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
  • C14C1/00—Chemical treatment prior to tanning
  • C14C1/08—Deliming; Bating; Pickling; Degreasing

Definitions

• the invention relates to enzymatically assisted liming and pickling processes using alkaline lipases, preferably in combination with proteolytic enzymes.
• lipase and amylase in the form of pancreatin
• Hungarian patent 3325 Chem. Abstr. 77, 7341 k
• lipases offers itself for degreasing hides and skins, especially the high-fat pigskins and sheepskins and waste.
• there are recommendations for use in degreasing e.g. LH Posorske J. Am. Oil Chem.Soc. 61 (11) 1758 - 1760 (1984); K. Yeshodha et al. Leather sei (Madras) 25 (2) 77 - 86 (1978 ), Chem. Abstr. 89, 199097; T. Nielsen Fette, Seifen, Anstrichm. 82 (1) 15 - 19 (1985) also have negative experiences, eg with pickled and
• Literature reference is made to enzymatic fat degradation by means of lipases or lipase-containing enzyme preparations in a pH range below 8, preferably in the moderately acidic pH range.
• the stain also prepares fat-rich nakedness
• alkaline lipases AL have a pH optimum at about 9-11.
• the effect is particularly pronounced when the lipases mentioned are used in an enzyme combination EK together with neutral or alkaline proteases P, which are selected according to the substep in question. These are preferably the proteases used in technology.
• the liming is in the generally carried out in the pH range 12-13, either in the form of the so-called "hydroxyl ash", where calcium hydroxide in particular is used in addition to alkali hydroxide, ammonia and other alkaline earth hydroxides, or in the form of the so-called sulfide ash, the active components of which are alkali metal or alkaline earth metal sulfides, optionally in a mixture with others are basic alkalis or alkaline earths.
• the liming process according to the invention very largely follows the processes of the prior art (Ullmann's Encyclopedia of Industrial Chemistry 5th Ed. Vol.
• the liming operation can be carried out with a liquor length of 50-250%, preferably 80-150%.
• Water based on the weight of the skins can be carried out.
• the liming process generally takes 12 to 36 hours, in particular 16 to 20 hours.
• the hides and skins are neutralized and enzymatically ashed.
• the hides or skins are first washed and preferably using weak acids, for example organic acids such as lactic acid, formic acid,
• weakly acidic inorganic compounds such as sodium bisulfite, sulfophthalic acid, ammonium sulfate or carbonic acid.
• the enzymatic pickling component in particular enzymes of the pancreatic complex, is added after a certain time.
• Enzymes of the pancreatic complex can also include lipases (DE-A 37 04 465). The range between 32 and 37 degrees C has proven to be expedient for the pickling temperature.
• the pickling time is generally in the
• the enzymatic batches in particular the sequestering agents SM known per se with the enzyme combination EK, contain in advance for the purpose
• the liquor length corresponds to that when the liming is carried out.
• the lipases to be used according to the invention are those having the same definitions.
• Esterases which hydrolyze glycerol esters of fatty acid in aqueous emulsion (E.C. 3.1.1.3.).
• the triglycerides are preferably cleaved in the 1,3 position. In contrast to the lipases of the
• the lipases used according to the invention have a state of the art with a range of use of pH 6-9 pronounced optimum effect (eg against olive oil or tributyrin) between pH 9 and 11.
• Such alkaline lipases have been specially developed for the detergent industry. They are of microbiological origin.
• Lipases come e.g. in Pseudomonas strains. Rhizopus sp., Candida sp., Chromobacterium sp. as a lipase supplier. Other important lipase producers are Geotrichium sp., Aspergillus sp., Mucor sp., Penicillium sp., Corynebacterium sp.,
• Lipolase TM 30 T commercially available lipase (NOVO INDUSTRI A / S, DK 2880 Bagsvaerd, Denmark).
• the activity determination of lipases is carried out in a conventional manner with olive oil as a substrate, furthermore with triacetin and tributyrin. [See. M. Semeriva et al.
• Lipase activity is given in LCA units, but is measured at pH 9.5. According to the
• Lipases used in such a way that a lipase activity of 100-10,000 LCA, preferably 2,000 to 4,000 LCA per kg skin is present in the liquor at pH 9.5.
• proteases in the liming, which is in the pH range between 9 and 13 a sufficient proteolytic enzyme
• Alkaline proteases that develop their optimum activity in the pH range 8.5 - 13. This includes
• alkaline bacterial proteases which mostly belong to the serine type and alkaline fungal proteases.
• the proteases from Bacillus strains such as B.subtilis, B.licheniformis, B.firmus,
• B.alcalophilus B.polymixa, B.mesentericus, further Streptomyces strains such as S.alcalophilus.
• Bacterial proteases are generally at 40-60 degrees C, with fungal proteases more at 20-40 degrees C.
• Alkaline fungal proteases include those from Aspergillus strains such as A. oryzae
• Paecilomyces persicinus and others The activity of the alkaline fungal proteases is predominantly in the pH range 8.0 - 11.0. As a rule of thumb, enzyme activity can be assumed to be between 8,000 and 10,000 Löhlein-Volhard units [LVE] per gram of enzyme.
• Neutral proteases with optimal activity in the range of pH 6.0 - 9.0 include in particular neutral bacterial proteases, which are usually among the
• Neutral bacterial proteases develop their activity optimally at working temperatures of 20 - 50 degrees C, whereas the most favorable working temperature for neutral fungal proteases is 35 - 40 degrees C.
• LVE Löhlein-Volhard unit
• protease activity is in the
• the process according to the invention usually requires amounts of proteases between 0.05 and 0.8% by weight, as a rule of thumb about 0.1-0.25% by weight, based on the weight of the hides and skins used.
• Emulsifiers for example of the following types:
• anionic emulsifiers for example of the following types:
• Cationic emulsifiers are less advantageous e.g. of types:
• radical R above is a long-chain alkyl radical with 8-24 carbon atoms
• radicals R 1 , R 2 or R 3 are generally short-chain alkyl radicals with up to 6 carbon atoms.
• the emulsifiers which can be used according to the invention have an HLB value (O / W emulsion) of 8-18, preferably 9-15, especially 12-15 (cf. Ullmanns Encyklopadie der Techn. Chemie, 4th edition, vol. 19). Combinations of emulsifiers, in particular nonionic and anionic ones, can advantageously also be used
• the amount of emulsifiers in the liquors is - in
• the precipitations to be expected according to the above composition occur when using the
• the sequestering agents are selected from the group consisting of the polyphosphates, phosphonates,
• EDTA ethylenediaminetetraacetic acid
• Nitrilotriacetic acid diethylenetriamineopentaacetic acid.
• the content of the sequestering agents in the soft liquor can be 0 to 0.5% by weight, preferably 0.05 to 0.15% by weight.
• the lipases used correspond to the label given above, as do the proteases. Ashtray process
• the dosage of the product is usually in the range of 0.05-1% in terms of salt weight or fresh weight of the skins.
• the temperature is preferably
• the skins or skins are soft as usual. It was
• the switch is followed by a hair immunization step in which - based on DE-A 38 02 640 - lime hydrate and organic thio compounds together with amines in approximately 80% water at approximately pH 12 can be used. This is usually followed by a level of hair loosening.
• a greatly reduced amount of sulfide is used, for example 0.4% by weight sodium sulfhydrate (72%) based on the skins.
• the skins are hair-free for about 2 hours. It is advisable to add about 70% by weight of water together with about 2% by weight of lime hydrate and approx. 0.3% by weight of sodium hydroxide solution (50%) and leaves for a certain period of time, expediently approx. 14 hours at 28 degrees C with intervals,
• the skin material prepared in the usual way e.g.
• Fleshed and split pelts are usually first washed and descaled in the usual way (see above).
• about the same amount of water is again added, preferably at 35 ° C., and the enzymes are preferably added as an enzyme combination EK.
• Enzyme combinations EK of the following typical composition are generally used: 50 - 1 00 KLVE pancreatic enzyme complex
• the product according to the invention is at 30-35 degrees C for 20-120 minutes at 0.5-2% based on the
• the manufacturer's specifications are in the pH range 10 - 11, both under the conditions of the liming at a pH of approx. 13 and in the stain in the pH range 7 - 9
• alkaline lipase ® Lipolase 100 T NOVO
• Emulsifier combination ES
• Fat content in the nakedness 0.25% in terms of dry weight
• Tanning drum (details refer to weight)
• nonionic emulsifier based on C 13 fatty alcohol with 8 moles of ethylene oxide

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• 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)
• Cosmetics (AREA)
• Preparation Of Compounds By Using Micro-Organisms (AREA)
• Immobilizing And Processing Of Enzymes And Microorganisms (AREA)
• Enzymes And Modification Thereof (AREA)
• Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
• Materials For Medical Uses (AREA)

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• 1991
  • 1991-03-26 CZ CS923435A patent/CZ285164B6/cs not_active IP Right Cessation
  • 1991-03-26 DE DE4109826A patent/DE4109826A1/de not_active Withdrawn
• 1992
  • 1992-03-19 ES ES92104751T patent/ES2103845T3/es not_active Expired - Lifetime
  • 1992-03-19 HU HU9203708A patent/HU217020B/hu not_active IP Right Cessation
  • 1992-03-19 SK SK3435-92A patent/SK277863B6/sk unknown
  • 1992-03-19 PL PL92297166A patent/PL168197B1/pl unknown
  • 1992-03-19 BR BR9204797A patent/BR9204797A/pt not_active IP Right Cessation
  • 1992-03-19 JP JP92506477A patent/JPH05507522A/ja active Pending
  • 1992-03-19 AU AU14247/92A patent/AU645412B2/en not_active Ceased
  • 1992-03-19 DE DE59208598T patent/DE59208598D1/de not_active Expired - Lifetime
  • 1992-03-19 WO PCT/DE1992/000233 patent/WO1992017613A1/de not_active Ceased
  • 1992-03-19 EP EP92104751A patent/EP0505920B1/de not_active Expired - Lifetime
  • 1992-03-19 AT AT92104751T patent/ATE154396T1/de not_active IP Right Cessation
  • 1992-03-19 RU RU9292016365A patent/RU2052506C1/ru active
  • 1992-03-26 ZA ZA922207A patent/ZA922207B/xx unknown
  • 1992-03-26 TW TW081102326A patent/TW203102B/zh active
  • 1992-11-25 KR KR1019920702971A patent/KR100201731B1/ko not_active Expired - Fee Related

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