JPH07169360A - Cover member for push-button switch and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a cover member for a push-button switch having a high- grade appearance, which is used for the input device of an electronic apparatus such an electronic calculator and a remote control device and of which the character display part excels in wear resistance, and a manufacturing method thereof. CONSTITUTION:An arbitrary design having a recess 2 of 5 to 50mum depth is provided in the surface of the key-top part of a cover material 1 for a push- button switch, and a colored part 3 having a different color from that of the key-top in the recess is provided. This manufacturing method comprises the steps of providing a recess 2 of 5 to 50mum depth with an arbitrary design in the surface of a key-top and providing a colored part 3 of 150 to 400 poise ink 7 with screen printing by using polyester preparation of mesh density of 300 to 500pcs./in. to which plasma treatment is applied in the recess.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cover member for a push button switch, which is used in an input device for an electronic device such as a remote controller and a telephone, and whose design indication of characters and the like is excellent in abrasion resistance, and a manufacturing method thereof. It is a thing.

[0002]

2. Description of the Related Art Regarding cover members for push button switches,
The top surface of the key top is usually provided with any design such as numbers, symbols, characters, and patterns to clearly indicate the input operation.These designs are screen printed or pad printed. In this case, the ink 10 as the colored portion is convexly attached to the top surface of the key top portion as shown in FIG. There is a disadvantage that the colored portion easily disappears.

For this reason, the push button switch cover member is provided with a depression having a depth of 100 to 1,000 μm on the top surface of the key top portion, and a coloring portion is also provided here. As shown in FIG. 4, a polyester plate 11 is used on the top surface of the key top to form the ink 13 supplied by a squeegee 12 by screen printing, and the dent 14 is filled with the ink 13 or a dispenser is used to form the dent. A method of filling the ink 14 into the ink 14 or a method of filling the recess 14 with the ink 13 and then removing the masking is used.

[0004]

However, as described above, in the cover member for the push button switch in which the top surface of the key top portion is provided with the depression of 100 to 1,000 μm and the ink is filled therein, it takes time to dry the ink. However, when rapid heating is performed to accelerate drying, there is a disadvantage that the design quality cannot be maintained because the foamed film 15 is formed as shown in FIG. 5 due to volatilization of the volatile components contained in the ink 13. In addition, the method of forming colored portions by the above-described various methods has a disadvantage in that the ink cannot be stably filled in the depressions, and the number of steps increases depending on the method.

Further, for example, when this is carried out by screen printing, if a uniform amount of ink can be filled in a predetermined position at the finest pitch as possible, an excellent design quality can be obtained. In screen printing, if the mesh density is 270 or less / inch, it is not possible to uniformly fill the entire depression of the top surface of the key top with ink, and the filling amount varies, resulting in a mesh density of 270 or more / inch. However, the polyester plate has an adhesive property that makes it difficult for the ink to pass through the mesh, and the formed design will bleed.Therefore, the method of filling the ink in the recess with a dispenser is a hemispherical state. Is effective for filling, but it is not suitable for precise pattern shapes such as letters and patterns. Further, after which precisely masked except depressions in advance key top portion top surface, the ink filling the recesses, there is a disadvantage that the method for peeling the masking after ink curing takes too much number of steps for desorption of masking.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a cover member for a push button switch and a method for manufacturing the same, which solves the above disadvantages and problems, and the cover member for a push button switch is optional on the top surface of a key top portion. Is designed to have a recess having a depth of 5 to 50 μm, and a colored portion different in color from the key top portion is provided in this recess. This manufacturing method is the top surface of the key top portion. The depth of the arbitrary design is 5 to 50 μm, and the plasma density is 300 mesh / inch.
It is characterized in that a colored portion of ink of 150 to 400 poise is formed by screen printing using a polyester plate of 500 lines / inch.

That is, the inventors of the present invention have made various studies to develop a cover member for a push button switch which can solve the disadvantages of the above-mentioned conventional method, can maintain the design quality, and has excellent wear resistance. The depth of the dent provided on the top surface of the key top part of the cover member for
If the depth is 5 to 50 μm, which is shallower than 1,000 μm, the disadvantage that it takes time to dry the ink filled here is solved, and the ink does not foam during this drying process. It has been found that a display portion with good design quality can be obtained by providing a colored portion different in color from the key top portion.

Regarding the formation of the colored portion, in the ordinary polyester plate making, if the mesh density is made fine in order to make the ink passage amount uniform, it becomes difficult for the ink to pass therethrough, and blurring occurs in the printed characters. When the surface of the polyester plate is roughened and modified by plasma treatment with corona discharge, etc., it becomes non-adhesive, and even if the mesh density is made fine, the ink easily passes through the plate,
In this case, it was confirmed that if the viscosity of the ink is 150 to 400 poise, the amount of ink passing through is stable and the formation of the colored portion is facilitated, and the present invention was completed. This will be described in more detail below.

[0009]

The present invention relates to a cover member for a push button switch and a method for manufacturing the cover member. The cover member for a push button switch has a depth of 5 to 5 in any design on the top surface of the key top portion.
The feature is that a recess of 50 μm is provided, and a colored part different in color from the key top part is provided in this recess. This manufacturing method has a depth of any design of 5 on the top surface of the key top part. By using a polyester plate with a pit of ~ 50μm and a plasma density of 300 pits / inch to 500 pits / inch, which was plasma-treated in the pit, screen printing 1
It is characterized by forming a colored part with ink of 50 to 400 poise, but this cover part for push button switch has a thin colored part and volatilized components quickly evaporate, so a display part with good design quality should be provided. With this manufacturing method, the filling of the ink in the recess is stable, and the advantage that the cover member for the push button switch having the colored portion with excellent wear resistance can be easily obtained. Given.

The cover member for a push button switch of the present invention is filled with synthetic rubber such as natural rubber, silicone rubber or ethylene-propylene rubber, or thermoplastic elastomer such as polyester, urethane or olefin as in the conventional method. Fill the mold with an uncrosslinked material containing agents, crosslinkers, etc., and at 10 to 100 kgf / cm ² at a molding temperature of 130 to 200 ° C.
It may be manufactured by compression molding under a molding pressure of 2 to 10 minutes, but it may be manufactured by injection molding.

However, in the cover member for a push button switch of the present invention, as shown in FIG. 1, for example, a depression 2 is formed in a pattern such as a display character on the top surface of the key top portion of the cover member 1 for a push button switch. Although the colored portion 3 is formed on the surface of the concave portion with this, the durability of the design is improved, but if the depth of the recess 2 is more than 50 μm,
Since it takes too long to dry the ink and the ink foams in the ink drying step, the depth of the recess 2 is required to be 5 to 50 μm. Further, as described above, the colored portion 3 is formed in the recess 2 with ink or the like. However, in the cover member for a push button switch of the present invention, the colored portion 3 is preferably different in color from the key top portion. According to this, the advantage of improving visibility is provided.

It should be noted that the depression may be provided with a protrusion having a predetermined shape at a corresponding portion of the mold, and the depth of the depression depends on the size of the key top portion, usage method, design, etc.
It may be arbitrarily set in the range of up to 50 μm. Also, as this width increases, the wear resistance decreases, so
The thickness may be in the range of 1,000 μm, but the colored layer provided in the recess may be integrally moldable like a silicone-based ink if the base material is silicone rubber. Further, the colored portion may be provided in layers over the top surface of the key top portion as long as the recessed portion is provided.

The push button switch cover member of the present invention is manufactured, for example, by the method shown in FIG. FIG. 2 is a schematic vertical sectional view of a push button switch cover member manufacturing apparatus of the present invention. This is a depression on the top surface of the key top portion of a push button switch cover member 1 manufactured by a conventionally known method. 2 is provided, a plasma-treated polyester plate 4 is provided thereon, and ink 7 is poured into the ink passage portion 5 of the polyester plate by using a squeegee 6, and the ink 7 is dropped into the recess 2 to deposit the colored portion 3 there. Should be provided. As described above, in order to form the colored portion, the polyester plate treated with plasma such as corona discharge is used as described above. According to this, since it becomes non-adhesive to ink, the mesh density is 300 / inch ~ 5
Even if it is 00 lines / inch, the ink can easily pass through the plate. However, the ink at this time must be 150 to 400 poise, and the ink other than the ink passing part of this polyester plate must be used. When the emulsion is provided in a thickness of 10 μm or less, preferably 2 to 10 μm, the surface to be printed can have a higher quality.

In the cover member for a push button switch according to the present invention, since the colored portion is formed in the recess having a depth of 5 to 50 μm provided on the top surface of the key top portion, this portion is repeatedly rubbed by pressing or the like. However, it does not wear out, and the design is given the advantage of staying sharp, and the products made by this manufacturing method can be filled with a uniform amount of ink at a fine pitch in a predetermined recess. However, this will be of excellent design quality, and if the area where this ink does not pass is coated with an emulsion with a thickness of 10 μm or less, even if the permeability of the ink to the plate is increased by the plasma treatment, Since the passing amount is appropriately adjusted in the emulsion layer, there is an advantage that ink dripping is less likely to occur.

[0015]

EXAMPLES Next, examples and comparative examples of the present invention will be described. Example 1 In molding a cover member for a push button switch having 15 key top parts, a number of 0 to 9 having a width of 500 μm and a depth of 30 μm in the dug part for forming the key top part of this mold. And +,-, ×, ÷, =, etc. are formed in a protruding manner, and a silicone rubber compound / KE-9 is added to this mold.
51U [Shin-Etsu Chemical Co., Ltd. trade name] 100 parts by weight of a compound containing 2 parts by weight of a cross-linking agent C-8 [Shin-Etsu Chemical Co., Ltd. trade name] was filled, and the molding temperature was 180 ° C. Molding pressure 50kg
Molding was performed under molding conditions of / cm ² for 10 minutes to produce a molded body.

Next, 100 parts of silicone type printing ink Silmark TM [trade name of Shin-Etsu Chemical Co., Ltd.], 8 parts of curing agent Cat-TM [trade name of Shin-Etsu Chemical Co., Ltd.] and catalyst Cat-PL -2 [Shin-Etsu Chemical Co., Ltd. product name] 0.3 parts by weight and 5 parts by weight of black pigment are added to make a printing ink of 200 poise, the molded body is positioned by a jig, and the plasma-processed mesh density is 300. Polyester plate SE-300B [product name by Sonocom Co., Ltd.], which has a shape corresponding to the recess of the molded body in books / inch, and is made with a pitch
(An emulsion layer with a thickness of 9 μm was provided on the part that does not allow ink to pass through.), Screen printing was performed using this ink, and the molded body was left in a dryer at 200 ° C for 15 minutes to print. When the ink was fixed to the molded body, the yield was 95%.

Next, in order to confirm the wear resistance of the design of the cover member for the push button switch, a sand eraser No. 5002 [a product manufactured by Lion Co., Ltd. No.] was pressed under a load of about 300 g, and a wear resistance test was performed at a sliding distance of 8 mm and a sliding speed of 2 reciprocations / second. The results are shown in Table 1 below, and the results of [6] The shape was retained.

COMPARATIVE EXAMPLE 1 A molded body having substantially the same structure as that of Example 1, except that the cover member for a push button switch having no depression on the top surface of the key top portion is formed of a normal polyester plate and has a mesh density of 250 pieces /
Inch type, T-250B [trade name of Sonocom Co., Ltd.] was used for screen printing, and when printing ink was placed on the key top portion with a line width of 500 μm and a thickness of 20 μm, the yield was 95%. However, when the same abrasion resistance test as in Example 1 was carried out, this had low abrasion resistance and showed the results as shown in Table 1 below.

Example 2 A molded product having substantially the same structure as that of Example 1, but a cover member for a push button switch in which the depth of the depression on the top surface of the key top portion is 5 μm is used as the polyester plate SE-300B of Example 1. When screen-printing was carried out using, the abrasion resistance showed the results as shown in Table 1 described later.

Example 3 A molded body having substantially the same structure as that of Example 1, but having a depression depth of the top surface of the key top portion of 50 μm for a push button switch cover member The polyester plate / SE-3 of Example 1
When screen printing was carried out using 00B, the yield and abrasion resistance showed the results as shown in Table 1 described later.

COMPARATIVE EXAMPLE 2 A molded product having substantially the same structure as that of Example 1, but a cover member for a push button switch in which the depth of the depression on the top surface of the key top portion is 100 μm is used.
When screen printing was performed using, the ink in the dents foamed during the drying process, resulting in a yield of 30%,
This product showed the results as shown in Table 1 which will be described later with respect to wear resistance.

Example 4 The molded body having the recess depth of 30 μm of Example 1 was subjected to the plasma treatment used in Example 1, and the mesh density was 300 /
Inch polyester production SE-300B, emulsion thickness
When screen printing was performed using a material of 15 μm, the abrasion resistance showed the results as shown in Table 1 below, and the yield was 80% due to the occurrence of sagging on the printed surface.

[0023]

[Table 1]

[0024]

The present invention relates to a cover member for a push button switch and a method for manufacturing the same, and as described above, the cover member for a push button switch has a recess having a depth of 5 to 50 .mu.m with an arbitrary design on the top surface of the key top portion. The key top portion is provided with a colored portion different in color from that of the key top portion. This manufacturing method has a depth of any design of 5 to 50 μm on the top surface of the key top portion. With a dent,
The mesh density of plasma treatment in this dent is 3
This is characterized by forming a colored part with ink of 150 to 400 poise by screen printing using a polyester plate of 00 lines / inch to 500 lines / inch, which is sufficient for this push button switch cover member. It has excellent abrasion resistance and is given the advantage of being of high quality in appearance. According to this manufacturing method, since it is screen printing, there is no need for masking and the process is complicated. Therefore, the advantage that characters can be formed with high yield is given.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a cover member for a push button switch according to the present invention.

FIG. 2 is a vertical sectional view of a manufacturing apparatus at the time of manufacturing the cover member for a push button switch of the present invention.

FIG. 3 is a vertical cross-sectional view of a conventional cover member for a push button switch.

FIG. 4 is a vertical sectional view showing a conventional cover member for a push button switch, which is manufactured.

FIG. 5 is a vertical sectional view of a cover member for a push button switch which is another conventional example.

[Explanation of Codes] 1 ... Cover member for push button switch, 2 ... Indentation having a depth of 5 to 50 μm, 3 ... Colored part, 4, 11 ... Polyester plate subjected to plasma treatment, 5 ... Ink passage part, 6, 12 … Squeegee, 7, 13… Ink, 10… Ink layer, 14… Recess, 15… Foam film.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Naoto Komine 4-3-5 Nihonbashi Honcho, Chuo-ku, Tokyo Shin-Etsu Polymer Co., Ltd. (72) Inventor Masanori Sakuma 2-14-9 Tamagawadai, Setagaya-ku, Tokyo No. Kyocera Corporation Tokyo Yoga Works (72) Inventor Kazura Suda 2-14-9 Tamagawadai, Setagaya-ku, Tokyo Kyocera Corporation Tokyo Yoga Works

Claims (3)

[Claims] 1. A push-button switch characterized in that a recess having a depth of 5 to 50 μm is formed on the top surface of the key top portion by an arbitrary design, and a colored portion different in color from the key top is provided in the depression. Cover member. 2. The top surface of the key top portion is provided with recesses having a depth of 5 to 50 μm in an arbitrary design, and the plasma-treated mesh density is 300 / inch to 500 /
Screen printing using inch polyester plate
A method of manufacturing a cover member for a push button switch, which comprises forming a colored portion with ink of 150 to 400 poise. 3. The method for producing a cover member for a push button switch according to claim 2, wherein an emulsion layer having a thickness of 10 μm or less is provided on the surface of the polyester plate other than the ink passage portion.