JP2002069102A - Eliminating process by supercritical extraction for odor of natural rubber latex, odor of curing agent and allergenic protein - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for eliminating an allergen which develops latex allergy and exists within protein contained in latex. SOLUTION: The cases of immediate type allergy capable of developing dyspnea or anaphylaxis to the people of using products from natural rubber latex (gloves and a catheter) are reported increasingly, including cases of death. The allergenic protein and odorous substance contained in latex are eliminated by extraction with carbon dioxide supercritical fluid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to deodorization of natural rubbers, odor of vulcanizing agents, extraction and removal of allergic proteins and the like.

[0002]

2. Description of the Related Art The Society of Rubber Industry, Japan, Vol. 71, No. 12 (19
98) has published a study on natural rubber, and the medical bulletin “Clinical Allergy 19 (9) 1999” reports the current state of latex allergy. There is an urgent need to establish a technology for de-allergenic proteins in natural rubber latex products. Natural rubber latex is produced by adding ammonia to a white sap collected from a rubber tree and then vulcanizing. Latex-containing products include rubber rings, balloons, pacifiers, gloves, condoms, catheters, adhesives, elastic tapes, and the like, and are widely used from industrial products to medical and household products. It is said that this natural rubber latex contains non-rubber components such as proteins, lipids and carbohydrates in addition to the main component rubber hydrocarbons.
In recent years, people using natural rubber latex products (gloves and catheters) have been reported to have reported cases of dyspnea and immediate allergies leading to anaphylaxis, and deaths have occurred. Has been reported. It has been confirmed and identified that the causative substance of latex allergy is in allergic proteins contained in latex.
It has been said that the development of low-allergenic, high-purity, deproteinized natural rubber latex, which removes proteins and the like from natural rubber latex, has already been successful. Contains protein of the kind, and adheres to rubber particles in the state of water-soluble protein,
It is also contained in the rubber body. At present, the following methods can be used to remove proteins. Alkali treatment method Utilization of proteolytic enzyme There is a method of decomposing and removing proteins contained in latex by washing the proteolytic enzyme with a surfactant in combination. In the above-mentioned method for decomposing and removing protein in latex,
The effects have been recognized respectively. Since these are deproteinization treatments using a water-soluble solvent, the difficulty of removing residual water after washing with bag-like latex products, such as gloves and condoms, and the difficulty of the drying process hinder the removal of allergic proteins. It is a factor. At present, powder is sprayed on the product to remove moisture after removing the washing water used in the manufacturing process of gloves and condoms, and to improve practical use, preventing adhesion of rubber to each other and preventing slippage. It is well known that improvements are being made. Exposure to this powder is said to increase the number of latex-allergic patients. In recent years, many cases of immediate allergy leading to dyspnea and anaphylaxis have been reported in Japan. This suggests that allergic proteins were not sufficiently reduced and removed from the rubber products.

[0003]

The natural rubber latex product is obtained by purifying a white sap collected from a rubber tree.
Although it is manufactured by vulcanization, immediate-type allergies caused by repeated exposure to the soluble protein contained in this latex product, that is, "latex allergies" are increasing rapidly. Clinical "19 (9) 1999. Latex-containing products include rubber rings, balloons, pacifiers, condoms, adhesives, elastic tapes, and the like.
There are about 200 types of proteins contained in natural rubber latex, which are said to be present as water-soluble proteins attached to rubber or bound to rubber particles. Preventing latex allergy is to avoid contact with latex products and to reduce the amount of rubber protein contained.For healthcare professionals, use non-latex gloves or powder-free low protein gloves It does not matter that this leads to prevention. In addition, the use of powder-free low protein gloves can reduce the exposure of latex allergic protein antigens and reduce the floating of powder adsorbed latex into the air. On the other hand, in medical care, natural rubber latex gloves are important medical tools to prevent various infections to healthcare workers and patients, and latex gloves are materials that are very easy to use because of their fit and strength. Yes, usability is permeating the people involved. Furthermore, natural rubber latex products are produced by adding a vulcanizing agent, but the odor is often disliked as a bad odor in practical use. It is also expected to supply products with reduced odor and odorlessness caused by the vulcanizing agent. Natural rubber latex products and natural rubber latex raw materials contain latex allergic substances and odorous substances.
It is necessary to reduce or remove allergic proteins and odorous proteins by a method that does not cause changes in basic physical properties even when proteins of allergic sources and odor sources are removed from natural rubber.

[0004]

SUMMARY OF THE INVENTION Latex allergy has been confirmed and identified as being caused by allergic proteins contained in latex. Various methods for extracting and removing allergic proteins, which are allergic substances, have been proposed. According to the present invention, since the allergic proteins are water-soluble, a highly soluble supercritical fluid is effective for the target proteins. Allergic proteins can be extracted and removed from latex rubber products and latex rubber raw materials to reduce allergic substances. Further, when ethanol is added to the supercritical fluid, the solubility increases, and the effect of extracting the target substance is enhanced. . About 200 proteins are contained in natural latex.
It is said that there are kinds. Among these proteins, allergic proteins that act as allergens have been identified.
Conventional rubber products contain water-soluble protein allergens in and around the product, some of which are free or taken up in latex. Under excess conditions, it is possible to extract and remove by utilizing the properties of the following supercritical fluids. (A) Since the density can be controlled using temperature and pressure as operating variables, many solvent characteristics expressed as a function of the density can be obtained.Therefore, by setting the optimal pressure and temperature for the protein to be extracted, Is separated and extracted. (A) It has low viscosity and excellent permeability to solid materials due to its high diffusivity, and can be expected to have a high mass transfer rate. The contained allergic proteins can be separated, extracted and removed under appropriate pressure and temperature. (C) Since the kinematic viscosity is smaller than that of gas-liquid and natural convection is extremely likely to occur, it can be made to work much more effectively with respect to substances and heat transfer than liquid solvents. After extracting and removing allergic substances and odorous substances adhering to the latex using the properties of supercritical fluids such as By reducing the pressure of the supercritical fluid to atmospheric pressure, not only the target substance can be extracted and removed, but also the drying can be performed. A microscopic examination of the rubber body shows that the action of the vulcanizing agent causes the rubber polymer to bind at the cross-linking points of the molecular chains to form a network structure, thereby ensuring rubber properties. Between networks
The highly permeable solvent freely permeates and elutes the target substance for dissolution / elution out of the rubber body by the action of molecular motion. When the molecular weight of the target substance to be eluted is large, it takes a certain amount of time to move the target substance to be dissolved outside the rubber body through the rubber network gap. . The solvent that has penetrated into the network dissolves the target substance to be eluted and removed, but if the environmental pressure is suddenly reduced, it rapidly expands in the rubber according to Boyle's law, forming bubbles in the rubber. . If the pressure is gradually reduced, the solvent and the elution target substance in the bubble chamber move out of the rubber body and elute with the passage of time. Sudden pressure transformation destroys the network structure in the rubber
A bubble chamber may be formed or the bubble chamber may be destroyed and lost. In the case of rubber raw materials, since the network structure is not formed, even if the environmental pressure is rapidly lowered, the bubble extraction is not formed and maintained, and the dissolution and extraction of the target substance proceeds. Conventional odor and allergic substances have been washed with water.However, rubber products, especially bag-shaped condoms and gloves, have poor drying properties. Spraying to prevent mutual adhesion of rubber. According to this method, that is, the product drying is completed at the same time as the completion of the atmospheric pressure decompression treatment, so that the drying step is simplified and the target substance is prevented from remaining. . The fact that the enzyme KP-3939 is effective in decomposing natural rubber latex allergic proteins is reported in detail in "Studies on High Purity Natural Rubber" (Journal of the Rubber Association of Japan / Vol. 71, No. 12, 1998). . After the above allergic decomposition treatment, effective extraction is performed in a supercritical fluid in which natural convection is extremely likely to occur, thereby extracting and removing allergic substances and odorous substances. . Enzyme KP-3939 and other proteolytic enzymes, surfactants, ethanol and / or, together with latex material in a supercritical fluid with low viscosity, high diffusivity and natural convection
Water is injected to promote enzymatic degradation and then extract and remove allergic proteins and odorous substances.

[0005]

[Action]. A natural rubber latex product is a porous elastic material, and a low-viscosity, high-diffusion supercritical fluid is allowed to permeate into a rubber product under appropriate set critical conditions to extract and remove the first target substance. can do. . After the term has been extracted, the second
The second or third target substance can be specifically extracted by changing the supercritical condition for extracting and removing the target substance in this way and setting new conditions in accordance with the appropriate temperature and pressure of the target substance. . The carbon dioxide supercritical fluid has high solubility and excellent extractability of the target substance, but further enhances the extractability of the specific substance by mixing with ethanol. Carbon dioxide is not reactive under supercritical conditions and does not alter latex rubber products or latex rubber raw materials.

[0006]

Industrial Applicability The present invention is intended to dissolve and extract water-soluble allergic proteins contained in natural rubber latex by utilizing the high solubility of a supercritical fluid, and to further increase the solubility under super-supercritical conditions. To provide a method for effectively extracting and removing allergic substances and odorous substances in the porous rubber body because the extraction process is continued for a predetermined period of time by press-filling ethanol into the mixture. In addition, deodorization and deproteinization of low-odor latex rubber products and latex rubber raw materials are easy, so that products and raw materials can be easily obtained. In addition, when taken out in the atmospheric pressure after the supercritical treatment, not only carbon dioxide but also ethanol is evaporated, and the drying is automatically completed. Therefore, the powder application is not required and the process can be simplified. By treating latex products and latex raw materials according to the present invention, the amount of allergic proteins and odorous substances in various latex rubber products are reduced, the exposure to allergic proteins is extremely reduced, and the rapid increase in latex allergic patients is suppressed. Not only can it be done, but also the odor removal in practical use is achieved. One example in which a condom was deodorized under supercritical conditions is shown below. FIGS. 1 and 2 show the residual states of the first odor substance and the second odor substance before and after the supercritical treatment. In addition, Table 1 shows the results of a test in which a protein was eluted from the sample and subjected to absorption analysis.

[0007]

[Table 1]

[0008]

3 and 4 show a flow of supercritical carbon dioxide extraction. Hereinafter, the extraction flow will be described with reference to FIG. The critical point of carbon dioxide is as follows: pressure: 75.3 kg / cm 2, temperature:
31.1 ° C.

[0009]

[First Embodiment] A method of dissolving and extracting allergic proteins and odorous substances from a latex rubber product. The flowchart is shown in FIG. Liquefied carbon dioxide serving as a solvent is supplied from the liquid carbon dioxide cylinder 1 by opening the on-off valve 2, and is pressurized to a critical pressure or higher by the high-pressure liquefied carbon dioxide pump 3. The pressurized liquefied carbon dioxide is heated to a set temperature by the heat exchanger 4 via the on-off valve 5 and stored in the high-pressure extraction tank 6. High pressure extraction tank 6
Latex rubber products (not shown),
For example, a condom may be exposed to a first predetermined suitable pressure and temperature under supercritical conditions of the solvent carbon dioxide, resulting in high permeability, diffusivity, and low kinematic viscosity compared to gas-liquid. First, an allergic protein substance, which is a first target substance, is extracted by the action of the supercritical fluid. Then, the opening / closing valve 5 is closed. The supercritical fluid in which the target substance is dissolved and extracted in the high-pressure extraction tank moves to the separation tank 8 by opening the control valve 7, and then the control valve 7 is closed. After the opening / closing valve 5 is opened again, the control function of the high-pressure liquefied carbon dioxide pump 3 is preset by the high-pressure liquefied carbon dioxide pump 3 so that the liquefied carbon dioxide becomes the second supercritical condition newly set. The operation is adjusted by the high-pressure carbon dioxide pump 3 and the heat exchanger 4 so that the stored pressure and the temperature set in advance in the control function of the heat exchanger 4 become the second supercritical fluid into the high-pressure extraction tank 6. Fluid is replenished. Under the second supercritical extraction condition, the inside of the extraction tank 6 is exposed to the supercritical fluid for a preset time, and the extraction process of the odor substance as the second target substance from the latex product is started. After the supercritical fluid in which the first extraction substance is dissolved and extracted into the separation tank 8, the control valve 7 is closed.
When the on-off valve 9 is opened, liquefied carbon dioxide is released and the pressure in the separation tank 8 is gradually reduced, and the extracted substance is released in the separation tank 8 together with ethanol, and the pressure is reduced to the atmospheric pressure. Then, ethanol and allergic proteins as the first extractable substance are removed from the opening / closing valve 10. In the supercritical fluid introduced into the high-pressure extraction tank 6 for the extraction of the second extractable substance, the second extractable substance is dissolved and extracted under a preset pressure and temperature for a preset time. After a lapse of a set time, the control valve 7 is opened, the supercritical fluid in which the second target substance is dissolved and extracted is moved to the separation tank 8, and the control valve 7 is closed, and then the open / close valve 9 is opened. Eventually, the pressure is reduced to the atmospheric pressure, and after the odor substance of the second extracted substance is removed by opening the on-off valve 10, the on-off valve 10 is closed and the extraction process is completed. After the opening / closing valve 5 is closed, the control valve 11 is opened, the pressure in the high-pressure extraction tank 6 is reduced to atmospheric pressure, the opening / closing door 12 of the high-pressure extraction tank 6 is opened, and the latex charged into the inside is opened. The rubber product (condom) is taken out. At this time, the liquefied carbon dioxide gas is completely vaporized and dried. However, even when residual ethanol is present, the liquefied carbon dioxide gas is naturally dried, and the drying is completed. As stated in the above process, the first target substance, for example, an allergic substance or Then, the second target substance, for example, the odor substance is sequentially extracted, and the extraction of each target substance of the first batch of latex rubber product is completed. An appropriate amount of the second batch of latex rubber product, for example, a condom, is charged into the high-pressure extraction tank 6, and the second batch extraction process is started. The above processing is sequentially repeated. When the pressure in the high-pressure extraction tank 6 is reduced, the control valve 7 is controlled so that the pressure reduction rate does not exceed a predetermined speed.
Alternatively, since the control knob of the control valve 11 is adjusted and the pressure is returned to the atmospheric pressure, the supercritical fluid or liquefied carbon dioxide gas which has entered the rubber product is suddenly decompressed and expanded under reduced pressure, and foams inside the rubber. It does not leave or leave scratches due to foaming.

[0010]

[Second Embodiment] A second embodiment of the present invention is to dissolve and extract a water-soluble target substance from a latex rubber raw material in a supercritical fluid. Figure 4 shows the flow chart. The liquefied carbon dioxide serving as a solvent is supplied from the liquefied carbon dioxide cylinder 31 by opening the on-off valve 32, and is supplied by the high-pressure liquefied carbon dioxide pump 33.
The pressure is raised to a predetermined critical pressure or higher than the critical pressure, and the temperature is raised to a predetermined temperature via a heat exchanger 34 by opening an on-off valve 35, and the high pressure extraction tank 36 is opened.
, And stored at a predetermined supercritical state. On the other hand, the additive tank 50 is charged with an appropriate amount of a decomposing enzyme for decomposing latex allergic protein or odor protein, a surfactant, ethanol and / or water. Further, a latex raw material is charged, mixed and accumulated in the additive tank 50, and is maintained at substantially the same temperature as the supercritical fluid stored in the high-pressure extraction tank 36. Additive opening / closing valve 6
When the valve 2 is opened and the additive high pressure pump 61 is operated, the mixed solution (latex raw material, protease, surfactant, ethanol and / or water, etc.) in the additive tank 50 is filled in the high pressure extraction tank 36. The additive is pressurized by a high-pressure pump 61 and mixed with a supercritical fluid, whereby allergic proteins and odorous proteins are decomposed by the action of a protease and dissolved and extracted in the supercritical fluid. When a preset time has elapsed, the control valve 37 is opened, the supercritical fluid in which allergic proteins and odorous proteins are dissolved moves to the separation tank 38, and the control valve 37 is closed. Thereafter, when the open / close valve 39 is opened, the carbon dioxide in the separation tank 38 is released into the atmosphere, the inside of the separation tank 38 returns to the atmospheric pressure, and the open / close valve 39 is closed. Allergic substances, odor substances, and / or ethanol / water accumulated in the separation tank 38 are discharged and removed from the on-off valve 40. The latex remaining in the high-pressure extraction tank 36 is decompressed at a decompression speed lower than a predetermined decompression speed of the on-off valve 41 and returns to the atmospheric pressure. The purified latex from which allergic proteins and odor proteins have been extracted and removed is taken out by opening the high-pressure extraction tank opening / closing door 42 of the high-pressure extraction tank 36, and is sent to the product forming process as a low-allergy product and a low-odor latex rubber raw material. Thus, de-allergic and deodorized latex rubber products are produced.

[Brief description of the drawings]

FIG. 1 is a gas chromatogram before supercritical treatment of two types of odor substances in a latex rubber product (condom).

FIG. 2 is a gas chromatogram after supercritical treatment of two types of odor substances in a latex rubber product (condom).

FIG. 3 is a flow chart of extracting odor and allergic substances of a latex product using a carbon dioxide supercritical fluid.

FIG. 4 is a flow chart of extracting the odor of a latex raw material and allergic substances using a carbon dioxide supercritical fluid.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquefied carbon dioxide cylinder 2 Opening / closing valve 3 High pressure liquefied carbon dioxide pump 4 Heat exchanger 5 Opening / closing valve 6 High pressure extraction tank 7 Control valve 8 Separation tank 9 Opening / closing valve 10 Opening / closing valve 11 Control valve 12 High pressure extraction tank opening / closing door 13 Opening / closing valve 31 Liquefied carbon dioxide cylinder 32 Open / close valve 33 High pressure liquefied carbon dioxide pump 34 Heat exchanger 35 Open / close valve 36 High pressure extraction tank 37 Control valve 38 Separation tank 39 Open / close valve 40 Open / close valve 41 Control valve 42 High pressure extraction tank open / close door 43 Open / close valve 50 Addition Agent tank 61 Additive high pressure pump 62 Additive valve 63 Additive valve 64 Open / close valve

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ryoko Nishihira 2-4-6 Itoyacho, Chuo-ku, Osaka Jex Corporation F-term (reference) 4D056 AB11 AB20 AC24 BA16 CA01 CA03 CA13 CA21 CA22 CA26 CA31 CA39 DA06

Claims (5)

[Claims] A natural rubber latex product is exposed to carbon dioxide supercritical conditions, and after an extraction treatment for 12 to 18 minutes,
A method of extracting and removing odors and allergic proteins which are reduced to atmospheric pressure after a decompression time of 30 minutes or more. 2. A natural rubber latex material is injected under supercritical conditions of carbon dioxide, extracted for 4 to 6 minutes, and then subjected to atmospheric pressure reduction after about 20 minutes or more of decompression time. Removal method. 3. The method according to claim 1, wherein the supercritical condition is kept substantially constant for 12 to 18 minutes, and
Odor, allergy characterized by setting the half-reduction pressure treatment time to about 1/10 or less of the total atmospheric pressure reduction time after the secondary extraction treatment for 10 minutes with the supercritical condition almost constant newly. Protein extraction removal method. 4. A product of natural rubber latex and enzyme KP-3
2. The method for extracting and removing odors and allergic proteins according to claim 1, after performing proteolytic treatment with 939 or a mixture of various proteases, surfactants, ethanol and / or water. 5. Raw material of natural rubber latex and enzyme KP-3
3. The method for extracting and removing odors and allergic proteins according to claim 2, after performing proteolytic treatment with 939 or a mixture of various proteases, surfactants, ethanol and / or water.