JPH0381146A - Laminate - Google Patents

Abstract

PURPOSE:To obtain laminate having heat resistance, water resistance and strong adhesion by a method wherein prime layer has epoxy resin oligomer, hardener and elastomer and at least either one of olefin-based resin layer or the primer layer contains organic peroxide. CONSTITUTION:The laminate concerned consists of three layers of olefin-based resin layer, primer layer and metal layer. The primer has epoxy resin oligomer, the hardener of the epoxy resin oligomer and elastomer, which has double bond and is sold in normal temperature. At least, either one of the olefin-based resin layer or the primer layer contains organic peroxided. Or thin layer made of the organic peroxide is provided between the olefin-based resin layer and the primary layer. The water resistance and heat resistance as the primary are fulfilled by the epoxy resin oligomer. At the same time, flexible elastomer relieves and disperses stressed applied and adhesive interface. Further, the organic peroxide reacts with both the olefin-based resin layer and the primer layer so as to produce chemical bonding.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a laminate having a three-layer structure including an olefin resin layer, a primer layer, and a metal layer.

(Prior Art) Conventionally, laminates made by coating a metal body with an olefin resin layer via a primer layer have been attracting attention and being used as synthetic resin-coated steel pipes, automobile interior and exterior materials, building materials, and other industrial materials. , Research is being actively conducted to obtain products with many quality characteristics such as interfacial adhesion, corrosion resistance, and heat resistance.

Since polyolefins do not have any functional groups and are nonpolar, they do not adhere to metals at all. Initially, polyolefins were grafted with silane compounds, maleic anhydride compounds, etc., and used as modified polyolefins with polar groups introduced. This was attempted. However, even with this modified polyolefin, it is not possible to obtain the desired adhesive strength when used under certain conditions, such as when used at high temperatures, and the modified polyolefin itself has poor water resistance, so it cannot be used in hot water. When immersed in water for a long period of time, there are problems such as interfacial peeling between the modified polyolefin layer and the metal layer, blistering, and even rusting on the surface of the metal layer. Therefore, it was considered to adhere the two through a primer layer.

For example, (a) Japanese Patent Publication No. 50-30547 discloses a composition containing an unsaturated carboxylic acid-modified propylene polymer, an amorphous propylene polymer, and an ethylene polymer. Japanese Patent Publication No. 40477 discloses a composition in which a specific crystalline polyamide and a copolymer obtained by grafting an unsaturated carboxylic acid onto a polyolefin are laminated by coextrusion;
In Japanese Patent Publication No. 57-26622, a vinyl acetate-unsaturated silane compound terpolymer is used as a composition comprising an ethylene copolymer having a functional group that reacts with an epoxy group, an epoxy compound, and a curing agent. Each is disclosed in which polyethylene powder is added.

(Problems to be Solved by the Invention) However, in the conventional technologies (a) to (c) above, none of them have heat resistance, water resistance, and solvent resistance as a constituent component of the primer layer compared to thermosetting resins. Because an inferior thermoplastic resin is used, and the interfacial adhesion between the primer layer and the olefin resin layer relies only on intermolecular forces, it cannot be used under harsh conditions, such as long-term immersion in hot water. Under such conditions, there is a problem that not only the interface ff1lJ separation occurs, but also the rust prevention effect on the metal surface cannot be expected.To solve this problem, in the conventional technology described in (d) above, the components of the primer layer It has been proposed to use a thermosetting resin as a material.

It is true that the rust prevention effect is improved by using thermosetting resin, but stress remains during the curing process, and since it has no rubber elasticity, the stress remaining at the adhesive interface cannot be relaxed and absorbed. However, it is not possible to obtain the desired adhesion force, and furthermore, the adhesion at the interface between the olefin resin layer and the primer layer depends on intermolecular forces, so this is not a fundamental solution. do not have.

The present invention solves the problems of the prior art described above and provides a primer that can be used for multiple purposes by providing a strong adhesive interface for both an olefin resin layer made of polyolefin, modified polyolefin, etc. and a metal layer. The object of the present invention is to provide a laminate having a three-layer structure of an olefin resin layer, a primer layer, and a metal layer, which can be used in the following.

(Means for Solving the Problems) The present invention provides a laminate having a three-layer structure of an olefin resin layer, a primer layer, and a metal layer, in which the primer contains an epoxy resin oligomer and the epoxy resin oligomer as the main components of the primer. It has a curing agent for a resin oligomer and an elastomer that is solid at room temperature and has double bonds, and a chemical agent is added to at least one of the olefin resin layer or the primer layer by reacting with both the olefin resin and the primer component. The gist thereof is a laminate characterized in that it contains an organic peroxide that forms a bond, or that a thin layer of the organic peroxide is provided between an olefin resin layer and a primer layer. It is something.

In the present invention, the epoxy resin oligomer used as a primer includes bisphenol type bifunctional epoxy resin, phenol type polyfunctional epoxy resin, novolac type polyfunctional epoxy resin, glycidylamine type polyfunctional epoxy resin, etc. Examples include those commonly used as structural adhesives.

The epoxy resin oligomer may be either liquid or solid at room temperature, but if it has a large molecular weight and is solid at room temperature, it must be dissolved in a solvent and used in the form of a solution. On the other hand, even if the molecular weight is small and it is liquid at room temperature, if it has a high viscosity and cannot be used in the lamination process, it is used after being diluted with a solvent. The type of solvent at this time varies depending on the type and grade of the oligomer, but -
For boat fishing, toluene, xylene, methyl ethyl ketone,
Acetone etc. are used.

It is preferable to select a solvent that is common to the elastomer described later, since a uniform solution can be prepared and the epoxy resin oligomer and elastomer can be applied evenly.

For example, when a bisphenol type bifunctional epoxy resin is used as the epoxy resin oligomer and 1,4-polybutadiene is used as the elastomer,
Xylene is suitable as the common solvent.

In addition, the amount of the solvent added varies depending on the primer lamination method, and in the case of the brush coating method, it is 0.3 to 3 when the sum of the weights of the epoxy resin oligomer and elastomer is 1.
It is advisable to add parts by weight of solvent.

In the present invention, in order to cure the epoxy resin oligomer into a three-dimensional network structure, it is necessary to use a curing agent. As a curing agent, aliphatic amines such as ethyleneamine group, N-aminoethylpiperazine, metaxylene diamine, polyamide, etc., cycloaliphatic amines such as paramenthanediamine, metsphoronediamine, 2-ethyl-4-methylimidazole, etc. , metaphenylenediamine, 4.4
°-Diaminodiphenylmethane, aromatic amines such as dicyanthiad, phthalic anhydride, pyromellitic anhydride,
There are acid anhydrides such as nadic acid anhydride, etc. - For boat fishing,
The curing temperature and the heat resistance temperature of the cured product are highest for acid anhydrides, and decrease in the order of aromatic amines, cycloaliphatic amines, and aliphatic amines. In short, the most suitable curing agent may be selected and used depending on the curing temperature, curing time, required performance of the product, etc.

The blending ratio of these curing agents to the epoxy resin oligomer is preferably within the range of ±20% of the weight part given by the following formula with respect to 100 weight parts of the epoxy resin oligomer.

[Acid equivalent or amine equivalent/epoxy equivalent of curing agent] x 1
00 In the present invention, examples of the elastomer having a double bond in the molecule and solid at room temperature include polybutadiene, styrene-butadiene copolymer, nitrile-butadiene copolymer, chloroprene, isoprene, and the like. It is usually used by dissolving it in a solvent, and the above-mentioned toluene, xylenedi, methyl ethyl ketone, acetone, etc. are used as the solvent. If the manufacturing process requires the use of a solid state, or if there is no common solvent with the epoxy resin oligomer, it is preferable to use it as a powder pulverized to a diameter of 10 to 100 μm. If it exceeds 100μ, it will not be uniformly dispersed in the epoxy resin oligomer solution. The method of pulverizing the solid elastomer can be arbitrarily selected, such as a mechanical pulverization method or a chemical pulverization method.

Therefore, before adding the elastomer to the epoxy resin oligomer solution, when masticating using a kneading machine such as an elastomer roll, the vulcanizing agent, vulcanization accelerator, vulcanization accelerator, vulcanization It may be modified as appropriate by adding additives such as retarders, anti-aging agents, anti-stick agents, tackifiers, anti-tack agents, dispersants, softeners, fillers, and reinforcing agents.

The more polar the elastomer is, the better the compatibility between the elastomer and the epoxy resin oligomer, and generally decreases in the order of nitrile-butadiene copolymer, chlorobrene, styrene-butadiene copolymer, isoprene, and polybutadiene. It is preferable to select according to the target performance required of the cured product.

In connection with this compatibility, a polar group such as an epoxy group or a hydroxyl group may be introduced into the molecular chain or at the end of the elastomer. Those into which these polar groups are introduced have improved compatibility with epoxy resin oligomers.

Similarly, an elastomer in which a functional group that reacts with the epoxy resin oligomer, such as an axon group or a carboxyl group, is introduced into the molecular chain or at the end thereof may be used. However, in this case, the amino group or carboxyl group in the elastomer reacts with the epoxy group in the epoxy resin oligomer,
Since both functional groups are consumed, the amount of curing agent added to the epoxy resin oligomer is slightly smaller than the amount of curing agent added above. For example, epoxy resin oligomer 10
In a system in which X parts by weight of an elastomer having a functional group that reacts with the epoxy resin oligomer is added to 0 parts by weight, add a curing agent in the range of ±20% of the parts by weight given by the following formula. is desirable.

((100/epoxy equivalent) - (X/acid equivalent or amine equivalent of elastomer)] x acid equivalent or amine equivalent of curing agent. The amount of the elastomer itself added to the epoxy resin oligomer is determined by the target performance of the primer. Although it differs depending on the
．． It is preferably 1 to 10 parts by weight.

The olefin resin used in the present invention includes polyethylene, polypropylene, polybutadiene, copolymers thereof, or mixtures thereof, or modified polyolefins such as silane-modified polyolefins, maleic acid-modified polyolefins, and chlorosulfonated polyolefins. be.

Therefore, in the present invention, in order to firmly adhere the primer used in the present invention and the olefin resin layer, an organic peroxide is used which reacts with both to form a chemical bond. be.

The organic peroxide may be liquid or solid at room temperature, and includes benzoyl peroxide, t-butyl peroxybenzoate, dicumyl peroxide, t-
Butyl peroxide, 2,5-dimethyl-2,5-di-
Examples include t-butylperoxyhexane, 2,4-dichlorobenzoylperoxide, di-t-butylperoxydi-isopropylbenzene, and the like.

The organic peroxide reacts with both the olefin resin layer and the primer layer containing an epoxy resin oligomer, elastomer, etc. to form a chemical bond.

The organic peroxide may be mixed in advance with the primer or olefin resin, or may be applied independently onto the primer layer.

When an organic peroxide is mixed with a primer or an olefin resin, when the organic peroxide is solid at room temperature, it is preferable to grind it into a powder with a diameter of 1 to 100 μm and add it. If the diameter exceeds 100μ, it will not be dispersed uniformly when mixed into the primer solution, the reactivity between the primer layer and the olefin resin layer will decrease, the chemical bond will not be formed uniformly, and the adhesive strength will vary. occurs.

The amount of organic peroxide added depends on the characteristics of the organic peroxide, the reactivity of the primer and olefin resin involved in chemical bonding,
It is preferable to add 0.1 to 25 parts by weight per 100 parts by weight of the elastomer, although it varies depending on factors such as reaction temperature.

When selecting an organic peroxide, it is preferable to select one whose reaction temperature between the organic peroxide and the elastomer matches the reaction temperature between the organic peroxide and the olefin resin. This is because chemical bonds are generated between the olefin resin and the elastomer by the organic peroxide, and at the same time, chemical bonds are generated in the olefin resin and in the elastomer. In other words, in order to prevent these side reactions and preferentially generate chemical bonds between the olefin resin and the elastomer, if the reaction temperatures of both are the same, both reactions will occur simultaneously. There is a high possibility that the disease will progress.

Further, in order to control the reaction temperature of both, a vulcanization accelerator, an early vulcanization inhibitor, a vulcanization retarder, a crosslinking aid, etc. may be added as necessary.

In the present invention, fillers, reinforcing agents, antioxidants, colorants, etc. may be added to the primer and olefin resin as necessary.

Next, an example of a method for manufacturing the laminate of the present invention will be described.

First, an epoxy resin oligomer and an elastomer that is liquid at room temperature are mixed and stirred. At this time, a solvent common to both the epoxy resin oligomer and the elastomer is added as necessary. Next, a curing agent for the epoxy resin oligomer is added to the primer solution containing the organic peroxide and applied onto the metal layer during the pot life when the epoxy resin oligomer is in an uncured state.

Application of such a primer solution can be done using a spatula, a brush, a brush, or
Application equipment such as a hand roller, a roller with a tank, a roll coater, a flow gun, a flow brush, and a spray gun is used.

Next, after most of the solvent is evaporated by air drying or using a blower or vacuum dryer, the primer composition is heated to begin curing. A resin layer is coated on the primer layer by a lining method, a coating method, or the like. This is because the adhesive strength tends to reach its maximum before the curing reaction is completely completed, and then tends to decrease as the reaction progresses.

Further, the above organic peroxide may be blended into the olefin resin layer at this time before laminating the olefin resin. If the organic peroxide is solid at room temperature, this compounding method involves co-extruding the olefin resin and organic peroxide onto the primer, or forming the organic peroxide into a material with a diameter in the range of 50 to 300μ. There are methods such as pulverizing the organic peroxide, tri-blending it with powdered olefin resin, and applying powder coating.Also, if the organic peroxide is liquid at room temperature, the olefin resin layer can be coated. There are methods such as immersion in this liquid.

Note that when an organic peroxide is mixed in the olefin resin layer, the organic peroxide does not need to be mixed in the primer layer.

In the present invention, the organic peroxide may be provided in a thin layer between the olefin resin layer and the primer layer. If the oxide is solid at room temperature, it may be crushed to a diameter of 50 to 300μ and sprayed with an air gun.
When the organic peroxide is in liquid form, a layer of the organic peroxide may be provided on the primer layer by a method such as spray coating.

(Function) The main components of the primer of the present invention include an epoxy resin oligomer, a curing agent for the epoxy resin oligomer, and an elastomer that is solid at room temperature and has a double bond, and the olefin resin layer or primer layer At least one of the organic peroxides contains an organic peroxide, or a thin layer of organic peroxide is provided between the olefin resin layer and the primer layer, so the epoxy resin oligomer provides water resistance and water resistance as a primer. In addition to being heat resistant, the highly flexible elastomer relaxes and disperses stress acting on the adhesive interface, and the organic peroxide is used to form an olefin resin layer and a primer containing epoxy resin oligomers, elastomers, etc. It reacts with both layers and forms chemical bonds.

(Examples) Next, the present invention will be specifically explained by examples, but the present invention is not limited by these examples.

Example 1 ■ Primer 3 type epoxy resin oligomer (“Epico-828” epoxy 1187 manufactured by Yuka Shell Epoxy Co., Ltd., liquid at room temperature)
66 parts by weight, a nitrile butadiene copolymer with a carboxyl group introduced at the end of the molecular chain as an elastomer (rPNC-25J carboxylic acid i1900 manufactured by Nihon Gosei Rubber Co., Ltd.)
, solid at room temperature) was dissolved and mixed in 200 parts by weight of xylene, which is a common solvent for both. Next, as a curing agent for the epoxy resin oligomer, a high temperature curing type heterocyclic amine ("Ebome" manufactured by Yuka Shell Epoxy Co., Ltd.) LXIN J was used.
Amine equivalent: 112.2, pot life: 20''C, 70 minutes, liquid at room temperature) 35.4 parts by weight were added and stirred.

■ Lamination of metal layer and primer This primer solution is applied with a brush onto a steel plate that has been degreased with toluene for 10 minutes using an ultrasonic cleaner.
The sample was left to stand for 5 minutes to volatilize a portion of the solvent, and placed in a blower heated to 180°C for 5 minutes to accelerate curing.

■ Di-1-butyl peroxide (“Verbutyl D” manufactured by NOF Corporation) is added to the primer as an organic peroxide when laminating the metal layer/primer layer with an organic peroxide or an olefin resin layer. About 0.1 g of active oxygen content 10.94%, decomposition temperature 124°C to obtain a half-life of 10 hours (liquid at room temperature) was immediately sprayed onto linear low-density polyethylene (liquid at room temperature of 300μ or less). Asahi Kasei Corporation r LM7625
J density 0.926, melting point 128°C, melting index 20>
was painted with an electrostatic gun. Then, it was inserted again into a blower heated to 180° C. for 20 minutes to promote curing of the primer layer and melting of the polyethylene, thereby obtaining a laminate with a primer layer thickness of 40 μm and a polyethylene layer thickness of 550 μm.

Comparative Example ■ Example 1 was repeated except that di-t-butyl peroxide, which is an organic peroxide, was not sprayed, and the thickness of the primer layer was 43 μm, and the thickness of the polyethylene layer was 540 μm.
A laminate of μ was obtained.

Comparative Example 2 Example 1 except that 39 parts by weight of a heterocyclic amine was used instead of polybutadiene in the primer components.
In the same manner, a laminate was obtained in which the primer layer had a thickness of 37 μm and the polyethylene layer had a thickness of 530 μm.

Comparative Example 3 A nitrile-butadiene copolymer was not used in the primer components, but vinyltrimethoxysilane (KBM 1003J boiling point 1, manufactured by NOF Corporation) was added to 100 parts by weight of polyethylene.
Add 0.5 parts by weight of 2 specific gravity 0.97) and 0.04 parts by weight of the above dibutyl peroxide and heat at 200°C.
A laminate having a primer layer thickness of 42 .mu.m and a polyethylene layer thickness of 550 .mu.m was obtained in the same manner as in Example 2, except that linear low-density polyethylene extruded and silane-modified was used.

Regarding the laminates obtained in the above Examples and Comparative Examples, the interfacial adhesive strength between the polyethylene layer and the primer layer was measured at room temperature (2
5°C) and a 90 degree peel test at a peeling rate of 50 defects/min. For the heat resistance test, the polyethylene layer side was
A temperature gradient test was conducted in which the metal layer side was immersed in hot water at 45°C to accelerate deterioration, and the measurement results are shown in Table 1. In addition, in the examples and each comparative example, the primer layer was firmly adhered to the metal.

Table 1 (Effects of the Invention) In the present invention, the main components of the plastic/f-mer are composed of an epoxy resin oligomer, a curing agent for the epoxy resin oligomer, and an elastomer that is solid at room temperature and has a double bond. At least one of the olefin resin layer or the primer layer contains an organic peroxide, or 3N of organic peroxide is provided between the olefin resin layer and the primer layer. The epoxy resin oligomer provides the primer layer with heat resistance and water resistance, and the highly flexible elastomer relieves and disperses the stress acting on the adhesive interface, resulting in strong adhesive strength. The oxide is an olefin resin layer,
Because it reacts with both the primer layer containing epoxy resin oligomers and elastomers, and forms chemical bonds, the interface between the primer layer and the olefin resin layer is also firmly bonded, resulting in an overall superior laminate. .

The thus obtained laminate of the present invention comprises a synthetic resin-coated steel pipe,
It can be used for a variety of purposes such as automobile interior and exterior materials, building materials, and other industrial materials, and is particularly suitable for applications that require relatively strong adhesive strength or water resistance at high temperatures.

Claims (1)

[Claims] 1. A laminate consisting of a three-layer structure of an olefin resin layer, a primer layer, and a metal layer, the main components of the primer layer being an epoxy resin oligomer, a curing agent for the epoxy resin oligomer, and a double bond. and an elastomer that is solid at room temperature and has an elastomer that is solid at room temperature, and at least one of the olefin resin layer or the primer layer contains an organic peroxide that reacts with both the olefin resin and the primer component to form a chemical bond. A laminate, characterized in that a thin layer of the organic peroxide is provided between the olefin resin layer and the primer layer.