Method of preparing protein polypeptide retanning agent

Abstract

The invention provides a method for preparing a protein polypeptide re-tanning agent. The method comprises the following steps: chrome leather waste is placed into an aqueous solution dissolved with calcium lignosulphonate and sodium hydroxide, subjected to hydrolysis reaction at a temperature of between 100 and 110 DEG C, and subjected to temperature reduction after hydrolysis reaction; and the pH value of the mixture is adjusted to between 6.5 and 7.5, and the protein polypeptide re-tanning agent is obtained, wherein the mass ratio of the chrome leather waste to the calcium lignosulphonate to the sodium hydroxide is 3.5-4.0 to 1.6-1.9 to 1. The method has the advantages that the adequate hydrolysis technology is adopted, and products obtained by hydrolysis of collagen are more stable and more simple and convenient to use, and are difficult to delaminate; and due to addition of the calcium lignosulphonate, the method is favorable for dispersing the chrome leather waste into a sodium hydroxide aqueous solution, promoting hydrolysis of the chrome leather waste, making the hydrolysis reaction tend to be consistent, causing the molecular weight of hydrolysis products to be controlledwithin a small range between 5,000 and 10,000, realizing uniform hydrolysis of the collagen of the chrome leather waste, and making the final products stable, difficult to delaminate and having better re-tanning function.

Description

(1) Technical field

[0001] The invention relates to a preparation method of an environmentally friendly novel protein polypeptide retanning agent. (2) Background technology

[0002] The leather industry is a pillar industry in my country's light industry. In recent years, with the rapid development of the leather and shoe-making industries, it has become a major leather-making country in the world and one of the most active and promising markets for leather trade.

[0003] Although my country's leather chemical materials are developing rapidly, there are many low-level repetitions, few innovations or high-level ones, unstable quality, weak corporate innovation capabilities, and low manufacturing process levels. Compared with countries, there are obvious gaps such as poor quality, poor brand and price difference, so in-depth research on the combination mechanism of various leather chemicals and leather collagen fibers, and various mechanical properties, thermodynamic properti...

Examples

Embodiment 1

[0022] Take 128g of calcium lignosulfonate, add 120mL of water, and stir evenly; dissolve 80g of sodium hydroxide in 160mL of water to form NaOH aqueous solution; control the temperature at about 60°C, add NaOH aqueous solution into the aqueous solution of calcium lignosulfonate, Calcium sulfonate aqueous solution is made into a paste, and then 280g of pigskin chrome leather scraps are gradually added into it, and 85mL of water is added in the middle, the temperature is raised to 100°C, and the reaction is carried out for 6.5h. The chrome leather scraps are all hydrolyzed into an aqueous solution of protein and polypeptide. Due to the presence of calcium lignin sulfonate, the solution is thicker. Cool the water bath to about 30°C, add formic acid solution drop by drop to neutralize the alkaline hydrolyzate until the pH value is 6.8, add about 75mL of formic acid, the neutralization and dropping time is controlled at 2.5-3h, and the protein polypeptide hydrolyzate A is obtained,...

Embodiment 2

[0024] Take 140g of calcium lignosulfonate, add 120mL of water, and stir evenly; dissolve 80g of sodium hydroxide in 160mL of water to form NaOH aqueous solution; control the temperature at about 60°C, add NaOH aqueous solution into the aqueous solution of calcium lignosulfonate, lignin Calcium sulfonate aqueous solution is made into a paste, and then 300g of pigskin chrome leather scraps are gradually added to it, and 100mL of water is added in the middle, the temperature is raised to 105°C, and the reaction is carried out for 7.5h. The chrome leather scraps are all hydrolyzed into protein polypeptide aqueous solution. Due to the presence of calcium lignin sulfonate, the solution is thicker. Cool the water bath to about 30°C, add formic acid solution drop by drop to neutralize the alkaline hydrolyzate until the pH value is 6.5, add about 78mL of formic acid, the neutralization and dropping time is controlled at 2.5-3h, and the protein polypeptide hydrolyzate B is obtained, the...

Embodiment 3

[0026] Take 150g of calcium lignosulfonate, add 120mL of water, and stir evenly; dissolve 80g of sodium hydroxide in 160mL of water to form NaOH aqueous solution; control the temperature at about 60°C, add NaOH aqueous solution into the aqueous solution of calcium lignosulfonate, Calcium sulfonate aqueous solution is made into a paste, and then 320g of pigskin chrome leather scraps are gradually added to it, and 120mL of water is added in the middle, the temperature is raised to 110°C, and the reaction is carried out for 8 hours. The chrome leather scraps are all hydrolyzed into an aqueous solution of protein and polypeptide. Due to the presence of calcium lignin sulfonate, the solution is thicker. Cool the water bath to about 30°C, add formic acid solution drop by drop to neutralize the alkaline hydrolyzate until the pH value is 7.5, add about 70mL of formic acid, the neutralization and dropping time is controlled at 2.5-3h, and the protein polypeptide hydrolyzate C is obtaine...

(1) Technical field

[0001] The invention relates to a preparation method of an environmentally friendly novel protein polypeptide retanning agent. (2) Background technology

[0002] The leather industry is a pillar industry in my country's light industry. In recent years, with the rapid development of the leather and shoe-making industries, it has become a major leather-making country in the world and one of the most active and promising markets for leather trade.

[0003] Although my country's leather chemical materials are developing rapidly, there are many low-level repetitions, few innovations or high-level ones, unstable quality, weak corporate innovation capabilities, and low manufacturing process levels. Compared with countries, there are obvious gaps such as poor quality, poor brand and price difference, so in-depth research on the combination mechanism of various leather chemicals and leather collagen fibers, and various mechanical properties, thermodynamic properti...

Examples

Embodiment 1

[0022] Take 128g of calcium lignosulfonate, add 120mL of water, and stir evenly; dissolve 80g of sodium hydroxide in 160mL of water to form NaOH aqueous solution; control the temperature at about 60°C, add NaOH aqueous solution into the aqueous solution of calcium lignosulfonate, Calcium sulfonate aqueous solution is made into a paste, and then 280g of pigskin chrome leather scraps are gradually added into it, and 85mL of water is added in the middle, the temperature is raised to 100°C, and the reaction is carried out for 6.5h. The chrome leather scraps are all hydrolyzed into an aqueous solution of protein and polypeptide. Due to the presence of calcium lignin sulfonate, the solution is thicker. Cool the water bath to about 30°C, add formic acid solution drop by drop to neutralize the alkaline hydrolyzate until the pH value is 6.8, add about 75mL of formic acid, the neutralization and dropping time is controlled at 2.5-3h, and the protein polypeptide hydrolyzate A is obtained,...

Embodiment 2

[0024] Take 140g of calcium lignosulfonate, add 120mL of water, and stir evenly; dissolve 80g of sodium hydroxide in 160mL of water to form NaOH aqueous solution; control the temperature at about 60°C, add NaOH aqueous solution into the aqueous solution of calcium lignosulfonate, lignin Calcium sulfonate aqueous solution is made into a paste, and then 300g of pigskin chrome leather scraps are gradually added to it, and 100mL of water is added in the middle, the temperature is raised to 105°C, and the reaction is carried out for 7.5h. The chrome leather scraps are all hydrolyzed into protein polypeptide aqueous solution. Due to the presence of calcium lignin sulfonate, the solution is thicker. Cool the water bath to about 30°C, add formic acid solution drop by drop to neutralize the alkaline hydrolyzate until the pH value is 6.5, add about 78mL of formic acid, the neutralization and dropping time is controlled at 2.5-3h, and the protein polypeptide hydrolyzate B is obtained, the...

Embodiment 3

[0026] Take 150g of calcium lignosulfonate, add 120mL of water, and stir evenly; dissolve 80g of sodium hydroxide in 160mL of water to form NaOH aqueous solution; control the temperature at about 60°C, add NaOH aqueous solution into the aqueous solution of calcium lignosulfonate, Calcium sulfonate aqueous solution is made into a paste, and then 320g of pigskin chrome leather scraps are gradually added to it, and 120mL of water is added in the middle, the temperature is raised to 110°C, and the reaction is carried out for 8 hours. The chrome leather scraps are all hydrolyzed into an aqueous solution of protein and polypeptide. Due to the presence of calcium lignin sulfonate, the solution is thicker. Cool the water bath to about 30°C, add formic acid solution drop by drop to neutralize the alkaline hydrolyzate until the pH value is 7.5, add about 70mL of formic acid, the neutralization and dropping time is controlled at 2.5-3h, and the protein polypeptide hydrolyzate C is obtaine...