CN101717832A - Method for tanning pigskin first layer shoe lining leather by utilizing non-chromium metal compound tanning agent - Google Patents

Abstract

The invention discloses a method for tanning pigskin top layer shoe lining leather with a non-chrome metal compound tanning agent, which includes oiling and tanning steps. LTA-100 metal (chrome-free) compound tanning agent, chrome-free Tanning partner D6 and tanning agent GM-40, etc., are characterized by the fact that the shrinkage temperature of industrially produced leather can reach above 90°C, which meets the requirements of shoemaking processing; meets the testing requirements of hexavalent chromium and total chromium for environmental labeling products; and has no phosphorus pollution , no formaldehyde release; tanning sludge can be directly incinerated; no special adjustments to the post-tanning process and materials are required, and it is well compatible with the current tanning process. The invention can meet the limited requirements of environmental labeling products on hexavalent chromium and total chromium content, has high shrinkage temperature, and creates a new way for tannery enterprises to produce high-grade environment-friendly shoe linings.

Description

A method for tanning pigskin top shoe lining leather with non-chrome metal compound tanning agent

technical field

The invention belongs to the field of leather tanning, and specifically refers to a method for tanning pigskin top layer shoe lining with a non-chromium metal compound tanning agent.

Background technique

Chrome tanning, which has a history of more than 100 years, has been the mainstream technology of leather tanning because it can impart excellent performance to leather, and it is almost unshakable. Chromium pollution in the tanning industry has three sources: first, pollution in the production and processing of chromium-containing materials; second, pollution in sewage, sludge, and chromium-containing solid waste in the tanning production process; Third, secondary pollution to the environment after consumption of chromium-containing products. This pollution is often ignored by people, but it accounts for about 70% of the total chromium pollution in the whole leather industry, and it is quite scattered, which is not conducive to treatment or recovery. With the development of the global economy and the progress of society, the enhancement of people's awareness of environmental protection and the lack of chromium resources, the pollution of chromium, the safety problems of wearing chrome-tanned leather products and the disposal of waste chrome-tanned leather products are increasingly concerned.

There are three common chrome-free tanning techniques in terms of tanning mechanism. One is based on aldehyde tanning. Typical tanning agents include (modified) glutaraldehyde, oxazolidine, tetrakis hydroxymethylphosphine ( Organophosphorus), etc.; one is tannin tanning agent; the other is other inorganic metal compound tanning agent. These three technologies have one or more of the following problems in the actual industrial production engineering: the shrinkage temperature of leather cannot be stabilized above 90°C; the performance of leather is far behind that of chrome tanned leather; Some leather processing technology systems have brought pollution problems such as organic phosphorus and formaldehyde after eliminating chromium pollution.

The leather is machine-split, the upper layer containing the dermis (or grain layer) is called the head layer, and the shoe lining is generally pigskin, which can be divided into pigskin top layer shoe lining and pigskin second layer shoe lining . Pigskin top layer shoe lining maintains the unique "pin"-shaped natural pore pattern of pigskin, which has the characteristics of beautiful appearance, good strength, wear resistance, good air permeability and high utilization rate. Due to the particularity of wearing the upper shoe lining leather, the requirements for ecological indicators are particularly strict. In the "Technical Requirements for Environmental Labeling Products for Leather and Synthetic Leather (Draft for Comment)", it is clearly stipulated that the hexavalent chromium content should be less than 5ppm, and the total chromium content should be low At 50ppm, the formaldehyde content should be lower than 75ppm. In addition, the process of shoemaking processing requires shoe lining to have a higher shrinkage temperature. Conventional chrome-tanned shoe linings are difficult to meet the detection requirements of environmental labeling products for hexavalent chromium and total chromium, while conventional chrome-free tanned shoe linings cannot stabilize the shrinkage temperature of finished leather above 90°C.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art, and provide a kind of finished leather whose shrinkage temperature can be stabilized above 90 degrees, which meets the requirements of shoemaking processing, and meets the requirements of environmental labeling products on hexavalent chromium and total A method for tanning pigskin top layer shoe lining with non-chromium metal compound tanning agent required for chromium detection.

In order to achieve the above object, the technical solution of the present invention comprises the following steps, wherein the raw materials used are in parts by weight:

(1) Refueling: Squeeze and weigh the pickled pigskin taken from the upper layer of the dermis and passed through the conventional caustic soda process, and place it in the drum. The weight of the skin will increase to 250% to 300%. After the internal weight gain, the weight of the material is 100 parts; add 150-200 parts of normal temperature salt water with a concentration of 6-8 Baume into the drum, add 0.5-1.5 parts of non-ionic oil, and rotate for 20-40 minutes; In the split layer of the leather machine, the upper layer containing the dermis (or grain layer) is called the head layer, and the lower layer that is all the reticular layer is called the second layer. The pickled pigskin of the present invention is taken from the upper layer of the dermis of the dermis.

(2) Non-chromium metal compound tanning: add 10-16 parts of non-chromium metal compound tanning agent, 2.5-4.0 parts of chrome-free tanning partner D6, rotate for 120-180 minutes; add 1.2-2.0 parts of tanning agent GM- 40, rotate for 180-120 minutes; then add baking soda to adjust the pH to 3.2-4.0; finally add 100-150 parts of 60°C hot water, keep the inner temperature at 36°C-38°C, and rotate for 60-90 minutes; let stand At least 6 more hours, then wash out the drum.

Further setting is that described step (1) will be taken from the corium upper layer of the dermis and also carry out the uniform treatment of the buttocks before weighing through the pickled pigskin of the conventional caustic soda leather process. Note: Due to the differences in the parts of the animals when they grow, the buttocks of raw pig hides are generally thicker than other parts. In order to ensure the consistency of the leather finished product, special treatment can be carried out on the buttocks of the pigskin, such as adding a smoothing process to make the thickness of the leather more uniform. This process is known in the art as shaving the buttocks.

In the tanning step:

The non-ionic oil is NIFE-2 non-ionic oil, which is a non-ionic leather fatliquoring agent; the dosage of the non-ionic oil is preferably 1-1.5 parts.

Described non-chrome metal compound tanning agent is LTA-100 metal (chromium-free) compound tanning agent, it is a kind of non-chromium metal compound tanning agent mainly with zirconium; The consumption of described non-chrome metal compound tanning agent is the best 10 to 12 servings.

The chrome-free tanning partner D6 is a complex of multiple polycarboxylic acid compounds; the dosage of the chrome-free tanning companion D6 is 1/6-1/4 of that of non-chrome metal complex tanning agents.

The sharp tanning agent GM-40 is an organic complexing agent with a special molecular structure; the dosage of the sharp tanning agent GM-40 is 1/12-1/8 of that of the non-chrome metal complex tanning agent.

In the present invention:

(1) The NIFE-2 nonionic oil is a nonionic leather fatliquoring agent. Its technical indicators are as follows:

(1) Appearance: sapphire thick liquid;

(2) Effective content: ≥40.0% (weight/weight);

(3) pH value (10% aqueous solution): 5.0 to 7.0;

(4) (1:9) water emulsification stability: 24h, no stratification, no oil slick;

(5) Storage period: 6 months at room temperature without deterioration.

(2) The LTA-100 metal (chrome-free) compound tanning agent is a chrome-free tanning agent made by adding various auxiliary tanning materials and special antifreeze materials based on zirconium salt. Its technical indicators are as follows:

(1) Appearance: pale yellow transparent liquid;

(2) Total solids: ≥42.0% (weight/weight);

(3) Content of non-chrome metal tanning agent (calculated as ZrO2): (16.0±2.0)% (weight/weight);

(4) Freeze-thaw stability (-15°C, 72h): no crystallization, no freezing.

(3) The chrome-free tanning partner D6 is a special supporting material for the LTA type metal (chrome-free) compound tanning agent, which is used simultaneously with the LTA type metal (chrome-free) compound tanning agent; it is helpful for the chrome-free tanning agent in leather Penetrate to promote a more uniform distribution of chrome-free tanning agent in the leather; use chrome-free tanning partner D6 to make the grain of chrome-free tanned leather finer; it does not contain APEO and aldehyde substances restricted by the European Commission. Its technical indicators are as follows:

(1) Appearance: yellow transparent aqueous solution;

(2) Charge type: anionic;

(3) Solid content: ≥30.0% (weight/weight);

(4) pH value (10% aqueous solution): 4.0 to 7.0;

(5) Water solubility: miscible with any proportion of normal temperature water.

(4) The tanning agent GM-40 is a special supporting material specially developed for the normal use of LTA metal (chrome-free) compound tanning agent; when LTA type metal (chrome-free) compound tanning agent and chrome-free tanning partner D6 It can be added after the medium is basically penetrated evenly, which can play the role of complex tanning with tanning agents, help to improve the tanning effect of chrome-free tanning agents, and promote the increase of shrinkage temperature of chrome-free tanned leather; it can promote the formation of firmness between chrome-free tanning agents and leather Combination; does not contain APEO and aldehyde substances restricted by the European Commission. Its technical indicators are as follows:

(1) Appearance: light yellow transparent aqueous solution;

(2) Solid content: ≥35.0% (weight/weight);

(3) pH value (10% aqueous solution): 4.0 to 7.0;

(4) Water solubility: miscible with any proportion of normal temperature water.

The NIFE-2 non-ionic oil, LTA-100 type metal (chrome-free) compound tanning agent, chrome-free tanning partner D6 and sharp tanning agent GM-40 are all developed and provided by Wenzhou University Leather Research Institute, and other chemical materials can be found at buy in the market.

The invention can meet the limited requirements of environmental labeling products on hexavalent chromium and total chromium content, has high shrinkage temperature, and creates a new way for tannery enterprises to produce high-grade environment-friendly shoe linings.

This tanning technology does not have the pollution problems of organic phosphorus, formaldehyde and chromium, and the materials used are not limited by the Comprehensive Wastewater Discharge Standard of the People's Republic of China (GB8978-1996). The tanning sludge can be directly incinerated, which is an environmentally friendly leather tanning technology. technology.

The post-tanning process of the pig tanned leather produced by the invention is well compatible with the existing tanning process system, does not require special post-tanning processes and materials, and has a good factory industrial production basis.

The present invention will be further introduced below in combination with specific embodiments.

Detailed ways

The present invention is specifically described below by the embodiment, only for further illustrating the present invention, can not be interpreted as the limitation of protection scope of the present invention, the technical engineer of this field can make some non-essential improvements and improvements to the present invention according to the content of the above-mentioned invention Adjustment.

Example 1

(1) refueling: the pickled pigskin of the conventional caustic soda skin technology is squeezed, the buttocks are cut, weighed, placed in the drum, the weight of the skin is increased to 250%, and the weight of the material in the drum is 100 parts; Add 150 parts of normal temperature salt water with a concentration of 6 Baume into the drum, add 0.5 part of non-ionic oil, and rotate for 20 minutes;

(2) Tanning: add 10 parts of non-chrome metal compound tanning agent, 2.5 parts of chrome-free tanning partner D6, and rotate for 120 minutes; add 1.2 parts of sharp tanning agent GM-40, and rotate for 180 minutes; The pH is 3.2; finally add 100 parts of hot water at 60°C, keep the internal temperature at 36°C, and rotate for 60 minutes; overnight, wash out the drum with water the next day.

Example 2

(1) Refueling: the pickled pigskin of the conventional caustic soda peeling process is squeezed, the buttocks are cut, weighed, placed in the drum, the weight of the skin is increased to 280%, and the weight of the material in the drum is 100 parts; Add 180 parts of normal temperature salt water with a concentration of 7 Baume degrees in the drum, add 1.0 parts of non-ionic oil, and rotate for 30 minutes;

(2) Tanning: add 10 parts of non-chrome metal compound tanning agent, 2.5 parts of chrome-free tanning partner D6, and rotate for 120 minutes; add 1.2 parts of sharp tanning agent GM-40, and rotate for 180 minutes; The pH is 3.2; finally add 100 parts of hot water at 60°C, keep the internal temperature at 36°C, and rotate for 60 minutes; overnight, wash out the drum with water the next day.

Example 3

(1) refueling: the pickling pigskin of the conventional caustic soda peeling process is squeezed, the buttocks are cut, weighed, placed in the drum, the weight of the skin is increased to 300%, and the weight of the material in the drum is 100 parts; Add 200 parts of normal temperature salt water with a concentration of 8 degrees Baume into the drum, add 1.5 parts of non-ionic oil, and rotate for 40 minutes;

(2) Tanning: add 10 parts of non-chrome metal compound tanning agent, 2.5 parts of chrome-free tanning partner D6, and rotate for 120 minutes; add 1.2 parts of sharp tanning agent GM-40, and rotate for 180 minutes; The pH is 3.2; finally add 100 parts of hot water at 60°C, keep the internal temperature at 36°C, and rotate for 60 minutes; overnight, wash out the drum with water the next day.

Example 4

(1) refueling: the pickled pigskin of the conventional caustic soda skin technology is squeezed, the buttocks are cut, weighed, placed in the drum, the weight of the skin is increased to 250%, and the weight of the material in the drum is 100 parts; Add 150 parts of normal temperature salt water with a concentration of 6 Baume into the drum, add 0.5 part of non-ionic oil, and rotate for 20 minutes;

(2) Tanning: Add 12 parts of non-chrome metal compound tanning agent, 3.0 parts of chrome-free tanning companion D6, and rotate for 150 minutes; add 1.5 parts of sharp tanning agent GM-40, and rotate for 150 minutes; The pH is 3.5; finally add 120 parts of hot water at 60°C, keep the internal temperature at 37°C, and rotate for 60 minutes; overnight, wash out the drum with water the next day.

Example 5

(1) Refueling: the pickled pigskin of the conventional caustic soda peeling process is squeezed, the buttocks are cut, weighed, placed in the drum, the weight of the skin is increased to 280%, and the weight of the material in the drum is 100 parts; Add 180 parts of normal temperature salt water with a concentration of 7 Baume degrees in the drum, add 1.0 parts of non-ionic oil, and rotate for 30 minutes;

(2) Tanning: Add 12 parts of non-chrome metal compound tanning agent, 3.0 parts of chrome-free tanning companion D6, and rotate for 150 minutes; add 1.5 parts of sharp tanning agent GM-40, and rotate for 150 minutes; The pH is 3.5; finally add 120 parts of hot water at 60°C, keep the internal temperature at 37°C, and rotate for 60 minutes; overnight, wash out the drum with water the next day.

Example 6

(1) refueling: the pickling pigskin of the conventional caustic soda peeling process is squeezed, the buttocks are cut, weighed, placed in the drum, the weight of the skin is increased to 300%, and the weight of the material in the drum is 100 parts; Add 200 parts of normal temperature salt water with a concentration of 8 degrees Baume into the drum, add 1.5 parts of non-ionic oil, and rotate for 40 minutes;

(2) Tanning: Add 12 parts of non-chrome metal compound tanning agent, 3.0 parts of chrome-free tanning companion D6, and rotate for 150 minutes; add 1.5 parts of sharp tanning agent GM-40, and rotate for 150 minutes; The pH is 3.5; finally add 120 parts of hot water at 60°C, keep the internal temperature at 37°C, and rotate for 60 minutes; overnight, wash out the drum with water the next day.

Example 7

(1) refueling: the pickled pigskin of the conventional caustic soda skin technology is squeezed, the buttocks are cut, weighed, placed in the drum, the weight of the skin is increased to 250%, and the weight of the material in the drum is 100 parts; Add 150 parts of normal temperature salt water with a concentration of 6 Baume into the drum, add 0.5 part of non-ionic oil, and rotate for 20 minutes;

(2) Tanning: add 16 parts of non-chrome metal compound tanning agent, 4.0 parts of chrome-free tanning companion D6, and rotate for 180 minutes; add 2.0 parts of sharp tanning agent GM-40, and rotate for 120 minutes; The pH is 4.0; finally add 150 parts of hot water at 60°C, keep the internal temperature at 38°C, and rotate for 60 minutes; overnight, wash the drum out with water the next day.

Example 8

(1) Refueling: the pickled pigskin of the conventional caustic soda peeling process is squeezed, the buttocks are cut, weighed, placed in the drum, the weight of the skin is increased to 280%, and the weight of the material in the drum is 100 parts; Add 180 parts of normal temperature salt water with a concentration of 7 Baume degrees in the drum, add 1.0 parts of non-ionic oil, and rotate for 30 minutes;

(2) Tanning: add 16 parts of non-chrome metal compound tanning agent, 4.0 parts of chrome-free tanning companion D6, and rotate for 180 minutes; add 2.0 parts of sharp tanning agent GM-40, and rotate for 120 minutes; The pH is 4.0; finally add 150 parts of hot water at 60°C, keep the internal temperature at 38°C, and rotate for 60 minutes; overnight, wash the drum out with water the next day.

Example 9

(1) refueling: the pickling pigskin of the conventional caustic soda peeling process is squeezed, the buttocks are cut, weighed, placed in the drum, the weight of the skin is increased to 300%, and the weight of the material in the drum is 100 parts; Add 200 parts of normal temperature salt water with a concentration of 8 degrees Baume into the drum, add 1.5 parts of non-ionic oil, and rotate for 40 minutes;

(2) Tanning: add 16 parts of non-chrome metal compound tanning agent, 4.0 parts of chrome-free tanning companion D6, and rotate for 180 minutes; add 2.0 parts of sharp tanning agent GM-40, and rotate for 120 minutes; The pH is 4.0; finally add 150 parts of hot water at 60°C, keep the internal temperature at 38°C, and rotate for 60 minutes; overnight, wash the drum out with water the next day.

Example 10

(1) refueling: the pickled pigskin of the conventional caustic soda skin technology is squeezed, the buttocks are cut, weighed, placed in the drum, the weight of the skin is increased to 250%, and the weight of the material in the drum is 100 parts; Add 150 parts of normal temperature salt water with a concentration of 7 degrees Baume into the drum, add 1.5 parts of non-ionic oil, and rotate for 30 minutes;

(2) Tanning: add 12 parts of non-chrome metal compound tanning agent, 3.0 parts of chrome-free tanning companion D6, and rotate for 180 minutes; add 1.5 parts of sharp tanning agent GM-40, and rotate for 120 minutes; The pH is 3.5; finally add 120 parts of hot water at 60°C, keep the internal temperature at 38°C, and rotate for 60 minutes; overnight, wash the drum out with water the next day.

Example 11

(1) refueling: the pickling pigskin of the conventional caustic soda peeling process is squeezed, the buttocks are cut, weighed, placed in the drum, the weight of the skin is increased to 300%, and the weight of the material in the drum is 100 parts; Add 200 parts of normal temperature salt water with a concentration of 6 Baume into the drum, add 1.2 parts of non-ionic oil, and rotate for 40 minutes;

(2) Tanning: add 10 parts of non-chrome metal compound tanning agent, 2.5 parts of chrome-free tanning companion D6, and rotate for 150 minutes; add 1.2 parts of sharp tanning agent GM-40, and rotate for 150 minutes; The pH is 3.8; finally add 150 parts of hot water at 60°C, keep the internal temperature at 36°C, and rotate for 60 minutes; overnight, wash out the drum with water the next day.

Claims (7)

1. a method for tanning pigskin head layer shoe lining leather with non-chromium metal compound tanning agent, its feature The method comprises the following steps, wherein the raw materials used are in parts by weight: (1) Refueling: Squeeze and weigh the pickled pigskin taken from the upper layer of the dermis and passed through the conventional caustic soda process, and place it in the drum. The weight of the skin will increase to 250% to 300%. The weight of the material after internal weight gain is 100 parts; add 150 to 200 parts of normal temperature salt water with a concentration of 6 to 8 degrees Baume into the drum, add 0.5 to 1.5 parts of non-ionic oil, and rotate for 20 to 40 minutes; (2) Non-chromium metal compound tanning: add 10-16 parts of non-chromium metal compound tanning agent, 2.5-4.0 parts of chrome-free tanning partner D6, rotate for 120-180 minutes; add 1.2-2.0 parts of tanning agent GM- 40, rotate for 180-120 minutes; then add baking soda to adjust the pH to 3.2-4.0; finally add 100-150 parts of 60°C hot water, keep the inner temperature at 36°C-38°C, and rotate for 60-90 minutes; let stand At least 6 more hours, then wash out the drum. 2. a kind of method according to claim 1 with non-chromium metal complex tanning agent tanning pigskin head layer shoe lining leather, it is characterized in that: after described step (1) is processed through routine caustic soda leather process The pickled pigskin is evenly processed by cutting the buttocks before weighing. 3. according to claim 1 or 2, a kind of method for tanning pigskin top layer shoe lining leather with non-chromium metal compound tanning agent, it is characterized in that: described non-chromium metal compound tanning agent is LTA-100 type Metallic chrome-free complex tanning agent. 4. a kind of method for tanning pigskin top layer shoe lining leather with non-chrome metal complex tanning agent according to claim 3, it is characterized in that: described nonionic oil is NIFE-2 nonionic oil. 5. according to a kind of method described in claim 1 or 2 or 4 with non-chromium metal compound tanning agent tanning pigskin top layer shoe lining leather method, it is characterized in that: the consumption of described non-chromium metal compound tanning agent is 10-12 servings. 6. A method of tanning pigskin top layer shoe lining with non-chrome metal compound tanning agent according to claim 5, characterized in that: the amount of said chrome-free tanning partner D6 is non-chrome metal compound tanning 1/6 to 1/4 of the dosage of the tanning agent, and the dosage of the sharp tanning agent GM-40 is 1/12 to 1/8 of the dosage of the non-chrome metal complex tanning agent. 7. according to claim 1 or 2 or 4 described a kind of method of tanning pigskin top layer shoe lining leather with non-chrome metal complex tanning agent, it is characterized in that: the consumption of described chrome-free tanning partner D6 is non-chrome 1/6-1/4 of the amount of the metal-like compound tanning agent, and the amount of the sharp tanning agent GM-40 is 1/12-1/8 of the amount of the non-chromium metal compound tanning agent.