RU2016008C1 - Rubber mixture for hot vulcanization - Google Patents

Abstract

FIELD: footwear production. SUBSTANCE: rubber mixture contains, mass parts: butadiene acrylonitrile caoutchouc (content of acryl acid monomer units being 26-34% ), solid novolac phenol-formaldehyde resin 18-22, sulfur 1-15, 2-mercaptobenzthiazole 0.5-1.0, zinc oxide 6-12, hexamethylenetetramine 0.5-2, stearine 2-3, calcium stearate 0.5-1.5, colophony 1-2.7, phthalic anhydride 0.5-1.5, lithopone 1-2.5, lime 1-1.5, silica filler having specific surface 150 m²/g 4-8, leather filler 30-75. Mass portion of free phenol in mentioned above phenol-formaldehyde resin is not more 7.5%, dynamic viscosity of said resin being 80-180 mPa s. Wastes of Russian leather as shavings 5-10 mm is length, 1-5 mm in width and 0.5-2 mm in thick are used as mentioned above leather filler. Rubber prepared of proposed mixture has density 1.02-1.07 g/cm³, wear resistance 6.8-7.2 J/cm³, heat conductivity 0.028 103-112 kgf/cm², vulcanization temperature being 125-135 C. EFFECT: improves quality of desired product. 2 tbl

Description

 The invention relates to light industry, in particular to shoe production, and can be used in the manufacture of shoes by hot vulcanization, as well as in the production of various rubber products.

The known composition of the rubber mixture of hot vulcanization, containing kaolin as a filler, in the following ratio of components, parts by weight: Binder 266.70
Fillers
(kaolin, soot, lamp and white zinc) 346.83 Softeners 34.70 Dye 3.30 Vulcanizing group 13.20 Pore former 2.00
A disadvantage of the known rubber composition is its high density, which entails a large weight of shoes, significant thermal conductivity of the sole. The vulcanization process is carried out at a temperature of 170 ^about C for 10 minutes, which requires significant energy consumption.

The closest in technical essence is the composition of the artificial material of the bottom of the shoe with the adhesive method of fastening - plastkozha, containing chrome tanning leather waste and textile fiber as a filler, with the following ratio of components,%: Rubber SKS-30 24.20 Plasten regenerate 10.61 Fiber ( absolute dry) 35.97 Soot lamp 14.76 Sulfur 0.97 Kaptax 0.77 Tiuram 0.19 Zinc white 2.12 Rubrax 6.36 Rosin 4.05
The disadvantages of the known material include high stiffness, low flexibility, material is inferior to rubber in terms of wear resistance. In addition, the tanning leather waste of chrome tanning, which is part of the plastic, increases the density and thermal conductivity of the material.

This composition can be used only for the bottom of the shoes with the adhesive method of fastening, due to the low elastic properties. The vulcanization of the material is carried out at a temperature of 170 ^about C.

 The aim of the invention is to reduce the density and thermal conductivity of rubbers from this rubber compound.

This goal is achieved by the fact that SF-050 resin is additionally introduced into the mixture, and yuft leather wastes shredded as shavings are used as a leather filler in the following ratio of components, parts by weight: SKN-26 rubber 78.0-82.0 Resin SF-050 18.0-22.0 Leather yuft shavings 30.0-75.0 White carbon black 4.0-8.0 Zinc oxide 6.0-12.0 Lime 1.0-1.5 Sulfur 1.0 -1.5 Urotropin 0.5-2.0 Kaptax 0.5-1.0 Calcium stearate 0.5-1.5 Phthalic anhydride 0.5-1.5 Lithopone 1.0-2.5 Stearin 2.0 -3.0 Rosin 1.0-2.7
Unlike chrome tanning leather wastes (used as filler in the prototype), crushed shavings of yuft leathers have a fibrous structure with many active groups, i.e. It is an active filler chemically bound to rubber, which contributes to the vulcanization process. This reduces the temperature and vulcanization time of rubber. The low density of yuft leather shavings provides a reduction in the density of finished rubbers and, therefore, the material consumption of the products. Lowering the temperature of vulcanization of rubber allows you to save leather chips without destruction, to reduce the destruction of all ingredients, which positively affects the above properties of rubber. In addition, leather yuft chip, due to its fibrous structure, reinforces rubber and helps to increase the strength characteristics of the material. The introduction of the phenol-formaldehyde resin SF-050 into the rubber composition contributes to the vulcanization process and to increase the strength characteristics of the vulcanizate.

PRI me R. The composition of the rubber is prepared as follows. 80 kg of SKN-26, 20 kg of SF-050 resin are successively loaded into a rubber mixer and mixed. Then (with stirring), fillers are introduced (30 kg of leather yuft shavings, 4 kg of white carbon black and 6 kg of zinc oxide), 1 kg of lime, 1 kg of sulfur, 2 kg of urotropin, 2 kg of stearin, 0.5 kg of captax, 1.5 kg of calcium stearate, 0.5 kg of phthalic anhydride, 1 kg of lithopone, 2 kg of rosin. The mixture is thoroughly mixed and plasticized on rollers at a temperature of 135 ^about C.

The resulting material has the following physico-mechanical properties: density 1.07 g / cm ³ , tensile strength 102.8 kgf / cm ² ; hardness according to TM-2 93 srvc .; abrasion resistance 6.8 J / cm ³ ; thermal conductivity of 0.025 W (m.k.); volumetric heat capacity 2.20 kJ (m ³ ˙K).

 In this case, SKN-26 rubber, SF-050 resin (GOST 18594-80), BS-150 white soot, lime (GOST 9262-82), leather yuft shavings (waste from leather or shoe production 5-10 long, 1 wide) are used. -5, a thickness of 0.5-2 mm), the remaining ingredients of the brands "tech." or "clean."

 The composition of the rubber compounds and the properties of the rubber are presented in tables 1 and 2.

As can be seen from table 2, the rubber from this rubber mixture has a density of 1.02-1.07 g / cm ³ , abrasion resistance of 6.8-7.2 J / cm ³ , thermal conductivity of 0.025-0.028 W / (m˙K ), while the vulcanization temperature is 125-135 ^about With (examples 1-4).

 The use of these components of the mixture outside the claimed ratios (examples 5-6) leads to a deterioration in the physicomechanical and thermotechnical characteristics of the vulcanizate.

Proposed rubber compound as compared with the prior art (Example 7) reduces the density at 1-3%, the thermal conductivity of 7-15%, vulcanization temperature at 25-35 ^{° C,} enhance the resistance to abrasion by 8-15% while maintaining the strength values.

 The inventive rubber mixture of hot vulcanization allows you to expand the raw material base of shoe and rubber-technical industries through the use of leather leather waste, as well as reduce material consumption and improve product quality.

Claims (1)

RUBBER MIXTURE OF HOT VOLCANIZATION, including copolymer butadiene rubber, sulfur, 2-mercaptobenzothiazole, zinc oxide, rosin and tanning filler, characterized in that, in order to reduce the density and thermal conductivity of rubbers, the mixture includes copolymer butadiene rubber and nitrile rubber acrylic acid 26 - 34 wt.%, as a leather filler - waste yuft leather in the form of chips with a length of 5 - 10, a width of 1 - 5 and a thickness of 0.5 - 2 mm and additionally contains a solid novolac nolformaldehyde resin with a dropping point of 90 - 105 ^o С, dynamic viscosity of a resin solution of 80 - 180 MPa.s and a mass fraction of free phenol of not more than 7.5%, as well as hexamethylenetetramine, stearin, calcium stearate, phthalic anhydride, lime, lithopone and white carbon black with a specific surface area of 150 m ² / g in the following ratio of ingredients, parts by weight:
Nitrile butadiene rubber with a content of nitrile units of acrylic acid 26 - 34 wt.% 78 - 82
Specified solid novolac phenol-formaldehyde resin 18-22
Sulfur 1.0 - 1.5
2-mercaptobenzthiazole 0.5 - 1.0
Zinc Oxide 6 - 12
Hexamethylenetetramine 0.5 - 2.0
Stearin 2 - 3
Calcium Stearate 0.5 - 1.5
Rosin 1.0 - 2.7
Phthalic anhydride 0.5 - 1.5
Lithopone 1.0 - 2.5
Lime 1.0 - 1.5
White carbon black with a specific surface area of 150 m ² / g 4 - 8
The specified leather filler 30 - 75

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