JPH07502059A - Method for tanning leather with tanning agents - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Method for tanning leather with a tanning agent gent).

Most used tanning agents are chromium-based; -based tanning agents are environmentally undesirable and therefore alternative tanning agents are environmentally undesirable. Suitable ones are always welcome.

Achieving immobilization of tanning agents within collagen matrices in the tanning industry However, since the quality of the leather improves with increasing degree of fixation, and also The reason why contamination would decrease with increasing degree of fixation and uptake of tanning agents. This goal is based on both facts. By the way, the damage caused by tanning agents Prior art methods for fixing have left unresolved issues regarding improvements in the degree of fixation. ing.

Therefore, the object of the present invention is to provide a method for tanning leather with a tanning agent, In this connection, the degree of fixation and incorporation of tanning agents is determined by prior art methods of this type. considerably increased compared to.

Now, surprisingly, according to the present invention, if tanning is carried out in a tanning tank (tannin), g bath), if it is assisted by an enzyme belonging to a specific enzyme category, the If specific primary and secondary substrates for this enzyme are added in sequence, this species It is possible to significantly increase the degree of fixation compared to prior art methods of Found out.

Therefore, the present invention relates to the tanning of leather with a tanning agent in a tanning bath. The method is that in addition to the skin, the tank contains oxidoreductase and aroma as a tanning agent. compounds and possibly their ability to react with this skin and/or this aroma compound. containing other compounds and also introducing an oxidizing agent into the equilibration tanning bath. It is characterized by

A further advantage of the present invention is that a toxic aid for use in the crosslinking of organic tanning agents is provided. The fact is that the use of agents (eg formaldehyde) is avoided. Furthermore, the present invention environmentally friendly, because the commonly used timber produced by extraction of timber from tropical forests is This is because an inexpensive synthetic tanning agent can be used instead of a tanning agent.

U.S. No. 3.212.996 describes a method for the enzymatic modification of organic tanning agents. ing. This prior art process uses the same enzymes and and the same organic tanning agent, but the modified type in this prior art method The tanning agent is produced independently of the leather, while the method according to the invention A modified tanning agent is produced in situ on the leather.

Based on this in-situ process, the degree of fixation of the modified tanning agent is lower than that of conventional technology. The method according to the present invention is superior to the conventional method.

rEnzyme Nomenclature 1984. Academic press, Inc., New York.

The oxidoreductase defined and explained in Londo belongs to a class of enzymes that catalyze the transport of electrons from one substance to another (oxidation-reduction) . These include dehydrogenases, reductases, oxidases, and transhydrogenases. These include enzymes, peroxidases, and oxygenases. Specific examples include Western Horseradish peroxidase, ligninase and other peroxidases, e.g. Chloroperoxidase and lactoperoxidase, and oxidases, e.g. Examples include laccase and tyrosinase. These enzymes are of microbial origin It is preferable that

Examples of microorganisms that can be used for the production of suitable oxidoreductases include: Trametes, Rhizoctonia, Pseudomonas (Pseu+Jomonas), Bacillus (Bacillus) ), Streptomysis (Sjreptoa+yces), Biclophorus ( Hygrophorus), Coprinus, Polyporus (Polyporus), Candida (Candida), Curbularia (Cu rvuiaria) and Cercospora. but However, the present invention is not limited to enzymes derived from the above taxonomic groups. have the desired properties All microorganisms that produce oxidoreductase may be used in connection with the present invention. sell.

The primary substrate for oxidoreductase is an aromatic compound, preferably phenol. and is a vegetable or synthetic tan or tanning agent. Usually from plant material An example of vegetable tongue, which is an extracted polyphenol compound, is catecholtan (or Commonly known as condensed tan) and pyrogallolkun (or hydrolysable tan), they are Part 3゜Tanning Processes, Lealher Tec hnician's 1landbook, J, 11.5parpho floating tang■ (Ed), Lcalhcr Producers As5oc, King s Park Road, Moullon r’arkNorthampton on, NN 31 JD, 1989. Examples of synthetic tan include: Limited (but not limited to) ■ or more than one of the following functional groups, i.e. -halogen, - OH, -3O, H-, -COOH, -NN2, -QC)1. , or aryl, Alkyl, alkene, which may be substituted with the above substituents mono- or oligomeric aromatic or aliphatic compounds optionally substituted with groups included. Further compounds that can be used as tanning agents include the same functional groups as above. Includes heterocyclic and aliphatic compounds with Oxide reductor in the present invention Specific examples of aromatic compounds that can serve as primary substrates for Aniline, tyrosine, catenine, aromatic amino acids and their derivatives, pyrogallo gallic acid, ferulic acid, 2-methyl-l naphthol, 2,6-disubstituted mono Fer, guaiacol, coniferyl alcohol, protocatechuic acid, reso Rucinol, hydroquinone, m-cresol caffeic acid, p-fumaric acid, anisyl syringaldazine and syringaldehyde.

The oxidant, which is the second substrate for oxidoreductase, is If the tase is a peroxidase, use hydrogen peroxide, methyl peroxide, or ethyl peroxide. Possibly, and if oxidoreductase is an oxidase, it is oxygen.

In the last mentioned case, the hide and tanning bath contains oxidase and tanning agents. Acid-free to prevent uncontrolled polymerization prior to sufficient penetration into the skin matrix Keep it under normal conditions.

In an equilibration tanner, oxidases and tanning agents are present in the hide matrix. permeates to such an extent that an equilibrium state has been reached.

In the leather industry, several leather processing processes are involved, as evident from the table below. Enzymes are traditionally used.

By the way, as far as the applicant knows, the introduction of enzyme treatment during tanning does not belong to the prior art. Therefore, it represents a pioneering achievement.

However, peroxidases and oxidases are involved in a wide variety of oxidative polymerization of nol-based compounds (e.g., U.S. Pat. No. 4,900. 671 and 4.647.952), This heavy reliance belongs to the prior art.

In addition, oxidase and peroxidase catalysts including phenol group intervening The reaction may be carried out in both aqueous and solvent-based systems, provided that the organic solvent is water-miscible. However, it also belongs to the prior art that it may be water immiscible.

In the method according to the present invention, a tanning agent and oxidoreductase are first applied to the skin separately. It is carried out by application as a solution or as a mixture. collagen ma Once a homogeneous dispersion of the enzyme and tanning agent in the trix is obtained, the next step is to add the oxidizing agent. Polymerization is initiated by adding

When using an oxidase substrate, the enzyme and possible solvent are transferred into the skin matrix. Before sufficient penetration of this oxidoreductase/tanning agent is achieved, Contact with the peel is made under anoxic conditions to prevent any further polymerization from occurring. use depending on the type of substrate and oxidoreductase used and the desired characteristics of the skin. , the polymerization process is carried out in a purely aqueous system or in a solvent system, where the solvent is water-miscible. It may be either miscible or immiscible with water. When using a water-containing system, its pt+ is always buffers (e.g. phosphoric acid, carbonate/bicarbonate, tartaric acid, carbonate or acetate buffers) -) may be used for adjustment. Polymerization process metered addition of peroxide or oxygen Further adjustment may be made by

Enzymatic reactions involve careful metering of the oxidizing agent by chemical or thermal inactivation of the enzyme. or in cases where peroxidase is used, e.g. This can be stopped by adding enzyme.

The enzymatic reaction may be carried out at room temperature, but temperatures between 0 and 95°C can also be used, but However, most enzymes will not work well at temperatures above about 60-70°C. cormorant. The pH range for this process will be 2-11 depending on the enzyme used. Professional Process conditions include relative concentrations of organic and inorganic substrates, polarity and concentration of solvent, enzyme concentration, etc. It can be further optimized by changing .

Peroxidases and oxidases are known to exhibit broad substrate specificity, and therefore The present invention achieves the following by enabling the use of new and improved tanning agents. Enables a “TaylorMate” (special) process for rice. Therefore, new conventional and/or additional functional groups (e.g. positively or negatively charged substituents). In addition to known or unknown tanning agents, water retention, shrinkage temperature, or collagen The support, such as the degree of fixation within the matrix, can be improved.

A preferred embodiment of the method according to the present invention is that the oxidoreductase is a peroxidase. and the tanning agent is a synthetic or vegetable aromatic tanning agent. Ru. In this way, high quality leather, especially leather with a high shrinkage temperature, is produced. It can be built.

In a preferred embodiment of the present invention, the oxidoreductase is an oxidase, The tanning agent is a synthetic or vegetable aromatic tanning agent. This person According to the law, high-quality leather, especially leather with a high shrinkage temperature, can be manufactured and .

A preferred embodiment of the method according to the present invention is that the oxidoreductase is Polyporus pinsitus (Trametes villosa) Trametes villosa): characterized by higher productivity Ru.

In this method, commercially available and inexpensive oxidoreductase can be used. I can do it.

A preferred embodiment of the method according to the present invention is that the oxidoreductase is produced by polyporus. It is characterized by being a highly productive laccase.

In this method, commercially available and inexpensive oxidoreductase can be used. I can do it.

In a preferred embodiment of the method according to the present invention, the oxidoreductase is Coprinus cinereus is characterized by its productivity shall be. In this method, commercially available and inexpensive oxidoreductase can be used. It could be possible.

A preferred embodiment of the method according to the present invention is that the oxidoreductase is It is a peroxidase that is produced by Trametes villosa. It is characterized by. In this method (1) a commercially available and inexpensive oxidoreductor It may become possible to use ze.

A preferred embodiment of the method according to the invention is characterized in that the tanned cypress is water-based. . In this method, tanning can be carried out in environmentally friendly conditions.

A preferred embodiment of the method according to the present invention is characterized in that the tanning tank is organic. Ru. In this way, an improved polymerization, an improved degree of fixation is obtained. sell.

A preferred embodiment of the method according to the present invention is that the pH of the tanning tank is 2 to 2, preferably 2 to 2. It is characterized by being 8. Within such a pH interval, the enzyme exhibits satisfactory activity. , therefore a satisfactory degree of fixation (1 can be obtained).

The invention is illustrated by the following examples.

Example 1 Extracted from the official inspection area IUC/2 or IUP/2, respectively, and 10 pieces of leather each measuring 1cm x 6cm are 0. All-purpose IM bag in a mixture of 100 ml of a solution of 2 mM catechol in fur, pH 5.5. Introduced. This mixture was stirred at room temperature for 2 hours. Next, 100ml of laccase (235 PODU/ml) was added. This ligase is Polyporus pinsi Produced by Russ, Novo Nordisk A/S, Novo A11e .

DK-2880Bagsvaerd, available on request from Denmark Product sheet 5P504. Please refer to Be2O-GB50. P.O. [1Ui-! Defined in AF279/2-GB, but hydrogen peroxide is without addition, and) Kutufa is sodium acetate (I) H7 at pH 5 O, IN. A laccase active unit with 0.1M glue I acid (replacement of sofa) It is. This mixture was stirred on a magnetic starter at room temperature for about 2.5 days. , then set the shrinkage temperature to Messung der Schrumpfungste. +nperatur, Bib1iothek desLeders, Volume 1θ , pp. 157-154, Joachim Lange, 1982. l1m5c It was measured according to the method described in Hau Verlag. During stirring, the oxidizing agent Oxygen was used.

In a control experiment, 10 pieces of leather were mixed with 0.1M all-purpose solution at pH 5.5. 100+ nl of a solution of 2mM catechol in buffer and 0.1M all purpose buffer was introduced into a mixture with 100 ml of air. Measure the shrinkage temperature of this mixture. The mixture was stirred on a magnetic stirrer for about 2.5 days.

The contraction temperature is: 58°C in control experiments; and 66°C in experiments with enzymes. there were.

It has been shown that a higher degree of immobilization results in higher shrinkage temperatures.

The value of the parameter not shown in Examples 2 to 4 is the value shown in Example 1. is the same as

Example 2 10 pieces of leather each having dimensions of l em x 6 c1n were Mixing of a solution of 100 ml of 2+nM phenol in functional buffer pt15.5 The material was introduced into 100ml of water. This mixture was stirred at room temperature for 2 hours. Then 100m 1 of laccase (235 PODU/m) was added. The mixture was magnetically Stir overnight on a scoiler at room temperature, after which time the shrinkage temperature was measured.

In a control experiment, 10 pieces of leather were mixed in 0.1 M universal buffer pH 5. , 100 ml of a solution of 2 mM phenol in 0.1 M universal buffer p) 15.5 was added to the mixture with 100ml. Add this mixture to the magnetic cooler. - for about 2 hours before measuring the shrinkage temperature.

The contraction temperature is 58°C for control experiments and 62°C for experiments with enzymes. there were.

Example 3 Stock solution of Insulin AT™ Lignin (from Westwaco) was made as follows. 0.1M all-purpose buffer pi (craft resource in 5.5) The gunin suspension was heated at 80°C for 15 minutes, then centrifuged and filtered to create a Kraft reagent. Only the soluble part of gunin was used. p) Solubility at 15.5 is 5.5 mg/ml Met.

10 pieces of leather each measuring 1cm x 6cm are placed in a 100m1 space. introduced into the tok solution. This mixture was stirred at room temperature for 2 hours. Then +00o+ 1 of laccase (235 PODU/ml) was added. Stir this mixture overnight at room temperature. After stirring, the shrinkage temperature was measured.

In a control experiment, 10 pieces of leather were mixed with 100 ml of stock solution and 10 0m1 of 0. IM universal buffer p) 15.5 was introduced into the solution mixture.

The mixture was placed on a magnetic scooter for approximately 20 hours before measuring the shrinkage temperature. It was stirred with

The contraction temperature is 64°C for control experiments and 70°C for experiments with enzymes. there were.

Example 4 Ten pieces of leather each measuring 1 cm x 6 c+o are lignosa in loOml in universal buffer y-pH 5,5 (100mg/ml) Lignosite 431 Sodium Lignosulfone) (Geo into 100 ml of a mixture of RGIA Pacific Corp.) solution. Ta. This mixture was stirred at room temperature for 2 hours. Next, looml ligase (2 35 PODU/ml) was added. This mixture was mixed before measuring the shrinkage temperature. and stirred at room temperature for 20 hours.

In a control experiment, 10 pieces of leather were Sodium lignosulfonate looml solution in H5,5 and 0.1M and 100 ml of functional buffer pt15.5. Collect the mixture It was stirred on a magnetic stirrer for about 20 hours before measuring the condensation temperature.

The contraction temperature is 59°C for control experiments and 65°C for experiments with enzymes. there were.

Similar experiments were performed with P. peroxidase. Nov.

-2880 Bagsv for Nordisk A/S, Novo A11e, D Product sheet 5P5 available on request from aerd, Demark In this case, the oxidizing agent is hydrogen peroxide, pH 7, 0 all-purpose powder, and the reaction was brought to room temperature in a magnetic cooler (S Using an enzyme dose of 4000 PODU/ml for one night, The concentration of hydrogen was set to 10mM. Also, add an excessive amount of hydrogen peroxide (serious 5 o'clock) was added every 15 minutes during the reaction.

Cobrinus Regarding the shrinkage temperature of leather pieces regarding experiments with peroxidase The results of Examples 1-4 (ul?: similar to the results shown here).

Claims (10)

[Claims] 1. A method for tanning leather with a tanning agent in a tanning tank, comprising: In addition to the skin, the bath contains oxidoreductase and aromatic compounds as tanning agents as well as functionally containing this peel and/or other compounds capable of reacting with this aroma compound. further comprising introducing an oxidizing agent into the equilibration tanning tank. Method. 2. The oxidoreductase is a peroxidase, and the tanning agent is synthetic or A method according to claim 1, characterized in that is a vegetable aromatic tanning agent. 3. The oxidoreductase is an oxidase, and the tanning agent is synthetic or 2. The method according to claim 1, wherein the tanning agent is a physical aromatic tanning agent. 4. Oxidoreductase is produced from Polyporspincitus (Trametes villosa) 2. The method according to claim 1, characterized in that the method is 5. Oxidoreductase is a laccase that is more productive than polyporus 2. A method according to claim 1, characterized in that. 6. Characterized by oxidoreductase being more productive than Cobrinus cinereus The method according to claim 1, wherein: 7. Oxidoreductase is produced from Polyporspincitus (Trametes villosa) The method according to claim 1, characterized in that the peroxidase is a biogenic peroxidase. 8. 8. Process according to claim 1, characterized in that the tanning bath is aqueous. 9. 8. Process according to claim 1, characterized in that the tanning tank is organic. 10. The tanning tank has a pH of 2 to 11, preferably 2 to 8. The method according to claims 1 to 9.