CS260339B1 - Non-flammable antistatic rubber-textile conveyor belt - Google Patents

Abstract

A non-flammable antistatic rubber-textile conveyor belt made of a textile skeleton impregnated with a solution of RFL (resorcinol-formaldehyde resin using a latex component in combination with butadiene styrene and vinylpyridine), a coating mixture for textiles and covering layers of chloroprene rubber, relates to the field of rubber production. The essence of the solution is that the coating mixture contains fillers silicon dioxide S1O2 and kaolin, flame retardants antimony trioxide Sb2O3, hydrated alumina Al(01-1)3, chloroparaffin and a friction reducing agent low molecular weight polyethylene, while the covering layer mixture partially filled with electroconductive carbon black contains flame retardants antimony trioxide Sb2O3, hydrated alumina Al(0H)3 and chloroparaffin as well as a friction reducing agent low molecular weight polyethylene. The solution can be used exclusively in the rubber industry for the production of rubber-textile conveyor belts.

Description

The invention relates to a method of producing a non-flammable antistatic rubber-textile conveyor belt intended primarily for deep mines.

The conveyor belts manufactured so far consisting of a textile polyamide] skeleton rubberized] with a mixture of chloroprene rubber with the addition of kaolin, antimony trioxide Sb2O3, PVC and liquid chloroparaffin and covering layers of SBR or chloroprene rubber with the addition of antimony trioxide Sb2O3 and PVC do not meet the requirements for conveyor belts used mainly in. mining in coal mining under the millstone. In the event of uncontrolled] heating of the belt — by friction of the roller when the rollers are blocked and heated, it ignited and a fire broke out. In mining in coal mining under the millstone, in order to prevent the formation and spread of fire through the conveyor belt, non-flammable antistatic conveyor belts are needed.

To increase fire safety, the homologation tests for mining conveyor belts have been tightened. The testing methodology for the friction test was changed, where the wall thickness of the friction roller was changed from the original 12 mm to 6 mm and a burning test over a gas burner in a test mine fire corridor was introduced.

Existing non-flammable conveyor belts do not comply with the amended testing methodology. The friction test results in the belt heating up and the burning test over a gas burner results in its complete combustion. The covering layers of conveyor belts made of chloroprene rubber do not meet the requirements for the dissipation of static electricity, which creates a risk of methane explosion.

It is generally known that the basic components for sustaining combustion are fuel, oxygen and heat. In order to prevent the combustion of polymers, this triangle must be broken. The prevention of the formation of flammable gaseous products, as well as the increase in the incompleteness of their combustion and thus the reduction of the amount of heat released and the prevention of heat development are possible by the presence of flame retardants and friction reducing agents.

The above-mentioned shortcomings are eliminated by the method of manufacturing non-flammable antistatic rubber-textile conveyor belts according to the invention, the essence of which is that the coating mixture contains fillers silicon dioxide S1O2 and kaolin, flame retardants antimony trioxide Sb2O3, hydrated aluminum oxide A1(OH)3, chloroparaffin and a friction reducing agent low molecular weight polyethylene, while the mixture for the covering layer partially filled with electroconductive carbon black contains flame retardants antimony trioxide Sb2O3, hydrated aluminum oxide A1(OH)3 and chloroparaffin and a friction reducing agent low molecular weight polyethylene. The belt skeleton is made of polyamide, polyester, viscose, cotton textile or their combination, impregnated with a solution of RFL — resorcinol-formaldehyde resin using a latex component in combination with butadienestyrene and vinylpyridine.

To ensure the required electrical surface resistance of the belt, the cover layers contain electrically conductive carbon black, the most suitable carbon black Chezacarb EC. The reduction of the friction coefficient between the belt and the drive drum in the event of blockage and thus the reduction of belt heating is ensured by adding low molecular weight polyethylene to the rubber mixtures.

To improve the processing mixtures, a part of natural, polybutadiene, polyisoprenone or SBR rubber up to 30 parts per million can be added to the rubber mixtures. In the cover layer for better tensile and dynamic properties, it is appropriate to use chloroprene rubber modified with sulfur or mercaptan. The rubber-textile conveyor belt produced by the method according to the invention guarantees non-flammability and antistatic properties and fully complies with the new methodology of mining fire tests.

The retarding effect of chloroparaffin and Sb2O3 lies in the synergistic effect between halogen and antimony compounds, which reduce or suffocate the flame. The retarding effect of Al(OH)3 lies in its decomposition at 200 ^° C to Al2O3 and water vapor. The endothermic effect of the loss of water vapor cools the polymer and the released water vapor prevents combustion. The reduction of the development of adhesive]·.! Lr provides low molecular weight polyethylene, which melts at a temperature of 80°C and acts as a lubricant to prevent further development of heat.

The invention can be used exclusively in the rubber industry for the production of conveyor belts.

Example of use

On conventional rubber machines,

prepare a coating mixture for textiles in the following composition: Chemicals kg Chloroprene rubber (M-41 DAY) 70 to 100 Polybutadiene rubber (SKD) 0 to 30 Stearin 0.3 to 2 MgO 2 to 5 Silicon dioxide SiO2 10 to 30 FEF Carbon Black 0 to 20 Kaolin 10 to 60 A1(OH)3 20 to 50 Liquid chlorinated paraffin 40% off 10 to 40 Solid chlorinated paraffin 70% 10 to 20 PVC (Slovinyl — E 602) 0 to 40 Retar 131 (Triaryl phosphate) 0 to 10 Antimony trioxide Sb2O3 5 to 15

I

Low molecular weight Stearin 0.3 to 2 polyethylene AC 617/1 2 to 5 Paraffin 1 to 4 ZnO 3 to 6 Antioxidant PBN Sulfur 0.5 to 1.5 (Phenyl-B-naftyl-amine) 1 to 3 Denax (Diphenylguanidine) 0.5 to 1.5 HAF carbon black 20 to 50 TMTD (Tetramethyl- Chezacarb EC carbon black 2 to 5 thiuram disulfide) 0.5 to 1.5 Al(OH)3 20 to 50 Rhodanine S-62 (2-Mercaptoimidazoline) 0 to 1 Chloroparaffin solid 70% 10 to 30 The coating mixture is used to coat textiles and Liquid chloroparaffin 40% 5 to 15 the frame of the transport vehicle is made ready-made Retar 131 (Triaryl Phosphate) 0 to 8 on which the coverings are applied layers according to PVC (Slovinyl — E 602) 0 to 40 of the following composition: Sb2O3 5 to 15 Topcoat mixture Low molecular weight polyethylene AC 617/A 2 to 6 Chemicals kg ZnO Ground Sulfur 3 to 6 0 to 0.5 Chloroprene rubber MBTS (Altax-Benzthiazyldisulfide) 0 to 2 (Neoprene GW) 70 to 100 Textile frame provided covering layer- Polybutadiene rubber SKD 0 to 30 mi is vulcanized in a press at a temperature of 140 to MgO 3 to 6 160 °C at a vulcanization pressure of min. 0.5 MPs.

SUBJECT

Claims (2)

A non-flammable antistatic rubber-textile conveyor belt formed from a textile skeleton impregnated with a solution of resorcinol-formaldehyde resin using a latex component in a combination of butadiene-styrene with vinylpyrride, a textile coating layer and chloroprene rubber coating layers containing conventional rubber fillers; that the deposition mixture and THE INVENTION Covering Layers Include flame retardants Sb2O3 5 to 15 parts by weight, hydrated alumina AlfOH 20 to 50 parts by weight, chloroparaffin 5 to 40 parts by weight and trenle reducing agent low molecular weight polyethylene 2 to 6 parts by weight, wherein the coating composition comprises electrically conductive carbon black 2 to 0 parts by weight per 100 parts of rubber.