EP0022067A1 - Process for the one-bath dyeing and tanning of skins and furs - Google Patents

Abstract

1. A process for dyeing and tanning pelts in a single bath, wherein these materials, which can be fat-liquored before-hand, are (a) dyed with at least one anionic dye and simultaneously pickled, and (b) tanned with at least one tannin, at a temperature in the range from 158 to 458C and in an aqueous liquor which has been adjusted to a pH value of 1 to 4.

Description

The present invention relates to a method for single-bath dyeing and tanning of skins or furs.

When dyeing natural skins and furs, pickled and tanned material is usually used. This means that these three tasks, namely pickling, tanning and dyeing, are carried out in 2 or 3 separate baths, which results in a long treatment time, numerous manipulations and a large amount of personnel. In addition, the coloring can only be carried out at an elevated temperature of at least 50 ° C.

In contrast, the invention has set itself the task of avoiding these disadvantages by specifying a method in which the dyeing is carried out before tanning, with the achievement of uniform and deep shades, and these operations can be carried out in a single bath, thereby reducing the time and Energy and the cost of materials can be significantly reduced.

• (a) mit mindestens einem anionischen Farbstoff: färbt und zugleich pickelt und
• (b) mit mindestens einem Gerbmittel gerbt.

To achieve the object, a method for single-bath dyeing and tanning of furs or furs, in particular sheepskins, is proposed, which is characterized in that these materials, which may have been previously greased, at a temperature of 15 to 45 ° C. and in a pH -Value from 1 to 4 aqueous liquor

• (a) with at least one anionic dye: colors and pimples and
• (b) tanned with at least one tanning agent.

The process according to the invention is single-bath, i.e. performed using only one treatment fleet. The liquor ratio can be chosen within a wide range e.g. 1: 4 to 1:50, preferably 1:10 to 1:40. The temperature at which process steps (a) and (b) are carried out is at least 15 ° C. and as a rule is not higher than 45 ° C. It is preferably in the range from 35 to 40 ° C. The execution of the Process stages (a) and (b) can take a maximum of 24 hours.

All natural skins and furs such as e.g. Sheep, goat, beef, veal, foal, rabbit and seal skins, as well as fox, mink fur and other fine furs, including in particular wool sheepskins. These skins and furs are first softened in the usual way by adding a surfactant and then removed on the machine. They are then washed with wetting agents and detergents, if necessary with the addition of alkalis such as e.g. Washed sodium carbonate To largely remove the excess natural fat, dirt and urine residues. The skins or furs are then conveniently wilted or centrifuged.

Before they are dyed and tanned according to the invention, the skins or furs can also be greased with leather greasing agents in the same treatment liquor. Greasing is also carried out at a temperature of 15 to 45 ° C, preferably 30 to 40 ° C. The pH of the greasing can be from 4 to 6.

Suitable leather greasing agents are, for example, oils or waxes of natural or synthetic origin, as are generally used for greasing skins and furs. Natural or as waxes Mineral origin as well as mineral or vegetable or animal oils or waxes can be considered. Examples of suitable oils and waxes are castor oil, coconut oil, soybean oil, claw oils, tears, tallow fat, lanolin, cereal germ oil, paraffin oil, white oil, lanolin waxes, paraffin wax, chlorinated and / or sulfated paraffins, fatty acid esters with mono- or polyhydric alcohols such as Oleic acid triglyceride, fatty acid amides or mixtures thereof, optionally also in a mixture with the fatty acids themselves.

The oils or waxes are preferably used in combination with an anionic, amphoteric or nonionic surfactant or mixtures thereof, which serve as emulsifiers.

The anionic surfactants are, for example, acidic, ether groups or ester groups of organic or inorganic acids, preferably sulfated, addition products of allcylene oxides, especially ethylene oxide and / or propylene oxide or also styrene oxide onto aliphatic 'hydrocarbon radicals with a total of at least 8 carbon atoms, organic hydroxyl, carboxyl, Amino and / or amido compounds such as higher fatty alcohols, fatty acids, fatty amines, fatty acid amides or alkylphenols or mixtures of these substances. These addition products can have a degree of alkoxylation of about 2 to 100, in particular 5 to 40, ethoxy and / or propoxy groups. The acidic ethers or esters can be used as free acids or as salts e.g. Alkali metal, alkaline earth metal, ammonium or amine salts are present.

Examples of amphoteric surfactants are amines or polyamines with 2 or more basic nitrogen atoms, preferably 2 to 5, which have at least one acidic, etherified or esterified polyglycol ether chain and at least one lipophilic substituent and can be partially or completely quaternized. Acid monosulfuric acid esters are among the amphoteric surfactants products of 1 mole of fatty amine or fatty amine mixtures such as tallow fatty amine with 2 to 15 moles of ethylene oxide are particularly preferred.

The nonionic surfactants are expediently alkylene oxide addition products of 1 to 50 moles of alkylene oxide, for example ethylene oxide and / or propylene oxide, on 1 mole of an aliphatic monoalcohol with at least 4 carbon atoms, a 3- to 6-valent aliphatic alcohol, one optionally by alkyl or phenyl substituted phenol or a fatty acid having 8 to 22 carbon atoms.

Of the nonionic surfactants, the addition products of 2 to 15 moles of ethylene oxide with 1 mole of fatty alcohol, fatty acid each with 8 to 18 carbon atoms or alkylphenols with 4 to 12 carbon atoms in the alkyl part are particularly preferred as emulsifiers.

The fatliquoring agents used in the process according to the invention are generally used in amounts of 1 to 10 g per liter of liquor.

The anionic dyes are, for example, salts of heavy metal-containing or preferably metal-free mono-, dis- or polyazo dyes including the formazan dyes and the anthraquinone, xanthene, nitro, triphenylmethane, naphthoquinoneimine and phthalocyanine dyes. The anionic character of these dyes can be caused by metal sample formation alone and / or preferably by acidic, salt-forming substituents, such as carboxylic acid groups, sulfuric acid and phosphonic acid ester groups, phosphonic acid groups or sulfonic acid groups. These dyes can also have so-called reactive groups in the molecule, which form a covalent bond with the fur to be dyed. The so-called acidic metal-free dyes are preferred.

The 1: 1 or 1: 2 metal complex dyes are also of interest. The 1: 1 metal complex agents preferably have one or two sulfonic acid groups. As metal, they contain a heavy metal atom such as Copper, nickel or especially chrome.

The 1: 2 metal complex dyes contain a heavy metal atom as the central atom, e.g. a cobalt atom or in particular a chromium atom. Two complex-forming components are connected to the central atom, at least one of which is a dye molecule, but preferably both are dye molecules. The two dye molecules involved in the complex formation can be the same or different from one another. The 1: 2 metal complex dyes can e.g. contain two azomethine molecules, a disazo dye and a monoazo dye, or preferably two monoazo dye molecules. The azo dye molecules can have water solubilizing groups such as e.g. Acid amide, alkylsulfonyl or the above acidic groups. Preference is given to 1: 2 cobalt or 1: 2 chromium complexes of monoazo dyes which have acid amide, alkylsulfonyl or a total of a single sulfonic acid group.

Mixtures of the anionic dyes can also be used. Dye mixtures of at least 2 or 3 anionic dyes are particularly preferred for the production of level dichromia or trichromatic dyes.

The amount of dyes added to the liquor depends on the desired depth of color. In general, amounts of 0.001 to 10, in particular 0.1 to 5 g, per liter of liquor have proven successful.

The dyeing process is preferably carried out in the presence of a leveling agent or dyeing accelerator, which are generally added to the liquor before the dye. The leveling agents can also serve as color accelerators. Non-ionic, cationic or amphoteric surfactants or mixtures thereof can be used as leveling agents or color accelerators. Cationic surfactants have proven to be particularly favorable as leveling agents. proven by attachment from 5 to 15 moles of ethylene oxide are obtained on fatty amines or fatty amine mixtures. These surfactants can also be used in a mixture with nonionic surfactants made from fatty alcohols or alkylphenols and 2 to 15 moles of ethylene oxide.

The leveling agent or dyeing accelerator in the dye bath is advantageously 0.5 to 3 g per liter of liquor.

In addition to the dye and the leveling agent, the dyebath can additionally contain an organic solvent which is only partially miscible with water and which acts as a color-deepening component. The solvent can advantageously be emulsified with the above-mentioned nonionic surfactants. Preferred organic solvents are those that boil above 80 ° C.

Such solvents are e.g. mono- or dihydric aliphatic alcohols with at least 4 carbon atoms, e.g. Butanol, 2-ethylbutanol, 2-ethylhexanol, trimethylhexanol, neopentylglycol; phenoxyethanol, chlorophenoxyethanol; Dialkylene glycol monoalkyl ethers such as e.g. Diethylene glycol monomethyl ether, monoethyl ether, monobutyl ether and monohexyl ether; Acetic acid esters such as e.g. Butyl acetate, phenyl acetate and benzyl acetate; Ethyl benzoate, methyl salicylic acid, methyl lactate, ethyl lactate; propylene carbonate; also benzyl alcohol, furfuryl alcohol, diacetone alcohol, benzaldehyde, acetophenone, benzophenone, cyclohexanone, isophorone, tetralone, tetramethyl tetralone and tributyl phosphate, triisobutyl phosphate, tricresyl phosphate, dibutyl phthalate, dioctyl phthalaffinate and polyhalogenated paraffin and polyhalogenated paraffin. Particularly preferred solvents are butanol, benzyl alcohol, phenoxyethanol and especially tributyl phosphate.

The amounts in which these organic solvents are added to the dyebaths alone or as mixtures range from 0.1 g to 80 g, preferably 0.5 to 50 g, per liter of dye liquor.

In addition to the dye, the color-deepening component and the leveling agent or dyeing accelerator, the dyeing baths can contain other conventional additives, such as Contain electrolytes, bactericides, fillers, wetting agents, dispersants, fixatives, diffusion accelerators or defoamers.

The fur can be dyed in such a way that the material to be dyed is first treated with the leveling agent or dyeing accelerator for 5 to 15 minutes and then with the dye for 15 to 45 minutes. The dyeing process should take place at a pH of 1 to 4, preferably 2 to 3. For this reason, the dye liquor is acidified. Mineral acids, such as sulfuric acid or phosphoric acid, or preferably lower aliphatic carboxylic acids, such as e.g. Formic, acetic, oxalic, glycolic or lactic acid. Mixtures of these acids can also be used.

For this purpose, 2 to 8 g of acid per liter of liquor are expediently used.

Thanks to the very low pH value of the dyeing liquor, the fur is also pecked at the same time as dyeing, i.e. prepared for tanning. The coloring and picking of the fur can take a total of 4 to 24 hours, preferably 6 to 12 hours.

Suitable tanning agents are, for example, vegetable tanning extracts, synthetic tanning agents, resin tanning agents, aldehydes such as formaldehyde or acetaldehyde or dialdehydes such as glutaraldehyde, dialdehyde starch or mixtures thereof, and acid-reacting auxiliary tanning agents such as condensation products from naphthalenesulfonic acids and formaldehyde, or acid-releasing salts with a tanning effect, such as chromium, aluminum, potassium aluminum or zirconium sulfates, and aluminum silicates. Chromium-containing synthetic tanning agents, preferably based on chromium sulfate, are preferred.

The tanning agents can be used in solid or liquid form. The amounts used in which the tanning agents, based on their dry content, are added to the treatment liquors are between 2 to 20 g, preferably 5 to 15 g, per liter of liquor.

The tanning should also take place at a pH of 1 to 4. The pH of the liquor for tanning stage (b) is preferably 2.5 to 4. The duration of the tanning can vary depending on the requirements, but is usually 2 to 15 hours.

After tanning the colored material, the liquor is usually neutralized with a base. In addition come e.g. Alkali metal or alkaline earth metal hydroxides, carbonates, bicarbonates, phosphates or borates, especially sodium carbonate, sodium bicarbonate, sodium hydroxide or magnesium hydroxide, as well as aqueous ammonia and lower alkanolamines such as monoethanol, diethanol and triethanolamine. These bases can be used in amounts of 2 to 5 g per liter of liquor. The neutralization step can take 1 to 15 hours depending on the addition of the base.

Following the neutralization of the liquor, the fur material is preferably stored for a further 6 to 48 hours at room temperature. After storage, the dyed and tanned fur material is rinsed with water, optionally neutralized with the above-mentioned alkalis and dried and finished in the usual way.

After the _'process of this invention is obtained by a multistage process, which is carried out in one bath, a uniform dyed skins and furs, which are both extremely soft and supple. The hair side of the fur or fur is mainly dyed, while the leather side is only slightly dyed. This is particularly advantageous for car seat skins, for example.

The valuable fastness properties of fur dyes such as Light fastness and rub fastness as well as fastness to ironing, tear resistance, fastness to dry cleaning are in no way adversely affected by the single-bath method according to the invention.

• - Färbung, Pickel und Gerbung können in einer einzigen Flotte durchgeführt werden. Bisher waren mindestens 3 Bäder für Pickel, Gerben, Neutralisieren und Färben erforderlich.
• - niedrigere Färbetemperatur, 15 bis 45° C anstatt der üblichen Temperatur für Pelzfärbung von 50 bis 70° C.
• - Die Dauer der Färbung und Gerbung des Pelzmaterials kann insgesamt auf 24 Stunden gekürzt werden; bisher waren 40 bis 50 Stunden notwendig. Ausserdem kann der manuelle Arbeitsaufwand sehr stark verringert werden, wobei Beladen, Entleeren und Zentrifugieren für die separate Färbung entfallen. Somit kann eine einfache, rationelle und sichere Durchführung unter Zeit-, Aufwand-Wasser- und Energieeinsparung erzielt werden.

The method according to the invention offers the following advantages over the previously known working methods, in which already tanned fur material is dyed

• - Coloring, pimples and tanning can be carried out in a single liquor. So far, at least 3 baths for pimples, tanning, neutralizing and dyeing were required.
• - lower dyeing temperature, 15 to 45 ° C instead of the usual temperature for fur dyeing from 50 to 70 ° C.
• - The duration of the coloring and tanning of the fur material can be reduced to a total of 24 hours; previously 40 to 50 hours were necessary. In addition, the manual workload can be reduced considerably, with loading, emptying and centrifuging for the separate coloring being eliminated. In this way, simple, rational and safe implementation can be achieved while saving time, effort, water and energy.

In the following examples, the percentages are by weight unless otherwise specified. The quantities relate to commercially available, that is to say coupe goods, for the dyes and to the pure substance for the components. The five-digit Color Index numbers (CI) refer to the 3rd edition of the Color Index.

Example 1: 100 g of wet sheepskin, which has first been soaked, fleshed and washed, are at 38 to 40 ° C in 1 liter of an aqueous liquor containing 50 g of sodium chloride, 0.5 g of 85% formic acid and 8 g of a synthetic Leather greasing agent based on chlorinated and sulfonated paraffin and a mixture of an oxyethylation product of oleic acid reacted with 7 moles of ethylene oxide and the acidic monosulfuric acid ester of the adduct of 14 moles of ethylene oxide with 1 mole of a C ₁₆ -C ₁₈ fatty amine mixture and a pH of 5 , 5, treated for 30 minutes. Then 1 g of a cationic leveling agent based on an adduct of 14 moles of ethylene oxide and 1 mole of a C ₁₆ -C ₁₈ fatty acid mixture is added to the liquor and treated for 10 minutes at 38 to 40 ° C. The liquor is then 0.1 g of an acid dye, Acid Orange 3 CI 10385 added and the sheepskin treated at 38 to 40 ° C for a further 30 minutes. Then the liquor is adjusted to pH 2.8 with 3 g of 85% formic acid and the sheepskin is treated again at 38 to 40 ° C. for 5 hours. 15 g of a chromium-containing synthetic tanning agent are then added to the liquor and the tanning is carried out Fur through at 38 to 40 ° C for 5 hours. The liquor is also slowly with the solution of 3 g of sodium carbonate. added, whereupon the sheepskin is left in the liquor for 12 hours (final pH of the liquor 3.5 to 4). The fur is then stored for 24 hours at room temperature, then rinsed, spun, stretched and dried with warm air. A deep yellow color is obtained on the hair side of the fur with completely open hair.

If, in this example, one of the dyes mentioned in the following table, column 2, is used instead of the dye mentioned and the procedure is otherwise the same, deep colorations of the shades mentioned in column 3 are likewise obtained.

Example 14: 100 g of wet sheepskin, which has first been soaked, fleshed and washed, are at 38 ° C. in 1 liter of an aqueous liquor containing 50 g of sodium chloride, 5 g of a synthetic leather greasing agent based on chlorinated and sulfonated paraffin and one with Contains 7 moles of ethylene oxide reacted oxyethylation product of oleic acid and the acidic monosulfuric ester of the adduct of 14 moles of ethylene oxide with 1 mole of a C ₁₀ -C ₁₈ fatty acid mixture and 40 g of benzyl alcohol, treated for 30 minutes.

• 0,12 g eines gelben Farbstoffs der Formel
• 
  0,38 g eines roten Farbstoffs der Formel
  
  und
• 0,5 g eines blauen Farbstoffs der Formel
  
  zugesetzt und das Schaffell weitere 30 Minuten bei 38°C behandelt. Alsdann stellt man die Flotte mit 3 g 85%iger Ameisensäure auf pH 2,8 ein und behandelt das Schaffell 5 Stunden wiederum bei 38°C. Hierauf gibt man der Flotte 10 g eines chromhaltigen Gerbmittels zu und führt die Gerbung des Felles während 3 Stunden bei 38°C durch. Die Flotte wird ferner mit der Lösung von 3 g Natriumcarbonat versetzt, worauf das Schaffell 12 Stunden in der Flotte gelassen wird (End-pH-Wert der Flotte 3,8). Das Fell wird schliesslich 24 Stunden bei Raumtemperatur gelagert, mit Natriumcarbonatlösung neutralisiert, dann gespült, geschleudert, gestreckt und mit warmer Luft getrocknet. Man erhält eine tiefviolette Färbung der Haarseite des Felles.

Then 1 g of a cationic leveling agent based on an adduct of 14 moles of ethylene oxide and 1 mole of a C ₁₆ -C ₁₈ fatty amine mixture is added to the liquor and treated at 38 ° C. for 10 minutes. After that, the fleet

• 0.12 g of a yellow dye of the formula
• 
  0.38 g of a red dye of the formula
  
  and
• 0.5 g of a blue dye of the formula
  
  added and the sheepskin treated at 38 ° C for a further 30 minutes. The liquor is then adjusted to pH 2.8 with 3 g of 85% formic acid and the sheepskin is again treated at 38 ° C. for 5 hours. 10 g of a chromium-containing tanning agent are then added to the liquor and the fur is tanned at 38 ° C. for 3 hours. A solution of 3 g of sodium carbonate is also added to the liquor, whereupon the sheepskin is left in the liquor for 12 hours (final pH of the liquor 3.8). The fur is finally stored for 24 hours at room temperature, neutralized with sodium carbonate solution, then rinsed, spun, stretched and dried with warm air. A deep purple coloring of the hair side of the fur is obtained.

Example 15: -100 g of wet sheepskin, which has first been soaked, fleshed and washed, are at 38 ° C in 1 liter of an aqueous liquor containing 50 g of sodium chloride, 5 g of a synthetic leather greasing agent based on chlorinated and sulfonated paraffin and a Mixture of an oxyethylation product of oleic acid reacted with 7 mol of ethylene oxide and the acidic monosulfuric acid ester of the adduct of 14 mol of ethylene oxide with 1 mol of a C ₁₆ -C ₁₈ fatty acid mixture and 1 g of tributyl phosphate, treated for 30 minutes.

zugesetzt und das Schaffell weitere 30 Minuten bei 38°C behandelt. Alsdann stellt man die Flotte mit 3 g 85%iger Ameisensäure auf pH 2,8 ein und behandelt das Schaffell 3 Stunden wiederum bei 38°C. Hierauf gibt man zu der Flotte 12 g eines chromhaltigen synthetischen Gerbmittels und führt die Gerbung des Felles während 12 Stunden bei 38°C durch. Die Flotte wird ferner langsam mit der Lösung von 3 g Natriumcarbonat versetzt, worauf das Schaffell 3 Stunden in der Flotte gelassen wird (End-pH-Wert der Flotte 3,5 bis 4). Das Fell wird schliesslich 24 Stunden bei Raumtemperatur gelagert, mit Natriumcarbonatlösung neutralisiert, dann gespült, geschleudert, gestreckt und mit warmer Luft getrocknet. Man erhält eine tiefbraune Färbung der Haarseite des Felles mit einem vollkommen offenen Haar.a C ₁₆ -C ₁₈ fatty acid mixture and an adduct of 7 moles of ethylene oxide esterified with sulfamic acid and 1 mole of a C ₁₆ -C ₁₈ fatty acid mixture were added to the liquor and treated at 38 ° C. for 10 minutes. After that, the fleet

added and the sheepskin treated at 38 ° C for a further 30 minutes. The liquor is then adjusted to pH 2.8 with 3 g of 85% formic acid and the sheepskin is again treated at 38 ° C. for 3 hours. Then 12 g of a chrome-containing synthetic tanning agent are added to the liquor and the tanning of the fur is carried out at 38 ° C. for 12 hours. The solution of 3 g of sodium carbonate is also slowly added to the liquor, whereupon the sheepskin is left in the liquor for 3 hours (final pH of the liquor 3.5 to 4). The fur is then stored for 24 hours at room temperature, neutralized with sodium carbonate solution, then rinsed, spun, stretched and dried with warm air. A deep brown coloring of the hair side of the fur with a completely open hair is obtained.

Example 16: 100 g of wet sheepskin, which has first been soaked, fleshed and washed, are at 25 ° C in 1 liter of an aqueous liquor containing 50 g of sodium chloride and 5 g of a synthetic leather greasing agent based on chlorinated and sulfated paraffin and a mixture of one 7 moles of ethylene oxide reacted Oxäthylierungsprodukt of oleic acid and the acidic Monoschwefelsäureester of the adduct of 14 mol of ethylene oxide with 1 mole of a C ₁₀ - ₁₈ includes -Fettamingemisches, treated for 30 minutes.

Then 1 g of a cationic leveling agent based on an adduct of 14 mol of ethylene oxide and 1 mol of a Cl6-Cl8-fatty amine mixture is added to the liquor and treated at 25 ° C. for 10 minutes. Then the fleet 0.1 g of a Acid dye, Acid Orange 3 CI 10385 added and the sheepskin treated at 25 ° C for a further 30 minutes. The liquor is then adjusted to pH 2.8 with 3 g of 85% formic acid and the sheepskin is again treated at 25 ° C. for 5 hours. Then 10 g of a chromium-containing tanning agent are added to the liquor and the fur is tanned for 3 hours at 25 ° C. The liquor is further slowly mixed with the solution of 3 g of sodium carbonate, whereupon the sheepskin is left in the liquor for 12 hours (final pH of the liquor 3.5 to 4). The fur is finally stored for 24 hours at room temperature, neutralized with sodium carbonate solution, then rinsed, spun, stretched and dried with warm air. You get a deep yellow coloring of the hair side of the fur with a completely open hair.

Claims (13)

1. A process for single-bath dyeing and tanning of furs or furs, characterized in that these materials, which may have been previously greased, at a temperature of 15 to 45 ° C. and in an aqueous liquor which has been adjusted to a pH of 1 to 4 (a) dyes with at least one anionic dye and pimples at the same time
and (b) tanned with at least one tanning agent. 2. The method according to claim 1, characterized in that process steps (a) and (b) are carried out at a temperature of 35 to 40 ° C. 3. The method according to any one of claims 1 and 2, characterized in that process step (a) is carried out at a pH of the liquor of 2 to 3. 4. The method according to any one of claims 1 to 3, characterized in that the materials have been previously greased with lubricants based on mineral, vegetable or animal oils or waxes or mixtures thereof. 5. The method according to claim 4, characterized in that the oils or waxes are used in a mixture with emulsifiers. 6. The method according to any one of claims 1 to 5, characterized in that acidic metal-free dyes or 1: 2 metal complex dyes are used as anionic dyes. 7. The method according to any one of claims 1 to 6, characterized in that one uses at least two or three anionic dyes. 8. The method according to any one of claims 1 to 7, characterized in that the dyeing process (a) is carried out in the presence of a leveling agent. 9. The method according to any one of claims 1 to 8, characterized in that the dyeing process (a) is carried out in the presence of a water-miscible organic solvent. 10. The method according to claim 9, characterized in that the organic solvent has a boiling point above 80 ° C. 11. The method according to any one of claims 1 to 10, characterized in that the tanning is carried out with mineral, vegetable and / or synthetic tanning agents. 12. The method according to claim 11, characterized in that the tanning is carried out with a chromium-containing synthetic tanning agent. 13. The method according to any one of claims 1 to 12, characterized in that the tanning stage (b) is carried out at a pH of 2.5 to 4.