JPS60250926A - Manufacture of synthetic resin molding excellent in antistatic performance - Google Patents

Abstract

PURPOSE:To obtain a synthetic resin molding excellent in the antistatic performance by laminating a thermoplastic resin film or sheet with an antistatic film applied on one side thereof and a synthetic resin layer injected by injection molding integral in a mold. CONSTITUTION:Thermoplastic polycarbonate resin films or sheets 5 and 5' with an antistatic film applied on one side thereof are punched in the shape the same as the desired part of a synthetic resin molding and set previously into cavities of molding dies 7 and 7'. Then, a melted resin layer 6 injected through a runner 3 and a gate 4 is thermally fused monolithically on resin films or sheets 5 and 5'. Thus, a synthetic resin molding excellent in antistatic performance can be manufactured economically.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a method for producing synthetic resin molded products with excellent antistatic properties, and is suitable for use in optical parts such as eyeglass lenses, safety gear such as protective face pieces, machine covers, instrument covers, displays, mirrors,
It can provide window glass, office equipment, automobile parts, etc.

[Conventional technology and its problems]

When using synthetic resin molded products, because they have excellent electrical insulation properties, dirt may become noticeable due to dust adhering to the surface of the molded product, and scratches may occur when wiped with a cloth to remove the dust. There is a drawback that the product value is significantly reduced. As a countermeasure to this problem, antistatic agents are added to synthetic resin molded products, but since the antistatic agent is uniformly dispersed in the molded product, it has no effect on protecting the surface layer on which the flakes adhere. , the usual amount added is not fully satisfactory, and although improvements can be made by increasing the amount added, there are disadvantages such as deterioration of other physical properties and adhesion of antistatic agent to the mold during molding. There was.

On the other hand, there is a method in which a paint containing an antistatic agent is applied to the surface of a synthetic resin molded product and a protective film is formed by baking, but this method improves the antistatic property, but it does not affect the individual molded products. There is a drawback that the painting process increases, and the solvent in the paint component causes cracks in the synthetic resin molded product, resulting in poor appearance and deterioration of physical properties.Also, it is difficult to limit the painting to only the desired areas. Therefore, there were limitations in terms of product design.

[Means for solving problems]

The present invention provides a method for producing synthetic resin molded articles that improves or overcomes the drawbacks of conventional methods.

That is, in the present invention, a thermoplastic PlusDeck film or sheet coated on one side with excellent antistatic properties is mounted in a mold, and then a synthetic resin material is injected into the mold by injection molding. A synthetic resin molded product with excellent antistatic properties characterized by laminating and integrating a thermoplastic plastic snack film or sheet coated with a coating with excellent antistatic properties on one side and a resin layer formed by injection molding. In a preferred embodiment, a polycarbonate resin is used as a plastic film or sheet coated on one side with a coating having excellent antistatic properties.
The synthetic resin material used for injection molding is one that is heat-fused to a polycarbonate resin film or sheet during injection molding, and the manufacturing process includes (1) a coating with excellent antistatic properties on one side; A process of punching out a thermoplastic film or sheet into the same shape as the desired part of the synthetic resin molded product to create a punched piece, (2) inserting the punched piece into a cavity corresponding to the desired part of the mold for the molded product. (3) closing the mold and injecting the molten resin at high pressure by injection molding means;
a step of integrally molding the punched piece and the molten resin into 1iRR;
and (4) taking out the molded product from the mold, and also includes the step of taking out the molded product from the mold, and applying a thermoplastic film or sheet coated on one side with a film with excellent antistatic properties to the desired shape of the synthetic resin molded product. This process consists of simultaneously performing the steps of punching out the same shape to create a punched piece and attaching it to a part of the cavity corresponding to the desired part of a synthetic resin mold when the mold is closed. .

First, in order to facilitate understanding of the present invention, the present invention will be explained using drawings.

FIG. 1 is an example of a perspective view of a synthetic resin molded product which is a machine cover molded according to the present invention, and FIG. 2 is a sectional view taken along line AA' in FIG. 1. Figure 3 is an enlarged view of part B in Figure 2, in which a thermoplastic film or sheet 5.5' coated with an antistatic coating on one side and resin N6 formed by injection molding of molten resin are laminated. It is integrated. Furthermore, FIG. 4 is an explanatory diagram schematically showing the injection molding process according to the present invention, in which a thermoplastic resin molded article with an antistatic coating applied on one side is attached in advance to a mold 7.7" for molding a synthetic resin molded product. The plastic film or sheet 5.5' is thermally fused and integrated with the molten resin layer 6 flowing through the tube 3 and the gate 4. Here, a thermoplastic film coated with an antistatic coating on one side is integrated Alternatively, the sheet 5.5' can be easily fixed to the mold cavity by static electricity, suction force such as vacuum, or other conventionally known methods.

Although the above description has been made with reference to drawings, the shape of the synthetic resin molded product of the present invention is not limited to that shown in the drawings, and can take various shapes. It is also one of the preferred embodiments of the present invention that the frame, the mounting portion or the fixture, and other functional parts are integrally molded.

A thermoplastic film or sheet coated with an antistatic coating on one side is a thermoplastic plastic film or sheet.
For example, polycarbonate resin, polycarbonate resin-polybutylene terephthalate resin composition, polymethyl methacrylate (PMMA), acrylonitrile-styrene copolymer (AS resin), rubber-modified vinyl aromatic compound copolymers (AB'S, MBS) ,MAS, ,MM
The normal thickness of clear to opaque plastics such as AS resin, polystyrene, acetyl cellulose, etc.
A film of 100 to 1000 μm, especially 200 to 5001 μm, is laminated with a film of a (meth)acrylate copolymer containing an antistatic agent using a conventionally known method. A method is used in which an antistatic paint such as an acrylic resin is coated and then cured using heat or ultraviolet rays.

An example of manufacturing a plastic film or sheet with a film with excellent antistatic properties on one side using polycarbonate resin is the extrusion 1゛ die method using polycarbonate resin with a molecular weight of 25,000 or more. A method of thermally laminating a (meth)acrylate copolymer film containing an antistatic agent when producing a polycarbonate resin film or sheet by extrusion T
A method includes applying a (meth)acrylate copolymer coating containing an antistatic agent to a polycarbonate resin film or sheet produced by a die method or the like by a wire bar method or the like, and then heating and drying the coating.

Next, examples of thermoplastic plastics used in the injection molding of the present invention include those similar to those used for the above-mentioned antistatic film-coated film or sheet.

Here, the plus rank type used for films or sheets with an antistatic coating on one side and the thermoplastics used for injection molding are usually the same type of plastics with different heat fusion properties and optical uniformity. Films made from molten resin by injection molding are preferable from this point of view, and the melt viscosity of the plus rank used for the film or sheet is higher than the melt viscosity of the thermoplastic plastic used for injection molding, that is, the one with a higher molecular weight. Alternatively, it is preferable in terms of preventing the sheet from losing its shape. In the case of polycarbonate resin, it is preferable to use one with a molecular weight of 25,000 or more for films or sheets with an antistatic coating formed on one side, and one with a molecular weight of 15,000=25,000 for injection molding.

Note that it is also possible to use different polymers for these thermoplastic plastic films or sheets and for injection molding; in this case,
For the purpose of promoting heat fusion with the thermoplastic resin to be injection molded or to prevent the film from melting and losing its shape due to the resin being injection molded, a primer coat - for example, a molding resin is applied. It is also a preferable method to apply a coating mainly composed of a higher molecular weight substance of the same type as the antistatic coating, or a heat- or ultraviolet-curable coating, to the opposite side of the antistatic coating.

In addition, dyes and pigments, ultraviolet absorbers, infrared absorbers, compounds with photochromic properties, etc. are added to films or sheets coated with an antistatic coating on one side, or to plastics for injection molding to achieve special performance. It is also possible to grant.

〔Example〕

Examples will be explained below.

Example-1 An antistatic paint (Skytough T, manufactured by Achilles Aki) was coated on one side of an extruded polycarbonate film with molecules 13o, ooo and a thickness of 200μ using the wire barcode method.
-4,05) was applied and dried at 120°C for 30 minutes to form an antistatic film with a thickness of 5μ. (referred to as film A).

In the process of extruding a polycarbonate sheet with a molecular weight of 28,000 and a thickness of 400μ, the thickness is 601μ! Antistatic film (manufactured by Mitsubishi Sensand 0 Kiku, product name: Astron)
were adhered using a thermal lamination method, and an antistatic coating was applied to one side. (referred to as film B).

Manufacture of antistatic film with excellent antistatic property attached to the mold. Next, a polycarbonate resin (PC) having a molecular weight of 23,000 was injection molded.

In the obtained molded product, the antistatic film-forming film and the molded resin part were completely integrated, and no boundary line was discernible. Furthermore, damage to the antistatic coating and abnormal appearance were unacceptable.

Example 2 Film A of Example 1 was used and molded according to Example 1, except that a modified polyphenylene ether resin (trade name: Iupiace^C 60) was used as the injection molding material.

In the obtained molded article, the antistatic film-forming film and the molded resin material were completely integrated.

Example=1.2 in 1. A molded article was obtained in the same manner except that no antistatic film was used. 'These molded products (
Using the molded products of Comparative Examples 1 and 2) and Examples 1 and 2, the surface resistance of the molded products and the surface were measured with a dry cloth.
After rubbing it back and forth 5 times, an ash test was conducted in which it was brought close to cigarette ash. The results are shown in Table 1. In addition, in the ash test in the table, ○: No adhesion, ×: Adhesion.

are shown respectively.

Table 1 [Operations and Effects of the Invention] As described above, the present invention provides optical components such as eyeglass lenses, safety equipment such as protective face pieces, which are excellent in antistatic properties and economical efficiency.
We can provide synthetic resin molded products suitable for machine covers, instrument covers, displays, mirrors, window glass, office equipment, automobile parts, etc. In addition, in a preferred embodiment of the method for producing a synthetic resin molded product of the present invention, (1) an antistatic film is formed on the surface of the synthetic resin molded product, so that antistatic properties can be improved extremely efficiently. can.

(2) A coating with excellent antistatic properties is applied to one side, and the polycarbonate resin film or Seai is integrated with the molten resin layer in the injection mold by heat-sealing, so the desired coating can be achieved without going through a special painting process. A synthetic resin molded product with antistatic properties is obtained, which is excellent in productivity and eliminates defects that tend to occur during the painting process.

(3) A coating with excellent antistatic properties is applied to one side, and the molecular weight or melt flow value of the synthetic resin used for the polycarbonate resin film or sheet and the resin layer that constitutes the base of the molded product can be independently selected, making it possible to A highly fluid molding material can be used as the resin constituting the base body without worrying about cracking or deterioration of physical properties.

etc.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a machine cover molded product according to an example of the present invention, Fig. 2 is a sectional view taken along line AA' in Fig. 1, Fig. 3 is a partially enlarged view of part B in Fig. 2, and Fig. 4. FIG. 1 is a schematic diagram illustrating the state of injection molding of the synthetic resin molded product of the present invention. The numbers in the figure are as follows: 1: molded product, 2 varnish blue, 3: runner, 4: gate, 5.5": one-sided antistatic film forming film, 6: molten resin layer by injection molding, 7.7": No mold shown. Patent Applicant Mitsubishi Gas Chemical Co., Ltd. Representative Kazuyoshi Nagano Hata Figure 1/Zhu Figure 2 Book 3 Figure #4

Claims (1)

[Scope of Claims] 1. A thermoplastic film or sheet coated with a film with excellent antistatic properties on one side is installed in a mold,
Next, a synthetic resin material is injected into the mold by injection molding, and a thermoplastic film or sheet coated on one side with an excellent antistatic property is laminated and integrated with a resin layer formed by injection molding. A method for producing synthetic resin molded products with excellent antistatic properties. 2. The method for producing a synthetic resin molded article according to claim 1, wherein the plastic film or sheet coated on one side with a coating having excellent antistatic properties is a polycarbonate resin. 3. The method for producing a synthetic resin molded product according to claim 2, wherein the synthetic resin material used for injection molding is thermally fused to a polycarbonate resin film or sheet during injection molding. 4: (L) A step of punching out a thermoplastic plastic film or sheet coated with a film with excellent antistatic properties on one side in the same shape as the desired part of the synthetic resin molded product to create a punched piece, (2) the step of creating a punched piece. a step of attaching the punched piece to a part of the cavity corresponding to the desired part of the mold for the molded product; (3) closing the mold and injecting molten resin at high pressure by an injection molding means to combine the punched piece and the molten resin; and (4) taking out the molded product from the mold. The process of punching out a thermoplastic plastic film or sheet coated on one side into the same shape as the desired part of the synthetic resin molded product to create a punched piece, and a part of the cavity corresponding to the desired part of the synthetic resin molding die. A method for producing a synthetic resin molded product according to claim 4, which comprises simultaneously carrying out the step of attaching the product to the mold and the step of closing the mold.