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
  • D06P5/00—Other features in dyeing or printing textiles, or dyeing leather, furs, or solid macromolecular substances in any form
  • D06P5/22—Effecting variation of dye affinity on textile material by chemical means that react with the fibre
• • 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
  • D06P5/00—Other features in dyeing or printing textiles, or dyeing leather, furs, or solid macromolecular substances in any form
  • D06P5/002—Locally enhancing dye affinity of a textile material by chemical means
• • 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
  • D06P5/00—Other features in dyeing or printing textiles, or dyeing leather, furs, or solid macromolecular substances in any form
  • D06P5/15—Locally discharging the dyes
  • D06P5/151—Locally discharging the dyes with acids or bases
• • 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
  • D06P5/00—Other features in dyeing or printing textiles, or dyeing leather, furs, or solid macromolecular substances in any form
  • D06P5/15—Locally discharging the dyes
  • D06P5/155—Locally discharging the dyes with reductants

Definitions

• This invention relates to the printing of fabrics.
• discharge printing An important type of textile printing is known as discharge printing in which a dyed fabric is printed with a suitable printing ink which contains chemicals capable of destroying the ground colour of the fabric during heating or steaming treatment. The fabric is then washed off to remove undesirable residues and to give a coloured fabric with a design of substantially uncoloured material.
• the printing ink contains colouring matters which are resistant to the chemical degradation process of discharging and which are fixed to the fabric during the heating treatments which are involved. In this way, so-called “illuminated” discharge prints may be produced using vat dyes or resin bonded pigments as colouring matters.
• the colouring matters used for the production of illuminated discharge prints may normally be fixed to the fabric, generally cotton or some other cellulosic or substantially cellulosic material, by colouration processes which do not require washing off, when the colouring matters are used in discharge printing, a washing off stage is involved due to the need to remove the residues of the chemicals involved in the discharge processes.
• Discharge pigment printing processes have been described in which a fabric, dyed with a dye or a mixture of dyes susceptible to chemical degradation to produce colourless or virtually colourless products, is printed with an ink containing a discharge agent, finely dispersed pigments in an aqueous medium, a resin binder capable of polymerising to bond the pigment particles to the fabric, and various catalysts etc. to enhance the reactions.
• the fabric is dried and then steamed for a period of minutes to produce the discharge.
• the fabric is then baked to polymerise the resin binder and washed off to remove undesirable residues.
• discharge prints have been successfully produced for many years on fabrics in a continuous web.
• discharge printing has not been used for decorating garments, or garment panels from which garments are to be made, because textile materials in such a form cannot be washed off without creating expense as well as inconvenience in later processing. Any decoration process used for such materials thus has to be substantially dry, and various dry processes have indeed been developed for textile printing.
• a further reason for avoiding wet processing garments or garment panels is that it is essential to maintain the dimensional stability of the material in order to control either the garment size or the fit of the decorated panels with other non-decorated panels in making up the garment.
• the opportunities offered by discharge printing have, until now, been wholly unavailable to the printer of garments and garment panels.
• colouring materials is used to indicate a pigment or a dyestuff or a mixture of both which will give a coloured effect, and the term is used to include both black and white, as well as spectral colours.
• a process of decorating fabric which comprises printing desired image areas forming a design on the fabric using a printing paste, and subjecting the fabric so printed to a heat treatment prior to drying the paste to fix the printed design in the fabric, wherein the printing paste contains water, a substantial proportion of humectant, colouring materials and/or decolouring materials, and the heat treatment includes a stage at a temperature greater than 100°C during which the fabric is confined between a pair of impermeable layers.
• the fabric may then be subjected to a second heat treatment, the conditions of which are designed to fix any colouring materials in the printing paste to the fabric to give a fast to washing result.
• discharge printed or decolourised areas may be overprinted with colouring material to produce a design in a second printing step.
• the paste needs to contain at least one reagent capable of reacting with the dye in the fabric at least substantially to destroy its colour (i.e. a discharge agent) together with agents assisting the reaction such as acids, alkalies, reduction catalysts and the like.
• a discharge agent capable of reacting with the dye in the fabric at least substantially to destroy its colour
• agents assisting the reaction such as acids, alkalies, reduction catalysts and the like.
• the fabric is subject to pressure, e.g. by being passed through a roller nip while being confined between two impermeable layers or by being held between two heated plates coated with impermeable material for an appropriate period of time.
• the first heat treatment referred to above needs to be carried out for only a relatively short period of time and, immediately thereafter, if the discharge printing process is being used, the discharge process is complete. Thus, the printer may judge more accurately, and at an early stage in the printing operation, whether the print is satisfactory.
• the exact time necessary for the first heat treatment stage will vary with the fabric, the quantity of discharge ink applied and if the discharge printing process is being used the nature of the dyestuff applied to the fabric and which it is necessary to discharge, but using appropriate temperatures and apparatus it can be as low as 10 seconds. Usually 20 to 30 seconds is convenient, though longer treatment times, e.g. up to 60 seconds, can be used if desired.
• humectants may be used of which the following are particularly suitable: Urea Glycerol Polyethylene Glycols Thiodiglycol Ethoxylated esters
• humectants are known to be used in textile printing to prevent inks drying on the silk screens used in printing. Normally for this purpose they are present in relatively low concentration in the printing ink, i.e. 3-4%. In the inks of the present invention they are required to constitute at least 8-9% of the ink formulation, preferably 12-15%.
• a particular advantage of the printing process of the present invention is the soft handle conferred by the heat treatment especially when the ink incorporates pigments and binders to produce a coloured discharge.
• the printing ink incorporates a pigment or a mixture of pigments which are chemically stable to the discharge agent and a pigment binder or mixture of binders together with any desired catalysts which will promote the curing of the binder or binders in a second heat treatment following the first discharging heat treatment.
• Agents enhancing softness of handle or any other desired effect may also be included as required.
• Suitable pigment binders are well known in the general field of pigment printing textiles but due to the special conditions associated with the production of the colour discharge, not all of the binders which are used under normal circumstances will give a fully satisfactory result due to discolouration or other degradation reactions which may occur. The printer should therefore select suitable binders by experiment.
• Another kind of pigment dispersion which may be used in this form of the invention is that known as water based or water compatible plastisol inks. These may be mixed with the discharge agent and the humectant and printed in the usual way. The fabric is then heat treated to produce the discharge effect using heating between impermeable blankets as described. Due to the thermoplasticity of plastisol inks, it can be advantageous to cover the print with a sheet of release paper to prevent adhesion to the impermeable blankets during this stage of the process. After the discharge is complete, the print is fully cured by passage through a hot oven in the usual way for such inks. This procedure offers considerable advantage over the simple application of these inks on to dyed materials since discharging the colour makes it unnecessary to have sufficient ink present to mask the ground shade and consequently softer, better defined prints with a more attractive handle can be obtained.
• a special advantage of the present invention is the rapidity with which the full discharge effect becomes apparent. This enables the discharged area of a final print to be produced in the course of a sequence of application of different inks to the fabric to produce a final design.
• the whole area to be decorated may be printed with a colourless binder free discharge ink constituted in accordance with the present invention and the printed fabric heated between hot plates for a short period or a succession of short periods, e.g. two times 5 seconds at 160°C.
• the discharge printed area may then be printed with a variety of white or coloured inks without the requirement that the colouring matters be stable to the discharge reaction.
• Imperon Binder 506 10.6% Alcoprint PHL 17.6% Water 45.5% Titanium Dioxide (as a 50% aqueous dispersion) 13.6% Diammonium Hydrogen Phosphate 3.3% Viscalex HV30 2.8% Zinc Formaldehyde Sulphoxylate 6.6%
• Imperon Binder 506 is an aqueous emulsion of acrylic polymers manufactured by Hoechst UK Ltd.
• Alcoprint PHL is a mixture of organic salts and ethoxylated esters manufactured by Allied Colloids Ltd.
• Viscalex HV30 is a mixture of polyacrylic acid derivatives manufactured by Allied Colloids Ltd.
• a design is printed by silk screen on to a cotton fabric dyed to a full red shade using Remazol Brilliant Red F3B (Hoechst UK Ltd).
• the printed fabric is then passed into a hot oven at 180°C between two continuous impermeable blankets held together to prevent drying for 30 seconds.
• the blankets are so arranged that, before emerging from the oven, the fabric passes between pressure rollers. It can be seen that, as the fabric emerges from the oven, the red dye is discharged in the printed areas to give a white design.
• the fabric is then passed through a hot oven at 180°C for 1 minute to complete polymerisation of the binder and fixation of the white pigment.
• the design produced in this manner is fast to washing at 60°C, to wet or dry rubbing and to light.
• a printing ink is prepared containing the following (% by weight): Acramine Binder SLN 11.1% Glycerol 19.1% Titanium Dioxide (as a 50% aqueous dispersion) 13.1% Copper Phthalocyanine as an aqueous dispersion) 5.0% Water 34.4% Isopropanolamine 3.5% Viscalex V30 6.8% Formamidine Sulphinic Acid 7.0% Acramine Binder SLN is an aqueous emulsion of acrylic polymers manufactured by Bayer.
• a design is printed by silk screen on to a cotton fabric dyed to a yellow shade by the pad-batch (cold) process using Remazol Brilliant Yellow 4GL (Hoechst UK Ltd).
• the printed fabric is then heated for 25 seconds in a book press at 175°C between impermeable felts. On removal of the fabric from the press, it is seen that it is printed with a bright blue design on a yellow ground.
• the fabric is then passed through a hot oven for 2 minutes at 185°C to complete fixation of the white and blue pigments.
• the design produced in this way is fast to washing at 60°C, to wet and dry rubbing and to light. It possesses a soft attractive handle.
• a printing ink is prepared containing the following (% by weight): Hydroxymethyl cellulose 5.0% Alcoprint PHL 12.5% Monoethanolamine 3.5% Formamidine Sulphinic Acid 7.0% Water 72.0%
• a cotton garment panel dyed to a violet shade with Remazol Violet 5R (Hoechst UK Ltd) is mounted on a carrier board in a multicolour screen printing unit and printed with a design using the above ink.
• the mounted panel is then moved to the second station on the machine where it is pressed between heated plates at 165°C for 5 seconds. It is then moved to the third station where it is pressed between plates as before. At this point, it can be seen that the panel has a white discharged design in the printed areas.
• Printing may then be continued using the fourth and subsequent printing stations to apply any desired coloured ink containing dyes or pigments as required. These may be fixed by any appropriate method to produce their normal fastness but with their normal shade due to their having been printed on a white ground as results of the discharge produced.

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Coloring (AREA)
• Multicomponent Fibers (AREA)
• Decoration Of Textiles (AREA)
• Treatment Of Fiber Materials (AREA)

Applications Claiming Priority (2)

Publications (3)

Family

ID=10662530

Family Applications (1)

Country Status (4)

Cited By (5)

Families Citing this family (1)

Citations (2)

• 1989
  • 1989-09-05 GB GB898920004A patent/GB8920004D0/en active Pending
• 1990
  • 1990-09-05 AT AT90309697T patent/ATE133215T1/de not_active IP Right Cessation
  • 1990-09-05 DE DE69024882T patent/DE69024882T2/de not_active Expired - Fee Related
  • 1990-09-05 EP EP90309697A patent/EP0416888B1/de not_active Expired - Lifetime

Patent Citations (2)

Also Published As

Similar Documents

Legal Events