Classifications

• • C—CHEMISTRY; METALLURGY
  • C14—SKINS; HIDES; PELTS; LEATHER
  • C14C—CHEMICAL TREATMENT OF HIDES, SKINS OR LEATHER, e.g. TANNING, IMPREGNATING, FINISHING; APPARATUS THEREFOR; COMPOSITIONS FOR TANNING
  • C14C9/00—Impregnating leather for preserving, waterproofing, making resistant to heat or similar purposes
• • C—CHEMISTRY; METALLURGY
  • C14—SKINS; HIDES; PELTS; LEATHER
  • C14C—CHEMICAL TREATMENT OF HIDES, SKINS OR LEATHER, e.g. TANNING, IMPREGNATING, FINISHING; APPARATUS THEREFOR; COMPOSITIONS FOR TANNING
  • C14C9/00—Impregnating leather for preserving, waterproofing, making resistant to heat or similar purposes
  • C14C9/02—Impregnating leather for preserving, waterproofing, making resistant to heat or similar purposes using fatty or oily materials, e.g. fat liquoring

Definitions

• This invention relates to a treating method which imparts leather with waterproofness in a greasing step which falls in the last treating step in a leather tanning process.
• leather is produced by a tanning treating process which comprises soaking of hide which has been salted, liming treatment, deliming and bating treatment -- pickling treatment -- chrome tanning and re-chrome tanning treatment -- neutralization tanning'treatment -- dyeing treatment -- greasing treatment -- finishing treatment.
• the greasing step in the above-described tanning treatment is conducted in order that the hide, which has been degreased by the proceeding treatment and the water absorption and permeation of which has been increased, be decreased in the water absorption and permeation and be imparted with softness and oily feel by adding a greasing agent.
• hydrophobic property and oily feel vary depending on the amount of the greasing agent imparted to the hide, and with an increase in the degree of greasing, both hydrophobic property and oily feel are enhanced.
• leather still has another problem of gas permeability, and this gas permeability has a tendency to decrease with the degree of greasing.
• the present inventors have been intensively studying on the waterproofing treatment of leather and, as a result, have discovered that on greasing treatment, by imparting a waterproofing agent together with a greasing agent, the waterproofness may be enhanced without decreasing the gas permeability.
• the waterproofness generated by the greasing treatment is even further enhanced by subsequent water-repellent treatment and the waterproofness may be maintained even when after use over an extended period of time.
• an object of this invention is to provide a novel waterproofing treating method which can produce leather having excellent waterproofness without losing softness and gas permeability by simultaneous use of a greasing agent and a waterproofing agent plus water-repellent treatment after greasing and waterproofing treatment.
• This invention having the above-described object stipulates as a first condition that hide after dyeing treatment is subjected to greasing treatment using both of a plurality of greasing agents having a hydrophobic effect and a waterproofing agent having a softening effect. Further, it stipulates as a second condition that said greasing treated hide is subjected to re-chrome tanning treatment and subsequently subjected to water-repellent treatment.
• the hide treated by the these two conditions will have softness and oily feel and at the same time have waterproofness maintainable for a prolonged period of time without losing gas permeability regardless of the treating steps from the starting water soaking to the dyeing treatment.
• the greasing agent used in this invention is a greasing composition exerting two hydrophobic effects which comprises a greasing agent comprising a mixture of triethanolamine and a carboxylic acid and a greasing agent comprising a mixture of a polymeric alkane and a sulfinated synthetic ester.
• waterproofing agent a mixture of a higher paraffin and a polymeric sulfosuccinic acid ester is used.
• the mixture of the greasing agent and the waterproofing agent is formulated such that the amount of each of the greasing agents be somewhat smaller than the amount of the waterproofing agent and the amounts of both greasing agents be equal.
• the amount of the mixture used is in the range of 10 - 20% based on the tanned hide weight,-preferably about 16%, and is used in solution in water weighed in a proportion of 200% based on the tanned hide weight in a drum. Further, about 2% of synthetic tanning is added to the water in the drum, and dyeing r treated hide is placed therein, drummed for about 10 minutes and, after adding about 1% of formic acid, drummed again for about 10 minutes.
• the greasing and waterproofing treated hide is washed with water, then re-chrome tanned, further washed with water, and water-repellent treated.
• the water-repellent agent used in this water-repellent treatment is preferably a fluorine type water-repellent oil agent and used in an amount of 3 - 5% based on the tanned hide weight by adding to 200% of water.
• the treatment is conducted by drumming for about 30 minutes, and after the treatment, washing with cold water and subsequent drying treatment are conducted.
• the temperature on measurement is 20°C and the relative humidity is 50%.
• the waterproof leather imparted with waterproof finish according to the method of this invention is remarkably excellent in water resistance while maintaining good gas permeability and that the water permeating time by the dynamic waterproofing test is long and the water absorption on water permeation is low.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Treatment And Processing Of Natural Fur Or Leather (AREA)

Priority Applications (1)

Applications Claiming Priority (1)

Publications (1)

Family

ID=8194811

Family Applications (1)

Country Status (1)

Citations (5)

• 1986
  • 1986-01-03 EP EP86100048A patent/EP0235307A1/de not_active Withdrawn

Patent Citations (5)

Non-Patent Citations (2)

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