JP2000182470A - Key top - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize feel which is soft to touching and facilitate frosting by applying so as to form an irregular surface with beads a coating material prepared by mixing elastic beads in a photo-curing resin to the surface. SOLUTION: This key top 10 is formed by bending a flexible sheet 11 so as to project upwards, and molding mold resin 21 in a recess formed on the backside of a bent part. A coating 30 for ornament is printed on the surface of the key top 10, and a frosting coating 40 is over-coated thereon. A coating material of the frosting coating 40 is prepared by mixing elastic beads with elastic photo-curing resin, and coated to form irregular surface with the beads on the coating 40. The photo-curing resin is selected so that the breaking elongation of the coating film is 30-100%. For example, transparent acrylic urethane, having a breaking elongation of 100-200% and a particle size of 40 μm, is blended at 20 pts.wt. as the beads with respect to 100 pts.wt. photo-curing resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a key top which is a mat type and whose surface is soft and can be softly touched.

[0002]

2. Description of the Related Art Conventionally, some key tops are made of a transparent or translucent synthetic resin and illuminated from the back side.
There is an illuminated key top that illuminates characters and symbols provided on the key top brightly.

[0003]

By the way, the conventional key tops are made of a synthetic resin whose touch when touched is apparently made of a synthetic resin, or made of a rubber whose touch is apparently soft.

[0004] On the other hand, some key tops are required to have a hard but slightly soft touch feeling in order to improve the feel when touching the key top.

When the key top is hard, a finger (especially a nail) touching the key top sometimes slips. However, it has been demanded to prevent the slip.

[0006] Further, in order to give the key tops a high-class feel, there is a case where the key tops are matted, but in that case, the surface of the key tops needs to be subjected to a satin finish, which is complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide a soft touch when touching a key top, and to make it easier to gloss without finger (especially nails) slipping. It is to provide a key top that can be erased.

[0008]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention relates to a key top made of resin and having a pressing portion for pressing a switch contact directly or indirectly via another member. A matte coating is formed on the surface of the key top by applying a coating made by mixing elastic beads in a photo-curable resin so that the irregularities of the beads appear on the surface. . In addition, it is preferable to use a material having elasticity as the photocurable resin, so that the matte coating applied to the key top surface has a breaking elongation of 30 to 100%. Preferably, the beads are made of a material having a breaking elongation of 100 to 200%.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing a key top plate 1 to which the present invention is applied. FIG. 1A is a plan view, and FIG. 1B is a cross-sectional view taken along line AA of FIG. As shown in FIG. 1, the key top plate 1 is configured by providing a total of 20 key tops 10 in five rows and four rows in a flat flexible sheet 11.

Each key top 10 is a flexible sheet 1
1 is formed so as to be convex upward, and a mold resin 21 is molded and integrated into a concave portion formed on the back surface side of the curved portion. In the center of the lower surface of the mold resin 21,
A protruding pressing portion 23 that directly or indirectly presses a switch contact formed on a substrate (not shown) or the like via another member is provided.

By the way, although not shown, numerals, symbols, patterns and the like are formed on the surface of each key top 10 by printing.

FIG. 2 is an enlarged side sectional view showing one key top 10 in an enlarged manner. As shown in FIG.
On the surface of No. 0, a normal paint 30 for decoration is printed and formed, and then a matte paint 40 is applied so as to overcoat the paint.
Is formed.

Here, the key top plate 1 is formed as an illuminating type in which light from a light source (not shown) installed on the back side (lower side in the figure) is guided to the front side. That is, the flexible sheet 11 and the mold resin 21 are both made of a transparent material, and the coating 30 is made of a material that does not transmit light or a material that is difficult to transmit light.

A blank design portion M such as a character is formed in a portion of the coating 30 on the upper surface of the key top 10. It is to be noted that the coating 30 has various conventional structures, and it is needless to say that various modifications are possible, such as forming illumination type characters or the like by a method other than the drawing pattern.

FIG. 3 is a schematic enlarged sectional side view of a part of the matte coating 40 (part B in FIG. 2) according to the present invention. As shown in the figure, the matte coating 40 is formed by applying to the outermost layer on the surface of the key top 10, and the material of the coating is the elasticity of a photo-curable resin 41 rich in elasticity. The beads 43 are mixed. The matte coating 40 is applied on the surface of the key top 10 so that irregularities due to the beads 43 appear.

The beads 43 have an elongation at break (JIS
Use a transparent material having a breaking elongation at break of 100 to 200% when the test piece specified in the tensile test is pulled (rupture elongation) (composed of transparent synthetic rubber (for example, silicone rubber) in addition to synthetic resin) May be).

On the other hand, a photo-curable resin 41 is also used which has high elasticity, and is photo-curable (especially preferably UV-curable) and translucent. After drying, the elongation at break of the coating film (elongation until the matte coating 40 formed is peeled off from the flexible sheet 11 and stretched to break) is 30 to
Use a material that becomes 100%.

Examples 1 to 5 of specific materials are as follows.

First, the composition of the photocurable resin (UV curable resin) commonly used in each of the following Examples 1 to 5 is as follows. -40 parts by weight of polyester acrylate-40 parts by weight of urethane acrylate-20 parts by weight of epoxy acrylate-4 parts by weight of phosphoric acid acrylate-2 parts by weight of benzophenone-2 parts by weight of 2,2 dimethoxy-2-phenylacetophenone-0.1 part by weight of silicon 50 parts by weight of a solvent (a mixture of 30 parts by weight of toluene, 20 parts by weight of butyl acetate, 20 parts by weight of ethyl cellosolve, and 30 parts by weight of isopropyl alcohol)

The compositions of Examples 1 to 5 are as follows. [Example 1] To 100 parts by weight of the photocurable resin having the above composition,
20 parts by weight of acrylic urethane beads (bead diameter: about 40 μm (average)).

Example 2 Photocurable resin 10 having the above composition
0 parts by weight of acrylic beads (bead diameter about 15 μm
(Average)) Stirring 20 parts by weight.

Example 3 Photocurable resin 10 having the above composition
0 parts by weight of polyethylene beads (bead diameter of about 40
(μm (average)) 20 parts by weight.

Example 4 Photocurable resin 10 having the above composition
0 parts by weight of nylon beads (bead diameter of about 40 μm
(Average)) Stirring 20 parts by weight.

Example 5 Photocurable resin 10 having the above composition
0 parts by weight of polypropylene beads (bead diameter of about 4
A mixture obtained by stirring 20 parts by weight (0 μm (average)).

Here, the matte coating 40 is applied, for example, by applying beads 4 to the surface of the key top plate 1 on which the coating 30 has been completed.
3 is coated (for example, by spray coating), and then dried with hot air (for example, at 50 to 70 ° C. for 5 minutes).
After the solvent is blown off, UV irradiation (for example, 60 to 120
(Sec)) to cure the resin.

Next, the operation of the matte coating 40 will be described. That is, light emitted from a light source (backlight) (not shown) on the back side of the key top 10 passes through the transparent mold resin 21 and the flexible sheet 11 to form a coating 30.
, Light passes through the blank design portion M, and is emitted from the surface through a layer of the transparent matte paint 40.

As described above, since the matte coating 40 is applied so that irregularities due to the beads 43 appear on its surface, when light passes through the part of the matte coating 40, the matte coating 40 is formed by the lens effect of the beads 43. Diffusely reflected and diffused,
Therefore, the matte light in a matte state illuminates the surface of the design portion M brightly.

In the case of the present invention, light is irregularly reflected by using the beads 43. Therefore, it is not necessary to separately treat the painted surface with a matte finish, and a matte state can be easily obtained. Even when light is not irradiated from the back side, the surface of the matte coating 40 is reflected from the front side (upper side in the figure) and reflected by the surface of the matte coating 40 due to irregularities of the matte coating 40 surface. It will be in the erased state.

If various reflective materials (aluminum powder, pearl powder, etc.) are separately mixed into the matte coating 40, it is possible to obtain a design coating film which exerts not only light diffusion but also light reflection effect. Can be.

On the other hand, when the key top 10 is pressed with a finger, the photocurable resin 41 and the beads 43 constituting the matte coating 40 have elasticity as described above. Feel the elasticity and the softness of the pressing is a little softer.

The surface of the matte coating 40 is formed by beads 43.
As a result, when the key top 10 is pressed with a finger (especially a nail), the finger (especially a nail) does not slip.

In the above embodiment, a transparent material of an illumination type is used as the key top 10, but a material other than a transparent material, that is, an opaque material may be used as the key top 10. In this case, the light is not of an illuminated type, but light incident on the surface of the key top from above is irregularly reflected by the matte coating 40 that has been made uneven by the beads 43, again giving a matte surface. In addition, the touch when pressed with a finger also becomes a soft touch similarly to the above, and there is no danger of slipping.

In the above embodiment, the key top 10 is
The key top structure is not limited to this embodiment. The key top structure is not limited to this embodiment. For example, a key top formed only by the mold resin may be used, or a through hole may be formed in a flat flexible substrate. Key tops having other various structures, such as a key top formed by molding a molding resin above and below it, may be used. In short, any key top may be used as long as it is made of resin and has a pressing portion that directly or indirectly presses the switch contact via another member.

[0034]

As explained in detail above, according to the present invention, the following excellent effects can be obtained at the same time. The touch when touching the key top is not too hard and not too soft, and a unique feeling that is hard but slightly soft is obtained.

A finger (especially a nail) does not slip.

A mat type can be easily obtained.
Optical texture can be improved.

[Brief description of the drawings]

FIG. 1 is a view showing a key top plate 1 to which the present invention is applied, wherein FIG. 1 (a) is a plan view and FIG. 1 (b) is A of FIG. 1 (a).
It is -A sectional drawing.

FIG. 2 is an enlarged side sectional view showing the key top 10 in an enlarged manner.

FIG. 3 is a schematic enlarged side sectional view of a part of the matte coating 40;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Key-top board 10 Key-top 11 Flexible sheet 21 Mold resin 23 Pressing part 30 Painting M Extraction design part 40 Matte coating 41 Photocurable resin 43 Bead

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 4D075 CA03 CB02 DA07 DC19 EA21 EC24 4J038 CB022 CB082 CG142 CJ282 DG322 DH002 FA212 FA252 FA261 FA281 KA18 NA01 NA11 PA17 5G006 CB05 CB09 JA01 JF01 5G023 AA12 CA21 CA50

Claims (3)

[Claims] 1. A key top made of resin and provided with a pressing portion for pressing a switch contact directly or indirectly via another member, wherein the surface of the key top has elasticity in a photocurable resin. A key top characterized by forming a matte coating by applying a coating made of mixed beads so that the unevenness of the beads appears on the surface. 2. The elongation at break of a matte coating film applied to the surface of the key top is set to 30 to 100% by using an elastic material as the photocurable resin. Item 1. Key top according to item 1. 3. The beads having an elongation at break of 100.
3. The key top according to claim 1, wherein the key top is made of a material having a material content of about 200%.