JPS6153016A - Manufacture of metal/synthetic resin composite molded item - Google Patents

Abstract

PURPOSE:To make it possible to produce, with simple and dimensional accuracy, a metal/composite molded item that has a resin surface and a metal layer as an intermediate layer, by applying a metal skin onto a resin molded item by a metal spraying method, and integrating the resin molded item and a resin molding material in a mold under pressure. CONSTITUTION:A metal skin is applied onto one surface of a resin molded item (A) by a metal spraying method, the resin molded item is placed in a mold in such a manner that the metal skin surface will be exposed to a resin molding material that will be introduced, and then the resin molding material is molded under pressure thereby the resin molded item (A) having the metal skin and the resin molding material are integrated via the metal skin. As a resin molding material used can be mentioned a bulk molding compound that has been previously molded into the shape of a mass or a sheet molding compound that has been previously molded into the shape of a sheet. These compounds can be obtained by adding a fibrous reinforcing material, a filler, a hardening agent, a bodying agent, etc. to an unsaturated polyester resin and are excellent in moldability and adhesiveness to the sprayed metal skin and easy in handling.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for manufacturing a metal composite resin molded product having a resin surface and a metal layer as an intermediate layer, and relates to a method for manufacturing a metal composite resin molded product having a resin surface and a metal layer as an intermediate layer.
The present invention provides a method for easily manufacturing resin molded products with excellent electromagnetic shielding properties and other properties with good dimensional accuracy, and is particularly useful in the fields of electromagnetic shielding casings, radio wave reflectors, and the like.

[Conventional technology]

BACKGROUND ART Resin molded products have been used for various purposes in a wide range of fields because they have good mechanical strength and can be molded relatively easily. However, one of its drawbacks is that it has a high electrical resistance, making it extremely difficult to apply it to electromagnetic shielding cases for electrical circuits, radio wave reflectors, and equipment that needs to prevent static electricity. As one method for solving this problem, a widely used method is to apply metal spraying to the resin molded product to adhere a metal layer to the surface of the resin molded product. However, when such a method is used, there is a problem that the bonding force between the resin molded product and the sprayed metal layer is small, so that the metal layer is likely to peel off. It is also widely practiced to coat resin molded products with conductive paint, but in general, the electrical conductivity of conductive paint is much lower than that of metals, so it is difficult to obtain the necessary electrical properties, or it is difficult to coat resin molded products with conductive paint. Since the bonding force between the conductive paint and the coating film is small, the coating film tends to peel off easily. In addition, it has been widely considered to make resin molded products electrically conductive by mixing resin molding materials with electrically conductive dust fillers such as short metal fibers, carbon fibers, and carbon powder. ing. However, when such methods are used, the electrical properties obtained are often insufficient, or the mechanical properties of the molded product are often significantly impaired, and so far no satisfactory product has been obtained. . On the other hand, as a method for easily manufacturing resin molded products with a metal layer firmly bonded to the surface with good dimensional accuracy, a metal coating is applied to the auxiliary mold in advance by metal spraying, and then the auxiliary mold is used for pressure molding. The resin molding material is placed in a mold and molded under pressure to form a metal coating and the resin molding material, and then the molded product is demolded from the mold and the auxiliary mold to have a metal layer on the surface. A method for obtaining a resin molded article has already been proposed by the present inventors.

By following this method, it is possible to obtain molded products with excellent performance, but depending on the type of metal used, there may be problems with corrosion resistance, or there may be a risk of electric shock due to the conductive layer on the surface. Problems are also foreseen, and in such cases, it is necessary to apply additional coating, which has the disadvantage of increasing the number of man-hours.

[Problem that the invention seeks to solve]

As a result of intensive research in view of the current situation, the inventors of the present invention have found that by integrating a resin molded product to which a metal film has been previously attached using a metal spraying method and a resin molding material in a mold under pressure, the surface can be made of resin. Metal composite resin molded products with a metal layer in the middle layer can be manufactured easily and with high dimensional accuracy.
Furthermore, the inventors discovered that since the metal layer is encapsulated as an intermediate layer, a molded article with excellent corrosion resistance, weather resistance, and surface electrical insulation can be obtained, leading to the present invention.

[Means and effects for solving the problem] In other words, the present invention provides a method for pressure-molding a resin molding material using a pressure-molding mold, by applying a pressure-molding method to one side of a resin molded product (a) prepared in advance. After attaching the metal film by a metal spraying method, the metal film is impregnated with a resin composition if necessary, and then the resin molded product (A) with the metal film attached is placed so that the metal film surface faces the resin molding material. The resin molding material is placed in the mold as shown in FIG. The present invention provides a method for manufacturing a metal composite resin molded article.

The pressure molding mold used in the present invention is composed of a male mold and a female mold, and can form a desired space when the male and female molds are closed, and can fill the space with resin molding material. It is constructed so that it can be held under pressure, and the molds that are generally used when molding thermoplastic resin molding materials or thermosetting resin molding materials under pressure are of this type. satisfy the following conditions.

The resin molding materials used in the present invention include phenolic resin,
Thermosetting resins such as epoxy resins and unsaturated polyester resins, thermoplastic resins such as polyethylene, polypropylene, polyvinyl chloride, and polystyrene, and foamable resins such as polyurethane, as well as glass fibers, carbon fibers, and boric resins, as needed. Thermoplastic resins are compounded with pigments, thickeners, low shrinkage agents, blowing agents, blowing aids, etc., but thermoplastic resins have excellent moldability and can be used with various additives to meet various requirements. It is possible to satisfy the physical properties in a well-balanced manner,
It is desirable as a general-purpose resin molding material, and
Thermosetting resins have excellent strength, weather resistance, chemical resistance, and heat resistance, and are desirable for applications that require such physical properties.

A so-called sheet molding compound (hereinafter referred to as SMC) that is blended and preformed into a sheet shape.
The so-called bulk molding compound (hereinafter referred to as BMC), which is preformed into a mass or mass, is desirable because it has excellent moldability and is easy to handle, and also has excellent adhesion to thermally sprayed metal coatings. .

In the present invention, the resin composition used for the purpose of impregnating the metal film as necessary is the thermosetting resin or thermoplastic resin used in the resin molding material.
It is made by blending additives such as a curing agent and an accelerator, and it is also possible to blend it with a diluent in order to improve impregnation into the metal film.

The resin molded product used in the present invention has a metal film adhered to one surface by metal spraying, and is then placed in the pressure molding mold, and the resin molding material is molded in the mold. When doing so, it is integrated with the resin molding material via a metal film, and becomes a part of the resulting metal composite resin molded product. The material can be used without particular limitation as long as it can be used to attach a metal film by metal spraying and does not deteriorate or change in quality due to pressure during molding or heat if necessary. The shape of the resin molded product (6) is such that the metal coating surface of the resin molded product (6) faces the resin molding material when the resin molding material is molded under pressure in the pressure molding mold. Any material that can maintain a predetermined position within the mold can be used without particular limitation.

Resin molded products used when pressure is high during pressure molding (5
The shape of the resin molded product (
A) is preferable because it is easy to maintain the predetermined position and maintains the dimensional accuracy of the obtained metal composite resin molded product,
The surface of the resin molded product that is in contact with the inner surface of the mold is processed in advance to have the same shape as the inner surface of the mold, or it is deformed by heat depending on the pressure and necessity during molding. It is desirable to select and use a material that will adhere closely to the inner surface of the mold. However, when the pressure during pressure molding is low, such as when a foamable resin is used as the resin molding material, it is not necessarily necessary to form a shape that closely contacts the inner surface of the mold, and the resin molded product (A ) can be used in various shapes as long as the shape is not such that the desired structure and shape cannot be obtained due to being sealed in the resin during pressure molding. It is also possible to mold metal composite resin molded products with various configurations and shapes, regardless of the inner surface shape of the pressure molding die. Therefore, the resin molded product used in the present invention may be a resin molding material molded in advance using a mold, or a resin film molded by means such as calendar molding.

In particular, when a thermoplastic resin molded product is used as the resin molded product (A), it is not only easy to mold, but also deforms moderately during pressure molding and adheres closely to the pressure molding die. It is desirable because it causes less damage to the mold. However, it is necessary to select an appropriate material so that it does not deteriorate or change in quality due to the pressure and heat during molding.

Among the thermoplastic resin molded products used as the resin molded product (5), when using a thermoplastic resin film, it is easy to handle, and it is rolled up while continuously applying metal spraying on the film, and then cut into an appropriate shape. It can also be used as a stand-alone device, and productivity is extremely high.

Among thermoplastic resin films, it is desirable to use a polyester film because it has excellent durability and weather resistance, and provides a metal composite resin molded product with a beautiful appearance.

In addition, if a so-called laminate film in which two or more types of thermoplastic resin films are laminated on the thermoplastic resin film as the resin molded product (A) is used, the film located on the side forming the outer surface of the metal composite resin molded product can be used. A film that satisfies various physical properties required for a surface material such as weather resistance, heat resistance, and chemical resistance is placed on the surface, and the film located on the side that comes into close contact with the thermally sprayed metal layer has a film that meets the requirements for adhesion to the metal layer during thermal spraying. It is possible to obtain a single-layer film that simultaneously satisfies the physical properties generally required for a surface material and the physical properties required for the surface in contact with the thermal spray layer, by performing operations such as disposing a material with excellent adhesive strength and high adhesive strength. Considering the difficulty, it is particularly desirable to use a laminate film made by laminating resin films that meet various requirements. Among these, a laminate film made by laminating a polyester film and a film obtained from a thermoplastic resin composition with a softening point of 150°C or less is used, with the polyester film positioned on the side that forms the outer surface of the metal composite resin molded product. When used, the resulting metal composite resin molded product has excellent weather resistance and chemical resistance, and is desirable because it has high adhesive strength between the surface film and the metal sprayed layer.

In order to obtain a thermoplastic resin molded product as the resin molded product (A) in the present invention, it is possible to mold it using a general molding method such as injection molding or calendar molding. It is also possible to apply a solution of a thermoplastic resin composition dissolved in a solvent or the like to a mold by brushing or spraying, and then evaporate the solvent to form a thermoplastic resin molded product in the form of a film. The molding method is not particularly limited.

In addition, when a thermosetting resin molded product is used as the resin molded product (A), it is relatively easy to mold, and has good heat resistance and
It is desirable because it has excellent durability, chemical resistance, and weather resistance, and high strength can be easily obtained. Among them, if molded from SMC or BMC using unsaturated polyester resin is used as the inside of the resin molded product, the molding is easy.
It is also desirable in terms of durability and heat resistance.

In this way, various resin materials can be used for the resin molded product (6), but the type of resin material used for the resin molded product (A) has the required heat resistance, durability, chemical resistance, and weather resistance. The material should be selected in consideration of a number of factors, such as various physical properties such as and the required adhesive strength between the metal film and the resin molded product (A). The inside of such a resin molded product can be created using the general molding method described above.
A suitable processing method can be adopted depending on the material, shape, required surface precision, etc. of the resin molded product (a).

The surface to which the metal coating of the resin molded product (A) used in the present invention is attached may be a mirror surface, but part or all of one surface of the resin molded product to be subjected to metal spraying may be coated with fine particles. If processed to have unevenness, the bonding force between the resin molded product (A) and the thermally sprayed metal coating will increase, and problems such as the resin molded product (A) peeling off from the resulting metal composite resin molded product will be avoided. It can be prevented. Furthermore, when a metal with a high melting point is thermally sprayed or when it is necessary to attach a relatively thick metal film, it is desirable to perform such an uneven process.

The uneven processing of the resin molded product (A) can be performed by blasting, sanding, or other machining means, and the resin molded product (5) can be molded using a mold processed to reproduce the uneven pattern. However, it is also possible to perform uneven processing on resin molded products.

Thermal spraying used in the present invention includes gas spraying, arc spraying,
This refers to a method such as plasma spraying in which a porous sprayed layer is formed by spraying a molten or semi-molten metal material. Further, as the metal material used when performing metal spraying, it is possible to appropriately select and use metal materials commonly used in the industry. However, metals with low melting points such as zinc and tin adhere well to resin molded products with mirror surfaces (5), but metals with high melting points such as copper, iron, aluminum, and stainless steel adhere well to resin molded products with mirror surfaces (5). ) is difficult to adhere to, so it is preferable to spray on a resin molded product (A) that has been subjected to uneven processing, and the resin molded product (5
) It is desirable to select a metal material that is compatible with the surface conditions of the

In carrying out the present invention, metal is first applied to a part or all of one surface of the resin molded product (A), the other surface of which is to be coated with a metal coating, has been processed to have a mirror surface or fine irregularities, by metal spraying. Attach a film.

At this time, if the resin molding material is in the form of a film or sheet and is made of a material that can be easily cut or otherwise processed, it is preferable to apply the metal film and then perform the cutting or other processing. It is also possible to make dimensions.

Next, if necessary, the metal film is impregnated with a resin composition. By carrying out such operations, it is possible to reduce the number of air bubbles that may be present in the metal coating, and it is also possible to increase the bonding force between the resin molded product (a) and the metal coating, resulting in a good overall result. A metal composite resin molded product having certain physical properties can be obtained.

Next, the resin molded product with the metal film attached is placed so that the metal film surface faces the resin molding material and the other surface of the resin molded product (A) faces the inner surface of the pressure molding mold. Placed in the mold. At this time, it is also possible to use a plurality of resin molded articles. It is also possible to cover the entire surface of a metal composite resin molded article obtained by appropriately arranging two or more resin molded articles (A) with the resin molded article (A).

After placing the resin molded product (A) with the metal film attached in the pressure molding mold as described above, the resin molding material is supplied into the mold, and the resin is molded by heating or cooling under pressure. A metal composite resin molded product having a metal layer as an intermediate layer by curing or fixing the material and a resin molded product (6) with a metal film attached together through the metal film, and then removing the mold from the mold. can be obtained.

〔Effect of the invention〕

As described above, according to the manufacturing method shown in the present invention, a resin molded product having a metal layer as an intermediate layer can be easily molded with good dimensional accuracy, and furthermore, the resin molded product (A) can be molded with high dimensional accuracy. By appropriately selecting the material, shape, and resin molding material used to mold the metal composite resin molded product,
It can provide various physical properties such as excellent heat resistance, durability, chemical resistance, and weather resistance, and due to the function of the metal layer located in the middle layer, it has excellent electrical conductivity, radio wave reflection properties, electromagnetic shielding properties, etc. The following physical properties can be imparted.

Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited to these examples.

Example 1 8MC (manufactured by Nippon Shokubai Chemical Industry Co., Ltd., "Eboratsu Mat"
2068B) 100.9 was supplied into the mold and heated and pressed for 4 minutes at a mold temperature of 145°C and a molding pressure of 50 kg/cJ to form a disc-shaped SMC product with a thickness of 1.8 wm. A resin molded product (hereinafter referred to as resin molded product (1)) was obtained. Next, one side of the resin molded product (1) was blasted with Steel Grid +40 to create an uneven surface, and then an arc spray gun (375EF8, manufactured by TAFA, USA) was used.
Zinc was thermally sprayed to a thickness of about 100 microns over the entire surface of the resin molded product (1) that had been subjected to the uneven processing. Next, the resin molded product (1) to which the zinc spray coating has been adhered is placed in the female mold of the pressure molding mold so that the sprayed metal surface faces the male mold, and then the resin molded product (1) is placed in the female mold for pressure molding. The same SMC2501I used for molding the resin molded product (1) was placed in the female mold.
The mold was closed and molded by heating and pressing at a mold temperature of 145°C and a molding pressure of 9/cJ for 4 minutes to form the resin molded product (1) with the thermal spray coating attached and the SMC. The resulting molded product was cured integrally through the metal film, and the resulting molded product was removed from the mold to form a disk-shaped product with a diameter of 200 mm and a thickness of 6.3 mm, with the intermediate layer being a zinc film and the surface being SMC. A metal composite resin molded article (hereinafter referred to as composite molded article (1)) was obtained.

The volume resistivity of the zinc film located in the intermediate layer of the composite molded article (1) was lXl0'Ω·cm. Zinc coating is SM
It adheres strongly to the cured product of C, and after placing it in a dryer at 100°C for 30 minutes and then placing it in ice water at 0°C for 30 minutes,
Even after 20 cycles of cold and hot cycle tests, no changes such as peeling were observed.

Example 2 A polyester film (LumiPearl Φ125, manufactured by Toshi ■) with a thickness of 125 microns and a diameter of 19
A 9 mm disk shape was cut out to obtain a resin molded product made of polyester film (hereinafter referred to as resin molded product (2)). One side of the obtained resin molded product (2) was sanded with +250 sandpaper to create an uneven shape, and then an arc spray gun was applied between the bodies (manufactured by TAFA, 3751FS).
The aluminum was sprayed to a thickness of approximately 50 microns using a . Next, place the resin molded product (2) with the sprayed aluminum coating on it in the same pressure molding mold used in Example 1 so that the sprayed metal surface faces the resin molding material, and roughly The same SMC250 used in Example 1 was placed in the mold.
g was supplied and molded by heating and pressurizing under the same conditions as in Example 1, the resin molded product (2) to which the thermal spray coating was attached and the SMC were integrally cured via the metal film, and the obtained molded product was The mold is removed from the mold, and the intermediate layer is an aluminum film and the surface is a cured product of polyester film and SMC.
A disk-shaped metal composite resin molded product (hereinafter referred to as composite molded product (2)) having a thickness of 111111 and a thickness of 46 mm was obtained.

The volume resistivity of the aluminum film located in the middle layer of the composite molded product (2) was 5×10′Ω·cm. The aluminum film was firmly adhered to the cured product of SMC and the polyester film, and no changes such as peeling were observed even after 20 cycles of the same cold cycle test as in Example 1.

Example 3 Height: 100 mm, width: 50 mm, depth: 30 mm, wall thickness: 2 ■
A pressure molding mold consisting of a pair of male and female molds used for molding a box with an open top was prepared, and a mold with a length of 90 mm, a width of 40 mm, and a depth of 1.5 mm was placed in the center of the male mold. A depression was created. Next, a 1.5 mm thick acrylic resin plate with a grid-like pattern engraved on one side at intervals of one cylinder was cut to fit perfectly into the recessed part of the male mold, and a grid-like pattern was carved on one side. A resin molded product made of acrylic resin having a pattern (hereinafter referred to as resin molded product (3)) was obtained. Next, an arc spray gun (manufactured by TAFA, USA, 3751F) was obtained.
Using S), aluminum bronze was thermally sprayed to a thickness of about 50 microns onto the goggle pattern of the resin molded product (3). Next, a resin molded product with a sprayed aluminum bronze coating (
3) is fitted into the recessed part of the male mold so that the sprayed metal surface faces the female mold of the pressure molding mold, and then the injection pressure is 8
00kg10a, resin temperature 240℃, mold temperature 60℃,
Nylon resin (manufactured by Unitika Co., Ltd., First Cyclol Nylon A10308R) was injected into the pressure molding mold under a cycle of 30 seconds to form a resin molded product (3) with a thermal spray coating attached and a nylon resin. are solidified together through a metal film, and then the molded product obtained is molded into a metal composite resin molded product (hereinafter referred to as composite molded product (3)).
). ) was obtained.

The Lumi Bronze film was firmly adhered to the solidified nylon resin and the acrylic resin, and no changes such as peeling were observed even after 20 cycles of the same cold-heat cycle test as in Example 1.

Example 4 One side of the same resin molded IjII (2) used in Example 2 was processed into an uneven shape in exactly the same manner as in Example 2, and then aluminum was sprayed to a thickness of about 50 microns. Next, the resin molded product (2
) was placed in the same pressure molding mold used in Example 1 so that the sprayed metal surface faced the resin molding material, and the foamed urethane W resin (manufactured by Toyo Rubber Industries, Ltd.) was roughly placed in the mold. , Soflan R1356-BHR) 1! A urethane resin composition mixed with 15 g of a curing agent (Soflan R1356-BHP, Toyo Rubber Industries, Ltd.) was sprayed on M, and the mold was immediately closed, and the mold temperature was 40°C and the molding pressure was 1 kg/c. - The resin molded product with the thermal spray coating attached (2
) and a foamed urethane resin composition are integrally foamed and cured, and then the resulting molded product is removed from the mold to form a diameter in which the intermediate layer is an aluminum film and the surface is a cured product of polyester film and foamed resin. 200mm% thickness 15m
m disc-shaped metal composite resin molded product (hereinafter referred to as composite molded product)
4). ) was obtained.

The volume resistivity of the aluminum film located in the middle layer of the composite molded product (4) was 5xio'Ω·cm.

The aluminum film was firmly adhered to the foamed cured product of the foamed urethane resin composition and the polyester film, and no changes such as peeling were observed even after 20 cycles of the same cold and hot cycle test as in Example 1.

Claims (1)

[Claims] 1. When pressure molding a resin molding material using a pressure mold, a metal film is attached to one surface of a resin molded product (A) prepared in advance by a metal spraying method. After that, if necessary, the resin composition is impregnated into the metal film, and then the resin molded product (A) with the metal film attached is placed in the mold so that the metal film surface faces the resin molding material. Production of a metal composite resin molded product, characterized in that the resin molded product (A) to which a metal film is attached by molding a resin molding material under pressure and the resin molding material are integrated via a metal film. Method. 2. The method for manufacturing a metal composite resin molded article according to claim 1, wherein the resin molding material is a sheet molding compound or a bulk molding compound using an unsaturated polyester resin. 3. The method for producing a metal composite resin molded product according to claim 1, wherein the resin molded product (A) is a thermoplastic resin molded product. 4. The method for producing a metal composite resin molded product according to claim 3, wherein the thermoplastic resin molded product is a thermoplastic resin film. 5. The method for producing a metal composite resin molded article according to claim 4, wherein the thermoplastic resin film is a polyester film. 6. The method for manufacturing a metal composite resin molded article according to claim 4, wherein the thermoplastic resin film is a laminate film in which two or more types of thermoplastic resin films are laminated. 7. The method for manufacturing a metal composite resin molded article according to claim 6, wherein the laminate film is a laminate film in which a polyester film and a film obtained from a thermoplastic resin composition having a softening point of 150° C. or less are laminated. 8. The method for producing a metal composite resin molded product according to claim 1, wherein the resin molded product (A) is a thermosetting resin molded product. 9. The method for producing a metal composite resin molded article according to claim 8, wherein the thermosetting resin molded article is molded from a sheet molding compound or a bulk molding compound using an unsaturated polyester resin. 10. The method for manufacturing a metal composite resin molded product according to claim 1, wherein the resin molded product (A) is processed so that part or all of the surface to which the metal film is attached has irregularities.