CN115261528A

CN115261528A - Retanning and dyeing method of ecological environment-friendly furniture leather

Info

Publication number: CN115261528A
Application number: CN202210519618.3A
Authority: CN
Inventors: 夏皓帆; 徐胜林; 范恩源; 胡玲歌; 袁凌清; 陈启峰; 马豆豆
Original assignee: Henan Zhongniu Industry Co ltd
Current assignee: Henan Zhongniu Industry Co ltd
Priority date: 2022-05-13
Filing date: 2022-05-13
Publication date: 2022-11-01
Anticipated expiration: 2042-05-13
Also published as: CN115261528B

Abstract

The invention belongs to the technical field of leather making, and particularly discloses a retanning and dyeing method of ecological environment-friendly furniture leather.

Description

Retanning and dyeing method of ecological environment-friendly furniture leather

Technical Field

The invention belongs to the technical field of leather making, and particularly relates to a retanning and dyeing method of ecological and environment-friendly furniture leather.

Background

Leather has a long history and plays an important role in the development process of human beings, wherein chrome tanned leather has light softness and bright color and can greatly shorten the process time so as to enable leather products to be popularized to the public, but chromium in the chrome tanned leather as a heavy metal element possibly has carcinogenicity, so that an ecological environment-friendly tanning method for producing chromium-free leather is urgently needed. The chrome tanning has the advantages of light softness, good elasticity, fullness and the like, mainly depends on the special structure of the leather collagen fiber, researches find that the collagen fiber mainly contains amino and carboxyl, and chromium can be crosslinked with the collagen carboxyl to form a stable ligand so as to endow the chrome tanning with the special characteristics, a similar effect to chromium must be found to replace chrome tanning, a tanning agent aldehyde is a good choice, but the aldehyde is also harmful to human bodies and the hand feeling of the finished leather is not full and soft, so the development of a chromium-free and aldehyde-free retanning dyeing method for ecological environment-friendly furniture leather is a trend of the leather making industry development and a brand-new leather production technology, and accords with the pursuit of people for green ecological environment protection.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a retanning and dyeing method of ecological environment-friendly furniture leather.

In order to achieve the purpose, the invention adopts the technical scheme that:

a retanning and dyeing method of ecological environment-friendly furniture leather comprises the following steps:

1) Preparation before tanning: putting the wet white leather into a constant-temperature rotary drum at 45 ℃, adding formic acid to adjust the pH value to 3.3, degreasing the leather by using a biodegradable nonionic degreasing agent DNC, adding acid protease to treat loose collagen fibers of the embryonic leather to open the leather grain caused by the growth of the wet white leather, continuously rotating for 180min, wherein the pH value is about 3.3, the acid protease can mildly disperse the leather fibers, and the neck growth grain and the belly grain are opened to ensure that the leather grain of the finished leather is soft and full in hand feeling and does not have a loose surface and reduce the part difference, so that the finished leather achieves the comfort of chrome tanning;

2) Modulation of collagen fiber binding points: the white wet skin treated in the step 1) is subjected to water bath change, the white wet skin is placed in a solution added with NG and sodium formate, the solution is continuously rotated for 20min at the temperature of 33 +/-1 ℃, sodium bicarbonate is added to adjust the pH =6.5 +/-0.1, the solution is continuously rotated for 30min, soda is added to continuously rotate for 70min, the pH7.5 +/-0.1 is added, the solution is continuously rotated for 20min after being stopped to rotate for the next night day for water washing, neutralization tannin NG is selected to be matched with sodium formate and sodium bicarbonate to mask electropositivity of amino groups in collagen fibers, so that the subsequent materials can be permeated, and the later stage adopts soda to improve the pH of leather to replace traditional ammonium salt, so that the ammonia nitrogen content in wastewater can be fundamentally reduced, the wastewater treatment cost is reduced, and the ecological environment is protected;

3) Lubricating sheath fibers: adding anionic emulsified phospholipid and alkylated phosphate ester synthetic oil into the washed embryonic leather in the step 2) at the temperature of 33 +/-1 ℃ and continuously rotating for 30min to perform oil pre-tanning treatment on the lubricated collagen fibers, namely adding a lubricant into the skin fibers to open a skin collagen fiber channel so as to facilitate subsequent materials to smoothly permeate into the skin core and endow the leather with mellow and comfortable hand feeling;

4) Pre-tanning and filling of synthetic tanning agent and vegetable tanning agent: adding an aromatic sulfonic acid synthetic tanning agent SWL, a soft synthetic tanning agent HL, an auxiliary naphthalenesulfonic acid plant tanning agent, a synthetic tanning agent high-efficiency dispersant GMF, a phenol synthetic tanning agent E-33 and a wattle bark tanning extract FS into the solution drum in the step 3), and mixing and filling;

5) Fat liquoring: and (3) adding natural lecithin modified alkyl phosphate BLP and anionic emulsified phospholipid MSG into the rotary drum in the step 4) in an equivalent manner every time by adopting a step-by-step fat-liquoring mode, mixing at 32-34 ℃, and enabling the leather to absorb more grease by adopting step-by-step fat-liquoring compared with one-step fat-liquoring, so that the grease is more uniformly distributed in the leather, and the potential risk that a greasy coating of the leather is not firmly adhered when the grease amount in one-step fat-liquoring is large and the grease deposited on the surface of the leather is excessive is avoided. The middle fatting agent is prepared from anionic emulsified phospholipid MSG and natural lecithin modified alkyl phosphate BLP, has excellent permeability, has good emulsifying property, can endow leather with good softness without showing the softness and fullness of oily finished leather, has elasticity and strong oily feeling, has certain thickening and filling effects and better waterproof property, has good dyeing assisting effect, can endow leather with good uniformity and softness, enables the finished leather to have plump hand feeling and fine grain surface, and has light and floating feeling to be beneficial to coating. Effectively reducing COD and enabling the discharged sewage to be cleaner;

6) Main filling and dyeing: adding a substituted sulfone synthetic tanning agent VR, a wattle bark tannin extract FS, an auxiliary naphthalenesulfonic acid plant tanning agent synthetic tanning agent high-efficiency dispersant GMF, a soft synthetic filler HL, a high-content phospholipid SQS and an environment-friendly dye into the rotary drum in the step 5), continuously rotating, mixing, checking, adding water at 55 ℃, adjusting the temperature in the rotary drum to 39-41 ℃, adding 1.5% formic acid, and adjusting the pH of the solution to 4.0 +/-0.1, draining and washing;

7) Washing and greasing: washing the embryonic leather obtained in the step 6), placing the washed embryonic leather in a rotary drum with an internal temperature of 40 +/-1 ℃, adding sodium formate to adjust the pH value of the solution, adding a fatting agent, mixing, adding 65 ℃ water until the temperature in the rotary drum is 48 +/-1 ℃, and adding 1;

8) Adjusting surface hand feeling: adding a cationic fatliquor GS into the rotary drum treated in the step 7);

9) Washing with water to remove rust: and adding EDTA water to wash out the drum and squeezing the water to form a toggling decoration to obtain the ecological environment-friendly furniture leather.

Further, the adding amount of the raw materials in the step 1) based on the weight percentage of the white wet hide is as follows: 250% of water, 1.0% of formic acid, 0.4% of degreasing agent DNC and 3% of acid protease.

Further, the adding amount of the raw materials in the step 2) based on the weight percentage of the white wet hide is as follows: water 1500%, NG 3%, sodium formate 1.5%, baking soda 1.7%, soda ash 0.6%.

Further, the adding amount of the raw materials in the step 3) based on the weight percentage of the white wet hide is as follows: 30% of water, 3% of anionic emulsified phospholipid MSG and 3% of alkylated phosphate ester synthetic oil SWK.

Further, the adding amount of the raw materials in the step 4) based on the weight percentage of the white wet hide is as follows: 8% of a substitute type yellowing-resistant synthetic tanning agent SWL, 2% of a soft synthetic filler HL, 2% of a synthetic tanning agent high-efficiency dispersant GMF, 2% of a phenol liquid synthetic tanning agent E-33% and 6% of a wattle bark tanning extract FS.

Further, the adding amount of the raw materials in the step 5) based on the weight percentage of the white wet hide is as follows: 2.0% of natural lecithin modified alkyl phosphate BLP and 2.0% of anionic emulsified phospholipid MSG.

Further, the adding amount of the raw materials in the step 6) based on the weight percentage of the white wet hide is as follows: VR 6%, FS 4%, HL2%, environment-friendly dye X%, SQS 1%, GMF2%, water 150% and formic acid 1.5%, wherein the formic acid is added in three times in equal amount, and the mixing time is 10min, 10min and 20min after the formic acid is added.

Further, the adding amount of the raw materials in the step 7) based on the weight percentage of the white wet hide is as follows: 1% of sodium formate, and the fat liquor comprises the following components: 80% of water, 4% of anionic emulsified phospholipid MSG, 2% of WP2% and 2% of alkylated phosphate synthetic oil SWK; 100% of water, 1.5% of formic acid and 20min of formic acid are added in two times.

Further, the adding amount of the raw materials in the step 8) based on the weight percentage of the white wet hide is as follows: and (4) cationic fatliquor GS 1%.

Further, the adding amount of the raw materials in the step 9) based on the weight percentage of the white wet hide is as follows: 300% of water and 0.3% of EDTA.

The invention has the following beneficial effects: the process is simple and easy to control, multiple processes of backwater degreasing, softening, pH adjustment by formic acid, chrome retanning, alkali extraction, neutralization and the like are required for the conventional chrome tanning pretreatment, multiple water washing and bath changing are required in the whole process, the process is complicated and wastes a large amount of water resources, the sewage treatment difficulty is increased, the environment is not favorable for environmental protection, chromium heavy metal ions are used, the process omits the link, the tanning can be performed only by slightly treating white wet skins and shielding collagen binding sites, the efficiency is high, chromium-free and aldehyde-free retanning is adopted in the process, the pollution of heavy metal ions chromium and the potential carcinogenicity of aldehyde are fundamentally avoided, and the content of ammonia nitrogen in wastewater is reduced by NG. For the problem that the pore space of the skin fiber is narrow and is not beneficial to the infiltration of melting materials, a similar lubricant treatment is adopted to add grease so as to ensure the lubrication solution. The environment-friendly dye is selected during dyeing, so that the sewage treatment difficulty is reduced. The problem that the hand feeling of the white and wet leather is not dry, mellow and plump is solved by surface greasing before the drum discharging. The scheme of adding waterproof oil at the later stage is adopted to improve the problem of strong water absorption of the wet white leather, and meanwhile, the process is filled step by step with the greasing compact type combined retanning to reduce the water consumption in the leather making process, namely, the wastewater discharge amount is reduced, the process time is shortened, the using amount of the greasing agent is reduced, the COD and BOD of the wastewater are reduced, and the production process is clean, ecological and environment-friendly. Meanwhile, the prepared furniture leather is plump and soft, has mellow hand feeling and high elasticity, has the characteristics of chrome tanned leather, improves the grade of finished products, and is popular in the market to respond to the national environmental protection policy.

Detailed Description

The present invention will be further described with reference to the following examples, wherein the raw materials are added in amounts based on the weight percentage of the white wet hide.

1) Preparing before tanning:

the wet white leather is put into a constant-temperature rotary drum, the temperature is set at 45 ℃, and formic acid is added to adjust the pH value of the wet white leather so as to keep the pH values of the inside and the outside of crust leather consistent. And (3) degreasing by adopting an environment-friendly and general biodegradable nonionic degreasing agent DNC. The addition of acid protease to the embryo leather treats loose collagen fibers to open the skin lines caused by the growth of the white and wet leather. The rotation is continued for 180min, and the pH value is about 3.3. The acidic protease can disperse leather fibers mildly, opens the neck growth lines and the belly lines to enable leather lines of the finished leather to be stretched, soft and full in hand feeling and not loose, reduces the position difference, enables the finished leather to achieve the comfort of chrome tanned leather, and the addition amount of raw materials is as follows: 250% of water, 1.0% of formic acid and 0.4% of degreasing agent DNC, wherein PK568C is selected as the acidic protease, and the dosage of the PK568C is 3% of the mass of the white wet skin.

2) Regulating collagen fiber binding points:

draining the wet white leather after the step 1), changing bath, putting the wet white leather into a solution added with the neutral tannin NG and sodium formate, continuously rotating for 20min at the temperature of 33 +/-1 ℃, adding sodium bicarbonate to adjust the pH =6.5 +/-0.1, continuously rotating for 30min, adding soda, continuously rotating for 70min at the pH of 7.5 +/-0.1, stopping the drum, rotating for 20min after the night day, draining and washing, wherein the adding amount of each raw material is as follows: water 1500%, NG 3%, sodium formate 1.5%, baking soda 1.7%, soda ash 0.6%. The neutralization tannin NG is selected to be matched with sodium formate and baking soda for use to mask electropositivity brought by amino in collagen fibers, so that subsequent materials can be permeated, and the pH of the leather is increased by adopting soda ash in the later period to replace the traditional ammonium salt, so that the ammonia nitrogen content in the wastewater can be fundamentally reduced, the wastewater treatment cost is reduced, and the ecological environment is protected.

3) Lubricating sheath fibers:

adding anionic emulsified phospholipid and alkylated phosphate ester synthetic oil into the washed embryonic leather in the step 2) at the temperature of 33 +/-1 ℃ and continuously rotating for 30min. Carry out lubricated collagen fiber of oil pretanning treatment and be equivalent to add the emollient and open skin collagen fiber passageway in the skin fibre in order to do benefit to follow-up material and permeate the skin core more smoothly, give the leather mellow and comfortable feel simultaneously, wherein the raw materials quantity is: 30% of water, 3% of anionic emulsified phospholipid MSG and 3% of alkylated phosphate ester synthetic oil SWK;

4) Pre-tanning and filling of synthetic tanning agent and vegetable tanning agent:

adding aromatic sulfonic acid synthetic tanning agent SWL, soft synthetic tanning agent HL, auxiliary naphthalenesulfonic acid plant tanning agent, synthetic tanning agent high-efficiency dispersant GMF, phenol synthetic tanning agent E-33, and wattle bark tannin extract FS into a pre-grease solution, namely an oil pre-tanning rotary drum, and rotating for 30min; the pre-tanning filling components of the synthetic tanning agent and the vegetable tanning agent are as follows: 8% of SWL, 2% of HL, 2% of GMF, 2% of E-33 and 6% of FS;

5) Intermediate greasing:

adding natural lecithin modified alkyl phosphate BLP and anionic emulsified phospholipid MSG into a rotating drum filled with synthetic tanning agent and vegetable tanning agent for pre-tanning, and rotating for 30min at 33 +/-1 ℃, wherein the mass of the natural lecithin modified alkyl phosphate BLP is 2.0% of the tare weight, and the mass of the anionic emulsified phospholipid MSG is 2.0% of the tare weight. Compared with one-time greasing, the process can ensure that the leather absorbs more grease by adopting step-by-step greasing, so that the grease is more uniformly distributed in the leather step by step, and the potential danger that a leather-formed grease coating is not firmly adhered when the grease consumption in one-time greasing is large and the grease deposited on the surface of the leather is excessive is avoided. The middle fatting agent is prepared from anionic emulsified phospholipid MSG and natural lecithin modified alkyl phosphate BLP, has excellent permeability, has good emulsifying property, can endow leather with good softness without rendering the finished leather soft and plump, has elasticity and strong oily feeling, has certain thickening and filling effects and better waterproof property, has good dyeing assisting effect, can endow leather with good uniformity and softness, enables the finished leather to feel plump and fine, and has light and brisk feeling and is favorable for coating. Effectively reduces COD and makes the discharged sewage cleaner.

6) Main filling and dyeing:

adding a substituted sulfone synthetic tanning agent VR, a wattle bark tannin extract FS, an auxiliary naphthalene sulfonic acid plant tanning agent synthetic tanning agent high-efficiency dispersing agent GMF, a soft synthetic filler HL, a high-content phospholipid SQS and an environment-friendly dye X into a middle greased rotary drum, continuously rotating for 90min, and checking through. Then hot water with the temperature of about fifty-five ℃ is added to adjust the internal temperature of the rotary drum to 40 +/-1 ℃, then 1.5 percent formic acid is added into the mixture in three times, the solution is adjusted to have the pH value of 4.0 +/-0.1, and the mixture is drained and washed with water. The main filling and dyeing comprises the following components: VR 6%, FS 4%, HL2%, environment-friendly dye 0.5-2.5%, SQS 1%, GMF2%, water 150%, 55 ℃, formic acid 1.5%.

7) Washing with water and adding grease:

the main filled and dyed crust leather is washed, placed in a rotating drum with the internal temperature of 40 +/-1 ℃, added with sodium formate to adjust the pH value of the solution and rotated for 10min. And then adding a fatting agent, continuously rotating for 70min, checking that the fatting effect is qualified, adding hot water at about sixty-five ℃ 100%, rotating for 10min, adjusting the internal temperature of the rotary drum to 48 +/-1 ℃, adding 1.5% of diluted formic acid at 1: the fat liquor comprises the following components: 80% of water, 40 +/-1 ℃, 4% of anionic emulsified phospholipid MSG, 2% of WP, 2% of alkylated phosphate synthetic oil SWK, 100% of water, 65 ℃ and 1.5% of formic acid;

8) Adjusting surface hand feeling:

adding 1% of cationic fatting agent GS into the rotary drum added with the formic acid, and rotating for 20min;

9) Washing with water to remove rust:

and (3) adding 0.3% of EDTA during washing, rotating for 10min to remove ferric ions in water and tannin extract so as to prevent rust pollution from affecting the quality of finished leather, washing out the drum with water, and squeezing water and trimming the toggling plate to obtain the ecological environment-friendly furniture leather, wherein the washing liquid is 300%, and the temperature is normal temperature.

The embodiments described above are intended to facilitate a person skilled in the art to understand and use the invention. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the embodiments described herein, and those skilled in the art should understand that they can make improvements and modifications without departing from the scope of the present invention.

Claims

1. The retanning and dyeing method of the ecological environment-friendly furniture leather is characterized by comprising the following steps:

1) Preparation before tanning: putting the wet white leather into a constant-temperature rotary drum at 45 ℃, adding formic acid to adjust the pH value to 3.3, degreasing the wet white leather by using a biodegradable nonionic degreasing agent DNC, and adding acid protease to mix uniformly;

2) Modulation of collagen fiber binding points: draining the wet white hides treated in the step 1) for bath change, putting the wet white hides into a solution added with neutralized tannin and sodium formate, uniformly mixing at 32-34 ℃, adding baking soda to adjust the pH value to 6.4-6.6, continuously mixing, adding soda ash to mix until the pH value is 7.4-7.6, stopping the drum for overnight, and draining and washing the water the next day;

3) Lubricating sheath fibers: adding anionic emulsified phospholipid and alkylated phosphate synthetic oil into the water-washed embryonic leather in the step 2) at the temperature of 32-34 ℃ for mixing and lubrication;

5) Fat liquoring: adding natural lecithin modified alkyl phosphate BLP and anionic emulsified phospholipid MSG into the rotary drum in the step 4) in an equivalent manner every time by adopting a step-by-step fat-adding mode, and mixing at the temperature of 32-34 ℃;

6) Main filling and dyeing: adding a substituted sulfone synthetic tanning agent VR, a wattle bark tannin extract FS, an auxiliary naphthalenesulfonic acid plant tanning agent synthetic tanning agent efficient dispersant GMF, a soft synthetic filler HL, a high-content phospholipid SQS and an environment-friendly dye into the rotary drum in the step 5), continuously rotating and mixing, then thoroughly checking, adding water at 55 ℃ to adjust the temperature in the rotary drum to 39-41 ℃, adding 1.5% formic acid, and adjusting the pH of the solution to 4.0 +/-0.1 for water drainage and washing;

7) Washing with water and adding grease: washing the embryonic leather obtained in the step 6), placing the washed embryonic leather in a rotary drum with the internal temperature of 40 +/-1 ℃, adding sodium formate to adjust the pH value of the solution, adding a fatting agent, mixing, adding 65 ℃ water until the temperature in the rotary drum is 48 +/-1 ℃, and adding 1;

8) Adjusting the surface hand feeling: adding a cationic fatliquor GS into the rotary drum treated in the step 7);

9) Washing with water to remove rust: and adding EDTA water to wash out the drum and squeezing the water to trim the toggling plate to obtain the ecological environment-friendly furniture leather.

2. The retanning dyeing method of eco-friendly furniture leather as claimed in claim 1, characterized in that: the addition amount of the raw materials in the step 1) based on the weight percentage of the white wet hide is as follows: 250% of water, 1.0% of formic acid, 0.4% of degreasing agent DNC and 3% of acid protease.

3. The retanning dyeing method of eco-friendly furniture leather as claimed in claim 1, characterized in that: the addition amount of the raw materials in the step 2) based on the weight percentage of the white wet hide is as follows: 1500% of water, 3% of NG, 1.5% of sodium formate, 1.7% of baking soda and 0.6% of soda ash.

4. The retanning dyeing method of eco-friendly furniture leather according to claim 1, characterized by comprising: the adding amount of the raw materials in the step 3) based on the weight percentage of the white wet hide is as follows: 30% of water, 3% of anionic emulsified phospholipid MSG and 3% of alkylated phosphate ester synthetic oil SWK.

5. The retanning dyeing method of eco-friendly furniture leather according to claim 1, characterized by comprising: the adding amount of the raw materials in the step 4) based on the weight percentage of the white wet hide is as follows: 8% of a substitute type yellowing-resistant synthetic tanning agent SWL, 2% of a soft synthetic filler HL, 2% of a synthetic tanning agent high-efficiency dispersant GMF, 2% of a phenol liquid synthetic tanning agent E-33% and 6% of a wattle bark tanning extract FS.

6. The retanning dyeing method of eco-friendly furniture leather according to claim 1, characterized by comprising: the adding amount of the raw materials in the step 5) based on the weight percentage of the white wet hide is as follows: 2.0% of natural lecithin modified alkyl phosphate BLP and 2.0% of anionic emulsified phospholipid MSG.

7. The retanning dyeing method of eco-friendly furniture leather as claimed in claim 1, characterized in that: the addition amount of the raw materials in the step 6) based on the weight percentage of the white wet hide is as follows: the method comprises the following steps of adding substituted sulfone synthetic tanning agents VR 6%, wattle bark tannin extract FS 4%, soft synthetic filler HL2%, environment-friendly dye 0.5-2.5%, high-content phospholipid SQS 1%, synthetic tanning agent efficient dispersant GMF2%, water 150% and formic acid 1.5%, wherein the formic acid is added in three times in equal amount, and mixing time is 10min, 10min and 20min after adding.

8. The retanning dyeing method of eco-friendly furniture leather as claimed in claim 1, characterized in that: the addition amount of the raw materials in the step 7) based on the weight percentage of the white wet hide is as follows: 1% of sodium formate, and the fat liquor comprises the following components: 80% of water, 4% of anionic emulsified phospholipid MSG, 2% of WP2% and 2% of alkylated phosphate synthetic oil SWK; 100% of water, 1.5% of formic acid and 20min of formic acid are added in two times.

9. The retanning dyeing method of eco-friendly furniture leather as claimed in claim 1, characterized in that: the adding amount of the raw materials in the step 8) based on the weight percentage of the white wet hide is as follows: and (4) cationic fatliquor GS 1%.

10. The retanning dyeing method of eco-friendly furniture leather as claimed in claim 1, characterized in that: the adding amount of the raw materials in the step 9) based on the weight percentage of the white wet hide is as follows: 300% of water and 0.3% of ethylene diamine tetraacetic acid EDTA-2Na.