Solutions of U.V. Absorbers Useful for Improving the Light Fastness of Dyeings on Polyester

The invention relates to compositions for dyeing polyester material, especially for use in the automotive industry.

For various shades of colour it is necessary to dye using mixtures of dyestuffs. The dyestuffs present in the mixture must be chosen on the basis of high light fastness and not, as is desirable, on the basis of having similar dyeing properties. The selection of dyestuffs of the highest light fastness leads therefore to the use of dyestuff combinations which have widely different dyeing properties; this, in turn, leads to problems of level dyeing and reproducibility. Hence, it is necessary to use a dyeing assistant such as a carrier or migration assistant in such situation. However, by using such products, the light fastness of the resultant dyeing is usually decreased.

To alleviate the problem of obtaining good light fastness properties whilst employing a carrier or migration assistant there is provided a solution of one or more U.V. absorbers selected from resorcinol monobenzoate, phenyl salicylate and compounds of formula I ##STR1## in which

R.sub.1 is selected from OH, halogen, C.sub.1-4 alkyl, CN, C.sub.1-4 alkoxy and hydrogen;

each R.sub.2 independently, is selected from C.sub.1-4 alkoxy, CN, halogen, hydrogen, C.sub.1-4 alkyl or OH;

and an emulsifier in an organic solvent system.

It has been found that in addition to being U.V. absorbers these U.V. absorbers also act as carrier active material.

In this Specification preferably C.sub.1-4 alkyl is methyl, ethyl or propyl, more preferably methyl or ethyl; preferably C.sub.1-4 alkoxy is methoxy or ethoxy and preferably halogen is chlorine or bromine.

Preferably at least one R.sub.2 is OH, methoxy or hydrogen, more preferably both R.sub.2 's are hydrogen.

Preferably R.sub.1 is in the 4-position and is selected from chloro, methoxy and OH.

Preferably there is provided a solution of one or more U.V. absorbers selected from resorcinol monobenzoate, 4-chloro-2,2',4'-trihydroxybenzophenone, 2,2',4-trihydroxybenzophenone, 2,4-dihydroxy-4'-methoxy benzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone and phenyl salicylate; and an emulsifier in an organic solvent system.

Preferably the U.V. absorber is phenyl salicylate or a mixture of phenyl salicylate and 2-hydroxy-4-methoxy benzophenone.

Preferably a solution according to the invention is clear and on adding to water forms an emulsion.

Preferably the emulsifier is an C.sub.4-12 alkyl phenol ethoxylated with 5 to 20 moles of EtO, di-C.sub.4-12 alkyl phenol ethoxylated with 5 to 20 moles of EtO, C.sub.8-18 alcohol ethoxylated with 5 to 30 moles of EtO, C.sub.12-18 fatty acid ethoxylated with 5 to 20 moles of EtO and castor oil ethoxylated with 5 to 50 moles of EtO. More preferably the emulsifier is an ethoxylated nonylphenol; most preferably the emulsifier is nonylphenol ethoxylated with 10 moles EtO. (EtO is ethylene oxide.)

Preferably the solvent system is a mixture of a hydrophobic solvent (preferably an ester of a fatty acid or an aromatic ester or an aromatic hydrocarbon) and a hydrophilic solvent (preferably a heterocyclic saturated compound such as pyrrolidone). A more preferred solvent system is a mixture of trimethylbenzene and N-methyl pyrrolidone (preferably in a ratio of 2:3 to 5:1 trimethylbenzene to N-methyl pyrrolidone) or a mixture of metil oil and N-methyl pyrrolidone (preferably in a ratio of 2:1 to 4:1 metil oil to N-methyl pyrrolidone). Metil oil is a mixture of methyl esters of C.sub.14-18 fatty acids.

A further preferred solvent system may also include a chlorinated paraffin, a dibenzoate and heterocyclic saturated compounds such as pyrrolidones.

Preferably in a solution according to the invention, 20 to 50% U.V. absorber; 10 to 30% emulsifier and 10 to 60% solvent are present. All ratios given are by weight.

In the dyebath the solution according to the invention is used in amounts from 0.5 to 10% based on the weight of the material.

The solutions according to the invention may be used in all dyeing methods, including rapid dyeing.

Using solutions according to the invention dyeings are produced that are more level and are more reproducible because the U.V. absorber in the composition of the invention assists in maintaining good light fastness of dyeings whilst acting at the same time as a carrier.

The invention will now be illustrated by the following Examples in which all percentages are by weight of substrate to be dyed, all parts are by weight of 100 parts and all temperatures are in .degree.C.

A product A comprising:

27 parts of 2-hydroxy-4-methoxybenzophenone

45 parts of trimethylbenzene

10 parts of N-methyl pyrrolidone and

18 parts of nonyl phenol 10 ethoxylate

is prepared by stirring the components together at room temperature.

A dyebath is prepared as follows:

0.38% C.I. Disperse Yellow 42;

0.21% Foron Red SE LKJ

0.18% Foron Blue SE LKJ

0.46% C.I. Disperse Blue 87

2 g/l Sandacid PB

3.0% of product A above.

A polyester fabric is immersed in the dyebath at a goods to liquor ratio of 1:12 at 60.degree. and the dyebath is raised to 130.degree. at a rate of 3.degree. per minute and the bath is maintained at this temperature for a further hour.

The dyeing prepared from this bath is dried at 100.degree. and fixed for 30 seconds at 170.degree..

The dyeing prepared is grey in colour and, compared to dyeings made under identical conditions except that the dyebath does not contain 3% of the product A, the light fastness of the dyeing is significantly better when exposed for 72 hours to a Hannaue Sun Test Lamp.

Following the process of Example 1 but using a dyebath comprising:

2.00% C.I. Disperse Orange 37

0.14% C.I. Disperse Red 167

0.61% C.I. Disperse Blue 73

2 g/l Sandacid PB and

3.0% of the product A of Example 1,

a dyeing of a brown colour is obtained and compared with a dyeing made under identical conditions except that the dyebath does not contain 3% of the product A, the light fastness of the dyeing is significantly better.

The Foron dyestuffs are commercially available from Sandoz Ltd., as is Sandacid PB, which is a buffer comprising mixed dicarboxylic acids, naphthalene sulphonic acid-formaldehyde condensate and ammonium sulphate.

A product B comprising:

40 parts of phenyl salicylate

30 parts of metil oil

20 parts of nonyl phenol 10 ethoxylate

10 parts of N-methyl pyrrolidone

is prepared by stirring the components together at room temperature until a clear solution is obtained.

This can be substituted for product A in either Example 1 or Example 2.

A product C comprising:

26.6 parts of 2-hydroxy-4-methoxy benzophenone

13.4 parts of phenyl salicylate

10.0 parts of N-methyl-2-pyrrolidone

7.5 parts of diethylene glycol dibenzoate

20.0 parts of Cerechlor 50 LU (a chlorinated paraffin)

22.5 parts of nonyl phenol 10 ethoxylate

is prepared by stirring the components together at room temperature until a clear solution is obtained.

This can be substituted for product A in either of Examples 1 or 2.