CS216477B1 - Material for the production of base plates for punching out pieces of natural leather and leather - Google Patents

Abstract

The invention relates to the use of polyamide blocks based on 6-caprolactam, or its copolymers with higher lactams of 1-amino acids, plasticized with polyurethane.

Description

The present invention relates to the use of polyamides based on 6-caprolactam (polyamide-6) or copolymers thereof with β higher lactams of L 1 -amino acids softened with polyurethane.

In the leather and footwear industry, underlaying boards (so-called blocks) of various sizes are used on a large scale when punching parts made of natural leather and plastic leather. Most often, these bars are made of plasticized or otherwise modified polyvinyl chloride, a material called cubic, and various polyolefin-based materials available under various trade names such as Sustilen (NSR). Many of these materials are imported from the capitalist countries, which represents significant foreign exchange claims annually. A characteristic but undesirable feature of almost all of these materials is the low durability due to rapid wear.

The present invention is based on the use of polyamide-based blocks

6-caprolactam or its copolymers with higher lactams of <X> -amino acids prepared by anionic copolymerization using the catalytic system of the general formula

N _and Al (OCH ₂ CH ₂ OCH ₃ ) / N (CH ₂ ) _n O / _{4 - x} , wherein x is a number from 0 to 2 inclusive and n is 5 to 11, in the presence of 0.5 to 4 wt. polyurethane containing -NC-ϊ- repeating units in the chain,

Wherein Z, Y are oxygen or sulfur atoms and R is hydrogen, a lactam melt-soluble aryl or alkyl group, as a material for the production of backing sheets for punching both leather and plastic parts in the leather and footwear industry.

Polyamide-6 plasticized to the desired degree has my entirely physico-mechanical properties. However, the main benefit is its up to several times higher wear resistance compared to the materials used up to now. In addition, it is no problem to recover the damaged surface by milling. The preparation of the material is practically based on domestic raw materials and waste polyurethane foam can be used for modification. Unplasticized polyamide sheets are manufactured in CSSR, but due to their lower toughness and high hardness, they do not meet the requirements for leather and footwear applications.

Examples of use

1. Block of polyamide-6 pin? by block anionic polymerization of 6-caprolactam in the presence of 2% by weight of polyurethane with dimensions of 92 x 46 x 6 cm was used as a base material in the manufacture of fine leather goods, where it still has satisfactory properties after 16 months. The polyvinyl chloride blocks used so far lasted a maximum of 2 to 3 months under these conditions.

2. In the production of medium leather haberdashery, where leather of higher strength and hardness is used, a polyamide block plasticized with 1.5% by weight polyurethane was used.

216 477 showed a much longer service life than previously used Sustllen plates and similar materials.

Claims (1)

SUBJECT OF THE INVENTION Use of blocks of polyamides based on 6-caprolactam or its copolymers with higher lactams of α-amino acids prepared by anionic polymerization using a catalytic system of the general formula NaAl (OCH ₂ CH ₂ OCH ₃ ) / Ν (ΟΗ ₂ ) _η 0θ / ₄ _ _χ , where x is a number from 0 to 2 inclusive and n is 5 to 11, in the presence of 0.5 to 4 wt. polyurethane containing repeating units in the chain -N-C-Y- Wherein Z, Y are oxygen or sulfur atoms, and R is hydrogen, a lactam melt-soluble aryl or alkyl group, as a material for the production of backing sheets for punching both leather and plastic parts in the leather and footwear industry.