JPH0967408A - Deproteinization from natural rubber molded cured material and natural rubber product produced by the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of allergy, etc., by dipping a molded cured material in an aqueous solution of protease, decomposing protein, extracting, thus efficiently removing the protein from a molded cured material of a natural rubber. SOLUTION: Protein is decomposed by dipping a molded cured material in an aqueous solution of protease or dipping in a mixed solution of an aqueous solution of protease and an aqueous solution of lipase, the decomposed protein is extracted to remove the protein from a molded cured material of natural rubber. Preferably, a nonionic surfactant is combinedly used to decompose.extract the protein.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing proteins that may cause allergies from natural rubber products after molding and vulcanization.

[0002]

2. Description of the Related Art Conventionally, when a product made from natural rubber is a solid rubber, it is washed with water or boiling to remove non-rubber components such as proteins from the product after compounding, molding and vulcanizing. In addition, in the case of products using natural rubber latex as a raw material, leaching (extraction with warm water etc.) has been performed to remove non-rubber components after compounding, molding and vulcanization.

However, in recent years, it has been reported that a protein contained in natural rubber acts as an allergen for a person with a certain allergic constitution and causes a serious anaphylactic reaction. Since there is a certain limit to removal,
It has been desired to develop a method for efficiently obtaining a higher degree of deproteinization.

In order to deal with this, for example, Japanese Patent Laid-Open No. 6-
Deproteinized natural rubber described in JP-A-56902 (first prior art), a method for producing stabilized protein natural rubber latex described in JP-A-6-322003 (second prior art) or JP-A-6-329702. Many proposals have been made such as the method for producing the modified natural rubber described above (third prior art).

The above-mentioned first conventional technique is obtained by adding a proteolytic enzyme to the latex to decompose the protein, and then repeatedly washing with a surfactant. The second conventional technique is To obtain a deproteinized natural rubber latex with improved stability by newly adding a specific surfactant, oligomer or polymer to the natural rubber latex deproteinized with a proteolytic enzyme and a surfactant. In the prior art No. 3, the protein in the natural rubber latex is adjusted to have a nitrogen content of 0.1% by weight or less, and then the natural rubber is graft-copolymerized with an organic compound having an unsaturated bond, or the natural rubber is epoxy-modified. It is converted into and modified.

[0006]

As described above, even in the conventional technique, it is possible to obtain an effective means for coping with allergy by reducing the protein in natural rubber.

However, all of the above conventional techniques are intended to deproteinize natural rubber latex or the like before processing. Natural rubber latex becomes very unstable when protein is removed, resulting in poor processability. Therefore, in order to stabilize it, it is necessary to add various additives such as surfactants, and in order to reduce the residual protein from the conventional value by the conventional method, it requires a large amount of equipment and requires it. There is a risk that problems such as a longer time may occur. In addition, there is a problem that the physical properties of the molded product deteriorate.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a deproteinized natural rubber product which has a simple structure and has excellent physical properties equivalent to those of conventional natural rubber in a short time. It is what

[0009]

The above object can be achieved by a method for deproteinizing a natural rubber molded vulcanized product and a natural rubber product produced by the method described in the appended claims. That is, (1) a method for removing protein from a natural rubber product that has been molded and vulcanized, in which the molded and vulcanized product is immersed in an aqueous solution of a protease to decompose the protein, and the decomposed protein is extracted. Deproteinization method from natural rubber molding vulcanizate.

(2) A method for removing proteins from a natural rubber product that has been molded and vulcanized, wherein the molded and vulcanized product is immersed in a mixed solution of a proteolytic enzyme aqueous solution and a lipolytic enzyme aqueous solution to act. A method for deproteinizing a natural rubber vulcanized product for extracting protein.

(3) The method for deproteinizing a natural rubber molded vulcanized product according to any one of (1) to (2), wherein a nonionic surfactant is used in combination for protein decomposition and extraction.

(4) The natural rubber molding vulcanization according to any one of (1) to (3), which is provided with a deproteinization step by immersing in dilute acid or dilute alkaline water after the action of each enzyme aqueous solution. Deproteinization method from products.

(5) A natural rubber product produced by a method of immersing a natural rubber product, which has been molded and vulcanized, in a proteolytic enzyme aqueous solution to decompose the protein and extract the decomposed protein.

(6) A natural rubber product produced by a method of extracting a protein by immersing a natural rubber product, which has been molded and vulcanized, in a mixed solution of an aqueous solution of a proteolytic enzyme and an aqueous solution of a lipolytic enzyme to act on it.

(7) Produced by the method for deproteinizing a natural rubber molded vulcanized product according to any one of (1) to (2), wherein a nonionic surfactant is used in combination for protein decomposition and extraction. Natural rubber products.

(8) Natural rubber molding vulcanization according to any one of (1) to (3), wherein after the action of each enzyme aqueous solution, a deproteinization step by immersing in dilute acid or dilute alkaline water is provided. It is a natural rubber product manufactured by the deproteinization method from the product. Hereinafter, embodiments will be described including the operation of the present invention.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described.
A description will be given based on the results of experiments conducted by the inventors of the present application. FIG. 1 is a diagram for explaining an experimental step of a method for removing a protein from a rubber thin film made of natural rubber latex which has been vulcanized and molded.

First, a natural rubber latex added with a compounding agent such as a vulcanizing agent is molded and vulcanized into a predetermined shape. (Figure 1
(A)).

Next, the molded vulcanized product is dipped in a deproteinizing solution (FIG. 1 (b)). As the deproteinization treatment solution, an aqueous solution of proteolytic enzyme or an aqueous solution of a mixture of proteolytic enzyme and lipolytic enzyme is used. At this time, the product may be left on the mold or may be released from the mold.

When an aqueous solution of proteolytic enzyme is used, in this example, a protease (proteolytic enzyme) produced from a strain of Bacillus licheniformis and containing subtilisin A as a main enzyme component is used.
Protease (proteolytic enzyme) produced from strains of lus lentus, Bacillus coagulaus, Bacillus subtilli
s, Aspergillus niger, Aspergillus melleus, Aspergillu
Enzymes produced by soryzae, Mucor pusillus, etc. are also effective.

In the present example, the lipolytic enzyme is Aspergillus or
It uses the enzyme produced by yzae, but also Aspergillus niger,
Enzymes produced by Mucor pusillus and the like are used.

These enzymes are 0.001-1.0% by weight
It is used after being dissolved in water at the concentration of. This is due to the activity and type of enzyme per unit. Also, pH
It depends on the enzyme, but 5-11 is suitable, and it is adjusted by adding sodium dihydrogen phosphate, sodium hydrogen carbonate, or the like.

The temperature is preferably 20 to 80 ° C. When the temperature is lower than this, the activity is low, and when it is higher, the activity is deactivated.
The period of action is 1 minute to 72 hours.

The surface active agent to be added is a nonionic surface active agent such as ether type such as polyoxyethylene lauryl ether, alkylphenol type such as polyoxyethylene nonylphenyl ether, or polyoxyethylene monolaurate. A surfactant such as an ester type, a rylbitan ester type, a rylbitan ester ether type, or an ethylene propylene block polymer type can be used.

[0025]

[Table 1]

FIG. 1 shows the flow of the experiment, and Table 1 shows specific treatment solutions and deproteinizing effect.

As is clear from the above test results, the method for deproteinizing a natural rubber molded vulcanized product according to the present invention and the natural rubber product produced by the method are
It has the following features.

(1) The nitrogen content (N%) of the natural rubber molded product of FIG. 1 (a) was 0.17% for the current product.
The present invention can reduce up to 0.03% and reduce residual N% to about 20% of current products.

(2) Although not described in the above test results, as a result of the physical property test conducted in FIG. 1 (d), no problem was found in general physical properties, and particularly in tensile strength. While the conventional deproteinization method yielded only about 80% of natural rubber, the method according to the present invention yielded tensile strength equivalent to that of natural rubber.

[0030]

As described above, according to the present invention, the following effects can be obtained. By reducing the amount of protein contained in a natural rubber product to 20% of the current value, it can greatly contribute to the prevention of allergies and the like.

By performing the molding and vulcanization of the natural rubber in a state in which the workability before removing the protein is good, it is possible to improve the accuracy of the product and to improve the work efficiency.

With respect to the tensile strength of the natural rubber molded vulcanized product, it is possible to obtain a product having a force almost equal to that of natural rubber.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an experimental step of a method for removing a protein from a natural rubber latex thin film that has been molded and vulcanized.

Claims (8)

[Claims] 1. A method for removing protein from a natural rubber product that has been molded and vulcanized, wherein the molded and vulcanized product is immersed in an aqueous solution of a protease to decompose the protein, and the decomposed protein is extracted. A method for deproteinizing a natural rubber molded vulcanized product, which is characterized in that 2. A method for removing proteins from a natural rubber product which has been molded and vulcanized, wherein the molded and vulcanized product is immersed in a mixed solution of an aqueous solution of proteolytic enzyme and an aqueous solution of lipolytic enzyme to act, A method for deproteinizing a natural rubber molded vulcanized product, which comprises extracting 3. The method for deproteinizing a natural rubber molded vulcanized product according to claim 1, wherein a nonionic surfactant is used in combination for decomposing / extracting the protein. 4. The natural rubber molding according to claim 1, further comprising a deproteinization step of immersing in dilute acid or dilute alkaline water after the action of each enzyme aqueous solution. Deproteinization method from vulcanized products. 5. A natural rubber product produced by a method of immersing a natural rubber product, which has been molded and vulcanized, in a proteolytic enzyme aqueous solution to decompose the protein and extract the decomposed protein. 6. A natural rubber produced by a method of extracting a protein by immersing a natural rubber product, which has been molded and vulcanized, in a mixed solution of an aqueous solution of proteolytic enzyme and an aqueous solution of lipolytic enzyme to act on the natural rubber product. Rubber product. 7. The method for deproteinizing a natural rubber molded vulcanized product according to claim 1, wherein a nonionic surfactant is used in combination for protein decomposition / extraction. Characteristic natural rubber products. 8. The natural rubber molded vulcanized product according to claim 1, further comprising a deproteinization step of immersing in dilute acid or dilute alkaline water after the action of each enzyme aqueous solution. A natural rubber product characterized by being manufactured by the deproteinization method of.