GB1575399A

GB1575399A - Disperse dye compositions

Info

Publication number: GB1575399A
Application number: GB2514478A
Authority: GB
Original assignee: Yorkshire Chemicals Ltd
Current assignee: Yorkshire Chemicals Ltd
Priority date: 1978-05-31
Filing date: 1978-05-31
Publication date: 1980-09-24
Also published as: JPS5523179A; DE2922223A1

Description

(54) DISPERSE DYE COMPOSITIONS (71) We, YORKSHIRE CHEMICALS LIMITED, a British company of Black Bull Street, Leeds, LS10 1HIP. do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: It is well known that, when dyeing textile materials with mixtures of two or more dyes to produce a particular shade, it is advantageous to use dyes which are compatible with one another. Apart from the obvious requirements of physical compatibility, the dyes should be compatible in terms of their rate of absorption on to the fibre. This is often known as "on-tone build-up" and is condusive of levelness of dyeing and reproducibility of shade.

In the case of cationic (basic) dyes, for example, as applied to acrylic fibres there has been established a system of Compatibility Values (see J.S.D.C.1973, 203) which are widely used to allow dyers to select combinations of dyes which will be compatible with each other. This has proved extremely useful to the dyer in enabling him to prepare a recipe with an "on-tone build-up" and thus assist him in his purpose of achieving a level. on-shade dyeing. Each basic dye has a particular compatibility value which is independent of the concentration of dye being applied and this makes the system very easy to operate.

With disperse dyes as applied to polyester fibres, however, no such simple system applies and it is very difficult to choose compatible mixtures of dyes so as to obtain on-tone build-up for a particular shade. This is largely because the rate of absorption of a dye is very dependant on the depth of shade (i.e. the concentration of dye) at which it is being applied and hence a mixture of two or more dyes may or may not be compatible depending on the concentrations at which they are being applied to achieve a given shade.

The rates of absorption of disperse dyes have been studied by us in some detail and we have produced information which enbles the dyer to predict the compatibility of a given mixture of dyes. It has now been found that this information can be used to formulate mixtures of dyes of similar hue (referred to as primary dye compositions) e.g. two or more yellow dyes to make a yellow dye composition in such a way that two or more of these primary dye compositions of different hues can be mixed together in widely varying proportions and still give an on-tone build-up. By this means it is possible to formulate dye compositions in primary hues such as yellow, golden-yellow, red, blue and then use these to match any desired shade knowing that the total mixture of the dves will give an on-tone build-up. thus giving rise to improve dyeing properties as will be demonstrated later.

The expression primary dye composition as used throughout the specification including the claims means a mixture of dyes of the same or similar hue.

It is important that individual dyes, which are in the same primary combination, be of generally similar hue. Thus it would not be advantageous to have a blue dye mixed with yellow dyes in the same primary combination, or a scarlet dye mixed with blue dyes in another primary combination. It is, however, permissible to formulate a primary combination from, for example neutral yellows and reddish yellows or even yellowish oranges, or another primary combination from yellowish reds and bluish reds.

It is a feature of the invention that the dye compositions are formulated using a knowledge of the V number of the individual dye components which is relatable to the rate of dyeing of each dye in the composition and is dependent upon the amount of the composition being applied to the fibre.

According to the present invention there is provided a primary dye composition comprising a mixture of at least two disperse dyes of the same or similar hue having V numbers as hereinafter defined, at the same concentration, which differ by at least 0.5 preferably no more than 6.0 and more particularly from 0.5 to 3.0 Where more than two dyes are present at least two dyes must differ in V number at the same concentration by at least 0.5 and it is preferred that there is a range of V numbers each differing from the next by at least 0.5. The dye composition of the invention may comprise 2,3,4 or more disperse dyes.

Also according to the present invention there is provided a process of preparing a primary dye composition which comprises admixing at least two disperse dyes of the same or similar hue, in which at least two of said dyes have been selected by reference to their V numbers (as hereinafter defined) so as to have V numbers at the same concentration which differ by at least 0.5.

By selecting the V number of the dyes in accordance with the invention the temperature range over which the mixture of dyes can be effectively used being wider than the temperature range over which any one of the dyes in the mixture can be effectively used.

The primary dye compositions of the invention are so formulated that under given dyeing conditions, dyeings may be obtained which build up evenly over a relatively wide range of dyeing temperatures, independently of the amount of dye being applied. Such primary dye compositions are thus compatible with one another at all depths and may thus be mixed one with another in any proportion to produce secondary dye compositions and still give an even build-up of shade over the normal dyeing temperature range.

The ability of these compositions to give compatible, on-tone build up when used in any concentration is unusual, and it has not been possible using previous knowledge to produce disperse dye compositions possessing this highly desirable property. Important savings in total dyeing time may be brought about by using the dye compositions of the invention.

More rapid dyeing is achieved by the ability to put down the time required for both the heating up phase to the dyeing temperature as well as the time at top dyeing temperature.

Because the dye compositions of the invention build up on tone in a compatible manner these reductions in time may be effected whilst still maintaining a level dyeing. This is a very important feature of the dye compositions of the invention.

Mixtures of two or more of the so-called primary due compositions of the invention, termed herein as "secondary dye composition" are within the scope of the invention and indeed a primary composition of the invention may be mixed in any proportions with other primary compositions of the invention to produce compositions which give even build up of shade over the normal dyeing temperature range.

The invention therefore also includes a secondary dye composition comprising a mixture of two or more primary dye compositions of the invention.

The disperse dye compositions of the invention are formulated using a knowledge of the rate of dyeing characteristics of the individual dye components of the mixture. By the term rate of dyeing is meant the amount of disperse dye that has been absorbed in a unit time from the dyebath onto or into the fibre to be dyed. The dyebath is taken to mean a reservoir of the disperse dyes in water together with any other auxiliaries such as dispersing agents, levelling agents, acids and fibre swelling agents as well as the fibre to be dyed. The fibre is taken to mean any hydrophobic fibre to which disperse dyes are normally applicable, for example, secondary cellulose acetate, cellulose triacetate, nylon and in particular polester fibres.The rate of dyeing of the invidual dye components of the dye compositions of the invention are for convenience measured in terms of the time of half dyeing of these components. The term time of half dyeing is defined as the time at which 50% of the total amount of dye that is capable of being absorbed by the fibre from the given dye bath is taken up by that fibre. If, under the conditions of measurement of this time of half dyeing, the temperature of the dyebath is raised at a uniform rate of increase, then the time of half dyeing corresponds to a certain temperature. This temperature is termed the critical dyeing temperature and refers to the temperature at which 50% of the availble dyestuff has exhausted onto the fibre when the temperature of the dyebath has been raised at a particular rate of increase. It is a feature of the high temperature disperse dyeing of polyester that this critical temperature is also the temperature at which the rate of dyeing is at a maximum in the particular dyeing cycle under examination. It is apparent that as the time of half dyeing increases then the rate or speed of dyeing decreases. A figure, termed the V number has been devised by ourselves that corresponds to the apparent rate of dyeing in that as V increases so does the rate of dyeing. V is calculated using the following formula: V= 70 10 where t2 is the time of half dyeing in minutes. V thus relates to the rate of dyeing of the disperse dye and is dependent upon the concentration of dye being applied to the particular fibre and the chemistry and molecular weight of the disperse dye being applied.The dyeing charateristics of given dyes under specific conditions can therefore be defined in terms of a graph of V number against depth of shade to be dyed. It is a feature of this invention that the disperse dye compositions are formulated using the information contained in such graphs, one graph for each of the individual dye components available, the most suitable components then being chosen to produce a mixture which will give a composition that has the unique properties that have previously been outlined. The V number decreases as the amount of dye being applied to the fibre increases. That is, a small concentration of dye has a large V number and a large concentration of dye a much smaller V number.

As an example of the way in which this information is used in the formulation of dye compositions of the invention the V number of any particular concentration of a series of disperse dyes may be studied, for example at 0.02%. Dyes which are of broadly similar hue are then picked out which have a low V number, medium V number and high V number at this particular concentration. There will be a difference in V number, AV, at this particular depth which will be at least 0.5 between the V numbers of any of the individual components of the dye mixture. This AV of at least 0.5 should be maintained at all concentrations of the individual components of the mixture above 0.02%. The mixtures will then contain components which build up at different temperatures and times throughout the dyeing cycle thus maintaining an overall steady build up.It is thus possible to choose by consideration of the V numbers a mixture of, for example, three yellow disperse dyes of similar hue, one with low V number, one with medium V number and one with high V number. This mixture of yellow dyes will dye the fibre uniformly and progressively from low dyeing temperatures up to high dyeing temperatures without there being a particular temperature at which the rate of dyeing is at a marked maximum. The V numbers of the individual components of the yellow mixture are then looked at for a wide range of concentrations to check that the components maintain similar differences in V number, AV at least 0.5, for all depths of shade of the mixture.

The same procedure can then be used to pick out mixtures using as components red or blue disperse dyes or any other shade that will show this uniform uptake of the dye by the fibre throughout the period over which the temperature of the dyebath is increased.

This information is then utilised to formulate the disperse dye compositions of the invention in whih the dyes concerned are physically mixed, such a mixture subsequently being utilised by the dyes as if it were a single dye. These dye compositions of the invention are not restricted to mixtures of three dyes as described above, but may contain from 2 to 12 dyes, preferably 2 to 6. A certain concentration of a single disperse dye normally exhausts onto the material being dyed over a relatively narrow critical temperature region. When two or more different disperse dyes are dyed in admixture it is possible that the critical temperature regions of these dyes are very different.This can lead to shade variations on the material or unlevelness, because each dye will exhaust at different rates and possibly on to different parts of the material, as these may not all be at the same temperature. This is normally described as incompatibility When a similar shade is dyed using the dye compositions of the invention, a very compatible result is obtained, with on tone build up of the dye throughout the whole dyeing cycle. By on tone build up is meant that the dyes exhaust onto the material at any time or temperature in a similar ratio to that of the original dye concentractions in the dyebath. The possibility of achieving unlevelness and shade variation when any shade is dyed using the disperse dye compositions of the invention is therefore very much reduced.The important advantage of the dye compositions of the invention is therefore that they can be claimed to be compatible when used to dye any shade. It is a well known fact that as the concentration of any disperse dye applied to a fibre increases, then the critical dyeing temperature increases, resulting in the need for longer dyeing times and higher dyeing temperatures. Since the amount of any individual dye in the mixtures of the invention being applied to the fibres is less than would be the case if the shade were being dyed with an individual dyestuff (i.e. not a mixture), the overall dyeing temperature for the shade is lowered. This can be made use of in that the dye mixtures of the invention can be used to advantage in a dyeing system that aims to be more rapid and economic.These savings in dyeing costs can be brought about by using th disperse dye compositions of the invention because they are less liable to cause unlevel dyeings at higher rates of temperature rise and consequently the total dyeing time may be reduced. It has also been found that the dye mixtures may be applied at a reduced maximum dyeing temperature, e.g. 120-125"C instead of 1300C which loads to further savings in dyeing costs.

The dye compositions of the invention are mixtures of at least two and not more than twelve, optionally two to six disperse dyes which build up on tone when dyed. Any disperse dye can be used in the composition of the invention provided that it has the appropriate v number chosen as previously outlined.

The invention also provides a dyebath containing a dye composition of the invention, a method of colouring hydrophobic fibres using a dye composition of the invention, and hydrophobic fibres so coloured. Dyeing is carried out uner normal conditions for hydrophobic fibres e.g. at 700C to 1300C.

The invention will now be further described by reference to the follwing Examples which are not intended to limit the scope of the invention.

Example 1 - A primary dye composition was prepared by selecting two disperse dyes by reference to their V numbers and admixing them. the composition was as follows: Composition 1 V (conc" number to) 1 part Serilene Yellow 7G-LS d.1.100 (2.8 (0.02%) C.I. Disperse Yellow 126 (2.2 (0.1%) 1.7 0.5%) 3 parts Serilene Yellow 2G-LS d.1.33 5.8 0.02%) C.I. Disperse Yellow 206 5.6 0.1% (4.0 0.5%) Example 2 -A primary dye composition was prepared by selecting four disperse dyes by reference to their V numbers, and admixing them. The composition was as follows: Composition 2 V (conch number to) 1 part Serisol Fast Yellow PL 150 C.I. Disperse Yellow 9 5.2 (0.02%) 1 part Serilene Golden Yellow 2R-LS C.I.Disperse Orange 93 4.7 (0.02%) 1 part Serilene Yellow SR C.I. Disperse Yellow 7 5.5 (0.02%) 1 part Serisol Fast Yellow GWD C.I. Disperse Yellow 27 4.4 (0.02%) Example 3 -A primary dye composition was prepared by selecting four disperse dyes by reference to their V numbers, and admixing them. The composition was as follows: Composition 3 V (conch number to) 1 part Serilene Dark Red FL C.I. Disperse Red 65 2.5 (0.5) (0.5%) 1 part Serisol Fast Red GRL C.I. Disperse Red 1033.0 1 part Serilene Red R-LS C.I. Disperse Red 177 2.0 (0.5%) 1 part Serilene Red 2BL C.I. Disperse Red 60 3.3 (0.5%) Example 4 -A primary dye composition was prepared by selecting three disperse dyes by reference to their V number, and admixing them. The composition was as follows: Composition 4 V (conch number to) 2 parts Serilene Blue RL C.I. Disperse Blue 56 3.3 (0.5%) 1 part Serilene Blue 3RLN C.I. Disperse Blue 64 2.7 (0.5%) 1 part Serilene Navy Blue G-LS C.I. Disperse Blue 171 1.5 (0.5%) Example 5 A dyeing test is carried out in a laboratory dyeing machine whereby a 5 gm. piece of texturised polyester fabric is put into each of six dyeing tubes together with 100 cc. of water, 1% on the weight of fbric of acetic acid (glacial) and 1.5% on the weight of fabric of Composition 1.

The temperature of the dyebath is taken up to 700C and the tubes are rotated in the machine. The temperature of the dyebath is then increased at a rate of rise 1"C per minute to 1300C and tubes are taken out of the machine when the temperature reaches 90"C, 100"C, llO"C, 1200C, 1300C. The dyeings produced at these temperatures are washed in cold water and reduction cleared in a solution of 0.2% sodium dithionite and 0.1% of a non ionic detergent at 750C for 15 minutes.

A final dyeing tube is taken off after 30 minutes at 1300C and the dyeing washed and reduction cleared as with the other patterns.

The dyeings shown an even build up of the two components of the yellow composition to give a greenish yellow shade at all temperatures up to and including 1300C.

Example 6 A dyeing test was carried out as in Example 5 but in place of 1.5% Composition 1 being used to dye the fabric, there was used 1.0% of Composition 2 on the weight of fabric.

The dyeing gave an even build up of the four yellow components to give a golden yellow shade at all the temperatures up to an including 30 minutes at 1300C. It was noted that the dyestuff mixture was being absorbed at lower temperature than 1% of any of the individual components of the mixture on its own.

Example 7 A further dyeing test is carried out as in Example 6 but in place of 1.0% Composition 2 there is used 2.0% of Composition 3 on the weight of fabric.

Very uniform build up of the neutral red shade is observed with no difference in shade at any of the temperatures. Surprisingly high build up of the dye is obtained at the lower dyeing temperatures especially when compared to dyeing tests carried out in a similar manner with 2% of any of the individual components of the mixture.

Example 8 A dyeing test is carried out as in Example 7 but in place of 2.0% of Composition 3 there is used 2.5% of Composition 4 on the weight of fabric.

The dyeings show an even build up of the three components of the blue mixture at any temperatue or time to give a bright royal blue shade. It is noted that the requisite dyeing temperature of the 2.5 % of the blue mixture is much lower than that for 2.5% of any of the components on their own.

Example 9 A dyeing test is carried out as in Example 4 using the following recipe to dye a grey shade: - 0.10% Composition 2 0.21% Composition 3 0.40% Composition 4 A grey shade was obtajined at all temperatures ranging from 90"C to 1300C showing minimum difference in shade at any temperature. The recipe was seen to be very compatible indeed.

Example 10 Another dyeing test was carried out as in Example 9 using the following recipe: 0.70% Composition 2 0.12% Composition 3 0.05% Composition 4 A fawn shade was obtained that showed remarkably good compatibility throughout the whole dyeing test.

Example 11 A further dyeing test was carried out as in Example 10 using the following dye recipe: 0.30% Composition 4 0.30% Composition 3 0.08% Composition 1 A plum shade was obtained that again showed uniform dye uptake at all temperatures with no difference in shade at any of the temperatures involved in the dyeing process.

Example 12 A dyeing test was carried out as in Example 11 using the following dye recipe: 0.2% Composition 4 0.5% Composition 3 0.6% Composition 2 A medium brown shade was obtained that showed extremely good compatibility at all temperatures throughout the dyeing process with uniform build up of the brown shade up to and including 1300C.

Example 13 A dyeing was carried out as in Example 9 but instead of using a rate of temperature rise of 1"C per minute, a rate of rise of 5"C per minute was used.

The dyeing built up on tone to give a grey shade. The compatibility of the dyes was as good as that in Example 5.

Example 14 The dyeings obtained from Examples 9, 10, 11 and 12 after 30 minutes at 1300C were compared to dyeings carried out for 30 minutes at 1200C using the recipes in Examples 7, 9, 10, 11 and 12.

There was no significant difference between the depth of shade of the dyeings carried out at 1200C and 1300C.

WHAT WE CLAIM IS: 1. A primary dye composition comprising a mixture of at least two disperse dyes of the same or similar hue and in which at least two of these dyes have V numbers (as hereinbefore defined) at the same concentration, which differ by at least 0.5.

2. A dye composition as claimed in claim 1 comprising only two disperse dyes.

3. A dye composition as claimed in claim 1, comprising three disperse dyes each having a V number which differs from the V number of the next by at least 0.5.

4. A dye composition as claimed in claim 1 comprising four or more disperse dyes each having a V number which differs from the V number of the next by at least 0.5.

5. A dye composition as claimed in any one of the preceding claims, in which the V number of the various dyes differs by no more than 6.0.

6. A dye composition as claimed in any one of the preceding claims, in which the V number of the various dyes differ by from 0.5 to 3.0.

7. A primary dye composition substantially as hereinbefore described in any one of the foregoing Examples.

8. A secondary dye composition comprising a mixture of at least two primary dye compositions as claimed in any one of the preceding claims.

9. A secondary dye composition as claimed in claim 8 substantially as hereinbefore described in any one of the foregoing Examples.

10. A dyebath containing a dye composition as claimed in any one of the preceding

Claims

claims.

11. A dyebath as claimed in claim 10, substantially as hereinbefore described in any one of the foregoing Examples.

12. A method of colouring hydrophobic fibres, in which the dye is a dye composition as claimed in any one of claims 1 to 9.

13. A method as claimed in claim 12 substantially as hereinbefore described in any one of the foregoing Examples.

14. Hydrophobic fibres whenever dyed by a process as claimed in claim 12 or 13.

15. A method of preparing a primary dye composition which comprises admixing at least two disperse dyes of the same or similar hue, in which at least two of said dyes have been selected by reference to their V numbers (as hereinbefore defined) so as to have V numbers at the same concentration which differ by at least 0.5.

16. A method as claimed in claim 15 in which only two disperse dyes are admixed.

17. A method as claimed in claim 15 in which three or more disperse dyes are admixed, each said dye being selected by reference to its V number so as to differ from the V number of the next dye by at least 0.5.

18. A method as claimed in any one of claims 15 to 17, in which the various dyes are selected so as to have V numbers which differ by no more than 6.0.

19. A method as claimed in any one of claims 15 to 18 in which the various dyes are selected so as to have V numbers which differ by from 0.5 to 3.0.

20. A method as claimed in claim 15 substantially as hereinbefore described in any one of Examples 1 to 4.

21. A primary dye composition whenever prepared by a process as claimed in any one of claims 15 to 20.