JP2017010883A - Resin for coating nonaqueous secondary battery active substance, coating active substance for nonaqueous secondary battery, and method for manufacturing nonaqueous secondary battery active substance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin for coating a nonaqueous secondary battery active substance capable of manufacturing a lithium ion secondary battery which has a low internal resistance of a battery and can keep excellent cycle characteristics, and to provide an active substance covering the same.SOLUTION: There is provided a resin for coating a nonaqueous secondary battery active substance which is formed by polymerization of a monomer composition containing an ester compound (a11) of monovalent aliphatic alcohol having 4 to 12 carbon atoms and a (meth)acrylic acid and a (meth)acrylic acid (a12), where a weight ratio [ester compound (a11)/(meth)acrylic acid (a12)] of the ester compound (a11) and the (meth)acrylic acid (a12) is 10/90 to 90/10.SELECTED DRAWING: None

Description

The present invention relates to a resin for coating a non-aqueous secondary battery active material, a coating active material for a non-aqueous secondary battery, and a method for producing a coated active material for a non-aqueous secondary battery.

A non-aqueous secondary battery represented by a lithium ion secondary battery generally comprises an electrode formed by applying a slurry containing a positive electrode or negative electrode active material, a binder and a solvent to a current collector for a positive electrode or a negative electrode, respectively. Yes.
The binder must have adhesion to the active material and conductive aid, affinity with the electrolyte, and high voltage decomposition resistance. As a binder excellent in high voltage decomposition resistance used for the positive electrode, polyvinylidene fluoride is used. (Hereinafter abbreviated as PVdF), and styrene-butadiene rubber (hereinafter abbreviated as SBR) and carboxymethylcellulose (hereinafter abbreviated as CMC) as binders having high adhesion to the active material and conductive additive in the negative electrode. Is used.

However, PVdF, SBR, and CMC have insufficient adhesiveness to the active material and may peel off and cause an increase in the internal resistance of the battery. It is conceivable to increase the amount of binder added in order to prevent the active material and the binder from peeling off, but increasing the binder increases the internal resistance of the battery and reduces the amount of active material in the battery to reduce the battery capacity. Will also decrease.
Therefore, a non-aqueous secondary battery that has a low internal resistance of the battery and can maintain good cycle characteristics is desired.

A composite oxide containing lithium such as LiCoO ₂ can be used as the positive electrode active material, and a graphite-based material, a silicon-based material, or the like can be used as the negative electrode active material. In the charging / discharging process of the lithium ion secondary battery, a lithium ion deinsertion reaction occurs, so that there is a problem that volume change occurs in the positive electrode active material and the negative electrode active material, and sufficient cycle characteristics cannot be exhibited.

Patent Document 1 discloses a positive electrode using a positive electrode active material in which a surface of an active material is coated with a composite coating of a conductive agent and a binder as a positive electrode that is less susceptible to stress due to expansion / contraction of the active material during a charge / discharge cycle. Is known (see Patent Document 1).

JP 2007-265668 A

However, the lithium ion secondary battery described in Patent Document 1 does not have sufficiently low internal resistance, and the cycle characteristics are not sufficient.

The problem to be solved by the present invention is to provide a resin for coating a non-aqueous secondary battery active material capable of producing a lithium ion secondary battery with low internal resistance and good cycle characteristics, and an active material coated therewith. Is to provide.

As a result of intensive studies to achieve the above object, the present inventors have reached the present invention.
That is, the present invention provides a monomer composition comprising an ester compound (a11) of a monovalent aliphatic alcohol having 4 to 12 carbon atoms and (meth) acrylic acid and (meth) acrylic acid (a12). The weight ratio of the ester compound (a11) to the (meth) acrylic acid (a12) [the ester compound (a11) / the (meth) acrylic acid (a12)] is 10/90 to 90/10. Non-aqueous secondary battery active material coating resin; non-aqueous secondary battery active material coating resin bound to the surface of the non-aqueous secondary battery active material (Y) Substance: A cross-linked resin obtained by cross-linking the non-aqueous secondary battery active material coating resin with a cross-linking agent (b) having two or more functional groups capable of reacting with a carboxyl group is a non-aqueous secondary battery active material (Y). For non-aqueous secondary batteries bound to the surface A non-aqueous secondary battery active material coating resin, a crosslinking agent (b) having two or more functional groups capable of reacting with carboxyl groups, and a non-aqueous secondary battery active material ( Non-aqueous secondary battery coating comprising: a resin coating step of distilling off the organic solvent while mixing Y); and a crosslinking step of reacting the non-aqueous secondary battery active material coating resin with the crosslinking agent (b) It is a manufacturing method of an active material.

The resin for coating a non-aqueous secondary battery active material of the present invention is excellent in adhesion to the active material and has high electrical conductivity when used as an electrode, and therefore covers the surface of the active material for a non-aqueous secondary battery. Therefore, the increase in the internal resistance of the battery is suppressed, and the battery is not peeled off from the active material surface even during continuous use. Therefore, it is possible to provide a nonaqueous secondary battery that can maintain good cycle characteristics without increasing the internal resistance of the battery.

Hereinafter, the present invention will be described in detail.
The resin for coating a non-aqueous secondary battery active material of the present invention comprises ester compounds (a11) and (meth) acrylic acid (a12) of a monovalent aliphatic alcohol having 4 to 12 carbon atoms and (meth) acrylic acid. Polymerization of the monomer composition comprising the above, the weight ratio of the ester compound (a11) and the (meth) acrylic acid (a12) [the ester compound (a11) / the (meth) acrylic acid (a12) ] Is 10/90 to 90/10.

The content of the ester compound (a11) is preferably 10 to 90% by weight, more preferably 15 to 75% by weight, based on the total weight of the monomer composition, from the viewpoint of adhesiveness to the active material and the like. %, More preferably 20 to 60% by weight.

First, the monovalent aliphatic alcohol having 4 to 12 carbon atoms constituting the ester compound (a11) will be described.
Examples of monovalent aliphatic alcohols having 4 to 12 carbon atoms include butyl alcohol (n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol), pentyl alcohol (n-pentyl alcohol, 2-pentyl alcohol, and neopentyl alcohol). ), Hexyl alcohol (such as 1-hexanol, 2-hexanol and 3-hexanol), heptyl alcohol (such as n-heptyl alcohol, 1-methylhexyl alcohol and 2-methylhexyl alcohol), octyl alcohol (n-octyl alcohol, 1-methylheptanol, 1-ethylhexanol, 2-methylheptanol, 2-ethylhexanol, etc.), nonyl alcohol (n-nonyl alcohol, 1-methyloctanol, 1-ethylheptanol, -Propylhexanol and 2-ethylheptyl alcohol), decyl alcohol (n-decyl alcohol, 1-methylnonyl alcohol, 2-methylnonyl alcohol, 2-ethyloctyl alcohol, etc.), undecyl alcohol (n-undecyl alcohol, 1-methyldecyl alcohol, 2-methyldecyl alcohol and 2-ethylnonyl alcohol), lauryl alcohol (n-lauryl alcohol, 1-methylundecyl alcohol, 2-methylundecyl alcohol, 2-ethyldecyl alcohol and 2- Butylhexyl alcohol, etc.).

Subsequently, (meth) acrylic acid (a12) will be described.
In this specification, (meth) acrylic acid indicates acrylic acid and / or methacrylic acid, and may be a mixture of acrylic acid and methacrylic acid.

In the monomer composition constituting the resin for coating a non-aqueous secondary battery active material of the present invention, the weight ratio of the ester compound (a11) to the (meth) acrylic acid (a12) is 10/90 to 90/10. Therefore, a resin obtained by polymerizing this has good adhesiveness with the active material and is difficult to peel off.
The weight ratio is more preferably 30/70 to 85/15, still more preferably 40/60 to 70/30.

The content of (meth) acrylic acid (a12) is preferably 10 to 90% by weight, more preferably 15 based on the total weight of the monomer composition from the viewpoint of adhesiveness to the active material and the like. It is -65 weight%, More preferably, it is 20-60 weight%.

The monomer composition constituting the resin for coating a non-aqueous secondary battery active material of the present invention further comprises an ester compound (a13) of a monovalent aliphatic alcohol having 1 to 3 carbon atoms and (meth) acrylic acid. It is preferable to contain. By containing the ester compound (a13), the effect of suppressing the volume change of the active material due to the resin coated on the active material is further improved.
Examples of the monovalent aliphatic alcohol having 1 to 3 carbon atoms constituting the ester compound (a13) include methanol, ethanol, 1-propanol, and 2-propanol.

The content of the ester compound (a13) is preferably 10 to 60% by weight, more preferably 15 to 55%, based on the total weight of the monomer composition, from the viewpoint of suppressing the volume change of the active material. % By weight, more preferably 20-50% by weight.

The resin for coating a non-aqueous secondary battery active material of the present invention further contains a salt (a14) of an anionic monomer having a polymerizable unsaturated double bond and an anionic group from the viewpoint of internal resistance and the like. It is preferable to do.
Examples of the structure having a polymerizable unsaturated double bond include a vinyl group, an allyl group, a styryl group, and a (meth) acryloyl group.
Examples of the anionic group include a sulfonic acid group and a carboxyl group.
An anionic monomer having a polymerizable unsaturated double bond and an anionic group is a compound obtained by a combination thereof, such as vinyl sulfonic acid, allyl sulfonic acid, styrene sulfonic acid and (meth) acrylic acid. It is done.
The (meth) acryloyl group means an acryloyl group and / or a methacryloyl group.
Examples of the cation constituting the salt (a14) of the anionic monomer include lithium ion, sodium ion, potassium ion and ammonium ion.

Examples of the anionic monomer salt (a14) include sodium allyl sulfonate, lithium styrene sulfonate, sodium styrene sulfonate, and lithium methacrylate.

The content of the anionic monomer salt (a14) is preferably 0.1 to 15% by weight, more preferably 1 based on the total weight of the monomer composition from the viewpoint of internal resistance and the like. -15% by weight, more preferably 2-10% by weight.

The weight average molecular weight of the nonaqueous secondary battery active material coating resin of the present invention is preferably 20,000 to 500,000, more preferably 22,000 to 500,000 from the viewpoint of adhesion to the active material and the like. It is 480,000, More preferably, it is 25,000-450,000.
In addition, the weight average molecular weight of the resin for coating a non-aqueous secondary battery active material in this specification is measured by gel permeation chromatography (hereinafter abbreviated as GPC) measured under the following conditions.
<GPC measurement conditions>
Apparatus: Alliance GPC V2000 (manufactured by Waters)
Solvent: Orthodichlorobenzene Standard substance: Polystyrene Sample concentration: 3 mg / ml
Column stationary phase: PLgel 10 μm, MIXED-B 2 in series (manufactured by Polymer Laboratories)
Column temperature: 135 ° C

The monomer composition includes an ester compound (a11), a (meth) acrylic acid (a12), an ester compound (a13) and a salt of an anionic monomer (a14) and a copolymer containing no active hydrogen. The vinyl monomer (c) may be contained.
Examples of the copolymerizable vinyl monomer (c) containing no active hydrogen include the following (c1) to (c5).
In addition, when (c) is included in the monomer composition, the weight of (c) is also included in the total weight of the monomer composition.
The content of the copolymerizable vinyl monomer not containing active hydrogen is preferably 0.5 to 15% by weight, more preferably 1 to 15% by weight, based on the total weight of the monomer composition. More preferably, it is 2 to 10% by weight.

(C1) Carbyl (meth) acrylate formed from monool having 13 to 20 carbon atoms and (meth) acrylic acid As the monool, (i) aliphatic monool having 13 to 20 carbon atoms (tridecyl alcohol, Tetradecyl alcohol, pentadecyl alcohol, cetyl alcohol, heptadecyl alcohol, stearyl alcohol, isostearyl alcohol, nonadecyl alcohol, arachidyl alcohol, etc.), (ii) alicyclic monools (cyclohexyl alcohol, etc.), (iii) aroma Examples include aliphatic monools (such as benzyl alcohol) and mixtures of two or more thereof.

(C2) Poly (n = 2 to 30) oxyalkylene (2 to 4 carbon atoms) alkyl (1 to 18 carbon atoms) ether (meth) acrylate [methanol ethylene oxide (hereinafter abbreviated as EO) 10 mol adduct (meth) Acrylate, propylene oxide of methanol (hereinafter abbreviated as PO), 10 mol adduct (meth) acrylate, etc.].

(C3) Nitrogen-containing vinyl compound (c3-1) Amido group-containing vinyl compound (i) (meth) acrylamide compound having 3 to 30 carbon atoms such as N, N-dialkyl (1 to 6 carbon atoms) or diaralkyl (carbon number) 7-15) (Meth) acrylamide (N, N-dimethylacrylamide, N, N-dibenzylacrylamide, etc.) and diacetone acrylamide.
(Ii) an amide group-containing vinyl compound having 4 to 20 carbon atoms, excluding the (meth) acrylamide compound, for example, N-methyl-N-vinylacetamide, cyclic amide [pyrrolidone compound having 6 to 13 carbon atoms (N-vinylpyrrolidone) etc)].

(C3-2) (meth) acrylate compound (i) dialkyl (1 to 4 carbon atoms) aminoalkyl (1 to 4 carbon atoms) (meth) acrylate [N, N-dimethylaminoethyl (meth) acrylate, N, N -Diethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate, morpholinoethyl (meth) acrylate, etc.].
(Ii) Quaternary ammonium group-containing (meth) acrylate {tertiary amino group-containing (meth) acrylate [N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, etc.] halogenated) A quaternized product quaternized with a quaternizing agent such as alkyl}.

(C3-3) Heterocycle-containing vinyl compound A pyridine compound having 7 to 14 carbon atoms (such as 2- and 4-vinylpyridine), an imidazole compound having 5 to 12 carbon atoms (such as N-vinylimidazole), and 6 to 13 carbon atoms. Pyrrole compounds (such as N-vinylpyrrole) and pyrrolidone compounds having 6 to 13 carbon atoms (such as N-vinyl-2-pyrrolidone).

(C3-4) Nitrile group-containing vinyl compound A nitrile group-containing vinyl compound having 3 to 15 carbon atoms [(meth) acrylonitrile, cyanostyrene, cyanoalkyl (1 to 4 carbon atoms) acrylate, etc.].

(C3-5) Other vinyl compounds A nitro group-containing vinyl compound having 8 to 16 carbon atoms (such as nitrostyrene).

(C4) Vinyl hydrocarbon (c4-1) Aliphatic vinyl hydrocarbon olefin having 2 to 18 or more carbon atoms (ethylene, propylene, butene, isobutylene, pentene, heptene, diisobutylene, octene, dodecene, octadecene, etc.), Dienes having 4 to 10 or more carbon atoms (butadiene, isoprene, 1,4-pentadiene, 1,5-hexadiene, 1,7-octadiene, etc.) and the like.

(C4-2) alicyclic vinyl hydrocarbon cyclic unsaturated compound having 4 to 18 or more carbon atoms {cycloalkene (cyclohexene, etc.), (di) cycloalkadiene [(di) cyclopentadiene, etc.], terpene (pinene) , Limonene, indene, etc.)}.

(C4-3) Aromatic vinyl hydrocarbon aromatic unsaturated compound having 8 to 20 or more carbon atoms and derivatives thereof (styrene, α-methylstyrene, vinyltoluene, 2,4-dimethylstyrene, ethylstyrene, isopropyl Styrene, butyl styrene, phenyl styrene, cyclohexyl styrene, benzyl styrene, etc.).

(C5) Vinyl ester, vinyl ether, vinyl ketone and unsaturated dicarboxylic acid diester (c5-1) Vinyl ester aliphatic vinyl ester [Alkenyl ester of aliphatic carboxylic acid having 4 to 15 carbon atoms (mono- or dicarboxylic acid) (vinyl acetate , Vinyl propionate, vinyl butyrate, diallyl adipate, isopropenyl acetate, vinyl methoxyacetate, etc.).
Aromatic vinyl esters [alkenyl esters of aromatic carboxylic acids (mono- or dicarboxylic acids) having 9 to 20 carbon atoms (such as vinyl benzoate, diallyl phthalate and methyl-4-vinyl benzoate) and aromatic ring-containing esters of aliphatic carboxylic acids] (Acetoxystyrene etc.) etc.].

(C5-2) Vinyl ether aliphatic vinyl ether [vinyl alkyl having 3 to 15 carbon atoms (1 to 10 carbon atoms) ether (such as vinyl methyl ether, vinyl butyl ether and vinyl 2-ethylhexyl ether), vinyl alkoxy (1 to 6 carbon atoms) ) Alkyl (C1-C4) ether (vinyl-2-methoxyethyl ether, methoxybutadiene, 3,4-dihydro-1,2-pyran, 2-butoxy-2'-vinyloxydiethyl ether and vinyl-2- Ethyl mercaptoethyl ether, etc.), poly (2-4) (meth) allyloxyalkanes (2-6 carbon atoms) (diallyloxyethane, triaryloxyethane, tetraallyloxybutane, tetrametaallyloxyethane, etc.), etc. ].
Aromatic vinyl ethers having 8 to 20 carbon atoms (such as vinyl phenyl ether and phenoxystyrene).

(C5-3) Vinyl ketone Aliphatic vinyl ketone having 4 to 25 carbon atoms (such as vinyl methyl ketone and vinyl ethyl ketone).
Aromatic vinyl ketone having 9 to 21 carbon atoms (such as vinyl phenyl ketone).

(C5-4) Unsaturated dicarboxylic acid diester Unsaturated dicarboxylic acid diester having 4 to 34 carbon atoms [dialkyl fumarate (two alkyl groups are linear, branched or alicyclic having 1 to 22 carbon atoms) Groups) and dialkyl maleates (two alkyl groups are straight, branched or alicyclic groups having 1 to 22 carbon atoms)

The glass transition point [hereinafter abbreviated as Tg, measuring method: DSC (scanning differential thermal analysis) method] of the resin for coating a non-aqueous secondary battery active material of the present invention is preferably 50 to 200 from the viewpoint of the heat resistance of the battery. ° C, more preferably 70 to 180 ° C, particularly preferably 80 to 150 ° C.

As a method for polymerizing the monomer composition constituting the resin for coating the non-aqueous secondary battery active material of the present invention, a known polymerization method (bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization, etc.) is used. Can do.
In the polymerization, known polymerization initiators {azo initiators [2,2′-azobis (2-methylpropionitrile), 2,2′-azobis (2,4-dimethylvaleronitrile) and 2,2 ′ -Azobis (2-methylbutyronitrile), etc.], peroxide initiators (benzoyl peroxide, di-t-butyl peroxide, lauryl peroxide, etc.), etc.} can be used.
The amount of the polymerization initiator used is preferably 0.01 to 5% by weight, more preferably 0.05 to 2% by weight, based on the total weight of the monomers.
The monomer means each monomer constituting the monomer composition [for example, ester compound (a11), (meth) acrylic acid (a12), ester compound (a13), anionic monomer salt (a14) And a copolymerizable vinyl monomer (c)] containing no active hydrogen.

Examples of the solvent used in the case of solution polymerization include esters (having 2 to 8 carbon atoms such as ethyl acetate and butyl acetate), alcohols (having 1 to 8 carbon atoms such as methanol, ethanol, isopropanol and octanol), and 5 carbon atoms. -8 hydrocarbons having a linear, branched or cyclic structure (eg pentane, hexane, heptane, octane, cyclohexane, toluene and xylene), amides [eg N, N-dimethylformamide (hereinafter abbreviated as DMF) and dimethylacetamide ] And ketones (3-9 carbon atoms such as methyl ethyl ketone), and the amount used is usually 5 to 900%, preferably 10 to 400% based on the total weight of the monomers, and the monomer concentration is usually 10 to 10%. 95% by weight, preferably 20 to 90% by weight.

Examples of the dispersion medium in emulsion polymerization and suspension polymerization include water, alcohol (for example, ethanol), ester (for example, ethyl propionate), and light naphtha. As the emulsifier, higher fatty acid (having 10 to 24 carbon atoms) metal salt. (For example, sodium oleate and sodium stearate), higher alcohols (10 to 24 carbon atoms) sulfate metal salts (for example, sodium lauryl sulfate), ethoxylated tetramethyldecynediol, sulfoethyl sodium methacrylate, dimethylaminomethyl methacrylate, etc. Is mentioned. Furthermore, you may add polyvinyl alcohol, polyvinylpyrrolidone, etc. as a stabilizer.
The monomer concentration of the solution or dispersion is usually from 5 to 95% by weight, and the amount of the polymerization initiator used is usually from 0.01 to 5% based on the total weight of the monomers, preferably from the viewpoint of adhesive strength and cohesive strength. 05 to 2%.
In the polymerization, known chain transfer agents such as mercapto compounds (such as dodecyl mercaptan and n-butyl mercaptan) and halogenated hydrocarbons (such as carbon tetrachloride, carbon tetrabromide and benzyl chloride) can be used. The amount used is usually 2% or less based on the total weight of the monomer, and preferably 0.5% or less from the viewpoint of adhesive strength and cohesive strength.

The system temperature in the polymerization reaction is usually −5 to 150 ° C., preferably 30 to 120 ° C., the reaction time is usually 0.1 to 50 hours, preferably 2 to 24 hours, and the end point of the reaction is unreacted It can be confirmed that the amount of monomer is usually 5% by weight or less, preferably 1% by weight or less of the total amount of monomers used.

The non-aqueous secondary battery coating active material of the present invention is a non-aqueous secondary battery active material coating resin bound to the surface of a non-aqueous secondary battery active material (Y).
In view of the internal resistance of the battery and the like, it is preferable to use a conductive additive (X) for the coating active material for the non-aqueous secondary battery of the present invention. That is, the non-aqueous secondary battery covering active material is formed by binding the non-aqueous secondary battery active material coating resin of the present invention and the conductive auxiliary agent (X) to the surface of the non-aqueous secondary battery active material (Y). It may be worn.
Further, the nonaqueous secondary battery active material coating resin of the present invention, which is coated with the nonaqueous secondary battery coating active material of the present invention, has a cross-linking having two or more functional groups capable of reacting with a carboxyl group, which will be described later. It may be cross-linked by the agent (b).

The conductive auxiliary (X) is selected from materials having conductivity.
Specifically, metals [aluminum, stainless steel (SUS), silver, gold, copper, titanium, etc.], carbon [graphite and carbon black (acetylene black, ketjen black, furnace black, channel black, thermal lamp black, etc.), etc. , And mixtures thereof, but are not limited thereto.
These conductive auxiliary agents (X) may be used individually by 1 type, and may be used together 2 or more types. Moreover, these alloys or metal oxides may be used. From the viewpoint of electrical stability, aluminum, stainless steel, carbon, silver, gold, copper, titanium and mixtures thereof are preferred, silver, gold, aluminum, stainless steel and carbon are more preferred, and carbon is particularly preferred. is there. In addition, these conductive assistants (X) may be those obtained by coating a conductive material [a metal of the above (X)] by plating or the like around a particulate ceramic material or resin material.

The shape (form) of the conductive auxiliary agent (X) is not limited to the particle form, and may be a form other than the particle form, and is practically used as a so-called filler-based conductive resin composition such as carbon nanofiber or carbon nanotube. It may be a form.

The average particle diameter of the conductive auxiliary agent (X) is not particularly limited, but is preferably about 0.01 to 10 μm from the viewpoint of the electric characteristics of the battery. In the present specification, “particle diameter” means the maximum distance L among the distances between any two points on the contour line of the conductive additive (X). As the value of “average particle diameter”, the average value of the particle diameter of particles observed in several to several tens of fields using an observation means such as a scanning electron microscope (SEM) or a transmission electron microscope (TEM). The calculated value shall be adopted.

The mixing ratio of the resin for coating the non-aqueous secondary battery active material and the conductive additive (X) is not particularly limited, but from the viewpoint of the internal resistance of the battery, the non-aqueous secondary battery active material is coated by weight. Resin for resin (resin solid content weight): Conductive auxiliary agent (X) = 1: 0.01-1: 50 is preferable, and 1: 0.2-1: 3.0 is more preferable.

The coated active material for a non-aqueous secondary battery of the present invention includes a resin for coating a non-aqueous secondary battery active material of the present invention, an active material for a non-aqueous secondary battery (Y), and a conductive auxiliary agent (X) as necessary. It can manufacture by mixing.
The order of mixing the non-aqueous secondary battery active material coating resin, the non-aqueous secondary battery active material (Y), and the conductive additive (X) is not particularly limited. For example, the non-aqueous secondary battery mixed in advance is used. A resin composition comprising an active material coating resin and a conductive additive (X) may be further mixed with a nonaqueous secondary battery active material (Y), or a nonaqueous secondary battery active material coating resin, non- The aqueous secondary battery active material (Y) and the conductive additive (X) may be mixed at the same time, or the nonaqueous secondary battery active material coating resin is mixed with the nonaqueous secondary battery active material (Y). Furthermore, you may mix a conductive support agent (X).

The coated active material for a non-aqueous secondary battery of the present invention is a crosslinked material obtained by crosslinking the resin for coating a non-aqueous secondary battery active material of the present invention with a crosslinking agent (b) having two or more functional groups capable of reacting with a carboxyl group. The resin and the conductive additive (X) added as necessary may be bound to the surface of the non-aqueous secondary battery active material (Y).

The crosslinking agent (b) has two or more functional groups capable of reacting with a carboxyl group.
Examples of the functional group capable of reacting with a carboxyl group include a hydroxyl group and an epoxy group. Examples of the compound having two or more functional groups include a polyepoxy compound (b1) having two or more epoxy groups and a polyol compound (b2) having two or more hydroxyl groups.

Examples of the polyepoxy compound (b1) include those having an epoxy equivalent of 80 to 2,500, such as glycidyl ether [bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, pyrogallol triglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol. Diglycidyl ether, neopentyl glycol diglycidyl ether, trimethylolpropane triglycidyl ether, glycerin triglycidyl ether, pentaerythritol polyglycidyl ether (such as pentaerythritol diglycidyl ether, pentaerythritol triglycidyl ether and pentaerythritol tetraglycidyl ether), polyethylene Glycol (Mw200-2,000) diglycidyl Ether, polypropylene glycol (Mw 200-2,000) diglycidyl ether and diglycidyl ether of alkylene oxide 1-20 mol adduct of bisphenol A, etc.]; glycidyl ester (phthalic acid diglycidyl ester, trimellitic acid triglycidyl ester, dimer) Acid diglycidyl ester and adipic acid diglycidyl ester, etc.); glycidylamine (N, N-diglycidylaniline, N, N-diglycidyltoluidine, N, N, N ′, N′-tetraglycidyldiaminodiphenylmethane, N, N N, N ′, N′-tetraglycidylxylylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane and N, N, N ′, N′-tetraglycidylhexamethylenediamine, etc.); aliphatic Epoxy (Epoxidized polybutadiene and epoxidized soybean oil and the like), alicyclic epoxides (limonene dioxide and dicyclopentadiene dioxide, etc.).

Examples of the polyol compound (b2) include low-molecular polyhydric alcohols {aliphatic and alicyclic diols having 2 to 20 carbon atoms [ethylene glycol, diethylene glycol, propylene glycol, 1,3-butylene glycol, 1,4- Butylene glycol, 1,6-hexanediol, 3-methylpentanediol, neopentyl glycol, 1,9-nonanediol, 1,4-dihydroxycyclohexane, 1,4-bis (hydroxymethyl) cyclohexane and 2,2-bis (4,4'-hydroxycyclohexyl) propane and the like]; aromatic diol having 8 to 15 carbon atoms [m- or p-xylylene glycol and 1,4-bis (hydroxyethyl) benzene and the like]; 8 triols (such as glycerin and trimethylolpropane); And higher polyhydric alcohols [pentaerythritol, α-methylglucoside, sorbitol, xylit, mannitol, glucose, fructose, sucrose, dipentaerythritol, polyglycerin (degree of polymerization 2-20, etc.), etc.] and their alkylenes (C2-C4) oxide adduct (degree of polymerization = 2-30) is mentioned.

By crosslinking the non-aqueous secondary battery active material coating resin of the present invention using the crosslinking agent (b), the resin strength and the resistance to the electrolyte can be further improved.

The content of the cross-linking agent (b) is preferably 1 to 5% by weight based on the weight of the non-aqueous secondary battery active material coating resin.

As a method for crosslinking the coating resin for non-aqueous secondary battery active material using the crosslinking agent (b), the non-aqueous secondary battery active material coating resin of the present invention is used as the non-aqueous secondary battery active material coating resin (Y). And a method of cross-linking at the same time while coating.
Specifically, as a method of crosslinking after coating, the resin material containing the non-aqueous secondary battery active material (Y) and the non-aqueous secondary battery active material coating resin of the present invention is mixed to remove the solvent. After producing a coated active material in which the active material for a secondary battery is coated with a resin, a solution containing the crosslinking agent (b) is mixed with the coated active material and heated to cause a solvent removal and a crosslinking reaction. And a method of coating the secondary battery active material with the obtained crosslinked polymer.
As a method of simultaneously crosslinking while coating, specifically, a mixed solution containing a resin solution containing the non-aqueous secondary battery active material coating resin of the present invention and a crosslinking agent (b) was mixed with the coating active material. A method of removing the solvent later, causing a crosslinking reaction simultaneously with the solvent removal, and coating the active material for the secondary battery with the crosslinked polymer simultaneously with the production of the crosslinked polymer can be mentioned.
The heating temperature is preferably 120 ° C. or higher when the polyepoxy compound (b1) is used as a crosslinking agent, and is preferably 190 ° C. or higher when the polyol compound (b2) is used.

Examples of the non-aqueous secondary battery active material (Y) include a positive electrode active material (Y1) for a lithium ion secondary battery and a negative electrode active material (Y2) for a lithium ion secondary battery.
The positive electrode active material (Y1) for a lithium ion secondary battery is not particularly limited as long as it can be used as a positive electrode active material for a lithium ion secondary battery, but a composite oxide of lithium and a transition metal is preferable. {Composite oxides with one transition metal (LiCoO ₂ , LiNiO ₂ , LiAlMnO ₄ , LiMnO _2, LiMn ₂ O _4, etc.), composite oxides with two transition metal elements (for example, LiFeMnO ₄ , LiNi _{1− x} Co _x O ₂ , LiMn _1-y Co _y O ₂ , LiNi _1/3 Co _1/3 Al _1/3 O ₂ and LiNi _0.8 Co _0.15 Al _0.05 O ₂ ) and 3 metal elements composite oxide is more than [e.g. _{LiM a M 'b M''} c O 2 (M, M' and M '' is a different transition metal element, respectively, a + b + c Satisfies 1. For example _{LiNi 1/3 Mn 1/3 Co 1/3 O 2} ) , etc.] or the like}, lithium-containing transition metal phosphate (e.g. LiFePO _4, LiCoPO _4, LiMnPO ₄ and LiNiPO _4), a transition metal oxide Products (eg MnO ₂ and V ₂ O ₅ ), transition metal sulfides (eg MoS ₂ and TiS ₂ ) and conductive polymers (eg polyaniline, polyvinylidene fluoride, polypyrrole, polythiophene, polyacetylene and poly-p-phenylene and poly Carbazole) and the like, and two or more of them may be used in combination.
The lithium-containing transition metal phosphate may be one in which a part of the transition metal site is substituted with another transition metal.
The negative electrode active material (Y2) for the lithium ion secondary battery is not particularly limited as long as it can be used as the negative electrode active material of the lithium ion secondary battery. Preferred examples thereof include graphite, amorphous carbon, and polymer compound firing. Bodies (for example, those obtained by baking and carbonizing phenol resin and furan resin), cokes (for example, pitch coke, needle coke and petroleum coke), carbon fibers, conductive polymers (for example, polyacetylene, polyquinoline and polypyrrole), tin, Examples thereof include silicon and metal alloys (for example, lithium-tin alloy, lithium-silicon alloy, lithium-aluminum alloy, and lithium-aluminum-manganese alloy).

The coated active material for a non-aqueous secondary battery of the present invention can be obtained by coating the active material for a non-aqueous secondary battery (Y) with the resin for coating a non-aqueous secondary battery active material of the present invention. In a state where the non-aqueous secondary battery active material (Y) is put in a universal mixer and stirred at 30 to 500 rpm, a resin solution containing the non-aqueous secondary battery active material coating resin is dropped over 1 to 90 minutes. Mixing and further mixing the conductive auxiliary agent (X) as necessary, raising the temperature to 50 to 200 ° C. with stirring, reducing the pressure to 0.007 to 0.04 MPa, and holding for 10 to 150 minutes. be able to.

The blending ratio of the nonaqueous secondary battery active material (Y) and the nonaqueous secondary battery active material coating resin in the nonaqueous secondary battery coated active material of the present invention is not particularly limited, but the weight ratio And non-aqueous secondary battery active material (Y): non-aqueous secondary battery active material coating resin = 1: 0.001 to 1: 0.1.

Of the coated active materials for non-aqueous secondary batteries of the present invention, the resin for coated non-aqueous secondary batteries of the present invention is crosslinked with a crosslinking agent (b) having two or more functional groups capable of reacting with carboxyl groups. A coated active material for a nonaqueous secondary battery in which a crosslinked resin (hereinafter also referred to as a crosslinked polymer) is bound to the surface of the active material for a nonaqueous secondary battery (Y) is an active material for a nonaqueous secondary battery (Y ) Can be obtained by coating with a crosslinked polymer.
For example, a resin solution containing the non-aqueous secondary battery active material coating resin of the present invention, a crosslinking agent (b) having two or more functional groups capable of reacting with carboxyl groups, a non-aqueous secondary battery active material (Y ) And, if necessary, a resin coating step for distilling off the organic solvent while mixing the conductive auxiliary agent (X), and a cross-linking for reacting the non-aqueous secondary battery active material coating resin with the cross-linking agent (b). It can be manufactured through processes.

About a resin coating process and a bridge | crosslinking process, it is as having already demonstrated as a method of bridge | crosslinking a monomer composition using a crosslinking agent (b).
A cross-linking resin obtained by cross-linking a resin for coating a non-aqueous secondary battery active material with a cross-linking agent (b) in a resin coating step and a cross-linking step, and a conductive auxiliary agent (X) to be used as needed are for a non-aqueous secondary battery. A coated active material for a non-aqueous secondary battery bound to the surface of the active material (Y) is obtained.
Since the coated active material for non-aqueous secondary batteries of the present invention is coated with the resin for coating an active material for non-aqueous secondary batteries of the present invention, it is not necessary to add a conductive additive or binder when preparing an electrode. However, adding carbon fiber to the slurry is useful from the viewpoint of further reducing the electrical resistance (internal resistance) of the electrode.

A positive electrode for a lithium ion secondary battery is obtained by using a positive electrode active material (Y1) for a lithium ion secondary battery as an active material (Y) for a non-aqueous secondary battery, and a negative electrode active material for a lithium ion secondary battery ( By using Y2), a negative electrode for a lithium ion secondary battery is obtained.

When producing an electrode for a lithium secondary battery, for example, an electrode slurry in which the coating active material for a non-aqueous secondary battery of the present invention is dispersed in a solvent is prepared, and this electrode slurry is applied to a current collector and dried. A method is mentioned. You may add a conductive support agent (X) and a binder to the said electrode slurry as needed.

Examples of the solvent used for the electrode slurry include 1-methyl-2-pyrrolidone, methyl ethyl ketone, DMF, dimethylacetamide, N, N-dimethylaminopropylamine, and tetrahydrofuran.
Examples of the current collector to which the electrode slurry is applied include copper, aluminum, titanium, stainless steel, nickel, baked carbon, conductive polymer, and conductive glass.
The shape of the current collector is preferably a sheet shape or a foil shape.
Examples of the binder contained in the electrode slurry include polymer compounds such as starch, polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose, polyvinyl pyrrolidone, tetrafluoroethylene, styrene-butadiene rubber, polyethylene, and polypropylene.

The binder content in the electrode slurry is preferably less than 5% by weight based on the weight of the active material, and more preferably 0% by weight.
Usually, the binder is used to fix the active materials and between the active material and the current collector to maintain necessary battery performance.
On the other hand, the coated active material for a non-aqueous secondary battery according to the present invention has an active material surface coated with the resin for coating a non-aqueous secondary battery active material according to the present invention. The active material and the current collector are in close contact with each other, and there is no need to use a binder.
When a binder is added to the electrode slurry, the binder binds the non-aqueous secondary battery coating active material of the present invention or between the non-aqueous secondary battery coating active material of the present invention and the current collector. Therefore, the internal resistance increases by the amount of the added binder.

A lithium ion secondary battery using an electrode containing a coated active material for a non-aqueous secondary battery according to the present invention is combined with a counter electrode, accommodated in a cell container together with a separator, injected with an electrolyte, Obtained by sealing.
In addition, a positive electrode is formed on one surface of the current collector, and a negative electrode is formed on the other surface to produce a bipolar electrode. The bipolar electrode is laminated with a separator and stored in a cell container. It can also be obtained by pouring and sealing the cell container.
Moreover, it is good also considering a positive electrode and a negative electrode as a lithium ion secondary battery as an electrode containing the coating active material for non-aqueous secondary batteries of this invention.

As separators, polyethylene, polypropylene film microporous membrane, porous polyethylene film and polypropylene multilayer film, polyester fiber, aramid fiber, nonwoven fabric made of glass fiber, etc., and silica, alumina, titania etc. on their surface And those having ceramic fine particles attached thereto.

As the electrolytic solution, an electrolytic solution containing an electrolyte and a non-aqueous solvent used for manufacturing a lithium ion secondary battery can be used.

As the electrolyte, those used in ordinary electrolytic solutions can be used. For example, lithium salts of inorganic acids such as LiPF ₆ , LiBF ₄ , LiSbF ₆ , LiAsF ₆ and LiClO ₄ , LiN (CF ₃ SO ₂ ) ₂ , lithium salts of organic acids such as LiN (C ₂ F ₅ SO ₂ ) ₂ and LiC (CF ₃ SO ₂ ) ₃ . Among these, LiPF ₆ is preferable from the viewpoint of battery output and charge / discharge cycle characteristics.

As the non-aqueous solvent, those used in ordinary electrolytic solutions can be used, for example, lactone compounds, cyclic or chain carbonates, chain carboxylates, cyclic or chain ethers, phosphates, nitriles. Compounds, amide compounds, sulfones, sulfolanes and mixtures thereof can be used.

Examples of the lactone compound include a 5-membered ring (γ-butyrolactone, γ-valerolactone, etc.) and a 6-membered lactone compound (δ-valerolactone, etc.).

Examples of the cyclic carbonate include propylene carbonate, ethylene carbonate (EC) and butylene carbonate (BC).
Examples of the chain carbonate include dimethyl carbonate (DMC), methyl ethyl carbonate (MEC), diethyl carbonate (DEC), methyl-n-propyl carbonate, ethyl-n-propyl carbonate, and di-n-propyl carbonate. .

Examples of chain carboxylic acid esters include methyl acetate, ethyl acetate, propyl acetate, and methyl propionate.
Examples of the cyclic ether include tetrahydrofuran, tetrahydropyran, 1,3-dioxolane, 1,4-dioxane and the like. Examples of the chain ether include dimethoxymethane and 1,2-dimethoxyethane.

Examples of phosphate esters include trimethyl phosphate, triethyl phosphate, ethyl dimethyl phosphate, diethyl methyl phosphate, tripropyl phosphate, tributyl phosphate, tri (trifluoromethyl) phosphate, tri (trichloromethyl) phosphate, Tri (trifluoroethyl) phosphate, tri (triperfluoroethyl) phosphate, 2-ethoxy-1,3,2-dioxaphospholan-2-one, 2-trifluoroethoxy-1,3,2- Examples include dioxaphospholan-2-one and 2-methoxyethoxy-1,3,2-dioxaphosphoran-2-one.
Examples of the nitrile compound include acetonitrile. Examples of the amide compound include DMF. Examples of the sulfone include dimethyl sulfone and diethyl sulfone.
A non-aqueous solvent may be used individually by 1 type, and may use 2 or more types together.

Of the non-aqueous solvents, lactone compounds, cyclic carbonates, chain carbonates and phosphates are preferable from the viewpoint of battery output and charge / discharge cycle characteristics, and lactone compounds, cyclic carbonates and chains are more preferable. The carbonic acid ester is particularly preferable, and a mixed solution of a cyclic carbonate and a chain carbonate is particularly preferable. Most preferred is a mixed solution of ethylene carbonate (EC) and dimethyl carbonate (DMC).

EXAMPLES Next, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the examples without departing from the gist of the present invention. Unless otherwise specified, “part” means “part by weight” and “%” means “% by weight”.

<Example 1>
In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen gas introduction tube, 70.0 parts of DMF was charged and heated to 75 ° C. Subsequently, 70.0 parts of 2-ethylhexyl methacrylate, 30.0 parts of methacrylic acid and 20 parts of DMF were mixed with a monomer, 0.8 part of 2,2′-azobis (2,4-dimethylvaleronitrile) and 2 parts , 2'-azobis (2-methylbutyronitrile) 1.6 parts in DMF 10.0 parts and an initiator solution, while blowing nitrogen into a four-necked flask and stirring with a dropping funnel over 2 hours Then, radical polymerization was carried out by dropping continuously. After completion of dropping, the temperature was raised to 80 ° C. and the reaction was continued for 5 hours to obtain a copolymer solution having a resin concentration of 50%. The obtained copolymer solution was transferred to a Teflon (registered trademark) vat and dried under reduced pressure at 120 ° C. and 0.01 MPa for 3 hours to distill off DMF to obtain a copolymer. This copolymer was roughly pulverized with a hammer and then additionally pulverized in a mortar to obtain a powdery resin (A-1).
Table 1 shows the compounding amounts of the ester compound (a11) and (meth) acrylic acid (a12) used.
The weight average molecular weight of the copolymer measured by GPC under the following conditions was 26,000.
<GPC measurement conditions>
Apparatus: Alliance GPC V2000 (manufactured by Waters)
Solvent: Orthodichlorobenzene Standard substance: Polystyrene Sample concentration: 3 mg / ml
Column stationary phase: PLgel 10 μm, MIXED-B 2 in series (manufactured by Polymer Laboratories)
Column temperature: 135 ° C

<Example 2>
In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen gas introduction tube, 70.0 parts of DMF was charged and heated to 75 ° C. Subsequently, 40.0 parts of dodecyl methacrylate, 60.0 parts of methacrylic acid, and 20 parts of DMF were mixed with a monomer, and 0.22 of 2,2′-azobis (2,4-dimethylvaleronitrile) and 2,2 An initiator solution prepared by dissolving 0.8 parts of '-azobis (2-methylbutyronitrile) in 10.0 parts of DMF and continuously blowing with a dropping funnel for 2 hours while stirring nitrogen into a four-necked flask. The mixture was dropped dropwise to perform radical polymerization. After completion of dropping, the reaction was continued at 75 ° C. for 3 hours. Subsequently, the temperature was raised to 80 ° C., and the reaction was continued for 3 hours to obtain a copolymer solution having a resin concentration of 50%. The obtained copolymer solution was transferred to a Teflon (registered trademark) vat and dried under reduced pressure at 120 ° C. and 0.01 MPa for 3 hours to distill off DMF to obtain a copolymer. This copolymer was roughly pulverized with a hammer and then additionally pulverized in a mortar to obtain a powdery resin (A-2).
Table 1 shows the compounding amounts of the ester compound (a11) and (meth) acrylic acid (a12) used.
The weight average molecular weight of the copolymer measured by GPC was 96,000.

<Example 3>
In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen gas introduction tube, 70.0 parts of DMF was charged and heated to 75 ° C. Subsequently, 20.0 parts of dodecyl methacrylate, 70.0 parts of acrylic acid, 10.0 parts of methyl methacrylate and 20 parts of DMF, and a monomer mixture solution and 2,2′-azobis (2,4-dimethylvaleronitrile) An initiator solution prepared by dissolving 0.3 part and 0.8 part of 2,2′-azobis (2-methylbutyronitrile) in 10.0 part of DMF and blowing nitrogen into a four-necked flask while stirring, Radical polymerization was carried out by continuously dropping with a dropping funnel over 2 hours. After completion of dropping, the reaction was continued at 75 ° C. for 3 hours. Subsequently, the temperature was raised to 80 ° C., and the reaction was continued for 3 hours to obtain a copolymer solution having a resin concentration of 50%. The obtained copolymer solution was transferred to a Teflon (registered trademark) vat and dried under reduced pressure at 120 ° C. and 0.01 MPa for 3 hours to distill off DMF to obtain a copolymer. The copolymer was roughly pulverized with a hammer and then additionally pulverized in a mortar to obtain a powdery resin (A-3).
Table 1 shows the compounding amounts of the ester compound (a11), (meth) acrylic acid (a12) and ester compound (a13) used.
The weight average molecular weight of the copolymer measured by GPC was 70,000.

<Example 4>
In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen gas introduction tube, 70.0 parts of DMF was charged and heated to 75 ° C. Next, 20.0 parts of butyl methacrylate, 40.0 parts of methacrylic acid, 35.0 parts of methyl methacrylate, a monomer mixture containing 5 parts of a mixture of cetyl methacrylate and stearyl methacrylate and 20 parts of DMF, and 2 , 2'-azobis (2,4-dimethylvaleronitrile) 0.08 parts and 2,2'-azobis (2-methylbutyronitrile) 0.8 parts in DMF 10.0 parts with an initiator solution While nitrogen was blown into the four-necked flask, radical polymerization was carried out by continuously dropping with a dropping funnel over 2 hours under stirring. After completion of dropping, the reaction was continued at 75 ° C. for 3 hours. The temperature was then raised to 80 ° C. and the reaction was continued for 3 hours. Next, an initiator solution in which 0.2 part of 2,2′-azobis (2-methylbutyronitrile) was dissolved in 1.0 part of DMF was added, and the reaction was continued for 3 hours to obtain a copolymer having a resin concentration of 50%. A solution was obtained. The obtained copolymer solution was transferred to a Teflon (registered trademark) vat and dried under reduced pressure at 120 ° C. and 0.01 MPa for 3 hours to distill off DMF to obtain a copolymer. The copolymer was roughly pulverized with a hammer and then additionally pulverized in a mortar to obtain a powdery resin (A-4).
Table 1 shows the blending amounts of the ester compound (a11), (meth) acrylic acid (a12), ester compound (a13), and copolymerizable vinyl monomer (c) containing no active hydrogen.
The weight average molecular weight of the copolymer measured by GPC was 180,000.

<Example 5>
In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen gas introduction tube, 70.0 parts of DMF was charged and heated to 75 ° C. Then, 44.5 parts of 2-ethylhexyl methacrylate, 30.0 parts of methacrylic acid, 25.0 parts of methyl methacrylate, 0.5 part of sodium styrenesulfonate and 20 parts of DMF, and 2,2 ′ Four initiators of initiator solution prepared by dissolving 0.3 part of azobis (2,4-dimethylvaleronitrile) and 0.8 part of 2,2′-azobis (2-methylbutyronitrile) in 10.0 parts of DMF While nitrogen was blown into the flask, radical polymerization was carried out by continuously dropping the mixture with a dropping funnel over 2 hours while stirring. After completion of dropping, the reaction was continued at 75 ° C. for 3 hours. Subsequently, the temperature was raised to 80 ° C., and the reaction was continued for 3 hours to obtain a copolymer solution having a resin concentration of 50%. The obtained copolymer solution was transferred to a Teflon (registered trademark) vat and dried under reduced pressure at 120 ° C. and 0.01 MPa for 3 hours to distill off DMF to obtain a copolymer. The copolymer was roughly pulverized with a hammer and then additionally pulverized in a mortar to obtain a powdery resin (A-5).
Table 1 shows the compounding amounts of the ester compound (a11), (meth) acrylic acid (a12), ester compound (a13) and anionic monomer salt (a14) used.
The weight average molecular weight of the copolymer measured by GPC was 62,000.

<Example 6>
In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen gas introduction tube, 70.0 parts of DMF was charged and heated to 75 ° C. Subsequently, 35.0 parts of 2-ethylhexyl methacrylate, 45.0 parts of methacrylic acid, 15.0 parts of methyl methacrylate, 5.0 parts of lithium styrenesulfonate and 20 parts of DMF, and 2,2 ′ Four initiators of an initiator solution in which 0.6 parts of azobis (2,4-dimethylvaleronitrile) and 1.2 parts of 2,2′-azobis (2-methylbutyronitrile) are dissolved in 10.0 parts of DMF While nitrogen was blown into the flask, radical polymerization was carried out by continuously dropping the mixture with a dropping funnel over 2 hours while stirring. After completion of dropping, the temperature was raised to 80 ° C. and the reaction was continued for 5 hours to obtain a copolymer solution having a resin concentration of 50%. The obtained copolymer solution was transferred to a Teflon (registered trademark) vat and dried under reduced pressure at 120 ° C. and 0.01 MPa for 3 hours to distill off DMF to obtain a copolymer. The copolymer was roughly pulverized with a hammer and then additionally pulverized in a mortar to obtain a powdery resin (A-6).
Table 1 shows the compounding amounts of the ester compound (a11), (meth) acrylic acid (a12), ester compound (a13) and anionic monomer salt (a14) used.
The weight average molecular weight of the copolymer measured by GPC was 48,000.

<Example 7>
In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen gas introduction tube, 70.0 parts of DMF was charged and heated to 75 ° C. Next, a monomer compounded liquid containing 30.0 parts of 2-ethylhexyl methacrylate, 40.0 parts of methacrylic acid, 17.0 parts of methyl methacrylate, 8.0 parts of lithium styrenesulfonate, 5.0 parts of styrene and 20 parts of DMF. And an initiator in which 0.3 part of 2,2′-azobis (2,4-dimethylvaleronitrile) and 0.8 part of 2,2′-azobis (2-methylbutyronitrile) are dissolved in 10.0 parts of DMF. The solution was continuously dropped with a dropping funnel over 2 hours with stirring while nitrogen was blown into a four-necked flask to perform radical polymerization. After completion of dropping, the reaction was continued at 75 ° C. for 3 hours. Subsequently, the temperature was raised to 80 ° C., and the reaction was continued for 3 hours to obtain a copolymer solution having a resin concentration of 50%. The obtained copolymer solution was transferred to a Teflon (registered trademark) vat and dried under reduced pressure at 120 ° C. and 0.01 MPa for 3 hours to distill off DMF to obtain a copolymer. This copolymer was roughly pulverized with a hammer and then additionally pulverized in a mortar to obtain a powdery resin (A-7).
Amounts of used ester compound (a11), (meth) acrylic acid (a12), ester compound (a13), anionic monomer salt (a14) and copolymerizable vinyl monomer (c) containing no active hydrogen Is shown in Table 1.
The weight average molecular weight of the copolymer measured by GPC was 79,000.

<Example 8>
In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen gas introduction tube, 70.0 parts of DMF was charged and heated to 75 ° C. Subsequently, 20.0 parts of butyl methacrylate, 55.0 parts of acrylic acid, 22.0 parts of methyl methacrylate, 3 parts of sodium allyl sulfonate and 20 parts of DMF, and 2,2′-azobis (2 , 4-dimethylvaleronitrile) and an initiator solution prepared by dissolving 0.8 part of 2,2′-azobis (2-methylbutyronitrile) in 10.0 part of DMF and nitrogen in a four-necked flask. Then, radical polymerization was carried out by continuously dropping with a dropping funnel over 2 hours under stirring. After completion of dropping, the temperature was raised to 80 ° C. and the reaction was continued for 5 hours to obtain a copolymer solution having a resin concentration of 50%. The obtained copolymer solution was transferred to a Teflon (registered trademark) vat and dried under reduced pressure at 120 ° C. and 0.01 MPa for 3 hours to distill off DMF to obtain a copolymer. This copolymer was roughly pulverized with a hammer and then additionally pulverized in a mortar to obtain a powdery resin (A-8).
Table 1 shows the compounding amounts of the ester compound (a11), (meth) acrylic acid (a12), ester compound (a13) and anionic monomer salt (a14) used.
The weight average molecular weight of the copolymer measured by GPC was 51,000.

<Example 9>
In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen gas introduction tube, 70.0 parts of DMF was charged and heated to 75 ° C. Next, a monomer compounding solution in which 10.0 parts of 2-ethylhexyl methacrylate, 45.0 parts of methacrylic acid, 42.0 parts of methyl methacrylate, 3.0 parts of lithium methacrylate and 20 parts of DMF were blended, and 2,2′- A four-necked flask with an initiator solution in which 0.3 part of azobis (2,4-dimethylvaleronitrile) and 0.7 part of 2,2′-azobis (2-methylbutyronitrile) are dissolved in 10.0 parts of DMF While nitrogen was blown into the inside, radical polymerization was carried out by continuously dropping the mixture with a dropping funnel over 2 hours under stirring. After completion of dropping, the reaction was continued at 75 ° C. for 3 hours. Subsequently, the temperature was raised to 80 ° C., and the reaction was continued for 3 hours to obtain a copolymer solution having a resin concentration of 50%. The obtained copolymer solution was transferred to a Teflon (registered trademark) vat and dried under reduced pressure at 120 ° C. and 0.01 MPa for 3 hours to distill off DMF to obtain a copolymer. This copolymer was roughly pulverized with a hammer and then additionally pulverized in a mortar to obtain a powdery resin (A-9).
Table 1 shows the compounding amounts of the ester compound (a11), (meth) acrylic acid (a12), ester compound (a13) and anionic monomer salt (a14) used.
The weight average molecular weight of the copolymer measured by GPC was 65,000.

<Example 10>
In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen gas introduction tube, 70.0 parts of DMF was charged and heated to 75 ° C. Next, a monomer compounded solution prepared by blending 50.0 parts of 2-ethylhexyl methacrylate, 50.0 parts of methacrylic acid and 20 parts of DMF, 0.8 part of 2,2′-azobis (2,4-dimethylvaleronitrile) and 2 parts , 2'-azobis (2-methylbutyronitrile) 1.6 parts in DMF 10.0 parts and an initiator solution, while blowing nitrogen into a four-necked flask and stirring with a dropping funnel over 2 hours Then, radical polymerization was carried out by dropping continuously. After completion of dropping, the temperature was raised to 80 ° C. and the reaction was continued for 5 hours to obtain a copolymer solution having a resin concentration of 50%. The obtained copolymer solution was transferred to a Teflon (registered trademark) vat and dried under reduced pressure at 120 ° C. and 0.01 MPa for 3 hours to distill off DMF to obtain a copolymer. This copolymer was roughly pulverized with a hammer and then additionally pulverized in a mortar to obtain a powdery resin (A-10).
Table 1 shows the compounding amounts of the ester compound (a11) and (meth) acrylic acid (a12) used.
The weight average molecular weight of the copolymer measured by GPC was 26,000.

<Example 11>
In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen gas introduction tube, 70.0 parts of DMF was charged and heated to 75 ° C. Next, a monomer compounded solution containing 30.0 parts of 2-ethylhexyl methacrylate, 10.0 parts of acrylic acid, 60.0 parts of methyl methacrylate and 20 parts of DMF, and 2,2′-azobis (2,4-dimethylvalero) Nitrile) and an initiator solution prepared by dissolving 0.8 part of 2,2′-azobis (2-methylbutyronitrile) in 10.0 parts of DMF and stirring while blowing nitrogen into the four-necked flask. Then, radical polymerization was carried out by continuously dropping with a dropping funnel over 2 hours. After completion of dropping, the temperature was raised to 80 ° C. and the reaction was continued for 5 hours to obtain a copolymer solution having a resin concentration of 50%. The obtained copolymer solution was transferred to a Teflon (registered trademark) vat and dried under reduced pressure at 120 ° C. and 0.01 MPa for 3 hours to distill off DMF to obtain a copolymer. This copolymer was roughly pulverized with a hammer and then additionally pulverized in a mortar to obtain a powdery resin (A-11).
Table 1 shows the compounding amounts of the ester compound (a11), (meth) acrylic acid (a12) and ester compound (a13) used.
The weight average molecular weight of the copolymer measured by GPC was 24,000.

<Example 12>
In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen gas introduction tube, 70.0 parts of DMF was charged and heated to 75 ° C. Subsequently, a monomer compounded liquid containing 30.0 parts of 2-ethylhexyl methacrylate, 10.0 parts of methacrylic acid, 60.0 parts of methyl methacrylate and 20 parts of DMF, and 2,2′-azobis (2,4-dimethylvalero) Nitrile) and an initiator solution prepared by dissolving 0.3 part of 2,2′-azobis (2-methylbutyronitrile) in 10.0 part of DMF and stirring while blowing nitrogen into a four-necked flask Then, radical polymerization was carried out by continuously dropping with a dropping funnel over 2 hours. After completion of dropping, the reaction was continued at 75 ° C. for 3 hours. Subsequently, the temperature was raised to 80 ° C., and the reaction was continued for 3 hours to obtain a copolymer solution having a resin concentration of 50%. The obtained copolymer solution was transferred to a Teflon (registered trademark) vat and dried under reduced pressure at 120 ° C. and 0.01 MPa for 3 hours to distill off DMF to obtain a copolymer. The copolymer was roughly pulverized with a hammer and then additionally pulverized in a mortar to obtain a powdery resin (A-12).
Table 1 shows the compounding amounts of the ester compound (a11), (meth) acrylic acid (a12) and ester compound (a13) used.
The weight average molecular weight of the copolymer measured by GPC was 80,000.

<Example 13>
In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen gas introduction tube, 70.0 parts of DMF was charged and heated to 75 ° C. Next, 30.0 parts of butyl methacrylate, 30.0 parts of methacrylic acid, 25.0 parts of methyl methacrylate, 3.0 parts of lithium styrenesulfonate, 12.0 parts in total of a mixture of cetyl methacrylate and stearyl methacrylate DMF10 was prepared by mixing 20 parts of DMF with a monomer mixture, 0.6 part of 2,2′-azobis (2,4-dimethylvaleronitrile) and 1.6 parts of 2,2′-azobis (2-methylbutyronitrile). The initiator solution dissolved in 0.0 part was continuously dropped in a dropping funnel over 2 hours with stirring while nitrogen was blown into a four-necked flask to perform radical polymerization. After completion of dropping, the temperature was raised to 80 ° C. and the reaction was continued for 5 hours to obtain a copolymer solution having a resin concentration of 50%. The obtained copolymer solution was transferred to a Teflon (registered trademark) vat and dried under reduced pressure at 120 ° C. and 0.01 MPa for 3 hours to distill off DMF to obtain a copolymer. The copolymer was roughly pulverized with a hammer and then additionally pulverized in a mortar to obtain a powdery resin (A-13).
Amounts of used ester compound (a11), (meth) acrylic acid (a12), ester compound (a13), anionic monomer salt (a14) and copolymerizable vinyl monomer (c) containing no active hydrogen Is shown in Table 1.
The weight average molecular weight of the copolymer measured by GPC was 48,000.

<Example 14>
In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen gas introduction tube, 70.0 parts of DMF was charged and heated to 75 ° C. Next, a monomer compounded solution containing 40.0 parts of 2-ethylhexyl methacrylate, 40.0 parts of methacrylic acid, 15.0 parts of methyl methacrylate, 5.0 parts of sodium styrenesulfonate and 20 parts of DMF, and 2,2 ′ Four initiators of initiator solution prepared by dissolving 0.3 part of azobis (2,4-dimethylvaleronitrile) and 0.8 part of 2,2′-azobis (2-methylbutyronitrile) in 10.0 parts of DMF While nitrogen was blown into the flask, radical polymerization was carried out by continuously dropping the mixture with a dropping funnel over 2 hours while stirring. After completion of dropping, the reaction was continued at 75 ° C. for 3 hours. Subsequently, the temperature was raised to 80 ° C., and the reaction was continued for 3 hours to obtain a copolymer solution having a resin concentration of 50%. The obtained copolymer solution was transferred to a Teflon (registered trademark) vat and dried under reduced pressure at 120 ° C. and 0.01 MPa for 3 hours to distill off DMF to obtain a copolymer. The copolymer was roughly pulverized with a hammer and then additionally pulverized in a mortar to obtain a powdery resin (A-14).
Table 1 shows the compounding amounts of the ester compound (a11), (meth) acrylic acid (a12), ester compound (a13) and anionic monomer salt (a14) used.
The weight average molecular weight of the copolymer measured by GPC was 60,000.

<Example 15>
In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen gas introduction tube, 70.0 parts of DMF was charged and heated to 75 ° C. Next, 30.0 parts of 2-ethylhexyl methacrylate, 9.0 parts of butyl methacrylate, 35.0 parts of acrylic acid, 20.0 parts of methyl methacrylate, 1.0 part of lithium styrenesulfonate, 5.0 parts of styrene and DMF10 was prepared by mixing 20 parts of DMF with a monomer mixture, 0.6 part of 2,2′-azobis (2,4-dimethylvaleronitrile) and 1.6 parts of 2,2′-azobis (2-methylbutyronitrile). The initiator solution dissolved in 0.0 part was continuously dropped in a dropping funnel over 2 hours with stirring while nitrogen was blown into a four-necked flask to perform radical polymerization. After completion of dropping, the temperature was raised to 80 ° C. and the reaction was continued for 5 hours to obtain a copolymer solution having a resin concentration of 50%. The obtained copolymer solution was transferred to a Teflon (registered trademark) vat and dried under reduced pressure at 120 ° C. and 0.01 MPa for 3 hours to distill off DMF to obtain a copolymer. The copolymer was roughly pulverized with a hammer and then additionally pulverized in a mortar to obtain a powdery resin (A-15).
Amounts of used ester compound (a11), (meth) acrylic acid (a12), ester compound (a13), anionic monomer salt (a14) and copolymerizable vinyl monomer (c) containing no active hydrogen Is shown in Table 1.
The weight average molecular weight of the copolymer measured by GPC was 38,000.

<Example 16>
In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen gas introduction tube, 70.0 parts of DMF was charged and heated to 75 ° C. Next, 15.0 parts of 2-ethylhexyl methacrylate, 10.0 parts of dodecyl methacrylate, 30.0 parts of methacrylic acid, 40.0 parts of methyl methacrylate, 1.0 part of lithium styrene sulfonate, and 4.0 parts of lithium methacrylate. Part and 20 parts of DMF, a monomer mixture, 0.6 part of 2,2′-azobis (2,4-dimethylvaleronitrile) and 1.4 part of 2,2′-azobis (2-methylbutyronitrile) The initiator solution dissolved in 10.0 parts of DMF was continuously dropped with a dropping funnel over 2 hours with stirring while blowing nitrogen into a four-necked flask to perform radical polymerization. After completion of dropping, the temperature was raised to 80 ° C. and the reaction was continued for 5 hours to obtain a copolymer solution having a resin concentration of 50%. The obtained copolymer solution was transferred to a Teflon (registered trademark) vat and dried under reduced pressure at 120 ° C. and 0.01 MPa for 3 hours to distill off DMF to obtain a copolymer. The copolymer was roughly pulverized with a hammer and then additionally pulverized in a mortar to obtain a powdery resin (A-16).
Table 1 shows the compounding amounts of the ester compound (a11), (meth) acrylic acid (a12), ester compound (a13) and anionic monomer salt (a14) used.
The weight average molecular weight of the copolymer measured by GPC was 41,000.

<Example 17>
In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen gas introduction tube, 70.0 parts of DMF was charged and heated to 75 ° C. Then, 20.0 parts of dodecyl methacrylate, 40.0 parts of methacrylic acid, 34.0 parts of methyl methacrylate, 1.0 part of sodium allyl sulfonate, 5.0 parts of styrene and 20 parts of DMF, An initiator solution prepared by dissolving 0.9 part of 2,2′-azobis (2,4-dimethylvaleronitrile) and 1.6 part of 2,2′-azobis (2-methylbutyronitrile) in 10.0 parts of DMF; Was continuously dripped in a dropping funnel over 2 hours with stirring while nitrogen was blown into the four-necked flask to perform radical polymerization. After completion of dropping, the temperature was raised to 80 ° C. and the reaction was continued for 5 hours to obtain a copolymer solution having a resin concentration of 50%. The obtained copolymer solution was transferred to a Teflon (registered trademark) vat and dried under reduced pressure at 120 ° C. and 0.01 MPa for 3 hours to distill off DMF to obtain a copolymer. The copolymer was roughly pulverized with a hammer and then additionally pulverized in a mortar to obtain a powdery resin (A-17).
Amounts of used ester compound (a11), (meth) acrylic acid (a12), ester compound (a13), anionic monomer salt (a14) and copolymerizable vinyl monomer (c) containing no active hydrogen Is shown in Table 1.
The weight average molecular weight of the copolymer measured by GPC was 20,000.

<Example 18>
In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen gas introduction tube, 70.0 parts of DMF was charged and heated to 75 ° C. Next, a monomer compounded liquid containing 40.0 parts of 2-ethylhexyl methacrylate, 30.0 parts of methacrylic acid, 25.0 parts of methyl methacrylate, 5.0 parts of sodium styrenesulfonate and 20 parts of DMF, and 2,2 ′ 4 initiators with 0.9 parts of azobis (2,4-dimethylvaleronitrile) and 1.4 parts of 2,2′-azobis (2-methylbutyronitrile) dissolved in 10.0 parts of DMF While nitrogen was blown into the flask, radical polymerization was carried out by continuously dropping the mixture with a dropping funnel over 2 hours while stirring. After completion of dropping, the temperature was raised to 80 ° C. and the reaction was continued for 5 hours to obtain a copolymer solution having a resin concentration of 50%. The obtained copolymer solution was transferred to a Teflon (registered trademark) vat and dried under reduced pressure at 120 ° C. and 0.01 MPa for 3 hours to distill off DMF to obtain a copolymer. This copolymer was roughly pulverized with a hammer and then additionally pulverized in a mortar to obtain a powdery resin (A-18).
Table 1 shows the compounding amounts of the ester compound (a11), (meth) acrylic acid (a12), ester compound (a13) and anionic monomer salt (a14) used.
The weight average molecular weight of the copolymer measured by GPC was 28,000.

[Creation of coated positive electrode active material for lithium ion secondary battery]
<Example 19: No crosslinking agent>
A resin mixed solution was prepared by blending 2 parts of the powdery resin (A-1) prepared in Example 1 and 10.4 parts of DMF.
Thereafter, 94 parts of lithium cobaltate and the above resin mixture were charged into a coffee mill, and mixed and stirred at room temperature for 1 minute. Next, 4 parts of acetylene black [manufactured by Denki Kagaku Kogyo Co., Ltd.] was added, and the mixture was further stirred for 5 minutes to obtain an active material cake.
The active material cake was transferred to a Teflon (registered trademark) vat and dried under reduced pressure at 120 ° C. and 0.01 MPa for 1 hour. After drying under reduced pressure, the mixture was returned to the coffee mill and stirred for 10 seconds for pulverization to obtain a coated negative electrode active material (D-1) according to Example 19. Table 2 shows the composition of the coated positive electrode active material.

<Examples 20 to 29: no crosslinking agent>
Example 19 and the amount of powdered resin (resin for coating non-aqueous secondary battery active material) and the amount of DMF, lithium cobaltate and acetylene black were changed to the numbers shown in Table 2, and Example 19 The coated positive electrode active materials (D-2) to (D-11) according to Examples 20 to 29 were obtained in the same procedure. Table 2 shows the composition of each coated positive electrode active material.

<Comparative Example 1>
The coated positive electrode active material (D′-1) was prepared in the same manner as in Example 19 except that 2 parts of polyvinylidene fluoride (manufactured by Kureha Co., Ltd.) was used instead of 2 parts of the powdered resin (A-1). )

<Example 30: With crosslinking agent>
2 parts of powdery resin (A-10) prepared in Example 10 and 0.05 part of Denacol EX-810 [manufactured by Nagase ChemteX Corp.] and 10.4 parts of DMF are blended as the crosslinking agent (b). A resin mixture was prepared.
The coffee mill was charged with 94 parts of lithium cobaltate and the above resin mixture, and mixed and stirred at room temperature for 1 minute. Subsequently, 4 parts of acetylene black [manufactured by Denki Kagaku Kogyo Co., Ltd.] was added, and further mixed and stirred for 5 minutes to obtain an active material cake.
The active material cake was transferred to a Teflon (registered trademark) vat and heated at 120 ° C. for 1 hour to carry out a crosslinking reaction of the coating resin. Thereafter, vacuum drying was performed at 0.01 MPa for 1 hour. After drying under reduced pressure, it was returned to the coffee mill and stirred and crushed for 10 seconds to obtain a coated positive electrode active material (D-12) according to Example 30.

<Examples 31 to 38: with a crosslinking agent>
In addition to changing the powdery resin (non-aqueous secondary battery active material coating resin), the type and amount of the crosslinking agent (b), and the amounts of DMF, lithium cobaltate and acetylene black as shown in Table 2. Obtained the coated positive electrode active materials (D-13) to (D-20) according to Examples 31 to 38 in the same procedure as in Example 30. Table 2 shows the composition of each coated positive electrode active material.

[Production of coated negative electrode active material for lithium ion secondary battery]
<Example 39: No crosslinking agent>
2 parts of powdery resin (A-1) prepared in Example 1 and 17.6 parts of DMF were blended to prepare a resin mixed solution.
88 parts of graphite powder [manufactured by Nippon Graphite Industry Co., Ltd.] and the above resin mixture were charged into a coffee mill, and mixed and stirred at room temperature for 1 minute. Next, 10 parts of acetylene black [manufactured by Denki Kagaku Kogyo Co., Ltd.] was added, and the mixture was further stirred for 5 minutes to obtain an active material cake.
The active material cake was transferred to a Teflon (registered trademark) vat and dried under reduced pressure at 120 ° C. and 0.01 MPa for 1 hour. After drying under reduced pressure, the mixture was returned to the coffee mill and stirred for 10 seconds to crush to obtain a coated negative electrode active material (E-1) according to Example 39. Table 3 shows the composition of the coated negative electrode active material.

<Examples 40 to 49: No crosslinking agent>
The same as in Example 39, except that the type and amount of powdered resin (non-aqueous secondary battery active material coating resin) and the amounts of DMF, graphite powder and acetylene black were changed as shown in Table 3. In this procedure, coated negative electrode active materials (E-2) to (E-11) according to Examples 40 to 49 were obtained. Table 3 shows the composition of each coated negative electrode active material.

<Comparative example 2>
The coated positive electrode active material (E′-1) was prepared in the same manner as in Example 39 except that 2 parts of polyvinylidene fluoride (manufactured by Kureha Co., Ltd.) was used instead of 2 parts of the powdered resin (A-1). )

<Example 50: With crosslinking agent>
2 parts of powdery resin (A-10) prepared in Example 10, 17.6 parts of DMF, and 0.025 part of Denacol EX-810 [manufactured by Nagase ChemteX Corporation] as a crosslinking agent (b) were blended. A resin mixture was prepared.
88 parts of graphite powder [manufactured by Nippon Graphite Industry Co., Ltd.] and a resin mixed solution were charged into a coffee mill and mixed and stirred at room temperature for 1 minute. Next, 10 parts of acetylene black [manufactured by Denki Kagaku Kogyo Co., Ltd.] was added, and the mixture was further stirred for 5 minutes to obtain an active material cake.
The active material cake was transferred to a Teflon (registered trademark) vat and dried under reduced pressure at 120 ° C. and 0.01 MPa for 1 hour. After drying under reduced pressure, the mixture was returned to the coffee mill and stirred for 10 seconds for pulverization to obtain a coated negative electrode active material (E-12) according to Example 50. Table 3 shows the composition of the coated negative electrode active material.

<Examples 51 to 58: with a crosslinking agent>
Except that the powdery resin (non-aqueous secondary battery active material coating resin), the type and amount of the crosslinking agent (b), and the amounts of DMF, graphite powder and acetylene black were changed as shown in Table 3. The coated positive electrode active materials (E-13) to (E-20) according to Examples 51 to 58 were obtained in the same procedure as in Example 50. Table 3 shows the composition of each coated negative electrode active material.

<Production Examples 1-39>
[Preparation of positive electrode for lithium ion secondary battery]
10 parts of any of the coated positive electrode active materials (D-1) to (D-20) and (D′-1) prepared in Examples 19 to 38 and Comparative Example 1 and 5 parts of diethyl carbonate were put into a mortar and kneaded. Thus, a positive electrode slurry was obtained. The obtained slurry was applied to one side of an aluminum electrolytic foil having a thickness of 20 μm using a wire bar in the air, dried at 50 ° C. for 15 minutes, and further dried under reduced pressure at 120 ° C. and 0.01 MPa for 12 hours. This was punched to 15 mmφ to produce a positive electrode for a lithium ion secondary battery.

[Preparation of negative electrode for lithium ion secondary battery]
Subsequently, 10 parts of any one of the coated negative electrode active materials (E-1) to (E-20) and (E′-1) prepared in Examples 39 to 58 and Comparative Example 2 and 5 parts of diethyl carbonate in a mortar. The negative electrode slurry was obtained by charging and kneading. The obtained slurry was applied to one side of a 20 μm-thick copper electrolytic foil in the air using a wire bar, dried at 50 ° C. for 15 minutes, and then further dried under reduced pressure at 120 ° C. and 0.01 MPa for 12 hours. This was punched out to 15 mmφ to produce a negative electrode for a lithium ion secondary battery.

[Production of lithium ion secondary battery]
Combine the positive electrode for the lithium ion secondary battery and the negative electrode for the lithium ion secondary battery at both ends in the 2032 type coin cell so that the active materials constituting the electrodes are the combinations shown in Table 4, respectively, Were placed so as to face the coated surface of the positive electrode, and three separators (Celguard 2500: made of polypropylene) were inserted between the electrodes to produce a cell for a lithium ion secondary battery. An electrolytic solution was injected and sealed in the cell, and the internal resistance was evaluated by the following method.
Table 4 shows the coated positive electrode active material and the coated negative electrode active material used.

<Production Example 40: Conductive auxiliary agent (acetylene black) added>
A lithium ion secondary battery was produced in the same manner as in Production Examples 1 to 39 except that 9.9 parts of (D-7), 0.1 part of acetylene black, and 5 parts of diethyl carbonate were used in preparing the positive electrode slurry. A positive electrode was prepared.
In addition, when preparing the negative electrode slurry, 9.9 parts of (E-7), 0.1 part of acetylene black, and 5 parts of diethyl carbonate were used, and lithium ion 2 was prepared in the same manner as in Production Examples 1 to 39. A negative electrode for a secondary battery was produced.
A positive electrode for a lithium ion secondary battery and a negative electrode for a lithium ion secondary battery are arranged at both ends in the 2032 type coin cell so that the coated surface of the negative electrode faces the coated surface of the positive electrode, and a separator (Cell Guard 2500: Three sheets of polypropylene) were inserted to produce a lithium ion secondary battery cell. An electrolytic solution was injected and sealed in the cell, and the internal resistance was evaluated by the following method.
Table 4 shows the coated positive electrode active material, the coated negative electrode active material, and the conductive additive (X) used.

<Production Example 41: Conductive auxiliary agent (carbon nanofiber) added>
Production Examples 1 to 39 except that 9.9 parts of (D-16), 0.1 part of carbon nanofiber [manufactured by Showa Denko KK] and 5 parts of diethyl carbonate are used in preparing the positive electrode slurry. A positive electrode for a lithium ion secondary battery was produced in the same manner.
Further, in preparing the negative electrode slurry, 9.9 parts of (E-16), 0.1 part of carbon nanofiber [manufactured by Showa Denko KK], and 5 parts of diethyl carbonate are used, except for Production Examples 1 to 1. A positive electrode for a lithium ion secondary battery was produced in the same manner as in Example 39.
A positive electrode for a lithium ion secondary battery and a negative electrode for a lithium ion secondary battery are arranged at both ends in the 2032 type coin cell so that the coated surface of the negative electrode faces the coated surface of the positive electrode, and a separator (Cell Guard 2500: Three sheets of polypropylene) were inserted to produce a lithium ion secondary battery cell. An electrolytic solution was injected and sealed in the cell, and the internal resistance was evaluated by the following method.
Table 4 shows the coated positive electrode active material, the coated negative electrode active material, and the conductive additive (X) used.

<Production Example 42: Added binder (PVdF)>
(D-1) Using the positive electrode slurry obtained by charging 9.0 parts, acetylene black 0.5 parts, polyvinylidene fluoride 0.5 parts, and N-methylpyrrolidone 5 parts into a mortar and kneading the first time A positive electrode for a lithium ion secondary battery was produced in the same manner as in Production Examples 1 to 39 except that the drying temperature was changed from 50 ° C. to 80 ° C.
Moreover, using the negative electrode slurry obtained by putting and kneading 8.5 parts of (E-1), 1.0 part of acetylene black, 0.5 part of polyvinylidene fluoride, and 5 parts of N-methylpyrrolidone in a mortar, A negative electrode for a lithium ion secondary battery was produced in the same manner as in Production Examples 1 to 39 except that the first drying temperature was changed from 50 ° C to 80 ° C.
A positive electrode for a lithium ion secondary battery and a negative electrode for a lithium ion secondary battery are arranged at both ends in the 2032 type coin cell so that the coated surface of the negative electrode faces the coated surface of the positive electrode, and a separator (Cell Guard 2500: Three sheets of polypropylene) were inserted to produce a lithium ion secondary battery cell. An electrolytic solution was injected and sealed in the cell, and the internal resistance was evaluated by the following method.
Table 4 shows the coated positive electrode active material, the coated negative electrode active material, and the conductive additive (X) used.

<Comparative Production Example 1: What does not contain the coating active material of the present invention>
A positive electrode for a lithium ion secondary battery was produced in the same manner as in Production Examples 1 to 39 except that 10 parts of (D′-1) and 5 parts of diethyl carbonate were used when producing the positive electrode slurry.
Moreover, the negative electrode for lithium ion secondary batteries was produced by the method similar to manufacture examples 1-39 except using 10 parts of (E'-1) and 5 parts of diethyl carbonate when producing a negative electrode slurry.
A positive electrode for a lithium ion secondary battery and a negative electrode for a lithium ion secondary battery are arranged at both ends in the 2032 type coin cell so that the coated surface of the negative electrode faces the coated surface of the positive electrode, and a separator (Cell Guard 2500: Three sheets of polypropylene) were inserted to produce a lithium ion secondary battery cell. An electrolytic solution was injected and sealed in the cell, and the internal resistance was evaluated by the following method.
Table 4 shows the coated positive electrode active material, the coated negative electrode active material, and the conductive additive (X) used.

<Comparative Production Example 2: Using no coated active material>
Using positive electrode slurry obtained by charging and kneading 9.0 parts of lithium cobaltate, 0.5 part of acetylene black, 0.5 part of polyvinylidene fluoride and 5 parts of N-methylpyrrolidone in a mortar, the first drying A positive electrode for a lithium ion secondary battery was produced in the same manner as in Production Examples 1 to 39 except that the temperature was changed from 50 ° C to 80 ° C.
In addition, a negative electrode slurry obtained by adding and kneading 8.5 parts of graphite powder, 1.0 part of acetylene black, 0.5 part of polyvinylidene fluoride, and 5 parts of N-methylpyrrolidone into a mortar is used for the first time. A negative electrode for a lithium ion secondary battery was produced in the same manner as in Production Examples 1 to 39 except that the drying temperature was changed from 50 ° C to 80 ° C.
A positive electrode for a lithium ion secondary battery and a negative electrode for a lithium ion secondary battery are arranged at both ends in the 2032 type coin cell so that the coated surface of the negative electrode faces the coated surface of the positive electrode, and a separator (Cell Guard 2500: Three sheets of polypropylene) were inserted to produce a lithium ion secondary battery cell. An electrolytic solution was injected and sealed in the cell, and the internal resistance was evaluated by the following method. Table 4 shows the positive electrode active material, negative electrode active material, and conductive additive (X) used.

[Evaluation of internal resistance at the beginning and end of cycle]
Under room temperature (25 ° C.), constant current and constant voltage charging was performed up to 4.2 V using a charge / discharge measuring device “Battery Analyzer 1470 type” [manufactured by Toyo Technica Co., Ltd.]. After a 10-minute pause, discharging was performed to 2.5 V at a current value of 0.1 C. The second cycle was discharged with a current of 0.2 C, and the third cycle was discharged with a current of 0.5 C. After that, discharge at a current of 1 C is performed for 194 cycles up to the 197th cycle, the current at 198 is 0.5 C, the current at 199 is 0.2 C, the current at 200 is 0.1 C. Discharge was performed.
From the [difference (ΔV) between the “voltage at the start of discharge” and the “voltage after 10 seconds after discharge”] and the current value (I) of each cycle in the first to fourth cycles, [drop voltage (ΔV ) -Current (I)], a resistance value R satisfying ΔV = RI was calculated using the least square method, and used as the internal resistance at the beginning of the cycle.
In the same procedure, R calculated from ΔV and I in the 197th to 200th cycles was defined as the internal resistance at the end of the cycle. The results are shown in Table 4.

なお、製造例４２及び比較製造例２は電極スラリー作製時にバインダーとしてポリフッ化ビニリデン（ＰＶｄＦ）を用いている。

In Production Example 42 and Comparative Production Example 2, polyvinylidene fluoride (PVdF) is used as a binder when preparing the electrode slurry.

From the results shown in Table 4, the coating for the non-aqueous secondary battery of the present invention produced by coating the surface of the active material for the lithium ion secondary battery with the resin for coating the non-aqueous secondary battery of the present invention. Lithium ion secondary batteries using active materials (D-1) to (D-20) and (E-1) to (E-20) have a low internal resistance and further suppress an increase in internal resistance due to aging. You can see that you can.

The resin for coating a non-aqueous secondary battery active material of the present invention can suppress the internal resistance of the battery by covering the surface of the lithium ion secondary battery active material. In addition, the resin for coating a non-aqueous secondary battery active material of the present invention is excellent in adhesiveness with the active material, so that even when charging and discharging are repeated, the resin is difficult to peel off from the surface of the active material. An increase in internal resistance can be suppressed.
Further, the coated active material for non-aqueous secondary batteries obtained by the present invention is used for bipolar secondary batteries and lithium ion secondary batteries used for mobile phones, wearable devices, personal computers and hybrid vehicles, electric vehicles, etc. Useful as an active material.

Claims (13)

Polymerizing a monomer composition comprising an ester compound (a11) of a monovalent aliphatic alcohol having 4 to 12 carbon atoms and (meth) acrylic acid and (meth) acrylic acid (a12), Non-aqueous secondary in which the weight ratio of the ester compound (a11) to the (meth) acrylic acid (a12) [the ester compound (a11) / the (meth) acrylic acid (a12)] is 10/90 to 90/10 Battery active material coating resin. The non-aqueous secondary battery active material according to claim 1, wherein the monomer composition further contains an ester compound (a13) of a monovalent aliphatic alcohol having 1 to 3 carbon atoms and (meth) acrylic acid. Resin for coating. The resin for coating a non-aqueous secondary battery active material according to claim 2, wherein the content of the ester compound (a13) is 10 to 60% by weight based on the total weight of the monomer composition. The non-aqueous system according to claim 1, wherein the monomer composition further contains a salt (a14) of an anionic monomer having a polymerizable unsaturated double bond and an anionic group. Secondary battery active material coating resin. At least one anionic monomer selected from the group consisting of vinylsulfonic acid, allylsulfonic acid, styrenesulfonic acid and (meth) acrylic acid, and lithium, sodium, The resin for coating a non-aqueous secondary battery active material according to claim 4, which is a salt with at least one selected from potassium and ammonia. The non-aqueous secondary battery according to claim 4 or 5, wherein a content of the salt (a14) of the anionic monomer is 0.1 to 15% by weight based on a total weight of the monomer composition. Resin for active material coating. The content of the (meth) acrylic acid (a12) is 10 to 90% by weight based on the total weight of the monomer composition, and the non-aqueous secondary battery activity according to any one of claims 1 to 6. Material coating resin. The content of the ester compound (a11) is 10 to 90% by weight based on the total weight of the monomer composition, for coating a non-aqueous secondary battery active material according to any one of claims 1 to 7. resin. The resin for coating a non-aqueous secondary battery active material according to claim 1, having a weight average molecular weight of 20,000 to 500,000. A coated active material for a nonaqueous secondary battery, wherein the resin for coating a nonaqueous secondary battery active material according to any one of claims 1 to 9 is bound to the surface of the active material for a nonaqueous secondary battery (Y). A cross-linked resin obtained by cross-linking the non-aqueous secondary battery active material coating resin according to claim 1 with a cross-linking agent (b) having two or more functional groups capable of reacting with a carboxyl group is a non-aqueous secondary battery. A coated active material for a non-aqueous secondary battery bound to the surface of the battery active material (Y). The coated active material for a non-aqueous secondary battery according to claim 11, wherein the content of the crosslinking agent (b) is 1 to 5% by weight based on the weight of the resin for coating the non-aqueous secondary battery active material. A resin solution containing the resin for coating a non-aqueous secondary battery active material according to any one of claims 1 to 9, a crosslinking agent (b) having two or more functional groups capable of reacting with a carboxyl group, and a non-aqueous secondary A resin coating step of distilling off the organic solvent while mixing the battery active material (Y);
The manufacturing method of the coating active material for non-aqueous secondary batteries which has a bridge | crosslinking process with which the said resin for non-aqueous secondary battery coating | coated and the said crosslinking agent (b) are made to react.