JP6830238B2 - Adhesive and laminate made from it - Google Patents

Description

The present invention relates to an adhesive for a polypropylene resin member, a polypropylene resin member or a metal member having an adhesive layer formed from the adhesive, and a laminate bonded via the adhesive layer.

Many metal members such as steel plates are used in automobiles, home appliances, OA equipment, and the like. A metal member to which a predetermined shape is given by press working of a metal plate is often used as a composite molded body bonded to another metal member or a resin member, and the resin member has particularly mechanical properties. Polypropylene resin, which has excellent moldability, is lightweight, and is low in cost, is widely used.

Polypropylene resin is a resin that does not have a polar group in the molecule and is chemically stable, so that it is difficult to bond with an adhesive. In particular, a polypropylene resin member molded by injection molding or the like is injection-molded. It is known that due to the injection stress at that time, the polymer chains on the surface layer are highly oriented and crystallized, which makes adhesion even more difficult.

Patent Documents 1 and 2 disclose a technique for joining a polypropylene resin in which the polymer chains of the surface layer portion are highly oriented and crystallized and a metal member by thermocompression bonding or insert molding.
That is, Patent Document 1 discloses a laminate in which a metal member and a polypropylene resin member are bonded to each other via a chlorinated acid-modified polypropylene resin. Further, a paint containing a chlorinated acid-modified polypropylene resin is applied to the metal member to form an adhesive layer, and the polypropylene resin is insert-molded or thermocompression bonded to join the metal member.
Further, in Patent Document 2, a modified polypropylene adhesive is applied on an aluminum alloy member having a base treatment film to form an adhesive layer, and then a polypropylene film having specific physical properties is laminated by thermal lamination, and the laminate is subjected to heat lamination. By insert-molding polypropylene resin, the resin member and the metal member are joined.

On the other hand, since a composite molded body of a polypropylene resin member and a metal member is used in various environments, for example, in addition to the joint strength, heat resistance, water resistance, weather resistance, moisture heat resistance, and heat resistance are applied to the joint portion. Many performances such as chemical resistance (for example, ink resistance, alcohol resistance, gasoline resistance, etc.) are required.

Japanese Unexamined Patent Publication No. 2014-159125 JP-A-2016-016584

However, in Patent Document 1, the bonding strength between the acid-modified polypropylene layer formed by using the aqueous dispersion of chlorinated polypropylene and the polypropylene resin member whose surface layer portion is highly oriented and crystallized by injection molding is not sufficient. The resulting composite molded product had limited usable applications. In addition, since relatively high temperature heat is required during crimping, the polypropylene resin member may be deformed or deteriorated. Further, since the layer formed from the chlorinated polypropylene aqueous dispersion is inferior in water resistance and chemical resistance, the joint portion tends to be inferior in water resistance and chemical resistance. In addition, chlorinated polypropylene containing chlorine in its structure generates harmful substances such as acid gas and dioxins when it is disposed of by incineration, and therefore, in recent years, its use has tended to be withheld from the viewpoint of environmental consideration.

In Patent Document 2, a toluene dispersion of modified polypropylene is used as the modified polypropylene adhesive. In recent years, the use of organic solvents such as toluene has tended to be restricted from the viewpoints of environmental protection, resource saving, regulation of dangerous substances by the Fire Service Act, and improvement of the working environment. Further, in Patent Document 2, there are many pretreatment steps such that it is necessary to further provide a polypropylene resin layer having specific physical properties by thermal lamination on the outside of a layer formed by applying a modified polypropylene adhesive on an aluminum member. There is a problem that the manufacturing process becomes complicated and the productivity decreases, and the cost increases accordingly.

The subject of the present invention is to solve the above-mentioned problems, and in the bonding of polypropylene resin members, particularly polypropylene resin members whose surface layer portion is highly oriented and crystallized (surface melting heat amount is 80 J / g or more), the bonding property is excellent, and the process Is simple and versatile, has excellent water resistance and chemical resistance, can be thermocompression bonded at low temperatures, and provides an environmentally friendly adhesive.

As a result of diligent studies to solve the above problems, the present inventors have obtained an aqueous dispersion containing an acid-modified polypropylene resin having a specific structure as an adhesive for a polypropylene resin member whose surface layer portion is highly oriented and crystallized. It was found to be suitable and came to the present invention.

That is, the gist of the present invention is as follows.
(1) An adhesive for polypropylene resin members having a surface melting heat of 80 J / g or more.
It comprises a polyolefin resin aqueous dispersion containing a polyolefin resin (I), a polyolefin resin (II), and an aqueous medium.
The polyolefin resin (I) contains an olefin component and an unsaturated carboxylic acid component as a copolymer component,
The olefin component consists of propylene (A) and olefin (B) other than propylene.
The olefin (B) other than propylene contains butene and does not contain ethylene.
The mass ratio (A / B) of propylene (A) to olefin (B) other than propylene is 60/40 to 95/5.
Propylene and (A), the total of 100 parts by mass of the non-propylene olefin (B), the content of the unsaturated carboxylic acid component as the copolymer component state, and are at least 1 part by weight,
The polyolefin resin (II) contains an olefin component, a (meth) acrylic acid ester component, and an unsaturated carboxylic acid component as a copolymer component.
The total 100 parts by weight of the polyolefin resin (I) and the polyolefin resin (II), the adhesive content, characterized by 10 to 50 parts by mass der Rukoto of the polyolefin resin (II).
(2) The adhesive according to (1), wherein the polyolefin resin aqueous dispersion further contains a cross-linking agent and / or a polyurethane resin .
(3 ) A polypropylene resin member having a surface melting heat of 80 J / g or more.
A polypropylene resin member characterized in that an adhesive layer formed of the adhesive according to (1) or (2) is laminated.
( 4 ) It is a metal member and
A metal member characterized in that an adhesive layer formed of the adhesive according to (1) or (2) is laminated.
( 5 ) A polypropylene resin member having a surface melting heat amount of 80 J / g or more and a metal member are joined via an adhesive layer formed by the adhesive according to (1) or (2). Laminated body.
( 6 ) The laminate according to ( 5 ) above.
A laminate characterized in that a polypropylene resin member and a metal member are joined by a thermocompression bonding method or an insert molding method via an adhesive layer.

The adhesive for polypropylene resin members of the present invention is useful for joining polypropylene resin members whose surface layer portion is highly oriented and crystallized such that the surface melting heat amount is 80 J / g or more, and the members are subjected to complicated pretreatment. At the very least, it shows excellent bondability. Further, the joint portion has excellent water resistance and chemical resistance, and can be thermocompression bonded at a low temperature. In addition, the adhesive of the present invention can solve the above problems without using chlorinated polypropylene or an organic solvent, and therefore has an extremely small impact on the environment.
By using the adhesive of the present invention for joining a polypropylene resin member and a metal member, it is possible to obtain a laminate in which the polypropylene resin member and the metal member are joined, which has bonding strength applicable in a wide range of applications. Become.

Hereinafter, the present invention will be described in detail.
The polypropylene resin adhesive of the present invention (hereinafter, may be abbreviated as an adhesive) comprises a polyolefin resin aqueous dispersion containing a polyolefin resin (I) and an aqueous medium.

<Polyolefin resin (I)>
The polyolefin resin (I) in the present invention contains an olefin component and an unsaturated carboxylic acid component as a copolymerization component, and the olefin component contains propylene (A) and an olefin (B) other than propylene. ..
In the present invention, the mass ratio (A / B) of propylene (A) to olefin (B) other than propylene is determined from the viewpoint of reducing the dispersed particle size of the polyolefin resin (I) and to the polypropylene resin member of the adhesive layer. From the viewpoint of improving the adhesiveness of the above, it is necessary to be 60/40 to 95/5, and preferably 60/40 to 80/20. When the proportion of propylene (A) is less than 60% by mass, the adhesiveness to the polypropylene resin member is lowered, while when it exceeds 95% by mass, the dispersed particle size of the polyolefin resin (I) becomes large and the resin Aqueous dispersion may be difficult.

The olefin (B) other than propylene constituting the polyolefin resin (I) needs to contain butene and does not contain ethylene.
By containing butene (1-butene, isobutene, etc.) as the olefin (B) other than propylene, the polyolefin resin (I) can be easily produced and made water-based, and the adhesiveness to the polypropylene resin member, particularly the amount of heat of surface melting is 80 J / It has excellent adhesiveness to highly crystallized polypropylene resin members of g or more.
The polyolefin resin (I) does not contain ethylene as an olefin (B) other than propylene. In general, when a polyolefin resin contains ethylene as a copolymerization component, the adhesiveness to the polypropylene resin member tends to decrease. Further, it is known that a polyolefin resin containing ethylene as a copolymerization component competitively causes a cross-linking reaction when the unsaturated carboxylic acid component is copolymerized by a method as described later. When the cross-linking reaction proceeds, the weight of the polyolefin resin obtained by acid denaturation is increased, which may reduce the operability of acid denaturation. Further, the particle size of the polyolefin resin in the aqueous dispersion may increase, and further, depending on the ethylene content, it may be difficult to disperse the polyolefin resin in water. Therefore, in the present invention, the olefin component of the polyolefin resin (I) needs to be composed of other than ethylene.
As olefins (B) other than propylene, in addition to butene, alkenes such as 1-pentene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-hexene, 1-octene, norbornene, and butadiene Dienes such as and isoprene can be mentioned, but the content of these olefins other than butene in the olefin (B) other than propylene is preferably 20% by mass or less.

In the polyolefin resin (I), the copolymerization form of each component is not limited, and examples thereof include random copolymerization, block copolymerization, and graft copolymerization. However, from the viewpoint of ease of polymerization, random copolymerization or graft copolymerization It is preferably polymerized.

The polyolefin resin (I) in the present invention is a resin containing the above-mentioned olefin component and unsaturated carboxylic acid component as a copolymerization component. The content of the unsaturated carboxylic acid component as a copolymerization component is 1 part by mass with respect to 100 parts by mass in total of propylene (A) and olefin (B) other than propylene from the viewpoint of dispersibility in an aqueous medium. It is necessary that it is 1 to 15 parts by mass, more preferably 1 to 10 parts by mass, further preferably 1 to 8 parts by mass, and 1.5 to 7 parts by mass. Most preferably, it is a part. When the content of the unsaturated carboxylic acid component is less than 1 part by mass, it becomes difficult to make the polyolefin resin (I) water-based, and when the content exceeds 15 parts by mass, the resin is usually made water-based. However, the adhesiveness to the polypropylene resin member may decrease.

Examples of the unsaturated carboxylic acid component include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, aconitic acid, aconitic anhydride, fumaric acid, crotonic acid, citraconic acid, mesaconic acid, and allylsuccinic acid. In addition, compounds having at least one carboxyl group or acid anhydride group in the molecule (in the monomer unit) such as half ester and half amide of unsaturated dicarboxylic acid can also be used. Among them, maleic anhydride, acrylic acid, and methacrylic acid are preferable, and maleic anhydride is preferable from the viewpoint of ease of introduction into a polyolefin resin (hereinafter referred to as an unsaturated polyolefin resin) that does not contain an unsaturated carboxylic acid component. More preferred.
Therefore, in the present invention, as the polyolefin resin (I), butene is used as the olefin (B) other than propylene as described above. Therefore, as the polyolefin resin (I), the ternary copolymer of propylene / butene / maleic anhydride is used. It is preferable to use coalescence.

The unsaturated carboxylic acid component may be copolymerized in the polyolefin resin (I), and its form is not limited. For example, random copolymerization, block copolymerization, graft copolymerization and the like can be mentioned.
The acid anhydride component introduced into the polyolefin resin (I) tends to have an acid anhydride structure in a dry state, and a part or all of the acid anhydride component is opened in an aqueous medium containing a basic compound described later. Tends to be a carboxylic acid or a salt thereof.

The method for introducing the unsaturated carboxylic acid component into the unmodified polyolefin resin (I) is not particularly limited. For example, the unsaturated carboxylic acid component (I) and the unsaturated carboxylic acid component are introduced into the unmodified polyolefin in the presence of a radical generator. A method of heating and melting above the melting point of the resin (I) to cause a reaction, or a method of dissolving an unsaturated polyolefin resin (I) and an unsaturated carboxylic acid component in an organic solvent, and then heating and stirring in the presence of a radical generator. A method of graft-copolymerizing an unsaturated carboxylic acid component with the unmodified polyolefin resin (I) can be mentioned as a method of causing the reaction.
Examples of the radical generator used for graft copolymerization include di-tert-butyl peroxide, dicumyl peroxide, tert-butyl hydroper oxide, tert-butyl butyl peroxide, benzoyl peroxide, and dilauryl peroxide. Examples thereof include organic radicals such as cumene hydroperoxide, tert-butyl peroxybenzoate, ethyl ethyl ketone peroxide and di-tert-butyl diperphthalate, and azo compounds such as azobisisobutyronitrile. These may be appropriately selected and used depending on the reaction temperature.

The polyolefin resin (I) in the present invention may contain components other than the above, if necessary. Other components include maleic acid esters such as dimethyl maleate, diethyl maleate, and dibutyl maleate, alkyl vinyl ethers such as (meth) acrylic acid amides, methyl vinyl ether, and ethyl vinyl ether, vinyl formate, vinyl acetate, and the like. Vinyl esters such as vinyl propionate, vinyl pivalate, vinyl versaticate, vinyl alcohols obtained by saponifying vinyl esters with basic compounds, 2-hydroxyethyl acrylate, glycidyl (meth) acrylate, (meth) acrylonitrile , Styrene, substituted styrene, vinyl halides, billinidene halides, carbon monoxide, sulfur dioxide and the like, and mixtures thereof may be used. The content of these other components is generally preferably 10% by mass or less of the polyolefin resin (I).

The polyolefin resin (I) in the present invention has a weight average molecular weight of preferably 5,000 to 200,000, more preferably 10,000 to 150,000, and 20,000 to 120,000. More preferably, it is particularly preferably 30,000 to 100,000, and most preferably 35,000 to 80,000. When the weight average molecular weight of the polyolefin resin (I) is less than 5,000, the adhesiveness to the member tends to decrease, and the obtained adhesive layer tends to be hard and brittle, while the weight average molecular weight is 200,000. If it exceeds, it tends to be difficult to make the resin water-based. The weight average molecular weight of the resin can be determined by using gel permeation chromatography (GPC) with polystyrene resin as a standard.

Generally, polyolefin resins are sparingly soluble in solvents, which may make it difficult to measure their molecular weight. In such a case, the melt flow rate value indicating the fluidity of the molten resin should be used as a guideline for the molecular weight.

<Aqueous medium>
The adhesive of the present invention comprises a polyolefin resin aqueous dispersion containing the above-mentioned polyolefin resin (I) and an aqueous medium, and the polyolefin resin (I) is dispersed or partially dissolved in the aqueous medium. In the present invention, the aqueous medium is a liquid containing water as a main component, and may contain an organic solvent or a basic compound described later in order to promote the aqueous conversion of the polyolefin resin (I).

Basic compounds include ammonia, triethylamine, N, N-dimethylethanolamine, isopropylamine, aminoethanol, dimethylaminoethanol, diethylaminoethanol, ethylamine, diethylamine, isobutylamine, dipropylamine, 3-ethoxypropylamine, 3- Diethylaminopropylamine, sec-butylamine, propylamine, n-butylamine, 2-methoxyethylamine, 3-methoxypropylamine, 2,2-dimethoxyethylamine, monoethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine, pyrrole , Pyridine and the like. The blending amount of the basic compound is preferably 0.5 to 10 times equivalent, more preferably 0.8 to 5 times equivalent, and 0.9 to 3.0 times equivalent with respect to the carboxyl group in the polyolefin resin. Is particularly preferable. If it is less than 0.5 times equivalent, the effect of adding the basic compound is not recognized, and if it exceeds 10 times equivalent, the drying time at the time of forming the coating film may be lengthened or the stability of the aqueous dispersion may be lowered. is there.

In the present invention, it is preferable to add a hydrophilic organic solvent at the time of watering in order to promote watering of the polyolefin resin (I) and reduce the dispersed particle size. The content of the hydrophilic organic solvent is preferably 50% by mass or less, more preferably 1 to 45% by mass, further preferably 2 to 40% by mass, and particularly preferably 3 to 35% by mass with respect to the entire aqueous medium. preferable. When the content of the hydrophilic organic solvent exceeds 50% by mass, it cannot be regarded as an aqueous medium substantially, which not only deviates from one of the objects of the present invention (environmental protection) but also uses a hydrophilic organic solvent. In some cases, the stability of the aqueous dispersion may decrease.
The hydrophilic organic solvent preferably has a solubility in water at 20 ° C. of 10 g / L or more, more preferably 20 g / L or more, and more preferably 50 g / L, from the viewpoint of obtaining an aqueous dispersion having good dispersion stability. Those of L or more are more preferable.
The hydrophilic organic solvent preferably has a boiling point of 150 ° C. or lower from the viewpoint of being efficiently removed from the coating film in the process of film formation. Hydrophilic organic solvents having a boiling point of more than 150 ° C. tend to be difficult to disperse from the coating film by drying, and in particular, the water resistance of the adhesive layer during low-temperature drying and the adhesiveness to members may decrease. is there.

Preferred hydrophilic organic solvents include, for example, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert-. Alcohols such as amyl alcohol, 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol, cyclohexanol, ketones such as methyl ethyl ketone, methyl isobutyl ketone, ethyl butyl ketone, cyclohexanone, tetrahydrofuran, dioxane, etc. Ethers, ethyl acetate, -n-propyl acetate, isopropyl acetate, -n-butyl acetate, isobutyl acetate, -sec-butyl acetate, -3-methoxybutyl acetate, methyl propionate, ethyl propionate, diethyl carbonate, carbonate Esters such as dimethyl, glycol derivatives such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol ethyl ether acetate, and 1-methoxy-2-propanol, 1 -Ethoxy-2-propanol, 3-methoxy-3-methyl-1-butanol, methoxybutanol, acetonitrile, dimethylformamide, dimethylacetamide, diacetone alcohol, ethyl acetoacetate, 1,2-dimethylglycerin, 1,3-dimethyl Examples thereof include glycerin and trimethylglycerin.
Among them, ethanol, n-propanol, isopropanol, n-butanol, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, and diethylene glycol monomethyl ether promote the waterification of polyolefin resins. More effective and preferred.
In the present invention, a plurality of these hydrophilic organic solvents may be mixed and used.

A hydrophobic organic solvent may be further added in order to further promote the waterification of the polyolefin resin (I). As the hydrophobic organic solvent, an organic solvent having a solubility in water at 20 ° C. of less than 10 g / L and a boiling point of 150 ° C. or lower is preferable for the same reason as described above. Examples of such hydrophobic organic solvents include olefin solvents such as n-pentane, n-hexane, n-heptane, cycloheptane, cyclohexane and petroleum ether, aromatic solvents such as benzene, toluene and xylene, and four. Examples thereof include halogen-based solvents such as carbon chloride, 1,2-dichloroethane, 1,1-dichloroethylene, trichlorethylene, 1,1,1-trichloroethane, and chloroform. The amount of these hydrophobic organic solvents added is preferably 15% by mass or less, more preferably 10% by mass or less, and further preferably 5% by mass or less with respect to the aqueous dispersion. If the amount of the hydrophobic organic solvent added exceeds 15% by mass, gelation or the like may occur.

<Polyolefin resin aqueous dispersion>
In the polyolefin resin aqueous dispersion constituting the adhesive of the present invention, the particle size of the polyolefin resin (I) particles dispersed in the aqueous dispersion is not particularly limited, but low temperature film forming property and coating density. From the viewpoint of transparency, transparency, and mixing stability with other materials, the weight average particle size is preferably 0.50 μm or less, more preferably 0.30 μm or less, and further preferably 0.10 μm or less. It is preferably 0.001 to 0.10 μm, and particularly preferably 0.001 to 0.10 μm.

Further, in the present invention, the degree of dispersion (weight average particle size / number average particle size) related to the particle size distribution of the polyolefin resin (I) in the aqueous dispersion is preferably 2.6 or less, and particularly for the coating film. From the viewpoint of smoothness, it is preferably 2.0 or less, more preferably 1.5 or less, and further preferably 1.3 or less.

In the present invention, the zeta potential is preferably −20 mV or less, and more preferably −30 mV or less. The polyolefin resin aqueous dispersion is excellent in dispersion stability when the zeta potential is −20 mV or less, and is also excellent in mixing stability when mixed with various additives.

In the present invention, the content of the polyolefin resin (I) in the aqueous dispersion can be appropriately selected depending on the film forming conditions, the thickness of the coating film, the performance, and the like, and is not particularly limited, but the viscosity of the aqueous dispersion. It is preferably 1 to 60% by mass, more preferably 3 to 55% by mass, and 5 to 50% by mass in terms of maintaining an appropriate amount and exhibiting a good coating film forming ability. It is more preferably 10 to 45% by mass, and particularly preferably 10 to 45% by mass.

The aqueous dispersion in the present invention preferably contains substantially no non-volatile aqueous aid. Although the present invention does not exclude the use of the non-volatile aqueous aid, the polyolefin resin (I) can be finely and stably dispersed in the aqueous medium without using the aqueous aid. Therefore, the adhesive layer characteristics in low-temperature drying, particularly water resistance, adhesiveness to members, and heat sealability are excellent, and these performances hardly change even in the long term.

Here, the "water-based auxiliary agent" is a drug or compound added for the purpose of promoting water-based dispersion or stabilizing the aqueous dispersion in the production of the aqueous dispersion, and the "nonvolatile" means. It means that it does not have a boiling point at normal pressure or has a high boiling point at normal pressure (for example, 300 ° C. or higher).

"Substantially free of non-volatile water-based auxiliaries" means that such auxiliaries are not used during production (during resin hydration) and the resulting dispersion does not eventually contain this auxiliaries. means. Therefore, it is particularly preferable that the content of such an aqueous aid is zero, but the content is 5% by mass or less, preferably 2% by mass or less, and further, as long as the effect of the present invention is not impaired. Preferably, it may be contained in an amount of less than 0.5% by mass.

Examples of the non-volatile aqueous aid described in the present invention include emulsifiers, compounds having a protective colloidal action, modified waxes, acid-modified compounds having a high acid value, and water-soluble polymers, which will be described later.

Examples of the emulsifier include a cationic emulsifier, an anionic emulsifier, a nonionic emulsifier, and an amphoteric emulsifier, and in addition to those generally used for emulsion polymerization, surfactants are also included. For example, examples of anionic emulsifiers include sulfate ester salts of higher alcohols, higher alkyl sulfonates, higher carboxylates, alkylbenzene sulfonates, polyoxyethylene alkyl sulfate salts, polyoxyethylene alkyl phenyl ether sulfate salts, and vinyl sulfosuccinates. Examples of the nonionic emulsifier include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyethylene glycol fatty acid ester, ethylene oxide propylene oxide block copolymer, polyoxyethylene fatty acid amide, and ethylene oxide-propylene oxide. Examples thereof include compounds having a polyoxyethylene structure such as copolymers and sorbitan derivatives such as polyoxyethylene sorbitan fatty acid ester, and examples of amphoteric emulsifiers include lauryl betaine and lauryl dimethylamine oxide.

Compounds with protective colloid action, modified waxes, acid-modified compounds with high acid value, and water-soluble polymers include polyvinyl alcohol, carboxyl group-modified polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, modified starch, and polyvinylpyrrolidone. , Polyacrylic acid and salts thereof, carboxyl group-containing polyethylene wax, carboxyl group-containing polypropylene wax, carboxyl group-containing polyethylene-propylene wax and other acid-modified polyolefin waxes having a number average molecular weight of usually 5000 or less and salts thereof, acrylic acid-anhydrous. Maleic acid copolymer and its salt, styrene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid copolymer, isobutylene-maleic anhydride alternating copolymer, (meth) acrylic acid- (meth) A carboxyl group-containing polymer having an unsaturated carboxylic acid content of 10% by mass or more, such as an acrylic acid ester copolymer and a salt thereof, polyitaconic acid and a salt thereof, a water-soluble acrylic copolymer having an amino group, gelatin, and gum arabic. , Casein and the like, which are generally used as dispersion stabilizers for fine particles.

As described above, the polyolefin resin (I) constituting the polyolefin resin aqueous dispersion in the present invention contains an olefin component and an unsaturated carboxylic acid component as a copolymerization component, and is unsaturated as a copolymerization component. From the viewpoint of dispersibility in an aqueous medium, the content of the carboxylic acid component needs to be 1 part by mass or more with respect to 100 parts by mass of the total components other than the unsaturated carboxylic acid component.

<Manufacturing method of polyolefin resin aqueous dispersion>
Next, an example of a method for producing the polyolefin resin aqueous dispersion will be described.
In the present invention, the method for obtaining the polyolefin resin aqueous dispersion is not particularly limited, but each of the above-mentioned components, that is, the polyolefin resin (I), the aqueous medium, an organic solvent, a basic compound and the like, if necessary, can be used. A method of heating and stirring in a sealable container can be adopted, and this method is most preferable.

As the container, an apparatus used as a solid / liquid agitator or an emulsifier can be used, and it is preferable to use an apparatus capable of pressurizing 0.1 MPa or more. The stirring method and the rotation speed of the stirring are not particularly limited, but the stirring may be performed at a low speed such that the polyolefin resin (I) is suspended in the aqueous medium. Therefore, high-speed stirring (for example, 1000 rpm or more) is not essential, and an aqueous dispersion can be produced even with a simple device.

For example, raw materials such as polyolefin resin (I) and an aqueous medium are put into the above apparatus, and the mixture is preferably stirred and mixed at a temperature of 40 ° C. or lower. Then, while maintaining the temperature in the tank at 80 to 240 ° C., preferably 100 to 220 ° C., more preferably 110 to 200 ° C., particularly preferably 110 to 190 ° C., stirring is continued until there are no coarse particles. (For example, 5 to 300 minutes).

Then, at least one selected from a basic compound, an organic solvent and water is further added to the system, and the mixture is heated and stirred again in a closed container at a temperature of 80 to 240 ° C. As described above, the weight average particle size of the polyolefin resin (I) can be reduced to 0.15 μm or less by adding the material constituting the aqueous medium, heating and stirring again. Further, it is preferable to make the resin water-based by the two-step process in this way in order to adjust the dispersity of the particle size distribution to a preferable range.
The method of additionally blending the basic compound, the organic solvent, and water is not particularly limited, but the method of blending under pressure using a gear pump or the like, the method of blending after the temperature in the system is once lowered to normal pressure, etc. There is.
The ratio of the basic compound to be additionally blended, the organic solvent, and water may be appropriately determined according to the desired solid content concentration, particle size, dispersity, and the like. The total of the basic compound, the organic solvent, and water is preferably adjusted so that the solid content concentration after blending is 1 to 50% by mass, more preferably 2 to 45% by mass, and 3 to 3 to 45% by mass. An amount of 40% by mass is particularly preferable.

In the above step, if the temperature in the tank is less than 80 ° C., it becomes difficult for the polyolefin resin (I) to become water-based, while if the temperature in the tank exceeds 240 ° C., the molecular weight of the polyolefin resin decreases. Sometimes.

When the above organic solvent is used in the production of the aqueous dispersion, a part of the organic solvent is distilled off from the system by a solvent removal treatment generally called "stripping" after the resin is made water-based. The content may be reduced. By stripping, the content of the organic solvent in the aqueous dispersion can be 10% by mass or less, more preferably 5% by mass or less, and more preferably 1% by mass or less from the environment. In the stripping process, substantially all of the organic solvent used for hydration can be distilled off, but this productivity is increased because it is necessary to increase the decompression degree of the device and lengthen the operation time. In consideration, the lower limit of the organic solvent content is preferably about 0.01% by mass.
Examples of the stripping method include a method in which the aqueous dispersion is heated with stirring under normal pressure or reduced pressure to distill off the organic solvent. Further, since the solid content concentration is increased by distilling off the aqueous medium, for example, when the viscosity increases and the workability decreases, water is added to the aqueous dispersion in advance. May be good.

The solid content concentration of the aqueous dispersion can be adjusted by, for example, a method of distilling off an aqueous medium or a method of diluting with water.

By adopting the above production method, it becomes possible to prepare a uniform liquid aqueous dispersion in which the polyolefin resin (I) is efficiently dispersed or partially dissolved in the aqueous medium. Here, the term "uniform liquid" means that, in appearance, no part having a solid content concentration that is locally different from other parts, such as precipitation, phase separation, or skinning, is found in the aqueous dispersion. To say.

<Additives>
The aqueous dispersion constituting the adhesive of the present invention may further contain a polyurethane resin, a cross-linking agent, a polyolefin resin (II), or the like in order to further improve the performance.

As the polyurethane resin, a polymer having a urethane bond in the main chain can be used. For example, a polymer obtained by reacting a polyol compound with a polyisocyanate compound can be used.

In the present invention, the polyol component constituting the polyurethane resin is not particularly limited, and for example, water, ethylene glycol, diethylene glycol, triethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,2- Propanediol, 1,3-propanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, methyl-1,5-pentanediol, 1,8-octanediol, 2-ethyl-1 , 3-Hexanediol, Diethylene glycol, Triethylene glycol, Dipropylene glycol and other low molecular weight glycols, Trimethylol propane, Glycerin, Pentaerythritol and other low molecular weight polyols, Ethylene oxide and polyol compounds with propylene oxide units, polyether Examples thereof include high molecular weight diols such as diols and polyester diols, bisphenols such as bisphenol A and bisphenol F, and dimer diols obtained by converting the carboxyl group of dimer acid into a hydroxyl group.

As the polyisocyanate component, one or a mixture of two or more known diisocyanates belonging to aromatic, aliphatic or alicyclic groups can be used. Specific examples of diisocyanates include tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,3-phenylenediocyanate, hexamethylene diisocyanate, xylylene diisocyanate, 1,5-naphthalenediocyanate, isophorone diisocyanate, dimethyl diisocyanate, and lysine diisocyanate. , Hydrous 4,4'-diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate, dimerized isocyanate obtained by converting the carboxyl group of dimer acid into an isocyanate group, and adducts, biurets, isocyanurates and the like thereof. Further, as the diisocyanates, trifunctional or higher functional polyisocyanates such as triphenylmethane triisocyanate and polymethylene polyphenyl isocyanate may be used.

In the present invention, commercially available water-based polyurethane resins include Takelac series manufactured by Mitsui Chemicals (part number: W-615, W-6010, W-511, etc.) and Adeka Bontiter series manufactured by Adeka Corporation (product number: HUX). -232, HUX-320, HUX-380, HUX-401, etc.), Superflex series manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. (Product numbers: 500, 550, 610, 650, etc.), Hydran manufactured by Dainippon Ink and Chemicals Co., Ltd. Series (product numbers: HW-311, HW-350, HW-150, etc.) can be mentioned.

As the cross-linking agent used in the present invention, a cross-linking agent having self-cross-linking property, a compound having a plurality of functional groups reacting with an unsaturated carboxylic acid component in the molecule, a metal having a multivalent coordination bond, or the like can be used. it can.
Specific examples thereof include oxazoline group-containing compounds, carbodiimide group-containing compounds, isocyanate group-containing compounds, melamine compounds, urea compounds, epoxy compounds, zirconium salt compounds, silane coupling agents, and the like. You may use a mixture. Above all, from the viewpoint of ease of handling and adhesion, it is preferable to add a compound containing an oxazoline group and / or a compound containing an epoxy group and / or a silane coupling agent.

As the oxazoline group-containing compound, a compound having two or more oxazoline groups in the molecule can be preferably used. For example, 2,2'-bis (2-oxazoline), 2,2'-ethylene-bis (4,4'-dimethyl-2-oxazoline), 2,2'-p-phenylene-bis (2-oxazoline). , A compound having an oxazoline group such as bis (2-oxazolinylcyclohexane) sulfide, an oxazoline group-containing polymer, and the like. One or more of these can be used. Among these, an oxazoline group-containing polymer is preferable because of its ease of handling.

The oxazoline group-containing polymer is generally obtained by polymerizing an addition-polymerizable oxazoline such as 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline and 2-isopropenyl-2-oxazoline. The oxazoline group-containing polymer may be copolymerized with other monomers, if necessary. The polymerization method of the oxazoline group-containing polymer is not particularly limited, and a known polymerization method can be adopted. Examples of commercially available oxazoline group-containing polymers include the Epocross series manufactured by Nippon Shokubai Co., Ltd. Specific product names include, for example, water-soluble types "WS-500" and "WS-700"; emulsion types "K-1010E", "K-1020E", "K-1030E", and "K-". Examples thereof include "2010E", "K-2020E", and "K-2030E".

The epoxy group-containing compound is not particularly limited as long as it has at least two or more epoxy groups in the molecule. For example, bisphenol A diglycidyl ether, bisphenol Aβ-dimethylglycidyl ether, bisphenol F diglycidyl ether, tetrahydroxyphenylmethane tetraglycidyl ether, resorcinol diglycidyl ether, brominated bisphenol A diglycidyl ether, chlorinated bisphenol A diglycidyl ether, Hydrogenated bisphenol A diglycidyl ether, bisphenol A alkylene oxide adduct diglycidyl ether, novolak glycidyl ether, polyalkylene glycol diglycidyl ether, glycerin triglycidyl ether, pentaerythritol diglycidyl ether, glycidyl ether type such as epoxy urethane resin; Glysidyl ether ester type such as p-oxybenzoic acid glycidyl ether ester; phthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, acrylic acid diglycidyl ester, dimer acid diglycidyl ester Glycidyl ester type such as glycidyl aniline, tetraglycidyl diaminodiphenylmethane, triglycidyl isocyanurate, glycidyl amine type such as triglycidyl aminophenol; linear aliphatic epoxy resin such as epoxidized polybutadiene and epoxidized soybean oil; 3,4- Epoxy-6 methylcyclohexylmethyl-3,4-epoxy-6methylcyclohexanecarboxylate, 3,4-epoxycyclohexylmethyl (3,4-epoxycyclohexane) carboxylate, bis (3,4-epoxy-6methylcyclohexylmethyl) Examples thereof include alicyclic epoxy resins such as adipate, vinylcyclohexene diepoxyside, dicyclopentadiene oxide, bis (2,3-epoxycyclopentyl) ether, and limonendioxide. One or more of these can be used.
Examples of commercially available epoxy compounds include water-based compounds suitable for the present invention, such as the Denacol series (EM-150, EM-101, etc.) manufactured by Nagase Chemtech, and the ADEKA resin series manufactured by Asahi Denka Kogyo Co., Ltd. From the viewpoint of improving UV ink adhesion and scratch resistance, ADEKA Resins EM-0517, EM-0526, EM-11-50B, EM-051R and the like manufactured by Asahi Denka Co., Ltd., which are polyfunctional epoxy resin emulsions, are preferable.

Known silane coupling agents can be used. Specifically, for example, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N- (β-aminoethyl) -γ- Amino group-containing silane coupling agents such as aminopropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane; γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxy Glycydoxy group (or epoxy group) -containing silane coupling agent such as silane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxymethyldimethoxysilane, 2- (3,4 epoxycyclohexyl) ethyltrimethoxysilane; vinyl Vinyl group-containing silane coupling agents such as trimethoxysilane, vinyltriethoxysilane and vinyltris (β-methoxyethoxy) silane; γ-methacryloxypropyltrimethoxysilane and other methacryloxy group-containing silane coupling agents; γ-mercaptopropyltri Examples thereof include mercapto group-containing silane coupling agents such as methoxysilane and γ-mercaptopropylmethyldimethoxysilane; halogen group-containing silane coupling agents such as γ-chloropropylmethoxysilane and γ-chloropropyltrimethoxysilane. These silane coupling agents may be used alone or in combination of two or more. Among these, an amino group-containing silane coupling agent and a glycidoxy group (or epoxy group) -containing silane coupling agent are preferable in that the bonding strength of the finally obtained metal plate composite resin molded product as a whole is good.

The aqueous dispersion in the present invention may contain either or both of a polyurethane resin and a cross-linking agent.
When the polyurethane resin is used in the aqueous dispersion without using a cross-linking agent, the content thereof is preferably 1 to 300 parts by mass, more preferably 1 to 150 parts by mass with respect to 100 parts by mass of the polyolefin resin (I). It is by mass, more preferably 2 to 130 parts by mass, and particularly preferably 3 to 100 parts by mass. If the content of the polyurethane resin is less than 1 part by mass, the adhesiveness between the metal member and the adhesive layer becomes insufficient, and it becomes difficult to obtain sufficient adhesiveness and heat resistance as a laminated body. On the other hand, if it exceeds 300 parts by mass, the adhesiveness between the polypropylene resin member and the adhesive layer becomes insufficient, and it becomes difficult to obtain sufficient adhesiveness and heat resistance as a laminated body.

When a cross-linking agent is used in the aqueous dispersion without using the polyurethane resin, the content thereof is preferably 0.1 to 50 parts by mass, more preferably 0, with respect to 100 parts by mass of the polyolefin resin (I). .5 to 40 parts by mass, more preferably 1 to 30 parts by mass. If the content of the cross-linking agent is less than 0.1 parts by mass, the cross-linking is insufficient, so that the adhesion between the metal member and the adhesive layer is poor, and it becomes difficult to obtain sufficient adhesiveness and heat resistance as a laminated body. On the other hand, if it exceeds 50 parts by mass, the adhesiveness between the polypropylene resin member and the adhesive layer becomes insufficient, and it becomes difficult to obtain sufficient adhesiveness and heat resistance as a laminated body.

When the aqueous dispersion contains both the polyurethane resin and the cross-linking agent, the range is 50 parts by mass or less of the cross-linking agent and 300 parts by mass or less of the polyurethane resin with respect to 100 parts by mass of the polyolefin resin (I), but either one. It is preferable that the component of is contained in an amount of 0.1 part by mass or more. If any of the components is less than 0.1 parts by mass, the adhesiveness between the metal member and the adhesive layer becomes insufficient, and it becomes difficult to obtain sufficient adhesiveness and heat resistance as a laminated body. On the other hand, if any one of the components exceeds the above range, the adhesiveness between the polypropylene resin member and the adhesive layer becomes insufficient, and it becomes difficult to obtain sufficient adhesiveness and heat resistance as a laminate.

The aqueous dispersion constituting the adhesive of the present invention contains a polyolefin resin (I) and a polyolefin resin (II) containing an olefin component, an unsaturated carboxylic acid component and a (meth) acrylic acid ester component as copolymerization components. It is preferable to contain it. By containing the polyolefin resin (II), the bonding strength between the polypropylene resin member and the metal member is improved, and a laminate having excellent water resistance and chemical resistance can be obtained.

The olefin component of the polyolefin resin (II) is not particularly limited, and ethylene, propylene, 1-butene, isobutene, 1-pentene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-hexene, 1- Alkenes such as octene and norbornene and dienes such as butadiene and isoprene can be preferably used, and ethylene is preferable.

The polyolefin resin (II) needs to contain a (meth) acrylic acid ester component. Examples of the (meth) acrylic acid ester component include methyl (meth) acrylate, ethyl (meth) acrylate, and butyl (meth) acrylate. Since the polyolefin resin (II) contains a (meth) acrylic acid ester component, the joint portion tends to have improved water resistance and chemical resistance. The content of the (meth) acrylic acid ester component is preferably 50% by mass or less, more preferably 30% by mass or less, and particularly preferably 1 to 20% by mass of the polyolefin resin (II). .. When the content of the (meth) acrylic acid ester component exceeds 50% by mass, the initial strength of the joint tends to decrease.

The polyolefin resin (II) may have the above-mentioned olefin component and (meth) acrylic acid ester component, and other configurations, physical properties, water-based methods, physical properties of the aqueous dispersion, etc. shall be the above-mentioned polyolefin resin. It is similar to those in (I).
Specific examples of the polyolefin resin (II) include ethylene-methyl acrylate-maleic anhydride copolymer, ethyl ethylene-ethyl acrylate-maleic anhydride copolymer, methyl propylene-methyl acrylate-maleic anhydride copolymer, and the like. Examples thereof include a propylene-ethyl acrylate-maleic anhydride copolymer, and an ethylene-ethyl acrylate-maleic anhydride copolymer is preferable.
The content of the polyolefin resin (II) is preferably 100 parts by mass or less, more preferably 50 parts by mass or less, based on the polyolefin resin (I).

In addition, the aqueous dispersion constituting the adhesive of the present invention may contain a small amount of a polymer other than the above in order to further improve the performance depending on the intended purpose. Examples of other resins include polyethylene resin, polyester resin, polyvinyl acetate, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, ethylene- (meth) acrylic acid copolymer, and styrene-maleic acid resin. , Styrene-butadiene resin, butadiene resin, acrylonitrile-butadiene resin, poly (meth) acrylonitrile resin, (meth) acrylamide resin, chlorinated polyethylene resin, chlorinated polypropylene resin, modified nylon resin, rosin-based and terpen-based adhesive Examples thereof include resins, phenol resins, silicone resins, and epoxy resins. If necessary, a plurality of substances may be mixed and used. The polyester resin preferably contains a polybasic acid component and a polyhydric alcohol component as main components, and the polyester resin may be copolymerized with a monocarboxylic acid, a monoalcohol, or a hydroxycarboxylic acid.

The above additives may be used alone or in combination of two or more. Further, it is preferable to use a water-soluble or aqueous dispersible additive from the viewpoint of ease of addition and mixing.

The method for preparing the polyolefin resin aqueous dispersion containing the additive is not limited. For example, the aqueous dispersion containing the polyolefin resin (I) and (II) is prepared by mixing the previously prepared polyolefin resin (I) aqueous dispersion and the polyolefin resin (II) aqueous dispersion. Alternatively, the polyolefin resins (I) and (II) may be simultaneously dispersed in water.

<Use of adhesive>
The polypropylene resin member of the present invention is a polypropylene resin member having a surface melting heat amount of 80 J / g or more, and is laminated with an adhesive layer formed by the adhesive of the present invention. Further, the metal member of the present invention is formed by laminating adhesive layers formed by the adhesive of the present invention.
The adhesive layer can be formed by applying the adhesive of the present invention to a polypropylene resin member or a metal member and drying and removing the aqueous medium.

The resin constituting the polypropylene resin member is not particularly limited as long as the main component is polypropylene, and a polypropylene homopolymer or a polypropylene copolymer can be used.
Since the polypropylene resin on the surface layer of the injection-molded polypropylene resin member is highly oriented and crystallized due to the stress at the time of injection, the surface melting heat amount measured by cutting out about 0.5 mm of the surface layer of the polypropylene resin member is 80 J / g. That is all. Such a polypropylene resin member having a high amount of heat for melting on the surface and having a highly oriented and crystallized surface tends to have extremely low bondability. Since the adhesive of the present invention is composed of a specific aqueous dispersion, it has excellent bonding properties with respect to a polypropylene resin member having a surface melting heat amount of 80 J / g or more, which is generally difficult to bond.
The amount of heat of surface melting can be measured by differential scanning calorimetry (DSC) or the like.

Polypropylene resin members include reinforcing fibers such as glass fiber and carbon fiber, inorganic fillers such as calcium carbonate and silica, organic fillers such as cellulose and wood powder, pigments and dyes, flame retardants, antibacterial agents, and antioxidants, if necessary. Known additives such as agents, plasticizers and lubricants may be added.

The surface of the polypropylene resin member may be surface-treated or pretreated before being joined. Examples of the surface treatment and pretreatment include degreasing, corona treatment, plasma treatment, ultraviolet irradiation, ozone treatment, and primer treatment. By performing surface treatment or pretreatment on the surface of the polypropylene resin member, the wettability of the adhesive can be improved and the bonding strength between the polypropylene resin member and the metal member can be improved.

Examples of the metal plate constituting the metal member include cold-rolled steel sheet, hot-dip galvanized steel sheet (GI), alloyed hot-dip Zn-Fe-plated steel sheet (GA), alloyed hot-dip Zn-5% Al-plated steel sheet (GF), and electricity. Examples thereof include pure galvanized steel sheets (EG), electric Zn-Ni plated steel sheets, aluminum plates, aluminum alloy plates, titanium plates, galvalume steel plates (registered trademarks) and the like.
The thickness of the metal member can be appropriately selected depending on the intended use, and is not particularly limited.
The surface of the metal member may be treated for adhesiveness improvement or other purposes, such as cleaning treatment, polishing treatment, laser treatment, chemical treatment such as chromate treatment, electrochemical treatment, plasma treatment and other activities. Gas treatment, primer treatment, etc. can be performed.

The method for applying the adhesive of the present invention can be appropriately selected depending on the shape of the member, and is not particularly limited, but known methods such as spray coating, dipping coating, brush coating, wire bar coating, curtain flow coating, and gravure roll. Coating, reverse roll coating, air knife coating, etc. can be adopted.

The coating amount of the adhesive of the present invention is appropriately selected depending on the intended use, and the dry film thickness (adhesive layer thickness) is preferably 1 to 100 μm, more preferably 3 to 70 μm, and 5 to 50 μm. Is even more preferable.
In order to obtain an adhesive layer having a uniform thickness, in addition to appropriately selecting the device used for coating and its usage conditions, an adhesive whose concentration and viscosity are adjusted according to the device and usage conditions is used. Is preferable.

As a heating device for drying the adhesive applied to the member, a normal hot air circulation type oven, an infrared heater, or the like can be used.
The heating temperature and heating time are appropriately selected depending on the characteristics of the member and the amount of the additive contained in the adhesive. The heating temperature is preferably 50 to 250 ° C, more preferably 80 to 200 ° C, and even more preferably 100 to 180 ° C. The heating time is preferably 5 seconds to 180 minutes, more preferably 30 seconds to 120 minutes, and even more preferably 1 minute to 60 minutes.
When a cross-linking agent is contained as an additive, the heating temperature and time may be appropriately selected depending on the type of the cross-linking agent in order to sufficiently proceed the reaction between the carboxyl group of the polypropylene resin or other polymer and the cross-linking agent. desirable.

The laminate of the present invention is a polypropylene resin member having a surface melting heat of 80 J / g or more and a metal member bonded via an adhesive layer formed by the adhesive of the present invention. Is a polypropylene resin member / adhesive layer / metal member laminated in this order.

The method of joining the polypropylene resin member and the metal member using the adhesive of the present invention is not particularly limited, and examples thereof include injection molding methods such as thermocompression bonding, in-mold molding and insert molding, and friction stir welding.

In the case of bonding by thermocompression bonding, for example, the polypropylene resin member or a metal member is coated with the adhesive of the present invention and dried to form an adhesive layer, which is bonded to the mating member and heat and pressure are applied to the polypropylene resin member. It is possible to obtain a laminate obtained by joining the metal member with the metal member.
The conditions for thermocompression bonding may be appropriately selected depending on the type of resin component contained in the adhesive and the size and shape of the polypropylene resin member and the metal member. The temperature at the time of thermocompression bonding is preferably 60 to 180 ° C., more preferably 70 to 150 ° C., and even more preferably 75 to 140 ° C. The pressure during thermocompression bonding is preferably 5 MPa or less, more preferably 2 MPa or less. If the temperature and pressure during thermocompression bonding are high, the bonding strength tends to be high, but the polypropylene resin member may be deformed or thermally decomposed. On the other hand, if the temperature and pressure during thermocompression bonding are low, the joint strength tends to be low.

In the case of joining by injection molding, for example, first, the adhesive of the present invention is applied and dried to form a metal plate having an adhesive layer formed into a desired shape to produce a metal member. After that, this metal member was charged into the mold of the injection molding machine, the mold was fastened, the molten polypropylene resin was injected into the mold, and the resin was cooled and solidified to join the polypropylene resin member and the metal member. A laminate can be obtained. By adopting the injection molding (in-mold molding or insert molding) method, it is possible to mass-produce the laminate in a short time and with high efficiency.
The injection molding conditions may be appropriately selected according to the type and purpose of the member to be used. For example, in the case of polypropylene resin to which no additive is added, the cylinder temperature is 230 to 250 ° C, the mold temperature is 45 to 55 ° C, the injection holding time is 5 to 8 seconds, and the cooling time is about 20 to 30 seconds. By doing so, a laminate obtained by joining the polypropylene resin member and the metal member can be obtained.

In the case of joining by friction stir welding, for example, first, a polypropylene resin member or a metal member having the adhesive of the present invention applied and dried to form an adhesive layer is prepared. The polypropylene resin member and the metal member are superposed via the adhesive layer, and the polypropylene resin member and the metal member are joined by using a friction stir welding device to join the metal member by the frictional heat when the joining tool is pressed against the back surface of the metal member. Can be obtained as a laminated body.

Since the adhesive of the present invention is used for bonding, the adhesive strength between the polypropylene resin member and the metal member constituting the laminate of the present invention can be 2 MPa or more, and the adhesive strength must be 6 MPa or more. preferable. If the adhesive strength of the laminate is 2 MPa or more, it can exhibit sufficient performance in some applications such as home appliances and OA equipment where the adhesive of the present invention is expected to be used, and if it is 6 MPa or more. , Sufficient performance can be exhibited in various applications such as automobile parts.
Further, the laminate of the present invention can have a bonding strength retention rate of 50% or more in a water resistance test, a chemical resistance test, or the like, and the retention rate is preferably 70% or more, preferably 90% or more. Is more preferable. If the retention rate of the laminated body is 70% or more, sufficient bonding strength can be maintained even in an environment where water or various chemicals come into contact with the laminated body.
The adhesive strength can be evaluated by a known method, and as an example, it can be evaluated by measuring the tensile shear stress with a tensile tester.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited thereto.
Various characteristics were measured or evaluated by the following methods.

1. 1. Polyolefin resins (I), (II)
(1) Content of unsaturated carboxylic acid component The content of unsaturated carboxylic acid component contained in the polyolefin resin is determined by infrared absorption spectrum analysis (Perkin Elmer System-2000 Fourier transform infrared spectrophotometer, resolution 4 cm ^-1 ). Obtained by.

(2) Composition of resin other than unsaturated carboxylic acid component The mass ratio of the component other than the unsaturated carboxylic acid component contained in the polyolefin resin is ^{1 1} H-NMR at 120 ° C. in orthodichlorobenzene (d ₄ ), ¹³ It was determined by performing C-NMR analysis (manufactured by Varian, 300 MHz). ^{13 In} C-NMR analysis, measurement was performed based on a gated decoupling method in consideration of quantitativeness.

(3) Weight average molecular weight For the weight average molecular weight, GPC analysis (HLC-8020 manufactured by Tosoh Co., Ltd., two KF-804L columns manufactured by SHODEX and one KF805L manufactured by SHODEX were linked and used) was used, and tetrahydrofuran was used as the eluent. , The flow rate was 1 mL / min, and the measurement was carried out at 40 ° C. Approximately 10 mg of resin was dissolved in 5.5 mL of tetrahydrofuran, and the sample filtered through a PTFE membrane filter was used as a measurement sample. The weight average molecular weight was determined from the calibration curve prepared with a polystyrene standard sample. If it was difficult to dissolve in tetrahydrofuran, it was dissolved in ortodichlorobenzene.

2. 2. Aqueous dispersions of polyolefin resins (I) and (II) (1) Number average particle size, weight average particle size, and degree of dispersion of polyolefin resin particles Using a Nanotrac Wave-UZ152 particle size distribution measuring device manufactured by Nikkiso Co., Ltd. The average particle size (mn) and the weight average particle size (mw) were measured. The refractive index of the resin was 1.5.
The degree of dispersion was calculated based on the following formula.
Dispersity = weight average particle size (mw) / number average particle size (mn)

(2) Zeta potential Measured using the apparatus described in (1) above.

(3) Viscosity The aqueous dispersion after 300 mesh filtration was measured for rotational viscosity (mPa · s) at a temperature of 20 ° C. using a B-type viscometer (DVL-BII type digital viscometer manufactured by Tokimec).

3. 3. Laminated body (polypropylene resin member / adhesive layer / metal member)
(1) Initial strength 20 of the laminates (polypropylene resin member / adhesive layer / metal member) produced in each Example, Comparative Example and Reference Example using a tensile tester (Intesco Precision Universal Material Tester 2020). The joint strength of the laminate was measured by a tensile shear test under the condition of a tensile speed of 100 mm / min in an atmosphere of ° C. and 65% RH. The measurement was performed with 15 samples, and the average value was defined as the adhesive strength (initial strength) and evaluated according to the following criteria.
⊚: 6 MPa or more ○: 2 MPa or more, less than 6 MPa ×: less than 2 MPa

(2) Water resistance The laminates prepared in each Example, Comparative Example and Reference Example were immersed in warm water at 50 ° C. for 24 hours.
After the immersion, the laminate dried at room temperature for 24 hours was subjected to a tensile shear test in the same manner as in (1) above, and the joint strength was measured. From the joint strength before and after immersion in hot water, the retention rate of the joint strength was calculated based on the following formula, and the water resistance was evaluated according to the following criteria.
[Joint strength retention rate] (%) = [Joint strength after immersion in warm water] / [Initial strength] x 100
⊚: Bond strength retention rate is 90% or more ○: Bond strength retention rate is less than 90%, 70% or more Δ: Bond strength retention rate is less than 70%, 50% or more ×: Bond strength retention rate is less than 50%

(3) Ink resistance The laminates prepared in each Example, Comparative Example and Reference Example were immersed in ink at 50 ° C. (yellow ink contained in Epson printer ink cartridge ICY54L) for 24 hours.
After the immersion, the laminate dried at room temperature for 24 hours was subjected to a tensile shear test in the same manner as in (1) above, and the joint strength was measured. From the bonding strength before and after ink immersion, the retention rate of bonding strength was calculated based on the following formula, and the ink resistance was evaluated according to the following criteria.
[Joint strength retention rate] (%) = [Joint strength after ink immersion] / [Initial strength] x 100
⊚: Bond strength retention rate is 90% or more ○: Bond strength retention rate is less than 90%, 70% or more Δ: Bond strength retention rate is less than 70%, 50% or more ×: Bond strength retention rate is less than 50%

(4) Alcohol resistance The laminates prepared in each Example, Comparative Example and Reference Example were immersed in isopropanol at 50 ° C. for 24 hours.
After the immersion, the laminate dried at room temperature for 24 hours was subjected to a tensile shear test in the same manner as in (1) above, and the joint strength was measured. From the bonding strength before and after immersion in alcohol, the retention rate of the bonding strength was calculated based on the following formula, and the alcohol resistance was evaluated according to the following criteria.
[Joint strength retention rate] (%) = [Joint strength after immersion in alcohol] / [Initial strength] x 100
⊚: Bond strength retention rate is 90% or more ○: Bond strength retention rate is less than 90%, 70% or more Δ: Bond strength retention rate is less than 70%, 50% or more ×: Bond strength retention rate is less than 50%

(5) Heat for surface melting From the laminates (polypropylene resin member / adhesive layer / metal member) produced in each Example, Comparative Example and Reference Example, a surface layer of about 0.5 mm of the polypropylene resin member in contact with the adhesive layer was cut out. Approximately 8 mg is precisely weighed and measured using an input compensation type differential scanning calorimetry device (Diamond DSC type manufactured by Perkin Elmer, detection range: -50 ° C to 200 ° C) at a heating rate of 10 ° C / min. The area of the melting peak in the obtained temperature rise curve (first run) was determined and used as the surface melting heat amount.

Resins for polyolefin resins (I) and (II) were produced by the following methods.
Production Example 1: Polyolefin resin P-1
After 280 g of a propylene-butene copolymer (mass ratio: propylene / 1-butene = 80/20) was heat-dissolved in 470 g of xylene in a four-necked flask in a nitrogen atmosphere, the temperature inside the system was maintained at 140 ° C. Under stirring, 40.0 g of maleic anhydride as an unsaturated carboxylic acid and 28.0 g of dicumyl peroxide as a radical generator were added over 2 hours, respectively, and then reacted for 6 hours. After completion of the reaction, the obtained reaction product was put into a large amount of acetone to precipitate a resin.
The precipitated resin is washed once with an acetone solution of triethylamine (mass ratio: triethylamine / acetone = 1/4), and then washed with acetone to remove unreacted maleic anhydride, and then a vacuum dryer. The polyolefin resin P-1 was obtained by drying under reduced pressure. The characteristics of the obtained resin are shown in Table 1.

Production Examples 2, 4, 5, 6, 7: Polyolefin Resin P-2, 4, 5, 6, 7
In Production Example 2, a propylene-butene copolymer having a mass ratio of propylene / 1-butene = 65/35, and in Production Example 4, a propylene-ethylene copolymer having a mass ratio of propylene / ethylene = 92/8. In Production Example 5, a propylene-butene-ethylene copolymer having a mass ratio of propylene / 1-butene / ethylene = 65/24/11 was used, and in Production Example 6, a mass ratio of propylene / 1-butene = 97. The same operation as in Production Example 1 except that the propylene-butene copolymer of / 3 was used in Production Example 7 and the propylene-butene copolymer having a mass ratio of propylene / 1-butene = 50/50 was used. To obtain polyolefin resins P-2, 4, 5, 6 and 7, respectively.

Production Example 3: Polyolefin Resin P-3
After 280 g of a propylene-butene copolymer (mass ratio: propylene / 1-butene = 80/20) was heated and dissolved in 470 g of chlorobenzene in a four-necked flask under a nitrogen atmosphere, the temperature inside the system was maintained at 130 ° C. Under stirring, 9.5 g of maleic anhydride as an unsaturated carboxylic acid and 10.0 g of dicumyl peroxide as a radical generator were added over 2 hours, respectively, and then reacted for 10 hours. After completion of the reaction, the obtained reaction product was put into a large amount of acetone to precipitate a resin, which was then dried under reduced pressure in a vacuum drier to obtain a polyolefin resin P-3.

Production Example 8: Polyolefin resin P-8
The same method as in Production Example 1 was carried out except that the amount of maleic anhydride added was 2.0 g instead of 40.0 g and the amount of dicumyl peroxide added was 1.4 g instead of 28.0 g. , Polyolefin resin P-8 was obtained.

Production Examples 9 and 10: Polyolefin resins PA-1, PA-2
Based on the methods described in British Patent 2091745, US Patent 4617366 and US Patent 4644044, an ethylene-ethyl acrylate-maleic anhydride copolymer was prepared, and an acetone solution of triethylamine (mass ratio: triethylamine / acetone = 1) was prepared. The unreacted maleic anhydride was removed by washing once with / 4) and then with acetone, and then the mixture was dried under reduced pressure in a vacuum drier to obtain polyolefin resins PA-1 and PA-2.

Table 1 shows the configurations and characteristics of the polyolefin resins P-1 to 8 and PA-1 to 2 obtained in Production Examples 1 to 10.

Aqueous dispersions of polyolefin resins (I) and (II) were prepared by the following methods.
Preparation Example 1
Using a stirrer equipped with a sealed glass container with a pressure resistance of 1 L with a heater, 60.0 g of polyolefin resin P-1, 45.0 g of ethylene glycol-n-butyl ether, and 8.0 g of N, N-dimethylethanol. When amine (DMEA) and 137.0 g of distilled water were placed in a glass container and stirred at a stirring blade rotation speed of 300 rpm, no resin sedimentation was observed at the bottom of the container, and the container was in a floating state. Was confirmed. Therefore, while maintaining this state, the heater was turned on and heated after 10 minutes. Then, the temperature inside the system was maintained at 160 ° C., and the mixture was further stirred for 60 minutes.
Then, it was cooled by air cooling until the internal temperature became 80 ° C., opened, and 45.0 g of tetrahydrofuran, 5.0 g of DMEA and 30.0 g of distilled water were added. Then, the mixture was sealed, the rotation speed of the stirring blade was set to 300 rpm, the temperature inside the system was maintained at 140 ° C., and the mixture was further stirred for 60 minutes.
Then, after cooling to room temperature (about 25 ° C.) while stirring at a rotation speed of 300 rpm by air cooling, pressure filtration (air pressure 0.2 MPa) is performed with a 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weave). , A slightly cloudy aqueous dispersion E-1 was prepared. At this time, almost no resin remained on the filter.

Preparation Examples 2-7
Instead of the polyolefin resin P-1, P-2 in Preparation Example 2, P-3 in Preparation Example 3, P-4 in Preparation Example 4, P-5 in Preparation Example 5, and P- in Preparation Example 6. Aqueous dispersions E-2 to 7 were prepared in the same manner as in Preparation Example 1 except that P-7 was used in Preparation Example 7.

Preparation Example 8
When the same operation as in Preparation Example 1 was performed except that P-8 was used instead of the polyolefin resin P-1, a large amount of resin was confirmed on the filter. The polyolefin resin P-8 did not substantially disperse, and an aqueous dispersion of the polyolefin resin P-8 could not be prepared.

Preparation Example 9
A 2 L glass container equipped with a stirrer and a heater was charged with 50 g of polyolefin resin PA-1, 150 g of n-propanol, 3 g of DMEA and 297 g of distilled water. When the stirring blade was stirred at a rotation speed of 300 rpm, no precipitation of resin granules was observed at the bottom of the container, and it was confirmed that the stirring blade was in a floating state. Therefore, while maintaining this state, the heater was turned on and heated after 10 minutes. Then, the temperature inside the system was maintained at 130 ° C., and the mixture was further stirred for 120 minutes to disperse. Then, when the mixture was cooled to about 80 ° C. with stirring at a rotation speed of 300 rpm, the pressure inside the system was gradually reduced to remove n-propanol and water. After removing 300 g or more of n-propanol and water, when the temperature inside the system reaches 35 ° C., water is added to adjust the concentration of the polyolefin resin in the aqueous dispersion to 20% by mass, and 180 mesh. The aqueous dispersion EA-1 was prepared by pressure filtration through the stainless steel filter of.

Preparation Example 10
An aqueous dispersion EA-2 was prepared by carrying out the same operation as in Preparation Example 9 except that PA-2 was used instead of the polyolefin resin PA-1.

Preparation Example 11
In Preparation Example 1, except that Neugen EA-190D (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., a nonionic surfactant), which is a non-volatile aqueous aid, was added so as to be 3% by mass with respect to the polyolefin resin. The resin was made water-based by the same method to prepare an aqueous dispersion E-9.

Table 1 shows the physical characteristics of the aqueous dispersions prepared in Preparation Examples 1 to 11.

The following substances were used as the cross-linking agent and urethane resin.
Oxazoline group-containing cross-linking agent: Epocross WS-500 (manufactured by Nippon Shokubai Co., Ltd., solid content concentration 39% by mass)
Epoxy group-containing cross-linking agent: Adeka Resin EM-0517 (manufactured by ADEKA, solid content concentration 51% by mass)
Silane coupling agent: KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd., 100% active ingredient)
Urethane resin emulsion: Takelac W-6010 (manufactured by Mitsui Chemicals, solid content concentration 30% by mass)

Reference example 8
An aqueous dispersion E-1 of polyolefin resin P-1 is used as an adhesive, and a resin layer after drying with a bar coater is used on the surface of a 1.0 mm thick aluminum alloy plate (chromate treated, acetone degreased). Was applied so as to have a thickness of 30 μm, and heated at 120 ° C. for 10 minutes to obtain a metal plate having an adhesive layer.
Next, the metal plate having the adhesive layer was cut into 100 mm × 25 mm, and a polypropylene resin molded piece containing 30% by mass of glass fiber (manufactured by Prime Polymer Co., Ltd .; Prime Polypro E7000, 100 mm × 23 mm × 3 mm injection molded product). , Corona treated, acetone degreased) and 16 mm long x 23 mm wide, and heat-pressed with a press machine at 130 ° C. and 0.1 MPa for 3 minutes from the polypropylene resin member / adhesive layer / metal member. A laminate was obtained.

Examples 15 to 20, Reference Examples 9 to 21, Comparative Examples 1 to 8
The types of polyolefin resins (I) and (II), cross-linking agents, and polyurethane resins, and the mass parts of the solid content (active ingredient) are as shown in Tables 2 and 3, and the respective aqueous dispersions and the like are used. The mixture was mixed to prepare an aqueous dispersion of polyolefin resin.
A laminate composed of a polypropylene resin member / adhesive layer / metal member was obtained in the same manner as in Reference Example 8 except that the obtained aqueous dispersion was used as an adhesive.

Examples 23 to 24, Reference Examples 22 to 23, Comparative Example 9
A metal plate having an adhesive layer was obtained in the same manner as in Examples 1 6 and 20, Reference Examples 8 and 21, and Comparative Example 6.
Next, insert molding was performed using an injection molding machine (manufactured by Nissei Resin Industry Co., Ltd .; NEX-110). That is, the metal plate having the adhesive layer is cut into 100 mm × 25 mm, placed in a mold, and a polypropylene resin (manufactured by Prime Polymer Co., Ltd .; Prime Polypro E7000) containing 30% by mass of glass fibers is melted to obtain 100 mm ×. Injection molding was performed so as to have a thickness of 23 mm × 3 mm. The resin and the metal plate were adhered so as to overlap each other in a length of 8 mm × a width of 23 mm to obtain a laminate composed of a polypropylene resin member / adhesive layer / metal member. At this time, the injection conditions were a cylinder temperature of 240 ° C., a resin molding temperature of 240 ° C., a mold temperature of 50 ° C., an injection pressure of 50 MPa, an injection holding time of 6.5 seconds, and a cooling time of 25 seconds.

Example 26-27, Example 24, Comparative Example 10
Example 1 6,20, Reference Example 8, in the same manner as in Comparative Example 6, respectively, to obtain a metal plate having an adhesive layer.
Next, the metal plate having the adhesive layer was cut into 100 mm × 25 mm, and a polypropylene resin molded piece containing 30% by mass of glass fiber (manufactured by Prime Polymer Co., Ltd .; Prime Polypro E7000, 100 mm × 23 mm × 3 mm injection molded product). , Corona treated, acetone degreased) and 16 mm long x 23 mm wide, and heat-pressed with a press machine at 100 ° C. and 0.1 MPa for 10 minutes from the polypropylene resin member / adhesive layer / metal member. A laminate was obtained.

Reference examples 1-3
A metal plate having an adhesive layer was obtained in the same manner as in Reference Example 8 and Comparative Examples 1 and 3, respectively.
Next, the metal plate having the adhesive layer was cut into 100 mm × 25 mm, and an unstretched polypropylene film (manufactured by Mitsui Chemicals Tohcello Co., Ltd .; CP GHC, length direction 100 mm × width direction 23 mm × thickness 50 μm, corona treated, acetone Degreased, hereinafter referred to as "CPP"), overlapped with a length of 16 mm x width of 23 mm, heat-bonded with a press machine at 100 ° C. and 0.1 MPa for 1 minute, and then in the length direction of the overlapped portion. A laminate made of a polypropylene resin member / adhesive layer / metal member was obtained by making a notch in the CPP so that 1 mm was joined. The joint area in the laminated body is 1 mm length × 23 mm width.

Reference examples 4 to 6
A metal plate having an adhesive layer was obtained in the same manner as in Reference Example 8 and Comparative Examples 1 and 3, respectively.
Next, the metal plate having the adhesive layer was cut into 100 mm × 25 mm, and a stretched polypropylene film (manufactured by Mitsui Chemicals Tohcello Co., Ltd .; OPU-1, length direction 100 mm × width direction 23 mm × thickness 50 μm, corona treated, It is laminated with acetone degreased (hereinafter referred to as "OPP") in a length of 16 mm x width of 23 mm, heat-bonded with a press machine at 120 ° C. and 0.1 MPa for 1 minute, and then the length of the overlapped portion. A notch was made in the OPP so that 1 mm was joined in the direction to obtain a laminate composed of a polypropylene resin member / adhesive layer / metal member. The joint area in the laminated body is 1 mm length × 23 mm width.

Reference example 7
In Reference Example 8 , the same operation was carried out except that the aqueous dispersion E-9 was used instead of the aqueous dispersion E-1, to obtain a laminate composed of a polypropylene resin member / adhesive layer / metal member.

The test results using the laminate composed of the polypropylene resin member / adhesive layer / metal member obtained in Examples 15 to 20 , 23 to 24 , 26 to 27, Comparative Examples 1 to 10 and Reference Examples 1 to 24 are shown in the table. Shown in 2 and 3.
The amount of heat of surface melting of the polypropylene resin member in contact with the adhesive layer in the obtained laminate was 103 J / g for the injection-molded product, 57 J / g for the CPP, and 78 J / g for the OPP.

The laminates of Examples 15 to 20 and 23 to 24 are bonded via an adhesive layer obtained from an adhesive containing the polyolefin resin (I) specified in the present invention, and are bonded to a polypropylene resin member having a large amount of heat of surface melting. It was excellent in bonding strength, and also excellent in water resistance, ink resistance, and alcohol resistance. In both the thermocompression bonding and insert molding joining methods, the laminate showed good bondability, and in particular, the insert molded laminate showed strong bondability. Further, even in the laminates of Examples 26 to 27 in which thermocompression bonding was performed at a low temperature, sufficient bonding strength was obtained, and water resistance, ink resistance, and alcohol resistance were also excellent.
In the laminates of Examples 1 9 to 20 , 24 , and 27, water resistance, ink resistance, and alcohol resistance were improved because the adhesive contained a cross-linking agent and / or a polyurethane resin.
In the laminates of Examples 15 to 20, 23 to 24, and 26 to 27, since the adhesive contained the polyolefin resin (II), the water resistance, ink resistance, and alcohol resistance were dramatically improved.

On the other hand, in Comparative Examples 1 to 6 and 9 to 10, the composition of the polyolefin resin (I) is out of the range specified in the present invention, and the laminate is inferior in initial bonding strength, and is also water resistant and ink resistant. It was also inferior in properties and alcohol resistance.
In Comparative Examples 7 to 8, since the polyolefin resin of the adhesive was only the polyolefin resin (II) and did not contain the polyolefin resin (I), the laminate was inferior in the initial bonding strength.

Reference Examples 1 to 6 are examples in which CPP or OPP having a surface melting heat amount less than the specification of the present invention is used as a polypropylene resin member for bonding. For polypropylene resin members with a small amount of heat for surface melting, good bonding properties can be obtained by using an adhesive containing a polyolefin resin (I) specified in the present invention as well as an adhesive containing a non-specified polypropylene resin. Has been obtained.

In the adhesive of Reference Example 7 containing a surfactant in the aqueous dispersion, although the initial bonding strength was good, water resistance, ink resistance, and alcohol resistance were not exhibited.

Claims (6)

An adhesive for polypropylene resin members having a surface melting heat of 80 J / g or more.
It comprises a polyolefin resin aqueous dispersion containing a polyolefin resin (I), a polyolefin resin (II), and an aqueous medium.
The polyolefin resin (I) contains an olefin component and an unsaturated carboxylic acid component as a copolymer component,
The olefin component consists of propylene (A) and olefin (B) other than propylene.
The olefin (B) other than propylene contains butene and does not contain ethylene.
The mass ratio (A / B) of propylene (A) to olefin (B) other than propylene is 60/40 to 95/5.
Propylene and (A), the total of 100 parts by mass of the non-propylene olefin (B), the content of the unsaturated carboxylic acid component as the copolymer component state, and are at least 1 part by weight,
The polyolefin resin (II) contains an olefin component, a (meth) acrylic acid ester component, and an unsaturated carboxylic acid component as a copolymer component.
The total 100 parts by weight of the polyolefin resin (I) and the polyolefin resin (II), the adhesive content, characterized by 10 to 50 parts by mass der Rukoto of the polyolefin resin (II). The adhesive according to claim 1, further characterized in that the polyolefin resin aqueous dispersion contains a cross-linking agent and / or a polyurethane resin. A polypropylene resin member having a surface melting heat of 80 J / g or more.
A polypropylene resin member characterized in that an adhesive layer formed of the adhesive according to claim 1 or 2 is laminated. It is a metal member
A metal member characterized in that an adhesive layer formed of the adhesive according to claim 1 or 2 is laminated. A laminate characterized in that a polypropylene resin member having a surface melting heat amount of 80 J / g or more and a metal member are joined via an adhesive layer formed by the adhesive according to claim 1 or 2 . The laminated body according to claim 5 .
A laminate characterized in that a polypropylene resin member and a metal member are joined by a thermocompression bonding method or an insert molding method via an adhesive layer.