GB1564542A

GB1564542A - Radiation curable coatings

Info

Publication number: GB1564542A
Application number: GB4745878A
Authority: GB
Original assignee: Dennison Manufacturing Co Ltd; Dennison Manufacturing Co
Current assignee: Dennison Manufacturing Co Ltd; Dennison Manufacturing Co
Priority date: 1976-08-07
Filing date: 1976-08-07
Publication date: 1980-04-10

Description

(54) IMPROVEMENTS IN AND RELATING TO RADIATION CURABLE COATINGS (71) We, DENNISON MANUFACTURING CO. LIMITED, a Company organised under the laws of England, of Colonial Way, Watford, Hertfordshire, 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: This invention relates to radiation curable, and radiation cured, coatings for providing films, inks, varnishes, overcoatings and release coatings. It relates more particularly to coatings formed from suitable prepolymer materials and suitable waxy materials and to methods of preparing them. The coatings are curable by various forms of "radiation" which is the term used for electromagnetic radiation, such as ultraviolet, and also for plasma arc and electron beam bombardment.

Coatings and inks for paper, foil, film, panels, tiles and other surfaces are desired which can be easily applied, are solvent and abrasion resistant, and are tough and flexible. It is also desirable to eliminate solvents, to reduce cost, avoid pollution, and achieve improved performance. In addition, if surfaces with low adhesion can be obtained, they can be used for transfer printing, temporary cover sheets to protect pressure-sensitive adhesives, and the expeditious handling of multiple articles in machinery or the like.

Existing radiation curable coatings, while useful for many purposes, do not sufficiently satisfy the foregoing criteria. Either they have limited strength, abrasion and solvent resistance, or they require long exposure times to radiation, especially ultraviolet light. Suitable low adhesion materials heretofore have required a solvent solution, or have had to be applied as hot melts.

It is an object of the invention to mitigate one or more of the foregoing disadvantages. It is believed that it is possible to produce, by means of the invention, release surfaces which can employ a wide variety of film-forming materials and which can be readily applied without substantial solvent and quickly cured by radiation, generally in one second or less under moderate exposure.

It is also believed possible to produce, by means of the invention, radiation curable materials, and coatings resulting therefrom, which cure rapidly under moderate exposure to give films with a desirable combination of toughness, flexibility and resistance to solvents and to abrasion. Such films are useful as inks, release coatings, or protective varnishes.

According to the present invention there is provided a radiation curable coating composition comprising a radiation curable liquid prepolymer which includes a waxy or oily material therein, the waxy or oily material being of limited compatibility with the liquid prepolymer so that a thin layer of the waxy or oily material migrates to the surface of the coating.

Hereinafter, the term "waxy" is intended to describe both waxy and oily materials.

As more fully described hereinafter, a valuable new class of release materials may thus be provided. Preferably the waxy materials are included in the radiation curable, film-forming liquid such that the thin layer will migrate to the surface of a thin film of the liquid prior to cure. The waxy materials have good slip or release properties, are generally lipophilic, and can comprise natural and synthetic waxes, oils, silanes, siloxanes particularly silicones, and fluorocarbons. While generally non-reactive in the polymerizable liquid, they can contain reactive groups. For example, stearyl acrylate can be used with acrylate monomers and will migrate to the surface and orient with the stearyl groups toward the surface prior to reaction.

The quantity of waxy material is not critical, provided enough is used to be effective, generally between about 0.5 and 10% by weight of the film-forming liquid. Undue excess should be avoided to avoid property degradation in the film. About 3% to 4% by weight is usually most preferred.

The invention also extends to a laminate comprising a design or decorative layer in removable contact with a release surface formed by a radiation curable composition in accordance with the invention.

The invention further extends to a method of preparing a transfer with a releasable design or decoration comprising forming a liquid film of a radiation curable coating composition in accordance with the invention on a substrate to provide a waxy surface layer, curing the film by radiation; and applying a transfer material containing the said design or decoration to the surface of the cured film; or applying the mirror image of the said design or decoration to the said surface for transfer printing.

While waxes have been used with radiation curable materials to form an oxygen barrier and facilitate curing in air, they have not been used to provide release and transfer properties. The addition of a single wax component can provide high gloss coatings with release characteristics. The introduction of vanous mixtures of waxy materials has been found to give particularly suitable release properties.

The waxy materials above described can be incorporated in any suitable radiation curable liquid including pre-polymers having ethylenic unsaturation, such as polyurethane/acrylate prepolymers, polyamides with a plurality of reactive amine groups reacted with ethylenically unsaturated polybasic carboxylic acids, acrylated epoxides, and epoxide resins catalytically polymerized with catalysts released under exposure to ionizing radiation, all as more fully described hereinafter and in the Examples.

Preferred radiation curable liquids comprise an unsaturated prepolymer mixed with acrylic monomers and additives as further described below. Suitable unsaturated prepolymers are unsaturated polyether-polyurethane pre-polymers prepared by reacting secondary polyether polyols with bis-or polyisocyanates and an ethylenically unsaturated reactive hydrogen containing compound as described and claimed in British Patent Application No. 18911/76 (Serial No. 1564541), from which the present Application is divided or modified polyamides prepared by reacting polyamide polyamines with unsaturated polybasic carboxylic acids their anhydrides or their lower alkyl esters as described and claimed in the Applicants' British Patent Application No. 47459/78 (Serial No. 156543). In the preparation of these prepolymers a step of driving off volatile materials such as solvents can be avoided if an acrylic monomer is used as the solvent (i.e. a monomer which normally would be admixed in the succeeding formulation step). Sometimes an agent for inhibiting further polymerization (depending upon the nature of the prepolymer) is present.

The prepolymers, which in some cases already contain an acrylic ester reagent, if an acrylic monomer is used as a solvent and/or if an excess of acrylic hydroxyalkyl ester was used in the prepolymer preparation, may then be compounded on a mill with a further quantity of unsaturated reagent, in this case one or more acrylic or methacrylic esters (whether or not the same unsaturated reagent was used in preparing the prepolymer). Additives, as further described below, may be approximately added at this formulating stage. After milling the material is spread as a film and then irradiated briefly to cure it.

l he most preferred modified polyether polyurethane prepolymer comprises reacting one isocyanato group of toluene diisocyanate (TDI) with a polyether triol, three mols TDI per mol of triol, and then reacting substantially all of the other remaining isocyanato groups with an ethylenically unsaturated, reactive hydrogen containing compound copolymerizable with the acrylate monomers. TDI is particularly suitable, both 2,4 TDI and 2,6 TDI, because its two isocyanato groups have different reactivities facilitating this stepwise condensation.

Polyethers based on polypropylene oxide are the preferred triols and trimethylol propane condensed with propylene oxide with a molecular weight between about 300-4500, preferably 700-1500, is most preferred. Hydroxyl-lower alkyl acrylate or methacrylate are the preferred active hydrogen containing unsaturated compounds, where "lower" indicates a typical chain length of up to about 4. It has been discovered that such prepolymers polymerize readily and rapidly under radiation to form inks and coatings with an excellent combination of properties. Such preferred prepolymers are shown in the Examples, particularly Examples 1 to 9, and comprise condensation of 1 mol of triol with 3 mols TDI and substantially 3 mols of hydroxy-lower alkyl acrylate (or methacrylate).

It has been found that prepolymer materials described and claimed in British Patent Application No. 18911/76 (Serial No. 1564541), from which the present Application is divided, cure extremely well with ultraviolet light and with electron beams. The films of the order of one mil or less cure readily with ultraviolet light. Thick films may require more penetrating radiation, particularly if a pigment is present, and for these plasma arc radiation, electron beam radiation, or X-rays are desirable.

The preparation of unsaturated polyether-polyurethane prepolymers for making radiation curable coatings in accordance with the invention generally begins with reacting a diisocyanate with a polyol at a temperature not exceeding 75"C. in the presence of a catalyst chosen for a low degree of promotion of side reactions. Stannous octoate is preferred as a catalyst.

Stannous butyrate and stannous laurate have also been found usable. Because of the high viscosity of the reaction product, the reaction is carried out in a solvent. The solvent may be either a hydrocarbon such as toluene, in which case it must be removed by evaporation later, or it may be an acrylate material of the class of materials suitable for use in ink and coating formulations, in which case the solvent may be allowed to remain in the product. Examples of the latter type of acrylate monomer solvents are: trimethylolpropane triacrylate, 1,6hexanediol-diacrylate, 1,3-butanediol diacrylate, neopentylglycol diae -ylate, and pentaerythritol tetramethacrylate. The solvent must be dry to avoid the production of by-products.

The reaction in the solvent is carried out in a vessel equipped with an agitator and blanketed with nitrogen. The mixture is stirred at room temperature as the polyol is added to the diisocyanate and the addition is carried out at such a rate that with the available water cooling the temperature of the reaction mixture does not rise about 50"C. Then after an hour or so of maintaining the reaction mixture at 50"C. or just below that temperature, an ethylenically unsaturated reactive hydrogen containing compound, e.g. an alcohol or a hydroxy ester is added, preferably somewhat in excess, as for example 10% in excess, of the amount needed to react with those isocyanate groups which are left unreacted after the reaction with the polyether polyol. At this point it is preferable to switch from blanketing the reaction mixture with dry nitrogen to blanketing with dry air (oxygen is a good polymerization inhibitor). During this addition the reaction mixture may be permitted to rise to 750C., but no further. After the addition is terminated, the temperature is raised to 90"C. and after an hour or so a small amount of p-methoxyphenol is added to inhibit premature polymerization. When a hydrocarbon solvent is to be removed, it is best to remove the solvent under reduced pressure at a temperature as low as possible, in order to avoid premature polymerization of the prepolymer.

The modified prepolymer as above prepared may then be compounded with one or more acrylate monomers esters on a roller mill. It is preferred to have trimethylolpropane triacrylate included as one of the components of this material, and of course sometimes this component is already there for having been used as a solvent in the previous step. Other acrylate monomer components for use at this stage are acrylated epoxidized soybean oil, hydroxyethyl acrylate, hydroxyethyl methacrylate, 1,4-butanediol diacrylate, neopentyl glycol diacrylate, pentaerythritol tetra-acrylate, pentaerythritol triacrylate, hexanediol diacrylate, butyl acrylate, isodecyl acrylate, octadecylacrylate, dimethyl aminoethyl methacrylate, acrylic acid, methacrylic acid, acrylamide and/or methylene bis-acrylamide. It is preferred that the radiation curable liquid contain at least one acrylate monomer which is trifunctional (ethylenically unsaturated groups) or higher to promote cross-linking in the cured film.

Acrylic monomers useful in this invention may include acrylic or methacrylic acids, preferably esters thereof, and preferably esters thereof condensed with polyols and polyamines to form polyacrylates, that is monomers having two or more, and preferably three or more unsaturated acrylate groups.

It is also preferred to introduce at this stage a small to moderate amount of a photoinitiator for coatings to be cured by UV or plasma arc radiation (i.e. by actinic light generally).

Coatings to be cured by electron beam or X-ray radiation do not generally require a photoinitiator. The following are suitable photoinitiators: benzil, benzoin, benzoin alkyl ethers, acyloin derivatives in general, benzophenone, acetophenone and Micler's ketone.

Other compounds useful as photoinitiators for this purpose are those listed in Table 5-13, page 132,MolecularPhotochemistry by N.J. Turro (W. Benhamin, Inc., 1967). Since acrylate monomers are essentially transparent to UV, sufficient photosensitizer should be used to permit rapid polymerization under moderate irradiation, preferably under 1 second. From about 0.5 to about 20%by weight can be used with about 10% by weight of coating solution being preferred.

To provide a release coating or oxygen barrier, there may be introduced at this stage generally between one half of 1% and a few percent of wax, e.g., between about 0.5% and about 10% by weight, either paraffin wax, ester wax, a fluorocarbon wax or some other waxy material such as a higher alkyl alcohol or acid or oleamide, or a waxy silicon-containing material such as siloxane (including polysiloxanes) particularly silicone, or a silane or a mixture of some of these. Even a small quantity of such waxy material tends to migrate to the surface of the coating and provides a release type surface with characteristics similar to those of fluorocarbon polymers or silicones.

When the monomers added at this stage are such as to produce a mixture of low viscosity, the result is a coating material very useful as an overprint varnish. The coating can be cured by an exposure to ultraviolet radiation from a medium pressure mercury lamp for from 0.1 second to several seconds to form a hard glossy coating. When the monomers added are such as to produce a heavy oil, the resulting material is useful for coating rigid panels, such as paperboard or veneer panels, with a film having a thickness of one to several mils. In this case ultraviolet light may be insufficient to provide quick curing and higher energy radiation can be used, such as electron beam radiation or X-rays. In the absence of air, an exposure to about 2-6 Mrad is sufficient for curing with electron beam radiation. In the presence of air, 10-20 Mrad or more are sometimes needed.

For the manufacture of inks, pigments such as Lithol rubine pigment, molybdate orange, chrome yellow, phthalocyanine blue, carbon black or dyes are mixed in at the same time as most of the acrylic monomers. Here also it is necessary to add 5-20% by weight of a photoinitiator to inks intended to be curable by UV or plasma arc radiation. The resulting ink may be printed onto paper, paperboard, plastics film, metal or other stock, and the printing can be rapidly cured by exposure for a fraction of a second to ultraviolet light from a low pressure mercury lamp. An abrasion resistant and solvent resistant printing is thereby produced, which does not require an overprint varnish.

It has further been found advantageous to include in the radiation curable liquid solution an essentially linear polymer which is soluble therein, preferably one having a molecular weight of at least about 4,000 up to the limit of solubility, and more preferably between about 10,000 and 20,000. Such addition has been found to improve the physical properties of the cured films of reinforcement and to limit shrinkage. This is especially useful with acrylate monomers which may have relative high shrinkage on curing and which are highly crosslinked.

The foregoing aspects of the invention are illustrated in detail in the following examples wherein all parts are by weight. Examples 1-9 and 14-20 illustrate the preparation of prepolymers used in the formulations described in Examples 10-13 and 21-23. Examples 24-65 and 68-98 refer particularly to release type coatings. Examples 99-108 illustrate the advantageous inclusion of linear polymers in the radiation curable coatings.

Example 1 522 parts 2,4-toluene diisocyanate, 500 parts dried toluene and 0.5 parts stannous octoate are placed in a vessel equipped with an agitator and blanketed with nitrogen. With stirring, a solution of 735 parts polypropylene oxide) triol (Dow Voranol (Registered Trade Mark), CP700, Hydroxyl No.229; 0.02%H2O) in 750 parts dried toluene is added at such a rate that the temperature of the reactive mixture does not exceed 50"C. The reaction mixture is stirred at 50"C for 1 hour. Then the nitrogen blanket is replaced by a dry air blanket and 383 parts hydroxyethyl acrylate (10 % excess mixed with 100 parts of dried toluene, are added at such a rate that the temperature of the mixture does not rise above 75"C. After the addition is completed. the reaction mixture is kept stirring at 90"C for 1 hour. 1 part p-methoxy phenol (polymerization inhibitor) is added and the solvent is removed under reduced pressure at or below 30"C. 1650 parts of a clear, colourless, resinous oil, containing a trace of toluene solvent are obtained. Analysis of this material shows 0.06% by weight isocyanate content.

Example 2 522 parts 2,4-toluene diisocyanate, 500 parts dried toluene and 0.5 part stannous octoate are placed in a vessel equipped with an agitator and blanketed with nitrogen. With stirring, a solution of 735 parts poly (propylene oxide) triol (Dow Voranol CP700; Hydroxyl No. 229; 0.02% H20) in 750 parts dried toluene is added at such a rate that the temperature of the reaction mixture does not exceed 50"C. The reaction mixture is stirred at 500C. for 1 hour.

Then 191.4 parts allyl alcohol (10% excess) are added at such a rate that the temperature of the mixture does not rise above 85"C. After the addition is completed, the reaction mixture is kept stirring at 90"C. for 1 hour. 1 part p-methoxy phenol (polymerization inhibitor) is added and the solvent is removed under reduced pressure at or below 300C. 1440 parts of a clear, colourless, resinous oil, containing a trace of toluene, are obtained. Analysis of the resulting material shows 0.04% by weight isocyanate content.

Example 3 522 parts 2,4-toluene diisocyanate, 780 parts trimethylol propane triacrylate, and 0.5 parts stannous octoate are placed in a vessel equipped with an agitator and blanketed with nitrogen. With stirring, 735 parts of poly (propylene oxide) triol (Dow Voranol CP700; hydroxyl No. 229; 0.02% H2O) are added at such a rate that the temperature of the reaction mixture does not rise above 50"C. The reaction mixture is kept at this temperature for an additional 1 hour. Then the nitrogen blanket is replaced by a dry air blanket and 383 parts hydroxyethyl acrylate (10% excess) are added at such a rate that the temperature of the reaction mixture does not exceed 75"C. The reaction mixture is stirred for an additional 1 hour at 90"C. Then 1 part pmethoxy phenol is added and the reaction mixture is allowed to cool to room temperature. The product, 1605 parts of unsaturated prepolymer in 780 parts of trimethylolpropane triacrylate and 35 parts of hydroxyethyl acrylate, is a clear, colourless, viscous oil. Analysis of the resulting material shows 0.06% by weight isocyanate content.

Example 4 522 parts 2,4-toluene diisocyanate, 780 parts trimethylolpropane triacrylate, and 0.5 part stannous octoate are placed in a vessel equipped with an agitator and blanketed with nitrogen. With stirring, 735 parts of poly (propylene oxide) triol (Dow Voranol CP700; Hydroxyl No. 229; 0.02% H2O) are added at such a rate that the temperature of the reaction mixture does not rise above 50"C. The reaction mixture is kept at this temperature for an additional 1 hour. Then 191.4 parts allyl alcohol (10% excess) are added at such a rate that the temperature of the reaction mixture does not exceed 75"C. The reaction mixture is stirred for an additional 1 hour at 90"C. Then 1 part p-methoxy phenol is added and the reaction mixture is allowed to cool to room temperature. The product consists of 1413 parts unsaturated prepolymer in 780 parts trimethylolpropane triacrylate and 17.4 parts allyl alcohol. It is a clear, colourless, viscous oil. Analysis of the resulting material shows 0.3% by weight isocyanate content.

Example 5 504 parts 1,6-hexamethylene diisocyanate, 750 parts trimethylolpropane triacrylate, and 0.5 parts stannous octoate are placed in a vessel equipped with an agitator and blanketed with nitrogen. With stirring, 735 parts of poly (propylene oxide) triol (Dow Voranol CP700; Hydroxyl No. 229; 0.02 % H2O) are added at such a rate that the temperature of the reaction mixture does not rise above 50"C. The reaction mixture then is kept at 60"C. for 2 hours with stirring. Following this, 409.2 parts 5-norbornene-2-methanol (10% excess) are added at such a rate that the temperature of the reaction mixture does not rise above 75"C. After the addition is completed, the temperature is raised to 900C. and the reaction mixture is stirred at this temperature for an additional 2 hours. Then the reaction mixture is allowed to cool to room temperature. The product consists of 1611 parts unsaturated prepolymer in 700 parts trimethylolpropane triacrylate and 37.2 parts 5-norbornene-2-methanol. It is a clear, colourless, viscous oil. Analysis of the resulting material shows 0.08 % by weight isocyanate content.

Example 6 750 parts p,p'-diphenylmethane diisocyanate, 1000 parts toluene, and 0.5 part stannous octoate are placed in a vessel equipped with an agitator and blanketed with nitrogen The mixture is stirred at room temperature and 258 parts poly (propylene oxide) triolVoranol (Registered Trade Mark) CP260; Hydroxyl No. 653; 0.02% H2O) are added at such a rate that the temperature of the reaction mixture does not rise above 50"C. The reaction mixture is kept at this temperature for an additional 1 hour. Then the nitrogen blanket is replaced by a dry air blanket and 383 parts of hydroxy-ethyl acrylate (10% excess) are added at such a rate that the temperature of the reaction mixture does not exceed 75"C. After the addition is terminated, the temperature of the reaction mixture is raised to 90"C. for 1 hour. After adding 1.0 part p-methoxy phenol, the reaction mixture is allowed to cool to room temperature and the solvent is removed under reduced pressure at or below 30"C. The liquid product, 1398 parts, is a clear off-white resin. Analysis of the resulting material shows 0.01 %by weight isocyanate content.

Example 7 1746 parts dimeryl diisocyanate, 500 parts dried toluene, and 1.0 part stannous octoate are placed in a vessel equipped with an agitator and blanketed with nitrogen. With stirring, 258 parts poly (propylene oxide) triol (Dow Voranol CP260; Hydroxyl No. 653; 0.02%H20) are added at such a rate that the temperature of the reaction mixture remains below 50"C. After the addition is completed, the reaction mixture is kept at 60"C. for 2 hours with stirring. Then 191.4 parts of allyl alcohol (10% excess) are added at such a rate that the temperature of the reaction mixture does not exceed 75"C. After the addition is completed the temperature is raised to 90"C. and the reaction mixture is kept stirring at this temperature for 2 hours. Then 1.0 part p-methoxy phenol is added, and the solvent is removed under reduced pressure.

2185 parts clear, colourless heavy oil is obtained as the product. Analysis of the resulting material shows 0.08% by weight isocyanate content.

Example 8 774 parts 4,4'-dicyclohexylmethane diisocyanate, 1000 parts trimethylolpropane triacrylate, and 0.5 part stannous octoate are placed in a vessel equipped with an agitator and blanketed with nitrogen. The mixture is stirred at room temperature and 735 parts of poly (propylene oxide) triol (Dow Voranol CP700; Hydroxyl No. 229; 0.02%H20) are added at such a rate that the temperature does not exceed 50"C. After the addition is completed, the reaction mixture is kept stirring at 50"C. for an additional 1 hour. Then the nitrogen blanket is replaced by a dry air blanket and 383 parts hydroxyethyl acrylate (10%excess) are added at such a rate that the temperature of the reaction mixture does not rise above 75"C. Following this step the reaction mixture is stirred for 2 hours at 900C. Then 1.0 part p-methoxyphenol is added and the reaction mixture is allowed to cool to room temperature. The product, a clear, colourless, viscous oil, consists of a mixture of 1857 parts unsaturated prepolymer, 1000 parts trimethylolpropane triacrylate, and 35 parts hydroxyethyl acrylate. Analysis of the resulting material shows 0.06% by weight isocyanate content.

Example 9 348 parts 2,4-toluene diisocyanate, 500 parts dried toluene, and 0.5 part stannous octoate are placed in a vessel equipped with an agitator and blanketed with nitrogen. Then 407 parts poly (propylene oxide) diol (Dow Voranol P400; Hydroxyl No.275; 0.02 % H20) are added at such a rate that the temperature of the reaction mixture does not rise above 50"C. The reaction mixture is stirred at this temperature for an additional hour. Following this step, 286 parts hydroxyethyl methacrylate (10% excess) are added at such a rate that the temperature of the reaction mixture is raised to 90"C. and the stirring continued for an additional 1 hour.

At the end of this period 1.0 part p-methoxy phenol is added and the solvent is removed under reduced pressure. A clear, colourless, viscous oil is obtained as the product. Analysis of the resulting material shows 0.02% by weight isocyanate content.

Example 10 - UV Curable Overprint Varnish 100 parts of the product of Example 1, 235 parts trimethylolpropane triacrylate, 30 parts hydroxyethyl acrylate, 3 parts stearyl acrylate and 25 parts benzoin isobutyl ether are mixed well on a roller mill. A clear, colourless homogeneous light oil is obtained as the product.

Films of 0.4 mil thickness are applied with a wire wound coating rod onto paper, aluminium foil, vinyl coated aluminium foil, polyester coated Mylar (Registered Trade Mark), and steel.

The coated substrates are exposed for 1/10 second to the UV radiation given off by a medium pressure mercury vapour lamp (Hanovia (Registered Trade Mark) 200 W/inch) at a distance of 5" from the lamp. This distance coincides with the second focal point created by the elliptical reflector.

After this exposure all samples are cured to hard, glossy coatings with a pencil hardness of at least 2H and a rub-resistance of at least 40 rubs, using methyl ethyl ketone as the solvent.

Example 11 - UV Curable Overprint Varnish 20 parts reaction product from Example 3, 8 parts trimethylolpropane triacrylate, 12 parts 1 .4-butanediol diacrylate, 10 parts acrylated epoxidized soybean oil (Union Carbide Co.

Actomer X-70), 10 parts acrylic add 0.4 part ste second as described in Example 10.

As previously mentioned, modified polyamide prepolymers may be prepared which are also radiation curable and likewise useful for overprint varnishes, for protective films on panels and tiles and for abrasion and solvent resistant inks.

Preferably the starting material for the preparation of these modified prepolymers is a polyamide polyamine, which may be made by condensing an excess of polyamine with polycarboxylic acids, giving a still reactive condensation product. These are available in some variety, for example, under the Registered Trade Marks Versamid and Emerez. The production of the polyamide polyamine may form part of the process for the production of the prepolymer as was above described in connection with the polyurethane process. It is convenient, however, to use these polyamide polyamine materials as starting materials. The materials are sometimes known as reactive polyamide resins and contain primary and secondary amine groups.

The above-described starting material is preferably mixed with a smaller portion of an unsaturated dicarboxylic acid an ethyl or methyl ester, or an anhydride of such an acid. The reaction mixture is stirred at a temperature such as 90"C for a few hours and a slow stream of nitrogen may be used to carry off the methanol or ethanol, which may be recovered by a cold trap. The reaction mixture is then conveniently stripped at low pressure (0.1 mm Hg), while stirring at 90"C to remove unreacted ester and more methanol or ethanol. Finally, the product is preferably allowed to cool in the presence of a small amount of p-methoxyphenol to inhibit premature polymerization. The ester that is recovered during low pressure stripping may be an isomerization product of the ester supplied to the reaction. Thus, dimethyl maleate may be rearranged into dimethyl fumarate, and dimethyl itaconate may be partly isomerized to the mesaconate and the citraconate.

The products of the reaction described are in some cases oils and in other cases resins.

Thereafter they may be compounded on a roller mill with acrylic monomer esters, additives and then films are prepared and cured from the resulting mixture in substantially the same manner as already described in connection with the unsaturated polyether-polyurethane prepolymers. Further details regarding this aspect of the invention will be apparent from the following illustrative examples.

Example 14 205 parts of a reactive polyamide resin (derived from the condensation of polymerized fatty acids with polyalkylamines and containing primary and secondary amine groups; General Mills Chemicals, Versamide 115, amine number 238) and 30 parts of dimethyl maleate are mixed in a vessel equipped with an agitator. The vessel is swept with a slow stream of nitrogen while the reaction mixture is stirred at 90"C. for 3 hours. During this time 3 parts of methanol (identified by gas chromatography) are recovered from the off-gas by means of a cold trap. In order to remove any unreacted dimethyl maleate, the reaction mixture is stripped at 0.1 mm Hg pressure while stirring at 90"C. During this time another 2 parts of methanol are recovered, but no unreacted dimethyl maleate. Then 0.1 part p-methoxyphenol is added and the product is allowed to cool to room temperature. 230.2 parts of a resinous, clear, but slightly vellowish oil are obtained. It is calculated that the ratio (dimethyl maleate reaction)/ (amine is equal to 0.25.

Example 15 This preparation is carried out as described in Example 14. 100 parts Versamid 115 are reacted with 40 parts dimethyl maleate for 3 hours at 90"C. Or stripping under reduced pressure approximately 17 parts of dimethyl fumarate and approximately 4 parts of methanol are recovered (both components are identified by gas chromatography). After adding 0.05 part p-methoxyphenol, the product is allowed to cool at room temperature. 117 parts of a greenish-yellow resinous liquid are obtained. It is calculated that the ratio (dimethyl maleate reacted)/(amine) is equal to 0.35.

Example 16 This preparation is carried out as described in Example 14. 99.1 parts Versamid 115 and 40 parts dimethyl maleate are reacted at 90"C for 5 hours. Approximately 6 parts methanol are formed during this time. After adding 0.05 part p-methoxyphenol, the reaction mixture is stripped under reduced pressure. Approximately 13 parts of dimethyl fumarate are recovered. 124 parts of a greenish resinous liquid are obtained. It is calculated that the ratio (dimethyl maleate reacted)/(amine) is equal to 0.52.

Example 17 100 parts reactive polyamide resin (General Mills Chemicals, Versamid 100, amine number 90) and 30 parts diethyl maleate are reacted for 5 hours as described in Example 14.

During this time 5 parts ethanol are formed. Then 0.05 part p-methoxyphenol is added. On stripping under reduced pressure an additional small amount of ethanol and 6 parts diethyl fumarate are recovered. 116 parts product are obtained as a residue. The product is a clear, yellowish resinous liquid. It is calculated that the ration (diethyl maleate reacted)/(amine) is equal to 0.80.

Example 18 100 parts reactive polyamide resin (Emery Industries, Emerez 1515; amine number 345) and 50 parts dimethyl maleate are reacted for 4 hours at 90"C as described in Example 14.

During this time 8 parts methanol are recovered from the off gas in a cold trap. On stripping under reduced pressure 5 parts unreacted dimethyl fumarate are recovered. Then 0.05 part p-methoxyphenol is added and the product is taken as a residue. 135 parts clear, yellow resin resinous liquid are obtained. It is calculated that the ratio (dimethyl maleate reacted)/(amine) is equal to 0.51.

Example 19 100 parts reactive polyamide resin (General Mills Chemicals, Versamid 115, amine number 238) and 15 parts dimethyl maleate are reacted for 3 hours as described in Example 14. After stripping at 900C and 0.1 mm Hg pressure, 20 parts of 5norbornene-2,3-dicarboxylic anhydride are added. The reaction mixture is stirred at 900C under a nitrogen blanket for another 3 hours. Then 0.05 part p-methoxyphenol is added and the reaction mixture is allowed to cool to room temperature. An extremely viscous resinous liquid is obtained. It is calculated that 24.5/ of the amine groups are reacted with dimethyl maleate and 28.7% with 5-norbornene-2,3-dicarboxylic anhydride.

Example 20 100 parts Versamid 115 are reacted with 45 parts dimethyl itaconate for 3 hours at 90"C as described in Example 14. Then the reaction mixture is stripped at 0.1 mm Hg pressure.

Approximately 3 parts of methanol and 20 parts of a mixture of dimethyl mesaconate, dimethyl itaconate and dimethyl citraconate (identified by gas chromatography) are removed from the reaction mixture. 0.05 parts p-methoxyphenol is added and the product is taken as a residue. 120 parts clear, yellowish viscous oil are obtained.

Example 21 U. V. Curable Overprint Varnish 100 parts of the product of Example 14, 135 parts trimethylolpropane triacrylate, 30 parts hydroxyethyl acrylate, 2 parts paraffin wax (Esso (Registered Trade Mark) wax 3150; m.p.

135"C), and 10 parts benzoin isobutyl ether are mixed well on a roller mill. A clear, almost colourless, medium oil is obtained.

Films of 0.4 mil thickness are applied with a wire wound coating rod onto paper, aluminium foil, vinyl coated aluminium foil, polyester coated Mylar, and steel. The coated substrates are exposed for 1/10 second to the UV radiation given off by a medium pressure mercury vapour lamp (Hanovia, 200 W/inch) at a distance of 5" from the lamp. This distance coincides with the second focal point created by the elliptical reflector.

After this exposure, all the coatings are cured. They have a pencil hardness of at least 3H and rub resistance of at least 40 rubs using methyl ethyl ketone as the solvent.

Example 22 - Electron Beam Curable Coating 20 parts product from Example 20, 10 parts trimethylolpropane triacrylate, 10 parts 1,6-hexane-diol diacrylate, 10 parts acrylated epoxidized soybean oil (Union Carbide Co., Actomer X-70), and 1 part stearyl acrylate are milled on a roller mill until homogeneous. A clear, almost colourless, medium viscosity oil is obtained. Coatings of 4 mil thickness are applied with a film knife to asphalt tile, vinyl tile and wood. The coated substrates are exposed to 5 Mrad electron beam radiation under exclusion of air. After the exposure the coatings are tough, clear colourless, not affected by solvents, and are very abrasion resistant.

Example 23 - UV Curable Ink 50 parts of reaction product from Example 15, 20 parts trimethylolpropane triacrylate, 10 parts Lithol rubine pigment, and 3 parts stearyl acrylate are mixed and ground on a three-roll mill until homogeneous. Then 5.5 parts benzoin isobutyl ether, dissolved in 10 parts trimethylolpropane triacrylate are added and the milling is continued for a short time. The ink is applied to paper stock as a film of 0.1-0.4 mil thickness by means of a rubber roller.

Complete cure of the ink is achieved by exposure to UV radiation for 0.5 seconds as described in Example 10.

The radiation curable coatings of this invention are extremely useful for making hard coatings without the application of extensive heat to the coated surface, and without the necessity of depositing an already cured resin from a solvent which must then be evaporated and recovered. The modified prepolymers used in the present invention make it possible to prepare hard coatings by spreading a prepolymer material of convenient fluidity and then quickly curing the film to make it resistant to abrasion and to solvents.

Example 24 10 parts dimethyl maleate - modified reactive polyamide resin (Versamid 115 -- General Mills Chemicals -- reacted with 40% by weight of dimethyl maleate at 90"C. for 3 hours, excess dimethyl maleate removed under reduced pressure) are mixed with 10 parts pentaerythritol tetraacrylate, 0.01 part phenothiazine, 0.4 part Esso wax 3150 (paraffin wax, m.p. approx. 132"C.), 0.8 part benzoin isobutyl ether and 20 parts methylene chloride. A clear, low viscosity oil is obtained.

A farrier paper made of smooth clay coated sheet weighing about 16 pounds per ream (500 sheets, 20 x 25 inches) is coated with the above solution using a &num;20 Mayer rod. The coated paper then is exposed for 1/10 second to the UV radiation given off by a medium pressure mercury vapour lamp (Hanovia, 200 W/inch) at a distance of 5 inches from the lamp. This distance coincides with the second focal point created by the elliptical reflector. By this exposure, the coating is cured to a hard, glossy film which has a pencil hardness of 3H.

The radiation cured release coating is then print coated with a clear lacquer composed of 6 parts cellulose acetate - butyrate (Eastman EAB 171-40), 55 parts ethylacetate, 28 parts toluene, and 11 parts 95% ethanol (Printing grade). Print coating is accomplished using a regular varnish etch cylinder having a depth of about 20 to 40 microns, 120 line screen and a 15-20 wall (equivalent to &num;8 Mayer rod). The applied lacquer coating is dried at 1400F. for 1 minute.

The design print is then printed over the clear lacquer layer using polyamide - nitrocellul ose modified ink containing pigment or dye of the colour desired ZYROTO WHITE, sold by Gotham Ink and Color Co., which contains a titanium dioxide pigment). The area of the design print is smaller than that of the printed lacquer layer and falls wholly within the margin of the lacquer layer.

Over the ink, as an overprint, there is then coated a clear adhesive layer comprising a solution of heat-activatable thermoplastic polyamide resin in lacquer form (VERSAMIDE (Registered Trade Mark) 940, sold by General Mills) followed by drying the adhesive to a dry non-tacky state. The area of the adhesive overprint is smaller than that of the lacquer and it falls wholly within the margins of the lacquer layer.

There is no pick-up during the three printing operations.

The heat transfer label, as formed above, is then put in contact with a polyethylene bottle, the surface of which has been treated to render it more print receptive in a conventional manner such as by flame contact. Heat and pressure are applied to the temporary backing to effect pressing of the adhesive layer against the polyethylene surfaces. As heat is applied, approximately 350"F., there is no softening of the release layer or the cellulose acetate layer, but the adhesive overprint is heat-activated to a highly tacky state and bonds to the polyethylene surface of the bottle. The temporary backing may then be stripped from the transfer label or may be left on the transfer and stripped at a subsequent time without danger of delaminating the transfer from the polyethylene surface. No portion of the release layer is left over the transfer after stripping of the temporary backing and no portion of the lacquer is removed with the release layer. After cooling and peeling of the temporary backing, the bottle so coated is flame treated and the adherence of the label thereto is determined.

Adherence was excellent.

Example 25 Same as Example 24, except that 1.0 part of cyclododecane is used in place of the Exxo Wax?3150.

Example 26 Same as Example 24, except that 1.0 part stearic acid is used in place of Esso Wax 3150.

Example 27 Same as Example 24, except that 1.4 parts -methanacryl oxypropyl trimethoxy silane (Union Carbide (Registered Trade Mark) silane A-174) are used in place of the Esso Wax 3150.

Example 28 Same as Example 24, except that 0.6 part E-wax (Farbwerke Hoechst AB, Montan type wax) is used in place of the Esso Wax 3150.

Example 29 Same as Example 24, except that 1.0 part FL-wax (Farbwerke Hoechst AB, Montan type wax) is used in place of the Esso wax 3150.

Example 30 Same as Example 24, except that 1.4 parts F-wax (Farbwerke Hoechst AB, Montan type wax) are used in place of the Esso wax 3150.

Example 31 Same as Example 24 except that that 0.5 part octadecanol is used in place of the Esso wax 3150.

Example 32 Same as Example 24, except that 1.0 part oleamide (Armour Industrial Chemical Co., Armid (Registered Trade Mark) 0) is used in place of the Esso wax 3150.

Example 33 Same as Example 24, except that 1.4 parts stearyl acrylate are used in place of the Esso wax 3150.

Example 34 Same as Example 24, except that 0.6 part isodecyl acrylate is used in place of the Esso wax 3150.

Example 35 Same as Example 24, except that 1.0 part Fluorolube LG-160 (Hooker Chemical Co.) is used in place of the Esso wax 3150.

Example 36 Same as Example 24, except that 1.4 part halocarbon wax (Halocarbon Products Corp.) is used in place of the Esso wax 3150.

Example 37 Same as Example 24, except that 1.0 part silicone S-30 (Union Carbide Co.) is used in place of the Esso wax 3150.

Example 38 Same as Example 24, except that 1.0 part silicone L-31 (Union Carbide Co.) is used in place of the Esso wax 3150.

Example 39 Same as Example 24, except that 0.5 part Syl-Off 291 (Down Corning Co.) is used in place of the Esso wax 3150.

Example 40 Same as Example 24, except that 1.0 part Syl-Off 291 containing 6% Catalyst 23A (Dow Corning Co.) is used in place of the Esso wax 3150.

Example 41 Same as Example 24, except that 1.0 part V-wax (Farbwerke Hoechst AG, poly (octadecyl vinyl ether) is used in place of the Esso wax 3150.

Example 42 Same as Example 24, except that 1.4 parts W-wax (Farbwerke Hoechst AG, hydrogenated animal fat) is used in place of the Esso wax 3150.

In the reactive polyamide prepolymers described in Examples 24-42 the polyamide preferably has primary amine end groups and at least one secondary amine group in the polymer chain. They may be prepared, for example, from essentially saturated dibasic acids such as dimerized fatty acids and triamines such as diethylene triamine, excess amine being employed to provide amine end groups. Each reactive polyamide resin molecule is then preferably reacted with at least three molecules of an unsaturated polybasic carboxylic acid, reaction 'oeing terminated when the acid molecule has formed one amide linkage and before significant cross-linking occurs. The unsaturated dibasic acids may be maleic, fumaric, itaconic or 5-norbornene-2,3 dicarboxylic acids, or their lower alkyl ester or anhydrides. The unsaturated groups of these acids co-polymerize with radiation polymerizable vinyl monomers to provide radiation cured films, but do not react with the amine groups of the reactive polyamine when condensed therewith. These prepolymers are especially useful as inks and can be diluted with vinyl monomers including acrylates, styrene, vinyl ethers and vinyl acetate which can be radiation co-polymerized therewith.

Example 43 22.6 parts unsaturated polyurethane prepared from 1 mole polyether triol, 3 moles 2,4-toluene diisocyanate, and 3 moles 2-hydroxyethyl acrylate, 20.4 parts 2-hydroxyethyl acrylate, 20.15 parts pentaerythritol tetraacrylate, 18.38 parts 1 ,6-hexanediol diacrylate, 12.44 parts trimethylolpropane triacrylate, 6.03 parts acrylated epoxidized soybean oil (Union Carbide Co.,) Actomer X-70), 6.0 parts benzoin isobutyl ether, 2.0 parts Esso wax 3150 (paraffin wax, melting point approx. 132"C.) and 30 parts methylene chloride are mixed well until a homogeneous solution is obtained.

A carrier paper made of smooth clay coated sheet weighing about 16 pounds per ream (500 sheets, 10 inches x 25 inches) is coated with the above solution (using a &num;20 Mayer rod). The coated paper then is exposed for 1/10 second to the UV-radiation given off by a medium pressure mercury vapor lamp (Hanovia, 200 2/inch) at a distance of 5 inches from the lamp.

The distance coincides with the second focal point created by the elliptical reflector. By this exposure, the coating is cured to a hard, glossy film which has a pencil hardness of 3H.

The radiation cured release coating is then print coated with a clear lacquer composed of 6 parts cellulose acetatbutyrate (Eastman EAB 171-40), 55 parts ethylacetate, 28 parts toluene and 11 parts 95% ethanol (printing grade). Print coating is accomplished using a regular varnish etch cylinder having a depth of about 20 to 40 microns, 120 line screen and a 15-20 wall (equivalent to &num;8 Mayer rod). The applied lacquer coating is dried at 1400F. for 1 minute.

The design printing is then printed over the clear lacquer layer using polyamide - nitrocellulose modified ink containing pigment or dye of the colour desired (ZYROTO WHITE, sold by Gotham Ink and Color Co., which contains a titanium dioxide pigment). The area of the design print is smaller than that of the printed lacquer layer and falls wholly within the margin of the lacquer layer.

Over the ink, as an overprint, there is then coated a clear adhesive layer comprising a solution of a heat-activatable thermoplastic polyamide resin in lacquer form (VERSAMIDE 940, sold by General Mills) followed by drying the adhesive to a dry non-tacky state. The area of the adhesive overprint is smaller than that of the lacquer and it falls wholly within the margins of the lacquer layer.

There is no pick-up during the three printing operations.

The heat transfer label, as formed above, is then put in contact with a polyethylene bottle, the surface of which has been treated to render it more print receptive in a conventional manner such as by flame contact. Heat and pressure are applied to the temporary backing to effect pressing of the adhesive layer against the polyethylene surfaces. As heat is applied, approximately 350"F., there is no softening of the release layer or the cellulose acetate layer, but the adhesive overprint is heat-activated to a highly tacky state and bonds to the polyethylene surface of the bottle. The temporary backing may then be stripped from the transfer label or may be left on the transfer and stripped at a subsequent time without danger of delaminating the transfer from the polyethylene surface. No portion of the release layer is left over the transfer after stripping of the temporary backing and no portion of the lacquer is removed from the release layer. After cooling and peeling of the temporary backing, the bottle so coated is flame treated and the adherence of the lable thereto is determined.

Adherence was excellent.

Example 44 Same as Example 43, except that 3.0 parts of cyclododecane are used in place of the Esso wax 3150.

Example 45 Same as Example 43, except that 2.0 parts stearic acid are used in place of Esso wax 3150.

Example 46 Same as Example 43, except that 2.4 parts methacryl oxypropyl trimethoxy silane (Union Carbide silane A-174) are used in place of the Esso wax 3150.

Example 47 Same as Example 43, except that 3.0 parts E-wax (Farbwerke Hoechst AG, Montan type "wax) are used in place of the Esso wax 3150.

Example 48 Same as Example 43, except that 2.0 parts Fl-wsx (Farbwerke Hoechst AG, Montan type wax) are used in place of the Esso wax 3150.

Example 49 Same as Example 43, except that 2.4 parts F-wax (Farbwerke Hoechst AG, Montan type wax) are used in place of the Esso wax 3150.

Example 50 Same as Example 43, except that 3.0 parts ocadecanol are used in place of the Esso wax 3150.

Example 51 Same as Example 43, except that 4.0 parts oleamide (Amour Industrial Chemical Co., Armid 0) are used in place of the Esso Wax 3150.

Example 52 Same as Example 43, except that 3.0 parts stearyl acrylate are used in place of the Esso wax 3150.

Example 53 Same as Example 43, except that 2.5 parts isodecyl acrylate are used in place of the Esso wax 3150.

Example 54 Same as Example 43, except that 3.0 parts fluorolube LG-160 (Hooker Chemicals Co.) are used in place of the Esso wax 3150.

Example 55 Same as Example 43, except that 3.0 parts halocarbon wax (Halocarbon Products Corp.) are used in place of the Esso wax 3150.

Example 56 Same as Example 43, except that 4.0 parts silicone S-30 (Union Carbide Co.) are used in place of the Esso wax 3150.

Example 57 Same as Example 43, except that 4.0 parts silicone L-31 (Union Carbide Co.) are used in place of the Esso wax 3150 Example 58 Same as Example 43, except that 2.0 parts Syl-Off 291 (Dow Corning Co.) are used in place of the Esso wax 3150.

Example 59 Same as Example 43, except that 4.0 parts Syl-Off 291 containing 6% Catalyst 23A (Dow Corning Co.) are used in place of the Esso wax 3150.

Example 60 Same as Example 43, except that 3.0 parts V-wax (Farbwerke Hoechst AG, poly (octadecyl vinyl ether) ) are used in place of the Esso wax 3150.

Example 61 Same as Example 43 except that 2.4 parts W-wax (Farbwerke Hoechst AG, hydrogenated animal fat) are used in place of the Esso wax 3150.

Example 62 66.3 parts unsaturated polyurethane, prepared from 1 mole polyether triol (Voranol CP700), 3 moles 2,4-toluene diisocyanate, and 3 moles 2-hydroxyethyl acrylate, 72.3 parts trimethylolpropane triacrylate, 1.5 parts 2-hydroxyethyl acrylate, 68 parts 1 ,4-butanediol diacrylate, 50 parts acrylated epoxidized soybean oil (Union Carbide Co., Actomer X-70), 2 parts stearyl acrylate, 15.6 parts benzoin isobutyl ether and 5.0 parts Union Carbide Co.

silicone rubber W-982 (polydimethyl siloxane with some unsaturation) are mixed well on a roller mill. A clear, colourless homogeneous light oil is obtained as the product.

Films of 0.2-1 mil thickness are applied with wire wound coating rods onto paper. The coated paper is exposed to the UV-radiation given off by a medium pressure mercury vapor lamp (Hanovia, 200 W/inch) at a distance of 5 inches from the lamp (second focal point created by the elliptical reflector). After this exposure the films are cured to hard, glossy coatings.

9 lbs./ream removable adhesive is cast on a paper substrate; then the coated paper is laminated to the release paper. The force to peel a 1 inch wide strip at 12 inches/min. is 43 g./linear inch.

Example 63 66.3 parts unsaturated polyurethane, prepared from 1 mole polyether triol (Voranol CP700), 3 moles 2,4-toluene diisocyanate and 3 moles 2-hydroxyethyl acrylate, 72.3 parts trimthylolpropane triacrylate, 15. parts 2-hydroxyethyl acrylate, 68 parts 1 ,4-butanediol diacrylate, 50 parts acrylated epoxidized soybean oil (Union Carbide Co., Actomer X-70), 2 parts stearyl acrylate, 15.6 parts benzoin isobutyl ether and 10.0 parts Viscasil 60000 (General Electric; poly (dimethylsiloxane) viscosity 60'000 ctsk) are mixed well on a roller mill. A clear colourless homogeneous light oil is obtained as the product.

9 lbs./ream removable adhesive is cast on a paper substrate; then the coated paper is laminated to the release paper. The force to peel a 1 inch wide strip at 12 inches/min. is 55 g./linear inch.

Example 64 66.3 parts unsaturated polyurethane, prepared from 1 mole polyether triol (Voranol CP700), 3 moles 2,4-toluene diisocyanate, and 3 moles 2-hydroxyethyl acrylate, 72.3 parts trimethylolpropane triacrylate, 1.5 parts 2-hydroxyethyl acrylate, 68 parts 1,4-butanediol diacrylate, 50 parts acrylated epoxidized soybean oil (Union Carbide Co., Actomer X-70), 2 parts stearyl acrylate, 15.6 parts benzoin isobutyl ether and 6.43 parts silicone L-31 (Union Carbide Co; poly (methyl hydrogen siloxane) are mixed well on a roller mill. A clear, colourless light oil is obtained as the product.

9 lbs./ream removable adhesive is cast on a paper substrate; then the coated paper is laminated to the release paper. The force to peel a 1 inch wide strip at 12 inches/min. is 80 g/linear inch.

Example 65 66.3 parts unsaturated polyurethane, prepared from 1 mole polyether triol (Voranol (Registered Trade Mark) CP700), 3 moles 2,4-toluene diisocyanate, and 3 moles 2-hydroxyethyl acrylate, 72.3 parts trimethylolpropane triacrylate, 1.5 parts 2-hydroxyethyl acrylate, 68 parts 1,4-butanediol diacrylate, 50 parts acrylated epoxidized soybean oil (Union Carbide Co., Actomer X-70), 2 parts stearyl acrylate, 15.6 parts benzoin isobutyl ether and 2.65 parts silicone L-522 (Union Carbide Co., poly dimethyl siloxane with some hydroxyethyl groups) are mixed well on a roller mill. A clear, homogeneous light oil is obtained as the product.

Films of 0.2-1 mil thickness are applied with wire wound coating rods onto paper. The coated paper is exposed to the UV-radiation given off by a medium pressure mercury vapour lamp (Hanovia, 200 W/inch) at a distance of 5 inches from the lamp (second focal point created by the elliptical reflector). After this exposure the films are cured to hard, glossy coatings.

9lbs./ream removable adhesive is cast on a paper substrate; then the coated paper is laminated to the release paper. The force to peel a 1 inch wide strip at 12 inches/min. is 30 g./linear inch.

Examples 66 and 67 illustrate further polyurethane prepolymers.

Example 66 864 parts of a tetra isocyanate (Desmodur (Registered Trade Mark) HLTDI isocyanurate; prepared from 4 moles of 2,4-toluene diisocyanate and 1 mole hexamethylene diisocyanate; MW 864; isocyanate equivalent 216), 1000 parts dried tetrah Example 73 0.94 parts cyclododecane dissolved in 3 parts MC 4.7 parts dimethyldiphenyl polysiloxane (General Electric Co., SF-1153 Silicone) Example 74 0.94 parts cyclododecane, dissolved in 3 parts MC 4.7 parts vinyl triethoxy silane (Union Carbide Corp., Silane A-151) Example 75 0.94 parts cyclododecane, dissolved in 3 parts MC 4.70 parts silicone oil (Union Carbide, Silicone Y-2902) Example 76 0.94 parts cyclododecane, dissolved in 3 parts MC 4.70 parts non-ionic organosilicone fluid (Union Carbide, Silicone L-49) Example 77 0.94 parts cyclododecane, dissolved in 3 parts MC 4.70 parts non-ionic organosilicone fluid (Union Carbide, Silicone L-7001) Example 78 0.94 parts cyclododecane, dissolved in 3 parts MC 4.70 parts N-beta (aminoethyl) -gamma aminopropyltrimethoxy silane (Union Carbide, Silane A-1120) Example 79 0.94 parts cyclododecane, dissolved in 3 parts MC 4.70 parts non-ionic organosilane fluid (Union Carbide, Silicone L-522 Example 80 2.29 parts fluorochlorocarbon wax (Halocarbon Products Corp., Halocarbon wax 6.000), dissolved in 9.3 parts tetrahydrofuran.

Example 81 0.93 parts dim ethyl polysiloxane oil (Union Carbide, Silicone L-522) 2.78 parts fluorochlorocarbon oil (Halocarbon Products Corp., Halocarbon oil 437) Examples 82, 83, 87, 88 and 89 illustrate radiation curable release coating prepared from acrylated epoxy resins dispersed in acrylate monomers. Examples 84, 85 and 86 illustrate release coating prepared from unsaturated polyester resins dispersed in acrylate monomers.

Exaples 90 is a release coating formulation of acrylate monomers. Examples 91, 92, 93, 94 and 95 illustrate release coatings prepared from epoxide resins polymerizable by release of catalyst on exposure to ionizing radiation. Examples 96, 97 and 98 illustrate release coatings prepared from polyunsaturated urethanes in acrylate esters.

Example 82 33.06 parts Epoxryl 25-A-60 (Shell Chem. Co., 60% dimethacrylate ester of bis glycidyl ether of Bisophenol A in acetone solvent), 33.06 parts trimethylolpropane triacrylate, 14 parts pentaerythritol tetraacrylate, 14 parts neopentylglycol diacrylate, 33.46 parts 1,6hexanediol diacrylate, 14 parts 2-hydroxyethyl acrylate, 8.26 parts acrylated epoxidized soybean oil (Union Carbide Co., Actomer X-70), 9.91 parts benzoin isobutyl ether, and 2,64 parts gamma-methacryloxy propyltrimethoxysilane (Union Carbide Co., Silane A-174) are mixed well until a homogeneous solution is obtained.

The resulting solution is then processed further as set forth in Example 68.

Example 83 20.00 parts Epocryl DRH-303 (Shell Chem. Co., diacrylate ester of liquid bisphenol A resin), 20.00 parts trimethylolpropane triacrylate, 13.00 parts pentaerythritol tetraacrylate, 15.21 parts neopentylglycol diacrylate, 18.25 parts 1 ,6-hexanediol diacrylate, 14 parts 2-hydroxyethyl acrylate, 8.50 parts acrylated epoxidized soybean oil (Union Carbide Co., Actomer X-70),10.20 10.20 parts benzoin isobutyl ether 1.10 part cyclododecane, dissolved in 3.5 parts methylene chloride, and 5.00 parts Nbeta-aminoethyl-gamma-aminopropyltrimethoxysilane (Union Carbide Co., Silane A-1120) are mixed well until a homogeneous solution is obtained.

The resulting solution is then processed further as set forth in Example 68.

Example 84 20.10 parts unsaturated polyester, made from adipic acid, maleic anhydride, and hexanediol; molecular weight approx. 3000, 4 double bonds per polyester; 20.00 parts trimethylolpropane triacrylate,20 parts pentaerythritol tetraacrylate, 20.00 parts neopentylglycol diacrylate, 20.00 parts 1,6-hexanediol diacrylate, 5.10 parts 2-hydroxyethyl acrylate 5.50 parts acrylated epoxidized soybean oil (Union Carbide Co., Actomer X-70), 10.00 parts benzoin isobutyl ether, 1.50 parts cyclododecane, dissolved in 4.5 parts methylene chloride, and 1.50 parts fluorochlorocarbon oil (Halocarbon Products Corp., Halocarbon oil 437) are mixed well until a homogeneous solution is obtained.

The resulting solution is then processed further as set forth in Example 68.

Example 85 20.00 parts unsaturated polyester, made from adipic acid,maleic anhydride, and hex anediol; molecular weight approx. 3000; 4 double bonds per polyester; 20.00 parts trimethylolpropane triacrylate,15 parts pentaerythritol tetraacrylate, 20.00 parts neopen tylglycol diacrylate, 20.00 parts 1 ,6-hexanediol diacrylate, 6.00 parts 2-hydroxyethyl acry late, 5.00 parts acrylated epoxidized soybean oil (Union Carbide Co., Actomer X-70), 9.00 parts benzoin isobutyl ether, 1.20 parts cyclododecane, dissolved in 3.6 parts methylene chloride, and 5.00 parts N-beta-aminoethylgamma-aminopropyltrimethoxysilane (Union Carbide, Co., Silane A-1120) are mixed well until a homogeneous solution is obtained.

The resulting solution is then processed further as set forth in Example 68.

Example 86 20.00 parts unsaturated polyester, made from adipic acid, maleic anhydride, and hex anediol; molecular weight approx. 3000; 4 double bonds per polyester, 20.00 parts trimethylolpropane triacrylate,20 parts pentaerythritol tetraacrylate, 20.00 parts neopen tylglycol diacrylate, 20.00 parts 1,6-hexanediol diacrylate, 5.00 parts 2-hydroxyethyl acry late, 7.00 parts acrylated epoxidized soybean oil (Union Carbide Co., Actomer X-70), 10.00 parts benzoin isobutyl ether, 1.20 parts cyclododecane, dissolved in 3.6 parts methylene chloride, and 5.00 parts dimethyl diphenyl polysiloxane (General Electric Co., Silicone SF-1153) are mixed well until a homogeneous solution is obtained.

The resulting solution is then processed further as set forth in Example 68.

Example 87 20.00 parts Epoxryl DRH-303 (Shell Chem. Co., diacrylate ester of liquid bisphenol A resin), 20.00 parts trimethylolpropane triacrylate, 12.00 parts pentaerythritol tetraacrylate, 20.00 parts neopentylglycol diacrylate, 15.00 parts 1,6-hexanediol diacrylate, 5.00 parts 2-hydroxyethyl acrylate, 6.00 parts acrylated epoxidized sovbean oil (Union Carbide Co.

Actomer X-70), 10.00 parts benzoin isobutyl ether, 1.50 parts cyclododecane, dissolved in -4.5 parts methylene chloride, and 1.50 parts fluorochlorocarbon oil (halocarbon Products Corp., Halocarbon oil 437) are mixed well until a homogeneous solution is obtained.

The resulting solution is then processed further as set forth in Example 68.

Example 88 20.0 parts Epocryl DRH-303 (Shell Chem. Co., diacrylate ester of liquid bisphenol A resin), 20.00 parts trimethylolpropane triacrylate, 12.00 parts pentaerythritol tetraacrylate, 20.00 parts neopentylglycol diacrylate, 15.00 parts 1,6-hexanediol diacrylate, 5.00 parts 2-hydroxyethyl acrylate, 6.00 parts acrylated epoxidized soybean oil (Union Carbide Co., Actomer X-70), 10.00 parts benzoin isobutyl ether, 1.20 parts cyclododecane, dissolved in 3.6 parts methylene chloride, 5.00 parts dimethyl diphenyl polysiloxane (General Electric Co., Silicone SR-1153) are mixed well until a homogeneous solution is obtained.

The resulting solution is then processed further as set forth in Example 68.

'Example 89 20.00 parts Epocryl DRH-303 (Shell Chem. Co., diacrylate ester of liquid bisphenol A resin), 20.00 parts trimethylolpropane triacrylate, 12.00 parts pentaerythritol tetraacrylate, 20.00 parts neopentylglycol diacrylate, 15.00 parts 1,6-hexanediol diacrylate, 5.00 parts 2-hydroxyethyl acrylate, 6.00 parts acrylated epoxidized soybean oil (Union Carbide Co., Actomer X-70), 10.00 parts benzoin isobutyl ether, and 2.00 parts cyclodcdecane, dissolved in 6.00 parts methylene chloride are mixed well until a homogeneous solution is obtained.

The resulting solution is then processed further as set forth in Example 68.

Example 90 Ingredients 20.0 parts polypropylene glycol TP 340 triacrylate 15.0 parts trimethylolpropane triacrylate 15.0 parts pentaerythritol tetraacrylate 15.0 parts neopentylglycol diacrylate 15.0 parts 1,6-hexanediol diacrylate 10.0 parts 2-hydroxyethyl acrylate 5.0 parts acrylated epoxidized soybean oil (Union Carbide Co., Actomer X-70) 10.0 parts benzoin isobutyl ether 1.0 part cyclododecane, dissolved in 3.0 parts methylene chloride 4.0 parts dimethyl diphenyl polysiloxane (General Electric Silicone SF-1153).

Example 91 Ingredients 212.0 parts Diglycidyl ether of bisphenol A 106.0 parts (3,4-epoxycyclohexyl)-methyl 3,4-epoxycyclohexane carboxylate.

3.18 parts Alkyl glycidyl ether in which alkyl groups are predominantly dodecyl and tetradecyl parts propylene carbonate, containing dissolved 2.45 parts of p-chlorobenzene diazomum hexafluorophosphate as the catalyst precursor 0.75 part.N,N-dimethyl acetamide as gelation inhibitor 3.0 parts cyclododecane dissolved in 9.0 parts methylene chloride 12.0 parts nonionic organosilicone fluid (Union Carbide L-522 Silicone).

Example 92 Ingredients 212.0 parts Diglycidyl ether of bisphenol A 106.0 parts (3,4-epoxycyclohexyl)-methyl 3,4-epoxyclohexane carboxylate 3.18 parts alkyl glycidyl ether in which alkyl groups are predominantly dodecyl and tetra decyl 4.0 parts propylene carbonate, containing dissolved 2.45 parts of p-chlorobenzene diazonium hexafluorophosphate as the catalyst precursor 0.75 part N,N-dimethyl acetamide as gelation inhibitor 3.0 parts Halocarbon wax 6.00 (Halocarbon Products Corp.).

Example 93 Ingredients 534.0 parts bis(dialkyl amine) adduct of bis glycidyl ether of bisphenol A 488.0 parts pentaerythritol tetra-beta-mercaptopropionate 1.0 part dibenzosuberone 30.0 parts Halocarbon oil 437 (Halocarbon Produccts Corp.).

Example 94 Ingredients 534.0 parts bis (diallyl amine) adduct of bisglycidyl ether of bisphenol A 488.0 parts pentaerythritol tetra-beta-mecaptopropionate 1.0 nart dibenzosuberone 10.0 parts cyclododecane, dissolved in 30 parts methylene chloride 50.0 parts N-beta-aminoethyl -gamma-aminopropyltrimethoxy silane (Union Carbide Co., Silane A-1120).

Example 95 Ingredients 584.0 parts bis(diallylamine) adduct of Epon 828 (Shell Chemical Co.; bis glycidyl ether of bisphenol A type resin with epoxy equivalent of approx. 195) 488.0 parts pentaerythritol tetra-beta-mercaptopropionate 1.5 parts dibenzosuberone 10.0 parts cyclododecane, dissolved in 30 parts methylene chloride 50.0 parts dimethyl diphenyl polysiloxane (General Electric Co., Silicone SF-1153).

Example 96 Ingredients 20.0 parts diunsaturated polyetherurethane [made from 324 parts poly (tetra-methylene ether) glycol (Quaker Oats Co.; OH -No.37.1348 parts toluene diisocyanate, and 232 parts 2-hydroxy ethyl acrylate] 15.0 parts pentaerythritol tetra acrylate 15.0 parts trimethylol propane triacrylate 15.0 parts 1,6-Hexane diol diacrylate 15.0 parts neopentylglycoldiacrylate 10.0 parts 2-hydroxyethyl acrylate 10.0 parts benzoin isobutyl ether 1.0 part cyclododecane, dissolved in 3.0 parts methylene chloride 2.0 parts Halocarbon oil 437 (Halocarbon Products Corp.).

Example 97 Ingredients 20.0 parts diunsaturated polyurethane [made from 458 parts Adiprene (Registered Trade Mark) L-100 (duPont) diisocyanate and 53.4 parts 2-hydroxyethyl acrylate 15.0 parts pentaerythritol tetracrylate 15.0 parts trimethylol propane triacrylate 15.0 parts 1 ,6-hexanedioldiacrylate 15.0 parts neopentylglycol diacrylate 10.0 parts 2-hydroxyethylacrylate 10.0 parts benzoin isobutyl ether 1.0 part cyclododecane, dissolved in 3.0 parts methylene chloride 3.0 parts gamma-methacryl oxypropyltrimethoxy silane (Union Carbide Co., Silane A-174).

Example 98 Ingredients 20.0 parts diunsaturated polyester-urethane [made from 323 parts polyesterdiol (RC polyester S 101-35 by Hooker Chemical Co.; MW 3232), 34.8 parts toluenedlisocyanate, and 23.2 parts 2-hydroxyethyl acrylate) 15.0 parts pentaerythritol tetra acrylate 15.0 parts trimethylol propane triacrylate 15.0 parts 1,6-hexane diol diacrylate 15.0 parts neopentyl glycol diacrylate 10.o parts 2-hydroxyethyl acrylate 10.0 parts benzoin isobutyl ether 1.0 part cyclododecane, dissolved in 3.0 parts methylene chloride 4.0 parts nonionic organosilicone fluid (Union Carbide Co., Silicone L-522).

Examples 99-108 illustrate coatings and films which are radiation curable and which have good film strength, good adhesion, good abrasion and solvent resistance, and which can also be cast. They incorporate, in the radiation curable films as herein disclosed, other essentially linear polymers of generally higher molecular weight which are soluble in the radiationcurable liquid composition. They should preferably have a molecular weight of at least about 4,000 up to the limit of solubility, and more preferably about 10,000 to 20,000. These polymers add bulk, strength, and control shrinkage in the cured composite films. The added polymers are pre-polymerized and generally do not react during radiation curing, although they can advantageously include reactive groups, such as ethylenic unsaturation, for example, as end groups, which will co-polymerize during curing. By inclusion of a wax or wax-like material of limited compatibility as herein disclosed, and which migrate to the surface, an oxygen barrier is provided which permits the films to be cured in the presence of oxygen, e.g., in air, and which provide films with release properties.

Example 99 The following ingredients are mixed well, all parts being by weight.

11.4 parts unsaturated polyether-polyurethane prepolymer, prepared from 1 mole polyether triol, 3 moles 2,4 toluenediisocyanate, and 3 moles 2-hydroxyethyl acrylate, according to Example 1 above 17.35 parts trimethylol propane triacrylate 10.65 parts neopentyl glycol diacrylate 2.4 parts acrylated epoxidized soybean oil (ACTOMER X-70, Union Carbide Corp.) 3.95 parts 2-hydroxyethyl acrylate 0.45 parts cyclododecane, dissolved in 2.3 parts methylene chloride 50.0 parts methyl methacrylate copolymer, 40% solids in a mixture of toluene and isopropanol (ELVACITE (Registered Trade Mark) 6014, DuPont).

After mixing well, the solvents are removed at room temperature in the dark, under reduced pressure, and in the presence of copper shaving as polymerization inhibitor. Thereafter, the following ingredients are added.

6.0 parts benzoin isobutyl ether (photoinitiator) 2.15 parts N-beta (aminoethyl)-gamma-aminopropyl trimethoxy silane (Silane A- 1120, Union Carbide Corp.), (a limited-compatibility waxy material). The resulting liquid composition can be coated as hereinbefore described. It can also be cast, e.g. over an optical reflective pattern on a steel surface, with or without release agent, rapidly cured with radiation and stripped to provide a self-supporting film containing on one surface a good replica of the optical pattern.

Examples 100- 108 Examples 100-108 below illustrate other additional polymers which can be substituted for ELVACITE 6104 in Example 99 to provide, by the same procedure, good radiation curable casting films and release films or coatings.

Table 1 Example No. Parts Ingredients 100 17.0 G.CURE 869 S, General Mills Chemicals Inc., a hydroxy functional acrylic copolymer, 60% solids in a mixture of xylene and cellosolve (Registered Trade Mark) acetate.

101 10.0 PM Polymer (Phillips Petroleum Co., a mercaptan terminated hydrocarbon polymer).

102 42.0 Bakelite (Registered Trade Mark) T-24 a vinyl alcohol-vinyl acetate copolymer, 25% solids in toluene).

103 40.0 Bakelite Vinyl Butyral XYLS-4 (Union Carbide Corp., 25% solids).

104 10.0 Polyketone Resin 250 (Union Carbide Corp., dissolved in 50 parts toluene) 105 17.0 Spencer-Kellogg DV-2230, an aliphatic polyurethane lacquer, 30% solids in a mixture of tetrahydrofuran and isopropanol.

106 10.0 Castomer (Registered Trade Mark) P-0010 (Witco Chemical Co., an unsaturated polyurethane dis solved in 50 parts methylene chloride.

107 20.0 Acryloid AT-71 (Rohm & Haas Co., a polyacrylate with carboxyl functionality, 50% solids).

108 20.0 Acryloid AT-63 (Rohm & Haas Co., a polyacrylate with hydroxyl functionality, 50% solids in xylene).

WHAT WE CLAIM IS: 1. A radiation curable coating composition comprising a radiation curable liquid prepolymer which includes a waxy or oil material therein, the waxy or oily material being of limited compatibility with the liquid prepolymer so that a thin layer of the waxy or oily material migrates to the surface of the coating.

2. A coating composition as claimed in Claim 1 in which the liquid prepolymer comprises the reaction product of a polyisocyanate with a secondary polyether polyol and an ethylenically unsaturated reactive hydrogen containing compound.

3. A coating composition as claimed in Claim 1 in which the liquid p epolymer comprises the reaction product of an amine containing polyamide with an ullsaturated polybasic carboxylic acid or an anhydride or lower alkyl ester of such an acid.

4. A coating composition as claimed in Claim 1 or Claim 2 or Claim 3 further including an acrylic ester monomer copolymerizable by radiation with the liquid pre-polymer to provide coating viscosity.

5. A coating composition as claimed in any preceding Claims which includes a photoinitiator for promoting rapid cure under exposure to radiation.

6. A coating composition as claimed in any preceding Claim further including a polymer to act as a strengthening and shrink control agent.

7. A coating composition as claimed in Claim 2 or any of Claims 4 to 6 when dependent on Claim 2 in which: the polyisocyanate is toluene diisocyanate, the secondary polyether polyol is a polyether triol and the ethylenically unsaturated reactive hydrogen containing compound is an unsaturated alcohol selected from allyl alcohol, 5-norbornene 2-methanol and hydroxy lower alkyl esters of acrylic or methacrylic acid; and the acrylic ester monomer is selected from trimethylolpropane triacrylate, hydroxyethyl acrylate, neopentyl glycol diacrylate, acrylated epoxidized soybean oil, hexanediol diacrylate, 1,4-butanediol diacrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, butyl acrylate, isodecylacrylate, octadecyl acrylate and mixtures of two or more of these and the photoinitiator therein is a benzoin lower alkyl ether and/or acetophenone and/or benzophenone and/or Michler's k tone or any of these

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

Table 1 Example No. Parts Ingredients

100 17.0 G.CURE 869 S, General Mills Chemicals Inc., a hydroxy functional acrylic copolymer, 60% solids in a mixture of xylene and cellosolve (Registered Trade Mark) acetate.

101 10.0 PM Polymer (Phillips Petroleum Co., a mercaptan terminated hydrocarbon polymer).

102 42.0 Bakelite (Registered Trade Mark) T-24 a vinyl alcohol-vinyl acetate copolymer, 25% solids in toluene).

103 40.0 Bakelite Vinyl Butyral XYLS-4 (Union Carbide Corp., 25% solids).

104 10.0 Polyketone Resin 250 (Union Carbide Corp., dissolved in 50 parts toluene)

105 17.0 Spencer-Kellogg DV-2230, an aliphatic polyurethane lacquer, 30% solids in a mixture of tetrahydrofuran and isopropanol.

106 10.0 Castomer (Registered Trade Mark) P-0010 (Witco Chemical Co., an unsaturated polyurethane dis solved in 50 parts methylene chloride.

107 20.0 Acryloid AT-71 (Rohm & Haas Co., a polyacrylate with carboxyl functionality, 50% solids).

108 20.0 Acryloid AT-63 (Rohm & Haas Co., a polyacrylate with hydroxyl functionality, 50% solids in xylene).

WHAT WE CLAIM IS: 1. A radiation curable coating composition comprising a radiation curable liquid prepolymer which includes a waxy or oil material therein, the waxy or oily material being of limited compatibility with the liquid prepolymer so that a thin layer of the waxy or oily material migrates to the surface of the coating.
2. A coating composition as claimed in Claim 1 in which the liquid prepolymer comprises the reaction product of a polyisocyanate with a secondary polyether polyol and an ethylenically unsaturated reactive hydrogen containing compound.
3. A coating composition as claimed in Claim 1 in which the liquid p epolymer comprises the reaction product of an amine containing polyamide with an ullsaturated polybasic carboxylic acid or an anhydride or lower alkyl ester of such an acid.
4. A coating composition as claimed in Claim 1 or Claim 2 or Claim 3 further including an acrylic ester monomer copolymerizable by radiation with the liquid pre-polymer to provide coating viscosity.
5. A coating composition as claimed in any preceding Claims which includes a photoinitiator for promoting rapid cure under exposure to radiation.
6. A coating composition as claimed in any preceding Claim further including a polymer to act as a strengthening and shrink control agent.
7. A coating composition as claimed in Claim 2 or any of Claims 4 to 6 when dependent on Claim 2 in which: the polyisocyanate is toluene diisocyanate, the secondary polyether polyol is a polyether triol and the ethylenically unsaturated reactive hydrogen containing compound is an unsaturated alcohol selected from allyl alcohol, 5-norbornene 2-methanol and hydroxy lower alkyl esters of acrylic or methacrylic acid; and the acrylic ester monomer is selected from trimethylolpropane triacrylate, hydroxyethyl acrylate, neopentyl glycol diacrylate, acrylated epoxidized soybean oil, hexanediol diacrylate, 1,4-butanediol diacrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, butyl acrylate, isodecylacrylate, octadecyl acrylate and mixtures of two or more of these and the photoinitiator therein is a benzoin lower alkyl ether and/or acetophenone and/or benzophenone and/or Michler's k tone or any of these

photinitiators together with a coinitiator comprising a hydroxyalkyltertiaryamine.
8. A coating composition as claimed in any preceding Claim in which the waxy or oily material is selected from silanes, siloxanes, polysiloxanes, halocarbons, cyclododecane, fatty acrylates and natural synthetic waxes.
9. A radiation curable coating composition as claimed in Claim 1 substantially as described herein with reference to any one of Examples 10 to 13 or 21 to 23.
10. A radiation curable release coating composition as claimed in Claim 1 substantially as described herein with reference to any one of Examples 24 to 65 or 68 to 98.
11. A radiation curable release coating composition as claimed in Claim 1 substantially as described herein with reference to any one of Examples 99 to 108.
12. A laminate comprising a design or decorative layer in removable contact with a release surface formed by a radiation curable composition as claimed in any preceding Claim.
13. A method of coating a substrate which comprises applying to the substrate a coating composition as claimed in any of Claims 1 to 11 and irradiating the coating.
14. A method of preparing a transfer with a releasable design or decoration which corn rises: (a) Forming a liquid film of a radiation curable coating composition as claimed in any of Claims 1 to 11 on a substrate to provide a waxy surface layer; b) Curing the film by radiation; and c) Applying a transfer material containing the said design or decoration to the surface of the cured film; or applying the mirror image of the said design or decoration to the surface for transfer printing.