Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/025—Duplicating or marking methods; Sheet materials for use therein by transferring ink from the master sheet
  • B41M5/035—Duplicating or marking methods; Sheet materials for use therein by transferring ink from the master sheet by sublimation or volatilisation of pre-printed design, e.g. sublistatic
  • B41M5/0355—Duplicating or marking methods; Sheet materials for use therein by transferring ink from the master sheet by sublimation or volatilisation of pre-printed design, e.g. sublistatic characterised by the macromolecular coating or impregnation used to obtain dye receptive properties
• • 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
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S8/00—Bleaching and dyeing; fluid treatment and chemical modification of textiles and fibers
  • Y10S8/916—Natural fiber dyeing

Definitions

• From EP-PS 14 901 is a method for printing a substrate that is resistant to heating when heated above 220 ° C. after the transfer printing process by coating the substrate with a plastic that is affine to the printing inks, placing an auxiliary carrier printed with sublimable dispersion dyes on the plastic coating and transferring the dispersion dyes known by dry heat treatment in the plastic coating.
• Crosslinkable thermosets from the group of phenoplasts, aminoplasts, polyesters, polyphenylene sulfide resins, silicone resins, acrylate resins, alkyd resins, polyethylene sulfide resins and / or unsaturated polyester resins are used as the plastic for coating the substrate.
• the object underlying the invention was therefore to obtain a method with which leather can be printed in high quality in the simplest possible manner without disadvantageously changing the mechanical properties, the appearance and the feel of the leather.
• the inventive method for printing on leather substrates by the transfer printing process by surface treatment of the substrate, placing a printed with sublimable dyes subcarrier and transfer of the dyes by dry heat treatment on the substrate is characterized in that orkondensates the substrate surface with an aqueous solution of a V a urea Aldehyde resin or melamine-aldehyde resin impregnated, the solvent is removed at a temperature which does not yet cause condensation of the precondensate, and the dyes are transferred at a temperature between 140 and 250 ° C for a sufficiently long time to simultaneously condense out the precondensate.
• the process according to the invention has the advantage that the handle and the appearance of the treated printed leather do not change compared to untreated leather, so that the treatment never gives the impression of an artificial product.
• the process can be applied to all types of leather, such as cowhide, calf leather, buffalo leather, horse leather, sheep and lamb leather, goat leather, pig leather, red suede leather, chamois leather, antelope leather, moose leather, reindeer leather, camel leather, kangaroo leather, etc.
• the method is particularly suitable, however, for printing mineral-tanned leather qualities, particularly those which Chrome tanning.
• chrome leather as such has superior properties, such as being water-resistant and heat-resistant and having particularly good strength properties.
• cow box, horse box, box calf, calfskin boxcalf, goatskin Chevreau, chrome-soft sheepskin leather, chrome suede leather with a cut, flesh side and nubuck leather with a sanded grain side can be printed according to the invention without any problems.
• the light fastness, wash and cleaning fastness of the prints are excellent, which was not to be expected for the expert.
• the pretreatment according to the method according to the invention results in retanning of the leather, which further improves its properties.
• concentration of the aqueous impregnation solution can vary in both areas.
• a preferred concentration of the precondensate is 4-12%.
• the aldehyde component in the precondensate is preferred.
• Formaldehyde but can also be glyoxal, glutaraldehyde or an other aldehyde.
• Epichlorohydrin can also be used as an aldehyde-equivalent component.
• the urea may be unsubstituted or substituted, such as dimethylolurea, a cyclic dimethylolurea compound, such as a dimethylol compound of ethylene urea, dihydroxyethylene urea, popylene urea and its derivatives.
• the melamine component of the precondensate can also be unsubstituted or substituted, such as a methylolmelamine compound, such as tetramethylolmelamine or a water-soluble etherified methylolmelamine compound.
• the preferred pre-condensates are urea-formaldehyde resins or melamine-formaldehyde resins unsubstituted or substituted urea and melamine components.
• acidic or potentially acidic catalysts such as magnesium chloride, diammonium sulfate, zinc nitrate, zinc chloride or magnesium nitrate, are also added to the impregnation solution.
• suitable catalysts are the metal salts of polycarboxylic acids, such as magnesium, zinc, aluminum, zirconium, iron, nickel, copper and sodium salts of ethylenediaminetetraacetic acid, nitrilotriacetic acid, diethylenetriaminepentaacetic acid, citric acid, tartaric acid or succinic acid.
• the dimagnesium salt of ethylenediaminotetraacetic acid is particularly suitable.
• the catalyst can also be incorporated into the auxiliary carrier for transfer printing, such as, for example, magnesium chloride, with which the paper acting as auxiliary carrier is impregnated.
• the impregnation of the leather surface with the impregnation solution is advantageously carried out by spraying the leather surface with the aqueous solution or suspension. This diffuses into the micellar cavities until they are saturated. Then it is carefully dried at a temperature at which the solution water of the impregnation solution is removed from the leather surface, but at which no condensation of the precondensate is yet brought about.
• the drying temperature is expediently a maximum of 120, preferably a maximum of 110 ° C., the drying being able to be assisted by applying a vacuum.
• the precondensate and possibly catalyst are deposited in the micellar cavities and essentially not on the leather surface. This has the advantage that by condensing out the precondensate, the appearance and feel of the leather are practically unchanged compared to the untreated product.
• the transfer i.e. the transfer of the dyes from the auxiliary carrier to the leather surface takes place by heating to a temperature between 140 and 250 ° C. Heating can be done on a discontinuous press or a continuous calender. At the specified temperature, not only are the dyes sublimed from and onto the leather surface, but at the same time the precondensate is condensed out, care being taken to ensure that the heating time is sufficient to achieve sufficient condensation of the precondensate.
• Preferred temperatures are in the range from 160 to 220, particularly in the range from 180 to 200 or from 180 to 220 ° C.
• the dyes are converted into the gaseous state in a purely physical process and sublimate 20 to 60 gm into the leather surface.
• the simultaneous condensation of the precondensate is condensed under the catalytic influence of the acid catalyst added and / or under the catalytic influence of the mineral tanning agent embedded in the leather surface, such as Cr 2 0 3 or Al 2 O 3 , with the escape of water molecules to form a larger molecule, which is affinity for dye. Since this larger molecule forms in the micropores of the leather surface, the dye is simultaneously fixed in these pores.
• Formaldehyde not only reacts with free amino groups, but also with acid amides to form methylol compounds: R-CO-NH 2 + HCHO ⁇ R-CO-NH-CH 2 -OH,
• Cyclic peptide compounds also react with formaldehyde, like the two acid amide groups of diketopiperazine, to form dimethyldiketopiperazine.
• the unusually high migration resistance of the printed leather achieved with the method according to the invention is also caused by colloidal reactions of secondary valency, with the molecular lattice being irreversibly solidified by methylene bridges between regularly recurring peptide groups of parallel polypeptide chains. Resistance to migration means that the dyes do not migrate or practically do not migrate within the leather surface, thus blurring the printed pattern or image or changing it to shades of gray.
• a particularly useful type of dyestuff is that of the fat- or oil-soluble dyestuffs, particularly those which can be converted into the gaseous state of aggregation between 160 and 220 ° C.
• Such dyes are, for example, azo dyes and anthraquinone dyes which do not dissolve in fats, oils, waxes, resins, hydrocarbons, chlorinated hydrocarbons, alcohols, ethers, etc., but in water.
• Such dyes are for example known under the name udanfarbstoffe S (trademark of BASF). So far, such dyes have been used for coloring mineral oil products, such as gasoline fuels, diesel oil, heating oil, etc., of mineral oil fractions, of wax products, such as shoe creams, bean paste, candles, etc. They will too built into sunscreens and used to manufacture pyrotechnic articles for colored smoke formation.
• fat or oil-soluble dyes are amino azo dyes and oxyazo dyes, such as those of the formulas p-dimethylamino-azobenzene Sundan brown (pigment brown)
• fat and oil-soluble dyes are monoazo, diazo, azomethine, quinoline, ketoimine dyes, complexes of acidic and basic dyes, acridines, xanthenes, triarylmethanes, anthraquinone dyes and phthalocyanine compounds.
• Such dyes have little lightfastness when printed on paper. It is all the more surprising that, according to the invention, they have no good to excellent lightfastness when printed on pretreated leather. From a coloristic point of view, these dyes can be adjusted particularly sensitively to reproducible fashion shades.
• Another group of dyes which is advantageous for the process according to the invention is that of the basic dyes. They result in particularly brilliant colors and good fastness properties.
• the cationic dyes are mostly those of the monoazo series, such as aminoazo dyes, which are formed by coupling diazonium salts with amines. Examples are the following:
• a third group of dyes expediently used in the process according to the invention is that of the disperse dyes which are also used in other transfer printing processes but have no affinity for proteins, wool or leather. Nevertheless, with such disperse dyes you get wash-proof, dry-cleanable and light-fast prints on leather.
• Disperse dyes are particularly suitable which contain reactive hydroxyl, amino, amide, sulfo or carboxyl groups.
• the disperse dyes used according to the invention can be divided into two classes taking into account the temperature behavior, such as softening, melting, gluing, oxidizing, decomposing, etc.
• dyes are the following compounds: 1-amino-2-phenoxy-4-hydroxyanthraquinone, 4-phenylazo-N-phenylaniline, 1,4-diamino-2-methoxyanthraquinone, 1,4-diaminoanthraquinone, 3-methyl-4-p -nitrophenylazo-N, N-dihydroxy-ethylaniline, 1,4-dimethylaminoanthraquinone, 1,4,5,8-tetraaminoanthraquinone and analogous compounds.
• Dispersionstarbstotien that can be used in the present process, 14 to 901 can be found in DE-PS 26 42 350 and in EP-PS, the dyes and dye groups described therein is B e-train made here.
• Disperse dyes used with preference are anthraquinone, monoazo and / or azomethine dyes.

Landscapes

• Coloring (AREA)
• Treatment And Processing Of Natural Fur Or Leather (AREA)
• Synthetic Leather, Interior Materials Or Flexible Sheet Materials (AREA)
• Thermal Transfer Or Thermal Recording In General (AREA)
• Printing Methods (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=6288429

Family Applications (1)

Country Status (7)

Cited By (5)

Families Citing this family (4)

Family Cites Families (7)

• 1985
  • 1985-12-14 DE DE19853544239 patent/DE3544239A1/de not_active Withdrawn
• 1986
  • 1986-11-18 EP EP86115985A patent/EP0226818A3/fr not_active Withdrawn
  • 1986-12-01 FI FI864885A patent/FI864885L/fi not_active IP Right Cessation
  • 1986-12-09 JP JP61291689A patent/JPS62140872A/ja active Pending
  • 1986-12-12 US US06/940,926 patent/US4892556A/en not_active Expired - Fee Related
  • 1986-12-12 DK DK597886A patent/DK597886A/da not_active Application Discontinuation
  • 1986-12-12 NO NO865038A patent/NO865038L/no unknown

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