Patent ID: 8481169

Claim:
A leather obtained by a process comprising (1) pre-treatment before tanning, (2) a tanning process where glutaraldehyde is used as a tanning agent, (3) a process where a re-tanning agent is used which is constituted by 20 to 30 percent by weight of synthetic tannin and 13 to 25 percent by weight of resin, both relative to 100 percent by weight of shaved leather, while the aforementioned synthetic tannin is constituted by (a) 0.45 to 0.50 of condensation product of aromatic sulfonic acid with formaldehyde (b) 0.38 to 0.43 of methylene cyclic polymer of aromatic sulfonic acid with hydroxy aromatic compound and (c) 0.10 to 0.15 of glyoxal (all are weight ratios, the total of which is 1.00), while the aforementioned resin is constituted by (a) 0.67 to 0.72 of acrylic acid, and copolymer(s) thereof and (b) 0.28 to 0.33 of polycondensation product of melamine with formaldehyde (all are weight ratios, the total of which is 1.00), wherein a fatliquoring agent constituted by (a) synthetic oil and natural oil and (b) mixture of synthetic oil and natural constituent is used in an amount of 15 to 19 percent by weight relative to 100 percent by weight of shaved leather, wherein a sample taken from a part of the leather obtained by re-tanning and subsequent post-treatment meets conditions including a BLC stiffness/softness of 4.42 mm or more but 4.90 mm or less and maximum set ratio of 10.7 or more but 12.4 or less.