JP2003094561A - Composite molded product and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite molded product composed of a metallic sheet and a thermoplastic material formed in one piece with firm adhesion by an injection insert-molding process. SOLUTION: This composite molded product has the metallic sheet and two thermoplastic material layers, i.e., layers (A) and (B), sequentially formed on the metallic sheet in one piece. In this composite molded product, the layer (A) is a mixed adhesive resin of a modified polyolefin and a modified styrene thermoplastic elastomer. Thus the layer (A) is formed by applying the modified polyolefin and the modified styrene thermoplastic elastomer on the metallic sheet. Further, the layer (B) is integrally formed by thermally fusion-bonding a thermoplastic material to the layer (A). The method for manufacturing the composite molded product is described.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a composite molded article and a method for producing the same. More specifically, the present invention is a composite molding suitable for applications such as a gasket with a lid used for housing electronic equipment, in which a metal plate and a thermoplastic material layer are integrated with good adhesiveness via an adhesive resin layer. The present invention relates to a body and a method for easily and efficiently manufacturing the body.

[0002]

2. Description of the Related Art In recent years, the development of electronic equipment has been remarkable, and these electronic equipment use integrated circuits using semiconductors and are printed on a substrate, and are miniaturized.
The weight is reduced. Since these electronic devices do not like water, dust, etc., the sealing property of the case that houses the electronic devices is an important factor for the performance and durability of the electronic devices.

A case for accommodating electronic equipment is composed of a box body and a lid body, and the box body and the lid body sandwich a gasket made of vulcanized rubber, urethane foam, thermoplastic material or the like on their mating surfaces. It is integrated. Usually the gasket is
Since there is no good method of adhering the gasket to the lid body in the form of a gasket with a lid fixed to the lid body, this fixing is (1) a method of fixing the gasket to the lid body with a double-sided tape, (2) a lid A method is used in which a hole is opened in the body and the gasket material is fixed by sandwiching the hole from both sides of the lid. The lid with gasket is fixed to the box with screws. Therefore, since the gasket is adhered to the lid, the work of fixing with the screw becomes extremely easy. As a method of fixing the gasket to the lid with the double-sided tape of (1), usually, a sheet-shaped gasket material to which the double-sided tape is attached is punched into a gasket shape, and the gasket is fixed to the lid. There is. However, in this method, most of the sheet-shaped gasket material after punching is discarded as waste material, and since the gasket material is punched into a gasket shape and fixed to the lid, the process becomes complicated and the manufacturing cost is high. There is a problem that you cannot escape. In addition, the gasket with a lid manufactured by a method of sandwiching a lid with holes with a gasket material exposes the gasket material to the upper part of the lid, and thus becomes narrower with the recent miniaturization of electronic device parts. When the lid is inserted into the space of the electronic device body, the gasket material exposed on the top of the lid may be rolled up, which causes a problem of poor sealing performance. .

On the other hand, usually, a thermoplastic material is adhered to a metal plate which is a lid body by subjecting the surface of the thermoplastic sheet to a surface treatment by corona discharge or the like and then using an adhesive such as an epoxy or urethane adhesive. However, it is not applicable to gaskets for electronic devices because the work is complicated and there is a problem of gas generation due to the curing reaction residue of the adhesive. Therefore, in recent years, a composite molded body has been developed in which a thermoplastic material is injected by an insert molding method to be thermally fused and integrated with a metal plate provided with an adhesive resin layer.

[0005]

SUMMARY OF THE INVENTION Under the above circumstances, the present invention provides a lid used for housing electronic equipment, etc., in which a metal plate and a thermoplastic material are integrated by injection insert molding with extremely good adhesion. It is an object of the present invention to provide a composite molded body that is suitably used for applications such as an attached gasket by a simple method without requiring complicated steps.

[0006]

Means for Solving the Problems As a result of intensive studies to achieve the above-mentioned object, the present inventors have found that by providing a specific adhesive resin layer on a metal plate in advance, in the injection insert molding method. It has been found that a thermoplastic material can be heat-bonded to the adhesive resin layer with excellent adhesion to achieve its purpose. The present invention has been completed based on such findings.

That is, the present invention has a metal sheet and a composite molded article which has two thermoplastic material layers (A) layer and (B) layer which are sequentially provided on the metal sheet and which are integrated with each other. In the above, there is provided a composite molded article characterized by using a mixed adhesive resin of a modified polyolefin and a modified styrene thermoplastic elastomer as the (A) layer.

The present invention also provides a layer (A) by coating a mixed adhesive resin of a modified polyolefin and a modified styrene thermoplastic elastomer on a metal plate, and then forming a thermoplastic material on the layer (A). The present invention also provides a method for producing a composite molded body, characterized in that (B) layer is formed by heat-sealing the above, and is integrated.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The composite molded article of the present invention has a metal plate and two thermoplastic material layers, a layer (A) and a layer (B), which are sequentially provided on the metal plate, and these layers are integrated. It has been done. The metal plate is not particularly limited, and is, for example, a cold-rolled steel plate, a galvanized steel plate, an aluminum / zinc alloy-plated steel plate, a stainless steel plate, an aluminum plate, an aluminum alloy plate, a magnesium plate, a magnesium alloy plate, or the like, which is a composite molding. It can be appropriately selected and used according to the use of the body. As these metal plates are cheap,
A metal plate that has been subjected to electroless nickel plating, which has excellent corrosion resistance, is suitable. As this electroless nickel plating method, a known method that has been conventionally applied to metal materials, for example, nickel sulfate, sodium hypophosphite, lactic acid, propionic acid, etc. is contained at an appropriate ratio to a pH of 4.0 to 5.
A method of immersing the metal plate in an electroless nickel plating bath composed of an aqueous solution having a temperature of about 0 and a temperature of about 85 to 95 ° C. can be used. The thickness of the metal plate used in the present invention is appropriately selected depending on the application of the composite molded body,
It is usually 0.1 to 2 mm, preferably 0.2 to 1 mm.

The layer (A) provided on the metal plate is a layer made of a mixed adhesive resin of a modified polyolefin and a modified styrene thermoplastic elastomer. Here, examples of the polyolefin used as a raw material of the modified polyolefin include ethylene; propylene; butene-
1; 3-methylpentene-1; 4-methylpentene-1
Α-olefin homopolymers and copolymers thereof, and copolymers of these with other copolymerizable unsaturated monomers. As typical examples, high density, medium density, low density polyethylene and linear low density polyethylene, polyethylenes such as ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, propylene homopolymer, propylene- Polypropylene such as ethylene block copolymer, random copolymer, propylene-ethylene-diene compound copolymer, polybutene-
1, poly 4-methyl pentene-1 etc. can be mentioned.

The modified polyolefin is modified by a known method using a compound having a functional group such as an acid anhydride group, a carboxyl group, a carboxylic acid ester group and a chlorosulfonic acid group, or a halogen atom. Can be obtained. In the present invention, one type of modified polyolefin may be used alone, or two or more types may be used in combination.

On the other hand, examples of the styrene-based thermoplastic elastomer used as a raw material for the modified styrene-based thermoplastic elastomer include styrene-butadiene-styrene block copolymer (SBS) and hydrogenated styrene-butadiene-styrene block copolymer ( SEBS), styrene-isoprene block copolymer (SIR), styrene-isoprene-styrene block copolymer (SI
S), hydrogenated styrene-isoprene-styrene block copolymer (SEPS), styrene-isobutylene-styrene block copolymer (SIBS) and the like.

The modified styrene thermoplastic elastomer is
By modifying these styrene-based thermoplastic elastomers with a compound having a functional group such as an acid anhydride group, a carboxyl group, a carboxylic acid ester group, and a chlorosulfonic acid group, or a halogen atom, by a known method. ,Obtainable. In the present invention, the modified styrene-based thermoplastic elastomer may be used alone or in combination of two or more kinds.

As the mixed adhesive resin used in the (A) layer, from the viewpoint of adhesion between the (A) layer and the (B) layer, the ratio of the modified polyolefin and the modified styrene thermoplastic elastomer is weight. The ratio is preferably 50:50 to 9
9.5: 0.5, more preferably 65:35 to 9
9: 1, more preferably 70:30 to 99: 1. When the weight ratio of the modified polyolefin is less than 50%, the adhesive force is improved, but the coating property is remarkably sacrificed, and it becomes difficult to apply the modified polyolefin uniformly and precisely. The present invention has been made in view of providing a precise rubber / metal integrated type part, and the coating property of the mixed adhesive resin is
Extremely important. In the present invention, as a result of earnest research, if the ratio of the modified polyolefin to the modified styrene-based thermoplastic elastomer is in the range of 50:50 to 99.5: 0.5 by weight, excellent coatability is maintained. However, it was discovered that necessary and sufficient adhesive strength could be expressed, and its industrial use was taken as a measure. In the present invention, the thickness of this (A) layer is usually 3 to 100 μm, preferably 5
It is selected in the range of ˜30 μm.

In the composite molded article of the present invention, a thermoplastic material layer as a (B) layer is formed on the (A) layer by heat fusion. The thermoplastic material forming the layer (B) is not particularly limited, and can be appropriately selected from various materials and used according to the application of the composite. For example, when the composite is used as a seal member and the gasket portion is the (B) layer, the thermoplastic material forming the (B) layer has a JIS-A hardness of 60 °.
A low hardness thermoplastic material of less than is preferred. Examples of the low-hardness thermoplastic material include styrene-based thermoplastic elastomer, olefin-based thermoplastic elastomer, urethane-based thermoplastic elastomer, and acrylic-based thermoplastic elastomer. Especially in cases for housing electronic devices, it is preferable to use materials that reliably block moisture and air and do not generate halogen-based gas and acid gas. From the point,
A JIS-A hardness of less than 60 ° is preferable. Especially, those of 15 ° to 45 ° are preferable. As such a thermoplastic material, a styrene-based thermoplastic elastomer is preferable, and examples thereof include styrene-butadiene-styrene block copolymer (SBS) and hydrogenated styrene-butadiene-.
Styrene block copolymer (SEBS), styrene-isoprene block copolymer (SIR), styrene-isoprene-styrene block copolymer (SIS), hydrogenated styrene-isoprene-styrene block copolymer (SEPS), styrene- Examples thereof include isobutylene-styrene block copolymer (SIBS).

Specific examples of the styrene-based thermoplastic elastomer include Lavalon manufactured by Mitsubishi Chemical Co., Septon manufactured by Kuraray Co., Ltd. and Elastomer AR manufactured by Aron Kasei Co., Ltd. Lavalon MJ4300B (trade name, JIS-A hardness 45
°), Lavalon T320C (trade name, JIS-A hardness 1
5 °), Septon 2063 (trade name, JIS-A hardness 3
6 °). Further, a styrene elastomer compound prepared by compounding an oil, another polymer, a resin, etc. with a commercially available product as a pure polymer may be used. Styrene-based thermoplastic elastomer does not require vulcanization for molding, unlike EPDM rubber and butyl rubber,
And since it can be recycled, it greatly contributes to cost reduction. As the olefin-based thermoplastic elastomer, Santoprene 111-45 (trade name, JIS-A hardness 4 of AES Japan Co., Ltd.) is used.
5 °). These thermoplastic materials forming the layer (B) may be used alone or in combination of two or more kinds. In the composite of the present invention, the thickness of the (B) layer provided by heat fusion on the (A) layer is not particularly limited and is appropriately selected according to the application of the composite. Is usually 0.1 to 5 mm, preferably 0.2 to 2 mm.

In the present invention, the thermoplastic material layer of the layer (B) may optionally contain an antioxidant (anti-aging agent), an ultraviolet absorber, and an ultraviolet absorber, as long as the object of the present invention is not impaired.
Light stabilizers and various fillers, specifically carbon black, talc, barium sulfate, calcium carbonate, magnesium carbonate, metal oxides, mica, graphite, aluminum hydroxide, various metal powders, wood chips, glass powders, ceramics Powder, granular or powder polymer, glass fiber, metal fiber, organic fiber and the like, further containing a softening agent such as process oil, an adhesion improver such as maleic anhydride modified polypropylene resin and acrylic acid-polyethylene copolymer be able to.

The method for producing the composite molded article of the present invention is not particularly limited as long as it is a method capable of obtaining the composite molded article having the above-mentioned constitution, but according to the method of the present invention shown below, A desired composite molded body can be efficiently manufactured by a simple process. In the method of the present invention, the layer (A) is first formed on a metal plate, preferably a metal plate that has been subjected to electroless nickel plating. The metal plate or the electroless nickel-plated metal plate may be subjected to blast treatment, hairline treatment, etching treatment, if necessary.
Surface treatment such as crack plating treatment, oxidation treatment, anodic oxidation treatment, corona discharge treatment, plasma treatment, and primer coating may be performed.

To form the layer (A) on the metal plate, for example, a hydrocarbon solvent such as benzene, toluene, xylene, a ketone solvent such as methyl ethyl ketone or methyl isobutyl ketone, an alcohol solvent such as methanol or ethanol is used. A modified polyolefin and a modified styrene-based thermoplastic elastomer in a predetermined ratio are dissolved in an appropriate solvent such as to prepare (A) a layer-forming coating solution, which is coated on a metal plate and dried. Can be used. The solid content concentration of the coating liquid for forming the layer (A) is not particularly limited as long as it has a viscosity capable of coating, but is usually about 10 to 30% by weight.

The method of coating on a metal plate is not particularly limited. For example, in addition to general-purpose brush coating, brush coating, cotton swab coating, coating using an existing dispenser type coating machine, pad printing machine, etc. can do. The drying treatment can be performed at room temperature, but may be performed at high temperature. In particular, drying at a temperature above the melting point of the modified polyolefin is advantageous because it strengthens the coating film.

Next, a thermoplastic material layer is formed on the thus formed layer (A) by an injection insert molding method and integrated. Specifically, a metal plate provided with the (A) layer is set in a mold, and a thermoplastic material is injected and injected into the metal plate to form a thermoplastic material having a desired thickness on the (A) layer. A layer [(B) layer] is formed. At this time, when SEBS or SEPS, which is a styrene-based thermoplastic elastomer, is used as the thermoplastic material, the injection injection temperature is about 170 to 250 ° C. In this way, the composite molded article of the present invention in which the metal plate and the thermoplastic material are integrated is obtained. Although the layer (B) has a role as a gasket portion, the gasket portion is not necessarily provided on the entire surface of the metal plate, but is generally provided partially. In that case, the (A) layer may be provided in a portion where the (B) layer is provided, and need not be provided on the entire surface of the metal plate.

The composite molded article of the present invention is suitable for use as a seal member, particularly a gasket with a lid used in electronic equipment and the like. Further, by mixing a conductive material with an adhesive resin or a thermoplastic material, it is possible to prevent dust and the like from adhering and electromagnetic wave leakage. Furthermore, by mixing a material having a good heat dissipation property into the adhesive resin, the heat generated inside can be dissipated to the outside, so that heat storage in the hard disk can be prevented.

[0023]

EXAMPLES The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples. Examples 1 to 14 and Comparative Examples 1 to 4 The modified styrenic thermoplastic elastomer and the modified polyolefin in the proportions shown in Table 1 were dissolved in the solvents shown in Table 1 to prepare coating solutions having a concentration of 20% by weight. did. Next, thickness 5
A thickness of 0.1 μm provided with an electroless nickel plating film.
After coating the coating liquid on a 5 mm aluminum plate, it was dried under the conditions shown in Table 1 to form an adhesive resin coating film having a thickness of 30 μm.

Then, on the adhesive resin coating film on the aluminum plate, 0.5 mm of the thermoplastic material shown in Table 1 was applied.
With a thickness of 2 mm, an injection molding machine was used to perform insert molding under the conditions of a nozzle and cylinder temperature of 200 ° C. and an insert aluminum plate temperature of room temperature, to produce a composite molded body. The room temperature adhesive strength between the aluminum plate and the thermoplastic material layer in this composite molded body was measured by the following method. The results are shown in Table 1.

The room-temperature adhesive force was calculated based on the maximum force measured by a general-purpose rubber tensile tester by tearing the metal plate upward and the rubber downward.
The applicability was judged by whether or not the adhesive could be applied with a uniform width when the adhesive was applied using a general-purpose dispenser and applied at a speed of 10 cm / min with a width of 1 mm. Polymer A1: Maleic anhydride modified SEBS Polymer A2: Maleic anhydride modified SBS Polymer A3: Maleic anhydride modified SEPS Polymer B1: Maleic anhydride modified polypropylene (melting point 130 ° C. or higher) Polymer B2: Maleic anhydride modified polyethylene (melting point 90 ° C.) Or more) Polymer B3: acrylic acid-polyethylene copolymer (melting point: 50 ° C. or more)

Injection resin C1: SEPS [Kuraray's "Septon 4077"] 100 parts by weight, process oil [Idemitsu Kosan's "Diana Process Oil PW380"] 1
50 parts by weight and 25 parts by weight of syndiotactic polypropylene ["Achieve 1605" manufactured by Exxon Chemical Co., Ltd.].

Injection resin C2: SEPS [Kuraray's "Septon 4077"] 100 parts by weight, process oil [Idemitsu Kosan's "Diana Process Oil PW380"] 1
50 parts by weight and acrylic acid-polyethylene copolymer ["Nucrel AN4312" manufactured by Mitsui DuPont Polychemical Co., Ltd.]
C "] 25 parts by weight.

Injection resin C3: 100 parts by weight of SEBS [Asahi Kasei's "Taffetac H1272"], process oil [Idemitsu Kosan's "Diana Process Oil PW38"
0 "] and 150 parts by weight and 25 parts by weight of syndiotactic polypropylene [" Achieve 1605 "manufactured by Exxon Chemical Co., Ltd.].

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

[Table 3]

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yasushi Imai             1274-9-3 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture             −303 F-term (reference) 4F100 AB01A AB10 AB16A AK01B                       AK01C AK03B AK03G AK07                       AK12B AK12C AK12G AL05B                       AL05G AL06B AL06G AL09B                       AL09C AL09G BA03 BA07                       CB00B CB00G EH71C GB41                       JB16B JB16C JL00 YY00B                 4F206 AA13 AA45 AD03 AD08 AD34                       AG03 AH13 JA07 JB13 JL02

Claims (7)

[Claims] 1. A metal plate and two thermoplastic material layers of a layer (A) and a layer (B), which are sequentially provided on the metal plate,
A composite molded article obtained by using a mixed adhesive resin of a modified polyolefin and a modified styrene-based thermoplastic elastomer as the (A) layer in a composite molded article formed by integrating them. 2. The weight ratio of the modified polyolefin to the modified styrene-based thermoplastic elastomer in the mixed adhesive resin used in the layer (A) is 50:50 to 99.
The composite molded article according to claim 1, which is in a range of 5: 0.5. 3. The composite molded article according to claim 1, wherein the layer (B) is a layer containing a styrene-based thermoplastic elastomer as a main component. 4. The composite molded body according to claim 1, wherein the metal plate is subjected to electroless nickel plating treatment. 5. The composite molded article according to claim 1, which is used as a seal member. 6. The composite molded body according to claim 5, wherein the seal member is a gasket with a lid for a hard disk drive. 7. A layer (A) is provided by coating a mixed adhesive resin of a modified polyolefin and a modified styrene-based thermoplastic elastomer on a metal plate, and then this (A) layer is formed.
A method for producing a composite molded article, which comprises forming a layer (B) by heat-sealing a thermoplastic material to the layer and integrating the layer.