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
  • C14C9/04—Fixing tanning agents in the leather
• • 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 present invention relates to aminosiloxane or aminopolysiloxane-containing waterproofing agents for leather.
• waterproofing or repelling (hydrophobing) of leather during or at the end of the wet dressing and in whole or in part instead of greasing (also called barrel hydrophobization) by treatment with preparations from aliphatic hydrocarbons, synthetic or natural oils and fats in combination with halogenated hydrocarbons and Suitable emulsifiers have been widely introduced in the leather industry in addition to other hydrophobing methods.
• a particular advantage of this barrel water repellent treatment on wet leather compared to water repellent treatment with silicones or fluorocarbons, which are applied to dry leather in an aftertreatment mostly from water-immiscible organic solutions, is that they are used completely or at least partially in place of the customary licker lubrication can and in addition to the actual hydrophobization softens the leather (see e.g. preparations made from natural and / or synthetic fatty substances and waxes as well as paraffin hydrocarbons with emulsifiers, which are fixed by fixation with acids or metal salts and thereby lose their hydrophilicity).
• This additional aftertreatment can be carried out on dry leather with silicones or fluorocarbons which are dissolved in organic solvents or on wet leather with silicones which are used from an aqueous emulsion or an alcoholic / aqueous dispersion.
• silicones or fluorocarbons which are dissolved in organic solvents
• wet leather with silicones which are used from an aqueous emulsion or an alcoholic / aqueous dispersion.
• the aftertreatment agents according to the invention give excellent results with regard to the waterproofness of the leather.
• the values for water resistance are significantly higher than for barrel water repellency with silicone free emulsions and are - without further aftertreatment - comparable to watertightness, which can usually be achieved by barrel hydrophobization (silicone-free) and additional aftertreatment with silicone and / or fluorocarbons.
• saturated and unsaturated straight and branched chain paraffins with C numbers from 10 to 24, preferably 15 to 20, and solid predominantly straight chain and saturated paraffins, preferably technical paraffin mixtures with softening points from 35 to 50 ° C, preferably 40 to 45 ° C and oil fractions of less than 5%.
• hydrocarbons described above are preferably used together with halogen-containing, preferably chlorinated, hydrocarbons.
• Chlorine paraffins from straight-chain paraffins with 10 to 20, preferably 15-18, carbon atoms and 15 to 25, preferably 18 to 22% chlorine content have proven to be particularly suitable.
• Particularly suitable emulsifiers c) are the amides of saturated and unsaturated, aliphatic carboxylic acid with 15 to 20, preferably 18 C atoms and alkylaminoacetic acids, preferably methylaminoacetic acid or their alkali, ammonium, mono-, di-, trialkylammonium and Mono-, di- and trialkanol, preferably ethanolamine salts.
• aminosiloxanes b) can be represented by the following general formula units:
• R 1 independently of one another is an alkyl group having 1 to 6 C atoms, a vinyl group or a phenyl group, preferably a methyl group, R2 alkyl or aryl radicals containing amino groups with primary, secondary, tertiary or quaternary amino groups
• R3 is an alkyl group with 1 to 6 carbon atoms
• R4 is an alkyl group, phenyl group or aminoalkyl group with 1 to 12 C atoms
• q, x and m 0 to 5
• the aminosiloxanes can e.g. by reaction of ⁇ -aminopropyl-trialkoxysilane with ⁇ , ⁇ -hydroxy-terminated polydimethylsiloxanes or by equilibration with amino-functional siloxanes.
• R3 has the above meaning and Y has the above value and R represents hydrogen, an alkyl or aminoalkyl radical, used.
• the hydrocarbons are used in amounts of 25 to 65% by weight, based on the sum of components a) to d); preferably 37 to 52% by weight.
• the proportion of chlorinated hydrocarbons can be 20 to 40, preferably 25 to 35% by weight.
• the emulsifier is added in an amount of 2 to 15, preferably 5 to 10% by weight and the aminosiloxane in an amount of 5 to 20, preferably 10 to 13% by weight.
• the hydrophobizing agent can be prepared anhydrous or as an aqueous emulsion with up to 68% water, preferably 24 to 48% by weight water.
• the water-free preparations from components a) to c) can separate at temperatures below 10 ° C. and are expediently emulsified in water before use on leather, the preparation of emulsions which can be diluted with water is particularly recommended.
• an aminosiloxane preparation obtained by reacting 74 g of ⁇ , ⁇ -hydroxy-terminated polydimethylsiloxane having a viscosity of 500 mm2 / sec with 5 g of N- ⁇ -aminoethyl-aminopropyltrimethoxysilane at 70 to 75 ° C. (stirring for 1 hour) are obtained with 310.6 g chlorine paraffin (C chain length 10 to 18 and 20% chlorine content), 153.3 g n-paraffin mixture (softening point 40 to 42 ° C and oil content approx.
• chrome-tanned cowhide leather folded to 2.0 to 2.1 mm is washed, neutralized, optionally dyed and retanned, as described in detail in the following recipe, and then treated with 6.5% of a water-dilutable water repellent emulsion prepared according to Example 1.1 and then fixed with a 33% basic chromium III sulfate. After overnight storage in a moist state, vacuum and hanging drying as well as studs, ventilation and re-vacuuming, the leathers are extremely waterproof.
• the pressure is reduced to 30 to 40 mbar and distilled at this bottom temperature up to 140 ° C.
• the template is then changed, the pressure is reduced to 5 to 10 mbar and baked for 1 hour at 140 ° C. and 5 to 10 mbar. After cooling to below 30 ° C and pressure equalization with nitrogen, the mixture is filtered.
• the resulting, clear and slightly yellow aminosiloxane oil has the following characteristics: Viscosity: 344 m.Pas (Köppler 23 ° C) Solids content: 95.1% (according to DIN 53 182) Titration: 0.133 mmol NH2 / g Density: 0.975 g / ml at 23 ° C
• the percentages in the following recipe relate to the fold weight of the chrome-tanned split leather.

Landscapes

• 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)

Applications Claiming Priority (2)

Publications (3)

Family

ID=6321824

Family Applications (1)

Country Status (5)

Cited By (1)

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Family Cites Families (3)

• 1987
  • 1987-02-26 DE DE19873706203 patent/DE3706203A1/de not_active Withdrawn
• 1988
  • 1988-02-16 EP EP88102224A patent/EP0280152B1/fr not_active Expired - Lifetime
  • 1988-02-16 DE DE3889558T patent/DE3889558D1/de not_active Expired - Fee Related
  • 1988-02-19 JP JP63035419A patent/JPS63210200A/ja active Pending
  • 1988-02-25 BR BR888800310A patent/BR8800810A/pt not_active Application Discontinuation
  • 1988-02-26 KR KR1019880001968A patent/KR880010136A/ko not_active Withdrawn

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