EP1405948A1 - Textile printing process - Google Patents

Abstract

A textile printing process in which a flat textile structure with a base color, preferably dark, is provided with a printing pattern in a pattern region, where a reserve ink is printed onto the pattern region under pressure by means of an ink jet printer, where the reserve ink in the pattern region hinders permanent fixing of the base color is new. Independent claims are included for: (1) a reserve ink for application to the textile by an ink jet printer, containing a reservation agent (sic), preferably based on sulfite or sulfite adduct for hindering fixation of the base color; (2) an etching ink for application to a flat textile structure by means of an ink jet printer containing a reducing agent, especially sulfoxylate for breaking down the base color.

Description

The invention relates to a textile printing method in which a textile fabric preferably colored dark with a basic dye and in a pattern area is provided with a printed pattern. The invention further relates to a reserve or etching ink for application to a textile Sheet.

In classic textile printing with screen printing stencils it is possible to print patterns or to print motifs on dark background surfaces. in principle a distinction is made between white printing, reserve printing and etching printing technology. With white printing, the background is covered with white paint while The base color is completely or partially prevented from being fixed during reserve printing and the coloring is locally destroyed during the etching print. The disadvantage is the high manufacturing costs for the stencils, especially for short ones Worn and higher-colored motifs.

In addition to the classic methods, there is also printing on textile surfaces a direct ink jet printing technique known to any To reproduce image motifs by digital processing in high resolution. There is always a print with a dark or colored background possible by printing the opaque color and the motif side by side. The problem here is high consumption with regard to the covering color, lack of levelness, limited color space and limited color depth and no copy. Added to this is the so-called dithering for critical ones Color tones, which creates undesirable visible color dots.

Proceeding from this, the invention is based on the object in the state the disadvantages of the technology to avoid and the textile printing of Motifs on a dark or colored background largely without design To enable restrictions with the least possible production effort.

To solve this problem is that in the independent claims each specified combination of features proposed. Advantageous configurations and further developments of the invention result from the dependent Claims.

The invention is based on the idea of controlling inkjet printing Do not color or keep the motif free of the basic color. Accordingly, it is proposed according to the invention that the Reserve ink applied to sample area by inkjet printing with the reserve ink being permanently fixed in the pattern area of the basic dye prevented. Alternatively, it is provided that the pattern area an etching ink is applied by ink jet printing, wherein the etching ink in the pattern area destroys the basic dye.

This makes it possible to have a level basic color even with difficult ones Color nuances through a simple dyeing process in a separate process step to enable while printing the reserve or Etching ink in the motif area a flexible design by using digital Techniques allowed.

For fixation-inhibiting effect, it is advantageous if the reserve ink Reserving agents based on sulfites, sulfite adducts, thiourea or Preparations thereof.

On the other hand, it is favorable to destroy the basic dye if the etching ink contains a suitable reducing agent, in particular sulfoxylates.

A further improvement can be achieved that the basic dye is formed by a vinyl sulfone dye.

The full coloring of the fabric with the basic dye can by a block process before or after the reserve or Etching ink done. This allows brilliant colorations with high color strength receive.

In a further process step, the textile fabric is preferred subjected to a fixation treatment by the action of saturated steam. A pH regulator can preferably be selected from the group soda, hydrogen carbonate, Sodium hydroxide solution, water glass or potassium carbonate can be activated.

An embodiment of the invention provides that the print pattern as a white reserve or white etching is formed. By applying colored dyes alternatively, preferably based on monochlorotriazines, it is possible that the print pattern is formed as a color reserve or color sets.

In a preferred embodiment of the invention, one is preferred multicolored printing ink for the print pattern and the reserve or etching ink via different ink channels of a digitally controlled inkjet printer sprayed in a grid pattern on the sample area. The print head is working line by line, with a large number of parallel channels or pressure nozzles are present to different colors printed closely side by side Print dots additively a halftone dot as the pixel of a digital image or to create a motif.

It is advantageous here if the reserve or etching ink uses the spot color principle via a separate ink channel of the inkjet printhead is applied.

In order not to thermally stress the ink, it is advantageous if a piezo-based one working inkjet printer is used.

In view of the special circumstances in inkjet printing proposed according to the invention that the reserve or etching ink a viscosity regulator based on glycols, especially polyethylene glycol or contains polyacrylates, a viscosity in the range from 2 to 10 mPas is favorable for the formation of drops at the nozzle. To adjust the Surface tension advantageously in the range from 20 to 50 mN / m the reserve or etching ink may contain a preferably nonionic surfactant. To prevent drying out, it is advantageous if the reserve or etching ink hygroscopic additives, such as urea or Contains glycerin. Biodegradation, for example, by bacteria delayed because the reserve or caustic ink is a preservative like contains formaldehyde.

The reserve or etching ink advantageously contains demineralized water as a carrier.

In order not to damage the inkjet printhead, the conductivity of the Reserve or etching ink is less than 60 mS / cm.

To optimize the printing operation, it is advantageous if the reserve or Etching ink is degassed using ultrasound before use.

Another aspect of the invention resides in a reserve ink for application on a textile fabric by inkjet printing, preferably containing one Reserving agent based on sulfites or sulfite adducts to inhibit the fixation of a basic dye. Yet another object of the invention is an etching ink to be applied to a textile fabric by inkjet printing, containing a reducing agent, in particular Sulfoxylates to destroy a basic dye.

A preferred use of a reserve or etching ink according to the invention lies in digital textile printing on a dark background using inkjet technology.

• Reservierungsmittel auf Basis von Natriumhydrogensulfit, Sulfitaddukten, Thioharnstoff und Zubereitung davon, mit einer Leitfähigkeit von < 60 mS/cm im Endprodukt;
• Viskositätsregulator auf Basis von Polyethylenglykol und anderen Glykolen und Verdickungsmitteln zur Einstellung einer Viskosität von 2 bis 10 mPas;
• Nichtionisches Tensid zur Einstellung einer Oberflächenspannung im Bereich von 20 - 50 mN/m;
• 0 - 200 g/kg hygroskopische Zusätze, wie beispielsweise Harnstoff oder Glycerin;
• Demineralisiertes Wasser;
• Konservierungsmittel wie Formaldehyd.

In the following exemplary embodiments, the invention is explained in more detail with regard to digital textile printing on a dark background.
The printing process provides that a textile fabric made of a natural or synthetic fiber material is provided with a print pattern by applying a reserve ink or etching ink to a defined pattern area by means of an inkjet printer, so that a permanent fixation of a dark one applied by the block process is fixed in the pattern area Basic dye is prevented or the basic dye is destroyed. If there is no further overprinting, a white reserve or white etching is obtained at these points, while overprinting with colored dyes based on monochlorotriazine dyes or other reactive dyes not containing vinylsulfone forms a colored reserve or colored etching. In the latter case, the colored dyes for the print pattern are sprayed onto the pattern area in a grid pattern via individually assigned ink channels of an ink jet printhead as differently colored printing inks and the reserve or etching ink. The reserve or etching ink can be processed as a spot color, using a piezo-based inkjet printer.
A preferred composition of the reserve ink contains the following components:

• Reserving agents based on sodium hydrogen sulfite, sulfite adducts, thiourea and preparation thereof, with a conductivity of <60 mS / cm in the end product;
• Viscosity regulator based on polyethylene glycol and other glycols and thickeners to set a viscosity of 2 to 10 mPas;
• Non-ionic surfactant for setting a surface tension in the range of 20 - 50 mN / m;
• 0 - 200 g / kg hygroscopic additives, such as urea or glycerin;
• Demineralised water;
• Preservatives such as formaldehyde.

A suitable etching ink contains a reducing agent instead of the reservation agent, especially sulfoxilates to destroy the base dye.

Before use, the ink should be degassed using ultrasound to ensure an undisturbed flow through the ink channels.

Some process variants for reserve pressure are explained below: Example 1 - form reserve

The textile is pre-padded with a thickener solution based on natural alginates or based on synthetic thickener systems and then dried. The pre-block fleet is composed as follows: 5 - 50 g / kg Na alginate as a thickener; 0-150 g / kg Urea to increase depth of color; 3 g / kg Complexing agents, for example based on polyphosphates; x g / kg Water demineralized.

The squeezing effect should be around 80%.

The padded goods are, as described above, with the inkjet printer the reserve ink and possibly additionally monochlorotriazine colored dyes printed.

• Fondfarbstoff auf Basis von Vinylsulfonen;
• Alkali (Natriumhydrogencarbonat, Soda, Wasserglas, Pottasche);
• Migrationsverhinderer (Salz- bzw. Verdickungsmittelzusätze).

The goods are then padded with a padding liquor of the following composition:

• Fund dye based on vinyl sulfones;
• Alkali (sodium hydrogen carbonate, soda, water glass, potash);
• Migration inhibitor (salt or thickener additives).

Prescription example:

10 - 80 g / kg Vinyl sulfone dye as a base; 5 - 50 g / kg Alginate as a migration inhibitor; 0-100 g / kg Sodium carbonate or other alkali dispenser (sodium hydrogen carbonate, soda, water glass, potash); x g / kg Water.

The squeezing effect should be approx. 80%.

The fixation takes place under saturated steam conditions or with superheated steam in 2 up to 10 minutes. Then the prints, as with reactive dyes usual, washed to the boil.

Example 2 - Overpressure reserve with an alkaline dispenser

The goods are padded with a padding liquor that contains an alkali dispenser (sodium trichloroacetate or sodium hydrogen carbonate) and the vinyl sulfone dye intended for the fund as well as an anti-migration aid, according to the following recipe example: 10 - 80 g / kg Vinylsulfonfarbstoff; 0-150 g / kg Urea; 3 - 20 g / kg Phosphate; 5 - 50 g / kg alginate; 10 - 100 g / kg Alkalis; x g / kg Water.

After careful drying below 100 ° C, reserve ink and colored illumination dyes printed simultaneously with the inkjet technology. Subsequently the goods are fixed and washed out as described above.

Example 3 - Overpressure reserve without alkali dispenser (2-phase method)

The product comes with a fund dye and alginate or synthetic Block liquor containing thickener and then dried.

Recipe example for the pre-block fleet: 10 - 80 g / kg Vinylsulfonfarbstoff; 0-150 g / kg Urea; 0-10 g / kg Ludigol; 5 - 50 g / kg alginate; 2 g / kg Monosodium phosphate (pH 6-7) as a buffer; x g / kg Water.

The padded goods are printed with the inkjet printer as described.

The prints are fixed with an alkaline and saline padding liquor padded and then fixed in saturated steam.

Recipe example for the padding fleet: 0-100 g / kg Glauber's salt; 5 - 150 g / kg Soda; 0 - 50 g / kg Potash or other alkali dispenser; 0-30 g / kg sodium bicarbonate; x g / kg Water.

Example 4 - Color reserves

With all three variants, color reserves according to the one described above can also be used Procedure are made.

Claims (25)

Textile printing method in which a textile fabric with a basic dye is preferably dyed dark and provided with a print pattern in a pattern area, characterized in that the pattern area is acted upon by inkjet printing with a reserve ink, the reserve ink preventing the basic dye from being permanently fixed in the pattern area. A method according to claim 1, characterized in that the reserve ink contains a reservation agent based on sulfites, sulfite adducts, thiourea or preparations thereof. Textile printing method in which a textile fabric with a basic dye is preferably dyed dark and provided with a print pattern in a pattern area, characterized in that the pattern area is acted upon by an etching ink by ink-jet printing, the etching ink in the pattern area destroying the basic dye. A method according to claim 3, characterized in that the etching ink to destroy the base dye contains reducing agents, especially sulfoxylates. Method according to one of claims 1 to 4, characterized in that the base dye is formed by a vinyl sulfone dye. Method according to one of claims 1 to 5, characterized in that the fabric is colored over the entire surface with the base dye by a padding process before or after the application of the reserve or etching ink. Method according to one of claims 1 to 6, characterized in that the textile fabric is preferably subjected to a fixing treatment by the action of saturated steam. A method according to claim 7, characterized in that in the fixing treatment, a pH regulator is preferably activated from the group of soda, hydrogen carbonate, sodium hydroxide solution, water glass or potassium carbonate. Method according to one of claims 1 to 8, characterized in that the print pattern is formed as a white reserve or white etch. Method according to one of claims 1 to 8, characterized in that the print pattern is formed as a color reserve or color sets by applying colored dyes, preferably based on monochlorotriazines. Method according to one of claims 1 to 8, characterized in that a preferably multicolored printing ink for the printing pattern and the reserve or etching ink are sprayed onto the pattern area in a grid pattern via different ink channels of a digitally controlled inkjet printer. Method according to one of claims 1 to 11, characterized in that the reserve or etching ink is applied according to the spot color principle via a separate ink channel of an ink jet print head. Method according to one of claims 1 to 12, characterized in that an ink jet printer working on a piezo basis is used. Method according to one of claims 1 to 13, characterized in that the reserve or etching ink contains a viscosity regulator based on glycols, in particular polyethylene glycol or polyacrylates. Method according to one of claims 1 to 14, characterized in that the reserve or etching ink has a viscosity in the range of 2 to 10 mPas. Method according to one of claims 1 to 15, characterized in that the reserve or etching ink contains a preferably nonionic surfactant for adjusting the surface tension. Method according to one of claims 1 to 16, characterized in that the reserve or etching ink has a surface tension in the range of 20 to 50 mN / m. Method according to one of claims 1 to 17, characterized in that the reserve or etching ink contains hygroscopic additives, for example urea or glycerin. Method according to one of claims 1 to 18, characterized in that the reserve or etching ink contains a preservative such as formaldehyde. Method according to one of claims 1 to 19, characterized in that the reserve or etching ink contains demineralized water as a carrier substance. Method according to one of claims 1 to 20, characterized in that the conductivity of the reserve or etching ink is less than 60 mS / cm. Method according to one of claims 1 to 21, characterized in that the reserve or etching ink is degassed by means of ultrasound before use. Reserve ink for application to a textile fabric by inkjet printing, containing a preferably based on sulfites or Reservite formed by sulfite adducts to inhibit fixation of a Basic dye. Etching ink for application to a textile fabric by inkjet printing, containing a reducing agent, especially sulfoxylates to destroy a basic dye. Use a reserve or etching ink according to one of the previous ones Claims for digital textile printing on dark ground below Use of inkjet technology.