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

Definitions

• trimethylol acetaldehyde for tanning hides, skins and furskins is known from German patent specification 1 154 593 and the associated German additional patent specification.
• the trimethylol acetaldehyde can be used alone or in combination with other known mineral, synthetic or vegetable tanning agents.
• the fur skins tanned using trimethylol acetaldehyde are distinguished e.g. due to its softness and particularly light weight.
• the reaction is preferably catalyzed under alkaline conditions.
• the formylamino compound can have one, two or more formylamino groups of the formula I. where R is hydrogen or -CH 2 OH. Hydrogen is preferred for R 1 .
• the alkyl and alkenyl radicals which stand for R can be straight-chain or branched.
• (C 1 -C 6 ) alkyl radicals are preferred and in the case of the alkenyl radicals which are R (C 2 -C 6 ) alkenyl radicals are preferred.
• the vinyl radical is particularly preferred for the alkenyl radicals.
• the number m in particular means 0 or 1
• the number n in particular means 1.
• Suitable formylamino compounds can also contain 3 or more formylamino groups of the formula I in the molecule.
• Formylamino compounds of the type mentioned are known or can be synthesized by the processes known for the preparation of formylamino compounds.
• suitable formylamino compounds are: formamide; Methyl, ethyl, propyl, i-propyl, butyl, i-butyl, sec-butyl, pentyl or i-pentyl formamide; Vinyl, allyl, methallyl, crotyl formamide; N-hydroxymethyl-N-methyl-, -ethyl-, -propyl-formamide; N, N'-bis-formyl hydrazine; Methylene bis-formamide; Methylene bis (N-hydroxymethyl formamide); Ethylene bis-formamide; Trimethylene bis-formamide; Tetramethylene-bis-formamide; Methylene bis (O-form hydroxamic acid) ((H
• Formylamino compounds suitable as starting products for the preparation of the tanning agent according to the invention are also homopolymers or copolymers which contain building blocks of the formula III in the polymer contain.
• Such polymers are, for example, homopolymers of vinylformamide, and also copolymers of vinylformamide with, for example, acrylic acid, methacrylic acid, unsaturated sulfonic acids, such as, for example, vinylsulfonic acid, acrylamidopropanesulfonic acid, unsaturated phosphonic acids, such as, for example, vinylphosphonic acid and esters of unsaturated phosphonic acids, diallyldimethylammonium chloride, vinylamides, such as, for example, vinyl nitriletylamide, such as, for example, vinyl nitriletylamide.
• Such homo- or copolymers are water-soluble and have an average molecular weight of approximately 5000 to 500,000.
• a formylamino compound or a mixture of different formylamino compounds can be used in the preparation of the tannins according to the invention.
• the reaction is generally carried out in the aqueous phase, preferably catalyzed by an alkali.
• An alkalizing agent is added for alkaline catalysis.
• Suitable alkalizing agents are, for example, alkali metal hydroxides, such as sodium, potassium or lithium hydroxide, alkaline salts, such as, for example, alkali carbonates, such as sodium, potassium or lithium carbonate, or tertiary nitrogen bases, such as pyridine.
• sodium carbonate is used as the alkalizing agent.
• Per mole of acetaldehyde are usually 0.008 to 0.3 mol, preferably 0.01 to 0.2 mol, of the alkalizing agent used.
• the reaction can be carried out batchwise or continuously and is highly exothermic. If the reaction is carried out in batches, it is advisable to place one or two reactants in the aqueous phase with cooling (for example to +10 ° C.) and to add the remaining reaction component or the remaining reaction components and the alkalizing agent, whereupon the reaction starts immediately with an increase in temperature. When carrying out the reaction batchwise, it is normally also advisable not to bring the total amount of the reactants to the reaction at once, but to divide them into two or more portions and to add the remaining portions only after the reaction has subsided.
• the reaction temperatures are generally between 0 and 140 ° C, preferably 5 and 130 ° C.
• the first reaction phase is often carried out under cooling, at reaction temperatures of up to about 60 to 70 ° C, and after the decay of the temperature development, the reaction at elevated temperature of eg is guided 60 0 C or more to an end.
• the reaction is carried out at temperatures above the boiling point of the reaction mixture at normal pressure in a pressure reactor at the excess pressure of, for example, 4 to 6 bar. Carrying out the reaction at temperatures above 100.degree. C., for example 100 to 140.degree. C., in particular 100 to 130.degree. C., enables short reaction times, as a result of which the thermal load on the products produced can be considerably reduced. This is particularly true when the reaction is carried out continuously, which is preferred.
• Formaldehyde is generally used in the form of commercially available aqueous solutions, for example 39% aqueous solutions.
• the solution obtained after completion of the reaction which normally has an active substance content of about 30 to about 70% by weight, is expediently filtered and washed with an alkalizing agent, e.g. of the type already mentioned, set to a neutral or approximately neutral pH.
• an alkalizing agent e.g. of the type already mentioned
• the liquid products obtained in this way are clear or nearly clear and have a slightly yellowish to brownish color. Under normal conditions they can be kept for at least two years and can be diluted with water as required. They solidify at temperatures below approx. -10 C, but are fully usable again after careful thawing.
• the products according to the invention which can be assumed to contain a mixture of different reaction products, are, as such or in the form of their aqueous solutions, outstandingly suitable as tanning agents for hides, skins and furskins, either alone or in combination with mineral, vegetable or others synthetic tanning agents. They are also excellently compatible with dyes and greasing agents in the various stages of leather and fur production. Compared to the use of trimethylol acetaldehyde, the elasticity, fullness and softness are significantly improved. In addition, the shrinkage temperature is increased and the scar strength is improved. In the case of leather dyeing, inadequate dyeing can be eliminated with the help of the products according to the invention.
• the softening effect of the fatliquor is increased and the risk of loose grain is reduced by adding the products according to the invention. Since the products according to the invention have a favorable effect on the speed and softness of the leather, they are special suitable for the production of white glove leather and nappa clothing leather.
• the products according to the invention have a tanning effect in the pH range from 2 to 9.
• Examples 1 to 16 relate to the production of products according to the invention by the process according to the invention, and Examples 17 to 23 relate to the use of the products according to the invention in tannery.
• the 39% strength formaldehyde mentioned in Examples 1 to 4 is a commercially available aqueous solution with a formaldehyde content of 39%.
• the reaction starts immediately, the temperature rising to about 60 ° C. in the course of 10 minutes.
• the solution is cooled down to 30 ° C.
• a further 145 g of 39% strength formaldehyde and 6.5 g of soda are then added in one portion.
• the temperature then rises again to about 40 ° C. in the course of about 20 minutes.
• the solution is heated and stirred for 1 h at 60 ° C, 70 ° C and 80 ° C, then cooled to room temperature and adjusted to pH 7.0 ⁇ 0.5 with soda. It is filtered off. An almost clear, yellowish solution is obtained.
• the reaction begins immediately and the temperature rises to about 55 to 60 ° C. in a few minutes, a pressure of 0.9 to 1.1 bar building up.
• the solution is then heated to 105 to 110 ° C., a pressure of 4.5 to 5 bar being established, and kept at this temperature for 5 to 10 minutes. Then it is cooled again to room temperature. After filtration, an almost clear, yellowish brown colored, ready-to-use solution is obtained, which is adjusted if necessary to a pH of 7.0 +0.5 with soda.
• Metering pumps continuously feed 1 mol of acetaldehyde, 1 mol of formaldehyde, 39% and 2 mol of formamide and small amounts of 10% aqueous soda solution into a pressure vessel equipped with a stirrer, with acetaldehyde, formaldehyde and formamide being premixed in the feed system.
• the reaction temperature in the pressure vessel is 110 to 115 0 C at a pressure of 4 bar.
• the reak tion mixture in the upper part of the pressure reactor cooled in a cooling tube to room temperature and filtered through a filter cartridge. A clear, almost colorless, ready-to-use solution is obtained which, if necessary, is adjusted to a pH of 7.0 + 0.5 with soda.
• the semichromgar or purely chromegarden leather which has been well rolled on in the usual way, is allowed to run for 15 minutes with 1.5 to 2% (based on dry weight) of a product according to the invention (e.g. according to Example 3) and then dyed in the same bath in the usual way. Uniform and deep colorations are obtained.
• Well-softened fur skins such as Zickel, muskrat, mink or the like are tanned after pickling and possibly thin cutting as follows: 800% liquor 28 to 30 ° C., 2 g / liter liquor of a product according to the invention (for example according to Example 3) in 2 portions at 20 minute intervals, 2 hours.
• the fur is very soft and the hair has an excellent shine and stand.

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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)
• Compounds Of Unknown Constitution (AREA)
• Tea And Coffee (AREA)
• Carbon And Carbon Compounds (AREA)
• Ceramic Products (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (3)

Family

ID=6285850

Family Applications (1)

Country Status (8)

Cited By (1)

Families Citing this family (5)

Family Cites Families (3)

• 1985
  • 1985-11-12 BR BR8605597A patent/BR8605597A/pt unknown
  • 1985-11-13 DE DE19853540211 patent/DE3540211A1/de not_active Withdrawn
• 1986
  • 1986-10-09 US US06/917,600 patent/US4828570A/en not_active Expired - Fee Related
  • 1986-11-08 ES ES86115504T patent/ES2010502B3/es not_active Expired
  • 1986-11-08 AT AT86115504T patent/ATE46190T1/de not_active IP Right Cessation
  • 1986-11-08 EP EP86115504A patent/EP0225491B1/fr not_active Expired
  • 1986-11-08 DE DE8686115504T patent/DE3665483D1/de not_active Expired
  • 1986-11-12 PT PT83727A patent/PT83727B/pt unknown
  • 1986-11-12 JP JP61267879A patent/JPS62115100A/ja active Pending

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