JP3375707B2 - Method for producing solvent-based resin composition containing ultrafine silk fibroin powder, method for producing film or sheet, and method for producing laminate - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to a related <br/> the manufacturing process, film or sheet production method and a production method of a laminate using the same silk fibroin ultrafine powder solvent-based resin composition containing , film, sheet, artificial leather, production side such as a synthetic leather
Available for law .

[0002]

2. Description of the Related Art In recent years, various products have been proposed which are improved in touch feeling, moisture absorption and desorption by incorporating fine silk fibroin powder. For example, there is an artificial leather containing silk fibroin fine powder, which is produced by blending silk fibroin fine powder in a synthetic resin. Conventionally, various methods have been proposed as a method for producing such silk fibroin fine powder.

For example, according to Japanese Patent Publication No. 39-1941,
After dissolving silk fibroin in a copper-ethylenediamine aqueous solution or the like, alcohols are added to the silk fibroin aqueous solution obtained by dialysis, the precipitate is dried, and then the dried product is pulverized to produce silk fibroin fine powder. Further, according to Japanese Patent Laid-Open No. 4-300369, silk fibers are hydrolyzed with hydrochloric acid to be deteriorated, and then mechanically ground to produce silk fibroin fine powder.

However, since the silk fibroin fine powder obtained by the production method according to Japanese Patent Publication No. 39-1941 has the structure of silk fiber once destroyed by chemical treatment, the original texture of the silk fiber is impaired. There is a possibility that it has been. Also,
With respect to the silk fibroin fine powder obtained by the production method disclosed in Japanese Patent Laid-Open No. 4-300369, the original texture of silk may not be maintained.

Therefore, various products produced by containing the silk fibroin fine powder obtained by such a production method do not always obtain good moisture absorption / release properties, moisture permeability and touch feeling. Therefore, the present invention is a method for producing a silk-based fibroin ultrafine powder-containing solvent-based resin composition, which is always provided with good moisture absorption / release properties, moisture permeability and touch feeling,
Method for producing film or sheet and laminated body using the same
It aims at providing the manufacturing method of.

[0006]

Solvent-based resin composition containing ultrafine silk fibroin powder according to the first aspect of the present invention
The manufacturing method of the method comprises a first pulverizing step of pulverizing silk fibroin into coarse powder by a dry mechanical pulverizing means, and a second pulverizing step of pulverizing the silk fibroin coarse powder into a fine powder by a dry mechanical pulverizing means using a ball mill . A pulverizing step and a third pulverizing step of pulverizing the silk fibroin fine powder into ultrafine powder having an average particle diameter of 10 μm or less by a dry mechanical pulverizing means using a jet mill . the Rikinu fibroin ultrafine powder by the applying β process on silk fibroin powder in at least one step during or after grinding step
It is characterized in that it is produced and this ultrafine silk fibroin powder is mixed in a solvent-based resin solution .

The average particle size of the coarse powder is approximately 100 μm.
It is around m. The average particle size of the fine powder is approximately 20μ.
It is around m. The dry mechanical crushing means used in the first crushing step may be any such as a rotary blade mill, but the dry mechanical crushing means used in the second crushing step is a ball mill, and The dry mechanical crushing means used in the crushing step of 3 is preferably a jet mill. As described above, the pulverization process by the dry mechanical pulverization means is combined in three stages so that powders having a small particle size can be successively obtained, so that an ultrafine powder that cannot be obtained by only one mechanical pulverization is obtained. You will get it.

Further, since all the steps are dry, the work is easy and the original texture of silk is maintained. The β-treatment is a treatment in which silk fibroin is immersed in an appropriate liquid to increase the proportion of β structure, and the liquid for this treatment includes an organic solvent. For example, alcohols such as methanol and ethanol, acetone and the like. The β-treatment may be performed at least once in any one of the first, second, and third pulverization steps, or may be performed twice or more as necessary.

By performing such β-treatment, the crystallinity increases. And preferably 70% of natural silk
By producing the product with the above crystallinity,
The ultrafine silk fibroin powder can be uniformly dispersed in a solvent-based resin solution, an aqueous resin solution, or the like. As a result, it is possible to obtain a product which is excellent in moisture absorption and desorption, moisture permeability and touch feeling while maintaining the texture peculiar to silk, and is also excellent in antistatic performance. As a typical example of the solvent-based resin solution,
Polyurethane resin, acrylic resin, polyamide resin, etc. are available.

The solvent of the solvent-based polyurethane solution includes dimethylformamide, methyl ethyl ketone, toluene, isopropyl alcohol and the like. The method for producing a film or sheet containing ultra-fine powder of silk fibroin according to the second aspect of the present invention applies the solvent-based resin composition containing ultra-fine powder of silk fibroin obtained by the method of claim 1.
It is characterized by doing. In the film or sheet of the present invention, depending on the purpose of stabilizing the quality and the use environment, additives commonly used in this field, such as fibers, antioxidants,
In addition to the ultraviolet absorber, a necessary amount of a plasticizer, a stabilizer, a processability improving agent such as a lubricant, a filler, a dye, a colorant such as a pigment, and the like may be added.

The mixing ratio of the ultrafine silk fibroin powder and the synthetic resin is in the range of 90 to 1% by weight of the ultrafine silk fibroin powder with respect to the solid content of the synthetic resin of 10 to 99% by weight. If the proportion of the ultrafine powder exceeds 90 wt%, the film or sheet becomes brittle, and if it is less than 1 wt%, the effect of addition is not obtained. However, the ultrafine powder in synthetic resin is 5 to 50 wt% in the case of film.
%, And in the case of a sheet, 5 to 60 wt% is preferable. The thickness of the film or sheet is preferably 5 μm or more, and the ultrafine powder is preferably dispersed uniformly. Further, the ultrafine powder may be exposed on the surface, and in this case, it is useful for improving touch feeling and warm feeling.

Examples of the method for forming the film or sheet include dry or wet knife coating, gravure coating, spraying and dipping. A method of manufacturing a laminate according to the third aspect of the present invention is characterized by laminating the silk fibroin ultrafine powder containing film or sheet on a substrate.

Examples of the base material include woven fabrics, cotton fabrics, and woven fabrics made of natural or chemical fibers as described above, as well as films or sheets of synthetic resin, paper, and the like. If necessary, the laminate may be surface-finished by buffing, embossing, or the like. As a lamination method,
For example, when using a polyuritan resin, a method of impregnating the substrate with the silk fibroin ultrafine powder-containing resin solution,
Wet method of applying the solution to a substrate to form a coating film, or dry method of forming the ultrafine powder-containing film or sheet with the solution or the like and laminating the film or sheet on the substrate directly or via an adhesive. Can be used.

[0014]

Example The silk fibroin ultrafine powder used in this example was obtained as follows. First, raw silk was cut into 2-3 cm with a cutter blade type mill, and then silk fibroin was soaked in warm water or warm water containing an enzyme to be refined to obtain a silk fibroin raw material from which sericin was completely removed. When unrefined silk fibroin is used as a raw material, the touch feeling of the obtained powder is deteriorated or light brown coloring is caused.

Next, the cut silk fibroin was put into a rotary wing type mill [Orient rigid crusher V manufactured by Orient Co., Ltd.].
M-32 (trade name)] was pulverized into a silk fibroin coarse powder having an average particle size of about 100 μm, and the silk fibroin coarse powder was put into a fluid dryer or the like and dried at 100 ° C. for 6 hours. The temperature condition for this drying is 130 ° C or lower, preferably 90 ° C.
~ 110 ℃. Above 130 ℃, it may turn yellow. The time is 1 hour or more. If this drying is not performed sufficiently, during the subsequent ball mill grinding,
When the wall surface of the ball mill is made of general stainless steel, the wall surface of the ball mill is worn and the coloring of the powder becomes severe.

In this embodiment, the particle size of the powder is a laser rotary particle size analyzer [SK LAS manufactured by Seishin Enterprise Co., Ltd.].
ER PRO 7000S (trade name), dispersion medium: ethanol, dispersion condition: ultrasonic wave 60 seconds]. Next, using a ball mill (manufactured by Kondo Kagaku Kikai Seisakusho), the coarse silk fibroin powder was ground for 12 hours to obtain fine silk fibroin powder having an average particle size of about 20 μm. The wall surface of the ball mill is made of ceramic and the balls are made of alumina in order to prevent coloring of the powder.

Although it is possible to reduce the average particle size to 20 μm or less by this ball mill crushing, it becomes possible to perform jet mill crushing with such a particle size, and in consideration of work efficiency, the average particle size 20
The ball mill crushing is completed at about μm. That is, if it is attempted to further reduce the particle diameter with a ball mill, it takes much time, and there is no great difference in the particle diameter of the particles obtained by the subsequent jet mill pulverization.

Then, methanol was poured into the silk fibroin fine powder in the ball mill, and the mixture was operated at room temperature for 15 minutes and sufficiently stirred to perform β-treatment for increasing the crystallinity, and then the silk fibroin fine powder was removed from the ball mill. The powder was removed and the silk fibroin fine powder was dried. By performing this β-formation treatment, the obtained powder can be favorably dispersed in a resin solution or the like for producing a product. Next, the silk fibroin fine powder was jet milled [by Co., Ltd.].
It was crushed using a single track jet mill (trade name) manufactured by Seishin Enterprise Co., Ltd. to obtain ultrafine powder having an average particle size of 3.252 μm. The throughput of this pulverization was 5 kg / h.

Next, examples of each product using the above-mentioned silk fibroin ultrafine powder will be described. Example 1 (Film containing silk fibroin ultrafine powder) Polyurethane solution for synthetic leather (Resamine ME manufactured by Dainichiseika Co., Ltd.)
-3612LP) 90% by weight solid content of silk fibroin ultrafine powder is 10% by weight, and a resin solution (resin solids content 20% by weight) of the two is mixed on a release paper with a coater, and 70 ° C.
A film having a thickness of 30 μm was prepared by drying. Example 2 (Silk fibroin ultrafine powder-containing film) A film was prepared in the same manner as in Example 1 except that the dry silk fibroin ultrafine powder was mixed at 30 wt% with respect to the solid content of 70 wt% of the polyurethane solution. .

Example 3 (Film containing silk fibroin ultrafine powder) A film was prepared in the same manner as in Example 1 except that 50% by weight of the solid content of the polyurethane solution was mixed with 50% by weight of the silk fibroin ultrafine powder. It was made.

Example 4 (Synthetic Leather Containing Ultrafine Silk Fibroin Powder) Using a dry coating apparatus shown in FIG. 1, a coating liquid (6% by weight of ultrafine silk fibroin powder on a solid content basis was mixed on a release paper 11. After applying a solution obtained by adding a small amount of an auxiliary agent to the dry polyurethane resin solution prepared above, 12
It was dried at 130 ° C. to prepare a 20 μm thick leather powder-containing polyurethane film 14. Next, using an adhesive (polyurethane adhesive containing 5% by weight of ultrafine silk fibroin powder based on the solid content) 15, this film 14 with a denier of 1
After adhering to a substrate 16 made of 70 g / m ² of polyester nonwoven fabric, it was dried at 140 ° C. by a dryer 17 to produce a synthetic leather 18 having a 40 μm thick silk fibroin ultrafine powder-containing polyurethane resin layer. Next, using the gravure coating apparatus shown in FIG. 2, a coating liquid (silk fibroin ultrafine powder on a solid content basis was applied to the surface of the synthetic leather 18).
Polyurethane resin solution containing 12 wt%) 12A was applied and then dried by a dryer 13A.

Example 5 (Synthetic leather containing silk fibroin ultrafine powder) Nylon 50 was used by using the wet coating apparatus shown in FIG.
% And Tetoron 50% mixed base fiber 21 coating liquid (wetting polyurethane resin solution containing 30 wt% of silk fibroin ultrafine powder based on solid content with a small amount of filler added) 22 Was applied. Next, the base material 21 is continuously passed through a plurality of coagulation / water washing tanks 23A to 23C and then dried at 140 ° C. by a dryer 24 to obtain a 0.70 mm thick silk fibroin ultrafine powder-containing ester polyurethane. A synthetic leather 25 having a resin layer was produced. Thereafter, the synthetic leather 25 was spray-coated with a coating solution (a polyurethane resin solution containing 30 wt% of ultrafine silk fibroin powder based on the solid content).

Example 6 (Artificial Leather Containing Silk Fibroin Ultrafine Powder) Using the impregnation coating apparatus shown in FIG. 4, a base material made of a polyester non-woven fabric having a denier of 2 and a basis weight of 70 g / m ^2.
31 is introduced into the impregnation tank 32, and an impregnating liquid (3 parts by weight of a filler is added to an ester-based polyurethane resin solution [silver fibroin ultrafine powder (25 wt% based on solid content))] is added. 33) was impregnated to a dry weight of 30 g / m ² . Subsequently, the base material 31 is passed through a coagulation / washing tank 34 and then dried at 130 ° C. by a dryer 35 to be impregnated.
Got 36.

Next, using the impregnation coating apparatus shown in FIG. 4, the impregnated substrate 36 was coated with a coating liquid (silk fibroin ultrafine powder in an amount of 30 wt% based on the solid content of an ester-based polyurethane resin solution [resin solid content). 15 wt%] with a filler and a foaming agent added) 22 and then introduced into coagulation / washing tanks 23A to 23C and further dried by a dryer 24 at 130 ° C to obtain a porous polyurethane having a thickness of 0.4 mm. An artificial leather having a resin layer was manufactured.

Comparative Example 1 A film was prepared in the same manner as in Example 1 except that the silk fibroin ultrafine powder according to the above Example was not used. Comparative Examples 2 to 4 Comparative Examples 2 to 4 are respectively made to correspond to Examples 4 to 6 except that the silk fibroin ultrafine powder according to the above Examples is not used. The sheet, the synthetic leather or the artificial leather according to 1. was manufactured. Next, the film, sheet, synthetic leather or artificial leather of each of the above Examples and Comparative Examples was tested for moisture permeability, moisture absorption, moisture release or surface touch feeling. The results are shown in Tables 1 and 2. The test method is as follows.

(1) Water vapor permeability Measured according to JIS K6549. (2) One side of a sample that has reached a flat state at a moisture absorption of 23 ° C and 30% RH (any surface may be used in the case of a single layer, but in a sample composed of two or more layers, (Surface) was placed in an atmosphere of 23 ° C. and 80% RH, and the weight increase was measured.

(3) When one side of a sample that reached a uniform state at a moisture release amount of 23 ° C. and 80% RH (measurement surface is the same as the moisture absorption amount) was placed in an atmosphere of 23 ° C. and 30% RH Weight loss was measured. (4) Touch feeling on the surface It was performed by comparing the feeling when the surface of the sample was touched by hand. Twenty randomly selected people were evaluated according to the following criteria (expressed as an average). 5 points: very good touch, 4 points: good touch, 3 points: normal, 2 points, poor touch, 1 point
Very bad touch

[0028]

[Table 1]

[0029]

[Table 2]

From Tables 1 and 2, since the film, sheet, synthetic leather or artificial leather according to this example contains the ultrafine silk fibroin powder obtained in this example, it has moisture permeability and hygroscopicity. It can be seen that the moisture release property or surface touch feeling property is good. On the other hand, according to the film, the sheet, the synthetic leather or the artificial leather according to the comparative example, since the silk fibroin ultrafine powder obtained in this example is not contained, the moisture permeability, the hygroscopicity, the moisture releasing property or the surface touch feeling It can be seen that the characteristics are poor.

[0031]

Method for producing silk fibroin ultrafine powder containing solvent-based resin composition according to the present invention, a film or sheet
According to the manufacturing method and a manufacturing method of a laminate using the same,
Since it contains silk fibroin ultrafine powder, good moisture absorbing / releasing property, moisture permeability and touch feeling are always obtained.

[Brief description of drawings]

FIG. 1 is a schematic view of a dry coating apparatus used in an embodiment of the present invention.

FIG. 2 is a schematic view of a gravure coating apparatus used in an example of the present invention.

FIG. 3 is a schematic view of a wet coating apparatus used in an embodiment of the present invention.

FIG. 4 is a schematic view of an impregnation coating device used in an example of the present invention.

[Explanation of symbols]

12,12A, 22 Coating solution containing ultrafine silk fibroin powder 18 Synthetic leather containing ultrafine silk fibroin powder 25 Synthetic leather containing ultrafine silk fibroin powder 33 Impregnating solution containing ultrafine silk fibroin powder

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI B32B 27/12 B32B 27/12 C08J 5/18 CFF C08J 5/18 CFF C08L 89/00 C08L 89/00 D06M 15/15 D06M 15 / 15 23/08 23/08 D06N 3/00 D06N 3/00 // B29K 75:00 B29K 75:00 105: 16 105: 16 B29L 7:00 B29L 7:00 9:00 9:00 (56) Reference Documents JP-A-4-300369 (JP, A) JP-A-1-293142 (JP, A) JP-A-2-53841 (JP, A) JP-A-7-90182 (JP, A) JP-A-6- 329809 (JP, A) JP 1-313530 (JP, A) JP 1-55191 (JP, A) JP 61-180800 (JP, A) JP 58-46097 (JP, A) JP-A-58-45232 (JP, A) JP-A-56-92296 (JP, A) JP-A-56-40695 JP, A) JP flat 5-247855 (JP, A) JP flat 5-93373 (JP, A) (58 ) investigated the field (Int.Cl. ^7, DB name) C08L 1/00 - 101/16 B02C 19/06 B29C 41/24 B32B 27/04 B32B 27/10 B32B 27/12 D06M 15/15 D06M 23/08 D06N 3/00

Claims (3)

(57) [Claims] 1. A first pulverizing step of pulverizing silk fibroin into coarse powder by a dry mechanical pulverizing means, and a second pulverizing step of pulverizing the silk fibroin coarse powder into a fine powder by a dry mechanical pulverizing means using a ball mill . A pulverizing step and a third pulverizing step of pulverizing the silk fibroin fine powder into ultrafine powder having an average particle diameter of 10 μm or less by a dry mechanical pulverizing means using a jet mill . the Rikinu fibroin ultrafine powder by the applying β process on silk fibroin powder in at least one step during or after grinding step
A method for producing a silk-based fibroin ultrafine powder-containing solvent-based resin composition, which is produced and blended with a solvent-based resin solution. 2. A silk fib obtained by the method according to claim 1.
Applying solvent-based resin composition containing ultrafine powder of loin
A method for producing a film or sheet containing silk fibroin ultrafine powder, which is characterized . 3. A method for producing a laminate, which comprises laminating a <br/> silk fibroin ultrafine powder containing film or sheet obtained by the production method according to claim 2 on a substrate.