KR102553615B1 - Polyolefin adhesive composition - Google Patents

Abstract

[PROBLEMS] To provide an adhesive composition containing an acid-modified polyolefin and a polyfunctional polyisocyanate curing agent, which has good pot life, good adhesion between a metal substrate and a polyolefin resin substrate, chemical resistance and moldability.
[Solution] An adhesive composition containing an acid-modified polyolefin (A), a polyfunctional polyisocyanate curing agent (B), and an organic solvent (C), wherein the acid-modified polyolefin (A) has an acid value of 2 to 50 mgKOH/g-resin , An adhesive composition having an acetone extract component ratio of 0.01 to 2% by mass.

Description

Polyolefin adhesive composition

The present invention relates to an adhesive composition exhibiting good adhesion between a polyolefin resin substrate and a metal substrate, chemical resistance, and moldability. More specifically, it relates to an adhesive composition containing an acid-modified polyolefin, a polyfunctional polyisocyanate curing agent, and an organic solvent. In particular, it relates to an adhesive composition for a lithium ion battery (hereinafter abbreviated as LiB) and a packaging material which is a laminate comprising the same.

In recent years, LiBs capable of being ultra-thin and miniaturized have been actively developed as batteries used in portable terminal devices such as personal computers and mobile phones, video cameras, satellites, and the like. Unlike metal tubes conventionally used, this LiB packaging material is lightweight and has the advantage that the shape of the battery can be freely selected, so that a laminate having a structure such as a substrate layer/barrier layer/sealant layer has been used.

LiB is an electrolyte prepared by dissolving a lithium salt in an aprotic solvent such as propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, or ethyl methyl carbonate, together with a positive electrode material and a negative electrode material as battery contents, or a polymer gel impregnated with the electrolyte. It includes an electrolyte layer made of. When such a strongly penetrating solvent passes through the sealant layer, the strength of the lamination between the barrier layer and the sealant layer is lowered, resulting in delamination, resulting in leakage of the electrolyte solution. In addition, materials such as LiPF6 and LiBF4 are used as lithium salts, which are battery electrolytes. However, these salts generate hydrofluoric acid by a hydrolysis reaction with moisture, and the hydrofluoric acid corrodes the barrier layer, thereby reducing the strength of the laminate. The battery packaging material is required to have resistance to the electrolyte in this way.

In addition, assuming that LiB is used under various environments, it is necessary to have more severe tolerance. For example, when used in mobile devices, liquid leakage resistance is required in a high-temperature environment of 60 to 70° C., such as inside a car. In addition, assuming that it is used in a mobile phone and accidentally dropped into water, water resistance is also required so that moisture does not enter.

Under these circumstances, various packaging materials for lithium batteries with improved electrolyte resistance have been proposed (eg, see Patent Literatures 1 to 3).

Further, in a battery packaging material, when sealing a battery element, it is molded with a mold to form a space for accommodating the battery element. During this molding, there is a problem that cracks and pinholes easily occur in the barrier layer in the flange portion of the mold due to sagging of the battery packaging material. In particular, in accordance with the recent demand for miniaturization and thinning of batteries, thinner battery packaging materials are required, and these problems are more likely to occur more remarkably.

Under these circumstances, battery packaging materials with improved formability have been proposed (eg, see Patent Literatures 4 to 5).

Patent Document 1: Japanese Unexamined Patent Publication No. 2001-243928 Patent Document 2: Japanese Unexamined Patent Publication No. 2004-42477 Patent Document 3: Japanese Unexamined Patent Publication No. 2009-238475 Patent Document 4: Japanese Unexamined Patent Publication No. 2002-216714 Patent Document 5: Japanese Unexamined Patent Publication No. 2003-31188

However, the packaging materials for lithium batteries proposed above are still unsatisfactory in terms of electrolyte resistance and formability. Moreover, even if the improvement of electrolyte solution resistance and moldability was large, a problem was seen.

Specifically, it is difficult to ensure both pot life and electrolyte resistance of the adhesive after blending the curing agent (Patent Document 1), and bonding by extrusion lamination restricts the lamination base, or bonding at high temperatures. As a result, the polyolefin base material is affected by heat shrinkage (Patent Document 2), and since the polyolefin base material is water-based, the drying time is long and production conditions are limited (Patent Document 3). In addition, a process of coating the surface of the outer layer film with an amide-based slip agent has to be provided, which lowers productivity, and the laminated strength between the outer layer film and aluminum foil is not sufficiently obtained by the coated amide-based slip agent (patented Document 4), since only the unstretched polypropylene resin film is disposed on the inner layer side of the aluminum foil, or only the blended resin film of polypropylene and polyethylene is disposed on the inner layer side of the aluminum foil, Problems such as occurrence of pinholes in the aluminum foil during molding or breakage (cracking) in the aluminum foil are likely to occur, and insufficient formability is obtained (Patent Document 5).

An object of the present invention is to provide an adhesive composition excellent in adhesiveness, chemical resistance (electrolytic solution resistance) and moldability, without problems such as pot life or restrictions in production conditions. It is also to provide a battery packaging material comprising an adhesive layer made of the adhesive composition and a battery using the packaging material.

In order to achieve the above object, the present inventors intensively studied and found that it is effective to dispose a layer capable of sufficiently following the elongation during molding not only on the outer layer side of the aluminum foil but also on the inner layer side, and propose the following invention. has reached

An adhesive composition containing an acid-modified polyolefin (A), a polyfunctional polyisocyanate curing agent (B), and an organic solvent (C), wherein the acid-modified polyolefin (A) has an acid value of 2 to 50 mgKOH/g-resin, an acetone extract component The adhesive composition whose ratio is 0.01-2 mass %.

It is preferable to contain 0.5 to 40 parts by mass of a polyfunctional polyisocyanate curing agent (B) and 80 to 2000 parts by mass of an organic solvent (C) with respect to 100 parts by mass of the acid-modified polyolefin (A). The organic solvent (C) is a mixture of solvent (C1) and solvent (C2), wherein the solvent (C1) is at least one solvent selected from the group consisting of aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons, and halogenated hydrocarbons; The solvent (C2) is one or more solvents selected from the group consisting of alcohol solvents, ketone solvents, ester solvents and glycol ether solvents, solvent (C1) / solvent (C2) = 50 to 97/50 to 3 ( mass ratio) is preferred.

The adhesive composition is preferably used for adhesion between a polyolefin resin substrate and a metal substrate.

A laminate of a polyolefin resin substrate and a metal substrate bonded by the adhesive composition, and a packaging material for a lithium ion battery comprising the laminate as a constituent member.

The adhesive composition according to the present invention contains an acid-modified polyolefin, a polyfunctional polyisocyanate curing agent and an organic solvent, and can maintain good pot life without causing thickening or gelation even when stored for a long period of time. In addition, even when bonding is performed at a low temperature such as 120 ° C. or less, where the effect of heat shrinkage of the polyolefin base material is small, and aging is performed at a low temperature such as 40 ° C. or lower, good adhesion between the polyolefin resin base material and the metal base material, chemical resistance, and moldability are compatible. it is possible

ADVANTAGE OF THE INVENTION According to this invention, it can fully harden by an aging process after bonding, and excellent adhesiveness and chemical resistance can be expressed, maintaining favorable pot life property. In addition, it is possible to obtain an adhesive layer satisfying the storage modulus and elongation at break required for expressing excellent formability.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail.

<Acid Modified Polyolefin (A)>

The acid-modified polyolefin (A) used in the present invention is an acid-modified polyolefin having an acid value of 2 to 50 mgKOH/g-resin and an acetone extract component ratio of 0.01 to 2% by mass.

Although the acid-modified polyolefin (A) used in the present invention is not limited, by grafting at least one of α,β-unsaturated carboxylic acids and acid anhydrides thereof to at least one of polyethylene, polypropylene, and propylene-α-olefin copolymers, It is desirable to obtain

The propylene-α-olefin copolymer is obtained by copolymerizing α-olefin with propylene as the main component. As the α-olefin, for example, one or several kinds of ethylene, 1-butene, 1-heptene, 1-octene, 4-methyl-1-pentene, and vinyl acetate can be used. Among these α-olefins, ethylene and 1-butene are preferred. Although the ratio of the propylene component and the α-olefin component of the propylene-α-olefin copolymer is not limited, the propylene component is preferably 50 mol% or more, more preferably 70 mol% or more.

Examples of at least one of α,β-unsaturated carboxylic acids and acid anhydrides thereof include maleic acid, itaconic acid, citraconic acid, and acid anhydrides thereof. Among these, an acid anhydride is preferable and maleic anhydride is more preferable. Specifically, maleic anhydride-modified polypropylene, maleic anhydride-modified propylene-ethylene copolymer, maleic anhydride-modified propylene-butene copolymer, maleic anhydride-modified propylene-ethylene-butene copolymer, etc. are exemplified. Modified polyolefins can be used singly or in combination of two or more.

The acid value of the acid-modified polyolefin (A) is required to be in the range of 2 to 50 mgKOH/g-resin from the viewpoints of adhesion between the polyolefin resin substrate and metal substrate and resistance to electrolyte solution. It is preferably in the range of 3 to 45 mgKOH/g-resin, more preferably in the range of 5 to 40 mgKOH/g-resin, and particularly preferably in the range of 7 to 35 mgKOH/g-resin. If it is less than the said value, compatibility with a hardening|curing agent may become insufficient. Therefore, the crosslinking density is low, and the adhesive strength and chemical resistance (electrolytic solution resistance) may decrease. When the above value is exceeded, the molecular weight is low and the cohesive force is weakened, so the adhesive strength and chemical resistance (electrolytic solution resistance) may decrease. Moreover, since manufacturing efficiency also falls, it is unpreferable.

The acid value of the acid-modified polyolefin (A) can be adjusted by the amount of the α,β-unsaturated carboxylic acid, the acid anhydride of the α,β-unsaturated carboxylic acid, and the radical generator.

The proportion of the acetone-extracting component in the acid-modified polyolefin (A) is required to be in the range of 0.01% by mass to 2% by mass from the viewpoint of adhesion between the polyolefin resin substrate and metal substrate and resistance to electrolyte solution. It is preferably 0.03% by mass to 1.7% by mass, more preferably 0.05% by mass to 1.4% by mass, still more preferably 0.07% by mass to 1.2% by mass, and particularly preferably 0.1% by mass to 1% by mass. is the range If it is less than the above value, the production efficiency is lowered, which is not preferable. When the above value is exceeded, the cohesive force may be weakened and the adhesiveness, chemical resistance, and moldability may be poor.

The storage modulus (E') of the acid-modified polyolefin (A) at 25°C is preferably in the range of 10 to 2000 MPa from the viewpoint of adhesion between the polyolefin resin substrate and metal substrate and chemical resistance (electrolytic solution resistance). do. It is more preferably 15 to 1700 MPa, still more preferably 20 to 1400 MPa, particularly preferably 25 to 1100 MPa, and most preferably 30 to 800 MPa. If the value is less than the above value, the cohesive force of the adhesive layer made of the adhesive composition may be insufficient, and the adhesiveness and chemical resistance (electrolytic solution resistance) may be inferior. When the above value is exceeded, the trackability of the adhesive layer made of the adhesive composition may decrease, resulting in poor adhesiveness. Further, within the above range, since adhesiveness and followability to substrates are improved, and moldability of the laminate is also improved, it is more preferable as a packaging material for lithium ion batteries.

The tensile elongation at break (Eb) at 25°C of the acid-modified polyolefin (A) is preferably in the range of 50% to 1000%. More preferably, it is 80% to 900%, still more preferably 120% to 800%, particularly preferably 160% to 700%, and most preferably 200% to 600%. When the value is less than the above value, the followability of the adhesive layer made of the adhesive composition is lowered, leading to pinholes during molding and poor moldability in some cases. In general, the tensile elongation at break (Eb) and the storage modulus (E') are opposite properties, and if the value is exceeded, the storage modulus (E') is lowered, and the adhesiveness and electrolyte resistance may be inferior. In addition, within the above range, since adhesiveness and followability to substrates are improved, and moldability of the laminate is also improved, it is more preferable as a packaging material for lithium ion batteries.

The weight average molecular weight (Mw) of the acid-modified polyolefin (A) is preferably in the range of 10,000 to 200,000. It is more preferably in the range of 20,000 to 180,000, still more preferably in the range of 30,000 to 160,000, particularly preferably in the range of 40,000 to 140,000, and most preferably in the range of 50,000 to 110,000. If it is less than the said value, cohesion force may become weak and adhesiveness may be inferior. On the other hand, when the above value is exceeded, the fluidity is low, and a problem may arise in the operability at the time of bonding. If it is within the said range, since a hardening reaction with a hardening|curing agent is exhibited, it is preferable.

Crystallinity in acid-modified polyolefin (A) refers to the fact that the temperature is raised from -100 ° C to 250 ° C at 20 ° C / min using a differential scanning calorimeter (DSC), and a clear melting peak is displayed during the heating process. .

By making the acid-modified polyolefin crystalline, it is advantageous because the cohesive force is stronger than that of the amorphous polyolefin, and the adhesiveness and chemical resistance are excellent.

The melting point (Tm) of the acid-modified polyolefin (A) is preferably in the range of 50°C to 120°C. It is more preferably in the range of 60°C to 100°C, and most preferably in the range of 70°C to 90°C. If the value is less than the above value, the cohesive force derived from the crystal may be weakened, and the adhesiveness or chemical resistance may be poor. On the other hand, when the above value is exceeded, the solution stability and fluidity are low, and a problem may arise in the operability at the time of bonding.

The heat of fusion (ΔH) of the acid-modified polyolefin (A) is preferably in the range of 1 J/g to 60 J/g. It is more preferably in the range of 3 J/g to 50 J/g, and most preferably in the range of 5 J/g to 40 J/g. If the value is less than the above value, the cohesive force derived from the crystal may be weakened, and the adhesiveness or chemical resistance may be poor. On the other hand, when the above value is exceeded, the solution stability and fluidity are low, and a problem may arise in the operability at the time of bonding.

The method for producing the acid-modified polyolefin (A) is not particularly limited. For example, a radical grafting reaction (i.e., a radical species is generated with respect to the main chain polymer, and an unsaturated carboxylic acid and an acid anhydride are grafted using the radical species as a polymerization starting point) polymerization reaction) and the like.

Although it does not specifically limit as a radical generating agent, It is preferable to use an organic peroxide. The organic peroxide is not particularly limited, but di-tert-butyl peroxyphthalate, tert-butyl hydroperoxide, dicumyl peroxide, benzoyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxy-2-ethyl peroxides such as hexanoate, tert-butyl peroxypivalate, methyl ethyl ketone peroxide, di-tert-butyl peroxide, and lauroyl peroxide; Azonitriles, such as azobisisobutyronitrile and azobisisopropionitrile, etc. are mentioned.

<Polyfunctional polyisocyanate curing agent (B)>

The polyfunctional polyisocyanate curing agent (B) used in the present invention is not particularly limited as long as it is a polyisocyanate having two or more isocyanate groups in one molecule, and well-known diisocyanates and compounds derived therefrom can be preferably used.

For example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, hexamethylene diisocyanate, bis(4- and diisocyanates such as isocyanate cyclohexyl)methane or hydrogenated diphenylmethane diisocyanate. In addition, a compound derived from the diisocyanate, that is, an isocyanurate form, an adduct form, a biuret form, a uretdione form, an allophanate form, and a prepolymer having an isocyanate residue of the diisocyanate (obtained from diisocyanate and polyol) oligomers), or composites thereof. These may be used independently or may be used in combination of two or more types arbitrarily.

Further, a compound obtained by reacting some isocyanate groups of the above isocyanate compound with a compound having reactivity with isocyanate groups may be used as the polyfunctional isocyanate curing agent. Examples of the compound having reactivity with an isocyanate group include compounds containing an amino group such as butylamine, hexylamine, octylamine, 2-ethylhexylamine, dibutylamine, ethylenediamine, benzylamine, and aniline; compounds containing a hydroxyl group such as methanol, ethanol, propanol, isopropanol, butanol, hexanol, octanol, 2-ethylhexyl alcohol, dodecyl alcohol, ethylene glycol, propylene glycol, benzyl alcohol, and phenol; Allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, cyclohexane dimethanol diglycidyl compounds having an epoxy group such as ether; and compounds containing carboxylic acids such as acetic acid, butanoic acid, hexanoic acid, octanoic acid, succinic acid, adipic acid, sebacic acid, and phthalic acid.

As the polyfunctional polyisocyanate curing agent (B) used in the present invention, it is preferable to have an isocyanurate form of the above diisocyanate because of its excellent electrolyte resistance.

The compounding amount of the polyfunctional polyisocyanate curing agent (B) used in the present invention is preferably in the range of 0.5 to 40 parts by mass, more preferably 1 to 35 parts by mass, based on 100 parts by mass of the acid-modified polyolefin (A), It is more preferably 2 to 30 parts by mass, and particularly preferably 3 to 25 parts by mass. If it is less than the above value, sufficient curing effect may not be obtained, and adhesiveness and chemical resistance may be low. When the above range is exceeded, pot life and adhesiveness may be reduced, and pinholes may be generated during molding due to a decrease in followability. Moreover, it is undesirable from a viewpoint of a cost aspect.

<Organic solvent (C)>

The organic solvent (C) used in the present invention is not particularly limited as long as it dissolves the acid-modified polyolefin (A) and the polyfunctional polyisocyanate curing agent (B). Specifically, for example, aromatic hydrocarbons such as benzene, toluene and xylene, aliphatic hydrocarbons such as hexane, heptane, octane and decane, alicyclic hydrocarbons such as cyclohexane, cyclohexene, methylcyclohexane and ethylcyclolexane, trichlorethylene , halogenated hydrocarbons such as dichloroethylene, chlorobenzene, and chloroform, alcohol solvents such as methanol, ethanol, isopropyl alcohol, butanol, pentanol, hexanol, propanediol, and phenol, acetone, methyl isobutyl ketone, methyl ethyl ketone, Ketone solvents such as pentanone, hexanone, cyclohexanone, isophorone, and acetophenone, cellosolves such as methyl cellosolve and ethyl cellosolve, methyl acetate, ethyl acetate, butyl acetate, methyl propionate, and butyl formate Ester solvents such as ethylene glycol mono-n-butyl ether, ethylene glycol mono-iso-butyl ether, ethylene glycol mono-tert-butyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol mono-iso- Glycol ether type solvents, such as butyl ether, triethylene glycol mono-n-butyl ether, and tetraethylene glycol mono-n-butyl ether, etc. can be used, These 1 type or 2 or more types can be used together.

The organic solvent (C) is preferably in the range of 80 to 2000 parts by mass based on 100 parts by mass of the acid-modified polyolefin (A). It is more preferably 90 to 1600 parts by mass, still more preferably 100 to 1200 parts by mass, and particularly preferably 110 to 800 parts by mass. If it is less than the above range, the solution state and pot life may decrease, and if it exceeds the above range, the laminate and the packaging material for LiB including the laminate may be disadvantageous in terms of productivity, manufacturing cost, and transportation cost. .

The organic solvent (C) is one or more solvents (C1) selected from the group consisting of aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons, and halogenated hydrocarbons, alcohol-based solvents, and ketone-based solvents, from the viewpoint of the solution state and pot life of the adhesive composition. A liquid mixture of one or more solvents (C2) selected from the group consisting of solvents, ester solvents and glycol ether solvents is preferred. The mixing ratio is preferably in the range of solvent (C1)/solvent (C2) = 50 to 97/50 to 3 (mass ratio), more preferably 55 to 95/45 to 5 (mass ratio), and 60 to 90/50 to 3 (mass ratio). It is more preferably 40 to 10 (mass ratio), and particularly preferably 70 to 80/30 to 20 (mass ratio). Outside the above range, the solution state and pot life of the adhesive composition may decrease. Further, it is particularly preferred that the solvent (C1) is an aromatic hydrocarbon or an alicyclic hydrocarbon, and the solvent (C2) is a ketone solvent.

<Adhesive composition>

The adhesive composition according to the present invention is a mixture of the acid-modified polyolefin (A), a polyfunctional polyisocyanate curing agent (B), and an organic solvent (C), and the acid-modified polyolefin (A) and the curing agent (B) are an organic solvent ( C) may be dissolved or dispersed. It is preferable to melt|dissolve from a viewpoint of pot life property.

The adhesive composition according to the present invention, in addition to the acid-modified polyolefin (A), the polyfunctional polyisocyanate curing agent (B) and the organic solvent (C), various tackifiers, thermoplastic elastomers, A plasticizer may be used in combination. Although it does not specifically limit as a tackifier, Polyterpene type resin, rosin type resin, aliphatic type petroleum resin, alicyclic type petroleum resin, copolymerization type petroleum resin, hydrogenated petroleum resin, etc. are mentioned. In addition, as a thermoplastic elastomer, styrene-ethylene-butylene-styrene copolymer resin, styrene-type elastomers, such as styrene-ethylene-propylene-styrene, ethylene-propylene copolymer resin, ethylene-butene copolymer resin, ethylene-vinyl acetate copolymer resin, ethylene - Olefin type elastomers, such as ethyl acrylate copolymer resin, etc. are mentioned. Moreover, as a plasticizer, Preferably, liquid rubber, such as polyisoprene and polybutene, process oil, etc. are mentioned. In addition, these tackifiers, thermoplastic elastomers, and plasticizers may be used alone or in combination of two or more.

The adhesive composition according to the present invention may be used in combination with various curing agents in addition to the acid-modified polyolefin (A), the polyfunctional polyisocyanate curing agent (B), and the organic solvent (C) within a range that does not impair the performance of the present invention. . Although it does not specifically limit as a hardening|curing agent, Epoxy resin, a carbodiimide compound, an oxazoline compound, coupling agents, etc. are mentioned. As the epoxy resin, glycidyl ester types such as hexahydrophthalic acid glycidyl ester and dimer acid glycidyl ester, triglycidyl isocyanurate, 3,4-epoxycyclohexylmethylcarboxylate, epoxidized polybutadiene , alicyclic or aliphatic epoxides such as epoxidized soybean oil, glycidyl ether type epoxy resins, or glycidyl amine type epoxy resins. Moreover, as a carbodiimide compound, dimethyl carbodiimide, diisopropyl carbodiimide, dicyclohexyl carbodiimide, t-butyl isopropyl carbodiimide, diphenyl carbodiimide, di-β-naphthylcarbodiimide Monocarbodiimide compounds such as mead, or organic diisocyanates such as aliphatic diisocyanates, aromatic diisocyanates, or alicyclic diisocyanates are produced by carrying out a decarboxylation condensation reaction in the absence of a solvent or in an inert solvent in the presence of a condensation catalyst. and polycarbodiimide compounds that can be used. In addition, as an oxazoline compound, 2-oxazoline, 2-methyl-2-oxazoline, 2-phenyl-2-oxazoline, 2,5-dimethyl-2-oxazoline or 2,4-diphenyl-2 -Monooxazoline compounds such as oxazoline, 2,2'-(1,3-phenylene)-bis(2-oxazoline), 2,2'-(1,2-ethylene)-bis(2-oxa) zoline), 2,2'-(1,4-butylene)-bis(2-oxazoline), or 2,2'-(1,4-phenylene)-bis(2-oxazoline). An oxazoline compound etc. are mentioned. Moreover, as a coupling agent, a silane coupling agent, a titanate coupling agent, etc. are mentioned.

The adhesive composition according to the present invention, in addition to the acid-modified polyolefin (A), the polyfunctional polyisocyanate curing agent (B) and the organic solvent (C), can be used in combination with a curing accelerator within a range that does not impair the performance of the present invention. there is. Examples of the curing accelerator include, but are not particularly limited to, metal carboxylate salts, tertiary amines, quaternary ammonium salts, organic peroxides, hydrazine compounds, metal chelate compounds, phosphorus-containing compounds, and basic vulcanizers. As said carboxylic acid metal salt, the metal salt of a C1-C30 carboxylic acid is mentioned. Examples of the carboxylic acid constituting the carboxylic acid metal salt include acetic acid, butyric acid, octanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, behenic acid, octenoic acid, erucic acid, and elide. aliphatic carboxylic acids such as acid, adipic acid, malonic acid, succinic acid, glutaric acid, citric acid, tartaric acid, malic acid, and diglycolic acid; aromatic carboxylic acids such as benzoic acid, chlorobenzoic acid, anisic acid, aminobenzoic acid, phthalic acid, terephthalic acid, naphthoic acid, naphthalene dicarboxylic acid, and benzene tricarboxylic acid; naphthenic acid; Acetic acid etc. are mentioned. Examples of the metal constituting the carboxylic acid metal salt include Li, Na, K, Mg, Ca, Zn, Al, Cu, Pb, Co, Fe, Mn, Sn, and Ti. As the metal carboxylic acid salt, specifically, lithium acetate, sodium acetate, magnesium acetate, aluminum acetate, potassium butyrate, calcium butyrate, zinc butyrate, sodium octanoate, calcium octanoate, potassium decanoate, magnesium decanoate, zinc decanoate, la Lithium urate, sodium laurate, calcium laurate, aluminum laurate, potassium myristate, sodium myristate, aluminum myristate, sodium palmitate, zinc palmitate, magnesium palmitate, stearate Sodium stearate, potassium stearate, calcium stearate, zinc stearate, sodium oleate, sodium behenate, sodium benzoate, zinc benzoate, sodium phthalate, aluminum phthalate, magnesium terephthalate, calcium naphthalene dicarboxylate, dibutyltin laurate, laur Tributyltin acid, dioctyltin laurate, tributyltin acetate, dibutyltin diacetate, dioctyltin diacetate, dibutyltin 2-ethylhexoate, tetrabutyl titanate, tetraisobutyl titanate, tetra 2 - Ethylhexyl titanate, cobalt naphthenate, copper naphthenate, magnesium naphthenate, cobalt acetoacetate, etc. are mentioned. Among these, lithium laurate, sodium laurate, calcium laurate, aluminum laurate, potassium myristate, sodium myristate, aluminum myristate, sodium palmitate, palmitic acid are preferred. and zinc, magnesium palmitate, sodium stearate, potassium stearate, calcium stearate, zinc stearate and sodium oleate. Moreover, as a metal salt of carboxylic acid, the polymer which has a metal salt structure of carboxylic acid can also be used. Examples of such a polymer include those having a structure obtained by copolymerizing ethylene with a salt of a metal (e.g., Li, Na, K, Mg, Ca, Zn, Al, etc.) of group IA, IIA, IIB, or IIIB of a radical polymerizable carboxylic acid; and those having a structure in which ethylene and a metal salt of a radically polymerizable carboxylic acid and other radically polymerizable carboxylic acids and/or derivatives thereof are multi-copolymerized. Examples of the tertiary amines include dimethylaniline, triethanolamine, and dimethyl-p-toluidine. Moreover, as said hydrazine compound, 1-acetyl-2-phenylhydrazine etc. are mentioned, for example. Moreover, as said metal chelate compound, vanadium acetylacetonate etc. are mentioned, for example. Moreover, as said phosphorus containing compound, dimethylphosphine, triphenylphosphine, etc. are mentioned, for example. Moreover, examples of the basic vulcanizers include hexamethylenetetramine, n-butylaldehyde-aniline condensates, and the like.

In the present invention, such an adhesive composition may be used by mixing various additives in addition to the acid-modified polyolefin (A), the polyfunctional polyisocyanate curing agent (B), and the organic solvent (C) within the range of not impairing the performance of the present invention. Although it does not specifically limit as an additive, It is preferable to use a flame retardant, a pigment, an antiblocking agent, etc.

<Laminate>

The laminate of the present invention is obtained by laminating a polyolefin resin substrate and a metal substrate with the adhesive composition according to the present invention.

As a method of laminating, a conventionally known laminate manufacturing technique can be used. For example, although not particularly limited, an adhesive composition is applied to the surface of a metal substrate using an appropriate coating means such as a roll coater or a bar coater, and then dried. After drying, while the adhesive composition layer (adhesive layer) formed on the surface of the metal substrate is in a molten state, the polyolefin resin substrate is laminated and adhered to the coated surface (laminate bond) to obtain a laminate.

The thickness of the adhesive layer formed of the adhesive composition is not particularly limited, but is preferably 0.5 to 10 μm, more preferably 0.8 to 9.5 μm, and still more preferably 1 to 9 μm.

<Polyolefin resin substrate>

What is necessary is just to select suitably from conventionally well-known polyolefin resin as a polyolefin resin base material. For example, although not particularly limited, polyethylene, polypropylene, ethylene-propylene copolymer and the like can be used. Among them, use of a polypropylene unstretched film (hereinafter also referred to as CPP) is preferable. The thickness is not particularly limited, but is preferably 20 to 100 μm, more preferably 25 to 95 μm, and even more preferably 30 to 90 μm. In addition, a pigment or various additives may be blended with the polyolefin resin substrate as necessary, or a surface treatment may be performed.

<Metal Substrate>

The metal substrate is not particularly limited, but various metals and alloys thereof such as aluminum, copper, steel, chromium, zinc, duralumin, and die-cast can be used. In addition, as its shape, it can take arbitrary shapes, such as a metal foil, a rolled steel plate, a panel, a pipe, a can, and a cap. In general, aluminum foil is preferable from the viewpoints of workability and the like. In addition, although it differs depending on the purpose of use, it is generally used in the form of a sheet having a thickness of 0.01 to 10 mm, preferably 0.02 to 5 mm.

In addition, the surface of these metal substrates may be subjected to surface treatment in advance, or may remain untreated. In either case, an equivalent effect can be exhibited.

Hereinafter, the present invention will be described in more detail by way of examples. However, the present invention is not limited to the examples. In Examples and Comparative Examples, simply describing parts as parts indicates parts by mass.

<Manufacture example of acid-modified polyolefin (A)>

manufacturing example One

In a 1 L autoclave, 100 parts by mass of a propylene-ethylene copolymer (320 MPa of storage modulus at 25 ° C., 760% of tensile elongation at break at 25 ° C.), 233 parts by mass of toluene and 1 part by mass of maleic anhydride, di After adding 0.5 part by mass of -tert-butyl peroxide and raising the temperature to 140°C, the mixture was further stirred for 1 hour (herein referred to as "reaction" for 1 hour). Then, after cooling the obtained reaction solution to 100 ° C., poured into a container containing 717 parts by mass of toluene and 950 parts by mass of methyl ethyl ketone previously heated to 40 ° C. while stirring, cooled to 40 ° C., further stirred for 30 minutes, and added The resin was precipitated by cooling to 25° C. (here, an operation in which the reaction solution is poured into a solvent such as methyl ethyl ketone while stirring and cooled to precipitate the resin is referred to as “re-precipitation”). Thereafter, by centrifuging the slurry containing the resin, an acid-modified propylene-ethylene copolymer graft-polymerized with maleic anhydride, maleic anhydride (poly), and a low molecular weight product were separated.

Further, the acid-modified propylene-ethylene copolymer taken out by centrifugation was added while stirring to a new container containing 2000 parts by mass of methyl ethyl ketone previously kept at 25°C, and stirring was continued for 1 hour. Thereafter, by centrifuging the slurry liquid, acid-modified propylene/ethylene copolymer, (poly)maleic anhydride and low molecular weight material were further separated. Purification was performed by repeating the above operation twice (here, the acid-modified propylene-ethylene copolymer taken out by centrifugation was added to methyl ethyl ketone with stirring, and centrifugation was performed again to enhance purification. called).

After purification, by drying at 70 ° C. for 5 hours under reduced pressure, an acid-modified polyolefin, maleic anhydride-modified propylene-ethylene copolymer (PO-1, acid value 2 mgKOH / g-resin, acetone extract component ratio 0.1% by mass, 25 ° C. 300 MPa of storage modulus, 600% of tensile elongation at break at 25°C, weight average molecular weight of 190,000, Tm of 88°C, and ΔH of 37 J/g) were obtained.

manufacturing example 2

By changing the injection amount of maleic anhydride to 3 parts by mass, changing the number of times of reslurry once, and changing the amount of methyl ethyl ketone introduced during reslurry to 1000 parts by mass, in the same manner as in Production Example 1, an acid-modified polyolefin Maleic anhydride-modified propylene-ethylene copolymer (PO-2, acid value 5 mgKOH / g-resin, acetone extract component ratio 1.8% by mass, storage modulus at 280 MPa at 25 ° C., tensile elongation at break at 25 ° C. 650 %, weight average molecular weight 180,000, Tm 88°C, ΔH 36 J/g).

manufacturing example 3

The injected amount of toluene is 150 parts by mass, the injected amount of maleic anhydride is 40 parts by mass, the injected amount of di-tert-butyl peroxide is 8 parts by mass, the reaction time is 3 hours, the solvent used for reprecipitation is 700 parts by mass of methyl ethyl ketone, Maleic anhydride-modified propylene-ethylene copolymer (PO-3, acid value 48 mgKOH/g-resin, acetone extract component ratio 0.1 Mass %, storage modulus at 25°C of 180 MPa, tensile elongation at break at 25°C of 350%, weight average molecular weight of 31,000, Tm of 85°C, and ΔH of 31 J/g) were obtained.

manufacturing example 4

The injected amount of toluene is 150 parts by mass, the injected amount of maleic anhydride is 40 parts by mass, the injected amount of di-tert-butyl peroxide is 8 parts by mass, the reaction time is 3 hours, the solvent used for reprecipitation is 700 parts by mass of methyl ethyl ketone, Maleic anhydride-modified propylene-ethylene copolymer (PO-4, acid value 48 mgKOH / g-resin, acetone extract component ratio 1.8% by mass, storage modulus at 25 ° C. 150 MPa, tensile elongation at break 300% at 25 ° C., weight average molecular weight 27,000, Tm 85 ° C., △H 30 J /g) was obtained.

manufacturing example 5

The injected amount of toluene is 150 parts by mass, the injected amount of maleic anhydride is 20 parts by mass, the injected amount of di-tert-butyl peroxide is 6 parts by mass, the reaction time is 3 hours, the solvent used for reprecipitation is 700 parts by mass of methyl ethyl ketone, Maleic anhydride-modified propylene-ethylene copolymer (PO-5, acid value 25 mgKOH / g-resin, acetone extract component ratio 0.9% by mass, storage modulus at 25 ° C. 400 MPa, tensile elongation at break 500% at 25 ° C., weight average molecular weight 60,000, Tm 87 ° C., △H 35 J /g) was obtained.

manufacturing example 6

100 parts by mass of propylene-ethylene copolymer (52 MPa of storage modulus at 25°C, 1050% elongation at break at 25°C), 150 parts by mass of toluene, 30 parts by mass of maleic anhydride, The injection amount of di-tert-butyl peroxide was 6 parts by mass, the reaction time was 3 hours, the solvent used for reprecipitation was 700 parts by mass of methyl ethyl ketone, the solvent used for reslurry was 1000 parts by mass of methyl ethyl ketone, and the number of reslurry was 2 By doing the same as in Production Example 1 except for changing the circuit, an acid-modified polyolefin maleic anhydride-modified propylene-ethylene copolymer (PO-6, acid value 25 mgKOH / g-resin, acetone extract component ratio 1.0% by mass, 25 ° C. A storage modulus of 12 MPa, tensile elongation at break at 25°C of 900%, weight average molecular weight of 60,000, Tm of 58°C, and ΔH of 7 J/g) were obtained.

manufacturing example 7

100 parts by mass of propylene homopolymer (2100 MPa of storage modulus at 25°C, 900% elongation at break at 25°C), 150 parts by mass of toluene, 30 parts by mass of maleic anhydride, di- The injection amount of tert-butyl peroxide was 6 parts by mass, the reaction time was 3 hours, the solvent used for reprecipitation was 700 parts by mass of methyl ethyl ketone, the solvent used for reslurry was 1000 parts by mass of methyl ethyl ketone, and the number of reslurry was changed to 2 times In the same manner as in Production Example 1 except that, an acid-modified polyolefin, maleic anhydride-modified propylene homopolymer (PO-7, acid value 25 mgKOH / g-resin, acetone extract component ratio 0.9% by mass, storage at 25 ° C. Elastic modulus of 1800 MPa, tensile elongation at break at 25°C of 60%, weight average molecular weight of 60,000, Tm of 85°C, and ΔH of 5 J/g) were obtained.

manufacturing example 8

Propylene-ethylene copolymer (2720 MPa storage modulus at 25 ° C., 400% tensile elongation at break at 25 ° C.) 100 parts by mass, 186 parts by mass of toluene, 20 parts by mass of maleic anhydride, The injection amount of di-tert-butyl peroxide was 6 parts by mass, the reaction time was 3 hours, the solvent used for reprecipitation was 700 parts by mass of methyl ethyl ketone, the solvent used for reslurry was 1000 parts by mass of methyl ethyl ketone, and the number of reslurry was 2 By doing the same as in Production Example 1 except for changing the circuit, an acid-modified polyolefin maleic anhydride-modified propylene-ethylene copolymer (PO-8, acid value 25 mgKOH / g-resin, acetone extract component ratio 1.0% by mass, 25 ° C. A storage modulus of 2350 MPa, tensile elongation at break at 25°C of 38%, weight average molecular weight of 60,000, Tm of 125°C, and ΔH of 63 J/g) were obtained.

manufacturing example 9

The injected amount of toluene is 186 parts by mass, the injected amount of maleic anhydride is 20 parts by mass, the injected amount of di-tert-butyl peroxide is 6 parts by mass, the reaction time is 3 hours, the solvent used for reprecipitation is 1200 parts by mass of methyl ethyl ketone, Maleic anhydride-modified propylene-ethylene copolymer (PO-9, acid value 25 mgKOH / g-resin, acetone extract component ratio 1.2% by mass, storage modulus at 25 ° C. 7 MPa, tensile elongation at break at 25 ° C. 1200%, weight average molecular weight 60,000, no Tm peak, △H 0 J /g) was obtained.

manufacturing example 10

100 parts by mass of propylene-ethylene copolymer (500 MPa of storage modulus at 25°C, 680% elongation at break at 25°C), 150 parts by mass of toluene, 0.5 part by mass of maleic anhydride, The injection amount of di-tert-butyl peroxide was 0.2 parts by mass, the reaction time was 1 hour, the solvent used for reprecipitation was 1000 parts by mass of methyl ethyl ketone, the solvent used for reslurry was 1000 parts by mass of methyl ethyl ketone, and the number of reslurry was 2 By doing the same as in Production Example 1 except for changing the circuit, an acid-modified polyolefin, maleic anhydride-modified propylene-ethylene copolymer (PO-10, acid value 1 mgKOH/g-resin, acetone extract component ratio 0.1% by mass, 25 ° C. 400 MPa of storage modulus, 600% of tensile elongation at break at 25°C, weight average molecular weight of 65,000, Tm of 71°C, and ΔH of 35 J/g) were obtained.

manufacturing example 11

The injected amount of toluene is 150 parts by mass, the injected amount of maleic anhydride is 50 parts by mass, the injected amount of di-tert-butyl peroxide is 10 parts by mass, the reaction time is 3 hours, the solvent used for reprecipitation is 700 parts by mass of methyl ethyl ketone, Maleic anhydride-modified propylene-ethylene copolymer (PO-11, acid value 55 mgKOH / g-resin, acetone extract component ratio 1.0% by mass, storage modulus at 25 ° C. 150 MPa, tensile elongation at break 320% at 25 ° C., weight average molecular weight 30,000, Tm 83 ° C., △H 25 J /g) was obtained.

manufacturing example 12

Manufacturing example except that the injection amount of toluene was 150 parts by mass, the injection amount of maleic anhydride was 40 parts by mass, the injection amount of di-tert-butyl peroxide was 8 parts by mass, the reaction time was 3 hours, and the number of reslurries was changed to 3 times. By the same as 1, maleic anhydride-modified propylene-ethylene copolymer (PO-12, acid value 46 mgKOH / g-resin, acetone extract component ratio 4.5% by mass, storage modulus at 25 ° C. 110 MPa, which is an acid-modified polyolefin) , tensile elongation at break at 25°C of 90%, weight average molecular weight of 35,000, Tm of 86°C, and ΔH of 30 J/g).

(Production of Topic 1)

In a 500 ml four-necked flask equipped with a water-cooled reflux condenser and a stirrer, 100 parts by mass of maleic anhydride-modified propylene-ethylene copolymer (PO-1) obtained in Production Example 1, 280 parts by mass of methylcyclohexane and methyl ethyl ketone 120 parts by mass of was added, the temperature was raised to 80° C. while stirring, and stirring was continued for 1 hour, followed by cooling to obtain the subject matter 1. The solution state is shown in Table 1.

(Production of topics 2 to 19)

Subject matter 2 to 19 were produced in the same manner as subject matter 1, by changing the acid-modified polyolefin and organic solvent as shown in Table 1. Table 1 shows the blending amount and solution state.

Example One

500 parts by mass of subject matter 1 and 1 part by mass of Smidul (registered trademark) N-3300 as a polyfunctional polyisocyanate curing agent (B) were blended to obtain an adhesive composition. Table 2 shows the evaluation results of pot life, adhesiveness, chemical resistance and moldability.

Example 2~21, comparative example 1 to 3

Examples 2 to 21 and Comparative Examples 1 to 3 were carried out in the same manner as in Example 1, changing the main agents 1 to 19 and each curing agent as shown in Tables 2 and 3. The results of the compounding amount, pot life, adhesiveness, chemical resistance and moldability are shown in Tables 2 and 3.

The curing agents used in Tables 2 and 3 are as follows.

<Polyfunctional polyisocyanate curing agent (B)>

Isocyanurate form of hexamethylene diisocyanate: Smidul (registered trademark) N-3300 (manufactured by Bayer)

Biret form of hexamethylene diisocyanate: Duranate (registered trademark) 24A-100 (manufactured by Asahi Kasei Chemical Co., Ltd.)

Each of the acid-modified polyolefins, main agents, and adhesive compositions obtained as described above were analyzed, measured, and evaluated based on the following methods.

of the acid value measurement

The acid value (mgKOH/g-resin) in the present invention refers to the amount of KOH required to neutralize 1 g of acid-modified polyolefin (A), and was measured according to the test method of JIS K0070 (1992). . Specifically, after dissolving 1 g of acid-modified polyolefin in 100 g of xylene temperature-adjusted to 100 ° C., using phenolphthalein as an indicator at the same temperature, a 0.1 mol/L potassium hydroxide ethanol solution [trade name “0.1 mol/L ethanol] Potassium hydroxide solution", manufactured by Wako Pure Chemical Industries, Ltd.] was titrated. At this time, the acid value (mgKOH/g) was calculated by converting the amount of potassium hydroxide required for titration into mg.

Measurement of Acetone Extraction Component Ratio

The acetone extraction component ratio in the present invention was measured by refluxing with acetone for 2 hours using a Soxhlet extractor. Specifically, after weighing 50 g of acid-modified polyolefin (A) on a cylindrical filter paper, putting it in a Soxhlet extraction tube, attaching a flat bottom flask containing 1100 mL of acetone and a cooling tube, and refluxing in a water bath for 2 hours, Acetone extraction was performed. After that, the cylindrical filter paper was taken out, the acetone extract in the flat bottom flask was filtered off, and the weight of the residue after further drying under reduced pressure at 100°C for 1 hour was measured, and the value was calculated according to the following formula.

Acetone extraction component ratio (mass %) = (extraction residue weight / sampling amount) × 100

at 25°C Measurement of storage modulus (E')

The storage elastic modulus (E') in the present invention was measured based on the test method of JIS K7244-4 (1999). Specifically, it is a value measured using a dynamic viscoelasticity measuring device DVA-200 manufactured by ITGEI Corporation, at a frequency of 10 Hz, while raising the temperature from -50°C at a rate of 5°C/min.

at 25°C Tensile elongation at break ( Eb ) of the measurement

The tensile elongation at break (Eb) in the present invention was measured based on the test method of JIS K7161 (2014). Specifically, it is a value obtained by measuring the elongation (%) at break in tension at a speed of 50 mm/min in a 25°C environment using Tensilon RTM-100 manufactured by Orient Tech Corporation.

Measurement of weight average molecular weight (Mw)

The weight average molecular weight in the present invention is Nippon Waters Co., Ltd. gel permeation chromatograph Alliance e2695 [hereinafter referred to as GPC, standard substance: polystyrene resin, mobile phase: tetrahydrofuran, column: Shodex KF-806 + KF-803, column temperature : 40°C, flow rate: 1.0 ml/min, detector: photodiode array detector (wavelength: 254 nm = ultraviolet ray)].

Measurement of melting point and heat of fusion

Melting point and heat of fusion in the present invention are measured using a differential scanning calorimeter (hereinafter referred to as DSC, TA Instruments Japan, Q-2000) at a rate of 20 ° C / min. It is a value measured from the top temperature and area of the melting peak when the temperature is raised and melted again.

Assessment of subject solution condition

The solution state of main subjects 1 to 19 was evaluated by measuring the solution viscosity at 25°C using a Brookfield viscometer TVB-10M (hereinafter also referred to as a B-type viscometer) manufactured by Toki Sangyo Co., Ltd.

<Evaluation Criteria>

◎ (excellent for practical use): less than 500 mPa s

○ (practical use): 500 mPa s or more and less than 1000 mPa s

× (impracticable): 1000 mPa s or more or viscosity cannot be measured due to gelation

Fort Life Castle evaluation

The pot life property refers to the stability of a solution immediately after blending a crosslinking agent or curing agent with an acid-modified polyolefin or after a certain period of time has elapsed after blending. When the pot life property is good, it indicates that the solution has little increase in viscosity and can be stored for a long period of time. is difficult to apply and long-term storage is impossible.

The pot life of the adhesive composition obtained in Examples 1 to 21 and Comparative Examples 1 to 3 was evaluated by measuring the solution viscosity at 25 ° C. using a B-type viscometer after storing for 24 hours in an atmosphere of 25 ° C. and 40 ° C. did The evaluation results are shown in Tables 2 and 3.

<Evaluation Criteria>

◎ (excellent for practical use): less than 500 mPa s

○ (practical use): 500 mPa s or more and less than 1000 mPa s

× (impracticable): 1000 mPa s or more or viscosity cannot be measured due to gelation

metal substrate and polyolefin resin substrate laminated produce

An aluminum foil (8079-0, manufactured by Sumika Aluminum Haku Co., Ltd., thickness 40 μm) was used for the metal substrate, and an unstretched polypropylene film [Pyrene (registered trademark) film CT manufactured by Toyobo Co., Ltd., thickness 40 μm) was used for the polyolefin resin substrate. ] (hereinafter also referred to as CPP) was used.

The adhesive compositions obtained in Examples 1 to 19 and Comparative Examples 1 to 15 were applied to a metal substrate using a bar coater to adjust the film thickness of the adhesive layer after drying to be 3 μm. The coated surface was dried for 1 minute in an atmosphere of 100° C. using a warm air dryer to obtain a metal substrate on which an adhesive layer having a film thickness of 3 μm was laminated. A polyolefin resin base material is polymerized on the surface of the adhesive layer, and bonded at 0.3 MPa and 1 m/min at a lamination temperature of 80° C. or 120° C. using a small tabletop test laminator (SA-1010-S) manufactured by Tester Sangyo. Then, a laminate was obtained by curing at 25°C and 50% RH for 36 hours.

About the laminated body obtained by doing it above, it evaluated by the following method.

Evaluation of adhesion

The laminate was cut to a size of 100 mm x 15 mm, and adhesion was evaluated by a T-shaped peel test according to the following criteria. An evaluation result is shown to Tables 2-3.

<T-type peeling test>

In accordance with the test method of ASTM-D1876-61, the peel strength was measured at a tensile speed of 50 mm/min in a 25°C environment using Tensil RTM-100 manufactured by Orient Tech Corporation. The peel strength (N/cm) between the metal substrate/polyolefin resin substrate was taken as the average value of 5 test values.

<Evaluation Criteria>

☆ (Excellent in practical use): 8.0 N/cm or more or CPP breaks again (hereinafter, simply referred to as "rebreaking"). Re-blue means that peeling does not occur at the interface between the metal substrate/CPP and the metal substrate or CPP is destroyed.

◎ (excellent in practical use): 7.5 N/cm or more and less than 8.0 N/cm

○ (practical): 7.0 N / cm or more and less than 7.5 N / cm

× (impracticable): less than 7.0 N/cm

Evaluation of chemical resistance

In order to examine the usability of LiB as a packaging material, evaluation of chemical resistance (hereinafter also referred to as electrolyte resistance) by an electrolyte solution test was performed. The laminate was cut to a size of 100 mm × 15 mm, and an electrolyte [lithium hexafluorophosphate was added in an ethylene carbonate / diethyl carbonate / dimethyl carbonate = 1/1/1 (volume ratio)] at 85 ° C. Soaked for days. Thereafter, the laminate was taken out, washed with ion-exchanged water, wiped off with a paper wiper, sufficiently dried to remove moisture, and chemical resistance was evaluated according to the following criteria by a T-shaped peel test. An evaluation result is shown to Tables 2-3.

<Evaluation Criteria>

☆ (especially excellent in practical use): 8.0 N / cm or more or break

◎ (excellent in practical use): 7.5 N/cm or more and less than 8.0 N/cm

○ (practical): 7.0 N / cm or more and less than 7.5 N / cm

× (impracticable): less than 7.0 N/cm

Formability evaluation

Similarly, in order to examine the usability of LiB as a packaging material, moldability was evaluated by a deep bridge tester.

The laminate was cut into a size of 80×120 mm and cold-formed. Specifically, using an injection molding machine manufactured by Amada Co., Ltd. (part number: TP-25C-X2), a forming mold (female mold) having a diameter of 55 mm × 35 mm, and a forming mold (male mold) corresponding to this Then, cold forming was performed on each of 10 samples (laminated body) by changing the molding depth in increments of 0.5 mm from the molding depth of 0.5 mm at a pressing pressure of 0.4 MPa in a 25°C atmosphere. For the sample after cold forming, the deepest forming depth at which wrinkles, pinholes and cracks did not occur in all 10 samples was set as the limit forming depth of the sample. From this critical molding depth, the moldability of the battery packaging material was evaluated according to the following criteria. An evaluation result is shown to Tables 3-4.

<Judgment Criteria>

☆ (especially excellent in practical use): limit molding depth of 6.0 mm or more

◎ (excellent in practical use): limit molding depth of 4.0 mm or more and less than 6.0 mm

○ (practical): limit molding depth of 2.0 mm or more and less than 4.0 mm

×: less than 2.0 mm limit molding depth

The adhesive composition according to the present invention contains an acid-modified polyolefin, a polyfunctional polyisocyanate curing agent, and an organic solvent, maintains good pot life without causing thickening or gelation even when stored for a long period of time, and also maintains a metal substrate and a polyolefin resin. It is possible to achieve both good adhesiveness of the base material, resistance to electrolyte solution, and moldability. Therefore, the laminate of the polyolefin resin base material and the metal base material formed from the adhesive composition of the present invention is used not only in fields such as home appliance outer panels, furniture materials, and building interior members, but also lithium used in personal computers, mobile phones, video cameras, etc. It can also be used widely as a packaging material (pouch form) for batteries.

Claims (6)

An adhesive composition containing an acid-modified polyolefin (A), a polyfunctional polyisocyanate curing agent (B), and an organic solvent (C), wherein the acid-modified polyolefin (A) has an acid value of 2 to 50 mgKOH/g-resin, an acetone extract component The adhesive composition in which the ratio is 0.01 to 2% by mass, and the acid-modified polyolefin (A) is crystalline. The adhesive composition according to claim 1, which contains 0.5 to 40 parts by mass of a polyfunctional polyisocyanate curing agent (B) and 80 to 2000 parts by mass of an organic solvent (C) based on 100 parts by mass of the acid-modified polyolefin (A). The organic solvent (C) according to claim 1 or 2, wherein the solvent (C1) is a mixed liquid of solvent (C1) and solvent (C2), and the solvent (C1) is a group consisting of aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons and halogenated hydrocarbons. , and the solvent (C2) is at least one solvent selected from the group consisting of alcohol-based solvents, ketone-based solvents, ester-based solvents, and glycol ether-based solvents, and solvent (C1) / solvent (C2) = The adhesive composition which is 50-97/50-3 (mass ratio). The adhesive composition according to claim 1 or 2, which is used for bonding between a polyolefin resin substrate and a metal substrate. A laminate of a polyolefin resin substrate and a metal substrate bonded by the adhesive composition according to claim 1 or 2. A packaging material for a lithium ion battery comprising the laminate according to claim 5 as a constituent member.