CS233263B1 - Self-curing rubber film laminate - Google Patents

Abstract

The subject of the invention is a composition of a self-vulcanizing laminated film for repairing rubber materials, which is formed from a supporting reinforcing fabric, provided on the front or both front and back side with a vulcanized layer of rubber mixture and from a rubber self-vulcanizing mixture applied to the back side of the reinforcing fabric consisting of 20 to 50 wt. % butyl rubber, 10 to 60 wt. % reinforcing fillers, 0.1 to 5 wt. % plasticizers or substances facilitating processability, 0.1 to 5 wt. % synthetic, natural resins or asphalt, characterized in that the rubber self-vulcanizing mixture contains 0.2 to 1 wt. % stearic acid, 1 to 4 wt. % zinc oxide, 0.3 to 1 wt. % 2-mercaptobenzothiazole, 0.2 to 4 wt. % of dithiocarbamic acid derivative, 1 to 4 wt. % of sulfur and, if applicable, 0.1 to 3 wt. % of cyclohexylethylamine. The advantage of the solution according to the invention can be seen in its use also for repairs of materials operating at temperatures up to 100 °C, higher resistance to aggressive chemicals and cyclic stress.

Description

The invention relates to a self-vulcanizing laminated film composition for the repair of rubber materials.

For repairs of rubber materials, e.g. damaged work clothes made of rubberized textile, securing joints, repairing cracked hoses, etc., the material according to AO 222 332 has been used so far. The essence of this invention is the composition of a laminated film enabling a quick method of assembly repairs of rubber materials. The reinforcing fabric can be made of synthetic fibers based on polyamide, polyester or natural cotton fibers* The fabric is provided with a layer of adhesive unvulcanized rubber mixture on the reverse side, the application then consists in pressing or wrapping the laminated film on the damaged or repaired area. The disadvantage of this material is the relatively low strength of the joint at higher temperatures, e.g. when repairing cracked hoses (car cooling hoses) and the low strength of the joint in products exposed to multiple cyclic stress (bending points of work clothes made of rubberized textile). The low heat resistance of the joints is caused by the heat resistance of the unvulcanized rubber compound, which is provided with the laminated film. The rubber compound does not contain any vulcanizing additives, therefore it softens at temperatures above 25°C, which results in a decrease in the strength of the joints created using these systems. The shortcomings of this method of implementation are manifested especially at temperatures above 50°C. The consequence of the above shortcomings is a decrease in the functional reliability of the repaired damaged areas and a possible loss of function of the entire product.

The above-mentioned shortcomings are eliminated by the subject matter of the invention, which is point 1 of the feature.

The essence of the invention is the composition of a self-vulcanizing laminated film for repairing rubber materials, which is made of polyamide, polyester or cotton fabric, which can be provided on one or both sides with a vulcanized rubber mixture, while the reverse side of the film is

233 263 is coated with a self-vulcanizing rubber mixture based on butyl rubber with high adhesion. Depending on the SAS and ambient temperature, the back adhesive layer of the film vulcanizes, thereby increasing the thermal resistance of the joint and resistance to cyclic stress. At room temperature, vulcanization is gradual and can be regulated as needed by adjusting the accelerator system. The rubber self-vulcanizing mixture retains high adhesion and cohesion with the reinforcing foil and the repaired material! even after complete vulcanization. The thickness of the self-vulcanizing layer of the mixture can be 0.1 - 0.5 mm, the thickness of the reinforcing fabric 0.2 - 1.5 ππα. Depending on the requirements for mechanical and chemical resistance, the reinforcing fabric can be rubberized on one or both sides; in the case of extreme requirements for flexibility and compliance of the repaired material, a non-rubberized reinforcing fabric can be used. The self-vulcanizing laminated film is protected against mutual sticking with a suitable release agent, e.g. paper with a silicone layer, etc. The self-vulcanizing laminated film can be produced in widths of up to 1,500 mm and, if necessary, cut to the required dimensions, e.g. a width of 30 mm, etc.

The advantage of the self-vulcanizing repair film according to the invention is its application for repairs of materials operating at temperatures up to 100°C, for repairs of materials exposed to aggressive chemicals and increased cyclic stress.

The use of the self-vulcanizing repair film according to the invention increases the efficiency and reliability of the systems thus created. Example 1

This is a laminated film for repairing rubber materials consisting of a supporting reinforcing polyamide fabric provided on both sides with a layer of vulcanized rubber mixture based on butyl rubber, which is provided on the back side with an adhesive layer of unvulcanized rubber mixture (mixture no. 1) and a self-vulcanizing mixture according to the invention (mixture no. 2). The mixtures on the back side of the laminated film were applied to a rubberized textile on both sides on a four-roller. The joint was created with the laminated film by pressing the film onto the rubberized textile fabric and rolling it. The strength of the joint in unsticking was measured after 24 hours, aging at a temperature of 23°C and after 24 hours of vulcanization at a temperature of 100°C.

butyl rubber carbon black kaolin asphalt coumarone-indene resin stearic acid zinc oxide 2-mercaptobenzothiazole zinc ethylphenyldithiocarbamate sulfur peel strength 24 h/23°C 24 h/100°C

Mixture No. 1 Mixture S. wt. % mass ¹ 40 40 20 20 35 32 3 1 2 1 - 0.5 2 - 0.5 - 2 — 1

N/15mm 18,W15mm

N/15 mm 23 1V15 mm

Example of execution 2

This is a laminated film for repairing rubber materials consisting of a supporting reinforcing polyamide fabric on one side provided with a layer of vulcanized rubber mixture based on butyl rubber, which is provided on the reverse side with an adhesive layer of unvulcanized rubber mixture (mixture No. 3) and a self-vulcanizing mixture according to the invention (mixture No. 4X). The mixtures on the reverse side of the laminated film were applied to a rubberized textile on one side in the form of a 50% solution in organic solvents; after evaporation of the solvents, the composition of the reverse layer corresponds to the formulas and features of the invention below. *

The joint was created in the manner described in Example 1.

- 4,233,263

Mixture No. 3 wt.%

Mixture No. 4 wt.# butyl rubber 20 20 carbon black 40 40 kaolin 35 32 coumarone-indene resin 2 1.5 mineral oil 2 2 stearic acid 1 0.2 zinc oxide - 2

2-mercaptobenzothiazole ~ 0.3 zinc ethylphenyldithiocarbamate - 1.5 sulfur - 0.4 cyclohexylethylamine - 0.1 peel bond strength 24 h/23°C 24 h/100°C

N/15mm 19 N/15mm 16.3H/15mm 25M/15mm

Example of execution 3

It is a laminated film for repairing rubber materials consisting of a supporting reinforcing polyamide fabric, which is provided on the reverse side with an adhesive layer of unvulcanized rubber mixture Cmixture No. 5)) and a self-vulcanizing mixture according to the invention Cmixture No. &).

The mixtures on the reverse side of the laminated film were applied to the polyamide fabric in the form of a 50% solution in organic solvents; after evaporation of the solvents, the composition of the dry matter corresponds to the formulas and characteristics of the invention given below. The joint was formed in the manner described in Example 1.

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with meat no.5 wt.SB Mixture no. íx wt. Si butyl rubber 50 50 soot 30 30 kaolin 18 8 asphalt 0.5 0.5 coumarone-indene resin 0.5 0.5 zinc stearate 1 1 zinc oxide - 3.5 2-mercaptobenzothiazole - 1 zinc ethylphenyldithiocarbamate 2 zinc diethyldithiocarbamate 2 sulfur — 1.5 bond strength in peeling 24 h/23°C 15N/15mm 15,& N/15 mm 24 h/10°C 14.9N/15mm 18N/15mm

The examples given document the advantages and increased effect of the self-vulcanizing films according to the invention.

Claims (1)

SUBJECT OF THE INVENTION 233 2B3 Selfcuring foil laminate repair rubber materiólů _of which is composed of a supporting reinforcing fabric provided on a front or obverse and reverse side zvulkanizavanou layer of rubber mixtures and rubber mixtures selfcuring applied to the backside of the reinforcing fabric consisting of 20 to 50 wt. % butyl rubber, 10 to 60 wt. % of fillers, 0.1 to 5 wt. 0.1 to 5 wt.% plasticizers or process aids; % of synthetic, natural resins or asphalt, characterized in that the rubber self-vulcanizing composition comprises 0.2 to 1 wt. % stearic acid, 1 to 4 wt. 0.3% to 1% by weight of 2-mercapto-benzothiazole, 0.2 to 4% by weight of a dithiocarbamic acid derivative, 1 to 4 wt.% Sulfur and, if desired, 0.1 to 3 wt. % cyclohexylethylamine. Printed by Moravian Printing Works,