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
  • C14C9/00—Impregnating leather for preserving, waterproofing, making resistant to heat or similar purposes

Definitions

• the invention relates to a process for waterproofing leather and furs with a silicone oil and the salt of an N- (C9-C20-acyl) amino acid as an emulsifier for the silicone oil, which is carried out in the aqueous phase during or after retanning, and the use of salts of N- (C9-C20-acyl) amino acids for emulsifying silicone oil in the aqueous phase in the waterproofing of leather and furs and the mixtures used.
• a wide variety of methods for waterproofing are known for leather and furs.
• silicone oils are also used for this finishing stage.
• the polysiloxanes used are always dissolved in organic solvents such as gasoline or chlorinated hydrocarbons. Disadvantages when working with these solvents are the harmful and polluting effects as well as the fire risk when using gasoline.
• the hydrophobization with the help of organic solvents also means an additional work step and thus a considerably increased effort.
• N-acylamino acids especially fatty acid sarcosides, e.g. N-oleoyl sarcosine, in the form of their salts, are known as emulsifiers for paraffins and waxes, which can also be used, for example, in the waterproofing of leather.
• emulsifiers for paraffins and waxes which can also be used, for example, in the waterproofing of leather.
• the effects that can be achieved with waxes and paraffins are not always sufficient for today's high requirements and are usually supplemented by a separate post-hydrophobic treatment with, for example, fluorochemicals or silicone oils that are applied from the organic phase.
• the object of the invention is to develop a process for hydrophobizing leather and furs, in which organic solvents are not necessary and can be rendered hydrophobic with a silicone oil in the aqueous phase, the technical application effect on leather and furs being at least equivalent to that of silicone oils from organic Solvents should be.
• the solution to the problem consists in a process for waterproofing leather and furs, in which a silicone oil with the salt of an N- (C9-C20-acyl) amino acid as an emulsifier in an aqueous liquor onto the leather or furs to be finished during or after of retanning.
• the invention is based on the observation that N- (C9-C20-acyl) amino acids, in particular fatty acid sarcosides, in the form of their salts are excellent emulsifiers for silicone oils, so that the use in water repellent treatment of leather and furs in aqueous liquors can be demonstrated for the first time .
• Sufficiently stable aqueous emulsions of silicone oils can only be achieved with the indicated emulsifier without additional aids for the purposes of use. This was all the more surprising since the emulsifiers to be used according to the invention can also be absorbed onto the leather during use, so that one could have expected the emulsion to be destabilized.
• the invention also relates to the use of amino acids with 2 to 6 carbon atoms and with the acyl residue of a saturated or unsaturated fatty acid with 9 to 20 carbon atoms on the amine nitrogen atom, which may optionally be substituted by methyl, in the form of an alkali metal, Ammonium or alkanolamine salt for emulsifying silicone oil in the aqueous phase in the waterproofing of leather and furs during or after retanning.
• the invention thus also relates to the use of the aqueous emulsion a) or of the anhydrous mixture b) of the above-mentioned composition in aqueous liquors for hydrophobicizing leather or furs during or after retanning in an amount of from 0.5 to 20% by weight on the fold weight of the leather or wet weight of the furs.
• the particular advantage of the process according to the invention is that, in a simple procedure while avoiding organic solvents, an emulsifier for the silicone oil has been found which emulsifies the silicone oil sufficiently so that the silicone oil can penetrate the leather, followed by the addition of acid and optionally one polyvalent metal salt, the N-acylamino acid salt used is rendered ineffective as an emulsifier, so that the full hydrophobizing effect of the silicone oil comes into play. It should be emphasized that the use of organic solvents and additional auxiliaries, for example nonionic emulsifiers, can be avoided.
• Suitable silicone oils are the commercially available silicone oils with viscosities of 30 to 1,000 mPa ⁇ s, preferably 80 to 500 mPa ⁇ s. Such silicone oils can be readily used by those skilled in the art, for example Römpps Chemie-Lexikon, 7th edition, Stuttgart, 1975, pp. 3223ff, or Ullmanns Enzyklopadie der techn. Chemie, 4th ed., 1982, volume 21, pp. 512ff.
• silicone oils are suitable in which the remaining valences of silicon are saturated by hydrocarbon radicals, in particular methyl, but also ethyl, propyl or phenyl.
• silicone oils which in their hydrocarbon radicals carry organofunctional groups such as amino, mercapto or carboxyl groups. Because of these functional groups, they are easier to emulsify and thus better bind to the leather fibers.
• organofunctional groups such as amino, mercapto or carboxyl groups. Because of these functional groups, they are easier to emulsify and thus better bind to the leather fibers.
• the viscosities given are a practical measure of the molecular weights, which can often only be determined with great effort.
• Preferred silicone oils are dimethylpolysiloxanes with a viscosity of 80 to 110 mPa ⁇ s, phenylmethyl polysiloxanes with a viscosity of 85 to 120 mPa ⁇ s, dimethylpolysiloxanes with amino groups as reactive groups, characterized by an amine number of about 0.8 to 1.0 and a viscosity of 30 to 50 mPa ⁇ s, and dimethylpolysiloxanes with carboxyl groups as reactive groups, on average with 2 to 10 carboxyl groups per molecule.
• Dimethylpolysiloxanes the methyl groups of which are partly replaced by mercaptopropyl (-CH2-CH2-CH2-SH) or aminopropyl groups (-CH2-CH2-NH2) as reactive groups, are very particularly preferred. As a rule, 1 to 5%, preferably approx. 3%, of the methyl groups in the chain are replaced by these reactive substituents. It is commercially available dimethylpolysiloxanes with terminal -Si (CH3) 3 groups, which can be characterized by a viscosity range from 130 to 200, preferably 145 to 180 mPa ⁇ s. The preferred and particularly preferred silicone oils are commercially available products.
• N- (C9-C20-acyl) amino acids with 2 to 6 C atoms are those with 2 to 4 C atoms, with the amino group in the ⁇ -position to the carboxyl group and which are additionally substituted on the amine nitrogen atom by a methyl group, prefers.
• the fatty acid sarcosides of saturated or unsaturated fatty acids with 9 to 20, preferably 16 to 18, carbon atoms have a particularly superior effect.
• Suitable salts are the alkali metal salts, in particular sodium or potassium, the ammonium salts or salts of a mono-, di- or trialkanolamine having 2 to 4 carbon atoms in the alkanol radical, in particular mono-, di- or triethanolamine.
• the particularly preferred sarcoside is oleic acid sarcoside or N-oleoyl sarcosine (medialanic acid). Furthermore, the N-stearoyl sarcosine, N-lauroyl sarcosine and N-isononanoyl sarcosine are to be emphasized, in each case in the form of the salts mentioned above.
• the silicone oil and the salt of N-acylamino acid are advantageously in the form of an aqueous emulsion as a concentrate, consisting of 15 to 90% by weight of an above-mentioned silicone oil, 5 to 30% by weight of an above-mentioned salt of an N- (C9-C20- Acyl) amino acid and at least 5 to the rest of 100% by weight of water, a pH of 5 to 12, preferably 7 to 10, having been set using an alkali metal hydroxide, ammonia or an alkanolamine.
• the preferred concentrate contains 30 to 60% by weight of silicone oil, 5 to 30% by weight of salt of an N- (C9-C20-acyl) amino acid and 65 to 10% by weight of water, the pH being within a very preferred range has been set from 7.5 to 8.5.
• anhydrous concentrate consisting of 70 to 90% by weight of silicone oil and 10 to 30% by weight of one of the N-acylamino acids defined above in the form of a mono-, di- or trialkanolamine salt is used.
• the silicone oil in the aqueous phase is automatically emulsified by the salt used.
• aqueous emulsion defined above is preferred as the concentrate to be used.
• hydrophobization according to the invention can be combined with a known hydrophobizing agent, for example based on a paraffin or wax emulsion, i.e. at the same time or following a hydrophobization which is customary in aqueous liquors. A significant improvement in the water repellency effects is achieved.
• the concentrates described above can, based on the total weight of the mixture, additionally 5 to 45, preferably 10 to 30,% by weight of solid and / or liquid paraffin, for example paraffin with a melting point of 20 to 100 ° C., paraffin oil or white oil, one contain natural fats or oils, such as fish oil or bone oil, or a synthetic or natural wax, such as polyethylene waxes, polyisobutylene waxes, beeswax or carnauba wax, the weight ratio of silicone oil to paraffin expediently not exceeding the value of 1: 1.
• Solid paraffin with a melting point between 40 and 60 ° C. and white oil are particularly preferred for such a combination.
• the specified amounts of paraffin, fats, oils or waxes are easily absorbed by the concentrates.
• an above-mentioned concentrate based on the shaved weight of the leather or wet weight of the furs, in an amount of 0.5 to 20% by weight, preferably 2 to 10% by weight, optionally together with dyes, during or after the retanning. % used.
• the concentrate used is expediently diluted with water in a ratio of 1: 2 to 1: 5 and added to the working liquor.
• the hydrophobization according to the invention can also be carried out in two stages during and after retanning.
• Useful tanning agents for retanning are vegetable tanning agents and synthetic tanning agents, for example based on phenolsulfonic acid-formaldehyde condensates.
• Suitable dyes which can be used simultaneously are, for example, the customary acidic, substantive or basic aniline dyes.
• the actual hydrophobization according to the invention during or after retanning is carried out by milling in a suitable device usual way: ie with fleet lengths of 50 to 2,000%, preferably 100 to 400%, based on the fold weight of the leather or wet weight of the furs, temperatures of 20 to 60 ° C, preferably 35 to 50 ° C, with the pH at the beginning -Values are generally between 4.5 and 8.0, preferably 4.8 to 5.5.
• the hydrophobization is completed in a time between 20 to 240, preferably 30 to 120 minutes.
• the emulsifier is fixed with acid, preferably formic acid, by adjusting a pH of 3.0 to 5.0, preferably 3.8 to 4.0.
• the effect of the hydrophobization can be enhanced by an aftertreatment with a tetravalent, normal or tetravalent metal salt, in particular with a basic chromium sulfate, with aluminum sulfate, zirconium, titanium sulfate, calcium chloride or magnesium sulfate.
• salts mentioned 0.5 to 5% by weight, preferably 1 to 2% by weight, is expediently used, based on the shaved weight of the leather or wet weight of the furs.
• specified salts basic chromium sulfate and aluminum sulfate are preferred.
• Parts are parts by weight, percentages relate to the weight, unless stated otherwise.
• Example 1 160 parts of the dimethylpolysiloxane characterized in Example 1 and 40 parts of N-oleyl sarcosine (oleic acid sarcoside) are mixed with stirring and heated to 60 ° C. Then a mixture of 160 parts of water and 17.5 parts of triethanolamine heated to 60 ° C. is slowly added with stirring. The mixture is allowed to cool with stirring.
• N-oleyl sarcosine oleic acid sarcoside
• silicone oil emulsions 50.0 parts of a commercially available polysiloxane to be used according to the invention are mixed with 10.0 parts of N-oleoyl-sarcosine with stirring and heated to 60.degree. Then a mixture of 36 parts of water and 4 parts of 25% aqueous sodium hydroxide solution heated to 60 ° C. is slowly added with stirring. The complete conversion to the sodium salt is achieved by stirring until the pH is constant. The pH of the mixture is then adjusted to 7.8 to 8.0 and cooled to room temperature with stirring.
• Example 8 The commercially available polysiloxane used in Example 8 was a dimethylpolysiloxane with a viscosity of approximately 95 mPa ⁇ s, in Example 9 a phenylmethyl polysiloxane with a viscosity of approximately 95 mPa ⁇ s, in Example 10 an amino-functional dimethylpolysiloxane with an amine number of approximately 0.8 to 1.0 and a viscosity of 30 to 50 mPa ⁇ s and in Example 11 a dimethylpolysiloxane with 4 carboxyl groups in the molecule.
• Chromium pre-tanned cowhide with a fold thickness of 2.2 mm which has been deacidified to a pH value of 5.0 to 6.0, based on the fold weight, with 5% by weight of commercially available mimosa extract and 3% by weight of a commercially available synthetic tanning agent based on phenolsulfonic acid-formaldehyde condensate, 1% by weight of a commercially available aniline dye and 5% by weight of the silicone oil emulsion specified in Example 1, drummed for 1.5 hours in a tanning drum at 40 ° C., the pH of the treatment liquor being 100% 5. Is 2 to 5.5.
• Example 1 In the fresh bath of 100% water and 40 ° C., a further 3% by weight, based on the shaved weight, of the silicone emulsion specified in Example 1 is rolled into the leather within 30 minutes. It is acidified with 85% formic acid to a pH of 3.8 to 4.0 and with 2% by weight of a commercially available chrome tanning agent (Cr2O3 content of 25% and a basicity of 33%) for 90 minutes at 40 ° C fixed. The leathers are then washed, mechanically stretched and dried.
• chrome tanning agent Cr2O3 content of 25% and a basicity of 33
• chrome tanning agent chromium oxide content approx. 25%, basicity approx. 33%). After washing out, the usual drying takes place.
• Chromium-tanned cowhide (wet blue) is used for post-tanning after deacidification to pH 5.0 to 6.0, each based on the shaved weight of the leather, 7.5% by weight of a mixture of vegetable and synthetic commercial tannins based on naphthalenesulfonic acid-formaldehyde -Condensate, 1.5% by weight of a commercially available aniline dye and 7% by weight of a customary water repellent for leather based on a paraffin emulsion, drummed for 60 minutes in the drum and then for a further 30 minutes with 3% by weight of the silicone oil emulsion according to Example 1 in the drum tumbled. With further walking for 30 minutes, the mixture is acidified to a pH of 4.0 with formic acid and fixed with 1.5% by weight of commercially available chromium tanning agent within 90 minutes.
• the leather is rinsed and dried as usual.
• the wetblue leathers deacidified to a pH of 5.0 to 6.0 with commercially available deacidifying agents are retanned, dyed, as indicated in Example A, and with, based on the shaved weight, 8% by weight of a commercially available, non- Fat-repellent mixture with a hydrophobic effect, greased, acidified to a pH of 4.0 and rinsed.
• the mixture is then drummed in fresh liquor (100%, 40 ° C.) for 30 minutes with 4% by weight of the silicone oil emulsion described in Example 3 with paraffin and white oil and fixed with 1.5% by weight of commercially available chrome tanning agent for 60 minutes.
• the chrome-tanned leather deacidified to a pH of 5.0 to 6.0, is retanned with 7% by weight of a mixture of commercially available vegetable and synthetic tanning agents based on phenol condensate, based in each case on the shaved weight of the leather 1.2% by weight of aniline dye and greased with 5% by weight of commercially available, non-hydrophobic grease licker for 40 minutes.
• the mixture is then drummed with a mixture of 3% by weight of the silicone oil emulsion specified in Example 1 and 3% by weight of a commercially available hydrophobicizing agent based on paraffin emulsion, acidified to pH 3.8 to 4.0, for 30 minutes and with 5 wt.% Of a commercially available aluminum salt (Al2SO4) 3 ⁇ 18 H2O fixed for 60 min, washed out and stretched and dried as usual.
• Al2SO4 aluminum salt

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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)
• Materials Applied To Surfaces To Minimize Adherence Of Mist Or Water (AREA)

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• 1985
  • 1985-08-21 DE DE19853529869 patent/DE3529869A1/de not_active Withdrawn
• 1986
  • 1986-08-12 DE DE8686111130T patent/DE3661933D1/de not_active Expired
  • 1986-08-12 EP EP86111130A patent/EP0213480B1/fr not_active Expired
  • 1986-08-13 US US06/895,686 patent/US4701269A/en not_active Expired - Lifetime
  • 1986-08-14 CA CA000515970A patent/CA1255855A/fr not_active Expired
  • 1986-08-19 JP JP61192226A patent/JPS6245700A/ja active Granted
  • 1986-08-21 ES ES8601254A patent/ES2001252A6/es not_active Expired

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