CH689291GA3 - A process for preparing resist printing stains. - Google Patents

Description

The invention relates to a process for the production of reserve printing dyeings on two-dimensional textile materials, which is characterized in that the places on the upper side of the textile material intended for reservation are treated with a hydrophobizing agent containing a fluorocarbon polymer or copolymer mixed with an aqueous isocyanate Crosslinking agent, impregnated, the textile material dries, the impregnation is fixed and then the textile material as a whole, on one side, from the back, is subjected to a dyeing treatment with an aqueous liquor.

The impregnation is fixed in the usual way, e.g. by heat treatment.

Both white reserve prints and, if a dye is added to the paste with the hydrophobizing agent, colored reserve prints can be produced.

The process according to the invention is extremely efficient and environmentally friendly: the reserves on the substrates are obtained without destroying dyes and without excessive use of dyeing aids, in particular aggressive or environmentally harmful chemicals.

An essential point in the process according to the invention is the hydrophobizing agent. It prevents the areas printed with it from being impregnated with the dye liquor which is subsequently applied from the rear, so that later dyeing cannot take place at the areas printed with it.

The second essential point is the type of fund coloring, whereby the dye liquor is only applied from the back. This measure enables the production of precisely sharp patterns (white and colored reserves) on the front.

The hydrophobizing agents used in the process according to the invention are fluorocarbon polymers and copolymers, in particular the commercially available perfluoroalkyl / acrylic copolymers which are present in aqueous-organic solution. These can be fixed on the substrates to be treated according to the invention in such a way that they at least survive the subsequent dyeing process without bleeding out significantly. Nonionic water repellents are preferred, but in some cases (weakly) anionic or cationic compounds also serve the desired purpose.

The special cross-linking agents, such as Hydroperm MF liquid (aqueous isocyanate compound), improve the water repellency effects.

Fond coloring from the back of the substrate is done e.g. by means of a so-called 1000-point roller, a squeegee roller (on a rotary film printing machine), a floor stencil (on a flat film printing system) or a slapping or spraying device.

In principle, all substrates that can be dyed from aqueous solution can be treated according to the invention. Printing with the hydrophobizing agent and optionally a dye / dye mixture is carried out in a generally known manner. The corresponding printing pastes contain a conventional thickening agent and optionally other printing aids, e.g. small amounts of a wetting agent and / or fixing accelerator and / or buffer substances.

Accordingly, the present invention further provides a method as described above, which is characterized in that the impregnation with the hydrophobizing agent is carried out with a printing paste and that this printing paste contains a dye or a mixture of dyes to achieve colored reserves.

The hydrophobizing agent is generally used in amounts of 30 to 100 g / kg of printing paste. After printing, the substrate is dried, then the hydrophobizing and crosslinking agent and any dye present are fixed, and the substrate is then, if necessary, freed of the thickener and any other auxiliaries present by washing. The fixing is preferably carried out, depending on the type of fixing agent and any dye used, e.g. by dry heat treatment or with the help of superheated steam or saturated steam at 102 ° C. After fixing and, if washed, after drying the print, the substrate as a whole, as stated above, is over-dyed from the back, then fixed and finished in the usual way, by washing again and / or rinsing.

As already said, all fibrous substrates dyeable from aqueous solution, e.g. in the form of fabrics, knitted fabrics, nonwovens or carpets, are treated according to the invention. Substrates made from fiber mixtures can also be treated in this way.

In the following example, parts are parts by weight and percentages are percentages by weight. The temperatures are given in degrees Celsius.

example

A fabric consisting of 100% mercerized cotton is pattern-printed with the following reserve printing paste using a flat stencil: <tb> <TABLE> Columns = 3 <tb> <SEP> C.I. Reactive Blue 207 (commercial form) <SEP> 50 <SEP> parts by weight <tb> <SEP> urea <SEP> 100 <CEL AL = L> parts by weight <tb> <SEP> m-nitrobenzenesulfonic acid sodium <SEP> 10 <SEP> parts by weight <tb> <CEL AL = L> sodium bicarbonate <SEP> 25 <SEP> parts by weight <tb> <SEP> water <SEP> 205 <SEP> parts by weight <tb> <CEL AL = L> Sodium alginate thickening 10% <SEP> 500 <SEP> parts by weight <tb> <SEP> fluorocarbon polymer (trade name Sandofluor GPC) <SEP> 80 <SEP> parts by weight <tb> <SEP> aqueous isocyanate compound (trade name Hydroperin MF) <CEL AL = L> 30 <SEP> 1000 <SEP> parts by weight parts by weight <tb> </TABLE>

After drying at 110 °, the pressure is fixed with hot air at 170 ° for 30 seconds and poured over from the back with a liquor of the following composition: <tb> <TABLE> Columns = 3 <tb> <SEP> C.I. Reactive Black 8 (commercial form) <SEP> 70 <SEP> parts by weight <tb> <SEP> urea <SEP> 50 <CEL AL = L> parts by weight <tb> <SEP> water <SEP> 745 <SEP> parts by weight <tb> <SEP> Sodium alginate thickening 10% <CEL AL = L> 100 <SEP> parts by weight <tb> <SEP> m-nitrobenzenesulfonic acid sodium <SEP> 10 <SEP> parts by weight <tb> <CEL AL = L> sodium bicarbonate <SEP> 25 <SEP> 1000 <SEP> parts by weight <SEP> parts by weight <tb> </TABLE>

Then, by means of a vacuum slot, so much liquor is sucked off from the back that a liquor absorption of 80%, based on the weight of the goods, results.

It is then dried at 110 °, steamed for 10 minutes with saturated steam at 102 °, rinsed cold and, as is customary for reactive dye prints, washed at the boil, rinsed cold and dried. You get a sharply delimited turquoise pattern on a black background.

Claims (2)

1. A process for the production of reserve printing dyeings on two-dimensional textile materials, characterized in that the areas intended for reservation on the upper side of the textile material are impregnated with a hydrophobizing agent containing a fluorocarbon polymer or copolymer in a mixture with an aqueous isocyanate crosslinking agent Textile material dries, the impregnation is fixed and then the textile material as a whole, on one side, from the back, is subjected to a dyeing treatment with an aqueous liquor. 2. The method according to claim 1, characterized in that the impregnation with the hydrophobizing agent is carried out with a printing paste and that this printing paste contains a dye or a mixture of dyes to achieve colored reserves.