JP2824630B2 - Method for producing silkworm silk fibroin membrane - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a membrane using silkworm fibroin.

[0002]

2. Description of the Related Art Although silkworm silk fibroin has been used as a material for clothing fibers and miscellaneous goods, it has not been used in the form of a membrane.

[0003] In order to use the silkworm silk as a new material as well as a fiber for clothing and to expand its use, it is necessary to dissolve the silkworm silk fibroin to enhance its use. Conventionally, silkworm silk fibroin can be dissolved using neutral salts such as lithium bromide and calcium chloride as solvents, but silkworm silk fibroin hardly dissolves in these solvents, so it can only be used directly as fibers. Was.

[0004]

The object of the present invention is to develop a method for dissolving the silkworm silk fibroin and producing a membrane from this solution, and to use the silkworm fibroin as a new material membrane. is there.

[0005]

According to a first aspect of the present invention, there is provided a method for producing a silkworm silk fibroin membrane comprising the steps of: converting a silkworm silk fibroin into cupric hydroxide: ethylenediamine = 6.0;
After dissolving with a copper ethylenediamine solution having a mixing ratio of 8.3 to 8.6 (g / 100 cc, water), a copper ion dissociating agent solution is added to the silkworm silk fibroin dissolving solution to dissociate copper ions. It is characterized in that a water-soluble silkworm silk fibroin film is formed from the regenerated silkworm silk fibroin solution, and then insolubilized with ethanol.

The method for producing a silkworm silk fibroin membrane according to claim 2 is characterized in that the copper ion dissociating agent solution has a concentration of from 1.23 to 1.23.
It is characterized by using any one of sulfuric acid, citric acid, tartaric acid and acetic acid of 1.24N. The method for producing a silkworm fibroin membrane according to the third aspect of the present invention is characterized in that the insolubilization treatment is performed by treating the mixture at 60 ° C. and 75% ethanol for 30 minutes.

Hereinafter, the present invention will be described in detail. A silkworm silk fibroin obtained by scouring cords and screws produced as by-products when the silkworm cocoon layer and the silkworm are reeled is used. First, this silkworm silk fibroin is dissolved. As this solvent, a copper ethylenediamine solution that binds to a protein to form a chelate compound and solubilize it is used.

The copper ethylenediamine solution is prepared from cupric hydroxide and ethylenediamine, and the solution preparation ratio for dissolving the silkworm silk fibroin is as follows: cupric hydroxide: ethylenediamine = 6.0: 8.3 to 8.6 ( g / 100cc,
Water) is preferred. The copper ethylenediamine solution of this blending ratio is 2.5 times larger than that of the solution blending ratio used for dissolving the conventional silkworm silk fibroin.
Up to 3.5 times the amount can be dissolved.

As described above, the copper ion contained in the solution is dissolved in the solution of the silk fibrin dissolved in the silkworm silk obtained by adding the copper ethylenediamine solution to the fibroin of the silkworm silk. As a method of removing this copper ion,
After adding the copper ion dissociating agent, it is dialyzed off. Since the bond between the silk fibroin and the copper ion is strong and difficult to dissociate, it is necessary to dissociate the copper ion without gelling the silk fibroin.

The copper ion dissociator solution is 1.23
It is effective to use any one of sulfuric acid, citric acid, tartaric acid and acetic acid of up to 1.24N. Although the structure of the membrane changes depending on the type of the copper ion dissociating agent, sulfuric acid and citric acid are superior in ion permeability.

This adjusted solution is filled in a cellulose tube, and dialyzed with running water at about 10 ° C. for 4 to 5 days and with purified water for 2 days to obtain a regenerated silkworm silk fibroin solution. The regenerated silkworm silk fibroin solution is spread on an acrylic plate or the like, and dried at room temperature of 20 to 25 ° C. for 2 days by a gentle air current of a fan to obtain a water-soluble silkworm silk fibroin membrane.

The water-soluble silkworm silk fibroin membrane thus formed is water-soluble and is less likely to be insolubilized than the silkworm silk fibroin membrane. Therefore, the water-soluble silkworm silk fibroin membrane is treated with 75% ethanol at 60 ° C. for 30 minutes. To obtain a practical insoluble silkworm silk fibroin membrane.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below in detail. The silkworm silk fibroin used as a raw material for preparing the silkworm silk fibroin membrane of the present invention is obtained by scouring the cocoon layer of the silkworm silk and the cord or screw produced as a by-product when the silkworm is reeled.

First, a method for preparing the silkworm fibroin membrane of the silkworm silk will be described. The silkworm silk fibroin is obtained by scouring twice at a temperature of 98 ° C. for 40 minutes twice at a volume of 0.67% Marcel's soap.

The silkworm silk fibroin is hardly soluble in solvents such as neutral salt lithium bromide and calcium chloride which dissolve the silkworm silk fibroin, but can be dissolved by applying a copper ethylenediamine solution. 2.5-3.5 g of the silkworm silk fibroin was used as the cupric hydroxide: ethylenediamine = 6.0: 8.3-8.6 of the present invention.
(G / 100cc, water)
Dissolve at room temperature of 20-25 ° C for 5 minutes.

The silkworm silk fibroin-dissolving solution thus obtained can be dialyzed as a copper ion dissociating agent without gelling silkworm silk fibroin from 1.23 to 1.24.
The pH of the dissolution solution is adjusted to 7.4 to 7.7 by adding about 100 cc of specified sulfuric acid. The same applies to the case where citric acid, tartaric acid and acetic acid as other copper ion dissociating agents are used.

This adjusted solution is filled in a cellulose tube and dialyzed with running water at about 10 ° C. for 4 to 5 days and with purified water for 2 days to obtain a regenerated silkworm silk fibroin solution. The regenerated silkworm silk fibroin solution is spread on an acrylic plate or the like, and dried at room temperature of 20 to 25 ° C. for 2 days by a gentle air current of a fan to obtain a water-soluble silkworm silk fibroin membrane. Next, this membrane was subjected to an insolubilization treatment at 60 ° C. and 75% ethanol for 30 minutes to obtain a practical insoluble silkworm silk fibroin membrane.

[0018]

EXAMPLE A method for producing a silkworm fibroin membrane of the silkworm silkworm will be described with reference to the accompanying drawings. In FIG. 1, the cocoon layer 1 of the silkworm was replaced with 0.67% Marcel stone soap 1.
Treated twice with a 100-fold solution at 98 ° C for 40 minutes,
After washing well with water, scoured silkworm silk fibroin 2 is obtained. 2.5 to 3.5 g of the scoured silkworm silk fibroin 2 was added to cupric hydroxide: ethylenediamine = 6.0: 8.3 to 8.6.
(G / 100 cc, water) 100 cc of solution and 20
Dissolve at ２５25 ° C. for 5 minutes. About 100 cc of 1.23 to 1.24N sulfuric acid was added as a copper ion dissociating agent to the silkworm silk fibroin dissolving solution 3 to adjust the pH of the dissolving solution to 7.4 to
Adjust to 7.7.

This adjusted solution is filled in a cellulose tube and dialyzed with running water at about 10 ° C. for 4 to 5 days and with purified water for 2 days to obtain a regenerated silkworm silk fibroin solution 4. The regenerated natural silkworm silk fibroin solution 4 is spread on an acrylic plate, and at room temperature of 20 to 25 ° C, the air is blown by a fan to obtain 2
After drying for a day, a water-soluble silkworm fibroin membrane 5 is obtained.
The membrane 5 was subjected to insolubilization treatment at 60 ° C. and 75% ethanol for 30 minutes to obtain an insoluble natural silkworm silk fibroin membrane 6.

The structure of the insoluble silkworm silk fibroin membrane changes depending on the type of the copper ion dissociating agent.
The ion permeability when sulfuric acid, citric acid, tartaric acid and acetic acid were used as the copper ion dissociating agent was examined, and the results were shown in FIG.
Shown in FIG. 3 shows the change in the in-film charge depending on the type of the copper ion dissociating agent. Therefore, the type of the copper ion dissociating agent to be used can be selected according to the intended use of the insoluble silkworm silk fibroin membrane.

[0021]

As described above, according to the method of the present invention for producing a silkworm silk fibroin membrane, the water-soluble silkworm silk fibroin membrane formed as an intermediate can be stored for a long period of 5 years or more. . The water-soluble silkworm silk fibroin membrane can be reconstituted into a fibroin solution by dissolving it in water, and can be used as a silkworm silk fibroin solution. It can be used as a practical film such as a film.

[Brief description of the drawings]

FIG. 1 is a production process diagram showing a method for producing a silkworm silk fibroin membrane.

FIG. 2 is a graph showing the effect of a copper dissociating agent on ion permeation in a silkworm fibroin membrane.

FIG. 3 is a graph showing the effect of charge on ion permeation in a silkworm fibroin membrane

[Explanation of symbols]

Reference Signs List 1 silkworm cocoon layer 2 silkworm silk fibroin 3 silkworm silk fibroin dissolving solution 4 regenerated silkworm silk fibroin solution 5 water-soluble silkworm silk fibroin membrane 6 insoluble silkworm silk fibroin membrane 10 copper ion dissociator sulfuric acid pH 6.7 11 copper ion dissociator sulfuric acid pH7. 4 12 Copper ion dissociating agent Sulfuric acid pH 7.7 13 Copper ion dissociating agent Sulfuric acid pH 8.5 14 Copper ion dissociating agent Citric acid pH 7.0 15 Copper ion dissociating agent Tartaric acid pH 7.0 16 Copper ion dissociating agent Acetic acid pH 7.0 17 Kp transmission Constant 18 C ₂ ion concentration 19 Ko true transmission constant

Claims (3)

(57) [Claims] 1. A silkworm silk fibroin was prepared by adding cupric hydroxide: ethylenediamine = 6.0: 8.3 to 8.6 (g / g).
(100 cc, water) by dissolving with a copper ethylenediamine solution having a compounding ratio of, and adding a copper ion dissociating agent solution to the solution of the silk fibrin solution of the silkworm silk to dissociate the copper ions. A method for producing a silkworm fibroin membrane comprising forming a silk fibroin membrane and then performing an insolubilization treatment with ethanol. 2. A copper ion dissociating agent solution having a concentration of 1.23 to 1.23.
The method for producing a silkworm silk fibroin membrane according to claim 1, wherein one of sulfuric acid, citric acid, tartaric acid and acetic acid of 1.24N is used. 3. The method for producing a silkworm fibroin membrane according to claim 1, wherein the insolubilization treatment is performed at 60 ° C. and 75% ethanol for 30 minutes.