AU2003250493B2 - A process for the preparation of a synthetic tanning agent - Google Patents
A process for the preparation of a synthetic tanning agent Download PDFInfo
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- AU2003250493B2 AU2003250493B2 AU2003250493A AU2003250493A AU2003250493B2 AU 2003250493 B2 AU2003250493 B2 AU 2003250493B2 AU 2003250493 A AU2003250493 A AU 2003250493A AU 2003250493 A AU2003250493 A AU 2003250493A AU 2003250493 B2 AU2003250493 B2 AU 2003250493B2
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- 238000000034 method Methods 0.000 title claims description 38
- 238000002360 preparation method Methods 0.000 title claims description 11
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 33
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 33
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 claims description 27
- 150000001491 aromatic compounds Chemical class 0.000 claims description 25
- 239000011541 reaction mixture Substances 0.000 claims description 25
- 239000003795 chemical substances by application Substances 0.000 claims description 24
- 239000000203 mixture Substances 0.000 claims description 23
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 18
- 239000011651 chromium Substances 0.000 claims description 17
- 229910052804 chromium Inorganic materials 0.000 claims description 16
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 15
- 239000010985 leather Substances 0.000 claims description 14
- UFWIBTONFRDIAS-UHFFFAOYSA-N Naphthalene Chemical compound C1=CC=CC2=CC=CC=C21 UFWIBTONFRDIAS-UHFFFAOYSA-N 0.000 claims description 12
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 claims description 12
- XNGIFLGASWRNHJ-UHFFFAOYSA-N phthalic acid Chemical compound OC(=O)C1=CC=CC=C1C(O)=O XNGIFLGASWRNHJ-UHFFFAOYSA-N 0.000 claims description 10
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 claims description 9
- 239000013110 organic ligand Substances 0.000 claims description 9
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 claims description 8
- 229920001002 functional polymer Polymers 0.000 claims description 8
- YGSDEFSMJLZEOE-UHFFFAOYSA-N salicylic acid Chemical compound OC(=O)C1=CC=CC=C1O YGSDEFSMJLZEOE-UHFFFAOYSA-N 0.000 claims description 8
- 229920002125 Sokalan® Polymers 0.000 claims description 6
- MWPLVEDNUUSJAV-UHFFFAOYSA-N anthracene Chemical compound C1=CC=CC2=CC3=CC=CC=C3C=C21 MWPLVEDNUUSJAV-UHFFFAOYSA-N 0.000 claims description 6
- 238000010438 heat treatment Methods 0.000 claims description 5
- 239000004584 polyacrylic acid Substances 0.000 claims description 5
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 claims description 4
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 claims description 4
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 claims description 4
- FJKROLUGYXJWQN-UHFFFAOYSA-N papa-hydroxy-benzoic acid Natural products OC(=O)C1=CC=C(O)C=C1 FJKROLUGYXJWQN-UHFFFAOYSA-N 0.000 claims description 4
- 229960004889 salicylic acid Drugs 0.000 claims description 4
- 229910000030 sodium bicarbonate Inorganic materials 0.000 claims description 4
- 235000017557 sodium bicarbonate Nutrition 0.000 claims description 4
- 125000004432 carbon atom Chemical group C* 0.000 claims description 3
- 238000001035 drying Methods 0.000 claims description 3
- 235000006408 oxalic acid Nutrition 0.000 claims description 3
- 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 2
- 238000002036 drum drying Methods 0.000 claims description 2
- 235000019253 formic acid Nutrition 0.000 claims description 2
- 239000011261 inert gas Substances 0.000 claims description 2
- 159000000000 sodium salts Chemical class 0.000 claims description 2
- 238000001694 spray drying Methods 0.000 claims description 2
- 239000000243 solution Substances 0.000 description 23
- 239000000047 product Substances 0.000 description 12
- 238000006243 chemical reaction Methods 0.000 description 9
- 238000003756 stirring Methods 0.000 description 7
- WSFSSNUMVMOOMR-NJFSPNSNSA-N methanone Chemical compound O=[14CH2] WSFSSNUMVMOOMR-NJFSPNSNSA-N 0.000 description 6
- 239000000843 powder Substances 0.000 description 5
- 239000002002 slurry Substances 0.000 description 5
- VZCYOOQTPOCHFL-OWOJBTEDSA-N Fumaric acid Chemical compound OC(=O)\C=C\C(O)=O VZCYOOQTPOCHFL-OWOJBTEDSA-N 0.000 description 4
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 4
- 238000001816 cooling Methods 0.000 description 4
- 239000004744 fabric Substances 0.000 description 4
- 239000000706 filtrate Substances 0.000 description 4
- 230000035515 penetration Effects 0.000 description 4
- 229920003023 plastic Polymers 0.000 description 4
- 229920000642 polymer Polymers 0.000 description 4
- 239000011148 porous material Substances 0.000 description 4
- 238000006277 sulfonation reaction Methods 0.000 description 4
- VZCYOOQTPOCHFL-UHFFFAOYSA-N trans-butenedioic acid Natural products OC(=O)C=CC(O)=O VZCYOOQTPOCHFL-UHFFFAOYSA-N 0.000 description 4
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 3
- 229920002845 Poly(methacrylic acid) Polymers 0.000 description 3
- 238000007539 photo-oxidation reaction Methods 0.000 description 3
- 229920000058 polyacrylate Polymers 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- BDHFUVZGWQCTTF-UHFFFAOYSA-N sulfonic acid Chemical compound OS(=O)=O BDHFUVZGWQCTTF-UHFFFAOYSA-N 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
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- OFOBLEOULBTSOW-UHFFFAOYSA-N Propanedioic acid Natural products OC(=O)CC(O)=O OFOBLEOULBTSOW-UHFFFAOYSA-N 0.000 description 2
- 239000004280 Sodium formate Substances 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 230000032683 aging Effects 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 125000003118 aryl group Chemical group 0.000 description 2
- HNEGQIOMVPPMNR-IHWYPQMZSA-N citraconic acid Chemical compound OC(=O)C(/C)=C\C(O)=O HNEGQIOMVPPMNR-IHWYPQMZSA-N 0.000 description 2
- 229940018557 citraconic acid Drugs 0.000 description 2
- 238000010668 complexation reaction Methods 0.000 description 2
- 238000009833 condensation Methods 0.000 description 2
- 230000005494 condensation Effects 0.000 description 2
- LDHQCZJRKDOVOX-NSCUHMNNSA-N crotonic acid Chemical compound C\C=C\C(O)=O LDHQCZJRKDOVOX-NSCUHMNNSA-N 0.000 description 2
- 239000001530 fumaric acid Substances 0.000 description 2
- 231100001261 hazardous Toxicity 0.000 description 2
- VZCYOOQTPOCHFL-UPHRSURJSA-N maleic acid Chemical compound OC(=O)\C=C/C(O)=O VZCYOOQTPOCHFL-UPHRSURJSA-N 0.000 description 2
- 239000011976 maleic acid Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 125000000962 organic group Chemical group 0.000 description 2
- 238000005554 pickling Methods 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 229910000029 sodium carbonate Inorganic materials 0.000 description 2
- HLBBKKJFGFRGMU-UHFFFAOYSA-M sodium formate Chemical compound [Na+].[O-]C=O HLBBKKJFGFRGMU-UHFFFAOYSA-M 0.000 description 2
- 235000019254 sodium formate Nutrition 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 231100000419 toxicity Toxicity 0.000 description 2
- 230000001988 toxicity Effects 0.000 description 2
- LDHQCZJRKDOVOX-UHFFFAOYSA-N trans-crotonic acid Natural products CC=CC(O)=O LDHQCZJRKDOVOX-UHFFFAOYSA-N 0.000 description 2
- OSSNTDFYBPYIEC-UHFFFAOYSA-N 1-ethenylimidazole Chemical compound C=CN1C=CN=C1 OSSNTDFYBPYIEC-UHFFFAOYSA-N 0.000 description 1
- HIXDQWDOVZUNNA-UHFFFAOYSA-N 2-(3,4-dimethoxyphenyl)-5-hydroxy-7-methoxychromen-4-one Chemical compound C=1C(OC)=CC(O)=C(C(C=2)=O)C=1OC=2C1=CC=C(OC)C(OC)=C1 HIXDQWDOVZUNNA-UHFFFAOYSA-N 0.000 description 1
- XHZPRMZZQOIPDS-UHFFFAOYSA-N 2-Methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid Chemical compound OS(=O)(=O)CC(C)(C)NC(=O)C=C XHZPRMZZQOIPDS-UHFFFAOYSA-N 0.000 description 1
- IULJSGIJJZZUMF-UHFFFAOYSA-N 2-hydroxybenzenesulfonic acid Chemical compound OC1=CC=CC=C1S(O)(=O)=O IULJSGIJJZZUMF-UHFFFAOYSA-N 0.000 description 1
- AYKYXWQEBUNJCN-UHFFFAOYSA-N 3-methylfuran-2,5-dione Chemical compound CC1=CC(=O)OC1=O AYKYXWQEBUNJCN-UHFFFAOYSA-N 0.000 description 1
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical compound NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 description 1
- 241000283690 Bos taurus Species 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-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
- STNJBCKSHOAVAJ-UHFFFAOYSA-N Methacrolein Chemical compound CC(=C)C=O STNJBCKSHOAVAJ-UHFFFAOYSA-N 0.000 description 1
- 208000002193 Pain Diseases 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 239000005864 Sulphur Substances 0.000 description 1
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- -1 acrylic ester Chemical class 0.000 description 1
- 238000005273 aeration Methods 0.000 description 1
- 239000000783 alginic acid Substances 0.000 description 1
- 229920000615 alginic acid Polymers 0.000 description 1
- 229960001126 alginic acid Drugs 0.000 description 1
- 235000010443 alginic acid Nutrition 0.000 description 1
- 150000004781 alginic acids Chemical class 0.000 description 1
- 125000004183 alkoxy alkyl group Chemical group 0.000 description 1
- 244000309466 calf Species 0.000 description 1
- 230000000711 cancerogenic effect Effects 0.000 description 1
- 239000004202 carbamide Substances 0.000 description 1
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 1
- 231100000315 carcinogenic Toxicity 0.000 description 1
- 150000001844 chromium Chemical class 0.000 description 1
- 229910001430 chromium ion Inorganic materials 0.000 description 1
- DSHWASKZZBZKOE-UHFFFAOYSA-K chromium(3+);hydroxide;sulfate Chemical compound [OH-].[Cr+3].[O-]S([O-])(=O)=O DSHWASKZZBZKOE-UHFFFAOYSA-K 0.000 description 1
- 229910000356 chromium(III) sulfate Inorganic materials 0.000 description 1
- 239000011696 chromium(III) sulphate Substances 0.000 description 1
- 235000015217 chromium(III) sulphate Nutrition 0.000 description 1
- 230000000536 complexating effect Effects 0.000 description 1
- 229940125810 compound 20 Drugs 0.000 description 1
- 239000007859 condensation product Substances 0.000 description 1
- 238000007334 copolymerization reaction Methods 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
- HQWKKEIVHQXCPI-UHFFFAOYSA-L disodium;phthalate Chemical compound [Na+].[Na+].[O-]C(=O)C1=CC=CC=C1C([O-])=O HQWKKEIVHQXCPI-UHFFFAOYSA-L 0.000 description 1
- 238000004043 dyeing Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- RTZKZFJDLAIYFH-UHFFFAOYSA-N ether Substances CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 1
- 235000021323 fish oil Nutrition 0.000 description 1
- SLGWESQGEUXWJQ-UHFFFAOYSA-N formaldehyde;phenol Chemical compound O=C.OC1=CC=CC=C1 SLGWESQGEUXWJQ-UHFFFAOYSA-N 0.000 description 1
- 229920000578 graft copolymer Polymers 0.000 description 1
- 125000000623 heterocyclic group Chemical group 0.000 description 1
- 125000002768 hydroxyalkyl group Chemical group 0.000 description 1
- 238000002386 leaching Methods 0.000 description 1
- FPYJFEHAWHCUMM-UHFFFAOYSA-N maleic anhydride Chemical compound O=C1OC(=O)C=C1 FPYJFEHAWHCUMM-UHFFFAOYSA-N 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- FQPSGWSUVKBHSU-UHFFFAOYSA-N methacrylamide Chemical compound CC(=C)C(N)=O FQPSGWSUVKBHSU-UHFFFAOYSA-N 0.000 description 1
- 125000001570 methylene group Chemical group [H]C([H])([*:1])[*:2] 0.000 description 1
- 150000002772 monosaccharides Chemical class 0.000 description 1
- PSZYNBSKGUBXEH-UHFFFAOYSA-N naphthalene-1-sulfonic acid Chemical compound C1=CC=C2C(S(=O)(=O)O)=CC=CC2=C1 PSZYNBSKGUBXEH-UHFFFAOYSA-N 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 229920001542 oligosaccharide Polymers 0.000 description 1
- 150000002482 oligosaccharides Chemical class 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 230000036407 pain Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 150000007965 phenolic acids Chemical class 0.000 description 1
- 229920001568 phenolic resin Polymers 0.000 description 1
- 150000002989 phenols Chemical class 0.000 description 1
- 229940070721 polyacrylate Drugs 0.000 description 1
- 230000000379 polymerizing effect Effects 0.000 description 1
- 229920001282 polysaccharide Polymers 0.000 description 1
- 239000005017 polysaccharide Substances 0.000 description 1
- 150000004804 polysaccharides Chemical class 0.000 description 1
- 102000004169 proteins and genes Human genes 0.000 description 1
- 108090000623 proteins and genes Proteins 0.000 description 1
- 238000010526 radical polymerization reaction Methods 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 239000012260 resinous material Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 239000001509 sodium citrate Substances 0.000 description 1
- NLJMYIDDQXHKNR-UHFFFAOYSA-K sodium citrate Chemical compound O.O.[Na+].[Na+].[Na+].[O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O NLJMYIDDQXHKNR-UHFFFAOYSA-K 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 125000000446 sulfanediyl group Chemical group *S* 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 125000004434 sulfur atom Chemical group 0.000 description 1
- 231100000606 suspected carcinogen Toxicity 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 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
- C14C3/22—Chemical tanning by organic agents using polymerisation products
-
- 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
- C14C3/18—Chemical tanning by organic agents using polycondensation products or precursors thereof
- C14C3/20—Chemical tanning by organic agents using polycondensation products or precursors thereof sulfonated
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Treatment And Processing Of Natural Fur Or Leather (AREA)
Description
WO 2005/014865 PCT/IB2003/003592 A PROCESS FOR THE PREPARATION OF A SYNTHETIC TANNING AGENT Technical Filed The present invention relates to a process for the preparation of a synthetic tanning agent. More particularly the present invention provides a process for the preparation of a organo polymeric substance, which is free from formaldehyde, using for tanning leather. This polymeric substance has enormous potential application as pretanning as well as retanning agent in leather processing industry. Background Art Synthetic tanning agents are conventionally prepared by the condensation of naphthalene/phenol sulphonic acid or urea with formaldehyde as reported by Sharphouse (Leather Technicians Handbook, Vernon Lock Ltd., London, 1983). As reported by Stille and Campbell (High Polymer, 27, 14, 1972), the phenol formaldehyde condensed product, which is essentially a low molecular weight resinous material, has always a possibility of eliminating unreacted phenol or formaldehyde, thereby posing a risk of adding to toxicity. Denzinger et al (U.S. Patent 5,425,784, 1995) have prepared water-soluble graft polymers of monosaccharides, oligosaccharides, polysaccharides and derivatives with crotonic acid, maleic acid, maleic anhydride, fumaric acid, citraconic acid, citraconic anhydride, C 1 -Cs alkyl- and hydroxyalkyl esters of acrylic acid, methacrylic acid or crotonic acid, mono and di- C 1
-C
8 -alkyl and -hydroxyalkyl esters of maleic acid, fumaric acid and citraconic acid, acrylamide, methacrylamide, methacrolein, acrylamido-methylpropanesulfonic acid, N-vinylimidazole and mixtures, and used as a tanning agent for the self-tanning, pretanning, simultaneous tanning and retanning of pelts and skins. But these polymers do not produce leathers having fine grain, good fullness, affordable heat stability and uniform colour. Wehling et al (U.S. Patent 5,340,365, 1994) have used naphthalene sulphonic acid condensate in the 'production of chrome leathers. They have reported that this condensation product can be used for pretreatment of delimed and bated pelts. Even though the properties of the chrome tanned leathers do not differ from those of conventionally chrome tanned, the condensed product was prepared using formaldehyde, which on ageing may undergo photo oxidation and release formaldehyde which may pose occupational hazards (Suspected carcinogens: A sub life of the National Institute for Occupational Safety and Health (NIOSH) substances list, 2nd ed. Washington DC: US WO 2005/014865 PCT/IB2003/003592 2 Dept of Health, Education and Welfare NIOSH, 1976.). Moreover the developed chrome 5 tanning method is associated with release of chromium in the effluent beyond the stipulated limit (2 ppm as Cr) as reported by Buljan (World Leather, November, 65, 1996). Thus it is observed that even though the phenols and phenolic acid resins based on formaldehyde condensation have exhibited freedom of choice with respect to degree of 10 cross linking, molecular weight, particle size etc, the main limitations of using these polymeric condensates are the following. a) They considerably lighten the color and when the amount used is too large, it will lead to a rubber-like handle of the leather. b) The tanned leathers undergo photo oxidation due to the presence of active methylene bridge. c) Slow release of formaldehyde from the tanned leathers on ageing may pose hazardous environment. Current chrome tanning method poses severe problems due to its associated environmental problems. Industry has taken great pains to improve the chromium exhaustion. Prentiss and Sigafoos (Journal of American Leather Chemists Association, 70, 481, 1975) have reported that the use of poly acrylic and poly methacrylic acids in chrome tanning improves the chrome exhaustion. Lakshminarayana et al (Journal of the American Leather Chemists Association, 85, 425, 1990) recommends an acrylic acid based syntan as retanning agent for chrome tanned leathers, which is prepared by the graft co polymerization of acrylic ester and methacrylic acid onto a mixture of sulfated fish oil and alginic acid using free radical polymerization. But the major limitation associated with this product is that it leads to poor light fastness and heat resistance. Moreover, the acrylic syntans, which are generally attached to the protein through weak linkage, result in either low exhaustion in processing bath or more leaching out during subsequent wet operations. Christner et al (U.S. patent No 4,961,750, 1990) have reported the preparation of thio containing chromium poly acrylate tanning agents by complexing the chromium ion and an acrylate polymer together with a heterocycle containing nitrogen, oxygen, or sulfur atom, having a molecular weight between 200 and 30,000, which can be offered to pickled skins or hides. The main disadvantage in this tanning agent is the slow release of oxides of sulphur, which is carcinogenic. The above limitations have prompted the researchers to explore possibilities of incorporating metal ion onto a polymeric matrix to form a complex for using as tanning 3 salt. Keeping in mind the toxic hazards caused by formaldehyde, attempts have been made to prepare synthetic tanning agent, which is free from formaldehyde, as reported by Suresh et al (Journal of Cleaner Production, 9, 483, 2001) and Thanikaivelan et al (Journal of American Leather Chemists Association, 97, 127, 2002), who have also demonstrated the use of a synthetic tanning agent based on complexation of chromium with acrylic polymer and sulfonated aromatic condensates in the presence of organic ligands for self-tanning of delimed pelts and retanning applications. The use of this product result in improved exhaustion of chromium when applied on delimed pelts and hence reduces the total dissolved solids in the effluent. The major limiting feature here is that the preparation of the syntan involves employing chromium salt for complexation, thereby giving rise to the problem of toxicity associated with chrome. Objects of the invention The main objective of the present invention is to provide a process for the preparation of a synthetic tanning agent, which obviates the drawbacks as detailed above. It would be desirable to prepare a chromium exhaust aid, which can be offered to delimed pelts along with commercial BCS thus avoiding pickling process thereby reducing the total dissolved solids in the effluent. It would be further desirable to prepare a formaldehyde free polymeric network, which helps in preventing the precipitation of chromium at lower pH values. It would be yet further desirable to prepare a polymeric product, which can be used as a retanning agent and provides leathers with improved fullness, grain firmness with uniform dyeing. Description of the Invention Accordingly, the present invention provides a process for the preparation of synthetic organo-polymeric tanning agent essentially free from formaldehyde used for tanning leather, said process comprising the steps of: (a) reacting an aromatic compound with sulfuric acid at temperature in the range of 40 to 60*C to obtain sulfonized aromatic compound; (b) adding one or more organic ligands to the sulfonized aromatic compound obtained in step (a) and heating the mixture at temperature in the range of 60 to 80* C; 4 (c) adding one or more multi-functional polymers to the mixture of step (b) and heating the same at temperature in the range of 40 to 1000 C to obtain a reaction mixture; (d) adding water to the reaction mixture of step (c) and adjusting the pH .value of the same in the range of 3.0 to 3.5; and (e) optionally, aerating the reaction mixture and drying the reaction mixture of step (d) to obtain the synthetic organo-polymeric tanning agent. In an embodiment of the present invention wherein in step (a), the aromatic compound 20 used contains 1-14 carbon atoms. In another embodiment of the present invention wherein in step (a), the aromatic compound is reacted with sulfuric acid for a time period in the range of 50 to 250 minutes. In yet another embodiment of the present invention wherein in step (a), I to 5 moles of sulfuric acid is used per mole of aromatic compound. In still another embodiment of the present invention wherein in step (a), the aromatic compound used is selected from the group consisting of naphthene, anthracene, or phenol. In one more embodiment of the present invention wherein in step (b), the organic ligand used is selected from the group consisting of formic acid, citric acid, phthalic acid, salicylic acid, oxalic acid or their sodium salts ether individually or in combination. In one another embodiment of the present invention wherein in step (b), 0.01 to 0.1 mole of organic ligand is used per mole of the aromatic compound. In a further embodiment of the present invention wherein in step (c), the multi-functional polymer is selected from the group consisting of polyacrylic acid, methacrylic acid or mixture thereof. In an embodiment of the present invention wherein in step (c), 0.001 to 0.01 mole of multi-functional polymer is used per mole of the aromatic compound. In another embodiment of the present invention wherein in step (d), 5 to 25 moles of 10 water per mole of aromatic compound is added to the reaction mixture. In yet another embodiment of the present invention wherein in step (d), the pH of the reaction mixture is adjusted by adding sodium bicarbonate or by sodium hydroxide solution. In still another embodiment of the present invention wherein in step (e), the reaction mixture is aerated by passing air /inert gas through the same.
4a In one more embodiment of the present invention wherein in step (e), the reaction mixture is aerated for the time period in the range of 30 to 60 minute. In one another embodiment of the present invention wherein in step (e), the reaction mixture is dried either by drum drying or by spray drying.
WO 2005/014865 PCT/IB2003/003592 5 In a further embodiment of the present invention wherein in step (e), the reaction mixture is dried at temperature in the range of 130 to 260 0 C. In a further more embodiment o f the present invention wherein the synthetic organo polymeric tanning agent thus obtained has chromium exhaust in the range of 90 to 99 %. The process of the present invention is described below in detail. An aromatic compound having up to 14 carbon atoms is sulfonated by known method using 1 - 5 moles sulfuric acid per mole of aromatic compound for a period of not less than 90 min at a temperature in the range of 40 - 160'C. The temperature of the reaction mass is then adjusted in the range of 60 - 80 0 C and an aqueous mixture of 0.01 - 0.1 mole of organic ligand per mole of aromatic compound is added to the said mass. 0.0001 - 0.01 mole of multi functional polymer per mole of aromatic compound is then added to the said reaction mixture. Heating is allowed to continue for a period not less than 60 minutes at a temperature in the range of 60 - 80 0 C, pH of the resulting mixture is then adjusted at a range of 3.0 - 3.5 by known method to obtain the synthetic tanning agent in slurry form. The above slurry is subjected, as optional step, to aeration for a period of 30-60 minutes followed by conventional drying at a temperature in the range of 130 - 260'C to obtain the synthetic tanning agent in powder form. The novelty and non-obviousness of the present invention lies in polymerizing the multi functional polymer with sulfonated aromatic compound, pretreated with organic ligand, thereby forming an organo-polymeric matrix, free from formaldehyde, having potential application in leather industry for not only ensuring an eco-friendly approach in chrome tanning by way of eliminating the conventional pickling process and the resulting problem of total dissolved solids (TDS) associated with the effluent, but also suggesting an exhaust aid for chrome because of its multiple carboxyl groups, thereby ensuring an economical eco-benign approach for leather tanning. The invention is described in detail in the following examples, which are provided by way of illustrations only and therefore should not be construed to limit the scope of the present invention. Example 1 500 gms of naphthalene and 771 ml of concentrated sulfuric acid were taken into a 2 litre round bottom flask fitted with a stirrer. The contents of the flask were heated for 180 minutes at 40 0 C with constant stirring. A drop of the resulting mass was taken in a beaker and 2 ml of water was added to the beaker with shaking. A clear solution, without free WO 2005/014865 PCT/IB2003/003592 6 naphthalene smell was obtained. This confirms the completion of sulfonation. The sulfonated mass was transferred to a reactor fitted with a thermometer, stirrer and a dropping funnel. The mass was stirred continuously for a period of 10 min while maintaining the temperature at 60'C. A mixture of 14 gins sodium citrate, 17 gins phthalic acid, 11 gms sodium formate in 70 ml of water was added to the above sulfonated mass and stirring was continued at 60'C. 40 gins of polyacrylic acid was added to the sujphonic acid mixture and the mixture was heated to 80'C for 1 hour. A small portion of the reaction mixture was taken in a beaker and 2 ml water was added to the mass. The pH of the solution in the beaker was adjusted to 3.5 and a clear solution was obtained indicating the completion of the reaction. About 1400 ml of water was added to the mass and transferred to a bucket after cooling the reaction mass to room temperature. The pH of the mass was raised to 3.5 by adding a solution of 140 gins of sodium hydroxide in 350 ml water, followed by the addition of an aqueous solution of 350gms of sodium b icarbonate in 7 00 ml water. The s lurry was filtered using a cloth of pore size 5-1Ou. The filtrate was drum dried at 130 C and the white powder was stored in a plastic container. The product was offered to delimed goatskins at an offer of 1.5% along with 5% BCS at a float of 20%. The drum was run for 1 hr and 80% water was added. Running was continued for another hr and the penetration was assessed by checking uniform blue color along the cut section. The pH of the solution and the cut section was found to be 4.2. The bath was drained and the wet blue leathers were piled. Next day the leathers were post tanned using a conventional upper leather-processing recipe. The chromium exhaustion of the spent tan liquor was found to be 94%. The fullness of the crust leathers was found to be superior to that of conventional chrome tanned leathers. Example 2 534 gins of anthracene and 326 ml of concentrated sulfuric acid were taken in a 2 litre round bottom flask fitted with a stirrer. The contents of the flask were heated to 140'C for 90 minutes with continuous stirring, ml of the mass was taken in a beaker and 3 ml water was added with shaking. It was observed to forma clear solution without free naphthalene smell, confirming the completion of sulfonation. The sulfonated mass was transferred to a reactor fitted with a thermometer, stirrer and a dropping funnel. The mass was stirred continuously for a period of 10 min. while maintaining the temperature at 80'C. A mixture of 5.4 gms oxalic acid, 4.14 gins salicylic acid and 10 gins phthalic acid dissolved in 50 ml water was added to the above sulfonated mass and stirring was continued at 80'C.
WO 2005/014865 PCT/IB2003/003592 7 1.5 gins of poly methacrylic acid was added to the sulphonic acid mixture and the mixture was heated to 80 0 C for 1 hour. A small portion of the reaction mixture was taken in a beaker and 2 ml water was added to the mass. The pH of the solution in the beaker was adjusted to 3 and a clear solution was obtained indicating the- completion of the 30 reaction. About 540 ml of water was added to the mass and transferred to a bucket after cooling the reaction mass to room temperature. The pH of the mass was raised to 3 by adding a solution of 220 gms of sodium hydroxide in 500ml water, followed by the addition of an aqueous solution of 200 gins of sodium carbonate in 400ml water. The slurry was aerated for 45 minutes conventionally and filtered using a cloth of pore size 5 10pt. The filtrate was spray dried at 260'C and the white powder was stored in a plastic container. The prepared syntan was added to the delimed sheepskins at an offer of 1.0% along with 5% BCS at a float of 20%. The drum was run for 1 hr and 80% water was added. Running was continued for another hr and the penetration was assessed by checking uniform blue color along the cut section. The pH of the solution and the cut section was 10 found to be 4.4. The bath was drained and the wet blue leathers were piled. Next day the leathers were post tanned using a conventional garment leather processing recipe. The chromium exhaustion of the spent tan liquor was found to be 95%. The fullness of the crust leathers was found to be superior to that of conventional chrome tanned leathers. Example 3 94 gins of phenol and 54 ml of concentrated sulfuric acid were taken in a 250 ml round bottom flask fitted with a stirrer. The contents of the flask were heated to 80'C for 100 minutes with continuous stirring. 1 ml of the resulting mass was taken in a beaker and 3 ml water was added. On shaking, a clear solution was obtained confirming the completion of sulfonation. The sulfonated mass was transferred to a reactor fitted with a 20 thermometer, stirrer and a dropping funnel. The mass was stirred continuously for a period of 10 min while maintaining the temperature at 80*C. A mixture of 1.1 gm citric acid, 0.28 gin salicylic acid and 0.56 gins sodium phthalate dissolved in 10 ml of water was added to the above sulfonated mass and stirring was continued at 70'C. 20 gins of polyacrylic acid was added to the sulphonic acid mixture and the mixture was heated to 70*C for 1 hour. A small portion of the reaction mixture was taken in a beaker and 2 ml water was added to the mass. The pH of the solution in the beaker was adjusted to 3.5 and a clear solution was obtained indicating the completion of the reaction. About WO 2005/014865 PCT/IB2003/003592 8 90 ml of water was added to the mass and, transferred to a bucket after cooling the reaction mass to room temperature. The pH of the mass was raised to 3.5 by adding a solution of 40 gins of sodium carbonate dissolved in 100 ml water, followed by the addition of a solution of 20 gins sodium bicarbonate dissolved in 50 ml water. The slurry was filtered using a cloth of pore size 5-10u. The filtrate was spray dried at 260'C and the white powder was stored in a plastic container. The product was offered to delimed cow sides at an offer of 1.5% along with 8% BCS at a float of 20%. The drum was run for 2 hrs and 80% water was added. Running was continued for another 4 hrs and the penetration was assessed by checking uniform blue color along the cut section. The pH of the solution and the cut section was found to be 4.0. The bath was drained and the wet blue leathers were piled. Next day the leathers were post tanned using a conventional upper leather processing recipe. The chromium exhaustion of the spent tan liquor was found to be 92%. The fullness of the crust leathers was found to be superior to that of conventional chrome tanned leathers. Example 4 256 gms of naphthalene and 544 ml of concentrated sulfuric acid were taken in a 2 litre round bottom flask fitted with a stirrer. The contents of the flask were heated to 160'C for 90 minutes. 1 ml of the resulting m ass w as taken in a beaker and 2ml water was added to the mass with shaking. It was observed that the solution was clear indicating the completion of sulfonation. The sulfonated mass was transferred to a reactor fitted with a thermometer, stirrer and a dropping funnel. The mass was stirred continuously for a period of 10 min. while maintaining the temperature at 80 0 C. A mixture of 8.4 gins citric acid, 16.6 gms phthalic acid and 4 gms sodium formate dissolved in 50 ml water was added to the above sulfonated mass and stirring was continued at 80'C. A mixture of 20 gins poly methacrylic acid and 5 gins polyacrylic acid was added to the sulphonic acid mixture and the mixture was heated to 60'C for 1 hour. A small portion of the reaction mixture was taken in a beaker and 2 ml water was added to the mass. The pH of the solution in the beaker was adjusted to 3.5 and a clear solution was obtained indicating the completion of the reaction. About 900 ml of water was added to the mass and is transferred to a bucket after cooling the reaction mass to room temperature. The pH of the mass was raised to 3.5 by adding a solution of 100 gms of sodium hydroxide dissolved in 200 ml water, followed by the addition of a solution of 300 gms sodium bicarbonate dissolved in 600 ml water. The slurry was filtered using a cloth of pore size 5- 9 10[t. The filtrate was drum dried at 130*C and the white powder was stored in a plastic container. The product was offered to delimed buff calfs at an offer of 1.5% along with 8% BCS at a float of 20%. The drum was run for 2 hrs and 80% water was added. Running was continued for another 4 hrs and the penetration was assessed by checking uniform blue color along the cut section. The pH of the solution and the cut section was found to be 4.0. The bath was drained and the wet blue leathers were piled. Next day the leathers were post tanned using a conventional upper leather-processing recipe. The chromium exhaustion of the spent tan liquor was found to be 94%. The fullness of the crust leathers was found to be superior to that of conventional chrome tanned leathers. The following are the advantages of the present invention: 1. The process is very simple and does not require any complicated and critical control measures. 2. Cheaper and indigenously available starting materials are used for the preparation of the polymeric syntan ensuring its cost effectiveness. 3. The process results in a polymer which is free from the hazardous elements like formaldehyde and chromium. 4. The polymeric product is freely soluble in water and hence can be offered along with basic chromium sulfate on delimed pelts. 5. The process ensures no precipitation of chromium when it is offered on delimed pelts at a pH in the range of 8 - 8.5. 6. The process ensures high uptake of chromium when compared to normal wet blue process. 7. The polymer is incorporated with aromatic sulphonic acids to impart fullness to the tanned leathers. 8. This syntan enhances the chrome up take and no release of formaldehyde in the tan liquor ensuring an eco-friendly and economically viable tanning process. 9. The product produces wet blue leathers with required fullness apart from serving as chrome exhaust aid. 10. The product can be used a co-tanning agent along with BCS and as a retanning agent. 11. The shelf life of the product is about 5-2 years.
10 12. The tanned leathers do not undergo photo oxidation since it does not contain any active methylene groups in the system unlike in other condensed tanning agents. Comprises/comprising and grammatical variations thereof when.used in this specification are to be taken to specify the presence of stated features, integers, steps or components or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.
Claims (17)
1. A process for the preparation of synthetic organo-polymeric tanning agent essentially free from formaldehyde used for tanning leather, said process comprising the steps of: a) reacting an aromatic compound with sulfuric acid at temperature in the range of 40 to 60*C to obtain sulfonized aromatic compound; b) adding one or more organic ligands to the sulfonized aromatic compound obtained in step (a) and heating the mixture at temperature in the range of 60 to 80* C; c) adding one or more multi-functional polymers to the mixture of step (b) and heating the same at temperature in the range of 40 to 1000 C to obtain a reaction mixture; d) adding water to the reaction mixture of step (c) and adjusting the pH value of the same in the range of 3.0 to 3.5; and e) optionally, aerating the reaction mixture and drying the reaction mixture of step (d) to obtain the synthetic organo-polymeric tanning agent.
2. A process as claimed in claim 1 wherein in step (a), the aromatic compound used contains 1-14 carbon atoms.
3. A process as claimed in claim I wherein in step (a), the aromatic compound is reacted with sulfuric acid for a time period in the range of 50 to 250 minutes.
4. A process as claimed in claim 1 wherein in step (a), 1 to 5 moles of sulfuric acid is used per mole of aromatic compound.
5. A process as claimed in claim 1 wherein in step (a), the aromatic compound used is selected from the group consisting of naphthene, anthracene, or phenol.
6. A process as claimed in claim I wherein in step (b), the organic ligand used is selected from the group consisting of formic acid, citric acid, phthalic acid, salicylic acid, oxalic acid or their sodium salts either individually or in combination. 12
7. A process as claimed in claim I wherein in step. (b), 0.01 to 0.1 mole of organic ligand is used per mole of the aromatic compound.
8. A process as claimed in claim 1 wherein in step (c), the multi-functional polymer is selected from the group consisting of polyacrylic acid, methacrylic acid or mixture thereof.
9. A process as claimed in claim I wherein in step (c), 0.001 to 0.01 mole of multi functional polymer is used per mole of the aromatic compound.
10. A process as claimed in claim 1 wherein in step (d), 5 to 25 moles of water per mole of aromatic compound is added to the reaction mixture.
11. A process as claimed in claim 1 wherein in step (d), the pH of the reaction mixture is adjusted by adding sodium bicarbonate or by sodium hydroxide solution.
12. A process as claimed in claim 1 wherein in step (e), the reaction mixture is aerated by passing air /inert gas through the same.
13. A process as claimed in claim I wherein in step (e), the reaction mixture is aerated for the time period in the range of 30 to 60 minute.
14. A process as claimed in claim I wherein in step (e), the reaction mixture is dried either by drum drying or by spray drying.
15. A process as claimed in claim 1 wherein in step (e), the reaction mixture is dried at temperature in the range of 130 to 260*C.
16. A process as claimed in claim 1, wherein the synthetic organo-polymeric tanning agent thus obtained has chromium exhaust in the range of 90 to 99 %.
17. A process for the preparation of a synthetic organo-polymeric tanning agent substantially as hereinbefore described with reference to the Examples.
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PCT/IB2003/003592 WO2005014865A1 (en) | 2003-08-12 | 2003-08-12 | A process for the preparation of a synthetic tanning agent |
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EP (1) | EP1656460B1 (en) |
CN (1) | CN100535126C (en) |
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CN102260763B (en) * | 2011-06-23 | 2013-09-25 | 陕西科技大学 | Modified chitosan amphoteric polymer retanning agent and preparation method thereof |
CN103667544A (en) * | 2013-11-07 | 2014-03-26 | 齐河力厚化工有限公司 | High-absorption chrome tanning agent and preparation method thereof |
CN104450991B (en) * | 2014-09-26 | 2017-02-22 | 山东力厚轻工新材料有限公司 | No-pickling chromium powder and preparation method thereof |
CN107400738B (en) * | 2017-08-15 | 2019-09-10 | 陕西科技大学 | Both sexes phenols syntans and preparation method thereof |
CN107619890B (en) * | 2017-08-24 | 2020-09-29 | 南通市宏飞橡胶制品有限公司 | Composite tanning agent |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
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EP0428481A1 (en) * | 1989-11-13 | 1991-05-22 | Ciba-Geigy Ag | Method of treating leather and furs |
US5340365A (en) * | 1991-09-19 | 1994-08-23 | Bayer Aktiengesellschaft | Process for producing chrome leather |
WO1994026789A1 (en) * | 1993-05-17 | 1994-11-24 | Peach State Labs, Inc. | Polyacrylic acid compositions for textile processing |
-
2003
- 2003-08-12 CN CNB03827048XA patent/CN100535126C/en not_active Expired - Fee Related
- 2003-08-12 WO PCT/IB2003/003592 patent/WO2005014865A1/en active Application Filing
- 2003-08-12 AU AU2003250493A patent/AU2003250493B2/en not_active Ceased
- 2003-08-12 EP EP03817975A patent/EP1656460B1/en not_active Expired - Fee Related
- 2003-08-12 DE DE60327001T patent/DE60327001D1/en not_active Expired - Fee Related
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0428481A1 (en) * | 1989-11-13 | 1991-05-22 | Ciba-Geigy Ag | Method of treating leather and furs |
US5340365A (en) * | 1991-09-19 | 1994-08-23 | Bayer Aktiengesellschaft | Process for producing chrome leather |
WO1994026789A1 (en) * | 1993-05-17 | 1994-11-24 | Peach State Labs, Inc. | Polyacrylic acid compositions for textile processing |
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CN1839207A (en) | 2006-09-27 |
AU2003250493A1 (en) | 2005-02-25 |
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