JPH09118756A - Resin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a silk-textured resin film having good skin touch by using a resin film containing a silk material having a specified particle diameter and prepared by wet-grinding silk in the presence of a solvent as the grinding medium. SOLUTION: This resin film is made of a resin-film-forming component partially consisting of a ground silk powder having a particle diameter smaller than 6μm and prepared by wet-grinding a silk material in the form of a powder, particles or short fibers in the presence of a solvent (e.g. dimethylformamide or toluene) as the grinding medium.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a silk-like resin film formed by using 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 blended with the resin for molding the film to give the film a characteristic close to that of the natural silk material. The purpose of this is 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 film other than the fiber silk-like, the new use development of the silk material was tried.

However, it is necessary to pulverize the silk material into a fine powder in order to pulverize the silk material into the resin film to form a film having silk-like surface characteristics. When the particle size of the silk powder is large, the surface of the film obtained by mixing and blending 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 shear crushing or grinding of a silk material, the crushed and formed silk powders are entangled in a cotton-like shape, and the resulting silk powder is incorporated into the resin for film formation. However, when these crushed silk powders were mixed and mixed, there was a drawback that the crushed silk powder mixed and mixed in the resin was not uniformly dispersed.

Further, the crushed silk powder is entwined in a cotton shape,
The phenomenon of becoming larger lumps occurs not only when these silk powders are mixed and mixed with a molding resin, but also during the molding process of the silk powders and during the storage process of the silk powders.
From this, when mixed with the molding resin, there is a drawback that the crushed silk powder is not uniformly dispersed in the resin only by preventing flocculation of these mixed and mixed silk powders.

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
The purpose is to form a film having a thickness of 0.02 to 0.002 mm by using silk powder having a finer particle size than m and having a uniform particle size.

[0020]

The resin film using the crushed silk powder according to the present invention achieves the above object by preparing a silk material in the form of powder, granules or short fibers. Is made into a resin film containing silk powder which is finely pulverized in a finer range than 6 μm by wet pulverization using an organic solvent such as dimethylformamide and toluene as a medium. Compounded in the resin material together with the solvent as a wet medium used in, mainly 0.
It produces a film with a thickness of 02 to 0.006 mm.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION A resin film 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 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 typically an organic solvent, and a solvent suitable for a resin material such as a resin solution containing the crushed silk powder is used. And, this solvent requires that silk powder containing protein as a main component is insoluble, and typically dimethylformamide, toluene, other methanol such as methyl ethyl ketone, 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, etc. 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 the wet crushing of powder, granules or short fibrous substances, and among the various ball mills, those suitable for the wet crushing are mainly used. .

The crushing by the crusher is continued until the particle 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 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.

As described above, 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 resin together with a solvent at the time of 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 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 mixed with 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 granular or powdery or short fiber silk material pulverized by the above-mentioned turbo-mill 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. Since dimethylformamide has a higher viscosity than toluene, the silk powder 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. Also, when the silk material was crushed with a wet ball mill using dimethylformamide without previously adjusting the particle size of the powder, granules or short fibrous silk material as in Example 1 above, the particle sizes were uniformed. It was necessary to lengthen the crushing time by about 30 minutes as compared to the use of silk material. 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 finely crushed to a size of 6 μm in this manner is mixed with the molding resin together with the solution used for crushing the silk powder. The method of this compounding and the amount of the compounding are appropriately determined according to the characteristics of the resin film to be molded.
The resin blended with the solvent having the silk powder is the resin of the resin solution for molding produced by blending this solvent, and the above-mentioned resin is usually used by using a solvent suitable for the resin material of the resin film to be molded. Makes crushed silk powder.

Therefore, various resin films can be formed by selecting the solvent and the resin material used for the wet pulverization. Further, the resin mixed with the solvent containing the silk powder is
It may be in the form of a strike, powder or liquid,
By adjusting the blending amount of this solvent, a paste-like or highly viscous solution or a low-viscosity dilute solution is obtained.

In this way, a film is produced by using a solvent-blended resin having a silk powder finer than 6 μm. As a method for producing this film, an appropriate method such as inflation molding is used, or after coating the surface of the release paper, the release paper is peeled off to make a film. Further, the surface of this film is subjected to sanding or various surface treatments.

The film produced in this way is
Since the particle size of the silk powder contained in these materials is in the finer range than 6 μm, the film thickness is 0.02
Even within the range of ~ 0.002 mm, the mixed silk powder does not rise or protrude from the surface of this film,
The 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 film, a large number of pores finer than several microns can be provided on the surface of this film.

By providing pores finer than 2 to 3 μm on the surface of the film, the film is provided with air permeability, and particularly, the air permeability of the film is about 0.0004 μm. Since it has the characteristic of allowing water vapor of a certain diameter to pass through and impervious to water droplets, it imparts water resistance and moisture permeability to the film. Therefore, when a film having a thickness of 0.02 to 0.002 mm containing the above-mentioned silk powder is attached to the surface of various fabrics, leather or wooden products, and a part of the silk powder component in this film is eluted, this film is The silk powder and the leached holes in the inside provide water resistance and moisture permeability characteristic of these fabrics, leathers, wood products, and the like. By the way, the diameter of a raindrop is 2000 μm, which is 100 μm even in the case of fine rain.
However, it does not pass through the fine holes provided in this film. Also, raindrops attached to the film surface or the like do not seep through the fine holes due to the surface tension.

Example 3 A polyurethane resin film was prepared by using a solvent containing silk powder in a finer range than 6 μm, and this film was transferred onto the surface of a woven or knitted fabric. 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 film having a thickness of 0.008 mm.

Also, 1.5m without peeling off this film
The release paper was peeled off while adhering to the surface of the non-woven fabric having a thickness of m to form a film skin layer on the surface of the non-woven fabric. Then, when this nonwoven fabric was immersed in warm water at 60 ° C. and washed with hot water for 15 minutes, a part of the silk powder contained in the film was eluted, and the film surface was softened. In addition, when the film was produced while increasing the mixing amount of the silk powder between 3 parts by weight and 30 parts by weight in increments of 5 parts by weight, the film was produced when the proportion of the silk powder was 3 parts by weight in the ratio of Example 3. The resulting film had good gloss and sufficient abrasion resistance, but had a sticky feeling upon contact. Also, the film surface containing 35 parts by weight of silk powder has smooth contact resistance and good gloss and texture peculiar to silk, but on the other hand, it has poor abrasion resistance, and when a strong force acts on the film surface, This film surface wrinkles, and in the product obtained by laminating the film,
In some cases, the underlying fabric surface was exposed when the surface was twisted. Therefore, the optimal amount of the silk powder is 3 to 30 parts by weight. However, the amount of the silk powder can be further changed depending on the type of the resin for forming the film, the 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 film produced in this Example 4 has gloss and a texture unique to silk, and has flexibility. As compared with the usual vinyl chloride film, it had a good feel to the touch, significantly increased stretchability, and provided a moisture absorption function.

Example 5 Toluene 70 parts by weight Silk powder finer than 6 μm 15 parts by weight Acrylic resin 30 parts by weight The film produced by the compounding ratio of this example 5 is superior in weather resistance to the film of example 4. Despite its good wear resistance, there is no sticky feeling when contacting,
The gloss of the film surface was also good.

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 The film produced by the compounding ratio of this Example 6 is the same as that of Example 5 above.
The film had a tendency to be inferior in abrasion resistance as compared with the film No. 1, but had good touch and feel and good adhesiveness at the time of lamination.

Example 7 A release paper was coated with a mixed solution obtained by blending 100 parts by weight of a urethane resin with 40 parts by weight of silk powder.
The 0.006 mm thick film obtained after drying 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 8 A one-pack type urethane resin containing silk powder (a liquid mixture containing 30% by weight of non-volatile content of silk ethyl-containing methyl ethyl ketone as a solvent) was coated on release paper with 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. There was no sticky feeling on the surface of the nonwoven fabric having the surface of the laminate film, and the same adhesive strength as that of the laminate adhesive containing no silk powder was obtained.

[0053]

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. As a result, the silk material was easily crushed, and the crushed powder was granulated.

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

Further, 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.

Further, since the finely pulverized silk powder is dispersed in a solvent in a suspended state, these silk powders do not become entangled in a cotton shape, and the film is blended with the molding resin. It has the characteristics that it is smooth and easy and that the silk powder is uniformly dispersed in these resin mixture liquids. Therefore, when a film is formed using a resin mixed solution containing silk powder belonging to a finer range than 6 μm, the film is formed in a state where the silk powder is uniformly dispersed in the film. . From this, the moisture absorption and release characteristic of silk,
It has the characteristics of providing gloss and texture, moderate contact resistance, and strong elongation, and preventing electrostatic charging.

Since the particle size of the silk powder contained in this film is finer than 6 μm, it was possible to make this film thin. Especially as a film.
A 006 mm-thick film was made, and the mixed silk powder did not stand up or stick out from the surface of the formed film, and it had a smooth feel and a smooth silky surface.

Further, since the silk powder is uniformly exposed on the surface of the film to be formed, the surface of the film is effectively provided with adsorptivity and a good feel to the touch.
Furthermore, when a part of the silk material is eluted from the surface of the film to be formed, the surface of this film will be provided with innumerable microscopic holes of a few microns, which is characteristic of the surface of the film to be formed. It has the feature of providing a moisture releasing function, especially a water vapor permeable function.

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

The film using the silk powder according to the present invention is used for various clothing, personal belongings such as furniture or bags, or interior materials for automobiles, etc. as a silk-like surface material because of the characteristic contents of the above. It is used as a surface material for various electronic devices and keyboards for these operators by taking advantage of its static-free characteristics. Moreover, the film having the above silk powder can be created and used by the same method or method as the molding method of the usual film not containing the silk powder, and all the commodities around us everyday, especially clothing. It can be used as a means for molding or surface cosmetics.

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 resin film is characterized in that the crushed silk powder contained in the solvent is a part of the resin film composition.