JP2022042995A - Porous layer for non-aqueous electrolyte solution secondary battery - Google Patents

Abstract

To provide a porous layer for a non-aqueous electrolyte solution secondary battery which achieves both high voltage resistance and adhesion.SOLUTION: A porous layer for a non-aqueous electrolyte solution secondary battery contains a block copolymer, and a filler, in which the block copolymer has a block A containing a unit represented by -(NH-Ar1-NHCO-Ar2-CO)- as a main component, and a block B containing a unit represented by -(NH-Ar3-NHCO-Ar4-CO)- as a main component, 50% or more of all of the Ar1 has such a structure that two aromatic rings are connected to each other by a sulfonyl bond, 50% or less of all the Ar3 has such a structure that the two aromatic rings are connected to each other by a sulfonyl bond, and 30-70% of all the Ar1 and Ar3 has such a structure that the two aromatic rings are connected to each other by a sulfonyl bond.SELECTED DRAWING: None

Description

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

Non-aqueous electrolyte secondary batteries, especially lithium-ion secondary batteries, are widely used as batteries for personal computers, mobile phones, mobile information terminals, etc. due to their high energy density, and have recently been developed as in-vehicle batteries. Has been done.

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

Patent Document 1 is an example of a document that discloses a resin having such properties. The document discloses a total 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 same document, this all-aromatic polyamide has little discoloration even when a high voltage is applied.

Japanese Patent Application Laid-Open No. 2003-40999

One of the functional groups having an electron-withdrawing property is a sulfonyl group. Therefore, if a resin containing a sulfonyl group is used, it can be expected that a porous layer for a non-aqueous electrolytic solution secondary battery that does not deteriorate even under high voltage conditions can be obtained. However, as examined by the present inventors, the porous layer for a non-aqueous electrolytic solution secondary battery containing a resin containing a sulfonyl group and a filler has poor adhesion to a polyolefin porous film and is peeled into powder. It turned out that it would (powder fall off).

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

The present inventors have described the above with a porous layer for a non-aqueous electrolytic solution secondary battery containing a block copolymer having a block having a large number of sulfonyl groups (block A) and a block having a small number of sulfonyl groups (block B). It was 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
Block A whose main component is the unit represented by the following formula (1), and
-(NH-Ar ¹ -NHCO-Ar ² -CO)-Equation (1)
Block B whose main component is the unit represented by the following equation (2), and
-(NH-Ar ³ -NHCO-Ar ⁴ -CO) -Equation (2)
Has a porous layer for non-aqueous electrolyte secondary batteries:
During the ceremony
Ar ¹ , Ar ² , Ar ³ and Ar ⁴ may be different from unit to unit.
Ar ¹ , Ar ² , Ar ³ and Ar ⁴ are divalent groups each independently having one or more aromatic rings.
More than 50% of all Ar ^1s have a structure in which two aromatic rings are linked by a sulfonyl bond.
Less than 50% of all Ar ^3s have a structure in which two aromatic rings are linked by a sulfonyl bond.
Of all Ar ¹ and Ar ³ , 30-70% have a structure in which two aromatic rings are linked by a sulfonyl bond.
<2>
Of the units of the formula (1) contained in the block A, 50% or more are 4,4'-diphenylsulfonyl terephthalamide.
Of the units of the formula (2) contained in the block B, 50% or more are paraphenylene terephthalamides.
The porous layer for a non-aqueous electrolytic solution 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 tri-block 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
The number of units of the formula (1) included in the block A is 10 to 1000.
The number of units of the formula (2) included in the block B is 10 to 500.
The porous layer for a non-aqueous electrolytic solution 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 the formula (1) and further contains a polymer having 5 to 200 units of the formula (2). For porous layer.
<6>
Assuming that the weight of the porous layer for the non-aqueous electrolyte secondary battery is 100% by weight, the content of the filler in the porous layer for the non-aqueous electrolyte secondary battery is 20 to 90% by weight, <1. > To the porous layer for a non-aqueous electrolyte secondary battery according to any one of <5>.
<7>
The porous layer for a non-aqueous electrolytic solution secondary battery according to any one of <1> to <6>, wherein the filler contains an aluminum oxide.
<8>
A laminated separator for a non-aqueous electrolytic solution secondary battery, wherein the porous layer for the non-aqueous electrolytic solution secondary battery according to any one of <1> to <7> is laminated on one side or both sides of the polyolefin porous film. ..
<9>
Non-water, comprising the porous layer for the non-aqueous electrolyte secondary battery according to any one of <1> to <7> or the laminated separator for the 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 has both high voltage resistance and adhesiveness.

An embodiment of the present invention will be described below, but the present invention is not limited thereto. The present invention is not limited to the configurations described below, and various modifications can be made within the scope of the claims, and the technical means disclosed in the different embodiments may be appropriately combined. The obtained embodiments are also included in the technical scope of the present invention. Unless otherwise specified in the present specification, "A to B" representing a numerical range means "A or more and B or less".

[1. Porous layer for non-aqueous electrolyte secondary battery]
The porous layer for a non-aqueous electrolytic solution secondary battery according to an embodiment of the present invention contains a block copolymer and a filler. Hereinafter, each component will be described in detail.

In the present specification, the porous layer for a non-aqueous electrolyte secondary battery may be simply abbreviated as "porous layer". Further, in the present specification, the laminated separator for a non-aqueous electrolytic solution secondary battery may be simply abbreviated as "laminated separator".

[Block copolymer]
The block copolymer has block A and block B. The main component of the block A is a unit represented by the following formula (1). The block B contains a unit represented by the following formula (2) as a main component.
-(NH-Ar ¹ -NHCO-Ar ² -CO)-Equation (1)
-(NH-Ar ³ -NHCO-Ar ⁴ -CO) -Equation (2).

The ratio of the unit of the formula (1) to all the units contained in the block A is preferably 80% or more, more preferably 90% or more, still more preferably 95% or more. In one embodiment, the block A is represented by the unit of the formula (1) as a whole except for the end. The ratio of the unit of the formula (2) to all the units contained in the block B is preferably 80% or more, more preferably 90% or more, still more preferably 95% or more. In one embodiment, block B is represented entirely by the unit of formula (2) except for the ends.

If the units represented by the formulas (1) and (2) are contained in the above range, the block copolymer will have the properties of an aromatic polyamide. Aromatic polyamide is excellent in heat resistance and the like, and is suitable as a material for a porous layer for a non-aqueous electrolytic solution secondary battery.

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 divalent groups each independently having one or more aromatic rings.

As used herein, the term "aromatic ring" refers to a cyclic compound satisfying Hückel's rule. Examples of aromatic rings include benzene, naphthalene, anthracene, azulene, pyrrole, pyridine, furan and 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 a 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. Of all Ar ¹ and Ar ³ , the lower limit of the ratio occupied by 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, preferably 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.

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

Of all Ar ³ , Ar ³ having a structure in which two aromatic rings are linked by a sulfonyl bond accounts for 50% or less, preferably 20% or less, and more preferably 10% or less. In one embodiment, not all Ar ^3s have a structure in which two aromatic rings are linked by a sulfonyl bond.

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

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

The following is an example of a structure in which two aromatic rings are not linked by a sulfonyl bond.

In one embodiment, the structure in which the two aromatic rings are linked by a sulfonyl bond is 4,4'-diphenylsulfonyl. In one embodiment, the non-structural structure in which two aromatic rings are linked by a sulfonyl bond is paraphenyl.

In one embodiment, at least a portion of the unit of formula (1) contained in Block A is 4,4'-diphenylsulfonyl terephthalamide. Of the units of the formula (1) contained in the block A, the lower limit of the proportion of 4,4'-diphenylsulfonyl terephthalamide 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 easily available.

In one embodiment, at least a portion of the unit of formula (2) contained in block B is paraphenylene terephthalamide. Of the units of the formula (2) contained in the block B, the lower limit of the proportion of paraphenylene terephthalamide is preferably 50% or more, more preferably 80% or more, still more preferably 90% or more. Paraphenylene terephthalamide is easy to handle and the monomer is easily available.

The block copolymer may have a structure composed of units other than those represented by the formulas (1) and (2). An example of such a structure is a polyimide skeleton.

(Structure of block copolymer)
The number of blocks contained in the block copolymer 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 triblock structure of block A-block B-block A or block B-block A-block B. In one embodiment, the block copolymer has a tetrapod structure of block A-block B-block A-block B. Among the above-mentioned structures, the triblock structure of block B-block A-block B is preferable.

Of one molecule of the block copolymer, the number of units of the formula (1) contained in the block A is preferably 10 to 1000, more preferably 20 to 300. When the number of units of the formula (1) is in 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 increased. Of one molecule of the block copolymer, the number of units of the formula (2) contained in the block B is preferably 10 to 500, more preferably 15 to 200. When the number of units of the formula (2) is in the above range, the adhesiveness of the porous layer is high.

Here, the number of units of the formulas (1) and (2) described as preferable 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 obtained experimentally, for example, by gel permeation chromatography.

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. When the molecular weight is in 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, with the weight of the porous layer being 100% by weight. When the content is in the above range, the porous layer can be sufficiently imparted with high voltage resistance due to the electron-withdrawing property of the sulfonyl group of the block copolymer.

(Manufacturing method of block copolymer)
Block copolymers can be synthesized according to conventional methods. For example, a block copolymer having a diblock structure of block A-block B can be synthesized by following the procedure below (block copolymers having other block structures can also be synthesized by applying the following procedure). ..
1. 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. Then, it is polymerized according to a known method for polymerizing aromatic polyamides. As a result, the block A having the unit of the formula (1) is synthesized.
2. 2. After the synthesis of block A is completed, the diamine represented by NH ₂ -Ar ³ -NH ₂ and the dicarboxylic acid represented by XOOC-Ar ⁴ -COOX (X is a halogen atom such as F, Cl, Br, I) An acid halide is used as a monomer and polymerized according to a known method for polymerizing aromatic polyamides. As a result, the block B having the unit of the formula (2) is synthesized while being connected to the block A.

(Polymer containing the unit of formula (2) without containing the unit of formula (1))
When a block copolymer is synthesized by the above procedure, a by-product consisting of only the last synthesized block can also be produced. For example, when synthesizing a block copolymer having a tri-block structure of block B-block A-block B, the polymer consisting only of block B (that is, the unit of the formula (1) is not included, and the formula (2) is included. (Polymer containing the unit of) can be produced as a by-product.

Therefore, even if the porous layer for a non-aqueous electrolytic solution secondary battery according to the embodiment of the present invention does not contain the unit of the formula (1) but contains the polymer containing the unit of the formula (2). good. Further, the porous layer for a non-aqueous electrolyte secondary battery according to an embodiment of the present invention does not include the unit of the formula (i) (1), but contains the polymer of the formula (2) and (ii). ) Block B-block A-block B may contain a block copolymer having a tri-block structure.

The polymer which does not contain the unit of the formula (1) and contains the unit of the formula (2) has 5 to 200 units of the 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 the formula (2) is contained in the porous layer without containing the unit of the formula (1) can be determined from the molecular weight distribution of the resin component of the porous layer. Specifically, if the peak corresponding to the polymer not containing the unit of the formula (1) and containing the unit of the formula (2) is present in the molecular weight distribution curve, the polymer is contained in the porous layer. It can be said that it is. In this case, the molecular weight distribution curve of the resin component of the porous layer has two or more peaks. The molecular weight distribution curve is experimentally determined by gel permeation chromatography.

The number of units of the formula (2) possessed by the polymer not including the unit of the formula (1) and containing the unit of the formula (2) can be calculated from the molecular weight distribution curve. The abundance ratio of the polymer not including the unit of the formula (1) and containing the unit of the formula (2) 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 other single polymers or copolymers of two or more; polytetrafluoroethylene, tetrafluoride. Fluorine-based resins such as ethylene-6 fluorinated propylene copolymer, tetrafluoroethylene-ethylene copolymer, and polyvinylidene fluoride; melamine resin; urea resin; polyolefin; polymethacrylate and the like can be mentioned. The organic filler 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 oxide (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 filler may be used alone or in combination of two or more. Among these inorganic fillers, aluminum oxide is preferable in terms of chemical stability.

Examples of the shape of the filler include substantially spherical, plate-like, columnar, needle-like, whisker-like, fibrous and the like, and any particle can be used. Since it is easy to form uniform pores, substantially spherical particles are preferable.

The average particle size of the filler contained in the porous layer is preferably 0.01 to 1 μm. As used herein, the "average particle size of the filler" means the volume-based average particle size (D50) of the filler. D50 means a particle diameter having a value at which the integrated distribution based on the volume becomes 50%. The D50 can be measured using, for example, a laser diffraction type particle size distribution meter (manufactured by Shimadzu Corporation, trade names: SALD2200, SALD2300, etc.).

The content of the filler in the porous layer is preferably 20 to 90% by weight, more preferably 40 to 80% by weight, with the weight of the porous layer being 100% by weight. When the content of the filler is in 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 the filler. For example, the porous layer may contain a resin other than the block copolymer.

Examples of such resins include polyolefins; (meth) acrylate resins; fluororesins; polyamide resins; polyimide resins; polyamideimide resins; polyester resins; rubbers; melting point or glass transition temperature of 180 ° C. Examples thereof include the above resins; water-soluble polymers; polycarbonates, polyacetals, polyether ether ketones and the like.

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

As the polyolefin, polyethylene, polypropylene, polybutene, an ethylene-propylene copolymer and the like are preferable.

Examples of the fluororesin include polyvinylidene fluoride (PVDF), polytetrafluoroethylene, vinylidene fluoride-hexafluoropropylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer weight. Combined, vinylidene fluoride-tetrafluoroethylene copolymer, vinylidene fluoride-trifluoroethylene copolymer, vinylidene fluoride-trichloroethylene copolymer, vinylidene fluoride-vinyl fluoride copolymer, vinylidene fluoride-hexafluoro Examples thereof include a propylene-tetrafluoroethylene copolymer, an ethylene-tetrafluoroethylene copolymer, and the like, and among the fluororesins, a fluororubber having a glass transition temperature of 23 ° C. or lower.

As the polyamide-based resin, aramid resins such as aromatic polyamides and all aromatic polyamides are preferable.

Specific examples of the aramid resin include poly (paraphenylene terephthalamide), poly (metaphenylene isophthalamide), poly (parabenzamide), poly (metabenzamide), and poly (4,4'-benzanilide terephthalamide). 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 and the like. Of these, poly (paraphenylene terephthalamide) is more preferable.

As the polyester-based resin, aromatic polyesters such as polyarylate and liquid crystal polyesters are preferable.

Examples of the rubber include a styrene-butadiene copolymer and its hydride, a methacrylate ester copolymer, an acrylonitrile-acrylic acid ester copolymer, a styrene-acrylic acid ester copolymer, an ethylene propylene rubber, and polyvinyl acetate. Can be mentioned.

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

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

As 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 Non-Water Electrolyte Secondary Battery]
One aspect of the present invention is a laminated separator for a non-aqueous electrolytic solution secondary battery in which the above-mentioned porous layer is laminated on one side or both sides of a polyolefin porous film.

[Polyolefin porous film]
The laminated separator for a non-aqueous electrolytic solution secondary battery according to an embodiment of the present invention includes a polyolefin porous film. The porous polyolefin film has a large number of pores connected to the inside thereof, and it is possible to allow gas and liquid to pass from one surface to the other. The polyolefin porous film can be a base material for a laminated separator for a non-aqueous electrolytic solution secondary battery. The polyolefin porous film melts when the battery generates heat to make the laminated separator for the non-aqueous electrolytic solution secondary battery non-porous, thereby imparting a shutdown function to the laminated separator for the non-aqueous electrolytic solution secondary battery. It can be a thing.

Here, the "polyolefin porous film" is a porous film containing a polyolefin-based resin as a main component. Further, "mainly composed of a polyolefin resin" means that the ratio of the polyolefin resin to the porous film is 50% by volume or more, preferably 90% by volume or more of the whole material constituting the porous film. , More preferably, it means that it is 95% by volume or more.

The polyolefin-based resin that is the main component of the polyolefin porous film is not particularly limited, but is, for example, thermoplastic resins such as ethylene, propylene, 1-butene, 4-methyl-1-pentene and / or 1-hexene. Examples thereof include homopolymers and copolymers obtained by polymerizing monomers. That is, examples of the homopolymer include polyethylene, polypropylene and polybutene, and examples of the copolymer include ethylene-propylene copolymer. The polyolefin porous film may be a layer containing these polyolefin resins alone, or a layer containing two or more of these polyolefin resins. Of these, polyethylene is more preferable because it can prevent (shut down) the flow of an excessive current at a lower temperature, and polyethylene having a high molecular weight mainly composed of ethylene is particularly preferable. In addition, the polyolefin porous film does not prevent the inclusion of components other than polyolefin as long as the function is not impaired.

Examples of polyethylene include low-density polyethylene, high-density polyethylene, linear polyethylene (ethylene-α-olefin copolymer), ultra-high molecular weight polyethylene and the like. Of these, ultra-high molecular weight polyethylene is more preferable, and it is even more preferable that a high molecular weight component having a weight average molecular weight of ⁵ × 10 ⁵ to 15 × 106 is contained. In particular, it is more preferable that the polyolefin-based resin contains a high-molecular-weight component having a weight average molecular weight of 1 million or more because the strength of the polyolefin porous film and the laminated separator for a non-aqueous electrolytic solution secondary battery is improved.

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

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

The air permeability of the porous polyolefin film is preferably 30 to 500 s / 100 mL in terms of Garley value, and more preferably 50 to 300 s / 100 mL. As a result, the laminated separator for a non-aqueous electrolytic solution secondary battery 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 retention amount of the electrolytic solution and reliably prevent (shut down) the flow of an excessive current at a lower temperature.

A known method can be used for producing the polyolefin porous film, and the method 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 of 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, the following is made from the viewpoint of manufacturing cost. It is preferable to produce by a method including the steps (1) to (4) shown.

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

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

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

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 by, for example, the intrinsic viscosity of the resin and the basis weight of the porous layer. Generally, as the intrinsic viscosity of the resin decreases, the Garley value tends to decrease. Further, as the basis weight of the porous layer becomes smaller, the Garley value tends to become smaller.

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

The laminated separator may have another layer, if necessary, in addition to the polyolefin porous film and the porous layer. Examples of such a layer include an adhesive layer and a protective layer.

[Manufacturing method of 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. Examples of the coating liquid forming method include a mechanical stirring method, an ultrasonic dispersion method, a high pressure dispersion method, and a media dispersion method. As the solvent, for example, N-methylpyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide and the like can be used.

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

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

The solvent (dispersion medium) is generally removed by drying. Examples of the drying method include natural drying, blast drying, heat drying and vacuum drying, but any method can be used as long as the solvent (dispersion medium) can be sufficiently removed. Further, the solvent (dispersion medium) contained in the coating material may be replaced with another solvent before drying. As a method of replacing the solvent (dispersion medium) with another solvent and then removing the solvent, specifically, there is a method of replacing with a low boiling point poor solvent such as water, alcohol, or acetone, precipitating, and drying.

[3. Non-aqueous electrolyte secondary battery components and non-aqueous electrolyte secondary batteries]
The member for a non-aqueous electrolytic solution secondary battery according to an embodiment of the present invention comprises a positive electrode, the above-mentioned laminated separator for a non-aqueous electrolytic solution secondary battery, and a negative electrode arranged in this order. Further, the non-aqueous electrolytic solution secondary battery according to the embodiment of the present invention includes the above-mentioned laminated separator for the non-aqueous electrolytic solution secondary battery. The non-aqueous electrolyte secondary battery usually has a structure in which a negative electrode and a positive electrode face each other via the above-mentioned laminated separator for the non-aqueous electrolyte secondary battery. In the non-aqueous electrolytic solution secondary battery, a battery element in which the structure is impregnated with the electrolytic solution is enclosed in an exterior material. For example, the non-aqueous electrolyte secondary battery is a lithium ion secondary battery that obtains an electromotive force by doping / 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 the material include a lithium composite oxide containing at least one transition metal such as V, Ti, Cr, Mn, Fe, Co, Ni, and Cu. Examples of the lithium composite oxide include a solid solution lithium-containing transition metal oxidation composed of a lithium composite oxide having a layered structure, a lithium composite oxide having a spinel structure, and a lithium composite oxide having both a layered structure and a spinel structure. Things can be mentioned. Further, lithium cobalt composite oxide and lithium nickel composite oxide can also be mentioned. 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 substituted with other elements.

The lithium composite oxide obtained by substituting a part of the transition metal atom which is the main component of the lithium composite oxide with another element is, for example, a lithium cobalt composite oxide having a layered structure represented by the following formula (3), the following. Lithium-nickel composite oxide represented by the formula (4), lithium manganese composite oxide having a spinel structure represented by the following formula (5), solid solution lithium-containing transition metal oxide represented by the following formula (6), etc. Can be mentioned.

Li [Li _x (Co _1-a M ¹ _a ) _1-x ] O ₂ ... (3)
(In the 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 It is at least one metal selected from the group consisting of W and satisfies −0.1 ≦ x ≦ 0.30, 0 ≦ a ≦ 0.5).

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

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

Li _{1 + w} M ⁴ _d M ⁵ _e O ₂ ... (6)
In formula (6), M ⁴ and M ⁵ are at least one metal selected from the group consisting of Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mg and Ca. 0 <w ≦ 1/3, 0 ≦ d ≦ 2/3, 0 ≦ e ≦ 2/3, w + d + e = 1 are satisfied.)

Specific examples of the lithium composite oxide represented by the above formulas (3) to (6) include LiCoO ₂ , LiNiO ₂ , LiMnO ₂ , LiNi _0.8 Co _0.2 O ₂ , and LiNi _0.5 Mn _{0. 5} O ₂ , LiNi _0.85 Co _0.10 Al _0.05 O ₂ , LiNi _0.8 Co _0.15 Al _0.05 O ₂ , LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , LiNi _0.6 Co _0.2 Mn _0.2 O ₂ , LiNi _0.33 Co _0.33 Mn _0.33 O ₂ , LiMn ₂ O ₄ , LiMn _1.5 Ni _0.5 O ₄ , LiMn _1.5 Fe _0.5 O ₄ , LiCoMnO ₄ , Li _1.21 Ni _0.20 Mn _0.59 O ₂ , Li _1.22 Ni _0.20 Mn _0.58 O ₂ , Li _1.22 Ni _0.15 Co _0. Examples thereof include ₁₀ Mn _0.53 O ₂ , Li _1.07 Ni _0.35 Co _0.08 Mn _0.50 O ₂ , Li _1.07 Ni _0.36 Co _0.08 Mn _0.49 O ₂ .

Further, 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 a lithium composite oxide include LiNiVO ₄ , LiV ₃ O ₆ , Li _1.2 Fe _0.4 Mn _0.4 O ₂ , and the like.

Examples of materials other than the lithium composite oxide that can be preferably used as the positive electrode active material include phosphate having an olivine-type structure, and phosphoric acid having an olivine-type structure represented by the following formula (7). Salt is mentioned.

Li _v (M ⁶ _f M ⁷ _g M ⁸ _h M ⁹ _i ) _j PO ₄ ... (7)
(In formula (7), M ⁶ is Mn, Co, or Ni, M ⁷ is Ti, V, Cr, Mn, Fe, Co, Ni, Zr, Nb, or Mo, and M ⁸ is. , VIA and VIIA elements are arbitrarily excluded from the transition metal or typical element, and M ⁹ is a transition metal or typical element from which the VIA and VIIA elements are arbitrarily excluded, 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 particles of the lithium metal composite oxide constituting the positive electrode active material. Examples of the material constituting the coating layer include metal composite oxides, metal salts, boron-containing compounds, nitrogen-containing compounds, silicon-containing compounds, sulfur-containing compounds, and the like, and among these, the metal composite oxide is preferably used. Be done.

As the metal composite oxide, an oxide having lithium ion conductivity is preferably used. As such a metal composite oxide, for example, at least one selected from the group consisting of Li and Nb, Ge, Si, P, Al, W, Ta, Ti, S, Zr, Zn, V and B. A metal composite oxide with an element 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 life of the obtained secondary battery can be extended. Further, it is possible to suppress the formation of a high resistance layer at the interface between the positive electrode active material and the electrolyte, and to realize high output of the obtained secondary battery.

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

Examples of the binder include polyvinylidene fluoride, a copolymer of vinylidene fluoride, polytetrafluoroethylene, a copolymer of vinylidene fluoride-hexafluoropropylene, and a copolymer of tetrafluoroethylene-hexafluoropropylene. Tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, ethylene-tetrafluoroethylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, vinylidene fluoride-trifluoroethylene copolymer, vinylidene fluoride -Polymer of trichloroethylene, polymer of vinylidene fluoride-vinyl fluoride, copolymer of vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene, thermoplastic resins such as thermoplastic polyimide, polyethylene, and polypropylene, acrylic Examples include resins and styrene butadiene rubbers. The binder also has a function as a thickener.

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

As a method for producing a sheet-shaped positive electrode, for example, a positive electrode active material, a conductive agent and a binder to be a positive electrode mixture are pressure-molded on a positive electrode current collector; a positive electrode active material using an appropriate organic solvent. , The conductive agent and the binder are made into a paste to obtain a positive electrode mixture, the positive electrode mixture is applied to a positive electrode current collector, and this is dried to add a sheet-shaped positive electrode mixture. Examples thereof include a method of fixing to the positive electrode current collector by applying pressure.

[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 can be doped and dedoped with lithium ions at a potential lower than that of the positive electrode. And so on.

Examples of the carbon material that can be used as the negative electrode active material include graphite such as natural graphite and artificial graphite, coke, carbon black, pyrolytic carbon, carbon fiber, and a calcined body of an organic polymer compound.

Examples of the oxide that can be used as the negative electrode active material include an oxide of silicon represented by the _formula SiO _x (where _x is a positive real number) such as SiO ₂ , SiO; Titanium oxide represented by (where x is a positive real number); V ₂ O ₅ , VO ₂ , etc. Formula V _x Oy (where x and _y are positive real numbers) of vanadium Oxide; Fe ₃ O ₄ , Fe ₂ O ₃ , FeO, etc. Formula Fe x Oy (where x and y are positive real numbers), iron oxide represented by the formula Fe _x O _y (where _x and y are positive real numbers); SnO ₂ , SnO, etc. Here, x is an oxide of tin represented by a positive real number); an oxide of tungsten represented by the general formula WO _x (where x is a positive real number) such as WO ₃ and WO ₂ ; Li ₄ Ti. ₅ O ₁₂ , a composite metal oxide containing lithium such as LiVO ₂ and titanium or vanadium; and the like.

Examples of the sulfide that can be used as the negative electrode active material include Titanium sulfide represented by the formula Ti _x S _y (where x and y are positive real numbers) such as Ti ₂ S ₃ , TiS ₂ , and TiS; V ₃ S ₄ , VS ₂ , VS, etc. Formula VS _x (where x is a positive real number), vanadium sulfide; Fe ₃ S ₄ , FeS ₂ , Fe S, etc. Formula Fe _x S _y (here, x is a positive real number) , X and y are positive real numbers); Sulfide of molybdenum represented by the formula Mo _x S _y (where x and y are positive real numbers) such as Mo ₂ S ₃ and Mo S ₂ . Object; Sulfide of tin represented by the formula SnS _x (where x is a positive real number) such as SnS ₂ , SnS; tungsten represented by the formula WS _x (where x is a positive real number) such as WS ₂ . Sulfide of Sb ₂ S ₃ etc. Antimony sulfide represented by the formula Sb _x S _y (where x and y are positive real numbers); the formula Se _x S _y such as Se ₅ S ₃ , Se S ₂ , Se S and the like. (Here, x and y are positive real numbers); sulphides of selenium; can be mentioned.

Nitridees that can be used as the negative electrode active material include, for example, Li ₃ N, Li _3-x A _x N (where A is either or both of Ni and Co, and 0 <x <3. ) And the like can be mentioned.

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

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

Further, a composite material containing Si or Sn as the first constituent element and the second and third constituent elements in addition thereof may 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 high battery capacity and excellent battery characteristics can be obtained, as the metal material, silicon or tin alone (may contain a trace amount of impurities), SiO _v (0 <v ≦ 2), SnO _w (0). ≦ w ≦ 2), Si—Co—C composite material, Si—Ni—C composite material, Sn—Co—C composite material, Sn—Ni—C composite material are preferable.

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

As a method for manufacturing a sheet-shaped negative electrode, for example, a method of pressure-molding a negative electrode active material to be a negative electrode mixture on a negative electrode current collector; a negative electrode active material is made into a paste using an appropriate organic solvent to form a negative electrode. After obtaining the agent, the negative electrode mixture is applied to the negative electrode current collector, dried, and the obtained sheet-shaped negative electrode mixture is pressurized to adhere to the negative electrode current collector. Can be mentioned. The paste preferably contains the conductive agent and the binder.

[Non-water electrolyte]
As the non-aqueous electrolytic solution, for example, a non-aqueous electrolytic solution obtained by dissolving a lithium salt in an organic solvent can be used. Examples of the lithium salt 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 (SO ₂ CF ₃ ) (COCF ₃ ), Li (C ₄ F ₉ SO ₃ ), LiC (SO ₂ CF ₃ ) ₃ , Li ₂ B ₁₀ Cl ₁₀ , 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. Among them, the lithium salt is composed of 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 the organic solvent 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 1,2-dimethoxyethane, 1,3-dimethoxypropane, pentafluoropropylmethyl ether, 2,2,3,3-tetrafluoropropyldifluoromethyl ether, tetrahydrofuran, 2-methyltetraethers and the like. Esters such as methyl formate, methyl acetate, γ-butyrolactone; nitriles such as acetonitrile and butyronitrile; amides such as N, N-dimethylformamide, N, N-dimethylacetamide; 3-methyl-2-oxazolidone and the like. Carbamates; sulfur-containing compounds such as sulfolane, dimethylsulfoxide, 1,3-propanesartone; or those in which a fluoro group is further introduced into these organic solvents (one or more of the hydrogen atoms of the organic solvent are replaced with fluorine atoms). Can be used.

It is preferable to mix two or more of the above organic solvents and use them as a mixed solvent. Of these, a mixed solvent containing carbonates is preferable, and a mixed solvent of cyclic carbonate and acyclic carbonate and a mixed solvent of cyclic carbonate and ethers are more preferable. As the mixed solvent of the cyclic carbonate and the acyclic carbonate, a mixed solvent containing ethylene carbonate, dimethyl carbonate and ethyl methyl carbonate is preferable. A non-aqueous electrolytic solution using such a mixed solvent has a wide operating temperature range, is not easily deteriorated even when used at a high voltage, is not easily deteriorated even when used for a long time, and is made of natural graphite as an active material for a negative electrode. It has the advantage of being persistently decomposable even when a graphite material such as artificial graphite is used.

Further, as the non-aqueous electrolyte solution, in order to enhance the safety of the obtained non-aqueous electrolyte secondary battery, a non-aqueous electrolyte solution containing a lithium salt containing fluorine such as LiPF ₆ and an organic solvent having a fluorine substituent should be used. Is preferable. A mixed solvent containing ethers having a fluorine substituent 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.

[Members for non-aqueous electrolyte secondary batteries and methods for manufacturing non-aqueous electrolyte secondary batteries]
Examples of the method for manufacturing the member for the non-aqueous electrolytic solution secondary battery include a method in which the positive electrode, the above-mentioned laminated separator for the non-aqueous electrolytic solution secondary battery, and the negative electrode are arranged in this order.

Moreover, as a method of manufacturing a non-aqueous electrolytic solution secondary battery, for example, the following method can be mentioned. First, the member for the non-aqueous electrolyte secondary battery 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 a non-aqueous electrolytic solution, the container is sealed while reducing the pressure. This makes it possible to manufacture a non-aqueous electrolyte secondary battery.

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

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

[Measurement method of various physical properties]
In the examples and comparative examples described later, each physical property was measured by the following method.

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

(2) High voltage resistance A test battery equipped with the laminated separator for the non-aqueous electrolyte secondary battery prepared in the example or the comparative example was prepared, and the trickle charge test was imposed on this battery under high voltage conditions. .. After the test, the test battery was disassembled, and the color of the portion of the porous layer for the non-aqueous electrolyte secondary battery that was in contact with the positive electrode active material layer was visually confirmed. The evaluation criteria are as follows.
◯: The porous layer was colorless. That is, even if the trickle charge test was imposed under high voltage conditions, the 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.

The specific test procedure is as follows.
1. 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 Yayama 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 Yayama 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 the binder, and 1 part by weight of carboxymethyl cellulose.
2. 2. A member for a non-aqueous electrolyte secondary battery was manufactured. In the laminated pouch, the positive electrode, the laminated separator and the negative electrode were laminated in this order. 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 with each other, and (ii) the polyethylene porous film of the laminated separator and the negative electrode active material layer of the negative electrode are in contact with each other. A laminated separator was placed.
3. 3. A member for a non-aqueous electrolytic solution secondary battery was housed in a bag in which an aluminum layer and a heat-sealed layer were laminated, and 230 μL of the non-aqueous electrolytic solution was injected. The non-aqueous electrolytic solution is obtained by dissolving LiPF ₆ having a concentration of 1 mol / L in a mixed solvent prepared by mixing ethylene carbonate, ethyl methyl carbonate, and diethyl carbonate at a ratio of 3: 5: 2 (volume ratio).
4. The bag was heat-sealed while decompressing the inside of the bag. As a result, a test battery was produced.
5. The test battery was charged with a constant current using a charge / discharge test device manufactured by Toyo System Co., Ltd. The conditions for constant current charging were temperature: 25 ° C., current: 1C, final voltage: 4.5V (that is, 4.6V (vs Li / Li ⁺ )).
6. Trickle charging was applied to the test battery using a charge / discharge test device manufactured by Toyo System Co., Ltd. The conditions for trickle charging were temperature: 25 ° C., voltage: 4.5V (that is, 4.6V (vs Li / Li ⁺ )), and time: 168 hours.
7. After the trickle charge was completed, 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 The surface of the porous layer of the laminated separators produced in Examples and Comparative Examples was visually confirmed, and the adhesiveness was evaluated. The evaluation criteria are as follows.
◯: No peeling of the porous layer is observed. That is, the adhesiveness between the polyolefin porous film and the porous layer is high.
Δ: No peeling of the porous layer was observed, but the adhesiveness between the polyolefin porous film and the porous layer was low.
X: Scale-like exfoliation is observed in the porous layer. That is, the adhesiveness between the polyolefin porous film and the porous layer is low.

[Synthesis example]
[Synthesis Example 1]
By the following procedure, a block copolymer in which block A occupies 50% of the whole molecule and block B occupies 50% of the whole molecule was synthesized. Block A consists of poly (4,4'-diphenylsulfonyl terephthalamide). Block B is made of poly (paraphenylene terephthalamide).
1. 1. A 0.5 L separable flask having a stirring blade, a thermometer, a nitrogen inflow tube and a powder addition port was sufficiently dried.
2. 2. 420 g of N-methylpyrrolidone was charged in the flask. 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. 3. After the calcium chloride was completely dissolved, 20.34 g of 4,4'-diaminodiphenyl sulfone was added at 100 ° C. to completely dissolve the calcium chloride.
4. The resulting solution was cooled to room temperature. While keeping the temperature of the solution at 25 ± 2 ° C., a total of 16.54 g of terephthalic acid dichloride was added in 3 portions and reacted for 1 hour. As a result, block A was synthesized.
5. To the obtained solution, 8.87 g of 1,4-phenylenediamine was added and dissolved over 30 minutes.
6. While keeping the temperature of the solution at 25 ± 2 ° C., a total of 16.46 g of terephthalic acid dichloride was added in 3 portions and reacted for 1 hour. As a result, block B was extended on both sides of block A.
7. The solution was aged for 1 hour while keeping the temperature at 25 ± 2 ° C. Then, the mixture was stirred under reduced pressure for 30 minutes to remove air bubbles. In this way, a solution containing the block copolymer (1) was obtained.

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

[Comparative synthesis example 1]
A solution containing the comparative block copolymer (1) according to the same procedure as in Synthesis Example 1, except that the amount of the monomer was changed so that block A occupies 25% of the whole molecule and block B occupies 75% of the whole molecule. Got The intrinsic viscosity of the comparative block copolymer (1) was 2.10 dL / g.

[Comparative synthesis example 2]
A solution containing the comparative block copolymer (2) according to the same procedure as in Synthesis Example 1, except that the amount of the monomer was changed so that block A occupies 90% of the whole molecule and block B occupies 10% of the whole molecule. Got The intrinsic viscosity of the comparative block copolymer (2) was 1.10 dL / g.

[Comparative synthesis example 3]
In the following procedure, a random copolymer was synthesized in which 50% of the diamine units were derived from 4,4'-diaminodiphenyl sulfone and 50% was derived from 1,4-phenylenediamine.
1. 1. A 0.5 L separable flask having a stirring blade, a thermometer, a nitrogen inflow tube and a powder addition port was sufficiently dried.
2. 2. 420 g of N-methylpyrrolidone was charged in the flask. 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. 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. With the temperature of the solution kept at 25 ± 2 ° C., a total of 16.46 g of terephthalic acid dichloride was added in 5 portions.
5. The solution was aged for 1 hour while keeping the temperature of the obtained solution at 25 ± 2 ° C. to obtain a solution containing the comparative random copolymer (1).

A part of the solution containing the comparative random copolymer (1) was collected, and a sample of the comparative random copolymer (1) was precipitated with water. When measured using this sample, the intrinsic viscosity of the comparative random copolymer (1) was 0.75 dL / g.

[Comparative synthesis example 4]
The procedure was the same as in Comparative Synthesis Example 3 except that the amount of the monomer was changed so that 25% of the diamine units were derived from 4,4'-diaminodiphenyl sulfone and 75% was derived from 1,4-phenylenediamine. Obtained a solution containing the comparative random copolymer (2). The intrinsic viscosity of the 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 amount of the resin contained in the solution obtained in Synthesis Example 1. The obtained mixture was diluted with NMP and uniformly dispersed by a pressure type disperser to obtain a coating liquid (1). The solid content concentration of the coating liquid (1) was 5% by weight.

The coating liquid (1) is applied to a polyethylene porous film (thickness: 10 μm) and then treated in an oven at 50 ° C. and a humidity of 70% for 2 minutes to form a porous layer (1) on the polyethylene porous film. ) Was formed. Then, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator provided with the 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 amount of the resin contained in the solution obtained in Comparative Synthesis Example 1. The obtained mixture was diluted with NMP and uniformly dispersed by a pressure type disperser to obtain a comparative coating liquid (1). The solid content concentration of the comparative coating liquid (1) was 5% by weight.

The comparative coating liquid (1) was applied to a polyethylene porous film (thickness: 10 μm) and then 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. (1) was formed. Then, the polyethylene porous film was washed with water and dried to obtain a laminated separator provided with the 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 size: 0.013 μm) was added to 100 parts by weight of the total amount of the resin contained in the solution obtained in Comparative Synthesis Example 2. The obtained mixture was diluted with NMP and uniformly dispersed by a pressure type disperser to obtain a comparative coating liquid (2). The solid content concentration of the comparative coating liquid (2) was 5% by weight.

The comparative coating liquid (2) was applied to a polyethylene porous film (thickness: 10 μm) and then 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. Then, the polyethylene porous film was washed with water and dried to obtain a laminated separator provided with the comparative porous layer (2). In the laminated separator provided with the comparative porous layer (2), the film thickness could not be measured stably because the porous layer peeled off like a fish scale.

[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 amount of the resin contained in the solution obtained in Comparative Synthesis Example 3. The obtained mixture was diluted with NMP and uniformly dispersed by a pressure type disperser to obtain a comparative coating liquid (3). The solid content concentration of the comparative coating liquid (3) was 5% by weight.

After applying the comparative coating liquid (3) to a polyethylene porous film (thickness: 10 μm), it is 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. (3) was formed. Then, the polyethylene porous film was washed with water and dried to obtain a laminated separator provided with the comparative porous layer (3). In the laminated separator provided with the comparative porous layer (3), the film thickness could not be measured stably because the porous layer peeled off like a fish scale.

[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 amount of the resin contained in the solution obtained in Comparative Synthesis Example 4. The obtained mixture was diluted with NMP and uniformly dispersed by a pressure type disperser to obtain a comparative coating liquid (4). The solid content concentration of the comparative coating liquid (4) was 5% by weight.

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

[Synthesis Example 2]
A solution containing the block copolymer (2) was prepared by the same procedure as in Synthesis Example 1 except that the amount of the monomer was changed so that the block A occupies 60% of the whole molecule and the block B occupies 40% of the whole molecule. Obtained. The intrinsic viscosity of the block copolymer (2) was 1.20 dL / g.

[Synthesis Example 3]
A solution containing the block copolymer (3) was prepared by the same procedure as in Synthesis Example 1 except that the amount of the monomer was changed so that the block A occupies 40% of the whole molecule and the block B occupies 60% of the whole molecule. Obtained. The intrinsic viscosity of the block copolymer (3) was 1.25 dL / g.

[Synthesis Example 4]
A solution containing the block copolymer (4) was prepared by the same procedure as in Synthesis Example 1 except that the amount of the monomer was changed so that the block A occupies 30% of the whole molecule and the block B occupies 70% of the whole molecule. Obtained. The intrinsic viscosity of the block copolymer (4) was 1.42 dL / g.

[Synthesis Example 5]
By the following procedure, a block copolymer in which block A occupies 50% of the whole molecule and block B occupies 50% of the whole molecule was synthesized.
1. 1. A 0.5 L separable flask having a stirring blade, a thermometer, a nitrogen inflow tube and a powder addition port was sufficiently dried.
2. 2. 420 g of N-methylpyrrolidone was charged in the flask. 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. 3. After the calcium chloride was completely dissolved, 13.84 g of 4,4'-diaminodiphenyl sulfone was added at 100 ° C. to completely dissolve the calcium chloride.
4. The resulting solution was cooled to room temperature. While keeping the temperature of the solution at 25 ± 2 ° C., a total of 11.24 g of terephthalic acid dichloride was added in 3 portions and reacted for 1 hour. As a result, block A was synthesized.
5. 6.02 g of 1,4-phenylenediamine was added to the obtained solution and dissolved over 30 minutes.
6. While keeping the temperature of the solution at 25 ± 2 ° C., a total of 11.22 g of terephthalic acid dichloride was added in 3 portions and reacted for 1 hour. As a result, block B was extended on both sides of block A.
7. The solution was aged for 1 hour while keeping the temperature at 25 ± 2 ° C. Then, the mixture was stirred under reduced pressure for 30 minutes to remove air bubbles. In this way, a solution containing the block copolymer (5) was obtained. The intrinsic viscosity of the block copolymer (5) was 1.60 dL / g.

[Comparative synthesis example 5]
A solution containing the comparative block copolymer (3) according to the same procedure as in Synthesis Example 1, except that the amount of the monomer was changed so that block A occupies 10% of the whole molecule and block B occupies 90% of the whole molecule. Got

[Comparative synthesis example 6]
By the following procedure, a block copolymer in which block A occupies 50% of the whole molecule and block B occupies 50% of the whole molecule was synthesized.
1. 1. A 0.5 L separable flask having a stirring blade, a thermometer, a nitrogen inflow tube and a powder addition port was sufficiently dried.
2. 2. 420 g of N-methylpyrrolidone was charged in the flask. 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. 3. After the calcium chloride was completely dissolved, 12.01 g of 4,4'-diaminodiphenyl sulfone was added at 100 ° C. to completely dissolve the calcium chloride.
4. The resulting solution was cooled to room temperature. While keeping the temperature of the solution at 25 ± 2 ° C., a total of 9.76 g of terephthalic acid dichloride was added in 3 portions and reacted for 1 hour. As a result, block A was synthesized.
5. To the obtained solution, 9.67 g of 4,4'-diaminodiphenyl ether was added and dissolved over 30 minutes.
6. While keeping the temperature of the solution at 25 ± 2 ° C., a total of 9.74 g of terephthalic acid dichloride was added in 3 portions and reacted for 1 hour. As a result, block B was extended on both sides of block A.
7. The solution was aged for 1 hour while keeping the temperature at 25 ± 2 ° C. Then, the mixture was stirred under reduced pressure for 30 minutes to remove air bubbles. In this way, a solution containing the comparative block copolymer (4) was obtained.

[Comparative synthesis example 7]
By the following procedure, a block copolymer in which block A occupies 50% of the whole molecule and block B occupies 50% of the whole molecule was synthesized.
1. 1. A 0.5 L separable flask having a stirring blade, a thermometer, a nitrogen inflow tube and a powder addition port was sufficiently dried.
2. 2. 420 g of N-methylpyrrolidone was charged in the flask. 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. 3. After the calcium chloride was completely dissolved, 11.94 g of 4,4'-diaminodiphenyl sulfone was added at 100 ° C. to completely dissolve the calcium chloride.
4. The resulting solution was cooled to room temperature. While keeping 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 reacted for 1 hour. As a result, block A was synthesized.
5. To the obtained solution, 5.19 g of 1,4-phenylenediamine was added and dissolved over 30 minutes.
6. While keeping 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 reacted for 1 hour. As a result, block B was extended on both sides of block A.
7. The solution was aged for 1 hour while keeping the temperature at 25 ± 2 ° C. Then, the mixture was stirred under reduced pressure for 30 minutes to remove air bubbles. In this way, a solution containing the comparative block copolymer (5) was obtained.

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

The coating liquid (2) is applied to a polyethylene porous film (thickness: 10 μm) and then treated in an oven at 50 ° C. and a humidity of 70% for 2 minutes to form a porous layer (2) on the polyethylene porous film. ) Was formed. Then, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator provided with the 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 size: 0.013 μm) was added to 100 parts by weight of the total amount of the resin contained in the solution obtained in Synthesis Example 3. The obtained mixture was diluted with NMP and uniformly dispersed by a pressure type disperser to obtain a coating liquid (3). The solid content concentration of the coating liquid (3) was 5% by weight.

The coating liquid (3) is applied to a polyethylene porous film (thickness: 10 μm) and then treated in an oven at 50 ° C. and a humidity of 70% for 2 minutes to form a porous layer (3) on the polyethylene porous film. ) Was formed. Then, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator provided with the 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 size: 0.013 μm) was added to 100 parts by weight of the total amount of the resin contained in the solution obtained in Synthesis Example 4. The obtained mixture was diluted with NMP and uniformly dispersed by a pressure type disperser to obtain a coating liquid (4). The solid content concentration of the coating liquid (4) was 5% by weight.

The coating liquid (4) is applied to a polyethylene porous film (thickness: 10 μm) and then treated in an oven at 50 ° C. and a humidity of 70% for 2 minutes to form a porous layer (4) on the polyethylene porous film. ) Was formed. Then, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator provided with the 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 amount of the resin contained in the solution obtained in Comparative Synthesis Example 5. The obtained mixture was diluted with NMP and uniformly dispersed by a pressure type disperser to obtain a comparative coating liquid (5). The solid content concentration of the comparative coating liquid (5) was 5% by weight.

The comparative coating liquid (5) was applied to a polyethylene porous film (thickness: 10 μm) and then 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. Then, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator provided with the 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 size: 0.013 μm) was added to 100 parts by weight of the total amount of the resin contained in the solution obtained in Comparative Synthesis Example 6. The obtained mixture was diluted with NMP and uniformly dispersed by a pressure type disperser to obtain a comparative coating liquid (6). The solid content concentration of the comparative coating liquid (6) was 5% by weight.

The comparative coating liquid (6) was applied to a polyethylene porous film (thickness: 10 μm) and then 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. Then, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator provided with the comparative porous layer (6). In the laminated separator provided with the comparative porous layer (6), the film thickness could not be measured stably because the porous layer peeled off like a fish scale.

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

The comparative coating liquid (7) was applied to a polyethylene porous film (thickness: 10 μm) and then 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. Then, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator provided with the comparative porous layer (7). In the laminated separator provided with the comparative porous layer (7), the film thickness could not be measured stably because the porous layer peeled off like a fish scale.

[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 amount of the resin contained in the solution obtained in Synthesis Example 5. The obtained mixture was diluted with NMP and uniformly dispersed by a pressure type disperser to obtain a coating liquid (5). The solid content concentration of the coating liquid (5) was 5% by weight.

The coating liquid (5) is applied to a polyethylene porous film (thickness: 10 μm) and then treated in an oven at 50 ° C. and a humidity of 70% for 2 minutes to form a porous layer (5) on the polyethylene porous film. ) Was formed. Then, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator provided with the 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 amount of the resin contained in the solution obtained in Synthesis Example 5. The obtained mixture was diluted with NMP and uniformly dispersed by a pressure type disperser to obtain a coating liquid (6). The solid content concentration of the coating liquid (6) was 5% by weight.

The coating liquid (6) is applied to a polyethylene porous film (thickness: 10 μm) and then treated in an oven at 50 ° C. and a humidity of 70% for 2 minutes to form a porous layer (6) on the polyethylene porous film. ) Was formed. Then, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator provided with the 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 amount of the resin contained in the solution obtained in Synthesis Example 5. The obtained mixture was diluted with NMP and uniformly dispersed by a pressure type disperser to obtain a coating liquid (7). The solid content concentration of the coating liquid (7) was 5% by weight.

The coating liquid (7) is applied to a polyethylene porous film (thickness: 10 μm) and then treated in an oven at 50 ° C. and a humidity of 70% for 2 minutes to form a porous layer (7) on the polyethylene porous film. ) Was formed. Then, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator provided with the 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 amount of the resin contained in the solution obtained in Synthesis Example 5. The obtained mixture was diluted with NMP and uniformly dispersed by a pressure type disperser to obtain a coating liquid (8). The solid content concentration of the coating liquid (8) was 5% by weight.

The coating liquid (8) is applied to a polyethylene porous film (thickness: 10 μm) and then treated in an oven at 50 ° C. and a humidity of 70% for 2 minutes to form a porous layer (8) on the polyethylene porous film. ) Was formed. Then, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator provided with the 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 size: 0.013 μm) was added to 100 parts by weight of the total amount of the resin contained in the solution obtained in Synthesis Example 5. The obtained mixture was diluted with NMP and uniformly dispersed by a pressure type disperser to obtain a comparative coating liquid (8). The solid content concentration of the comparative coating liquid (8) was 5% by weight.

The comparative coating liquid (8) was applied to a polyethylene porous film (thickness: 10 μm) and then 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. (8) was formed. Then, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator provided with the comparative porous layer (8). In the laminated separator provided with the comparative porous layer (8), the film thickness could not be measured stably because the porous layer peeled off like a fish scale.

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

The comparative coating liquid (9) was applied to a polyethylene porous film (thickness: 10 μm) and then 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. Then, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator provided with the 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) with respect to 100 parts by weight of the total amount of resin contained in the solution obtained in Synthesis Example 5. Parts were added. The obtained mixture was diluted with NMP and uniformly dispersed by a pressure type disperser to obtain a coating liquid (9). The solid content concentration of the coating liquid (9) was 6% by weight.

The coating liquid (9) is applied to a polyethylene porous film (thickness: 10 μm) and then treated in an oven at 50 ° C. and a humidity of 70% for 2 minutes to form a porous layer (9) on the polyethylene porous film. ) Was formed. Then, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator provided with the 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 high voltage resistance and adhesiveness of the porous layers prepared in Examples and Comparative Examples.

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

On the other hand, the porous layer according to Comparative Example 1 had good adhesiveness but was inferior in high voltage resistance. It is considered that this is because the ratio of the block A contained in the porous layer was too small and the sulfonyl group could not be sufficiently contained. The porous layer according to Comparative Example 2 was inferior in adhesiveness, and the battery could not be assembled. It is considered that this is because the proportion of block B contained in the porous layer was too small. The porous layers according to Comparative Examples 3 and 4 were inferior in adhesiveness, and the battery could not be assembled. This suggests that the random copolymer 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. It is considered that this is because the ratio of block A was too small and the sulfonyl group could not be sufficiently contained. The porous layers according to Comparative Examples 6 to 8 were inferior in adhesiveness, and the battery 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 to a polyethylene porous film (thickness: 10 μm) as a coating liquid, and then treated in an oven at 50 ° C. and 70% humidity for 2 minutes. Then, the reference porous layer (1) was formed on the polyethylene porous film. Then, the obtained polyethylene porous film was washed with water and dried to obtain a laminated separator provided with the reference porous layer (1). Reference When the surface of the porous layer (1) was visually observed, no peeling of the porous layer was observed. From this, the problem regarding the adhesiveness of the porous layer to be solved by one aspect of the present invention does not occur when only the resin having a sulfonyl group is used, but arises when a resin and a filler having a sulfonyl group are used. Is suggested.

The present invention can be used, for example, in a non-aqueous electrolyte secondary battery.

Claims (9)

A porous layer for a non-aqueous electrolyte secondary battery containing a block copolymer and a filler.
The block copolymer is
Block A whose main component is the unit represented by the following formula (1), and
-(NH-Ar ¹ -NHCO-Ar ² -CO)-Equation (1)
Block B whose main component is the unit represented by the following equation (2), and
-(NH-Ar ³ -NHCO-Ar ⁴ -CO) -Equation (2)
Has a porous layer for non-aqueous electrolyte secondary batteries:
During the ceremony
Ar ¹ , Ar ² , Ar ³ and Ar ⁴ may be different from unit to unit.
Ar ¹ , Ar ² , Ar ³ and Ar ⁴ are divalent groups each independently having one or more aromatic rings.
More than 50% of all Ar ^1s have a structure in which two aromatic rings are linked by a sulfonyl bond.
Less than 50% of all Ar ^3s have a structure in which two aromatic rings are linked by a sulfonyl bond.
Of all Ar ¹ and Ar ³ , 30-70% have a structure in which two aromatic rings are linked by a sulfonyl bond. Of the units of the formula (1) contained in the block A, 50% or more are 4,4'-diphenylsulfonyl terephthalamide.
Of the units of the formula (2) contained in the block B, 50% or more are paraphenylene terephthalamides.
The porous layer for a non-aqueous electrolytic solution secondary battery according to claim 1. The porous layer for a non-aqueous electrolyte secondary battery according to claim 1 or 2, wherein the block copolymer has a tri-block structure of block B-block A-block B. The molecule corresponding to the mode of the molecular weight distribution of the block copolymer is
The number of units of the formula (1) included in the block A is 10 to 1000.
The number of units of the formula (2) included in the block B is 10 to 500.
The porous layer for a non-aqueous electrolytic solution 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 the formula (2) without containing the unit of the formula (1). For porous layer. The claim that the content of the filler in the porous layer for a non-aqueous electrolytic solution secondary battery is 20 to 90% by weight, assuming that the weight of the porous layer for the non-aqueous electrolytic solution secondary battery is 100% by weight. The porous layer for a non-aqueous electrolytic solution secondary battery according to any one of 1 to 5. The porous layer for a non-aqueous electrolyte secondary battery according to any one of claims 1 to 6, wherein the filler contains an aluminum oxide. A laminated separator for a non-aqueous electrolytic solution secondary battery, wherein the porous layer for the non-aqueous electrolytic solution secondary battery according to any one of claims 1 to 7 is laminated on one side or both sides of the polyolefin porous film. .. Non-water, comprising the porous layer for the non-aqueous electrolyte secondary battery according to any one of claims 1 to 7 or the laminated separator for the non-aqueous electrolyte secondary battery according to claim 8. Electrolyte secondary battery.