Nonaqueous battery electrode and battery using the electrode |
| JP2004227972A (en) * | 2003-01-24 | 2004-08-12 | Sumitomo Chem Co Ltd | Separator for non-aqueous electrolytic solution secondary battery |
| JP2006248826A (en) * | 2005-03-09 | 2006-09-21 | Sekisui Chem Co Ltd | Thermoplastic resin sheet and laminate |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3435441A4 (en) * | 2016-03-23 | 2019-10-09 | Shanghai Energy New Materials Technology Co., Ltd. | Isolation membrane for electrochemical apparatus, and preparation method and application thereof |
| JP2020087791A (en) * | 2018-11-28 | 2020-06-04 | トヨタ自動車株式会社 | Method for manufacturing secondary battery separator |
| JP7001964B2 (en) | 2018-11-28 | 2022-02-04 | トヨタ自動車株式会社 | How to manufacture a separator for a secondary battery |
| JP2022542567A (en) * | 2019-07-30 | 2022-10-05 | エルジー・ケム・リミテッド | Composite separation membrane for electrochemical device and electrochemical device including the same |
| JP7372438B2 (en) | 2019-07-30 | 2023-10-31 | エルジー・ケム・リミテッド | Composite separation membrane for electrochemical devices and electrochemical devices containing the same |
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