The present invention refers to a resin composition curable by ultraviolet light, which resin composition comprises at least one cycloaliphatic epoxy resin or epoxide compound, vinyl ether and/or oxetane, at least one polycarbonate diol, triol and/or polyol and at least one cationic photoinitiator, and optionally at least one sensitiser material sensitising and increasing the reactivity of said photoinitiator, at least one radical monomer or oligomer and/or at least one free radical photoinitiator. In a further aspect, the present invention refers to the use of said resin composition.

Cationic photopolymerisation is a ring opening polymerisation process of oxiranes and/or oxetanes initiated by a strong protonic acid generated by the photolysis of onium salts, such as diaryliodonium and/or triarylsulphonium salts. Photosensitisers, such as thioxanthones and anthracene derivatives, as well as free radical photoinitiators can be used to enhance the activity of the onium salt. The living character of the polymerisation will continue to develop after ultraviolet (UV) exposure, providing a beneficial post cure effect. This effect can be enhanced by a thermal treatment. The ring opening mechanism results in a low shrinkage and the outstanding adhesion on many substrates is one of the main features of cationic systems over free radical polymerisation. Furthermore, the oxonium ion and the carbocation are inactive towards oxygen which allows a high curing speed in air.

Cationic radiation curing resins are typically used in printing inks, varnishes, coatings, rapid prototyping, electronic coatings, insulation coatings and in adhesives.

The main components of cationic formulation are cycloaliphatic epoxy resins and/or epoxide compounds, such as 3,4-epoxy cyclohexyl methyl-3,4 epoxy cyclohexane carboxylate, as main compound and oxetanes, such as 3-ethyl-3-hydroxymethyl-oxetane, as reactive diluent.

The ring opening of the three membered epoxide group and/or the four membered oxetane group can be accompanied by crosslinldng with hydroxyl functional compounds like caprolactone polyols, polyether polyols, polyester polyols, such as dendritic polymers. These

polyols act as chain transfer crosslinkers and flexibilisers and they can be used in concentration up to for instance 30% by weight.

A number of other components, such as epoxides, that is epoxy and epoxide resins and compounds having one or more three membered epoxide groups, vinyl ethers, Novolac resins, epoxidized oils, epoxidized polybutadiene, can be used to fine tune the end properties of the coatings. The cationic polymerisation of expoxides, that is compounds and resins having one or more three membered epoxide groups, and oxetanes, that is compounds and resins having one or more four membered oxetane groups, can be combined, in a so called hybrid formulation, with free radical polymerisation of for instance acrylate systems to build interpenetrating polymer networks.

It is known for skilled in the art that current cationic inks, based on for instance hydrophilic polyethers or hydrolytically unstable polyester polyols and caprolactone polyols, are poor in withstanding the rigors of autoclave sterilisation processes due to poor hydrolytic and heat stability.

Low moisture sensitivity is a prerequisite for rapid prototyping resin compositions. The currently available polyols, such as caprolactones, polyetlier and polyester polyols, are known in the art to suffer from too high a hydrophilicity altering the mechanical properties of the prototype when exposed to different ambient conditions.

It is, furthermore, known in the art that the rheology of an ink is essential for obtaining good printing quality. Due to the overall high hydrophilicity of compounds used in cationic radiation curing, the ink is suffering from a strong pseuplastic behaviour when formulating with organic pigments. This is detrimental to the ink transfer and printing quality.

Aliphatic polycarbonate diols, triols and polyols have long been known. They are prepared from non- vicinal diols, triols and polyols by reaction with diarylcarbonates, dialkylcarbonates, dioxolanones, phosgene, bischlorocarbonic acid esters or urea. Polycarbonate diols, triols and polyols are outlined in Polymer Reviews 9 "Chemistry and Physics of Polycarbonates " pp. 9-20, 1964.

Many diols, triols and polyols can be used in the transcarbonylation process in the preparation of polycarbonates polyols. Examples of suitable diols, triols and polyols include, but are not limited to, 1,4-butanediol, 1,5-pentanediol, 3-methyl-l,5-pentanediol, 1,6-hexanediol, neopentylglycol, 2-butyl-2-ethyl-l,3-propanediol, trimethylolethane, trimethylolpropane, pentaerythrytol, di-trimethylolpropane, dipentaeryhtritol, hyperbanched polymer polyols and the like. Further suitable diols, triols and polyols include alkoxylated species of for instance neopentyl glycol, 2-butyl-2-ethyl-l,3-propanediol, trimethylolethane, trimethylolpropane, pentaerythritol, ditrimethylolethane, ditrimethylolpropane and dipentaerythritol. Mixtures of polyols can be used, and mixtures are often preferred when physical property modifications, such as reduced crystallinity or a lower melting point is desired.

Polyether diols, such as polyethylene glycol and polypropylene glycol, and polyester diols and polyols, such as polyethylene glycol adipate, and dendritic and branched polyols are also suitable hydroxyfunctional compounds. Block copolymers of polyethers or polyesters and polycarbonates can be prepared using these diols, triols and polyols as starting materials in the transesterification process.

Polycarbonate diols, triols and polyols offer outstanding resistance to hydrolysis making them particularly suitable in the production of long life articles. The advantages of the use of polyolcarbonates for exterior coating applications have in US 6,350,523 been disclosed in free radical radiation curable coatings. The resistance to heat and hydrolysis of diol, triol and polyol carbonates has in JP 2003-246830 been disclosed in hot melt urethane adhesives.

The objects of the invention is the use of polyolcarbonates as chain transfer crosslinkers and flexibilisers in cationic actinic polymerisation protective coatings, inks, adhesives, rapid prototyping and electronics. A further embodiment is the superior outdoor durability, heat and hydrolytic stability of the formulations based on these polycarbonate polyols for cationic ultraviolet or electron beam (UV/EB) curing coatings compared to formulations based on polyester polyols, caprolactone polyols and polyether polyols. The present compositions are suitable for a wide variety of applications. The better hydrolytic stability provides superior ink properties for demanding conditions like packagings withstanding sterilisation and pasteurisation process. Further benefits like improved rheology of pigmented systems have

been found when using hydrophobic diol, triol or polyol carbonates leading to superior inlc transfer and printing quality. The high hydrophobicity makes these diol, triol or polyol carbonates very suitable in stable resin compositions for rapid prototyping.

The active energy radiation curing resin composition of the present invention comprises in its simplest form an epoxy functional monomer or polymer, an oxetane compound, a polycarbonate diol, triol or polyol and a photocationic polymerisation initiator. Above composition can optionally be combined with free radical components, such as (meth)acrylates and vinyl ethers, and other unsaturated compounds and a suitable free radical photoinitiator, yielding a so called hybrid system.

These formulations can be used as or in protective coatings, inks and adhesives as well as in electronic, rapid prototyping and ink jet applications. The polycarbonate diol, triol or polyol provides for example coatings with superior outdoor durability, heat and moisture resistance and improved dimensional stability and stable mechanical properties in rapid prototyping systems and adhesives, improved hydrolytic stability in sterilisation and pasteurisation of printing inks and varnishes as well improved rheological behaviour, such as more Newtonian behaviour, in inks.

The present invention accordingly refers to a resin composition curable by ultraviolet light, which resin composition comprises: a) from 25 to 95% by weight of at least one cycloaliphatic epoxy resin or epoxide compound, which epoxy resin or epoxide compound has one or more three membered epoxide groups, at least one oxetane resin or compound, which resin or compound has one or more four membered oxetane groups, and/or at least one vinylether or a mixture thereof, b) from 1 to 40% by weight of at least one polycarbonate diol, triol or polyol reactable with component (a), c) from 0.1 to 10% by weight of at least one cationic photoinitiator, and optionally d) from 1 to 70% by weight of at least one radically polymerisable monomer and/or oligomer, and/or

e) from 0.1 to 10% by weight of at least one free radical photoinitiator.

Said cycloaliphatic epoxy resin or epoxide compound is preferably and typically a resin or compound having a linking aliphatic ester group and two cyclohexene oxide groups, such as 3 ,4-epoxy-6-methylcyclohexylmethyl-3 ^-epoxy-β-methylcyclohexanecarboxylate, di(3 ,4- -epoxycyclohexylmethyl)hexanedioate, diCS^-epoxy-β-methylcyclohexylmethy^hexane- dioate, 3,4-epoxycyclohexylmethyl-3 ₅ 4-epoxycyclohexanecarboxylate and ethylenebis- (3 ^-epoxycyclohexanecarboxylate) .

Said oxetane resin or compound is in various embodiments of said resin composition preferably selected from the group consisting of 3-ethyl-3-hydroxymethyloxetane, 3-(meth)allyloxymethyl-3-ethyloxetane, (3-ethyl-3-oxetanylmethoxy)methylbenzene, (3-ethyl- -3-oxetanylmethoxy)-benzene, 4-fluoro-[l-(3-ethyl-3-oxetanyhnethoxy)methyl]benzene,

4-methoxy-[ 1 -(3-ethyl-3 -oxetanyhnethoxy)methyl]benzene, [ 1 -(3 -ethyl-3 -oxetarrylmethoxy)- ethyljphenylether, isobutoxymethyl(3-ethyl-3-oxetanyhnethyl)ether, isobornyloxyethyl- (3 -ethyl-3 -oxetanyl-methyl)ether, isobomyl(3-ethyl-3-oxetanylmethyl)ether, 2-ethylhexyl- (3-ethyl-3-oxetanyhnethyl) ether, ethyldiethyleneglycol(3-ethyl-3-oxetanyhnethyl)ether, dicyclopentadiene-(3-ethyl-3-oxetanylmethyl)ether, dicyclopentenyloxyethyl(3-ethyl-3-

-oxetanyhnethyl)ether, dicyclopentenyl(3-ethyl-3-oxetanyhnethyl)ether, tetrahydrofurfuryl- (3-ethyl-3-oxetanylmemyl) ether, tetrabromophenyl(3-ethyl-3-oxetanyhnethyl)ether, 2-tetrabromophenoxyethyl-(3-ethyl-3-oxetanyhnethyl)ether, tribromophenyl(3-ethyl-

-3-oxetanylmethyl)ether, 2-tribromophenoxyethyl(3-ethyl-3-oxetanyhnethyl)ether,

2-hydroxyethyl(3 -ethyl-3 -oxetanyhnethyl)ether, 2-hydroxypropyl(3~ethyl-3-oxetanyl- methyl)ether, butoxyethyl(3-ethyl-3-oxetanyhnethyl)ether, pentachlorophenyl-(3-ethyl- -3-oxetanyhnethyl)ether, pentabromophenyl(3-ethyl-3-oxetanyhnethyl) ether, bornyl- (3-ethyl-3 -oxetanylmethyl)ether, 3 ,7-bis(3-oxetanyl)-5-oxa-nonane, 3 ,3 '-( 1 ,3 -(2-methylenyl)- propanediylbis(oxymemylene))-bis(3-ethyloxetane), 1,4-bis [(3 -ethyl-3 -oxetanylmethoxy)- methyl]benzene, 1 ,2-bis[(3-etliyl-3-oxetanylniethoxy)methyl]ethane ₅ 1 ,3-bis[(3-ethyl-3- -oχetanyknethoxy)methyl]propane, ethyleneglycolbis(3-ethyl-3-oxetanylmethyl)ether, dicyclo ρentenylbis-(3-ethyl-3-oxetanyhnethyl)ether, triethyleneglycolbis(3-ethyl-3-oxetanyl- methyl)ether, teti-aethyleneglycolbis(3-ethyl-3-oxetanylmethyl)ether, tricyclodecanediyl-

dimethylene-(3 -ethyl-3 -oxetanylmethyl) ether, trimethylolprop anetris(3 -ethyl-3 -oxetanyl- methyl)ether, 1 ,4-bis(3-ethyl-3-oxetanylmethoxy)butane, l,6-bis(3-ethyl-3-oxetanylmethoxy)- hexane, pentaerythritoltris(3-ethyl-3-oxetanylmemyl)ether, pentaervthritoltetrakis(3-ethyl-3- -oxetanylmethyl)ether, polyethyleneglycolbis(3 -ethyl-3 -oxetanylmethyl) ether, dipentaerythritolhexalds-(3-ethyl-3-oxetanyhnethyl)ether, dipentaerythritolpentakis-

-(3-ethyl-3-oxetanylmethyl)ether, dipentaerythritoltetrakis(3 -ethyl-3 -oxetanylmethyl)ether, caprolactone modified dipentaerythritolhexakis(3-ethyl-3-oxetanyhnethyl)ether, caprolactone modified dipentaerythritolpentalds(3-ethyl-3-oxetanylmethyl)ether, ditrimethylolpropane- tetrakis-(3 -ethyl-3 -oxetanylmethyl)ether, ethylene oxide modified bisphenol-A-bis(3-ethyl-3- -oxetanyhnethyl)ether, propylene oxide modified bisphenol-A-bis(3-ethyl- -3-oxetanylmethyl)ether, ethylene oxide modified hydrogenated bisphenol-A-bis- (3-ethyl-3-oxetanylmethyl)ether, propylene oxide modified hydrogenated bisphenol-A- -bis(3-ethyl-3-oxetanyhnethyl)ether and/or ethylene oxide modified bisphenol-F- (3 -ethyl-3 -oxetanylmethyl)ether.

A vinylether compound is in embodiments of the present invention advantageously selected among divinyl or trivinyl ether compounds, such as ethylene glycol divinyl ether, ethylene glycol monovinyl ether, diethylene glycol divinyl ether, Methylene glycol monovinyl ether, Methylene glycol divinyl ether, propylene glycol divinyl ether, dipropylene glycol divinyl ether, butanediol divinyl ether, hexanediol divinyl ether, cyclohexane dimethanol divinyl ether, hydroxyethyl monovinyl ether, hydroxynonyl monovinyl ether and trimethylolpropane trivinyl ether, and monovinyl ether compounds such as ethylvinylether, n-butylvinylether, ώø-butylvinylether, octadecylvinylether, cyclohexylvinylether, hydroxyburylvinylether, 2-ethylhexylvinylether, cyclohexanedimethanolmonovinylether, ra-propylvinylether, isopropyl- vinylether, isopropenylether-o-propylenecarbonate, dodecylvinylether, diethyleneglycol- monovinylether, octadecylvinylether and the like.

Polycarbonate diols, triols and polyols included in the resin composition of the present invention are suitably and for example produced in a transesterification process as disclosed in US 5,171,830 which disclosure in its entirety by reference is herein is included. Polycarbonate diols, triols and polyols possible to include in said resin composition are, however, not limited

to polycarbonates prepared by said process. Diols, triols and polyols suitable for preparation of said polycarbonates include, but is not limited to, 2,2-dialkyl-l,3-propanediols, 2-alkyl-2-hydroxyalkyl-l,3-propanediols, 2,2-dihydroxyalkyl- 1,3 -propanediols and dimers, trimers and polymers thereof. Suitably and advantageously used diols, triols and polyols can be exemplified by 1,4-butanediol, neopentylglycol, 2-butyl-2-ethyl-l,3-propanediol, diethyleneglycol, 1,6-hexanediol, triethylene glycol, 1,3-dimethanol-cyclohexane, 1,4-dimethanol-cyclohexane, 1,3-dimethanolbenzene, 1,4-dimethanolbenzene, bis-hydroxyethyl bisphenol A, dimethanol tricyclodecane, trimethylolethane, trimethylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, anhydroenneaheptitol, l,4-butanediol-2, bis-hydroxyethylhydroquinone and dendritic or hyperbranched polyester and/or polyether polyols.

Any suitable type of photoinitiator that upon exposure to actinic radiation forms cations that initiating the reactions of the cationically polymerisable compounds, such as epoxy resins, can be used in the resin composition of the present invention. There is a large number of known and technically proven catiom ^' c photoinitiators that are suitable. They include, for example, onium salts with anions having a weak nucleophilicity. Examples are halonium salts, iodosyl salts and sulphoniuni salts, such as those disclosed in the European patent application 0 153 904 and in WO 98/28663, sulphoxonium salts, such as those disclosed in the European patent applications 0 035 969, 0 044 274, 0 054 509 and 0 164 314, and diazonium salts, such as those disclosed in US Patents 3,708,296 and 5,002,856 and in GB 2396153. All of these eight disclosures are hereby incorporated in their entirety by reference. Further cationic photoinitiators are for instance metallocene salts, such as those disclosed in European applications EP 0 094 914 and 0 094 915, which disclosures hereby also are incorporated in their entirety by reference.

A survey of other currently available onium salt initiators and/or metallocene salts can be found in "UV Curing, Science and Technology", Editor S. P. Pappas, Technology Marketing Corp., USA and in "Chemistry & Technology of UV & EB Formulation for Coatings, Inlcs & Paints", Vol. 3, edited by P.K.T. Oldring.

Said optional radically polymerisable monomer or oligomer can be exemplified by and in embodiments of the present resin composition include ethylene glycol di(meth)acrylate, dicyclopentenyl di(meth)acrylate, triethylene glycol diacrylate, tetraethylene glycol di(meth)acrylate, tricyclodecanediyldimethylene di(meth)acrylate, trimethylolpropane tri(meth)acrylate, alkylene oxide, such as ethylene and/or propylene oxide, modified trimethylolpropane tri(meth)acrylate, tripropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, alkylene oxide modified neopentyl glycol di(meth)acrylate, such as ethylene oxide modified neopentyl glycol di(meth)acrylate and propylene oxide modified neopentyl glycol di(meth)acrylate, (meth)acrylic adducts of bisphenol A diglycidyl ether, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, alkylene oxide, such as ethylene oxide and/or propylene oxide, modified pentaerythritol tri(meth)acrylate and tetra(meth)acrylate, polyethylene glycol di(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol tetra(meth) aery late, alkylene oxide, such as ethylene and/or propylene oxide modified dipentaerythritol hexa(meth)acrylate, penta(meth)acrylate and tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, alkylene oxide, such as ethylene oxide and/or propylene oxide, modified ditrimethylolpropane tetra(meth)acrylate, alkylene oxide, such as ethylene and/or propylene oxide, modified bisphenol A, hydrogenated bisphenol A and bisphenol F di(meth)acrylate, (meth)acrylates of phenolic novolak polyglycidyl ethers and the like.

The resin compositions of the present invention may in embodiments thereof employ one or more free radical photoinitiators. Examples of such photoinitiators include benzoin and benzoin derivatives, such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin phenyl ether and benzoin acetate, acetophenones, such as acetophenone, 2,2-dimethoxyacetophenone, 4-(phenylthio)acetophenone and 1,1-dichloroacetophenone, benzil and benzil ketals, such as benzil dimethyl ketal and benzil diethyl ketal, anthraquinones, such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertbutylanthraquinone, 1-chloroanthraquinone and 2-amylanthraquinone, triphenylphospliine, benzoylphosphine oxides, such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide, benzophenones, such as benzophenone, dimethoxybenzophenone, diphenoxybenzophenone and 4,4'-bis

(N,N'-dimethylamino)benzophenone, thioxanthones and xanthones, acridine derivatives, phenazene derivatives, quinoxaline derivatives, I-phenyl-1, 2-propanedione- -2-O-benzoyloxime, I-aminophenyl ketones and 1-hydroxyphenyl ketones, such as 1-liydroxycyclohexylphenyl ketone, phenyl(l-hydroxyisopropyl) ketone and 4-isopropylphenyl-(l-hydroxyisopropyl) ketone, and triazine compounds, such as, 4"'-methyl- thiophenyl-l-di(trichloromethyl)-3, 5-S-triazine, S-triazine-2-(stilbene)-4, 6-bistrichloromethyl and paramethoxy styryl triazine.

The resin composition of the present invention may additionally comprise at least one organic or inorganic pigment, filler and/or colorant, all well known per se in the art. Non-limiting examples of typically suitable organic colorants include phthalocyanine blue, monoarylide yellow, diarylide yellow, arylamide yellow, azored, quinacridone magenta and black pigments, such as finely divided carbon and the like.

Stabilisers may be added to the compositions in order to prevent for instance viscosity build-up, such as a viscosity build-up when used in a solid imaging process. Preferred stabilisers include those disclosed in US Patent ^" 5,665,792 of which the entire disclosure is hereby incorporated by reference. Such stabilisers are usually hydrocarbon carboxylic acid salts of group IA and IIA metals. The most preferred examples of these salts are sodium bicarbonate, potassium bicarbonate and rubidium carbonate. Furthermore, one or more sensitisers, such as l-chloro-4-propoxy-thioxanthone, in an amount of for instance 0.1-5.0% by weight, sensitising the cationic photoinitiators and thus increase its reactivity, may also be added to the resin composition according to the present invention.

In a further aspect, the present invention refers to the use of a resin composition, as herein disclosed, decorative and/or protective coatings, varnishes, inks, such as printing inks, and adhesives as well as in rapid prototyping compositions.

Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilise the present invention to its fullest extent. The following preferred specific embodiments are, therefore, to be construed as merely illustrative and not limitative of the remainder of the disclosure in any way whatsoever. In the following Examples 1 and 2 refer to

synthesis of polycarbonat diols used in embodiments of the present invention and Examples 3-6 to preparation and evaluation of resin compositions, coatings and inks, according to embodiments of said invention. Evaluation results are given in Tables 1 and 2.

Example 1

The synthesis is performed in two steps, a transcarbonylation step at atmospheric pressure followed by a polymerisation step at a reduced pressure. The transcarbonylation, by which dimethylcarbonate (DMC) forms the mono and dimethylcarbonate esters of neopentyl glycol, is performed to avoid losses of DMC in the polymerisation step due to the azeotrop formed with methanol. The synthesis gave a yield of more than 90% polycarbonate of neopentyl glycol, which product was a white solid with melting range of 100-110°C and a hydroxyl value of ll2 mg KOH/g.

Step 1: 169 g (1.88 mole) of DMC and 140 g (1.34 mole) of neopentyl glycol were charged to a 500 ml glass reactor provided with heating and stirring. 1.07 g (0.013 mole) of NaOH (50% in water) was slowly added drop wise when the neopentyl glycol began to go into solution. The mixture was set to reflux at a starting temperature of 94°C. Formed methanol and remaining DMC were distilled of under atmospheric pressure when the temperature reached 81 ⁰ C. The distillation temperature interval was 82-124 ⁰ C.

Step 2: In this polymerisation step the pressure was during 25 minutes reduced to 7 mbar and the reaction was completed by maintaining said pressure for 60 minutes at 12O ⁰ C.

Example 2

The synthesis is performed in two steps, a transcarbonylation step at atmospheric pressure followed by a polymerisation step at a reduced pressure. The transcarbonylation, by which dimethylcarbonate (DMC) forms the mono and dimethylcarbonate esters of 2-butyl-2-ethyl-l,3-propanediol (BEPD), is performed to avoid losses of DMC in the polymerisation step due to the azeotrop formed with methanol. The synthesis gave a yield of more than 90% polycarbonate of BEPD, which product was liquid at room temperature with a hydroxyl value of 112 mg KOH/g.

Step 1: 126.1 g (1.4 mole) of DMC and 162.25 g (1.34 mole) of BEPD were charged to a 500 ml glass reactor provided with heating and stirring. 0.04 g (0.0005 mole) of NaOH (50% in water) was slowly added drop wise when the neopentyl glycol began to go into solution. The mixture was set to reflux at a starting temperature of 99°C. Formed methanol and remaining DMC were distilled of under atmospheric pressure when the temperature reached 81°C. Step 2: In this polymerisation step the pressure was during 25 minutes reduced to 15 mbar and the reaction was completed by maintaining said pressure for 270 minutes at 12O ⁰ C.

Example 3

Resin compositions, clear coatings, according to embodiments of the present invention and comprising the products obtained in Examples 1 and 2 (Embodiment Formulations 3 and 4) were prepared and compared with clear coatings without said Example 1 and 2 products (Formulation 1 and 2). Components and amounts thereof are listed below.

*1: Cycloaliphatic epoxy resin (Dow Chemicals, USA).

*2: Caprolactone polyol (Dow Chemicals, USA).

*3 : Triarylsulphonium salt (photoinitiator, Dow Chemicals, USA).

*4: 3-Ethyl-3-hydroxymethyloxetane (Perstorp Specialty Chemicals AB, Sweden).

Example 4

The resin compositions, clear coatings, prepared in Example 3 were applied on glass panels (film thickness: 15 μm wet). The coatings were cured in air by being passed twice under a 80 W/cm UV H bulb at a speed of 10 m/min and characterised by methylethyl keton (MEK) double rubs, pendulum hardness (Konig pendulum) according to ASTM D4366-95 and

Erichsen flexibility according to ASTM E-643. The viscosity was measured by a cone and plate viscosimeter at 25 ⁰ C. The result is given in Table 1 below.

Example 5

Resin compositions, inks, according to embodiments of the present invention and comprising the product obtained in Example 2 (Embodiment Formulations 5, 7 and 9) were prepared and compared with inks without said Example 2 product (Formulations 6, 8 and 10). All inks were prepared at 50°C in a high speed dispersing equipment. Components and amounts thereof are listed below.

*1: Cy clo aliphatic epoxy (Dow Chemicals, USA).

*2: Caprolactone polyol (Dow Chemicals, USA).

*3: Dispersing agent (Lubrizol, Germany).

*4: Organic pigments (Clariant, Switzerland).

*5: Organic pigment (CIBA ₅ Switzerland).

*6: Iodonium salt (photoinitiator, CIBA, Switzerland).

*7: l-Chloro-4-ρropoxythioxanthone (sensitiser, Lambson Ltd, UK).

*8: Free radical photoinitiator (Ciba, Switzerland).

*9: Wetting agent (Byk Chemie GmbH, Germany).

Example 6

The rheology of the resin compositions, inks, prepared in Example 5 were evaluated with a Stresstech viscosimeter and the shortness index was measured. The shortness index is the viscosity ratio between low shear and high shear rates (herein 2.5 s-1 and 2500 s-1). A shortness index of 1 represents a Newtonian behaviour and the higher the shortness index, the higher the pseudoplasticity of the ink. The viscosity at a shear rate of 369 s-1 is given in Table 2 below wherein can be seen that resin compositions, inks, according to the present invention exhibit much lower shortness index compared with inks without said BEPD carbonate.

Table 1

Table 2