JPH0381145A - Laminate - Google Patents

Abstract

PURPOSE:To contrive to improve the adhesion between intermediate layer and olefin-based resin layer by a method wherein ionomer or the like is used as the intermediate layer, which is used for laminating the specified olefin-based resin layer and metal layer to each other. CONSTITUTION:The laminate concerned consists of olefin-based resin layer, intermediate layer and metal layer, which are laminated to one another in the order named. As the intermediate layer, ionomer or based resin for forming ionomer is used. At the same time, as the olefin-based resin layer, olefin-based resin layer containing metal salt of acetic acid is used. Accordingly, ionic bond is produced between the metal salt of acetic acid in the olefin-based resin layer and the carboxyl group in the intermediate layer and intermolecular force is developed due to their similar chemical constitution. Further, as for the intermedate layer and the metal layer, chemical bonding or intermolecular force is developed between the carboxyl group in the intermediate layer and the oxide layer on the surface of metal. And, by providing a second intermediate layer made of thermosetting resin in addition to the first intermediate layer made of ionomer or base resin for forming ionomer, the thermosetting resin excellent in heat resistance can protect the surface of metal.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a laminate comprising an olefin resin layer, an intermediate layer, and a metal layer.

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

As one of them, Japanese Patent Application Laid-open No. 56-59876 states,
A technology using an ionomer as an intermediate layer is described, and this technology consists of a composition containing a polyolefin ionomer, a hydrocarbon, a softener, and a pigment, and has excellent interfacial adhesion, corrosion resistance, cathodic protection, and heat resistance. The purpose is to obtain excellent results such as Also, JP-A-61-
Publication No. 152443 discloses a technique of interposing an adhesive composition consisting of a polyamide resin, an ionomer, and an aminosilane compound between a metal layer and a polymer layer and bonding them under heat. The purpose is to improve the adhesive strength of the intermediate layer.

All of the above conventional technologies have in common that they use an ionomer as a component of the intermediate layer, and this is mainly due to the chemical bonding force between the carboxyl group in the ionomer molecule and the metal surface, which is a polar substance. The aim is to improve the interfacial adhesion by utilizing this.

(Problem to be Solved by the Invention) However, in the above conventional technology, the interfacial adhesive force between the olefin resin layer and the intermediate layer relies exclusively on intermolecular force, so the adhesive force is relatively weak and water resistance is poor. Where required,
Or when used in an environment where stress acts on the adhesive interface,
There was a problem in that interfacial peeling was likely to occur.

In the present invention, an ionomer or the like is used as an intermediate layer used for laminating an olefin resin layer and a metal layer, and a specific olefin resin is used while maintaining excellent chemical bonding strength with the metal. By doing so, the purpose is to obtain an excellent adhesive force between the intermediate layer and the olefin resin layer.

(Means for solving the problems) The present invention has the following features:1. an olefin resin layer containing metal acetate;
2. A laminate characterized in that an intermediate layer made of an ionomer or a base resin for forming an ionomer and a metal layer are laminated in this order; and 2. A metal acetate-containing olefin resin layer, a first intermediate layer made of an ionomer or a base resin for forming an ionomer, a second intermediate layer made of a thermosetting resin, and a metal layer are laminated in this order. The gist of the invention is a laminate having the following characteristics.

In the present invention, polyethylene, polypropylene, etc. having various densities and molecular weights can be used as the olefin resin.

However, in the present invention, in order to firmly bond the olefin resin layer and the intermediate layer, the olefin resin must contain a metal acetate due to the relationship with the constituent components of the intermediate layer, which will be described later. There is.

Examples of the metal acetate include zinc acetate, potassium acetate, calcium acetate, sodium acetate, copper acetate, barium acetate, and other salts that are solid at room temperature and that form ionic bonds with the ionomer or the base resin for forming the ionomer. can be suitably used.

In order to incorporate this metal acetate into an olefin resin to produce the metal acetate-containing olefin resin used in the present invention, it is first necessary to crush these metal acetates into a powder with a particle size of 200 μm or less. be. If the particle size is 200 a
If it exceeds m, the metal acetate will not be uniformly dispersed in the olefin resin, and further problems will occur such as non-uniform adhesive strength with the intermediate layer when formed into a laminate.

Incidentally, the method for pulverizing the metal acetate may be either a mechanical method or a chemical method. Furthermore, if there is a commercially available metal acetate salt that satisfies the above particle size conditions, it may be used.

Next, the method for incorporating the metal acetate salt powdered into the olefin resin depends on the method used to laminate the metal acetate-containing olefin resin in the intermediate layer when producing the laminate.

That is, when using a powder coating method such as a fluidized dipping method or an electrostatic coating method, a powdered olefin resin with a particle size of 300 μm or less and acetic acid metal salt powder are mixed in a crusher or a super duster. It is sufficient to simply tri-blend using . Further, when extrusion coating the intermediate layer with the metal acetate-containing olefin resin using an extrusion method, it is necessary to mix both powdered components in advance and knead them well using a roll.

Therefore, the amount of metal acetate added to the olefin resin is 0.1 to 100 parts by weight of the olefin resin.
It is used in a proportion of 25 parts by weight. If the amount of metal acetate added is less than 0.1 part by weight, the desired effect on the intermediate layer cannot be obtained, and if it exceeds 25 parts by weight, the heat resistance, water resistance, etc. of the olefin resin itself will decrease. There is a tendency to

In addition, in the present invention, an ordinary olefin resin may be appropriately mixed with the metal acetate-containing olefin resin.

In the ionomer or base resin for forming the ionomer, which is the component C of the intermediate layer of the laminate of the present invention,
Both are composed of copolymers of α-olefins such as ethylene and propylene, and acrylic acid, methacrylic acid, or maleic acid. In the present invention, a copolymer in which the content of acrylic acid, methacrylic acid, or maleic acid with respect to α-olefin is 5 to 30% by weight is used, and the base resin for forming an ionomer in the present invention refers to It refers to a copolymer of this α-olefin and acrylic acid, methacrylic acid, or maleic acid.

Therefore, in the present invention, ions of various metals such as sodium, potassium, silver, copper, calcium, barium, zinc, and iron are added to the copolymer instead of the base resin for forming the ionomer. It is also possible to use a so-called ionomer in which a metal ion and acrylic acid, methacrylic acid, or maleic acid contained in the above copolymer form an ionic bond to have a crosslinked structure.

Both ionomers and base resins for forming ionomers have carboxyl groups in their molecules that are not involved in ionic bonding, so they firmly adhere to the metal surface layer, which is a polar substance. That is, this is because a chemical bond or intermolecular force is generated between the ionomer and the oxide film on the metal surface, and this is the reason why an ionomer is used for the intermediate layer in the prior art.

Therefore, in the present invention, the characteristics of the carboxyl group in the intermediate layer are also utilized for adhesion to the olefin resin layer. That is, the metal acetate and carboxyl group contained in the olefin resin form an ionic bond. Additionally, in general, olefin resins and ionomers or base resins for forming ionomers have similar chemical structures, which also generates intermolecular forces, which together create strong adhesion. .

In the combination of the metal acetate-containing olefin resin layer and the intermediate layer, when polyethylene is used as the olefin resin in the metal acetate-containing olefin resin layer, polyethylene is used as the α-olefin in the intermediate layer. When ethylene is used and polypropylene is used as the olefin resin, it is preferable to use propylene as the α-olefin in terms of increasing the compatibility of both layers and obtaining a larger intermolecular force.

In the laminate of the present invention, a thermosetting resin layer such as epoxy resin or phenol resin may be further provided as a second intermediate layer between the intermediate layer made of the ionomer or the base resin for forming the ionomer and the metal layer, By doing so, a laminate with better water resistance can be obtained.

In general, thermoplastic resins such as olefin resins and ionomers have poorer water resistance than thermosetting resins, and when used in environments where the laminate is immersed in high-temperature water, If the heat penetrates into the interface between the intermediate layer and the metal layer, the adhesion force at that interface may decrease.However, if the second intermediate layer is provided, the metal surface will absorb this heat. It is protected by the second intermediate layer made of a curable resin, thereby improving heat resistance.

In the laminate of the present invention, it is optional to further provide a conventional olefin resin layer on the acetate-containing olefin resin layer in order to protect the acetate-containing olefin resin layer.

In the laminate of the present invention, fillers, reinforcing agents, antioxidants, coloring agents, etc., which are normally added or mixed with the constituent components of each layer, are added to the constituent components for the intended purpose of the present invention. It is also optional to use it within a range that does not inhibit.

(Function) In (1) of the present invention, an intermediate layer made of an ionomer or a base resin for forming an ionomer is used as the intermediate layer, and an olefin resin layer containing a metal acetate is used as the olefin resin layer. In the intermediate layer, the metal acetate contained in the olefin resin layer and the carboxyl group in the intermediate layer form an ionic bond, and their similar chemical structures generate intermolecular forces. Further, between the intermediate layer and the metal layer, a chemical bond or intermolecular force is generated between the carboxyl group of the intermediate layer and the oxide film on the metal surface.

In addition, the second aspect of the present invention has a first intermediate layer made of an ionomer or a base resin for forming an ionomer, and a second intermediate layer made of a thermosetting resin, so that the second intermediate layer is made of an ionomer or a base resin for forming an ionomer. Thermosetting resin with excellent heat resistance protects metal surfaces.

(Example) Examples of the present invention will be described in detail below.

Asado ■ Particle size of 200μ as a base resin for forming a laminated ionomer between a metal layer and an intermediate layer.
Prepare a copolymer resin of ethylene and methacrylic acid (R1214J manufactured by Dupont Mitsui Borikakancal Co., Ltd., melting index 14, density o 94, methacrylic acid content M12% by weight, melting point 94 ° C) crushed to a size of , as a metal layer,
A steel plate was degreased with toluene for 10 minutes using an ultrasonic cleaner and inserted into a blower heated to 140'C for 10 minutes.The copolymer resin, which is a component of the intermediate layer, was electrostatically applied to the steel plate. It was painted and placed in the blower for 5 minutes.

■ Laminated linear low-density polyethylene (LM76 manufactured by Asahi Kabo Kogyo Co., Ltd.) consisting of an olefin resin layer and an intermediate layer/metal layer.
Zinc acetate (manufactured by Yoneyama Chemical Industry Co., Ltd.; molecular weight 219.50) to prepare a metal acetate-containing olefin resin.

Next, the metal acetate-containing polyethylene was electrostatically applied to the intermediate layer side of the intermediate N/metal layer laminate taken out from the blower. Then, it was inserted into a blower heated to 140'C, taken out after 10 minutes, and electrostatically coated with the above metal acetate-containing polyethylene again.
The mixture was baked in a blower heated to C. to obtain a laminate having a three-layer structure of metal acetate-containing polyethylene layer/intermediate layer/metal layer. The thickness of the intermediate layer of the laminate was 120 pm, and the thickness of the metal acetate-containing polyethylene resin layer was 270 μm.

As the resin layer constituting the olefin-based resin layer for ranosalmon, linear low-density polyethylene (R L M7625J manufactured by Asahi Kakogyo Co., Ltd.; density 0.926, melting index 20) that does not contain metal acetate was used. A laminate was obtained in the same manner as in Example 1 except for the above. The thickness of the intermediate layer of the laminate was 140 μm, and the thickness of the polyethylene layer was 250 μm.

The components constituting the Dairobangyo intermediate layer are a copolymer of ethylene and methacrylic acid, and an ionomer consisting of zinc ions (R 1765 manufactured by DuPont Mitsui Polychemical Co., Ltd.; melting index 14, density 0.95, methacrylic acid Content 15% by weight,
Ionization degree 22%, melting point 91°C) with a particle size of 200 μm
Except for using powder that was crushed as follows.
A laminate was obtained in the same manner as in Example 1. The thickness of the intermediate layer of the laminate is 130 μm, and the thickness of the polyethylene layer is 240 μm.
It was m.

1 Polyethylene N/metal acetate-containing polyethylene N
A laminate having a four-layer structure of /intermediate layer/metal layer was obtained. The thickness of the intermediate layer of the laminate was 130 μm, the thickness of the metal acetate-containing polyethylene layer was 130 μm, and the thickness of each polyethylene layer was 150 μm.

An undercoat layer made of a thermosetting resin is formed on the steel plate, which is a metal layer. ), 60 parts by weight of a curing agent (manufactured by Yuka Shell Epoxy Co., Ltd. "Evomate LX-IN with amine equivalent of 112.2, pot life 20°C 70 minutes, liquid at room temperature)", and 200 parts by weight of xylene were mixed. Example 1 except that the solution obtained by stirring was undercoated with a brush, left at room temperature for about 10 minutes to volatilize a part of the solvent, and then inserted into a blower heated to 140 ° C. and cured. In the same manner as above, a laminate having a four-layer structure of metal acetate-containing polyethylene N/intermediate layer/thermosetting resin layer/metal layer was obtained.

The thickness of the intermediate layer of the laminate was 130 μm, the thickness of the metal acetate-containing polyethylene layer was 280 μm, and the thickness of the thermosetting resin layer was 38 μm.

Example 5 Metal acetate-containing polyethylene N/intermediate layer/metal was prepared in the same manner as in Example 1 except that sodium acetate (manufactured by Yoneyama Chemical Industry Co., Ltd.; molecular weight 136.08) was triblended with linear low-density polyethylene. A laminate consisting of a three-layer structure of layers was obtained. The thickness of the intermediate layer of the laminate was 110 μm, and the thickness of the metal acetate-containing polyethylene layer was 220 μm.

Regarding the laminates obtained in each of the above examples and comparative examples,
The interfacial adhesion between the metal acetate-containing olefin resin layer and the intermediate layer was measured by a 90 degree peel test at 25°C and a peeling rate of 50 mm/min.
The measurement results are shown in Table 1.

Regarding the interfacial adhesive force in Example 4, the interfacial adhesive force between the metal acetate-containing olefin resin layer and the first intermediate layer was measured.

(Margin below) Table 1 Note) *l; Cohesive failure of olefin resin layer *2; Interfacial peeling between olefin resin layer and intermediate layer (effects of the invention) In the first aspect of the present invention, as an intermediate layer, It has an intermediate layer made of an ionomer or a base resin for forming an ionomer, and an acetate-containing olefin resin layer is used as the olefin resin layer. The metal salt and the carboxyl group in the intermediate layer form an ionic bond, and
Their similar chemical structures create intermolecular forces, and together they exert strong adhesive force. Further, the intermediate layer and the metal layer are strongly adhered to each other due to the chemical bond or intermolecular force between the carboxyl group of the intermediate layer and the oxide film on the metal surface. In this way, it is possible to provide a laminate as a whole that is highly practical and free from interfacial peeling.

The second aspect of the present invention has a first intermediate layer made of an ionomer or a base resin for forming an ionomer, and a second intermediate layer made of a thermosetting resin, so that the thermosetting resin with excellent heat resistance is Protects the surface and can withstand long-term use under high-temperature water.

The laminate obtained by the present invention includes synthetic resin-coated steel pipes,
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)

[Scope of Claims] 1. A laminate comprising a metal acetate-containing olefin resin layer, an intermediate layer made of an ionomer or a base resin for forming the ionomer, and a metal layer, which are laminated in this order. 2. A metal acetate-containing olefin resin layer, a first intermediate layer consisting of an ionomer or a base resin for forming an ionomer, and a second intermediate layer consisting of a thermosetting resin;
A laminate characterized in that a metal layer is laminated in this order.