EP3046778A1

EP3046778A1 - Heat transfer films for the dry coating of surfaces

Info

Publication number: EP3046778A1
Application number: EP14766739.8A
Authority: EP
Inventors: Manfred Biehler; Dieter Litzcke
Original assignee: LS Industrielacke GmbH; BASF SE
Current assignee: LS INDUSTRIELACKE GmbH; BASF SE
Priority date: 2013-09-18
Filing date: 2014-09-18
Publication date: 2016-07-27
Anticipated expiration: 2034-09-18
Also published as: PT3046778T; RU2674190C2; JP2016538165A; RU2016114693A; US10710388B2; US20190315144A1; RU2016114693A3; NO3046778T3; ES2663451T3; ES2663451T5; EP3046778B1; CN105555545A; SI3046778T1; DK3046778T3; WO2015040113A1; CN105555545B; US20160297226A1; DK3046778T4; PL3046778T5; EP3046778B2

Abstract

The present invention relates to heat transfer films, comprising: a) a carrier film (2), b) at least one, for example one, two or three, coating layer(s) (3) arranged directly on the carrier film (2), c) at least one, in particular precisely one, hot-sealable polymer adhesive layer (4), wherein the coating layer is based on a non-aqueous, radiation-curable, liquid composition which contains at least 60 wt%, in particular at least 70 wt%, based on the total weight of the composition, curable constituents selected from organic oligomers which have ethylenically unsaturated double bonds and mixtures of these oligomers with monomers which have at least one ethylenically unsaturated double bond. The invention also relates to the use of the heat transfer films for the dry coating of surfaces. The invention also relates to the production of such heat transfer films and to a method for coating or lacquering surfaces of objects using the heat transfer films according to the invention.

Description

Thermal transfer foils for the dry coating of surfaces

The present invention relates to thermal transfer films and their use for the dry coating of surfaces. The invention also relates to the production of such thermal transfer films and to a process for coating or coating surfaces of articles using the thermal transfer films according to the invention.

Usually surfaces of articles are coated by wet coating, d. H. a liquid lacquer is applied to the surface to be coated and then dried, whereby a lacquer layer is formed on the surface. In an industrial coating, the coating is usually carried out in Lackierstra- Shen, wherein for drying regularly longer dry sections are necessary in which the paint is dried and cured with relatively high energy consumption. Such methods are therefore time, energy and also staff-intensive. In addition, after completion of the painting, the coating devices of the paint lines must be cleaned, resulting in service life. In addition, the waste generated when cleaning the machines must be disposed of as special waste. Some two-component paints have a limited processing time, and unused residues must also be disposed of as hazardous waste.

There have been various reports on coating or painting techniques in which one or more paint layers are transferred to the surface to be coated by means of hot stamping foils, also referred to as thermal transfer foils. These films comprise a carrier film on which one or more polymer layers and optionally an adhesive layer are arranged. During coating, the at least one polymer layer is transferred by means of pressure and / or heat from the carrier film to the surface to be coated. In this way, the at least one polymer layer on the surface to be coated forms a lacquer layer without having to use organic solvents in the coating process. By combining decorative and lacquer layers, the most varied designs of the surface can be reproducibly achieved in the simplest possible way.

EP 573676 describes a method for applying a lacquer with colored decoration to a substrate, for example on wood or plastic surfaces, in which a film is used, which has a decorative layer applied to a carrier with release properties and a partially crosslinked lacquer layer applied to the decorative layer having. The film is applied with the lacquer layer on the surface to be coated and transferred by pressure and elevated temperature with the decorative layer on the surface, which at the same time comes to a curing of the lacquer layer. As paints thermally curable coatings are used. Due to the high temperatures required in the process during paint curing, the choice of substrates is severely restricted.

EP 1702767 discloses thermal transfer films which have a decorative layer arranged on a carrier layer and a heat-activatable adhesive layer arranged on the decorative layer, wherein the carrier layer has a metallic functional layer lying directly on the decorative layer, which facilitates detachment of the decorative layer from the carrier layer and thus to ensure improved transfer of the decorative layer to the substrate. Due to the metallization is limited in the decorative layer.

EP 1970215, in turn, describes thermal transfer films suitable for the coating of surfaces which have a base coat layer, a colored decorative layer and a transfer layer with adhesive effect connected to a carrier film, the layers on aqueous coating systems comprising the heat-drying aqueous polymer dispersions Contain binder based. The surface hardness and abrasion resistance of the resulting coatings are often unsatisfactory. High abrasion resistant coatings can not be obtained with the thermal transfer foils described there.

EP 2078618 describes thermal transfer films which have at least one topcoat layer disposed on a carrier film and a thermally activatable adhesive layer, wherein the topcoat layer is preferably based on an aqueous coating composition comprising a UV-curable, dispersed polyurethane. Admittedly, the thermal transfer foils described there lead to an improved surface hardness in comparison with thermal transfer foils whose lacquer layers are based on heat-drying aqueous polymer dispersions. For some applications, however, this is not satisfactory. In addition, the use of aqueous coating compositions is associated with an increased drying effort in the production of thermal transfer films. The coatings described therein are not always satisfactory in terms of abrasion resistance and surface properties. High abrasion resistant coatings can not be obtained with the thermal transfer films described there. It has surprisingly been found that thermal transfer films which have at least one lacquer layer arranged on the carrier film and which are based on a nonaqueous radiation-curable, liquid composition which is at least 60% by weight, in particular at least 70% by weight, based on the total weight of the composition containing crosslinkable components selected from organic oligomers having ethylenically unsaturated double bonds and mixtures of these oligomers with monomers having at least one ethylenically unsaturated double bond and having a heat-sealable polymeric adhesive layer (4) containing at least one radiation-curable component contains, are particularly suitable for coating surfaces. Thus, the use of such thermal transfer films to particularly resistant surfaces adhere particularly well to the coated substrates. In addition, the use of nonaqueous, radiation-curable coating compositions with a high proportion of crosslinkable constituents allows the targeted adaptation of the thermal transfer film for different substrates, namely for both hard as well as highly elastic substrates. In contrast to thermal transfer films with lacquer layers based on thermally curable coating materials, the temperature load of the material to be coated during transfer of the lacquer layer (s) on the surface to be coated is comparatively low, since a final curing easily by irradiating the coated surface with high-energy radiation such as UV or electron radiation can be performed and no subsequent annealing is necessary.

Due to the use of liquid compositions having a high proportion of crosslinkable constituents which are cured by high-energy radiation, in particular by UV radiation, moreover, long drying times in the production of the thermal transfer films can be dispensed with, so that their production can be carried out very efficiently. Accordingly, a first aspect of the present invention relates to a thermal transfer film (1) comprising:

a) a carrier film (2),

b) at least one, z. B. one, two or three, directly on the carrier film (2) arranged lacquer layer (s) (3),

c) at least one, in particular precisely heat-sealable, polymeric adhesive layer (4),

wherein the lacquer layer is based on a non-aqueous, radiation-curable, liquid composition which is at least 60% by weight, in particular at least

70% by weight, based on the total weight of the composition, of curable contains constituents which are selected from organic oligomers having ethylenically unsaturated double bonds and mixtures of these oligomers with monomers having at least one ethylenically unsaturated double bond and wherein the heat-sealable polymeric adhesive layer (4) contains at least one radiation-curable component.

The invention also relates to the preparation of the thermal transfer films according to the invention, which comprises the following steps: i. applying the non-aqueous, radiation curable, liquid composition to obtain a high energy radiation curable coating;

ii. Irradiation of the in step i. obtained curable coating with high-energy radiation, in particular with UV light, to obtain the lacquer layer (3); iii. optionally applying a decorative layer on the curable coating or on the lacquer layer (3); and

iv. Applying the heat-sealable polymeric adhesive layer (4).

Another object of the invention is the use of thermal transfer foils according to the invention for the dry coating of objects.

The invention also provides a process for coating surfaces of objects, comprising the following steps:

a) applying the thermal transfer film (1) according to the invention with the adhesive layer to the surface to be coated;

b) heat-sealing the transfer film to obtain a surface coated with the transfer film;

c) irradiation of the surface coated with the transfer film with high-energy radiation, in particular with UV or electron radiation, especially with UV radiation; and

d) optionally detaching the carrier film (2).

The thermal transfer sheets according to the invention have at least one lacquer layer which is based on a nonaqueous, radiation-curable, liquid composition. This is understood to mean that the lacquer layer or the lacquer layers are obtained by curing one or more layers of the liquid radiation-curable composition by irradiation with high-energy radiation, in particular with UV radiation. Unlike lacquer coatings based on aqueous coating compositions with radiation-curable binders, the lacquer coatings according to the invention Those prepared using non-aqueous, radiation-curable, liquid compositions have a more uniform structure and crosslinking within the lacquer layer and fewer defects. This is presumably due to the fact that unlike the aqueous coating compositions, the curable, ie, polymerizable, constituents in the uncured coating form a coherent phase, so that the covalent bonds formed upon irradiation between the curable components of the composition be able to train evenly within the layer. The radiation-curable, liquid compositions used for the preparation of the lacquer layer contain at least 60 wt .-%, in particular at least 70 wt .-%, z. B. 60 to 99 wt .-%, in particular 70 to 95 wt .-%, based on the total weight of the composition, curable components which have ethylenically unsaturated double bonds. In this case, the constituents are preferably selected such that in the composition 1, 5 to 8 mol, in particular 2.0 to 7 mol and especially 2.5 to 6.5 mol ethylenically unsaturated double bonds per kg of the coating composition are present.

The ethylenically unsaturated double bonds of the curable constituents of the liquid, radiation-curable composition which forms the lacquer layer are preferably in the form of acrylic groups, methacrylic groups, allyl groups, fumaric acid groups, maleic acid groups and / or maleic anhydride groups, in particular at least 90% or 100%. based on the total amount of ethylenically unsaturated double bonds present in the composition, in the form of acrylic or methacrylic groups and especially in the form of acrylic groups. The acrylic and methacrylic groups may be in the form of (meth) acrylamide or (meth) acrylate groups, the latter being preferred. In particular, the curable components of the radiation-curable composition forming the lacquer layer comprise at least 90% or 100%, based on the total amount of ethylenically unsaturated double bonds present in the composition, of acrylate groups.

According to the invention, the liquid, radiation-curable compositions which are used to prepare the lacquer layer contain at least one oligomer which has ethylenically unsaturated double bonds. The oligomers preferably have on average a functionality in the range from 1.5 to 10, in particular

Range of 2 to 8.5, ie, the number of ethylenically unsaturated double bonds per molecule is on average in the range of 1, 5 to 10 and in particular in the range of 2 to 8.5. Also suitable are mixtures of different oligomers with different Functionality, wherein the average functionality is preferably in the range of 1, 5 to 10, in particular in the range of 2 to 8.5.

The oligomers typically have a linear or branched backbone which carries on average more than one ethylenically unsaturated double bond, preferably in the form of the abovementioned acrylic groups, methacrylic groups, allyl groups, fumaric acid groups, maleic acid groups and / or maleic anhydride groups, in particular in the form of acrylic or Methacryl groups, wherein the ethylenically unsaturated double bonds may be linked via a linker to the skeleton or are part of the skeleton. Suitable oligomers are, in particular, oligomers from the group of polyethers, polyesters, polyurethanes and epoxide-based oligomers. Preference is given to oligomers which have substantially no aromatic structural units and mixtures of oligomers having aromatic groups and oligomers without aromatic groups.

In particular, the oligomers are selected from polyether (meth) acrylates, i. H. Polyethers having acrylic or methacrylic groups, polyester (meth) acrylates, d. H. Polyesters having acrylic or methacrylic groups, epoxide (meth) acrylates, d. H. Reaction products of polyepoxides with hydroxyl-functionalized acrylic or methacrylic compounds, urethane (meth) acrylates, d. H. Oligomers having a (poly) urethane backbone and acrylic or methacrylic groups, for example reaction products of polyisocyanates with hydroxyl-functionalized acrylic or methacrylic compounds, and unsaturated polyester resins, d. H. Polyesters having a plurality of preferably present in the polymer backbone ethylenically unsaturated double bonds, for. As condensation products of maleic acid or fumaric acid with aliphatic di- or polyols, and mixtures thereof.

Unlike the monomers which may also be included in these curable compositions, the oligomers typically have a number average molecular weight of at least 400 g / mol, especially at least 500 g / mol, e.g. B. in the range of 400 to 4000 g / mol and in particular in the range of 500 to 2000 g / mol. In contrast, the monomers typically have molecular weights below 400 g / mol, z. B. in the range of 100 to <400 g / mol.

Suitable polyether (meth) acrylates are, above all, aliphatic polyethers, in particular poly (C 2 -C 4) -alkylene ethers, which on average have from 2 to 4 acrylate or methacrylate groups. Examples of these are the Laromer® grades P033F, LR8863, GPTA, LR8967, LR8962, LR9007 from BASF SE, which in some cases are blends with monomers. Suitable polyester (meth) acrylates are, in particular, aliphatic polyesters which on average have from 2 to 6 acrylate or methacrylate groups. Examples of these are the Laromer® grades PE55F, PE56F, PE46T, LR9004, PE9024, PE9045, PE44F, LR8800, LR8907, LR9032, PE9074, PE9079, PE9084 from BASF SE, which in some cases are blends with monomers.

Suitable polyurethane acrylates are, above all, urethane group-containing compounds which have on average from 2 to 10, in particular from 2 to 8.5, acrylate or methacrylate groups and which are preferably obtainable by reaction of aromatic or aliphatic diol oligoisocyanates with hydroxyalkyl acrylates or hydroxyalkyl methacrylates. Examples of these are the Laromer® grades UA19T, UA9028, UA9030, LR8987, UA9029, UA9033, UA9047, UA9048, UA9050, UA9072, UA9065 and UA9073 from BASF SE, some of which are blends with monomers.

In preferred embodiments of the invention, the radiation-curable, liquid composition forming the lacquer layer comprises at least one oligomer selected from urethane acrylates and polyester acrylates and mixtures thereof, and optionally one or more monomers.

In particular embodiments of the invention, the radiation-curable, liquid composition which forms the lacquer layer comprises at least one urethane acrylate and optionally one or more monomers. In other particular embodiments of the invention, the radiation-curable, liquid composition forming the lacquer layer comprises at least one polyester acrylate and optionally one or more monomers.

In specific embodiments of the invention, the radiation-curable, liquid composition which forms the lacquer layer comprises at least one urethane acrylate and at least one polyester acrylate and optionally one or more monomers.

In further specific embodiments of the invention, the radiation-curable, liquid composition which forms the lacquer layer comprises at least one aliphatic urethane acrylate and at least one aromatic urethane acrylate or at least two different aliphatic urethane acrylates and optionally one or more monomers. In further specific embodiments of the invention, the radiation-curable, liquid composition which forms the lacquer layer comprises at least one aliphatic urethane acrylate, at least one aromatic urethane acrylate and at least one polyester acrylate and optionally one or more monomers.

In addition to the oligomers having ethylenically unsaturated double bonds, the crosslinkable constituents of the radiation-curable, liquid composition used to prepare the lacquer layer may contain one or more monomers, which are also referred to as reactive diluents. The monomers typically have molecular weights below 400 g / mol, e.g. B. in the range of 100 to <400 g / mol. Suitable monomers generally have 1 to 6, in particular 2 to 4, ethylenically unsaturated double bonds per molecule. The ethylenically unsaturated double bonds are preferably present in the form of the abovementioned acrylic groups, methacrylic groups, allyl groups, fumaric acid groups, maleic acid groups and / or maleic anhydride groups, in particular in the form of acrylic or methacrylic groups and especially as acrylate groups.

Preferred monomers are selected from esters of acrylic acid with 1- to 6-hydric, in particular 2- to 4-hydric aliphatic or cycloaliphatic alcohols which preferably have 2 to 20 carbon atoms, such as monoesters of acrylic acid with Ci-C2o Alkanols, benzyl alcohol, furfuryl alcohol, tetrahydrofurfuryl alcohol, (5-ethyl-1,3-dioxan-5-yl) methanol, phenoxyethanol, 1,4-butanediol or 4-tert-butylcyclohexanol; Diesters of acrylic acid with ethylene glycol, 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, dipropylene glycol or tripropylene glycol; Triesters of acrylic acid with trimethylolpropane or pentaerythritol and the tetraesters of acrylic acid with pentaerythritol. Examples of suitable monomers are in particular trimethylolpropane diacrylate, trimethylolpropane triacrylate, ethylene glycol diacrylate, butanediol diacrylate, hexanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diarylate, phenoxyethyl acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, 4-t-butylcyclohexyl acrylate, 4-hydroxybutyl acrylate and trimethylolformalomonoacrylate (acrylic acid). 5-ethyl-1,3-dioxan-5-yl) methyl ester).

In preferred embodiments of the invention, the radiation-curable, liquid composition forming the lacquer layer comprises at least one oligomer, e.g. B. 1, 2 or 3 oligomers, especially at least one, z. B. 1, 2 or 3, the oligomers mentioned as preferred and at least one monomer, for. B. 1, 2 or 3 monomers, especially at least one, z. B. 1, 2 or 3, the monomers mentioned as preferred. In these compositions, the oligomer preferably forms the main constituent of the curable constituents of the composition, ie the oligomer (s). less than 50 wt .-%, in particular at least 60 wt .-%, based on the total amount of oligomer and monomer. The weight ratio of oligomer to monomer is in particular in the range from 1: 1 to 20: 1 and especially in the range from 3: 2 to 10: 1.

In other, likewise preferred embodiments of the invention, the radiation-curable, liquid composition used to prepare the lacquer layer comprises exclusively or almost exclusively, i. H. at least 90% by weight, in particular at least 95% by weight, especially at least 99% by weight, based on the total amount of radiation-curable constituents of the composition, of one or more oligomers, eg. B. 2, 3 or 4 oligomers, in particular 2, 3 or 4 of the oligomers mentioned as preferred. Accordingly, the proportion of monomers is at most 10% by weight, in particular not more than 5% by weight, especially not more than 1% by weight or 0% by weight, based on the total amount of radiation-curable constituents of the composition. Such compositions preferably contain at least one polyester acrylate and / or polyurethane acrylate and at least one polyether acrylate.

In addition to the curable constituents, the radiation-curable, liquid composition used to prepare the lacquer layer generally contains one or more further constituents, such as photoinitiators, inert fillers, abrasives, leveling agents, coloring constituents, in particular color pigments, organic solvents and the like. According to the invention, these constituents do not exceed 40% by weight, in particular not more than 30% by weight, eg. B. 1 to 40 wt .-%, in particular 5 to 30 wt .-%, based on the total weight of the radiation-curable, liquid composition. Preferably, the radiation-curable, liquid composition contains no or not more than 10% by weight, based on its total weight, of non-polymerizable volatiles. In this context, volatile substances are understood as meaning substances which have a boiling point or an evaporation point below 250 ° C. under atmospheric pressure, for example organic solvents.

The radiation-curable, liquid composition used to prepare the lacquer layer preferably contains at least one photoinitiator. By "photoinitiators" is meant substances which upon irradiation with UV radiation, ie light of wavelength below 420 nm, in particular below 400 nm, decompose to form free radicals and thus trigger a polymerization of the ethylenically unsaturated double bonds. Preferably, the radiation-curable, liquid composition comprises at least one photoinitiator having at least one absorption band, which has a maximum in the range of 220 to 420 nm, in particular in the range of 240 to 400 nm and which is coupled with the initiation of the decay process. The nonaqueous, liquid, radiation-curable composition preferably comprises at least one photoinitiator which has at least one absorption band with a maximum in the range from 220 to 420 nm, in particular a maximum in the range from 240 to 400 nm.

Examples of suitable photoinitiators are

alpha-hydroxyalkylphenones and alpha-dialkoxyacetophenones such as

1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone,

2-Hydroxy-1 - {4- [4- (2-hydroxy-2-methylpropionyl) benzyl] phenyl} -2-methylpropan-1-one, 2-hydroxy-1 - [4- (2-hydroxyethoxy) phenyl] 2-methyl-1-propanone or 2,2-dimethoxy-1-phenylethanone;

Phenylglyoxalic acid esters, such as phenylglyoxalic acid methyl ester;

Benzophenones such as benzophenone, 2-hydroxybenzophenone, 3

Hydroxybenzophenone, 4-hydroxybenzophenone, 2-methylbenzophenone, 3

Methylbenzophenone, 4-methylbenzophenone, 2,4-dimethylbenzophenone, 3,4-

Dimethylbenzophenone, 2,5-dimethylbenzophenone, 4-benzoylbiphenyl, or 4-

methoxybenzophenone;

Benzil derivatives such as benzil, 4,4'-dimethylbenzil and benzil dimethyl ketal;

Benzoins such as benzoin, benzoin ethyl ether, benzoin isopropyl ether and benzoin methyl ether;

Acylphosphine oxides such as 2,4,6-trimethylbenzoyl-diphenylphosphine oxide,

Ethoxy (phenyl) phosphoryl- (2,4,6-trimethylphenyl) methanone and bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide;

Titanocenes such as the product sold under the name Irgacure® 784 by BASF SE,

Oxime esters such as the product sold under the name Irgacure® OXE01 and OXE02 by BASF SE,

alpha-aminoalkylphenones such as 2-methyl-1 - [4 (methylthio) phenyl-2-morpholinopropan-1-one, 2- (4-methylbenzyl) -2-dimethylamino-1 - (4-morpholinophenyl) -1-butanone or 2-Benzyl-2-dimethylamino-1 - (4-morpholinophenyl) -1-butanone. Preferred photoinitiators are selected, in particular, from the groups of the alpha-hydroxyalkylphenones, alpha-dialkoxyacetophenones, phenylglyoxalic acid esters, benzophenones, benzoins and acylphosphine oxides. Preferably, the liquid, radiation-curable composition contains at least one photoinitiator having an absorption band with a maximum _ma x in the range of 230 to 340 nm.

The non-aqueous, liquid, radiation-curable composition used to prepare the lacquer layer preferably comprises at least two photoinitiators which differ from one another and in which the maxima of the absorption bands differ, preferably by at least 40 nm and in particular by at least 60 nm.

In particular, such a non-aqueous, liquid, radiation-curable composition contains a mixture of at least two mutually different photoinitiators, wherein at least one photoinitiator (hereinafter photoinitiator I) has an absorption band with a maximum _ma x in the range of 340 to 420 nm and especially in the range of 360 to 420 nm and wherein at least one further photoinitiator (hereinafter photoinitiator II) has an absorption band with a maximum _ma x in the range of 220 to 340 and especially in the range of 230 to 320 nm. Preferably, the weight ratio of the total amount of photoinitiators I to the total amount of photoinitiators II is in the range of 2: 1 to 1:20.

Preferred photoinitiators which have an absorption band with a maximum _ma x in the range of 220 to 340 and especially in the range of 230 to 320 nm are the abovementioned alpha-hydroxyalkylphenones, alpha-dialkoxyacetophenones, phenylglyoxalic acid esters, benzophenones and benzoins.

Preferred photoinitiators which have an absorption band with a maximum _ma x in the range 340 to 420 nm and especially in the range of 360 to 420 nm, are the abovementioned Acylphosphinoxide. In preferred embodiments, the photoinitiators comprise at least one alpha-hydroxyalkylphenone or alpha-dialkoxyacetophenone and at least one acylphosphine oxide and optionally a phenylglyoxalic acid ester and optionally a benzophenone. The weight ratio of acylphosphino oxide to alpha-hydroxyalkylphenone or alpha-dialkoxyacetophenone is preferably in the range from 2: 1 to 1:20.

The total amount of photoinitiators is typically in the range of 0.5 to 10% by weight, especially 1 to 5% by weight, based on the total weight of the non-aqueous, liquid, radiation-curable composition. The nonaqueous, liquid, radiation-curable compositions according to the invention can also be formulated without initiators, in particular when the subsequent curing is carried out by means of electron beams.

Furthermore, the non-aqueous, liquid, radiation-curable compositions may contain one or more fillers, i. H. solid, non-soluble in the oligomers and the monomers, particulate components. These include, in particular, aluminum oxides, for example in the form of corundum and also silicon dioxide, such as pyrogenic silica and synthetic, amorphous silica, eg. B. precipitated silica. The average particle sizes of the fillers (weight average) can vary over wide ranges and are typically in the range from 1 nm to 100 μm, in particular in the range from 10 nm to 50 μm, depending on the nature of the filler. The total amount of filler will generally not exceed 40% by weight, in particular 30% by weight, based on the total weight of the composition and, if present, is typically in the range from 1 to 39.5% by weight. and in particular in the range of 2 to 29 wt .-%.

Preferably, the non-aqueous, liquid, radiation-curable compositions contain one or more abrasives. Abrasive are fillers, which are the

Lacquer layer give increased surface hardness and improved abrasion resistance. These include especially corundum, quartz flour, glass powder, z. As glass flakes and nanoscale silicas. In addition, the non-aqueous, liquid, radiation-curable compositions may contain one or more further additives, for example leveling agents, for. B. siloxane-containing polymers such as Polyethersiloxancopolymere, as well as UV stabilizers, eg. B. sterically hindered amines (so-called HALS stabilizers). Typical compositions of the non-aqueous, liquid, radiation-curable compositions which are used to prepare the lacquer layer are given in the following Tables A1, A2 and A3.

Table A1:

Raw material Quantity [% by weight] ¹ >

Urethane acrylate, 15-30

Functionality about 2.0 to 6.0

Polyester acrylate, 5 - 15

Functionality 3.0 to 3.5 Trimethylolpropane formal monoacrylate 5-15

Trimethylolpropane triacrylate 10-20

Dipropylene glycol diacrylate 10-20

Aliphatic urethane acrylate, 3-15

Functionality 1.5 to 3.5

Alumina (corundum) 20-30

Pyrogenic silica 0.1 - 5

Phenylglyoxylate 0.5-3

Acylphosphine oxide 0.2-1 alpha-hydroxyalkylphenone 0.5-3

1) based on the total weight of the composition

Table A2:

Raw material quantity [wt .-%] ⁾

Urethane acrylate, 20-35

Functionality about 2.0 to 6.0

Aliphatic urethane acrylate, 12-25

Functionality 1, 5 to 2.0

Trimethylolpropane formal monoacrylate 5-15

Phenoxyethyl acrylate 10-20

Dipropylene glycol diacrylate 10-20

Synthetic silica 5-15

Pyrogenic silica 0.1 -5

Flow control agent (eg polyethersiloxane) 0.2-5

Phenylglyoxylate 0.5-3

Acylphosphine oxide 0.1-0.5 alpha-hydroxyalkylphenone 0.5-3

Benzophenone 0.5-3

1) based on the total weight of the composition

Table A3:

Raw material quantity [wt .-%] ⁾

Mixture of two or three polyester acrylates, 40-65 average functionality 2.0 to 4.0

Trimethylolpropane formal monoacrylate 5-20

Acrylate of an ethoxylated phenol 5- 20

Dipropylene glycol diacrylate 5-20

Pyrogenic silica 1 - 10 Flow control agent (eg polyethersiloxane) 0.2-5

Phenylglyoxylate 0.5-3

Acylphosphine oxide 0.1 - 1

alpha-hydroxyalkylphenone 0.5-3

Benzophenone 0,5 - 3

1) based on the total weight of the composition

The thermal transfer films according to the invention can have one or more paint layers arranged one above the other, which according to the invention are based on the above-described nonaqueous, liquid, radiation-curable compositions.

The total layer thickness of the lacquer layer, d. H. in the case of several lacquer layers, the sum of all layer thicknesses is typically in the range from 10 to 120 μm, in particular in the range from 30 to 80 μm. In one layer, therefore, the layer thickness of the paint layer is preferably in the range from 10 to 120 μm, in particular in the range from 30 to 80 μm. In the case of several layers, the individual layer thicknesses are typically in the range from 10 to 100 μm, in particular in the range from 20 to 70 μm.

In a first embodiment of the invention, the thermal transfer foil according to the invention comprises exactly one lacquer layer arranged on the carrier foil.

In a further embodiment, the thermal transfer film according to the invention comprises a coating layer arranged on the carrier film and one or more, for. One or two further paint layers based on the non-aqueous, liquid, radiation-curable compositions described above. The lacquer layers can be arranged directly on one another. A decorative layer can also be provided between two lacquer layers in order to give the article coated with the thermal transfer film a colored design. Decorative layers typically have layer thicknesses in the range from 0.5 to 5 μm, in particular in the range from 0.5 to 2.5 μm, and especially in the range from 1 to 1.5 μm.

Furthermore, the thermal transfer films according to the invention have at least one polymeric adhesive layer, in particular exactly one adhesive layer. The adhesive layer is arranged either directly on the lacquer layer, or in the case of several lacquer layers directly on the uppermost lacquer layer, or a decorative layer can also be provided between the lacquer layer and the adhesive layer. The adhesive layer is heat sealable according to the invention, ie it is not sticky at room temperature and develops its adhesive effect only when heated. It has proved to be advantageous if the adhesive layer contains at least one component which is radiation-curable, ie crosslinked upon exposure to high-energy radiation, for example when irradiated with UV light or electron radiation. This constituent is typically organic oligomers or polymers containing ethylenically unsaturated double bonds.

The heat-sealable adhesive layer according to the invention preferably comprises at least one polymer as the main constituent. The polymer itself may be radiation-curable or blended with one or more radiation-curable oligomers or polymers having ethylenically unsaturated double bonds.

The polymers which form the main constituent of the heat sealable adhesive layer are crosslinkable in a preferred embodiment, i. H. they crosslink upon heating and / or by the action of high-energy radiation, for example when irradiated with UV light and formation of covalent bonds between the polymer chains. In particular, it has proven to be advantageous if the adhesive layer comprises both oligomeric and / or polymeric components which can be crosslinked by heating, as well as components which are crosslinkable by the action of high-energy radiation. This can be achieved, for example, by the adhesive layer comprising both polymers which crosslink on heating and oligomers or polymers which are crosslinked by the action of high-energy radiation. The adhesive layer may also contain so-called dual-cure polymers, i. H. Polymers that crosslink both when exposed to high-energy radiation and when heated.

In a preferred embodiment, the adhesive layer contains at least one water-insoluble polymer, which is usually used for the production of adhesive layers, and which is especially selected from pure acrylate polymers, styrene acrylate polymers, polyurethanes, in particular polyester urethanes and polyether urethanes, and which is physically drying or self-crosslinking and at least one radiation-curing oligomer or polymer.

Physically drying polymers are those polymers which, upon drying, form a solid polymer film in which the polymer chains are uncrosslinked.

Self-crosslinking polymers are those polymers which, upon drying, form a solid polymer film in which the polymer chains are crosslinked. self- Polymers have reactive functional groups, for example hydroxyl groups, carboxyl groups, isocyanate groups, blocked isocyanate groups, ketocarbonyl groups or epoxide groups which can react with one another or with the reactive groups of a crosslinking agent to form covalent bonds.

In a particularly preferred embodiment, the adhesive layer contains at least one water-insoluble polymer which is selected from polyurethanes, in particular polyesterurethanes and polyetherurethanes, and which is physically drying or self-crosslinking, and at least one radiation-curing oligomer or polymer.

In a likewise particularly preferred embodiment, the adhesive layer contains at least one water-insoluble polymer selected from self-crosslinking pure acrylate polymers and self-crosslinking styrene-acrylate polymers, and at least one radiation-curing oligomer or polymer.

In a likewise particularly preferred embodiment, the adhesive layer comprises at least one water-insoluble polymer selected from self-crosslinking pure acrylate polymers and self-crosslinking styrene-acrylate polymers and at least one water-insoluble polymer selected from polyurethanes, in particular polyesterurethanes and polyetherurethanes, and physically drying or self-crosslinking, and at least one radiation-curing oligomer or polymer. The radiation-curable oligomers and polymers of the adhesive layer are basically those oligomers and polymers which have ethylenically unsaturated double bonds. These double bonds are preferably at least 90% or 100%, based on the total amount of ethylenically unsaturated double bonds, in the form of acrylic or methacrylic groups and especially in the form of acyl groups. The acrylic and methacrylic groups may be in the form of (meth) acrylamide or (meth) acrylate groups, the latter being preferred. In particular, at least 90% or 100% of the radiation-curable constituents of the adhesive layer, based on the total amount of the ethylenically unsaturated double bonds present in the adhesive layer, comprise acrylate groups.

The radiation-curable oligomers and polymers of the adhesive layer preferably have on average a functionality in the range of 2 to 20, in particular in the range of 2 to 10, ie the number of ethylenically unsaturated double bonds per molecule is on average in the range of 2 to 20 and in particular in the range of 2 to 10. Also suitable are mixtures of different oligomers or polymers with different functionality, the average functionality preferably being in the range from 2 to 20, in particular in the range from 2 to 10. In particular, the radiation-curable oligomers and polymers of the adhesive layer are selected from polyether (meth) acrylates, polyester (meth) acrylates, epoxide (meth) acrylates, urethane (meth) acrylates, for example reaction products of polyisocyanates with hydroxyl-functionalized acrylic or methacrylic compounds, and unsaturated polyester resins.

Specifically, the radiation-curable oligomers and polymers of the adhesive layer are selected from polyether (meth) acrylates, epoxy (meth) acrylates and

Urethane (meth) acrylates. Suitable polyurethane acrylates are, above all, urethane-containing polymers which have on average 2 to 10, in particular 2 to 8.5, acrylate or methacrylate groups, in particular polyether urethane arylates, and which are preferably obtainable by reacting isocyanate group-containing polyether urethanes with hydroxyalkyl acrylates or hydroxyalkyl methacrylates , Examples include the Laromer® grades LR 8949, LR 8983 and LR 9005 from BASF SE.

Furthermore, it has proved to be advantageous if the polymers which preferably form the main constituent of the heat-sealable adhesive layer, in the uncrosslinked state, have a glass transition temperature Tg, determined by means of differential scanning calorimetry (DSC) according to ASTM D3418 in the range from -60 to 90 ° C., in particular 0 to 90 ° C, and / or it is partially crystalline polymers having a melting point in the range of -60 to 90 ° C, in particular 0 to 90 ° C, determined by DSC is. If the adhesive composition contains a plurality of polymers, these may also have different glass transition temperatures in the uncrosslinked state. It is then preferred that at least a part, in particular at least 30% by weight of these polymers, based on the total amount of the polymer components of the adhesive composition, in the uncrosslinked state has a glass transition temperature Tg in the range from 0 to 90 ° C., in particular in the range from 20 to Adhesive compositions for producing heat-sealable polymer layers are familiar to the person skilled in the art and can be commercially obtained or prepared by blending commercially available adhesive raw materials according to known formulation formulations Preferred are liquid adhesive compositions Suitable in principle are solvent-based adhesives as well as water-based adhesives. The adhesive layer (4) is preferably based on at least one aqueous polymer dispersion, ie water-based adhesives are used to produce the adhesive layer, ie adhesives which contain the polymers and optionally oligomers in the form of aqueous polymer dispersion. Preference is given to liquid, water-based adhesive compositions containing not more than 10% by weight of volatile, organic, non-polymerizable constituents, such as organic solvents.

Suitable polymer dispersions are, above all, self-crosslinking aqueous polymer dispersions, ie. H. aqueous polymer dispersions containing a reactive dispersed polymer and optionally a crosslinking agent which reacts with the reactive groups of the reactive polymer upon drying and / or heating to form bonds. Especially suitable are self-crosslinking aqueous pure acrylate dispersions, self-crosslinking aqueous styrene-acrylate dispersions and self-crosslinking aqueous polyurethane dispersions, in particular aqueous polyetherurethane dispersions and polyesterurethane dispersions.

Pure acrylate dispersions are understood as meaning aqueous polymer dispersions based on alkyl acrylates and alkyl methacrylates. By styrene acrylates is meant aqueous polymer dispersions based on styrene, alkyl acrylates and optionally alkyl methacrylates. Polyurethane dispersions are understood as meaning aqueous dispersions of polyurethanes, in particular polyetherurethanes and polyesterurethanes.

In the self-crosslinking aqueous polymer dispersions, the polymers have reactive functional groups, for example hydroxyl groups, carboxyl groups, isocyanate groups, blocked isocyanate groups, ketocarbonyl groups or epoxide groups which can react with the reactive groups of the crosslinking agent to form covalent bonds. Suitable crosslinking agents are compounds having at least two reactive groups, for example hydrazide groups, amino groups, hydroxyl groups, epoxide groups, isocyanate groups. Examples of self-crosslinking aqueous polymer dispersions are the products available under the trade names Luhydran® A 849, Acronal® 849 S, Joncryl® 8330, Joncryl® 8383 from BASF SE and Alberdingk® AC 2742 from Alberdingk Boley GmbH.

Suitable aqueous polymer dispersions are, above all, UV-crosslinkable polymer dispersions, ie polymer dispersions which contain a dispersed polymer which has polymerizable ethylenically unsaturated double bonds, preferably in the form of the abovementioned acrylic groups, methacrylic groups, allyl groups, fumaric acid groups, maleic acid groups and / or maleic anhydride groups, especially in the form of acrylic or methacrylic groups, the ethyle- nisch unsaturated double bonds may be linked via a linker to the skeleton or are part of the skeleton. Examples of suitable UV-crosslinkable aqueous polymer dispersions are aqueous dispersions of polyester acrylates, urethane acrylates and epoxy acrylates, as are sold, for example, by BASF under the trade names Laromer® PE22WN, PE55WN, LR8949, LR8983, LR9005, UA9060, UA9095 and UA9064.

According to the invention, the aqueous adhesive composition contains, in addition to the polymer of a physically drying or self-crosslinking polymer dispersion, at least one radiation-curable component which is generally selected from the abovementioned polymers and oligomers which have ethylenically unsaturated double bonds and which is preferably likewise present in dispersed form.

The radiation-curable oligomers and polymers of the aqueous adhesive composition are, in particular, those oligomers and polymers whose double bonds are at least 90% or 100%, based on the total amount of ethylenically unsaturated double bonds, in the form of acrylic or methacrylic groups and especially in the form of acrylic groups. The acrylic and methacrylic groups may be in the form of (meth) acrylamide or (meth) acrylate groups, the latter being preferred.

The radiation-curable oligomers and polymers of the aqueous adhesive composition preferably have on average a functionality in the range from 2 to 20, in particular in the range from 2 to 10, ie the number of ethylenically unsaturated double bonds per molecule is on average in the range from 2 to 20 and in particular in the range from 2 to 10. Also suitable are mixtures of different oligomers or polymers with different functionality, the average functionality preferably being in the range from 2 to 20, in particular in the range from 2 to 10. In particular, the radiation-curable oligomers and polymers of the aqueous adhesive composition are selected from polyether (meth) acrylates, polyester (meth) acrylates, epoxide (meth) acrylates, urethane (meth) acrylates, and unsaturated polyester resins. In particular, the radiation-curable oligomers and polymers of the aqueous adhesive composition are selected from polyether (meth) acrylates, epoxide (meth) acrylates and polyurethane (meth) acrylates. Suitable polyurethane acrylates are, above all, urethane-containing polymers which have on average 2 to 10, in particular 2 to 8.5, acrylate or methacrylate groups and which are preferably obtainable by reacting isocyanate-group-containing polyurethanes with hydroxyalkyl acrylates or hydroxyalkyl methacrylates. Examples include the Laromer® grades LR 8949, LR 8983 and LR9005 from BASF SE.

Particularly suitable are also mixtures of at least two different aqueous polymer dispersions, in particular mixtures of at least one aqueous UV-crosslinkable polymer dispersion, for. An aqueous urethane acrylate dispersion and / or an aqueous epoxy acrylate dispersion, and at least one self-crosslinking aqueous polymer dispersion, e.g. B. a self-crosslinking aqueous pure acrylate, styrene acrylate or polyurethane dispersion.

The adhesive compositions used for the preparation of the polymeric adhesive layer may contain the additives customary therefor, for example waxes, tackifier resins, defoamers, leveling agents, surfactants, pH adjusters, one or more of the aforementioned fillers and UV stabilizers, e.g. B. sterically hindered amines (so-called HALS stabilizers).

If the adhesive composition used to make the polymeric adhesive layer contains a UV-curable polymer, it usually also contains at least one photoinitiator, which is generally selected from the aforementioned alpha-hydroxyalkylphenones, alpha-dialkoxyacetophenones, phenylglyoxalic acid esters, benzophenones, benzene derivatives, acylphosphine oxides , Oxime esters, alpha-aminoalkylphenones and benzoins. Preferred photoinitiators are, in particular, selected from the groups of the alpha-hydroxyalkylphenones, alpha-dialkoxyacetophenones, phenylglyoxalic acid esters, benzophenones, benzoins and acylphosphine oxides. If the adhesive composition used to make the polymeric adhesive layer contains a UV-curable polymer, it preferably contains at least one photoinitiator having an absorption band with a maximum _ma x in the range of 230 to 340 nm. In particular, it contains at least two mutually different photoinitiators in which the maxima of the absorption bands differ, preferably by at least 40 nm and in particular at least 60 nm. In particularly preferred embodiments, the photoinitiators comprise at least one alpha-hydroxyalkylphenone or alpha-dialkoxyacetophenone and at least one Acylphosphinoxid and optionally a Phenylglyoxalsäureester and optionally a benzophenone. Preferably, the weight ratio of acylphosphine oxide to alpha-hydroxyalkylphenone or alpha-dialkoxyacetophenone in the range from 2: 1 to 1:20. The total amount of photoinitiators is typically in the range from 0.5 to 10% by weight, in particular from 1 to 5% by weight. %, based on the total weight of the adhesive composition used to make the polymeric adhesive layer.

Examples of typical adhesive compositions are the following compositions, all parts being by weight, based on the total weight of the composition:

Adhesive composition 1 (UV-curable, unpigmented)

30-70 parts of a self-crosslinking aqueous acrylate dispersion (50% strength by weight)

10-50 parts of a radiation-curable polyurethane acrylate dispersion (40-50% by weight),

5-10 parts of a hydrophobized fumed silica

5-10 parts of a nonionic wax dispersion

1, 5-3 parts of a blend of an alpha-hydroxyalkylphenone and benzophenone

0.5-1 parts of an acylphosphine oxide

and optionally the following ingredients

0-20 parts water

0.8-1, 5 parts of a mineral-containing defoamer

0.4-1, 2 parts of a polyethersiloxane copolymer

0.5-1.0 parts of a fluorosurfactant-containing leveling agent

2-4 parts of butylglycol as a film-forming assistant

0.3-0.5 parts of a polyurethane thickener

Adhesive composition 2 (UV-curable, unpigmented)

75-95 parts of a radiation-curable aqueous polyetherurethane acrylate dispersion

(40-50% by weight)

0.8-1, 5 parts of a mineral-containing defoamer

5-10 parts of a hydrophobized fumed silica

5-10 parts of a nonionic wax dispersion

1, 5-3 parts of a blend of an alpha-hydroxyalkylphenone and benzophenone and optionally the following ingredients

0.4-1, 2 parts of a polyethersiloxane copolymer

0.5-1.0 parts of a fluorosurfactant-containing leveling agent 2-5 parts water

2-4 parts of butylglycol as a film-forming assistant

0.3-0.5 parts of a polyurethane thickener

Adhesive composition 3 (UV-curable, pigmented)

60-70 parts of a radiation-curable aqueous polyetherurethane acrylate dispersion

(40-50% by weight)

15-25 parts titanium dioxide

0.3-0.9 parts dispersing additive of a polymeric alkylolammonium salt

5-10 parts of an organic matting agent based on a polymethyl urea resin

3-5 parts of a hydrophobized fumed silica

2-6 parts of a nonionic wax dispersion

1, 5-3 parts of a blend of an alpha-hydroxyalkylphenone and benzophenone

0.5-1 parts of an acylphosphine oxide

and optionally the following ingredients

0.6-1.0 parts of a silicone defoamer

0.3-0.5 parts of a fluorosurfactant-containing leveling agent

0.6-1.0 parts of a polyethersiloxane copolymer

2-5 parts water

2-4 parts of butylglycol as a film-forming assistant

0.4-0.8 parts of a polyurethane thickener Adhesive composition 4 (UV-curable, unpigmented)

25-45 parts of a self-crosslinking aqueous acrylate dispersion (50% strength by weight) 10-20 parts of a radiation-curable aqueous polyether urethane acrylate dispersion

(40-50% by weight)

3-10 parts epoxy acrylate, water-dilutable

1 -5 parts of a fumed silica or a combination of a fumed silica and an amorphous synthetic silicate

1 - 6 parts of a nonionic wax dispersion

2-10 parts of a wax, z. As carnauba wax, polyethylene wax, a combination of carnauba wax and polyethylene wax or a combination of several polyethylene waxes

1 -3 parts of a blend of an alpha-hydroxyalkylphenone and benzophenone

0.5-1 parts of an acylphosphine oxide

and optionally the following ingredients 0.2-1.0 parts of a polyethersiloxane copolymer

1 -10 parts hydroxystyrene acrylate copolymer

0.1 -5 parts of plasticizer, e.g. B. triethyl citrate

0.5-5 parts water

0.5-5 parts of butyl glycol as a film-forming assistant

0.01-1 parts of base, e.g. As an organic amine

Adhesive composition 5 (UV-curable, pigmented) 25-45 parts of a self-crosslinking aqueous acrylate dispersion (50% by weight) 5-20 parts of a radiation-curable aqueous polyetherurethane acrylate dispersion

(40-50% by weight)

3-10 parts epoxy acrylate, water-dilutable

5-25 parts color pigment, z. As titanium dioxide or colored pigment

1 -8 parts of a fumed silica or an amorphous synthetic silicate or a combination of a fumed silica and an amorphous synthetic silicate

1 - 6 parts of a nonionic wax dispersion

1 -10 parts hydroxystyrene acrylate copolymer

1 -3 parts of a blend of an alpha-hydroxyalkylphenone and benzophenone 0.5-1 parts of an acylphosphine oxide

and optionally the following ingredients

0.1 -5 parts of plasticizer, e.g. B. triethyl citrate

0.2-1.0 parts of a polyethersiloxane copolymer

0.2-1, 0 parts of a defoamer, z. A silicone defoamer or a siloxane-free defoamer;

0.3-0.5 parts of a flow control agent, for. B. a fluorosurfactant-containing leveling agent 0.5-5 parts of water

0.5-5 parts of butyl glycol as a film-forming assistant

0.01-1 parts of base, e.g. As an organic amine

Adhesive composition 6 (UV-curable, not pigmented)

30-70 parts of a polyester urethane dispersion (40% strength by weight)

10-50 parts of a radiation curable aqueous polyetherurethane acrylate dispersion

(40-50% by weight) 1, 5-3 parts of a blend of an alpha-hydroxyalkylphenone and benzophenone 0.5-1 parts of an acylphosphine oxide

and optionally the following ingredients

0-20 parts water

0.8-1.5 parts of a polysiloxane defoamer

0.4-1, 2 parts of a polyethersiloxane copolymer

0.5-1.0 parts of a fluorosurfactant-containing leveling agent

0.01-0.5 parts of a polyurethane thickener Adhesive composition 7 (UV-curable, not pigmented)

15-60 parts of a polyester urethane dispersion (40% strength by weight)

15-60 parts of a self-crosslinking aqueous acrylate dispersion (50% strength by weight)

(40-50% by weight)

1, 5-3 parts of a blend of an alpha-hydroxyalkylphenone and benzophenone

0.5-1 parts of an acylphosphine oxide

and optionally the following ingredients

0-20 parts water

0.8-1.5 parts of a polysiloxane defoamer

0.4-1, 2 parts of a polyethersiloxane copolymer

0.5-1.0 parts of a fluorosurfactant-containing leveling agent

0.01-0.5 parts of a polyurethane thickener It may further be desirable for the adhesive layer (s) and / or the lacquer layer (s) to be colored. For this purpose, lacquer layer (s) and / or the adhesive layer (s) may contain one or more coloring constituents such as organic and / or inorganic pigments or dyes. Examples of these pigments are titanium dioxide as a white pigment, furthermore iron oxide pigments such as iron oxide yellow, iron oxide red, iron oxide black, black pigments such as carbon black, phthalocyanine pigments such as heliogen blue or heliogen green, bismuth pigments such as bismuth van yellow and diketopyrrolopyrrole red. Metallization effects may also include metal pigments such as iron pigments, pearlescent pigments and aluminum pigments. Preferred pigments typically have particle sizes in the range from 0.1 to 100 μm, in particular in the range from 1 to 50 μm.

Adhesive layers typically have layer thicknesses in the range of 5 to 25 μm. The thermal transfer films according to the invention naturally have at least one carrier foil on which the at least one lacquer layer is arranged. The carrier films are usually plastic films made of thermoplastic flexible polymers. In particular, these are polyester films, polyamide films, polypropylene films, films of polyvinyl alcohol or polyesteramide films. Also suitable are so-called coextrudate films, ie consisting of several layers of films, wherein the plastic material may be different in the individual layers. Preferably, the plastic material which forms the carrier film is predominantly amorphous. Waxed or siliconized papers are also suitable. The carrier film (2) preferably has a thickness in the range from 3 to 200 μm, in particular from 10 to 100 μm, and especially from 20 to 50 μm. Also suitable are thin carrier films with film thicknesses in the range of 3 to 30 μm.

The surface structure of the carrier film on which the lacquer layer is arranged naturally determines the degree of gloss of the lacquer layer which is obtained in the coating method according to the invention. Smooth surfaces result in shiny or glossy surfaces, whereas rough surfaces can achieve matt effects. It is possible to create coarser structures in the paint surface by a strong structuring of the surface.

The surface of the carrier film on which the lacquer layer is arranged may have a conventional release layer, which facilitates the detachment of the lacquer layer from the carrier film in the coating method according to the invention. The production of the thermal transfer foils can be carried out in analogy to conventional foil coating technologies, as also described in the cited prior art, with the difference that no heat-drying step is carried out during the production of the lacquer layer, but rather by applying the non-aqueous radiation-curable , Liquid composition obtained on the carrier film liquid lacquer layer is at least partially cured by treatment with high-energy radiation such as electron radiation or UV radiation.

The application of the non-aqueous, radiation-curable, liquid composition to the carrier film in step i) of the process according to the invention can be carried out in a manner known per se, for example by knife coating, rolling, pouring or spraying. In this way, one obtains a coating of the carrier film with the radiation-curable composition, which can then be cured by treatment with high-energy radiation. The order quantity is usually chosen such that a layer thickness results in the above-mentioned ranges. As a rule, the amount in the range of 10 to 120 g / m ² , in particular in the range of 30 to

80 g / m ² and in the case of several layers preferably in the range from 10 to 100 g / m ² and in particular from 20 to 70 g / m ² . In step ii) of the method according to the invention, the coating obtained in step i) is then at least partially cured by means of high-energy radiation. Optionally, a decorative layer can be applied to the not yet cured or partially cured coating prior to complete curing. Optionally, the adhesive layer may also be applied prior to curing. Preferably, in step ii) of the process according to the invention, the coating obtained in step i) is only partially cured. Preferably, however, prior to the application of the heat-sealable, polymeric adhesive layer and before the optional application of the decorative layer, the layer obtained in step i) is at least partially cured.

For hardening in step ii), the coating obtained in step i) is irradiated with high-energy radiation. The irradiation can be carried out by the carrier foil or by direct irradiation of the coating. Preference is given to direct irradiation. The irradiation can be effected by means of electron radiation or with UV light, for example with UV lamps or UV-emitting light-emitting diodes. Preferably, UV radiation is used for curing in step ii). In particular, UV radiation is used in the wavelength range from 200 to 400 nm. Preference is given to using medium-pressure mercury lamps or high-pressure mercury lamps for this purpose. In many cases, gallium or iron-doped high-pressure mercury lamps are used.

The irradiation in step ii) is preferably carried out in such a way that only partial polymerization of the ethylenically unsaturated double bonds contained in the nonaqueous, radiation-curable, liquid composition takes place. The radiation density required for this purpose can be determined by the expert by means of routine experiments.

Typically, the irradiation in step ii) takes place at a radiation density in the range from 80 to 2000 J / m ² , in particular in the range from 1 10 to 400 J / m ² .

The curing in step ii) can be carried out under air atmosphere or under an oxygen-poor atmosphere at residual oxygen concentrations below 2000 ppm, eg. B. at residual oxygen concentrations in the range of 50 to 1000 ppm, take place. The curing preferably takes place under air. If the thermal transfer film according to the invention comprises a plurality of lacquer layers, the individual lacquer layers can be applied, for example, in a liquid-liquid order, ie the second lacquer layer and any further lacquer layers are applied to the still liquid first coating before curing. Preferably, however, the first lacquer layer is at least partially cured by high-energy radiation before the application of the further lacquer layer (s).

Optionally, a decorative layer is applied to the lacquer layer prior to the application of the adhesive layer or, in the case of multiple lacquer layers, to the first lacquer layer. This decorative layer can be applied in a manner known per se by suitable printing methods, for example by flat, gravure, inkjet or digital printing. Preferably, the lacquer layer is partially cured before the decorative layer is applied, wherein the partial curing is preferably carried out only to the extent that it is just possible to apply the decorative layer. The printing inks used to produce the decorative layer can be conventional printing inks or UV-curing printing inks.

The application of the heat-sealable adhesive layer in step iv) of the method according to the invention can be carried out in a manner known per se. For this purpose, a liquid adhesive composition, in particular an aqueous adhesive composition in the usual manner, for example, by knife coating, rolling, casting or spraying on the paint layer or on the decorative layer is usually applied. Subsequently, the adhesive layer is dried, for example by heat. The application amount of the liquid adhesive composition is usually selected so that, after drying, a layer thickness results in the above ranges. In general, the application rate is in the range of 5 to 50 g solids per m ² , in particular in the range of 5 to 15 g solids per m ² . For example, with the method according to the invention, the following film constructions 1 to 12 can be produced by using the steps given there. Here, the film structures 7 to 12 correspond to the film structures 1 to 6 with the difference that a pigment-containing adhesive composition is used.

Film Structure 1:

1 . Providing a carrier sheet; 2. coating the carrier film with a liquid, radiation-curable, abrasion-free, colorless composition;

Partial hardening of the lacquer layer by means of UV radiation;

4. applying a water-based, pigment-free adhesive composition with radiation-curable constituents;

5. Air heat drying.

Foil structure 2:

1 . Providing a carrier sheet;

2. coating the carrier film with a liquid, radiation-curable, abrasive-free composition;

Partial hardening of the lacquer layer by means of UV radiation;

4. application of a decorative layer by gravure or digital printing using a UV-curable ink;

5. drying of the decorative layer by means of UV radiation;

6. applying a water-based, pigment-free adhesive composition having radiation-curable constituents to the decorative layer;

7. Air-heat drying.

Film Structure 3:

1 . Providing a carrier sheet;

2. coating the carrier film with a liquid, radiation-curable, abrasive-free, color pigment-containing composition;

Partial hardening of the colored lacquer layer by means of UV radiation;

4. applying a water-based, pigment-free adhesive composition having radiation-curable constituents to the lacquer layer;

5. Air heat drying.

Film Structure 4:

1 . Providing a carrier sheet;

2. coating the carrier film with a liquid, radiation-curable, corundum-containing composition;

3. Drying of the colored lacquer layer by means of UV radiation;

5. Air heat drying. Film Structure 5:

1 . Providing a carrier sheet;

Partial hardening of the lacquer layer by means of UV radiation;

5. drying of the decorative layer by means of UV radiation;

7. Air-heat drying. Foil structure 6:

1 . Providing a carrier sheet;

2. coating the carrier film with a liquid, radiation-curable, abrasive-containing, color pigment-containing composition;

Partial hardening of the colored lacquer layer by means of UV radiation;

5. Air heat drying. The resulting thermal transfer films can then be made up in the usual way, for. B. are wound into rolls.

The thermal transfer films according to the invention are particularly suitable for the dry coating of surfaces of objects. Here, as already described above, by application of heat and / or pressure, the lacquer layer or the lacquer layers on the surface to be coated of the article, hereinafter also referred to as a substrate transferred, the adhesive layer after irradiation a good bond between the or the paint layers and the substrate causes. The use of the thermal transfer films according to the invention is not limited to certain substrates, but they can be very versatile applied to both hard and elastic substrates.

The substrates may be, for example, articles made of plastic, for example ABS, polycarbonate, melamine, polyester, including glass fibers. strong polyester, hard PVC, soft PVC, rubber, wood including exotic natural woods, wood-based materials, eg. As veneer, MDF, HDF, Feinspan- or multiplex plates, mineral fibers, z. As mineral fiber boards, paper, textile including synthetic leather, metal or plastic-coated materials act. Preferably, the thermal transfer films according to the invention are suitable for smooth, preferably plane or slightly curved surfaces. In principle, however, even more complex structures can be coated in this way. The substrates to be coated may be undecorated or already have decorative surfaces. With the use of the thermal transfer films according to the invention, it is particularly advantageous to coat exotic natural woods, which in many cases cause problems in the case of wet painting since the contents bleed or adhesion problems are caused. The coated using the thermal transfer films of the invention objects, for. As wood fiber boards, MDF boards or natural wood panels that have been primed using the thermal transfer films of the invention can be readily coated with a conventional UV coating, with no intermediate sanding is required. Alternatively, such a primed article can also be dry-coated with a thermal transfer film according to the invention.

The thermal transfer films according to the invention allow almost waste-free coating of articles. In industrial production, a change from colorless to color, from dull to glossy, can take place very rapidly, without a cleaning step being required between these changes. Drying times are eliminated, and after the coating can be continued directly, z. B. applied a conventional paint job or the coated article to be packaged. The carrier film can be peeled off or initially remain as a protective film on the coated surface. In comparison to conventional painting processes, the use of the thermal transfer films according to the invention permits a dust-free coating. In addition, the space requirements and personnel costs compared to conventional painting process is much lower.

The thermal transfer films of the invention provide compared to the known from the prior art thermal transfer films surfaces with particularly high valence, especially high scratch and abrasion resistance. For example, surfaces of quality classes AC3 to AC4 (DIN EN 13329) can be achieved. The surfaces obtained using the thermal transfer films according to the invention regularly show values above 20 N when tested with the Hamberger planer. The surfaces thus obtained regularly meet the requirements of the highest stress group of the furniture standard DIN 68861. The use of the thermal transfer films according to the invention for coating surfaces of articles is typically carried out in a process which comprises the abovementioned steps a) to d), which are described in more detail below and which can be carried out in analogy to the procedure described in EP 2078618 A2 , The relevant content of EP 2078618 A2 is hereby incorporated by reference.

Here, the thermal transfer film of the invention is first applied to the surface of the substrate to be coated and then heat sealed. The heat sealing is typically carried out using pressure in suitable presses, wherein the temperature of the press is typically in the range of 100 to 250 ° C, preferably in the range of 160 to 220 ° C. Preference is given to roller presses, since in this way only a short contact is required, so that the object temperature in this case does not exceed a value of 70 ° C, in particular of 60 ° C. In this way, heat-sensitive substrates can be coated.

Subsequently, the thus coated substrate with high-energy radiation, d. H. irradiated with UV or electron radiation, the coating layer cures completely. The irradiation can be carried out before the carrier foil is removed or subsequently. For a number of applications, it is advantageous to carry out the irradiation before removing the carrier film, since then the carrier film remains as a protective film on the coated substrate.

The irradiation can by means of electron radiation, z. B. using Gallium radiators or with UV light, for example, with UV lamps or UV radiation emitting LEDs occur. Preferably, UV radiation is used for curing in step ii). In particular, UV radiation is used in the wavelength range from 200 to 400 nm. Preference is given to using mercury medium pressure or high-pressure mercury lamps for this purpose. In many cases, gallium or iron-doped high-pressure mercury lamps are used.

Typically, the irradiation in step ii) takes place at a radiation density in the range from 40 to 2000 J / m ² , in particular in the range from 100 to 400 J / m ² . A system for carrying out the method according to the invention comprises at least one commonly used thermal transfer device, which preferably has a cutting device and / or a winding device for the carrier film. Depending on the intended use of the finished painted article, the equipment may include a first thermal transfer device with which the article is primed and a second thermal transfer device, with which the article is finished, have.

A conventional thermal transfer device can be constructed as follows: From a film unwinding the wound as a roll thermal transfer film is fed to a heated roller press having at least one driven, heated, optionally rubberized roller, which is optionally adjustable in height. The roller press usually has one of the heated roller opposite counter-pressure roller, which may be rubberized. This causes the necessary pressing pressure, whereby the lacquer layer is transferred by means of the adhesive layer to the surface of an object which is guided between the two rollers. The counter-pressure roller can be designed so that it causes the separation of the carrier film from the paint layer. The separated carrier film can be removed with a cutter or fed to a Folienaufwickeleinrichtung. Instead of a roller press, it is also possible to use a plate press, which is opened after a predetermined time.

Subsequently, the coated article with the coated side is passed past a source of high energy radiation, such as an electron beam or UV emitter, exposing the coated side of the article to high energy radiation and achieving final cure. The article thus coated is subsequently fed to a collecting device, for example a stacking device. Before or after the irradiation, the carrier film can be removed with a cutter or fed to a film take-up device.

The object coated in the thermal transfer device can also be supplied to a further thermal transfer device after removal of the carrier film before or after curing by means of high-energy radiation, in which a further lacquer layer is applied to the coated surface of the article by means of a further thermal transfer film according to the invention. Preferably, following the application of the further lacquer layer, curing with high-energy radiation is carried out as described above.

A first embodiment of a device for the continuous implementation of the method according to the invention with solid substrates comprises a lay-on conveyor belt, a unwinding station for the wound as a roll thermal transfer film, a thermal transfer device with roller press, as described above, a Aufwickelvor- direction for the carrier film, a drying channel with UV emitter, a discharge belt and a stacking device on.

The substrates to be coated, preferably plates, are placed on the conveyor belt and guided through the thermal transfer device at the desired feed rate. In this case, the lacquer layer is transferred to the substrate and the carrier foil separated and taken up by the take-up device. Subsequently, the lacquer layer is cured in the drying channel. The winding station can also be arranged after the drying channel, so that the carrier film initially remains on the substrate and acts there as a protective film.

A second embodiment of an apparatus for continuously carrying out the method according to the invention with elastic substrates comprises a unwinding station for the substrate, a unwinding station for the wound up as a thermal transfer film, a thermal transfer device with roller press, as described above, a drying channel with UV emitter and a winding device for the coated substrate.

The substrate to be coated is guided through the thermal transfer device at the desired feed rate together with the thermal transfer film. Here, the thermal transfer film is bonded to the substrate. Subsequently, the thus coated substrate is passed through the drying channel, whereby the lacquer layer cures and received by the winding station. After cutting, the carrier film can be removed.

A third embodiment of a device for continuously carrying out the method according to the invention with solid substrates comprises a conveyor belt, an unwinding station for the wound as a roll thermal transfer film, a thermal transfer device with heated platen press and optionally a take-up device for the carrier film or a cutting device.

The substrates to be coated, preferably plates, are placed on the conveyor belt and fed together with the thermal transfer film in the plate press. The press is closed and pressurized with the desired pressure. In this case, the lacquer layer is transferred to the substrate. After opening the press, the substrate is driven out of the press and passed through the drying channel, whereby the lacquer layer cures. In this case, the carrier film can remain on the substrate and serve as a protective film. In this case, the carrier foil may be used before or after drying. be cut with a cutting device. Alternatively, it is possible to separate the film as a whole in front of the UV channel and supply it to the take-up device.

A further embodiment of a device for the discontinuous implementation of the method according to the invention with solid substrates comprises a conveyor belt, an unwinding station for wound as a roll thermal transfer film, a cutting device, thermal transfer device with heated platen press and a drying channel with UV lamp. The substrate to be coated is placed on the conveyor belt. The thermal transfer film is unwound to the desired length, placed with the adhesive layer on the substrate to be coated and cut. Substrate and foil are fed into the plate press. The press is closed and pressurized with the desired pressure. In this case, the lacquer layer is transferred to the substrate. After opening the press, the coated substrate is driven out of the press and passed through the drying channel, whereby the lacquer layer cures. In this case, the carrier film can remain on the substrate and serve as a protective film. Alternatively, it is possible to separate the film from the UV channel. For further details on this is in particular to the figures 2 to 6 of

EP 2078618 A2 and the explanations made there reference.

The following examples serve to illustrate the invention: I. Starting Materials for Radiation-Curable Composition

Urethane acrylate diluted with 35% by weight of dipropylene glycol diacrylate, functionality 2.0: Laromer® UA9065 from BASF SE

Aliphatic urethane acrylate 1 diluted with 35% by weight of dipropylene glycol diacrylate: Laromer® UA19T from BASF SE

Aliphatic urethane acrylate 2, diluted with 30% by weight of trimethylolpropane monoacrylate, functionality 1, 7: Laromer® UA9033 from BASF SE

Aliphatic urethane acrylate 3 diluted with 30% by weight of hexanediol diacrylate: Laromer® LR 8987 from BASF SE

Polyester acrylate 1, functionality 3.3, hydroxyl number 70: Laromer® PE9084 of

BASF SE

Polyester acrylate 2, functionality 3.2, hydroxyl number 50: Laromer® PE9074 from BASF SE Polyester acrylate 3, functionality 3.1, hydroxyl number 70: Laromer® PE55F from BASF SE

Polyester acrylate 4, functionality 2.5, hydroxyl number 60, blended with 20% by weight of tripropylene glycol diacrylate: Laromer® PE9045 from BASF SE

Phenoxyethyl acrylate: Laromer® POEA from BASF SE

Trimethylolpropane Formal Monoacrylate: Laromer® LR8887 from BASF SE

Trimethylolpropane triacrylate: Laromer® TMPTA from BASF SE

- dipropylene glycol diacrylate (DPGDA)

Pyrogenic silica: ACE Matt TS 100 from Evonik Industries AG

Matting agent based on silicic acid (Syloid ED 80)

- Aluminum oxide: Alodur ZWSK F320 / 280 from Treibacher

- Corundum 1: Alodur F280 Fa. Treibacher

- Corundum 2: Alodur F320 Fa. Treibacher

- Synthetic silicic acid: Syloid® RAD 2005 from Grace

- Synthetic, organically modified silicic acid: Gasil® UV 70C

Polyether siloxane: Tego Glide 435 from Evonik Industries AG

- Deaerator concentrate: Tego Airex 920 from Evonik

alpha-hydroxyalkylphenone: Irgacure® 184 from BASF SE

Acylphosphine oxide: Irgacure® 2100 from BASF SE

- phenylglyoxylate: Irgacure® MBF from BASF SE

Triazine-based UV absorber: mixture of 2- [4 - [(2-hydroxy-3-dodecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3, 5-triazine and 2- [4 - [(2-hydroxy-3-tridecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1, 3,5-triazine.

UV stabilizer (HALS): mixture of bis (1,2,2,5,5-pentamethyl-4-piperidyl) sebacate 1 - (methyl) -8- (1,2,2,5,5-pentamethyl -4-piperidyl) sebacate

From the above-mentioned raw materials, the following radiation-curable varnish formulations 1 to 7 were prepared by blending:

Paint formulation 1:

Raw material Quantity [wt.%] ¹⁾

Urethane acrylate diluted with 35% by weight of Dipropy30.0

glycol diacrylate, functionality 2.0

Polyester acrylate 1, 9.0

Functionality 3.3

Trimethylolpropane formal monoacrylate 9.8

Trimethylolpropane triacrylate 13.0

Aliphatic urethane acrylate 2 diluted to 30 8.5 % By weight of trimethylolpropane formal monoacrylate,

Functionality 1, 7

Alumina (corundum) 25.0

Deaerator concentrate 0,5

Pyrogenic silica 1, 0

Phenyl glyoxylate 1, 6

Acylphosphine oxide 0.4

alpha-hydroxyalkylphenone 1, 0

1) based on the total weight of the composition

Paint formulation 2:

Raw material Quantity [weight%] ¹ >

Urethane acrylate diluted with 35% by weight of Dipropy 37.0

glycol diacrylate, functionality 2.0

Aliphatic urethane acrylate 2, diluted at 24.7

30% by weight of trimethylolpropane formal monoacrylate,

Functionality 1, 7

Phenoxyethyl acrylate 24.7

Synthetic Silica 6.0

Synthetic, organically modified silica 2.5

Pyrogenic silica 1, 0

Polyethersiloxane 0.6

Deaerator concentrate 0,5

Phenyl glyoxylate 1, 0

Acylphosphine oxide 0.2

alpha-hydroxyalkylphenone 0.9

Benzophenone 0.9

1) based on the total weight of the composition

Paint formulation 3:

Raw material Quantity [weight%] ¹ >

Polyester acrylate 2 33.4

Trimethylolpropane triacrylate 14.3

Polyester acrylate 3 10.3

Trimethylolpropane formal monoacrylate 10.5

Phenoxyethyl acrylate 1 1, 0

Polyester acrylate 4 10.0

Deaerator concentrate 0,5 Phenyl glyoxylate 1, 6

Acylphosphine oxide 0.4

alpha-hydroxyalkylphenone 1, 0

1) based on the total weight of the composition

Paint formulation 4 ::

Raw material Quantity [weight%] ¹ >

Aliphatic urethane acrylate 3, diluted 30 80

% By weight hexanediol diacrylate

Dipropylene glycol diacrylate 10

Silicone defoamer 0,35

Matting agent based on silica 7.0

Phenyl glyoxylate 1, 3

Acylphosphine oxide 1, 35

1) based on the total weight of the composition

Paint formulation 5:

Raw material Quantity [weight%] ¹ >

Urethane acrylate diluted with 35% by weight of Dipropy 26.0

glycol diacrylate, functionality 2.0

Aliphatic urethane acrylate 2, diluted 8.5

30% by weight of trimethylolpropane formal monoacrylate

Polyester acrylate 1 8.0

Trimethylolpropane formal monoacrylate 7,0

Phenoxyethyl acrylate 7.0

Trimethylolpropane triacrylate 1 1, 0

Matting agent based on silica 5.0

Corundum 1 15.0

Corundum 2 10.0

Silicone defoamer 0.3

Rheology additive 0.2

Acylphosphine oxide 2.0

1) based on the total weight of the composition

Paint formulation 6:

Raw material Quantity [weight%] ¹ >

Aliphatic urethane acrylate 1 diluted 35 34.0

% By weight of dipropylene glycol diacrylate Aliphatic urethane acrylate 2, diluted with 1, 5

30% by weight of trimethylolpropane formal monoacrylate

Polyester acrylate 1 10.0

Trimethylolpropane formal monoacrylate 1 1, 0

Phenoxyethyl acrylate 10.0

Trimethylolpropane triacrylate 14.0

Matting agent based on silica 7.0

Silicone defoamer 0.3

Acylphosphine oxide 2.0

1) based on the total weight of the composition

Paint formulation 7 ::

Raw material Quantity [weight%] ¹ >

Aliphatic urethane acrylate 3, diluted 77.0

30% by weight of hexanediol diacrylate

Hexanediol diacrylate 12.0

Matting agent based on silica 5.0

Triazine-based UV absorber 2.0

UV stabilizer 1, 0

Silicone defoamer 0,35

Acylphosphine oxide 1, 3

Phenyl glyoxylate 1, 3

1) based on the total weight of the composition II. Adhesive composition feeds

Self-crosslinking, aqueous polyacrylate dispersion 1 (50% strength by weight): Acronal® A849S from BASF SE

Self-crosslinking, aqueous multiphase polyacrylate dispersion 2 (48% strength by weight), minimum film-forming temperature 50 ° C .;

Aqueous polyester urethane dispersion, 40% strength by weight, glass transition temperature <-50 ° C .;

Aqueous polyether urethane acrylate dispersion 1 (40% strength by weight): Laromer® LR9005 from BASF SE

Aqueous polyether urethane acrylate dispersion 2 (40% strength by weight): Syntholux® 1014 W from Synthopol Chemie

Aliphatic epoxy acrylate: Laromer® LR 8765 from BASF SE

Polyethersiloxane emulsion: Tego® Wet 270 from Evonik Industries AG - Polymeric fluorosurfactant: Tego® Twin from Evonik Industries AG Wetting additive 1: siloxane-gemini-surfactant

Wetting additive 2: polyethersiloxane

Carnauba wax dispersion: CA 30 from Münzing Liquid Technologies GmbH

Modified polyethylene wax, aqueous dispersion: Aquamat® 270 from Byk Chemie GmbH

Pyrogenic silica: ACE Matt TS 100, Evonik Industries AG

Micronized polyethylene wax: Aquaflour® 400 from Byk Chemie GmbH

Synthetic silicic acid: Sylysia from the company Finma Chemie

Aqueous polyurethane dispersion: Ecrothan 90 from Ecronova Polymer GmbH - dimethylpolysiloxane: Tego® Glide 482 from Evonik Industries AG

Styrene-acrylate copolymer: Acronal® S 813 from BASF SE

Triethyl citrate: Citrofol AI from Jungbunzlauer GmbH

alpha-hydroxyalkylphenone: Irgacure® 184

Acyl phosphine oxide: Irgacure® 2100

Bisacylphosphine oxide: Irgacure® 819 DW

Mixture of benzophenone and 1-hydroxycyclohexyl phenyl ketone;

Defoamer: silicone-based emulsion;

Thickener: Aqueous thickener solution (Vocaflex)

Aqueous titanium dioxide paste: Luconyl® white 0022 from BASF SE

The adhesive composition 1 was prepared by mixing the following ingredients.

Adhesive formulation 1:

Raw material Quantity [% by weight] ¹ >

Self-crosslinking aqueous polyacrylate 39.0

Dispersion 1

Aqueous polyether urethane acrylate 16.4

Dispersion 1

Polyether siloxane emulsion 0.44

Polymeric Fluorosurfactant 0.35

Carnauba wax dispersion 1, 20

Modified polyethylene wax 7.3

Pyrogenic silica 1, 5

Synthetic silica 1, 3

Micronized polyethylene wax 1, 7

Polyurethane dispersion 13.0

Dimethylpolysiloxane 0.4

Aliphatic epoxy acrylate 6.1 Styrene-acrylate dispersion (50%) 4.4

Triethyl citrate 1, 75

alpha-hydroxyalkylphenone 1, 0

Acylphosphine oxide 0.7

Benzophenone 0.85

Butyl glycol 1, 0

Water 1, 0

Aminoalcohol 0.17

1) based on the total weight of the composition

The adhesive formulation 2 was prepared by mixing the constituents indicated in the following table.

Adhesive formulation 2

1) based on the total weight of the composition

The adhesive formulation 3 was prepared by mixing the constituents indicated in the following table. Adhesive formulation 3

The adhesive formulation 4 was prepared by mixing the constituents indicated in the following table.

Adhesive formulation 4

1) based on the total weight of the composition

III. Production of the film materials according to the invention:

In the following examples, a device was used for the irradiation, in which the coated or printed film with a defined feed rate of a Ga-doped mercury beam with the power of 120 W / cm was passed.

For the films of Examples 1, 2 and 3, a UV-curable gravure ink based on an epoxy acrylate was used. Example 1: Film for use as a color lacquer in the furniture sector

On an undyed polyethylene terephthalate support film with a layer thickness of 23 μηη the paint formulation 4 was applied with a layer thickness of 40 g / m ² . The thus-coated film was passed past the Ga-doped mercury radiator at a feed rate of 30 m / min to gel the lacquer layer.

Subsequently, the UV-curable gravure ink was applied to the gelled lacquer layer. The so-printed film was again passed to the Ga-doped mercury lamp for curing at a feed rate of 30 m / min.

Then the adhesive formulation 3 with a layer thickness of 15 g / m ^{2 was} applied to the printed lacquer layer and thermally dried.

Example 2: Film for use as a color lacquer in the furniture sector

On an undyed polyethylene terephthalate support film with a layer thickness of 23 μηη the paint formulation 5 was applied with a layer thickness of 70 g / m ² . The thus-coated film was passed past the Ga-doped mercury radiator at a feed rate of 30 m / min to gel the lacquer layer.

Then the adhesive formulation 3 with a layer thickness of 15 g / m ^{2 was} applied to the printed lacquer layer and thermally dried. Example 3: Film for use as a clearcoat in the furniture sector

On an undyed polyethylene terephthalate support film with a layer thickness of 23 μηη the paint formulation 6 was applied with a layer thickness of 40 g / m ² . The thus-coated film was passed past the Ga-doped mercury radiator at a feed rate of 30 m / min in order to gel the lacquer layer.

Then the adhesive formulation 3 with a layer thickness of 15 g / m ^{2 was} applied to the printed lacquer layer and thermally dried. Example 4: Film for use as exterior color paint

On an undyed polyethylene terephthalate support film with a layer thickness of 23 μηη the paint formulation 7 was applied with a layer thickness of 45 g / m ² . The thus-coated film was passed past the Ga-doped mercury radiator at a feed rate of 30 m / min to gel the lacquer layer.

Then the adhesive formulation 3 with a layer thickness of 15 g / m ^{2 was} applied to the printed lacquer layer and thermally dried. IV. Testing of the Film Materials According to the Invention: a) Testing the Crosslinking of the Adhesive Layer

The film of Example 3 was laminated by means of a heated roller (180 ° C, object temperature 50 ° C maximum) on a beech wood panel. Subsequently, the thus laminated film was irradiated by Verbeiführen the laminated side at a feed rate of 20 m / min to two UV lamps (mercury radiator and Ga-doped mercury radiator), each with a power of 120 W / cm through the film. The sample thus obtained was analyzed by ATR-FTIR spectroscopy using an FT-IR spectrometer from Nicolet (Nicolet 380) and a Golden Gate® probe head. Compared to a non-irradiated sample, a significant decrease in the absorption bands characteristic of acrylate groups was observed at 810 cm-1 (> 40%) and 1410 cm-1 (> 30%). b) Checking the stability of the coating

The following tests were carried out: P1: Resistance to water (24 h) according to DIN 68861 -1: 201 1 -01. The rating was on a scale of 1 (poor) to 5 (good).

P2: Resistance to ethanol (6 h) according to DIN 68861 -1: 201 1 -01. The rating was on a scale of 1 (poor) to 5 (good). P3: Resistance to ethyl acetate (10 s) according to DIN 68861 -1: 201 1 -01. The rating was on a scale of 1 (poor) to 5 (good). P4: Testing with the Hamberger planer: For this purpose, a coin-like test specimen is drawn at a predetermined angle with variable force over the surface to be tested. The tester allows a stepless adjustment of the applied force. Indicated is the force in Newton at the just no damage to the surface can be seen.

P5: Scratch resistance in the diamond test according to EN 438-2: 205. Given is the numerical value of the highest applied force, which leaves no continuous surface scratch. P6: The cross-cut test was carried out according to DIN EN ISO 2409: 2013. The evaluation was carried out on a scale from GT 0 (good adhesion) to GT 5 (very strong flaking of the coating).

P7: Abrasion resistance according to the Falling Sand method according to DIN EN 14354: 2005-03

P8: Abrasion resistance according to the S24 method according to DIN 13329: 2013-12 The results of tests P1-P8 are summarized in Table P. Sample 1:

The film from Example 1 was laminated by means of a heated roller (180 ° C, object temperature 50 ° C maximum) at a constant contact pressure on an MDF board. Subsequently, the thus laminated plate was irradiated by passing the laminated side at a feed rate of 20 m / min on two UV lamps (mercury beam and Ga-doped mercury beam), each with a power of 120 W / cm through the film. Subsequently, the carrier film was removed.

Comparative sample V1:

For comparison purposes, the film of Example 1 was laminated by means of a heated roller (180 C, object temperature 50 C maximum) at the same contact pressure on an MDF board, but no subsequent irradiation was made.

Sample 2: The preparation was carried out in analogy to the preparation of Sample 1, using instead of the film of Example 1, the film of Example 2.

Comparative sample V2:

The preparation was carried out in analogy to the preparation of the comparative sample V1, using instead of the film of Example 1, the film of Example 2.

Sample 3:

The film from Example 3 was laminated by means of a heated roller (180 ° C, object temperature maximum 50 ° C) at a constant contact pressure on a beech wood panel. Subsequently, the thus laminated plate was irradiated by passing the laminated side at a feed rate of 20 m / min on two UV lamps (mercury radiator and Ga-doped mercury radiator), each with a power of 120 W / cm through the film. Subsequently, the carrier film was removed.

Comparative sample V3:

For comparison purposes, the film from example 3 was laminated to a beech wood panel by means of a heated roller (180 ° C., object temperature maximum 50 ° C.) at the same contact pressure, but no subsequent irradiation was carried out.

Sample 4:

The film from Example 43 was laminated by means of a heated roller (180 ° C, object temperature 50 ° C maximum) at a constant contact pressure on a PVC plate. Subsequently, the thus laminated plate was irradiated by passing the laminated side at a feed rate of 15 m / min at two UV lamps (mercury radiator and Ga-doped mercury radiator), each with a power of 120 W / cm through the film. Subsequently, the carrier film was removed. Comparative sample V4:

For comparison purposes, the film of Example 4 was laminated by means of a heated roller (180 C, object temperature 50 C maximum) at the same contact pressure on a PVC plate, but no subsequent irradiation was made.

Table P: Results of tests P1 - P8

Sample UV-P1 P2 P3 P4 P5 P6 P7 P8

Hardening [N] [N] [Umiir [Umin] 1 1

1 yes 5 5 5 20 1, 2 GTO n.b. n.d.

2 Yes 5 5 5 19 1, 0 GTO 620 1600

3 Yes 5 5 5 18 1, 1 GTO n.b. n.d.

4 Yes 5 5 5 19 1, 3 GT1 n.b. n.d.

V1 no 4-5 5 5 13 0.7 GT5 n.b. n.d.

V2 no 4-5 4-5 5 14 0.6 GT4 630 1550

V3 no 4 4 5 13 0,7 GT4 n.b. n.d.

V4 no 5 5 5 13 0.7 GT3 n.b. n.d.

The results show that good adhesion can only be achieved if the adhesive layer contains a radiation-curable component which is crosslinked by irradiation with UV radiation after lamination. In addition, in this way better surface hardness

Claims

Patent claims

1 . Thermal transfer film (1), comprising: a carrier film (2),

at least one lacquer layer (3) arranged on the carrier film (2), at least one heat-sealable, polymeric adhesive layer (4), the lacquer layer being based on a non-aqueous, radiation-curable, liquid composition which contains at least 60% by weight, based on the Total weight of the composition contains curable components selected from organic oligomers that have ethylenically unsaturated double bonds and mixtures of these oligomers with monomers that have at least one ethylenically unsaturated double bond

and wherein the heat-sealable polymeric adhesive layer (4) contains at least one radiation-curable component.

Thermal transfer film according to claim 1, characterized in that the radiation-curable composition which forms the lacquer layer contains 1.5 to 8 mol of ethylenically unsaturated double bonds per kg of the composition.

Thermal transfer film according to one of the preceding claims, characterized in that the oligomers in the radiation-curable composition which forms the lacquer layer have on average 1.5 to 10, in particular 2 to 8, ethylenically unsaturated double bonds per molecule.

Thermal transfer film according to one of the preceding claims, characterized in that the ethylenically unsaturated double bonds in the oligomers and the monomers of the radiation-curable composition which forms the lacquer layer are in the form of acrylic or methacrylic groups.

Thermal transfer film according to one of the preceding claims, characterized in that the oligomers of the radiation-curable composition which forms the lacquer layer are selected from polyether (meth)acrylates, polyester (meth)acrylates, epoxy (meth)acrylates and urethane (meth)acrylates and unsaturated Polyester resins and their mixtures are selected.

Thermal transfer film according to claim 5, characterized in that the radiation-curable composition which forms the lacquer layer is at least one oligomer selected from polyester acrylates and urethane acrylates and mixtures thereof.

Thermal transfer film according to one of the preceding claims, characterized in that the monomers are selected from esters of acrylic acid with 1- to 6-valent, in particular 2- to 4-valent, aliphatic or cycloaliphatic alcohols.

Thermal transfer film according to one of the preceding claims, characterized in that the radiation-curable, liquid composition contains at least one photoinitiator which has an absorption band with a maximum max in the range from 220 to 420 nm.

Thermal transfer film according to one of the preceding claims, characterized in that the lacquer layer (3) has a layer thickness of 10 to 120 μm.

Thermal transfer film according to one of the preceding claims, characterized in that it has a decorative layer between the lacquer layer (3) and the adhesive layer (4).

1 1 . Thermal transfer film according to one of the preceding claims, characterized in that the adhesive layer (4) is based on at least one aqueous polymer dispersion.

12. Thermal transfer film according to claim 1 1, wherein the aqueous polymer dispersion contains a UV radiation-curable oligomer or polymer in dispersed form.

Thermal transfer film according to claim 1 1, wherein the UV radiation-curable polymer is a polyurethane acrylate, in particular a polyetherurethane acrylate.

Thermal transfer film according to one of the preceding claims, characterized in that the adhesive layer (4) is based on at least two aqueous polymer dispersions, at least one polymer dispersion containing a UV-curable polymer in dispersed form and at least one further polymer dispersion containing a self-crosslinking polymer in dispersed form contains.

15. A method for producing a thermal transfer film according to one of the preceding claims, comprising:

i. applying the non-aqueous radiation curable liquid composition to form a high energy radiation curable coating;

ii. Irradiation in step i. obtained curable coating with high-energy radiation, obtaining the lacquer layer (3);

iii. optionally applying a decorative layer to the curable coating or to the lacquer layer (3); and

iv. Applying the heat-sealable, polymeric adhesive layer (4).

16. The method according to claim 15, wherein the irradiation of the coating curable by high-energy radiation takes place before the application of the adhesive layer and before the optional application of the decorative layer.

17. The method according to claim 15 or 16, wherein the irradiation of the high-energy radiation-curable coating is carried out in such a way that only partial polymerization of the ethylenically unsaturated double bonds contained in the non-aqueous, radiation-curable, liquid composition occurs.

Method for coating surfaces of objects, comprising the following steps:

a) applying the thermal transfer film (1) according to one of claims 1 to 14 with the adhesive layer to the surface to be coated;

b) heat sealing the transfer film to obtain a surface coated with the transfer film;

c) irradiating the surface coated with the transfer film with UV or electron radiation;

d) if necessary, detaching the carrier film (2).

19. Use of thermal transfer films according to one of claims 1 to 14 for dry painting of objects.