Oxime ester photoinitiator, photocurable resin composition and application thereof

Abstract

The present invention provides an oxime ester photoinitiator, a photocurable resin composition and an application. The above-mentioned oxime ester photoinitiator has a structure shown in the general formula (I): compared with the existing oxime ester photoinitiators, the oxime ester photoinitiator with the general formula (I) structure has better stability, so under the irradiation of ultraviolet light, it can effectively suppress the generation and volatilization of small molecule fragments, and almost no overflow gas is generated after curing; at the same time, because the above-mentioned oxime ester photoinitiator has a specific substituent group, it has a strong ultraviolet absorption performance, thereby improving its sensitivity, and the oxime ester photoinitiator also has a high yellowing resistance. In addition, the oxime ester initiator with the structure shown in the general formula (I) can be used in a UV-LED light curing system, and is particularly suitable for initiation under the action of a 365nm light source.

Description

Technical Field

[0001] The present invention relates to the field of organic chemistry, and in particular to an oxime ester photoinitiator, a photocurable resin composition and applications thereof. Background Art

[0002] In photopolymerization reactions, visible light irradiation light sources have the advantages of safety, convenience, easy access and low cost. As a type of visible light irradiation, LED light sources are characterized by low heat generation and low energy consumption. The excitation wavelengths of industrial LED irradiation light sources are generally 365nm, 385nm, 395nm, 405nm, 455nm and 532nm. Designing and developing new photoinitiators with good absorption in the visible light region is an important research topic.

[0003] Oxime ester initiators are widely used and are often used in the production of various photoresists. They can also be used in the fields of directed isomerized films, photospacers, ribs, nanoimprint materials, quantum dots and OLEDs. As effective free radical photoinitiators, oxime ester compounds have long been used in free radical photopolymerization due to their superior photoreactivity. After the NO bond of oxime ester compounds is broken, the acyloxy group undergoes a decarboxylation reaction and produces carbon dioxide, which solves the problem of inhibition of the photopolymerization process caused by oxygen in the air.

[0004] However, when existing oxime ester initiators are exposed to ultraviolet light, the oxime ester bond will break, generating small molecular fragments (outgas). If these small molecular fragments are not released, they are likely to remain in the reaction system and cause failure of the light-emitting device. Therefore, reducing the volatility of the decomposition fragments of oxime ester photoinitiators is one of the research directions of oxime ester photoinitiators.

[0005] Existing documents (publication number CN103998422A) disclose cyclopentanedione oxime esters and their applications. Existing documents (publication number CN112341359A) disclose fluorene oxime ester compounds, their preparation methods and applications. The above two existing documents respectively disclose different low molecular fragment oxime ester initiators, however, the yellowing performance and sensitivity of these photoinitiators still need to be further improved. Summary of the invention

[0006] The main purpose of the present invention is to provide an oxime ester photoinitiator, a photocurable resin composition and an application thereof, so as to solve the problem in the prior art that oxime ester photoinitiators are prone to produce small molecular fragments under ultraviolet light irradiation and have poor yellowing resistance and sensitivity.

[0007] In order to achieve the above object, the present invention provides an oxime ester photoinitiator on the one hand, wherein the oxime ester photoinitiator has a structure shown in general formula (I): R 1 Selected from C 1 ~C30 Alkyl, C 1 ~C 20 A halogenated alkyl group, a C 2 ~C 30 Alkyl, C 6 ~C 24 Aryl substituted C 1 ~C 20 Alkyl, C 6 ~C 24 Aryloxy substituted C 1 ~C 20 Alkyl, C 1 ~C 12 Alkyl substituted C 6 ~C 24 Aryl, or C 2 ~ C 30 The heterocyclic group; R 2 and R 2 ' are each independently selected from hydrogen, halogen, C 1 ~C 30 Alkyl, C 1 ~C 20 The halogenated alkyl, C 1 ~C 20 Hydroxyl substituted alkyl, C 2 ~C 40 Alkyl groups substituted with hydroxyalkoxy groups, C 1 ~ C 30 Alkyl, C 6 ~C 24 Aryl substituted C 1 ~C 20 Alkyl, C 6 ~C 24 Aryloxy substituted C 1 ~C 20 Alkyl, C 6 ~C 24 The aromatic group, C 1 ~C 10 Alkyl substituted C 6 ~C 24 Aryl, or C 1 ~C 30 Alkenyl; R 3 Selected from hydrogen, nitro, cyano, hydroxyl, halogen, C 1 ~C 30 Alkyl, C 1 ~C 20 The halogenated alkyl, C 1 ~C 20 Hydroxyl substituted alkyl, C 2 ~C 40A hydroxyalkoxy-substituted alkyl group, a C 2 ~C 20 Alkyl, C 2 ~C 20 Acyl or halogen substituted C 1 ~C 10 Acyl, C 6 ~C 18 Aryl acyl, halogen substituted C 6 ~C 18 Aryl acyl, C 1 ~C 12 Alkyl substituted C 6 ~C 18 Aryl acyl, C 1 ~C 20 Alkoxy substituted C 6 ~C 18 Aryl acyl, C 4 ~C 18 Heterocyclic acyl, C 4 ~C 24 Heterocyclic group, C 1 ~C 20 An alkoxy group or a group represented by formula (II): n is 1 or 2; A is a connecting bond or a carbonyl group.

[0008] Furthermore, R 1 Selected from C 1 ~C 22 Alkyl, C 1 ~C 10 A halogenated alkyl group, a C 2 ~C 20 Alkyl, C 6 ~C 20 Aryl substituted C 1 ~C 12 Alkyl, C 6 ~C 20 Aryloxy substituted C 1 ~C 12 Alkyl, C 1 ~C 8 Alkyl substituted C 6 ~C 20 Aryl, or C 4 ~C 24 The heterocyclic group; R 2 and R 2 'Each independently selected from C 1 ~C 22 Alkyl, C 1 ~C 10 The halogenated alkyl, C1 ~C 10 Hydroxyl substituted alkyl, C 2 ~C 20 Alkyl groups substituted with hydroxyalkoxy groups, C 2 ~C 20 Alkyl, C 6 ~C 20 Aryl substituted C 1 ~C 12 Alkyl, C 6 ~C 20 Aryloxy substituted C 1 ~C 12 Alkyl, C 6 ~C 20 The aromatic group, C 1 ~C 8 Alkyl substituted C 6 ~C 18 Aryl, or C 2 ~C 18 Alkenyl; R 3 Selected from C 1 ~C 20 Alkyl, C 1 ~C 10 The halogenated alkyl, C 1 ~C 10 Hydroxyl substituted alkyl, C 2 ~C 20 A hydroxyalkoxy-substituted alkyl group, a C 2 ~C 15 Alkyl, C 2 ~C 20 Straight-chain, straight-chain, monocyclic or condensed polycyclic aliphatic acyl, halogen-substituted C 1 ~C 10 Straight-chain or branched acyl, C 6 ~ C 18 Monocyclic or condensed polycyclic aromatic acyl, halogen atom substituted C 6 ~C 18 Monocyclic or condensed polycyclic aromatic acyl, C 1 ~C 12 Alkyl substituted C 6 ~C 18 Monocyclic or condensed polycyclic aromatic acyl, C 1 ~C 20 Alkoxy substituted C 6 ~C 18 Monocyclic or condensed polycyclic aromatic acyl, C 4 ~C 18 Monocyclic or condensed polycyclic heterocyclic acyl, C4 ~C 18 A heterocyclic group, or C 1 ~C 10 of alkoxy.

[0009] Furthermore, R 1 Selected from C 1 ~C 17 Alkyl, preferably C 1 ~C 10 A linear, branched, monocyclic or condensed polycyclic alkyl group; or, R 1 Selected from C 2 ~C 8 The halogenated alkyl group is preferably C 2 ~C 5 A straight-chain or branched haloalkyl group; or, R 1 Selected from C interrupted by one or more ether bonds or thioether bonds 2 ~C 15 The alkyl group is preferably a C 2 ~C 10 Alkyl, more preferably C 2 ~C 7 A straight-chain or linear alkyl group; or, R 1 Selected from C 6 ~C 18 Aryl substituted C 1 ~C 10 Alkyl or C 6 ~C 18 Aryloxy substituted C 1 ~C 8 Alkyl, preferably C 6 ~ C 10 Aryl substituted C 1 ~C 10 Alkyl or C 6 ~C 10 Aryloxy substituted C 1 ~C 6 Alkyl; or, R 1 Selected from C 1 ~C 6 Alkyl substituted C 6 ~C 18 Aryl, preferably C 1 ~C 4 Alkyl substituted C 6 ~C 10 Aryl; or, R 1 Selected from C 4 ~C 18 The heterocyclic group is preferably C 4 ~C 14The heterocyclic group is preferably C 4 ~C 10 The heterocyclic group.

[0010] Furthermore, R 2 and R 2 'Each independently selected from C 1 ~C 6 Straight-chain, branched, monocyclic or condensed polycyclic halogenated alkyl, C 1 ~C 6 A straight-chain or branched hydroxy-substituted alkyl or C 2 ~C 10 A linear or branched hydroxyalkoxy-substituted alkyl group; or, R 2 and R 2 ' are each independently selected from C 2 ~C 15 The alkyl group is preferably a C 2 ~C 7 A straight-chain or branched alkyl group; or, R 2 and R 2 'Each independently selected from C 6 ~C 18 Aryl substituted C 1 ~C 10 Alkyl, or C 6 ~C 18 Aryloxy substituted C 1 ~C 8 Alkyl, preferably C 6 ~C 10 Aryl substituted C 1 ~C 10 Alkyl or C 6 ~C 10 Aryloxy substituted C 1 ~C 6 Alkyl; or, R 2 and R 2 'Each independently selected from C 1 ~C 6 Alkyl substituted C 6 ~C 10 Aryl; or, R 2 and R 2 'Each independently selected from C 2 ~C 12 Alkenyl, preferably C 2 ~C 6 A straight-chain, branched, monocyclic or condensed polycyclic alkenyl group.

[0011] Furthermore, R 3 Selected from C 2~C 12 A straight-chain, branched, monocyclic or condensed polycyclic aliphatic acyl group, preferably C 2 ~C 7 A straight-chain, branched, monocyclic or condensed polycyclic aliphatic acyl group; or, R 3 Selected from halogen-substituted C 1 ~ C 6 A straight-chain or branched acyl group, preferably a halogen-substituted C 1 ~C 4 A straight-chain or branched acyl group; or, R 3 Selected from C 6 ~C 14 Monocyclic or condensed polycyclic aromatic acyl groups, or halogen-substituted C 6 ~C 14 A monocyclic or condensed polycyclic aromatic acyl group, preferably C 6 ~C 10 Monocyclic or condensed polycyclic aromatic acyl groups, or halogen-substituted C 6 ~C 10 A monocyclic or condensed polycyclic aromatic acyl group; or, R 3 Selected from C 1 ~C 8 Alkyl substituted C 6 ~C 14 Monocyclic or condensed polycyclic aromatic acyl, C 1 ~C 10 Alkoxy substituted C 6 ~C 14 A monocyclic or condensed polycyclic aromatic acyl group, preferably C 1 ~C 4 Alkyl substituted C 6 ~C 10 Monocyclic or condensed polycyclic aromatic acyl, C 1 ~C 4 Alkoxy substituted C 6 ~C 10 A monocyclic aryl acyl group or a condensed polycyclic aryl acyl group; or, R 3 Selected from C 4 ~C 14 A monocyclic or condensed polycyclic heterocyclic acyl group, preferably C 4 ~C 10 a monocyclic or condensed polycyclic heterocyclic acyl group; or, R 3 Selected from C 4 ~C 14 The heterocyclic group is preferably C 4 ~C 10 an aromatic or alicyclic heterocyclic group; or, R 3 Selected from C 1 ~C6 A straight-chain, branched, monocyclic or condensed polycyclic alkoxy group.

[0012] Furthermore, R 1 is selected from methyl, ethyl, phenyl or cyclohexyl; R 2 and R 2 'are independently selected from 1-butyl or allyl, R 3 Selected from nitro, 2-furyl, benzoyl, and a group represented by formula (II): 2-furoyl or 2-thenoyl.

[0013] Further, the oxime ester photoinitiator is selected from one or more compounds having the structure shown below:

[0014]

[0015] In order to achieve the above-mentioned object, another aspect of the present invention further provides a photocurable resin composition, which includes a photoinitiator, an alkali-soluble resin and a polymerizable monomer, wherein the photoinitiator includes the above-mentioned oxime ester photoinitiator provided in the present application.

[0016] Furthermore, the photocurable resin composition includes 0.5 to 10 parts of oxime ester photoinitiator and 20 to 80 parts of alkali-soluble resin, based on 100 parts by weight of the polymerizable monomer; preferably, the photocurable resin composition also includes 0 to 200 parts of solvent, based on 100 parts by weight of the polymerizable monomer; preferably, the polymerizable monomer is selected from one or more of the group consisting of (meth)acrylic monomers, styrene monomers, anhydride monomers and epoxy monomers.

[0017] Another aspect of the present invention provides an application of the oxime ester photoinitiator provided in the present application or the photocurable resin composition provided in the present application in the field of photocuring.

[0018] By applying the technical solution of the present invention, compared with the existing oxime ester photoinitiators, the oxime ester photoinitiator having the structure of general formula (I) has better stability, so under the irradiation of ultraviolet light, it can effectively inhibit the generation and volatilization of small molecule fragments, and almost no overflow gas is generated after curing; at the same time, because the above-mentioned oxime ester photoinitiator has a specific substituent group, it has a strong ultraviolet absorption performance, thereby improving its sensitivity, and the oxime ester photoinitiator also has a high yellowing resistance. In addition, the oxime ester initiator having the structure shown in general formula (I) can be used in a UV-LED light curing system, and is particularly suitable for initiation under the action of a 365nm light source. DETAILED DESCRIPTION

[0019] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0020] As described in the background art, existing oxime ester photoinitiators have the problems of easily generating small molecular fragments under ultraviolet light irradiation, poor yellowing resistance and low photosensitivity. In order to solve the above technical problems, the present application provides an oxime ester photoinitiator, which has a structure shown in general formula (I):

[0021]

[0022] R 1 Including but not limited to C 1 ~C 30 Alkyl, C 1 ~C 20 A halogenated alkyl group, a C 2 ~C 30 Alkyl, C 6 ~C 24 Aryl substituted C 1 ~C 20 Alkyl, C 6 ~C 24 Aryloxy substituted C 1 ~C 20 Alkyl, C 1 ~C 12 Alkyl substituted C 6 ~C 24 Aryl, or C 2 ~C 30 The heterocyclic group; R 2 and R 2 'Each independently includes but is not limited to hydrogen, halogen, C 1 ~C 30 Alkyl, C 1 ~C 20 The halogenated alkyl, C 1 ~C 20 Hydroxyl substituted alkyl, C 2 ~C 40 Alkyl groups substituted with hydroxyalkoxy groups, C 1 ~C 30 Alkyl, C 6 ~C 24 Aryl substituted C 1 ~C 20 Alkyl, C 6 ~C 24 Aryloxy substituted C 1 ~C 20 Alkyl, C6 ~C 24 The aromatic group, C 1 ~C 10 Alkyl substituted C 6 ~C 24 Aryl, or C 1 ~C 30 Alkenyl; R 3 Including but not limited to hydrogen, nitro, cyano, hydroxyl, halogen, C 1 ~C 30 Alkyl, C 1 ~C 20 The halogenated alkyl, C 1 ~C 20 Hydroxyl substituted alkyl, C 2 ~C 40 A hydroxyalkoxy-substituted alkyl group, a C 2 ~C 20 Alkyl, C 2 ~C 20 Acyl or halogen substituted C 1 ~C 10 Acyl, C 6 ~C 18 Aryl acyl, halogen substituted C 6 ~C 18 Aryl acyl, C 1 ~C 12 Alkyl substituted C 6 ~C 18 Aryl acyl, C 1 ~C 20 Alkoxy substituted C 6 ~C 18 Aryl acyl, C 4 ~C 18 Heterocyclic acyl, C 4 ~C 24 Heterocyclic group, C 1 ~C 20 An alkoxy group or a group represented by formula (II): n is 1 or 2; A is a connecting bond or a carbonyl group.

[0023] Compared with the existing oxime ester photoinitiators, the oxime ester photoinitiator with the structure of general formula (I) has better stability, so under the irradiation of ultraviolet light, it can effectively inhibit the generation and volatilization of small molecule fragments, and almost no overflow gas is generated after curing; at the same time, because the above-mentioned oxime ester photoinitiator has a specific substituent group, it has a strong ultraviolet absorption performance, thereby improving its sensitivity, and the above-mentioned oxime ester photoinitiator also has a high yellowing resistance. In addition, the oxime ester initiator with the structure shown in general formula (I) can be used in UV-LED light curing system, and is particularly suitable for initiation under the action of 365nm light source.

[0024] The oxime ester photoinitiator having the above structure has high sensitivity and yellowing resistance, and can also effectively inhibit the generation and volatilization of small molecule fragments and reduce its VOC content. 1 Including but not limited to C 1 ~ C 22 Alkyl, C 1 ~C 10 A halogenated alkyl group, a C 2 ~C 20 Alkyl, C 6 ~C 20 Aryl substituted C 1 ~C 12 Alkyl, C 6 ~C 20 Aryloxy substituted C 1 ~C 12 Alkyl, C 1 ~C 8 Alkyl substituted C 6 ~C 20 Aryl, or C 4 ~C 24 The heterocyclic group; R 2 and R 2 'Each independently includes but is not limited to C 1 ~C 22 Alkyl, C 1 ~C 10 The halogenated alkyl, C 1 ~C 10 Hydroxyl substituted alkyl, C 2 ~C 20 Alkyl substituted with hydroxyalkoxy, C 2 ~C 20 Alkyl, C 6 ~C 20 Aryl substituted C 1 ~C 12 Alkyl, C 6 ~C 20Aryloxy substituted C 1 ~C 12 Alkyl, C 6 ~C 20 The aromatic group, C 1 ~C 8 Alkyl substituted C 6 ~C 18 Aryl, or C 2 ~C 18 Alkenyl; R 3 Including but not limited to C 1 ~C 20 Alkyl, C 1 ~C 10 The halogenated alkyl, C 1 ~C 10 Hydroxyl substituted alkyl, C 2 ~C 20 A hydroxyalkoxy-substituted alkyl group, a C 2 ~C 15 Alkyl, C 2 ~C 20 Straight-chain, straight-chain, monocyclic or condensed polycyclic aliphatic acyl, halogen-substituted C 1 ~C 10 Straight-chain or branched acyl, C 6 ~C 18 Monocyclic or condensed polycyclic aromatic acyl, halogen atom substituted C 6 ~C 18 Monocyclic or condensed polycyclic aromatic acyl, C 1 ~C 12 Alkyl substituted C 6 ~C 18 Monocyclic or condensed polycyclic aromatic acyl, C 1 ~C 20 Alkoxy substituted C 6 ~C 18 Monocyclic or condensed polycyclic aromatic acyl, C 4 ~C 18 Monocyclic or condensed polycyclic heterocyclic acyl, C 4 ~C 18 A heterocyclic group, or C 1 ~ C 10 Alkoxy. 1 , R 2 , R 2 ' and R 3 Each independently includes but is not limited to the above-mentioned types of groups, and limiting them within the above-mentioned range is beneficial to further improve the stability of the oxime ester photoinitiator, and further improve the sensitivity and yellowing resistance of the oxime ester photoinitiator.

[0025] In a preferred embodiment, R 1 Including but not limited to C 1 ~C 17 Alkyl, preferably C 1 ~C 10 A linear, branched, monocyclic or condensed polycyclic alkyl group; or, R 1 Including but not limited to C 2 ~C 8 The halogenated alkyl group is preferably C 2 ~C 5 A straight-chain or branched haloalkyl group; or, R 1 Including but not limited to C interrupted by one or more ether bonds or thioether bonds 2 ~C 15 The alkyl group is preferably a C 2 ~C 10 Alkyl, more preferably C 2 ~C 7 A straight-chain or linear alkyl group; or, R 1 Including but not limited to C 6 ~C 18 Aryl substituted C 1 ~C 10 Alkyl or C 6 ~C 18 Aryloxy substituted C 1 ~C 8 Alkyl, preferably C 6 ~C 10 Aryl substituted C 1 ~C 10 Alkyl or C 6 ~C 10 Aryloxy substituted C 1 ~C 6 Alkyl; or, R 1 Including but not limited to C 1 ~C 6 Alkyl substituted C 6 ~C 18 Aryl, preferably C 1 ~ C 4 Alkyl substituted C 6 ~C 10 Aryl; or, R 1 Including but not limited to C 4 ~C 18 The heterocyclic group is preferably C 4 ~C 14 The heterocyclic group is preferably C 4 ~C 10 The heterocyclic group R 1Including but not limited to the above-mentioned types of groups, limiting them within the above-mentioned range is beneficial to further improve the stability of the oxime ester photoinitiator and further inhibit the generation and volatilization of small molecule fragments.

[0026] In a preferred embodiment, R 2 and R 2 'Each independently includes but is not limited to C 1 ~C 6 Straight-chain, branched, monocyclic or condensed polycyclic halogenated alkyl, C 1 ~C 6 A straight-chain or branched hydroxy-substituted alkyl or C 2 ~C 10 A linear or branched hydroxyalkoxy-substituted alkyl group; or, R 2 and R 2 'Each independently includes but is not limited to C interrupted by one or more ether bonds or thioether bonds 2 ~C 15 The alkyl group is preferably a C 2 ~C 7 A straight-chain or branched alkyl group; or, R 2 and R 2 'Each independently includes but is not limited to C 6 ~C 18 Aryl substituted C 1 ~C 10 Alkyl, or C 6 ~C 18 Aryloxy substituted C 1 ~C 8 Alkyl, preferably C 6 ~C 10 Aryl substituted C 1 ~C 10 Alkyl or C 6 ~C 10 Aryloxy substituted C 1 ~C 6 Alkyl; or, R 2 and R 2 'Each independently includes but is not limited to C 1 ~C 6 Alkyl substituted C 6 ~C 10 Aryl; or, R 2 and R 2 'Each independently includes but is not limited to C 2 ~C 12 Alkenyl, preferably C 2 ~C 6 Compared with other types of groups, R2 and R 2 The types of 'are limited within the above ranges, which is beneficial to further improve the sensitivity and yellowing resistance of the oxime ester photoinitiator.

[0027] In a preferred embodiment, R 3 Including but not limited to C 2 ~C 12 A straight-chain, branched, monocyclic or condensed polycyclic aliphatic acyl group, preferably C 2 ~C 7 A straight-chain, branched, monocyclic or condensed polycyclic aliphatic acyl group; or, R 3 Including but not limited to halogen substituted C 1 ~C 6 A straight-chain or branched acyl group, preferably a halogen-substituted C 1 ~C 4 A straight-chain or branched acyl group; or, R 3 Including but not limited to C 6 ~C 14 Monocyclic or condensed polycyclic aromatic acyl groups, or halogen-substituted C 6 ~C 14 A monocyclic or condensed polycyclic aromatic acyl group, preferably C 6 ~C 10 Monocyclic or condensed polycyclic aromatic acyl groups, or halogen-substituted C 6 ~C 10 A monocyclic or condensed polycyclic aromatic acyl group; or, R 3 Including but not limited to C 1 ~C 8 Alkyl substituted C 6 ~C 14 Monocyclic or condensed polycyclic aromatic acyl, C 1 ~C 10 Alkoxy substituted C 6 ~C 14 A monocyclic or condensed polycyclic aromatic acyl group, preferably C 1 ~C 4 Alkyl substituted C 6 ~C 10 Monocyclic or condensed polycyclic aromatic acyl, C 1 ~C 4 Alkoxy substituted C 6 ~C 10 A monocyclic aryl acyl group or a condensed polycyclic aryl acyl group; or, R 3 Including but not limited to C 4 ~C 14 A monocyclic or condensed polycyclic heterocyclic acyl group, preferably C 4 ~C 10a monocyclic or condensed polycyclic heterocyclic acyl group; or, R 3 Including but not limited to C 4 ~C 14 The heterocyclic group is preferably C 4 ~C 10 an aromatic or alicyclic heterocyclic group; or, R 3 Including but not limited to C 1 ~C 6 Compared with other types of groups, R 3 Limiting the types within the above range is beneficial to further improving the sensitivity and yellowing resistance of the oxime ester photoinitiator.

[0028] As R 1 Specific examples thereof include methyl, ethyl, propyl, n-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, octadecyl, isopropyl, isobutyl, isopentyl, sec-butyl, tert-butyl, sec-pentyl, tert-pentyl, tert-octyl, neopentyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, norbornyl, bornyl, 2-chloroethyl, 4-chlorobutyl, 2-chlorotert-butyl, 5-bromopentyl, 3-chloro-2-methylpropyl, 3-chloropropyl, 4-chlorobutyl, methyl, ethyl, propyl, n-butyl, hexyl, isopentyl, cyclohexyl, 2-chloroethyl, 4-chlorobutyl, 2-chloro-tert-butyl, 5-bromopentyl, methoxymethyl, ethoxymethyl, butoxymethyl, or (2-butoxyethoxy)methyl.

[0029] As R 1 Specific examples include phenylmethyl, 1-phenylethyl, 2-phenylethyl, 3-phenylpropyl, 4-phenylbutyl, 5-phenylpentyl, phenoxymethyl, 1-phenoxyethyl, 2-phenoxyethyl, 3-phenoxypropyl, and 4-phenoxybutyl.

[0030] As R 1 Specific examples include phenyl, o-tolyl, m-tolyl, p-tolyl, chlorotolyl, 3,5-dimethylphenyl, 4-cyanophenyl, 4-nitrophenyl, 4-methoxybenzyl, phenylmethyl, 1-phenylethyl, chlorophenylmethyl, 3-phenylpropyl, nitrophenylmethyl, phenoxymethyl, 1-phenoxyethyl, chlorophenoxymethyl, nitrophenoxymethyl, 1-naphthyl, and 2-ethoxy-1-naphthyl.

[0031] As R1 Specific examples include thienyl, thien-2-methyl, pyridyl, 2-furyl, quinolyl, pyranyl, imidazolyl, piperidinyl, morpholinyl, thioxanthenyl, and indolyl; preferably thienyl, thien-2-methyl, pyridyl, 2-furyl or quinolyl.

[0032] As R 2 Specific examples thereof include methyl, ethyl, propyl, n-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, eicosyl, docosyl, isopropyl, isobutyl, isopentyl, sec-butyl, tert-butyl, sec-pentyl, tert-pentyl, tert-octyl, neopentyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, norbornyl, bornyl, 2-chloroethyl, 4-chlorobutyl, 2-chlorotert-butyl, 5-bromopentyl, 3-chloro-2-methylpropyl, 3-chloropropyl, 4-chlorobutyl, 5-chloropentyl, 6-chlorohexyl, hydroxymethyl, hydroxyethyl, hydroxy-n-propyl, hydroxy-n-butyl, hydroxyisobutyl, hydroxy-n-pentyl, hydroxyisopentyl, hydroxy-n-hexyl, hydroxyisohexyl, hydroxymethoxymethyl, hydroxymethoxyethyl, hydroxymethoxypropyl, hydroxymethoxybutyl, hydroxyethoxymethyl, hydroxyethoxybutyl, hydroxyethoxypentyl, hydroxyethoxyhexyl, methoxymethyl, ethoxymethyl, butoxymethyl, (2-butoxyethoxy)methyl, ethoxyethyl, methoxy-ethoxy-ethyl, ethoxypropyl, methoxyethyl, methoxypropyl, methoxypropoxypropyl, and ethoxyisopropyl; preferably n-butyl, pentyl, hexyl, tetradecyl, behenyl, 4-chlorobutyl, 5-chloropentyl, 6-chlorohexyl, methoxyethyl, or ethoxyethyl.

[0033] As R 2 Specific examples include phenyl, phenylmethyl, 1-phenylethyl, chlorophenylmethyl, 1-phenylpropyl, 1-phenylpentyl, nitrophenylmethyl, phenoxymethyl, 1-phenoxyethyl, chlorophenoxymethyl, nitrophenoxymethyl, 1-naphthyl, and 2-ethoxy-1-naphthyl.

[0034] As R 2 Specific examples include vinyl, 1-propenyl, allyl, 2-butenyl, 3-butenyl, isopropenyl, isobutenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 5-hexenyl, cyclopentenyl, cyclohexenyl, 1,3-butadienyl, cyclohexadienyl, and cyclopentadienyl; preferably allyl, 3-butenyl, 4-pentenyl or 5-hexenyl.

[0035] As R 3Specific examples thereof include methyl, ethyl, propyl, n-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, eicosyl, docosyl, isopropyl, isobutyl, isopentyl, sec-butyl, tert-butyl, sec-pentyl, tert-pentyl, tert-octyl, neopentyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, norbornyl, bornyl, 2-chloroethyl, 4-chlorobutyl, 2-chlorotert-butyl, 5-bromopentyl, 3-chloro-2-methylpropyl, 3-chloropropyl, 4-chlorobutyl, 5-chloropentyl, 6-chlorohexyl, hydroxymethyl, hydroxyethyl, hydroxy-n-propyl, hydroxy-n-butyl, hydroxyisobutyl, hydroxy-n-pentyl, hydroxyisopentyl, hydroxy-n-hexyl, hydroxyisohexyl, hydroxymethoxymethyl, hydroxymethoxyethyl, hydroxymethoxypropyl, hydroxymethoxybutyl, hydroxyethoxymethyl, hydroxyethoxybutyl, hydroxyethoxypentyl, hydroxyethoxyhexyl, methoxymethyl, ethoxymethyl, butoxymethyl, (2-butoxyethoxy)methyl, ethoxyethyl, methoxy-ethoxy-ethyl, ethoxypropyl, methoxyethyl, methoxypropyl, methoxypropoxypropyl, and ethoxyisopropyl.

[0036] As R 3 Specific examples of the benzoyl group include acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, pivaloyl, cyclopentanoyl, cyclohexanoyl, trifluoroformyl, benzoyl, 1-naphthoyl, 2-naphthoyl, 2-chlorobenzoyl, 3-chlorobenzoyl, 3-trifluorobenzoyl, 4-fluorobenzoyl, toluoyl, 2-methylbenzoyl, 2-methoxybenzoyl, 4-methoxybenzoyl, 2-butoxyphenyl acyl, 2-thenoyl, 2-furoyl, nicotinoyl and isonicotinoyl; preferably acetyl, propionyl, butyryl, benzoyl, toluoyl, 2-thenoyl, or 2-furoyl.

[0037] As R 3 Specific examples include thienyl, thien-2-methyl, pyridyl, 2-furyl, quinolyl, pyranyl, imidazolyl, piperidinyl, morpholinyl, thioxanthenyl and indolyl; preferably thienyl, pyridyl, 2-furyl or morpholinyl.

[0038] As R 3Specific examples include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, dodecyloxy, octadecyloxy, isopropoxy, isobutoxy, isopentyloxy, sec-butoxy, tert-butoxy, sec-pentyloxy, tert-pentyloxy, tert-octyloxy, neopentyloxy, cyclopropyloxy, cyclobutyloxy, cyclopentyloxy, cyclohexyloxy, and adamantyloxy; preferably methoxy, ethoxy, propoxy, cyclopropyloxy, cyclobutyloxy, cyclopentyloxy or cyclohexyloxy.

[0039] In a preferred embodiment, R 1 Including but not limited to methyl, ethyl, phenyl or cyclohexyl; R 2 and R 2 'respectively independently include but are not limited to 1-butyl or allyl, R 3 Including but not limited to nitro, 2-furyl, benzoyl, and groups represented by formula (II): 2-furoyl or 2-thenoyl. 1 , R 2 , R 2 ' and R 3 Each independently includes but is not limited to the above-mentioned types of groups, and limiting them within the above-mentioned range is beneficial to further improve the stability of the oxime ester photoinitiator, and at the same time further improve the sensitivity and yellowing resistance of the oxime ester photoinitiator.

[0040] In order to further improve the synergistic effect between the substituents, thereby further improving the comprehensive performance of the above-mentioned oxime ester photoinitiator, in a preferred embodiment, the oxime ester photoinitiator includes but is not limited to one or more compounds having the following structure:

[0041]

[0042]

[0043] Compared with other substituent combinations, the above compounds 1 to 14 have good stability, rarely produce small molecule fragments during the curing process, and almost no outflow gas is generated after application; at the same time, the above compounds 1 to 14 have excellent sensitivity and yellowing resistance.

[0044] The second aspect of the present application also provides a preferred method for preparing an oxime ester photoinitiator, and the synthesis route thereof is as follows:

[0045]

[0046] The preparation method of the above-mentioned oxime ester fluorene photoinitiator comprises:

[0047] S1, under the action of n-butyl lithium, the structure represented by formula (III) and a borate ester compound undergo borylation reaction and hydrolysis reaction in a first solvent to obtain a first intermediate; The first intermediate is In the formula, X is a halogen atom, R 1 , R 2 and R 2 ' and R 3 R in the structure represented by general formula (I) 1 , R 2 and R 2 ' and R 3 have the same definition; preferably, the temperature of the boration reaction is -50 to -78°C, and the hydrolysis reaction further includes 1 mol / L of dilute hydrochloric acid or the pH of the hydrolysis reaction is 4 to 5;

[0048] S2, in the presence of a first catalyst, causing the first intermediate to undergo a Suzuki coupling reaction with the structure represented by formula (VI) in a second solvent to obtain a second intermediate; The second intermediate is Where R 2 , R 2 '、R 3 , n and A are respectively the same as R in the structure shown in the general formula (I) 2 , R 2 '、R 3 , n and A have the same definition, X is a halogen atom; preferably, the temperature of the Suzuki coupling reaction is 60 to 120° C.;

[0049] S3, under acidic conditions, the second intermediate is subjected to an oximation reaction with nitrous acid, nitrite or alkyl nitrite to obtain a third intermediate; the third intermediate is Where R 2 , R 2 '、R 3 , n and A are respectively the same as R in the structure shown in the general formula (I) 2 , R 2 '、R 3 , n and A have the same definition; preferably, the temperature of the oximation reaction is -15 to 50°C, more preferably 0 to 25°C;

[0050] S4, in a third solvent, allowing the third intermediate to undergo an esterification reaction with an acylating agent under the action of a base to obtain the oxime ester photoinitiator provided in the present application;

[0051] The oxime ester photoinitiator has a structure shown in the general formula (I):

[0052]

[0053] In the general formula (I), R 1 , R 2 , R 2 '、R 3 , n and A have the same definitions as above.

[0054] In an optional embodiment, when R 3 When it is a halogen, the bisoxime ester photoinitiator can be further synthesized by controlling the amount of the raw materials.

[0055] In a preferred embodiment, the boration reaction is carried out in a first solvent. There is no particular limitation on the type of the first solvent, as long as it can dissolve the reaction reagents and has no adverse effect on the boration reaction. For example, the first solvent can be tetrahydrofuran (THF), ether or 1,4-dioxane, preferably tetrahydrofuran (THF).

[0056] In a preferred embodiment, the second solvent is selected according to the actual situation of the reaction system of the Suzuki coupling reaction (such as the type of reaction reagents), and there is no particular limitation on the type of the second solvent, as long as the second solvent can dissolve the reaction reagents of the Suzuki coupling reaction and has no adverse effect on the Suzuki coupling reaction. For example, the second solvent can be tetrahydrofuran (THF), dioxane, N,N-dimethylformamide (DMF), dimethylacetamide (DMA), dimethyl sulfoxide (DMSO), etc. In a preferred embodiment, in the Suzuki coupling reaction, the first catalyst includes but is not limited to a palladium catalyst.

[0057] In a preferred embodiment, in the oximation reaction, the alkyl nitrite includes, but is not limited to, one or more of the group consisting of methyl nitrite, ethyl nitrite, isopropyl nitrite, butyl nitrite and isoamyl nitrite.

[0058] In a preferred embodiment, in the esterification reaction, the acylating agent includes but is not limited to acyl halides and / or acid anhydride compounds. Preferably, the acylating agent includes but is not limited to cyclohexanecarbonyl chloride, 2-propylpentanoyl chloride, 3,5,5-trimethylhexanoyl chloride, 3-chloropropionyl chloride, 5-chlorovaleryl chloride, 3-chloropivaloyl chloride, 6-bromohexanoyl chloride, methoxyacetyl chloride, ethoxyacetyl chloride, butoxyacetyl chloride, 3-(methylthio)propionyl chloride, (2-butoxyethoxy)acetyl chloride, benzoyl chloride, toluoyl chloride, 3,5-dimethylbenzoyl chloride, 4-methoxybenzoyl chloride, 4-cyanobenzoyl chloride, 4-nitrobenzoyl chloride, 4-phenylbenzoyl chloride, chlorobenzoyl chloride, phenylacetyl chloride, phenylpropionyl chloride, chlorophenylacetyl chloride, 4-phenylacetyl chloride, One or more of the group consisting of 1-nitrobutyryl chloride, 6-phenylhexanoyl chloride, nitrophenylacetyl chloride, phenoxyacetyl chloride, phenoxypropionyl chloride, chlorophenoxyacetyl chloride, nitrophenoxyacetyl chloride, 2-thiophenecarbonyl chloride, thiophene-2-acetyl chloride, chloronicotinoyl chloride, 2-furoyl chloride, quinolinecarbonyl chloride, naphthoyl chloride, 2-ethoxy-1-naphthoyl chloride, anthracenecarbonyl chloride, acetic anhydride, propionic anhydride, decanoic anhydride, stearic anhydride, isobutyric anhydride, t-valeric anhydride and 4-methoxyphenylacetic anhydride.

[0059] In a preferred embodiment, in the esterification reaction, the third solvent includes but is not limited to one or more of the group consisting of diethyl ether, acetonitrile, tert-butyl methyl ether, tetrahydrofuran, vinyl acetate, toluene, xylene, acetone, methyl ethyl ketone, dichloromethane, chloroform, chlorobenzene, dimethylacetamide and dimethylformamide.

[0060] In a preferred embodiment, in the esterification reaction, the base includes, but is not limited to, one or more of the group consisting of triethylamine, pyridine, diisopropylethylamine, potassium hydroxide, sodium hydroxide and sodium hydride.

[0061] The third aspect of the present application further provides a photocurable resin composition, which includes a photoinitiator, an alkali-soluble resin and a polymerizable monomer, wherein the photoinitiator includes the above-mentioned oxime ester photoinitiator provided in the present application.

[0062] Under the irradiation of light source, compared with other types of photoinitiators, the above-mentioned high-sensitivity oxime ester photoinitiator provided by the present application can absorb energy from the light source more efficiently and generate more active free radicals, thereby more quickly initiating the polymerization monomer in the photocuring system to undergo photopolymerization reaction, and after further curing reaction, a photocurable resin can be obtained. The above-mentioned photocurable resin composition provided by the present application has the characteristics of high sensitivity and excellent yellowing resistance; and the above-mentioned oxime ester initiator having the structure shown in general formula (I) can be used in UV-LED photocuring system, and is particularly suitable for initiation under the action of 365nm light source.

[0063] In a preferred embodiment, the photocurable resin composition includes 0.5 to 10 parts of oxime ester photoinitiator and 20 to 80 parts of alkali-soluble resin based on 100 parts by weight of the polymerizable monomer. Compared with other amounts, limiting the amounts of oxime ester photoinitiator, alkali-soluble resin and polymerizable monomer to the above ranges is beneficial to further improve the yellowing resistance of the photocurable resin composition, especially to improve the yellowing resistance under the action of a 365nm light source; at the same time, it is beneficial to inhibit the volatilization of small molecule fragments and greatly reduce the occurrence of light-emitting device failures.

[0064] In order to further improve the compatibility of the oxime ester photoinitiator, the alkali-soluble resin and the polymerizable monomer, and further improve the yellowing resistance of the photocurable resin composition, preferably, the photocurable resin composition further includes 0 to 200 parts of solvent based on 100 parts by weight of the polymerizable monomer.

[0065] In a preferred embodiment, the polymerizable monomers include, but are not limited to, one or more of the group consisting of (meth) acrylic monomers, styrene monomers, anhydride monomers, and epoxy monomers. Alternatively, the (meth) acrylic monomers include, but are not limited to, one or more of the group consisting of benzyl methacrylate, methyl methacrylate, dipentaerythritol hexaacrylate, butyl methacrylate, isobutyl methacrylate, and isoamyl acrylate.

[0066] In a preferred embodiment, the alkali-soluble resin includes, but is not limited to, a compound formed by polymerizing one or more of the group consisting of (meth)acrylic monomers, styrene monomers, anhydride monomers and epoxy monomers.

[0067] In a preferred embodiment, the solvent includes, but is not limited to, one or more of the group consisting of butanone, propylene glycol methyl ether acetate (PGMEA), ethyl 3-ethoxypropionate, propylene glycol methyl ether (PM), and ethylene glycol ethyl ether.

[0068] The fourth aspect of the present application also provides an application of the above-mentioned oxime ester photoinitiator provided by the present application or the above-mentioned photocurable resin composition provided by the present application in the field of photocuring.

[0069] Compared with the existing oxime ester photoinitiators, the oxime ester photoinitiator having the structure of the general formula (I) has better stability, and thus can effectively inhibit the generation and volatilization of small molecule fragments under the irradiation of ultraviolet light, and almost no overflow gas is generated after curing; at the same time, because the above-mentioned oxime ester photoinitiator has a specific substituent group, it has a strong ultraviolet absorption performance, thereby improving its sensitivity, and the above-mentioned oxime ester photoinitiator also has a high yellowing resistance. When applied in the field of photocuring, not only will small molecule fragments not be generated, but also the sensitivity and yellowing resistance of the photocurable resin composition can be improved. In addition, the above-mentioned oxime ester initiator having the structure shown in the general formula (I) or the above-mentioned photocurable resin composition can be used in the field of UV-LED photocuring, and is particularly suitable for initiation under the action of a 365nm light source.

[0070] The above-mentioned oxime ester fluorene photoinitiator provided in the present application can be used in the fields of paints, coatings, inks and molding materials, including but not limited to: coatings applied on substrates such as plastics, metals, glass, ceramics, wood, walls, etc.; photocurable adhesives, photodecomposable coatings; printing inks such as screen printing, offset printing, gravure printing, etc.; photocurable inks for inkjet printing and 3D printing; film materials such as hard coating agents, anti-fouling films, anti-reflection films, impact buffer films, interlayer insulating films, light extraction films, brightening films, and sealing films; optical components such as lenses, lens arrays, optical waveguides, light guide plates, light diffusers, and diffraction elements; optical molding resins such as color filters and black matrices (light-shielding films); optical recording media such as holographic imaging materials; photoresists for electronic circuits and semiconductor manufacturing; optical spacers; rib walls; materials for nanoimprinting; quantum dots; OLEDs, etc.

[0071] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0072] Example 1

[0073] The synthetic route of compound 1 in this embodiment 1 is as follows:

[0074]

[0075] A method for preparing an oxime ester fluorene photoinitiator comprises the following steps:

[0076] (1) Preparation of the first intermediate 1a

[0077]

[0078] Add 180g, 0.50mol of 2-bromo-9,9-dibutylfluorene and 1200mL of tetrahydrofuran to a four-necked flask, stir to dissolve, and cool to -78°C. Add 211mL of tetrahydrofuran solution of n-butyl lithium (2.5mol / L) dropwise; after the addition is complete, keep warm and continue stirring for 30min. Then add 94.8g of triisopropyl borate; after the addition is complete, the reaction solution naturally warms to room temperature and continues stirring for 1h. Add 600mL of water to the reaction solution to quench, then add 500mL of 1mol / L of dilute hydrochloric acid and stir at room temperature for 30min. Add ethyl acetate to the reaction solution, stir thoroughly for 30min, let stand to separate, and separate the upper organic phase; wash the organic phase with water 3 times, and concentrate the washed organic phase to obtain 129.2g of yellow oil, i.e., the first intermediate 1a.

[0079] The yield of the first intermediate 1a was 80.2%. The obtained first intermediate 1a was directly used in the next reaction.

[0080] (2) Preparation of the Second Intermediate 1b

[0081]

[0082] 129.2 g, 0.40 mol of the first intermediate 1a was dissolved in 600 mL of toluene, and 92.9 g of 5-bromoindanone, 4.6 g of Pd(PPh 3 ) 4 , 105.0g of triphenylphosphine and 81.0g of triethylamine. The reaction temperature of the Suzuki coupling reaction was raised to 80°C and stirred for 3h to obtain a reaction solution. When the thin layer chromatography (TLC) test results showed that the reaction was complete, the next step was performed. The reaction solution was filtered through diatomaceous earth while hot; the filtrate was cooled to room temperature, washed with water 3 times, the organic phase was concentrated, and the obtained yellow solid was slurried with 500mL of n-hexane at room temperature to obtain 138.1g of yellow solid, i.e., the second intermediate 1b.

[0083] The yield of the second intermediate 1b was 84.5% and the purity was 98.13%. The obtained second intermediate 1b was directly used for the next step reaction.

[0084] (3) Preparation of the Third Intermediate 1c

[0085]

[0086] Add 120g, 0.29mol of the second intermediate 1b and 480mL of ethyl acetate to the reaction flask, stir to dissolve; then add 51.0g of isoamyl nitrite and 44mL of concentrated hydrochloric acid, and stir at room temperature for 1h. Stop the reaction, add 500mL of water, and continue stirring for 30min; let stand to separate, separate the lower organic phase, wash with water until neutral, and concentrate the organic phase. The resulting viscous material is dissolved in methanol, stirred at room temperature for 5h, and a yellow solid is precipitated. Continue to cool to 5-10℃ and stir for 2h. After filtration, collect and obtain 92.1g of yellow solid, i.e., the third intermediate 1c.

[0087] The yield of the third intermediate 1c was 72.6% and the purity was 97.47%. The obtained third intermediate 1c was directly used for the next reaction.

[0088] (4) Preparation of Compound 1

[0089]

[0090] Under nitrogen protection, add 90g intermediate 1c (0.21mol), 22.9g triethylamine (TEA) and 360mL dichloromethane to the reaction bottle and stir to dissolve. Add 22.5g acetic anhydride dropwise at room temperature, stir at room temperature for 2h. Add 400mL water to the reaction solution and stir for 30min. Let stand for stratification, separate the lower organic phase, wash with water until neutral, concentrate the organic phase, dissolve the obtained solid in methanol, stir for 1h, and gradually precipitate the solid. Continue to cool to 5-10℃ with ice bath and stir for 2h. Filter to obtain a filter cake, wash the filter cake with methanol to obtain the crude product of compound 1. The crude product is dissolved in 160mL acetone, then 480mL methanol is added, stirred for crystallization, and continued to stir for 1h under ice bath (5-10℃). Filter, rinse the filter cake with 300mL methanol, collect the filter cake, and obtain 76.6g light yellow solid, namely compound 1.

[0091] The yield of compound 1 was 76.1% and the purity was 99.19%.

[0092] The chemical structure of compound 1 was confirmed by nuclear magnetic resonance hydrogen spectrum 1H-NMR and mass spectrometry MS, and the characterization results are as follows:

[0093] (1) The H-NMR data of compound 1 are as follows: 1H-NMR (500 MHz, Chloroform-d)

[0094] δ8.10(d,J=7.5Hz,1H),7.80(d,J=7.6Hz,1H),7.61-7.52(m,3H),7.50-7.37(m,3H),7.34(d,J=1.4Hz,1 H),7.33-7.28(m,1H),3.26(d,J=1.0Hz,2H),2.15(s,2H),2.03-1.88(m,4H),1.56-1.44(m,4H),1.42-1.31(m,4H),0.88(t,J=7.9Hz,6H).

[0095] (2) The mass spectrum data of compound 1 are as follows: MS (m / z): 420 [M-OAc] + .

[0096] Examples 2 to 14 According to the preparation method of the oxime ester fluorene photoinitiator of Example 1, the corresponding reaction raw materials or reagents were replaced to prepare the following compounds 2 to 14. The chemical structural formulas and the corresponding nuclear magnetic resonance hydrogen spectrum characterization data of compounds 2 to 14 are listed in Table 1 below.

[0097] Table 1

[0098]

[0099]

[0100]

[0101]

[0102] The photosensitivity of the compounds 1 to 14 prepared in the above examples 1 to 14 and the existing oxime ester photoinitiators (compound A and compound B) was evaluated.

[0103] Wherein, the chemical structural formula of compound A is: The chemical structural formula of compound B is:

[0104] It should be noted that the photocurable composition used in the photosensitivity test in all the embodiments and comparative examples of the present application is prepared according to the following ratio. Wherein, the photocurable composition includes, by weight: 100 parts of acrylate copolymer, 100 parts of dipentaerythritol hexaacrylate, 2 parts of photoinitiator, 25 parts of butanone (solvent), 5 parts of dye blue 15 (CAS: 147-14-8), and the above-mentioned acrylate copolymer (manufacturer: Changzhou Qiangli Electronic New Materials Co., Ltd.) is a copolymer of benzyl methacrylate / methacrylic acid / hydroxyethyl methacrylate (molar ratio of 70:10:20), Mw=15000.

[0105] In the above-mentioned photocurable composition, the photoinitiator is the oxime ester photoinitiator represented by the general formula (I) in the above content of the present application or a similar photoinitiator known in the prior art for comparison. The specific formulas of all the embodiments and comparative examples of the present application are shown in Table 1.

[0106] Table 1

[0107]

[0108]

[0109] (1) Sensitivity test

[0110] The above-mentioned photocurable composition was stirred in the dark and coated on the PET film with a 6# wire rod to form a coating with a wet film thickness of about 6 μm. A mercury lamp (RW-LED-YT200gl, single exposure of 100 mj / cm 2 ), UV-LED light source irradiation (RW-UVAP202-20gl, single exposure is 1000mj / cm 2 ) The coating film was exposed at different wavelengths, its curing film formation was observed, and evaluated by finger touch method.

[0111] The evaluation criteria for the finger touch method are as follows: 1: Oily, not solid; 2: Oily on the surface, solidified at the bottom layer; 3: Sticky on the surface, with heavy fingerprints after touch; 4: Basically dry on the surface, slightly astringent after touch, with light fingerprints; 5: Completely solidified, smooth surface, and no fingerprints after touch.

[0112] The sensitivity test results of all embodiments and comparative examples of the present application are shown in Table 2.

[0113] Table 2

[0114]

[0115] (2) Yellowing resistance test

[0116] The photocurable composition was prepared by referring to the specific formula shown in Table 1. After the photocurable composition was stirred in a yellow light room, it was coated on the tinplate using a 15# wire rod to form a coating with a wet film thickness of 10 μm. A 365nm-LED light source was used for exposure, receiving 2000mJ / cm 2 energy to fully cure it.

[0117] The yellowing test was performed using an X-Rite colorimeter, and the yellowing resistance of the photocurable resin was judged according to the △b value. The higher the △b value, the more obvious the yellowing and the worse the yellowing resistance. The yellowing resistance test results of all the examples and comparative examples of the present application are shown in Table 3.

[0118] Table 3

[0119]

[0120] (3) Small molecule fragments (outgas)

[0121] Using the GC-MS test method, 5 g of the sample membrane prepared in the same manner as above was taken and cut into suitable sizes and placed in a headspace bottle for later use. Headspace injection was used to observe whether small molecular fragments (outgas) were produced (except for carbon dioxide and self-contained solvent peaks). The test results are shown in Table 4.

[0122] The equipment and test conditions used are as follows:

[0123] Agilent 7890B gas chromatograph, chromatographic column: Agilent HP-5ms column; vaporization temperature: 280°C; program temperature rise: 60°C for 3 min, 20°C / min heating rate, 280°C for 10 min;

[0124] Agilent 7697A headspace sampler, headspace conditions: heating box: 110°C; quantitative loop: 120°C; transfer line: 140°C; equilibrium time: 30 min;

[0125] Agilent 7010B mass spectrometer, mass spectrometry conditions: ion source temperature: 280°C; electron energy: 70 eV; scanning range (m / z): 30-400;

[0126] Table 4

[0127]

[0128] From the above description, it can be seen that the above embodiments provided by the present invention achieve the following technical effects:

[0129] (1) The difference between each embodiment and the comparative example is only the type of photoinitiator used. Combined with the test results of sensitivity in Table 2, it can be seen that the curing efficiency of the photocurable composition in comparative example 1 under the irradiation of Hg lamp, 365nm-LED and 385nm-LED is worse than that of embodiments 1 to 14, and can only achieve basic surface drying; while the photocurable composition of comparative example 2 can only achieve basic surface drying under the irradiation of Hg lamp, which is worse than that of embodiments 1 to 14. At the same time, the curing efficiency under the irradiation of 365nm-LED and 385nm-LED is very low, so curing cannot be achieved, and the surface is sticky when touched. The photocurable compositions in embodiments 1 to 14 can achieve the effect of complete curing under the irradiation of Hg lamp, 365nm-LED and 385nm-LED. Therefore, compared with the existing oxime ester photoinitiators, the oxime ester initiator with the structure shown in general formula (I) provided in the present application has a higher curing efficiency when used in a UV-LED photocuring system.

[0130] (2) It can be seen from Table 3 that the Δb values ​​of the photocurable compositions in Examples 1 to 14 are 0.11 to 0.17, while the Δb value of the photocurable composition in Comparative Example 2 is 0.21, which is much higher than that in Examples 1 to 14. This indicates that the yellowing resistance of the photocurable composition in Comparative Example 2 is much worse than that in Examples 1 to 14, that is, compared with the existing initiator (Compound B) with better photosensitivity, Compounds 1 to 14 have better photosensitivity and are not easy to yellow.

[0131] (3) From the test results in Table 4, it can be seen that small molecule fragments were produced in Comparative Example 1, while Examples 1 to 14 did not produce small molecule fragments.

[0132] In summary, the oxime ester initiator shown in formula (I) disclosed in the present invention can be applied to conventional ultraviolet light curing systems, and can be cured well under mercury lamps and LED light sources. Compared with the current initiators with better photosensitivity, it has better photosensitivity and also has the characteristics of low yellowing and low outgas.

[0133] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those described herein, for example.

[0134] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An oxime ester photoinitiator, characterized in that: The oxime ester photoinitiator has a structure shown in general formula (I): The R1 is selected from C1~C 30 Alkyl, C1~C 20 A halogenated alkyl group, a C2-C 30 Alkyl, C6~C 24 Aryl substituted C1~C 20 Alkyl, C6~C 24 Aryloxy substituted C1~C 20 Alkyl, C1~C 12 Alkyl substituted C6~C 24 Aryl, C2~C 30 heterocyclic group, phenyl or cyclohexyl; The R2 and R2' are each independently selected from hydrogen, halogen, C1-C 30 Alkyl, C1~C 20 haloalkyl, C1~C 20 Hydroxyl substituted alkyl, C2~C 40 Alkyl groups substituted with hydroxyalkoxy groups, C1-C1 groups interrupted by one or more ether bonds or thioether bonds 30 Alkyl, C6~C 24 Aryl substituted C1~C 20 Alkyl, C6~C 24 Aryloxy substituted C1~C 20 Alkyl, C6~C 24 Aryl, C1~C 10 Alkyl substituted C6~C 24 Aryl, or C1~C 30 Alkenyl; The R3 is selected from hydrogen, nitro, cyano, hydroxyl, halogen, C1-C 30 Alkyl, C1~C 20 haloalkyl, C1~C 20 Hydroxyl substituted alkyl, C2~C 40 A hydroxyalkoxy-substituted alkyl group, a C2-C 20 Alkyl, C2~C 20 C1~C 10 Acyl, C6~C 18 C6~C 18 Aryl acyl, C1~C 12 Alkyl substituted C6~C 18 Aryl acyl, C1~C 20 Alkoxy substituted C6~C 18 Aryl acyl, C4~C 18 Heterocyclic acyl, C4~C 24 Heterocyclic group, C1~C 20 An alkoxy group or a group represented by formula (II): The n is 1 or 2; A is a carbonyl group.

2. The oxime ester photoinitiator according to claim 1, characterized in that The R1 is selected from C1~C 22 Alkyl, C1~C 10 A halogenated alkyl group, a C2-C 20 Alkyl, C6~C 20 Aryl substituted C1~C 12 Alkyl, C6~C 20 Aryloxy substituted C1~C 12 Alkyl, C1~C8 alkyl substituted C6~C 20 Aryl, or C4~C 24 A heterocyclic group; The R2 and R2' are each independently selected from C1 to C 22 Alkyl, C1~C 10 haloalkyl, C1~C 10 Hydroxyl substituted alkyl, C2~C 20 an alkyl group substituted with a hydroxyalkoxy group, a C2-C 20 Alkyl, C6~C 20 Aryl substituted C1~C 12 Alkyl, C6~C 20 Aryloxy substituted C1~C 12 Alkyl, C6~C 20 C6~C8 alkyl substituted 18 Aryl, or C2~C 18 Alkenyl; The R3 is selected from C1~C 20 Alkyl, C1~C 10 haloalkyl, C1~C 10 Hydroxyl substituted alkyl, C2~C 20 A hydroxyalkoxy-substituted alkyl group, a C2-C 15 Alkyl, C2~C 20 Straight-chain, monocyclic or condensed polycyclic aliphatic acyl, halogen-substituted C1~C 10 Straight-chain or branched acyl, C6~C 18 Monocyclic or condensed polycyclic aromatic acyl, halogen atom substituted C6~C 18 Monocyclic or condensed polycyclic aromatic acyl, C1~C 12 Alkyl substituted C6~C 18 Monocyclic or condensed polycyclic aromatic acyl, C1~C 20 Alkoxy substituted C6~C 18 Monocyclic or condensed polycyclic aromatic acyl, C4~C 18 Monocyclic or condensed polycyclic heterocyclic acyl, C4~C 18 Heterocyclic group, or C1~C 10 of alkoxy.

3. The oxime ester photoinitiator according to claim 1 or 2, characterized in that: The R1 is selected from C1~C 17 or Said R1 is selected from C2-C8 haloalkyl; or The R1 is selected from C2 to C 15 or The R1 is selected from C6~C 18 Aryl substituted C1~C 10 Alkyl or C6~C 18 C1-C8 alkyl substituted with aryloxy; or The R1 is selected from C1-C6 alkyl-substituted C6-C 18 aryl; or The R1 is selected from C4~C 18 The heterocyclic group.

4. The oxime ester photoinitiator according to claim 3, characterized in that The R1 is selected from C1~C 10 A straight-chain, branched, monocyclic or condensed polycyclic alkyl group.

5. The oxime ester photoinitiator according to claim 3, characterized in that The R1 is selected from a C2-C5 linear or branched halogenated alkyl group.

6. The oxime ester photoinitiator according to claim 3, characterized in that The R1 is selected from C2 to C 10 alkyl.

7. The oxime ester photoinitiator according to claim 6, characterized in that The R1 is selected from C2 to C7 straight-chain alkyl groups interrupted by one or more ether bonds or thioether bonds.

8. The oxime ester photoinitiator according to claim 3, characterized in that The R1 is selected from C6~C 10 Aryl substituted C1~C 10 Alkyl or C6~C 10 C1-C6 alkyl substituted with aryloxy.

9. The oxime ester photoinitiator according to claim 3, characterized in that: The R1 is selected from C1-C4 alkyl-substituted C6-C 10 Aryl.

10. The oxime ester photoinitiator according to claim 3, characterized in that: The R1 is selected from C4~C 14 The heterocyclic group.

11. The oxime ester photoinitiator according to claim 10, characterized in that The R1 is selected from C4~C 10 The heterocyclic group.

12. The oxime ester photoinitiator according to claim 1 or 2, characterized in that: The R2 and R2' are each independently selected from a C1-C6 linear, branched, monocyclic or condensed polycyclic halogenated alkyl, a C1-C6 linear or branched hydroxy-substituted alkyl or a C2-C 10 A straight-chain or branched hydroxyalkoxy-substituted alkyl group; or The R2 and R2' are each independently selected from C2 to C3 interrupted by one or more ether bonds or thioether bonds. 15 or The R2 and R2' are each independently selected from C6 to C 18 Aryl substituted C1~C 10 Alkyl, or C6~C 18 C1-C8 alkyl substituted with aryloxy; or The R2 and R2' are each independently selected from C1-C6 alkyl-substituted C6-C 10 aryl; or The R2 and R2' are each independently selected from C2 to C 12 of alkenyl.

13. The oxime ester photoinitiator according to claim 12, characterized in that: The R2 and R2' are each independently selected from a C2 to C7 linear or branched alkyl group interrupted by one or more ether bonds or thioether bonds.

14. The oxime ester photoinitiator according to claim 12, characterized in that: The R2 and R2' are each independently selected from C6 to C 10 Aryl substituted C1~C 10 Alkyl or C6~C 10 C1-C6 alkyl substituted with aryloxy.

15. The oxime ester photoinitiator according to claim 12, characterized in that: The R2 and R2' are each independently selected from a C2-C6 linear, branched, monocyclic or condensed polycyclic alkenyl group.

16. The oxime ester photoinitiator according to claim 12, characterized in that: The R3 is selected from C2~C 12 a straight-chain, branched, monocyclic or condensed polycyclic aliphatic acyl group; or The R3 is selected from a C1-C6 straight-chain or branched acyl group substituted with a halogen atom; or The R3 is selected from C6~C 14 Monocyclic or condensed polycyclic aromatic acyl, or halogen-substituted C6~C 14 a monocyclic or condensed polycyclic aromatic acyl group; or The R3 is selected from C1-C8 alkyl-substituted C6-C 14 Monocyclic or condensed polycyclic aromatic acyl, C1~C 10 Alkoxy substituted C6~C 14 a monocyclic or condensed polycyclic aromatic acyl group; or The R3 is selected from C4~C 14 a monocyclic or condensed polycyclic heterocyclic acyl group; or The R3 is selected from C4~C 14 or The R3 is selected from a C1-C6 linear, branched, monocyclic or condensed polycyclic alkoxy group.

17. The oxime ester photoinitiator according to claim 16, characterized in that The R3 is selected from a C2-C7 straight-chain, branched, monocyclic or condensed polycyclic aliphatic acyl group.

18. The oxime ester photoinitiator according to claim 16, characterized in that The R3 is selected from a C1-C4 straight-chain or branched acyl group substituted with a halogen atom.

19. The oxime ester photoinitiator according to claim 16, characterized in that The R3 is selected from C6~C 10 Monocyclic or condensed polycyclic aromatic acyl, or halogen-substituted C6~C 10 A monocyclic or condensed polycyclic aromatic acyl group.

20. The oxime ester photoinitiator according to claim 16, characterized in that The R3 is selected from C1-C4 alkyl-substituted C6-C 10 Monocyclic or condensed polycyclic aromatic acyl, C1-C4 alkoxy substituted C6-C 10 A monocyclic aryl acyl group or a condensed polycyclic aryl acyl group.

21. The oxime ester photoinitiator according to claim 16, characterized in that The R3 is selected from C4~C 10 A monocyclic or condensed polycyclic heterocyclic acyl group.

22. The oxime ester photoinitiator according to claim 16, characterized in that The R3 is selected from C4~C 10 an aromatic or alicyclic heterocyclic group.

23. The oxime ester photoinitiator according to claim 1, characterized in that The R1 is selected from methyl, ethyl, phenyl or cyclohexyl; The R2 and R2' are independently selected from 1-butyl or allyl, and the R3 is selected from nitro, 2-furyl, benzoyl, and a group represented by formula (II): 2-furoyl or 2-thenoyl.

24. The oxime ester photoinitiator according to any one of claims 16 to 23, characterized in that The oxime ester photoinitiator is selected from one or more compounds having the structure shown below:

25. A photocurable resin composition, characterized in that: The photocurable resin composition comprises a photoinitiator, an alkali-soluble resin and a polymerizable monomer, wherein the photoinitiator comprises the oxime ester photoinitiator according to any one of claims 1 to 24.

26. The photocurable resin composition according to claim 25, characterized in that: Based on 100 parts by weight of the polymerizable monomer, the photocurable resin composition includes 0.5 to 10 parts of the oxime ester photoinitiator and 20 to 80 parts of the alkali-soluble resin.

27. The photocurable resin composition according to claim 26, characterized in that: The photocurable resin composition further comprises 0 to 200 parts of a solvent based on 100 parts by weight of the polymerizable monomer.

28. The photocurable resin composition according to claim 26, characterized in that: The polymerizable monomer is selected from one or more of the group consisting of (meth)acrylic monomers, styrene monomers, acid anhydride monomers and epoxy monomers.

29. Use of the oxime ester photoinitiator according to any one of claims 1 to 24, or the photocurable resin composition according to any one of claims 25 to 28 in the field of photocuring.

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