JPH09118847A - Coating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coating material with silk powder dispersed homogeneously therein, good in skin touch feeling, and capable of giving smooth coating film, by pulverizing a silk material e.g. in powdery form with a solvent as medium and by using the ground silk powder suspending in the solvent. SOLUTION: A silk material in powdery, granular or short fiber form is ulverized into silk powder finer than 6μm in particle diameter by wet grinding using a solvent such as dimethylformamide or toluene as medium, and the resultant groud silk powder suspending in the solvent is used as a part of coating material components. For the wet grinding, a wet ball mill, for example, can be used. In order to conduct the wet grinding more efficiently, it is preferable that the silk material be preliminarily ground and then subjected to air classification based on true specific gravity or sieve classification based on bulkiness so that the silk powder finer than 50μm in particle diameter account for >=90wt.% of the whole silk powder. For the preliminary grinding, a dry grinder such as a turbo mill is normally used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silk cloth-like resin coating material containing crushed silk powder.

[0002]

2. Description of the Related Art Naturally, natural silk fibers are supple, soft to the touch, and have an appropriate degree of hygroscopicity, and are excellent in gloss, texture, strength and elongation, and impact resistance. It has been used in various fields as a textile product or yarn.

The characteristic of such a silk fiber is that sericin contained in the silk fiber is dissolved and removed to give glycine,
It is derived from the fact that it is composed of a fibroin molecule in which amino acid residues such as alanine, serine, and tyrosine are linearly linked, and has been an important material for clothes since ancient times.

Since this type of natural silk fiber is excellent in dyeability, it is not necessary to boil when dyeing by milling dyeing, and the dye is exhausted to silk at 80 to 90 ° C., causing damage during dyeing. Since it has a small number of dyes, it can be dyed in various color tones, and it has been used for an extremely thin woven or knitted fabric with a particularly bright color.

[0005]

However, the conventional silk material has rarely been used for other purposes besides being used as a thread or a woven or knitted material as a silk fiber.

The silk fiber made of this yarn or woven or knitted fabric is vulnerable to abrasion and has the disadvantage that it is easily discolored by the sun's rays, and its shape-retaining power when wet with water is also difficult.

Further, when using a silk material as a thread or a fiber, it is necessary to take out high-quality continuous silk fibroin, and it is impossible to effectively use all of the prepared cocoon fibers.

According to the present invention, such a naturally existing silk material is pulverized into a fine powder, and the fine powder is mixed into a paint to bring the characteristics close to those of the natural silk material to the paint film. This is intended to supplement the poor abrasion resistance, which has been regarded as a drawback of natural silk fibers, improve water resistance and moisture resistance, and eliminate the disadvantage of fading. Furthermore, by making the coating film other than the fiber silk-like, the new use development of the silk material was tried.

However, in order to pulverize such a silk material to be contained in the coating film to form a coating film having silk-like surface characteristics, it is necessary to pulverize the silk material into fine powder. When the particle size of the crushed silk powder is large, the surface of the coating film obtained by mixing and mixing the crushed silk powder becomes rough and there is a problem that a rough feeling is generated.

Therefore, it has been attempted to pulverize the silk material by various methods to form finely powdered silk powder, and mainly to pulverize the silk material by pulverization by mechanical shearing and grinding by a dry ball mill. .

Since the silk fibers are not crushed into particles by the shear crushing and the crushing and crushing under the dry condition and are made into a fluffy fiber mass having fine cilia, they are formed by the shear crushing or the crushing and crushing. There is a disadvantage that the silk powders are entangled in a cotton shape and aggregate.

Since such cotton-like agglomeration also occurs in the process of crushing silk powder, the crushing of the silk material is not uniform, and a crushed product in the form of a large fiber lump and an extremely fine hairy fiber powder are crushed. However, there is a drawback that silk powder having a uniform particle size cannot be obtained. Further, there is a drawback that it takes a long crushing time to make the silk material fine.

The cilia generated in the silk powder due to such crushing are
The more crushed the silk material is, the more it tends to occur, and the finer the crushed silk material, the more lithe-like cilia tend to occur in the crushed silk powder. .

As a result, when an attempt is made to obtain ultrafine silk powder by shearing or grinding the silk material, the crushed and formed silk powders are intertwined with each other in a cotton-like shape, and these particles are contained in the coating liquid of the paint. When the pulverized silk powder of No. 1 was mixed and blended, there was a defect that the pulverized silk powder mixed and blended in the coating liquid was not uniformly dispersed.

Further, the crushed silk powder is entwined in a cotton shape,
The phenomenon of larger lumps occurs not only in the case where these silk powders are mixed and mixed with a coating material, but also in the molding process of the silk powders and the storage process of the silk powders. From this fact, there is a drawback in that the crushed silk powder is not uniformly dispersed in the coating material only by preventing the flocculation of the blended silk powder in the mixing and blending with the coating material.

Further, in the shearing or grinding by the above-mentioned method, a large amount of heat due to friction or impact is generated during grinding,
The heat associated with this crushing may cause the fibroin of the crushed silk powder to deteriorate or discolor, and in particular, the crushed silk powder is fused or bonded to the inner wall surface of the grinding device or the surface of the grinding ball. There was an inconvenience.

Therefore, a powder or granular or short fiber silk material is mixed and mixed with a liquid polymer or a resin solution diluted with various solvents, and this powder, particle or short fiber silk material is mixed and mixed with the liquid. An attempt was made to throw the polymer or resin solution into a wet pulverizer and pulverize it.

In such a wet pulverization method, the flow resistance of the liquid polymer or resin solution is large, stirring and pulverization cannot be carried out smoothly, and the mixed and blended silk materials are not uniformly dispersed in the polymer. It was Especially when continuing stirring of this type of liquid polymer or resin solution,
The viscosity of these polymers or resin solutions tends to increase with time, and smooth pulverization by a wet pulverizer is often difficult. Then, when the pulverizing temperature in the pulverizer was increased with the stirring of the pulverizer, such inconvenience in pulverization occurred more remarkably.

According to the present invention, such silk powder can be easily and surely crushed, the crushed silk powder is prevented from being entangled with each other in a cotton-like shape and aggregated, and the crushed silk powder is crushed. The heat generation is eliminated, the quality does not change, and the particle size is uniform. 6 micron (If the particle is elongated, it means the particle size measured on the shorter diameter side, and will be referred to as μm hereinafter). We provide finer silk powder than
An object of the present invention is to provide a coating material suitable for forming a thin coating film by using silk powder having a finer particle size than m and having a uniform particle size.

[0020]

In order to achieve the above object, the coating material according to the present invention prepares a silk material in the form of powder, granules or short fibers, and uses this silk material for dimethylformamide, toluene, etc. (6) Silk powder finer than 6 μm, which was wet pulverized mainly using an organic solvent, was blended with a solvent together with a solvent as a medium containing the pulverized silk powder.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION A coating material according to a typical embodiment of the present invention will be described below.

First, the fibroin fiber is usually cut into an appropriate size while the cocoon is boiled in hot water to soften the sericin. Alternatively, the cocoon itself is pulverized in a state where the cocoon is heated and dried to remove the pupa therein, thereby obtaining appropriate powder, granules or short fibers. Furthermore, after sericin is dissolved and removed by scouring with a soap solution, fibroin fibers are pulverized to prepare a silk material having an appropriate size.

This silk material is dried to a water content of about 5% by weight and added to a solvent as a grinding medium.

With respect to the drying of this silk material, the higher the degree of drying, the easier the following pulverization becomes, and when it is blended with a resin or the like, it has the characteristic that it is smoothly and uniformly dispersed in these resin solutions. In addition, it has a feature that pinholes and the like due to generated steam are not generated in the formed coating film.

[0025] The silk material is dimethylformamide,
It is put into a wet crusher such as a wet ball mill together with a solvent such as toluene, and crushed in a state where the silk materials are not in contact with each other by this solvent. The pulverization by a pulverizer such as a wet ball mill is continued until the particle size of the pulverized silk powder becomes finer than 6 μm. In order to make the particle size of the silk powder crushed by this wet crusher uniform and to crush the crushed silk powder to the target particle size in a short time, classify the silk material to be put into the wet crusher. 50 pieces of powder or granules or short fiber silk powder
It is advisable to classify fine silk powder belonging to a finer range than μm with a sieve or an air flow classifier so as to be 90% by weight or more of the total amount of silk powder.

The solvent used in the above is a typical example of an organic solvent, and a solvent suitable for a coating material containing this crushed silk powder is used. And this solvent requires that the silk powder whose main component is protein is insoluble,
Typically, dimethylformamide, toluene, methyl ethyl ketone, etc. are used, as well as methanol, isopropyl alcohol, n-butanol, benzyl alcohol, ethyl acetate, butyl acetate, acetone, methyl isobutyl ketone, cyclohexane, tetrahydrofuran, dioxane, xylol, 2. Nitropropane, ethane dichloride,
Trichloroethylene, perchlorethylene, methyl cellosolve, ethyl cellosolve and the like are used.

Since such a solvent is one in which the silk material is insoluble, even if silk powder is mixed into the solvent, the silk powder does not swell or melt, and the water content in the silk powder does not occur. The silk powder is not absorbed by the solvent and hardens, and the silk material has the characteristic that the same state as when mixed with the solvent is promised in any of the crushing processes of the silk material.

Granules, powders or short fiber silk materials are put into a pulverizer using such a solvent as a wet medium for pulverization treatment. This crushing device may be any device as long as it is suitable for wet crushing powder, granules or short fibrous substances,
Of the various ball mills, those suitable for wet grinding are mainly used.

The pulverization by the pulverizer is continued until the grain size of the introduced particles or powder or the short fiber silk powder becomes finer than 6 μm. Therefore, crushing conditions such as crushing time by the crusher, the capacity of the crusher, the diameter and input amount of the ball used in the crusher, the type and input amount of the silk material to be input to the crusher, The type and amount of the solvent used, the stirring speed of the crusher, and various conditions such as the crushing temperature are changed as needed.However, crushing of the silk powder as long as the solvent temperature during crushing is not increased as much as possible Necessary in order not to cause deterioration of the powder quality.

In order to make the crushing by the above-mentioned crusher more effective, the crushed silk material is subjected to preliminary crushing and the particle size thereof is determined by air classification by true specific gravity or sieve classification by bulk. Is prepared in a range finer than about 50 μm, and is usually prepared by pulverization with a dry pulverizer such as a turbo mill.

Thus, in wet pulverization using a solvent in which the silk material is insoluble as a pulverizing medium, the silk material being pulverized does not dissolve, swell, or harden due to the solvent, Moreover, since the silk material is crushed in a state of being shielded from the outside air, it has the feature that there is no moisture absorption / release phenomenon of the silk material during crushing. As a result, in the process of crushing the silk material, the water content of the silk material is increased and the silk materials are not fused to each other, or become soft and not suitable for grinding or impact crushing. Has the characteristic that it has no cilia-like split ends and is crushed into particles. In addition, the quality of the silk material is not deteriorated until the water content of the silk material is lowered and the hydrophilicity is hindered in the process of crushing the silk material. The silk powder crushed in this way is used for molding a paint together with the solvent used for crushing.

Example 1 Silk fibroin fed from a cocoon was dried to a water content of 5% by weight, ground in this state with a turbo mill, and then classified to prepare the following silk material. The water content of this silk material was 5% by weight.
It was possible to use a silk material having a water content in the range of 10% by weight.

The above-mentioned silk powder was added to dimethylformamide 100
It was charged into the crusher at a ratio of 25 parts by weight with respect to parts by weight. Alumina-based balls with a diameter of 3 mm were used for this crusher at a volume ratio of 70
%, A solvent containing silk powder was added at a volume ratio of 25%, and the mixture was stirred for 90 minutes, whereby a silk powder having the following particle size could be obtained.

Example 2 The grain or powder or short fiber silk material pulverized by the above-mentioned terbomill was pulverized by a pulverizer filled with a zirconia-based ball having a diameter of 3 mm under the following conditions: 120 minutes- The particle size of the crushed silk powder became 6 μm or less in 180 minutes. Formulation liquid 50 in which 40 parts by weight of silk powder is mixed with 100 parts by weight of toluene
% (Volume ratio) 3mm diameter zirconia-based ball 50% (volume ratio)

The amount of silk powder blended in the solvent depends on the nature of the solvent, especially the viscosity of the solvent, and dimethylformamide has a higher viscosity than toluene. It is necessary to make the compounding amount of the compound less than that of toluene. Further, when the amount of silk material and solvent to be put into the crusher is increased, it takes a long crushing time to obtain the above-mentioned 6 μm silk powder corresponding to the increased amount. In addition, when the diameter of the ball put into the crusher was increased, the crushing time was shortened when the diameter was increased. However, silk powder having a large diameter and silk powder having cilia tended to remain. With the use of balls having a larger diameter, silk powder having a uniform particle size could not be obtained.

When the silk material was pulverized by a wet ball mill using dimethylformamide without adjusting the particle size of the powder or the particle or the short fiber silk material in advance as in Example 1, the particles were It was necessary to prolong the crushing time by about 30 minutes compared with the use of silk materials of uniform diameter. Even with this method, silk powder finer than 6 μm could be produced.

The silk powder pulverized by the above method was found to have the following features in the pulverization process and the produced silk powder. First, the granular or powdery or short-fibrous silk material put into the pulverizer is incorporated into mainly an organic solvent where the silk material is insoluble, and the silk materials are mutually exchanged by this solvent. Since the material is crushed in the wrapped state, the silk materials are not fused to each other, are crushed without generating hairy broken cilia, and are not fused to the ball or the surface of the crusher. In particular, since the heat generated by grinding or impact of the ball is dispersed by the solvent and is not directly transmitted to the silk material, there is no danger that the heat will alter the silk material or cause the fusion of the silk powder to each other. In addition, since the silk powder is crushed in a state of being covered with a solvent, the silk material is swelled with moisture in the crushing process of the silk powder, or the hardening phenomenon caused by evaporation and heating of water in the crushing process. Does not occur, and the silk material mixed with the solvent contains the water content when mixed in the solvent, and does not impair the swelling function peculiar to the silk material or the properties such as hydrophilicity and peculiar strength and elongation.
Also, in the process of crushing the silk material, the silk material becomes humid, and the crushing becomes difficult due to the strong elongation accompanying heating. Can be easily produced.

Further, the silk powder obtained by crushing has a particle size smaller than 6 μm in the case of the above-mentioned crushing method, and is fused or entangled with each other. In addition, it has the feature that it is uniformly dispersed in the solvent used for crushing, and that the silk powder is generally dispersed in the solvent like suspension.

Each of the silk powders in these solvents floats in the solvent in an independent state and is shielded from the outside air. This facilitates the management of the crushed silk powder, and the crushed silk powder does not become wet, harden, or fuse with each other after the crushing.

Prior to the crushing of the silk material, the silk material is heated with steam to sufficiently remove sericin, and the swelling heat is applied to the fibroin to measure the contraction of the fibroin tissue. The fibroin tissue was fragile by drying the swelling-heated fibroin so that the water content was less than 3% by weight. By this method, fibroin was coarsely pulverized to obtain fibroin powder, particles or short fibers having a diameter size smaller than 50 μm and pulverized by a wet pulverization method using the solvent as a medium.

The fibroin powder, particles or short fibers crushed by such a method have no cilia, and when these were crushed using a solvent as a medium, the crushed silk powder became substantially "grainy". In addition, when fibroin was pulverized using a solvent as a medium by such a method, it was revealed that the pulverization was extremely easy and smooth, and the pulverization efficiency was dramatically improved. Further, when fibroin was pulverized by such a method, the grain size of the pulverized silk powder was found to be in a range finer than 6 μm.

The silk powder thus finely pulverized to a size of less than 6 μm is added to the paint together with the solution used for pulverizing the silk powder. The blending method and blending amount are appropriately determined according to the characteristics of the coating material.

The paint containing a solvent containing silk powder is a paint suitable for forming a paint film formed by mixing the solvent, that is, a paint used for forming a formed paint film. The silk powder is ground with a suitable solvent. Such a coating is a part of a film forming auxiliary element or a film forming element and a pigment suitable for various applications,
A solvent having the above-mentioned silk powder as an improving and extending factor is added and blended, and is produced by general stirring and mixing.

The paint film thus produced is
Since the particle size of the silk powder contained in the material belongs to the finer range than 6 μm, the thickness of the coating film is 0.02 to 0.002 m.
Even within the range of m, the mixed silk powder did not stand up or stick out from the surface of the coating film, and the coating film was smooth and had a good feel to the touch. Further, by eluting a part of the composition of the silk powder contained in the resin molded product of this coating film, a large number of pores finer than several microns can be provided on the surface of this coating film. In the case of a coating film, the coating film may be 0.002 μm or less, and the surface of this coating film was also smooth.

By providing pores having a size smaller than 2 to 3 μm on the surface of the coating film, the coating film is provided with air permeability, and in particular, the air permeability provided to this coating film is 0.0004 μm. Since it has a feature of allowing water vapor having the particle diameters of the front and rear to pass through and preventing water droplets from passing, it imparts water resistance and moisture permeability to the coating film. Therefore, 0.02 to 0 containing the above-mentioned silk powder on the surface of various fabrics, leather or wooden products.
When a coating film with a thickness of 002 mm is formed and a part of the silk powder component in this coating film is eluted, the silk powder in this coating film and the eluted holes cause these cloths, leathers, wood products, etc. The water resistance and moisture permeability peculiar to this are brought about. By the way, the diameter of a raindrop is usually 2000 μm, and even in a fine rainstorm, it is 100 μm, and it does not pass through the fine pores provided in this coating film. Also, raindrops attached to the surface of the coating film will not seep through the fine pores because of the surface tension.

Example 3 A polyurethane resin coating solution was prepared by using a solvent containing silk powder in a range finer than 6 μm, and a film-like coating film was prepared by using this coating solution. Transferred to. Silk powder finer than 6 μm 15 parts by weight Toluene 70 parts by weight Polyurethane resin solid content 30 parts by weight This resin solution is applied on the surface of a release paper by a doctor knife coating method to a thickness of 0.008 mm and dried. After that, it was peeled off from the release paper to form a coating film having a thickness of 0.008 mm. Further, the release paper was peeled off while adhering to the surface of the non-woven fabric having a thickness of 1.5 mm without peeling off the coating film to form a coating film skin layer on the non-woven fabric surface. And this non-woven fabric 60
When soaked in warm water at ℃ and washed with hot water for 15 minutes, a part of the silk powder contained in the coating film was eluted and the surface of the coating film had a soft feel.

A coating film was prepared by increasing the amount of the above-mentioned silk powder by 3 parts by weight to 30 parts by weight by 5 parts by weight. As a result, the coating film produced had a good gloss and had sufficient abrasion resistance, but on the other hand, there was a sticky feeling upon contact. In addition, the coating surface containing 35 parts by weight of silk powder has smooth contact resistance and good gloss and texture peculiar to silk, but it has poor abrasion resistance and a strong force acts on the coating surface. In addition, wrinkles were generated on the surface of the coating film, and in the product obtained by laminating the coating film, the surface of the base material was partly exposed with the surface being distorted. Therefore, the optimal amount of the silk powder is 3 to 30 parts by weight. However, the blending amount of the silk powder can be further changed depending on the type of molding resin of the coating film, the blending amount of the solvent used, the molding conditions, and the like.

Example 4 Toluene 70 parts by weight Silk powder finer than 6 μm 15 parts by weight Polyvinyl chloride resin 30 parts by weight The PVC coating film produced in this Example 4 has gloss and a texture unique to silk, and is flexible. The film had a good touch and a significantly improved stretchability as compared with the usual PVC coating film, and also provided a moisture absorption function. Also, a paint was produced with the above-mentioned blending amount.

Example 5 Toluene 70 parts by weight Silk powder finer than 6 μm 15 parts by weight Acrylic resin 30 parts by weight A coating film was formed as a paint at the compounding ratio of this Example 5, and the same coating film prepared in Example 4 was obtained. In comparison, the coating film was excellent in abrasion resistance and had a moisture absorption function.

Example 6 Toluene 70 parts by weight Silk powder finer than 6 μm 15 parts by weight Polyvinyl chloride resin 15 parts by weight Acrylic resin 15 parts by weight A coating formed by using a paint containing a resin solution having the compounding ratio of Example 6 The film had good hygroscopicity and contact resistance and had an appropriate feel to the touch.

Example 7 Silk powder was crushed in toluene. Toluene having the crushed silk powder was blended with polyester of a two-component reaction type urethane paint, and then isocyanate was added and blended to obtain a 0.002 mm film thickness with a spray gun. A coating film was obtained. This coating film was excellent in matting effect, and the texture when touched by hand was good without stickiness. In this example, the amount of silk powder in the two-component reactive urethane resin coating material was set in the range of 10 to 40% by weight based on the total weight of polyester and silk powder.

Example 8 Liquid polyurethane resin liquid (yellowing-free one-component polyurethane,
Nonvolatile content 30%) using a mixture of methyl ethyl ketone
Adjust this to 20-50 poise (25 ℃), and use this urethane resin 100
50 parts by weight of silk powder are mixed with toluene in 100 parts by weight,
The mixture was stirred and mixed so as to obtain poise (25 ° C). When this mixture was sprayed onto a PVC plate with a spray gun and dried at 100 ° C. for 1 minute, a coating film having good hygroscopicity and high matting effect was obtained.

Example 9 A film having a thickness of 0.006 mm obtained by coating a release liquid with a mixed solution obtained by mixing a solvent containing 40 parts by weight of silk powder in 100 parts by weight of a urethane resin and drying it. The film-like coating was transferred to a textile substrate and laminated. The surface of the woven fabric thus produced was not sticky, had a good feel, and had a feeling unique to silk.

Example 10 A one-pack type urethane resin containing silk powder (a mixture containing 30% by weight of non-volatile content in a solvent containing methyl ethyl ketone containing silk powder) was coated on a release paper with a comma roll, dried and further coated. A two-component urethane resin containing silk powder (50% by weight non-volatile mixture of silk powder-containing methyl ethyl ketone as a solvent) is applied on the layer and dried to form a laminated film. The laminate was adhered to the surface of the non-woven fabric by peeling it off. The non-woven fabric surface having the surface of the laminated film-like coating film did not have a sticky feeling, and the adhesive strength was the same as that of the laminating adhesive containing no silk powder.

[0055]

According to the present invention, since the silk powder is crushed in the state of being separated by the solvent, the silk powders do not directly touch each other and are fused with each other. Does not cause hairy cilia.

From this fact, the silk material was easily crushed, and the crushed powder was made granular.

Further, when crushing the silk powder, heat is not generated due to grinding or impact crushing, and there is no inconvenience of fusion of silk powders or deterioration of quality due to heat change.

Furthermore, since the silk is crushed while being covered with the solvent, the silk powder is not dried or swelled during the crushing process. From this, there is no inconvenience that the hydrophilicity is not hindered by the drying of the silk powder, and the silk powder is viscous with the swelling and the pulverization is hindered. From these facts, it is possible to make sure that the silk powder belonging to the finer range than 6 μm is
Moreover, we were able to produce it efficiently in a short time.

Furthermore, since the finely pulverized silk powder is dispersed in a solvent in a suspended state, the silk powder is not entangled in a cotton shape, and the blending is smooth and easy. It has the feature that silk powder is uniformly dispersed in these paints. Therefore, when a coating film is formed using a paint containing silk powder belonging to a finer range than 6 μm above, this coating film is formed with the silk powder uniformly dispersed in this coating film. It From this fact, this coating film has the characteristic of absorbing and releasing moisture peculiar to silk, providing gloss and feeling, moderate contact resistance, and strong elongation property and preventing electrostatic charging.

The particle size of the silk powder contained in this coating film is 6 μm.
Since it is finer than m, it was possible to form this coating thinly. In particular, a coating film with a thickness of 0.002 mm was made, and the mixed silk powder did not rise or stick out from the surface of the formed coating film, and it had a good feel and a smooth surface like a silk material. Was done.

Further, since the silk powder is uniformly exposed on the surface of the coating film to be formed, the surface of the coating film is effectively adsorbed and a good feeling of touch is provided.

Furthermore, when a part of the silk material is eluted from the surface of the coating film to be formed, the surface of the coating film will be provided with innumerable microscopic holes of a few microns, and thus the coating film to be formed. It has the characteristic that it has a moisture absorption / release function peculiar to the surface, especially a water vapor transmission function.

When the surface of the coating film formed above is subjected to sanding treatment, the silk powder contained in the coating film has a moisture absorption function, a water vapor permeation resistance function, and a good feel and silky feel. The texture of is further promoted.

The coating material using the silk powder according to the present invention is used for various clothing, furniture, personal belongings such as bags, interior materials for automobiles, etc. as a silk-like surface material because of its characteristic content above. It is used in various electronic devices and keyboards for these operators by taking advantage of its static-free characteristics. Further, the paint containing silk powder on the surface can be created or used by the same method or method as the method of forming a coating film that does not contain silk powder, and it can be used for all products in daily life, especially It can be used as a means such as a surface decorative material for clothing.

Claims (1)

[Claims] 1. A silk material in the form of powder, granules or short fibers is pulverized by wet pulverization using a solvent such as dimethylformamide or toluene as a medium, and the pulverized silk powder has a particle size finer than 6 microns. In addition, the pulverized silk powder contained in this solvent is used as a part of the coating composition.