JP2969933B2 - Manufacturing method of illuminated switch parts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an illuminated switch, that is, a character or a mark having a light source inside and a character or a mark having a light source therein. However, it is a novel method of manufacturing switches that can be seen floating. The illumination switch is
It is widely used as buttons and switches for various electric and electronic devices such as automobiles, audio and VTRs.

[Conventional technology and its problems]

Conventionally, a method of inserting a thermoplastic resin sheet or film into an injection mold and integrating it with a resin to be injection-molded has been often used as a painting molding method or a molding transfer method.

However, in the conventional method, the sheet or film to be inserted is sized so as not to be inserted into the mold, or if it is inserted, the portion to be inserted does not become a product part, but is cut later. Met.

Also, for products that integrate a sized sheet or film with injection-molded resin by inserting it so that it does not get caught in the mold cavity and core, the resin is integrated over the entire surface of the sheet or film.
The resin to be injection molded must be transparent to make it light transmissive. In this case, the portion other than the inserted sheet or film is naturally formed of the resin itself and transmits light, so that the light shielding coating has to be applied in post-processing.

Therefore, there is a method of three-dimensionally processing the sheet or film to be inserted according to the shape of the switch button to prevent light leakage, but in this case, processing the sheet or film into a three-dimensional shape increases the cost. In addition, there is a drawback that the printing or hot stamping film applied to a sheet or film has a very small limit to processing into a three-dimensional shape, and is not versatile because it is limited to a simple shape.

[Means for solving the problem]

The present inventors have studied a method of overcoming such disadvantages and manufacturing an illuminated switch in which only characters or marks have optical transparency.As a result, the characters or marks are printed or hot stamped, and the other parts are light-shielding. A sheet or film made of an aromatic polycarbonate provided with is inserted into the mold, and the sheet or film is inserted into the cavity and the core of the mold having only the light transmitting portion, and the thermoplastic resin to be injected is exposed to the portion. They found a method of integrating them so that they would not enter, and solved a defect phenomenon occurring in a sheet to be sandwiched, and completed a method of obtaining a beautiful molded product.

That is, the present invention forms a predetermined light-shielding portion having light-transmitting characters and marks on a light-transmitting aromatic polycarbonate sheet having a thickness of 0.1 to 2.0 mm, and cuts the sheet into a predetermined shape. The cut piece is mounted on the cavity of the mold for mounting the cut piece and the cavity and the core of the mold having a cushioning property on one or both sides of the core, and the cut piece is formed by injection molding a thermoplastic resin. And an injection resin.

The sheet or film is inserted between the cavity and the core of the mold, and the thermoplastic resin to be injected and injected is integrated with other parts without flowing into the inserted part of the sheet. When doing, because the polycarbonate sheet or film is very soft compared to the steel material that is the mold material, when pressure is applied so that the resin injected into the pinched portion does not leak,
There is a defect that scars are formed on the sheet itself and the decorative decorative film on the surface, and the present invention solves this by providing the mold cavity or core with cushioning properties.
It is the one that eliminates scratches and dent marks.

The aromatic polycarbonate sheet of the present invention having a thickness of 0.1 to 2.0 mm may be a normal polycarbonate, and is not particularly limited. Further, the sheet surface may be a smooth surface having gloss or a mat surface having matte unevenness having no gloss. In addition, since the sheet resin forms light-transmitting characters to marks, if light for that purpose is transmitted,
It may be colored to a desired color with an appropriate dye or pigment. Further, from the viewpoint of adhesiveness with the resin used for injection molding, it is preferable that the sheet surface on the side integrated with the thermoplastic resin for injection molding has an adhesive layer formed appropriately. As an example of the adhesive layer, the injection resin is polycarbonate (PC), a polycarbonate-polyester resin composition, a polycarbonate-ABS resin composition, a polycarbonate-polyamide resin composition, and other polycarbonate resin compositions (PC Alloy), a polycarbonate sheet without an adhesive layer; the injection resin is an acrylic resin such as polymethyl methacrylate (PMMA), polystyrene (PS), methyl methacrylate-styrene copolymer (MS), acrylonitotyl-styrene copolymer ( AS),
Acrylonitrile-butadiene-styrene copolymer (AB
In the case of S) and the like, a polycarbonate sheet having an acrylic resin layer formed thereon; for polyvinyl chloride and other general-purpose applications not requiring heat resistance, a polycarbonate sheet having an EVA resin layer formed thereon is exemplified.

On the polycarbonate sheet, a light-shielding portion is formed substantially at the center of the light-shielding portion of the light-transmitting character or mark portion. This method is conventionally known silk screen printing,
There is no particular limitation on the hot stamping method, the coating method, the sputtering method, the plating method, and the like. Characters ~ marks are also various characters,
There is no particular limitation on marks, designs, and the like. Also,
Characters to marks etc. are naturally white if they are light-transmitting layers,
Milky white, clear coloring, and those printed with other paints or inks are also preferably used.

Here, the binder component of the ink or paint used for forming the light-shielding portion is not particularly limited, and may be any known one for a conventional polycarbonate resin. For example, as a binder component, acrylic, acrylic alkyd, amino alkyd,
Examples include urethane-based, acrylic / urethane-based, epoxy-based, vinyl chloride / vinyl acetate copolymers, and nitrocellulose. In addition to carbon black as a light-shielding component, inorganic pigments such as titanium dioxide, red iron oxide, oxides such as cobalt blue, sulfides such as zinc sulfide, sulfates such as precipitated barium sulfate, hydrated silicates, ultramarine blue, etc. There are silicates, ferrocyanides such as navy blue, metal powders such as aluminum powder and zinc powder, and various hydroxides, chromates, carbonates, and phosphates.As organic pigments, brilliant carmine 6B, disazo yellow Azo pigments, such as phthalocyanine blue, phthalocyanine pigments, such as
Nitro pigments such as naphthol yellow S, condensed polycyclic pigments such as quinacridone red, and other various organic pigments and dyes are appropriately used. Printing inks and paints are prepared by mixing these binders, colorants, suitable solvents, additives, and the like, and applied to a polycarbonate sheet and dried to form light-transmitting characters or marks. When a metal-like appearance is required, a method such as sputtering, vacuum deposition, plating, or the like is used by hot stamping or masking a character to a mark portion, and the under and top are coated if necessary.

The polycarbonate sheet on which the light-shielding portion having the light-transmitting characters and marks is formed as described above is cut into a cut piece by punching or other means as it is, or is preformed, and is used as a cut piece for a mold insert. Cut into pieces.

The method of preforming is selected mainly depending on the desired product shape and required appearance, and examples include simple bending, cold or hot compression molding, and vacuum molding. In particular, those that require deep drawing shapes include Drape forming and Plug as
It is easy and preferable to adopt a method of using a vacuum forming method such as sist forming or the like to reduce the change in the shape of the light transmitting character to the mark portion. After the preforming, usually, a desired punching process is performed. However, it is preferable to devise a preforming die and perform the punching process together with the preforming.

After inserting the cut piece produced above into a mold, a transparent to light transmitting or opaque to light shielding thermoplastic resin is injected to obtain an illuminated switch of the present invention. The type of thermoplastic resin used for injection molding is appropriately selected depending on the required performance of the illuminated switch, its shape, and the like, and the injection molding conditions and the like are within the known condition range of the thermoplastic resin molding material to be used. Things. Specific thermoplastic resin molding materials include polycarbonate (PC), polycarbonate-polyester resin compositions (PC / PBT, PC / PET, PC / PCT
A, PC / PES composition such as PC / PCTG), polycarbonate-A
BS resin composition (PC / ABS), polycarbonate-polyphenylene ether-polyester resin composition (PC / PPE
/ PES), polycarbonate-polyamide resin composition (PC
/ PA), polycarbonate-polyester-polyamide resin composition (PC / PES / PA), other polycarbonate-based resin compositions (PC alloy); acrylic resins such as polymethylmethacrylate (PMMA); polystyrene (PS) ,
Styrene resins such as methyl methacrylate-styrene copolymer (MS), acrylonitrile-styrene copolymer (AS), acrylonitrile-butadiene-styrene copolymer (ABS); polyphenylene ether-polystyrene resin composition (PPE / PS) ), Polyphenylene ether-polyamide resin composition (PPE / PA), polyphenylene ether-polyester resin composition (PPE / PES), other polyphenylene ether resin compositions (PPE alloy); polyacetal resin and its composition; Nylon-
6 (PA6), nylon-66 (PA66), nylon-6,10 (P
A610), polyamide resin (PA) such as nylon-12 (PA12), nylon-MXD6; polyethylene terephthalate (PET), polybutylene terephthalate (PBT), 1,4-
Polyester resins such as hexanedimethanol / terephthalic acid / isophthalic acid copolymer (PCTA) and 1,4-hexanedimethanol / ethylene glycol / terephthalic acid copolymer (PCTG); and polyvinyl chloride (PVC). In particular, engineering plastics and alloys thereof are preferred.

Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of an illuminated switch with a mark according to the present invention, and FIG. 2 is a schematic view showing a state in which a polycarbonate sheet is mounted on a mold. The numbers in the figure are
1: punched piece, 2: injection resin, 3: light transmitting portion, 4: core portion, 5: fixed mold, 6: movable mold, 7: cushion material.

In FIG. 2, a cushion material (for example, a silicon rubber sheet) is incorporated on the back surface of the core mold at a portion where the marked polycarbonate sheet is sandwiched between the cavity and the core of the mold, and the sheet is sandwiched between the molds. Prevents damage when it is spilled.

For example, if the rubber thickness is 2.1 mm, when a 0.5 mm thick sheet is installed, the core mold that sandwiches the sheet is compressed by 0.1 mm and generates about 60 kg / cm ² as the repulsive force of the rubber, and the resin is injected into the mold Force acting in the direction to open the core mold generated when
36 kg / cm ² can sufficiently oppose the (pressure-receiving area, 0.36 cm ² ÷ core bottom area, 3 cm ² of the mold internal pressure, about 300 kg / cm ² × core by resin), and so does not stick marks dent polycarbonate sheet Can be adjusted.

The pinching force of this sheet is adjusted according to the thickness of the sheet to be used, the hardness of the surface design process, and the scratched product, and damage to the polycarbonate sheet and the printing of characters or marks applied to the surface and the hot stamp film. It is devised not to give.

In the case of injection molding by further increasing the temperature of the mold, anticipate the reduction in the thermal expansion and compressive deformation limit stress of the polycarbonate sheet to be mounted, and also correct the mechanism that generates repulsive force, for example, rubber or elastomer. In this case, it is devised so as to compensate for the reduction in the expansion of the rubber itself and the rebound resilience in a high temperature range.

In the case of using an elastic body as rubber and elastomers, at 40 to 100 ° C. under a general mold temperature region used in injection molding, compression modulus 800 kg / cm ² before and after ~5000kgf / cm ² strength of those compression width Is preferred. For example, chloroprene rubber (CR), fluoro rubber (FPM), and silicone rubber (SiR) are preferable. In the region where the mold temperature is relatively low at 40-60 ° C,
Urethane rubber (UR) can be used.

The hardness is about 30 to 90, and when the printing or hot stamping film applied to the polycarbonate sheet is soft, using a rubber or elastomer having low hardness and low rebound resilience can prevent scratching. Even when a spring or damper mechanism (for example, a tamper mechanism with a cylinder / piston structure using gas or liquid on the back of the cavity or core) is used, when using a sheet whose surface design is soft, the mold Adjust the force generated when sandwiching between the cavity and the core to a minimum, and as a repulsion force 50 to 15
0 kgf / cm ^2, more preferably non-defective can be obtained as a range of 60~100kgf / cm ^2.

In the case of a surface-treated sheet having a hardness, for example, a sheet subjected to metal matte processing or a hard mat, a good appearance can be obtained without scratches even in a region of 100 to 150 kgf / cm ² .

Although the manufacturing method and the mold structure of the present invention have been described above, the present invention is not limited to the drawings as described above. For example, using a large number of molds, the parts where each sheet is sandwiched, each with a cushioning structure to prevent damage,
The sheet may be drawn in a mold, punched, and simultaneously sandwiched between the molds.

For the insert of the cut piece into the mold cavity, the preformed cut piece is attached to the inner surface of the illuminated switch, the cut piece is attached to the outer surface of the illuminated switch, and the cut piece is covered so as to cover the entire surface of the illuminated switch. It is manufactured by mounting and shaping the cut piece at the same time as the injection, manufacturing by mounting the cut piece at the intermediate surface position of the illuminated switch, manufacturing by simply mounting the cut piece on the inner surface equivalent part of the illuminated switch, Various methods can be adopted, such as manufacturing by mounting a preformed cut piece on the outer surface equivalent portion, and manufacturing by mounting usually a preformed cut piece on the inner surface equivalent portion of the illumination switch.

〔Example〕

 Hereinafter, the present invention will be described in detail with reference to examples.

Example 1 An 18 × 24 mm light-shielding portion having a light-transmitting mark portion having an outer diameter of 9 mmφ at the center was formed on a 0.5 mm-thick polycarbonate sheet by multilayer printing.

The sheet was punched to produce a punched piece having an outer shape of 15 mm × 20 mm. This punched piece is sandwiched between the cavity of the mold and the core and mounted, and 2.5 mm thick silicone rubber is incorporated on the back of the core mold, and when the mold is closed with the sheet attached, the rubber of 0.2 mm becomes It was compressed to generate a repulsive force of 80 kgf / cm ² .

A dark gray light-shielding polycarbonate resin containing carbon black and titanium white was injection-molded to obtain a predetermined illuminating switch component having a punched piece on the outer surface and integrated with the light-shielding polycarbonate resin.

Example 2 A 40 × 50 mm light-shielding portion having a light-transmitting portion having an outer diameter of 2 × 5 mm and a light-transmitting mark portion having a 6 × 12 line formed in a central portion by multilayer printing on a 0.7 mm-thick polycarbonate sheet. did. After processing this sheet into a box shape by vacuum forming (thickness was 0.6 mm), it was punched out to an outer diameter of 15 mm.
A punched piece having a size of 25 mm and a depth of 5 mm was manufactured. This punched piece had no light-transmitting portion and no displacement or deformation of the mark, and had no wrinkles or tears at the box-shaped corners.

This punched piece is attached to a mold with cushioning by incorporating a spring on the back of the core mold, and when the mold is closed, the light transmitting part and the mark part are sandwiched, and the spring has a compression repulsion force of 0.1 mm used as a 40 kgf / cm ^2, thickness 0.
The clearance between the core and the cavity was adjusted so that the repulsive force of a 6 mm sheet was 60 kgf / cm ² .

A semi-transparent milky white polycarbonate resin with a coloring agent mainly composed of titanium white was injection-molded to obtain a predetermined light switch component integrated with the light-shielding polycarbonate resin.

Comparative Example 1 In the mold of Example 2, a steel spacer was incorporated on the back of the core mold, and the clearance when the mold was closed was 0.7 mm.
As a result, when a 0.6 mm-thick polycarbonate sheet processed in the same manner as in Example 2 was mounted and injection-molded, the light-transmitting portion of the sheet sandwiched between the cavity and the core mold closed the mold of the molding machine ( 80ton) and only defective products with clear dent marks on the design were obtained.

In addition, the thickness of the spacer was adjusted to 0.6 mm, the same as the thickness of the sheet.However, if the mold temperature was as low as 40 ° C, the injection-molded resin would enter the gaps slightly, causing a defect to cover the light transmitting part. Conversely, when the mold temperature was as high as 80 ° C., the thermally expanded sheet of the attached sheet was compressed, and dent marks were generated.

[Functions and Effects of the Invention]

As is apparent from the detailed description of the invention and the examples, the method for manufacturing the illuminated switch component of the present invention is based on the method of manufacturing the desired light-transmitting characters, marks, designs, etc. by previously printing or hot stamping a polycarbonate sheet. By using the molded product, the molded product is integrated with the thermoplastic resin in the injection mold, and a molded product having good appearance can be obtained very easily.

In addition, by using a polycarbonate sheet, in addition to a method of attaching to a mold as a flat plate and integrating it with a resin to be injection-molded, a thermal processing such as vacuum molding or press molding is performed in advance to form a three-dimensional shape. It is also possible to use a mounting method, or a method in which a flat plate is mounted, but the mold is closed, and the surface is integrated with the resin to be injected and molded into the tertiary phase to obtain the phase.

In particular, in the method of changing the tertiary phase in the process of closing the mold, by giving the cushioning property to the mold where the sheet is sandwiched, the compressive force is gradually generated in the process of closing the mold and the sheet works Therefore, shaping is facilitated and defects such as wrinkles can be prevented very effectively.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an illuminated switch with a mark according to the present invention, and FIG. 2 is a schematic view showing a state where a punched polycarbonate sheet is mounted on a mold. The numbers in the figure respectively indicate 1: punched piece, 2: injection resin, 3: light transmitting portion, 4: core portion, 5: fixed mold, 6: movable mold, and 7: cushion material.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-147225 (JP, A) JP-A-53-108156 (JP, A) JP-A-2-501817 (JP, A) (58) Survey Field (Int.Cl. ⁶ , DB name) B29C 45/00-45/84

Claims (4)

(57) [Claims] 1. A light-shielding portion having light-transmitting characters and marks is formed on a light-transmitting aromatic polycarbonate sheet having a thickness of 0.1 to 2.0 mm, and the sheet is cut into a predetermined shape. The cut piece is mounted on the cavity of the mold for mounting the cut piece and the cavity and the core of the mold having a cushioning property on one or both sides of the core, and the cut piece is formed by injection molding a thermoplastic resin. A method for manufacturing an illuminating switch component, comprising: integrating an injection resin with a resin. 2. The method according to claim 1, wherein the mold having a cavity or a core having a cushioning property incorporates a soft rubber, elastomer or spring on the back surface of the cavity or the core. 3. The method according to claim 1, wherein the mold having a cushion or a cavity or a core has a cylinder / piston structure damper using a gas or a liquid at the back of the cavity or the core. 4. The cut piece is a preformed piece or a preformed and punched piece.
Manufacturing method of the illuminating switch component described in the above.