JPS60250927A - Manufacture of synthetic resin molding excellent in haze prevention performance - Google Patents

Abstract

PURPOSE:To obtain a synthetic resin molding excellent in the haze prevention performance by laminating thermoplastic resin films or sheets with a haze preventing film applied on one side thereof and a synthetic resin layer injected through an injection molding integral in a mold. CONSTITUTION:Thermoplastic polycarbonate resin films or sheets 5 and 5' with a haze preventing film applied on one side thereof are punched in the shaped 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 on the resin films or sheets 5 and 5'. Thus, a synthetic resin molding excellent in the haze prevention 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 anti-fogging properties, and is suitable for lenses such as corrective glasses, safety glasses, light-blocking glasses, underwater glasses, and sunglasses. kind, helmet shield,
It can provide ski goggles, protective facepieces, machine covers, instrument covers, mirrors, window glasses, sunroofs, etc.

[Conventional technology and its problems]

When synthetic resin molded products are used at low temperatures or high temperatures and high humidity, dew condensation occurs on the surface and the product becomes cloudy. In particular, in the case of transparent synthetic resin molded products, the light transmittance decreases due to clouding, and the commercial value significantly decreases.

As a countermeasure to this problem, antifogging agents are added to synthetic resin molded products, but since the antifogging agents are uniformly dispersed in the molded product, the protective effect on the surface layer where fogging occurs is limited. The normal 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 antifogging agent to the mold during molding). There was.

On the other hand, a paint containing an antifogging agent is applied to the surface of the synthetic resin molded product.1. There is a method of forming a protective film by baking, but this method improves antifogging properties, but requires an additional painting process of painting each molded product, and the solvent in the paint component may cause cracks on synthetic resin molded products. This method has disadvantages in that it tends to cause poor appearance and deterioration of physical properties, and it is also difficult to limit the coating to only desired areas, which limits 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 film or sheet coated with an excellent antifogging film on one side is installed in a mold, and then a synthetic resin material is injected into the mold by injection molding to form an antifogging film or sheet. A method for manufacturing synthetic resin molded products with excellent anti-fogging properties, which is characterized by laminating and integrating a thermoplastic plastic film or sheet coated on one side with a coating with excellent anti-fogging properties and a resin layer formed by injection molding. In a preferred embodiment, a polycarbonate resin is used for the plastic film or sheet that has a film with excellent antifogging properties on one side, and the synthetic resin material used for injection molding is a polycarbonate resin film or sheet during injection molding. The manufacturing process is as follows: (1) A thermoplastic film or sheet coated with a coating with excellent antifogging properties on one side is heated to the same shape as the desired part of the synthetic resin molded product. (2) attaching the punched piece to a part of the cavity corresponding to the desired part of the mold for the molded product; (3) close the mold and pour the molten resin into the mold. The process includes the steps of: injecting the die-cut piece and the molten resin under high pressure using injection molding means, and integrally molding the punched piece and the molten resin; and (4) taking out the molded product from the mold. A process of punching out a thermoplastic plastic film or sheet coated with a superior film on one side into the same shape as the desired part of the synthetic resin molded product to create a punched piece and a cavity corresponding to the desired part of the synthetic resin molding mold. This process consists of simultaneously performing the process of partially mounting the metal mold and the process of closing the mold.

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

FIG. 1 is an example of an overall view of a synthetic resin molded product which is a machine cover molded based on 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, showing a thermoplastic film or sheet 5.5° with an anti-fog coating applied on one side,
Resin N6 formed by injection molding of molten resin is laminated and 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 product with an anti-fog coating applied on one side is pre-attached to the molding die 7.7° for a synthetic resin molded product. The plastic film or sheet 5.5' is heat-sealed and integrated with the molten resin layer 6 flowing through the runner 3 and the gate 4.

Here, the thermoplastic plastic film or sheet 5.5' coated with an anti-fog coating on one side can be easily fixed to the mold cavity using static electricity, suction force such as vacuum, or other conventionally known methods. I can do it.

Although the above description has been made with reference to the 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 a preferred embodiment of the present invention to integrally mold the frame, the mounting portion or fixture, and other functional parts depending on the shape or design.

A thermoplastic plastic film or sheet having an anti-fogging coating on one side can be made of thermoplastic plastics such as polycarbonate resin, polycarbonate resin-polybutylene terephthalate resin composition, polymethyl methacrylate (PMMA), acrylonitrile-styrene copolymer. (AS resin), rubber-modified vinyl aromatic compound copolymer i (ABS, , MBS, , MAS, , MMAS
, MES, MEBS resin, etc.), polystyrene, acetyl cellulose, etc., the normal thickness of transparent to opaque plastics is 100 to 1000 μ, especially 200 to 5
00μ film or sheet by a conventionally known method,
For example, a method of laminating a synthetic resin film containing an antifogging agent, a method of coating with (meth)acrylic resin or other antifogging paint, and then curing with heat or ultraviolet rays, etc.

An example of manufacturing a plastic film or sheet with a film with excellent antifogging properties on one side using polycarbonate resin is to use a polycarbonate resin with a molecular weight of 25,000 or more using an extrusion T-die method. When manufacturing a polycarbonate resin film or sheet, anti-fog is applied to a polycarbonate resin film or sheet manufactured by a method of thermally laminating a film of a (meth)acrylate copolymer containing an anti-fog agent, an extrusion T-die method, etc. This method involves applying a solvent-based or thermosetting paint containing a (meth)acrylate copolymer, polyvinyl alcohol, or amine resin by a wire bar method or the like, and drying by heating.

Next, examples of the thermoplastic plastic used in the injection molding of the present invention include those similar to those used for the above-mentioned film or sheet with an anti-fog coating.

Here, the plus rank used for films or sheets with an anti-fog coating on one side and the thermoplastics used for injection molding are usually the same type of plastics with superior thermal adhesiveness 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 a film or sheet with an antifogging coating formed on one side, and one with a molecular weight of 15,000 to 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 preferable to apply a coating containing a higher molecular weight substance of the same type as the main component or a heat- or ultraviolet-curable coating to the opposite side of the anti-fog coating.

Furthermore, films or sheets coated with an anti-fog coating on one side, or plastics for injection molding, may contain dyes, pigments,
It is also possible to impart special performance by adding infrared absorbers, ultraviolet absorbers, compounds having photochromic properties, and the like.

〔Example〕

Examples will be explained below.

Example 1 A laminating paint (5K-1 manufactured by Sanyo Kogyo Co., Ltd.
30) and dried at 130℃ for 20 minutes to a film thickness of 5μ.
An anti-fog film was formed. (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, an anti-fog film (manufactured by Nippon Carbide @, trade name: Stretch Film), which is a (meth)acrylate copolymer and has a thickness of 50μ, is thermally laminated. and an anti-fog film was applied to one side. (referred to as film B).

Manufacture of synthetic resin molded product with excellent anti-fog properties - The anti-fog film forming film obtained above is punched out in the shape of the window of the machine cover molded product shown in Figure 1 to produce a molded product with the shape shown in Figure 1. It was attached to the mold for use. Next, polycarbonate resin (PC) having a molecular weight of 23,000 was injection molded.

In the obtained molded product, the antifogging film-forming film and the molded resin part were completely integrated, and no boundary line was discernible. Furthermore, no damage to the antifogging film or any abnormality in appearance was observed.

Example-2 Using film A of Example-1, modified polyphenylene ether resin (trade name: Iupiace AV-) was used as the injection molding material.
The molding was carried out in accordance with Example 1 except that 60) was used.

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

Molded articles were obtained in the same manner as in Examples 1 and 2, except that the antifogging film was not used. These molded products (comparative example-
Using the molded products of Examples 1 and 2) and Examples 1 and 2, the presence or absence of clouding was examined at 25°C. Also, the outer surface is 25°
The presence or absence of clouding was examined when C1 was exposed to saturated steam for 60 minutes at a humidity of 50% and an inner surface of 45°C. The results are shown in Table 1. In the table, ○: No clouding ×: Cloudy occurrence.

[Operation and effect of the invention]

As described above, the present invention has excellent anti-fog properties and economic efficiency (climbing, corrective glasses, safety glasses, light-shielding glasses, underwater glasses, lenses such as sunglasses, shields for helmets, etc.).
It is possible to provide synthetic resin molded products suitable for ski goggles, protective face pieces, machine covers, instrument covers, mirrors, window glasses, sunroofs, and the like. In addition, in a preferred embodiment of the method for producing a synthetic resin molded product of the present invention, (1) an antifogging film is formed on the surface of the synthetic resin molded product, so that the antifogging property can be improved extremely efficiently. .

(2) A coating with excellent heat resistance is applied to one side and the polycarbonate resin film or sheet is heat-sealed and integrated with the molten resin layer in the injection mold, so the desired anti-fog properties can be achieved without a special painting process. Synthetic resin molded products with excellent productivity can be obtained, and defects that tend to occur during the painting process are eliminated.

(3) A film with excellent antifogging 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.

It has such characteristics.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a machine cover which is an example of the synthetic resin molded product of the present invention, Fig. 2 is a sectional view taken along line A-A' in Fig. 1, and Fig. 3 is a partial enlarged view of part B in Fig. 2. , FIG. 4 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 1: molded product 1.2 varnish blue, 3: runner, 4: gate, 5.5": single-sided anti-fog film forming film, 6: molten resin layer by injection molding, 7.7° : Indicates the mold. Patent applicant Mitsubishi Gas Chemical Co., Ltd. Representative Kazuyoshi Nagano Hata 1, / Tame 2, Tame 3

Claims (1)

[Claims] (1) A thermoplastic film or sheet coated with a film with excellent antifogging properties on one side is installed in a mold, and then a synthetic resin material is injected into the mold by injection molding. , a synthetic resin molded product with excellent anti-fog properties characterized by laminating and integrating a thermoplastic plastic film or sheet coated with a film with excellent anti-fog properties on one side and a resin layer formed by injection molding. Manufacturing method. 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 antifogging 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. [J.) A process of punching out a thermoplastic plastic film or sheet coated with a film with excellent antifogging properties on one side in the same shape as the desired part of the synthetic resin molded product to create a punched piece, (2) 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, injecting the molten resin at high pressure using an injection molding means, and laminating and integrally molding the punched piece and the molten resin; and (4) taking out the molded product from the mold. 5, a method for producing a synthetic resin molded product according to claim 1, which comprises the step of: preparing a thermoplastic film or sheet coated with a film with excellent antifogging properties on one side to have the same shape as the desired portion of the synthetic resin molded product; The process of punching out a piece into the shape of a ladle, and the process of attaching it to a part of the cavity corresponding to the desired part of a synthetic resin mold, are performed simultaneously in the process of closing the mold. Method for producing synthetic resin molded products as described in Scope 4