JPH1142106A - Exterior component and electronic equipment equipped therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exterior component whose surface is made of a material with characteristics suited for use as the part making contact with the human skin, so that it does not cause discomfort and skin inflammation. SOLUTION: A two pack type paint solution composed chiefly of an acrylic resin, acrylic isocyanate, acrylic urethane, or acrylic silicone and to which an appropriate solvent or hardener is added, or a one pack baking type paint solution composed chiefly of an epoxy resin, are applied on the surface of a base 10 made of an ABS resin, a polycarbonate resin, stainless steel, etc. to form a bed layer 20. A paint solution in which an urethane resin 31 and silk yarn particles 32 are mixed is applied on the surface of the bed layer 20 to form a coat 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exterior component and an electronic device provided with the same, and more particularly to a surface material suitable for use on a part frequently touched by human skin such as a wristwatch.

[0002]

2. Description of the Related Art Conventionally, in the case of watch external parts such as a watch outer case and a watch band, there are cases where the surface of a base material is used after being finished in various states such as mirror finish, streak finish, and honing finish. The surface may be painted or plated. The coating film formed by painting is
It is a hard inorganic layer such as a resin layer or glass made of a synthetic resin as a base, which prevents abrasion on the base material surface, prevents corrosion of the base material surface, and prevents wearer's metal allergy. And so on.

[0003]

However, in the case of a watch such as a wristwatch which has a portion which is always in contact with the human skin, the skin may adhere to the surface of the timepiece exterior part, or sweat or the like may stagnate. By doing so, there are problems such as giving discomfort to humans, and dermatitis due to propagation of various bacteria and insufficient air permeability.

Accordingly, the present invention has been made to solve the above problems, and an object of the present invention is to provide an exterior provided with a surface material having characteristics suitable for a portion that comes into contact with human skin and hardly causing discomfort or skin irritation. To provide parts.

[0005]

Means for Solving the Problems The means taken by the present invention to solve the above-mentioned problems is an exterior part having a surface material obtained by mixing a silk powder into a synthetic resin.

[0006] According to this means, by providing an exterior part having a surface material made of a synthetic resin mixed with a powder of silk thread, it has a good touch and has improved water-absorbing and desorbing properties or moisture-absorbing and desorbing properties as compared with conventional materials. Therefore, it is possible to constitute a product that is unlikely to cause discomfort or skin irritation. Also, by containing the silk powder, the texture can be visually enhanced by the unevenness of the surface due to the particle size of the silk powder and the light scattering property of the silk powder, resulting in a high-quality appearance. Can be obtained.

Here, it is preferable to provide a surface layer made of the above surface material on at least a partial surface of the base material.

[0008] According to this means, by applying a surface layer made of a synthetic resin mixed with a powder of silk thread, it is possible to impart the characteristics of the above-mentioned surface material to a base material of an arbitrary material. High quality products can be provided at low cost.

The above surface layer may be formed on almost the entire surface of the exterior component, or may be formed only on a part of the surface.
For example, the surface layer may be printed and formed in a specific pattern or character shape. The coating can be performed when the surface layer is formed almost entirely, and can be performed by printing when the surface layer is formed only partially. It is also possible to form the whole exterior component with the above-mentioned surface material.

Here, it is preferable that an underlayer containing a synthetic resin is formed between the surface of the substrate and the surface layer.

According to this means, the adhesion between the base material and the surface layer can be improved by forming the base layer containing the synthetic resin. In particular, when a metal material is used as the base material, the adhesion can be greatly improved.

It is preferable that the surface layer is partially removed to display characters and figures on the surface.

According to this means, characters and figures for various displays can be represented by partially removing the surface layer, and the appearance of the surface layer containing the powder of silk thread can be enhanced and the removal of the surface layer can be improved. Characters and figures with good visibility can be formed by the contrast with the base.

Further, the present invention is an electronic device provided with the exterior component described in each of the above means.

As the electronic equipment, there are an electronic watch, a mobile phone, a pager, an IC card, a calculator small electronic dictionary, a personal computer, a word processor, a telephone, a copy machine, and the like.

It is effective to apply the above surface material or surface layer to an exterior part of a product which is likely to come into contact with human skin, particularly to an exterior case of a wristwatch, a back cover, a watch band, and the like. Is preferred.

[0017]

Next, an embodiment according to the present invention will be described with reference to the accompanying drawings. In the present embodiment, the surface of the outer case of a wristwatch is coated with a coating liquid in which a powder of silk thread is mixed. Particle size of silk powder is 0.5
A material of about μm to 300 μm can be used, but as a material for paint or printing, about 1 μm to about several tens μm,
Preferably, it is desirable that the thickness be about 3 to 9 μm.
This silk yarn powder is mixed with a urethane resin, and a solvent and a curing agent are added to form a coating liquid. The amount of the silk powder in the urethane-based resin can be appropriately set, but is usually 5 to 25 wt%, preferably about 10 wt%.

The silk powder mixed with the above coating liquid can be formed, for example, by the following method. The cocoon or silk thread is immersed in an aqueous solution of calcium chloride and heated to concentrate and gel the solution. Next, the solution is once frozen, then returned to room temperature, and thereafter, moisture is removed and freeze-dried to obtain a silk powder. Also, after putting the cocoon or silk in an aqueous solution of calcium carbonate and stirring, the precipitated coagulated product is taken out, mixed with water to form a suspension, and hydrochloric acid is added to generate oxygen dioxide, and then water is removed. There is also a method of powdering. Furthermore, there is a method in which a silk thread is hardened by an acid or alkali treatment and then crushed to be powdered.

After the silk powder is prepared as described above, it may be subjected to various treatments in order to improve mechanical and chemical properties. For example, mechanical strength, alkali resistance,
In order to improve swelling resistance and abrasion resistance, formal treatment may be performed. This formal treatment is performed, for example, by immersing the silk powder in a treatment liquid obtained by adding acetic acid to an aqueous solution of hexamethylenetetramine, heating, and then taking out the silk powder and further performing a heat treatment, followed by washing with a sodium sulfate solution or the like. After washing with water, it is dehydrated and dried. In some cases, urethane treatment is performed to improve mechanical properties. In this urethanization treatment, for example, silk powder is immersed in a solution in which a heat-reactive water-soluble urethane resin is mixed with water, a urethanization catalyst is added to cause a reaction, and then filtration, washing, and drying are performed. In this urethane treatment, silk is reacted with isocyanates.

In the coating using the above coating liquid, the coating liquid is sprayed with a spray gun and then dried at a temperature of about 60 ° C. for about 20 to 30 minutes. In this embodiment and each of the following examples, the thickness of the coating film after drying is 30.
〜40 μm.

As the base material on which the above-mentioned coating film is formed, various resins and metals can be used. In the present embodiment, ABS resin, polycarbonate resin, polyacrylate resin, reinforced polyamide resin, stainless steel and the like are used. investigated. Among them, the metal material had some problem in adhesion, but when the substrate was a resin, the coating performance without any trouble including the adhesion was obtained. After forming the above-mentioned coating film to a thickness of 35 μm using the base material as an ABS resin, a plurality of samples left for 3 days were prepared, and the following test results were obtained.

Pencil hardness H (Mitsubishi Uni use, 1 kg load) Good adhesion (Perform a peeling test on cellophane tape for 1 mm square area) Good water resistance (Perform the above peeling test after immersion in water at a temperature of 40 ° C. for 240 hours) Good (After leaving for 120 hours at a temperature of 40 ° C. and a humidity of 90%, the above-mentioned peeling test is carried out) Heat resistance Good (After leaving for 120 hours at a temperature of 60 ° C., carrying out the above peeling test) Good benzene resistance (One drop of benzene) Good dripping alkali resistance Good (Mypet (trade name, manufactured by Kao Corporation) 5 vol% aqueous solution, then left for 120 hours at 40 ° C, 90% humidity) Good fingerprint resistance (Fingerprint attached) Leave at 60 ° C for 120 hours and observe the appearance) Good abrasion resistance (Press cotton cloth at a pressure of 1 kg / cm ^{2 with} a gakushin abrasion tester 5000 times) Next, a water absorption test and a water release test were performed on the coating film formed on the surface of the ABS resin. The comparison target is
Nothing attached to the surface of ABS resin (unpainted product: A)
And the same coating (Stron Ace No. 17 (manufactured by Cashew, trade name, product number) containing acrylic-isocyanate as a main component) having a thickness of about 10 to 20 μm on the surface of the ABS resin. (Conventionally coated product: B) after coating and drying.

In Embodiment C, when immersed in warm water at 40 ° C. for one hour, as shown in FIG. 2, it exhibits higher water absorption than the uncoated product A and the conventional coated product B. In this case, it can be seen that the ABS resin as the base material also has water absorption, but shows higher water absorption than these cases.

Next, the product immersed in warm water for 1 hour as described above was naturally dried in an environment of a temperature of 20 ° C. and a humidity of 40%, and as shown in FIG. In contrast, the present embodiment C shows extremely high water release.

As described above, the coating film containing the above-mentioned silk yarn powder has high water absorption and water release, and has good touch. Therefore, it has a good feel and is very suitable as a surface paint for an outer case such as a wristwatch or a band. In particular, as shown in the examples described below, when the coating film is formed on the back cover that is in constant contact with human skin, even in a high-temperature and high-humidity environment, sweat and the like stay between the skin and the back cover. As a result, the probability of occurrence of skin inflammation was greatly reduced due to the significantly improved sweat effusibility. Also,
In terms of sensation, discomfort such as stickiness was wiped out, and extremely good wearability was obtained. Further, the product formed with the above-mentioned coating film has a high-class appearance in addition to the felt-like texture not found in the conventional coating and the characteristic of light scattering unique to silk thread powder. This is thought to be due to the fine irregularities on the surface due to the mixing of the silk powder and the optical characteristics of the silk powder.

The coating with the coating liquid containing the above-mentioned silk yarn powder is performed by:
As described above, it can be performed directly on the surface of the base material of the outer case. However, in order to enhance adhesion and corrosion resistance, as shown in FIG. And
It is preferable to form the coating film 30 on the surface of the underlayer 20. Here, the coating film 30 is obtained by dispersing fine silk particles 32 in the urethane resin 31 in the same manner as described above.

The base layer 20 has various types depending on the material of the base material 10 of the outer case. In general, when the base material 10 is made of a synthetic resin, the coating film 30 may be directly formed by using a coating liquid containing silk powder as described above. If the synthetic resin layer is formed as an undercoat after the base layer 20 is formed on the metal surface formed by the above method, the adhesion and the corrosion resistance can be improved.

The coating liquid for forming the underlayer 20 is a two-liquid mixing type containing an acrylic resin, acryl-isocyanate, acryl-urethane or acryl-silicone as a main component and adding an appropriate solvent and a curing agent. Coating liquid,
There is a one-liquid baking type coating liquid containing an epoxy resin as a main component. Here, the substrate surface is made of polycarbonate resin or ABS
In the case of a resin, Stron # 100 (manufactured by Cashew Co., Ltd., trademark, product number) containing acryl-isocyanate as a main component is preferable, and the surface of the base material is Lenny (polyamide MXD6 resin, manufactured by Mitsubishi Engineering-Plastics Corporation). Trademark) or U polymer (polyacrylate resin, made by Unitika, trademark).
Stron Ace No. containing isocyanate as a main component 1
7 (manufactured by Cashew Co., Ltd., product number). In the case of stainless steel such as SUS303B or SUS304, EP # 1100 (epoxy resin, product number manufactured by Cashew Co., Ltd.) is preferable.

When using EP # 1100 as a coating material for the base layer 20 and stainless steel as a base material, for example, a coating solution diluted with a solvent is sprayed with a spray gun and sprayed at 150 ° C. for 20 minutes. Is dried to form an underlayer having a thickness of about 10 to 20 μm.

As described above, an outer case of a wristwatch formed of each material of ABS resin, Reny (trademark), U polymer (trademark) and polycarbonate, and a back cover formed of stainless steel (corresponding to the above outer case) ), The underlayer 20 and the coating film 30 were respectively applied by the spraying and drying steps as described above. The sample Nos. 1 to 10 (Sample No. 11 is the same as the above-mentioned conventional coated product B), the material name of the base material, the surface color of the sample after forming the coating film, the coating liquid name of the base layer, Drying conditions,
Table 1 shows the finish drying conditions of the coating film.

[0031]

[Table 1]

Note that all of the samples of sample numbers 1 to 10 which are examples according to the present invention have higher hygroscopicity and hygroscopicity than the conventional one, similarly to the above embodiment.
It had a good touch. With respect to these 11 samples in total, a performance test as an outer case and a back cover of a wristwatch was performed. Table 2 shows the results.

[0033]

[Table 2]

Here, a circle indicates that the performance is almost the same as that of the conventional painted product, and a triangle indicates that the performance is lower than that of the conventional painted product, but is at a practical level. In addition, crosses indicate that the performance is worse than that of the conventional painted product and the product is not practical, but there is no corresponding product in Table 2. Double circles are shown only for items that show higher performance than conventional coated products.

With respect to the adhesion shown in Table 2, a bending test was conducted by bending the base material at 90 degrees to check whether or not there was any abnormality in the coating film. Was evaluated based on the results of two tests of a peel test for confirming whether or not peeling occurred. Practical only when there was no abnormality in both tests. Only the sample of sample No. 7 (exterior case made of polycarbonate) had some coating film floating, but it was practically no problem.

The abrasion resistance was evaluated by contacting the chamois with the surface, applying a load of 400 g · f, and performing a 30,000 reciprocating operation to evaluate the degree of abrasion. The abrasion resistance of each of the examples was lower than that of the conventional painted product. However, as a result of setting the state in which the substrate was not exposed by operation of 15,000 times or more to a practical level, all samples were within the practical level. Fit in.

The impact resistance was evaluated by dropping freely from 1.0 m and 1.5 m on the floor in six postures, up, down, left, right, front and rear, and performing a drop test to check for abnormalities in the appearance.
No abnormalities were observed for all samples when dropped from any height.

Regarding heat resistance, a high-temperature storage test for confirming the presence or absence of abnormalities after leaving for 2 hours and 5 hours in an atmosphere of 100 ° C., and the presence or absence of abnormalities when left at 60 ° C. for 16 hours and -10 ° C. And a thermal cycle test in which the temperature was repeatedly changed from 20 ° C. to 60 ° C. and from 60 ° C. to −20 ° C. for evaluation. No abnormalities were found in any of the tests in all samples.

With respect to water resistance, the test piece was immersed in warm water of 40 ° C., kept for 5 days, 10 days, and 15 days to check for abnormalities. Days, 7 days, and 10 days, it was evaluated by a high temperature water immersion test for confirming the presence or absence of abnormality. In the low-temperature water immersion test, no abnormality was found for all the samples even after immersion for up to 15 days. In the high-temperature water immersion test, some of the samples of sample No. 7 (polycarbonate outer case) had floating coating films. Further, with respect to the samples of Sample Nos. 3 and 4 (Lenny's outer case), the coating film floated on some of the samples after immersion for 10 days.

Regarding the moisture resistance, a temperature of 40 ° C. and a humidity of 90
% For 200 hours and checked for abnormalities. No abnormalities were found for all samples.

Regarding the corrosion resistance, it was left for 24 hours, 48 hours, and 72 hours in a state of being half-immersed in artificial sweat or saline (contact with gauze soaked in artificial sweat or saline) to determine whether there was any abnormality. confirmed. About sample No. 3 (black exterior case using Lenny base material) 48
After the lapse of time, some of the coatings floated.

Regarding chemical resistance, the tip of a cotton swab was immersed in each of ethanol, acetone, petroleum (kerosene) and dish detergent, and the surface was rubbed five times with the tip of a cotton swab. No abnormalities were observed for all samples.

The stain adhesion was soaked in coffee and soy sauce for 1 minute, washed with water, and checked for abnormalities. After the finger was pressed, wiping was performed to check for abnormalities. No abnormalities were observed for all samples.

Regarding the abrasion resistance, pencil hardness 2B, H
The surface was rubbed with a mechanical pencil having a core of B, 2H, or 4H at a pressure of 100 g · f, and the surface abnormality was observed. No abnormalities were observed for all samples.

Regarding the moisture absorption / desorption property, after drying for 2 hours in an environment of a temperature of 80 ° C., the sample was left for 1 hour in a high temperature and high humidity environment of a temperature of 40 ° C. and a humidity of 90%, and a change in weight was measured. A moisture absorption / desorption test for measuring a weight change after leaving for 1 hour and after leaving for 2 hours in an environment of a temperature of 20 ° C. and a humidity of 40%;
After drying for 2 hours in an environment of a temperature of 80 ° C, a temperature of 40 ° C
Immersed in warm water for 1 hour and then measured the weight change, and then performed a water absorption and discharge test to measure the weight change after 1 hour and 2 hours in an environment of a temperature of 20 ° C. and a humidity of 40%. Was evaluated. In addition, about sample number 8-10, since it was a stainless steel back cover, evaluation was made on the basis of 0 as moisture absorption, moisture release, water absorption, and water release.
All of the examples of the present application show high moisture absorption / desorption properties and high water absorption / desorption properties, and have a good touch.

With respect to the tactile sensation, the quality of the touch was inspected with reference to a conventionally painted product (sample No. 11). All of the samples of sample numbers 1 to 10 have extremely better touches than those of the conventional painted products, and in particular, for the samples of sample numbers 8 to 10 in which the coating film is formed on the surface of the back cover,
The wrist watch had a good wearing feeling and had no sticking feeling even when sweated.

In the back cover having the coating film 30 formed on the surface of the stainless steel, the thickness of the undercoat layer 20 and the coating film 30 is larger than the thickness of the conventional coating film. However, the markings and the engraved characters can be drawn by removing the coating film 30 by laser irradiation. Marking and engraving of characters can be easily performed because the coating film on the irradiated portion is decomposed and carbonized by laser irradiation. Also, by heating the coating,
The edge of the coating film facing the removed portion is generally slightly hardened, and there is no particular problem such as peeling or breakage of the coating film from the portion.

As described above, in each of the above-described embodiments, the surface structure of a watch exterior component having practically sufficient characteristics is formed. A watch exterior part that can be worn comfortably even in a high-humidity environment, and is inherently soft and soft to the touch with silk powder, has no danger of metal allergies, and is unlikely to induce rough skin. Can be provided.

The surface of the coating film of the present embodiment has a very high-quality appearance with a very high-grade appearance due to the characteristics of the silk powder, and the surface of the coating film has a natural uneven surface and a natural unevenness depending on the particle size of the silk powder and the outer surface state of the powder itself. Because light scattering characteristics can be obtained,
It has a felt-like appearance as a whole, and is often found in synthetic resins.
The so-called plain impression can be completely wiped off.

In each of the above embodiments and examples, the coating film as the surface layer is formed on the outer case or the back cover. However, the timepiece outer parts are limited to those described above. Without being limited to this, the present invention can be applied to a watch band or a band stopper. Further, the present invention is not limited to exterior parts for watches, but includes portable electronic devices such as mobile phones, pagers, and personal digital assistants, various accessories such as bracelets and rings, and various OA such as keyboards and mice.
It can be applied to the surface of exterior parts of equipment. Especially,
It is effective to apply it to the outer surface of an article that often touches human skin.

In the above description, the coating film, which is the surface layer in which the silk powder is mixed, is formed by painting.
Screen printing using silk-powder-mixed ink and other molding methods such as injection molding using resin mixed with silk-powder, etc. It may be.

Table 2 shows the characteristics of a wristwatch band formed by injection molding as Sample No. 12. This sample is a urethane-based resin containing a polyurethane elastomer as a main component (for example, “Resamine P4590”).
(Manufactured by Dainichi Seika Kogyo Co., Ltd., trademark, product number) "), 10% by weight of the same silk powder as above is kneaded, and using a predetermined mold, a molding temperature of about 210 ° C, a molding pressure of about 50 kg / cm ² , and injection. The injection molding was performed for a dwell time of 30 to 60 seconds.

In the example of sample No. 12, the same tactile sensation and appearance as in the other examples described above were obtained. In addition, there was almost no problem with respect to other characteristics besides adhesion, as described above. Further, the flexibility, elasticity and other mechanical properties and durability of the wristwatch band were not affected.

[0054]

As described above, according to the present invention, the following effects can be obtained.

According to the first aspect of the present invention, the exterior parts having a surface material made of a synthetic resin mixed with a silk yarn powder have a good touch and have improved water absorbing and releasing properties or moisture absorbing and releasing properties as compared with conventional materials. Therefore, it is possible to form a product that is less likely to cause discomfort or skin irritation. Also, by containing the silk powder, the texture can be visually enhanced by the unevenness of the surface due to the particle size of the silk powder and the light scattering property of the silk powder, resulting in a high-quality appearance. Can be obtained.

According to the second aspect, by applying the surface layer made of a synthetic resin mixed with the powder of silk thread, it is possible to impart the characteristics of the surface material to the underlayer of an arbitrary material. High-quality products can be provided at low cost.

According to the third aspect, the adhesion between the base material and the surface layer can be improved by forming the base layer containing the synthetic resin. In particular, when a metal material is used as the base material, the adhesion can be greatly improved.

According to the fourth aspect, characters and figures for various displays can be represented by partially removing the surface layer. The appearance of the surface layer containing the silk powder and the high texture can be improved. Characters and figures with good visibility can be formed by contrast with the removed base.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view showing a surface structure of an embodiment according to the present invention.

FIG. 2 is a graph showing the water absorption of a resin product having a coating film according to the present invention formed thereon.

FIG. 3 is a graph showing the water release of a resin product having a coating film according to the present invention formed thereon.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Substrate 20 Underlayer 30 Coating film 31 Urethane resin 32 Silk particle

Claims (5)

[Claims] 1. An exterior component having a surface material obtained by mixing silk thread powder in a synthetic resin. 2. The exterior component according to claim 1, further comprising a surface layer made of the surface material on at least a partial surface of the base material. 3. The exterior component according to claim 2, wherein an underlayer containing a synthetic resin is formed between the surface of the base material and the surface layer. 4. The exterior component according to claim 2, wherein the surface layer is partially removed to display characters and graphics on the surface. 5. An electronic device comprising the exterior component according to claim 1.