Thioxanthone photoinitiators

Abstract

The present invention relates to novel photoinitiators having low yellowing after curing and low migration potential, and to photopolymerization compositions containing said photoinitiators. The present invention also relates to a process for the photopolymerization of compositions comprising said photoinitiators, and to their use in the production of articles, including printed, coated and manufactured components.

Description

Technical Field

[0001] This invention relates to the field of novel photoinitiators. Background Technology

[0002] In recent years, the design and development of new photoinitiators (PIs) have received increasing attention because many photoinitiators have been or will soon be banned due to toxicity or reproductive toxicity. In addition, the migration and stability of photoinitiators are also important characteristics that need to be considered when dealing with sensitive applications.

[0003] Thioxanone photoinitiators are the most widely used type of photoinitiators in UV curing. Their ability to photopolymerize under LED lights (mainly 365 and 395 nm) and to photosensitize other photoinitiators are key to the success of this class of compounds. Unfortunately, their main drawback is that they turn yellow after curing.

[0004] CN103703030A discloses a photoinitiator that exhibits low migration tendency and has the following Markush formula:

[0005]

[0006] Wherein, G is the residue other than the olefin bond of acrylate or polyol acrylate, and PI includes thioxanthone residue.

[0007] The preferred G residue is as follows:

[0008]

[0009] In the example molecule, CN103703030A discloses the following, hereinafter referred to as structure A.

[0010]

[0011] (Example 3, compound VIII), said compound is a pale yellow solid (see paragraphs

[0062] and

[0063] ).

[0012] It is well known that solid photoinitiators are difficult to dissolve and often produce undesirable crystallization, leading to a loss of reactivity. Therefore, liquid and less viscous photoinitiators are generally preferred, as they exhibit better solubility and are easier to handle. Thus, it is understandable that there is always a need to find new thioxanthone photoinitiators with improved properties, namely low migration tendency, easier formulation, and very low post-curing yellowing. Summary of the Invention

[0013] The first object of the present invention is to provide novel and improved thioxanone initiators (PI), their use as photoinitiators, and photocurable compositions comprising these photoinitiators.

[0014] A further object of the present invention is to provide a photocurable composition comprising the novel PI of the present invention.

[0015] A further object of the present invention is to provide a method for using the novel PI photocurable olefinic unsaturated compound of the present invention, and a manufactured article produced by said method.

[0016] According to one aspect of the present invention, the present invention relates to compounds of formula (I).

[0017]

[0018] Wherein, "PEG 600-800" means that the (-CH2-CH2-O-) chain in parentheses represents the polyethylene glycol 600 to polyethylene glycol 800 portion, and Alk represents the C1-C12 alkyl chain, preferably the C1-C6 alkyl chain, more preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl.

[0019] Preferably, "PEG 600-800" refers to PEG 600, so that the compound of formula (I) is the compound of formula (II).

[0020]

[0021] Preferably, Alk is n-butyl, so that the compound of formula (I) is the same as the compound of formula (III).

[0022]

[0023] Preferably, "PEG 600-800" is PEG 600 and Alk is n-butyl, so that the compound of formula (I) is the compound of formula (IV).

[0024]

[0025] The compound of formula (III) is a preferred compound according to the present invention.

[0026] The compound of formula (IV) is a more preferred compound according to the present invention.

[0027] According to the present invention, PEG can be pure or can include molecules with a molecular weight distribution such that they can be polydisperse.

[0028] The compounds of the present invention can be prepared by any suitable method known to those skilled in the art.

[0029] For example, the compounds of the present invention can be prepared by reacting the desired PEG diacrylate with n-butylamine, and then reacting the resulting n-butyl derivative PEG diacrylate with a thioxanthone-2-oxoacetyl halide (e.g., thioxanthone-2-oxoacetyl chloride), wherein the molar amount of the thioxanthone-2-oxoacetyl halide is at least twice the molar amount relative to the N-butyl derivative PEG diacrylate. The above reaction can be carried out in a suitable solvent or solvent mixture, such as an aromatic solvent like toluene.

[0030] Detailed information about the above methods is provided in the experimental section below.

[0031] The reactants and starting materials are known and / or commercially available, or they can be prepared according to known methods.

[0032] According to another aspect of the invention, the present invention relates to a method for preparing a compound of formula (I), the method comprising performing the methods disclosed above and / or reported in the Experimental Section below, or similar methods.

[0033] Surprisingly, compounds of formula (I), containing the PEG 600-800 portion, particularly the PEG 600 portion, i.e., compounds of formula (III) or (IV), exhibit improved photoinitiation properties compared to compounds of structure A, as will be shown in the experimental section below. Furthermore, compounds of formula (IV) are low-viscosity liquids, a well-known valuable property of PI.

[0034] According to another aspect of the present invention, the present invention relates to a photopolymerizable composition comprising the following components:

[0035] a) Based on the total amount of the composition, 50% to 99.9% by weight, preferably 70% to 98.9% by weight, at least one olefinic unsaturated compound;

[0036] b) Based on the total amount of the composition, 0.1% to 35% by weight, preferably 0.1% to 20% by weight, and more preferably 0.2% to 15% by weight of at least one compound of formula (I) as defined above; and

[0037] c) Based on the total amount of the composition, 0% to 20% by weight, preferably 0% to 15% by weight, and more preferably 0.2% to 15% by weight of the promoter and / or initiator.

[0038] Preferably, component b) is a compound of formula (III) or (IV) as defined above, more preferably a compound of formula (IV).

[0039] Preferably, the content of component b) is between 1% and 30%, for example, 2%, 3%, 4%, 5%, 10%, 15%, 20%, 25% or 30%.

[0040] According to the present invention, the terms "photocuring" and "photopolymerization" and related terms are synonyms.

[0041] The statement “based on total weight of the composition” means that the weight % of any component is calculated relative to the sum of the weights of all components in the composition, including any possible additional components (other than a), b) and c) above, but water and / or solvents that may be present in the composition are not taken into account when calculating the weight %.

[0042] According to another aspect of the present invention, the present invention relates to a method for use in photocurable photopolymerizable compositions, coatings, adhesives, and inks, the method comprising:

[0043] i. Provide photopolymerizable compositions as defined above;

[0044] ii. Coating or printing the photopolymerizable composition onto a substrate, and

[0045] iii. The coated or printed composition is photocured on the substrate using a light source.

[0046] According to another aspect of the invention, the present invention relates to a method for three-dimensional printing, the method comprising photocuring a mixture comprising a composition as defined above using a light source.

[0047] According to another aspect of the present invention, the present invention relates to manufactured articles obtained by the method of the present invention.

[0048] The photocurable composition of the present invention may further include one or more of the following components: d) sensitizers and / or e) further photoinitiators and / or f) conventional additives, in addition to components a), b) and c) (if any).

[0049] According to a preferred embodiment, the photopolymerizable composition for use in the method of the present invention comprises at least components a), b), and c) as defined above, and more preferably at least components a), b), c), and e) as defined above.

[0050] The photoinitiator of the present invention can be used in photocurable compositions comprising an olefinically unsaturated component a). The unsaturated component a) may contain one or more olefinic double bonds. These may be low molecular weight (monomer) or high molecular weight (oligomer) compounds.

[0051] Suitable examples of low molecular weight monomers (monomer compounds) having a single double bond are alkyl or hydroxyalkyl acrylates or methacrylates, such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, or isobornyl acrylate; and methyl methacrylate or ethyl methacrylate. Other examples are silicone or fluorine-modified resins, such as silicone acrylates. Other examples of these monomers are acrylonitrile, acrylamide, methacrylamide, N-substituted (meth)acrylamide, styrene, alkylstyrene and halostyrene, vinyl esters (e.g., vinyl acetate), vinyl ethers (e.g., isobutyl vinyl ether, N-vinylpyrrolidone, vinyl chloride, or vinylidene chloride).

[0052] Examples of monomers having more than one double bond are ethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, hexamethylene glycol diacrylate, bisphenol A diacrylate, 4,4'-bis-(2-acryloyloxyethoxy)-diphenylpropane, trimethylolpropane triacrylate, pentaerythritol triacrylate or tetraacrylate, vinyl acrylate, divinylbenzene, divinyl succinate, diallyl phthalate, triallyl phosphate, triallyl isocyanurate, or tri-(2-acryloylethyl) isocyanurate. Examples of high molecular weight (oligomeric) polyunsaturated compounds are acrylated epoxy resins, acrylated polyesters or polyesters containing vinyl ethers or epoxy groups, acrylated polyurethanes, or acrylated polyethers. Other examples of unsaturated oligomers are unsaturated polyester resins, which are typically prepared from maleic acid, phthalic acid, and one or more diols and have a molecular weight of about 500 Da to 3,000 Da. These unsaturated oligomers can also be called prepolymers.

[0053] Examples particularly suitable for carrying out component a) of the present invention are esters of olefinically unsaturated carboxylic acids and polyols or polyepoxides, and polymers containing olefinically unsaturated groups in the chain or side groups, such as unsaturated polyesters, polyamides and polyurethanes and their copolymers, alkyl resins, polybutadiene and butadiene copolymers, polyisoprene and isoprene copolymers, polymers and copolymers having (meth)acrylic acid groups in the side chains, and mixtures thereof.

[0054] Illustrative examples of unsaturated carboxylic acids or anhydrides that can be used to prepare the above-mentioned esters are acrylic acid, methacrylic acid, maleic anhydride, crotonic acid, itaconic acid, cinnamic acid, and unsaturated fatty acids (e.g., linolenic acid and oleic acid). Acrylic acid and methacrylic acid are preferred.

[0055] Examples of polyols that can also be esterified are aromatic, aliphatic, and alicyclic polyols, with aliphatic and alicyclic polyols being preferred.

[0056] Aromatic polyols include, for example, hydroquinone, 4,4'-dihydroxybiphenyl, 2,2-bis(4-hydroxyphenyl)propane, and phenolic varnishes and resins. Esterifiable polyepoxides include those based on said polyols, particularly the reaction products of aromatic polyols with epichlorohydrin. Also suitable as polyols are polymers and copolymers containing hydroxyl groups in the polymer chain or side groups, such as polyvinyl alcohol and its copolymers, or polyhydroxyalkyl methacrylate or its copolymers. Other suitable polyols are low-polymer polyesters with hydroxyl end groups. Examples of aliphatic and alicyclic polyols include preferably alkylene glycols containing 2 to 12 carbon atoms, such as ethylene glycol, 1,2- or 1,3-propanediol, 1,2-, 1,3- or 1,4-butanediol, pentanediol, hexanediol, octanediol, dodecanediol, diethylene glycol, triethylene glycol, polyethylene glycol with a molecular weight preferably from 200 Da to 1,500 Da, 1,3-cyclopentanediol, 1,2-, 1,3- or 1,4-cyclohexanediol, 1,4-dihydroxymethylcyclohexane, glycerol, tri(β-hydroxyethyl)amine, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol, and sorbitol.

[0057] Other suitable olefinically unsaturated components a) are unsaturated polyamides obtained from unsaturated carboxylic acids and, preferably, aromatic, aliphatic, and alicyclic polyamines having 2-6, more preferably 2-4, amino groups. Examples of such polyamines are: ethylenediamine, 1,2- or 1,3-propanediamine, 1,2-, 1,3- or 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, octanediamine, dodecanediamine, 1,4-diaminocyclohexane, isophoronediamine, phenylenediamine, diphenylenediamine, di-(β-aminoethyl) ether, diethylenetriamine, triethylenetetramine, and di(β-aminoethoxy)ethane and di(β-aminopropoxy)ethane. Other suitable polyamines are polymers and copolymers that may contain additional amino groups in the side chain, as well as oligoamides containing amino terminal groups.

[0058] Specific examples of such unsaturated polyamides are: methylenebisacrylamide, 1,6-hexamethylenebisacrylamide, diethylenetriaminetrimethylacrylamide, bis(methacrylamide propoxy)ethane, and N-[(β-hydroxyethoxy)ethyl]acrylamide.

[0059] Unsaturated polyurethanes are also suitable as components a) in carrying out the invention, for example, those derived from saturated or unsaturated diisocyanates and unsaturated or saturated diols. Polybutadiene and polyisoprene and their copolymers may also be used.

[0060] Suitable monomers include, for example, olefins such as ethylene, propylene, butene and hexene, (meth)acrylates, acrylonitrile, styrene and vinyl chloride.

[0061] Polymers having unsaturated (meth)acrylate groups in their side chains can also be used as component a). These polymers can typically be reaction products of epoxy resins based on phenolic varnishes and (meth)acrylate; homopolymers or copolymers of vinyl alcohol or its hydroxyalkyl derivatives that have been esterified with (meth)acrylate; and homopolymers and copolymers of (meth)acrylates that have been esterified with hydroxyalkyl methacrylates. According to a preferred embodiment, the photocurable composition further comprises a co-initiator c), also known as an accelerator.

[0062] Examples of suitable promoters / co-initiators c) are alcohols, thiols, thioethers, amines or ethers having available hydrogens bonded to carbons adjacent to phosphine, disulfides and heteroatoms, for example as described in EP 438 123 and GB 2 180 358.

[0063] Suitable examples of amine promoters / co-initiators include, but are not limited to, aliphatic, alicyclic, aromatic, aryl-aliphatic, heterocyclic, oligomeric, or polymeric amines. They can be primary, secondary, or tertiary amines, such as butylamine, dibutylamine, tributylamine, cyclohexylamine, benzyl dimethylamine, dicyclohexylamine, N-phenylglycine, triethylamine, phenyl diethanolamine, triethanolamine, piperidine, piperazine, morpholine, pyridine, quinoline, esters of dimethylaminobenzoic acid, Mischel ketone (4,4'-bis(dimethylaminobenzophenone)) and its derivatives.

[0064] Amine-modified acrylate compounds can be used as amine promoters / co-initiators; examples of such amine-modified acrylates include acrylates modified by reaction with primary or secondary amines, as described in US 3,844,916, EP280222, US 5,482,649 or US 5,734,002.

[0065] Polyfunctional amines and polyamine derivatives are also suitable as co-initiators; some examples are from IGM Resins BV. ASA, from Rahn AG. AB-2, from Lambson Limited Those described in 7040 or US2013 / 0012611.

[0066] The photocurable compositions of the present invention can also be formulated as compositions further comprising water and / or solvents (e.g., organic solvents).

[0067] Based on the total amount of the composition, the content of photosensitizer d) can be from 0.01 to 15% by weight, preferably from 0.01 to 10% by weight.

[0068] Examples of sensitizers are those commonly used in the art, such as benzophenones, thioxanthones, anthraquinones, coumarins and 3-acylcoumarin derivatives, terphenyl, styrene ketones and 3-(aromaticylmethylene)-thiazoline, camphorquinone, and eosin, rhodamine and erythrosine dyes.

[0069] Examples of thioxanthones include thioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-dodecylthioxanthone, 2,4-diethylthioxanthone, 2,4-dimethylthioxanthone, 1-methoxycarbonylthioxanthone, 2-ethoxycarbonylthioxanthone, 3-(2-methoxyethoxycarbonyl)thioxanthone, 4-butoxycarbonylthioxanthone, 3-butoxycarbonyl-7-methylthioxanthone, 1-cyano-3-chlorothioxanthone, 1-ethoxycarbonyl-3-chlorothioxanthone, 1-ethoxycarbonyl-3-ethoxythioxanthone, 1-ethoxycarbonyl-3-aminothioxanthone, 1-ethoxycarbonyl-3-benzenesulfonylthioxanthone, 3,4-bis[2-(2-methoxyethoxy)ethoxycarbonyl]thioxanthone, and 1-ethoxycarbonyl-3-(1-methyl-1-morpholinylethyl)thioxanthone. 2-Methyl-6-dimethoxymethylthioxanthone, 2-methyl-6-(1,1-dimethoxybenzyl)thioxanthone, 2-morpholinylmethylthioxanthone, 2-methyl-6-morpholinylmethylthioxanthone, N-allylthioxanthone-3,4-dicarboximide, N-octylthioxanthone-3,4-dicarboximide, N-(1,1,3,3-tetramethylbutyl)-thioxanthone-3,4-dicarboximide, 1-phenoxythioxanthone, 6-ethoxycarbonyl-1-2-methoxythioxanthone, 6-ethoxycarbonyl-2-methylthioxanthone, thioxanthone-2-polyethylene glycol ester, 2-hydroxy-3-(3,4-dimethyl-9-oxo-9H-thioxanthone-2-yloxy)-N,N,N-trimethyl-1-propanium chloride (propanaminium) chloride), or those described in patent application PCT / EP2011 / 069514, such as n-dodecyl-7-methyl-thioxanthone-3-carboxylate and N,N-diisobutyl-7-methyl-thioxanthone-3-urea. Polymeric thioxanthone derivatives (e.g., those from IGM Resins) are also suitable. TX, Rahn AG TX-1, Lambson Ltd. 7010).

[0070] Examples of benzophenones include benzophenone, 4-phenylbenzophenone, 4-methoxybenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-dimethylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-dimethylaminobenzophenone, 4,4'-diethylaminobenzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, 4-(4-methylthiophenyl)benzophenone, 3,3'-dimethyl-4-methoxybenzophenone, methyl 2-benzoylbenzoate, and 4-(2-hydroxyethylthio)benzophenone. Ketones, 4-(4-toluenethio)benzophenone, 4-benzoyl-N,N,N-trimethylbenzamide chloride, 2-hydroxy-3-(4-benzoylphenoxy)-N,N,N-trimethyl-1-propanemium chloride monohydrate, 4-(13-acryloyl-1,4,7,10,13-pentatridecyl)benzophenone, 4-benzoyl-N,N-dimethyl-N-[2-(1-oxo-2-propenyl)oxoethyl-benzamide chloride, or those described in US9938231 (e.g., IGM Resins Corporation). 991).

[0071] Also suitable are polymeric benzophenone derivatives (e.g., all from IGM Resins). BP, 2702 and 682, Rahn AG Company BP-2, and Lambson Ltd. 7005).

[0072] Examples of 3-acylcoumarin derivatives are 3-benzoylcoumarin, 3-benzoyl-7-methoxycoumarin, 3-benzoyl-5,7-di(propoxy)coumarin, 3-benzoyl-6,8-dichlorocoumarin, 3-benzoyl-6-chlorocoumarin, 3,3'-carbonyl-bis[5,7-di(propoxy)coumarin], 3,3'-carbonyl-bis(7-methoxycoumarin), 3,3'-carbonyl-bis(7-diethylaminocoumarin), 3-isobutyrylcoumarin, 3-benzoyl-5,7-dimethoxycoumarin, 3-benzoyl-5,7-diethoxycoumarin, 3-benzoyl-5,7-dibutoxycoumarin, 3 -Benzoyl-5,7-di(methoxyethoxy)coumarin, 3-benzoyl-5,7-di(allyloxy)coumarin, 3-benzoyl-7-dimethylaminocoumarin, 3-benzoyl-7-diethylaminocoumarin, 3-isobutyryl-1,7-dimethylaminocoumarin, 5,7-dimethoxy-3-(1-benzoyl)coumarin, 5,7-dimethoxy-3(1-benzoyl)coumarin, 3-benzoylbenzo[f]coumarin, 7-diethylamino-3-thiopheneylcoumarin, 3-(4-cyanobenzoyl)-5,7-dimethoxycoumarin, or those described in EP2909243 and WO2017216699.

[0073] Examples of 3-(aromatic methyl)thiazoline are 3-methyl-1,2-benzoylmethylene-β-benzothiazoline, 3-methyl-2-benzoylmethylene-benzothiazoline, and 3-ethyl-2-propionylmethylene-β-benzothiazoline.

[0074] Other examples of aromatic carbonyl compounds are acetophenone, 3-methoxyacetophenone, 4-phenylacetophenone, benzyl (e.g., the kind described in WO 2013 / 164394), 2-acetylnaphthalene, 2-naphthaldehyde, 9,10-anthraquinone, 9-fluorenone, dibenzocycloheptanone, xanthonone, 2,5-bis(4-diethylaminobenzylidene)cyclopentanone, α-(p-dimethylaminobenzylidene), ketones such as 2-(4-dimethylamino-benzylidene)-indan-1-one or 3-(4-dimethylaminophenyl)-1-indan-5-yl-propenone, 3-phenylthiophthalimide, N-methyl-3,5-di(ethylthio)phthalimide.

[0075] Thioxanones, coumarins, and 3-acylcoumarins are particularly preferred.

[0076] It was observed that component d) improved the activity of photoinitiator b) without shortening the shelf life of the composition. Furthermore, such compositions have the particular advantage that appropriate selection of the sensitizer d) can shift the spectral sensitivity of the photoinitiator b) to any desired wavelength region. Those skilled in the art can select a suitable sensitizer d) to make the photoinitiator b) function in any desired wavelength region.

[0077] The content of other possible photoinitiators e) may be 0.5-15% by weight of the total composition, preferably 1-10% by weight of the composition. Examples of other suitable photoinitiators e) are camphorquinone, benzophenone, benzophenone derivatives, acetophenone, acetophenone derivatives, diekoxyacetophenone, α-hydroxy ketone, α-amino ketone, 4-aramid-1,3-dioxolane, benzoin alkyl ethers and benzyl ketals, such as benzyl dimethyl ketal, ketone sulfones, such as 1-[4-[(4-benzoyl-phenyl)-thio]-phenyl]-2-methyl-2-[(4-methyl-phenyl)-sulfonyl]-prop-1-one ( 1001 (from IGM Resins), 3-ketocoumarin, for example, as described in EP2909243 and WO2017216699, phenylglyoxylic acid and its derivatives, diphenylglyoxylic acid, peresters, such as benzophenone tetracarboxylic acid perester, for example, as described in EP126 541, acylphosphine photoinitiators (selected from monoacylphosphine oxide, diacylphosphine oxide, triacylphosphine oxide and polyfunctional mono or diacylphosphine oxide), halomethyltriazine, hexaaryl diimidazole / co-initiator systems, such as o-chlorohexaphenyl diimidazole with 2-mercaptobenzothiazole, ferrocene compounds or titanium calcein, such as dicyclopentadienyl-bis(2,6-difluoro-3-pyrrolo-phenyl)titanium, O-acyloxime ester photoinitiators.

[0078] Examples of α-hydroxy ketones and α-amino ketones are 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propanone, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propanoyl)-benzyl]phenyl}-2-methyl-1-propanone, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propanoyl)-phenoxy]-phenyl}-2-methyl-1-propanone, 2-methyl-1-(4-methylphenylthio)-2-morpholin-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinphenyl)-1-butanone, and (2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone).

[0079] Examples of O-acyl oxime photoinitiators are 1,2-octanedione, 1-[4-(phenylthio)phenyl]-2-(O-benzoyl oxime), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl] acetone-1-(O-acetyl oxime), or those described in GB 2339571.

[0080] Examples of acylphosphine photoinitiators include, but are not limited to, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-(2,4-dipentyloxyphenyl), 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and ethyl (2,4,6-trimethylbenzoyl)phenylphosphine sulfate, phenyl(2,4,6-trimethylbenzoyl)phosphine acid, and glycerol ethoxylated trimer (from IGM Resins). TP).

[0081] Examples of photoinitiators based on halomethyltriazine are 2-[2-(4-methoxy-phenyl)-vinyl]-4,6-bis-trichloromethyl[1,3,5]triazine, 2-(4-methoxy-phenyl)-4,6-bis-trichloromethyl[1,3,5]triazine, 2-(3,4-dimethoxyphenyl)-4,6-bis-trichloromethyl[1,3,5]triazine, and 2-methyl-4,6-bis-trichloromethyl[1,3,5]triazine.

[0082] When the photocurable composition according to the invention is used in a hybrid system (in this respect, a mixture of radical and cationic curing systems), a cationic photoinitiator may also be used as an additional photoinitiator (e). Examples of suitable cationic photoinitiators are aromatic thioonium salts, phosphonium salts, or iodonium salts, as described, for example, in US4,950,581, or cyclopentadienyl aromatic-iron(II) complex salts, such as (n6-isopropylbenzene)(n5-cyclopentadienyl)ferric(II) hexafluorophosphate, or oxime-based photocatalytic acids, for example, as described in GB 2,348,644, US4,450,598, US4,136,055, WO 00 / 10972, and WO 00 / 26219.

[0083] The photocurable composition according to the invention may further contain 0 to 10% of conventional additives based on the total amount of the composition. Additive f) may be, for example, a thermal initiator, a binder, a stabilizer, or a mixture thereof.

[0084] The choice of additives depends on the application area under discussion and the properties required for that area. The additives described above (f) are known in the art and are used accordingly in amounts conventionally used in the art.

[0085] For example, particularly in the case of a coloring composition, the composition may also contain a thermal initiator as an additional additive f), i.e., a compound that forms a free radical upon heating, such as an azo compound, such as 2,2'-azobis(4-methoxy-2,4-dimethylpentanonitrile), triazine, diazosulfide, pentazadiene, or a peroxide compound, such as hydroperoxide or peroxycarbonate, such as tert-butyl hydroperoxide, as described in EP245 639.

[0086] An adhesive may also be added to the photocurable composition of the present invention. The addition of an adhesive is particularly advantageous when the photocurable compound is a liquid or viscous substance. Based on the total amount of the composition (excluding possible water and solvents), the amount of adhesive may be, for example, 5 to 60% by weight, preferably 10 to 50% by weight. The choice of adhesive is based on the application and the desired properties, such as developability in aqueous and organic solvent systems, adhesion to substrates, and sensitivity to oxygen.

[0087] Suitable binders are, for example, polymers having a weight-average molecular weight (Mw) of about 5,000 Da to 2,000,000 Da, preferably 10,000 Da to 1,000,000 Da. Illustrative examples include: homopolymers and copolymers of acrylates and methacrylates, such as copolymers of methyl methacrylate / ethyl methacrylate / methacrylic acid, poly(alkyl methacrylate), poly(alkyl acrylate); cellulose esters and ethers, such as cellulose acetate, cellulose acetate butyrate, methyl cellulose, ethyl cellulose, polyvinyl butyral, polyvinyl formal, cyclized rubber, polyethers, such as polyethylene oxide, polypropylene oxide, polytetrahydrofuran, polystyrene, polycarbonate, polyurethane, chlorinated polyolefins, such as polyvinyl chloride, copolymers of vinyl chloride / vinylidene chloride, vinylidene chloride and acrylonitrile, copolymers of methyl methacrylate and vinyl acetate, polyvinyl acetate, copolymers (ethylene / vinyl acetate), polymers, such as polycaprolactam and poly(hexamethylene adipamide), polyesters, such as poly(ethylene glycol terephthalate) and poly(hexamethylene glycol succinate).

[0088] Suitable stabilizers include, for example, heat inhibitors such as hydroquinone, hydroquinone derivatives, p-methoxyphenol, β-benzol, or sterically hindered phenols such as 2,6-bis(tert-butyl)-p-cresol, which prevent premature polymerization. To increase dark storage stability, copper compounds such as copper naphthenate, copper stearate, or copper octanoate, phosphorus compounds such as triphenylphosphine, tributylphosphine, triethyl phosphite, triphenyl phosphite, or tribenzyl phosphite, quaternary ammonium compounds such as tetramethylammonium chloride or trimethylbenzylammonium chloride, or hydroxylamine derivatives such as N,N-diethylhydroxylamine can be used. To remove atmospheric oxygen during polymerization, paraffin or similar waxy substances that are insoluble in the polymer, migrate to the surface at the start of polymerization, and form a transparent surface layer that prevents air from entering. Light stabilizers, such as UV absorbers like hydroxyphenylbenzotriazole, hydroxyphenyl benzophenone, oxalamide, or hydroxyphenyl-S-triazine derivatives, can also be added. Such components may be used alone or in mixtures, with or without the use of sterically hindered amines (HALS).

[0089] The photocurable compositions according to the invention may further comprise photoreducible dyes as further additives (f), such as xanthene, benzoxanthene, benzothiol, thiazine, pyridine, porphyrin, or acridine dyes, and / or radiation-degradable trihalomethyl compounds. These compounds are described, for example, in EP445624.

[0090] Depending on the intended use, other commonly used additives f) include optical brighteners, fillers, pigments (white and colored pigments), colorants, antistatic agents, wetting agents, or flow improvers. Additives conventionally used in the art, such as antistatic agents, flow improvers, and adhesion enhancers, may also be used.

[0091] In addition to the components described above, other components may also be present in the compositions of the present invention.

[0092] Chain transfer agents conventionally used in the art can also be added to the compositions according to the invention. Examples include thiols, amines, and benzothiazoles.

[0093] The compositions of the present invention may also contain colorants and / or colored pigments. Inorganic and organic pigments may be used, depending on the intended use. Such additives are well known to those skilled in the art; some examples are carbon black, iron oxides such as iron oxide yellow, iron oxide red, chrome yellow, chrome green, nickel titanium yellow, ultramarine blue, cobalt blue, bismuth vanadate, cadmium yellow, and cadmium red. Examples of organic pigments are monoazo or diazo pigments and their metal complexes, phthalocyanine pigments, polycyclic pigments such as dinaphthalene, anthraquinone, indigo thiocyanate, quinacridone, or triphenylmethane pigments, and diketone-pyrrolo-pyrrole, isoindolineones such as tetrachloroisoindolineone, isoindoline, dioxazine, benzimidazolone, and quinolinephthalone pigments. Pigments may be used alone or in combination in the formulation.

[0094] Depending on the intended use, pigments may be added to formulations in amounts conventionally used in the art, such as 0.1 to 30% by weight or 10% to 25% by weight based on the total weight of the composition.

[0095] The composition may also contain, for example, a wide variety of organic colorants, such as azo dyes, methine dyes, anthraquinone dyes, and metal complex dyes. The concentration is typically, for example, 0.1 to 20% by weight, particularly 1 to 5% by weight, based on the total weight of the composition.

[0096] The photocurable composition of the present invention may contain water.

[0097] The photocurable compositions of the present invention are suitable for a variety of purposes, such as as printing inks (e.g., screen printing inks, flexographic printing inks, offset printing inks, and inkjet printing inks), as varnishes, as colored coatings (e.g., for wood or metal), as powder coatings, as coatings, especially for paper, wood, metal, or plastics, as sun-curable coatings for marking structures and roads, for photographic reproduction processes, for holographic recording materials, for image recording processes, or for producing printing plates that can be developed using organic solvents or aqueous alkaline media, for the production of screen printing masks, as dental filling compounds, as adhesives, as pressure-sensitive adhesives, as laminating resins, as photoresists (e.g., electroresists), and as... Etching resists or permanent resists, liquids and dry films, as photostructured dielectrics, and as solder resists for electronic circuits, are used as resists in the production of color filters or the creation of structures for any type of display in the following processes: manufacturing of plasma displays and electroluminescent displays; production of optical switches, gratings (interference gratings); manufacturing of three-dimensional articles by bulk curing (UV curing in a transparent mold) or according to stereolithography processes (as described in, for example, US4,575,330); in the manufacture of composite materials (e.g., styrene polyesters that may include glass fibers and / or other fibers and other auxiliaries) and other three-dimensional printing methods well known to those skilled in the art; in the coating or sealing of electronic components; or as a coating for optical fibers.

[0098] The photocurable compositions of the present invention are also suitable for the production of optical lenses (e.g., contact lenses or Fresnel lenses), the manufacture of medical devices, assistive devices or implants, and for use in dry film coatings.

[0099] The photocurable compositions of the present invention are also suitable for preparing gels with thermotropic liquid crystal properties. Such gels are described, for example, in DE 19700064 and EP 678534.

[0100] Articles comprising a compound of formula (I), preferably a compound of formula (III) or (IV), more preferably a compound of formula (IV), or comprising a photocurable composition of the present invention represent another subject of the present invention.

[0101] The compounds and compositions according to the present invention can also be used as free radical photoinitiators or photoinitiation systems for radiation-curable powder coatings.

[0102] The photocurable compositions according to the invention are suitable, for example, as coatings for a variety of substrates, such as wood, textiles, paper, ceramics, glass, plastics (e.g., polyester, polyethylene terephthalate, polyolefins and cellulose acetate, especially in film form), and metals (e.g., Al, Cu, Ni, Fe, Zn, Mg or Co and GaAs, Si or SiO2), on which a protective layer is to be applied or an image is to be applied, for example by imaging exposure.

[0103] A wide variety of light sources can be used in the method according to the invention, emitting wavelengths from about 200 nm to about 800 nm. Point sources and planar radiators (lamp blankets) are both suitable. Examples include: carbon arc lamps, xenon arc lamps, medium-pressure, high-pressure and low-pressure mercury arc radiators, metal halide-doped lamps (metal halide lamps) where appropriate, microwave-excited metal vapor lamps, excimer lamps, superluminescent fluorescent tubes, fluorescent lamps, argon incandescent lamps, flash lamps, photographic floodlights, light-emitting diodes (LEDs), electron beams, X-rays and lasers.

[0104] According to one embodiment, the light source includes UV light in at least one of the UVA, UVB, and UVC ranges.

[0105] According to a preferred embodiment, the light source is an LED source, particularly preferably an LED source emitting at a wavelength of 365nm to 420nm, and more preferably an LED source emitting at wavelengths of 365nm, 385nm, 395nm, and 405nm.

[0106] According to the present invention, the distance between the lamp and the substrate to be exposed can vary depending on the intended use and the type and intensity of the lamp, for example from 0.1 cm to 150 cm, preferably from 1 cm to 50 cm.

[0107] The photopolymerizable composition can also be coated onto a substrate that already contains a coating or printed layer. After photopolymerization of the photopolymerizable composition using the light source, the photopolymerizable composition can be overprinted or overcoated with one or more compositions suitable for printing or coating. Applying the photopolymerizable composition to the substrate by the coating or printing method, photopolymerizing it by the light source, and then further processing the article with or without further coating or printing, results in an article representing another aspect of the invention.

[0108] As described above, we were pleasantly surprised to find that, compared with the compounds of the prior art, the compounds of formula (I), preferably the compounds of formula (III) or (IV), and more preferably the compounds of formula (IV), exhibit good reactivity at UVA, UVB and UVC wavelengths and maintain very low yellowing after curing.

[0109] Furthermore, compounds of formula (I), preferably compounds of formula (III) or (IV), and more preferably compounds of formula (IV) exhibit a very low migration tendency.

[0110] The invention will be described in detail below with reference to the following examples, which are illustrative and not restrictive. Detailed Implementation

[0111] Experimental Section

[0112] In the entirety of this instruction manual, if the chemical name and chemical formula are inconsistent, the latter shall prevail.

[0113] 1 The H NMR spectra were recorded using a Bruker Ascend 300MHz NMR spectrometer.

[0114] Example 1

[0115] Synthesis of compounds of formula (IV)

[0116]

[0117] Step 1. Add 3.65 g (0.05 mol) of n-butylamine dropwise to a solution of 17.7 g (0.025 mol) of polyethylene glycol 600 diacrylate (PEG600DA) dissolved in 20 mL of toluene. The reaction was carried out at 50 °C for 24 hours, and the solvent was removed by vacuum distillation to obtain 21.4 g of polyethylene glycol 600 di(3-butylamino)propionate.

[0118] Step 2. Add dropwise 21.4 g of polyethylene glycol 600 di(3-butylamino)propionate (0.025 mol) and 5.6 g (0.055 mol) triethylamine obtained in the previous step to a solution of 15.2 g of thioxanone-2-oxoacetyl chloride (0.05 mol) dissolved in 150 mL of toluene. Maintain the reaction at 20–30 °C for 8 hours, then filter and add 3.0 g of ground ammonium carbonate to the filtrate, stir for 1 hour, and filter again. Remove the solvent under reduced pressure to obtain 34.5 g of the desired product as a yellow oil.

[0119] The product was analyzed by HPLC (ELSD detector, C18 column, eluent: water (0.1% triethylamine) / acetonitrile), and the purity was 95% after 28.1 min.

[0120] 1H-NMR (CDCl3, δppm):0.9-1.1(6H),1.3-1.5(4H),1.5-1.7(4H),2.7(4H),3.4( 4H),3.6-3.8(54H),4.2-4.4(4H),4.8-5(4H),7.4-7.7(10H),8.0(2H),8.6(2H)

[0121] Comparative Example (COMP-1)

[0122] Synthesis of the following compounds

[0123]

[0124] Step 1. Add 4.4 g (0.060 mol) of n-butylamine dropwise to a solution of 15.2 g (0.030 mol) of polyethylene glycol 400 diacrylate (PEG400DA) dissolved in 20 mL of toluene. React at 50 °C for 24 hours, and remove the solvent by vacuum distillation to obtain 19.4 g of polyethylene glycol 400 di(3-butylamino)propionate.

[0125] Step 2. Add dropwise 19.4 g of polyethylene glycol 400 di(3-butylamino)propionate (0.030 mol) and 6.7 g of triethylamine (0.066 mol) obtained in the previous step to a solution of 18.3 g of thioxanone-2-oxoacetyl chloride (0.060 mol) dissolved in 150 ml of toluene. Maintain the reaction at 20–30 °C for 8 hours, then filter. Add 3.0 g of ground ammonium carbonate to the filtrate, stir for 1 hour, and filter again. Remove the solvent under reduced pressure to obtain 32.8 g of the desired product as a yellow oil.

[0126] 1 H-NMR (CDCl3, δppm):0.9-1.1(6H),1.3-1.5(4H),1.5-1.7(4H),2.7(4H),3.4( 4H),3.6-3.8(36H),4.2-4.4(4H),4.8-5(4H),7.4-7.7(10H),8.0(2H),8.6(2H)

[0127] Comparative Test

[0128] The yellowing after curing was evaluated by comparing the compound of Example 1 with the corresponding compound prepared above (COMP-1) or with a commercially available reference product (COMP-2) sold by IGM Resins under the trade name OMNIPOL TX (CAS RN 813452-37-8).

[0129] The viscosity and stability of the compound in Example 1 are also compared.

[0130] Example 2

[0131] Yellowness Index (YI) Assessment

[0132] The photopolymerizable composition used for testing was prepared by dissolving 4% by weight of PI and 5% by weight of co-initiator (Omnipol ASA) in a solution of 50% Photomer 3016 (bisphenol A epoxy diacrylate), 15% Photomer 4335 (PETIA), 15% Photomer 4666 (DPHA), and 20% Photomer 4172 (PPTTA). The photopolymerizable composition was spread onto coated paperboard to a thickness of 12 micrometers using a rod coater, and then photopolymerization was performed using a 365nm LED lamp at a distance of 0.5 cm.

[0133] After 24 hours, the yellowing after curing was measured using a TECHKON SpectroDens Premium with a yellowness index (YI) of E313 and a light source of D65 / 2.

[0134] The results are shown in Table 1 below.

[0135] Table 1

[0136] Test compounds <![CDATA[YI–LED 365nm 16W / cm 2 ]]> Example 1 18.4 COMP-1 20.6 COMP-2 23.9

[0137] In the tests, the compound in Example 1 showed significantly less yellowing compared to the two comparison compounds.

[0138] Example 3

[0139] Viscosity assessment

[0140] Viscosity was measured using a Brookfield CAP2000+ (high torque-low temperature) cone-plate viscometer equipped with a CAP-S-03 cone, rotating at 5 RPM, corresponding to a shear rate of 66.66 s. -1 A 24 μL sample was placed on the instrument plate and heated to the setpoint temperature (accuracy ±0.1 °C). The viscosity was recorded after adjusting for 1 minute at the setpoint temperature and 5 RPM. Data obtained for different samples are shown in Table 2.

[0141] Table 2

[0142]

[0143] The viscosity of the compound in Example 1 is significantly lower than that of the reference compound and far lower than that of COMP-2, which is a noteworthy property that allows for easier handling of PI (and chemicals in general).

[0144] Example 4

[0145] Stability test

[0146] 5g of the test photoinitiator was placed in a 10mL glass vial, the cap was sealed, and the vial was placed in a 60℃ oven. After incubation at this temperature for 4 weeks, the content of small molecule products from decomposition in the sample was analyzed by HPLC. The analytical results are shown in Table 3.

[0147] Table 3

[0148] Test compounds After 4 weeks of decomposition Example 1 <0.1％ COMP-2 2.2％

[0149] As can be seen from the data in the table, the content of decomposition products of the compound in Example 1 is significantly lower than that of the decomposition products of COMP-2. Therefore, the compound in Example 1 shows better stability and a lower risk of small molecule migration due to decomposition.

[0150] Example 5

[0151] FT-IR double bond conversion

[0152] The composition was prepared by dissolving 4% (by weight) PI and 4% (by weight) initiator (Omnipol ASA) in an HDD.

[0153] A thin film was coated onto a glass slide using a 50 μm wire rod, and then subjected to a 395 nm LED UV lamp at 20 mW / cm². 2 Curing was performed once at an energy level and a belt speed of 3.6 m / min. After curing, the cured film was peeled off the glass slide and FT-IR was applied at 810 cm⁻¹. -1 The double bond conversion rate of the cured film was analyzed.

[0154] Repeat the same experiment, using the number of moles of Omnipol TX as a reference, dissolve an equimolar amount of PI in HDDA, and add 4% (by weight) of Omnipol ASA as an initiator.

[0155] Table 4 shows the results of the double bond conversion.

[0156] Table 4

[0157]

[0158] Surprisingly, we found that the compound of Example 1 was more reactive under all conditions, and when PI was used in molar amounts, it outperformed COMP-1 by 25%, while COMP-1 differed from the compound of the present invention only in the PEG chain, and should not have shown any difference.

Claims

1. A compound of formula (III) in, "PEG 600-800" means that the (-CH2-CH2-O-) chain in parentheses represents the polyethylene glycol 600 to polyethylene glycol 800 portion.

2. The compound according to claim 1, wherein it is a compound of formula (IV).

3. A photopolymerizable composition comprising the following components: a) Based on the total amount of the composition, 50% to 99.9% by weight, preferably 70% to 98.9% by weight, at least one olefinic unsaturated compound; b) Based on the total amount of the composition, 0.1% to 35% by weight, preferably 0.1% to 20% by weight, and more preferably 0.2% to 15% by weight of at least one compound of formula (III) or formula (IV) as defined in claim 1 or 2; and c) Based on the total amount of the composition, 0% to 20% by weight, preferably 0% to 15% by weight, and more preferably 0.2% to 15% by weight of a promoter and / or initiator.

4. The photocurable composition according to claim 3, further comprising one or more of the following components: d) Based on the total amount of the composition, 0.01% to 15% by weight of one or more photosensitizers; and / or e) Based on the total amount of the composition, 0.5% to 15% by weight of one or more photoinitiators.

5. The photocurable composition according to claim 3 or 4, characterized in that, The promoter and / or initiator is an amine, preferably a tertiary amine.

6. The photocurable composition according to any one of claims 3 to 5, wherein, Component b) is compound (IV).

7. A method for use in photocurable photopolymerizable compositions, coatings, adhesives, and inks, the method comprising: (i) providing a photopolymerizable composition as defined in any one of claims 3 to 6; (ii) Coating or printing the photopolymerizable composition onto a substrate; and (iii) Photopolymerizing the coated or printed composition on the substrate using a light source.

8. A method for 3D printing, the method comprising providing a photopolymerizable composition as defined in any one of claims 3 to 6, and photocuring the composition with a light source.

9. The method according to claim 7 or 8, characterized in that, The light source includes UV light in at least one of the UVA, UVB and UVC ranges.

10. The method according to any one of claims 7 to 9, characterized in that, The light source is an LED light source that emits light in the range of 350 to 420 nm.

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