JPH04208453A - Manufacture of plastic molded object with conductive circuit - Google Patents

Abstract

PURPOSE:To reduce the production cost by a method in which the sheet in which the woven cloth or unwoven cloth of inorganic fiber or organic fiber, etc., is coated with the method of low melting point in the shape of an electric circuit, is inserted in a mold, and said mold is filled with plastic material. CONSTITUTION:The woven cloth or the unwoven cloth produced by using glass fiber or organic fiber is coated with suitable metallic amount into a necessary shape by using the spray gun of metal with the melting point of 47-300 deg.C, whereby an aimed sheet is made. Said sheet is fitted into the mold for molding thermoplastic resin. When the mold is filled with the material melted at high temperature, the metallic particle coated with resin is instantaneously softened by the heat of the resin material at high temperature, while the metallic particle is pushed against the surface of the mold. Further, the metal and fiber material melted and softened by the material-filling pressure of the thermoplastic resin in injection molding are pushed against the mold wall with high pressure, whereby the metal becomes a metallic film and is cooled on the mold surface. Consequently, the film of conductive circuit excellent in uniformity and adhesion may be molded on the surface of the plastic.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention applies to woven or non-woven fabrics made of inorganic fibers, organic fibers, etc. that have a melting point of 70°C.
6 books related to a method of manufacturing a molded product in which a sheet (hereinafter referred to as a sheet) coated with a metal having a temperature of 300°C to 300°C in the shape of an electric circuit is inserted into a plastic mold, and an electric circuit is inseparably formed on the surface of the plastic. Since the molded product manufactured according to the invention has an electric circuit integrally formed on a plastic insulator, the molded product can be used as a heating element for electrical parts 9, an antistatic device 9, and the like.

(b) Conventional technology Electrical parts, control boxes, automobile interior parts, etc. that are commonly seen are made of plastic and come in various shapes of cases and boxes.

The structure is manufactured by manufacturing a structure, then incorporating an electric circuit such as a printed circuit board, and then connecting it with electric wires or the like. However, there are many requests to simplify such processes as much as possible in all fields. In order to meet these demands, 2. For example, various electrical circuits are formed using a chemical etching method using a plastic film covered with copper foil, and then an adhesive or the like is applied to this.

The method of integrating plastic materials through this adhesive by injection molding or compression molding is currently being carried out industrially4. However, this method involves a process of gluing metal foil onto a plastic film, a chemical etching process, The process of applying adhesive is required, leading to high production costs. Furthermore, since the elongation rate of metal foil is low, for example, if the film is placed in a mold and filled with plastic, a simple shape can be formed by the filling pressure of the material.

In applications where a high elongation rate is required, there is a problem in that the metal circuit is cut, making it impossible to form the desired electrical circuit on the surface of the plastic. Furthermore, the adhesive applied to the film must be selected from among various types depending on the type of plastic material; if this selection is inappropriate, the resulting molded product will be completely unusable. Another major drawback is that plastic materials that shrink significantly and are difficult to adhere to, such as polyethylene, polypropylene, and polyacetal 7-bolybutylene terephthalate, cannot be bonded to metal foil and plastic no matter what adhesive is used.

(c) Problems that the invention attempts to solve The present invention solves the above-mentioned problems faced by the prior art, namely.

An electric circuit can be easily and integrally formed on the surface of any shaped product, the process of forming an electric circuit can be performed at the same time as molding, and an electric circuit can be formed inseparably into any plastic material 7. Production cost The aim is to fundamentally solve problems such as low cost and no need for adhesives.

(d) Means for Solving the Problems The present invention forms an electric circuit on the surface of plastic using a method completely different from the above method. The sheet used for this purpose and the method for producing molded products using the same will be described in more detail.4 In other words, woven fabrics or nonwoven fabrics made of glass fibers, organic fibers, etc. have a melting point of 47 to
A sheet is created by applying an appropriate amount of 300℃ metal (hereinafter referred to as metal) into the required shape using a metal spray gun.4 In this state, the applied metal forms particles or scales on the surface of the fibrous material. It remains temporarily attached.

For example, when this is attached to a thermoplastic resin mold and filled with molding material melted at high temperature, the coated metal particles are pressed against the surface of the mold and are instantly heated by the high temperature material. soften. Furthermore, the general condition for injection molding of thermoplastic resin is to apply a high material filling pressure of 300 to 2000 kg/cm2, so the molten and softened metal and fibrous material are pressed against the mold wall by the material under high pressure. As a result, the metal becomes a perfect thin metal film and is cooled on the mold surface. As a result, a metal film can be instantaneously formed on the plastic surface in a mold.

(e) The metal thin film formed by action forming has a metallic appearance on its outer surface and is reinforced by the fiber material used. Furthermore, there are many unevenness and voids left in the fibrous material, but these parts are filled with plastic material, and a strong bond is created between the plastic and the sheet material without using any adhesive. . It can also be strongly bonded to any plastic material, and until now it was thought impossible to bond it to metal because no adhesive was found. Completely integrated electrically conductive membranes could be formed on polyethylene, polypropylene, acetal resin polybutylene terephthalate, polystyrene-modified polyphenylene oxide, etc. Other plastics such as polystyrene, polycarbonate, polyurethane, polyimide, polyamide, vinyl chloride, ABS resin, AS resin, acrylic resin, cellulose plastic, resins called so-called polymer alloys, super engineering resins, etc. can of course be used in the present invention. can. The sheet of the present invention can also be used with thermosetting resins.4 For example, the sheet may have an unsaturated polyester resin as its main component. The sheet of the present invention is placed in a heated mold for molding BMC, SMC, epoxy resin molding material, diaryl phthalate resin, etc., the thermosetting resin molding material is placed on top of this, and the mold is clamped under high pressure. Even in the process of taking out the molded product after the material has hardened, that is, compression molding, a molded product with a uniform and clean appearance on the surface can be obtained. By adjusting the weave of the grass, the fiber length, and the binder of nonwoven fabrics, it is possible to provide a large elongation rate that cannot be obtained with metal thin films.9 For example, it is possible to achieve an elongation rate of 100% or more. Therefore, a conductive layer can be formed on products with any complex shape.
In addition, no matter how the sheet is stretched, the metal particles will form a thin film depending on the final material filling pressure and temperature applied, so a uniform and defect-free conductive film circuit can be formed on the surface of the plastic. The metal used in the present invention is not particularly limited, but the metal itself or an alloy may be used depending on the purpose of use. The guideline for selection is the plasticization temperature of the plastic material used,
The temperature of the mold during molding, the amount of heat from the molding material, the required heat resistance, the characteristics required of the metal thin film, etc. 47℃), bismuth-lead-tin alloy (melting point 96℃), tin-indum alloy (melting point 117℃), bismuth-tin alloy (melting point 138℃), tin-lead-cadmium alloy (melting point 145℃), tin zinc Alloy (melting point 199°C),
Cadmu-antimony alloy (melting point 292°C), other car component metals such as soot, lead, bismuth, etc. with melting points of 300°C or less can be used.Examples Example 1 Polyester fibers, rayon fibers, glass Textile, cotton fiber.

A bismuth-lead-tin alloy with a melting point of 96°C and a tin-lead-cadmium alloy with a melting point of 145°C are applied to the surface of the woven and non-woven fabrics using a metal spray gun in the shape of 9 circuits of 1 square centimeter. Sheets were prepared by applying the metal in amounts of 0.03 g, 0.05 g, and 0.08 g. On the other hand, an injection molding machine with a mold clamping pressure of 100 tons was prepared, and a mold capable of forming a molded product of 100 mm square and 3 mm thick was attached to it. The molding materials used were polypropylene, ABS, and polycarbonate. The molding mold was adjusted to 80° C., and the sheet was sandwiched between the open molds and molded under standard molding conditions. The resulting molded product was tested for appearance, adhesion between the metal layer and plastic, electrical conductivity, etc.

1. Appearance test Type of fiber (fabric) Melting point of metal Molded product appearance Polyester 96℃ Good rayon
96 Good cotton 96
Good glass 96 Good type of fiber, non-woven fabric Melting point of metal Molded product appearance Polyester 145°C Good Rayon 1
45 Good cotton 145
Good Glass 145 Good The above results were obtained using polycarbonate as the plastic material, but ABS and polypropylene also showed similar results. The amount of metal applied was 0.05 g/cm2. When the amount of metal applied was small, the metallic luster was slightly lost, and when it was applied in a large amount, the appearance was extremely smooth.

24 adhesion test (90° peeling) Type of fiber (fabric) Melting point of metal Adhesion strength Polyester 96℃ Material failure rayon
96 /I cotton 96
/l glass 96 Type of fiber, non-woven fabric Melting point of metal Adhesion polyester 145℃ Material destruction rayon
145 /I cotton 145
〃Glass 145
! I The above results show that polypropylene is used as the molding material,
Metal is the result of measurement on a sample molded at 0.05 g/cm2 Example 2 Showing an example of molding with thermosetting resin Sheet material used Type of fiber, non-woven fabric Melting point of metal Coating amount Polyester 145℃ 0.05g/cm2 Rayon
145 0.05//cotton 1
45 0.05/1 glass 145
0.057/MC of molding material used Unsaturated polyester resin 30% Glass fiber (matte) 30% Calcium carbonate 10% Talc 20% Thickener 9% Hardening material 045% Pigment 0. 5% 100mm square,
A compression molding mold capable of molding a molded product with a thickness of 3 mm was attached to a compression molding machine, and the mold temperature was adjusted to 150°. Place the above sheet in this mold and weigh the SMC on top of it.
The mold was then clamped under a pressure of 150 kg/cm2, and the material was cured in 5 minutes. The mold was opened, the molded product was taken out, and various tests were conducted.

Appearance test: Showed mirror gloss.

Adhesion: Complete integration, material destruction Conductivity: All circuits showed a resistance value of 0.005 milliohm or less.

Example 3 Metal powder pulverized to 300 mesh or less (melting point 96°C) 1
Printing inks consisting of 00 g and 5 g of acrylic resin and solvent were produced and printed on a nonwoven fabric using a screen printing method.

Although the ink did not exhibit conductivity during the drying stage, when this sheet was pressed into a mold and injection molded using polypropylene as the molding material, Examples 1 and 2. We were able to form an electric circuit on the surface of the molded product that had almost the same characteristics as the one obtained in .

(g) Effects of the Invention In the present invention, metal materials exhibiting various melting points are applied to the surface of various fiber base materials in a circuit shape using an appropriate method 6, such as a metal spraying device, or a finely powdered metal is coated onto the surface of various fiber base materials. Ink mixed with a small amount of resin is screen-printed into an appropriate shape and inserted into a mold used for injection molding, compression molding, transfer molding, etc. to heat the plastic material.

It is possible to form a homogeneous and highly adhesive conductive circuit thin film on a plastic surface in one step by melting and softening metal particles or scales using mold temperature or pressure. Furthermore, the present invention can be applied to any plastic material, and a further advantage is that the metal layer and plastic layer can be firmly integrated in a mold without using any adhesive. . In addition, if the fiber base material is appropriately selected, large elongation properties can be obtained, so it can be applied to products with deep drawing shapes that could not be achieved with conventional metals. In addition to the advantages, it is possible to significantly reduce the cost of molded products due to the simple process in industrial production, no need for large-scale equipment, and excellent productivity.

Claims (2)

[Claims] 1. In plastic molding performed by injection molding, compression molding, transfer molding, etc., melting point is applied to woven or non-woven fabrics made from inorganic fibers, organic fibers, etc. in order to form electrically conductive circuits on the surface of the molded product. is 47℃
A sheet of metal that exhibits a temperature of 300°C to 300°C is spray-coated or screen-printed in the shape of an electrical circuit, and is then injection molded, compression molded,
It is placed on one or both sides of a mold during molding such as transfer molding, and the inner surface is filled with plastic material using injection molding, compression molding, or transfer molding, with the sheet serving as the outer layer. The granular metal in the inserted sheet is melted and rolled using the heat from the mold, the electric heat from the mold, and the filling pressure of the material, and is strongly composited into a fiber or nonwoven layer, and is also integrated with the filled plastic to manufacture it. A method of manufacturing a molded product with an electric circuit formed thereon. 2. A molded article manufactured according to claim 1.