HK1101700A - Radiation curable waterborne composition - Google Patents

Description

Radiation curable waterborne composition

The present invention relates to a radiation curable waterborne composition, such as an emulsion, dispersion or solution, comprising at least one amphiphilic dendritic polymer and at least one non-amphiphilic radiation curable oligomer or polymer, such as an unsaturated polyester or polyether and/or an acrylic oligomer or polymer. In a further aspect the present invention relates to the use of said amphiphilic dendritic polymer as a dispersing resin for non-amphiphilic radiation curable oligomers and polymers and the use of said radiation curable waterborne composition in coatings and inks.

Water-based coatings or resins, such as oligomers or polymers, are coatings or resins that are diluted with water prior to use. Although the primary volatile is water, many water-based coatings contain some solvent. Latex coatings occupy the architectural market, interior, and exterior trim in the case of flat, semi-gloss, and gloss coatings. Water-based systems can also be used for industrial maintenance coatings based on water-soluble or dispersible resin systems. Another group includes water-based alkyd resins and polyesters. Although no longer the main group of resins used in coatings, alkyds are still very important and a wide variety of alkyds have been made.

Radiation curable compositions are well known techniques and are used, for example, in printing inks, paints and varnishes for furniture and packaging materials, and in adhesives. Further fields of application include, for example, dental materials. Radiation curable compositions are environmentally suitable and pleasant because they do not contain volatile solvents. Furthermore, they show rapid curing and hardening when exposed to, for example, ultraviolet light (UV) or Electron Beam (EB). The compositions most often contain one or more oligomers or polymers having unsaturation, typically acrylates or maleates. These oligomers and polymers are generally highly viscous and, to achieve useful viscosities, are diluted with various monomers. The monomers are typically vinyl monomers such as esters of mono-, di-, tri-or polyfunctional alcohols and acrylic acid and styrene. The expression acrylic acid is understood hereinafter as any of the four commonly available unsaturated acids: acrylic acid (acrylic acid, vinyl formic acid), 2-methacrylic acid (methacrylic acid) and its cis (isocrotonic acid) and trans forms (crotonic acid) 2-butenoic acid (crotonic acid or beta-methacrylic acid), and acrylic acid and acrylic esters derived from any of the four unsaturated acids.

Unsaturated polyesters are cured and/or dried high molecular compounds used, for example, in composites, paints, varnishes and similar adhesives. Unsaturated polyesters are essentially based on unsaturated acids/anhydrides, such as maleic acid/anhydride and/or fumaric acid, and saturated acids, such as phthalic acid/anhydride, which are typically esterified with aliphatic saturated diols, such as ethylene glycol, propylene glycol and neopentyl glycol. Unsaturated alcohols such as allyl ethers of glycerol, trimethylolethane, trimethylolpropane and pentaerythritol are also generally used. Minor amounts of polyfunctional alcohols may also be included. Crosslinking of unsaturated polyesters is carried out by adding peroxides and cobalt salts or by adding initiators for Ultraviolet (UV), Infrared (IR) or Electron Beam (EB) curing. The use of unsaturated polyesters in applications such as castings, moldings, gel coats, UV-curable putties, and the like, typically includes some amount of a vinyl monomer, such as styrene and/or 4-t-butylstyrene.

Protective and decorative paints and varnishes, glues and other drying and curing compositions based on acrylic, methacrylic and/or crotonic oligomers and polymers meet increasing importance in many applications. The increased importance is essentially due to the use and unique properties of the polymers, such as short curing times, good film properties, low or no solvent content. Acrylic compositions for such and other applications often include a number of various components, such as one or more polyester acrylates, acrylic modified fumarates, urethane acrylates, epoxy acrylates and/or glycidyl acrylates and one or more functional monomers, such as esters of alcohols and acrylic acid. In addition to being a monomer, the functional monomer acts as a viscosity reducing diluent for the oligomers and polymers. The properties of acrylates, such as film formation, curing, drying, etc., are determined by, for example, the molecular weight and molecular structure as well as the chemical and physical structure of the acrylates.

For example, in "Chemistry & Technology of UV and EBformulations for Coatings, Inks and Paints" -Vol.2: compositions and techniques of radiation curable systems and acrylic monomers are further disclosed in "polymerizable Reactive monomers for UV and EB Current forms".

The use of water instead of monomers to reduce oligomer viscosity provides an interesting alternative. The excellent properties of dispersions cured without crosslinking monomers can be obtained without avoiding the use of monomers that achieve specific properties and/or properties. The two main techniques for making water-based systems are a) external emulsification, wherein the resin is emulsified in water using one or more emulsifiers, and b) internal or self-emulsifying systems, wherein the resin is modified by groups that can be neutralized, such as carboxyl groups, so that the resin can be emulsified in water.

Waterborne radiation curable systems are implicit and show easy spray application of coatings, low shrinkage, improved energy consumption and reduced or 0 monomer content compared to 100% liquid systems. Vinyl monomers, such as styrene and acrylic monomers, are generally highly reactive and, as such, potentially harmful, are irritants and possible sensitizers of the skin and eyes, are allergic, cause weakness and have a strong and unpleasant odor, all of which result in limited or prohibited use.

Waterborne radiation-curable systems based on cellulose, for example cellulose esters, are disclosed, for example, in US5254603, EP0426085, DE2436614, US3615792 and WO 01/16239. Radiation-cured polyesters are disclosed, for example, in EP0982339, EP0425947 and DE 3340489. EP0982339 teaches waterborne radiation curable polyester compositions obtained by mixing or pre-condensing water dilutable radiation curable emulsifying resins having unreacted acid groups to give an acid number of 20-300mg KOH/g, such as acrylated pentaerythritol ethoxylate, and water non dilutable radiation curable polymers having ester and/or ether groups, such as trimethylolpropane ethoxylate reacted with acrylic acid and carboxylic acids other than acrylic acid. EP0425947 discloses water dilutable binders containing at least one polymerizable unsaturation obtained by condensation of at least one polyoxyalkylene glycol, alkoxylated triol, alkoxylated 3-6 functional alcohol, polycarboxylic acid and unsaturated monocarboxylic acid. DE3340586 discloses water-emulsifiable radiation-curable polyesters prepared by condensation of anhydrides of dicarboxylic acids, polyether diols, alkoxylated triols and acrylic acid. A further species of waterborne radiation curable resins is disclosed in EP0574775, wherein an emulsifiable and polymerizable binder is obtained by reacting a (meth) acrylic prepolymer and a water emulsifiable unsaturated polyester with a polyfunctional isocyanate.

In addition, C.Decker et al in "UV Radiation Curing of Waterborn Coatings", Advances in Coatings Technology, ACT' 02International Conference, Katowice, Poland, Nov.5-8, 2002, p.11/1 and 11/3-11/10; davis et al, Development and applications of Water-Based Radiation-Curable Coatings, Waterborn Coatings and Adhesives, Special Publication (ISSN0260-6291), Royal Society of Chemistry 1995, p.81-94 and Frank J.Kosnik et al, application to Water-Based Radiation Coatings, Procedings of the Water-Borne and Higher-Solidscoatings Symposium, New Orleanans, USA, Feb.1-3, 1989, p.204-11.

The radiation curable composition of the present invention is a new waterborne radiation curable system because it uses dendritic structures to form the surface active compounds. The dendritic structure acts quite unexpectedly as an emulsifier, which has the advantage of being optionally curable, e.g. photo-curable. In contrast to external emulsifying waterborne systems using surfactants, the radiation curable compositions of the present invention provide a system that is sufficiently cross-linkable. Furthermore, the radiation curable compositions of the present invention reduce or eliminate the use of said monomers, thus reducing or eliminating said disadvantages.

The present invention discloses a novel waterborne radiation curable composition, such as an emulsion, dispersion or solution, comprising an amphiphilic dendritic polymer, which is optionally and preferably radiation curable, as non-amphiphilic radiation curable oligomer and/or polymer, such as unsaturated polyesters or polyethers typically used in conventional non-aqueous based systems, said polyesters or polyethers being acrylates, methacrylates or beta-methacrylates, the acrylic, methacrylic or beta-methacrylic acid modified maleate polyester, the epoxy acrylate, methacrylate or beta-methacrylate, the glycidyl ester of acrylic acid, methacrylic acid or beta-methacrylic acid, and a dispersant for the urethane acrylate, methacrylate or beta-methacrylate.

The waterborne composition of the present invention comprises at least one amphiphilic dendritic polymer, at least one non-amphiphilic radiation curable oligomer or polymer, water, and optionally at least one initiator initiating and/or promoting radiation curing, such as UV, IR or EB curing. The waterborne composition may optionally comprise at least one additional oligomer, polymer and/or monomer and/or at least one additional component, such as a pigment, filler, diluent, e.g. a reactive diluent, coalescent and/or additive, e.g. a neutralising, flow and/or levelling additive.

Amphiphilic dendritic polymers are nonionic and self-emulsifying polymers and are made of a dendritic core polymer of terminal hydroxyl groups, which is chain extended by a combination of a hydrophobic chain containing a carboxylic acid and a hydrophilic polyethylene glycol chain. In the composition of the invention, the amphiphilic dendritic polymer serves as a dispersing resin and stabilizer for emulsifying unsaturated polyesters or polyethers, polyester and polyether acrylates, acrylic modified maleates and polyesters, epoxy acrylates, glycidyl acrylates and/or urethane acrylates, such as typically used in non-aqueous based systems. The unsaturated polyesters, the polyester and polyether acrylates and the acrylic modified maleates and polyesters include dendritic species thereof. Here and in the following disclosure, acrylates are to be understood as described above, and acrylates and acrylic acids then include acrylates, methacrylates, beta-methacrylates (crotonates, isocrotonates), acrylic acid, methacrylic acid, and beta-methacrylates (crotonic acid, isocrotonic acid).

An amphiphilic dendritic polymer is made from a polyhydric dendritic core polymer having at least 4 terminal hydroxyl groups and thus a hydroxyl functionality (f) of at least 4, such as 8, 16, 32 or 64, and at least one monocarboxylic acid bonded to at least one and at most f-1 of said terminal hydroxyl groups, and also at least one adduct obtainable by addition of monoalkylated polyethylene glycol to a dicarboxylic acid or the corresponding anhydride bonded to at least one and at most f-1 of said terminal hydroxyl groups.

In various embodiments the dendritic core polymer in said amphiphilic dendritic polymer is a polyhydric dendritic polymer as disclosed in e.g. WO93/17060, WO93/18079, WO96/07688, WO96/12754, WO99/00439, WO99/00440, WO00/56802 and WO 02/40572. In these embodiments, the polyhydric dendritic core polymer is most preferably obtained by addition of at least one di, tri or polyhydric monocarboxylic acid to a di, tri or polyhydric core molecule in a molar ratio resulting in a polyhydric dendritic polymer comprising a core molecule and at least one branching generation bonded to the di, tri or polyhydric core molecule, or by ring opening addition of an alkylene oxide of at least one di, tri or polyhydric compound to a di, tri or polyhydric core molecule in a molar ratio resulting in a polyhydric dendritic polymer comprising a core molecule and at least one branching generation bonded to the di, tri or polyhydric core molecule.

Most preferably, the di-, tri-or polyhydroxy core molecule is a 1, omega-diol, 5-hydroxy-1, 3-dioxane, 5-hydroxyalkyl-1, 3-dioxane, 5-alkyl-5-hydroxyalkyl-1, 3-dioxane, 5-di (hydroxyalkyl) -1, 3-dioxane, 2-alkyl-1, 3-propanediol, 2-dialkyl-1, 3-propanediol, 2-hydroxy-2-alkyl-1, 3-propanediol, 2-hydroxyalkyl-2-alkyl-1, 3-propanediol, 2-di (hydroxyalkyl) -1, 3-propanediol, a dimer, trimer or polymer of said di-, tri-or polyhydric alcohol, or a reaction product of at least one alkylene oxide with said di-, tri-or polyhydric alcohol or said dimer, trimer or polymer.

The di, tri or poly hydroxy monocarboxylic acid is most preferably 2, 2-dimethylolpropionic acid, α, α -bis (hydroxymethyl) butyric acid, α, α, α -tris (hydroxymethyl) acetic acid, α, α -bis (hydroxymethyl) valeric acid, α, α -bis (hydroxymethyl) propionic acid, α, β -dihydroxypropionic acid and/or 3, 5-dihydroxybenzoic acid.

The alkylene oxide is most preferably a 3-alkyl-3- (hydroxyalkyl) alkylene oxide, a 3, 3-di (hydroxyalkyl) alkylene oxide, a 3-alkyl-3- (hydroxyalkoxy) alkylene oxide, a 3-alkyl-3- (hydroxyalkoxyalkyl) alkylene oxide, or a dimer, trimer or polymer of a 3-alkyl-3- (hydroxyalkyl) alkylene oxide, a 3, 3-di (hydroxyalkyl) alkylene oxide, a 3-alkyl-3- (hydroxyalkoxy) alkylene oxide, a 3-alkyl-3- (hydroxyalkoxyalkyl) alkylene oxide.

In embodiments of the amphiphilic dendritic polymer, said monocarboxylic acid added to said polyhydric dendritic core polymer by reaction is most preferably an aliphatic linear or branched unsaturated or saturated carboxylic acid having e.g. 8-24, e.g. 8-12 carbon atoms in its main carbon chain, such as lauric acid, tall oil fatty acid, soybean oil fatty acid, safflower fatty acid, sunflower fatty acid, cottonseed oil fatty acid, castor oil fatty acid, oleic acid, linoleic acid, linolenic acid, stearic acid and/or isostearic acid.

Among the unsaturated acids, further embodiments of said monocarboxylic acids found to provide, for example, radiation curable sites are, for example, vinyl and/or allyl functional carboxylic acids. Suitable vinyl and/or allyl functional carboxylic acids are exemplified by acrylic acid, methacrylic acid, beta-methacrylic acid (crotonic/isocrotonic acid) and allyloxycarboxylic acids. The vinyl and/or allyl functional carboxylic acid is preferably used in combination with one or more of the monocarboxylic acids having the 8 to 24 carbon atoms described previously.

The adduct added by reaction to the polyhydric dendritic polymer is preferably and advantageously made from at least one monoalkylated polyethylene glycol having a molecular weight of at least 500, such as 500-. The monoalkylated polyethylene glycol is most preferably a monomethylated polyethylene glycol.

In the waterborne composition according to the present invention, the preferred weight ratio of amphiphilic dendritic polymer to non-amphiphilic radiation curable oligomer or polymer is in the range of 1: 99 to 99: 1, such as 50: 50, 10: 90, 20: 80, 70: 30, 90: 10, 80: 20 or 70: 30. The most preferred weight ratio is typically 20-30 wt% of the amphiphilic dendritic polymer and 70-80 wt% of the non-amphiphilic oligomer or polymer.

In embodiments, the at least one initiator optionally included in the waterborne composition of the present invention is preferably a photoinitiator initiating and/or promoting uv curing, and is preferably mixed in an amount of, for example, 0.1 to 5% by weight, preferably 1 to 5% by weight, calculated on the solid polymer, oligomer, monomer and other included film forming components. Thus, in the most preferred embodiment of the present invention, the radiation curable waterborne composition of the present invention is a UV curable composition.

In a further aspect the present invention relates to the use of the amphiphilic dendritic polymer disclosed herein as a water dispersing resin for non-amphiphilic radiation curable oligomers and polymers, such as said unsaturated polyester or polyether, said polyester or polyether acrylate, methacrylate or-methacrylate, said acrylic, methacrylic or beta-methacrylic acid modified maleate polyester, said epoxy acrylate, methacrylate or beta-methacrylate, said glycidyl ester of acrylic, methacrylic or beta-methacrylate and said urethane acrylate, methacrylate or-methacrylate, and as a component in waterborne curable coatings and ink compositions, such as uv curable printing inks and industrial coatings.

In a still further aspect, the present invention relates to the use of the radiation curable compositions disclosed herein in waterborne radiation curable coatings and inks, such as uv curable printing inks and industrial coatings.

Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize 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. The following examples 1-6 illustrate the preparation of the components included in the present invention, embodiments of the resin composition of the present invention, and the evaluation of the embodiments in a UV curable coating. Table 1 lists the results according to the evaluation.

Example 1: synthesis of the polyalkoxylated adduct used in example 3.

Example 2: synthesis of fatty acid modified dendritic polyester used in example 3.

Example 3: synthesis of an amphiphilic dendritic adduct made from the fatty acid modified dendritic polyester obtained in example 2 and the polyalkoxylated adduct obtained in example 1, according to an embodiment of the present invention.

Example 4: synthesis of amphiphilic dendritic polymer containing acrylate group.

Example 5: synthesis of non-amphiphilic acrylate dendritic polyesters.

Example 6: preparation of a water-based UV-curable polyester composition containing the product obtained in example 3, according to an embodiment of the present invention.

Example 7: preparation of a water-based UV-curable polyurethane composition containing the product obtained in example 3, according to an embodiment of the present invention.

Example 8: preparation of water-based UV-curable polyester compositions containing the products obtained in examples 4 and 5.

Example 9: the compositions obtained in examples 6, 7 and 8 were evaluated in UV-curable coatings

Example 1

450g of monomethylated polyethylene glycol (molecular weight 750g/mol) and 58.8g of maleic anhydride were introduced into a 1 l reaction flask equipped with stirrer and nitrogen inlet and heated to 120 ℃ under nitrogen purge. At said temperature, the reaction is allowed to continue until all the maleic anhydride has reacted.

Example 2

A1 liter reaction flask equipped with a stirrer and a Dean Stark trap was charged with 246g Boltorn ® H20 (a hydroxyl-functional dendritic polyester with a molecular weight of 1750g/mol and a hydroxyl number of 495mg KOH/g, Perstorp Specialty Chemicals AB) and 440g sunflower fatty acid and heated to 125 ℃. 0.68g of benzoic acid, 0.07g of Fascat ® 4100 (esterification catalyst) and xylene are now added and the temperature is raised to 190 ℃ and held for about 5 hours. After said 5 hours the acid number was 2.5mg KOH/g and the xylene was removed under vacuum. The reaction was terminated by cooling to room temperature. The resulting product had a hydroxyl number of 62mg KOH/g.

Example 3

Into a 2 l reaction flask equipped with stirrer, thermometer, condenser and Dean Stark trap were introduced 450g of the dendritic product obtained in example 2, 249.9g of the adduct obtained in example 1, 59g of xylene (azeotropic solvent) and 0.7g of Fascat^®4100 (esterification catalyst, Elf Autochem). The reaction mixture was heated to 240 ℃ and the reaction was allowed to continue at said temperature until an acid value of less than 10mg KOH/g was obtained.

Example 4

In a device equipped with a stirrer and a Dean Stark trapA500 ml reaction flask was charged with 50g of Boltorn^®H20 (hydroxy-functional dendritic polyester with a molecular weight of 1750g/mol and a hydroxyl number of 495mg KOH/g, Perstorp Specialty Chemicals AB), 11.5g acrylic acid, 51g sunflower acid, 40g toluene, 0.8g methane sulfonic acid and 0.05g methoxyphenol and heated to 120 ℃ for reflux. The reaction was allowed to continue for 8 hours and the acid number was determined to be 10mg KOH/g. 70g of the adduct obtained in example 1 are now introduced into the reaction flask. The reaction was allowed to continue at the stated temperature until an acid number of less than 10mg KOH/g was reached. The reaction product was cooled to 60 ℃ and the toluene was removed by vacuum.

Example 5

100g of Boliorn was introduced into a 500ml reaction flask equipped with a stirrer and a Dean Stark trap^®H2003 (fatty acid modified hydroxy functional polyester, Perstorp specialty Chemicals AB), 41g acrylic acid, 1.6g methanesulfonic acid, 0.08g methoxyphenol, and 100g toluene, and heated to 120 ℃ for reflux. The reaction was allowed to continue for 8 hours, then the reaction mixture was cooled to room temperature. The reaction mixture was neutralized with an aqueous solution of KOH (4%). The organic phase was further washed twice with water and the toluene was evaporated under vacuum.

Example 6

20g of the amphiphilic dendritic polymer obtained in example 3 and 80g of the polyester acrylate oligomer (Ebecryl) were introduced and mixed in a round bottom flask^®EB 657, UCB). The mixture was neutralized to ph7.5 using dimethylethanolamine and heated to 70 ℃ with stirring. 100g of water was added slowly and continuously over a period of 15 minutes and mixed. The final emulsion had a solids content of 50% and a viscosity of 80mpa.s at 25 ℃. The emulsion is stable for at least 1 month at room temperature.

Example 7

20g of the amphiphilic dendritic polymer obtained in example 3 and 80g of the urethane acrylate oligomer (Ebecryl) were introduced and mixed in a round bottom flask^®EB 5129, UCB). And the mixture was heated to 70 ℃ with stirring. 100g of water were slowly and continuously added over a period of 15 minutes and mixed. The final emulsion had a solids content of 50% and a viscosity of 220mpa.s at 25 ℃. The emulsion is stable for at least 1 month at room temperature.

Example 8

10g of the amphiphilic dendritic polymer obtained in example 4 and 90g of the dendritic acrylate polymer obtained in example 5 were introduced and mixed in a round bottom flask. The mixture was neutralized to pH7 using dimethylethanolamine and heated to 70 ℃ with stirring. 100g of hot water was slowly and continuously added over a period of 15 minutes. The final emulsion had a solids content of 50% and a viscosity of 150mpa.s at 25 ℃.

Example 9

3% by weight, calculated on the solid polymer and oligomer, of a photoinitiator (Darocure) are added and mixed in the emulsions obtained in examples 6, 7 and 8^®1173, Ciba specialty chemicals). The film was applied to a glass plate (wet film thickness: 60 μm) and the water was flashed off in an oven at 70 ℃ for 10 minutes. The coating was cured in air by 5 passes under a UV bulb of 80W/cm at a speed of 20m/min and characterized by MEK-number of wipes (methyl ethyl ketone wipe), pendulum hardness according to ASTM D4366-95 (K ö nig pendulum), and Erichsen deflection according to ASTM E-643. The results are given in table 1 below.

TABLE 1

	Number of MEK rubs	Pendulum hardness K ö nig second	Erichsen deflection mm
				Coating of example 6	25	46	＞8
Coating of example 7	＞200	155	5.2
				Coating of example 8	＞200	135	4.4

Claims (20)

1. A radiation curable waterborne composition comprising at least one amphiphilic dendritic polymer, at least one non-amphiphilic radiation curable oligomer or polymer, and water, and optionally at least one initiator initiating and/or promoting radiation, such as UV, IR or EB curing, and optionally at least one additional oligomer, polymer and/or monomer, and/or optionally at least one additional component, such as a pigment, a filler, a diluent, such as a reactive diluent, and/or an additive, such as a neutralizing, flow and/or leveling additive,

characterised in that said at least one amphiphilic dendritic polymer is made of a polyhydric dendritic core polymer having at least 4 terminal hydroxyl groups and thus a hydroxyl functionality (f) of at least 4, such as 8, 16 or 32, and at least one monocarboxylic acid bonded to at least one and at most f-1 of said terminal hydroxyl groups, and at least one adduct obtainable by addition of at least one monoalkylated polyethylene glycol to at least one dicarboxylic acid or to at least one corresponding anhydride bonded to at least one and at most f-1 of said terminal hydroxyl groups; and the at least one non-amphiphilic radiation curable oligomer or polymer is at least one unsaturated polyester or polyether, at least one polyester or polyether acrylate, methacrylate or beta-methacrylate, at least one acrylic, methacrylic or beta-methacrylic modified fumarate or polyester, at least one urethane acrylate, methacrylate or beta-methacrylate, at least one epoxy acrylate, methacrylate or beta-methacrylate, and/or at least one glycidyl ester of acrylic, methacrylic or beta-methacrylic acid.

2. A radiation curable waterborne composition according to claim 1, wherein said amphiphilic dendritic polymer is radiation curable.

3. A radiation curable waterbome composition according to claim 1 or 2 c h a r a c t e r i z e d i n that said polyhydric dendritic core polymer is obtainable by addition of at least one di, tri or polyhydric monocarboxylic acid to a di, tri or polyhydric core molecule in a molar ratio resulting in a polyhydric dendritic polymer comprising a core molecule and at least one branching generation bonded to said di, tri or polyhydric core molecule.

4. A radiation curable waterbome composition according to claim 1 or 2 characterised in, that said polyhydric dendritic core polymer is obtainable by ring opening addition of alkylene oxide of at least one di, tri or polyhydric compound onto a di, tri or polyhydric core molecule in a molar ratio yielding a polyhydric dendritic polymer comprising a core molecule and at least one branching generation bonded to said di, tri or polyhydric core molecule.

5. A radiation curable waterborne composition according to any of the claims 1-4, wherein said at least one monoalkylated polyethylene glycol has a molecular weight of at least 500, such as 500-.

6. A radiation curable waterbome composition according to any of the claims 1-5 characterised in, that said at least one monoalkylated polyethylene glycol is a monomethylated polyethylene glycol.

7. A radiation curable waterbome composition according to any of the claims 1-6 characterised in, that said at least one dicarboxylic acid or anhydride is fumaric acid, maleic anhydride, succinic anhydride and/or glutaric acid.

8. A radiation curable waterbome composition according to any of the claims 1-7 characterised in, that said at least one carboxylic acid is an aliphatic linear or branched saturated or unsaturated carboxylic acid having 8-24 carbon atoms in its main carbon chain.

9. A radiation curable waterborne composition according to claim 8, wherein said at least one carboxylic acid is lauric acid, tall oil fatty acid, soya bean fatty acid, safflower fatty acid, sunflower fatty acid, cottonseed fatty acid, castor fatty acid, oleic acid, linoleic acid, linolenic acid, stearic acid and/or isostearic acid.

10. A radiation curable waterbome composition according to claim 8 or 9 characterised in, that said at least one monocarboxylic acid is a vinyl and/or allyl functional carboxylic acid.

11. A radiation curable waterbome composition according to claim 10 characterised in, that said at least one monocarboxylic acid is acrylic acid, methacrylic acid and/or β -methacrylic acid.

12. A radiation curable waterbome composition according to any of the claims 1-11 characterised in, that the weight ratio of said amphiphilic dendritic polymer to said non-amphiphilic radiation curable oligomer or polymer is between 1: 99 and 99: 1, such as 50: 50, 10: 90, 20: 80, 70: 30, 90: 10, 80: 20 or 70: 30.

13. A radiation curable waterbome composition according to any of the claims 1-12 characterised in, that said at least one unsaturated polyester or polyether, said polyester or polyether acrylate, methacrylate or β -methacrylate, said acrylic, methacrylic or β -methacrylic modified fumarate or polyester is a dendritic species thereof.

14. A radiation curable waterbome composition according to any of the claims 1-13 characterised in, that said at least one initiator is at least one photoinitiator.

15. A radiation curable waterbome composition according to any of the claims 1-14 characterised in, that said optional at least one initiator is a photoinitiator present in an amount of 0.1-5%, preferably 1-5% by weight calculated on the weight of the included or optional solid polymers, oligomers and monomers in said resin composition.

16. A radiation curable waterbome composition according to any of the claims 1-15 characterised in, that said resin composition is a uv curable resin composition.

17. Use of an amphiphilic dendritic polymer according to any of the claims 1-11 as water dispersing resin for a non-amphiphilic radiation curable oligomer or polymer.

18. Use according to claim 17, wherein the non-amphiphilic radiation curable oligomer or polymer is an unsaturated polyester or polyether, a polyester or polyether acrylate, methacrylate or β -methacrylate, an acrylic, methacrylic or β -methacrylic modified fumarate, a urethane acrylate, methacrylate or β -methacrylate, an epoxy acrylate, methacrylate or β -methacrylate, and/or a glycidyl ester of acrylic, methacrylic or β -methacrylic acid.

19. Use of an amphiphilic dendritic polymer according to any of the claims 1-11 in a radiation curable coating or ink composition, such as a UV curable industrial coating or a UV curable printing ink.

20. Use of a waterborne radiation curable composition according to any of claims 1-16 in a waterborne radiation curable coating or ink composition, such as a uv curable industrial coating or a uv curable printing ink.