JP2977673B2 - Deproteinizing agent for natural rubber and method for producing deproteinized natural rubber using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deproteinizing agent for removing proteins in natural rubber and a method for producing deproteinized natural rubber using the same.

[0002]

2. Description of the Related Art In general, field latex, which is a raw material of natural rubber, contains components such as proteins in addition to rubber components.
There are problems such as causing a strong allergic reaction to the person who uses the final product. In addition, natural rubber has a problem that the quality and quality of final rubber products are deteriorated due to differences in the amount and type of proteins mixed depending on the region, time of production, and climate.

[0003] To solve these problems, proteins are washed and removed by washing the field latex with water and then concentrating the latex, or adding a surfactant and washing and concentrating the protein. It is difficult to sufficiently remove mixed proteins. Further, a technique of treating a field latex with a fatty acid soap and a protease and a specific nonionic surfactant and a protease does not provide a sufficient removal effect.

Accordingly, a main object of the present invention is to remove proteins in natural rubber easily and efficiently.
As a result, a deproteinizing agent for natural rubber capable of obtaining a natural latex and rubber free from the possibility of causing allergies due to proteins and of obtaining a rubber product of stable quality by removing impurities in natural rubber can be obtained. To provide.

Another object of the present invention is to provide a method for producing a deproteinized natural rubber which can produce a deproteinized natural rubber with high productivity.

[0006]

Means and Actions for Solving the Problems The present inventors have found that washing with a proteolytic enzyme and an anionic surfactant having a high protein-dispersing ability and a high denaturing effect enables efficient removal of natural rubber. The inventors have found that it is possible to remove proteins, and have completed the present invention. That is, the present invention provides a natural rubber comprising a protease and one or more anionic surfactants selected from the group consisting of sulfonic acids, sulfates and phosphates as active ingredients. The present invention provides a deproteinizing agent.

[0007] The mechanism of protein removal by the deproteinizing agent of the present invention is not necessarily clear, but at the same time as the protein is released from the rubber component by the protease, the protein is degraded to a low molecular weight and the protein is removed by the anionic surfactant. This is considered to be due to the fact that the particles are modified into a shape in which they are easily dispersed, so that they are efficiently washed. Examples of the sulfonic acid surfactant in the present invention include alkyl benzene sulfonate, alkyl sulfonate, alkyl naphthalene sulfonate, naphthalene sulfonate, and diphenyl ether.
Tersulfonates and the like. Examples of the sulfate-based surfactants include alkyl sulfates, polyoxyalkylene alkyl sulfates, polyoxyalkylene alkyl phenyl ether sulfates, tristyrenated phenol sulfates, and distyrenated phenol sulfates. Ester salts, α-olefin sulfate esters,
Alkyl succinic acid sulfates, polyoxyalkylene tristyrenated phenol sulfates, polyoxyalkylenedistyrenated phenol sulfates and the like can be mentioned. As phosphate ester surfactants,
For example, alkyl phosphate ester salts, polyoxyalkylene phosphate ester salts and the like can be mentioned. As salts of these compounds, metal salts (Na, K, Ca, Mg, Zn, etc.),
An ammonium salt or an amine salt (such as a triethanolamine salt) can be used.

[0008] The alkyl group in the surfactant includes an alkyl group having 4 to 30 carbon atoms.
The polyoxyalkylene group may have 2 to 4 carbon atoms.
For example, those having an addition mole number of ethylene oxide of about 1 to 50 mol can be used. In using these enzymes and surfactants, other additives, such as phosphates and acetates such as potassium phosphate monobasic, potassium phosphate dibasic, and sodium phosphate as pH adjusters, and further, sulfuric acid and acetic acid , Hydrochloric acid, nitric acid, citric acid, succinic acid and the like, or salts thereof, or ammonia, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium hydrogencarbonate, and the like.
As enzymes, lipase, esterase, amylase
The enzyme can be used in combination with enzymes such as lyse, laccase and cellulase.

Further, if necessary, styrene sulfonic acid copolymer, naphthalene sulfonic acid formalin condensate, lignin sulfonic acid, polycyclic aromatic sulfonic acid copolymer,
Dispersants such as acrylic acid and maleic anhydride homopolymers and copolymers, and isobutylene-acrylic acid and isobutylene-maleic anhydride copolymers can also be used in combination.

The mixing ratio of the protease and the anionic surfactant in the deproteinizing agent of the present invention is not particularly limited, but is 1 / (1 to 200) by weight, preferably 1/200.
(1 to 100). The amount of protease is 1/200
If it is less than 1, sufficient effects cannot be exhibited, and if it exceeds 1/1, the cost increases. To remove proteins in natural rubber using the deproteinizing agent of the present invention, a rubber processing method of adding the deproteinizing agent of the present invention to field latex and ammonia-treated latex and washing latex particles is known. It is preferably adopted. At that time, the amount of the deproteinizing agent added is from 0.001 to 10% by weight, preferably from 0.1 to 3% by weight, based on the latex dispersion. The amount added is 0.
If the amount is less than 001% by weight, the added amount is too small to obtain a sufficient effect. The treatment time of the deproteinizing agent is not particularly limited, but it is preferable to perform the treatment for several minutes to about one week. In the treatment of the latex, stirring may be performed or standing may be performed. The temperature may be adjusted as needed, and the appropriate temperature is 5 ° C to 90 ° C, preferably 20 ° C to 6 ° C.
0 ° C. When the treatment temperature exceeds 90 ° C., the enzyme is quickly deactivated, and when the treatment temperature is less than 5 ° C., the reaction of the enzyme becomes difficult to proceed. The method for washing the latex particles is not particularly limited, but the latex particles and the washing solution may be separated by a centrifugal separation method, or the latex particles may be aggregated and separated. When washing natural rubber, synthetic rubber or synthetic rubber latex can be used in combination.

As the protease of the present invention, generally known ones can be used, and there is no particular limitation. Alkaline protease can be preferably used. The origin of the protease may be either bacterial origin, filamentous fungal origin, or yeast origin. Of these, it is preferable to use bacterial protease. The natural rubber in the present invention means a field latex and a solid rubber obtained from a natural rubber tree, and the latex may be either an aged one, a high ammonia latex or a fresh field latex. I can do it.

The natural rubber obtained by removing the protein at a high level according to the present invention can be used, for example, in gloves, contraceptives, medical devices,
It can be used in the fields of stringing, solid rubber products, sporting goods, tires and the like. Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

[0013]

【Example】

Examples 1-4 Natural rubber high ammonia latex was 30% in rubber content
After adjusting the pH to 9 with H ₃ PO ₄ ,
1% of a deproteinizing agent having the formulation shown in Table 1 was added. Then, it is allowed to stand at 30 ° C. for 24 hours and at 13000 rpm for 30 hours.
After centrifugation for minutes, the separated upper layer cream portion was taken out and redispersed in the same amount of water. After centrifugation twice and three times, after the first centrifugation, the cream portion is washed with a 1% solution of a surfactant (containing no protease), and centrifuged at 13000 rpm for 30 minutes. ,
Hereinafter, the same operation as the first time was repeated. This is a small amount of C
pouring into methanol containing aCl ₂ to precipitate the rubber,
Dry overnight under reduced pressure. Thereafter, the nitrogen content was determined by the Kjeldahl method to determine the remaining protein content. Note that the measurement accuracy of the nitrogen content is ± 0.0001%.

[0014]

[Table 1]

Comparative Examples 1 to 4 The same treatment as in Examples 1 to 4 was carried out except that the deproteinizing agent having the formulation shown in Table 2 was used, and the remaining protein was determined.

[0016]

[Table 2]

Table 3 shows the processing conditions and test results. In the table, the term "distilled water" indicates the nitrogen content when the sample was washed with only distilled water as a blank. Example 2 also shows the nitrogen content when the number of washings was one and two.

[0018]

[Table 3]

Table 3 shows that the protein can be efficiently and easily removed from natural rubber by treating the natural rubber latex with the deproteinizing agent of the present invention.

[0020]

As described above, since the deproteinizing agent of the present invention contains a protease and an anionic surfactant having excellent dispersibility as active ingredients, it efficiently converts proteins in natural rubber. Since it can be easily removed, it is useful as a countermeasure against allergy and has the effect of easily producing a deproteinized natural rubber having a stable quality.

Further, the method for producing a deproteinized natural rubber of the present invention has the effect of having high productivity because it only involves adding the deproteinizing agent to the natural rubber latex and washing the latex particles.

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naoya Ichikawa 41-1, Uozumi-cho, Akashi-shi, Hyogo Sumitomo Rubber Industries, Ltd. Uozumi-Ryo (56) References US Patent 2,096,481 (US, A) British Patent 1,366,934 (GB, B) UK Patent Application No. 2098222 (GB, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08C 1/04

Claims (6)

(57) [Claims] 1. A natural rubber comprising as an active ingredient a protease and one or more anionic surfactants selected from the group consisting of sulfonic acids, sulfates and phosphates. Deproteinizing agent. 2. The deproteinizing agent for natural rubber according to claim 1, wherein the protease is an alkaline protease. 3. The anionic surfactant is selected from the group consisting of alkyl benzene sulfonates, alkyl sulfates, alkyl phosphates, polyoxyalkylene alkyl sulfates, and polyoxyalkylene alkyl phosphates. One or more surfactants, and salts of these compounds are metal salts (Na salt, K
2. The deproteinizing agent for natural rubber according to claim 1, which is a salt, Ca salt, Mg salt or Zn salt), ammonium salt or amine salt. 4. The deproteinizing agent for natural rubber according to claim 1, wherein the weight ratio of said protease and anionic surfactant is 1 / (1-200). 5. A method for producing a deproteinized natural rubber, comprising adding the deproteinizing agent according to claim 1 to a field latex or an ammonia-treated latex to treat latex particles. 6. The method for producing a deproteinized natural rubber according to claim 5, wherein the amount of the deproteinizing agent added is 0.01 to 10% by weight based on the latex dispersion.