METHOD OF PRODUCING HEAT-RESISTANT LEATHER Russian patent published in 2010 - IPC C14C13/00 C14C3/06 C14C9/02 C14C9/04 

FIELD: chemistry.

SUBSTANCE: method involves chrome tanning and post-tanning a semi-finished product through chrome tanning in the presence of a product of reaction of 3-aminopropyltriethoxysilane and glycidylmethacrylate in molar ratio of 1:2 and consumption of the chrome tanning agent and reaction product of 3-4% and 2-3% of the weight of the semi-finished product respectively. Neutralisation and hydrophobisation with a polymer tanning agent are then carried out for 30-40 minutes with consumption of the tanning agent equal to 8-10% of the weight of the semi-finished product. After that dyeing is carried out in the presence of a synthetic tanning agent in amount of 3-4% of the weight of the semi-finished product. Post-tanning is carried out with a plant-material tanning agent and the semi-finished product is also treated for 20-30 minutes with a product of reacting hexamethylenediamine with phosphoric acid and urea in the presence of glycerin in molar ratio of 1:3:3:0.5 respectively, in amount of 3-4% of the weight of the semi-finished product and for 20-30 minutes with organic acid in amount of 0.5-1.0% of the weight of the semi-finished product. Further, the semi-finished product undergoes greasing and re-treated for 40-50 minutes with a product of reacting hexamethylenediamine with phosphoric acid and urea in the presence of glycerin in molar ratio of 1:3:3:0.5 and consumption of 7-8% of the weight of the semi-finished product, volume ratio of 0.8-1.0 and temperature of 20-22°C. Hydrophobisation with a polymer tanning agent, dyeing in the presence of a synthetic tanning agent, post-tanning with a plant-material tanning agent, further treatment with a product of reacting hexamethylenediamine with phoshoric acid and urea in the presence of glycerin in the said molar ratio and with organic acid is carried out in one bath. Separation and drying are carried out after all operations.

EFFECT: higher water-, fungus- and heat-resistance of leather under high moisture and temperature conditions, and wide range of special types of leather.

2 cl, 3 tbl, 5 ex