JP2001192918A - Rubber glove - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a styrene-butadiene rubber-made glove which has excellent processability, tensile strength, wearing touch, and so on. SOLUTION: This rubber glove is formed by a dipping method using a styrene-butadiene rubber latex which comprises a styrene-butadiene rubber latex containing a carboxyl-modified styrene-butadiene rubber and having a carboxyl group content of 3 to 20 mol.% based on the solid content of the rubber and zinc oxide in an amount of 1 to 10 pts.wt. per 100 pts.wt. of the rubber content in the latex.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a rubber glove made of styrene-butadiene rubber (SBR) modified with a carboxyl group.

[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 due to the protein contained in the natural rubber latex, there is a possibility of causing immediate allergy and the like, 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 have a moderate modulus, not so high, and are less comfortable to use than natural rubber gloves, but have very good fit to the hands and excellent operability when putting on and taking off. It is. 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] In addition to the natural rubber, glove materials further include a copolymer of acrylonitrile and butadiene or isoprene described in Japanese Patent Publication No. 9-505612.
The use of a latex film consisting of a cured mixture with a styrene-butadiene copolymer has been investigated.
However, acrylonitrile-butadiene rubber (N
BR) is about 3 times NR, and isoprene rubber (IR) is NR
It is not practical because it costs about five times as much as

[0005]

On the other hand, styrene-butadiene rubber (SBR) is an example of a general-purpose synthetic rubber which can be obtained at a low cost, but SBR has lower workability and lower tensile strength than natural rubber and the like. There is a problem that physical properties such as pod tear strength are low. Regarding the rubber gloves using the SBR, Japanese Patent Application Laid-Open No. 55-163202 discloses a method for manufacturing a working glove in which a film is formed using an SBR latex. However, the method disclosed in this publication forms a rubber coating on the surface of a cloth glove,
The structure is different from that of a glove made of a single rubber film of SBR.
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.

[0006] JP-A-9-157449 discloses SB
An antibacterial rubber molded product containing R rubber and an antibacterial agent is disclosed (see Example 2), and a rubber glove is disclosed as an example of the molded product. 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, the advantage that a rubber film having a uniform thickness can be formed by a simple process of dipping, which is a feature of the immersion method, cannot be obtained.

In Japanese Patent Publication No. 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, there is a problem that the manufacturing process is complicated and the material cost is high, so that the manufacturing cost is also high.

Japanese Patent Publication No. Hei 7-506624 discloses a glove using a styrene-butadiene-styrene (SBS) block or a graft copolymer. However, since SBS type copolymers are generally poor in flexibility, it is not possible to obtain gloves that have good wearing feeling such as touch and fit, and good handleability when detached. Further, the gazette does not disclose gloves using SBS type copolymer alone,
Only copolymers of the type are disclosed for use in gloves consisting of laminates with styrene-isoprene-styrene (SIS) copolymer (see Example 3). Since the glove obtained in Example 3 has a laminated structure, there is a problem that the manufacturing process is complicated and the manufacturing cost is high.

Accordingly, an object of the present invention is to provide a glove made of styrene-butadiene rubber which is excellent in workability, tensile strength and the like, and is also excellent in wearing feeling.

[0010]

Means for Solving the Problems and Effects of the Invention The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, modified styrene having a carboxyl group introduced at a predetermined ratio in the molecular chain. When butadiene rubber latex is used, rubber gloves that have good workability, can form a rubber film with excellent tensile strength, and have a very good feel such as skin feel and fit when worn They have found a new fact that they can be obtained and have completed the present invention.

That is, a rubber glove of the present invention comprises a styrene-butadiene rubber latex containing a carboxyl-modified styrene-butadiene rubber, wherein the content of carboxyl groups is adjusted to be 3 to 20 mol% of rubber solids; Styrene containing 1 to 10 parts by weight of zinc oxide based on 100 parts by weight of a rubber solid content in the latex.
It is characterized by being formed by a dipping method using butadiene rubber latex.

According to the present invention, since the styrene-butadiene rubber having a carboxyl group introduced into the molecular chain is used, the workability is improved. Further, since a predetermined amount of zinc oxide is blended in the SBR latex containing the carboxyl group-modified SBR, it is possible to obtain a rubber glove having excellent tensile strength and good wearing feeling. The rubber glove of the present invention is preferably SBR from the viewpoint of further improving the mechanical strength such as tensile strength and the feeling of wearing.
It is preferable that the content ratio of the carboxyl group in the latex is adjusted to be 5 to 15 mol% of the rubber solid.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the rubber glove of the present invention will be described in detail. (Styrene-butadiene rubber latex) The styrene-butadiene rubber (SBR) latex used in the present invention contains a carboxyl-modified styrene-butadiene rubber in which a carboxyl group is introduced into a molecular chain, and contains the carboxyl-modified SBR. The carboxyl group (—COOH) content derived from the latex is 3 to 20 mol%, preferably 5 to 15 mol%, based on the total rubber solid content of the latex.
It has been adjusted to be mol%.

Accordingly, in the present invention, a carboxylated latex of SBR having a carboxyl group content of 3 to 20 mol% of rubber solids can be used alone. Further, since the content ratio of the carboxyl group (hereinafter, referred to as “carboxyl group content”) may be adjusted so as to be finally 3 to 20 mol% of the rubber solid content, the latex of the carboxyl-modified SBR May be used alone or as a mixture of two or more, or an uncarboxylated SBR latex may be used as a mixture.

In the present invention, SBR which can be used alone
Specific examples of latex include, for example, Nippon Zeon Co., Ltd.
Trade name "LX472" (carboxyl group content: 5 mol%). In addition, the carboxyl group content is 3
Since it is out of the range of ２０20 mol%, it is necessary to adjust the carboxyl group content as a whole by mixing with other SBR latex.
Carboxyl-modified SBR latex such as trade name “LX426” (carboxyl group content 2 mol%), trade name “LX2570X5” (carboxyl group content 2 mol%), and trade name “Zeon Corporation” LX485
Various conventionally known commercially available products such as non-carboxylated SBR such as "0" can also be used.

Although not particularly limited, from the viewpoint of further improving the processability (film forming property) of the rubber glove, the glass transition temperature T of the rubber solid is considered.
_It is more preferable to use an SBR latex having a _{g in} the range of −25 to + 20 ° C. (Zinc Oxide) Examples of the zinc oxide used in the present invention include commercially available zinc white (zinc oxide, ZnO).

The content of the zinc oxide is set in the range of 1 to 10 parts by weight based on 100 parts by weight of the rubber solid content of the SBR latex. When the content of the zinc oxide is less than the above range, mechanical properties such as tensile strength of the gloves are reduced, or the fit of rubber gloves is impaired with the decrease in strength, and a problem of a decrease in wearing feeling. Occurs. Conversely, if the content of zinc oxide exceeds the above range, the rubber coating becomes too hard, resulting in a problem that the feeling of wearing gloves is reduced and the gloves are dropped from the mold at the time of glove production.

The content of zinc oxide is particularly preferably 1 to 5 parts by weight, more preferably 1 to 3 parts by weight in the above range. (Other ingredients) In the production of the rubber glove according to the present invention,
The SBR latex is blended with the above zinc oxide, a vulcanizing compound such as a vulcanizing agent and a vulcanization accelerator, and, if necessary, an antioxidant, a filler, a dispersant, a reinforcing agent, etc. of,
Various conventionally known compounding agents are added.

Examples of the vulcanizing agent include sulfur and organic sulfur-containing compounds. The amount of the vulcanizing agent is
It is appropriate that the amount is adjusted in the range of 0.1 to 2 parts by weight, preferably 0.3 to 1 part by weight, based on 100 parts by weight of the rubber solid content of the SBR latex. As the vulcanization accelerator,
For example, zinc N-ethyl-N-phenyldithiocarbamate (PX), zinc dimethyldithiocarbamate (P
Z), 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 solid content of the SBR latex.

In general, non-staining phenols are preferably used as the anti-aging agent, 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 solid content of the SBR latex. Examples of the filler include kaolin clay, hard clay, calcium carbonate and the like. The compounding amount is 10% of the solid rubber content of the SBR latex.
It is preferably 20 parts by weight or less with respect to 0 parts by weight.

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.

[0024]

[Manufacture of rubber gloves]

Example 1 Carboxyl group-modified SBR latex (trade name “LX472” manufactured by Zeon Corporation, content of carboxyl group: 5 mol%, glass transition temperature Tg = −21 ° C.) 100 parts by weight of rubber solids , Sulfur (vulcanizing agent), 1 part by weight, zinc white (zinc oxide), 10 parts by weight, and zinc dibutyldithiocarbamate (vulcanization accelerator, BZ), 1 part by weight.

This carboxyl group-modified SBR latex (hereinafter referred to as “modified SBR latex”) is heated to 70 ° C., and a rubber glove mold having a 35% calcium nitrate solution (coagulant) adhered to the surface in advance is used. Dipped.
Next, the thus obtained modified SBR latex film was vulcanized and dried in an oven at 100 ° C. for 30 minutes,
Further, the film was demolded to obtain a glove made of modified SBR rubber.

Examples 2 and 3 and Comparative Examples 1 and 2 The amounts of zinc white were set to the values shown in Table 1.
3 parts by weight (Example 2), 1 part by weight (Example 3), 15 parts by weight (Comparative Example 1), 0.5 parts by weight (Comparative Example 2)]
Otherwise, a glove made of modified SBR rubber was produced in the same manner as in Example 1. Comparative Example 3 As a modified SBR latex, trade name “LX426” manufactured by Zeon Corporation instead of “LX472” described above.
(Carboxyl group content 2 mol%, glass transition temperature T
g = −39 ° C.) except that gloves made of modified SBR rubber were obtained in the same manner as in Example 2.

Comparative Example 4 As a modified SBR latex, “LX2570X” manufactured by Nippon Zeon Co., Ltd. was used instead of “LX472” described above.
Gloves made of modified SBR rubber were obtained in the same manner as in Example 2 except that 5 "(carboxyl group content: 2 mol%, glass transition temperature Tg = -20 ° C) was used. Comparative Example 5 As the SBR latex, a carboxyl-modified SBR latex (trade name “LX2570X5” manufactured by Nippon Zeon Co., Ltd., a carboxyl group content of 2 mol%, a glass transition temperature Tg = −) was used instead of the above “LX472”. 20 ℃)
And a non-carboxylated SBR latex [trade name “LX4850”, glass transition temperature Tg =
−50 ° C.], and modified SB was used in the same manner as in Example 2 except that the rubber solid content was mixed so as to be 1: 1.
An R rubber glove was obtained.

In Comparative Example 5, the content of carboxyl groups in the whole SBR latex was 1 mol%. Comparative Example 6 The above carboxyl-modified SB was used as an SBR latex.
R latex “LX472” was replaced by an uncarboxylated SBR latex [trade name “LX4
850 ”], except that gloves made of modified SBR rubber were obtained in the same manner as in Example 2.

[Evaluation of Physical Properties of Gloves] (Workability) The difficulty of operations such as adjusting the thickness of the rubber film during the production of rubber gloves by the dipping method was comprehensively evaluated according to the following criteria. A: Workability was extremely good. ：: Workability was good. Δ: Workability suitable for practical use was not obtained. ×: Workability was extremely low.

(Feeling of Wearing) Five test subjects actually wear the gloves of the above Examples and Comparative Examples, and the feeling of wearing gloves (easiness of work while wearing rubber gloves. Evaluation was required for the degree of such a burden and the degree of tightening of the hands (so-called fit feeling) and the feeling of detachment (handling when attaching or detaching rubber gloves). The evaluation was performed according to the following criteria, and represented by the average of the evaluations of each subject.

A feeling of wearing ：: Very soft, fingers could be bent and stretched naturally, and it felt as if they were not wearing gloves. 〇: Soft, finger flexing and stretching could be performed naturally. Δ: The glove was felt somewhat hard, but there was no practical problem. X: Extremely bad, tiredness was felt in the hand after wearing for a long time.

A feeling of attachment / detachment ：: Very easy to wear (easy to wear) and easy to take off. ：: easy to wear and take off. Δ: Hard to wear and hard to remove. X: Extremely difficult to wear and take off. (Tensile strength)
Punch the gloves obtained in the above Examples and Comparative Examples,
A dumbbell-shaped No. 4 test piece specified in JIS K6251 (Tensile test method for vulcanized rubber) was prepared. Then, according to the test method described in JIS K 6251, to measure the tensile strength T _B (MPa).

The tensile strength T _B is more than 18 MPa, preferably is required to be not less than 20 MPa. The results are shown in Tables 1 and 2.

[0034]

[Table 1]

[0035]

[Table 2]

As is clear from Tables 1 and 2, SB
The content of carboxyl groups in the R latex is 3 to
20 mol%, and the content of zinc oxide is S
1 to 100 parts by weight of rubber solid content of BR latex
In Examples 1 to 3 in the range of 10 parts by weight, it was possible to obtain rubber gloves having good workability and excellent in feeling of wearing and tensile strength. On the other hand, in Comparative Examples 3 to 6 in which the content ratio of the carboxyl group was small, at least one of the workability, the feeling of wearing, and the tensile strength, particularly the tensile strength was insufficient. Such a result was remarkable as the content ratio of the carboxyl group was reduced.

In Comparative Example 2 in which the content of zinc oxide was less than the above range, sufficient tensile strength and a feeling of wearing could not be obtained. Conversely, in Comparative Example 1 in which the content of zinc oxide exceeds the above range, sufficient workability and a feeling of detachability could not be obtained.

Claims (2)

[Claims] 1. A rubber composition containing a carboxyl-modified styrene-butadiene rubber and having a carboxyl group content of 3% of rubber solids.
A styrene-butadiene rubber latex containing styrene-butadiene rubber latex adjusted to be ２０20 mol% and zinc oxide in an amount of 1 to 10 parts by weight based on 100 parts by weight of a rubber solid content in the latex. A rubber glove formed by using a dipping method. 2. The rubber glove according to claim 1, wherein the content of the carboxyl group is 5 to 15 mol% of the rubber solid.