JPH0736296B2 - Keytop manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a key top for various devices such as a word processor and a calculator, and more particularly to a method for forming a desired shape pattern such as letters and figures on the surface of a key top body. Then, a pattern body made of a radiation curable resin is projected on the surface of the key top body, and unevenness is formed by fine particles on the upper surface of the pattern body.

[0002]

2. Description of the Related Art A word processor, a calculator or the like is operated by pressing a key top arranged in parallel on a keyboard with a fingertip, and this kind of key top is required to have various quality requirements. That is, since the key top is pressed many times every day, the identification display pattern formed on the upper surface of the key top, which is the pressing operation surface, has a clear shape and is easy to identify, and it is easy to press with a fingertip. There must be. In addition, even if it is used for a long period of time, the paint that forms the pattern must not come off or deteriorate and discolor, so that its distinctiveness should not deteriorate. Also, since the key tops are liable to get dirty with dirt and dust, it is necessary to carefully wipe the key tops with a cleaning solution such as an alcohol solution on a regular basis. Do not drop or peel off. Furthermore, the key top is
What can be formed with good workability at low cost is desirable. Conventionally, this type of key top pattern forming method has good workability and can be formed at low cost. Therefore, a chemical paint is printed on the top surface of the key top body by various printing methods such as silk screen printing and hot stamping. The method of forming by this was widely adopted.

[0003]

However, since the pattern formed by such a method has low abrasion resistance and chemical resistance of the chemical paint for forming the pattern, it may be used or wiped with alcohol or the like. There is a drawback that the pattern gradually becomes unclear and its distinguishability deteriorates. Further, since the pattern surface is smooth and the surface friction is small, there are various drawbacks such as the fingertip being unnecessarily slippery when pressing the key top with the fingertip, and the patternability is not necessarily high.
Therefore, an object of the present invention is to provide a key top which has high usability and is excellent in durability such as abrasion resistance and chemical resistance, and whose pattern distinguishability does not deteriorate even after long-term use. To do.

[0004]

To this end, the present invention provides
Fine particles are mixed in advance with a radiation curable resin such as an ultraviolet curable resin (UV resin) or an electron beam curable resin (EB resin) ,
Using this, at least the upper surface of the keytop body (11)
When the identification pattern body (15) is projected on the surface including
In addition, the pattern body (15) is irradiated with radiation to obtain the pattern body.
(15) is cured .

[0005]

According to the above construction, the radiation curable resin 13 can form the pattern body 15 having many excellent characteristics with good texture and distinctiveness. Moreover, in this case, since the fine particles 16 are arranged before curing, it is possible to manufacture various patterns 15 for each pattern 15.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 (a) shows that a desired pattern is projected on the upper surface of the key top body by silk screen printing, and 11 is a truncated quadrangular pyramid-shaped key top body made of ABS resin. On the upper surface, a silk screen 12 is in contact with an unnecessary portion, leaving a desired pattern. 13 is a radiation curable resin as a printing paint,
A squeegee 14 having a spatula-like tip made of rubber, which is colored by mixing a coloring agent (for example, black pigment) of a desired color, is slid along the upper surface of the silk screen 12 to remove the resin 3. The pattern body 15 having a desired shape (for example, the shape of the letter "A") is extruded from the silk grain to project in a thick wall. Then, radiation is applied from above to cure the pattern body 15 (see FIGS. 1B and 1C). Fine particles 16 such as glass beads or urethane beads having a particle diameter of about 10 to 30 microns are mixed in the resin 13 in advance, and the fine particles 16 make the surface 6 of the pattern 15 uneven. In this case, since the fine particles 16 are arranged before curing, each pattern 15
Various dispersion amounts can be manufactured for each. By mixing the fine particles 16 in the resin 13 in this way, if the surface of the pattern body 15 is made uneven, it is possible to secure appropriate surface friction. When the fine particles 16 are mixed in the resin 13 as described above, the opening of the screen 12 must be of a size that allows passage of the fine particles 16 having a predetermined particle size. The present invention can be modified in various ways. For example, as a method of mixing the fine particles 16 with resin, after a desired pattern is projected on the surface of the keytop main body,
The fine particles 16 may be mixed into the pattern by spraying the fine particles 16 on the pattern with a spraying machine or the like. Further, the shape of the key top body may be a truncated quadrangular pyramid shape, a truncated cone shape, a truncated polygonal pyramid shape or a disc shape, and the pattern body is not only the upper surface of the key top body but also the key. It may be formed also on the side surface of the top body, as long as it is formed on the surface including at least the upper surface of the key top body. By the way, the radiation curable resin 13 that forms the pattern 15 is a resin that undergoes a chemical reaction such as a polymerization reaction, a condensation reaction, or a crosslinking reaction upon irradiation with radiation to be cured, and the curing is extremely fast. The pattern body 15 can be cured with extremely good workability. In addition, the chemical paints that have been conventionally used as paints for forming patterns of this kind of key tops are dried by the evaporation of the solvent contained in the paints, and not only do they take a long time to dry and cure. During curing, drying shrinkage occurs, and many fine cracks occur on the surface. In such a crack,
Moisture in the air or cleaning liquid for wiping easily enters due to its capillary action, and water etc. once entering the cracks is difficult to evaporate, so such water etc. accelerates deterioration of the paint and fading However, there is a drawback that the distinctiveness of the pattern is remarkably lowered during use. However, the radiation curable resin 13 that cures by causing the above-mentioned chemical reaction has almost no shrinkage associated with curing, and therefore cracks hardly occur. Possess sex.
Further, the radiation curable resin 13 which is cured by the above-mentioned chemical reaction
Has extremely high abrasion resistance and is not easily scratched even when hit by an object, etc., its structure is extremely dense, does not deteriorate and fade due to aging, and is generally used as a material for this type of keytop body. It has good adhesiveness to synthetic resins and metals, and does not peel off. It also has extremely strong chemical resistance to cleaning liquids such as alcohol. This key top pattern 15
Is formed of the radiation curable resin 13 having such various excellent characteristics, so that its distinguishability does not deteriorate even after long-term use. Further, the pattern body 15 is formed on the upper surface of the keytop main body 11 so as to project in a slightly thicker wall, and the upper surface of the keytop body becomes an uneven surface to ensure an appropriate surface friction. Since the fingertip does not unnecessarily slip when pressing with the fingertip, and the light is appropriately diffusely reflected upon entering the uneven top surface, it has various excellent usability such as easy viewing of the pattern body 15. There is. When a transparent or translucent resin is used as the radiation curable resin 13, the light incident on the uneven upper surface of the pattern body 15 is dispersed by the prism effect and a special visual effect is obtained. It will be easier to identify.

As described above, in the method of manufacturing the keytop according to the present invention, the fine particles 16 are mixed in advance.
Using the radiation curable resin 13, the key top body 11
At least on the surface including the upper surface, project the pattern 15 for identification display.
Since the pattern body 15 is hardened by irradiating the pattern body 15 with radiation, the key top has excellent durability such as abrasion resistance and chemical resistance and has high usability. It can be formed with good workability. Moreover, in the present invention, since the fine particles 16 are mixed in advance before curing, it is possible to manufacture various patterns 15 with various dispersion amounts.

[Brief description of drawings]

FIG. 1 is a side view and a perspective view during manufacturing of a keytop.

[Explanation of symbols]

 11 key top body 13 radiation curable resin 15 pattern

 ─────────────────────────────────────────────────── --- Continuation of the front page (56) Reference JP-A-53-135297 (JP, A) JP-A-54-142289 (JP, A) JP-A-56-149634 (JP, A) JP-A-57- 141461 (JP, A) JP 57-212264 (JP, A) JP 59-171417 (JP, A) JP 59-171418 (JP, A) JP 59-173915 (JP, A)

Claims (1)

[Claims] 1. A release containing fine particles (16) mixed in advance.
Using the radiation curable resin (13), the key top body (1
The pattern for identification display is provided on the surface including at least the upper surface of 1).
Projecting (15) and radiating to the pattern (15)
A method for producing a key top, characterized in that the pattern body (15) is cured by irradiating a line .