CN108517381B - Method for tanning leather by using carbodiimide-catalyzed amino-terminated hyperbranched polymer - Google Patents
Method for tanning leather by using carbodiimide-catalyzed amino-terminated hyperbranched polymer Download PDFInfo
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- CN108517381B CN108517381B CN201810337804.9A CN201810337804A CN108517381B CN 108517381 B CN108517381 B CN 108517381B CN 201810337804 A CN201810337804 A CN 201810337804A CN 108517381 B CN108517381 B CN 108517381B
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- C—CHEMISTRY; METALLURGY
- C14—SKINS; HIDES; PELTS; LEATHER
- C14C—CHEMICAL TREATMENT OF HIDES, SKINS OR LEATHER, e.g. TANNING, IMPREGNATING, FINISHING; APPARATUS THEREFOR; COMPOSITIONS FOR TANNING
- C14C3/00—Tanning; Compositions for tanning
- C14C3/02—Chemical tanning
- C14C3/08—Chemical tanning by organic agents
- C14C3/22—Chemical tanning by organic agents using polymerisation products
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G83/00—Macromolecular compounds not provided for in groups C08G2/00 - C08G81/00
- C08G83/002—Dendritic macromolecules
- C08G83/005—Hyperbranched macromolecules
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- Health & Medical Sciences (AREA)
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- Treatment And Processing Of Natural Fur Or Leather (AREA)
Abstract
The invention discloses a method for tanning leather by using carbodiimide to catalyze amino-terminated hyperbranched polymers, and particularly relates to a method for producing multi-point covalent crosslinking between carbodiimide to catalyze amino-terminated hyperbranched polymers and a raw hide collagen fiber net. Under the catalytic action of carbodiimide, the amino-terminated hyperbranched polymer has the capability of independently bearing a tanning agent, is not only a retanning filler, and increases the application range of the amino-terminated hyperbranched polymer in leather chemical industry. The tanning method of the invention adopts carbodiimide as tanning catalyst and amino-terminated hyperbranched polymer as base material, and is applied to leather tanning section, and the finished leather has excellent properties of good wet-heat resistance stability, excellent physical and mechanical properties, fullness, softness and the like.
Description
Technical Field
The invention relates to the technical field of leather tanning, in particular to a method for tanning leather by using carbodiimide-catalyzed amino-terminated hyperbranched polymer.
Background
China is a large processing country of the leather industry in the world, and the processing amount and export amount are the first place in the world for a long time, but the nonrenewable chrome tanning agent used in the traditional leather tanning process has great potential threat to the environment, which is one of the main problems preventing the sustainable development of the leather industry. Therefore, the development and application of sustainable and renewable organic synthetic tanning agent products to the leather processing process is the key point of research of domestic and foreign people. The amino-terminated hyperbranched polymer is used as an auxiliary tanning agent and a retanning agent for leather and has certain research in the past years, but the amino-terminated hyperbranched polymer is independently applied to leather tanned in a leather tanning section to have the defects of low shrinkage temperature, insufficient physical and mechanical properties, limited application range and the like, so that the application in the tanning industry is generally limited to the application of filling, high absorption of dye and the like in the retanning section.
Carbodiimide has the ability to catalyze covalent crosslinking of carboxyl groups with reactive amino groups. In conventional applications, most of them are used in the peptide-joining step in polypeptide synthesis. The reaction yield of the carbodiimide used as the water loss agent is high, and the price of the reagent is not expensive. Therefore, carbodiimide is introduced into the leather-making industry, and the amino-terminated hyperbranched polymer has the characteristic of a large number of active amino groups, so that the amino-terminated hyperbranched polymer and collagen carboxyl groups form multi-point covalent crosslinking under the catalytic action of the carbodiimide, and the moisture-heat resistance stability of crust leather tanned by the amino-terminated hyperbranched polymer is greatly improved, and the physical and mechanical properties and other physical and chemical properties are improved.
Disclosure of Invention
The invention aims to provide a method for tanning leather by using carbodiimide to catalyze an amino-terminated hyperbranched polymer, which uses carbodiimide as a catalyst to catalyze collagen carboxyl and active amino of the amino-terminated hyperbranched polymer to generate covalent crosslinking so as to improve the tanning effect of the amino-terminated hyperbranched polymer. Carbodiimide catalyzes the amino-terminated hyperbranched polymer to generate multi-point covalent crosslinking with a collagen fiber net of the hide, so that the humidity and heat resistance stability and other physical and mechanical properties of finished leather tanned by the amino-terminated hyperbranched polymer are improved.
The technical scheme of the invention is as follows: a method for tanning leather by using carbodiimide to catalyze an amino-terminated hyperbranched polymer, wherein the carbodiimide is used as a catalyst to greatly improve the multi-point covalent crosslinking degree between the amino-terminated hyperbranched polymer and a collagen fiber net of hide, the amino-terminated hyperbranched polymer is limited in leather functional retanning and is expanded to the whole tanning process of the leather, and meanwhile, the unique excellent performance of the amino-terminated hyperbranched polymer is kept, so that the tanning effect is improved, and the damp-heat resistance stability and the physical performance of the tanned crust leather are obviously improved.
The method for tanning leather by using carbodiimide-catalyzed amino-terminated hyperbranched polymer comprises the following steps:
acid recovery: and (3) returning acid to the sweet dry skins in acid liquor, wherein the bath liquid parameters comprise that the liquor ratio is 0.8-1.5, the pH is 2.5-3.5, and the salt is 4% -8%, and the acid returning time is the whole time until the skins are completely restored to the acid skin state.
Neutralizing: transferring 1.5-2.5% of neutralizing agent (DESOTANNT) and 0.3-0.6% of baking soda in a rotary drum for 30-40 min after acid recovery, and then adding 0.7-1.0% of baking soda for 2h to enable the pH to reach 5.5-6.5;
tanning: washing the neutralized raw hide with 200% of water for 30min, adding 6-10% of amino-terminated hyperbranched polymer in two times, wherein the first time of adding is 3-5% and the second time of adding is 3-5% and the mixture is completely tanned.
Catalyzing: 1-2 percent (based on the amount of the amino-terminated hyperbranched polymer) of carbodiimide is added for 2 hours, 1-3 percent of carbodiimide is added for 2 hours, and finally 2-4 percent of carbodiimide is added for overnight.
Washing with water: washing with 200% water for 30 min.
The procedures after dyeing, fat liquoring and the like are the same as the conventional procedures.
On the basis of the technical scheme, the invention has the following accessory technical characteristics in order to achieve better effect and more sufficient application:
the carbodiimide is a solid powder or liquid preparation of (1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride) (EDC).
The amino-terminated hyperbranched polymer is an amino-terminated hyperbranched polymer (NH) synthesized by taking N, N-Methylene Bisacrylamide (MBA) and diethylenetriamine (EDTA) as materials through reaction2-HBP)。
The dosage of the carbodiimide is 4-9% of the amino-terminated hyperbranched polymer.
The dosage of the amino-terminated hyperbranched polymer is 6-10% of the weight of the grey scale (calculated by 1.5 times of the weight of the acid scale).
The leather is common animal leather, such as pig, cow, sheep skin, etc.
The invention principle of the technical scheme is as follows: the first step of collagen carboxyl under the catalysis of carbodiimide is to generate acyl urea intermediate, the second step is to form urea derivative through transfer rearrangement of acyl urea intermediate, and the third step is to replace the urea derivative with active amino of amino-terminated hyperbranched polymer, so that the collagen carboxyl and the active amino of the amino-terminated hyperbranched polymer are crosslinked in a covalent bond mode. Tanning of leather is essentially the formation of multiple crosslinks of the tanning agent between collagen webs of the hide, causing the hide to become leather.
The invention has the following advantages:
1. the amino-terminated hyperbranched polymer used in the invention has a mature technology, simple preparation process and low cost, and is very suitable for leather-making industrial production; the application of carbodiimide in the field of protein chemistry has been long, and the catalytic efficiency of the carbodiimide is higher, so that the carbodiimide is more beneficial to the leather-making production process.
2. The invention provides a method for tanning leather by using carbodiimide to catalyze an amino-terminated hyperbranched polymer, so that the amino-terminated hyperbranched polymer can be applied to a tanning workshop section of leather instead of a chrome tanning agent to a certain extent, the sustainable development of the leather-making industry is met, and a new feasible option is added for the application of the amino-terminated hyperbranched polymer in the leather-making industry.
3. The finished leather produced by the invention has the advantages of high heat and humidity resistance stability, compact structure, firmness and fullness and good formability. Is suitable for tanning various animal skins such as pigskin, sheep skin, goat skin, cattle hide, buffalo hide, milk cow hide and yak hide, and is suitable for various purposes such as: the manufacturing process of clothing leather, shoe upper leather, shoe lining leather, fluff leather, automobile cushion leather and the like.
Detailed Description
Example 1
Acid recovery: and (3) returning the sweet dried skins to acid in acid liquor, wherein the bath liquid parameters are that the liquor ratio is 0.8, the pH value is 2.5, and the salt is 8%, and the whole acid returning time is up to the state that the skins are completely recovered to the acid skins.
Neutralizing: the acid-recovered hides were tumbled with 1.5% neutralizer (DESOTANNT), 0.3% baking soda for 30min in a tumbler, and then tumbled for 2h with 0.7% baking soda to achieve a pH of 5.5;
tanning: washing the neutralized hide with 200% water for 30min, adding 6% of amino-terminated hyperbranched polymer in two times, wherein the first time is 3% for 2h, and the second time is 3% for complete tanning.
Catalyzing: 1% (based on the amount of the amino-terminated hyperbranched polymer) of (1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride was added for 2h, 1% of (1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride) was added for 2h, and finally 2% of (1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride) was added overnight.
Washing with water: washing with 200% water for 30 min.
The procedures after dyeing, fat liquoring and the like are the same as the conventional procedures.
Example 2
Acid recovery: and (3) carrying out acid recovery on the sweet dried skins in acid liquor, wherein the bath liquid parameters are that the liquor ratio is 1.5, the pH value is 3.5, and the salt is 4%, and the acid recovery time is up to the time when the skins are completely recovered to the acid skin state.
Neutralizing: the acid-recovered hides were tumbled with 2.5% neutralizer (DESOTANNT), 0.6% baking soda for 40min in a tumbler, and then 1.0% baking soda for 2h to achieve a pH of 6.5;
tanning: and washing the neutralized hide with 200% water for 30min, adding 10% of amino-terminated hyperbranched polymer in two times, wherein the first time of adding is 5% for 2h, and the second time of adding is 5% for completely tanning.
Catalyzing: 2% (based on the amount of the amino-terminated hyperbranched polymer) of 1-ethyl- (3-dimethylaminopropyl) carbodiimide hydrochloride was added for 2h, 3% of 1-ethyl- (3-dimethylaminopropyl) carbodiimide hydrochloride was added for 2h, and finally 4% of 1-ethyl- (3-dimethylaminopropyl) carbodiimide hydrochloride was added overnight.
Washing with water: washing with 200% water for 30 min.
The procedures after dyeing, fat liquoring and the like are the same as the conventional procedures.
Example 3
Acid recovery: and (3) carrying out acid recovery on the sweet dried skins in acid liquor, wherein the bath liquid parameters are that the liquor ratio is 1.2, the pH value is 3, and the salt is 6%, and the acid recovery time is up to the time when the skins are completely recovered to the acid skin state.
Neutralizing: transferring the acid-recovered hide with 2% neutralizer (DESOTANNT), 0.45 baking soda in a rotary drum for 35min, and adding 0.85 baking soda for 2 hr to reach pH 6;
tanning: and washing the neutralized hide with 200% water for 30min, adding 8% of amino-terminated hyperbranched polymer in two times, wherein the first time of adding 4% is changed to 2h, and the second time of adding 4% is changed to complete tanning.
Catalyzing: 1.5% (based on the amount of amino-terminated hyperbranched polymer) of 1-ethyl- (3-dimethylaminopropyl) carbodiimide hydrochloride was added for 2h, 2% of 1-ethyl- (3-dimethylaminopropyl) carbodiimide hydrochloride was added for 2h, and finally 3% of 1-ethyl- (3-dimethylaminopropyl) carbodiimide hydrochloride was added overnight.
Washing with water: washing with 200% water for 30 min.
The procedures after dyeing, fat liquoring and the like are the same as the conventional procedures.
Example 4
Acid recovery: and (3) carrying out acid recovery on the sweet dried skins in acid liquor, wherein the bath liquid parameters are that the liquor ratio is 1.2, the pH value is 3, and the salt is 6%, and the acid recovery time is up to the time when the skins are completely recovered to the acid skin state.
Neutralizing: transferring the acid-recovered hide with 2% neutralizer (DESOTANNT), 0.45 baking soda in a rotary drum for 35min, and adding 0.85 baking soda for 2 hr to reach pH 6;
tanning: and washing the neutralized hide with 200% water for 30min, adding 8% of amino-terminated hyperbranched polymer in two times, wherein the first time of adding 4% is changed to 2h, and the second time of adding 4% is changed to complete tanning.
Catalyzing: 1.5% (based on the amount of amino-terminated hyperbranched polymer) of N- (3-dimethylaminopropyl) -N ' -ethyl-carbodiimide hydrochloride was added for 2h, 2% of N- (3-dimethylaminopropyl) -N ' -ethyl-carbodiimide hydrochloride was added for 2h, and finally 3% of N- (3-dimethylaminopropyl) -N ' -ethyl-carbodiimide hydrochloride was added overnight.
Washing with water: washing with 200% water for 30 min.
The procedures after dyeing, fat liquoring and the like are the same as the conventional procedures.
Example 5
Leather tanned by the carbodiimide-catalyzed amino-terminated hyperbranched polymer prepared by the invention is used as an experimental group, common tanned leather which is not treated by the invention and has the same other treatment steps is used as a control group, and the shrinkage temperature of each group of samples is measured according to QB/T2713-2005; the tensile strength and the tearing strength of each group of samples are measured according to the ISO 3376-2011 standard; the thickness of the leather is measured by adopting a multipoint measurement method, namely 9 points are selected equidistantly on each sample block to measure the thickness of the leather, and the average value is taken to calculate the thickening rate; the softness of each set of samples was measured according to QB/T4870-. The results of the above tests were summarized to give the results of Table 1. Table 1 is a comparison table of tanning performance of carbodiimide catalyzed amino terminated hyperbranched polymer:
the results in table 1 show that the carbodiimide-catalyzed amino-terminated hyperbranched polymer can replace a chrome tanning agent to a certain extent to be applied to a tanning section of leather, and the finished leather produced by the method has the advantages of high humidity and heat resistance stability, good physical and mechanical properties and the like.
The method for tanning leather by using the carbodiimide-catalyzed amino-terminated hyperbranched polymer has good applicability to different types of leather and different styles of leather.
It should be understood that equivalents and modifications of the technical solution and inventive concept thereof may occur to those skilled in the art, and all such modifications and alterations should fall within the scope of the appended claims.
Claims (6)
1. A method for using carbodiimide-catalyzed amino-terminated hyperbranched polymer for leather tanning is characterized by comprising the following steps:
adding an amino-terminated hyperbranched polymer in the tanning process of the leather, and fully tanning until the amino-terminated hyperbranched polymer is completely tanned in the leather; and (3) continuously tanning, adding carbodiimide, and fully reacting in the tanning process to obtain the leather tanned by the carbodiimide-catalyzed amino-terminated hyperbranched polymer.
2. The method for tanning leather using carbodiimide catalyzed amino-terminated hyperbranched polymer as claimed in claim 1, wherein the amino-terminated hyperbranched polymer is prepared from N, N-Methylene Bisacrylamide (MBA) or diethylenetriamine (EDTA)Preparing the obtained amino-terminated hyperbranched polymer NH2-HBP。
3. The method for leather tanning by using carbodiimide-catalyzed amino-terminated hyperbranched polymer as claimed in claim 1, wherein the carbodiimide is (1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride) EDC.
4. The method for leather tanning by using carbodiimide-catalyzed amino-terminated hyperbranched polymer according to any one of claims 1 to 3, wherein the mass of the carbodiimide is 4 to 9% of that of the amino-terminated hyperbranched polymer.
5. The method for tanning leather by using carbodiimide-catalyzed amino-terminated hyperbranched polymer as claimed in claim 4, is characterized by comprising the following specific steps:
1) tanning: washing the neutralized raw hide with water with the weight of 200% of the hide for 30min, adding amino-terminated hyperbranched polymers with the weight of 6% -10% of the hide in two times, tanning for 2h by adding the amino-terminated hyperbranched polymers with the weight of 3% -5% of the hide in the first time, and tanning to be completely tanned by adding the amino-terminated hyperbranched polymers with the weight of 3% -5% of the hide in the second time;
2) catalyzing: adding 1-2% by mass of carbodiimide into the leather completely tanned in the step 1) for tanning for 2h, then adding 1-3% by mass of carbodiimide into the amino-terminated hyperbranched polymer for tanning for 2h, and finally supplementing 2-4% by mass of carbodiimide into the amino-terminated hyperbranched polymer for overnight.
6. The method for tanning leather by using carbodiimide-catalyzed amino-terminated hyperbranched polymer as claimed in claim 5, is characterized by comprising the following specific steps:
1) acid recovery: the sweet dry skins are subjected to acid recovery in acid liquor, the bath liquor ratio is 0.8-1.5, the pH is 2.5-3.5, the salt consumption is 4-8% of the skins, and the acid recovery time is up to the time when the skins are completely recovered to the acid skin state;
2) neutralizing: transferring 1.5-2.5% of neutralizer DESOTANNT and 0.3-0.6% of baking soda in a rotary drum for 30-40 min after acid recovery of the hide, and then adding 0.7-1.0% of baking soda in the rotary drum for 2h to make the pH value reach 5.5-6.5;
3) tanning: washing the neutralized raw hide with water with the weight of 200% of the hide for 30min, adding amino-terminated hyperbranched polymers with the weight of 6% -10% of the hide in two times, tanning for 2h by adding the amino-terminated hyperbranched polymers with the weight of 3% -5% of the hide in the first time, and tanning to be completely tanned by adding the amino-terminated hyperbranched polymers with the weight of 3% -5% of the hide in the second time;
4) catalyzing: adding carbodiimide with the mass being 1-2% of that of the amino-terminated hyperbranched polymer into completely tanned leather for tanning for 2 hours, adding carbodiimide with the mass being 1-3% of that of the amino-terminated hyperbranched polymer for tanning for 2 hours, and finally supplementing carbodiimide with the mass being 2-4% of that of the amino-terminated hyperbranched polymer for overnight;
5) washing with water: washing with water 200% of tare weight for 30 min;
6) dyeing;
7) and (4) fat liquoring.
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| CN114774594A (en) * | 2022-05-05 | 2022-07-22 | 陕西科技大学 | Collagen-hyperbranched amphoteric polymer retanning agent and preparation method thereof |
| CN115679019A (en) * | 2022-11-15 | 2023-02-03 | 陕西科技大学 | Aminated modified skin collagen and preparation method and application thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101086026A (en) * | 2007-06-08 | 2007-12-12 | 陕西科技大学 | End carboxyl super branched polymer as high absorption chrome tanning adjuvant and its synthesis method |
| CN101603100A (en) * | 2009-06-30 | 2009-12-16 | 陕西科技大学 | Hold the method for amino branching thing and THPS combination tanned leather |
| CN103215391A (en) * | 2013-04-23 | 2013-07-24 | 何裕华 | Non-chromium leather tanning method |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101086026A (en) * | 2007-06-08 | 2007-12-12 | 陕西科技大学 | End carboxyl super branched polymer as high absorption chrome tanning adjuvant and its synthesis method |
| CN101603100A (en) * | 2009-06-30 | 2009-12-16 | 陕西科技大学 | Hold the method for amino branching thing and THPS combination tanned leather |
| CN103215391A (en) * | 2013-04-23 | 2013-07-24 | 何裕华 | Non-chromium leather tanning method |
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