EP0038527B1 - Transfer printing sheets, process for their preparation and their use - Google Patents

Description

in welcher X Wasserstoff, Chlor oder Brom ist, R' für Methoxy oder Ethoxy, oder, wenn X Chlor oder Brom ist, auch für Wasserstoff oder Methyl steht, R² Alkyl mit 1 bis 4 Kohlenstoffatomen ist, R³ Wasserstoff ist oder die Bedeutung von R² hat und R⁴ Alkyl mit 1 bis 4 Kohlenstoffatomen ist, oder Mischungen solcher Farbstoffe enthält.The invention relates to transfer printing media which are impregnated or printed with a preparation which contains a monoazo dye, characterized in that the preparation comprises a dye of the formula (1)

in which X is hydrogen, chlorine or bromine, R 'is methoxy or ethoxy, or, if X is chlorine or bromine, also represents hydrogen or methyl, R ^{2 is} alkyl having 1 to 4 carbon atoms, R ^{3 is} hydrogen or the meaning of R ² and R ^{4 is} alkyl of 1 to 4 carbon atoms, or contains mixtures of such dyes.

Preferred transfer printing supports according to the invention are impregnated or printed with preparations which contain dyes of the formula (I) in which X represents chlorine or bromine.

The invention further relates to a process for the preparation of the supports according to the invention, which is characterized in that the support material is impregnated or printed with preparations which contain a dye of the formula (I) or mixtures of such dyes.

The invention also relates to the use of the supports according to the invention for dyeing and printing sheet-like structures by the thermal transfer printing process. The sheet-like structures preferably consist of synthetic or partially synthetic polymeric materials or of materials which have been prepared with such synthetic or partially synthetic polymeric materials. The sheet-like structures can also consist of or contain natural fiber materials, but are then treated with preparations which give these natural materials an affinity for the dyes of the formula (I).

The dyes of the formula (I) are known as such and can be obtained by the preparation processes customary for azo dyes. Dyes of the formula (I) and their use for dyeing polyethylene terephthalate from an aqueous dispersion with the addition of a carrier are known from US Pat. No. 4,076,498. In this literature reference it is stated that the dyeings produced with the dyes disclosed in Examples 1-3 there (these dyes fall under the formula (I) of the present invention) have very good or good fastness to sublimation on polyester yarn. As is well known, in the case of disperse dyes in general, a sublimation-fast dyeing only with relatively poorly subliming, i.e. H. To achieve sublimation-resistant dyes, it was surprising that the disperse dyes of the general formula (I) used according to the invention can be used to achieve excellent transfer prints on sheetlike structures made of, for example, synthetic or partially synthetic polymeric materials.

, worin R₂ einen Alkyl_C2-C4-Rest bedeutet, der zwingend 1 oder 2 Chlor- oder Bromatome enthält, während die Kupplungskomponenten der erfindungsgemäss zur Anwendung gelangenden Farbstoffe prinzipiell kein Halogenatom enthalten. Im Hinblick darauf, dass in der weiter oben zitierten US-PS 4 076 498 beschrieben wird, dass die mit den in den dortigen Beispielen 1-3 offenbarten Farbstoffen hergestellten Färbungen auf Polyestergarn sehr gute bzw. gute Sublimationsechtheit aufweisen, war nicht zu erwarten, dass eine Anwendung von den gemäss der DE-OS 2 655 882 eingesetzten Dispersionsfarbstoffen mit einer im Sinne der erfindungsgemäss zur Anwendung gelangenden Farbstoffe abgewandelten Struktur hervorragende Transferdrucke auf flächenförmigen Gebilden aus beispielsweise synthetischen oder halbsynthetischen polymeren Materialien ergibt. Hinzukommt, dass durch die erforderliche Einführung von Chlor- oder Bromatomen in die Kupplungskomponente bei deren Herstellung auch die Synthese der dort angewandten Farbstoffe wesentlich aufwendiger ist.DE-OS 2 655 882 relates to a non-textile transfer web with monoazo dyes of a certain structure and to a sublimation transfer printing process of textiles made of hydrophobic synthetic fibers by transferring such a dye. With regard to the structure, the dyes used there contain the substituents on the benzene nucleus of the coupling component

, in which R _{2 is} an alkyl _C2-C4 radical which contains 1 or 2 chlorine or bromine atoms, while the coupling components of the dyes used according to the invention in principle contain no halogen atom. In view of the fact that it is described in US Pat. No. 4,076,498 cited above that the dyeings produced with the dyes disclosed in Examples 1-3 there have very good or good fastness to sublimation on polyester yarn, it was not to be expected that an application of the disperse dyes used according to DE-OS 2 655 882 with a structure modified in the sense of the dyes used according to the invention results in excellent transfer prints on sheetlike structures made of, for example, synthetic or semisynthetic polymeric materials. In addition, due to the required introduction of chlorine or bromine atoms into the coupling component during their production, the synthesis of the dyes used there is also much more complex.

DE-AS 2364475 describes a method for printing on hydrophobic fiber materials according to the transfer printing principle, wherein sulfo group-free monoazo dyes of a certain structure are used. These dyes differ from the monoazo dyes used according to the invention in that they necessarily contain 1-3 trifluoromethyl groups on the benzene nucleus of the diazo component and can contain one or more trifluoromethyl groups on the benzene nucleus of the coupling component. In the cited literature reference it is stated that it is to be regarded as extremely surprising that the dyes used there, which are characterized by the combination of a CFg group-containing diazo component and a special type of aniline coupling component, have excellent transfer properties, since structurally comparable dyes, the formally similar radicals instead of the CF ₃ groups, such as. B. the methyl group, or contain a bromine atom, are less suitable for transfer printing. In view of this statement, it must be regarded as surprising that the dyes used according to the invention are so outstandingly suitable for transfer printing. With regard to the supra The moments of excellent suitability of the dyes used in transfer printing according to the invention also apply to what has been said in the discussion of DE-OS 2,655,882 in relation to the cited US Pat. No. 4,076,498. In addition, the preparation of diazo components which contain a CF ₃ group on the benzene nucleus, and thus also the preparation of the monoazo dyes to be synthesized therefrom, is extremely complex and the complete diazotization of, for example, the diazo component 2-amino-3,4-dinitro-trifluoromethylbenzene causes great difficulties.

In view of the cited prior art, as is evident from the three literature references dealt with above, the task was to find disperse dyes which are not only suitable for incorporation into a preparation, and which can be used for impregnating or printing transfer printing media, and that have good transfer properties when dyeing or printing sheet-like structures using the thermal transfer printing process, produce color prints with a sharp-dot print image and prints of high color strength and good light fastness, and have the advantage of enabling easy-to-pour low-electrolyte and dispersant printing pastes of high dye concentration, but also according to the usual ones Synthetic processes are accessible without special effort.

In fact, the dyes used in accordance with the invention not only show extremely good transfer properties, but also provide color-deep prints with a dot-sharp printed image. They are therefore also well suited in combination with other transfer printing dyes, for which it is known that it is assumed that all dyes show a largely similar transfer characteristic under the conditions used.

The dyes of the formula (I) have good lightfastness and have significantly higher color strengths than the blue anthraquinone dyes used in transfer printing. The dyes of the formula (I) also have the advantage that they can be used to produce easily pourable low-electrolyte and dispersant printing pastes with a high concentration of dyes, which are very sought-after because of the small amount of printing paste on paper.

It is known that all sheet-like structures which are inert to the dyes applied and which do not hinder sublimation are suitable as the carrier material for the transfer printing supports according to the invention. Sheet structures made of metal, such as aluminum foil, or of natural or regenerated cellulose materials, such as foils, woven fabrics, knitted fabrics or preferably paper webs, are suitable.

The formulations which contain the dyes of the formula (I) and with which the carrier materials are impregnated or printed can be aqueous printing pastes, as are customary in textile printing, or organic printing inks, as are used in graphic printing.

Aqueous printing inks contain the usual natural or synthetic thickeners, for example polyvinyl alcohols, methyl cellulose or polymerization products containing carboxy groups, for example polyacrylates.

The composition of the organic printing inks depends on the type of substrate, the substrate, the printing process and the equipment available. Such printing inks generally consist of one or more dyes of the formula (I), a binder, a dispersant and, if appropriate, solvents, fillers and preservatives.

Suitable binders are natural, semi-synthetic and synthetic resins, i.e. Polymerization, polycondensation and polyaddition products. Examples of suitable resins are: rosin and its derivatives, maleinate resins, oil-free alkyd resins, alkyd resins made from synthetic and natural fatty acids and arylated alkyd resins. Also suitable are terpene resins, polyvinyl resins such as polyvinyl acetate and polyvinyl chloride, copolymers and graft polymers with various vinyl monomers, acrylate resins, naphthalene-formaldehyde resins, ketone resins, silicone resins and cellulose derivatives such as cellulose esters, for example nitrocellulose or cellulose acetate, and cellulose ethers and others, such as, for example, methyl cellulose acetate, such as methyl derivative polysaccharide.

Nonionic and anionogenic products are used as dispersants. Examples of nonionic products are: addition products of about 5-70 mol of alkylene oxide to higher fatty acids, fatty alcohol polyglycol ethers, phenol and alkylphenol polyglycol ethers, but also oxalkylates of fatty acids esterified with polyhydric alcohols or of resin derivatives such as hydroabietyl alcohol. Suitable anionic dispersants are: naphthalenesulfonic acid-formaldehyde condensates, ligninsulfonates and sulfite waste products.

The type of solvent depends on the type of printing process. Esters, ketones or alcohols, for example butyl acetate, acetone, methyl ethyl ketone, ethanol, isopropanol or butanol, are particularly preferred.

The printing inks can be printed using all common printing methods, i.e. high, flat, gravure or screen printing. Rotogravure and rotary film printing are particularly suitable printing processes for the production of printed paper auxiliary substrates.

Suitable substrates are acetate sheet-like structures such as nonwovens, felts, furs, carpets, films, and especially woven and knitted fabrics made of synthetic or semi-synthetic materials, in particular aromatic polyesters, such as polyethylene glycol terephthalate or cellulose acetates such as cellulose triacetate and cellulose 2 _^1/2, or polyamides . These synthetic and semi-synthetic materials show an affinity for the Dyes of the formula I. However, it is also possible to dye and print other substrates after thermal transfer printing, which in themselves have no affinity for these dyes, namely by preparing such substrates with the synthetic or semi-synthetic materials mentioned, for example with a appropriate coating of such plastics. It is also possible to treat natural fiber materials which have no affinity for the dyes of the formula with suitable preparations, and in this way to make these substances affine to these dyes. Corresponding methods are known for example from DE-PS 2 551 410, DE-AS 2 436 783 or DE-OS 2 045 465.

Thermal transfer printing is generally known and is described in detail, for example, in FR-PSS 1223 330, 1 334829 and 1 585119. Here, the auxiliary carriers, which are impregnated or printed with the suitable preparations, are brought into close contact with the substrate to be colored or printed, whereupon the dye is transferred from the carrier to the substrate and fixed there under the action of heat and, if appropriate, pressure or vacuum . With the dyes of the formula 1, when used in accordance with the invention on the substrates, reddish-tinged to greenish-blue, strong colorations and prints with good fastness properties are obtained.

The invention is explained in more detail in the following examples. Unless otherwise stated, details of parts and percentages relate to the weight.

example 1

werden mit 80 Teilen eines nichtionogenen Dispergiermittels (Reaktionsprodukt von Glycerin mit Rizinusölfettsäure, umgesetzt mit 100 Mol Ethylenoxid) und 25 Teilen eines Ligninsulfonates sowie 150 Teilen Ethylenglykol, 200 Teilen Wasser und 5 Teilen Chloracetamid als Konservierungsmittel in einer Perlmühle mit Siliquarzitperlen gemahlen. Nach sieben Stunden erhält man eine Dispersion, deren Teilchen zu über 90% kleiner als 3 µm sind. Die Einstellung wird mit Wasser auf 1000 Teile ausgefüllt und von den Perlen abgetrennt.300 parts of the dry dye of the following constitution

are ground with 80 parts of a nonionic dispersant (reaction product of glycerol with castor oil fatty acid, reacted with 100 moles of ethylene oxide) and 25 parts of a lignin sulfonate as well as 150 parts of ethylene glycol, 200 parts of water and 5 parts of chloroacetamide as a preservative in a bead mill with silica quartz beads. After seven hours, a dispersion is obtained whose particles are more than 90% smaller than 3 µm. The setting is filled with water to 1000 parts and separated from the beads.

The preparation containing 30% of dye is stable in storage at room temperature and also at 50 ° C. The preparation can be easily mixed into a conventional pressure thickener (alginate-based) as well as into a synthetic pressure thickener (acrylic-based) and can be printed using the usual printing methods without affecting the viscosity. Transfer papers printed with the printing ink produce a greenish-blue, strong print after transfer to polyester (approx. 20s at 200 ° C).

Example 2

mit einem Feststoffgehalt von 46,4% werden mit 100 Teilen eines nichtionogenen Dispergiermittels (Blockpolymerisat aus Propylen- und Ethylenoxid) und 30 Teilen eines Kondensationsproduktes aus Methylnaphthalinsulfonsäure und Formaldehyd (wie es in Beispiel D der DE-PS 2 442 514 beschrieben ist), 180 Teilen Ethylenglykol und 5 Teilen Chloracetamid als Konservierungsmittel in einer Perlmühle mit Siliquarzitperlen gemahlen. Nach 5 Stunden erhält man eine Dispersion, deren Teilchen zu über 90% kleiner als 311m sind. Die Präparation wird mit Wasser auf 1000 Teile aufgefüllt und von den Perlen abgetrennt.538 parts of a moist press cake of the dye of the following constitution

with a solids content of 46.4% with 180 parts of a nonionic dispersant (block polymer made of propylene and ethylene oxide) and 30 parts of a condensation product of methylnaphthalenesulfonic acid and formaldehyde (as described in Example D of DE-PS 2 442 514), 180 Parts of ethylene glycol and 5 parts of chloroacetamide as a preservative are ground in a bead mill with silica quartz beads. After 5 hours, a dispersion is obtained, the particles of which are over 90% smaller than 311 m. The preparation is made up to 1000 parts with water and separated from the beads.

The setting containing 25% of the dye is stable in storage. Transfer papers printed with an aqueous printing ink made therefrom result in a reddish-navy-blue, strong print after transfer to polyester (approx. 20 s at 200 ° C).

Example 3

und 150 Teile des trockenen Farbstoffs der folgenden Konstitution

werden mit 85 Teilen eines nichtionogenen Dispergiermittels (Reaktionsprodukt von Glycerin mit Rizinusölfettsäure, umgesetzt mit 100 Mol Ethylenoxid) und 25 Teilen eines Ligninsulfonates sowie 160 Teilen Ethylenglykol, 200 Teilen Wasser und 5 Teilen Chloracetamid als Konservierungsmittel in einer Perlmühle mit Siliquarzitperlen gemahlen.150 parts of the dry dye of the following constitution

and 150 parts of the dry dye of the following constitution

are reacted with 85 parts of a nonionic dispersant (reaction product of glycerol with castor oil fatty acid, reacted with 100 mol Ethylene oxide) and 25 parts of a lignin sulfonate, as well as 160 parts of ethylene glycol, 200 parts of water and 5 parts of chloroacetamide as a preservative, ground in a bead mill with silica quartz beads.

After eight hours, a dispersion is obtained whose particles are more than 90% smaller than 3 ₁₁ m. The setting is made up to 1000 parts with water and separated from the beads.

The preparation containing 30% dye has a good shelf life both at room temperature and at 50 ° C. Transfer papers printed with an aqueous printing paste obtained therefrom result in a deep blue, strong print after transfer to polyester (approx. 20 s at 200 ° C.).

Example 4

und 25 Teile des trockenen Farbstoffs der folgenden Konstitution

70 g eines anionischen Dispergiermittels, z. B. eines Ligninsulfonates oder eines Kondensationsproduktes aus Naphthalinsulfonsäure und Formaldehyd, und 130 ml Wasser werden gemischt und in einer Kugelmühle durch 12-stündiges Mahlen in eine Dispersion übergeführt.75 parts of the dry dye of the following constitution

and 25 parts of the dry dye of the following constitution

70 g of an anionic dispersant, e.g. B. a ligninsulfonate or a condensation product of naphthalenesulfonic acid and formaldehyde, and 130 ml of water are mixed and converted into a dispersion in a ball mill by grinding for 12 hours.

The approx. 33% preparation thus obtained is stable on storage. The above aqueous dispersion can be processed into a printing paste as follows: 300 g are pasted with 350 g of a 10% locust bean gum ether thickener and 350 ml of water.

This printing paste is used to print paper using the gravure printing process. If you press this paper for 20-60 s at 210 ° C with a textile made of polyester fibers, you get a bright blue print.

blau

grünst. blau

blau

grünst. blau

blau

blau

blau

blau

blau

blau

blau

blau

blauThe following table shows other dyes and the shades obtainable by the process given in Example 1. The dyes can be mixed with one another.

blue

green. blue

blue

green. blue

blue

blue

blue

blue

blue

blue

blue

blue

blue

Claims (6)

1. A transfer printing carrier sheet which has been impregnated or printed with a preparation containing a monoazo-dyestuff, wherein the preparation contains a dyestuff of the formula (I)

in which

X is hydrogen, chlorine or bromine,

R' is methoxy or ethoxy, or, if X is chlorine or bromine, R' is also hydrogen or methyl,

R² is alkyl of 1 to 4 carbon atoms,

R³ is hydrogen or alkyl of 1 to 4 carbon atoms and

R⁴ is alkyl of 1 to 4 carbon atoms,

or a mixture of these dyestuffs.

2. The carrier sheet as claimed in claim 1, which has been impregnated or printed with a preparation containing a dyestuff of the formule (I) wherein X is chlorine or bromine.

3. A process for the preparation of a carrier sheet as claimed in claim 2, which comprises impregnating or printing the carrier material with a preparation containing a dyestuff of the formula (I) or mixtures of these dyestuffs.

4. Use of the carrier sheet as claimed in claim 1 and 2 for the dyeing or printing of flat structures according to the thermotransfer printing process.

5. Use of the carrier sheet as claimed in claim 4, wherein the flat structures consist of synthetic or partially synthetic polymer materials or have been treated therewith.

6. Use of the carrier sheet as claimed in claim 4, wherein the flat structures consist of or contain natural fibrous materials which have been treated with preparations imparting to these materials an affinity for the dyestuffs of the formula (I).