RU2558607C1 - Rubber mixture based on butadiene-methylstyrene caoutchouc - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: rubber mixture based on butadiene-methylstyrene caoutchouc includes a vulcanising agent, a mixture of vulcanisation accelerators - dibenzothiazoledisulphide and diphenylguanidine, zinc oxide, an organic vulcanisation activator, a modifying additive - zirconium dioxide and filler with a component ratio, wt. p.: butadiene-methylstyrene caoutchouc - 100.0; sulphur- 2.0; zinc oxide - 5.0; stearic acid - 2.0; dibenzothiazoledisulphide - 1.5; diphenylguanidine - 0.3; technical carbon - 40.0; zirconium dioxide - 25.0-40.0.

EFFECT: invention makes it possible to increase the heat- and fire resistance of vulcanisates with the preservation of high physical-mechanical indices.

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Description

The invention relates to the rubber industry, in particular to the development of a rubber mixture based on butadiene-methylstyrene rubber, products of which are characterized by increased heat and fire resistance

Known rubber mixture containing styrene butadiene rubber, sulfur, zinc oxide, calcium carbonate, silicon dioxide and azodicarbonamide as a blowing agent (Koshelev F.F. et al. General technology of rubber. M .: Chemistry, 1978, p. 492-501 )

A disadvantage of the known technical solution is the great complexity and significant energy costs in the manufacture of products from the above rubber mixture, since the vulcanization process is two-stage and requires complex and traumatic production equipment. In addition, the resulting products have physical and mechanical properties that do not meet the requirements.

Known rubber mixture based on butadiene-methylstyrene rubber containing sulfur, dibenzothiazoldisulfide, diphenylguanidine, zinc oxide, stearic acid, carbon black and sodium alginate (RU 2428440, IPC C08L 9/06, C08K 3/04, C08K 3/06, C08K 3 / 22, С08К 5/09, С08К 5/31, С08К 5/47, publ. 09/10/2011).

However, this rubber compound does not have increased heat and fire resistance.

Known rubber compound (RU 2052472, IPC C08L 9/06, C08K 13/02, C08L 97/00, C08K 3/04, C08K 3/06, C08K 3/22, C08K 5/09, C08K 5/31, C08K 5 / 47, publ. 20.01.1996) containing butadiene-methyl styrene rubber, sulfur, zinc oxide, altax, diphenylguanidine, stearic acid, carbon black and chlorinated epoxylignin. However, this rubber compound does not have increased heat and fire resistance.

Known rubber compound (RU 2044006, IPC C08L 9/06, C08L 9/00, С08К 13/02, С08К 3/06, С08К 3/22, С08К 3/34, С08К 3/36, С08К 5/09, С08К 5 / 3467, С08К 5/44, published September 20, 1995) containing butadiene-methyl styrene rubber, synthetic cis-1,4-polyisoprene rubber, sulfur, zinc oxide, N-cyclohexyl-2-benzthiazolylsulfenamide, stearic acid, molecular complex resorcinol with hexamethylenetetramine, phthalic anhydride, white soot and kaolin.

However, this rubber mixture has low physical and mechanical properties and does not have increased heat and fire resistance.

Known rubber compound (RU 2145616, IPC C08L 9/00, C08L 9/06, S08K 13/02, S08K 3/04, S08K 3/06, S08K 3/22, S08K 3/26, S08K 3/36, S08K 5 / 01, С08К 5/09, С08К 5/10, С08К 5/13, С08К 5/18, С08К 5/23, С08К 5/375, publ. 02.20.2000) containing butadiene-methylstyrene rubber, synthetic cis-1 , 4-polyisoprene rubber, sulfur, zinc oxide, stearic acid, phenyl-β-naphthylamine, filler and modifiers.

However, this rubber mixture has low physical and mechanical properties and does not have increased heat and fire resistance.

Known rubber compound (SU 1728263, IPC C08L 9/06, S08K 13/08, S08K 3/04, S08K 3/06, S08K 3/22, S08K 5/09, S08K 5/47, S08K 11/00, publ. 04/23/1992) containing butadiene-methylstyrene rubber, sulfur, di- (2-benzthiazolyl) disulfide, zinc oxide, stearin, carbon black and distillation residue of rectification of tetrahydrofurfuryl alcohol.

However, this rubber composition has low heat resistance and is unstable during thermo-oxidative aging.

Known polymer composition (US 2005288422, IPC C08K 5/02, C08K 5/3492, C08L 9/02, C08L 9/06, publ. 12/29/2005) based on acrylbutadiene styrene, natural rubber, nitrite, neoprene, vinylpyridine, isoprene or their co-polymers or ter-polymers containing a flame retardant, carbon black, sulfur, zinc oxide, zinc mercaptobutyltalate, zinc diethyldithiocarbamate, antioxidant and microcrystalline wax.

However, this rubber compound has low physical and mechanical properties.

Known polymer composition (WO 2012113145, IPC C08K 3/32, C08L 25/06, C08L 25/12, C08L 27/06, C08L 55/02, C08L 61/06, C08L 63/00, C08L 71/12, C08L 9 / 06, published February 24, 2011) based on butadiene-methylstyrene rubber, containing the calcium salt of hypophosphite and other organic and inorganic phosphorus compounds.

However, this composition is characterized by low environmental friendliness.

Known polymer composition (US 5773501 IPC С08К 13/02, С08К 3/00, С08К 3/22, С08К 5/00, С08К 5/02, С08К 5/06, С08К 5/109, С08К 5/1515, С08К 5 / 22, C08L 25/04, C08L 25/12, C08L 55/02, C08L 63/00, C08L 69/00, C08L 9/06, publ. 06/30/1998) based on butadiene-methyl styrene rubber containing halogen-free flame retardant and optionally antimony trioxide.

However, this composition is characterized by low environmental friendliness and low values of physical and mechanical properties.

Known polymer composition (WO 2013176868, IPC C08K 5/00, C08K 5/02, C08K 5/5333, C08L 25/04, C08L 27/18, C08L 55/02, C08L 9/06, publ. 28.11.2013) on based on butadiene-methylstyrene rubber containing brominated flame retardant, aluminum methylphosphonate and additionally antioxidant, dyes.

However, it does not have increased heat and flame retardant characteristics.

The closest to achieve the technical result is a rubber mixture based on butadiene-methyl styrene rubber (RU 2010814, IPC C08L 9/06, C08K 13/02, C08L 27/06, C08L 79/00, C08K 3/22, C08K 5/18, publ. 04/15/1994), including sulfur (0.5), altax (2.5), zinc oxide (5.0), stearic acid (2.0), carbon black (40.0) and additionally poly- ( N-3,5-di-tert-butyl-4-hydroxytolyl) ethyleneimide (1.0-1.5).

However, this rubber composition has low elongation and low fire resistance.

The objective of the invention is to develop a rubber mixture based on butadiene-methylstyrene rubber, the vulcanizates of which are characterized by increased heat and fire resistance.

The technical result is vulcanizates based on butadiene-methylstyrene rubber, which have increased heat and fire resistance, while maintaining high physical and mechanical properties.

The technical result is achieved using a rubber mixture based on butadiene-methyl styrene rubber, including a vulcanizing agent, a mixture of vulcanization accelerators, zinc oxide, an organic vulcanization activator, a modifying additive and a filler, while a mixture of dibenzothiazole disulfide and diphenyl guanidine is used as a mixture of vulcanization accelerators as a modifying additive - zirconium dioxide in the following ratio of components, parts by weight: butadiene-methylstyrene rubber - 100.0; sulfur - 2.0; zinc oxide - 5.0; stearic acid - 2.0; dibenzothiazole disulfide - 1.5; diphenylguanidine - 0.3; carbon black - 40.0; zirconium dioxide - 25.0-40.0.

Sulfur (GOST 127.4-93) was used as a vulcanizing agent in the rubber composition based on SKMS-30 ARKM-15 butadiene-methyl styrene rubber or SKS-30 ARKM-15 butadiene rubber (GOST 11138-78), as an activator of the accelerator vulcanization - zinc oxide (GOST 202-84), as a vulcanization activator - stearic acid (GOST 6484-96), as a filler - carbon black P234 or P324 (GOST 7885-86), as a mixture of vulcanization accelerators - a mixture of diphenylguanidine ( GOST 40-80) and dibenzothiazole disulfide (GOST 7087-75), and as modes fitsiruyuschey additives - zirconia (GOST 21907-76).

The declared amount of zirconium dioxide is optimal, since with a decrease in its amount, a decrease in the heat and fire resistance of vulcanizates is observed, and an increase in its dosage is impractical, since this does not significantly affect the further improvement of the complex of properties of rubber compounds.

The scaly shape of the particles of finely dispersed zirconium dioxide creates peculiar microbarriers in the surface layers of the vulcanizate. This barrier layer effectively protects rubber from burning under the influence of a flame.

An example of the preparation of a rubber compound.

The rubber mixture is prepared on rollers at a roll temperature of 65-70 ° C. Mixing time 25 minutes. Then the vulcanization of the rubber mixture is carried out at a temperature of 145 ° C for 30 minutes. Table 1 shows the compositions of the prepared mixtures and prototype.

Table 2 shows the physico-mechanical and heat-resistant indicators characterizing the properties of vulcanizates obtained on the basis of the proposed rubber compound and prototype.

Physico-mechanical properties were determined in accordance with GOST 270-75, GOST 267-73 and GOST 263-75, and fire resistance - by the decay time of the sample after removing it from the burner flame.

Resistance to thermal oxidative aging was determined in accordance with GOST 23785.7-77.

The proposed vulcanizates were tested for fire resistance as follows: the heating time of the reverse side of a sample made in the form of a washer with a diameter of 30 mm and a thickness of 6 mm was determined to a temperature of 100 ° C.

The sample was heated by an open flame of a plasma torch (a temperature of 2000 ° C was created on the surface). The sample was mounted in a tripod at an angle of 45 ° to the burner flame. To reduce the heat sink and reduce the experimental error, the sample was insulated with asbestos along the edge.

To measure the temperature on the unheated surface of the sample, we used a S-300.3 Photon pyrometer and a TPM-1 contact chromel-kopel thermocouple for the Aries controller.

Thus, the use of the proposed rubber mixture based on butadiene-methylstyrene rubber allows to obtain vulcanizates with increased heat and flame retardant properties while maintaining high physical and mechanical characteristics.

Claims (1)

A rubber mixture based on butadiene-methyl styrene rubber, including a vulcanizing agent, a mixture of vulcanization accelerators, zinc oxide, an organic vulcanization activator, a modifying additive and a filler, characterized in that a mixture of dibenzothiazole disulfide and diphenyl guanidine is used as a mixture of vulcanization accelerators, and as a modifying additive zirconium dioxide in the following ratio of components, parts by weight:
styrene butadiene rubber 100.0 sulfur 2.0 zinc oxide 5,0 stearic acid 2.0 dibenzothiazole disulfide 1,5 diphenylguanidine 0.3 carbon black 40,0 zirconium dioxide 25.0-40.0