RUBBER MIXTURE FOR HOT VULCANIZATION Russian patent published in 1994 - IPC

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