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
  • C14C1/06—Facilitating unhairing, e.g. by painting, by liming

Definitions

• leather is made from a raw skin in several process steps.
• the process steps summarized as a water workshop are at the beginning of this process and prepare the raw skin for tanning, i.e. takes place before the actual tanning.
• the water workshop includes the typical steps in this sequence: switch, liming, descaling, pickling and pimples.
• the liming takes place in aqueous liquor typically in so-called liming barrels or alternatively in liming reels.
• process chemicals and the action of movement remove the hair and other non-leather components of the skin and open up the skin by separating the collagen fibers.
• process chemicals and the action of movement remove the hair and other non-leather components of the skin and open up the skin by separating the collagen fibers.
• process chemicals and the action of movement remove the hair and other non-leather components of the skin and open up the skin by separating the collagen fibers.
• strong oxidizing agents eg H 2 O 2
• Lime or other alkaline substances are usually added to the skin.
• the object according to the invention is achieved by using pseudoalkali metal, alkali metal and / or alkaline earth metal salts of the sugar acids in leather production, in particular when using these substances as swelling regulators in the liming.
• Ammonium, sodium, potassium, calcium and / or magnesium salts of the sugar acids are preferably used in the present invention.
• Sodium and / or potassium salts of the sugar acids are particularly preferably used, very particularly preferably sodium salts of the sugar acids.
• Sugar acids are understood to be polyhydroxycarboxylic acids that are formed by oxidation from simple sugars (monosaccharides). These include aldonic acids (e.g. D-gluconic acid), uronic acids (e.g. D-glucuronic acid), aldar acids (e.g. D-glucaric acid, D-threaric acid, D-mannosugaric acid) and ketoaldonic acids (e.g. D-2-oxo-gluconic acid).
• aldonic acids e.g. D-gluconic acid
• uronic acids e.g. D-glucuronic acid
• aldar acids e.g. D-glucaric acid, D-threaric acid, D-mannosugaric acid
• ketoaldonic acids e.g. D-2-oxo-gluconic acid
• ammonium, sodium, potassium, calcium and / or magnesium salts of aldonic acids are preferably used.
• ammonium, sodium and / or potassium gluconate, preferably sodium and / or potassium gluconate and particularly preferably sodium gluconate are used.
• Pseudoalkali metal salts are understood to be salts whose cations are not alkali metals, but largely behave as such.
• the term is to be understood as ammonium and / or tetraalkylammonium salts.
• the effect of the salts of the sugar acids according to the invention can be improved by using them together with alkaline earth metal formates, preferably magnesium and / or calcium formate, particularly preferably with calcium formate.
• the effect of the salts of the sugar acids according to the invention can be optimized by combining them with alkaline earth metal salts of C 1 -C 3 carboxylic acids, preferably magnesium and / or calcium salts of formic, acetic or propionic acid, particularly preferably magnesium and / or Calcium salts of formic acid and most preferably used with calcium formate.
• alkaline earth metal salts of C 1 -C 3 carboxylic acids preferably magnesium and / or calcium salts of formic, acetic or propionic acid, particularly preferably magnesium and / or Calcium salts of formic acid and most preferably used with calcium formate.
• An increase in activity can also be achieved by using the salts of the sugar acids according to the invention together with ethanolamines (i.e. monoethanolamine, diethanolamine and / or triethanolamine) or urea.
• ethanolamines i.e. monoethanolamine, diethanolamine and / or triethanolamine
• the effect of the above salts of the sugar acids can be increased by using a combination of alkaline earth metal salts of C 1 -C 3 carboxylic acids and ethanolamines or urea.
• the salts of the sugar acids according to the invention in combination with alkali metal salts of the C 1 -C 3 carboxylic acids, in particular sodium formate, sodium acetate, sodium propionate, potassium formate, potassium acetate and / or potassium propionate, which may be used together with alkaline earth metal salts of C 1 -C 3 carboxylic acids, Ethanolamines or urea can be done.
• alkali metal salts of the C 1 -C 3 carboxylic acids in particular sodium formate, sodium acetate, sodium propionate, potassium formate, potassium acetate and / or potassium propionate, which may be used together with alkaline earth metal salts of C 1 -C 3 carboxylic acids, Ethanolamines or urea can be done.
• the present invention also relates to processes for the treatment of animal skins in the liming using pseudoalkali metal, alkali metal and / or alkaline earth metal salts of sugar acids, these being added to the liquor in which the treatment of the skins takes place.
• This treatment also includes variants in which the pseudoalkali metal, alkali metal and / or alkaline earth metal salts of the sugar acids are added to the liquor before the liming in the switch.
• the compounds listed above which support the action of the swelling regulators such as alkaline earth metal formates, alkaline earth metal acetates, alkaline earth metal propionates, ethanolamines and / or urea, are additionally added to the liquor.
• the liquor in which the skins are treated in the liming typically contains further compounds known to the person skilled in the art, such as reducing sulfur-containing products (for example Na 2 S, NaHS, mercaptoethanol, thioglycolic acids), strong oxidizing agents (for example H 2 O 2 ) and / or strongly alkaline substances (e.g. lime).
• reducing sulfur-containing products for example Na 2 S, NaHS, mercaptoethanol, thioglycolic acids
• strong oxidizing agents for example H 2 O 2
• strongly alkaline substances e.g. lime
• the present invention also relates to processes for the production of leather comprising the treatment of animal hides according to the invention.
• Said methods may further include steps of leather production familiar to those skilled in the art, such as Softening, fleshing, splitting, decalcification, enzymatic pickling, degreasing, pimples, tanning, dewatering, folding, bleaching, retanning, dyeing, greasing, stretching, drying, moistening, softening and dry dressing.
• the tanning is preferably carried out with mineral tanning agents such as aluminum salts, in particular alums, trivalent chromium salts, zirconium salts, iron, zinc or titanium salts, with polyphosphates, with aldehydes such as formaldehyde and glutardialdehyde, with synthetic tanning agents based on phenol derivatives (syntans) or with polymer tanning agents (Resin tanning agents) such as acrylates and polyurethanes or vegetable dyes.
• mineral tanning agents such as aluminum salts, in particular alums, trivalent chromium salts, zirconium salts, iron, zinc or titanium salts, with polyphosphates, with aldehydes such as formaldehyde and glutardialdehyde, with synthetic tanning agents based on phenol derivatives (syntans) or with polymer tanning agents (Resin tanning agents) such as acrylates and polyurethanes or vegetable dyes.
• the tanning
• the addition of ethanolamines and urea is dispensed with in the process according to the invention or in the use of salts of the sugar acids according to the invention, since the introduction of nitrogen into the waste water can thereby be reduced.
• alkali metal salts of gluconic acids are used in the processes according to the invention or in the use according to the invention.
• based on the salt weight of the raw skin used from 0.05 to 5.0% by weight, preferably from 0.1 to 2.0% by weight and particularly preferably from 0.2 to 1.0% by weight of pseudoalkali metal, alkali metal and / or alkaline earth metal salts of the sugar acids are used.
• the tanner understands by the salt weight the weight that the skin has after the preservation with salt.
• the preserved skin typically has a moisture content of 35% by weight.
• the present invention also includes leather auxiliary compositions comprising one or more pseudoalkali metal, alkali metal and / or alkaline earth metal salts of the sugar acids, preferably ammonium, sodium and / or potassium salts of the sugar acids, particularly preferably sodium salts of the sugar acids.
• leather auxiliary compositions according to the invention advantageously contain one or more pseudoalkali metal, alkali metal and / or alkaline earth metal salts of gluconic acid, preferably ammonium, sodium and / or potassium gluconate, particularly preferably sodium gluconate.
• Further advantageous leather auxiliary compositions additionally contain one or more compounds from the group comprising alkaline earth metal salts of C 1 -C 3 carboxylic acids, monoethanolamine, diethanolamine, triethanolamine and urea, preferably magnesium and / or calcium salts of formic, acetic or propionic acid, monoethanolamine, diethanolamine, Triethanolamine and urea, particularly preferably magnesium and / or calcium salts of formic or acetic acid and most preferably calcium formate.
• alkaline earth metal salts of C 1 -C 3 carboxylic acids preferably magnesium and / or calcium salts of formic, acetic or propionic acid, monoethanolamine, diethanolamine, Triethanolamine and urea, particularly preferably magnesium and / or calcium salts of formic or acetic acid and most preferably calcium formate.
• Further advantageous leather auxiliary compositions contain ammonium, sodium and / or potassium gluconate in combination with magnesium formate, calcium formate magnesium acetate and / or calcium acetate, preferably sodium and / or potassium gluconate in combination with magnesium formate and / or calcium formate.
• the leather auxiliary composition preferably contains sodium gluconate and one or more compounds from the group comprising calcium formate and magnesium formate, preferably calcium formate.
• the ratio is determined as the quotient from the total mass of the compounds of the above salts of the sugar acids to the total mass of the compounds of the above formates, acetates and propionates.
• the leather auxiliary compositions according to the invention are typically swelling regulators, in particular swelling regulators for the water workshop.
• the leather auxiliary compositions according to the invention can be in liquid or in solid form.
• the leather auxiliary composition according to the invention is at 25 ° C. as a solid, ideally in particulate form, such as, for example, as a powder, granulate or pellet.
• the screening tests were carried out on raw skin samples DIN A4. These were cut from the core area of a salted raw skin, so that all samples had a similar fiber structure. The samples of a series were taken from the same skin because the fiber structure of the skin differs from animal to animal. The test specimens were weighed individually. All percentages of the process recipe refer to this weight (the raw skin salt weight).
• test procedure included the process steps "switch” and "liming".
• the amounts of chemicals and products used in the process as well as the amount of water are in percent by weight based on the raw skin salt weight of the individual samples.
• the quantities were weighed on a balance with an accuracy of 0.5 g.
• test tanning drums diameter 300 mm with temperature regulation (manufacturer Dose).
• the process temperature was kept constant at 28 ° C +/- 1 ° C.
• test specimen was added individually to the sample barrel and 200% water (based on the salt weight) at a temperature of 28 ° C. and 0.3% Peltec BH softening agent (mixture of surfactant and bactericide from LANXESS Deutschland GmbH) were added.
• the test barrel was rotated at 10 RPM for 300 minutes.
• the liquor (process water) was then drained off.
• the specimen is now dabbed off, weighed and the average thickness is determined at four measuring points.
• the test specimen was put back into the test barrel and 200% water at a temperature of 28 ° C. was added and 15 min. rotates. The remaining salinity of the fleet was then determined. This should not exceed 3.5 ° Bé. If the salt content is too high, the fleet should be changed once.
• the swelling regulator was added to the fleet and the test keg 60 min. rotates. The weight was then determined and the average thickness was determined.
• the test specimen was returned to the liquor, 3% lime (Ca (OH) 2 ) and 2.5% Na 2 S were added and the mixture was rotated for 4 hours. Then there were 15 hours. Barrel rotation in interval mode (rotate 10 min. / 50 min. Break). The pH of the liquor was then measured (pH 12-12.5), the specimen was removed, weighed again and the average thickness measured. The swelling was determined from the increase in thickness.
• test specimens were then washed and with a standard chrome tanning (as described for example in E. Heidemann, Fundamentals of Leather Manufacturing, pp. 295-340, E. Roether Verlag, Darmstadt, 1993 ) tanned and then checked for firmness by bending the leather. If the surface in the crease was smooth, did not rise, and did not curl, a positive firm grain was found.
• chrome tanning as described for example in E. Heidemann, Fundamentals of Leather Manufacturing, pp. 295-340, E. Roether Verlag, Darmstadt, 1993

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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)

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• 2018
  • 2018-12-21 EP EP18215380.9A patent/EP3670675A1/de not_active Withdrawn
• 2019
  • 2019-12-16 WO PCT/EP2019/085260 patent/WO2020126987A1/de unknown
  • 2019-12-16 EP EP19828654.4A patent/EP3924523B1/de active Active
  • 2019-12-16 BR BR112021011977A patent/BR112021011977A8/pt unknown
  • 2019-12-16 CN CN201980084034.4A patent/CN113227407B/zh active Active
  • 2019-12-16 ES ES19828654T patent/ES2963618T3/es active Active
  • 2019-12-19 AR ARP190103788A patent/AR117464A1/es active IP Right Grant

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