CA1093257A - Fabric decoration transfers and inks therefor - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

Decoration materials, e.g. for decorating fabrics, are made of removable design layer on a flexible sub-strate. The layer comprises a base of thermoplastic film-forming polymeric material, a pigment, a cross-linking agent capable of cross-linking the thermoplastic polymer, a thermally activated catalyst promoting the cross-linking reaction, and a high temperature plasticiser. If the layer is formulated correctly, transfer and fixing of a pre-printed design on fabric may be effected by passing the fabric an decoration material between heated calender rolls.

Description

~093Z57 This invention relates to materials for the decoration of fabrics used as textile materials and ink compositions for making the same.
Our French Patent Specification No. 2 261 138, laid open to public inspection on September 12, 1975, describes and claims a method of decorating textile fabrics which comprises taking a flexible substrate having a removable layer thereon containing a dye and/or pigment and a film forming polymeric base which on heating becomes sufficiently adhesive to adhere under the effect of pressure to the textile fabric more strongly than the layer adheres to the fle~ ble substrate, pressing the layer onto a textile fabric while heating, removing the flexible substrate to leave the layer adhering to the textile fabric and subjecting the fabric to a fixation process which fixes the dye or the pigment to give a fast result and causes a thermal breakdown of the film so that the presence of its residues does not affect the textile properties of the fabric or the fastness of the coloured result.
As indicated in the aforesaid published French patent

2~ specification, within that general process a wide variety of materials may be used for the layer which is applied to the textile to be decorated.
According to the present invention there is provided a decoration material primarily for use in decorating textile ~0~3257 fabrics which has the advantage of giving an efficient transfer of the removable layer with very short contact times and which consists essentially of a flexible substrate having at least one removable dry ink layer thereon, the at least one layer comprising a base of thermoplastic film-forming polymeric material, a pigment, a cross-linking agent capable of cross-linking the thermoplastic polymer, a thermal-ly acti~ated catalyst for promoting the cross-linking reaction selected from the class consisting of amine and ammonium salts of strong acids and mixtures thereof, and a high temper-ature plasticiser, the polymer material being chosen and the at least one removable layer being formulated so that when the layer is transferred to a matexial to be decorated and subjected to heat and pressure in the transfer operation, and any necessary heat fixation treatment, the layer breaks down to provide a discontinuous non-superficial residual matrix capable of holding the pigment to the material, which does not significantly modify the properties of the material after decoration.
The re vable layer may contain more than one pig-ment and the pigment(s) may be inert or capable of reacting with the polymer and/or the cross.linking agent.
Such a material is used by bringing it into contact under heat and pressure with the material to ~e decorated, usually a textile fabric, in order to adhere together the removable pigment-containing layer and the material to be decorated and thereafter subjecting the material to a fixation . . ~

treatment which fixes the pigme~t to the material and nor- -mally breaks do~m the tra~sferred layer so that the properties of the material are not significantly ~odified by the presence of its residues. The use of a thermally acti~ated catalyst makRs lt possible, using the techDlques described in more detail below~ to use heat and pressure su$$icient to ~nitiate the ~xing which can then be all~Yed to go to co3pletion in time, e.g. a rew days, while the material to be decorated is - 3a -~.

simply stored. The flexible substrate may be removed prior to the fixing treatment or afterwards. Generally if it is to be removed after the fi~ing treatment a higher combination of temperature and pressure is required in the initial contacting treatment than if the flexible substrate is removed prior to the fixing treatment. In certain circumstances it is ad-vantageous to remove the flexible substrate after the fixing treatment to minimise the risk of contamination of parts of the machinery by pigment and removable layer materials.
10 The initial heat and pressure contacting may be of a very short duration making it possible to achieve transfer and optionally fixation also by a single passage through heated nip rollers i.e. an application of heat and pressure of the order of 10 2 or 10 3 seconds.
Polymers which are preferred as forming the basis of the removable layer are the polyvinylacetals such as polyvinylbutyrals and polyvinylformals. They may be used alone or in mixture with other polymers including acrylic polymers, polyamides, polyvinylacetate or polyvinyl alcohol.
~uitable cross linking agents which can be used include dialdehydes e.g. glyoxal, epoxy resin monomers and aminoplasts. Of particular value are the methylolated aminoplast monomers e.g. dimethylolurea, dimethylol-dihydroxy ethylene urea, dimethylolcyclic ethylene urea or methylolated melamine and their methyl esters such as trimethoxy methyl melamine.
~s noted above, the catalysts used to promote the cross linking action are thermally activated. This means that they are ineffective at normal ambient temperature, and so do not tend to cross-link the polymer compound of the decoration material during its manufacture or storage, giving that material a good shelf-life. The temperature at which the catalyst may be activated may vary, but is preferably greater than 100C.
Activation may take place by a heating treatment subsequent to transfer of the removable layer to the material to be decorated or simultaneously therewith.
The thermally activated catalysts used in the present invention, so-called "blocked" catalysts, are selected from amine and ammonium salts of strong acids and mixtures thereof, e.g. the ethanolamine or diethanolamine salts of mineral acids, and ammonium salts such as ammonium chloride, nitrate, phos-phate and sulphate. The activity of the amine or ammonium salt depends upon the disassociation of the salt. Until a critical temperature is reached the catalyst has no significant effect in the removable film. The catalysts suggested in our patent referred to above are acid or acid generating catalysts such as zinc nitrate as optional ingredients in order to pro-mote superior washing fastness. Acid catalysts and acidgenerating catalysts such as zinc nitrate show initiation at ~uite low temperatures, e.g. 50 to 60C or even lower, and there is no suggestion that by using thermally activated catalysts as proposed herein the threshold temperature can be raised with corresponding advantages as discussed below. The amine salts of p-toluene sulphonic acid (PKa = <2) are of especial value in this connection enabling the critical initiating temperature to be raised to as high as 120C with corresponding advantages in the heat stability of the releasable layer, the flow of the layer during transfer and the extent of thermal breakdown of the removable film during transfer and heat fixation. Suitable amine compounds for combination with p-toluene sulphonic acid include S-carbazide, mono- and di-ethanolamine.
It is particularly desirable to utilise a catalyst/cross linking agent combination that gives a precise temperature threshold for cross linking. Since during the course of forming the removable layer on the flexible substrate by coating or printing, for example, it may be necessary to heat the paper in order to remove solvents; it is important that no cross linking reactions are initiated by such heating.
During the transfer process, when heat and pressure are applied, they should initially be sufficient only to ensure that the materials of the removable layer flow readily without the development of the viscosity which is characteristic of the onset of cross linking; however, at the end of the transfer process, the heat and pressure may rise to activate 2Q the catalyst.

1(;~93Z57 High temperature plasticisers constitute a special sub-group of plasticisers and have the property of lowering the temperature of the rubber/melt transition. They may or may not also possess the property of normal plasticisers i.e. lower the temperature of the glass/rubber transition to give a softer more pliable film. Since the process of decoration requires that the continuous nature of the transferred film does not survive the fixation process normal plasticisers have no significant role to play. How-ever high temperature plasticisation improves the extentof penetration of the releasable film into the receiving substrate during transfer and the continuation of that process during the subsequent fixation treatment. Suitable materials for use as high temperature plasticisers include fatty acids such as palmitic or stearic acid, esters of stearic acid or palmitic acid with polyethylene glycol or glycerol, paraffin wax, stearamide or finely dispersed poly-ethylene.
The removable layer may be a continuous layer of one colour or may be a discrete layer in the form of a decorative pattern or the like. Such a discrete layer is conveniently produced by printing and in a further aspect the present in~ention provides printing inks comprising the ingredients of the layer as set forth above dissolved or dispersed in an appropriate solvent.
In another aspect, then, the present invention resides in a printing ink for use in the manufacture of decoration materials and comprising a liquid carrier medium, an ink vehicle of a thermoplastic polymer film-forming material capable of being cross-linked, a cross-linking agent capable of cross-linking the polymeric film-forming material, at least one pigment, a thermally activated catalyst for promoting the cross-linking reaction between the thermoplastic polymer film-forming material and the cross-linking agent selected from the class consisting of amine and ammonium salts of strong acids and mixtures thereof, and a high temperature plasticiser, the polymeric material being chosen and the ink being formulated so that when applied to a flexible substrate to provide at least one removable dry ink layer thereon and the at least one layer is transferred to a material to be decorated and subjected to heat and pressure in the transfer operation, and any necessary heat fixation treatment, the layer breaks down to provide a discontinuous non-superficial residual matrix capable of holding the pigment to the material, which does not significantly modify the properties of the material after decoration.
Such inks can be formulated according to normal ink making practice and can be adjusted in their consi-stency to the particular method of application required.

B

It is important to avoid excessi~e heat during ink formula-tion 80 that no initiatio~ of cross linking occ~rs and also to a~oid the use of acidic materials as additi~es for the same reason.
The remo~able layer may be a simple single layer or may be made up of a plurality of sub-layers. The essential feature of the removable layer is that it should contain, either throughout or in at least one of its sub-layers or in the combination of such sub-la~ers, the components previously described as ~ecessary compone~ts of the removable ; layer.
~he use Or a plurality of sub-layers may in certain cir-cumstances offer particular a~vantages when it is de-sirea to use particular printing methods. For example - 8a -~0~3;~S7 printing by lithography requires inks to possess particular properties in relation to their physical reactions with the lithographic plate. To achieve a satisfactory balance of such properties is not easy when the inks also require to possess properties and contain substances such as have been discussed. However by coating or printing the flexible sub-strate using any appropriate means with a releasable film comprising all of the ingredients necessary to the present invention, drying the coated substrate and then printing the decoration using a normal lithographic ink, a suitable decor-ation material can be built up. It may be advantageous with some lighographic inks to apply over the printed decoration a further coating similar in composition to the first in order to achieve the best transfer properties and fastness. It is particularly advantageous when lithographic inks are printed to use a thermoplastic base material such as is provided by ultra violet cured inks based on glycidyl methacrylate. Similarly in gravure printing good image production is dependent upon the acceptance of the ink re-ceiving surface of the ink in the engraved cells and theability of printed dots to flow together to give overall coverage. To assist in this process with the removable layer system of the present invention it may be advantageous previously to coat the flexible support with an overall removable coating of similar composition.

_g_ In the production of the decoration materials by any conventional mode of printing, the formation of a plurality of layers is in any case inevitable in multi-colour printing processes since the coloured decoration is built up by successive printing with different colours, mixture shades being produced by laying one printed coat on another.
It is important in printing by any method and par-ticularly when a plurality of layers is involved to avoid the use of drying temperatures which may initiate the cross linking reaction or cause the high temperature plasticiser to become operative~ The first will give papers of poor storage stability as cross linking may proceed for a period of time after heating ceases and the second will give rise to a tacky paper which cannot be stacked without adherence of separate sheets or layers in a roll of printed paper.
The flexible substrate may be chosen from a wide variety of materials the surface of which is either such that it inherently possesses the necessary release properties between it and the removable layer or which surface may have been treated to give the desired effect. Self-supporting films of cellulose acetate and nitrocellulose or aluminium and other metal foils may be used as such or paper may be used, e.g., coated with a surface having ap-propriate release properties such as wax, nitrocellulose, silicone or a rubbery coating e.g. comprising polybutadiene.
Silicone release coated paper, wax coated paper or paper "~ -10-~093257 coated with a thermoplastic coating such as are provided by unsaturated esters of acrylic or methacrylic acid cross-linked by ultraviolet irradiation in the presence of appropriate catalysts are the preferred flexible substrates.
Certain paper types are usable as such, i.e. without the provision of an applied release coating.
When the decoration materials of the present invention are used, the removable layer should first be transferred to the fabric to be decorated. This is done using the thermo-plastic properties of that removable layer, whereafter thelayer is subjected to an appropriate fixing treatment which serves to cross link the thermoplastic material to form a discontinuous matrix firmly holding the pigments to the material to be decorated.
Clearly if the removable layer remained during such processing as a layer, it would severely affect adversely the handle and appearance of the fabric after decoration.
It is accordingly essential to use a removable layer formulation which will break up on heating to give a discontinuous non-superficial layer and to employ transfer conditions which enable this process to occur. Accordingly the preferred transfer conditions are such that the high temperature plasticiser in the removable layer becomes oper-ative and the pressure employed promotes adequate flow of the fluid layer into the fabric to be decorated. The temperature to which the removable layer is raised during the transfer process may be such that ~r -11-r~

-` 10932S'7 - i t the cross l~nking reactio~ is initiated by activating tne catalyst, and i~ this is done, th~re is no need ~or any ~ubsequent heat treatment to fix the pigment, ~ixing to iull fastness taking place automatically over a period e,g,~o~ lO to 200 hours.
~ We ha~e fou~d that by choosing appropriate pressures and temperatures for the initial application of the de-coratio~ materials according to the present i~ve~tion o~to the fabric to be decorated,sufficient assimilation of the 10 removable layer into the material of the fabric can be achieved so that little or no adhesion remains between the fabric and the flexible substrate. I~ these circumstances it may be advantageous when using certain machine types for the fixatio~ treatme~t to lea~e the composite unsepPrated during fixation thus protecting parts of the machine from co~tamination. Normally satisfactor~ trausfer of the re-movable layer to the fabric to be decorated is obtai~ed using a calender with one or both rollers heated, We have iound temperatures from 80 to 102C and pressures be~leen 20 40 and 200 lbs per linear inch of the roller w~dth to give Ratis~actory results, The best results are obtained ~hen the transfer paper reaches a-temperature in the n~p such tha~ ~he high temperature plasticiser becomes operative, ~Jormally such plasticisers are selected so that operati~g roller temperatures lie betwee~ 80C aud 120C. ~lnning speeds can be slow e.g. 5-10 metres per minute or faster consi-stent with the fact that co~tact times will be of the order of 10 2 seconds or less and it is desirable to achie~e an appropriate traDsfer paper temperature i~ that short - ` ) 1093257 ~ . ~

time. If higher pressures are used the degree of transfer into the interstices of the fabric is ~ery high so that the considerations discussed above apply. The conditio~s cannot be strictly defined since the properties of the material to be decorated affect the tra~sfer conditions si~ce the thickness, density, compressibility etc. of the fabric all affect the extent of heat film transfer into the fabric under the hot high pressure conditions.
Although transfer using a very short duration heat/
pressure treatment for example, in a calender, is preferred it i8 possible to use a static press. Normal~y this will involve the application Or high pressures e.g. 800 psi to achieve satisfactory results and although the duration o* the transfer treatment will be longer than when a calender is used it will be much shorter than is ~ormally the case when static presses are used to produce transferred de¢orations. Normally a static pressure of 5-8 seconds will be required when the materials of the present inven-tion are used. ~is may be contrasted with periods Or 60 seconds used in,for example,sublimation transfer printing c.f.Defago et al ~.S. Pate~t Specification 3782896.
~he rabrics which may be decorated using the materials -of the prese~t inve~tion may be cellulosic e~g. cotton,viscose rayon, polynosic ra~Jon, cuprammonium, rayon, polyamide e.g. Nylon 66 or ~ylon 6, polyester, mixtures of fibres e.g.
polyester/cotton or wool/cotton blends, coated fabrics e.g.
pol~vinylchloride coated cotton fabrics, aluminium coated fabrics.

The following Examples will serYe to illustrate the invention:

A paper coated with a silicone release layer is printed to a dry film thickness of 3 microns with an ink containing in each 100 gms 2 gms of a copper phthalocyanine pigment 15 gms of polyvinyl butyral ("Butvar 98" - Monsanto Co.) 6 gms of stearylalcohol-ethylene oxide condensate

3 gms of a 20% aqueous solution of dimethylol dihydroxy cyclic ethylene urea 1 gm of ammonium nitrate 73 gms of 64 O.P. ethanol.
The printed paper is brought into contact with a mercerised cotton fabric and passed between two rollers set so as to give a pressure of 100 lbs per linear inch of nip.
The upper roller is made of steel and heated to 110C and the fabric paper composite is passed through the nip at 6 yards per minute. The composite is then passed over an oil heated drum at 165C under a felt blanket used to assist contact. The fabric is in contact with the heated surface and the contact time is 30 seconds. After the heat treatment the paper is removed and the fabric is printed with a brilliant blue design of high fastness to washing and light. Its ap-pearance and handle are substantially those of the unprinted fabric.

*Trademark.
"Butvar" is a registered trademark of Monsanto Company ~0932S7 If the nip pressure is reduced to 10 lbs per linear inch of nip and the same procedure adopted then the trans-ferred design is clearly present on the fabric surface.
Similarly if the paper is removed before passage round the oil heated drum, then the transferred film is observed to mark the blanket during fixation although the design is no longer fixed in a superficial way.

A paper coated with a silicone release layer is printed to a dry film thickness of 6 microns by screen printing with an ink containing in each 100 gms, 2 gms of Colour Index Pigment Yellow 1 15 gms of polyvinyl butyral ("Butvar 98" - Monsanto Co.) 8 gms of stearyl alcohol - ethylene oxide condensate 2 gms of a 20% solution in water of trimethylol melamine 1 gm of ammonium sulphate 40 gms of "Cellosolve"
33 gms of 64 O.P. ethanol.

The printed paper is brought into contact with cotton interlock fabric and passed between two rollers set so as to give a pressure of lS0 lbs per linear inch of nip. The upper (steel) roller is heated to 125C and the fabric/
paper composite is passed through the nip at 5 yards/minute.
The composite is then pressed in a garment press set at a temperature of 165C for 30 seconds and the paper subsequently removed.
The fabric is printed to a well penetrated yellow shade of high fastness to washing and to light. The handle of the *Registered Trademark for ethylene glycol monoethyl ether.
v~ -15-~093257 the fabric is excellent and the textile characteristics unimpaired.

The paper of Example l was used to print fabrics made of 67/33 polyester-cotton blends, 50/50 cotton-polyamide blends and viscose fabrics: similar results were obtained .

A paper coated with a silicone release layer is given a second overall coating to a dry layer thickness of 6 microns using a solution which contains in each lO0 gms, 16 gms polyvinyl butyral ("Butvar 98" - Monsanto Co.) 8 gms stearyl alcohol-ethylene oxide condensate 3 gms of a 20% aqueous solution of dimethylol di-hydroxy cyclic ethylene urea l gm ammonium nitrate 72 gms 64 O.P. ethanol.
To the doubly coated paper is applied a design with for example a brush or felt pad using an ink containing in each lO0 gms, 5 gms Colour Index Pigment Red 6 10 gms polyvinyl alcohol 85 gms water.
After drying the paper is contacted with a 50/50 cotton/
polyester blended fabric and subsequently treated as in Example 2.
The design is found to be transferred completely to the fabric to give a red decoration of excellent fastness to wet treatments and to light.

~093257 An ink is prepared containing in each lQ0 parts, 5 parts of a pigment selected from the list given below 10 parts of stearyl alcohol-ethylene oxide condensate 2 parts of trimethoxy methyl melamine (40~ aqueous solution) 1.5 parts of ammonium sulphate 1.5 parts of polyvinyl butyral 33.5 parts of 64 OP ethanol 33.0 parts of toluene.
The ink is printed onto silicone release paper or wax release paper by screen printing and dried.
The design may be transferred to a cotton-polyester or cotton fabric by contacting the printed side of the paper with the cloth and heating the composite under pressure (400 lbs per square inch) at 125C for 0.03 seconds. The composite may then be heated under light or no pressure for 30 seconds at 165C. The paper may then be removed leaving the printed design on the fabric providing a decoration which is fast to washing.
Alternatively the paper may be removed from the fabric after the first and before the second heat treatment.
Some pigments which may be used in the ink in this example are listed below, Copper phthalocyanine (blue shade) Carbon black (grey shade) Cl OH CONH

N = N ~
~ ~ (red shade) Cl ~ ~) C - OH
NH.CO.C N = N ~ Cl (yellow shade) - OH Cl 109~2S7 (violet shade) ` 10932S7 E~AM~,E 6 2 gm8 of a finely divided carbo~ blac~ pigme~t 15 gms of polyvinyl but~ral (n~utvar 98" - Monsanto Co.) 10 gms of stearyl alcohol - eth~le~e oxide conde~sate 2 gms Or trimethox~ meth~lmelami~e 1 gm of the monoethanolamine sal~ of p-toluene sulphonic acid 2 gms of Bentonite are dispersed in a mixture of 50 parts of pol~eth~le~e glycol 10 200 with 18 parts of diaceto~e alcohol to form a screeu pri~ti~g ink. A silico~e coated paper aS used i~ Example 1 is printed with the ink by screen printi~g and dried at s 75C. ~he pri~ted paper i8 then used to decorate a cotton fabric by passing the paper i~ contact with the fabric throug~ heated ~alender rollers operating at a pres-sure o~ 70 lbs per li~ear inch of ~ip with one roller heated to a temperature of 95C. ~he speed of passage is 20 metres p~r mi~ute. ~he paper is then peeled from the ; cotto~ fabric leaYing the pri~ted.desig~ thereo~. ~he 20 fabric i5 the~ heated f-or 30 seco~ds i~ an ove~ at 140C.
After the heat treatme~t the fabric is d~orat~ with a fast black desig~. The fast~ess is found to improve on B

standiDg to an eve~ higher sta~dard givi~g excellent fastness to the I.SØ No. 4 washiDg test.

E~A~PIE 7 If in ~xample 6, the carbo~ black pigment i8 replaced by a red pigme~t (a.I. Pigment Red 6) and the design i~
printed by screen printi~g onto a wax coated paper. An excellent trans~er o~ the design onto a rayo~ ~abric is ~chieved by increasing the calender pressure to 115 lbs per li~ear inch and the temperature of the heated roller to 110C. ~he fastne~s of the decoration a~ter heat treatment as described in ~xample 6 i8 excellent.

E3AnPIE 8 ~ n ink made up as sh~ in Eæample 6 is applied by screen prin~ing to a wax coated paper which is then used to decorate a cotto~ ~abric by passing the paper in contact ~ith the fabric between heated calender rollers at a pressure o~ 100 lbs per l~near inch of n~p with o~e roller heated to a tempe~ature of 190C and with a ru~ni~g speed o~ 1 yard per minute. The paper is then peeled from the fabric. After storage for 7 days the fastness of the decoration is greatly improved over ~hat whlch may be observed lmmediately af~er the paper is peeled a~d is eq~al to that observed of the pattern i5 produced by the transfer and fixation conditions employed in Example 5.

. ~

f .) . ~-10932S~

E~PTE 9 A coating solution of 15 parts of polyviDylbutyral dissolved in 85 parts o~ n-propanol is applied to a paper - coated with an ultra~iolet radiation cured butylmethacrylate composition containing a suitable photochemical initiator and dried. The polyvin~lbutyral coating is applied at a wet thickness of 6 ~.
$he coated paper is printed with a conventional lithographic ink containing a copper phthalocyamine pigment using normal procedures and then coated again with a solution containing - 15 parts of pol~in~l butyral 10 partæ of stearyl alcohol 2 parts of trimethoxy uethyl melamine 1 part of the diethanol2mine salt of p. tolue~e sulphonic acid dissol~ed 72 parts of n-propanol and dried at 50C. The wet thicknesg of the second coating is 6~.
~ he printed paper i8 then used to decorate a cotton/polyester blended ~hirting fabrio by bringing it into contact with the fabric and passing the composit~
through a heated calender set at a pressure Or 70 lbs per linear inch and the temperature of the heated roller at ~00C. After passage through the calender the paper is remo~ed leaviDg the decorating deæign on the fabric. ~he latter is then heated for 45 seconds at 135C to gi~e a blue decoration of ~ery high fastness to seYere washing a~d to light.

. , . ~
~ -- 22 --109325'7 8 parts of a copper phthalocyanine pigment 15 parts of polyvinyl butyral 12 parts of stearyl alcohol - ethylene oxide condensate 2 parts of trimethylolmelamine 2 parts of ammonium nitrate are dispersed in 61 parts of 64 O.P. ethanol to form a gravure printing ink. A design is then applied to an ultraviolet radiation cured butylmethacrylate coated paper as used in Example 8 by gravure printing using a force of 9 Kg cm 1 and a running speed of 20 cm sec 1.
The printed paper is then used to decorate a cotton fabric by the procedure described in Example 6.
The fabric is thus decorated with a blue design of very high washing and dry cleaning fastness.

Claims (33)

1. A decoration material consisting essentially of a flexible substrate having at least one removable dry ink layer thereon, the at least one layer comprising a base of thermo-plastic film-forming polymeric material, a pigment, a cross-linking agent capable of cross-linking the thermoplastic polymer, a thermally activated catalyst for promoting the cross-linking reaction selected from the class consisting of amine and ammonium salts of strong acids and mixtures thereof, and a high temperature plasticiser, the polymeric material being chosen and the at least one removable layer being formulated so that when the layer is transferred to a material to be decorated and subjected to heat and pressure in the transfer operation, and any necessary heat fixation treatment, the layer breaks down to provide a discontinuous non-superficial residual matrix capable of holding the pigment to the material, which does not significantly modify the properties of the material after decoration.

2. The decoration material of claim 1 wherein the remov-able layer contains at least one pigment capable of reacting with the polymer.

3. The decoration material of claim 1 wherein the remov-able layer contains at least one pigment capable of reacting with the cross-linking agent.

4. The decoration material of claim 1 wherein the thermoplastic film-forming polymer material is a polyvinylbutyral.

5. The decoration material of claim 1 wherein the thermoplastics film-forming polymer material comprises a mixture of a polyvinylacetal and at least one component selected from the class consisting of acrylic polymers, polyamides, polyvinyl acetate and polyvinyl alcohol.

6. The decoration material of claim 1 wherein the cross-linking agent is at least one dialdehyde.

7. The decoration material of claim 1 wherein the cross-linking agent is a methylolated aminoplast monomer.

8. The decoration material of claim 7 wherein the cross-linking agent is selected from the class consisting of dimethylolurea, dimethyloldihydroxy ethylene urea, dimethylolcyclic ethylene urea, methylolated melamine and trimethoxy methyl melamine.

9. The decoration material of claim 1 wherein the catalyst is selected from the class consisting of amine salts of strong acids.

10. The decoration material of claim 1 wherein the catalyst is an amine salt of p-toluene sulphonic acid.

11. The decoration material of claim 1 wherein the high temperature plasticiser is selected from the class consisting of high molecular weight fatty acids, esters of high molecular weight fatty acids with polyethylene, glycol, esters of high molecular weight fatty acids with glycerol, paraffin wax, stearamide and finely dispersed polyethylene.

12. The decoration material of claim 1 wherein the removable layer is present on the flexible substrate as a number of discrete areas.

13. The decoration material of claim 1 wherein the removable layer is present as a continuous coating over the whole of the flexible substrate.

14. The decoration material of claim 1 wherein the removable layer is made up of a plurality of sublayers.

15. The decoration material of claim 1 wherein the removable layer is made up of a first sublayer containing the components listed in claim 1 with the exception of the pigment, a lithographic image printed thereon in at least one colour and printed from pigment containing inks and a second sublayer over the lithographic image and of composition similar to the first sublayer.

16. The decoration material of claim 1 wherein the flexible substrate is selected from the class consisting of cellulose acetate films, nitrocellulose films, aluminium foils and surface treated papers.

17. The decoration material of claim 1 wherein the flexible substrate is a silicone release coated paper.

18. The decoration material of claim 1 wherein the flexible substrate is a wax coated paper.

19. The decoration material of claim 1 wherein the flexible substrate is a paper coated with a thermoplastic coating formed of a mixture of unsaturated esters of an acid selected from the class consisting of acrylic acid and methacrylic acid, cross-linked by ultraviolet irradiation.

20. The method of decorating a substrate which comprises applying the decoration material of claim 1 thereto under the action of heat and pressure, and subjecting the removable layer of such decoration material on the substrate to heat treatment to fix the decoration on the substrate, whereby the at least one layer breaks down to provide a discontin-uous non-superficial residual matrix holding the pigment to the substrate, which does not significantly modify the properties of the substrate after decoration.

21. The method of decorating a substrate according to claim 20 wherein the substrate is a textile fabric.

22. The method of decorating a substrate according to claim 20 wherein the flexible substrate is removed from the substrate prior to the fixing treatment.

23. The method of claim 20 wherein the decoration material and the substrate to be decorated are brought together between heated calender rolls under a line pressure of 40 to 200 lbs/
linear inch of roller width.

24. The method of claim 20 wherein the substrate to be decorated is a textile fabric and the fabric and the decoration material are passed through heated calender rolls at a speed of at least 5 m/minute.

25. The method of claim 20 wherein the heat and pressure are sufficient to activate the catalyst and initiate the fixation reaction.

26. A printing ink for use in the manufacture of decoration materials and comprising a liquid carrier medium, an ink vehicle of a thermoplastic polymeric film-forming material capable of being cross-linked, a cross-linking agent capable of cross-linking the polymeric film-forming material, at least one pigment, a thermally activated catalyst for pro-moting the cross-linking reaction between the thermoplastic polymeric film-forming material and the cross-linking agent selected from the class consisting of amine and ammonium salts of strong acids and mixtures thereof, and a high temperature plasticiser, the polymeric material being chosen and the ink being formulated so that when applied to a flexible substrate to provide at least one removable dry ink layer thereon and the at least one layer is transferred to a material to be decorated and subjected to heat and pressure in the transfer operation, and any necessary heat fixation treatment, the layer breaks down to provide a discontinuous non-superficial re-sidual matrix capable of holding the pigment to the material, which does not significantly modify the properties of the material after decoration.

27. The ink of claim 26 wherein the thermoplastic polymeric film-forming material is polyvinylbutyral.

28. The ink of claim 26 wherein the cross-linking agent is a dialdehyde.

29. The ink of claim 26 wherein the cross-linking agent is a methylolated aminoplast monomer.

30. The ink of claim 29 wherein the cross-linking agent it selected from the class consisting of dimethylolurea, dimethyloldihydroxyethyleneurea, dimethylolcyclic ethylene urea, methylolated melamine and trimethoxymethylmelamine.

31. The ink of claim 26 wherein the catalyst is selected from the class consisting of an amine salts of strong acids.

32. The ink of claim 26 wherein the catalyst is an amine salt of p-toluene sulphonic acid.

33. The ink of claim 26 wherein the high temperature plasticiser is selected from the class consisting of high molecular weight fatty acids, esters of high molecular weight fatty acids with polyethylene glycol, esters of high molecular weight fatty-acids with glycerol, paraffin waxes, stearamide and finely dispersed polyethylene waxes.