CS240858B1 - A mixture for the manufacture of dipped rubber gloves - Google Patents

Abstract

The invention relates to rubber protective gloves produced by dipping and coagulation of aqueous latex based on rubber and a copolymer of butyl acrylate, styrene and methacrylamide or acrylic or methacrylic acid. The gloves according to the invention have increased resistance to the action of detergent detergents and retain good physical and mechanical properties for a longer period of time even at elevated temperatures. They are intended mainly for household work or in service enterprises where detergents are used.

Description

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PETFILK STANISLAV RNDr., GOTTWALDOV; ORGANIST Jlfií ing., KROMĚfiíZ; KANÁNEK VÁCLAV ing., FRÝDEK-MÍSTBK; SULKE. VLADIMÍR, HRÁDEK NAD NISOU

Mixture for making dipped knitted gloves

The invention relates to rubber protective gloves produced by dipping and coagulation of aqueous latex based on rubber and a copolymer of butyl acrylate, styrene and methacrylamide or acrylic or methacrylic acid. The gloves according to the invention have increased resistance to the action of detergent detergents and retain good physical and mechanical properties for a longer period of time even at elevated temperatures. They are intended mainly for household work or in service enterprises where detergents are used.

240,858

The invention relates to a mixture for the production of dipped rubber ^240,858 protective gloves with increased resistance to detergents produced by dipping and coagulation of a mixture based on aqueous rubber latex.

Dipping and coagulation are currently used to produce most of the range of protective rubber products, such as surgical gloves, technical gloves (resistant to acids, alkalis, oils), dielectric gloves (protecting against the effects of electrical voltage), gloves for household use without treatment or with an inner suede treatment. Household gloves are mainly made from natural and/or synthetic rubber latex, containing the usual vulcanizing and other additives. The physical and mechanical properties of these gloves are generally sufficient for household cleaning, washing, etc. With the development of production and the expansion of the use of detergents, the use of protective rubber gloves is becoming necessary not only in households, but also in large laundries and dry cleaners of service companies as protection against the long-term effects of detergents on the skin. Long-term use of rubber gloves in detergents leads to a significant reduction in some mechanical properties, especially structural strength by up to 50%, which results in an increased possibility of mechanical damage (tearing of gloves). Also, the resistance of gloves to the action of hot air is relatively low and is manifested after exposure by a significant decrease in tensile properties and structural strength.

Surgical gloves used in hospitals and healthcare facilities are not disposable and cannot be reused. In most cases, they are reused.

- 3,240,858 after prior decontamination by washing in solutions of common detergent-type detergents and sterilization with hot air. Repeated washing gradually reduces both the strength of the gloves and, above all, the structural strength, and the gloves are discarded.

The purpose of the invention is therefore to create gloves that would eliminate the described disadvantages and, with their increased resistance to the effects of detergent detergents, ensure longer usability during continuous exposure to the effects of these agents.

It has been found that this purpose of the invention is substantially fulfilled by rubber protective gloves, their essence being that they are made of a latex mixture which, in addition to natural and/or synthetic rubber and common additives, also contains, per 100 parts by weight of dry matter, 0.1-20 parts by weight of dry matter of an acrylate copolymer mixture consisting of 45-75 parts by weight of butyl acrylate, 15-45 parts by weight of styrene and 0.5-25 parts by weight of methacrylamide and/or acrylamide and/or ether of their methylol compounds and optionally 0.1-8 parts by weight of acrylic or methacrylic acid.

The addition of an acrylic copolymer containing reactive carboxyl, amide or methylol functional groups to a dipping mixture of natural and/or synthetic rubber results in spatial crosslinking of the rubber chains, which is manifested by an increase in structural strength and resistance to the action of detergents,

To further clarify the nature of the invention, we present the following examples of production according to the invention, which do not limit the scope of the invention in any way.

Example 1: A mixture with the following composition (in parts by weight) was prepared on a stand mixer:

- 4 Natural rubber latex 240 858 (dry matter content 60%) 84.42

Aqueous dispersion of acrylate copolymer (dry matter content 45%) with a composition of 60 parts butyl acrylate, 25 parts styrene, 12 parts acrylamide, 2 parts N-butoxymethylmethacrylamide and 1 part acrylic acid 10.00

Dispersant (salt of alkylnaphthalenesulfonic acid) 0.20

Ground sulfur 0.53

Accelerator (zinc alkylthiocarbamate) 0.53

Titanium dioxide (rutile) 1.03

Silicone emulsion 0.06

Color masterbatch 0.03

Defoamer 0.01

Distilled water 3.19

Protective gloves with a suede surface were made from the mixture prepared in this way. The molds preheated to 50-70 °C were soaked in a coagulation solution (22% ethanol solution of calcium nitrate), then in a latex mixture for 70 seconds and the coating was dried in air. Then the mold was dipped in an adhesive latex mixture and textile fibers were applied in a stream of air. The gloves with the coating were dried (OQ nm at 80-90 °C), washed with water (15 min), vulcanized for 60 min. at 110 °C and removed from the mold.

For comparison, gloves were made from a mixture without acrylate copolymer dispersion using the same procedure.

The properties of the products after finishing and after exposure to detergents are shown in the following table.

240,858 Rubber gloves from a mixture without from a mixture with acrylate acrylate copolymer copolymer Tensile strength (MPa) 28.22 26.98 Elongation (%) 971 956 Structural strength 13.0 18.5

(N.mm ¹ )

After exposure to detergents 40 °C, 72 hrs.

BIOSAM (7.5 g.1 ¹ ) Tensile strength 21.8 17.0 Ductility 1050 920 Structural strength 9.1 14.2 SPRING EXTRA (1.1 g.1 ¹ ) Tensile strength 22.3 21.6 Ductility 970 980 Structural strength 13.1 17.4 HANKA (8 g.1 ¹ ) Tensile strength 24.0 22.3 Ductility 1080 1000 Structural strength 9.8 15.7 AZURE (7.5 g.1 ¹ ) ·» Tensile strength 26.3 25.7 Ductility 1010 1040 Structural strength 6.6 12.7

Example 2 240,858 Using a procedure similar to that in example 1, gloves without a suede surface treatment were prepared from a mixture based on butadiene acrylonitrile rubber with the following composition (in parts by weight): Butadiene-acrylonitrile latex (dry matter content 45%) 82.6 Aqueous dispersion of acrylate copolymer (dry matter content 45%) with the composition 70 parts butyl acrylate, 20 parts styrene, 5 parts methacrylamide, 2 parts N-methoxymethylacrylamide, 3 parts methacrylic acid 12.4 Dispersant (alkylnaphthalenesulfonic acid salt) 0.20· Ground sulfur 0.55 Accelerator (zinc alkylthiocarbamate) 0.55 Silicone emulsion 0.06 Color masterbatch 0.01 Defoamer 0.01 Distilled water 2.53 Similar to example 1, gloves made from a blend containing an acrylate copolymer show significantly better structural strength values. Example 3 For surgical purposes, gloves were made, similarly to example 1, from a mixture with the following composition (in parts by weight): Natural rubber latex (high ammoniacal, dry matter content 60%) 28.00

- 7,240,858

Natural rubber latex 37.00 (low ammonia, dry matter content 60%}

Aqueous dispersion of acrylate copolymer 10.00 (solids content 45%) composed of parts butyl acrylate, 31 parts styrene, parts methacrylamide, 3 parts N-butoxymethylacrylamide, 1 part acrylic acid Dispersant (salt of alkylnaphthalenesulfonic acid) 0.13

Ground sulfur 0.58

Accelerator (zinc alkylthiocarbamate) 0.30

Accelerator (zinc pentamethyldithiocarbamate) 0.10

Zinc oxide 0.08

Triethanolamine 0.07 concentrated ammonia 0.17

Silicone emulsion 0.05

Defoamer 0.01

Distilled water 23.51

The manufactured gloves were again compared with gloves made from a latex-free acrylate copolymer mixture, the properties are given in the table.

Tensile strength (MPa) of gloves without acrylate copolymer

30.9 from a mixture with acrylate copolymer

26.4

Ductility 950 ’ 916

Structural strength (N.mmB 13.9 16.9

After exposure to detergents 40 °C, 24 hours

BIOSAM (7.5 g/D Tensile strength

Ductility

Structural strength

HANKA (8 g/1) Tensile strength

Ductility

Structural strength

240,858

30.1 28.4

935 925

17.7 19.9

28.9 26.9

950 944

12.9 10.4

Accelerated aging in hot air (70°C, 168 hrs.)

Tensile strength -22.7 20.6

Ductility 840 855

Structural strength 6.0 13.1

A comparison of the properties of various types of mixtures 8 with and without acrylate copolymer in all cases shows that modification of the mixture with acrylate latex significantly contributes to increasing the structural strength of soaked products exposed to detergents and hot air.

Claims (1)

object of the invention 240 858 Mixture for the manufacture of dipped rubber gloves containing aqueous latex of natural and / or synthetic rubber containing vulcanizing additives or activators, retarders, fillers, stabilizers or pigments, characterized in that it contains from 0.1 to 25 parts by weight of dry matter per 100 parts by weight of dry matter an acrylate copolymer consisting of 45 to 75 parts by weight of butyl acrylate, 15 to 45 parts by weight of styrene and 0.5 to 20 parts by weight of methacrylamide and / or acrylamide and / or an ether of their methylol compounds and optionally 0.1 to 8 parts by weight of acrylic or methacrylic acid.