JP7307129B2 - Porous layer for non-aqueous electrolyte secondary battery - Google Patents

Description

The present invention relates to a porous layer for non-aqueous electrolyte secondary batteries.

Non-aqueous electrolyte secondary batteries, especially lithium-ion secondary batteries, have high energy density and are widely used in personal computers, mobile phones, personal digital assistants, etc. Recently, they are also being developed as batteries for vehicles. It is

The end-of-charge voltage of a conventional non-aqueous electrolyte secondary battery is about 4.1 to 4.2 V (4.2 to 4.3 V (vs Li/Li ⁺ ) as a voltage against a lithium reference electrode potential). rice field. On the other hand, in recent non-aqueous electrolyte secondary batteries, the capacity of the battery is increased by raising the final charge voltage to 4.3 V or higher, which is higher than before, to increase the utilization rate of the positive electrode. For this purpose, it is important that the resin contained in the porous layer for non-aqueous electrolyte secondary batteries does not deteriorate even when placed under high voltage conditions.

Patent Document 1 is cited as a document disclosing a resin having such properties. This document discloses a wholly aromatic polyamide in which the aromatic ring located at the end of the molecular chain does not have an amino group, and the aromatic ring has an electron-withdrawing substituent. ing. According to the document, this wholly aromatic polyamide shows little discoloration even when a high voltage is applied.

JP-A-2003-40999

A sulfonyl group is one of the electron-withdrawing functional groups. Therefore, if a resin containing a sulfonyl group is employed, it can be expected that a porous layer for a non-aqueous electrolyte secondary battery that does not deteriorate even under high voltage conditions can be obtained. However, as a result of studies by the present inventors, the porous layer for a non-aqueous electrolyte secondary battery containing a resin containing a sulfonyl group and a filler has poor adhesion to a polyolefin porous film and peels off in a powder form. It turned out that it would (powder omission occurs).

An object of one aspect of the present invention is to provide a porous layer for a non-aqueous electrolyte secondary battery that achieves both high voltage resistance and adhesiveness.

The present inventors found that the porous layer for a non-aqueous electrolyte secondary battery, which contains a block copolymer having a block with many sulfonyl groups (block A) and a block with few sulfonyl groups (block B), provides the above I found that the problem of can be solved. That is, the present invention includes the following configurations.
<1>
A porous layer for a non-aqueous electrolyte secondary battery containing a block copolymer and a filler,
The block copolymer is
A block A whose main component is a unit represented by the following formula (1);
—(NH—Ar ¹ —NHCO—Ar ² —CO)— Formula (1)
A block B whose main component is a unit represented by the following formula (2);
—(NH—Ar ³ —NHCO—Ar ⁴ —CO)— Formula (2)
A porous layer for a non-aqueous electrolyte secondary battery having:
During the ceremony,
Ar ¹ , Ar ² , Ar ³ and Ar ⁴ may vary from unit to unit;
Ar ¹ , Ar ² , Ar ³ and Ar ⁴ are each independently a divalent group having one or more aromatic rings,
50% or more of all Ar ¹ have a structure in which two aromatic rings are linked by a sulfonyl bond,
50% or less of all Ar ³ have a structure in which two aromatic rings are linked by a sulfonyl bond,
30 to 70% of all Ar ¹ and Ar ³ have a structure in which two aromatic rings are linked by a sulfonyl bond.
<2>
50% or more of the units of formula (1) contained in block A are 4,4'-diphenylsulfonylterephthalamide,
50% or more of the units of formula (2) contained in block B are paraphenylene terephthalamide,
The porous layer for a non-aqueous electrolyte secondary battery according to <1>.
<3>
The porous layer for a non-aqueous electrolyte secondary battery according to <1> or <2>, wherein the block copolymer has a triblock structure of block B-block A-block B.
<4>
The molecule corresponding to the mode of the molecular weight distribution of the block copolymer is
10 to 1000 units of formula (1) included in block A,
10 to 500 units of formula (2) included in the block B,
The porous layer for a non-aqueous electrolyte secondary battery according to any one of <1> to <3>.
<5>
The non-aqueous electrolyte secondary battery according to any one of <1> to <4>, which does not contain the unit of formula (1) and further contains a polymer having 5 to 200 units of formula (2). Porous layer for.
<6>
When the weight of the porous layer for nonaqueous electrolyte secondary batteries is 100% by weight, the content of the filler in the porous layer for nonaqueous electrolyte secondary batteries is 20 to 90% by weight, <1 A porous layer for a non-aqueous electrolyte secondary battery according to any one of > to <5>.
<7>
The porous layer for a non-aqueous electrolyte secondary battery according to any one of <1> to <6>, wherein the filler contains aluminum oxide.
<8>
A laminated separator for a non-aqueous electrolyte secondary battery, wherein the porous layer for a non-aqueous electrolyte secondary battery according to any one of <1> to <7> is laminated on one or both sides of a polyolefin porous film. .
<9>
Non-aqueous, comprising the porous layer for a non-aqueous electrolyte secondary battery according to any one of <1> to <7>, or the laminated separator for a non-aqueous electrolyte secondary battery according to <8> Electrolyte secondary battery.

According to one aspect of the present invention, there is provided a porous layer for a non-aqueous electrolyte secondary battery that achieves both high voltage resistance and adhesiveness.

An embodiment of the invention will be described below, but the invention is not limited thereto. The present invention is not limited to the configurations described below, and can be modified in various ways within the scope of the claims, by appropriately combining technical means disclosed in different embodiments. The resulting embodiment is also included in the technical scope of the present invention. In this specification, unless otherwise specified, "A to B" representing a numerical range means "A or more and B or less".

[1. Porous layer for non-aqueous electrolyte secondary battery]
A porous layer for a non-aqueous electrolyte secondary battery according to one embodiment of the present invention contains a block copolymer and a filler. Each component will be described in detail below.

In this specification, the porous layer for non-aqueous electrolyte secondary batteries may be simply abbreviated as "porous layer". Further, in this specification, the laminated separator for non-aqueous electrolyte secondary batteries may be simply abbreviated as "laminated separator".

[Block copolymer]
A block copolymer has an A block and a B block. Block A is mainly composed of a unit represented by the following formula (1). Block B is mainly composed of a unit represented by the following formula (2).
—(NH—Ar ¹ —NHCO—Ar ² —CO)— Formula (1)
—(NH—Ar ³ —NHCO—Ar ⁴ —CO)— Formula (2).

Of all the units contained in block A, the ratio of the units of formula (1) is preferably 80% or more, more preferably 90% or more, and even more preferably 95% or more. In one embodiment, block A is represented entirely by units of formula (1), except for the terminus. Of all the units contained in block B, the ratio of the units represented by formula (2) is preferably 80% or more, more preferably 90% or more, and even more preferably 95% or more. In one embodiment, block B is represented entirely by a unit of formula (2) except for the terminus.

If the units represented by formulas (1) and (2) are contained within the above range, the block copolymer will have the properties of aromatic polyamide. Aromatic polyamides are excellent in heat resistance and the like, and are suitable as materials for porous layers for non-aqueous electrolyte secondary batteries.

In the formula, Ar ¹ , Ar ² , Ar ³ and Ar ⁴ may be different for each unit. Ar ¹ , Ar ² , Ar ³ and Ar ⁴ are each independently a divalent group having one or more aromatic rings.

As used herein, the term "aromatic ring" represents a cyclic compound that satisfies Hückel's rule. Examples of aromatic rings include benzene, naphthalene, anthracene, azulene, pyrrole, pyridine, furan, thiophene. In one embodiment, the aromatic ring is composed only of carbon and hydrogen atoms. In one embodiment, the aromatic ring is a benzene ring or a fused ring of two or more benzene rings (naphthalene, anthracene, etc.).

At least part of Ar ¹ has a structure in which two aromatic rings are linked by a sulfonyl bond. Ar ³ may have a structure in which two aromatic rings are linked by a sulfonyl bond. Among all Ar ¹ and Ar ³ , the lower limit of the ratio of Ar ¹ and Ar ³ having a structure in which two aromatic rings are linked by a sulfonyl bond is 30% or more, preferably 35% or more, and 40% The above is more preferable. The upper limit of this ratio is 70% or less, preferably 65% or less, and more preferably 60% or less.

The ratio of Ar ¹ having a structure in which two aromatic rings are linked by a sulfonyl bond to all Ar ¹ is 50% or more, preferably 80% or more, and more preferably 90% or more. In one embodiment, all Ar ¹ have a structure in which two aromatic rings are linked by a sulfonyl bond.

The ratio of Ar ³ having a structure in which two aromatic rings are linked by a sulfonyl bond to all Ar ³ is 50% or less, preferably 20% or less, more preferably 10% or less. In one embodiment, all Ar ³ are not structures in which two aromatic rings are linked by a sulfonyl bond.

Therefore, it can be said that the block A has relatively many sulfonyl groups and the block B has relatively few sulfonyl groups. By adopting such a block copolymer having two types of blocks, a porous layer having both high voltage resistance and adhesiveness can be obtained.

Examples of structures in which two aromatic rings are linked by a sulfonyl bond include 4,4'-diphenylsulfonyl, 3,4'-diphenylsulfonyl, and 3,3'-diphenylsulfonyl.

Examples of structures other than structures in which two aromatic rings are linked by a sulfonyl bond include the following.

In one embodiment, the structure with two aromatic rings linked by a sulfonyl bond is 4,4'-diphenylsulfonyl. In one embodiment, the structure that is not a structure in which two aromatic rings are linked by a sulfonyl bond is paraphenyl.

In one embodiment, at least some of the units of formula (1) included in block A are 4,4'-diphenylsulfonylterephthalamide. Among the units of formula (1) contained in block A, the lower limit of the ratio of 4,4′-diphenylsulfonylterephthalamide is preferably 50% or more, more preferably 80% or more, and further 90% or more. preferable. 4,4'-Diphenylsulfonyl terephthalamide is easy to handle and the monomer is readily available.

In one embodiment, at least some of the units of formula (2) contained in block B are paraphenylene terephthalamide. The lower limit of the proportion of paraphenylene terephthalamide among the units of formula (2) contained in block B is preferably 50% or more, more preferably 80% or more, and even more preferably 90% or more. Paraphenylene terephthalamide is easy to handle and the monomer is readily available.

The block copolymer may have a structure composed of units other than those represented by formulas (1) and (2). Examples of such structures include polyimide backbones.

(Structure of block copolymer)
The number of blocks that the block copolymer has is not particularly limited. In one embodiment, the block copolymer has a block A-block B diblock structure. In one embodiment, the block copolymer has a block A-block B-block A or block B-block A-block B triblock structure. In one embodiment, the block copolymer has a block A-block B-block A-block B tetrablock structure. Among the above structures, the block B-block A-block B triblock structure is preferred.

The number of units of formula (1) contained in block A is preferably 10 to 1000, more preferably 20 to 300, in one molecule of the block copolymer. When the number of units of formula (1) is within the above range, a sufficiently large number of sulfonyl groups are contained in the molecule, and the high voltage resistance of the porous layer is enhanced. The number of units of formula (2) contained in block B is preferably 10 to 500, more preferably 15 to 200, in one molecule of the block copolymer. If the number of units of formula (2) is within the above range, the adhesiveness of the porous layer will be high.

Here, the number of units of formulas (1) and (2) described as preferred values is the number in the molecule corresponding to the mode of the molecular weight distribution of the block copolymer. The molecular weight distribution of the block copolymer can be determined experimentally by gel permeation chromatography, for example.

The molecular weight of the block copolymer is preferably 0.5 to 5 dL/g, more preferably 0.8 to 2.5 dL/g, in terms of intrinsic viscosity. If the molecular weight is within the above range, both good coatability and strength of the porous layer can be achieved.

The content of the block copolymer in the porous layer is preferably 10 to 80% by weight, more preferably 30 to 60% by weight, based on 100% by weight of the porous layer. If the content is within the above range, the porous layer can be sufficiently endowed with high voltage resistance due to the electron-withdrawing property of the sulfonyl group of the block copolymer.

(Method for producing block copolymer)
A block copolymer can be synthesized according to a conventional method. For example, according to the following procedure, a block copolymer having a block A-block B diblock structure can be synthesized (block copolymers having other block structures can also be synthesized by applying the following procedure). .
1. A diamine represented by NH ₂ -Ar ¹ -NH ₂ and a dicarboxylic acid halide represented by XOOC-Ar ² -COOX (X is a halogen atom such as F, Cl, Br, I) are used as monomers. and polymerized according to a known aromatic polyamide polymerization method. This synthesizes a block A having the unit of formula (1).
2. After the synthesis of block A is completed, a diamine represented by NH ₂ —Ar ³ —NH ₂ and a dicarboxylic acid represented by XOOC-Ar ⁴ —COOX (where X is a halogen atom such as F, Cl, Br, I) and an acid halide are used as monomers and polymerized according to a known aromatic polyamide polymerization method. This synthesizes a block B having the unit of formula (2) while being connected to the block A.

(Polymer containing unit of formula (2) but not containing unit of formula (1))
When synthesizing block copolymers according to the procedures described above, by-products can also be produced that consist only of the last synthesized block. For example, when synthesizing a block copolymer having a triblock structure of block B-block A-block B, a polymer consisting only of block B (i.e., without units of formula (1), units) can be produced as by-products.

Therefore, the porous layer for a non-aqueous electrolyte secondary battery according to one embodiment of the present invention does not contain the unit of formula (1), even if it contains a polymer containing the unit of formula (2). good. Further, a porous layer for a non-aqueous electrolyte secondary battery according to an embodiment of the present invention includes (i) a polymer that does not contain the unit of formula (1) but contains the unit of formula (2); ) a block copolymer having a block B-block A-block B triblock structure.

A polymer containing no units of formula (1) but containing units of formula (2) has 5 to 200 units of formula (2), preferably 10 to 150 units. The content of such a polymer in the porous layer is preferably 50 parts by weight or less, more preferably 20 parts by weight or less, based on 100 parts by weight of the block copolymer.

Whether or not the polymer containing the unit of formula (2) but not containing the unit of formula (1) is contained in the porous layer can be determined from the molecular weight distribution of the resin component of the porous layer. Specifically, if a peak corresponding to a polymer containing the unit of formula (2) but not containing the unit of formula (1) exists in the molecular weight distribution curve, the polymer is included in the porous layer. It can be said that In this case, the molecular weight distribution curve of the resin component of the porous layer has two or more peaks. A molecular weight distribution curve is determined experimentally by gel permeation chromatography.

The number of units of formula (2) possessed by the polymer containing units of formula (2) but not containing units of formula (1) can be calculated from the molecular weight distribution curve. The abundance ratio of the polymer containing the unit of formula (2) but not containing the unit of formula (1) to the block copolymer can also be calculated from the molecular weight distribution curve.

[Filler]
Types of fillers include organic fillers and inorganic fillers.

Examples of organic fillers include styrene, vinyl ketone, acrylonitrile, methyl methacrylate, ethyl methacrylate, glycidyl methacrylate, glycidyl acrylate, methyl acrylate, and copolymers of two or more of them; polytetrafluoroethylene, tetrafluoride; fluorine-based resins such as ethylene-propylene hexafluoride copolymer, ethylene tetrafluoride-ethylene copolymer, polyvinylidene fluoride; melamine resin; urea resin; polyolefin; The organic fillers may be used alone or in combination of two or more. Among these organic fillers, polytetrafluoroethylene powder is preferable in terms of chemical stability.

Examples of inorganic fillers include materials composed of inorganic substances such as metal oxides, metal nitrides, metal carbides, metal hydroxides, carbonates and sulfates. Specific examples include powders such as aluminum oxides (such as alumina), boehmite, silica, titania, magnesia, barium titanate, aluminum hydroxide and calcium carbonate; and minerals such as mica, zeolite, kaolin and talc. be done. The inorganic fillers may be used alone or in combination of two or more. Among these inorganic fillers, aluminum oxide is preferable in terms of chemical stability.

The shape of the filler includes substantially spherical, plate-like, columnar, needle-like, whisker-like, and fiber-like, and any particles can be used. Approximately spherical particles are preferable because uniform pores can be easily formed.

The average particle size of the filler contained in the porous layer is preferably 0.01 to 1 μm. In the present specification, the "average particle size of the filler" means the volume-based average particle size (D50) of the filler. D50 means the particle diameter at which the cumulative distribution on a volume basis is 50%. D50 can be measured using, for example, a laser diffraction particle size distribution analyzer (manufactured by Shimadzu Corporation, trade names: SALD2200, SALD2300, etc.).

The filler content in the porous layer is preferably 20 to 90% by weight, more preferably 40 to 80% by weight, based on the weight of the porous layer being 100% by weight. If the filler content is within the above range, a porous layer having sufficient ion permeability can be obtained.

[Other ingredients]
The porous layer may contain components other than the block copolymer and filler. For example, the porous layer may contain a resin other than the block copolymer.

Examples of such resins include polyolefins; (meth)acrylate resins; fluorine-containing resins; polyamide resins; polyimide resins; polyamideimide resins; polyester resins; The above resins; water-soluble polymers; polycarbonate, polyacetal, polyetheretherketone, and the like.

Among the above resins, (meth)acrylate resins, fluorine-containing resins, polyamide resins, polyimide resins, polyamideimides, polyester resins and water-soluble polymers are preferred.

Preferred polyolefins include polyethylene, polypropylene, polybutene, and ethylene-propylene copolymers.

Examples of fluorine-containing resins include polyvinylidene fluoride (PVDF), polytetrafluoroethylene, vinylidene fluoride-hexafluoropropylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer. coalescence, vinylidene fluoride-tetrafluoroethylene copolymer, vinylidene fluoride-trifluoroethylene copolymer, vinylidene fluoride-trichlorethylene copolymer, vinylidene fluoride-vinyl fluoride copolymer, vinylidene fluoride-hexafluoro Propylene-tetrafluoroethylene copolymers, ethylene-tetrafluoroethylene copolymers, etc., and among the fluorine-containing resins, fluorine-containing rubbers having a glass transition temperature of 23° C. or lower can be mentioned.

As polyamide-based resins, aramid resins such as aromatic polyamides and wholly aromatic polyamides are preferred.

Specific examples of aramid resins include poly(paraphenylene terephthalamide), poly(metaphenylene isophthalamide), poly(parabenzamide), poly(methabenzamide), poly(4,4'-benzanilide terephthalate amide), poly(paraphenylene-4,4′-biphenylenedicarboxylic acid amide), poly(metaphenylene-4,4′-biphenylenedicarboxylic acid amide), poly(paraphenylene-2,6-naphthalenedicarboxylic acid amide), Poly(metaphenylene-2,6-naphthalenedicarboxylic acid amide), poly(2-chloroparaphenylene terephthalamide), paraphenylene terephthalamide/2,6-dichloroparaphenylene terephthalamide copolymer, metaphenylene terephthalamide/2 , 6-dichloroparaphenylene terephthalamide copolymer. Among these, poly(paraphenylene terephthalamide) is more preferable.

Aromatic polyesters such as polyarylates and liquid crystalline polyesters are preferable as the polyester-based resin.

Rubbers include styrene-butadiene copolymer and its hydride, methacrylic acid ester copolymer, acrylonitrile-acrylic acid ester copolymer, styrene-acrylic acid ester copolymer, ethylene propylene rubber, polyvinyl acetate, etc. can be mentioned.

Examples of resins having a melting point or glass transition temperature of 180° C. or higher include polyphenylene ether, polysulfone, polyethersulfone, polyphenylene sulfide, polyetherimide, polyamideimide, and polyetheramide.

Examples of water-soluble polymers include polyvinyl alcohol, polyethylene glycol, cellulose ether, sodium alginate, polyacrylic acid, polyacrylamide, and polymethacrylic acid.

As for the resin used for the porous layer, only one type may be used, or two or more types may be used in combination.

[2. Laminated Separator for Nonaqueous Electrolyte Secondary Battery]
One aspect of the present invention is a laminated separator for a non-aqueous electrolyte secondary battery, in which the porous layer described above is laminated on one side or both sides of a polyolefin porous film.

[Polyolefin porous film]
A laminated separator for a non-aqueous electrolyte secondary battery according to one embodiment of the present invention includes a polyolefin porous film. A polyolefin porous film has a large number of interconnected pores therein, allowing gas and liquid to pass from one surface to the other surface. A polyolefin porous film can serve as a base material for a laminated separator for a non-aqueous electrolyte secondary battery. The polyolefin porous film melts when the battery heats up and renders the non-aqueous electrolyte secondary battery laminated separator non-porous, thereby imparting a shutdown function to the non-aqueous electrolyte secondary battery laminated separator. can be

Here, the "polyolefin porous film" is a porous film containing a polyolefin resin as a main component. In addition, "mainly composed of a polyolefin resin" means that the ratio of the polyolefin resin in the porous film is 50% by volume or more, preferably 90% by volume or more, of the entire material constituting the porous film. , more preferably 95% by volume or more.

The polyolefin resin, which is the main component of the polyolefin porous film, is not particularly limited, but for example, thermoplastic resins such as ethylene, propylene, 1-butene, 4-methyl-1-pentene and/or 1-hexene. Examples include homopolymers and copolymers obtained by polymerizing monomers. Examples of homopolymers include polyethylene, polypropylene and polybutene, and examples of copolymers include ethylene-propylene copolymers. The polyolefin porous film can be a layer containing one of these polyolefin resins, or a layer containing two or more of these polyolefin resins. Among these, polyethylene is more preferable because it can prevent (shutdown) the flow of an excessive current at a lower temperature, and a high-molecular-weight polyethylene mainly composed of ethylene is particularly preferable. The polyolefin porous film may contain components other than polyolefin as long as its functions are not impaired.

Polyethylene includes low density polyethylene, high density polyethylene, linear polyethylene (ethylene-α-olefin copolymer) and ultra high molecular weight polyethylene. Among them, ultra-high molecular weight polyethylene is more preferable, and it is more preferable to contain a high molecular weight component having a weight average molecular weight of 5×10 ⁵ to 15×10 ⁶ . In particular, when the polyolefin resin contains a high molecular weight component having a weight average molecular weight of 1,000,000 or more, the strength of the polyolefin porous film and the laminated separator for the non-aqueous electrolyte secondary battery is improved, which is more preferable.

The thickness of the polyolefin porous film is preferably 5 to 20 μm, more preferably 7 to 15 μm, even more preferably 9 to 15 μm. If the film thickness is 5 μm or more, the functions required for the polyolefin porous film (shutdown function, etc.) can be sufficiently obtained. If the film thickness is 20 μm or less, a thin laminated separator for a non-aqueous electrolyte secondary battery can be obtained.

The pore size of pores in the polyolefin porous film is preferably 0.1 μm or less, more preferably 0.06 μm or less. As a result, sufficient ion permeability can be obtained, and the entry of particles constituting the electrode can be further prevented.

The weight basis weight per unit area of the polyolefin porous film is usually preferably 4 to 20 g/m ² , more preferably 5 to 12 g/m 2 , so that the weight energy density and volume energy density of the battery can be increased. ² is more preferred.

The air permeability of the polyolefin porous film is preferably 30 to 500 s/100 mL, more preferably 50 to 300 s/100 mL in terms of Gurley value. Thereby, the laminated separator for non-aqueous electrolyte secondary batteries can obtain sufficient ion permeability.

The porosity of the polyolefin porous film is preferably 20 to 80% by volume, more preferably 30 to 75% by volume. As a result, it is possible to increase the holding amount of the electrolytic solution and reliably prevent (shut down) the flow of excessive current at a lower temperature.

A method for producing the polyolefin porous film may be a known method, and is not particularly limited. For example, as described in Japanese Patent No. 5476844, there is a method of adding a filler to a thermoplastic resin, forming a film, and then removing the filler.

Specifically, for example, when the polyolefin porous film is formed from a polyolefin resin containing ultra-high molecular weight polyethylene and a low molecular weight polyolefin having a weight average molecular weight of 10,000 or less, from the viewpoint of production cost, the following It is preferably produced by a method including steps (1) to (4) shown.

(1) 100 parts by weight of ultra-high molecular weight polyethylene, 5 to 200 parts by weight of low molecular weight polyolefin having a weight average molecular weight of 10,000 or less, and 100 to 400 parts by weight of an inorganic filler such as calcium carbonate are kneaded. obtaining a polyolefin-based resin composition;
(2) forming a sheet using the polyolefin resin composition;
(3) removing the inorganic filler from the sheet obtained in step (2);
(4) A step of stretching the sheet obtained in step (3).
In addition, the methods described in the above-mentioned patent documents may be used.

Moreover, as the polyolefin porous film, a commercially available product having the above characteristics may be used.

[Physical properties of laminated separator for non-aqueous electrolyte secondary battery]
The Gurley value of the air permeability of the laminated separator is preferably 500 s/100 mL or less, more preferably 300 s/100 mL or less. The Gurley value of the air permeability of the porous layer provided in the laminated separator is preferably 400 s/100 mL or less, more preferably 200 s/100 mL or less. If the air permeability is within the above range, it can be said to have sufficient ion permeability.

The air permeability of the porous layer is calculated by YX, where X is the air permeability of the polyolefin porous film and Y is the air permeability of the laminated separator. The air permeability of the porous layer can be adjusted, for example, by the intrinsic viscosity of the resin and the basis weight of the porous layer. In general, the Gurley value tends to decrease as the intrinsic viscosity of the resin decreases. In addition, when the basis weight of the porous layer becomes small, the Gurley value tends to become small.

The thickness of the porous layer provided in the laminated separator is preferably 10 μm or less, more preferably 7 μm or less, and even more preferably 5 μm or less.

The laminated separator may have other layers as needed in addition to the polyolefin porous film and the porous layer. Examples of such layers include adhesive layers and protective layers.

[Method for manufacturing laminated separator for non-aqueous electrolyte secondary battery]
A porous layer can be formed by using a coating liquid in which a block copolymer, a filler and optionally other components are dissolved or dispersed in a solvent. Methods for forming the coating liquid include, for example, a mechanical stirring method, an ultrasonic dispersion method, a high-pressure dispersion method, and a media dispersion method. Examples of solvents that can be used include N-methylpyrrolidone, N,N-dimethylacetamide and N,N-dimethylformamide.

Examples of the method for forming the porous layer include a method of preparing the above-described coating liquid, applying the coating liquid to a polyolefin porous film, and drying to form the porous layer.

As a method for applying the coating liquid to the polyolefin porous film, known coating methods such as knife, blade, bar, gravure, or die can be used.

The solvent (dispersion medium) is generally removed by drying. Drying methods include air drying, air drying, heat drying, and vacuum drying, but any method may be used as long as the solvent (dispersion medium) can be sufficiently removed. Alternatively, drying may be performed after replacing the solvent (dispersion medium) contained in the paint with another solvent. As a method of removing the solvent (dispersion medium) after replacing it with another solvent, specifically, there is a method of replacing with a poor solvent having a low boiling point such as water, alcohol, or acetone, precipitating, and drying.

[3. Non-aqueous electrolyte secondary battery member and non-aqueous electrolyte secondary battery]
A non-aqueous electrolyte secondary battery member according to an embodiment of the present invention comprises a positive electrode, the above laminated separator for a non-aqueous electrolyte secondary battery, and a negative electrode arranged in this order. Further, a non-aqueous electrolyte secondary battery according to one embodiment of the present invention includes the laminated separator for a non-aqueous electrolyte secondary battery described above. The above-mentioned non-aqueous electrolyte secondary battery usually has a structure in which a negative electrode and a positive electrode face each other with the above-described laminated separator for a non-aqueous electrolyte secondary battery interposed therebetween. In the non-aqueous electrolyte secondary battery, the battery element in which the structure is impregnated with the electrolyte is enclosed in the exterior material. For example, the non-aqueous electrolyte secondary battery is a lithium ion secondary battery that obtains an electromotive force by doping and dedoping lithium ions.

[Positive electrode]
As the positive electrode, for example, a positive electrode sheet having a structure in which an active material layer containing a positive electrode active material and a binder is formed on a current collector can be used. The active material layer may further contain a conductive agent.

Examples of the positive electrode active material include materials capable of doping and dedoping lithium ions.

Examples of such materials include lithium composite oxides containing at least one transition metal such as V, Ti, Cr, Mn, Fe, Co, Ni, and Cu. Lithium composite oxides include, for example, a lithium composite oxide having a layered structure, a lithium composite oxide having a spinel structure, and a solid solution lithium-containing transition metal oxide composed of a lithium composite oxide having both a layered structure and a spinel structure. things are mentioned. Lithium-cobalt composite oxides and lithium-nickel composite oxides are also included. Furthermore, some of the transition metal atoms that are the main constituents of these lithium composite oxides are Na, K, B, F, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mg, Ca , Ga, Zr, Si, Nb, Mo, Sn and W, and the like.

Lithium composite oxides in which some of the transition metal atoms that are the main constituent of the lithium composite oxide are replaced with other elements include, for example, lithium cobalt composite oxides having a layered structure represented by the following formula (3), Lithium nickel composite oxide represented by formula (4), lithium manganese composite oxide having a spinel structure represented by formula (5) below, transition metal oxide containing solid solution lithium represented by formula (6) below, etc. is mentioned.

Li[Li _x (Co _1-a M ¹ _a ) _1-x ]O ₂ (3)
(In formula (3), M ¹ is Na, K, B, F, Al, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn and At least one metal selected from the group consisting of W, and satisfies −0.1≦x≦0.30 and 0≦a≦0.5.)

Li[Li _y (Ni _1-b M ² _b ) _1-y ]O ₂ (4)
(In formula (4), ^M2 is Na, K, B, F, Al, Ti, V, Cr, Mn, Fe, Co, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn and At least one metal selected from the group consisting of W, satisfying -0.1 ≤ y ≤ 0.30 and 0 ≤ b ≤ 0.5.)

Li _z Mn _2-c M ³ _c O ₄ (5)
(In formula (5), ^M3 is Na, K, B, F, Al, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn and At least one metal selected from the group consisting of W, satisfying 0.9≦z and 0≦c≦1.5.)

_{Li1 +} ^wM4dM5eO2 _{( 6} ⁾
(In formula (6), ^M4 and ^M5 are at least one metal selected from the group consisting of Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mg and Ca, satisfy 0<w≦1/3, 0≦d≦2/3, 0≦e≦2/3, and w+d+e=1.)

Specific examples of the lithium composite oxides represented by the above formulas (3) to (6) include LiCoO ₂ , LiNiO ₂ , LiMnO ₂ , LiNi _0.8 Co _0.2 O ₂ , LiNi _0.5 Mn _{0 . 5O2 , LiNi0.85Co0.10Al0.05O2 , LiNi0.8Co0.15Al0.05O2 , LiNi0.5Co0.2Mn0.3O2 , LiNi _ _ _ _ _ 0.6Co0.2Mn0.2O2 , LiNi0.33Co0.33Mn0.33O2 , LiMn2O4 , LiMn1.5Ni0.5O4 , LiMn1.5Fe _ _ _ _ _ 0.5O4 , LiCoMnO4 , Li1.21Ni0.20Mn0.59O2 , Li1.22Ni0.20Mn0.58O2 , Li1.22Ni0.15Co0 . _ _ _ _ 10Mn0.53O2 , Li1.07Ni0.35Co0.08Mn0.50O2 , Li1.07Ni0.36Co0.08Mn0.49O2 and the like . _ _ _ _}

Lithium composite oxides other than the lithium composite oxides represented by the above formulas (3) to (6) can also be preferably used as the positive electrode active material. Examples of such lithium composite oxides include LiNiVO ₄ , LiV ₃ O ₆ , Li _1.2 Fe _0.4 Mn _0.4 O ₂ and the like.

Materials other than lithium composite oxides that can be preferably used as positive electrode active materials include, for example, phosphates having an olivine type structure, and phosphoric acid having an olivine type structure represented by the following formula (7): salt.

Li _v (M ⁶ _f M ⁷ _g M ⁸ _h M ⁹ _i ) _j PO ₄ (7)
(In formula (7), ^M6 is Mn, Co, or Ni, ^M7 is Ti, V, Cr, Mn, Fe, Co, Ni, Zr, Nb, or Mo, and ^M8 is , a transition metal or main group element arbitrarily excluding elements of groups VIA and VIIA, M ⁹ is a transition metal or main group element arbitrarily excluding elements of groups VIA and VIIA, 1.2 ≥ a ≧0.9, 1≧b≧0.6, 0.4≧c≧0, 0.2≧d≧0, 0.2≧e≧0, 1.2≧f≧0.9.)

The positive electrode active material preferably has a coating layer on the surface of the lithium metal composite oxide particles that constitute the positive electrode active material. Examples of materials constituting the coating layer include metal composite oxides, metal salts, boron-containing compounds, nitrogen-containing compounds, silicon-containing compounds, sulfur-containing compounds, etc. Among these, metal composite oxides are preferably used. be done.

As the metal composite oxide, an oxide having lithium ion conductivity is preferably used. Such metal composite oxides include, for example, Li and at least one selected from the group consisting of Nb, Ge, Si, P, Al, W, Ta, Ti, S, Zr, Zn, V and B. Metal composite oxides with elements can be mentioned. When the positive electrode active material has a coating layer, the coating layer suppresses a side reaction at the interface between the positive electrode active material and the electrolyte under high voltage, and the resulting secondary battery can have a long life. In addition, the formation of a high-resistance layer at the interface between the positive electrode active material and the electrolyte can be suppressed, and the output of the resulting secondary battery can be increased.

Examples of the conductive agent include carbonaceous materials such as natural graphite, artificial graphite, cokes, carbon black, pyrolytic carbons, carbon fibers, and baked organic polymer compounds.

Examples of the binder include polyvinylidene fluoride, vinylidene fluoride copolymer, polytetrafluoroethylene, vinylidene fluoride-hexafluoropropylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, Tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, ethylene-tetrafluoroethylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, vinylidene fluoride-trifluoroethylene copolymer, vinylidene fluoride - copolymers of trichlorethylene, copolymers of vinylidene fluoride-vinyl fluoride, copolymers of vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene, thermoplastic polyimides, thermoplastics such as polyethylene and polypropylene, acrylics resins, as well as styrene-butadiene rubber. In addition, the binder also has a function as a thickener.

Examples of positive electrode current collectors include conductors such as Al, Ni, and stainless steel. Among them, Al is more preferable because it is easy to process into a thin film and is inexpensive.

Examples of the method for producing a sheet-like positive electrode include a method of pressure-molding a positive electrode active material, a conductive agent, and a binder to be a positive electrode mixture on a positive electrode current collector; After obtaining a positive electrode mixture by making a paste of a conductive agent and a binder, the positive electrode mixture is applied to a positive electrode current collector, and the sheet-shaped positive electrode mixture obtained by drying is added. A method of fixing to the positive electrode current collector by applying pressure, and the like can be mentioned.

[Negative electrode]
As the negative electrode, for example, a negative electrode sheet having a structure in which an active material layer containing a negative electrode active material and a binder is formed on a current collector can be used. The active material layer may further contain a conductive agent.

Examples of the negative electrode active material include carbon materials, chalcogen compounds (oxides, sulfides, etc.), nitrides, metals or alloys, which are materials capable of doping and dedoping lithium ions at a potential lower than that of the positive electrode. etc.

Examples of carbon materials that can be used as the negative electrode active material include graphite such as natural graphite and artificial graphite, cokes, carbon black, pyrolytic carbons, carbon fibers, and baked organic polymer compounds.

Examples of oxides that can be used as the negative electrode active material include oxides of silicon represented by the formula SiO _x (where x _is a positive real number) such as SiO ₂ and SiO _; (where x is a positive real number); V ₂ O ₅ , VO _{2 ,} etc., represented by the formula V _x O _y (where x and y are positive real numbers); Oxides; _Fe3O4 , _Fe2O3 , _FeO , etc. Iron oxides represented by the formula _FexOy (where x and y are positive real numbers); _SnO2 , SnO _{, etc.} Formula _SnOx ( where x is a positive real number); tin oxides represented by the general formula WO _x (where x is a positive real number), such as WO ₃ and WO ₂ ; Li ₄ Ti composite metal oxides containing lithium and titanium or vanadium, such as ₅ O ₁₂ and LiVO ₂ ;

Examples of sulfides that can be used as negative electrode active materials include titanium sulfides represented by the formula Ti _{x Sy} (where x and y are positive real numbers) such as Ti ₂ S ₃ , TiS ₂ and TiS; Vanadium sulfide represented by _the formula VS _x ( _where x is a positive real number) such _{as V 3 S 4} , VS ₂ , _VS ; , x and y are positive real numbers ₎ ; sulfides of molybdenum represented by _the formula _MoxSy (where x and y are positive real numbers) such as _Mo2S3 , _MoS2, etc. tin sulfide represented by the formula SnS _x (where x is a positive real number) such as SnS ₂ and SnS; tungsten represented by the formula WS _x (where x is a positive real number) such as WS ₂ sulfides of antimony represented by the formula _SbxSy (where x and y are positive real numbers) _{, such} as _Sb2S3 ; _{formulas SexSy} , such as _Se5S3 , _SeS2 , _SeS (here, x and y are positive real numbers).

Nitrides that can be used as negative electrode active materials include, for example, Li ₃ N and Li _3-x A _x N (where A is either one or both of Ni and Co and 0<x<3 .) and other lithium-containing nitrides.

These carbon materials, oxides, sulfides and nitrides may be used alone or in combination of two or more. Moreover, these carbon materials, oxides, sulfides and nitrides may be either crystalline or amorphous. These carbon materials, oxides, sulfides, and nitrides are mainly used as electrodes by being carried on a negative electrode current collector.

Metals that can be used as the negative electrode active material include lithium metal, silicon metal, and tin metal.

Composite materials containing Si or Sn as a first constituent element and additionally containing second and third constituent elements can also be mentioned. The second constituent element is, for example, at least one of cobalt, iron, magnesium, titanium, vanadium, chromium, manganese, nickel, copper, zinc, gallium and zirconium. The third constituent element is, for example, at least one of boron, carbon, aluminum and phosphorus.

In particular, since a high battery capacity and excellent battery characteristics can be obtained, as the metal material, silicon or tin alone (which may contain trace amounts of impurities), SiO _v (0 < v ≤ 2), SnO _w (0 ≤w≤2), Si--Co--C composite materials, Si--Ni--C composite materials, Sn--Co--C composite materials, and Sn--Ni--C composite materials are preferred.

Examples of negative electrode current collectors include Cu, Ni, and stainless steel. Among them, Cu is more preferable, especially in a lithium ion secondary battery, because it is difficult to form an alloy with lithium and is easy to process into a thin film.

Examples of the method for producing a sheet-shaped negative electrode include a method of pressure-molding a negative electrode active material to be a negative electrode mixture on a negative electrode current collector; After obtaining the agent, the negative electrode mixture is applied to the negative electrode current collector, and the sheet-shaped negative electrode mixture obtained by drying this is pressed to adhere to the negative electrode current collector. mentioned. The paste preferably contains the conductive agent and the binder.

[Non-aqueous electrolyte]
As the non-aqueous electrolyte, for example, a non-aqueous electrolyte obtained by dissolving a lithium salt in an organic solvent can be used. Examples of lithium salts include LiClO ₄ , LiPF ₆ , LiAsF ₆ , LiSbF ₆ , LiBF ₄ , LiSO ₃ F, LiCF ₃ SO ₃ , LiN(SO ₂ CF ₃ ) ₂ , LiN(SO ₂ C ₂ F ₅ ) ₂ , LiN( _{SO2CF3 )} ( _COCF3 ), Li( _{C4F9SO3 )} , LiC _{( SO2CF3 ) 3} , _Li2B10Cl10 , _LiBOB (where BOB is bis ₍ oxalato ) borate.), lower aliphatic carboxylic acid lithium salt, LiAlCl ₄ and the like. These may be used alone or as a mixture of two or more. Lithium salts include LiPF ₆ , LiAsF ₆ , LiSbF ₆ , LiBF ₄ , LiSO ₃ F, LiCF ₃ SO ₃ , LiN(SO ₂ CF ₃ ) ₂ and LiC(SO ₂ CF ₃ ) ₃ containing fluorine. It is preferable to use one containing at least one selected from the group.

Examples of organic solvents include propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, ethylmethyl carbonate, 4-trifluoromethyl-1,3-dioxolan-2-one, 1,2-di(methoxycarbonyloxy)ethane. carbonates such as; esters such as methyl formate, methyl acetate and γ-butyrolactone; nitriles such as acetonitrile and butyronitrile; amides such as N,N-dimethylformamide and N,N-dimethylacetamide; carbamates; sulfur-containing compounds such as sulfolane, dimethylsulfoxide, and 1,3-propanesultone; ) can be used.

It is preferable that two or more of the above organic solvents are mixed and used as a mixed solvent. Among them, a mixed solvent containing carbonates is preferable, and a mixed solvent of a cyclic carbonate and a non-cyclic carbonate and a mixed solvent of a cyclic carbonate and an ether are more preferable. A mixed solvent containing ethylene carbonate, dimethyl carbonate and ethyl methyl carbonate is preferable as the mixed solvent of the cyclic carbonate and the non-cyclic carbonate. A non-aqueous electrolyte using such a mixed solvent has a wide operating temperature range, does not easily deteriorate even when used at a high voltage, and does not easily deteriorate even when used for a long time. It has the advantage of being resistant to decomposition even when a graphite material such as artificial graphite is used.

In addition, as the non-aqueous electrolyte, a non-aqueous electrolyte containing a fluorine-containing lithium salt such as _LiPF6 and an organic solvent having a fluorine substituent is used because the safety of the obtained non-aqueous electrolyte secondary battery is increased. is preferred. A mixed solvent containing ethers having fluorine substituents such as pentafluoropropylmethyl ether and 2,2,3,3-tetrafluoropropyldifluoromethyl ether and dimethyl carbonate has a capacity retention rate even when discharged at a high voltage. It is more preferable because it is expensive.

[Method for manufacturing non-aqueous electrolyte secondary battery member and non-aqueous electrolyte secondary battery]
As a method for manufacturing a member for a non-aqueous electrolyte secondary battery, for example, there is a method in which a positive electrode, the above-described laminated separator for a non-aqueous electrolyte secondary battery, and a negative electrode are arranged in this order.

Moreover, as a manufacturing method of a non-aqueous electrolyte secondary battery, for example, the following method can be mentioned. First, the non-aqueous electrolyte secondary battery member is placed in a container that serves as a housing for the non-aqueous electrolyte secondary battery. Next, after filling the inside of the container with the non-aqueous electrolyte, the container is sealed while reducing the pressure. Thereby, a non-aqueous electrolyte secondary battery can be manufactured.

The present invention is not limited to the above-described embodiments, but can be modified in various ways within the scope of the claims, and can be obtained by appropriately combining technical means disclosed in different embodiments. is also included in the technical scope of the present invention.

EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

[Methods for measuring various physical properties]
In Examples and Comparative Examples described later, physical properties were measured by the following methods.

(1) Intrinsic Viscosity A solution obtained by dissolving 0.5 g of the polymer to be measured in 100 mL of 96-98% sulfuric acid and 96-98% sulfuric acid were each measured for flow time at 30° C. using a capillary viscometer. From the measured flow time, the intrinsic viscosity was determined by the following formula.
Intrinsic viscosity = ln (T/T0)/C [unit: dL/g]
During the ceremony,
T: Flow time of sulfuric acid solution of polymer T0: Flow time of sulfuric acid C: Polymer concentration in solution (g/dL).

(2) High voltage resistance A test battery having the laminated separator for non-aqueous electrolyte secondary batteries prepared in Examples or Comparative Examples was prepared, and this battery was subjected to a trickle charge test under high voltage conditions. . After the test, the test battery was disassembled, and the color of the portion of the porous layer for non-aqueous electrolyte secondary battery that was in contact with the positive electrode active material layer was visually confirmed. Evaluation criteria are as follows.
Good: The porous layer was colorless. That is, even if a trickle charge test was performed under high voltage conditions, oxidation of the resin was suppressed.
x: The porous layer was discolored to brown. That is, the resin was oxidized by the trickle charge test under high voltage conditions.

A specific test procedure is as follows.
1. A positive electrode and a negative electrode were prepared. As the positive electrode, an electrode hoop having a thickness of 58 μm and a density of 2.5 g/cm ³ was purchased from Hachiyama Co., Ltd. and used. The composition of the positive electrode active material was 92 parts by weight of LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , 5 parts by weight of the conductive material, and 3 parts by weight of the binder. As the negative electrode, an electrode hoop having a thickness of 48 μm and a density of 1.5 g/cm ³ was purchased from Hachiyama Co., Ltd. and used. The composition of the negative electrode active material was 98 parts by weight of natural graphite, 1 part by weight of binder, and 1 part by weight of carboxymethyl cellulose.
2. A member for a non-aqueous electrolyte secondary battery was produced. A positive electrode, a laminated separator and a negative electrode were laminated in this order in a laminate pouch. At this time, (i) the porous layer of the laminated separator and the positive electrode active material layer of the positive electrode are in contact, and (ii) the polyethylene porous film of the laminated separator and the negative electrode active material layer of the negative electrode are in contact, Laminated separators were placed.
3. A non-aqueous electrolyte secondary battery member was placed in a bag formed by laminating an aluminum layer and a heat seal layer, and 230 μL of non-aqueous electrolyte was injected. The non-aqueous electrolyte is a mixed solvent of ethylene carbonate, ethyl methyl carbonate, and diethyl carbonate mixed at a volume ratio of 3:5:2 and LiPF ₆ having a concentration of 1 mol/L dissolved therein.
4. The bag was heat-sealed while decompressing the inside of the bag. Thus, a test battery was produced.
5. Using a charge/discharge tester manufactured by Toyo System Co., Ltd., the test battery was charged with a constant current. The constant current charging conditions were temperature: 25° C., current: 1 C, final voltage: 4.5 V (that is, 4.6 V (vs Li/Li ⁺ )).
6. Using a charge/discharge tester manufactured by Toyo System Co., Ltd., a trickle charge was applied to the test battery. The conditions for trickle charging were temperature: 25° C., voltage: 4.5 V (that is, 4.6 V (vs Li/Li ⁺ )), and time: 168 hours.
7. After completion of trickle charging, the test battery was disassembled and the laminated separator was taken out. The color of the surface of the porous layer was visually observed.

(3) Adhesiveness Adhesiveness was evaluated by visually confirming the surface of the porous layer of the laminated separators produced in Examples and Comparative Examples. Evaluation criteria are as follows.
◯: No peeling of the porous layer is observed. That is, the adhesion between the polyolefin porous film and the porous layer is high.
Δ: Peeling of the porous layer is not observed, but the adhesion between the polyolefin porous film and the porous layer is low.
x: Scale-like peeling is observed in the porous layer. That is, the adhesion between the polyolefin porous film and the porous layer is low.

[Synthesis example]
[Synthesis Example 1]
A block copolymer in which block A accounts for 50% of the whole molecule and block B accounts for 50% of the whole molecule was synthesized by the following procedure. Block A consists of poly(4,4'-diphenylsulfonylterephthalamide). Block B consists of poly(paraphenylene terephthalamide).
1. A 0.5 L separable flask equipped with a stirring blade, thermometer, nitrogen inlet tube and powder addition port was thoroughly dried.
2. A flask was charged with 420 g of N-methylpyrrolidone. Further, 27.27 g of calcium chloride (dried at 200°C for 2 hours) was added and the temperature was raised to 100°C.
3. After the calcium chloride was completely dissolved, 20.34 g of 4,4'-diaminodiphenyl sulfone was added at 100°C and completely dissolved.
4. The resulting solution was cooled to room temperature. While maintaining the temperature of the solution at 25±2° C., a total of 16.54 g of terephthaloyl dichloride was added in three portions and allowed to react for 1 hour. Block A was thus synthesized.
5. 8.87 g of 1,4-phenylenediamine was added to the resulting solution and allowed to dissolve for 30 minutes.
6. While maintaining the temperature of the solution at 25±2° C., a total of 16.46 g of terephthaloyl dichloride was added in 3 portions and reacted for 1 hour. Block B was thereby extended on both sides of block A.
7. The temperature of the solution was kept at 25±2° C. and aged for 1 hour. After that, the mixture was stirred under reduced pressure for 30 minutes to remove air bubbles. Thus, a solution containing block copolymer (1) was obtained.

A portion of the solution containing block copolymer (1) was taken, and a sample of block copolymer (1) was precipitated with water. When measured using this sample, the intrinsic viscosity of block copolymer (1) was 1.24 dL/g.

[Comparative Synthesis Example 1]
A solution containing comparative block copolymer (1) was prepared in the same manner as in Synthesis Example 1, except that the amounts of the monomers were changed so that block A accounted for 25% of the entire molecule and block B accounted for 75% of the entire molecule. got The intrinsic viscosity of Comparative Block Copolymer (1) was 2.10 dL/g.

[Comparative Synthesis Example 2]
A solution containing comparative block copolymer (2) was prepared in the same manner as in Synthesis Example 1, except that the amounts of the monomers were changed so that block A accounted for 90% of the entire molecule and block B accounted for 10% of the entire molecule. got The intrinsic viscosity of Comparative Block Copolymer (2) was 1.10 dL/g.

[Comparative Synthesis Example 3]
A random copolymer in which 50% of the diamine units were derived from 4,4'-diaminodiphenylsulfone and 50% were derived from 1,4-phenylenediamine was synthesized by the following procedure.
1. A 0.5 L separable flask equipped with a stirring blade, thermometer, nitrogen inlet tube and powder addition port was thoroughly dried.
2. A flask was charged with 420 g of N-methylpyrrolidone. Further, 27.27 g of calcium chloride (dried at 200°C for 2 hours) was added and the temperature was raised to 100°C.
3. After the calcium chloride was completely dissolved, the temperature of the solution was returned to room temperature. Then 20.34 g of 4,4'-diaminodiphenyl sulfone and 8.87 g of 1,4-phenylenediamine were added and completely dissolved.
4. A total of 16.46 g of terephthaloyl dichloride was added in 5 portions while maintaining the temperature of the solution at 25±2°C.
5. While the temperature of the obtained solution was kept at 25±2° C., the solution was aged for 1 hour to obtain a solution containing Comparative Random Copolymer (1).

A portion of the solution containing Comparative Random Copolymer (1) was taken, and a sample of Comparative Random Copolymer (1) was precipitated with water. When measured using this sample, the intrinsic viscosity of Comparative Random Copolymer (1) was 0.75 dL/g.

[Comparative Synthesis Example 4]
25% of the diamine units are derived from 4,4′-diaminodiphenylsulfone, and 75% is derived from 1,4-phenylenediamine, except that the amount of monomers is changed, the same procedure as in Comparative Synthesis Example 3. A solution containing the comparative random copolymer (2) was obtained. The intrinsic viscosity of Comparative Random Copolymer (2) was 1.30 dL/g.

[Example 1]
100 parts by weight of aluminum oxide (average particle size: 0.013 μm) was added to 100 parts by weight of the total resin contained in the solution obtained in Synthesis Example 1. The resulting mixture was diluted with NMP and uniformly dispersed using a pressure disperser to prepare a coating liquid (1). The solid content concentration of the coating liquid (1) was 5% by weight.

After applying the coating solution (1) to a polyethylene porous film (thickness: 10 μm), it was treated in an oven at 50° C. and 70% humidity for 2 minutes to form a porous layer (1) on the polyethylene porous film. ) was formed. After that, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator having a porous layer (1). The film thickness of the laminated separator provided with the porous layer (1) was 13 μm.

[Comparative Example 1]
100 parts by weight of aluminum oxide (average particle size: 0.013 μm) was added to 100 parts by weight of the total resin contained in the solution obtained in Comparative Synthesis Example 1. The resulting mixture was diluted with NMP and uniformly dispersed using a pressure disperser to obtain a comparative coating liquid (1). The solid content concentration of Comparative Coating Liquid (1) was 5% by weight.

After the comparative coating liquid (1) was applied to a polyethylene porous film (thickness: 10 μm), it was treated in an oven at 50° C. and 70% humidity for 2 minutes to form a comparative porous layer on the polyethylene porous film. (1) was formed. After that, the polyethylene porous film was washed with water and dried to obtain a laminated separator having a comparative porous layer (1). The film thickness of the laminated separator provided with the comparative porous layer (1) was 13 μm.

[Comparative Example 2]
100 parts by weight of aluminum oxide (average particle diameter: 0.013 μm) was added to 100 parts by weight of the total resin contained in the solution obtained in Comparative Synthesis Example 2. The resulting mixture was diluted with NMP and uniformly dispersed using a pressure disperser to obtain a comparative coating liquid (2). The solid content concentration of Comparative Coating Liquid (2) was 5% by weight.

After the comparative coating liquid (2) was applied to a polyethylene porous film (thickness: 10 μm), it was treated in an oven at 50° C. and a humidity of 70% for 2 minutes to form a comparative porous layer on the polyethylene porous film. (2) was formed. After that, the polyethylene porous film was washed with water and dried to obtain a laminated separator having a comparative porous layer (2). In the laminated separator having the comparative porous layer (2), the porous layer peeled off like fish scales, so the film thickness could not be stably measured.

[Comparative Example 3]
100 parts by weight of aluminum oxide (average particle size: 0.013 μm) was added to 100 parts by weight of the total resin contained in the solution obtained in Comparative Synthesis Example 3. The resulting mixture was diluted with NMP and uniformly dispersed using a pressure disperser to obtain a comparative coating liquid (3). The solid content concentration of Comparative Coating Liquid (3) was 5% by weight.

After the comparative coating liquid (3) was applied to a polyethylene porous film (thickness: 10 μm), it was treated in an oven at 50° C. and 70% humidity for 2 minutes to form a comparative porous layer on the polyethylene porous film. (3) was formed. Thereafter, the polyethylene porous film was washed with water and dried to obtain a laminated separator having a comparative porous layer (3). In the case of the laminated separator having the comparative porous layer (3), the porous layer peeled off like fish scales, so the film thickness could not be stably measured.

[Comparative Example 4]
100 parts by weight of aluminum oxide (average particle size: 0.013 μm) was added to 100 parts by weight of the total resin contained in the solution obtained in Comparative Synthesis Example 4. The resulting mixture was diluted with NMP and uniformly dispersed using a pressure disperser to obtain a comparative coating liquid (4). The solid content concentration of Comparative Coating Liquid (4) was 5% by weight.

After the comparative coating liquid (4) was applied to a polyethylene porous film (thickness: 10 μm), it was treated in an oven at 50° C. and 70% humidity for 2 minutes to form a comparative porous layer on the polyethylene porous film. (4) was formed. After that, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator having a comparative porous layer (4). In the laminated separator having the comparative porous layer (4), the porous layer peeled off like fish scales, so the film thickness could not be stably measured.

[Synthesis Example 2]
A solution containing block copolymer (2) was prepared in the same manner as in Synthesis Example 1, except that the amounts of the monomers were changed so that block A accounted for 60% of the entire molecule and block B accounted for 40% of the entire molecule. Obtained. The intrinsic viscosity of block copolymer (2) was 1.20 dL/g.

[Synthesis Example 3]
A solution containing block copolymer (3) was prepared in the same manner as in Synthesis Example 1, except that the amounts of the monomers were changed so that block A accounted for 40% of the entire molecule and block B accounted for 60% of the entire molecule. Obtained. The intrinsic viscosity of block copolymer (3) was 1.25 dL/g.

[Synthesis Example 4]
A solution containing block copolymer (4) was prepared in the same manner as in Synthesis Example 1, except that the amounts of the monomers were changed so that block A accounted for 30% of the entire molecule and block B accounted for 70% of the entire molecule. Obtained. The intrinsic viscosity of block copolymer (4) was 1.42 dL/g.

[Synthesis Example 5]
A block copolymer in which block A accounts for 50% of the whole molecule and block B accounts for 50% of the whole molecule was synthesized by the following procedure.
1. A 0.5 L separable flask equipped with a stirring blade, thermometer, nitrogen inlet tube and powder addition port was thoroughly dried.
2. A flask was charged with 420 g of N-methylpyrrolidone. Further, 27.27 g of calcium chloride (dried at 200°C for 2 hours) was added and the temperature was raised to 100°C.
3. After the calcium chloride was completely dissolved, 13.84 g of 4,4'-diaminodiphenyl sulfone was added at 100°C and completely dissolved.
4. The resulting solution was cooled to room temperature. While maintaining the temperature of the solution at 25±2° C., a total of 11.24 g of terephthaloyl dichloride was added in 3 portions and reacted for 1 hour. Block A was thus synthesized.
5. 6.02 g of 1,4-phenylenediamine was added to the resulting solution and allowed to dissolve for 30 minutes.
6. While maintaining the temperature of the solution at 25±2° C., a total of 11.22 g of terephthaloyl dichloride was added in three portions and reacted for 1 hour. Block B was thereby extended on both sides of block A.
7. The temperature of the solution was kept at 25±2° C. and aged for 1 hour. After that, the mixture was stirred under reduced pressure for 30 minutes to remove air bubbles. Thus, a solution containing block copolymer (5) was obtained. The intrinsic viscosity of block copolymer (5) was 1.60 dL/g.

[Comparative Synthesis Example 5]
A solution containing the comparative block copolymer (3) was prepared in the same manner as in Synthesis Example 1, except that the amounts of the monomers were changed so that the block A occupied 10% of the entire molecule and the block B occupied 90% of the entire molecule. got

[Comparative Synthesis Example 6]
A block copolymer in which block A accounts for 50% of the whole molecule and block B accounts for 50% of the whole molecule was synthesized by the following procedure.
1. A 0.5 L separable flask equipped with a stirring blade, thermometer, nitrogen inlet tube and powder addition port was thoroughly dried.
2. A flask was charged with 420 g of N-methylpyrrolidone. Further, 27.27 g of calcium chloride (dried at 200°C for 2 hours) was added and the temperature was raised to 100°C.
3. After the calcium chloride was completely dissolved, 12.01 g of 4,4'-diaminodiphenyl sulfone was added and completely dissolved at 100°C.
4. The resulting solution was cooled to room temperature. While the temperature of the solution was kept at 25±2° C., a total of 9.76 g of terephthaloyl dichloride was added in 3 portions and reacted for 1 hour. Block A was thus synthesized.
5. 9.67 g of 4,4'-diaminodiphenyl ether was added to the resulting solution and allowed to dissolve over 30 minutes.
6. While the temperature of the solution was maintained at 25±2° C., a total of 9.74 g of terephthaloyl dichloride was added in three portions and reacted for 1 hour. Block B was thereby extended on both sides of block A.
7. The temperature of the solution was kept at 25±2° C. and aged for 1 hour. After that, the mixture was stirred under reduced pressure for 30 minutes to remove air bubbles. Thus, a solution containing comparative block copolymer (4) was obtained.

[Comparative Synthesis Example 7]
A block copolymer in which block A accounts for 50% of the whole molecule and block B accounts for 50% of the whole molecule was synthesized by the following procedure.
1. A 0.5 L separable flask equipped with a stirring blade, thermometer, nitrogen inlet tube and powder addition port was thoroughly dried.
2. A flask was charged with 420 g of N-methylpyrrolidone. Further, 27.27 g of calcium chloride (dried at 200°C for 2 hours) was added and the temperature was raised to 100°C.
3. After the calcium chloride was completely dissolved, 11.94 g of 4,4'-diaminodiphenyl sulfone was added at 100°C and completely dissolved.
4. The resulting solution was cooled to room temperature. While maintaining the temperature of the solution at 25±2° C., a total of 14.09 g of 4,4′-oxybis(benzoyl chloride) was added in 3 portions and allowed to react for 1 hour. Block A was thus synthesized.
5. 5.19 g of 1,4-phenylenediamine was added to the resulting solution and allowed to dissolve for 30 minutes.
6. While maintaining the temperature of the solution at 25±2° C., a total of 14.07 g of 4,4′-oxybis(benzoyl chloride) was added in 3 portions and allowed to react for 1 hour. Block B was thereby extended on both sides of block A.
7. The temperature of the solution was kept at 25±2° C. and aged for 1 hour. After that, the mixture was stirred under reduced pressure for 30 minutes to remove air bubbles. Thus, a solution containing comparative block copolymer (5) was obtained.

[Example 2]
100 parts by weight of aluminum oxide (average particle diameter: 0.013 μm) was added to 100 parts by weight of the total resin contained in the solution obtained in Synthesis Example 2. The resulting mixture was diluted with NMP and uniformly dispersed using a pressure disperser to obtain a coating liquid (2). The solid content concentration of the coating liquid (2) was 5% by weight.

After applying the coating solution (2) to a polyethylene porous film (thickness: 10 μm), the porous layer (2 ) was formed. After that, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator having a porous layer (2). The film thickness of the laminated separator provided with the porous layer (2) was 13 μm.

[Example 3]
100 parts by weight of aluminum oxide (average particle diameter: 0.013 μm) was added to 100 parts by weight of the total resin contained in the solution obtained in Synthesis Example 3. The resulting mixture was diluted with NMP and uniformly dispersed with a pressure disperser to obtain a coating liquid (3). The solid content concentration of the coating liquid (3) was 5% by weight.

After applying the coating liquid (3) to a polyethylene porous film (thickness: 10 μm), the porous layer (3 ) was formed. After that, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator having a porous layer (3). The film thickness of the laminated separator provided with the porous layer (3) was 13 μm.

[Example 4]
100 parts by weight of aluminum oxide (average particle diameter: 0.013 μm) was added to 100 parts by weight of the total resin contained in the solution obtained in Synthesis Example 4. The resulting mixture was diluted with NMP and uniformly dispersed using a pressure disperser to obtain a coating liquid (4). The solid content concentration of the coating liquid (4) was 5% by weight.

After applying the coating solution (4) to a polyethylene porous film (thickness: 10 μm), the porous layer (4 ) was formed. After that, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator having a porous layer (4). The film thickness of the laminated separator provided with the porous layer (4) was 13 μm.

[Comparative Example 5]
100 parts by weight of aluminum oxide (average particle size: 0.013 μm) was added to 100 parts by weight of the total resin contained in the solution obtained in Comparative Synthesis Example 5. The resulting mixture was diluted with NMP and uniformly dispersed using a pressure disperser to obtain a comparative coating liquid (5). The solid content concentration of Comparative Coating Liquid (5) was 5% by weight.

After the comparative coating solution (5) was applied to a polyethylene porous film (thickness: 10 μm), it was treated in an oven at 50° C. and a humidity of 70% for 2 minutes to form a comparative porous layer on the polyethylene porous film. (5) was formed. After that, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator having a comparative porous layer (5). The film thickness of the laminated separator provided with the comparative porous layer (5) was 13 μm.

[Comparative Example 6]
100 parts by weight of aluminum oxide (average particle diameter: 0.013 μm) was added to 100 parts by weight of the total resin contained in the solution obtained in Comparative Synthesis Example 6. The resulting mixture was diluted with NMP and uniformly dispersed with a pressure disperser to obtain a comparative coating liquid (6). The solid content concentration of Comparative Coating Liquid (6) was 5% by weight.

After the comparative coating liquid (6) was applied to a polyethylene porous film (thickness: 10 μm), it was treated in an oven at 50° C. and a humidity of 70% for 2 minutes to form a comparative porous layer on the polyethylene porous film. (6) was formed. After that, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator having a comparative porous layer (6). In the laminated separator having the comparative porous layer (6), the porous layer was peeled off like fish scales, so the film thickness could not be stably measured.

[Comparative Example 7]
100 parts by weight of aluminum oxide (average particle diameter: 0.013 μm) was added to 100 parts by weight of the total resin contained in the solution obtained in Comparative Synthesis Example 7. The resulting mixture was diluted with NMP and uniformly dispersed using a pressure disperser to obtain a comparative coating liquid (7). The solid content concentration of Comparative Coating Liquid (7) was 5% by weight.

After the comparative coating liquid (7) was applied to a polyethylene porous film (thickness: 10 μm), it was treated in an oven at 50° C. and a humidity of 70% for 2 minutes to form a comparative porous layer on the polyethylene porous film. (7) was formed. After that, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator having a comparative porous layer (7). In the laminated separator having the comparative porous layer (7), the porous layer peeled off like fish scales, so the film thickness could not be stably measured.

[Example 5]
100 parts by weight of aluminum oxide (average particle diameter: 0.013 μm) was added to 100 parts by weight of the total resin contained in the solution obtained in Synthesis Example 5. The resulting mixture was diluted with NMP and uniformly dispersed using a pressure disperser to obtain a coating liquid (5). The solid content concentration of the coating liquid (5) was 5% by weight.

After applying the coating liquid (5) to a polyethylene porous film (thickness: 10 μm), the porous layer (5 ) was formed. After that, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator having a porous layer (5). The film thickness of the laminated separator provided with the porous layer (5) was 13 μm.

[Example 6]
120 parts by weight of aluminum oxide (average particle size: 0.013 μm) was added to 100 parts by weight of the total resin contained in the solution obtained in Synthesis Example 5. The resulting mixture was diluted with NMP and uniformly dispersed using a pressure disperser to obtain a coating liquid (6). The solid content concentration of the coating liquid (6) was 5% by weight.

After applying the coating solution (6) to a polyethylene porous film (thickness: 10 μm), the porous layer (6 ) was formed. After that, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator having a porous layer (6). The film thickness of the laminated separator provided with the porous layer (6) was 13 μm.

[Example 7]
25 parts by weight of aluminum oxide (average particle size: 0.013 μm) was added to 100 parts by weight of the total resin contained in the solution obtained in Synthesis Example 5. The resulting mixture was diluted with NMP and uniformly dispersed using a pressure disperser to obtain a coating liquid (7). The solid content concentration of Coating Liquid (7) was 5% by weight.

After applying the coating solution (7) to a polyethylene porous film (thickness: 10 μm), the porous layer (7 ) was formed. After that, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator having a porous layer (7). The film thickness of the laminated separator provided with the porous layer (7) was 13 μm.

[Example 8]
900 parts by weight of aluminum oxide (average particle size: 0.013 μm) was added to 100 parts by weight of the total resin contained in the solution obtained in Synthesis Example 5. The resulting mixture was diluted with NMP and uniformly dispersed using a pressure disperser to obtain a coating liquid (8). The solid content concentration of the coating liquid (8) was 5% by weight.

After applying the coating solution (8) to a polyethylene porous film (thickness: 10 μm), it was treated in an oven at 50° C. and 70% humidity for 2 minutes to form a porous layer (8 ) was formed. After that, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator having a porous layer (8). The film thickness of the laminated separator provided with the porous layer (8) was 13 μm.

[Comparative Example 8]
1900 parts by weight of aluminum oxide (average particle diameter: 0.013 μm) was added to 100 parts by weight of the total resin contained in the solution obtained in Synthesis Example 5. The resulting mixture was diluted with NMP and uniformly dispersed with a pressure disperser to obtain a comparative coating liquid (8). The solid content concentration of Comparative Coating Liquid (8) was 5% by weight.

After the comparative coating liquid (8) was applied to a polyethylene porous film (thickness: 10 μm), it was treated in an oven at 50° C. and 70% humidity for 2 minutes to form a comparative porous layer on the polyethylene porous film. (8) was formed. After that, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator having a comparative porous layer (8). In the laminated separator having the comparative porous layer (8), the porous layer was peeled off like fish scales, so the film thickness could not be stably measured.

[Comparative Example 9]
18 parts by weight of aluminum oxide (average particle diameter: 0.013 μm) was added to 100 parts by weight of the total resin contained in the solution obtained in Synthesis Example 5. The resulting mixture was diluted with NMP and uniformly dispersed using a pressure disperser to obtain a comparative coating liquid (9). The solid content concentration of Comparative Coating Liquid (9) was 5% by weight.

After the comparative coating solution (9) was applied to a polyethylene porous film (thickness: 10 μm), it was treated in an oven at 50° C. and a humidity of 70% for 2 minutes to form a comparative porous layer on the polyethylene porous film. (9) was formed. After that, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator having a comparative porous layer (9). The film thickness of the laminated separator provided with the comparative porous layer (9) was 13 μm.

[Example 9]
100 parts by weight of aluminum oxide (average particle size: 0.013 μm) and 100 parts by weight of aluminum oxide (average particle size: 0.7 μm) per 100 parts by weight of the total resin contained in the solution obtained in Synthesis Example 5 part was added. The resulting mixture was diluted with NMP and uniformly dispersed using a pressure disperser to prepare a coating liquid (9). The solid content concentration of Coating Liquid (9) was 6% by weight.

After applying the coating solution (9) to a polyethylene porous film (thickness: 10 μm), the porous layer (9 ) was formed. After that, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator having a porous layer (9). The film thickness of the laminated separator provided with the porous layer (9) was 13 μm.

〔result〕
Tables 1 to 4 show the evaluation results of the high voltage resistance and adhesiveness of the porous layers produced in Examples and Comparative Examples.

As shown in Tables 1 to 4, the porous layers according to Examples 1 to 9 were good in both high voltage resistance and adhesion.

On the other hand, the porous layer according to Comparative Example 1 had good adhesiveness, but was inferior in high voltage resistance. This is probably because the proportion of block A contained in the porous layer was too small and the sulfonyl groups could not be sufficiently contained. The porous layer according to Comparative Example 2 had poor adhesion, and the battery could not be assembled. This is probably because the proportion of block B contained in the porous layer was too small. The porous layers according to Comparative Examples 3 and 4 had poor adhesiveness, and batteries could not be assembled. This suggests that random copolymers cannot achieve both high voltage resistance and adhesiveness.

The porous layer according to Comparative Example 5 had good adhesiveness, but was inferior in high voltage resistance. This is probably because the proportion of block A was too small to contain a sufficient amount of sulfonyl groups. The porous layers according to Comparative Examples 6 to 8 had poor adhesiveness, and batteries could not be assembled. In the porous layer according to Comparative Example 9, the pores of the porous layer were not sufficiently formed, and the withstand voltage test could not be performed.

[Reference example]
A solution containing only poly(4,4'-diphenylsulfonyl terephthalamide) is applied as a coating liquid to a polyethylene porous film (thickness: 10 μm), and then treated in an oven at 50° C. and 70% humidity for 2 minutes. A reference porous layer (1) was formed on the polyethylene porous film. After that, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator having the reference porous layer (1). When the surface of the reference porous layer (1) was visually observed, no peeling of the porous layer was observed. Therefore, the problem of adhesion of the porous layer to be solved by one aspect of the present invention does not occur when using only a resin having a sulfonyl group, but occurs when using a resin having a sulfonyl group and a filler. is suggested.

INDUSTRIAL APPLICABILITY The present invention can be used, for example, in non-aqueous electrolyte secondary batteries.

Claims (8)

A porous layer for a non-aqueous electrolyte secondary battery containing a block copolymer and a filler,
The block copolymer is
A block A whose main component is a unit represented by the following formula (1);
—(NH—Ar ¹ —NHCO—Ar ² —CO)— Formula (1)
A block B whose main component is a unit represented by the following formula (2);
—(NH—Ar ³ —NHCO—Ar ⁴ —CO)— Formula (2)
and
50% or more of the units of formula (2) contained in the block B are paraphenylene terephthalamide,
When the weight of the porous layer for a non-aqueous electrolyte secondary battery is 100% by weight, the content of the filler in the porous layer for a non-aqueous electrolyte secondary battery is 20 to 90% by weight.
Porous layer for non-aqueous electrolyte secondary battery:
During the ceremony,
Ar ¹ , Ar ² , Ar ³ and Ar ⁴ may vary from unit to unit;
Ar ¹ , Ar ² , Ar ³ and Ar ⁴ are each independently a divalent group having one or more aromatic rings,
50% or more of all Ar ¹ have a structure in which two aromatic rings are linked by a sulfonyl bond,
50% or less of all Ar ³ have a structure in which two aromatic rings are linked by a sulfonyl bond,
30 to 70% of all Ar ¹ and Ar ³ have a structure in which two aromatic rings are linked by a sulfonyl bond. 50% or more of the units of formula (1) contained in block A are 4,4′-diphenylsulfonylterephthalamide,
The porous layer for a non-aqueous electrolyte secondary battery according to claim 1 . 3. The porous layer for a non-aqueous electrolyte secondary battery according to claim 1, wherein the block copolymer has a triblock structure of block B-block A-block B. The molecule corresponding to the mode of the molecular weight distribution of the block copolymer is
10 to 1000 units of formula (1) included in block A,
10 to 500 units of formula (2) included in the block B,
The porous layer for a non-aqueous electrolyte secondary battery according to any one of claims 1 to 3. The non-aqueous electrolyte secondary battery according to any one of claims 1 to 4, further comprising a polymer having 5 to 200 units of formula (2) but not containing units of formula (1). Porous layer for. The porous layer for a non-aqueous electrolyte secondary battery according to any one of claims 1 to 5 , wherein the filler contains aluminum oxide. A laminated separator for non-aqueous electrolyte secondary batteries, wherein the porous layer for non-aqueous electrolyte secondary batteries according to any one of claims 1 to 6 is laminated on one or both sides of a polyolefin porous film. . Non-aqueous, comprising the porous layer for non-aqueous electrolyte secondary batteries according to any one of claims 1 to 6 , or the laminated separator for non-aqueous electrolyte secondary batteries according to claim 7 Electrolyte secondary battery.