Polymeric aminoacrylate (methacrylate)

Abstract

1. A polymeric amino(meth)acrylate suitable for use in a radiation curable composition, said polymeric amino(meth)acrylate being the reaction product of a secondary amine-terminated copolymer (A) and a multifunctional acrylate(methacrylate) (B), said secondary amine-terminated copolymer being the reaction product of a difunctional acrylate(methacrylate) (Ai) and a direactive amine (Aii); and wherein the multifunctional acrylate(methacrylate) (B) is different from the difunctional acrylate(methacrylate) (Ai), and the multifunctional acrylate(methacrylate) contains two or more acrylate(methacrylate) groups.

Description

[Technical Field]

[0001] The present invention relates to polymeric aminoacrylates for use in radiation-curable compositions. The present invention also relates to methods for preparing the polymeric aminoacrylates (methacrylates); radiation-curable compositions containing the polymeric aminoacrylates (methacrylates); methods for coating substrate articles with such radiation-curable compositions; and the use of the polymeric aminoacrylates (methacrylates) in coatings and inks. The polymeric aminoacrylates (methacrylates) are particularly suitable for lithography or offset ink applications. The polymeric aminoacrylates (methacrylates) can be used as UV synergists in radiation-curable compositions. The polymeric aminoacrylates (methacrylates) of the present invention are suitable for improving the cure of coatings or inks using standard UV light and / or UV LED light. [Background technology]

[0002] UV LED lamps are increasingly being used for graphic ink applications because they are safer, more energy-efficient and more environmentally friendly than traditional mercury arc lamps. UV LED lamps emit monochromatic light essentially in the UV-A zone of the ultraviolet spectrum.

[0003] Oxygen inhibition is a long-standing problem for coatings that cure via free-radical polymerization. Molecular oxygen can physically quench the triplet state of photoinitiators / sensitizers or scavenge free radicals or active radical centers, generating unreacted peroxide radicals. This can result in a variety of problems, from reduced film properties to uncured, liquid surfaces. This problem is even more pronounced with low-intensity curing processes, such as UV-LED and UVA curing, which frequently result in sticky, uncured surfaces. There are known physical and chemical methods for reducing oxygen inhibition and improving surface cure.

[0004] Crosslinking of a UV-curable coating or ink is only effective if there is good overlap with the absorbance of the photoinitiator species (PI). Only a select set of PIs absorb efficiently in this specific wavelength range, all of which aim for good through-cure of the coating.

[0005] However, it is more noticeable that there is a significant problem of oxygen inhibition during use, leading to incomplete surface cure.

[0006] Amine synergists can be used to help mitigate oxygen inhibition and enhance surface reactivity. Amine synergists have long been used in radiation-curable compositions due to the synergistic effect induced by the presence of nitrogen atoms, which can act as electron donors. Amine synergists can be aliphatic or aromatic. The amino group is known to promote UV crosslinking in the presence of photoinitiators (PIs) such as benzophenone by participating in a bimolecular priming mechanism. This same electron-donating system efficiently generates a hydrogen-donating carbon atom alpha to the nitrogen atom, enhancing surface cure reactivity through the generation of fast-propagating radical species. Furthermore, they also act as oxygen scavengers in radiation-curable formulations.

[0007] Currently available amino synergists have drawbacks that limit their use in UV LED curing. Existing materials have proven less suitable for use in inks, for example, due to migration issues in food packaging and partial water solubility, which can disrupt the oil-water balance of offset inks. This is typically the case for aliphatic amines. Furthermore, known amino synergists often cause yellowing.

[0008] Aromatic amine synergists typically exhibit low water solubility and are suitable for offset ink applications. Frequently used aromatic amine synergists include ethyl 4-N,N-dimethylaminobenzoate (EDB) and 2-ethylhexyl 4-N,N-dimethylaminobenzoate (EHA). However, these aminobenzoates also contain migratory species in the cured coating. Furthermore, the toxicity profile of these compounds is not always positive.

[0009] As described in WO 2007 / 017298, polymeric aromatic amine synergists with polyether chains between aminobenzoate moieties can reduce migratory species, but the introduction of polyether chains can adversely affect the physical properties of the cured coating.

[0010] US 2010 / 0048756 describes the preparation and use of aminoacrylates by the reaction of difunctional acrylate monomers with (divalent) primary amines to improve adhesion to plastic substrates. Typically, these types of aminoacrylates contain significant amounts of low molecular weight di(meth)acrylate compounds that can migrate from the cured coating or ink.

[0011] EP 1731541 describes the preparation of aminoacrylates from (meth)acrylated ethoxylated / propoxylated polyols and primary and / or secondary amines to produce compounds with reduced tendency to migrate from the cured composition. EP 1731541 teaches that low molecular weight monomers such as hexanediol diacrylate (HDDA) and trimethylolpropane triacrylate (TMPTA) should be used in amounts less than 10% (w / w) of the energy-curable composition, more preferably less than 5% (w / w).

[0012] WO06131259 describes low-extractable radiation-curable compositions containing aminoacrylates based on ethoxylated and / or propoxylated tri- or tetraacrylates. The amine content of the described aminoacrylates is relatively low, making them less suitable for use in low-energy curing applications. Summary of the Invention

[0013] Therefore, there is a clear need for new amino (meth)acrylates that overcome at least some or all of the above-mentioned drawbacks.

[0014] Detailed Description The present inventors have surprisingly found compounds that overcome the above problems, if not completely, at least in part, by providing a polymeric amino(meth)acrylate as defined in claim 1. Accordingly, a first aspect of the present invention relates to a polymeric amino(meth)acrylate suitable for use in a radiation curable composition, wherein the polymeric amino(meth)acrylate is the reaction product of a secondary amine-terminated copolymer (A) and a multifunctional acrylate(methacrylate) (B), which in turn is the reaction product of a difunctional acrylate(methacrylate) (Ai) and a difunctional amine (Aii), wherein the multifunctional acrylate(methacrylate) (B) is different from the difunctional acrylate(methacrylate) (Ai), and the multifunctional acrylate(methacrylate) comprises two or more (meth)acrylic groups.

[0015] It has been surprisingly found that inks containing these polymeric aminoacrylates (methacrylates) offer excellent reactivity when cured with UV, EB, or LED light, provide ink-water balance equivalent to that of standard aminobenzoates (such as EDB or EHA), and provide inks with improved pigment compatibility compared to standard aminoacrylates. Furthermore, inks containing these polymeric aminoacrylates (methacrylates) have low odor and are suitable for low-migration inks due to the low content of low-molecular-weight difunctional or monofunctional acrylate (methacrylate) monomers. Furthermore, polymeric aminoacrylates (methacrylates) can replace aminobenzoates in offset inks. Furthermore, inks containing these polymeric aminoacrylates (methacrylates) do not exhibit significant viscosity increase even when stored at high temperatures for a certain period of time.

[0016] In the present invention, a direactive amine (Aii) is an amine having two reactive NH functional groups. The direactive amine has two secondary amine groups (-NH) or one primary amine group (-NH). It is also possible to use a mixture of a primary amine compound and a compound having two secondary amine groups in the preparation of a secondary amine-terminated copolymer.

[0017] In the present invention, a difunctional acrylate (methacrylate) (Ai) refers to a compound comprising two acrylate (methacrylate) groups. A multifunctional acrylate (methacrylate) B refers to a compound comprising two or more acrylate (methacrylate) groups. Preferably, the multifunctional acrylate (methacrylate) comprises three or more, more preferably four or more, acrylate (methacrylate) groups, such as five, six, seven, eight, nine, or ten acrylate (methacrylate) groups.

[0018] In the present invention, the term "acrylate (methacrylate)" is understood to encompass both acrylated and methacrylated compounds or derivatives, as well as mixtures thereof. "Acrylate (methacrylate)" more specifically refers to a compound containing at least one acrylate group (CH2=CHCOO-) and / or at least one methacrylate group (CH2=CCH3COO-). When both acrylate and methacrylate groups are present, they can be present on the same compound or on different compounds. It may also be referred to as "acrylic (methacrylic) ester group," which means that an acrylic group, a methacrylic group, or a mixture of both is present.

[0019] A second aspect relates to a method for preparing the above-mentioned polymeric amino(meth)acrylates, comprising the steps of: (i) reacting at least one di(meth)acrylate compound (Ai) containing two acrylate (meth)acrylate groups per molecule with at least one direactive amine (Aii) to form a secondary amine-terminated copolymer (A); and (ii) reacting at least one multifunctional acrylate (methacrylate) (B), which has at least two acrylate (methacrylate) ester groups and is different from the diacrylate (methacrylate) compound (Ai), with the secondary amine-terminated copolymer (A) to obtain a polymeric aminoacrylate (methacrylate).

[0020] A third aspect of the present invention relates to radiation curable compositions such as coatings or inks comprising polymeric amino(meth)acrylates.

[0021] A fourth aspect of the present invention relates to the use of such radiation curable compositions in offset printing.

[0022] A fifth aspect relates to a substrate coated with such a radiation curable composition.

[0023] A sixth aspect of the present invention relates to a method of coating an article or substrate, comprising the steps of: (a) providing a radiation-curable composition comprising the polymeric amino(meth)acrylate described above; (b) applying the composition onto a surface; (c) Applying optical radiation to a surface or article.

[0024] Another aspect relates to a method for improving surface cure in coatings and inks, comprising the steps of: (a) providing a radiation-curable composition comprising the polymeric amino(meth)acrylate described above; (b) applying the composition onto a surface; (c) Applying optical radiation to a surface or article.

[0025] In one embodiment according to the above aspect of the invention, the molar ratio of the multifunctional (meth)acrylate compound (B) to the secondary amine-terminated copolymer (A) is at least 2:1. Also, the molar ratio of the (meth)acrylate compound (B) to the amino copolymer (A) is preferably no greater than 10:1, more preferably no greater than 6:1.

[0026] Typically, a single type of multifunctional (meth)acrylate compound (B) is reacted with the amine-terminated copolymer (A), although mixtures of different types of multifunctional (meth)acrylate compounds can also be used.

[0027] In another embodiment, a molar excess of amine to (meth)acrylate functionality is used to prepare the secondary amine copolymer A, with the amount of di(meth)acrylate compound (Ai) relative to the direactive amine compound (Aii) being such that the molar ratio of di(meth)acrylate compound (Ai) to direactive amine compound (Aii) is less than 1. Preferably, the molar ratio of di(meth)acrylate compound (Ai) to direactive amine compound (Aii) is between 0.5 and 0.9, more preferably between 0.6 and 0.8.

[0028] Two or more types of direactive amines (Aii) and / or difunctional acrylates (methacrylates) (Ai) can be used. Preferably, one type of direactive amine (Aii) and / or one type of difunctional acrylates (methacrylates) (Ai) is used in the preparation of the secondary amine copolymer A.

[0029] In another embodiment, the amine-terminated copolymer (A) has a weight average molecular weight (Mw) as determined by gel permeation chromatography (GPC) of at least 250 daltons, more preferably at least 300 daltons, and even more preferably at least 500 daltons. The molecular weight is at most 10,000 daltons, more preferably at most 7,000 daltons, even more preferably at most 5,000 daltons, and most preferably at most 2,500 daltons.

[0030] Weight average molecular weight (Mw) and number average molecular weight (Mn) are typically measured by dissolving the sample in THF and performing GPC on a 3x PLgel 5 μm Mixed-D LS 300 x 7.5 mm column at 40 °C over the MW range of 162 - 377400 g / mol calibrated with polystyrene standards.

[0031] The polymeric amino(meth)acrylates of the present invention have high acrylate(meth)acrylate functionality. The polymeric amino(meth)acrylates may contain two acrylate(meth)acrylate groups. Preferably, the polymeric amino(meth)acrylates contain three or more, more preferably four or more, for example, five, six, seven, eight, nine, or ten acrylate(meth)acrylate groups.

[0032] The process for preparing polymeric amino(meth)acrylates includes (i) reacting at least one di(meth)acrylate compound (Ai) containing two acrylate(meth)acrylate groups per molecule with at least one direactive amine (Aii) to form a secondary amine-terminated copolymer (A), and (ii) reacting at least one multifunctional acrylate(methacrylate) (B) containing at least two acrylate(methacrylate) ester groups and different from the di(methacrylated) compound (Ai) with the secondary amine-terminated copolymer (A). The reactions (i) and (ii) are known as Michael addition reactions.

[0033] In one embodiment, reactions (i) and / or (ii) can proceed in the absence of a solvent and / or catalyst. Typically, the reaction can be carried out at a temperature between -30°C and +150°C, with preferred temperatures being between 25°C and 100°C. Most preferably, the reaction is carried out between 30°C and 80°C.

[0034] Reactions (i) and / or (ii) are preferably carried out under an inert gas atmosphere, such as nitrogen or argon, although this is not necessary for the reaction to be successful.

[0035] In some embodiments, a polymerization inhibitor is added to the reaction mixture of reactions (i) and / or (ii). This can help prevent undesired polymerization during the Michael addition reaction. Suitable polymerization inhibitors include known products such as substituted phenols such as 2,6-di-tert-butyl-p-cresol, hydroquinones such as methylhydroquinone, and thioethers such as thiodiglycol or phenothiazine. Other polymer stabilizers may also be added during or after the reaction. Typically, aromatic or aliphatic phosphites can be used.

[0036] In the present invention, the difunctional acrylate (methacrylate) (Ai) is a "diacrylate (dimethacrylate), or an acrylate (methacrylate) containing two acrylic acid (methacrylic acid) ester groups per molecule."

[0037] The difunctional acrylate (methacrylate) (Ai) is typically selected from acrylic (methacrylic) acid esters (Ai1), polyester acrylate (methacrylate) (Ai2), epoxy acrylate (methacrylate) (Ai3) and / or (poly)urethane acrylate (methacrylate) (Ai4). Such compounds are well known in the art.

[0038] The (meth)acrylic acid esters (Ai1) are esters of acrylic acid (methacrylic acid) with diols, i.e., compounds essentially containing two hydroxyl groups. Examples of suitable (meth)acrylic acid esters (Ai1) are esters of acrylic acid (methacrylic acid) with difunctional polyols. "(Meth)acrylic acid" refers to acrylic acid, methacrylic acid, or a mixture of both. In particular, acrylic acid is used in the context of the present invention. "Difunctional polyol" refers to a compound containing two hydroxyl groups. In most cases, the polyols used are aliphatic polyols. Cycloaliphatic polyols can also be used. Examples of suitable aliphatic difunctional polyols include: (i) dihydric alcohols, such as (poly)propylene glycols (e.g., propylene glycol, dipropylene glycol, and tripropylene glycol); 1,3-propanediol; (Poly)ethylene glycols (such as diethylene glycol, triethylene glycol, tetraethylene glycol, and polyethylene glycol); neopentyl glycol (2,2-dimethyl-1,3-propanediol); 2-methyl-1,3-propanediol (MPD); 2-ethyl-2-butyl-1,3-propanediol; 1-ethyl-2-methyl-1,3-propanediol; 2-methyl-2-methyl-1,3-propanediol; 1,3-butylene glycol; 1,4-butanediol; 2,3-butanediol; 2-butyl-2-ethyl-1,3propanediol (BEPD); pentanediol; 2-methyl-2-ethyl-1,3propanediol; 1,3 pentanediol; 2,2,4-trimethyl-1,3 pentanediol; hexylene glycol; 1,6-hexanediol; 1,8-octanediol; and 1,12-dodecanediol. Mention may be made of 3-hydroxy-2,2-dimethylpropanoate, hydroxypivalyl hydroxypivalate (HPHP); hydroxypivalate of neopentyl glycol) and / or 2,2,4-trimethyl-1,3-pentanediol (TMPD); and lactone or lactide modifications thereof, as well as ethoxylated or propoxylated versions thereof.Cycloaliphatic polyols are also suitable and may be selected from, for example, 1,4-cyclohexanediol, 3,5-dimethylcyclohexanol (cis / trans mixtures), 1,4-cyclohexanedimethanol, tricyclodecane dimethanol, 1,3-bis(4-hydroxycyclohexyl)propane, 2,2,4,4-tetramethylcyclobutane 1,3 diol, 1,3- and 1,4-cyclohexanediol, cyclooctanediol, norbornanediol, pinanediol, decalindiol, dioxane glycol, isosorbide and hydrogenated bisphenol A, (ib) arallyphatic polyols (such as 1,3-xylylenediol) and / or (ic) aromatic polyols such as 2,2-bis(4-hydroxyphenyl)propane bisphenol A. Preferred diols are neopentyl glycol (2,2-dimethyl-1,3-propanediol), 2-methyl-1,3-propanediol (MPD), dipropylene glycol, tripropylene glycol, 2-ethyl-2-butyl-1,3-propanediol, 1-ethyl-2-methyl-1,3-propanediol, tricyclodecane dimethanol, 2-ethyl-2-methyl-1,3-propanediol, 1,3-butylene glycol, 1,4-butanediol, 2,3-butanediol, 2-butyl-2-ethyl-1,3-propanediol (BEPD), pentanediol, 2-methyl-2-ethyl-1,3-propanediol, 1,3-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, hexylene glycol, 1,6-hexanediol, 1,8-octanediol, and 1,12-dodecanediol. 3-hydroxy-2,2-dimethylpropanoate, hydroxypivalyl hydroxypivalate (HPHP); hydroxypivalate of neopentyl glycol) and / or 2,2,4-trimethyl-1,3-pentanediol (TMPD); 1,4-cyclohexanediethanol, norbordanediol and / or isosorbide.Most preferably, the diol is neopentyl glycol (2,2-dimethyl-1,3-propanediol), 2-methyl-1,3-propanediol (MPD), 1,4-butanediol, pentanediol, 1,6-hexanediol, tricyclodecanediol, or isosorbide aniol. Mixtures of diols can also be used.

[0039] Other suitable difunctional acrylates (methacrylates) (Ai) are "polyester acrylates (methacrylates)" (Ai2). This refers to polyester acrylates, polyester methacrylates, or a mixture of both. Polyester acrylates (methacrylates) are prepared using hydroxyl-containing polyesters (polyester polyols). They can be prepared by esterification of polycarboxylic acids with polyols in a well-known manner (see, for example, P. J. Flory, J. Am. Chem. Soc. 58, 1877 (1936) and J. Am. Chem. Soc. 63, 3083 (1953)), or by the ring-opening reaction of polyols with lactones such as caprolactone or lactide. Since the polyol is a diol and the polycarboxylic acid is a dicarboxylic acid compound, polyester diacrylates (dimethacrylates) are obtained. A suitable compound is, for example, EBECRYL® 5849.

[0040] Other suitable difunctional acrylates (methacrylates) (Ai) are epoxy acrylates (methacrylates) (Ai3). In this case, the epoxy resin is reacted with a stoichiometric amount of acrylic acid (methacrylic acid) relative to the epoxy functionality. Diglycidyl ethers of bisphenol A are particularly suitable in this regard. The epoxy resin may also contain one or more hydroxyl groups. By reaction with acrylic acid and / or methacrylic acid, additional hydroxyl groups are formed. Such polyfunctional acrylic or methacrylic esters are referred to as "epoxy acrylates (methacrylates)" (Ai3). Here, epoxy acrylates, epoxy methacrylates, and mixtures of both are meant. Suitable compounds include, for example, EBECRYL® 600, EBECRYL® 3708, EBECRYL® 3701, and EBECRYL® 860.

[0041] Other suitable difunctional acrylates (methacrylates) (Ai) are (poly)urethane acrylate (methacrylates) (Ai4). These are formed by the addition of hydroxyl-containing (meth)acrylic esters, such as hydroxyethyl, hydroxypropyl, or hydroxybutyl acrylate (methacrylate), and their alkoxylated, lactone, or lactide-modified versions, to isocyanato-containing mono- or oligomers to give (poly)urethane acrylate (methacrylates) (Ai4). Note that "(poly)urethane" refers to both urethanes and polyurethanes, as well as mixtures of the two. Preferred are "polyurethane diacrylate (dimethacrylates)." The (poly)urethane acrylate (methacrylate) can be a polyurethane diacrylate, a polyurethane dimethacrylate, or a mixture thereof. Preferred are aliphatic polyurethane acrylate (methacrylate), more particularly aliphatic polyurethane diacrylate (dimethacrylate). Suitable compounds include EBECRYL® 8402, EBECRYL® 4858, and EBECRYL® 4859.

[0042] The difunctional acrylate (methacrylate) (Ai) used in the present invention can be a monomeric, oligomeric, and / or polymeric compound. Typically, compounds (Ai) having a weight-average molecular weight (Mw) of 150 to 2,000, more typically 200 to 2,000 daltons are used. Typically, the Mn of the compound (Ai) is at most 2,000, preferably at most 1,000, more preferably at most 500, most preferably 300 daltons, and preferably at least 150 and 200 daltons.

[0043] In a preferred embodiment of the present invention, the difunctional acrylate (methacrylate) (Ai) is selected from acrylic (methacrylic) esters (Ai1) and / or polyester acrylate (methacrylate)s (Ai2). Particularly preferred in the context of the present invention are diacrylic (methacrylic) esters (Ai1).

[0044] Direactive amine Aii A difunctional (meth)acrylate (Ai), as described above, is reacted with a direactive amine compound (Aii) to form a secondary amine-terminated copolymer (A).

[0045] The bireactive amine (Aii) can be any amine containing two reactive NH functional groups with respect to an acrylate (methacrylate) compound. For example, the amino compound (Aii) can be selected from an Aii-1 amino compound containing one (exactly one) primary amino group and / or an Aii-2 amino compound containing two (exactly two) secondary amino groups. The amino compound (Aii) used in the present invention preferably has a molecular weight of 500 daltons or less, more preferably 300 daltons or less, and even more preferably 200 daltons or less. In the present invention, the molecular weight is usually calculated from the chemical formula of the amine.

[0046] Examples of amino compounds (Aii-1) containing one primary amino group correspond to the formula R1-NH2 (I), where R1 represents alkyl, which is optionally substituted by hydroxy, alkoxy, and / or aryl groups. Compound (Aii-1) is, for example, selected from one or more of the following: methylamine, ethylamine, ethanolamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, 3-methylbutylamine, n-pentylamine, isopentylamine. Examples include n-hexylamine, n-octylamine, n-dodecylamine, 2-ethylhexylamine, isononylamine, cyclopentylamine, cyclohexylamine, 2-methylcyclohexylamine, benzylamine, 2-(2-aminoethoxy)ethanol, 5-aminopentanol, 3.5-aminopentanol, 3-amino-1-propanol, isopropanolamine, 2-amino-2-methyl-1-propanol, 2-methoxyethylamine, 2-ethoxyethylamine, 3-methoxypropylamine, 1-methoxyisopropylamine, 3-ethoxypropylamine, 3-isopropoxypropylamine, 3-(2-methoxyethoxy)propylamine, 3-(2-ethylhexyloxy)propylamine, furfurylamine, 4-(2-aminoethyl)morpholine, and mixtures thereof. One or more tertiary amino groups may be contained next to one primary amine compound. By way of example, suitable N,N-dialkyl-diaminoalkanes and N,N-dialkanol-diaminoalkanes include N,N-dialkyldiaminopropanes and / or N,N-dialkanoldiaminopropanes, such as N,N-dimethyl-1,3-diaminopropane (DMAPA), N,N-diethyl-1,3-diaminopropane, N,N-diethanol-1,3-diaminopropane, N,N-di-n-propyl-1,3-diaminopropane, 4-morpholinepropylamine, 3-(N-piperidino)propylamine and / or N,N-diphenyl-1,3-diaminopropane.

[0047] Suitable direactive amine compounds (Aii-2) that can be used are, for example, those of formula R2HNR4-NHR3 (II), where R2 and R3 each independently represent alkyl optionally substituted with hydroxy, alkoxy, tertiary amine, and / or aryl, with the proviso that R2 and R3 can be linked to form a ring, and R4 is selected from the group of alkylene and aralkylene chains, which may contain up to 50 carbon atoms (usually up to 20 carbon atoms) and 1 to 20 ether bridges (usually 1 to 8 ether bridges) and / or 1 to 3 tertiary amine bridges. As used herein, the term "alkylene" is meant to designate a divalent linear, branched, or cyclic hydrocarbon radical. As used herein, the term "aralkylene" is meant to designate an alkylene in which one or more hydrogen groups are replaced with an aryl group. Preferably, R4 is ethylene, 1,2-propylene, trimethylene, hexamethylene, 2,2-dimethylolpropylene, 1-methyltrimethylene, 1,2,3-trimethyltetramethylene, 2-methylpentamethylene, 2,2,4-(or 2,4,4-)trimethylhexamethylene, metaxylylene, 3,5,5-trimethylcyclohexyl-1-ene-3-methylene, bis(cyclohexyl)-4-enemethane. Examples of the olefin copolymer include bis(4-methylcyclohexyl-3-ene)methane, cyclohexyl-1,3-ene, cyclohexyl-1,4-ene, 1,4-bis(propoxyl-3-ene)butane, 3,6-dioxaoctylene, 3,8-dioxadodecylene, 4,7,10-trioxatridecylene, poly(oxytetramethylene), poly(oxypropylene) having 2 to 15 1,2-propylene oxide units, poly(oxypropylene-co-oxyethylene) having 2 to 15 propylene oxide units and 2 to 15 ethylene oxide units, and 2,2-dimethylolpropylene. Examples of the amino compound (Aii-2) include N,N-dimethylethylenediamine, 1,4,7-trimethyldiethylenetriamine, piperazine, 2,3,5,6-tetramethylpiperazine, and N,N'-di-tert-butylethylenediamine.

[0048] Preferred are alkylamines (Aii-1) in which the alkyl group contains 1 to 30 carbon atoms, particularly 1 to 18 carbon atoms, more particularly 1 to 14 carbon atoms, and even more particularly 1 to 8 carbon atoms, and the alkyl group is optionally substituted with one or more hydroxy groups. As used herein, the term "alkyl" is defined as including saturated monovalent hydrocarbon radicals having straight, branched, or cyclic moieties or combinations thereof.

[0049] Particularly preferred are ethylamine, n-propylamine, n-butylamine, n-hexylamine, 2-ethylhexylamine, cyclohexylamine, n-octylamine, n-dodecylamine, 2-(2-aminoethoxy)ethanol, 5-aminopentanol, ethanolamine, 3-amino-1-propanol, isopropanolamine, 2-amino-2-methyl-1-propanol, and N,N-dialkyldialkanes, and mixtures thereof. Particularly preferred are ethylamine, n-propylamine, isopropanolamine, n-butylamine, isobutylamine, n-pentylamine, isopentylamine, n-hexylamine, 2-ethylhexylamine, n-octylamine, and mixtures thereof. Most preferred are ethylamine, n-propylamine, n-butylamine, and mixtures thereof.

[0050] In preparing the secondary amine-terminated copolymer (A), the difunctional acrylate (methacrylate) (Ai) is preferably added to the direactive amine (Aii) so that an excess of amine is present throughout the reaction. It is also possible to reverse the order and add the direactive amine to the difunctional acrylate (methacrylate). In the latter case, a molar excess of the direactive amine is ultimately used.

[0051] Multifunctional acrylate (methacrylate) (B) The secondary amine-terminated copolymer (A) of the present invention can be further reacted with a polyfunctional acrylate (methacrylate) compound (B) different from the acrylate (methacrylate) compound (Ai) to form the aminoacrylate (methacrylate) of the present invention. The reaction conditions are the same as those for the reaction of the acrylate (methacrylate) compound (Ai) with the amino compound (Aii) described above; see reaction (ii) above.

[0052] Preferably, the molar ratio of the multifunctional (meth)acrylate compound (B) to the secondary amine-terminated copolymer (A) is at least 2:1, preferably no more than 10:1, more preferably no more than 6:1.

[0053] Usually, one type of polyfunctional acrylate (methacrylate) compound (B) is used, but one or more other polyfunctional acrylate (methacrylate) compounds may be mixed and used. The aminoacrylate (methacrylate) of the present invention has a high acrylate (methacrylate) functionality. Preferably, the functionality is 2 or more, preferably 3 or more, more preferably 4 or more, for example, 5, 6, 7, 8, 9, or 10.

[0054] The polyfunctional acrylate (methacrylate) compound (B) is different from the difunctional acrylate (methacrylate) compound (Ai). Preferably, the polyfunctional acrylate (methacrylate) compound (B) is a tri- or higher functional acrylate (methacrylate) compound. The acrylated (methacrylated) compound (B) is an ester of acrylic acid (methacrylic acid) with a polyol, i.e., an ester with a compound having three or more hydroxyl groups. Examples of tri- or higher functional polyols suitable for producing the methacrylated compound B include, but are not limited to, triaqueous alcohols such as trimethylolpropane, glycerol, lactone or lactide modified versions of these, and ethoxylated and / or propoxylated versions of these. These include, but are not limited to, tetrahydroalcohols such as pentaerythritol or trimethylolpropane dimer, lactone or lactide modified versions thereof, and ethoxylated and / or propoxylated versions thereof; and hexahydroalcohols such as dipentaerythritol, lactone or lactide modified versions thereof, and ethoxylated and / or propoxylated versions thereof.

[0055] Polymeric aminoacrylate (methacrylate) The polymeric amino(meth)acrylates of the present invention preferably have a double bond content (calculated as meq C=C / g) of 0.5 meq / g or more, more preferably 0.75 meq / g or more, and most preferably 1 meq / g or less. The nitrogen content of the polymeric amino(meth)acrylates of the present invention is preferably between 1 and 6 meq N / g, more preferably 1.2 and 5 meq N / g, and most preferably 1.4 and 4 meq N / g. Typically, the polymeric amino(meth)acrylates of the present invention are liquid at room temperature and have a viscosity at 25°C of 200 to 200,000 mPa·s, more preferably 500 to 100,000 mPa·s, and most preferably 1,000 to 75,000 mPa·s, which can typically be measured using a cone and plate rheometer MCR100 (Paar-Physica) according to ISO 3219. The measurement geometry for measuring the polymeric amino(meth)acrylates of the present invention was a 50 mm diameter cone with a 1° cone angle. Measurements were performed at 25°C with D = 0 s (zero viscosity) and flow curves at controlled shear rates ranging from D = 2.5 s to D = 2500 s.

[0056] The polymeric aminoacrylate (methacrylate) of the present invention has a low odor after curing and can be used in applications such as food packaging where off-odor must be absolutely avoided.

[0057] Furthermore, these amino(meth)acrylates exhibit a long enough pot life to be usable in industrial environments. Finally, these amino(meth)acrylates typically have low color (1 Gardner or less), allowing them to be used in clear coatings, adhesives, or varnishes.

[0058] Polymeric amino(meth)acrylates are highly effective, especially in low energy cure applications, but are also suitable for applications requiring high cure speeds, such as in the graphic arts industry.

[0059] The polymeric amino(meth)acrylates according to the present invention and / or radiation-curable compositions comprising them are highly suitable for use as surface cure boosters and are therefore able to increase the surface cure when used in coatings for UV applications, more particularly UV LED applications. They advantageously act as amino synergists.

[0060] The polymeric aminoacrylate (methacrylate) may be a polymer represented by formula (I). B'-Aii'-[Ai'-Aii']n-Ai'-Aii'-B' (I); where n is an integer between 0 and 10, Ai' is a unit derived from a diacrylate (dimethacrylate) compound Ai; Aii' is a unit derived from the direactive amine compound Aii; B′ is a unit derived from the polyfunctional acrylate (methacrylate) compound B.

[0061] The secondary amine-terminated copolymer can be represented by formula (II): Aii''-[Ai'-Aii']n-Ai'-Aii'' (II); where n is an integer between 0 and 10. Ai' is a unit derived from a diacrylate (dimethacrylate) compound Ai; Aii' is a unit derived from a divalent amine compound Aii. Aii'' is a unit derived from the direactive amine compound Aii and contains one secondary amine group.

[0062] The polymeric amino(meth)acrylates of the present invention can be used to produce coatings, paints, inks, varnishes (including overprint varnishes) and adhesives, but also gel coats, composites, molding compositions or 3D articles. The materials of the present invention are further suitable for use in 3D printing.

[0063] Radiation curable composition The radiation-curable composition used in the present invention preferably comprises at least 0.5 wt% (any of the above) of one or more polymeric amino(meth)acrylates as described above. More preferably, the composition comprises at least 2 wt% of one or more amino(meth)acrylates according to the present invention. Most preferably, the composition comprises at least 5 wt% of one or more amino(meth)acrylates according to the present invention. The amount of polymeric amino(meth)acrylates according to the present invention typically does not exceed 99 wt%. Preferably, the amount of polymeric amino(meth)acrylates according to the present invention typically does not exceed 90 wt%, more preferably 75 wt%, and most preferably 50 wt%.

[0064] The polymeric amino(meth)acrylates of the present invention have been found to be highly effective in UV and EB (electron beam) curing and can be used alone or in combination with other radiation-curable polymer precursors (C), where "other" means acrylates (methacrylates) different from the polymeric amino(meth)acrylates of the present invention.

[0065] The term polymer precursor is used to denote a monomer or oligomer or mixture thereof having suitable polymerizable functional groups, preferably comprising one or more acrylic, methacrylic, or vinyl groups at the chain end or laterally along the chain. The radiation-curable polymer precursor is generally a monomer or oligomer containing one or more acrylic, methacrylic, or vinyl groups. Preferably, the acrylated (methacrylated) compound (C) is different from the polymeric amino(methacrylate) according to the present invention. The radiation-curable composition may optionally contain 1% of one or more acrylated (methacrylated) compounds (C).

[0066] Preferred oligomers (C1) include acrylic (methacrylic) oligomers, aromatic acid acrylates (methacrylates), acrylic (methacrylic) polybutadienes, acrylic (methacrylic) polyesters, urethane acrylates (methacrylates), epoxy acrylates (methacrylates), and hyperbranched acrylates (methacrylates) such as hyperbranched polyester polyol acrylates (methacrylates). Preferred oligomers (C1) have a weight-average molecular weight of 1,000 or more and 6,000 or less daltons.

[0067] When used, the amount of oligomer (C1) in the radiation-curable composition is generally at least 1 wt%, more preferably at least 5 wt%, and most preferably at least 10 wt%. The amount of oligomer, based on the total weight, usually does not exceed 95 wt%, more preferably does not exceed 90 wt%, and most preferably does not exceed 75 wt%.

[0068] The radiation curable composition may also contain low molecular weight (meth)acrylated monomers (C2), such as acrylic acid (methacrylic acid), β-carboxyethyl acrylate (methacrylate), butyl acrylate (methacrylate), methyl acrylate (methacrylate), isobutyl acrylate (methacrylate), 2-ethylhexyl acrylate (methacrylate), cyclohexyl acrylate (methacrylate), n-hexyl acrylate (methacrylate), isobornyl acrylate (methacrylate), isooctyl acrylate (methacrylate), n-lauryl acrylate (methacrylate), octyl / decyl acrylate (methacrylate), 2-hydroxyethyl acrylate (methacrylate), phenoxyethyl acrylate (methacrylate). Nonylphenol ethoxylate monoacrylate (methacrylate), 2-(2-ethoxyethoxy)ethyl acrylate (methacrylate), 2-butoxyethyl acrylate (methacrylate), Cardora acrylate (methacrylate) (the acrylate (methacrylate) of the glycidyl ester of neodecanoic acid, known as Cardora(R) E-10P), phenyl glycidyl ether acrylate (methacrylate) and its ethoxylated and / or propoxylated derivatives, acrylates (methacrylates) obtained by esterification of aliphatic glycidyl ethers with acrylic acid (methacrylic acid), especially those in which the alkyl chain contains 6 to 24 carbon atoms, more preferably 8 to 18 carbon atoms, and / or glycidyl esters of saturated and unsaturated carboxylic acids, especially glycidyl esters of long-chain alkyl carboxylic acids in which the alkyl chain is 1,6-hexanediol diacrylate (dimethacrylate).Tricyclodecane dimethanol diacrylate (dimethacrylate), isosorbide diacrylate (dimethacrylate), di- or tripropylene glycol diacrylate (dimethacrylate), ethoxylated and / or propoxylated neopentyl glycol diacrylate (dimethacrylate), isosorbide diacrylate (dimethacrylate) and their ethoxylated and / or propoxylated derivatives, bisphenol A diacrylate (dimethacrylate) and its ethoxylated and / or propoxylated derivatives, trimethylol propane propanetriacrylate(methacrylate) and its ethoxylated and / or propoxylated derivatives, ditrimethylolpropanetriacrylate(methacrylate), glyceroltriacrylate(methacrylate) and its ethoxylated and / or propoxylated derivatives, pentaerythritoltriacrylate (PETIA) and its ethoxylated and / or propoxylated derivatives, penta- or hexaacrylate and its ethoxylated and / or propoxylated derivatives, dipentaerythritol penta- or hexaacrylate and its ethoxylated or propoxylated derivatives.

[0069] When used, the amount of monomer (C2) in the radiation-curable composition is generally at least 1% by weight, preferably at least 5% by weight, more preferably at least 10% by weight. The amount of oligomers usually does not exceed 99% by weight, preferably does not exceed 95% by weight, most preferably does not exceed 80% by weight, based on the total weight.

[0070] In a particular embodiment of the invention, compound (C) is an amino(meth)acrylate that is different from the polymeric amino(meth)acrylates of the invention. Examples of such amino(meth)acrylates are EBECRYL® 80, 81, 83, 85, LEO 10551, LEO 10552 or LEO 10553 available from Allnex. However, preferably, no such amino(meth)acrylates (C) are used.

[0071] The radiation-curable compositions used in the present invention generally contain at least one photoinitiator, which is a compound capable of generating radicals upon absorption of light, typically UV light. Typical photoinitiators are described in "The Chemistry of Free Radical Polymerization," edited by Graeme Moad and David H. Solomon; Pergamon (1995), pages 84 to 89. Photoinitiators usable in the compositions used in the present invention can be selected from hydroxyketones, aminoketones, benzil dimethyl ketals, acylphosines, benzophenone derivatives, thioxanthones, and mixtures thereof. Polymerizable or multifunctional photoinitiators, which are known to be less extractable than monomers, are preferred. Typically, the amount of photoinitiator in the composition is comprised between 0 and 15% by weight, more preferably between 1 and 10% by weight, and most preferably between 1 and 5% by weight.

[0072] Alternatively, the radiation-curable compositions of the present invention can be cured without the use of a photoinitiator, typically by electron beam, but can also be cured with ultraviolet light without the use of a photoinitiator, for example, when using an excimer lamp.

[0073] The radiation-curable composition can also contain additives commonly used in varnishes, coatings, coating agents, adhesives, and inks, such as substrate wetting agents, defoamers, dispersants, flow improvers, slip agents, plasticizing diluents, flame retardants, UV protectants, adhesion promoters, amine synergists, reinforcing agents, and stabilizers. The total amount of commonly used additives usually does not exceed 10% by weight. Preferably, the composition contains 0.01 to 5 percent by weight of commonly used additives, as described herein above.

[0074] The radiation-curable composition may also contain one or more pigments, dyes, or colorants. Colorants, dyes, and pigments that can be used in the compositions of the present invention are all pigments known in the art. A list of such pigments is provided in the Color Index. More specifically, such pigments include Process Yellow 13 (Diarylide Yellow - Irgalite BAW from Ciba, Permanent GR from Clariant), Process Magenta Pigment 57 (Bona Calcium - llobona 4BY from Sun, Irgalite SMA from IGM), Process Blue 15.3 (Copper Phthalocyanine - Irgalite GLO from IGM, Hostaperm Blue B2G from Clariant), and Process Black 7 (Oxidized Carbon Black - Special Black 250; Special Black 350 from Degussa). The colorants and / or pigments are preferably used in an amount of 0 to 50% by weight, more preferably 0 to 40% by weight, based on the total weight of the radiation-curable composition.

[0075] The radiation-curable composition may also contain 0 to 20% by weight of a filler or a non-reactive diluent or solvent. The radiation-curable composition of the present invention can be prepared by mixing the selected compounds by a conventional method. To facilitate mixing, the blend can be heated, if desired.

[0076] The radiation-curable compositions described herein are used to produce varnishes (including overprint varnishes), coatings, adhesives, and inks. By ink, liquid inks as well as paste inks are intended to be understood. In particular, flexographic, serigraphic, inkjet, offset, and / or xerographic inks can be produced using the amino(meth)acrylates according to the present invention. The inks generally contain pigments, dyes, and / or colorants, in addition to other possible additives such as fillers, wetting and flow improvers, leveling additives, viscosity modifiers, and dispersing additives. They can further be used to produce composites and gel coats, molding compositions, or 3D articles.

[0077] The polymeric amino(meth)acrylates according to the invention are also highly suitable for the preparation of coating compositions and for coating various types of substrates. Another aspect of the invention therefore relates to a method for coating an article or substrate comprising the following steps: (a) providing a radiation-curable composition comprising the polymeric amino(meth)acrylate described above; (b) applying the composition onto a surface; (c) Irradiating the surface with actinic radiation.

[0078] This method is particularly suitable for improving surface hardening.

[0079] In this method, advantageously UV LED lamps are used as radiation sources, more particularly those emitting at 365, 385, 395 or 405 nm.

[0080] In embodiments, the composition can be applied to a surface by any coating technique, including spray, curtain, dip, pad and roll coating techniques, and any printing technique, such as lithography, serigraphy, flexography, gravure and inkjet printing.

[0081] The substrate to be coated or inked can be any substrate, including wood, metal, paper, plastic, fabric, textile, ceramic, concrete, plaster, glass, etc. Good results have been obtained with flexible substrates, particularly paper and plastic substrates. The materials of the present invention allow the application of the inks, coatings, coatings and varnishes (including overprint varnishes) of the present invention to heat-sensitive materials such as MDF, some metal alloys, etc.

[0082] The coating can be a clear coating or a pigmented coating. The pigmented coating can be based on light pigments (white, light blue, etc.).

[0083] Irradiation of the surface can be done by high energy electrons (EB) or UV irradiation. For UV irradiation, several types of lamps can be used, ranging from classical medium pressure Hg to metal halide UV lamps to UV light emitting diodes (excluding other lamps / LEDs that emit UV light).

[0084] Various types of photoradiation can be used, such as ultraviolet (UV), gamma rays, and electron beams. The preferred means of radiation curing is ultraviolet. The radiation source can be any ultraviolet source, as long as a portion of the emitted light is absorbed by the photoinitiator (system). Examples of such sources include high- or low-pressure mercury lamps, cold cathode fluorescent lamps, black lights, UV-A lamps, xenon lamps, ultraviolet LEDs, ultraviolet lasers, flashlights, and even visible light sources. Currently, ultraviolet LEDs with wavelengths of 365 nm, 385 nm, 395 nm, and 405 nm are commercially available.

[0085] The coatings, varnishes (including overprint varnishes), coatings, adhesives and inks obtainable by the process according to the invention can be cured at high line speeds or with low energy radiation, making them well suited for packaging applications such as food packaging, but also for other types of packaging used for luxury goods such as cosmetics and pharmaceuticals. The invention also provides food packaging materials coated or imprinted with a radiation curable composition according to the invention (any of those described).

[0086] The present invention therefore also relates to coatings, varnishes (including overprint varnishes), coatings, adhesives and inks obtained using the process of the present invention and / or prepared from the polymeric amino(meth)acrylates according to the present invention.

[0087] UV LED technology is commonly used in the graphic arts market, wood coatings, electronics, composite manufacturing, gel coats, molding compounds, and 3D printing.

[0088] The invention is illustrated by the following non-limiting examples.

[0089] example The following examples illustrate aspects and embodiments of the present invention.

[0090] Example 1 A reaction vessel was charged with 292 g (4 moles) of n-butylamine (direactive amine Aii) and 200 ppm of stabilizer, based on the total amount of n-butylamine and HDDA. The reaction mixture was heated and the temperature was set to 50°C. 678 g of HDDA (3 moles) (difunctional acrylate (methacrylate) Ai) was added dropwise, ensuring the temperature did not exceed 75°C. After the addition was complete, the mixture was further reacted at 60°C for 16 hours. After this time, the reaction mixture was cooled to 40°C, and 932 g of ditrimethylolpropane tetraacrylate (2 moles) (DiTMPTA) (acrylate (methacrylate) compound B) was added over 30 minutes with stirring. After the addition was complete, the reaction temperature was increased to 70°C, and the near-infrared spectrum showed a peak at 1642 cm. -1 The mixture was allowed to age at this temperature until the secondary amine peak disappeared. A clear, low-odor product was formed with a viscosity of 41000 mPa.s at 25°C as measured by C&P. The product had a nitrogen content* of 2.1 meq / g and a double bond content** of 3.2 meq / g. The amount of residual difunctional acrylate HDDA was less than 100 ppm as measured by HPLC-UV.

[0091] Table 1 shows the amount of each compound used. [Table 1] * Calculate the N content meq / gN = ((weight bireactive amine Aii / Mw bireactive amine Aii x number of nitrogen atoms present in compound Aii) / (weight compound B + weight compound Ai + weight compound Aii) * 1000 Example 1 In example 1 meq / gN=((292g / 73g / mole x 1) / (932g+678g+292g)*1000 = 2.1 meq / g). ** Calculate the double bond content Double bond content (meq / g) = (Compound B *# moles of acrylate (methacrylate) functional groups + compound Ai * 2-Compound Aii * # moles of NH functional groups / (weight of compound B + weight of compound Ai + weight of compound Aii) × 10,000 Acrylate (methacrylate) content (meq / g) = ((2 mol x 4) + (3 mol x 2) - (4 mol x 2)) / (932 g + 678 g + 292 g) x 1000 = 3.2 meq / g *** Quantification of the hexanediol diacrylate (=HDDA) and dipropylene glycol diacrylate (DPGDA) content in Radcure products is carried out using high performance liquid chromatography with ultraviolet detection (HPLC-UV) at λ=210 nm on a reversed-phase C18 column.

[0092] Comparative Example Comparative Examples 1 and 2 are aminoacrylates made in a one-step reaction using an excess of (meth)acrylated compound (Ai) to amino compound (Aii). A drawback of these compounds is that they contain a large amount of low molecular weight difunctional acrylate compounds that can migrate from the cured coating.

[0093] In Comparative Example 1, a reaction vessel was charged with 219 g of n-butylamine (3 moles) and 200 ppm of stabilizer, based on the total amount of n-butylamine and HDDA. The reaction mixture was heated and the temperature was set to 50°C. 904 g of HDDA (4 moles) was added dropwise, ensuring the temperature did not exceed 75°C. Upon completion of the addition, the mixture was further reacted at 60°C for 16 hours until the free amine concentration, as determined by titration, was less than 0.02%. A clear product was formed with a viscosity of 1500 mPa.s, as measured by C&P at 25°C. The product had an amine content of 2.6 meq / g and a double bond content of 1.78 meq / g. The residual HDDA, as determined by HPLC-UV, was 3.8%.

[0094] Comparative Example 2 is prepared in the same manner as Comparative Example 1, except that n-butylamine is replaced with monoethanolamine. A clear product is formed with a viscosity of 5900 mPa.s at 25°C as measured by C&P. The product has an amine content of 2.7 meq / g and a double bond content of 1.8 meq / g. The residual HDDA content as measured by HPLC-UV is 3.5%.

[0095] Therefore, based purely on the residual amount of low molecular weight diacrylate, cured coatings or inks made with the amino(meth)acrylates of the present invention might be expected to produce lower levels of extractable compounds than Comparative Examples 1 and 2.

[0096] Comparative Example 3 is EBECRYL 10553, a low-migration aminoacrylate available from allnex. To prepare this example, no secondary amine-terminated copolymer was formed. This product has a viscosity of 200 mPa·s at 25°C as measured by C&P, an amine content of 0.5 meq / g, and a double bond content of 4.3 meq / g. EBECRYL 10553 is less suitable for use with low-energy curing devices such as UV LED lamps, possibly due to the lack of a secondary amine or low amine content.

[0097] Comparative Example 4 is EBECRYL LED 03, commercially available from allnex. To prepare this example, no secondary amine-terminated copolymer is formed. EBECRYL LED 03 has a viscosity of 450 mPa·s at 25°C as measured by C&P, an amine content of 3 meq / g, and a double bond content of 1.9 meq / g.

[0098] Comparative Example 5 is SpeedCure EDB (ethyl-4-(dimethylamine)benzoate) commercially available from Lambson.

[0099] Application Examples The following ink formulations (cyan inks) were prepared using the above compositions and several comparative compositions. The compositions of each ink formulation are shown in Table 2. EBECRYL 870 is a hexafunctional polyester acrylate oligomer, and EBECRYL 1608 is a bisphenol A-type epoxy acrylate diluted with OTA-480 from allnex. Omnirad TPO-L and Omnirad ITX are photoinitiators commercially available from IGM. Stab 12 / 1: Polymerization inhibitor (5% solution of NPAL in DPGDA DiPropylene Glycol DiAcrylate); NPAL = tris(N-nitroso-N-phenylhydroxylamine) aluminum sodium salt

[0100] [Table 2]

[0101] The offset ink formulations were tested for viscosity, reactivity, solvent resistance and lithographic behavior, and the results are summarized in Tables 3 and 4.

[0102] The ink is cured in an air-cooled Phoseon Firejet with a UV LED at a wavelength of 365 nm with a peak irradiance of 8 W / cm² (LED365). The lamp is 1 cm away from the substrate.

[0103] Cure speed is expressed as the maximum belt speed or minimum UV dose (under a given lamp) that gives a fully cured film. Surface cure of 1.8 μm ink coated on BOPP C58 film (bioreactive polypropylene) is tested using the graphite test. This is done by applying graphite carbon black (#2 pencil) to the coated surface, rubbing it with a finger, and then rubbing it with a cotton swab. As long as a black mark remains on the coated surface, the film is not fully cured and should be passed under the LED365 again. Curing is considered complete when no black stain remains on the surface. "10 m / min" indicates that a cure of 10 m / min was required to pass the graphite test. UV energy is automatically derived from UV irradiance (W / cm2) measured with a UV Power Puck® II radiometer, and values ​​are recorded for the UVA (320-390 nm) zone. Film through-cure is checked by double rubbing with an isopropanol-soaked wad (IPA). A minimum of 50 double rubs with isopropanol is required to obtain a fully cured coating with optimum performance.

[0104] [Table 3]

[0105] * EP%: The ink-water balance (water absorption) is evaluated using a hydroscope and expressed as EP%. The device consists of three rollers: a small rubber roller to measure the ink film tack, and two large, temperature-controlled metal rollers. Above the two metal rollers is a space (ink reservoir) that holds 10g of ink. The ink reservoir is sealed at the sides, and all of the ink and water are contained within. Precision pumps installed at two points above the ink reservoir drop the dampening solution into the ink reservoir at a rate of 1.3ml / min. The ink and fountain pen are forced through the opening between the rollers and are subjected to joint shear stress. When excess water begins to appear on the ink surface, the ink is "saturated" with water, indicating the emulsion point (unit: %).

[0106] [Table 4]

[0107] Table 4 shows that the compositions according to the invention make it possible to obtain inks with improved reactivity to CF1, to which no aminoacrylate is added, but also compared to formulations with a lower amino content CF5, for example EBECRYL 10553. Furthermore, the amino(meth)acrylates according to the invention can be used in offset inks, since they do not significantly affect the ink balance properties.

[0108] Table 5 shows that the compositions according to the invention also exhibit improved cure speeds relative to CF1 without added aminoacrylate when cured with an 80 W / cm mercury UV bulb from IST. Similar reactivity can be obtained with the commercially available aminobenzoate.

[0109] [Table 5]

[0110] Most common amino acrylates are often not stable in combination with pigments and exhibit an increase in viscosity after storage at elevated temperatures for a period of time. Some of the above compositions have been tested in the following magenta inks:

[0111] [Table 6]

[0112] After storing at room temperature for 24 hours, the initial viscosity was measured, then stored in a ventilated area at 60°C, and the viscosity of the ink was measured again after 28 days.

[0113] Table 7 below shows that the inks based on the amino(meth)acrylates of the present invention exhibit a much lower viscosity increase compared to Comparative Synthesis Example 2.

[0114] [Table 7]

[0115] The aminoacrylate (methacrylate) of the present invention is also suitable for use in overprint varnishes. The results shown in Table 8 indicate that F17 and F18 exhibit significantly higher reactivity when cured with a 365 nm 8 W LED lamp than comparative formulation CF9, which does not contain the aminoacrylate (methacrylate). It also indicates that it is possible to produce coatings with minimal yellowing after curing.

[0116] [Table 8]

[0117] * The surface cure reactivity and yellowing of the overprint varnishes were tested on 10 μm thick films applied to non-porous substrates (white paper, Silico Ultraflat). The yellowing of the samples was then evaluated after various periods by measuring the b value in the LAB system (measured with a Braive Supercolor Instrument). The b value is the value measured on the coated substrate minus the value measured on uncoated Silico Ultraflat white paper. The samples were cured at their surface cure reactivity. The yellowing index (b value) is expressed as the b value measured on the coated substrate minus the value on the uncoated substrate. The following is further disclosed in relation to the present invention. [1] A polymeric amino(meth)acrylate suitable for use in radiation-curable compositions, comprising: the polymeric amino(meth)acrylate is the reaction product of a secondary amine-terminated copolymer (A) and a multifunctional acrylate (meth)acrylate (B); the secondary amine-terminated copolymer is the reaction product of a difunctional (meth)acrylate (Ai) and a direactive amine (Aii); and The multifunctional acrylate (methacrylate) (B) is different from the difunctional acrylate (methacrylate) (Ai), in that the multifunctional acrylate (methacrylate) contains two or more acrylate (methacrylate) groups, as described above. [2] A polymeric aminoacrylate (methacrylate) suitable for the radiation-curable composition according to [1], wherein the molar ratio of the multifunctional acrylate (methacrylate) (B) to the secondary amine-terminated copolymer (A) is 2:1 or more. [3] The polymeric aminoacrylate (methacrylate) according to [1] or [2], wherein the molar ratio of the difunctional acrylate (methacrylate) (Ai) to the direactive amine (Aii) is less than 1, preferably 0.5 to 0.9. [4] The polymeric amino(meth)acrylate according to any of the preceding claims, wherein the multifunctional (meth)acrylate (B) contains two or more, preferably three or more, and most preferably four or more acrylate (meth)acrylate groups. [5] 10. The polymeric amino(meth)acrylate of claim 1, wherein the direactive amine (Aii) is selected from an amine containing two secondary amine groups, or an amine containing one primary amine group, or a mixture thereof. [6] The polymeric amino(meth)acrylate according to [1], wherein the direactive amine (Aii) is an aliphatic primary amine, preferably a C2-C8 aliphatic primary amine, an amine alcohol, or a piperazine. [7] The polymeric aminoacrylate(methacrylate) according to any of the preceding claims, wherein the difunctional acrylate(methacrylate) (Ai) is preferably an ester of acrylic acid and a difunctional polyol, and the difunctional polyol is preferably butanediol, pentanediol, hexanediol, dipropylene glycol, tripropylene glycol, tricyclodecanediol, isosorbide diol. [8] The polymeric amino(meth)acrylate of any of the preceding claims, wherein the polymeric amino(meth)acrylate contains two or more, preferably three or more, and most preferably four or more acrylate(meth)acrylate groups. [9] The polymeric amino(meth)acrylate of any preceding claim, wherein the polymeric amino(meth)acrylate has an amine content of at least 1 meq / g, more preferably at least 1.2 meq / g.

[10] 10. The polymeric amino(meth)acrylate of any of the preceding claims, wherein the polymeric amino(meth)acrylate has a double bond content of at least 1 meq / g, more preferably at least 1.5 meq / g, and even more preferably at least 2 meq / g.

[11] A method for preparing any of the polymeric amino(meth)acrylates described above, comprising the steps of: (i) reacting at least one di(meth)acrylate compound (Ai) containing two acrylate (meth)acrylate groups per molecule with at least one direactive amine (Aii) to form a secondary amine-terminated copolymer (A); and (ii) reacting at least one multifunctional acrylate (methacrylate) (B), which has at least two acrylate (methacrylate) ester groups and is different from the diacrylate (methacrylate) compound (Ai), with the secondary amine-terminated copolymer (A) to obtain a polymeric aminoacrylate (methacrylate).

[12] A radiation-curable composition containing the polymeric amino(meth)acrylate according to any one of [1] to

[10] .

[13]

[12] The radiation-curable composition according to

[12] , which is a radiation-curable coating or a radiation-curable ink.

[14] Use of the radiation-curable composition according to

[12] or

[13] in offset printing.

[15] A substrate coated with the radiation-curable composition according to

[12] or

[13] .

[16] A method of coating an article or substrate, comprising the steps of: (a) Providing a radiation-curable composition containing the polymeric aminoacrylate (methacrylate) according to any one of [1] to

[10] , (b) applying the composition onto a surface; and (c) irradiating said surface or article with optical radiation.

[17] The method according to

[16] , wherein the light radiation source is a UV LED lamp.

[18] A method for improving surface cure in coatings and inks comprising the steps of: (a) Providing a radiation-curable composition containing the polymeric aminoacrylate (methacrylate) according to any one of [1] to

[10] , (b) applying the composition onto a surface; and (c) irradiating said surface or article with optical radiation.

Claims

1. A polymeric amino(meth)acrylate suitable for use in radiation-curable compositions, comprising: the polymeric amino(meth)acrylate is the reaction product of a secondary amine-terminated copolymer (A) and a multifunctional acrylate (meth)acrylate (B); the secondary amine-terminated copolymer is the reaction product of a difunctional (meth)acrylate (Ai) and a direactive amine (Aii); and The multifunctional acrylate (methacrylate) (B) is different from the difunctional acrylate (methacrylate) (Ai), in that the multifunctional acrylate (methacrylate) contains two or more acrylate (methacrylate) groups.

2. A polymeric aminoacrylate (methacrylate) suitable for the radiation-curable composition described in claim 1, wherein the molar ratio of the multifunctional acrylate (methacrylate) (B) to the secondary amine-terminated copolymer (A) is 2 or more.

3. Polymeric amino(meth)acrylates according to claim 1 or 2, wherein the molar ratio of difunctional (meth)acrylate (Ai) to direactive amine (Aii) is less than 1, preferably between 0.5 and 0.

9.

4. 4. The polymeric amino(meth)acrylate according to any one of claims 1 to 3, wherein the multifunctional (meth)acrylate (B) contains 2 or more, preferably 3 or more, most preferably 4 or more acrylate (meth)acrylate groups.

5. 5. The polymeric amino(meth)acrylate of claim 1, wherein the direactive amine (Aii) is selected from an amine containing two secondary amine groups, or an amine containing one primary amine group, or a mixture thereof.

6. 2. The polymeric amino(meth)acrylate of claim 1, wherein the direactive amine (Aii) is an aliphatic primary amine, preferably a C2-C8 aliphatic primary amine, an amine alcohol, or a piperazine.

7. 7. The polymeric amino(meth)acrylate according to claim 1, wherein the difunctional acrylate (meth)acrylate (Ai) is preferably an ester of acrylic acid with a difunctional polyol, the difunctional polyol being preferably butanediol, pentanediol, hexanediol, dipropylene glycol, tripropylene glycol, tricyclodecanediol, isosorbide diol.

8. 8. The polymeric amino(meth)acrylate of any one of claims 1 to 7, wherein the polymeric amino(meth)acrylate contains 2 or more, preferably 3 or more, most preferably 4 or more acrylate (meth)acrylate groups.

9. The polymeric amino(meth)acrylate of any one of claims 1 to 8, wherein the polymeric amino(meth)acrylate has an amine content of at least 1 meq / g, more preferably at least 1.2 meq / g.

10. 10. The polymeric amino(meth)acrylate of any one of claims 1 to 9, wherein the polymeric amino(meth)acrylate has a double bond content of at least 1 meq / g, more preferably at least 1.5 meq / g, even more preferably at least 2 meq / g.

11. A method for preparing the polymeric amino(meth)acrylates of any one of claims 1 to 10, comprising the steps of: (i) reacting at least one di(meth)acrylate compound (Ai) containing two acrylate (meth)acrylate groups per molecule with at least one direactive amine (Aii) to form a secondary amine-terminated copolymer (A); and (ii) reacting at least one multifunctional acrylate (methacrylate) (B), which has at least two acrylate (methacrylate) ester groups and is different from the di(methacrylated) compound (Ai), with the secondary amine-terminated copolymer (A) to obtain a polymeric aminoacrylate (methacrylate).

12. A radiation-curable composition comprising the polymeric amino(meth)acrylate of any one of claims 1 to 10.

13. 13. The radiation curable composition of claim 12, which is a radiation curable coating or a radiation curable ink.

14. Use of the radiation curable composition according to claim 12 or 13 in offset printing.

15. A substrate coated with the radiation curable composition according to claim 12 or 13.

16. A method of coating an article or substrate, comprising the steps of: (a) providing a radiation-curable composition containing the polymeric amino(meth)acrylate according to any one of claims 1 to 10; (b) applying the composition onto a surface; and (c) irradiating said surface or article with actinic radiation.

17. 17. The method of claim 16, wherein the light radiation source is a UV LED lamp.

18. A method for improving surface cure in coatings and inks comprising the steps of: (a) providing a radiation-curable composition containing the polymeric amino(meth)acrylate according to any one of claims 1 to 10; (b) applying the composition onto a surface; and (c) irradiating said surface or article with actinic radiation.

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