A kind of preparation method of retanning agent based on chrome-free tanning 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: 2022-06-17
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 preparation method of a retanning agent based on chrome-free tanning shavings, comprising the following steps:

[0022] Using urea and hydrochloric acid to pretreat the chrome-free tanning shavings to obtain pretreated chrome-free tanning shavings;

[0023] Mixing the pretreated chrome-free tanned shavings with sodium hydroxide and a substance containing calcium oxide to carry out an alkaline hydrolysis reaction to obtain a hydrolyzate;

[0024] The hydrolyzed product is mixed with an emulsifier, (meth)acrylic acid and methyl methacrylate to carry out a polymerization reaction to obtain a retanning agent.

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

[0026] In the present invention, urea and hydrochloric acid are used to pretreat the chrome-free tanned leather scraps to obtain the pretreated chrome-free tanned leather sc...

Embodiment 1

[0048] (1) Preprocessing

[0049] 100kg moisture content is that the chrome-free tanning waste leather scraps of 20wt% are placed in the reactor, add water 500kg, be heated to 70 ℃, then add 5kg of urea, mass concentration is 2kg of hydrochloric acid of 37%, carry out pretreatment 60min, filter, Obtaining pretreated chrome-free tanning waste leather scraps;

[0050] (2) Hydrolysis

[0051] Add 500kg of water in the reactor containing the pretreated chrome-free tanning waste leather scraps, heat to 75°C, then add 3kg of sodium hydroxide and 6kg of lime, carry out basic hydrolysis reaction for 120min, and the molecular weight is 3000; Adjust its pH to be 6 with acetic acid 8kg, filter, obtain hydrolysis filtrate;

[0052] (3) Concentration

[0053] Take 1000kg of the hydrolysis filtrate, use a triple-effect energy-saving external circulation vacuum concentrator to concentrate it to a mass concentration of 35% by using an external heating type natural circulation type and a ne...

Embodiment 2

[0062] (1) Preprocessing

[0063] 100kg moisture content is that the chrome-free tanning waste leather scraps of 20wt% are placed in the reactor, add water 600kg, be heated to 80 ℃, then add urea 6kg, mass concentration is 37% hydrochloric acid 3kg, carry out pretreatment 90min, filter, Obtaining pretreated chrome-free tanning waste leather scraps;

[0064] (2) Hydrolysis

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

[0066] (3) Concentration

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

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PUM

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Abstract

The invention provides a method for preparing a retanning agent based on chrome-free tanning scraps, and relates to the technical field of resource utilization of waste biomass. The preparation method of the retanning agent provided by the present invention comprises the following steps: using urea and hydrochloric acid to pretreat chrome-free tanned leather shavings to obtain pretreated chrome-free tanned leather shavings; Leather shavings are mixed with sodium hydroxide and calcium oxide-containing substances to carry out basic hydrolysis to obtain a hydrolyzate; the hydrolyzate is mixed with an emulsifier, (meth)acrylic acid, and methyl methacrylate to carry out a polymerization reaction, Obtain retanning agent. The retanning agent prepared by the invention can endow leather with good retanning filling performance and natural hand feeling, and realize the high-value resource utilization of chrome-free tanning waste leather scraps.

Description

technical field [0001] The invention relates to the technical field of waste biomass resource utilization, in particular to a preparation method of a retanning agent based on chrome-free tanned leather scraps. Background technique [0002] Leather industry is one of the traditional characteristic industries in my country, which is to process raw hides, one of the by-products of animal husbandry, into genuine leather fabrics for people to use. In the process of leather production, tanning is an important process of converting leather into leather, which directly determines the quality of the finished leather. In the current tanning agent and the corresponding tanning method, the chrome tanned leather prepared by the chrome tanning agent has excellent comprehensive properties such as softness and plumpness, high strength, storage resistance, washing resistance, not easy to detanning, and good humidity and heat stability. Top of the list of all leather products. Therefore, mo...

Claims

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Application Information

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Patent Type & Authority Patents(China)
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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