US 12,163,197 B2Granted

Method of manufacturing leather

AssigneesMidori Auto Leather Co., Ltd., Toyota Jidosba Kabushiki Kaisha

InventorsTatsuaki Ujiie, Yasumitsu Suzuki, Haruki Oura, Seiji Yamaguchi, Yoshio Yamada

Life of this patent

Estimating the term…

Loading patent…

Abstract

The present invention provides a method of manufacturing leather, which not only significantly suppresses the occurrence of adhesive wrinkling and boarding/alighting wrinkling when used for an automobile seat, for example, but also exhibits appropriate flexibility. The present invention is a method of manufacturing leather including a pretreatment step, a tanning step, a retanning step, and a drying and finishing step in this order, the retanning process including, in the following order, subjecting a shaving leather obtained from the tanning process to a stage of performing treatment using a predetermined retanning agent and a predetermined resin, a stage of performing treatment using a predetermined retanning agent, a predetermined resin, and a predetermined fatliquoring agent, and a stage of performing treatment using a predetermined resin and a predetermined fatliquoring agent, and the drying in the drying and finishing process including, in the following order, subjecting a leather obtained from the retanning process to a stage of drying under reduced pressure under predetermined conditions and a step of drying at atmospheric pressure under predetermined conditions.

A method of manufacturing leather, the method comprising, in the following order:

(I) a pretreatment process;
(II) a tanning process;
(III) a retanning process;
and
(IV) a drying and finishing process, wherein:
(III) the retanning process comprises, in the following order, subjecting a shaving leather obtained from (II) the tanning process to:
(III-0) performing a retanning treatment using:
from 14.4 to 21.6 parts by mass of a retanning agent (d) consisting of chromium (d1) and glutaraldehyde (d2), and
from 7.0 to 10.6 parts by mass of at least one resin (b) selected from the group consisting of:
(b1) a polymer consisting of one selected from the group consisting of acrylic acid, methacrylic acid, acrylic acid ester and methacrylic acid ester, or a mixture of these polymers,
(b2) a polymer consisting of two or more selected from the group consisting of acrylic acid, methacrylic acid, acrylic acid ester and methacrylic acid ester, or a mixture of these polymers, and
(b3) a polycondensate of melamine and formaldehyde,
(III-1) performing a retanning treatment using from 12.8 to 19.2 parts by mass of a retanning agent (a) consisting of a polycondensate (a1) of aromatic sulfonic acid and formaldehyde, and from 19.7 to 29.5 parts by mass of the resin (b) and, at the same time, performing a fatliquoring treatment using from 3.4 to 5.2 parts by mass of a fatliquoring agent (c) consisting of (c1) a synthetic oil, a natural oil or any combination thereof, and
(III-2) performing a resin tanning treatment using from 5.3 to 7.9 parts by mass of the resin (b) and, at the same time, performing a fatliquoring treatment using from 7.0 to 10.4 parts by mass of the fatliquoring agent (c),
wherein an amount of each of the retanning agent (a), the resin (b), the fatliquoring agent (c), and the retanning agent (d), is an amount relative to 100 parts by mass in dry standard of a shaving leather, and
the drying in (IV) the drying and finishing process comprises, in the following order, subjecting a leather obtained from (III) the retanning process to:
(IV-1) drying at reduced pressure at from 35° C. to 45° C. for from 1 to 5 minutes, and
(IV-2) drying at atmospheric pressure at from 35° C. to 45° C. for from 10 to 40 minutes.

15 more elements

Abstract

Claims16