GB2023669A - Process and dyestuff preparations for dyeing mixtures of polyester and cellulose fibres - Google Patents

Abstract

The present invention relates to a process for dyeing fabrics or warp yarns of polyester fibres and cellulose fibres using disperse dyes and azo dyes that are water-insoluble and produced on the fibres, which comprises (a) padding the material with an aqueous alkaline liquor that contains a coupling component, (b) subsequently drying the impregnated material, (c) subsequently developing the dye with an aqueous acidic developing liquor that contains a diazo component and one or more disperse dyes, and (d) drying and thermosoling the dyeing thus obtained. In the past anionic dispersing systems have been used for the disperse dyes and these have reacted with cationic diazonium salts, resulting in precipitation and unsatisfactory dyeings. We have found that satisfactory results are obtained by using the disperse dye in a non-ionic dispersing system based on ethoxylated phenol-formaldehyde condensates in which the free hydroxyl groups may be alkylated. The present invention provides a dyeing process using this dispersing system and a dye preparation containing it.

Description

SPECIFICATION Process and dyestuff preparations for dyeing mixtures of polyester and cellulose fibres The present invention relates to the dyeing of fabrics or warp yarns of mixtures of polyester fibres and cellulose fibres.

Fabrics that consist of dyed warp threads and weft threads that are un-dyed or differently dyed may advantageously be dyed in accordance with a process in which the sizing and the dyeing of the warp threads are combined with one another. In the case of textile articles of this kind made of cellulose fibres, the dyeing technique mentioned has been practised for years on a large scale. In this connection the warp sizing-impregnating process and the warp sizing-dyeing process, which use azo dyes produced on the fibre, have acquired great importance. In the warp sizingimpregnation process the warps are sized and the coupling component applied in one operation. After drying, the warps are woven and the dye is then developed by treating the material with a diazonium salt solution.A variation of this process is the so-called warp sizing-dyeing process in which the dye formation is brought about prior to weaving by treating the sized and impregnated warp with a diazonium solution.

The warp sizing-dyeing process and warp sizing-impregnating process have also been used for dyeing warp yarns made of mixtures of polyester fibres and cellulose fibres in medium tones for denim articles using the components of water-insoluble azo dyes: the warp is padded with a size that contains a dissolved coupling component and then, either after drying and weaving or immediately after drying, the dye is developed in a second trough by overpadding the material with a solution of the diazo component, and the dye is subsequently thermosoled. In this process, the portion of the azo dye adhering to the surface of the polyester fibres diffuses into these fibres, and the hydrophobic portion of the fibre is thereby dyed. The fastness to light of a dyeing of this kind, however, compared with the dyeing on the cellulose fibres, is insufficient.Apart from this, the depth of colour of the polyester fibre component is unsatisfactory.

To obtain deeper colour tones with better light-fastness properties it is therefore necessary to add disperse dyes to the developer liquid at the same time as the diazo component. A process in which this procedure is carried out is described on pages 125-130 of the periodical ' "Chemiefasern/Textil-l ndustrie" 24/76 (9174). However, this reference expressly states that the method is only suitable for yellow, orange, red and maroon colour tones.The reason why the colour tones of blue through navy-biue to black, which are considerably more important for denim articles, are not available according to the above technique is that the diazo components with which the relevant colour tones can be produced exist only as salts and not (as in the case of the earlier mentioned lighter colour tones) as bases, and these salts together with the disperse dyes produce unstalbe and therefore useless padding liquors. The cationic diazonium compounds, such as diazotised aromatic amines (dye bases), e.g. the diazonium chloride of p-nitroaniline, in fact react with the anionic dispersing systems (stabilisers, dispersants and floating agents) of commercially available disperse dyes to produce precipitation. This can occur to such an extent that such deposits block the pipe networks between the starting vessel and the padding trough.Dyeings with such liquors are understandably not perfect and accordingly also not reproducible.

We have therefore realised that there is a need for a non-ionic dispersing system to replace the anionic dispersing systems of the commercially available disperse dyes, which on the one hand should have the desired dispersing properties and on the other hand should not reduce the yield of these dyes on the fibres.

We have found that satisfactory results are achieved by using the disperse dyes in a nonionic dispersing system based on ethoxylated phenol-formaldehyde condensates in which the free hydroxyl groups may be alkylated. To produce such dispersions the disperse dyes may be used in the form of a liquid or pastelike preparation or in powder form.

As well as the disperse dyes, azo dyes that are water-insoluble and produced on the fibre are used, and the procedure comprises (a) padding the material with an aqueous alkaline liquour that contains a coupling component, (b) drying the material impregnated in this manner, (c) subsequently developing the dye with an aqueous acidic developing liquor that contains a diazo component and one or more disperse dyes, and (d) drying and thermosoling the dyeing produced in this manner.

The material used in step (a) may be a warp yarn or a fabric, usually a polyester-cotton warp or a polyester-cotton fabric. If a warp is used in step (a), this may subsequently be woven with weft; the warp sizing-impregnating process and the warp sizing-dyeing process are suitable according to the invention.

The weft may be polyester-cotton, polyester or cotton; it may be dyed the same or a different colour from the weft or it may be un-dyed.

Accordingly, the present invention provides a process for producing a dyed warp or fabric comprising polyester and cellulose fibres us ing a disperse dye and an azo dye that is water-insoluble and produced on the fibres, which comprises (a) applying an aqueous alkaline liquor that contains a coupling component to a warp yarn or fabric, (b) drying the treated warp or fabric, and, in the case of a yarn, optionally weaving the yarn, (c) developing the dye with an aqueous acidic developing liquor that contains a diazo component, one or more disperse dyes and a nonionic dispersing system containing an ethoxylated phenolformaldehyde condensate in which some or all of the free hydroxyl groups may, if desired, be alkylated, and (d) drying the yarn or fabric and, in the case of a yarn, optionally weaving the yarn, and fixing the dyeing.

The present invention also provides a warp yarn or a fabric dyed by a process of the present invention and a dyed fabric prepared from a warp yarn dyed by a process of the present invention.

The fabric comprises polyester and cellulose; for example, the warp may be cellulose and the weft, for example, polyester or polyester-cellulose, but usually the warp is polyestercellulose or a fabric is used in the process of the invention.

The present invention also provides a nonionic dye preparation comprising a disperse dye and an ethoxylated phenol-formalehyde condensate in which some or all of the free hydroxyl groups may, if desired, by alkylated.

Preferred phenol-formaldehyde condensates are those in which the degree of ethyoxylation is 5 to 25 moles of ethylene oxide per aromatic radical and in which the optionally present alkyl groups have up to 10 carbon atoms each, e.g. methyl. The phenolic compound used is preferably unsubstituted phenol.

Mixtures of these dispersing agents with other nonionic addition compounds, such as ethyoxylated castor oil, especially the reaction products of 1 5 to 50 moles of ethylene oxide with 1 mole of castor oil, and/or tri-(alkylpolyglycol ether) ortho-phosphoric acid esters in which 1 or 2 alkylpolyglycol ether radicals may be replaced by polyglycol either radicals, in which advantageously the degree of ethoxylation is 9 to 30 moles of ethylene oxide per mole and the number of carbon atoms in the alkyl radicals is 4 to 20, are also suitable.

The above-mentioned dispersing systems have the advantage over other non-ionic agents that the disperse dyes used are not retained. They thus give full dye yields.

For the purposes of producing insoluble azo dyes on wound packages of cellulose fibres it is already known from DE-PS 1 220 826 to use ethoxylated phenol-formaldehyde condensates in the developing liquor containing a diazo component in order, firstly, to keep azo pigment formed in the liquor outside the fibres and, secondly, to keep decomposition products of the diazo compound in a dispersion that can be washed out. Such dispersing agents are additionally distinguished by the fact that they foam only a little and, because of their relatively slight surface activity, do not hinder the flow of the liquors through the wound packages.Despite these known properties of ethoxylated phenol-formaldehyde condensates, it has nevertheless not been suggested that, with the aid of such non-ionic products, disperse dyes as well could be formulated in the form of a preparation ready for dyeing, and that stable developing liquors can be obtained if these non-ionically formulated disperse dyes are used simultaneously in addition to the cationic diazonium compound. The experts have previously proceeded on the assumption that only dispersing systems of a predominantly anionic character are suitable for preparations of disperse dyes (DE-OS 2 523 659 and DE-OS 2 348 518).

The disperse dye is worked up preferably in an amount of from 30 to 500 % by weight, based on the pure dye content, with the above-described non-ionic dispersing system to form a liquid formulation and is used as such in the diazonium compound developing liquor. Advantageously a disperse dye suitable for dyeing according to the thermosol process is used for the dye preparation; the liquor prepared therewith is stable and the dyeings are therefore reproducible.

To prepare a dyeing according to the invention by the warp sizing-impregnating process the procedure is, for example, as follows: A low-substantive to middle-substantive coupling component is dissolved in the ordinary manner, usually according to the colddissolving process without formaldehyde, and this solution is added to a sizing composition consisting of starch and/or carboxymethylcellulose which has been pre-strengthened to 32.5% with 3-8 cm3/l of sodium hydroxide solution and to which, for reasons of improved re-wettability, there are added as desired 1 to 5 g/l of a low-foaming, preferably anionic, wetting agent, e.g. a combination of an alkylsulphonate having 8 to 1 2 carbon atoms in the chain, and the reaction product of isotridecanol and ethylene oxide having 5 to 10 moles, preferably 8 moles, of ethylene oxide per mole.

Normally, the size is boiled in an autoclave and then the solution is added to the coupling component. Alternatively, however, selected coupling components may be boiled and dissolved with the size.

The warp of the polyester fibre/cotton mixture is padded with this size and dried. Subsequently the warp thus impregnated is woven with a weft yarn. This fabric is then padded on a padding machine with a cold liquor that contains a diazo solution (a diazotised and neutralised diazo base or a diazo salt) and one External Internal Heat Heating Cost Temp. C Temp. t Loss. Electric Oil Gas 0 20 13.45 37.26p 15.74p 9.67p 5 20 10.08 27.92p 11.79p 7.92p 10 20 6.72 18.61p 7.86p 5.28p 15 20 3.36 9.97p 3.93p 2.64p 2. For double glazing with two sheets of 6 mm glass bounding a 20 mm air space (U = 2.9 watts/metre2 "C).

External Internal Heat Heating Cost Temp. C Temp. "C Loss. Electric Oil Gas 0 20 6.96 19.28p 8.14p 5.47p 5 20 5.22 14.46p 6.11p 4.1Op 10 20 3.48 9.63p 4.07p 2.73p 15 20 1.74 4.82p 2.04p 1.36p 3. For shutters according to the invention with a 1 3 mm core, trapping a 20 mm layer of air against a 6 mm sheet of glass (U = 0.9 watts/metre2 "C).

External Internal Heat Heating Cost Temp. C Temp. C Loss. Electric Oil Gas 0 20 2.39 6.62p 2.79p 1.87p 5 20 1.79 4.95p 2.09p 1.41p 15 , 20 1.19 3.30p 1.39p 0.94p 20 20 0.60 1.66 0.70p 0.47p The heat loss figures refer to the number of kilowatts loss in 1 2 hours through a window area of 10 square metres.

The fuel costs are based on domestic tariffs of 2.71p per kilowatt of electricity, 16.4p per Therm of Natural Gas (1500 Therms per year) and 36p per gallon of oil and assumed efficiency of Electricity 98%, Gas 70% and Oil 65%.

All the U values were calculated in accordance with Building Research Establishment digest No. 108 entitled "Standardised U values" dated August 1969, and were based on normal standard exposure. The double and single glazing U values are in accordance with Building Research Establishment digest No. 140 entitled "Double glazing and double windows" dated April 1972.

The U value of windows fitted with the shutters according to the invention are comparable, when the shutters are closed, to the U value of the external wall and during winter cold zones around windows can be drastically reduced.

Depending on the thickness of the shutters, the location and exposure of the windows, the internal temperature and the type of fuel used for heating, the return by fuel savings on the capital expenditure on the shutters can vary considerably. Based on Building Research Establishment digest No. 1 90 entitled "Heat loss from buildings" dated June 1976 it has been calculated that typical figures based on current prices might be: Electricity, capital recovered in 1.1 years; Oil, capital recovered in 2.5 years; and Gas, capital recovered in 3.7 years.

In addition to providing a thermal insulation screen, the shutters provide additional privacy and security against unwanted intrusion.

The invention is not restricted to the details of the foregoing embodiment.

Although the shutters shown are specifically designed for mounting on the inside of the glass, the shutters can if desired be made or covered with weather-resistant materials and be adapted for mounting externally.

The external surface of the shutters may be light in colour and/or reflective so that the shutters tend not to lose heat outwardly when they are used to retain heat within a building and also tend not to absorb heat from the outside when they are used to keep a building cool.

If desired the sealing strips 29 and 30 may be replaced by sealing strips mounted on the shutters themselves. This simplifies the installation of the shutters since there is no need to attach the sealing strips to the window recess. For example the upper and lower edge of each panel may be capped by an elongate member having the cross-section shown in Fig. 10. Each capping member has a first channel 34 to receive the panel, and a second T-shaped channel 35. When the panels of a shutter have been hinged together the shutter is opened out so that the panels lie in the same plane. In this position the channels 35 of the respective capping members co-operate to define a first substantially continuous T-shaped channel extending along the upper edge of the shutter and a second substantially continuous T-shaped channel extending along the lower edge of the shutter.A length of flexible wiping sealing strip is then fed through each substantially continuous channel to extend along the full length of each channel, the strip having the cross-section shown in Fig. 11. The foot 36 engages in the T-shaped channel, the blade 37 extending from the channel to provide a wiping seal to engage in use with a face of the window recess, Each strip is sufficiently flexible and resilient to permit the shutters to be folded into the open position, each strip taking up a zig-zag or concertina shape matching that of the open shutters, flexing and slight stretching of the strips occuring in the vicinity of the hinges.

Instead of manufacturing the panels as shown, the panels may be manufactured by extruding a hollow rectangular cross-section, with or without internal stiffening ribs or webs, cutting the extrusion into lengths equal to the desired length of the shutters, and filling the interior of each length of extrusion with thermal insulation foam. For example the lower edge of each extrusion can be capped, e.g. using an adhesively secured capping member as shown in Fig. 10. Liquid foam creating material can then be inserted into the extrusion, and when the materials have foamed up to fit the extrusion, the upper edges can be capped by adhesively securing a further capping member. Hinges may be formed by extruding the plastics material such that there is a continuous tube at each longitudinal edge of the rectangular cross-section of the extrusion.

Selected portions of the tubes can then be cut away such that when the panels are fitted together tubular portions of one panel register with tubular portions of an adjacent panel to form a substantially continuous tube along which a piano hinge type hinge pin can be passed to pivotally interconnect the panels.

Alternatively the extrusion may be formed such that each longitudinal edge is provided with a continuous groove with serrated walls to receive a hinge of the form shown in Fig. 7.

It may be inconvenient to make a number of extrusions of differing cross-sectional dimensions to enable shutters to be manufactured to fit a variety of different windows, but the same effect can be achieved by making each shutter from an appropriate number of standard size panels and then making up any shortfall in dimensions with one smaller panel. This panel may be manufactured by cutting one of the extrusions longitudinally to reduce its width and then capping the cut edge with a sealing capping member such as shown in Fig. 10 or, if a seal is not required at that location, with a plain capping strip having the cross-section shown in Fig.

12.

Another possibility which results from fitting the upper and lower sealing strips to the panels rather than to the window recess is that shutters can be made in standard sizes and the shutters can be arranged to close across window recesses of varying widths by varying the extent to which the shutters adopt a concertina or zig-zag position when closed. Indeed a shutter which is not in a planar position when closed may give a more pleasing visual effect.

Although the shutters are shown mounted on the opposite sides of a window, they may be mounted at the top and bottom of a window so that the hinges extend horizontally. Alternatively there may be a single shutter and the shutter may be attached to the top or bottom of a window.

Instead of being arranged to fold together in a concertina or zig-zag fashion, the panels making up a shutter may be arranged so that the shutter can be wound up into the collapsed position. The shutter may for example be windable around a storage drum or shaft. With such an arrangement it is preferred that the width of each panel is no wider than 5" to 6". If the panels are wider than this, then the roller up shutter has an excessively large radius.

It is not essential to use four panels for each shutter, and any desired number of panels may be used, although it is preferred that an even number is used, for example 2, 4, 6, or 8 panels.

Although the use of polyisocyanurate foam is preferred, other thermal insulation material may be used, for example polyurethene foam, or foamed polystyrene.

Instead of being built on a timber frame, the panels may be built on a frame of plastics materials or metal, or a combination of materials.

Instead of using wiping seals, compression seals may be used in which a strip of sealing material is compressed between two members to form the seal.

CLAIMS 1. A shutter for a window, the shutter comprising a plurality of panels of thermal insulation tion product of 1 mole of cresyl camphane and 1 9.5 moles of ethylene oxide, with a liquor pick-up of 60 % weight; after a brief exposure to air for approximately 30 seconds the goods were dried in a hot flue at 110"C and then thermosoled at 210"C for 60 seconds. After the subsequent treatment, as is customary for naphthol dyeings, by rinsing, soaping at 60"C and soaping while boiling combined with repeated rinsing, a fast blue fabric dyed uniformly in the polyester and the cotton fibre portions was obtained.

The ethoxylated phenol-formaldehyde condensate used in the non-ionic dispersing system may be, for example, any of the known ethoxylated phenolformaldehyde condensation products. In general, any suitable phenolic compound may be used for its preparation, for example a mononuclear phenol, e.g. phenol itself or substituted phenol. The condensation product may be formed directly or via a pre-condensate. After formation of the ethoxylated phenol-formaldehyde condensate, the product may be alkylated, for example methylated. Products mentioned in DE-PS 1 220 826 and British Patent 1 008 640 are suitable.

Claims (28)

1. A process for producing a dyed warp or fabric comprising polyester fibres and cellulose fibres using a disperse dye and an azo dye that is water-insoluble and produced on the fibres, which comprises (a) applying an aqueous alkaline liquor that contains a coupling component to a warp yarn or fabric, (b) drying the impregnated material, (c) developing the dye with an aqueous developing liquor that contains a diazo component and one or more disperse dyes in a non-ionic dispersing system comprising an ethoxylated phenolformaldehyde condensate in which the free hydroxyl groups may, if desired, by alkylated, and (d) drying, and thermosoling the dyeing obtained.

2. A process for dyeing fabrics or warp yarns that consist of mixtures of polyester and cellulose fibres using disperse dyes and azo dyes that are water-insoluble and produced on the fibre, which comprises (a) padding the material with an aqueous alkaline liquor that contains a coupling component, (b) subsequently drying the impregnated material, (c) subsequently developing the dye with an aqueous acidic developing liquour that contains a diazo component and one or more disperse dyes, and (d) drying and thermosoling the dyeing thus obtained, wherein the disperser dye or dyes are used in a non-ionic dispersing system comprising an ethoxylated phenolformaldehyde condensate, in which the free hydroxyl groups may, if desired, be alkylated.

3. A process as claimed in claim 1 or claim 2, wherein in the ethoxylated phenolformaldehyde condensate the degree of ethoxylation is 5 to 25 moles of ethylene oxide per aromatic radical.

4. A process as claimed in any one of claims 1 to 3, wherein the hydroxyl groups of the condensate are alkylated and the alkyl groups have up to 10 carbon atoms.

5. A process as claimed in any one of claims 1 to 4, wherein the phenolic compound of the condensate is phenol.

6. A process as claimed in any one of claims 1 to 5, wherein the non-ionic dispersing system contains ethoxylateEl castor oil or a tri-(alkylpolyglycol ether) ortho-phosphoric acid ester in which one or two alkylpolyglycol ether radicals may, if desired, be replaced by polyglycol ether radicals, or two or more such additives.

7. A process as claimed in claim 6, wherein in the ethoxylated castor oil the degree of ethoxylation is 1 5 to 50 moles of ethylene oxide per mole.

8. A process as claimed in claim 6 or claim 7, wherein in the phosphoric acid ester each alkyl group has from 4 to 20 carbon atoms and the degree of ethoxylation is 9 to 30 moles per mole.

9. A process as claimed in any one of claims 1 to 8, wherein step (a) is carried out on a warp yarn and the aqueous liquour applied in that step contains a sizing agent.

10. A process as claimed in claim 9, wherein the sized and impregnated warp yarn is developed and thermosoled after weaving with a weft yarn.

11. A process as claimed in claim 9, wherein the sized and impregnated warp yarn is developed and thermosoled before weaving with a weft yarn.

1 2. A process as claimed in any one of claims 1 to 8, wherein step (a) is carried out on a fabric.

1 3. A process as claimed in claim 1, carried out substantially as described in any one of the Examples 1 to 5 herein.

14. A warp yarn comprising polyester and cellulose fibres dyed by a process as claimed in any one of claims 1 to 9.

1 5. A warp yarn as claimed in claim 14, dyed by a process substantially as described in any one of the Examples 1 to 4 herein.

16. A dyed fabric comprising polyester and cellulose fibres produced by a process as claimed in claim 10 or 11.

1 7. A fabric as claimed in claim 16, produced by a process carried out substantially as described in any one of the Examples 1 to 4 herein.

1 8. A fabric comprising polyester and cellulose fibres dyed by a process as claimed in claim 12.

1 9. A fabric as claimed in claim 18, dyed by a process carried out substantially as described in Example 5 herein.

20. A fabric as claimed in any one of claims 1 6 to 19, wherein the weft is undyed or dyed differently from the warp.

21. A warp yarn or fabric as claimed in any one of claims 14 to 20, wherein the azo dye is blue or black.

22. A dye preparation comprising one or more disperser dyes in a non-ionic dispersing system comprising an ethoxylated phenol-formaldehyde condensate in which the free hydroxyl groups may, if desired, be alkylated.

23. A preparation as claimed in claim 22, wherein the ethoxylated phenol-formaldehyde condensate is as specified in any one of claims 3 to 5.

24. A preparation as claimed in claim 22 or claim 23, which contains one or more additives specified in any one of claims 6 to 8.

25. A preparation as claimed in any one of claims 22 to 24, which has been prepared from a disperse dye in the form of a liquid preparation or paste.

26. A preparation as claimed in any one of claims 22 to 24, which has been prepared from a disperse dye in powder form.

27. A preparation as claimed in claim 22, substantially as described in any of one of Examples 1, 3, 4 and 5 herein.

28. A developing liquor comprising a preparation as claimed in any one of claims 22 to 27 and a diazo component.