Method for removing protein-containing substances from rubber gloves and rubber glove products obtained therefrom

Abstract

An embodiment of the present invention relates to a method for removing protein content from rubber gloves, the method comprising the steps of heating the rubber gloves in water for 10-30 minutes, heating the rubber gloves in a base solution for 50-70 minutes, and washing the rubber gloves in wash water at least twice.

Description

[Technical Field]

[0001] The present disclosure relates to a method for removing protein-containing materials from rubber gloves and rubber glove products obtained by such a method. [Background technology]

[0002] Traditional methods of manufacturing rubber gloves from natural rubber or natural latex leave proteins on the glove product, which are a major source of allergies and other adverse effects when they come into contact with the user's skin. These undesirable effects have led to the use of alternatives such as nitrile gloves, which are made from synthetic rubber and pose a lower risk of allergies. Nevertheless, latex gloves are preferred due to their physical properties, which provide superior comfort to the user. For medical users, latex gloves also offer superior protection against microorganisms.

[0003] Conventionally, the method for manufacturing rubber gloves includes a step of removing residual protein content from the glove product. Conventionally, the removal of protein is performed by chlorination, which involves the use of chlorine, a toxic chemical species, and therefore requires several work steps to deal with toxicity. Nevertheless, chlorination cannot reduce the protein content to a desirable level, and the risk of allergies still remains.

[0004] Japanese Patent Publication No. 07-289564 disclosed a method aimed at reducing the protein content of gloves by washing the finished glove product multiple times in water of various temperatures. The publication claimed that this method could reduce the protein content to one-tenth of the protein content found in conventional surgical gloves at the time, but such a level of protein content still represented a significant risk of allergies.

[0005] Furthermore, Chinese Patent Application Publication No. 102059810 discloses a method for manufacturing low-protein medical rubber gloves, which includes stirring gloves in a deproteinization extraction solution formed from borax, aqueous ammonia, and water, followed by cooling to room temperature and rinsing with clean water. This method required several work steps over 24 hours to reduce the protein content of prototype gloves to 53.9% of the initial protein content.

[0006] Despite the above-mentioned previous attempts, there remains a need for simpler and more effective methods for removing protein content from rubber gloves, including latex gloves. Summary of the Invention [Problem to be solved by the invention]

[0007] It is an object of the present invention to provide a method that addresses the above-mentioned need for easier and more effective removal of protein content from rubber gloves, including latex gloves, and to provide rubber glove products resulting from the method that have a desired level of protein content. [Means for solving the problem]

[0008] The present inventors have discovered that the method according to the present invention is surprisingly simple and effective for the above-mentioned purpose. The present inventors have also found that the resulting rubber or latex glove products contain desirable levels of protein. Furthermore, the present inventors have tested the protein content of the resulting glove products in accordance with all applicable industrial / medical standards, specifically, the standards for total protein, antigenic protein, and the four major allergens. Remarkable results were obtained in all tests described below.

[0009] In a first aspect, one embodiment is a method for removing protein-containing materials from rubber gloves, the method comprising the steps of heating the rubber gloves in water for 10 to 30 minutes, heating the rubber gloves in a base solution for 50 to 70 minutes, and washing the rubber gloves in wash water at least twice.

[0010] Preferably, the rubber gloves are heated in water at a temperature of 50 to 70°C.

[0011] Preferably, the rubber gloves are heated in a base solution at a temperature of 50 to 70°C.

[0012] Also preferably, the base solution is an alkali or alkaline earth solution. More preferably, the base solution is a sodium carbonate solution. Even more preferably, the base solution is a 0.1 to 0.3% sodium carbonate solution.

[0013] Preferably, the washing water has a temperature of 50 to 70°C.

[0014] Preferably, the rubber gloves are washed in washing water at least twice, for 10 to 30 minutes each time.

[0015] Also preferably, the method further comprises the step of drying the rubber gloves.

[0016] The above-described embodiment is preferably performed after the rubber glove has been formed and the shape and structure of the rubber glove has been fixed, and is therefore essentially unaffected by the aforementioned operating parameters. For this reason, the embodiment is preferably performed after the rubber glove has been stripped.

[0017] Due to its simplicity, the aforementioned embodiment can be performed in less than two hours and can be incorporated into any large-scale manufacturing process as a subcomponent of a batch, continuous, or semi-continuous process. Additionally, the embodiment includes a base solution, most preferably a mild solution of 0.1-0.3% sodium carbonate, thereby solving the toxicity issues that plague current state-of-the-art chlorination processes.

[0018] The rubber gloves obtained from the above-described embodiments have a hydroxyl group content of 7 μg / dm 2 according to the ASTM D5712-15 standard. 2 less than 100 μg / ml of total protein, or an assay concentration of less than 2.2 μg / ml of total protein.

[0019] In addition, the rubber gloves obtained from the above-described embodiment have a 6 μg / dm 2 less than 100 μg / ml of total protein, or an assay concentration of less than 2.0 μg / ml of total protein.

[0020] Furthermore, the rubber gloves obtained from the above-described embodiments contain non-quantifiable major allergens according to the ASTM D7427-16 standard.

[0021] Furthermore, the rubber gloves obtained from the above-described embodiment have a cellulose ester content of 0.30 μg / dm3 according to the ASTM D6499-18 standard. 2 Contains less than 10 ...

[0022] In some cases, the rubber gloves according to the above embodiments are natural rubber latex gloves.

[0023] In a second aspect, one embodiment is a rubber glove product obtained from any of the above-described embodiments according to the first aspect. Preferably, the rubber glove product contains no detectable protein. Also preferably, the rubber glove product is a natural rubber latex glove.

[0024] The principles of the present invention and its advantages will become apparent from the following description when considered in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a schematic flow chart of a method according to a preferred embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0026] It should be understood that the following detailed description is directed to embodiments that are provided solely as examples to illustrate the concepts of the present invention. Indeed, the present invention is not limited to the particular embodiments described, as such embodiments may, of course, vary. It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims.

[0027] The detailed description of the present invention has been divided into various sections for the convenience of the reader only, and disclosure in any section may be combined with disclosure in another section.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0029] It must be noted that as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0030] The term "about," when used before numerical designations, such as dimensions, times, amounts, and the like, including ranges, indicates an approximation that may vary by (+) or (-) 10%, 5%, or 1%, or any subrange or subvalue therebetween.

[0031] "Comprising" or "comprises" is intended to mean that the compositions and methods include the recited elements, but do not exclude other elements. "Consisting essentially of," when used to define compositions and methods, is intended to mean excluding other elements that are essentially significant to the combination for the described purpose. Thus, a device or method consisting essentially of the elements defined herein does not exclude other materials or steps that do not materially affect the basic and novel characteristics of the claimed invention. "Consisting of" is intended to mean excluding other components and substantial method steps beyond trace elements. Embodiments defined by each of these transition terms are within the scope of the present invention.

[0032] In this application, "rubber gloves" refers to gloves made from natural rubber or natural latex, as distinguished from gloves made from synthetic latex or synthetic rubber, such as nitrile gloves or neoprene gloves.

[0033] In the present invention, a "basic solution" refers to a liquid solution that exhibits basic properties, i.e., a pH greater than 7, where the solute may be in a solid, liquid, or gaseous state at ambient conditions and may be an organic or inorganic compound, and the solvent may be water or any other suitable chemical species.

[0034] In the present invention, "washing water" refers to tap water, distilled water, or water purified in any other way, with or without impurities or additives such as detergents or water softeners / hardeners, as long as it consists essentially of water and is deemed suitable for cleaning carried out in industrial facilities, and in the case of rubber gloves of medical grade, for cleaning of medical grade industrial products. Said suitability can be determined by a person of ordinary skill in the relevant art.

[0035] Preferred Embodiments 1 shows a schematic flow chart of a method according to a preferred embodiment, wherein the method 100 for removing protein content from rubber gloves is preferably carried out after the rubber gloves have been stripped according to known stripping processes and preferably after the rubber gloves have been weighed. The method 100 includes the subcomponent steps of heating the rubber gloves in water 110, heating the rubber gloves in a base solution 120, washing the rubber gloves a first time in wash water 130, washing the rubber gloves a second time in wash water 140, and drying the rubber gloves 150.

[0036] The subcomponent steps of heating the rubber gloves in water 110, heating the rubber gloves in a base solution 120, first washing the rubber gloves in wash water 130, and second washing the rubber gloves in wash water 140 may be performed in different or the same vessels, depending on the design choice. The minimum requirement for the vessel for any of the foregoing steps is that it must be suitable for containing water, wash water, and base solution at the relevant temperatures. Preferably, such a vessel is capable of heating its contents to the relevant temperatures. The vessel is also preferably suitable for subjecting its contents to mechanical agitation, such as shaking and rotation.

[0037] Examples of suitable containers for the subcomponent step of heating the rubber gloves in water 110, the subcomponent step of heating the rubber gloves in a base solution 120, the subcomponent step of first washing the rubber gloves in wash water 130, and the subcomponent step of second washing the rubber gloves in wash water 140 include, but are not limited to, tanks or drums equipped with means for controlling the temperature of their contents. The containers also preferably have means for shaking, rotating, or tumbling their contents to promote mixing during immersion of the gloves in the liquid.

[0038] Examples of suitable equipment for the subcomponent step 150 of drying the rubber gloves include, but are not limited to, drying hoppers or ovens equipped with heating means including steam heating coils, electricity, and heated air. Preferably, the drying equipment includes means for shaking, rotating, or turning its contents to enhance exposure of the glove surfaces to the drying medium.

[0039] After stripping the gloves, they are preferably weighed so that the ratio of glove weight to water, base solution, or wash water used in the process is within the range of 0.05 to 0.15 kg per liter, as the case may be.

[0040] Preferably, in heating 110 the rubber gloves in water, the rubber gloves are heated in water at a temperature of 50 to 70° C., preferably for 10 to 30 minutes.

[0041] Preferably, in the step of heating the rubber gloves in the base solution 120, the rubber gloves are heated in the base solution at a temperature of 50 to 70° C., preferably for 50 to 70 minutes.

[0042] Also preferably, the base solution is an alkali or alkaline earth solution. More preferably, the base solution is a sodium carbonate solution. Even more preferably, the base solution is a 0.1 to 0.3% sodium carbonate solution.

[0043] Also preferably, in the first washing 130 and second washing 140 of the rubber gloves in washing water, the washing water has a temperature of 50 to 70° C., and preferably, steps 130 and 140 are carried out for 10 to 30 minutes.

[0044] More preferably, at least one of the heating steps 110, 120 and the washing steps 130, 140 is subjected to rotation at a speed of 10 to 20 revolutions per minute.

[0045] In some embodiments, the wash steps 130, 140 are performed consecutively with the same duration, wash water temperature, and rotation speed. In such embodiments, it is preferable not to use the same wash water for the first wash 130 and the second wash 140.

[0046] Also preferably, the drying step is carried out at a temperature of 80 to 130° C., also preferably for 50 to 70 minutes. [Example]

[0047] Examples of preferred embodiments The method according to the preferred embodiment was carried out according to the following details.

[0048] In this example, the rubber gloves were powder-free, polymer-coated, non-sterile natural rubber latex gloves. The gloves were stripped according to known stripping methods, dried, and then weighed to 100 kg.

[0049] In this example, the step 110 of heating the rubber gloves in water was carried out by heating the gloves in 1,000 liters of filtered tap water in a rotating drum at 65° C. for 20 minutes while rotating at a speed of 15 revolutions per minute, after which the filtered tap water was drained from the rotating drum.

[0050] Next, step 120 was performed, in which the rubber gloves were heated in a base solution. First, 1,000 liters of filtered tap water was charged into a rotating drum containing the gloves from the previous step, and the filtered tap water was then heated to a temperature of 65°C. Next, a 19-21 wt% solution of sodium carbonate in filtered tap water at substantially the same temperature, prepared from sodium carbonate powder, was added to the rotating drum with appropriate gentle agitation to obtain a 0.1 wt% solution of sodium carbonate. This temperature of the 0.1 wt% sodium carbonate solution was maintained in the rotating drum for 60 minutes, during which time the drum was also rotated at a speed of 15 revolutions per minute. The sodium carbonate powder used in this example contained, on a dry weight basis, a total alkalinity of 99.2% or more (as sodium carbonate), a total chloride content (as sodium chloride) of 0.70% or less, an iron content of 0.003% or less, a sulfate content of 0.03% or less, and a water-insoluble material content of 0.03% or less. The sodium carbonate powder was commercially obtained from Tianjin Red Triangle International Trading Co., Ltd. The sodium carbonate solution was then discharged from the rotating drum.

[0051] Next, a first washing step 130 of the rubber gloves in wash water was performed. 1,000 liters of filtered tap water was filled into the rotating drum containing the gloves from the previous step. The filtered tap water was then heated to a temperature of 65°C. This temperature was maintained for 20 minutes, during which time the drum was also rotated at a speed of 15 revolutions per minute. The filtered tap water was then drained. A second washing step 140 of the rubber gloves in wash water was then performed by repeating the above procedure for another 20 minutes, after which the filtered tap water was drained.

[0052] The gloves were then removed from the rotating drum and placed in a drying oven where the rubber gloves were dried for 60 minutes at a temperature of 100° C. The dried gloves were then cooled to room temperature before being removed from the drying oven for inspection.

[0053] Testing of gloves obtained from the preferred embodiment The above preferred embodiment examples were performed in triplicate, and the resulting gloves were then sampled and tested under the following standards: ASTM D5712-15, EN455-3, ASTM D7427-16, and ASTM D6499-18. These tests under the standards were also performed on "comparison samples" representing the state of the art. The comparison samples were gloves of the same type that had been deproteinized by conventional chlorination. The test results are shown in Tables 1-4 below.

[0054] Table 1 below shows the test results for total protein content according to standard ASTM D5712-15. The designation "BD" stands for "below detection limit." According to said standard, the detection limit is 2.2 μg / mL.

[0055] [Table 1]

[0056] Table 2 below shows the test results for total protein content according to standard EN455-3. The designation "BD" stands for "below detection limit." According to said standard, the detection limit is 2.0 μg / mL.

[0057] [Table 2]

[0058] Table 3 below shows the test results for the major allergens Hev b1, Hev b3, Hev b5, and Hev b6.02 according to standard ASTM D7427-16. The designation "UQ" stands for "unquantifiable." According to said standard, the "quantifiable" contents of Hev b1, Hev b3, Hev b5, and Hev b6.02 are ≥ 0.05 μg / g, ≥ 0.05 μg / g, ≥ 0.025 μg / g, and ≥ 0.025 μg / g, respectively.

[0059] [Table 3]

[0060] Finally, Table 4 below shows the test results for antigenic proteins according to standard ASTM D6499-18. The designation "BD" stands for "below the limit of detection." According to said standard, the limit of detection is 0.03 μg / mL.

[0061] [Table 4]

[0062] Tables 1 to 4 above show that the methods according to the embodiments and the rubber glove products obtained therefrom exhibited clearly and surprisingly improved results over chlorination treatments according to the state of the art.

Claims

1. A method for removing allergen protein content from rubber gloves, comprising: Heating the rubber gloves in water for 10 to 30 minutes; Heating the rubber gloves in a sodium carbonate solution for 50 to 70 minutes; washing the rubber gloves in wash water at least twice; wherein the allergen protein is selected from Hev b1, Hev b3, Hev b5, and Hev b6.

02.

2. 2. The method of claim 1, wherein the rubber glove is heated in the water at a temperature of 50 to 70°C.

3. 2. The method of claim 1, wherein the rubber glove is heated in the sodium carbonate solution at a temperature of 50 to 70°C.

4. 4. The method of claim 1, wherein the sodium carbonate solution is a solution of 0.1 to 0.3% sodium carbonate.

5. 10. The method of claim 1, wherein the wash water is at a temperature of 50 to 70°C.

6. 10. The method of claim 1, wherein the rubber gloves are washed in the wash water at least twice, for 10 to 30 minutes each time.

7. 10. The method of claim 1, further comprising the step of drying the rubber glove.

8. 10. The method of claim 1 performed after stripping the latex glove.

9. A method for removing allergen protein content from rubber gloves, comprising: Heating the rubber glove in water at a temperature of 50 to 70°C for 10 to 30 minutes; Heating the rubber glove in a 0.1-0.3% sodium carbonate solution at a temperature of 50-70°C for 50-70 minutes; Washing the rubber gloves in wash water at least twice, each time for 10 to 30 minutes at a temperature of 50 to 70°C; wherein the allergen protein is selected from Hev b1, Hev b3, Hev b5, and Hev b6.

02.

10. 10. The method of claim 9, further comprising the step of drying the rubber glove.

11. 10. The method of claim 9, performed after stripping the latex glove.

12. The rubber gloves obtained by the above method have a densitometric value of 7 μg / dm3 according to the ASTM D5712-15 standard. 2 10. The method of claim 1 or 9, comprising less than 1000 mg of total protein.

13. 10. The method of claim 1 or 9, wherein the rubber glove obtained from said method contains an assay concentration of total protein of less than 2.2 μg / ml according to ASTM D5712-15 standard.

14. The rubber gloves obtained by the above method have a chlorine content of 6 μg / dm 2 10. The method of claim 1 or 9, comprising less than 1000 mg of total protein.

15. 10. The method of claim 1 or 9, wherein the rubber gloves obtained from said method contain an assay concentration of total protein of less than 2.0 μg / ml according to the EN455-3 standard.

16. 10. The method according to claim 1 or 9, wherein the rubber gloves obtained from said method contain non-quantifiable major allergens according to ASTM D7427-16 standard.

17. The rubber gloves obtained by the above method have a cellulose acylate content of 0.30 μg / dm3 according to the ASTM D6499-18 standard. 2 10. The method of claim 1 or 9, comprising less than 10 ...

18. 12. The method of any one of claims 1 to 3 or 5 to 11, wherein the rubber glove is a natural rubber latex glove.

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