CN117418047A - High-absorption chrome tanning auxiliary agent containing dithiocarbamate structure, and preparation method and application thereof - Google Patents
High-absorption chrome tanning auxiliary agent containing dithiocarbamate structure, and preparation method and application thereof Download PDFInfo
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- CN117418047A CN117418047A CN202311354790.9A CN202311354790A CN117418047A CN 117418047 A CN117418047 A CN 117418047A CN 202311354790 A CN202311354790 A CN 202311354790A CN 117418047 A CN117418047 A CN 117418047A
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- chrome tanning
- dithiocarbamate
- absorption
- auxiliary agent
- absorption chrome
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- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 title claims abstract description 120
- 238000010521 absorption reaction Methods 0.000 title claims abstract description 81
- 239000012752 auxiliary agent Substances 0.000 title claims abstract description 43
- 150000004659 dithiocarbamates Chemical group 0.000 title claims abstract 10
- 238000002360 preparation method Methods 0.000 title abstract description 9
- 239000010985 leather Substances 0.000 claims abstract description 44
- 238000000034 method Methods 0.000 claims abstract description 42
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 27
- 230000008569 process Effects 0.000 claims abstract description 25
- 102000008186 Collagen Human genes 0.000 claims description 56
- 108010035532 Collagen Proteins 0.000 claims description 56
- 229920001436 collagen Polymers 0.000 claims description 56
- QGJOPFRUJISHPQ-UHFFFAOYSA-N Carbon disulfide Chemical compound S=C=S QGJOPFRUJISHPQ-UHFFFAOYSA-N 0.000 claims description 42
- 239000000413 hydrolysate Substances 0.000 claims description 42
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 33
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 claims description 15
- 238000006243 chemical reaction Methods 0.000 claims description 15
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 15
- 239000002253 acid Substances 0.000 claims description 14
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 claims description 10
- 239000002910 solid waste Substances 0.000 claims description 10
- 238000006460 hydrolysis reaction Methods 0.000 claims description 9
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 claims description 8
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 8
- 239000002994 raw material Substances 0.000 claims description 7
- 239000000243 solution Substances 0.000 claims description 7
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 6
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 6
- 239000003513 alkali Substances 0.000 claims description 6
- 239000007864 aqueous solution Substances 0.000 claims description 6
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 claims description 6
- 229920001184 polypeptide Polymers 0.000 claims description 6
- 102000004196 processed proteins & peptides Human genes 0.000 claims description 6
- 108090000765 processed proteins & peptides Proteins 0.000 claims description 6
- 239000000203 mixture Substances 0.000 claims description 5
- 229910000030 sodium bicarbonate Inorganic materials 0.000 claims description 5
- 235000017557 sodium bicarbonate Nutrition 0.000 claims description 5
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 claims description 4
- 239000000920 calcium hydroxide Substances 0.000 claims description 4
- 229910001861 calcium hydroxide Inorganic materials 0.000 claims description 4
- 230000003301 hydrolyzing effect Effects 0.000 claims description 4
- 230000035484 reaction time Effects 0.000 claims description 4
- 229910000029 sodium carbonate Inorganic materials 0.000 claims description 4
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 claims description 3
- PMMYEEVYMWASQN-DMTCNVIQSA-N Hydroxyproline Chemical compound O[C@H]1CN[C@H](C(O)=O)C1 PMMYEEVYMWASQN-DMTCNVIQSA-N 0.000 claims description 3
- ONIBWKKTOPOVIA-BYPYZUCNSA-N L-Proline Chemical compound OC(=O)[C@@H]1CCCN1 ONIBWKKTOPOVIA-BYPYZUCNSA-N 0.000 claims description 3
- ONIBWKKTOPOVIA-UHFFFAOYSA-N Proline Natural products OC(=O)C1CCCN1 ONIBWKKTOPOVIA-UHFFFAOYSA-N 0.000 claims description 3
- 125000000539 amino acid group Chemical group 0.000 claims description 3
- CKLJMWTZIZZHCS-REOHCLBHSA-N aspartic acid group Chemical group N[C@@H](CC(=O)O)C(=O)O CKLJMWTZIZZHCS-REOHCLBHSA-N 0.000 claims description 3
- PMMYEEVYMWASQN-UHFFFAOYSA-N dl-hydroxyproline Natural products OC1C[NH2+]C(C([O-])=O)C1 PMMYEEVYMWASQN-UHFFFAOYSA-N 0.000 claims description 3
- 235000019253 formic acid Nutrition 0.000 claims description 3
- 238000010438 heat treatment Methods 0.000 claims description 3
- 229960002591 hydroxyproline Drugs 0.000 claims description 3
- 125000002924 primary amino group Chemical group [H]N([H])* 0.000 claims description 3
- 239000011780 sodium chloride Substances 0.000 claims description 3
- FGMPLJWBKKVCDB-UHFFFAOYSA-N trans-L-hydroxy-proline Natural products ON1CCCC1C(O)=O FGMPLJWBKKVCDB-UHFFFAOYSA-N 0.000 claims description 3
- 239000002516 radical scavenger Substances 0.000 claims description 2
- 239000012429 reaction media Substances 0.000 claims description 2
- 239000011651 chromium Substances 0.000 abstract description 16
- 238000005406 washing Methods 0.000 abstract description 15
- 229910052804 chromium Inorganic materials 0.000 abstract description 12
- 238000004519 manufacturing process Methods 0.000 abstract description 6
- 239000002699 waste material Substances 0.000 abstract description 5
- 239000002351 wastewater Substances 0.000 abstract description 5
- 239000007788 liquid Substances 0.000 abstract description 4
- 230000009286 beneficial effect Effects 0.000 abstract description 2
- 238000004064 recycling Methods 0.000 abstract description 2
- 238000011160 research Methods 0.000 abstract description 2
- 230000015572 biosynthetic process Effects 0.000 abstract 1
- 230000001737 promoting effect Effects 0.000 abstract 1
- 238000003786 synthesis reaction Methods 0.000 abstract 1
- DKVNPHBNOWQYFE-UHFFFAOYSA-N carbamodithioic acid Chemical group NC(S)=S DKVNPHBNOWQYFE-UHFFFAOYSA-N 0.000 description 41
- 239000000047 product Substances 0.000 description 11
- 125000003277 amino group Chemical group 0.000 description 9
- 108010009736 Protein Hydrolysates Proteins 0.000 description 7
- 150000001844 chromium Chemical class 0.000 description 5
- 230000007062 hydrolysis Effects 0.000 description 5
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 4
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 4
- 239000008367 deionised water Substances 0.000 description 4
- 229910021641 deionized water Inorganic materials 0.000 description 4
- 239000012990 dithiocarbamate Substances 0.000 description 4
- 238000004108 freeze drying Methods 0.000 description 4
- 238000006386 neutralization reaction Methods 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 3
- 239000000835 fiber Substances 0.000 description 3
- 239000000706 filtrate Substances 0.000 description 3
- 229920002635 polyurethane Polymers 0.000 description 3
- 239000004814 polyurethane Substances 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 2
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 235000003704 aspartic acid Nutrition 0.000 description 2
- OQFSQFPPLPISGP-UHFFFAOYSA-N beta-carboxyaspartic acid Natural products OC(=O)C(N)C(C(O)=O)C(O)=O OQFSQFPPLPISGP-UHFFFAOYSA-N 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 125000002485 formyl group Chemical class [H]C(*)=O 0.000 description 2
- 125000000524 functional group Chemical group 0.000 description 2
- 239000002893 slag Substances 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 description 1
- FEWJPZIEWOKRBE-JCYAYHJZSA-N Dextrotartaric acid Chemical compound OC(=O)[C@H](O)[C@@H](O)C(O)=O FEWJPZIEWOKRBE-JCYAYHJZSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- OWIKHYCFFJSOEH-UHFFFAOYSA-N Isocyanic acid Chemical group N=C=O OWIKHYCFFJSOEH-UHFFFAOYSA-N 0.000 description 1
- 239000005058 Isophorone diisocyanate Substances 0.000 description 1
- 239000002202 Polyethylene glycol Substances 0.000 description 1
- DWAQJAXMDSEUJJ-UHFFFAOYSA-M Sodium bisulfite Chemical compound [Na+].OS([O-])=O DWAQJAXMDSEUJJ-UHFFFAOYSA-M 0.000 description 1
- FEWJPZIEWOKRBE-UHFFFAOYSA-N Tartaric acid Natural products [H+].[H+].[O-]C(=O)C(O)C(O)C([O-])=O FEWJPZIEWOKRBE-UHFFFAOYSA-N 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000004927 clay Substances 0.000 description 1
- 238000010668 complexation reaction Methods 0.000 description 1
- 238000007334 copolymerization reaction Methods 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- QFYNUCAKHMSPCY-UHFFFAOYSA-L disodium;nonanedioate Chemical compound [Na+].[Na+].[O-]C(=O)CCCCCCCC([O-])=O QFYNUCAKHMSPCY-UHFFFAOYSA-L 0.000 description 1
- 238000004821 distillation Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000002329 infrared spectrum Methods 0.000 description 1
- IQPQWNKOIGAROB-UHFFFAOYSA-N isocyanate group Chemical group [N-]=C=O IQPQWNKOIGAROB-UHFFFAOYSA-N 0.000 description 1
- NIMLQBUJDJZYEJ-UHFFFAOYSA-N isophorone diisocyanate Chemical compound CC1(C)CC(N=C=O)CC(C)(CN=C=O)C1 NIMLQBUJDJZYEJ-UHFFFAOYSA-N 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 125000000956 methoxy group Chemical group [H]C([H])([H])O* 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 229920001223 polyethylene glycol Polymers 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 150000003254 radicals Chemical class 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 150000003384 small molecules Chemical class 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 235000010267 sodium hydrogen sulphite Nutrition 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 238000000967 suction filtration Methods 0.000 description 1
- 235000002906 tartaric acid Nutrition 0.000 description 1
- 239000011975 tartaric acid Substances 0.000 description 1
- 238000002211 ultraviolet spectrum Methods 0.000 description 1
Classifications
-
- 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
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07K—PEPTIDES
- C07K14/00—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof
- C07K14/435—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from animals; from humans
- C07K14/78—Connective tissue peptides, e.g. collagen, elastin, laminin, fibronectin, vitronectin or cold insoluble globulin [CIG]
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
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- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Gastroenterology & Hepatology (AREA)
- General Chemical & Material Sciences (AREA)
- Toxicology (AREA)
- Zoology (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Biochemistry (AREA)
- Biophysics (AREA)
- General Health & Medical Sciences (AREA)
- Genetics & Genomics (AREA)
- Medicinal Chemistry (AREA)
- Molecular Biology (AREA)
- Proteomics, Peptides & Aminoacids (AREA)
- Treatment And Processing Of Natural Fur Or Leather (AREA)
Abstract
The invention discloses a high-absorption chrome tanning auxiliary agent containing a dithiocarbamate structure, and a preparation method and application thereof; the high-absorption chrome tanning auxiliary agent provided by the invention can better capture and coordinate and combine with the chrome tanning agent, improve the absorption and fixation of the chrome tanning agent, realize high-absorption chrome tanning, reduce the content of chromium in chrome tanning wastewater and the content of chromium in waste liquid in the later washing process, and is beneficial to promoting clean production in the leather industry; the invention has simple synthesis process and mild condition, and provides a new idea for the recycling of tanning waste and the research of high-absorption chrome tanning auxiliary agent.
Description
Technical Field
The invention belongs to the technical field of leather, and particularly relates to a high-absorption chrome tanning auxiliary agent containing a dithiocarbamate structure, and a preparation method and application thereof.
Background
In recent years, with the improvement of the living standard of people and the enhancement of environmental awareness, consumers have higher requirements on the quality of leather products, and meanwhile, the influence of leather processing on the environment is focused more. Currently, chrome tanning agents are the most commonly used tanning agents for tanning, and about 90% of leather worldwide is prepared by chrome tanning. However, in the conventional chrome tanning process, the absorption and utilization rate of the leather collagen fiber to the chrome tanning agent is 60% -70%, and the residual chrome tanning agent is discharged into the wastewater, so that not only is the huge waste of chromium resources caused, but also the environmental pollution load is increased.
By introducing the high-absorption chrome tanning auxiliary agent into the tanning system, the absorption of the leather collagen fiber to the chrome tanning agent in the tanning process can be effectively improved, and the chrome content in the waste liquid can be reduced. Bai Yunxiang et al synthesized SYY aldonic acid tanning agents with aldehydes, ammonia and acids under weak acid conditions. Application experiments show that when the dosage of SYY and chromium powder is 8 percent and 5 percent respectively, the shrinkage temperature of blue wet leather and the utilization rate of chromium salt can reach 96 ℃ and 96 percent respectively, and the Cr in wastewater can be obviously reduced 2 O 3 Content (Bai Yunxiang, wang Hongru. Structure and application research of aldehyde acid type chrome tanning auxiliary SYY [ J ]]The university of North-West light industry, 2002 (04): 12-17). Chen Wei et al prepared small molecule polycarboxy polyurethane products in a two-step process by first preparing a prepolymer from isophorone diisocyanate and tartaric acid and then capping the isocyanate group with sodium bisulfite. The combination of isocyanic acid groups on the polycarboxy polyurethane and amino groups on the collagen fibers of the leather increases the action point of chromium salt, so that the shrinkage temperature of the leather is increased to 113 ℃, and the absorption and utilization rate of the chromium salt are also increased (Chen Wei, jiang Xihuai, sun Zhe, and the like; study of tanning performance of sodium bisulphite-terminated polycarboxy polyurethane [ J]Leather science and engineering, 2016,26 (02): 9-13.). Chen Yongbo A high-absorption chrome tanning auxiliary PEGA is prepared by taking methoxy polyethylene glycol acrylate (PEGMA) and Acrylic Acid (AA) as raw materials and adopting a free radical copolymerization method. The PEGA can improve the absorption and utilization rate of the chrome tanning agent to 93.3 percent, the shrinkage temperature of the obtained blue wet leather is higher than 90 ℃, and simultaneously has excellent physical and mechanical properties (Chen Yongbo, zhu Ruixin, li Kaijun, and the like; the preparation and the application of the PEGA which is the high-absorption chrome tanning auxiliary agent)[J]Leather science and engineering, 2021,31 (05): 48-54.). Patent document CN112778206a discloses a preparation method and application of a high-absorption chrome tanning auxiliary agent containing a ketosulfonate structure, and the auxiliary agent is applied to a tanning process, so that the crust leather shrinkage temperature and the absorptivity of a chrome tanning agent can be obviously improved, and meanwhile, the crust leather has pure color, fine grain and soft leather body. Patent document CN102250294a discloses a method for preparing a mask retanning type high-absorption chrome tanning auxiliary agent, which is applied to a tanning process, can improve the absorptivity of a chrome tanning agent, and simultaneously ensures that grain lines of finished leather are fine and clear, and can achieve the effect of resin retanning in the chrome tanning process.
The high-absorption chrome tanning auxiliary molecules usually contain a large amount of carboxyl groups, and the action mechanism is that the carboxyl groups in the molecules can crosslink the chrome complex during tanning so as to achieve the purpose of high absorption. However, the complexation of carboxyl and chromium is still not strong enough, so that a part of chromium complex can be removed from crust leather and migrate into waste water in the subsequent procedures of washing, neutralization and the like, and new pollution is formed. Therefore, the exploration of new coordination functional groups and the design of novel high-absorption chrome tanning auxiliary agents on the basis of the new coordination functional groups, the enhancement of the binding fastness of a chrome complex and leather collagen, have become a concern of industry.
In addition, a large amount of solid waste is inevitably generated during the leather manufacturing process. Solid waste includes untanned grime edges, chrome-containing dander, and the like. How to fully and effectively utilize the solid wastes is also one of the hot problems in the industry.
Disclosure of Invention
Aiming at the defects of the prior art, particularly the defects that the chrome tanning auxiliary agent in the prior art is mainly complexed with carboxyl and chromium, and the complex effect is not strong enough to cause that chromium complex is easy to be removed from crust leather in the subsequent procedures of washing, neutralization and the like, migrate into waste water to form new pollution, and a large amount of solid waste generated in the existing tanning processing process cannot be effectively utilized. The invention provides a method for preparing a high-absorption chrome tanning auxiliary agent containing a dithiocarbamate structure in a molecule by utilizing tanning gray edges. By introducing a dithiocarbamate structure into the auxiliary agent molecule, the absorption rate of the chrome tanning agent in the main tanning process can be increased, and the combination amount of the chrome tanning agent in crust leather can be improved. Meanwhile, as the dithiocarbamate and the chrome tanning agent have better binding fastness, the bound chrome tanning agent can be prevented from being washed out in the subsequent processes of neutralization, retanning, water washing and the like, so that the content of chromium in the operating fluid is reduced.
The aim of the invention is realized by the following technical scheme:
a high-absorption chrome tanning auxiliary agent containing a dithiocarbamate structure is collagen polypeptide containing the dithiocarbamate structure in a molecular chain.
According to the present invention, preferably, the collagen polypeptide having a dithiocarbamate structure in the molecular chain is obtained by reacting carbon disulfide with the self-amino group in the collagen hydrolysate.
According to the invention, a preferred high-absorption chrome tanning aid containing a dithiocarbamate structure has the structure of formula I:
a formula I; r is R 1 、R 2 、R 3 N=5-30 for different amino acid residues.
According to the invention, preference is given to the formula I in which R 1 、R 2 、R 3 Independently selected from one of the residues of proline, hydroxyproline, aspartic acid, etc.
According to the invention, the preparation method of the high-absorption chrome tanning auxiliary agent containing the dithiocarbamate structure comprises the following steps:
collagen hydrolysate and carbon disulfide are used as raw materials, water is used as a reaction medium, and the raw materials react in the presence of an acid catching agent to obtain the high-absorption chrome tanning auxiliary agent containing a dithiocarbamate structure.
According to the invention, preferably, the collagen hydrolysate is obtained by hydrolyzing solid waste generated in the leather making process as a raw material; further preferably, the solid waste generated during the tanning process comprises untanned gray edges.
According to the invention, preferably, the collagen hydrolysate has a molecular weight in the range of 1000-5000 daltons.
According to the present invention, preferably, the collagen hydrolysate is obtained as follows:
the method comprises the steps of carrying out deashing pretreatment on leather making gray skin, and then hydrolyzing gray skin edges by using alkali or acid to obtain collagen hydrolysate.
According to the invention, preferably, the alkali is calcium hydroxide, sodium hydroxide or/and potassium hydroxide, and the acid is sulfuric acid or/and hydrochloric acid;
preferably, the mass ratio of alkali or acid to gray skin edge is 8% -10%: 1, a step of;
preferably, the hydrolysis reaction temperature is 90-100 ℃, and the hydrolysis reaction time is 5-18 h.
According to the invention, the deliming pretreatment of the tannery ash skin can be carried out according to the prior art in the leather field.
According to the invention, preferably, the molar ratio of the free amino content in the collagen hydrolysate to the carbon disulfide is 1:1-1:2 in the reaction process of the collagen hydrolysate and the carbon disulfide.
According to the invention, the reaction temperature of the collagen hydrolysate and the carbon disulfide is preferably 5-30 ℃ and the reaction time is 6-12 h.
According to the invention, preferably, the acid scavenger is sodium hydroxide, potassium hydroxide, sodium carbonate or sodium bicarbonate solution.
According to the invention, the application of the high-absorption chrome tanning auxiliary agent containing the dithiocarbamate structure in the leather chrome tanning process is provided.
According to the present invention, the conditions of the chrome tanning process are preferably as follows:
adding 100% of water and 6% of sodium chloride into the ash cortex, and rotating for 30min; adding formic acid aqueous solution with the mass concentration of 10% and the mass concentration of 0.4-0.5% of the ash skin for 3 times, and rotating for 60 minutes at intervals of 15 minutes each time; adding chromium powder with the alkalinity of 33.3 percent and the mass of 5-6 percent of the gray skin, and rotating for 2-4 hours at the temperature of 20-25 ℃; then adding sodium bicarbonate aqueous solution with the mass concentration of 10% and the mass concentration of 1.5-2.0% of the ash skin into the mixture for 3 times, adjusting the pH value to 3.6-3.8 at intervals of 20 minutes each time, and rotating the mixture for 60 minutes; adding a high-absorption chrome tanning auxiliary agent containing a dithiocarbamate structure, wherein the gray leather content is 3-5%, rotating for 60-90 min, heating to 40 ℃, rotating for 60-90 min, stopping the drum overnight, rotating for 30min in the next day, taking out the drum, and standing to obtain the blue wet leather.
The invention, which is not described in detail, is carried out according to the prior art in the leather field.
The invention has the beneficial effects that:
1. the high-absorption chrome tanning auxiliary agent contains a dithiocarbamate structure, so that the coordination capability of the dithiocarbamate and a chromium complex is stronger, free chromium complex is more easily captured and stably coordinated with the dithiocarbamate, the absorption rate and the binding fastness of the chrome tanning agent are improved, the chrome tanning agent is prevented from being eluted in subsequent procedures, and new pollution is avoided.
2. After the high-absorption chrome tanning auxiliary agent is applied, the high-absorption chrome tanning auxiliary agent has good chrome salt absorption rate and higher shrinkage temperature. For example: in one embodiment of the invention, after treatment with a high absorption chrome tanning aid containing a dithiocarbamate structure, the shrinkage temperature reaches 101.2 ℃ and the chrome salt absorption rate is 92.65%. The crust leather is washed twice, and the chromium content in the washing liquid is 0.102mg/mL and 0.041mg/mL respectively.
3. The invention fully utilizes the solid waste generated in the existing tanning processing process as the raw material to prepare the high-absorption chrome tanning auxiliary agent, thereby not only realizing the recycling of tanning waste, but also greatly reducing the preparation cost of the high-absorption chrome tanning auxiliary agent.
4. The high-absorption chrome tanning auxiliary agent containing the dithiocarbamate structure has the advantages of simple preparation process and mild reaction condition. The conventional tanning process steps are not changed, and only an auxiliary agent is needed to be added in the chrome tanning or chrome retanning process, so that the method is very convenient to apply.
Drawings
FIG. 1 is an infrared spectrum of a high absorption chrome tanning agent containing dithiocarbamate structure obtained in example 1.
FIG. 2 is a UV spectrum of a high absorption chrome tanning agent containing dithiocarbamate structure obtained in example 1.
Detailed Description
The high-absorption chrome tanning auxiliary agent containing the dithiocarbamate structure is collagen polypeptide containing the dithiocarbamate structure in a molecular chain; the collagen polypeptide with the molecular chain containing the dithiocarbamate structure is obtained by reacting carbon disulfide with self amino in collagen hydrolysate.
According to the invention, the dithiocarbamate structure is introduced into the auxiliary agent molecule, so that the absorption rate of the chrome tanning agent in the main tanning process can be increased, and the combination amount of the chrome tanning agent in crust leather can be increased. Meanwhile, as the dithiocarbamate and the chrome tanning agent have better binding fastness, the bound chrome tanning agent can be prevented from being washed out in the subsequent processes of neutralization, retanning, water washing and the like, so that the content of chromium in the operating fluid is reduced.
In a preferred embodiment, the dithiocarbamate structure-containing high-absorption chrome tanning aid has a structure of formula I:
a formula I; r is R 1 、R 2 、R 3 N=5-30 for different amino acid residues.
In a preferred embodiment, R in formula I 1 、R 2 、R 3 Independently selected from one of the residues of proline, hydroxyproline, aspartic acid, etc.
The invention is further illustrated by, but not limited to, the following specific examples.
The scum/skin edge described in the examples is a solid waste in the process of tanning.
Example 1
A process for preparing a dithiocarbamate structure-containing high-absorption chrome tanning aid comprising the steps of:
(1) 300g of deashed skin slag is added into a 1000mL four-necked flask, 300mL of deionized water and 24g of calcium hydroxide are added, hydrolysis is carried out for 15h at 100 ℃, the reaction is finished, then 50wt% sulfuric acid is used for regulating the pH of the solution to 7.0, the solution is kept stand and filtered, and the hydrolysate is freeze-dried to obtain collagen hydrolysate. The molecular weight range is 2000-5000 daltons.
(2) Preparing collagen hydrolysate with the mass fraction of 50% from the obtained collagen hydrolysate, taking 50mL of collagen hydrolysate, putting the collagen hydrolysate into a 100mL four-neck flask, adding 1.03g of sodium hydroxide at 0-5 ℃ (the molar ratio of free amino groups in the collagen hydrolysate to the sodium hydroxide is 1.0:1.2), and dropwise adding 1.95mLCS 2 (the molar ratio of free amino groups to carbon disulfide in the collagen hydrolysate is 1.0:1.5). The reaction system was allowed to react at 5 ℃ for 12h, and finally the pH of the product was adjusted to 6.0.
(3) And (3) precipitating and washing the product after the reaction with 3-5 times of absolute ethyl alcohol for 3-5 times, and freeze-drying to finally obtain the high-absorption chrome tanning auxiliary agent containing the dithiocarbamate structure.
And testing the infrared spectrogram of the obtained high-absorption chrome tanning auxiliary agent containing the dithiocarbamate structure, as shown in figure 1, and the ultraviolet spectrogram, as shown in figure 2.
In FIG. 1, the absorption peak at 1549cm-1 is the telescopic vibration absorption peak of the C-N bond in the dithiocarbamic acid group in DTCH, and the telescopic vibration absorption peaks of the N-C= S, C =S and C-S bonds appear at 1452cm-1, 1083cm-1 and 931cm-1, respectively, indicating that the dithiocarbamic acid group is contained in the product molecule.
In fig. 2, there are three absorption bands, where the absorption at 288nm is the pi-pi transition of the S-c=s group and the absorption at 253nm is the pi-pi transition of the N-c=s group, with the superimposed absorption band occurring at 210 nm.
Example 2
A process for preparing a dithiocarbamate structure-containing high-absorption chrome tanning aid comprising the steps of:
(1) 300g of deashed skin slag is added into a 1000mL four-neck flask, 300mL of deionized water and 24g of sodium hydroxide are added, hydrolysis is carried out for 15h at 100 ℃, and the reaction is finished; carrying out suction filtration on the hydrolysate for one time to obtain crude collagen hydrolysis filtrate; adding clay and activated carbon into the filtrate for physical adsorption, removing pigment and some micromolecular metal complexes, etc.; the pH of the filtrate was adjusted to about 7.0 using 2M hydrochloric acid, and then concentrated by distillation and freeze-dried to obtain collagen hydrolysate. The molecular weight range is 2000-5000 daltons.
(2) Preparing collagen hydrolysate with the mass fraction of 40% into collagen hydrolysate, taking 100mL of collagen hydrolysate, placing the collagen hydrolysate into a 500mL four-neck flask, adding 2.2g of sodium hydroxide at 10 ℃ (the molar ratio of free amino groups in the collagen hydrolysate to the sodium hydroxide is 1.0:1.5), and dropwise adding 4.42mL of CS 2 (the molar ratio of free amino groups to carbon disulfide in the collagen hydrolysate is 1.0:2.0). The reaction system was allowed to react at room temperature for 9h, and finally the pH of the product was adjusted to 6.5.
(3) Washing the product after the reaction with 3-5 times of absolute ethyl alcohol for 3-5 times, and freeze-drying to obtain the high-absorption chrome tanning auxiliary agent containing the dithiocarbamate structure.
Example 3
A process for preparing a dithiocarbamate structure-containing high-absorption chrome tanning aid comprising the steps of:
(1) 150g of deashed skin residue/skin edge is added into a 500mL four-neck flask, 150mL of deionized water and 24g of sulfuric acid are added, hydrolysis is carried out for 18h at 90 ℃, the reaction is finished, then 10wt% of calcium hydroxide is used for adjusting the pH of the solution to 7.0, the solution is kept stand and filtered, and the hydrolysate is frozen and dried to obtain collagen hydrolysate. The molecular weight range is 2000-5000 daltons.
(2) Preparing collagen hydrolysate with mass fraction of 35%, taking 50mL collagen hydrolysate, placing in a 100mL four-neck flask, adding 1.20g sodium carbonate (molar ratio of free amino groups in collagen hydrolysate to sodium carbonate is 1.0:1.5) at 20deg.C, and dropwise adding 2.40mLCS 2 (molar ratio of free amino groups to carbon disulfide in the collagen hydrolysate is 1.0:2.0), reacting for 9h, and finally adjusting the pH of the product to 6.0.
(3) Washing the product after the reaction with 3-5 times of absolute ethyl alcohol for 3-5 times, and freeze-drying to obtain the high-absorption chrome tanning auxiliary agent containing the dithiocarbamate structure.
Example 4
A process for preparing a dithiocarbamate structure-containing high-absorption chrome tanning aid comprising the steps of:
(1) 150g of deashing skin residue/skin edge is added into a 500mL four-neck flask, 150mL of deionized water and 24g of potassium hydroxide are added, hydrolysis is carried out for 18h at 100 ℃, the reaction is finished, the mixture is stood and filtered, and the hydrolysate is freeze-dried to obtain collagen hydrolysate. The molecular weight range is 2000-5000 daltons.
(2) Preparing collagen hydrolysate with the mass fraction of 40% from the obtained collagen hydrolysate, taking 50mL of collagen hydrolysate, putting the collagen hydrolysate into a 100mL four-neck flask, adding 0.85g of sodium hydroxide at 20 ℃ (the molar ratio of free amino groups in the collagen hydrolysate to the sodium hydroxide is 1.0:1.0), and dropwise adding 1.92mL of CS 2 (free amino groups and CS in collagen hydrolysate) 2 The molar ratio of (2) is 1.0:1.5), reacting for 9 hours, and finally adjusting the pH value of the product to 6.0-6.5.
(3) Washing the product after the reaction with 3-5 times of absolute ethyl alcohol for 3-5 times, and freeze-drying to obtain the high-absorption chrome tanning auxiliary agent containing the dithiocarbamate structure.
Example 5
The high-absorption chrome tanning auxiliary agent containing the dithiocarbamate structure prepared by the invention is subjected to tanning experiments.
Use of a high-absorption chrome tanning aid containing a dithiocarbamate structure prepared according to example 1 of the present invention in a leather tanning process: the method is applied to a high-absorption chrome tanning process: adding 100% of water and 6% of sodium chloride into the ash cortex, and rotating for 30min; adding formic acid aqueous solution (the mass concentration is 10%) with the mass of 0.4-0.5% of the ash skin for 3 times, and rotating for 60min at intervals of 15min each time; adding chromium powder with the alkalinity of 33.3 percent and the mass of 5-6 percent of the gray skin, and rotating for 2-4 hours at the temperature of 20-25 ℃; then adding sodium bicarbonate aqueous solution (the mass concentration is 10%) with the mass of 1.5-2.0% of the ash skin for 3 times, adjusting the pH value to 3.6-3.8 at intervals of 20min each time, and rotating for 60min; adding a high-absorption chrome tanning auxiliary agent with the gray leather content of 3-5%, rotating for 60-90 min, heating to 40 ℃, rotating for 60-90 min, stopping the drum overnight, rotating for 30min the next day, taking out the drum, and standing to obtain the blue wet leather.
Test example 1
The crust leather shrinkage temperature and chromium salt absorptivity in example 5 were measured. The experimental results show that: after treatment with the high-absorption chrome tanning auxiliary containing a dithiocarbamate structure, the shrinkage temperature is 101.2 ℃ and the chromium salt absorptivity is 92.65%.
Test example 2
To test the fastness to washing, 3% sodium azelate and the high-absorption chrome tanning aid obtained in example 1 were used for cross-linking chrome tanning, respectively. The wet blue leather obtained was subjected to a water washing experiment in a rotating drum. The method comprises the following steps: the water consumption is 200% of the weight of the leather and the temperature is 35-40 ℃; rotating for 120 minutes, and then measuring Cr in the washing liquid 2 O 3 The content, drain and change water are repeated once. For conventional chrome tannage, cr in the first wash liquor 2 O 3 The concentration of Cr in the second aqueous washing solution was 0.49mg/mL 2 O 3 The concentration was 0.093mg/mL. After being treated by high-absorption chrome tanning auxiliary agent, chrome tanning crust leather is washed twice with water to remove Cr 2 O 3 The concentrations of (C) are 0.102mg/mL and 0.041mg/mL, respectively.
Experimental results show that after the high-absorption chrome tanning auxiliary agent containing the dithiocarbamate structure provided by the invention is adopted, the combination fastness of the chrome complex and leather is further improved, and the water-washing resistance of crust leather is improved.
Claims (10)
1. A high-absorption chrome tanning auxiliary agent containing a dithiocarbamate structure, which is characterized in that the high-absorption chrome tanning auxiliary agent is collagen polypeptide containing the dithiocarbamate structure in a molecular chain.
2. The dithiocarbamate-structure-containing high-absorption chrome tanning agent according to claim 1, wherein the molecule chain of the dithiocarbamate-structure-containing collagen polypeptide is obtained by reacting carbon disulfide with self-amino groups in collagen hydrolysate.
3. The dithiocarbamate structure-containing high-absorption chrome tanning aid of claim 1, wherein the dithiocarbamate structure-containing high-absorption chrome tanning aid has a structure of formula i:
a formula I; r is R 1 、R 2 、R 3 N=5-30 for different amino acid residues.
4. A high-absorption chrome tanning agent containing a dithiocarbamate structure according to claim 3, wherein in formula i, R 1 、R 2 、R 3 Independently selected from one of proline, hydroxyproline, aspartic acid residues.
5. The method for preparing the dithiocarbamate-structure-containing high-absorption chrome tanning assistant as claimed in claim 1, comprising the following steps:
collagen hydrolysate and carbon disulfide are used as raw materials, water is used as a reaction medium, and the raw materials react in the presence of an acid catching agent to obtain the high-absorption chrome tanning auxiliary agent containing a dithiocarbamate structure.
6. The method for preparing the dithiocarbamate-structure-containing high-absorption chrome tanning auxiliary agent according to claim 5, wherein the collagen hydrolysate is obtained by hydrolyzing solid waste generated in the tanning process;
preferably, the solid waste generated during the tanning process comprises untanned gray edges;
preferably, the molecular weight of the collagen hydrolysate is in the range of 1000-5000 daltons.
7. The method for preparing the dithiocarbamate-structure-containing high-absorption chrome tanning assistant according to claim 5, wherein the collagen hydrolysate is obtained by the following method:
carrying out deashing pretreatment on the leather making gray skin, and then hydrolyzing the gray skin edges by using alkali or acid to obtain collagen hydrolysate;
preferably, the alkali is calcium hydroxide, sodium hydroxide or/and potassium hydroxide, and the acid is sulfuric acid or/and hydrochloric acid;
preferably, the mass ratio of alkali or acid to gray skin edge is 8% -10%: 1, a step of;
preferably, the hydrolysis reaction temperature is 90-100 ℃, and the hydrolysis reaction time is 5-18 h.
8. The method for preparing the dithiocarbamate-structure-containing high-absorption chrome tanning auxiliary according to claim 5, wherein the molar ratio of free amino content in the collagen hydrolysate to carbon disulfide is 1:1-1:2 in the reaction process of the collagen hydrolysate and the carbon disulfide.
9. The method for preparing the dithiocarbamate-structure-containing high-absorption chrome tanning auxiliary according to claim 5, wherein the reaction temperature of the collagen hydrolysate and the carbon disulfide is 5-30 ℃ and the reaction time is 6-12 h;
preferably, the acid scavenger is sodium hydroxide, potassium hydroxide, sodium carbonate or sodium bicarbonate solution.
10. Use of a high absorption chrome tanning aid containing a dithiocarbamate structure according to claim 1 in a leather chrome tanning process;
preferably, the conditions of the chrome tanning process are as follows:
adding 100% of water and 6% of sodium chloride into the ash cortex, and rotating for 30min; adding formic acid aqueous solution with the mass concentration of 10% and the mass concentration of 0.4-0.5% of the ash skin for 3 times, and rotating for 60 minutes at intervals of 15 minutes each time; adding chromium powder with the alkalinity of 33.3 percent and the mass of 5-6 percent of the gray skin, and rotating for 2-4 hours at the temperature of 20-25 ℃; then adding sodium bicarbonate aqueous solution with the mass concentration of 10% and the mass concentration of 1.5-2.0% of the ash skin into the mixture for 3 times, adjusting the pH value to 3.6-3.8 at intervals of 20 minutes each time, and rotating the mixture for 60 minutes; adding a high-absorption chrome tanning auxiliary agent containing a dithiocarbamate structure, wherein the gray leather content is 3-5%, rotating for 60-90 min, heating to 40 ℃, rotating for 60-90 min, stopping the drum overnight, rotating for 30min in the next day, taking out the drum, and standing to obtain the blue wet leather.
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