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
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/4935—Impregnated naturally solid product [e.g., leather, stone, etc.]

Definitions

• R is an alkyl radical of 16 to 24 carbon atoms.
• This invention relates primarily to treatment of suede leather and other types of unfinished 1 leather employed in the manufacture of shoes and garments.
• One of the problems with leather garments occurs when they are dry cleaned.
• the dry cleaning solvent extracts much of the fat liquor from the leather, thereby rendering it hard and undesirable by way of feel.
• the leather garment is immersed in the dry cleaning solvent which generally contains neatsfoot oil and thereafter removed from the solvent and dried and then sprayed with an emulsion or solution of wax or some other material to enhance softness.
• the water or solvent is evaporatediand it is necessary to brush the leather several times in order to obtain the original nap and softness. In general, at least two brushings is required and these are usually hand operations. If water repellency is desired, the garment is sprayed with a suitable product. Consequently, the dry cleaning of leather garments is quite expensive.
• This invention relates to a method of treating leather which comprises impregnating the leather with 1) a copolymer of units of the formula and (B) Me SiO units in amount of at least 3 moles 2 of (B) per mole of (A), and (2) a polysiloxane of the unit formula hie RSi O which can contain up to 96 mol percent copolymerized Me SiO units in which siloxanes (l) and Y is an acid anion,
• R is an alkylene radical of 2 to 6 inclusive carbon atoms
• R is a lower alkyl radical
• a has a value from 0 to l
• b has a value from 0 to 2
• R" is an alkyl or an aralkyl radical of at least 9 carbon atoms, and the weight ratio of (l) to (2) is from 4:1 to 0.75:1.
• compositions of matter consisting essentially of mixtures of (l) and (2).
• consisting essentially of means that the compositions can contain other ingredients normally employed in the treatment of leather which do not materially change the effects of the combination l) and (2).
• (1) and (2) can be applied to the leather either as a mixture (i.e., simultaneously) or they can be applied separately. In either case the application can be from solvent solutions or aqueous solutions or emulsions.
• the solvent solutions are generally preferred when employing (1) and (2) during dry cleaning of a leather garment.
• Aqueous emulsions are generally preferred when the (1) and (2) are applied to leather at the tannery during processing of the leather.
• the amount of (l) and (2) used on the leather is not critical, but can vary from 0.5 to 25% total (1) and (2) by weight based on the 2 Based on unit weight (i.e., 74 for MeaSiO).
• leather employed herein includes animal hide in general, including cowhide, pigskin, sheepskin, horsehide, etc.
• the treatment of this invention is particularly suitable to suede leather, that is leather having a nap, and such leather, as is well known is primarily employed in the manufacture of coats, jackets, and special types of shoes.
• Copolymer (1) employed in this invention is a copolymer of an aminoalkylsiloxane of the type shown and dimethylsiloxane.
• R can be any alkylene radical of from 2 to 6 carbon atoms, such as CH CH CH CH CH and R can be any lower alkyl radical such a methyl, ethyl, propyl, isopropyl or butyl and a can be or 1. Therefore the amine can be substituted on a silicon with no other substituents or on a silicon with one other substituent.
• Y can be any acid anion either from a carboxylic acid or other organic acids such as sulfonic acid, or phosphinic acid or acid alkyl sulphonate; or it can be derived from inorganic acids such as hydrochloric, hydrobromic, sulfuric, nitric, phosphoric, etc.
• Y is an anion of a monocarboxylic acid, such as acetic, formic, propionic, hexoic, etc.
• it is preferred to employ the amine salt when the composition is to be used in the form of an aqueous dispersion.
• the composition is to be employed in the form of solvent solutions, it is preferred that the amine per se be used.
• the ratio of aminosiloxane units and dimethylsiloxane units must be such that there is at least 3 mols of dimethylsiloxane units per mol of aminosiloxane unit.
• the upper limit of this ratio is not critical, however, it is preferred that there be no more than 1000 dimethylsiloxane units per amine siloxane units with optimum results often being obtained with no more than 100 Me SiO units per amine siloxane unit.
• Ingredient (2) of this invention can be an alkylmethylsiloxane or an aralkylmethylsiloxane of the formula RMeSiO in which R" can be a hydrocarbon radical having at least 9 carbon atoms such as alkyl radicals, such as decyl, dodecyl, tetradecyl, octadecyl, C H and myricyl; or any aralkyl radical such as beta-phenylpropyl If desired, composition (2) can have dimethylsiloxane copolymerized with the R"MeSiO and the dimethyl can be present in amounts up to 96 mol percent of the total composition (2).
• R" can be a hydrocarbon radical having at least 9 carbon atoms
• alkyl radicals such as decyl, dodecyl, tetradecyl, octadecyl, C H and myricyl
• any aralkyl radical such as beta-phenylprop
• Both components (1) and (2) can have silicon-bonded hydroxyls on the ends of the chain or they can be endblocked with triorgano-substituted siloxanes or with any other of the endblocking units normally employed in commercial siloxanes such as alkoxy groups, acetoxy groups, etc.
• (l) and (2) are not critical since these materials can be in the form of linear, branched or cyclic molecules or mixtures thereof.
• the leather can also be treated with other materials normally employed in leather to perform specific functions therein, such as, for example, glutaraldehyde, or other materials used in the tanning or fixing processes.
• the additional materials can be used in admixture with or in Separate steps with respect to (1) and (2).
• R represents radicals of the formula C H to (lliez) Bile MBgSiO SiO 4(Si0 SiMes C20H41; and 50 g. of perchloroethylene.
• EXAMPLE 2 53.4 g. of (1) of Example 1 and 26.6 g. of (2) of Example 1 was dissolved in 15 g. of an aliphatic hydrocarbon solvent and 5 g. of isopropanol. The above solution was added to an aliphatic hydrocarbon solvent in a commercial dry cleaning establishment during the dry cleaning of a suede leather coat in the amount of 4% by weight of (A) and (B) based on the dry weight of the leather. The garment was tumbled for 25 minutes, then centrifuged to remove the solvent and dried at roomtemperature for 48 hours and then 10 minutes at 65 C. After light brushing the coat had excellent sheen, nap and softness. It did not water spot and had a spray rating of 65.
• EXAMPLE 4 This example is given by way of comparison to show that dimethylsiloxane cannot be substituted for (2) in the compositions of this invention.
• the process of Example 1 was repeated except that three-fourths of composition (2) was replaced by lYlea Me si (Si 0 SiMe3 having a viscosity of 350 cs.
• the resulting suede leather had a poor appearance and the spray rating was less than 50.
• EXAMPLE This example illustrates the step-wise addition of (l) and (2).
• Four samples of pigskin suede leather were washed with water for 15 minutes at 130 F. then drained and covered with water in a Najort washer.
• a 40% aqueous emulsion of (2) of Example 1 was added in amount to give 5% by weight (2) based on the dry weight of the leather.
• the leather was then agitated for 30 minutes at 130 F. 2.5% glutaraldehyde was added based on the dry weight of the leather and agitation was continued 45 minutes at 130 F.
• 2.4 g. of a 0.2% by weight solution of sodium bicarbonate was added to the leather in three portions at intervals of 5 minutes. This was for the purpose of adjusting the pH of the leather.
• the leather was washed 15 minutes, drained and refloated in water at 130 F.
• a composition 1) was prepared by reacting 37.5%
• MeC O OH Me (MeCOOH-HaN CHzCHzNHCHzJIHCHzSi 02/2) 1 2 0) by weight of a hydroxyl-endblocked dimethylpolysiloxane fluid having 1.63% by weight silicon-bonded hydroxyl, 12.5% by weight hide (N180) SlCHzCH2CHNHCH2CH2NH2 and 6.8% by Weight acetic acid in 43.2% by weight isopropanol.
• This solution was added to the leather bath in amount to give 5% by weight (1) based on the dry weight of the leather. The bath was then agitated 30 minutes at 130 F. The leather was then removed and washed with water at 90 F.
• the resulting leather had good tracking, good temper and good water resistance, as shown by the fact that it absorbed only 21.2% by weight water after 4000 flexes on leather flex tester No. 1002, sold by Dow Corning Corporation, Midland, Mich.
• the product was a copolymer of the average formula 6 That which is claimed is: 1.
• a method of treating leather which comprises impregnating the leather with (1) a copolymer of the unit formula and (B) units of the formula Me SiO in amount of at least 3 mols of (B) per mole of (A), and
• ( 2) a polysiloxane of the unit formula Me RS iO which can contain up to 96 mol percent copolymerized Me SiO units in which siloxanes 1) and (2) Y is an acid anion, R is an alkylene radical of 2 to 6 inclusive carbon atoms, R is a lower alkyl radical, a has a value from 0 to 1, b has value from 0 to 2, and R" is an alkyl or an aralkyl radical of at least 9 carbon atoms, the weight ratio of (1) to (2) being from 4:1 to 0.75:1.
• a composition of matter consisting essentially of a mixture of 1) a copolymer of the unit formula (Y-)bH; NCH2CHzNHRSiO '2 and (B) units of the formula Me SiO in amount of at least 3 mols of (B) per mole of (A), and (2) a polysiloxane of the unit formula which can contain up to 96 mol percent copolymerized Me SiO units in which siloxanes (1) and (2) Y is an acid anion, R is an alkylene radical of 2 to 6 inclusive carbon atoms, R is a lower alkyl radical, a has a value from 0 to 1, b has a value from 0 to 2, and R" is an alkyl or an aralkyl radical of at least 9 carbon atoms, the weight ratio of (1) to (2) being from 4:1 to 0.75:1.
• composition of claim 6 in which (1) is a copolymer of NHzCHzCHzNHCHzCHCHgSiOa/z and Me SiO and ,(2) is a copolymer of 1 and Me SiO in which R" is an alkyl radical of at least 9 carbon atoms.
• composition of claim 6 in which (B) is present in amount of from 3 to 100 mols per mol of (A).

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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)

Applications Claiming Priority (1)

Publications (1)

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ID=24880290

Family Applications (1)

Country Status (6)

Cited By (4)

Families Citing this family (2)

Citations (1)

• 1968
  • 1968-03-28 US US3494977D patent/US3494977A/en not_active Expired - Lifetime
• 1969
  • 1969-03-05 GB GB1230953D patent/GB1230953A/en not_active Expired
  • 1969-03-25 FR FR6908751A patent/FR2004916A1/fr not_active Withdrawn
  • 1969-03-26 DE DE19691915482 patent/DE1915482A1/de not_active Withdrawn
  • 1969-03-27 AT AT302969A patent/AT289286B/de not_active IP Right Cessation
  • 1969-03-27 BE BE730569D patent/BE730569A/xx unknown

Patent Citations (1)

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