Preparation method of retanning agent based on chrome-free tanned leather shavings

A technology for chrome-free tanning and retanning agent is applied in the field of waste biomass resource utilization, and can solve the problems of detanning and treatment methods of chrome-free tanned leather scraps, etc.

Active Publication Date: 2021-09-17
JIAXING UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, there is no research on the detanning and treatment of chrome-free tanned leather shavings

Method used

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preparation example Construction

[0021] The invention provides a kind of preparation method based on the retanning agent of chrome-free tanning shavings, comprising the following steps:

[0022] Pretreating chrome-free tanned leather shavings by using urea and hydrochloric acid to obtain pretreated chrome-free tanned leather shavings;

[0023] mixing the pretreated chrome-free tanned leather shavings with sodium hydroxide and a substance containing calcium oxide, and performing an alkaline hydrolysis reaction to obtain a hydrolyzed product;

[0024] The hydrolyzate is mixed with an emulsifier, (meth)acrylic acid and methyl methacrylate, and polymerized to obtain a retanning agent.

[0025] In the present invention, unless otherwise specified, all raw material components are commercially available products well known to those skilled in the art.

[0026] The invention adopts urea and hydrochloric acid to pretreat the chrome-free tanned leather scraps to obtain the pretreated chrome-free tanned leather scraps....

Embodiment 1

[0048] (1) Pretreatment

[0049] Put 100kg of chrome-free tanned waste leather shavings with a moisture content of 20wt% in a reaction kettle, add 500kg of water, heat to 70°C, then add 5kg of urea, 2kg of hydrochloric acid with a mass concentration of 37%, pretreat for 60min, and filter. Obtain the chrome-free tanned waste leather shavings after pretreatment;

[0050] (2) Hydrolysis

[0051] Add 500kg of water into the reaction kettle equipped with the pretreated chrome-free tanned waste leather scraps, heat to 75°C, then add 3kg of sodium hydroxide and 6kg of lime, and carry out alkaline hydrolysis reaction for 120min, with a molecular weight of 3000; Regulate its pH with 8 kg of acetic acid to be 6, filter to obtain the hydrolysis filtrate;

[0052] (3) concentrated

[0053] Take 1000kg of the hydrolyzed filtrate, and use a three-effect energy-saving external circulation vacuum concentrator to concentrate it to a mass concentration of 35% by means of external heating nat...

Embodiment 2

[0062] (1) Pretreatment

[0063] Put 100kg of chrome-free tanned waste leather shavings with a moisture content of 20wt% in a reaction kettle, add 600kg of water, heat to 80°C, then add 6kg of urea, 3kg of hydrochloric acid with a mass concentration of 37%, pretreat for 90min, filter, Obtain the chrome-free tanned waste leather shavings after pretreatment;

[0064] (2) Hydrolysis

[0065] Add 600kg of water into the reaction kettle equipped with the pretreated chrome-free tanned waste leather scraps, heat it to 85°C, then add 4kg of sodium hydroxide and 8kg of lime, carry out alkaline hydrolysis reaction for 180min, and the molecular weight is 4000; Regulate its pH with acetic acid 10kg to be 7, filter to obtain the hydrolysis filtrate;

[0066] (3) concentrated

[0067] Take 1000kg of the hydrolyzed filtrate, and use a three-effect energy-saving external circulation vacuum concentrator to concentrate it to a mass concentration of 40% by using an externally heated natural c...

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PUM

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Abstract

The invention provides a preparation method of a retanning agent based on chrome-free tanned leather shavings, and relates to the technical field of waste biomass resource utilization. The preparation method of the retanning agent comprises the following steps: adopting urea and hydrochloric acid to conduct pretreatment on chrome-free tanning leather shavings to obtain pretreated chrome-free tanning leather scraps; mixing the pretreated chrome-free tanned leather scraps with sodium hydroxide and a substance containing calcium oxide, and carrying out an alkaline hydrolysis reaction to obtain a hydrolysis product; and mixing the hydrolysate with an emulsifier, (methyl) acrylic acid and methyl methacrylate, and carrying out polymerization reaction to obtain the retanning agent. The prepared retanning agent can endow leather with good retanning filling performance and natural hand feeling, and resource high-value utilization of chrome-free tanned waste leather scraps is achieved.

Description

technical field [0001] The invention relates to the technical field of resource utilization of waste biomass, in particular to a preparation method of a retanning agent based on chrome-free tanning scraps. Background technique [0002] The leather industry is one of my country's traditional characteristic industries, which processes raw hides, one of the by-products of animal husbandry, into genuine leather fabrics for people to use. In the leather production process, tanning is an important process of converting leather into leather, which directly determines the quality of finished leather. Among the current tanning agents and corresponding tanning methods, the chrome tanned leather prepared by chrome tanning agents has excellent comprehensive properties such as softness, fullness, high strength, storage resistance, washing resistance, not easy to detannage, and good moisture and heat stability. It ranks first among all leather products. Therefore, more than 90% of leath...

Claims

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Application Information

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IPC IPC(8): C14C3/22C08F220/06C08F220/14
CPCC14C3/22C08F220/06C08F220/14
Inventor 林语琪蔡燕婷罗建勋马贺伟钟绍宏吴佩君王泽胜田润喆
Owner JIAXING UNIV
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