Abstract: Provided is a natural leather having a novel coating layer which feels leathery. The coating film retains material properties such as strength and wearing resistance. When the user directly touches the natural leather, the coating layer present on the surface of the natural leather gives slick characteristics of natural leathers and smoothness. The natural leather has a coating film formed on a surface thereof, the coating film including: a color coat layer formed from a mixture of a hard component (10% modulus is more than 2.3 but no more than 3.0) and a soft component (10% modulus is more than 0.0 but no more than 1.0) of a two-component polyurethane resin; and a topcoat layer formed from a mixture of a medium component (resin having a 10% modulus of more than 1.0 but no more than 2.3) and a soft component (resin having a 10% modulus of more than 0.0 but no more than 1.0) of a two-component polyurethane resin.

Abstract: A leather obtained by a (1) pre-treatment before tanning, (2) tanning process where glutaraldehyde is used as a tanning agent, (3) process where a re-tanning agent is used which is constituted by synthetic tannin, resin and aluminum, of which the synthetic tannin is constituted by (a) condensation product of aromatic sulfonic acid with formaldehyde or mixture of aromatic sulfonic acid and condensation product of aromatic sulfonic acid with formaldehyde, (b) methylene cyclic polymer of aromatic sulfonic acid with hydroxy aromatic compound or mixture of aromatic sulfonic acid and methylene cyclic polymer of aromatic sulfonic acid with hydroxy aromatic compound and (c) glyoxal, while the resin is constituted by (a) acrylic acid, methacrylic acid, acrylic acid ester or methacrylic acid ester polymer(s) and mixture thereof, and copolymer(s) thereof or mixture thereof and (b) polycondensation product of melamine with formaldehyde, wherein the re-tanning agent having the aforementioned composition is used to perform

Abstract: Provided are a car-seat split crust leather and leather. A hide already subjected to pretreatment and subjected to tanning treatment is split into leather including a grain surface and into split leather with a thickness of 4 mm to 2.3 mm, the taken-out split leather is arranged so that a flesh side of the split leather can be located on an upper side and that a grain side of the split leather can be located on a lower side, split leather with a thickness of 2.6 mm to 1.8 mm is made, next, the flesh side of the split leather is shaved to thereby set the thickness of the split leather to 2.0 mm to 1.1 mm, and a car-seat split crust leather with a thickness of 1.6 mm to 1.0 mm is manufactured, which is then subjected to tanning and re-tanning treatment, and has a coating film formed thereon.

Abstract: A natural leather is treated with a tanning agent, a re-tanning agent, a dye and a greasing agent, wherein a treatment agent for inhibiting the generation of formaldehyde and acetaldehyde from the natural leather is added to the greasing step so that the natural leather is impregnated with the treatment agent. The treatment agent includes a hydrazide compound optionally together with sodium hydrogen sulfite.

Abstract: Provided is a natural leather having a novel coating layer which feels leathery. The coating film retains material properties such as strength and wearing resistance. When the user directly touches the natural leather, the coating layer present on the surface of the natural leather gives slick characteristics of natural leathers and smoothness. The natural leather has a coating film formed on a surface thereof, the coating film including: a color coat layer formed from a mixture of a hard component (10% modulus is more than 2.3 but no more than 3.0) and a soft component (10% modulus is more than 0.0 but no more than 1.0) of a two-component polyurethane resin; and a topcoat layer formed from a mixture of a medium component (resin having a 10% modulus of more than 1.0 but no more than 2.3) and a soft component (resin having a 10% modulus of more than 0.0 but no more than 1.0) of a two-component polyurethane resin.

Abstract: A leather is obtained by a process where a re-tanning agent is used which is constituted by synthetic tannin, resin and aluminum. The synthetic tannin is constituted by (a) condensation product of aromatic sulfonic acid with formaldehyde, (b) methylene cyclic polymer of aromatic sulfonic acid with hydroxy aromatic compound, and (c) glyoxal. The resin is constituted by (a) acrylic acid, methacrylic acid, acrylic acid ester or methacrylic acid ester polymer(s), and copolymer(s) thereof, and (b) polycondensation product of melamine with formaldehyde.

Abstract: This object relates to a natural leather which is obtained by forming a coating film through the greasing step following re-tanning and dyeing and the drying step. The purpose of this object is to provide a natural leather, wherein the generation of free formaldehyde and acetaldehyde is inhibited, and a treating agent to be added in the greasing step for natural leather. A natural leather wherein formaldehyde and acetaldehyde generated by a tanning agent, a re-tanning agent, a dye and a greasing agent having been incorporated into a leather are confined in the leather with a treating agent to be added in the greasing step for natural leather which contains a hydrazide compound optionally together with sodium hydrogen sulfite to thereby inhibit or prevent the generation of formaldehyde and acetaldehyde, and an automobile interior part coated with this natural leather.