Classifications

• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06P—DYEING OR PRINTING TEXTILES; DYEING LEATHER, FURS OR SOLID MACROMOLECULAR SUBSTANCES IN ANY FORM
  • D06P1/00—General processes of dyeing or printing textiles, or general processes of dyeing leather, furs, or solid macromolecular substances in any form, classified according to the dyes, pigments, or auxiliary substances employed
  • D06P1/44—General processes of dyeing or printing textiles, or general processes of dyeing leather, furs, or solid macromolecular substances in any form, classified according to the dyes, pigments, or auxiliary substances employed using insoluble pigments or auxiliary substances, e.g. binders
  • D06P1/46—General processes of dyeing or printing textiles, or general processes of dyeing leather, furs, or solid macromolecular substances in any form, classified according to the dyes, pigments, or auxiliary substances employed using insoluble pigments or auxiliary substances, e.g. binders using compositions containing natural macromolecular substances or derivatives thereof
  • D06P1/48—Derivatives of carbohydrates
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06P—DYEING OR PRINTING TEXTILES; DYEING LEATHER, FURS OR SOLID MACROMOLECULAR SUBSTANCES IN ANY FORM
  • D06P1/00—General processes of dyeing or printing textiles, or general processes of dyeing leather, furs, or solid macromolecular substances in any form, classified according to the dyes, pigments, or auxiliary substances employed
  • D06P1/44—General processes of dyeing or printing textiles, or general processes of dyeing leather, furs, or solid macromolecular substances in any form, classified according to the dyes, pigments, or auxiliary substances employed using insoluble pigments or auxiliary substances, e.g. binders

Definitions

• the present invention deals with a thickener for printing pastes based on polygalactomannans derivatives and an enzyme, and with textile printing pastes containing said thickener.
• the enzyme useful for this invention is a protease and the polygalactomannans derivatives are those commonly utilised in textile printing, such as depolymerised, hydroxyalkylated or carboxymethylated polygalactomannans.
• the fabrics printed with the textile printing pastes of the present invention show a better uniformity of dye distribution, as demonstrated by an improved visual effect noticeable on the final article.
• Textile printing pastes serve to transfer dyes onto the fabric in a controlled way through a silk-screen, in order to have the correct formation of the * desired pattern and decoration.
• the textile printing paste composition is critical and largely determines the quality of the final article.
• Printing pastes are prepared by solubilising a thickener in water and, successively, by adding the dye and other possible chemical auxiliaries useful to the process (such as pH regulators, antifoam agents, stabilisers and others) and have a solid content comprised between 7 and 20% by weight.
• Commonly used thickeners are mainly composed by one or more water soluble natural or semisynthetic polymers of varying molecular weight, such as starch and its derivatives, alginates, polysaccharides from tamarind kernels, cellulose derivatives, polygalactomannans in general and polygalactomannans from guar seeds and their derivatives in particular.
• water soluble natural or semisynthetic polymers of varying molecular weight, such as starch and its derivatives, alginates, polysaccharides from tamarind kernels, cellulose derivatives, polygalactomannans in general and polygalactomannans from guar seeds and their derivatives in particular.
• Guar is the common name of a leguminosae family plant (Cyamopsis tetragonoloba) cultivated mainly in the arid and pre-desertic area between India and Pakistan.
• the function of thickeners is to guarantee the viscosity to the paste in order to allow a better control in the pattern reproduction and sufficient fluidity for an easy passage through the silk-screen holes onto the fabric.
• Polygalactomannans and their derivatives are among the most used thickeners for printing with acid dyes on fabrics made of fibers like wool, silk and polyamide.
• a textile printing thickener containing one or more polygalactomannan derivatives and an enzyme, in particular a protease permits to obtain printing pastes free from dotting.
• polygalactomannans Due to their natural origin, commercially available polygalactomannans always contain a variable amount of proteins (usually comprised between 2.5 an 10% by weight) deriving from the germ of the guar seed, that is not possible to remove before or during milling of the vegetable structure containing them.
• a possible cause of dotting is that these proteins are potentially able to combine with acid dyes, thus forming complexes, and therefore can aggregate the colour in microscopic masses.
• the enzyme useful for the present invention is a serine protease of the subtilisin family of microbial origin, for example a protease chosen among: Purafect 4000G and Purafect 4000E by Genencor International; Alkalase, Durazym, Savinase, Esperase by Novozymes.
• the polygalactomannan derivatives useful for the present invention are depolymerised guar (depolymerised either by alkaline hydrolysis or by oxidation), hydroxyethylguar, hydroxypropylguar, carboxymethylguar having viscosity measured by Brookfield viscosimeter at 20°C and 20 rpm of about 20.000 mPa*s at a concentration comprised between 1 and 12 % by weight, preferably between 7 and 12% by weight.
• the polygalactomannans derivatives are those normally available on the market for use in the textile printing sector, for example they are commercialised by Lamberti SpA and Cesalpinia Chemicals SpA with the trade names of Printex and Indalca respectively.
• the textile printing thickener of this invention contains preferably from 40 to 99.5% by weight of one or more polygalactomannan derivatives and from 0.5 to 5% by weight, preferably from 0.8 to 2% by weight, of a protease, the eventual complement to 100% being accounted by one or more polymers commonly used in textile printing pastes and having thickening function, such as alginates, starch and its derivatives, tamarind derivatives, synthetic polymers, cellulose derivatives.
• the thickener according the present invention revealed itself particularly useful for the preparation of printing pastes containing acid dyes.
• the thickener contains from 95 to 99.5% by weight of one or more polygalactomannan derivatives and from 0.5 to 5% by weight, preferably from 0.8 to 2% by weight, of a protease.
• a textile printing paste containing one or more polygalactomannan derivatives and an enzyme forms a further essential object of this invention.
• the printing paste contains a serine protease of the subtilisin family of microbial origin in a quantity comprised between 0.015 and 0.35% by weight and from 1 to 7% by weight of one or more polygalactomannan derivatives chosen among depolymerised guar (both depolymerised by alkaline hydrolysis or by oxidation), hydroxyethylguar, hydroxypropylguar, carboxymethylguar. ' ' -
• the polygalactomannan derivatives useful for the preparation of the textile printing pastes of the present invention are, in particular, those that in aqueous solution have a viscosity, measured by a Brookfield viscosimeter at 20°C and 20 rpm of about 20.000 mPa*s at a concentration comprised between 1 and 12% by weight, preferably between 7 and 12% by weight.
• the textile printing paste according the invention can further contains one or more polymers having thickening function, chosen among alginates, starch and its derivatives, tamarind derivatives, synthetic polymers, cellulose derivatives, preferably in a quantity not higher than 4% by weight, and one or more additives among the ones commonly used for the formulation of textile printing pastes.
• Textile printing pastes of the invention can be prepared according to the usual procedures, by slowly adding the thickener to water, under mechanical stirring, until complete dissolution is achieved, and by adding to the thickener solution so obtained the specific auxiliaries (pH regulators, antifoam, and so on) and the dye, and finally by adjusting the water content to the desired volume.
• the textile printing pastes according the present invention contain from 2 to 10% by weight of an acid dye.
• the presence of an enzyme in the printing pastes has no negative effect on the printed article at the end of the printing cycle.
• a thickener is prepared by dry mixing:
• Printex PS10 depolymerised hydroxyethylguar commercialised by Lamberti SpA, having Brookfield viscosity at 20°C and 20 rpm of about 16.000-20.000 mPa*s at 7% by weight
• the solution is filtered on a polyester cloth of 54 micron.
• a printing paste is prepared proceeding exactly as described in the Example 1 , but using for the preparation of the mother paste a thickener made only by Printex PS10 (Paste 2).
• a silk fabric is printed side by side with Paste 1 and Paste 2 by using the same silk screen and a Zimmer laboratory printing machine.
• the fabric is dried at a temperature of 90°C for 1 minute in an oven.
• the colour is fixed in an Arioli vaporising machine at 102°C for 40 minutes.
• the fabric is washed at 30° in the presence of soap.
• the printed fabric is dried and ironed.
• a sample of fabric printed with Paste 1 is spread out on a flat surface and fixed in such a way as not to form creases, then suitably lighted with reflected light from a halogen lamp and a picture of 0.5 cm 2 of printed fabric is obtained using a professional camera with a 40x magnification lens. The picture is digitised and visualised by a personal computer and further zoomed in.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Molecular Biology (AREA)
• Coloring (AREA)

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Publications (1)

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• 2004
  • 2004-02-20 IT ITVA20040011 patent/ITVA20040011A1/it unknown
• 2005
  • 2005-02-17 EP EP05716720A patent/EP1716284A2/de not_active Withdrawn
  • 2005-02-17 CN CNB2005800052433A patent/CN100532704C/zh not_active Expired - Fee Related
  • 2005-02-17 WO PCT/EP2005/050700 patent/WO2005080668A2/en not_active Ceased
  • 2005-02-17 KR KR1020067019389A patent/KR20060129488A/ko not_active Ceased

Non-Patent Citations (1)

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