CA1064190A - U.v.-curable resinous compounds and compositions - Google Patents

Abstract

A B S T R A C T
UV-curable ethylenically unsaturated resinous compounds comprising the reaction products of (I) a polyhydroxy compound, (II) a diisocyanate, (III) an adduct of equivalent amounts of acrylic acid and a glycidyl ester of branched saturated aliphatic monocarboxylic acids, and ( N) optionally a hydroxy alkyl acrylate.

Description

The invention relates to novel ethylenically unsaturated resinous compounds and to their preparation. The novel compounds can be cured by U.V. radiation, and they are particularly useful for application in coating compositions and printing inks. Special advantages of the present ethylenically unsaturated compounds are the fast cure by U.V. radiation and the absence of tackiness after cure (tackiness after cure is one of the most troublesome drawbacks, caused by air inhibition, which this type of resins quite often display). The valuable properties of the novel resinous compounds-areattributed to their structure and to the selection of components for their -~
manufacture. The invention relates further to compositions containing in addition other ethylenically unsaturated compounds having a low viscosity, and to compositions containing other types of additives, such as photo-initiators, fillers, colourants and pigments. The invention further relates to the use of the novel compounds in radiation cure processes.
In recent years processes have been developed for cure of ethylenically unsaturated resins by radiation, in particular by electron beam radiation and by U.V. light.
Such radiation processes can find application in the field of surface coatings and for printing inks. These processes enable a very fast cure, at ambient temperature, in a way that flat substrates with a coverage of uncured resinous materials can be conveyed at high speed to a ~ ' ' 1~64~

place where a short exposition to the radiation will effect cure Or the resinous materials, and the treated article can be further processed without delay.
Interest in electron beam cure has led to proposals for certain types of resins. The advantage of electron beam cure is the very high energy of the electrons emitted, which is usually between 100,000 and 500,000 electron volts; this energy is high enough to initiate polymerization of substantially any type of ethylenically ~- 10 unsaturated compound without use of auxiliary materials.
Drawback, however, is the very high cost of the electron generator and of the heavy and complicated screening which is necessary to protect production staff against the X-rays emitted when theelectrons are slowed down.
U.V. radiation as polymerization initiator has the advantage of lower cost of apparatus and screening;
however, the quantum energy is considerably lower (3,3 ~ electron volts for U.V. radiation of 360 nm) and the - use of photo-initiators (also named sensitizers) is required to initiate the polymerization. As the U.V.
radiation has lower energy than the electron beam, more specific selections of resinous materials will be required for a complete and fast cure. In practice, resins for U.V. cure have generally been of the unsaturated polyester type.
A drawback common to most resins in radiation cure systems is the air inhibition phenomenon, which means _ 4 _ that in contact with air the surface of the cured layer tends to remain sticky even when the underlaying parts of the layer have hardened completely. This phenomenon has often to be eliminated by additional measures to protect the surface of the uncured material from interaction with oxygen, such as use of paraffin wax to cover the surface, or the use of inert gas in the conveyor street, or coverage of the surface by a thin clear thermoplastic sheet.
The invention is concerned with a resinous material, suitable for fast cure by U.V. radiation in contact with air, to provide a cured material having a tack-free - surface without specific precautions.
Some further advantages will be clear from the followi-ng specification.
The invention provides an UV-curable ethylenically ~.-, , .
unsaturated resinous compound, comprising the reaction product of (I) one mole of a polyhydroxy compound having m hydroxy groups per molecule, wherein m has a value of at least 2, (II) n moles of a diisocyanate, (III) 1 to n moles of an adduct of equivalent amounts of acrylic acid and a glycidyl ester of saturated aliphatic monocarboxylic acids in which carboxylic acids the carboxyl group is attached to a tertiary or quaternary carbon atom and which carboxylic acids have 9 to 11 carbon atoms per molecule, and (IV) (n-1) to 0 moles of a hydroxyalkyl acrylate of the formula " H
HO - R - 0 - C - C = CH2 wherein R is a divalent alkyl group, the sum of the number of moles of components (III) and (IV) being n, n being smaller than or equal to m, and the value of n being at least 2.
The polyhydroxy compounds O have preferably 2 to 6, more preferably 3 to 6 hydroxy groups per molecule. Examples of polyhydroxy compounds are polyhydric alcohols such as glycerol, pentaerythritol, trimethylol ethane, trimethylol propane, 1,2,6~hexane triol, sorbitol and reaction products of these alcohols with ethylene oxide or propylene oxide in a molar ratio of from 1:1 to 1:20;
the latter, so-called tipped polyols, contribute to the flexibility of the cured product. Other polyhydroxy compounds are condensation products of polycarboxylic acids or their anhydrides and optionally monocarboxylic acids with an excess of a polyhydric alcohol, such as compounds of the alkyd resin type. Other suitable poly-hydroxy compounds are solid reaction products of polyhydric phenols such as 2 3 2-bis(4-hydroxyphenyl)propane with epichlorohydrin having Durrans' softening points between ; 60C and 100C, and having 2 to 4 hydroxy groups per molecule; these reaction products have also about 2 epoxy groups per molecule, which may be suitable for a secondary -slower cure with polyamines. Other suitable polyhydroxy compounds are diacrylates of diglycidyl ethers of polyhydric phenols such as 2,2-bis(4-hydroxyphenyl)propane;
the acrylates are obtained by reaction of 2 moles of acrylic acid with 1 mole of said diglycidyl ethers, and obtain 2 hydroxy groups per molecule. Other polyhydroxy compounds are castor oil and hydrogenated castor oil;
polymers of 2-hydroxyalkyl- and optionally alkyl esters of acrylic or methacrylic acid; and triethanolamine.
Mixtures of two or more of the above named polyhydroxy compounds may also be used. Preferred are polyhydric alcohols, in particular those having 2 to 6 and preferably 3 to 6 hydroxy groups per molecule; particularly preferred are trimetylol propane and its reaction products with ethylene oxide in a molar ratio of from 1:6 to 1:20, and sorbitol.
Examples of diisocyanates are meta- and para-phenylene ~-diisocyanate, toluene-2,4- or 2,6-diisocyanate and mixtures of these isomers, m-xylene diisocyanate, naphthalene-1,5-di-isocyanate, diphenyl methane diisocyanate, diphenyl-4,4'-diisocyanate, 3,3'-dichloro diphenyl 4,4'-diisocyanate~
3,3'-dimethoxy diphenyl-4,4'-diisocyanate, 3,3'-dimethyl diphenyl-4,4'-diisocyanate, 3,3'-bisphenyl diphenyl-4,4'-diisocyanate, 3,3'-dimethyl dlphenylmethane-4,4'-di-isocyanate, diphenyl ether 4,4'-diisocyanate, N,N'-bis (4-methylphenyl)uretidindion 3,3'-diisocyanate, butane-1,4-diisocyanate, hexane-1,6-diisocyanate, 2,2,4-trimethyl .

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hexane diisocyanate, dodecane-1,12-diisocyanate, cyclohexane diisocyanate, di(cyclohexylmethane)4,4~-diisocyanate, 2-butene-1,4-diisocyanate, diethyl-sulphide 2,2'-diisocyanate, and isophorone diisocyanate.
Mixtures of two or more of those diisocyanates may also be used. The diisocyanate may be a crude product, or may have been purified, for example by distillation or crystallization; solid diisocyanates may have been liquified to facilitate handling. One mole of diisocyanate is defined as the amount containing two isocyanate equivalents.
Component III can be prepared by heating equimolar amounts of the components at temperatures from 100 to 150C
in the presence of a catalyst (an organic phosphine, a phosphonium salt, a tertiary amine, or a quaternary ammonium salt) and preferably in the presence of an inhibitor, for example hydroquinone, until determination of the epoxy content shows that the reaction is sub-' stantially complete.
The acids from which the glycidyl esters are made will for convenience further be named "branched mono-carboxylic acids~'. Aliphatic in the definition of the ' branched monocarboxylic acids will in this connection include acyclic aliphatic as well as cycloaliphatic.
Branched monocarboxylic acids can be obtained by reaction of formic acid or carbon monoxide and water with olefins such as cracked mineral oil fractions, .. - . : , ....................................... .
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propylene trimer, or diisobutylene in the presence of liquid strongly acidic catalysts, and such branched monocarboxylic acids are usually mixtures in which the carboxyl group is predominantly attached to a quaternary carbon atom.
Component (IV) may be, for example, hydroxyethyl acrylate or hydroxypropyl acrylate.
The relative amounts of components (III) and (IV) may be varied, with the condition that at least 1 mole of component (III) is used in the preparation of 1 mole of the ethylenically unsaturated resinous compound as defined above. The amount of component (III) may vary from 1 to n moles per mole of ethylenically unsaturated resinous compound, and accordingly the amount of component (IV) may vary from n-1 to 0 moles, the sum of the number of moles of components (III) and (IV) being n. The value ~`
of n is equal to or smaller than the value of m; the minimum value f~)r both is 2. In the cases that n is smaller than m the resinous compound will contain m-n hydroxy groups per molecule.
The ethylenically unsaturated resinous compounds as defined above are prepared from the components as defined above, preferably by two routes, each route being a two-stage process.
The preferred route is to react first the components (III) and optionally (IV) with the diisocyanate, preferably in the presence of a catalyst for isocyanate/hydroxy ' ' ,. :
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reactions. Such catalysts are known; examples are:
dibutyl tin dilaurate, cobalt naphthenate, and tertiary amines such as triethyl amine, N-methyl morpholine, triethylene diamine. Further, as the acrylate ester used may polymerize spontaneously, an inhibitor such as hydroquinone should be present in sufficient amount in any stage of the reactions. Reaction temperatures of from 20 to 100C may be contemplated, preferred reaction temperatures (using dibutyl tin dilaurate as catalyst) being 40-80C. To raise the selectivity in reacting only one isocyanate group of the diisocyanate, the monohydroxy compounds (III) and optionally (IV) are preferably added slowly, over some hours, to the diisocyanate. If both components (III) and (IV) are used, it is preferred (in view of a possible difference in reactivity) to react each of them separately with an equimolar amount of diisocyanate, and to mix the resulting products; if the reactivity is about the same, a mixture of (III) and (IV) may be added.
; 20 In the second stage of this first route the polyhydroxy compound is added, if desired with supplementary amounts of catalyst and/or inhibitor, and the reaction is allowed to proceed, preferably at a similar temperature as that during the first stage until isocyanate analysis shows that the reaction is substantially complete.

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This route will allow the preparation of resinous compounds having free hydroxy groups (m-n per molecule).
The first route is defined as a process for the preparation of an UV-curable ethylenically unsaturated resinous compound wherein first n moles of a diisocyanate (II) are reacted with 1 to n moles of component (III) and (n-l) to 0 moles of component IV, the sum of the number of moles of components III and IV being n, and wherein n moles of this product is reacted in a second stage with 1 mole of the polyhydroxy compound (I) having m hydroxy groups per molecule, n being smaller than or equal to m.
In the second route the steps of the first route are reversed: first the polyhydroxy compound is reacted with the diisocyanate, and then the compound (III) and optionally - (IV) are added. It will be clear that in this second route n will have to be equal to m, to avoid high viscosity and even - gelation as much as possible. An excess of components III
and optionally IV may be used to obtain a hydroxy-containing product, in which the excess has the function of a reactive diluent.There are indications that the second route is not quite so selective as the first one, which would result in a higher viscosity, and sometimes gelation. Therefore usually the first route will be preferred. The second route is defined as a process for the preparation of an UV-curable ethylenically unsaturated resinous compound wherein first , : . . ' ':

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1 mole of a polyhydroxy compound having m hydroxy groups per molecule is reacted with n moles of a diisocyanate, and this product is reacted in a second stage with 1 to n moles of component (III) and (n-1) to 0 moles of component (IV), the sum of the number of moles of components (III) and tIV) being at least n, and n being equal to m.
With regard to the ethylenically unsaturated resinous compounds according to the invention as defined above it should be kept in mind that the compounds or their intermedi&tes in the first stage are not purified, and that therefore the resinous compounds as defined are intended to include all impurities formed by side reactions.
Further, the amount of component to be ~dded in the second stage is commonly calculated on the base of the isocyanate equivalency of the product of the first stage, to account for side reactions in the first stage.
The ethylenically unsaturated compounds as def`ined and described above are usually solids or highly viscous liquids.The preferred compounds have on average more than two UV~polymerizable ethylenically unsaturated groups per molecule, and may be named "star shaped".
A variety of different ethylenically unsaturated - compounds, of low viscosity, either alone or in mixtures can be used as a diluent to bring the viscosity for application as a coating or printing ink down to the .
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desired level. These low-viscous diluents polymerize and copolymerize during UV-radiation, and so contribute both to the reduction of viscosity and the weight of the coating or print. These compounds of low viscosity contain one or more ethylenically unsaturated groups of the structure H
- C = CH2 per molecule, and can be represented by the formula H
R - C = CH2) in which p is a number from l to 4, and R is a p-valent ~- hydrocarbon,ether, or ester residue containing no urethane groups, and having up to 18 carbon atoms.
Examples are: styrene, vinyl esters of monocarboxylic acids such as vinyl acetate or preferably vinyl esters of "branched monocarboxylic acids" as hereinbefore defined, the adduct of acrylic acid and glycidyl esters of branched monocarboxylic acids ("component III"
as defined above), esters of acrylic acid and mono-or polyhydric alcohols such as ethyl acrylate, butyl acrylate, octyl acrylate, 2-ethyl hexyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, neopentyl glycol diacrylate, trimethylpropane di- and triacrylate, pentaerythritol di-, tri, and tetraacrylate and mixtures thereof, ethylene glycol diacrylate, diethylene glycol diacrylate, polyethylene glycol diacrylates. Preferred are diluents having a boiling point of at least 60C, .:

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more preferably above 100C, in particular above 150C, at atmospheric pressure, as the function of the diluent is to copolymerize, and not to evaporate. The amount of diluent may be from 5 to 60, and is preferably from 20 to 40 parts by weight per 100 parts by weight of the resinous compound. Diluents can often be added during preparation of the resinous compound, in the first and/or the second stage, to facilitate handling.
Examples of photo-initiators for UV cure are:
benzoin methyl ether, benzoin ethyl ether; 9,10-anthraquinone, 1,4-naphthoquinone and chloro, methyl, phenyl and benz-derivatives of these two compounds. Preferred are benzoin methyl (or ethyl) ether and 2-tertiary butyl anthraquinone.
The amount of photo-initiator is usually from 0.5 to 5 and preferably from 0.5 to 2 %w of resinous compound plus diluent.
- Compositions containing resinous compounds as defined above, photo-initiators, and optionally diluents as defined above and other components can be used for a variety of applications, for example: primings on wood;
clear and coloured lacquers on wood, chip plate, board plate, paper, steel, tin plate; printing inks for paper (resin about 5,000 poise, reduced to 1,000~2,000 poise - at 25C by diluent) and plastic sheet (resin about 500 poise, 25 reduced to about 100 poise at 25C by diluent). They can be applied to the substrate by methods known in the art, and .

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~ ' the treated substrate is passed at high speed under a source of W radiation, usually a mercury lamp, optionally containing also a source of I.R. radiation.
The compositions are preferably free from volatile solvents which do not poly-merize; however, plasticizing non-volatile components may be present.
Compositions containing resinous compounds as defined above, optionally diluents and other components (without photo-initiator~ can also be cured by electron beam radiation.
The invention is illustrated by examples. Parts and percen-tages therein are by weight, unless otherwise indicated. Examples 1 - 20 demonstrate preparation of resinous compounds with Or without reactive dilu-ents (all preparations carried out under nitrogen); examples 21 and 22 demon-strate evaluation results. "CARDURA" E is a glycidyl ester of branched mono-carboxylic acids with 9 - 11 carbon atoms, "EPIKOTE" 1001 is a polyglycidyl polyether of 2,2-bis(4-hydroxyphenyl~propane having 2 free hydroxy groups per molecule. "EPIKOTE" 828 is a polyglycidyl ether of 2,2-bis(4-hydroxyphenyl~-propane having an epoxy equivalent weight of 180 - 200. "VeoVa" 10 is a - vinyl ester of branched monocarboxylic acids having 10 carbon atoms per molecule. "CARDURA", "EPIKOTE" and "VeoVa" are trade marks.

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The adduct of "CARDURA" E and acrylic acid used in the examples 1-19 (abbreviated ACE adduct) was prepared as follows:
A mixture of "CARDURA" E (1235 g; 5 epoxy equivalents), acrylic acid (360.5 g; 5 mol), triphenyl phosphine (0.5 g) and hydroquinone (4.o g) was heated with stirring to 120C.
Heating was discontinued and the temperature was allowed to rise by means of the heat of reaction to 140C, where it was stabilized by intermittent cooling and heating. After an epoxy equivalent weight of 50,000 was reached (indicating ; that the reaction was more than 99% complete) the product was dumped and allowed to cool down. The cooled ACE
adduct was a clear, light yellow liquid of low viscosity.
Determination of active hydrogen gave a value of 345 milli-15 equivalents per 100 g, corresponding to a hydroxyl equivalent ; weight of 289. 5. In Example 20 a similar ACE adduct having a hydroxy equivalent weight of 314 was used (ACE adduct II).

A mixture of hexamethylene diisocyanate (433 g; 2.56 mole), 20 dibutyl tin dilaurate (1.5 g) and hydroquinone (o.6 g) was heated with stirring to 70C. In 6 hours a solution of ACE

adduct (743 g; 2.56 hydroxy equivalents)in styrene (394 g) was gradually added with stirring while maintaining the reaction temperature at 70C. A few minutes after completion 25 of the addition the isocyanate equivalent weight was 650.
Then a mixture of trimethylol propane (110 g), styrene (37 g), dibutyl tin dilaurate (1.64 g) and hydroquinone (o.6 g) ' :
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was added. The reaction temperature was kept at 70c until the isocyanate equlvalent weight was 40,000 (98% conversion). The cooled resinous product was a clear, lightly coloured viscous liquid.

Isophorone diisocyanate (167 g; 0.75 mole), ACE
adduct (217 g; 0.75 hydroxy equivalent), dibutyl tin dilaurate (0.2 g), "VeoVa" 10 (96 g)~ and hydroquinone (o.8 g) were mixed with stirring; the temperature was allowed to rise to 40C by means of the heat of reaction, and kept there until the isocyanate equivalent weight was 631. Then trimethylol propane (33.6 g), dibutyl tin dilaurate (0.1 g) and "VeoVa" 10 (8.4 g) were added;
the mixture was heated to 70C and maintained at that ~ 15 temperature until the isocyanate equivalent weight ;~ was approximately 5, ooo . The cooled resinous product was a clear, colourless highly viscous liquid.

Trimethylol propane (115 g; 2.56 hydroxy equivalents) 20 was added to a mixture of hexamethylene diisocyanate (433 g; 2.56 mole), styrene (350 g) and dibutyl tin dilaurate (1.5 g) with stirring; the temperature was raised to soc, and maintained there until the mixture became homogeneous. ThenACE adduct (740 g) and dibutyl 25 tin dilaurate (1.5 g) were added slowly (4 hrs) and the temperature was allowed to rise to 70C where it ~0~4~

was kept until the isocyanate equivalent weight was 51,000. The cooled resin was a clear, colourless, highly viscous liquid.

Example 1 was repeated with the exception that -~ the trimethylolpropane was replaced by an equivalent amount of triethanolamine. The cooled resin was a clear yellow viscous liquid.

Example 1 was repeated, except that the trimethylol-propane was replaced by an equivalent amount of a trimethylol-propane-ethylene oxide adduct containing 14 mole ethylene oxide per mole trimethylolpropane.

Example 1 was repeated, except that the trimethylolpropane was replaced by an equivalent amount (based on hydroxyl) of "EPIKOTE" 1001.

Example 1 was repeated, except that the trimethylolpropane was replaced by an equivalent amount (based on hydroxyl) of the diacrylate of "EPIKOTE" 828.

Example 1 was repeated, except that the hexamethylene diisocyanate was replaced by an equivalent amount (based on isocyanate) of isophorone diisocyanate.

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Example 1 was repeated, except that the hexamethylene diisocyanate was replaced by an equivalent amount (based . on isocyanate) of trimethylhexamethylene diisocyanate.

Example 1 was repeated, except that the styrene was replaced by the same weight of 2-ethylhexyl acrylate.
EXAMPLE 11 ~.
Example 1 was repeated, except that the styrene was ~10 omitted completely.

: Example 11 was repeated, except that the trimethylol-propane was replaced by an equivalent amount (based on ;hydroxyl) of the diacrylate of "EPIKOTE" 828.

Example 3 was repeated, except that the hexamethylene diisocyanate was replaced by an equivalent amount (based on isocyanate) of isophorone diisocyanate.

Example 3 was repeated, except that the styrene was replaced by the same weight of "VeoVa" 10.

Example 3 was repeated, except that the unsaturated solvent (styrene) was completely omitted.

Example 3 was repeated, except that the trimethylolpropane was replaced by an equivalent amount (based on hydroxyl) of triethanolamine.

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" 19 .. :

--- Example 2 was repeated, except that "VeoVa" 10 was omitted. The resulting resin was a clear, highly viscous mass.

Example 1 was repeated, except that hexamethylene diisocy-anate was replaced by an equivalent amount of 2.4-toluylene diisocyanate and the styrene was omitted. The product was a yellow brittle solid.
~ 10 EXAMPLE 19 - Example 2 was repeated, except that trimethylolpropane was replaced by an equivalent amountofatriol derived from glycerol and propylene oxide having an average molecular weight of 300.

Isophorone diisocyanate (167 g; 0.75 mole), ACE
adduct II (235.5 g; 0.75 hydroxy equivalents),dibutyl tin d~aurate (0.2 g) and hydroquinone (o.8 g) were mixed with stirring. The temperature was allowed to Fise to 40~C by means of the reaction heat, and kept there until the isocyanate equivalent weight was 525 Then sorbitol (45.5 g; 0.25 mole) and dibutyl tin dilaurate (0.1 g) were added, the mixture was heated to 100C
and maintained at that temperature until the isocyanate equivalent weight was approximately 5,000. The cooled resinous product was a clear,brittle material.

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- Evaluation of products of Examples 1-8 and 10-16 The products of these Examples were evaluated as coatings (approximately 15 microns thick) on paper by determination of the speed of cure when irradiated with an UV lamp. Benzoin ethyl ether (1 %w) was used as a photo-initiator, and reactive diluents were added to the products of Examples 11, 12 and 15 as indicated in Table I.
All irradiations were carried out using two Philips HOK-5 5000 Watt medium pressure, air-cooled mercury vapour lamps with a flux of 80 Watt/cm.
The armatures both contained elliptical reflectors.
The lamps are mounted at one of the foci. A conveyor belt of variable speed was used to control the exposure time. The lamps were so positioned that the object being irradiated passes through the second focus - a distance of 12 cm from the lamp.
; Evaluation results are collected in the following Table, as number of passes under the UV lamp as belt speed given until the coating was dry to the touch (tested with cotton wool).

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Table I

Product of Reactive Belt speed Number of passes diluent(m/min) - added Example 1 - 30 8 ~' 2 - 120 " 3 - 30 9 " 4 - 30 2 " 5 - 3 3 " 6 - 30 10 " 7 - 30 3 " 8 - 30 2 " 10 - 30 2 " 11 ACE(30 %w) 30 5 " 12 ACE(20 %w) 50 " 13 - 3 5 " 14 - 50 ; " 15 2-ethyl 30 2 hexyl acry-late (20 %w) ========_==================== :
%w is weight percent on product of the Examples.

Evaluation of products of Examples 17-20 All systems in this Example contained benZ~n/ethyl ether (2.5 %w) as photoinitiator. Drying speeds (touch-dry) were determined as described in Example 21. Further, the resinous products were evaluated as coatings.

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1(3 ~; - 22 -: (40-50 ~um thick clear films on phosphatized steel panels (Bonder 97, "Bonder" is a registered trade name).
The coated panels were cured by passing them twice - 5 at a belt speed of 30 m/min through the UV installation described in Example 21. Properties determined were:
Konig pendulum hardness, reverse impact resistance, adhesion (cross cut + tape test), and solvent resistance (scrubbing with a methyl ethyl k~.tone (MEK) - moistened cloth until the coating could be removed by scratching with the fingernail).
Results are collected in Table II.

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Product Reactive Touch-dry Film Properties of Diluent after (after 2 passes at 30 m/min) Example added *) (%w)Belt No. Hard- Reverse Adhes- MEK
speed of ness Impact ion**~ resi$~
m/min passes (K8nig) (cm kg) (No. of rubs) 17 (VeoVa (20)+ 120 1 78 4.5 2 45 17 ¦HEA (25) 120 1158 3.3 4 35 18 (VeoVa(20)+90 160 2.2 2 25 18 HEA (25) 120 1155 4.5 4 50 :
19 VA (5) 30 250***1 13.5***~ 5***2 10***~
-.............. 20 HEA (25) 120 1 144 4.5 3 45 ` 20 ~ 120 1 78 6. 2 45 : -.
. *) VA: vinylacetate, HEA: 2-hydroxyethyl aoylate, TMPTA: trimethylolpropane triacrylate HDDA: 1.6-hexan.ediol diacrylate .~
, **) 5: excellent adhesion 0: no adhesion ***) after 5 passes at 30 m/min.

Claims (21)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An UV-curable ethylenically unsaturated resinous compound, com-prising the reaction product of (I) one mole of a polyhydroxy compound having m hydroxy groups per molecule, wherein m has a value of at least 2, (II) n moles of a diisocyanate, (III) 1 to n moles of an adduct of equivalent amounts of acrylic acid and a glycidyl ester of saturated aliphatic monocar-boxylic acids in which carboxylic acids the carboxyl group is attached to a tertiary or quaternary carbon atom and which carboxylic acids have 9 to 11 carbon atoms per molecule, and (IV) (n-l) to 0 moles of a hydroxyalkyl acrylate of the formula wherein R is a divalent alkyl group, the sum of the number of moles of com-ponents (III) and (IV) being n, n being smaller than or equal to m, and the value of n being at least 2.

2. A resinous compound as claimed in Claim 1, wherein the poly-hydroxy compound (I) has 2 to 6 hydroxy groups per molecule.

3. A resinous compound as claimed in Claim 1 wherein the poly-hydroxy compound (I) has 3 to 6 hydroxy groups per molecule.

4. A resinous compound as claimed in any of Claims 1 to 3, where-in the polyhydroxy compound (I) is a polyhydric alcohol.

5. A resinous compound as claimed in Claim 1, wherein the poly-hydroxy compound (I) is trimethylolpropane.

6. A resinous compound as claimed in Claim 1, wherein the poly-hydroxy compound (I) is sorbitol.

7. A resinous compound as claimed in Claim 1, wherein the poly-hydroxy compound (I) is a reaction product of a polyhydric alcohol with ethylene oxide or propylene oxide in a molar ratio of from 1:1 to 1:20.

8. A resinous compound as claimed in any of Claims 5 to 7, wherein the diisocyanate (II) is isophorone diisocyanate.

9. A resinous compound as claimed in Claim 1 wherein the di-isocyanate (II) is isophorone diisocyanate.

10. A process for the preparation of an UV-curable ethyleni-cally unsaturated resinous compound as claimed in Claim 1, wherein first n moles of a diisocyanate (II) are reacted with 1 to n moles of component (III) and (n-1) to 0 moles of component IV, the sum of the number of moles of com-ponents III and IV being n, and wherein n moles of this product is reacted in a second stage with 1 mole of the polyhydroxy compound (I) having m hydroxy groups per molecule, n being smaller than or equal to m.

11. A process for the preparation of an UV-curable ethyleni-cally unsaturated resinous compound as claimed in Claim 1, wherein first 1 mole of a polyhydroxy compound having m hydroxy groups per molecule is reacted with n moles of a diisocyanate, and this product is reacted in a second stage with 1 to n moles of component (III) and (n-1) to 0 moles of component (IV), the sum of the number of moles of components (III) and (IV) being at least n, and n being equal to m.

12. UV-curable composition, comprising (A) per 100 parts by weight of an ethylenically unsaturated resinous compound as claimed in Claim 1, (B) from 5 to 60 parts by weight of one or more different UV-curable ethyleni-cally unsaturated compounds having one or more ethylenically unsaturated groups of the structure per molecule.

13. UV-curable composition as claimed in Claim 1, 3 or 5, comprising additionally a photo-initiator,

14. UV-curable composition as claimed in Claim 6 or 7, com-prising additionally a photo-initiator.

15. UV-curable composition as claimed in Claim 9 or 12, com-prising additionally a photo-initiator.

16. Surface coating composition comprising a composition as claimed in Claim 1, 3 or 5 and additionally including a photo-initiator.

17. Surface coating composition comprising a composition as claimed in Claim 6 or 7 and additionally including a photo-initiator.

18. Surface coating composition comprising a composition as claimed in Claim 9 or 12 and additionally including a photo-initiator.

19. Printing ink, comprising a composition as claimed in Claim 1, 3 or 5 and additionally including a photo-initiator.

20. Printing ink, comprising a composition as claimed in Claim 6 or 7 and additionally including a photo-initiator.

21. Printing ink, comprising a composition as claimed in Claim 9 or 12 and additionally including a photo-initiator.