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 the field of leather production, in particular an enzymatically assisted liming process wherein alkaline lipases are preferably used in combination with proteolytic enzymes.
• lipase and amylase in the form of pancreatin
• Hungarian Patent 3325 Chem. Abstr., 77, 7341k
• lipases for the degreasing of hides and skins, especially the high-fat pigskin and sheepskin and waste on.
• recommendations for use are in the Enffettung (eg LH Posorske J. Am Oil Chem Soc 61 (11) 1758-1760 (1984), K. Yeshodha et al Leather sci (Madras) 25 (2) 77 - 86 (1978 ), Chem. Abstr. 89, 199097, T. Nielsen Fette, Seifen, Anstrichm.
• Particularly suitable are derived from Aspergillus species and especially certain, genetically modified strains found, for example, an alkaline lipase from an Aspergillus oryzae strain obtained by recombination with a pronounced activity optimum between pH 9 and 11 and a labeled "LIPOLASE 100 T "commercially available lipase (NOVO INDUSTRI A / S, DK 2880 Bagsvaerd).
• the same company offers a similar lipase product for the enzymatic degreasing of hides and skins in the water workshop. It works exclusively degreasing eg in the stain or in the nachäscher. The simultaneous use of proteinases is not described.
• alkaline lipases AL for which a pH optimum at about 9-11, especially at 10 - 11 is characteristic, in the water workshop in the step of limewer in the pH range 11.5-14, in particular 12-13.5 , especially 12-13 in the aqueous liquor corresponding to this sub-step can be advantageously used simultaneously with alkaline proteinases.
• the effect is thus particularly pronounced when the said lipases are used in an enzyme combination EK together with neutral or alkaline proteases P.
• These are preferably the proteases used in the art. It has been shown that the enzyme combination EK shows a disproportionately good effect, which goes beyond the effect of the two individually applied enzyme species. It seems to be a synergistic effect of lipase and protease.
• the limber Under the limb is the well-known process of dermal swelling and loosening up to the removal of hair and awns under the influence of alkaline liming chemicals understood (see F. Stather, Gerschenemie and Gerbereitechnologie, pp 166-199, Akademie-Verlag 1967, Ullmann's Encyclopedia of Industrial Chemistry 5th Ed. Vol., A15, 259-282, VCH 1990).
• the limber may be hair-preserving or destructive to the hair.
• the liming is generally carried out in the pH range 12-13, either in the form of the so-called "Hydroxyläschers", where in particular calcium hydroxide in addition to alkali hydroxide, ammonia and other alkaline earth metal hydroxides is used, or in the form of the so-called Sulfidäschers whose active ingredients alkali or alkaline earth sulfides optionally in mixture with other basic alkalis or alkaline earths.
• the ashing process according to the invention follows very closely the processes of the prior art (Ullmann's Encyclopedia of Industrial Chemistry 5th Ed. Vol. 15A, pp. 259-282, VCH (1990); Ullmanns Enzyklopadie der Techn. Chemie, 4th ed.
• the operation of the limer can be carried out according to the invention with a liquor length of 50 to 250, preferably from 80 to 150% of water based on the weight of the skins.
• the limping process takes 12 to 36 hours, especially 16 to 20 hours to complete.
• the skins and skins are neutralized or enzymatically treated.
• the skins or skins are first washed and preferably by means of weak acids, for example organic acids such as lactic acid, formic acid, acetic acid, butyric acid, propionic acid, or dicarboxylic acids and the like. or weakly acidic inorganic compounds such as sodium bisulfite, sulfophthalic acid, ammonium sulfate or carbonic acid.
• weak acids for example organic acids such as lactic acid, formic acid, acetic acid, butyric acid, propionic acid, or dicarboxylic acids and the like.
• weakly acidic inorganic compounds such as sodium bisulfite, sulfophthalic acid, ammonium sulfate or carbonic acid.
• the subsequent stain is used to remove epidermis and hair residues and for additional skin disruption.
• the enzymatic pickling component in particular enzymes of the pancreatic complex
• the enzymes of the pancreatic complex may also include lipases (DE-A 37 04 465).
• the pickling temperature the range between 32 and 37 degrees C has proved to be useful.
• the pickling period generally lasts in the range of 1 hour to 3 hours.
• the enzymatic approaches, especially those carried out with the enzyme combination EK are still known sequestering agents SM in order to avoid lime soaps.
• the addition of emulsifying substances ES has proven that leads to particularly good fat emulsification.
• the length of the fleece corresponds to that during the operation of the limer.
• the lipases to be used according to the invention are esterases which hydrolyze glycerol esters of the fatty acid in aqueous emulsion (EC 3.1.1.3.).
• the cleavage of the triglycerides takes place in the 1,3-position.
• the lipases used according to the invention have a pronounced optimum of action (for example compared with olive oil) between pH 9 and 11.
• Such alkaline lipases have been developed especially for the detergent industry. They are of microbiological origin. Potential sources of such, optionally genetically modified microorganism strains are, in particular, fungi and bacteria.
• Certain alkaline lipases occur, for example, in Pseudomonas strains.
• Rhizopus sp. Candida sp., Chromobacterium sp. as lipase suppliers in question.
• Other important lipase producers are Geotrichium sp., Aspergillus sp., Mucor sp., Penicillium sp., Corynebacterium sp., Propionibacterium sp. and Achromobacter sp.
• Rhizopus arrhizus and Rh are Rhizopus arrhizus and Rh.
• Candida cyclindracea Chromobacterium viscosum, Geotrichium candidum, Mucor miehi, Mucor pusillus, Penicillium roqueferti and P. cyclopium, Corynebacterium acne, Propionibacterium shermanii, Achromobacter lipolyticum, Aspergillus niger, in particular Aspergillus oryzae.
• Certain genetically modified strains have also been found to be particularly suitable, for example an alkaline lipase from a recombinant Aspergillus oryzae strain having a pronounced activity optimum between pH 9 and 11, or a lipase commercially available under the name R Lipolase TM 30 T (NOVO INDUSTRI A / S, DK 2880 Bagsvaerd, Denmark).
• lipase activity is reported in LCA units, but measured at pH 9.5. According to the invention, the lipases are used so that at pH 9.5 in the liquor a lipase activity of 100-10,000 LCA, preferably 2000-4000 LCA per kg of skin is present.
• proteases in liming, which develop a sufficient proteolytic activity in the pH range between 9 and 13, is known per se. These are neutral (EC3.4.24) and in particular alkaline proteases (EC3.4.21) [cf. Kirk-Othmer, 3rd. Ed. pp. 199-202, J. Wiley 1990; Ullmann's Encyclopedia of Industrial Chemistry, Vol., A9, pp. 409-414, VCH 1987, L. Keay in "Process Biochemistry 17-21 (1971)].
• Alkaline proteases which develop their optimum effect in the range of pH 8.5 - 13, for example. These include alkaline bacterial proteases, which mostly belong to the serine type and alkaline fungal proteases.
• proteases from Bacillus strains such as B. subtilis, B. licheniformis, B. firmus, B. alcalophilus, B. polymixa, B. mesentericus, and also Streptomyces strains such as S. alcalophilus
• Bacillus strains such as B. subtilis, B. licheniformis, B. firmus, B. alcalophilus, B. polymixa, B. mesentericus, and also Streptomyces strains such as S. alcalophilus
• the most favorable working temperature with alkaline bacterial proteases is generally 40-60 degrees C, in alkaline mushroom proteases rather at 20-40 degrees C.
• alkaline fungal proteases may be mentioned, those from Aspergillus strains such as A. oryzae, from penicillin strains such as P. cyanofulvum or from Paecilomyces persicinus u.ä.
• the activity of the alkaline Fungal proteases are predominantly in the pH range 8.0-11.0. Frequently, the enzyme activity is adjusted to 8,000 to 10,000 Lohlein-Volhard units [LVE] per gram of enzyme.
• the proteolytic activity of the enzymes is commonly determined by the Anson-Haemoglobin method [ML Anson, J. Gen. Physiol, 22, 79 (1939)] or by the Löhlein-Volhard method [modified according to TEGEWA in Leder 22, 121-126 (1971)]. This corresponds to one Löhlein-Volhard unit (LVE) under the assay conditions (one hour, 37 degrees C) of an amount of enzyme which in 20 ml of casein filtrate causes an increase in hydrolysis product equivalent to 5.75 x 10 -3 ml of 0.1 N NaOH causes.
• the use activity of the protease is generally between 1 000 and 60 000 LU per kg of skin, preferably between 2 000 and 14 000 LU per kg of skin.
• protease amounts between 0.05 to 0.8 wt .-%, as a rule of thumb about 0.1 to 0.25 wt .-% based on the weight of the hides and skins used.
• the dosage of the product is usually in the range of 0.05-1% with respect to the salt weight or fresh weight of the skins.
• the guide value for the fleet length is 150 ⁇ 50%.
• the temperature is preferably 28 degrees C.
• the ash broth contains relatively low levels of liming chemicals, typically sodium sulphohydrate (72%) - as a guideline about 0.6% by weight - and sodium sulphide (60%) As a guideline about 0.2% by weight, as well as hydrated lime, as a guideline about 1.5% by weight, based on the hides, at a pH of 12.8.
• sulfide for example, 0.4 wt .-% sodium sulfide (72%) based on the hides.
• the skins After a relatively short time, for example about 2 hours, the skins are hair-free.
• the liquor is then drained off and further processing is continued in a customary manner.
• the limping process can be followed, for example, by the defloration and splitting of the skins.
• the next processing step is deliming.
• skin material eg entflete and split pelts is in usually washed first in the usual way and then treated with decalcifying agent (see above).
• decalcifying agent see above.
• enzyme combinations EK of the following typical composition are used for stain application: 50 - 1 000 KLVE Pancreatic enzyme complex 0.5-5% by weight alkaline lipase with the activity of 5,000 LU / mg 1.0-30% by weight Na tripolyphosphate ad. 100% by weight Na sulfate or ammonium sulfate
• This enzyme combination which in the composition corresponds approximately to the product according to the invention, can at 30-35 degrees C during 20 to 120 minutes at 0.5 to 2% based on the pelt weight after deliming.
• the product according to the invention is usable not only in the liming, but also in the stain. It is expedient for about 1 hour at 33 degrees C is moved, the pH is about 8 - 8.5. The liquor is then drained and usually washed with about 200% water at about 22 degrees C and with agitation. This can be followed by pimples and chrome tanning in the usual way.
• Decalcifier based on ammonium sulfate / dicarboxylic acids
• tanning drum
• tanning drum
• the treatment with the enzyme product according to the invention makes it possible to dispense with the post-scrubber.
• the skin digestion is optimal after 16 - 18 hours of processing time.

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

Applications Claiming Priority (2)

Publications (2)

Family

ID=6428184

Family Applications (1)

Country Status (16)

Families Citing this family (11)

Family Cites Families (4)

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

Also Published As

Similar Documents

Legal Events