JPH08217925A - Heat-sensitive adhesive film and multilayer laminate made thereof - Google Patents

Abstract

PURPOSE: To obtain a heat-sensitive adhesive film excellent in low-temperature adhesiveness and having excellent adhesion to various substrates and high heat creep resistance by mixing a specified ethylene copolymer with a polyhydric alcohol compound and a reaction promoter. CONSTITUTION: This heat-resistant adhesive film has a thickness of 10-150μm and comprises an ethylene copolymer (A) being a multi-component copolymer comprising ethylene, a radical-polymerizable acid anhydride and a radical- polymerizable comonomer other than the former anhydride and having a content of units derived from one radical-polymerizable acid anhydride of 0.1-5wt.% and a content of units derived from the other radical-polymerizable comonomer of 10-50wt.%, a polyhydric alcohol compound (B) having at least two OH groups in the molecule and a reaction promoter (C), wherein the molar ratio of the units derived from the radical-polymerizable acid anhydride of component A to the units of the hydroxyl groups of component B is 0.01-10, and the amount of component C is 0.001-20 pts.wt. per 100 pts.wt. component A.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a heat-sensitive adhesive film and a multilayer laminate using the adhesive film. Specifically, automobiles and vehicles that have strong adhesiveness to a wide variety of base materials that are used daily and have excellent heat resistance, and in particular, require both low-temperature heat adhesiveness and high-temperature heat-resistant creep resistance at the same time. The present invention relates to a heat-sensitive adhesive film made of a specific resin composition, which is suitable as an adhesive for use in an adhesive layer of a multilayer laminate for interior materials such as ships and houses, and a multilayer laminate using the adhesive film. .

[0002]

2. Description of the Related Art Conventionally, hot-melt type adhesives have been used in the adhesive layers of various multilayer laminates. Unlike solvent-based adhesives, hot-melt adhesives do not require painting, drying, aging, and other work when bonding, and the work process is simple, and the adverse effects on occupational health and fire caused by the use of organic solvents It is widely used because it does not cause problems such as danger.

On the other hand, it has been pointed out that hot-melt type adhesives generally have insufficient adhesive strength as compared with solvent-type adhesives, and in particular often have poor thermal creep resistance.
The applications used were limited. For example, as an interior material for automobiles, vehicles, ships, houses, other buildings,
A multi-layer laminate is used in which a skin material for enhancing indoor habitability and aesthetics and a substrate material for maintaining and enhancing functionality are laminated, and is conventionally used as an adhesive layer for this multi-layer laminate. Ethylene- (meth) acrylic acid ester-maleic anhydride copolymer (for example, Japanese Patent Publication No. 62-1294).
6, JP-A-57-80469, JP-A-5-14717
5,), ethylene-vinyl acetate copolymer (for example, JP-B-56-2112, JP-A-57-158276, JP-B-62-21835, JP-B-62-14592, JP-B-1.
-18955), a partially saponified ethylene-vinyl acetate copolymer (for example, JP-B-60-31350), an ethylene-acrylic acid ester copolymer (for example, JP-B-58-).
17514, JP-B-63-50366, JP-B-56-5
4350) or low melting point copolymer nylon (for example, Japanese Patent Publication No. 56-41671, Japanese Patent Publication No. 57-8838, Japanese Patent Publication No. 61-7234, Japanese Patent Publication No. 55-4352, and Japanese Patent Laid-Open No. 55-
65280, JP-A-55-54374, JP-A-56-4
Hot melt type adhesives such as 1672,) have the drawback that when they are left at a high temperature (about 80 ° C.) such as the temperature in the car under hot weather for a long time, they easily sag or peel off.

In order to impart heat resistance to a hot melt adhesive, a crosslinkable hot melt adhesive having a (pseudo) crosslinked structure introduced therein has been proposed. For example, a method of introducing a crosslinked structure by reacting a resin based on an ethylene acid anhydride-containing copolymer with a polyfunctional compound capable of reacting with an acid anhydride group (for example, an epoxy resin) in the presence of a reaction catalyst (for example, Tokuyo Sho 63-503549, Tokuhei 3-6936
5), a method of crosslinking a partially saponified ethylene-vinyl acetate copolymer with a polyisocyanate compound, an organic peroxide, etc. (for example, JP-A-58-217575, JP-A-56-56).
165074), a method of crosslinking a low-melting polyamide with a polyfunctional acid anhydride or the like (for example, JP-A-61-134747).
7) etc. However, in these conventional methods, the adhesive strength in low temperature adhesion and the heat resistant adhesiveness were not sufficient. The bonding strength can be increased by setting the heating temperature at a relatively high temperature of 120 ° C. or more during bonding, but in this case, there is a drawback that the skin material is likely to be damaged. Further, since the crosslinking reaction proceeds at the same time as mixing the respective components constituting the crosslinkable hot melt adhesive, it is necessary to perform the mixing immediately before the film forming or the bonding step. At that time, there was a problem that the heat stability was low and the mixture stayed in the film molding machine and a cross-linked product was generated as so-called gel lumps, which deteriorated the appearance of the molded film.

Further, conventionally, as a method for laminating and bonding a multilayer laminated body, a method using a hot press or a hot roll, as well as a method by vacuum pressure bonding has been used. In the method using a heat press or a heat roll, it is possible to use a conventional heat-sensitive adhesive because a sufficient pressure can be obtained,
Since a pressure of up to 760 mmHg / cm ² can be obtained at the maximum by the vacuum pressure bonding method, conventional ethylene-vinyl acetate copolymers, partially saponified ethylene-vinyl acetate copolymers, ethylene- (meth) acrylic acid ester copolymers are used. With heat-sensitive adhesives such as polymers and copolymer nylon, only extremely weak adhesive strength was obtained, and there was no choice but to use solvent-based adhesives, but it has the drawback of complicating the work process and increasing manufacturing costs. However, there are environmental and hygiene problems due to the use of organic solvents.

[0006]

The object of the present invention is to solve the above problems in the prior art and to be used as an adhesive layer for laminates for a wide range of applications, and particularly as an adhesive layer for interior materials for automobiles and the like. In this case, it is to provide a heat-sensitive adhesive film that simultaneously satisfies good low-temperature adhesiveness and heat-resistant creep resistance with respect to a skin material and a substrate material.

[0007]

In view of the above situation, the present inventors have conducted earnest studies to develop a heat-sensitive adhesive film that overcomes the drawbacks of the prior art. As a result, a heat-sensitive adhesive film consisting of a specific ethylene-based multi-component copolymer, a polyhydric alcohol compound having at least two hydroxyl groups in the molecule, and a reaction accelerator has high adhesive strength and heat resistance to a wide range of substrates. It has been found that, in addition to having creep properties, when the film is extrusion-molded, it has good thermal stability at a relatively high extrusion temperature and does not generate gels or lumps.
The present invention has been completed based on such findings.

That is, the gist of the present invention is (1) a multi-component copolymer comprising ethylene, a radical-polymerizable acid anhydride, and a radical-polymerizable comonomer other than the radical-polymerizable acid anhydride. Radical polymerization in the copolymer The ratio of the units derived from the acid anhydride is 0.1% by weight or more and 5% by weight or less, and the ratio of the units derived from other radically polymerizable comonomers is 10% or less.
To 50% by weight of ethylene-based copolymer, (2) a polyhydric alcohol compound having at least two hydroxyl groups in the molecule, and (3) a reaction accelerator, which is a radical-polymerizable acid anhydride in component (1). The molar ratio of the unit of the hydroxyl group in the polyhydric alcohol compound, which is the component (2), to the derived unit is in the range of 0.01 to 10, and the reaction accelerator, which is the component (3), is the component (1). Ethylene-based copolymer 100
A heat-sensitive adhesive film having a thickness of 10 μm to 150 μm inclusive, and a multilayer laminate using the adhesive film, in the range of 0.001 to 20 parts by weight with respect to parts by weight.

The ethylene-based copolymer which is the component (1) constituting the heat-sensitive adhesive film of the present invention is a multi-component composed of ethylene, a radical-polymerizable acid anhydride and a radical-polymerizable comonomer other than the radical-polymerizable acid anhydride. It is a copolymer. Here, the radical-polymerizable acid anhydride is a compound having at least one radical-polymerizable unsaturated bond and at least one acid anhydride group in the molecule, and capable of introducing an acid anhydride group into the molecule by polymerization. Means The acid anhydride group is preferably cyclic. Examples of such a compound include maleic anhydride, itaconic anhydride, citraconic anhydride, endic acid anhydride, dodecenyl succinic anhydride, 1-butene-
Examples thereof include 3,4-dicarboxylic acid anhydride, and alkadienyl succinic anhydride having a double bond at the terminal having at most 18 carbon atoms. These may be used alone or in combination of two or more kinds. Among these, maleic anhydride and itaconic anhydride are particularly preferable.

The ratio of the units derived from the radical-polymerizable acid anhydride in the ethylene copolymer as the component (1) is 0.
It is necessary to be in the range of 1 to 5% by weight, preferably 0.5 to 4.5% by weight, and particularly preferably 1.0 to 3.5% by weight. If the proportion of the radical-polymerizable acid anhydride is less than 0.1% by weight, the adhesive performance is insufficient and good adhesive strength cannot be obtained, and sufficient crosslink density cannot be obtained, resulting in sufficient heat creep resistance. I can't get it. On the other hand, if it exceeds 5% by weight, there is almost no effect of improving the adhesive strength, and further, it becomes difficult to manufacture it commercially, which is not preferable.

There are various compounds as the radical-polymerizable comonomer other than the radical-polymerizable acid anhydride constituting the ethylene-based copolymer as the component (1), such as an ethylenically unsaturated ester compound and an ethylene-based copolymer. Unsaturated amide compounds, ethylenically unsaturated acid compounds, ethylenically unsaturated ether compounds, ethylenically unsaturated hydrocarbon compounds,
Other compounds may be mentioned.

More specifically, the ethylenically unsaturated ester compounds include, for example, vinyl acetate, methyl (meth) acrylate, ethyl (meth) acrylate,
Propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, lauryl (meth) acrylate, benzyl (meth) acrylate, methyl fumarate, ethyl fumarate, Propyl fumarate, butyl fumarate, dimethyl fumarate,
Diethyl fumarate, dipropyl fumarate, dibutyl fumarate, methyl maleate, ethyl maleate, propyl maleate, butyl maleate, dimethyl maleate,
Examples thereof include diethyl maleate, dipropyl maleate, dibutyl maleate and the like. Examples of the ethylenically unsaturated amide compound include (meth) acrylamide and N-
Methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-propyl (meth) acrylamide,
N-butyl (meth) acrylamide, N-hexyl (meth) acrylamide, N-octyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N,
N-diethyl (meth) acrylamide etc. are mentioned.
Examples of the ethylenically unsaturated acid compound include (meth) acrylic acid, maleic acid, fumaric acid and the like. Examples of the ethylenically unsaturated ether compound include methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octadecyl vinyl ether, phenyl vinyl ether and the like.
Examples of the ethylenically unsaturated hydrocarbon compound include styrene, α-methylstyrene, norbornene, butadiene and the like. As other compounds, for example,
(Meth) acrylonitrile, acrolein, crotonaldehyde, trimethoxyvinylsilane, vinyl chloride, vinylidene chloride, N-vinylacetamide and the like can be mentioned. Among these, methyl (meth) acrylate, ethyl (meth) acrylate, and butyl (meth) acrylate are mentioned as particularly preferable compounds. These monomers may be used alone or in combination of two or more.

The ratio of the units derived from the radical-polymerizable comonomer in the ethylene copolymer which is the component (1) is 1
The amount is in the range of 0 to 50% by weight, preferably 10 to 40% by weight, more preferably 12 to 35% by weight. Here, the ratio of the radically polymerizable comonomer is 10
If it is less than wt%, the crystal melting point of the ethylene-based copolymer will not be sufficiently lowered, and the low temperature adhesiveness will not be sufficiently exhibited. On the other hand, if it exceeds 50% by weight, it becomes difficult to handle the resin and the heat resistance of the product deteriorates. Although various methods such as radical polymerization can be used as a method for producing the above-mentioned component (1), an ethylene-based copolymer, generally, a high-pressure process low-density polyethylene production facility and a technique therefor are generally used. Is manufactured using.

The ethylene-based copolymer which is the component (1) is
Since the resin composition of the present invention melts at a relatively low temperature and is rich in physicochemical interaction with various substrates and reactivity, it is possible for the resin composition of the present invention to exhibit a high adhesive force even during low temperature molding. Play a big role.

The polyhydric alcohol compound having at least two hydroxyl groups in the molecule, which is the component (2) constituting the heat-sensitive adhesive film of the present invention, means a compound having two or more hydroxyl groups, a so-called crosslinking agent. It has a function as. Examples of such polyhydric alcohol compounds include ethylene glycol, glycerin, 1,4
Alcohol compounds such as butanediol, 1,6 hexanediol, 1,8 octanediol, 1,10 decanediol, trimethylolmethane, trimethylolethane, trimethylolpropane and pentaerythritol;
Polyethylene glycols such as diethylene glycol, triethylene glycol and tetraethylene glycol; polyglycerins such as diglycerin, triglycerin and tetraglycerin; arbitol, sorbitol, xylose, arabinose, glucose, galactose, sorbose, fructose, palatinose, maltotriose, maresitose. , Saccharides such as sorbitan; dehydration condensation products of these saccharides; polyoxyalkylene compounds obtained by adding ethylene oxide or propylene oxide to the above various compounds; compounds obtained by partially esterifying the above various compounds with carboxylic acids; A compound obtained by partially esterifying the above polyoxyalkenylene compound with a carboxylic acid; and further adding ethylene oxide or ethylene oxide to the above partially esterified compound. Polyoxyalkylene compound to which ropylene oxide is added; saponified product of ethylene-vinyl acetate copolymer, polyvinyl alcohol, polyolefin oligomer having two or more hydroxyl groups, hydroxyl group of ethylene-hydroxyethyl (meth) acrylate copolymer, etc. The polymer etc. which have the above can be mentioned.

The melting point of the polyhydric alcohol compound is preferably 300 ° C. or lower. Further, these polyhydric alcohol compounds may be used in combination of two or more kinds at the same time.
Particularly preferred as the polyhydric alcohol compound as the component (2) is at least one compound selected from the following polyhydric alcohols. These compounds, in addition to having a function as a so-called cross-linking agent, impart thermal stability to the composition constituting the heat-sensitive adhesive film according to the present invention and, when molded at a relatively high temperature, form a gel in a molded body. , It has the effect of preventing the formation of spots.

First, the following general formula (I) (R ¹ ) _a C (CH ₂ 0H) _b (I) is used, wherein R ¹ is hydrogen or a chain or cyclic alkyl group having 1 to 12 carbon atoms. Represents an aralkyl group, a represents an integer of 0 to 2, b represents an integer of 2 to 4, and a
Selected to satisfy + b = 4. Or the following general formula _{(II) CH 2 (OH)} CH (OH) CH 2 O [CH 2 CHOHCH 2 O] m H (II) [ wherein, m is an integer of 0. Polyhydric polyoxyalkylene compound having ethylene oxide or propylene oxide was added to the structure to an alcohol compound or the following formula ^{(III) R 2 -COOH (III} ) [ wherein represented by], R ² is a carbon number 2 to 25 Represents a chain alkyl group, a cyclic alkyl group, an aralkyl group or an alkenyl group. ] One or more of polyglycerin esters having two or more hydroxyl groups in the molecule, which are obtained by dehydration condensation of the organic carboxylic acid compound represented by the above and the polyglycerin represented by the general formula (II). .

The above polyoxyalkylene compound can be easily prepared by adding ethylene oxide or propylene oxide to the polymethylol represented by the general formula (I) or the polyglycerin represented by (II) by an ordinary method. Can be obtained. Here, as the polymethylol represented by the general formula (I), for example, 1,3-dihydroxypropane; 2,2-dimethyl-1,3-dihydroxypropane; trimethylolethane; 1,1,1-trimethylol Propane; 1,1,1-trimethylolhexane;
1,1,1-trimethylol dodecane; 2-cyclohexyl-2-methylol-1,3-dihydroxypropane; 2- (p-methylphenyl) -2-methylol-
1,3-dihydroxypropane; pentaerythritol and the like. Examples of the polyglycerin represented by the general formula (II) include glycerin, diglycerin, hexaglycerin, octaglycerin, decaglycerin and the like. Polyoxyalkylene compounds obtained by adding ethylene oxide or propylene oxide to these compounds are usually extremely difficult to obtain as a single compound, and are generally obtained as a mixture of compounds having different structures, It can be used without any problem for the purpose of the present invention. Furthermore, a polyoxyalkylene compound obtained by simultaneously adding ethylene oxide or propylene oxide to two or more polyhydric alcohol compounds represented by the general formulas (I) and / or (II) may be used.

The addition amount of ethylene oxide or propylene oxide to the compound represented by the general formula (I) or (II) depends on the number of hydroxyl groups contained in the above-mentioned compound to be used, and therefore cannot be generally specified. Although not possible, it is preferable to add at least 2 mol of ethylene oxide or propylene oxide to at least 1 mol of the above compound. The upper limit of the addition amount is not particularly limited, but in general, when the addition amount exceeds 50 mols relative to 1 mol of the polyhydric alcohol represented by the general formula (I) or (II), the polyoxyalkylene compound obtained is This is not preferable because the molecular weight becomes too large, the mixing property at the time of adjusting the composition decreases, and problems such as bleeding after molding occur.

The polyglycerin ester has the general formula (III)
Can be easily prepared by dehydration condensation of an organic carboxylic acid represented by or its equivalent (eg, an alkali metal salt, an acid halide, etc.) and polyglycerol represented by the general formula (II) by a generally known method. Can be manufactured. Examples of the organic carboxylic acid represented by the general formula (III) include acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, hexanoic acid, caprylic acid, capric acid, stearic acid, oleic acid, lauric acid, phenylacetic acid and phenylpropione. Acid, phenylbutyric acid, etc. are mentioned. The polyglycerin ester compound used must have two or more hydroxyl groups in the molecule. Therefore, the amount of the organic carboxylic acid used for esterifying the polyglycerin of the general formula (II) needs to be determined in consideration of the number of hydroxyl groups contained in the polyglycerin.

As the polyglycerin ester compound,
For example, glycerin monostearate, glycerin monooleate, glycerin monolaurate, glycerin monocaprylate, glycerin monohexanoate, glycerin monophenethyl ester, glycerin monopropionate, diglycerin monostearate, diglycerin distearate. , Diglycerin monooleate, diglycerin monohexanoate, diglycerin dioctanoate, tetraglycerin monostearate, tetraglycerin tristearate, tetraglycerin tetrastearate, tetraglycerin trihexanoate, tetraglycerin monophenethyl Ester, hexaglycerin monostearate, hexaglycerin distearate, hexaglycerin pentastearate, hexaglycerin triolee Door, hexa-glycerin monolaurate, hexa-glycerin penta laurate, decaglycerol monostearate, decaglycerol octa stearate, decaglycerol pentaoleate, decaglycerol dilaurate, penta decaglycerol distearate,
Examples include pentadecaglycerin decaoleate and octadecaglycerin tetrastearate. Two or more of these polyglycerin esters can be used in combination.

The amount of the polyhydric alcohol compound used as the component (2) is such that the polyhydric alcohol compound is used with respect to the unit derived from the radical-polymerizable acid anhydride contained in the ethylene copolymer of the component (1). It is necessary that the molar ratio of the unit of the hydroxyl group contained in is in the range of 0.01 to 10, and 0.0
It is preferably in the range of 5 to 5. This molar ratio is 0.
When it is less than 01, it is insufficient to introduce the crosslinked structure into the composition in an effective amount. On the other hand, when the molar ratio exceeds 10, it is not preferable because it is meaningless in effectively introducing the crosslinked structure and also the cost becomes high.

The reaction accelerator which is the component (3) constituting the heat-sensitive adhesive film of the present invention is a carbonyl group contained in a unit derived from the radical-polymerizable carboxylic acid anhydride contained in the ethylene copolymer. It is a compound that activates and accelerates the reaction between the hydroxyl group and the acid anhydride. There are various kinds of reaction accelerators, and an example thereof is a metal salt of an organic carboxylic acid.

The metal salt of an organic carboxylic acid is a metal salt of a fatty acid having 1 to 30 carbon atoms, such as acetic acid, butyric acid, octanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, Aliphatic carboxylic acids such as behenic acid, octenoic acid, erucic acid, elaidic acid, adipic acid, malonic acid, succinic acid, glutaric acid, citric acid, tartaric acid, malic acid, diglycolic acid; benzoic acid, chlorobenzoic acid, anise Aromatic carboxylic acids such as acids, aminobenzoic acid, phthalic acid, terephthalic acid, naphthoic acid, naphthalenedicarboxylic acid, and benzenetricarboxylic acid, and metals of Group IA, IIA, IIB, and IIIB of the periodic table (for example, Li, Na, K, Mg, Ca, Zn, Al
Etc.). More specific examples are lithium acetate, sodium acetate, magnesium acetate, aluminum acetate, potassium butyrate, calcium butyrate, zinc butyrate, sodium octanoate, calcium octanoate, potassium decanoate, magnesium decanoate, zinc decanoate, and lauric acid. Lithium, sodium laurate, calcium laurate, aluminum laurate, potassium myristate, sodium myristate, aluminum myristate, sodium palmitate, zinc palmitate, magnesium palmitate, sodium stearate, potassium stearate, calcium stearate, stearic acid Metal salts of aliphatic carboxylic acids such as zinc, sodium oleate and sodium behenate; sodium benzoate, zinc benzoate, sodium phthalate Aluminum phthalic acid, magnesium terephthalate, and metal salts of aromatic carboxylic acids such as naphthalene calcium dicarboxylic acid. Of these, lithium laurate, sodium laurate, calcium laurate,
Aluminum laurate, potassium myristate, sodium myristate, aluminum myristate, sodium palmitate, zinc palmitate, magnesium palmitate, sodium stearate, potassium stearate, calcium stearate, zinc stearate, sodium oleate are preferred. .

Another example of the metal salt of an organic carboxylic acid is a polymer having a metal salt structure of a carboxylic acid. Such polymers include ethylene and radically polymerizable carboxylic acids of Group IA, Group IIA, Group IIB, and Group IIIB metals (eg, Li, Na, K, Mg, Ca, Zn, Al, etc.).
Examples thereof include those having a structure in which a salt is copolymerized, and those having a structure in which a metal salt of ethylene and a radical-polymerizable carboxylic acid and another radical-polymerizable carboxylic acid and / or a derivative thereof are multi-component copolymerized.

Further, a metal salt of the radical-polymerizable unsaturated carboxylic acid (free unsaturated carboxylic acid is graft-polymerized on a polyolefin resin such as polyethylene, polypropylene or ethylene-propylene copolymer, and then neutralized. Which has a structure obtained by graft polymerization of
One having a structure in which a metal salt of a radically polymerizable carboxylic acid and another radically polymerizable carboxylic acid and / or a derivative thereof are simultaneously co-grafted with a polyolefin polymer is mentioned. The radical-polymerizable carboxylic acid and its derivative used here include (meth) acrylic acid, maleic acid, fumaric acid, monomethyl maleate, monomethyl fumarate, monoethyl maleate, monoethyl fumarate, monobutyl maleate, monobutyl fumarate. , Methyl (meth) acrylate, dimethyl maleate, dimethyl fumarate, diethyl maleate, diethyl fumarate, dibutyl maleate, dibutyl fumarate and the like.

Other examples of the reaction accelerator relating to the present invention include tertiary amine compounds such as trimethylamine, triethylamine, dimethylethylamine and diethylcyclohexylamine. Other examples of the reaction accelerator relating to the present invention include, for example, tetramethylammonium tetrafluoroborate, tetramethylammonium hexafluorophosphate, tetramethylammonium bromide, tetraethylammonium bromide, tetraethylammonium iodide, methyltri-n-butylammonium. Examples thereof include quaternary ammonium salts such as chloride, tetrabutylammonium bromide and tetrahexyl ammonium bromide.

Further, as another example of the reaction accelerator relating to the present invention, for example, metal hydroxides such as calcium hydroxide, magnesium hydroxide and aluminum hydroxide, calcium chloride, calcium bromide, magnesium chloride and the like can be used. Metal halide, sodium nitrate, calcium nitrate,
Metal salts of oxo acids such as calcium phosphate, sodium carbonate, calcium carbonate, magnesium carbonate, sodium sulfate, zinc sulfate, potassium chlorate, sodium iodate, and further NaBF ₄ , KPF ₆ , NaPCl ₆ , NaFeCl ₄ , NaSnCl ₄ , NaSb
Lewis acid metal salts such as F ₆ , NaAsF ₆ and KAsCl ₆ and organic sulfonic acids such as sodium paratoluate sulfonate, potassium paratoluate sulfonate, aluminum chloroethane sulfonate, calcium ethyl methane sulfonate and zinc ethyl ethane sulfonate The metal salts of

Of the above-exemplified reaction accelerators, metal salts of polymers containing carboxyl groups and metal salts of organic carboxylic acids are preferably used. Further, two or more of the above-mentioned various reaction accelerators may be used in combination, if necessary.

The amount of the reaction accelerator used in the present invention is 0.001-2 based on 100 parts by weight of the ethylene copolymer.
It is necessary to be in the range of 0 parts by weight, and 0.01 to 1
It is preferably in the range of 5 parts by weight. This amount is 0.0
If the amount is less than 01 parts by weight, the reaction becomes too slow and it becomes difficult to effectively introduce a crosslinked structure into the composition.
If it exceeds 0 part by weight, not only is it meaningless in improving the reaction rate, but it is not economically preferable.

The heat-sensitive adhesive film of the present invention comprises a composition comprising component (1), component (2) and component (3),
An adhesive film formed by blending and molding a polyolefin resin as the component (4) can be used. Specific examples of the polyolefin-based resin here include low-density polyethylene, high-density polyethylene, polypropylene, polyisoprene, polyisobutylene, polybutene, poly-3-methylbutene-1, poly-4-methylpentene-1, and polybutadiene. Homopolymers of unsaturated hydrocarbon monomers having 2 to 10 carbon atoms can be mentioned. Further, a copolymer of two or more kinds of monomers selected from the monomers constituting these homocopolymers and other olefins, or the monomers constituting the above homocopolymers or other Copolymers of olefins and other radically polymerizable monomers having no acid anhydride, for example,
Ethylene-propylene; Styrene-butadiene copolymer; Ethylene-propylene-diene terpolymer; Linear low density polyethylene using butene-1, hexene-1, octene-1,4-methylpentene-1 etc. as comonomer; propylene A block copolymer of ethylene; a copolymer of ethylene and an unsaturated carboxylic acid or its derivative (for example, ethylene-vinyl acetate copolymer, ethylene-
(Meth) acrylic acid ester copolymer and the like). Furthermore, a mixture of each of the above resins can be used.

The polyolefin resin used here has the purpose of being a resin for diluting the heat-sensitive adhesive consisting of the above (1), (2) and (3), and also at a high temperature (80 ° C. or higher) after adhesion. In applications where the adhesive strength of is required, 10 of the above-mentioned polyolefin resins are used.
Crystal melting point of 0 ° C or higher (melting point here means DSC, D
Means melting peak temperature measured by equipment such as TA)
It is possible to play an auxiliary role for achieving the purpose by selecting one having That is, by adding the polyolefin resin, it is possible to more efficiently exhibit the contradictory performance of having low-temperature adhesiveness and capable of maintaining a certain degree of adhesive strength even after being adhered at a high temperature.

The amount of the polyolefin resin as the component (4) used is 5 to 80 parts by weight based on 100 parts by weight of the total resin composition comprising the components (1), (2) and (3). It is a range. When the amount of the polyolefin used exceeds 80 parts by weight, the amount contained in the heat-sensitive adhesive film of the component (1), which is originally capable of exhibiting adhesion to other base materials, becomes too small, and therefore the adhesion of the heat-sensitive adhesive film obtained. It is not preferable because the property is significantly reduced. When the amount is less than 5 parts by weight, it is meaningless to mix the polyolefin resin.

Further, various additives, compounding agents and fillers can be used in the composition constituting the heat-sensitive adhesive film of the present invention as long as the characteristics of the adhesive film are not impaired. Specific examples of these include antioxidants (heat resistance stabilizers), ultraviolet absorbers (light stabilizers), antistatic agents,
Anti-fog agent, flame retardant, lubricant (slip agent, anti-blocking agent), inorganic filler such as glass filler, organic filler,
Reinforcing agents, colorants (dye, pigment), foaming agents, fragrances and the like can be mentioned.

In order to produce the composition constituting the heat-sensitive adhesive film of the present invention, the components (1) to (3) and the polyolefin resin or additives used as required are mixed by various means. Good. As a mixing method, a generally known mixing method of various resins can be used. For example, a blender such as a Henschel mixer or a tumbler may be used for dry blending, and a Banbury mixer, a static mixer, a pressure kneader,
You may melt-knead using a mixer like an extruder and a roll mill. At this time, a uniform composition can be obtained by previously dry blending and melt-kneading the resulting mixture. Further, when molding the heat-sensitive adhesive film according to the present invention, the respective components are mixed (dry blended) in the form of pellets or powders, and melt-mixed in the extruder or injection molding machine at the stage of manufacturing the film or the like. You can also do it.

The heat-sensitive adhesive film according to the present invention can be obtained by molding by a conventionally known method. Examples of such a molding method include a (co) extrusion molding method, an inflation molding method, and a hot press molding method. Further, the heat-sensitive adhesive film can be directly laminated on the skin material or the substrate material by the extrusion lamination method. The temperature condition for molding is 130 to 2
A range of 80 ° C is preferred. The thickness of the heat-sensitive adhesive film according to the present invention needs to be 10 to 150 μm, and more preferably 20 to 100 μm. Where 1
If it is less than 0 μm, the adhesive strength becomes insufficient, which is not preferable, and if it exceeds 150 μm, the thermal conductivity is lowered, sufficient adhesive strength cannot be obtained, and the cost becomes high, which is not practical.

The use of the heat-sensitive adhesive film according to the present invention makes it possible to bond various base materials at a relatively low processing temperature to obtain a multilayer laminate. Examples of such an adherable substrate include high-quality paper, kraft paper, glassine paper, Japanese paper, and corrugated cardboard base paper. There is no particular limitation on the base material constituting the multilayer laminate according to the present invention,
Various kinds of paper such as synthetic paper, art paper, coated paper; cotton, linen,
Various woven or non-woven fabrics made of polyester, nylon, etc .; wooden boards; various metal plates or foils of iron, aluminum, copper, tinplate, etc .; polypropylene, polystyrene, polyethylene, polyester, nylon, polycarbonate, acrylic resin, phenolic resin, polyurethane, styrene- Plates, molded products, films or foams obtained by molding various plastics such as butadiene block copolymer (SBS resin), styrene-acrylonitrile copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin); Examples include various inorganic substances such as glass fiber and ceramics. Further, these base materials may be subjected to surface treatment, printing, coating, etc., if necessary.

The multilayer laminate of the present invention is particularly suitable for interior materials of automobiles and the like which use a skin material and a substrate material as a base material (for example, an automobile interior ceiling material, an automobile interior door member, an automobile interior dashboard member). , Automotive interior console boxes, automotive interior instool panel members, etc.) or interior materials for vehicles, ships, houses, etc.

The skin material and substrate material used here are not particularly limited, and various materials generally used as interior materials for automobiles, vehicles, ships, houses, etc. can be used. Specific examples of such a skin material include polyester non-woven fabric, brushed knit, fabric, suede-like synthetic leather, vinyl chloride (polyvinyl chloride) leather, polyurethane leather, polypropylene-based thermoplastic elastomer, or urethane foam, polyethylene foam on these materials, The thing which laminated | bonded the cushioning material of foamed polypropylene etc. is mentioned.

On the other hand, specific examples of the substrate material include resin felt, resin wood, glass fiber-containing phenol resin plate, corrugated cardboard, polypropylene honeycomb, polystyrene foam, glass fiber reinforced polypropylene plate, ABS resin plate, AS resin plate or non-woven fabric thereof. And the like.

Various molding methods can be employed in producing the multilayer laminate according to the present invention. For example, a substrate material is heated to a predetermined temperature, set in a vacuum forming machine, a heat-sensitive adhesive film formed into a film by inflation molding or T-die molding is placed on this, and then a skin material which is previously heated to a predetermined temperature is overlaid. Vacuum press-bonding method; sandwiching the above film between the skin material and the substrate material and heat-pressing; heat-pressing or heat-rolling the substrate material with the laminated material in which the heat-sensitive adhesive film is coated on the skin material by extrusion lamination molding. Method of crimping;
Further, there is a method in which the above-mentioned adhesive film is previously laminated on the adhesive side of the skin material with a heat roll, and then the substrate material is heated and pressed by a heat press or a heat roll.

In the above-described method for producing the multilayer laminate of the present invention, the heating temperature varies depending on the skin material used, the type of substrate material, the molding conditions, and the composition of each component constituting the heat-sensitive adhesive film. Although not stipulated, it is appropriately selected at a temperature not lower than the softening point of components constituting the heat-sensitive adhesive film and not higher than the temperature at which the skin material and the substrate material are not affected. The heat-sensitive adhesive film according to the present invention which functions as an adhesive layer has a relatively low crystalline melting point of about 60 to 130 ° C., and 0.1 to 2.
Strong adhesion is possible at a relatively low pressure of about 0 kg / cm ² , and the texture of the skin material and substrate material is
It can be manufactured without damaging the feel.

The thickness of each layer of the multi-layer laminate of the present invention varies depending on its material, application, required physical properties, etc. and is not particularly limited. The multilayer laminate of the present invention is composed of at least the above-mentioned two layers or three layers, and if necessary, further through an adhesive layer composed of the heat-sensitive adhesive according to the present invention, or another adhesive. It may be a laminate in which other materials are laminated with a layer or without an adhesive layer. Hereinafter, the present invention will be specifically described with reference to Reference Examples, Examples, and Comparative Examples.

[0044]

【Example】

<Ethylene Copolymer (A)> Ethylene-methyl acrylate-maleic anhydride ternary copolymer under the conditions of a polymerization temperature of 190 ° C. and a polymerization pressure of 1900 Kg / cm ² using equipment of a high-pressure low-density polyethylene production plant. The combined ethylene-based copolymer (A) was produced. The MFR of this ethylene copolymer (JIS-K7210, Table 1, Condition 4) is 1
0, the content of units derived from methyl acrylate is 25
The content of the unit derived from maleic anhydride is 1% by weight.
It was 6% by weight. The composition of the comonomer was determined by infrared absorption spectrum. <Ethylene-based Copolymer (B)> Using the equipment of a high-pressure low-density polyethylene manufacturing plant, and under the conditions of a polymerization temperature of 190 ° C. and a polymerization pressure of 1900 kg / cm ² , ethylene-methyl methacrylate-itaconic anhydride ternary copolymer An ethylene copolymer (B) which is a polymer was produced. MFR of this ethylene-based copolymer (JIS-K7210, Table 1, Condition 4)
20, the content of units derived from methyl methacrylate was 20% by weight, and the content of units derived from itaconic anhydride was 3.5% by weight. The composition of the comonomer was determined by infrared absorption spectrum. <Ethylene Copolymer (C)> Ethylene-methyl acrylate-maleic anhydride ternary copolymer under the conditions of a polymerization temperature of 200 ° C. and a polymerization pressure of 1900 Kg / cm ² using equipment of a high-pressure low-density polyethylene production plant. The combined ethylene-based copolymer (C) was produced. The ethylene-based copolymer had a MFR (JIS-K7210, Table 1, Condition 4) of 8, a content of units derived from methyl acrylate was 18% by weight, and a content of units derived from maleic anhydride was 2. 5
% By weight. The composition of the comonomer was determined by infrared absorption spectrum. <Ethylene Copolymer (D)> Ethylene / butyl acrylate / maleic anhydride ternary copolymer under the conditions of a polymerization temperature of 200 ° C and a polymerization pressure of 1800 Kg / cm ² using equipment of a high-pressure low-density polyethylene production plant. A combined ethylene-based copolymer (D) was produced. The ethylene-based copolymer had an MFR (JIS-K7210, Table 1, Condition 4) of 8, a content of units derived from butyl acrylate was 16% by weight, and a content of units derived from maleic anhydride was 1. 5
% By weight. The composition of the comonomer was determined by infrared absorption spectrum. <Ethylene Copolymer (E)> Ethylene-vinyl acetate-maleic anhydride terpolymer under the conditions of a polymerization temperature of 200 ° C. and a polymerization pressure of 1800 Kg / cm ² using equipment of a high-pressure low-density polyethylene production plant. To produce an ethylene-based copolymer (E). M of this ethylene copolymer
FR (JIS-K7210, Table 1, Condition 4) was 15, the content of units derived from vinyl acetate was 20% by weight, and the content of units derived from maleic anhydride was 2.5% by weight. The composition of the comonomer was determined by infrared absorption spectrum.

Reference Example (Reference Example 1) 89.5% by weight of ethylene copolymer (A), 0.5% by weight of trimethylolpropane (hereinafter abbreviated as TMP) as a polyhydric alcohol, and as a reaction accelerator. Ethylene-methacrylic acid copolymer (methacrylic acid content 1
0% by weight of Zn salt (2 units of units derived from methacrylic acid)
After 10% by weight (0 mol% neutralized) was dry blended with a Henschel mixer, the mixture was melt-kneaded at 190 ° C. using a 37 mmφ co-directional twin-screw extruder to obtain pellets of a heat-sensitive adhesive. The contents of this formulation are shown in Table 1.

Reference Examples 2 to 11 Heat sensitive adhesives were prepared in the same manner as in Reference Example 1 using the components (1), (2), (3) and (4) shown in Table 1. A pellet of the agent was obtained. The content of the formulation is shown in Table 1.

Comparative Reference Example 1 The procedure of Reference Example 1 was repeated except that the reaction accelerator of component (3) was not added,
Pellets of heat sensitive adhesive were obtained. The content of the formulation is shown in Table 1.

Comparative Reference Example 2 A heat-sensitive adhesive pellet was obtained in the same manner as in Reference Example 1 except that the polyhydric alcohol as the component (2) was not added. Table 1 shows the composition
It was shown to.

Comparative Reference Example 3 Reference Example 1 except that an ethylene-methyl methacrylate binary copolymer (methyl methacrylate content = 20% by weight, MFR = 3) was used as the component (1). The same operation was performed to obtain pellets of the heat-sensitive adhesive. The content of the formulation is shown in Table 1.

COMPARATIVE REFERENCE EXAMPLE 4 Component (1), component (2), component (3) and component (4) were used and operated in the same manner as in Reference Example 1 to obtain a heat-sensitive adhesive pellet. The content of the formulation is shown in Table 1.

(Example 1) The heat-sensitive adhesive obtained in Reference Example 1 was formed into a film having a thickness of 70 μm by a film forming machine with a T-type die having an extruder of 25 mmφ to obtain a film having a width of 20 cm. It was Using this film as the adhesive layer, the base materials (skin material and substrate material) actually used in the interior materials for automobiles were adhered, and the adhesiveness was tested. Polyethylene terephthalate (PET) non-woven fabric was used as the skin material, and resin felt (RF) was used as the substrate material. Bonding is done by hot pressing with the upper plate at 120 ° C and the lower plate at 70 ° C.
Sandwich from the top in order of skin material, the above film, substrate material,
The surface was pressed under the conditions of a surface pressure of 2.5 kg / cm ² and 10 seconds. The size of the press of the substrate material was 10 cm × 20 cm. After adhesion, after conditioning for 24 hours at 23 ° C. and 50% relative humidity, cut into 25 mm width test pieces, and 180 ° peeling test at room temperature (23 ° C.) using a tensile tester (peeling speed 200 mm / min) Was carried out. As a general rule, the adhesive strength (g / 25 mm) at the time of peeling was measured. However, when the skin material or the substrate material was broken before peeling, the strength at break was measured. Further, as a heat-resistant creep test, a load of 100 g was suspended on a test piece that had been partially peeled, and the peeling distance (mm) was measured when the specimen was left in an atmosphere at 80 ° C. for 24 hours, and used as a guide for heat resistance. The value of the adhesive strength is an average value (maximum, minimum 2 point cut) of 5 test pieces. The heat resistance is an average value of three test pieces. Table 2 shows the results.

(Examples 2 to 11) As shown in Table 2,
The same operation as in Example 1 was carried out except that the types of the heat-sensitive adhesive film for the adhesive layer, the skin material and the substrate material were changed. Table 2 shows the results.

(Example 12) Using the film obtained in Reference Example 3, 0.2 mm thick polypropylene-based thermoplastic elastomer as a skin material was stuck to the foamed polypropylene (PP-based TPO / foamed PP) having a thickness of 2 mm, The adhesion was tested using a glass fiber reinforced styrene-acrylonitrile copolymer (ASG) board as the plate material. For adhesion, first, a Teflon coat roll heated at 130 ° C. was used to overlay a heat-sensitive adhesive film on the foam layer side of the skin material, and a heat roll laminating process was performed at a speed of 5 m / min to bond the skin material and the heat-sensitive adhesive film. Next, the substrate material was heated to 70 ° C. for 5 minutes and the skin was heated to 120 ° C. and bonded by a vacuum bonding method. Table 2 shows the results
Shown in

(Examples 13 to 18) As shown in Table 2, the same operation as in Example 12 was carried out except that the kinds of the heat-sensitive adhesive film for adhesive layer, the skin material and the substrate material were changed. Table 2 shows the results.

(Comparative Examples 1 to 4) From the pellets obtained in Comparative Reference Example 1 or 4, a film was produced in the same manner as in Example 1. Using this film as an adhesive layer, Table 2
As shown in, the operation was performed in the same manner as in Example 1 except that the kinds of skin material and substrate material were changed. Table 2 shows the results.

Comparative Example 5 A film having a thickness of 5 μm was produced from the pellets obtained in Reference Example 2 in the same manner as in Example. Using this film as an adhesive layer, as shown in Table 2, the types of skin material and substrate material were changed, and the same operation as in Example 1 was carried out. Table 2 shows the results.

Comparative Example 6 A film having a thickness of 300 μm was produced from the pellets obtained in Reference Example 2 in the same manner as in Example. Using this film as an adhesive layer, as shown in Table 2, the types of skin material and substrate material were changed, and the same operation as in Example 1 was carried out. Table 2 shows the results.

Comparative Examples 7 and 8 Comparative Reference Example 1 or 3
A film was produced from the pellets obtained in 1. by the same method as in Example 1. Using this film as an adhesive layer, as shown in Table 2, the types of skin material and substrate material were changed, and the same operation as in Example 12 was carried out. Table 2 shows the results.

Looking at the results of the above test, Examples 1 to 11
Then, it is understood that the multilayer laminate using the heat-sensitive adhesive film according to the present invention exhibits excellent adhesive strength even in the hot pressing method under the condition that the substrate temperature is low and the surface pressure is low. Further, in Examples 11 to 18, even in the vacuum bonding method in which the bonding pressure is lower and the bonding time is shorter than that in the hot pressing method, the multilayer laminate using the heat-sensitive adhesive film according to the present invention has practically endurable adhesive strength, It can be seen that heat resistance can be obtained. Further, as shown in Comparative Examples 5 and 6, the film thickness is 1
When it was less than 0 μm or thicker than 150 μm, the adhesive strength was insufficient.

[0060]

[Table 1]

[0061]

[Table 2]

[0062]

As described above, the heat-sensitive adhesive film according to the present invention can be used in various substrates, especially automobiles, vehicles, ships,
It is possible to laminate skin materials and substrate materials used as interior materials for houses and the like under conditions of relatively low temperature and low pressure, and yet exhibit high adhesive strength. Therefore, a multilayer laminate using the heat-sensitive adhesive film as an adhesive layer is excellent in adhesive workability and workability and can be processed at a low temperature, so that the texture of the skin material is not impaired and the aesthetics are high. It can be suitably used as an interior material for vehicles, ships, houses, and other buildings.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location B32B 27/32 101 B32B 27/32 101 C08J 5/18 CES C08J 5/18 CES C08K 5/053 C08K 5/053 5/103 KEQ 5/103 KEQ

Claims (6)

[Claims] (1) A multi-component copolymer comprising ethylene, a radical-polymerizable acid anhydride and a radical-polymerizable comonomer other than the radical-polymerizable acid anhydride, which is a radical-polymerizable acid anhydride in the copolymer. The proportion of units derived from 0.1 wt% or more and 5 wt% or less, the proportion of units derived from other radically polymerizable comonomer is 10 wt% or more and 50 wt%
The following ethylene-based copolymer, (2) a polyhydric alcohol compound having at least two hydroxyl groups in the molecule, and
(3) The molar ratio of the unit of the hydroxyl group in the polyhydric alcohol compound as the component (2) to the unit derived from the radical-polymerizable acid anhydride in the component (1) which is composed of the reaction accelerator is 0.1.
It is in the range of 01 to 10, and the reaction accelerator which is the component (3) is in the range of 0.001 to 20 parts by weight with respect to 100 parts by weight of the ethylene copolymer which is the component (1), and the thickness is 10 μm or more. A heat-sensitive adhesive film having a thickness of 150 μm or less. 2. The polyhydric alcohol compound which is the component (2) has the following general formula (I) (R ¹ ) _a C (CH ₂ OH) _b (I) [wherein R ¹ is hydrogen or the number of carbon atoms]. 1 to 12 chain or cyclic alkyl groups or aralkyl groups, a represents an integer of 0 to 2, b represents an integer of 2 to 4, and a
Selected to satisfy + b = 4. Or the following general formula _{(II) CH 2 (OH)} CH (OH) CH 2 O [CH 2 CHOHCH 2 O] m H (II) [ wherein, m is an integer of 0. Polyoxyalkylene compound having a polyhydric alcohol compound obtained by adding ethylene oxide or propylene oxide structure represented by, or the following general formula ^{(III) R 2 -COOH (III} ) [ wherein, R ² is 2 carbon atoms ~ 25 chain alkyl groups, cyclic alkyl groups, aralkyl groups or alkenyl groups. ] One or more of polyglycerin esters having two or more hydroxyl groups in the molecule, which are obtained by dehydration condensation of the organic carboxylic acid compound represented by the above and the polyglycerin represented by the general formula (II). The heat-sensitive adhesive film according to claim 1. 3. The heat-sensitive adhesive film according to claim 1, wherein the reaction accelerator as the component (3) is a metal salt of a polymer containing a carboxyl group or a metal salt of an organic carboxylic acid. 4. A polyolefin-based resin (4) for 100 parts by weight of the total of the component (1), the component (2) and the component (3) constituting the heat-sensitive adhesive film according to any one of claims 1 to 3.
A heat-sensitive adhesive film containing 5 to 80 parts by weight. 5. A multilayer laminate comprising a base material layer and an adhesive layer, the adhesive layer comprising the heat-sensitive adhesive film according to claim 1. 6. The base material layer is resin felt, resin wood, acrylonitrile-butadiene-styrene copolymer resin plate, acrylonitrile-styrene copolymer plate, polypropylene resin plate, corrugated board, glass fiber reinforced polypropylene plate, polyester-based non-woven fabric, raised fabric. The multilayer laminate according to claim 5, which is at least one selected from knit, urethane foam, polypropylene polypropylene, and polyethylene foam.