COATED FILMS WITH PARTICULARLY HIGH RESISTANCE TO HYDROLYSIS, AND MOLDINGS MADE OF SAME

Abstract

The present invention concerns coated films, comprising a plastic film and a radiation-curable aqueous coating material, wherein the coating material comprises a polyurethane (meth)acrylate with particularly high hydrolysis resistance. Furthermore, it concerns a method for producing such films, the use of such films for producing mouldings, a method for producing mouldings with a radiation-cured coating and mouldings that can be produced by this method and the aqueous radiation-curable binding and coating material, which are contained in the coating.

Claims

1.-15. (canceled)

16. A coated film, comprising a plastic film and a radiation-curable aqueous coating material, wherein the coating material comprises a) a polyurethane (meth)acrylate which is obtained from the reaction of a reaction mixture comprising: A) one or more polyepoxy (meth)acrylates with an OH number of 20 to 300 mg of KOH/g of substance, B) different compounds from A) with at least one group reactive to isocyanate and at least one radiation-curable double bond, C) one or more linear aliphatic polycarbonate polyols with a hydroxyl value of 25 to 250 mg KOH/g of substance, D) optionally, one or more compounds having at least two groups reactive to isocyanate and a molecular weight of less than 300 g/mol, E) one or more compounds with at least one group reactive to isocyanate and additionally at least one group with hydrophilic action, F) dicyclohexylmethane 4,4-diisocyanate, G) optionally, different compounds from A) to F) with at least one amino function, H) optionally, reactive diluents, and b) inorganic nanoparticles with a mean particle size from 1 nm to 200 nm.

17. The coated film according to claim 16, wherein the coating material furthermore comprises the following a) 8.0-65.0% of w/w polyurethane (meth)acrylate, b) 5.0 to 50.0% w/w of inorganic nanoparticles, c) 0 to 57.0% w/w of polyurethane (meth)acrylate, different from a), d) 0 to 30.0% w/w of other binders or reactive diluents, e) 0.1 to 5.0% w/w of photoinitiators, f) 0 to 15% w/w of auxiliary and additional substances, g) 0 to 10% w/w of cross-linking agents, wherein the quantity data refer to dried film and the sum of the individual components does not exceed 100.

18. The coated film according to claim 17, wherein c) is contained in a quantity of 10.0 to 57.0% w/w.

19. The coated film according to claim 16, wherein the plastic for the plastic film is selected from the group consisting of thermoplastic polyurethane, polymethyl methacrylate (PMMA), modified variants of PMMA, polycarbonate (PC), copolycarbonate, acrylonitrile styrene acryl ester-copolymerisates (ASA), acrylonitrile butadiene-styrene copolymerisates (ABS) and polybutylene/terephthalate/polycarbonate.

20. The coated film according to claim 16, wherein in the polyurethane (meth)acrylate a) A) is a reaction product from acrylic acid and/or methacrylic acid with aromatic or aliphatic glycidyl ethers, and C) is obtained by transesterification of diphenyl carbonate, dimethylcarbonate or diethyl carbonate with linear, aliphatic diols, selected from the group consisting of 1,4-butane diol, 1,5-pentane diol, and 1,6-hexane diol.

21. The coated film according to claim 16, wherein the surface of the nanoparticles in the coating is modified by covalent and/or non-covalent linking of other compounds.

22. The coated film according to claim 16, wherein the nanoparticles are selected from the group consisting of particles of silicon oxide, aluminium oxide, ceroxid, zirconium oxide, niobium oxide and titanium oxide and have a mean particle size from 3 nm to 50 nm.

23. A method for producing the coated film according to claim 16, comprising: 1) preparing an aqueous radiation-curable coating material, wherein the aqueous radiation-curable coating material comprises at least one polyurethane (meth)acrylate a), obtained from the reaction of a reaction mixture comprising: A) one or more polyepoxy (meth)acrylates with a hydroxyl value of 20 to 300 mg KOH/g of substance, B) optionally, different compounds from A) with at least one group reactive to isocyanate and at least one radiation-curable double bond, C) one or more linear aliphatic polycarbonate polyols with a hydroxyl value of 25 to 250 mg KOH/g of substance, D) optionally, one or more compounds having at least two groups reactive to isocyanate and a molecular weight of less than 300 g/mol, E) one or more compounds with at least one group reactive to isocyanate and additionally at least one group with hydrophilic action, F) dicyclohexylmethane 4,4-diisocyanate and G) optionally, different compounds from A) to F) with at least one amino function, H) optionally, reactive diluents, and wherein the aqueous coating material furthermore comprises inorganic nanoparticles b) with a mean particle size from 1 nm to 200 nm; 2) coating at least a side of a plastic film with the aqueous coating material from step 1; 3) drying the coated film.

24. The method according to claim 23, wherein the aqueous coating material from step 1 is a 20-60% dispersion in water and, optionally, solvents, and wherein the following components, relative to the solid bodies, comprise: a) 8.0-65.0% w/w of polyurethane (meth)acrylate, b) 5.0 to 50.0% w/w of inorganic nanoparticle, c) 0 to 57% w/w of polyurethane(meth)acrylate, different from a), d) 0 to 30% w/w of other binders or reactive diluents, e) 0.1 to 5.0% w/w of photoinitiators, f) 0 to 15.0% w/w of auxiliary and additional substances, g) 0 to 10% w/w of cross-linking agents, wherein the sum of the individual components does not exceed 100.

25. A method for producing moldings comprising utilizing the coated film according to claim 16.

26. A method for producing a moulding, comprising: 1) preparing the coated film according to claim 16, 2) optionally printing, such as by screen printing, on the side of the film opposite the coating, 3) forming the moulding by thermoforming or high pressure forming, 4) curing the radiation-curable coating by actinic radiation.

27. The method according to claim 26, further comprising: 5) applying a polymer to the side of the film opposite the cured layer.

28. A moulding produced by the method according to claim 26.

29. An aqueous binder, obtained from the reaction of a reaction mixture comprising: A) one or more polyepoxy (meth)acrylates with a hydroxyl value of 20 to 300 mg KOH/g of substance, B) optionally, different compounds from A) with at least one group reactive to isocyanate and at least one radiation-curable double bond, C) one or more linear aliphatic polycarbonate polyols with a hydroxyl value of 25 to 250 mg KOH/g of substance, D) optionally, one or more compounds having at least two groups reactive to isocyanate and a molecular weight of less than 300 g/mol, E) one or more compounds with at least one group reactive to isocyanate and additionally at least one group with hydrophilic action, F) dicyclohexylmethane 4,4-diisocyanate and G) optionally, different compounds from A) to F) with at least one amino function, and H) optionally, reactive diluents.

30. A coating material, comprising a) the aqueous binder according to claim 29, b) inorganic nanoparticles with a mean particle size from 1 nm to 200 nm, c) optionally, polyurethane (meth)acrylate, different from a) d) optionally, other binders or reactive diluents, e) photoinitiators, f) optionally, auxiliary and additional substances, g) optionally, cross-linking agents, wherein the coating material is present as a 20 to 60-% dispersion in water and, optionally, solvent.

Description

EXAMPLES

[0315] The nco content was monitored in each case by titrimetric analysis according to DIN 53185.

[0316] The hydroxyl value was determined according to DIN 53240: titration with 0.1 mol/l meth. KOH solution after cold acetylisation with acetic acid anhydride with dimethylaminopyridine as a catalyst.

[0317] The solids content of the polyurethane dispersion was determined gravimetrically after evaporating off all non-volatile constituent parts according to DIN 53216.

[0318] The mean particle size was determined by laser correlation spectroscopy.

[0319] The outflow time was determined according to DIN 53211 using the 4 mm DIN beaker.

[0320] Room temperature was 23 C.

[0321] Unless otherwise indicated, the percentage data in the examples are expressed as % w/w.

[0322] The following commercial products were used in the examples: [0323] BYK 346: solution of a polyether-modified siloxane (Byk.Chemie) [0324] BYK 333: solution of a polyether-modified siloxane (Byk.Chemie) [0325] Esacure One: photoinitiators (Lamberti) [0326] Tinuvin 400 DW: light stabilisers (BASF SE) [0327] Bindzil CC401: nanoparticles (Hedinger GmbH & Co. KG) [0328] Borchi Gel 0625: non-ionic thickeners based on polyurethanes for aqueous coating material (OMG Borchers GmbH) [0329] Borchi Kat 24: highly reactive, tin-free catalyst based on metal carboxylate (OMG Borchers GmbH) [0330] Ebecryla 600: bisphenol-a-diglycidyl diacrylate (epoxy acrylate by Alinex Belgium SA with a hydroxyl value of 250 to 260 mg KOH/g determined according to DIN53240) [0331] Photomer 4399: dipentaerythriol pentaacrylate (BASF SE) [0332] Desmophen C 2200: linear hydroxyl-terminated aplihatic polycarbonate diol with a mean molecular weight of approx. 2000 g/mol (Covestro Deutschland AG) [0333] Desmophen C 2100: linear hydroxyl-terminated aplihatic polycarbonate diol with a mean molecular weight of approx. 1000 g/mol (Covestro Deutschland AG) [0334] Desmopheno PEI70HN: linear hydroxyl-terminated aplihatic polyester diol with a mean molecular weight of approx. 1700 g/mol (Covestro Deutschland AG) [0335] Laromer PE44F: polyester acrylate (BASF SE) [0336] Desmodura W: dicyclohexylmethane 4,4-diisocyanate (Covestro Deutschland AG) [0337] Desmodura I: isophorone diisocyanate (Covestro Deutschland AG) [0338] Desmodur H: hexamethylene diisocyanate (Covestro Deutschland AG) [0339] Miramer M600: reactive diluents (Miwon Speciality Chemical Co. Ltd.) [0340] Bayhydrol XP2648: aliphatic, polycarbonate-containing anionic polyurethane dispersion, free of solvents (Covestro Deutschland AG)

[0341] Production of the Aqueous Radiation-Curable Polyurethane (Meth)Acrylates

[0342] PUR Dispersion 1: Production of a Radiation-Curable, Aqueous Polyurethane (Meth)Acrylate a)

[0343] 220.28 g of Ebecryl 600 (component A), 550.70 g of DesmophenC 2200, (component C), 29.54 g of dimethylol propionic acid (component E), 293.81 g of Desmodur W, (component F), 0.32 g of BorchiKat 24 and 0.06 g of dibutyl phosphate were dissolved in 857 g of acetone and reacted to an nco content of 1.18% w/w at 60 C. while stirring. Then, 7.09 g parts of ethylene diamine in 31.5 g of acetone were added to the dispersion while stirring. The neutralisation was then carried out while stirring in 20.06 g of triethylamine. The clear solution was introduced into 1589.2 g of de-ionised water while stirring. Finally the acetone was evaporated out of the dispersion under a low vacuum. A radiation-curable, aqueous polyurethane dispersion with a solids content of 43.1% w/w, an outflow time of 18 sec, a mean particle size of 84 nm and a pH value of 7.9 was obtained.

[0344] PUR Dispersion 2: Production of a Radiation-Curable, Aqueous Polyurethane (Meth)Acrylate a)

[0345] 208.8 g of Ebecryl 600 (component A), 522.1 g of Desmophene 2200, (component C), 28.08 g dimethylol propionic acid (component E), 278.6 g of Desmodur W, (component F), 0.30 g of BorchiKat 24 and 0.06 g of dibutyl phosphate were dissolved in 813 g of acetone and reacted to an nco content of 1.07% w/w at 60 C. while stirring. Then, 6.72 g parts of ethylene diamine in 29.8 g of acetone were added to the dispersion while stirring. Then, 186.82 g of Miramer M600 (component H) was added and the neutralisation was then carried out while stirring in 19.08 g of triethylamine. The clear solution was introduced into 1506.7 g of de-ionised water while stirring. Finally the acetone was evaporated out of the dispersion under a low vacuum. A radiation-curable, aqueous polyurethane dispersion with a solids content of 48.1% w/w, an outflow time of 16 sec, a mean particle size of 136 nm and a pH value of 7.9 was obtained.

[0346] PUR Dispersion 3: Production of a Radiation-Curable, Aqueous Polyurethane (Meth)Acrylate a) (not According to the Invention)

[0347] 95.56 g of Ebecryl 600 (component A), 238.90 g of DesmophenC 2200, (component C), 12.81 g dimethylol propionic acid (component E), 107.59 g, of isophorone diisocyanate, (component F), 0.14 g of BorchiKat 24 and 0.03 g of dibutyl phosphate were dissolved in 365 g of acetone and reacted to an nco content of 1.30% w/w at 60 C. while stirring. Then, 3.08 g of ethylene diamine in 13.65 g of acetone were added to the dispersion while stirring. Then, 85.48 g of Miramer M600 (component H) was added and the neutralisation was then carried out while stirring in 19.08 g of triethylamine. The clear solution was introduced into 668.91 g of de-ionised water while stirring. Finally the acetone was evaporated out of the dispersion under a low vacuum. A radiation-curable, aqueous polyurethane dispersion with a solids content of 44.8% w/w, an outflow time of 44 sec, a mean particle size of 246 nm and a pH value of 8.7 was obtained.

[0348] PUR Dispersion 4: Production of a Radiation-Curable, Aqueous Polyurethane (Meth)Acrylate a) (not According to the Invention)

[0349] 223.3 g of Laromer PE44F (component B), 173.7 g of Desmophen C 2200 (component C), 14.75 g of dimethylol propionic acid (component E), 108.18 g of Desmodur W (component F), 0.12 g of Borchi Kat 24 and 0.02 g of dibutyl phosphate were dissolved in 387.4 g of acetone and reacted to an nco content of 0.7% w/w at 60 C. while stirring. Then, at 45 C., chain extension took place while stirring in 2.78 g of ethylene diamine (dissolved in 11.6 g of acetone), and 72.58 g of Miramer M600 (component H) were added, followed by neutralisation while stirring in 10.0 g of triethylamine. 695 g of de-ionised water were introduced into the clear solution. Finally the acetone was evaporated out of the dispersion under a low vacuum. A radiation-curable, aqueous polyurethane dispersion with a solids content of 44.6% w/w, an outflow time of 14 sec, a mean particle size of 267 nm and a pH value of 8.4 was obtained.

[0350] PUR Dispersion 5: Production of a Radiation-Curable, Aqueous Polyurethane (Meth)Acrylate a) (not According to the Invention, According to EP-A 1489120)

[0351] 20.85 g of a polyester acrylate with a hydroxyl value of 160 mgKOH/g (produced from 1 mol of adipinic acid, 0.72 mol of trimethylol propane, 1.9 mol of 1.6-hexane diol and 2 mol of acrylic acid), 220.6 g of Desmophen C 2200 (component C), 70.5 g of a difunctional polypropylene glycol with a hydroxyl value of 56.0 mg KOH/g, 12.21 g of a monofunctional polyalkylene oxide with a molecular weight (Mn) of 2250 g/mol (produced from diethylene glycolmonobutyl ether, propylene oxide and ethylene oxide (in a weight relationship of ethylene oxide to propylene oxide of approx. 5.4:1) (component E), 54.7 g of Desmodur H (component F), 0.13 g of dibutyl tin dilaurate were dissolved in 633 g of acetone and reacted to an nco content of 1.86% w/w at 60 C. while stirring. Then, at a temperature of 45 C., chain extension took place by adding a solution of 20.23 g of the sodium salt of the 2-aminoethyl-2-aminoethanesulfonic acid (as a 45% solution in water), 1.82 g of ethylene diamine and 0.9 g of hydrazine monohydrate in 89.5 g water. Then a further 475.6 g of water were added and the acetone was evaporated out of the dispersion under a low vacuum. A radiation-curable, aqueous polyurethane dispersion with a solids content of 42.6% w/w, an outflow time of 93 sec, a mean particle size of 134 nm and a pH value of 7.8 was obtained.

[0352] PUR Dispersion 6: Production of a Radiation-Curable, Aqueous Polyurethane (Meth)Acrylate a) (not According to the Invention; According to Example 3 in WO2006/101433)

[0353] 29.9 g of hydroxyethylacrylate, component B), 224.9 g of Desmophen C 2100 (component C), 17.3 g of trimethylolpropane (component D), 25.9 g of dimethylol propionic acid (component E), 199.7 g of Desmodur I (component F), 0.30 g of dibutlyl tin dilaurate and 25.4 g of n-methylpyrrolidone were reacted to an nco content of 2.4% w/w at 65 C. while stirring. Then cooled to 40 C., and neutralisation was carried out by adding and stirring in 17.6 g of triethylamine. 1034.7 g of de-ionised water were introduced to the clear solution while stirring. Then, 17.3 g part of ethylene diamine were added to the dispersion while stirring. A radiation-curable, aqueous polyurethane dispersion with a solids content of 35.7% w/w, an outflow time of 13 sec, a mean particle size of 69 nm and a pH value of 8.8 was obtained.

[0354] PUR Dispersion 7:

[0355] Commercially obtainable Bayhydrol XP2648

[0356] PUR Dispersion 8: Production of a Radiation-Curable Polyurethane (Meth)Acrylate c):

[0357] In a reaction vessel with a stirrer, internal thermometer and gas line (air flow 1 l/hr), 471.9 parts of the polyester acrylate Laromer PE 44 F (component B-1), 8.22 parts of trimethylolpropane (component D), 27.3 parts of dimethylol propionic acid (component E-1), 199.7 parts of Desmodur W (component F-1), and 0.6 parts of dibutlyl tin dilaurate were dissolved in 220 parts of acetone and reacted to an nco content of 1.47% w/w at 60 C. while stirring. 115.0 parts of the Photomer 4399 (component H-1) were added to the prepolymer solution thus obtained and stirred in.

[0358] It was then cooled to 40 C. and 19.53 g of triethylamine were added. After stirring for 5 minutes at 40 C., the reaction mixture was poured into 1200 g of water at 20 C. while stirring rapidly. Next, 9.32 g of ethylene diamine (component G-1) in 30.0 g water were added.

[0359] After 30 min of stirring again, without heating or cooling, the product was distilled in a vacuum (50 mbar, max. 50 C.), to achieve a solids content of 401% w/w. The dispersion had a pH value of 8.7 and a mean particle size of 130 nm. The outflow time was 18 sec.

[0360] PUR Dispersion 9: Production of a Radiation-Curable, Aqueous Polyurethane (Meth)Acrylate a) (not According to the Invention)

[0361] 112.08 of Ebecryl 600 (component A), 238.08 g of Desmophen PE170HN (non-inventive substitute for component C), 15.0 g of dimethylol propionic acid (component E), 149.4 g of Desmodur W, (component F) and 0.2 g of BorchiKat 24 were dissolved in 280 g of acetone and converted to an nco content of 1.2% w/w at 60 C. while stirring. Then, 3.6 g parts of ethylene diamine in 16.08 g of acetone were added to the dispersion while stirring. Next, neutralisation took place while stirring in 10.7 g triethylamine. The clear solution was introduced into 720.0 g of de-ionised water while stirring. Next, the acetone was evaporated out of the dispersion under a low vacuum. A radiation-curable, aqueous polyurethane dispersion with a solids content of 43.5% w/w, an outflow time of 21 sec, a mean particle size of 100 nm and a pH value of 8.5 was obtained.

[0362] Production of the Aqueous Radiation-Curable Coating Agent:

[0363] According to the quantity data in Table 1, the polymer dispersions 1-7 were produced while diacetone alcohol and 2-methoxypropanol were added. Esacure One was added while stirring and then was stirred at 23 C. into a complete solution of Esacure One. Then, the solution was filtered using a 5 m bag filter.

[0364] The PUR dispersions were added and stirred for 5 min at 500 rpm. While stirring rapidly (1000 rpm) the solution of the Esacure One produced previously was added within 5 min.

[0365] The additives Tinuvin 400 DW, Byk 333 and Byk 346 were added one after the other while stirring (500 rpm), with 5 minutes of stirring each time. The pH value was adjusted to pH 8.0 to 8.5 by adding while stirring (500 rpm). While continuing to stir (500 rpm), Bindzil CC 401 was added within 10 minutes and stirring continued for another 20 min. If the pH value dropped below 8 during this continued stirring, more n,n-dimethylethylamine was added to restore the pH to 8.0 to 8.5. Borchi Gel 0625 was dispersed in the solution with the dissolver while stirring rapidly (1000 rpm) and stirring continued for another 30 min at 1000 rpm. Finally, the dispersion was filtered through a 10 m beg filter.

[0366] Application the Polymer Dispersions on Plastic Films

[0367] The polymer dispersions 1-7 according to Table 1 were applied with a conventional scraper (nominal wet film thickness of 100 m) to one side of polycarbonate plastic films (Makrofol DE1-1, film thicknesses 250 m and 375 m, sheet size DIN A4). After a flash-off phase of 10 min at 20 C. to 25 C., the coated films were dried or pre-cross-linked for 10 min at 110 C. in a convection oven. At this stage in the process chain, the coated films thus produced could be handled.

[0368] UV Curing of the Coated Plastic Films

[0369] In order to be able to assess the properties of the coated films described above, the coating has to be UV cured. The UV curing of the coating was performed with a mercury vapour high pressure lamp of the evo 7 dr type (ssr engineering GmbH, Lippstadt, Germany). The installation is equipped with dicroitic reflectors and quartz plates and has a specific output of 160 W/cm. A UV dosage of 2.0 J/cm.sup.2 and an intensity of 1.4 W/cm.sup.3 was applied. The surface temperature was to reach >70 C.

[0370] The data for the UV dosage were evaluated with a Lightbug ILT 490 (International Light Technologies Inc., Peabody Mass., USA). The data for the surface temperature were evaluated with temperature test strips under the brand name RS (order number 285-936; RS components GmbH, Bad Hersfeld, Germany).

[0371] Testing the Hydrolysis Resistance

[0372] The hydrolysis resistance of the coated and cured films was tested in an environmental chamber. Inspired by Volkswagen AG's TL226, the films were stored standing upright in the vapour phase over a water reservoir. The temperature was maintained at a constant 90 C. and the relative atmospheric humidity at a constant 90%. The storage time varied across a wide range and is stated for the evaluated results in each case in the Tables. The minimum requirement is a lack of damage after 72 hours.

[0373] The evaluation of the films was conducted after removal from the environmental chamber immediately after wiping with a soft cloth. The visual appearance of the coating was evaluated. The surface of the coating should not have changed as far as possible.

[0374] The coating was tested for adhesion by cross cutting. To do this, a cutting device was used to cut a grid in the coating so that the cuts entered into the barrier layer in the base film. Six cuts were made, parallel to each other and 1 mm apart from each other. Next, another six cuts were made perpendicular to the first so that a square pattern of 25 squares was produced, each with sides 1 mm long. The cut surface was cleaned with a brush to remove dust from the cutting. A piece of duct tape (3M, Scotch) was stuck to the damaged coating surface and rubbed firmly on to the surface so that one end of the adhesive tape remained free for gripping by hand. Then, the adhesive tape was ripped, with sudden movement, from the surface by the free end and the quality of the cut edges in the upper squares was evaluated. Ideally, just straight cut edges would be found without any spalling (=GT0). In order to pass the test, no more than 5% of the coating surface should have been detached at the cut edges (=GT1). Scores greater than GT1 mean that the test was not passed, i.e. the coating was detached from more than 5% of the surface.

TABLE-US-00001 TABLE 1 Coating properties and Summary of the polymer dispersions 1 2 3 (V) 4 (V) 5 (V) 6 (V) 7 (V) 8 (V) Dispersion PUR 8 54.6 54.6 54.6 54.6 54.6 54.6 5.46 54.6 PUR 1 8.7 PUR 2 8.7 PUR 3 8.7 PUR 4 8.7 PUR 5 8.7 PUR 6 8.7 PUR 7 8.7 PUR 9 8.7 Esacure One 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 Diacetone alcohol 4.9 4.9 4.9 4.9 4.9 4.9 4.9 4.9 2-methoxypropanol 4.9 4.9 4.9 4.9 4.9 4.9 4.9 4.9 Tinuvin 400 DW 2.2 2.2 2.2 2.2 2.2 2.2 2.2 2.2 BYK 333 0.2 0.2 0.2 0.2 0.2 0.2 0 2 0.2 BYK346 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 n,n-dimethylethylamine 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Bindzil CC 401 23.0 23.0 23.0 23.0 23.0 23.0 23.0 23.0 Borchi Gel 0625 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Hydrolysis resistance Adhesion before GT0 GT0 GT0 GT0 GT0 GT0 GT0 GT0 hydrolysis Hydrolysis 90 C., 90% rel. humidity After 72 hrs GT0 GT0 GT5 GT5 GT5 GT5 GT5 GT5 After 96 hrs GT1 GT0 / / / / / / The quantity data in the formulation are in % w/w. V: Comparative example All PUR dispersions used have a solids content of 40% w/w.

[0375] The examples 1 to 8 show that it was only in the use of the PUR dispersions 1 and 2 that a better hydrolysis resistance (at least 72 hrs) was observed in the resulting radiation-curable coating of a plastic film.

[0376] The influence of the proportion of a polyurethane (meth)acrylate a) according to the invention in the polymer dispersion on the hydrolysis resistance is shown in Table 2.

TABLE-US-00002 TABLE 2 Influence of the proportion by weight of the dispersions according to the invention 2 9 (V) 10 11 12 13 Dispersion PUR 8 54.6 58.3 53.3 43.3 33.3 PUR 2 8.7 5.0 10.0 20.0 30.0 63.3 Esacure One 0.7 0.7 0.7 0.7 0.7 0.7 Diacetone alcohol 4.9 4.9 4.9 4.9 4.9 4.9 2-methoxypropanol 4.9 4.9 4.9 4.9 4.9 4.9 Tinuvin 400 DW 2.2 2.2 2.2 2.2 2.2 2.2 BYK 333 0.2 0.2 0.2 0.2 0.2 0.2 BYK346 0.3 0.3 0.3 0.3 0.3 0.3 n,n-dimethylethylamine 0.2 0.2 0.2 0.2 0.2 0.2 Bindzil CC 401 23.0 23.0 23.0 23.0 23.0 23.0 Borchi Gel 0625 0.3 0.3 0.3 0.3 0.3 0.3 Hydrolysis resistance Adhesion before hydrolysis GT0 GT0 GT0 GT0 GT0 GT0 Hydrolysis 90 C., 90% rel. humidity After 24 hrs GT0 GT0 GT0 GT0 GT0 GT0 After 48 hrs GT0 GT0 GT0 GT0 GT0 GT0 After 72 hrs GT0 GT5 GT0 GT0 GT0 GT0 After 144 hrs GT1 GT5 GT0 GT0 GT0 n.d. The quantity data in the formulation are in % w/w. V: Comparative example n.d: not determined

[0377] When using the PUR 2 particularly advantageously represented according to Table 1, the weight ratio between PUR 8 and PUR 2 was varied.

[0378] It is clear, when looking at the adhesion results in Table 2, that a quantity of 5% w/w of PUR 2 is not sufficient in the polymer dispersion to pass the required minimum test duration of 72 hours. By 72 hours, it has lost its adhesion completely.

[0379] An additional quantity of 8.7% w/w in the polymer dispersion results in a compound which goes safely beyond the required test conditions and, as a result, has clearly plenty to spare.

[0380] The test is passed even after 144 hours with a score of GT1.

[0381] Above a proportion of 10% w/w of PUR 2 in the polymer dispersion (Examples 10-13 in Table 2), the hydrolysis test is passed safely even up to 144 hours.