JP2001131812A - Rubber glove - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pair of inexpensive rubber gloves excellent in the touch of wear without bringing about allergy due to protein. SOLUTION: This pair of resin gloves is such one as to be made by a soaking method using a latex of a styrene-butadiene rubber with a glass transition temperature of <=20 deg.C; and this pair of gloves is characterized by that the percentage of stress relaxation (%) after a lapse of 6 minutes states from removing the tensile stress at 100% elongation, represented by formula (1): [M100(0)-M100(6)]/[M100(0)×100, is 50-70%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a rubber glove made of styrene-butadiene rubber (SBR).

[0002]

2. Description of the Related Art Conventionally, natural rubber latex is often used as a raw material for rubber gloves. This is because gloves made of natural rubber obtained by using the latex have extremely low modulus and have a good feeling of wearing that cannot be obtained with gloves made of conventional synthetic rubber. However, in recent years, it has been reported that immediate allergy and the like may be caused due to proteins contained in natural rubber latex, and rubber gloves used in direct contact with the skin, especially surgical gloves and the like, have been reported. In the case of rubber products, such a problem is serious.

Therefore, gloves made of vinyl chloride resin have been used instead of natural rubber. Gloves made of vinyl chloride resin are moderate in modulus and not so high. Although they have a lower fit to hands than natural rubber gloves, they have very good wearability when putting on and taking off. However, the use of vinyl chloride resin is being restricted, especially in recent years, because of the possibility of generating dioxin during disposal and the like.

[0004]

On the other hand, as a rubber material replacing natural rubber, Japanese Patent Application Laid-Open No. 9-505612 discloses a latex comprising a cured mixture of a copolymer of acrylonitrile and butadiene or isoprene and a styrene-butadiene copolymer. The use of films is being considered. However, acrylonitrile-
Butadiene rubber (NBR) costs about 3 times NR and isoprene rubber (IR) costs about 5 times NR,
Not practical.

Accordingly, an object of the present invention is to provide a rubber glove which uses an inexpensive rubber material, has a good wearing feeling, and does not cause allergy caused by proteins.

[0006]

Means for Solving the Problems and Effects of the Invention The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, the general-purpose styrene-butadiene rubber (SBR) has a glass transition temperature of a predetermined value. Rubber gloves that are inexpensive and have good wearability without the above-mentioned allergy problem when the following are used and the stress relaxation rate for tensile stress is adjusted to be smaller than a predetermined value. Have found a new fact that it is possible to obtain the present invention, and have completed the present invention.

That is, the rubber glove of the present invention is formed by a dipping method using a latex of styrene-butadiene rubber having a glass transition temperature of 20 ° C. or less. A stress relaxation rate after a lapse of 6 minutes from 50 to 70%. According to the rubber glove of the present invention, since it is formed of SBR having a glass transition temperature satisfying the above range, it exhibits good rubber elasticity at room temperature, obtains an appropriate modulus, and has a feeling of use such as operability. Is also good. In addition, since the stress relaxation rate after 6 minutes from the removal of the tensile stress of 100% elongation is 50 to 70%, the fit to the hand is very good. In addition, SBR
Since is a general-purpose inexpensive synthetic rubber, the manufacturing cost of rubber gloves can be reduced.

Further, according to the rubber glove of the present invention,
SBR as a raw rubber is a synthetic rubber and does not contain a protein unlike a natural rubber, and therefore does not cause allergy caused by the protein. The rubber gloves according to the present invention are used not only in work gloves but also in a wide range of fields such as surgical gloves because they do not cause allergy due to proteins, in addition to their excellent usability and wearability. can do.

In the rubber glove of the present invention, from the viewpoint of setting the stress relaxation rate within the above range, the rubber content in the latex of the styrene-butadiene rubber is 100%.
It is preferable that the amount of zinc white be adjusted to be 0.1 to 1.2 parts by weight with respect to parts by weight. The “stress relaxation rate” in the present invention is measured by the following method. First, using a sample piece conforming to the dumbbell-shaped No. 4 specified in JIS K6251 “Tensile test method for vulcanized rubber”, tensile stress is applied to both ends of the sample piece at a rate of 500 mm / min. . Next, the tensile stress M ₁₀₀ (0) [MP] at the time when the parallel portion (length: 20 mm) of the sample piece was extended to 40 mm (at 100% extension).
a], and the tensile stress M ₁₀₀ (6) [MPa] at the time when 6 minutes have passed since the 100% elongation.
From M ₁₀₀ (0) and M ₁₀₀ (6) thus measured, the equation (1) is obtained.
:

[0010]

(Equation 1)

Thus, the stress relaxation rate (%) is calculated. Incidentally, Japanese Patent Application Laid-Open No. 55-163202 discloses SBR.
A method for manufacturing a working glove having a film formed using latex is disclosed. However, in the method disclosed in this publication, a rubber coating is formed on the surface of a cloth glove, and the configuration is essentially different from that of a glove having a single rubber film of SBR rubber as in the above-described present invention. . Further, the work gloves disclosed in this publication have a rubber glove formed on the surface of a cloth glove, so that the manufacturing process is complicated, the manufacturing cost is increased, and the wearability such as fit to hands is low. There is a problem of being damaged.

On the other hand, Japanese Unexamined Patent Publication No. 9-157449 discloses an antibacterial rubber molded article containing SBR rubber and an antibacterial agent (see Example 2). As an example of the molded article, rubber gloves are used. It has been disclosed. However, the rubber molded product disclosed in this publication is not molded from a rubber latex by a dipping method, but is obtained by adding a compound such as an antibacterial agent and zinc white to raw rubber, and performing steps such as mastication, rolling and molding. It is something that can be done. Therefore, it is essentially different from that obtained by the dipping method like the rubber glove of the present invention. In addition, in the rubber molded article of the above publication, uniform processing is performed by a simple process by dipping which is a feature of the dipping method. The advantage that a rubber film having a large thickness can be formed cannot be obtained.
Further, in the embodiment disclosed in the publication, the SBR rubber 10
5 parts by weight of zinc flower is blended with respect to 0 parts by weight,
From the results of Examples and Comparative Examples of the present invention described later, in such a case, the stress relaxation rate of the rubber glove is reduced or the modulus is increased, and it is not possible to obtain a rubber glove having a good feeling of wearing. It is supposed to be.

In Japanese Patent Publication No. Sho 60-6655,
Medical gloves using styrene-butadiene rubber latex are disclosed. However, such gloves are intended to provide gloves that can be worn without using a separate lubricant, and include a layer of carboxylated styrene-butadiene rubber latex in which particulate matter such as starch particles is dispersed. Is formed on the surface of an inner layer made of an elastomer material. Therefore, the structure of the glove is essentially different from that of the rubber glove of the present invention. In addition, the medical glove of this publication has a complicated manufacturing process and a high material cost, so that the manufacturing cost is also high. There's a problem.

Japanese Patent Application Publication No. 7-506624 discloses a glove using a styrene-butadiene-styrene (SBS) block or a graft copolymer. However, in this publication, no consideration is given to the glass transition temperature and the stress relaxation rate of the SBS type copolymer. In addition, since the SBS type copolymer is generally poor in flexibility, it has a good feeling of use such as touch like the rubber glove made of SBR according to the present invention, and has a good fit to the hand and a good feeling of putting on and taking off. Can't get a good glove. Furthermore, the gazette does not disclose gloves using only the SBS-type copolymer, and the SBS-type copolymer is only slightly gloved with a styrene-isoprene-styrene (SIS) copolymer (Example 3). Only the example used for the glove of the present invention is disclosed, and the structure of the glove of this embodiment is essentially different from that of the rubber glove according to the present invention. Not only that,
Since the gloves obtained in the examples have a laminated structure, there is a problem that the manufacturing process is complicated and the manufacturing cost is high as compared with the present invention. In this publication, the purpose is to obtain a rubber glove that does not require vulcanization without mixing sulfur, zinc oxide (zinc white), etc., but this adjusts the compounding amount of zinc white. This is essentially different from the rubber glove of the present invention in which the stress relaxation rate is adjusted and the physical properties such as the wearability of the rubber glove are adjusted.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the rubber glove of the present invention will be described in detail. The rubber glove of the present invention, as described above,
S which is formed from a styrene-butadiene rubber latex by a dipping method and constitutes the rubber glove
The glass transition temperature of the BR rubber is 20 ° C. or less, and
The stress relaxation rate after a lapse of 6 minutes from the removal of the tensile stress of 00% elongation is 50 to 70%.

(SBR Latex) The SBR latex used in the present invention includes SBR latex in the latex.
It is sufficient that the glass transition temperature is not more than 20 ° C.
R latex can be used. The upper limit of the glass transition temperature of SBR is particularly preferably 15 ° C. or lower, more preferably 0 ° C. or lower, in the above range. On the other hand, the lower limit of the glass transition temperature is not particularly limited, but is usually about −20 ° C.

When a rubber glove is formed using a latex of SBR rubber having a glass transition temperature of more than 20 ° C., the rubber film becomes resinous and hard when the glove is actually used, and the flexibility is lost. In addition, it becomes impossible to obtain a rubber glove having good fit such as fit to a hand.
Further, since the processability (film-forming property) is low, it is not possible to obtain a rubber glove having a uniform and sufficient film thickness. (Stress relaxation rate) The stress relaxation rate of the rubber glove according to the present invention is:
According to the formula (1), the stress relaxation rate is required to be 50% or more and 70% or less in the present invention.

The stress relaxation rate represented by the above formula (1) is 50%
Below, the fit to the hand will be reduced,
Rubber gloves having excellent wearability cannot be obtained. On the other hand, if the stress relaxation rate represented by the formula (1) exceeds 70%, deformation occurs during use of the glove, and the glove cannot withstand actual use. The stress relaxation rate is more preferably 50 to 60% in the above range.

The stress relaxation rate can be appropriately adjusted by changing the amounts of zinc white, sulfur, vulcanization accelerator and the like to SBR. In order to set the stress relaxation rate represented by the above formula (1) in the above range, usually, the SBR
Zinc white may be blended in an amount of 0.1 to 1.2 parts by weight, preferably 0.3 to 1.0 part by weight, based on 100 parts by weight of the rubber component of the latex. If the amount of zinc white falls below the above range, stress relaxation may be too large, or sufficient strength may not be imparted to the glove. Conversely, if the amount of zinc white exceeds the above range, stress relaxation may be too small, or the gloves may be hard and the wearing feeling may be reduced.

When the stress relaxation rate is adjusted by using other metal oxides instead of zinc white, the amount of the compound is adjusted to be 0.1 to 100 parts by weight of the rubber content of the SBR latex.
What is necessary is just to set in the range of 1-2 weight part. The problems that can occur when the compounding amount of the other metal oxide falls below or exceeds the above range are the same as in the case of zinc white described above. (Compounding agent) In the production of the rubber gloves according to the present invention, SB
To the R latex, for example, a vulcanizing agent, a vulcanization accelerator and the like are added, and if necessary, various conventionally known compounding agents such as an antioxidant, a filler, a dispersant, and a reinforcing agent are added. Is done.

Examples of the vulcanizing agent include sulfur and organic sulfur-containing compounds. The amount of the vulcanizing agent is
0.1 parts per 100 parts by weight of rubber content of SBR latex
The amount is suitably adjusted within a range of from 2 to 2 parts by weight, preferably from 0.3 to 1 part by weight. Examples of the vulcanization accelerator include zinc N-ethyl-N-phenyldithiocarbamate (P
X), zinc dimethyldithiocarbamate (PZ), zinc diethyldithiocarbamate (EZ), zinc dibutyldithiocarbamate (BZ), zinc salt of 2-mercaptobenzothiazole (MZ), tetramethylthiuram disulfide (TT) and the like. . These can be used alone or in combination of two or more. The compounding amount is preferably about 0.5 to 3 parts by weight based on 100 parts by weight of the rubber component of the SBR latex.

In general, non-staining phenols are preferably used as the antioxidant, but amines may be used. The compounding amount of the antioxidant is preferably about 0.5 to 3 parts by weight based on 100 parts by weight of the rubber component of the SBR latex. Examples of the filler include kaolin clay, hard clay, calcium carbonate and the like. The compounding amount is preferably 20 parts by weight or less based on 100 parts by weight of the rubber component of the SBR latex.

Further, a dispersing agent may be blended to improve the dispersion of the above-mentioned additives in the rubber latex. Examples of such a dispersant include various anionic surfactants. The compounding amount of the dispersant is preferably about 0.3 to 1.0% by weight of the weight of the component to be dispersed. (Manufacturing method of rubber glove) The rubber glove according to the present invention is manufactured by using an SBR latex to which the above-mentioned compounding agent is added, according to a conventionally known dipping method.

That is, a preheated glove mold is immersed in the compounded latex as required, then the mold is pulled up, and the rubber film formed on the mold surface is dried and vulcanized to obtain the rubber glove of the present invention. Can be In the production of rubber gloves by the above-mentioned immersion method, a heat-sensitive agent or an anode coagulant may be compounded in the compounded latex. Examples of the heat-sensitizing agent include inorganic or organic ammonium salts such as ammonium nitrate, ammonium acetate, and zinc ammonium complex salt, or a cloud point such as polyvinyl methyl ether, polyalkylene glycol, polyether polyformal, and functional polysiloxane. Water-soluble polymers having a temperature of from room temperature to 100 ° C. are exemplified.

Examples of the anode adhesive include divalent or higher-valent metal salts such as calcium nitrate and calcium chloride, and organic alkylamine salts such as tetramethylammonium hydrochloride. The amounts of the heat sensitizer and the anode coagulant may be set according to a conventional method.
0.5 to 100 parts by weight of rubber content of BR latex
It may be set in the range of 5 parts by weight, particularly in the range of 0.5 to 2.0 parts by weight.

[0026]

[Manufacture of rubber gloves]

Example 1 As the SBR latex, trade name “Lx2570X5” (trade name of glass transition temperature Tg = −19, manufactured by Zeon Corporation)
° C) was used.

Rubber solid content of the above SBR latex 100
0.1 part by weight of zinc white, sulfur (vulcanizing agent)
1 part by weight and 1 part by weight of zinc dibutyldithiocarbamate (vulcanization accelerator BZ) were blended. Then, the type of glove was dipped into compounded latex thus obtained was dried rubber film formed on the mold surface, by demolding by vulcanizing about 30 minutes further 110 ° C., to obtain a rubber glove .

Examples 2 to 6 and Comparative Examples 1 to 3 Rubber gloves were obtained in the same manner as in Example 1 except that the amount of zinc white was changed. [Evaluation of physical properties] (Measurement of tensile stress and calculation of stress relaxation rate / stress retention rate) Rubber gloves obtained in the above Examples and Comparative Examples were punched out and specified in JIS K6251 "Tensile test method for vulcanized rubber". A dumbbell-shaped No. 4 sample was prepared.

Next, 500 mm /
The tensile stress M ₁₀₀ (0) [MP] at the time when the parallel portion (length 20 mm) of the sample piece is extended to 40 mm (at 100% elongation) is applied.
a] was measured. Further, the tensile stress M ₁₀₀ (6) [MPa] at the time when 6 minutes had passed since the 100% elongation was measured. From M ₁₀₀ (0) and M ₁₀₀ (6) thus measured, the stress relaxation rate (%) was calculated by the above equation (1).

The stress retention obtained by the equation (2) was also calculated.

[0031]

(Equation 2)

In the present invention, the stress holding ratio represented by the above equation (2) is 30-50% so that the stress relaxation rate represented by the above equation (1) is in the range of 50-70%. Each is adjusted so that (Evaluation of Wearability) The gloves obtained in the above Examples and Comparative Examples were evaluated for the operability (removability) at the time of wearing and detaching according to the following criteria. A: Ease of mounting and removal was extremely good. ：: Easy to mount and easy to remove. X: It was difficult to attach and it was hard to take off.

(Evaluation of Wearing Feeling) With respect to the gloves obtained in the above Examples and Comparative Examples, the touch during use and the fit to hands (wearing feeling) were evaluated according to the following criteria. ◎: Very good touch and hand fit. ：: Good touch and good fit to hands. X: The touch was poor and the fit was not sufficient.

Table 1 shows the measured values of the tensile stress, the calculated results of the stress relaxation rate and the stress retention rate, and the evaluation results of the wearability and the feeling of wearing, together with the composition of the compounded latex.

[0035]

[Table 1]

As is clear from Table 1, the rubber gloves of Examples 1 to 6 in which an SBR rubber having a glass transition temperature of 20 ° C. or less was used and the stress relaxation rate was adjusted to be 50 to 70%. In each case, the feel (feeling of use / wearing), the fit to the hand, and the operability (wearability) when attaching / detaching were very good. On the other hand, in Comparative Examples 1 to 3, since the stress relaxation rate is 50% or less, the touch (feel of use and wearing) is felt.
In addition, the fit to the hand and the operability at the time of attachment and detachment (wearability) were insufficient for practical use.

When no zinc white was added as in Comparative Example 4, the strength of the glove was too low and the stress relaxation rate was too high, which was not suitable for practical use.
As described in detail above, according to the rubber gloves of the present invention, it is possible to obtain rubber gloves that do not cause allergies and have extremely good fit such as fit to hands and operability at the time of attachment / detachment. it can. Such rubber gloves are suitably used not only in working gloves but also in a wide range of fields such as surgical gloves.

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 3B033 AC03 BA01 4J002 AC081 DE106 FD146 GC00 HA07

Claims (2)

[Claims] An immersion method using a latex of styrene-butadiene rubber having a glass transition temperature of 20 ° C. or lower has a stress relaxation rate of 50% after 6 minutes from the removal of 100% elongational tensile stress. Rubber gloves characterized by being 70% or less. 2. The rubber glove according to claim 1, wherein the latex contains zinc white at a ratio of 0.1 to 1.2 parts by weight based on 100 parts by weight of a rubber component in the latex.