Polymerization initiator or photosensitizer, polymerization initiation composition, and method for producing resin

Abstract

Provided are: a polymerization initiator or photosensitizer that has excellent heat resistance and is capable of promoting photopolymerization at high efficiency with light that includes a wavelength of 365 nm; a polymerization initiation composition; and a method for producing a resin.　A polymerization initiator or photosensitizer according to the present invention comprises component (A).　Component (A): a benzophenone derivative having two or more sulfide groups to which an optionally substituted aromatic hydrocarbon group is bonded

Description

Polymerization initiator or photosensitizer, polymerization initiator composition, and method for producing resin

[0001] The present invention relates to a polymerization initiator or photosensitizer, a polymerization initiator composition, and a method for producing a resin.

[0002] Resins, particularly thermoplastic resins, are produced by polymerizing monomers using a polymerization initiator. Photopolymerization initiators are known as polymerization initiators that start a polymerization reaction when irradiated with ultraviolet-visible light, and various compounds such as benzophenones and acylphosphine oxides are used.

[0003] In recent years, the use of LEDs as light sources has increased due to the energy saving of light sources for photopolymerization, and compounds that absorb ultraviolet light suitable for LEDs (e.g., light with wavelengths including 365 nm) and efficiently initiate photopolymerization reactions are in demand. As examples of such compounds, benzophenone-based polymerization initiators having a sulfide group-containing group, or polymerization initiator compositions containing a benzophenone-based polymerization initiator and an amine compound have been proposed (Patent Documents 1 to 3).

[0004] Japanese Patent Application Laid-Open No. 2022-145340 Japanese Patent Application Laid-Open No. 52-104592 Japanese Patent Application Laid-Open No. 2021-024974

[0005] However, the conventional benzophenone-based polymerization initiators and polymerization initiator compositions using them as described above suffer from the problem of insufficient reaction rates, leaving room for further improvement. For example, benzophenone-based polymerization initiators having one thioether group in their structure are known to have absorption at long wavelengths, but this is not yet sufficient, and they require the combined use of an anthracene-based sensitizer and an acylphosphine oxide-based polymerization initiator. Benzophenone-based polymerization initiators having two methylthio groups in their structure have longer wavelengths than those with one methylthio group, but their curability, i.e., reactivity, is still low, and they also have the problem of low heat resistance.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a polymerization initiator or photosensitizer, a polymerization initiator composition, and a method for producing a resin, which are capable of efficiently proceeding with photopolymerization using light having a wavelength of 365 nm and which also have excellent heat resistance.

[0007] As a result of intensive investigations conducted by the present inventors to solve the above problems, they found that a polymerization initiator composition containing a benzophenone having two or more thioethers incorporated as sulfide groups bonded to an aromatic hydrocarbon skeleton and various amine compounds has stronger sensitivity to ultraviolet light including that having a wavelength of 365 nm than conventional benzophenone initiators, and further has excellent photopolymerizability at this wavelength, which led to the completion of the present invention.

[0008] That is, the polymerization initiator or photosensitizer of the present invention is characterized by comprising the following component (A): Component (A): a benzophenone derivative having two or more sulfide groups bonded to aromatic hydrocarbon groups which may have a substituent.

[0009] The polymerization initiator composition of the present invention is characterized by containing the following components (A) and (B): Component (A): a benzophenone derivative having two or more sulfide groups bonded to aromatic hydrocarbon groups which may have a substituent; and Component (B): an amine compound having one or more hydrogen atoms on the carbon atom adjacent to the nitrogen atom.

[0010] The polymerization initiator composition of the present invention is characterized by containing the following components (A) and (C): Component (A): a benzophenone derivative having two or more sulfide groups bonded to an aromatic hydrocarbon group which may have a substituent; and Component (C): a polymerization initiator selected from an intramolecular cleavage-type radical polymerization initiator, a cationic polymerization initiator, and an anionic polymerization initiator.

[0011] The method for producing a resin of the present invention is characterized by adding the polymerization initiator or photosensitizer to a resin raw material containing a monomer, and irradiating the resin with light having a wavelength of 365 nm to polymerize the monomer by photopolymerization.

[0012] According to the polymerization initiator or photosensitizer, polymerization initiator composition, and resin manufacturing method of the present invention, photopolymerization can be efficiently carried out with a small amount of light containing a wavelength of 365 nm, and heat resistance is also excellent.

[0013] DETAILED DESCRIPTION OF THE INVENTION In the present specification, the numerical values ​​of carbon numbers represent integers.

[0014] (Polymerization initiator or photosensitizer) The polymerization initiator or photosensitizer of the present invention comprises the following component (A): Component (A): a benzophenone derivative having two or more sulfide groups bonded to aromatic hydrocarbon groups which may have a substituent.

[0015] When the polymerization initiator or photosensitizer of the present invention is a polymerization initiator, it becomes excited by irradiation with light having a wavelength of 365 nm, reacts with other compounds to generate radical species, and these radical species have the effect of initiating polymerization.

[0016] When the photosensitizer or photosensitizer of the present invention is a photosensitizer, it becomes excited by irradiation with light containing a wavelength of 365 nm, and transfers the excitation energy to another photopolymerization initiator, thereby causing the polymerization reaction to proceed. This is useful in that a light source of around 365 nm can be used even if a photopolymerization initiator with low sensitivity to 365 nm light is used.

[0017] The benzophenone derivative of component (A) has two or more sulfide groups bonded to aromatic hydrocarbon groups which may have a substituent. The number of sulfide groups is not particularly limited as long as it is two or more, but 2 to 4 is preferred, and 2 is more preferred. The bonding positions of the sulfide groups in the benzophenone derivative are not particularly limited, but 2- and 4-positions are preferred, and 4-position is more preferred. Among these, 2,2'-substituted, 2,4'-substituted, and 4,4'-substituted are preferred, and 4,4'-substituted is more preferred.

[0018] The sulfide group having an aromatic hydrocarbon group bonded thereto, which may have a substituent, is a group represented by the following formula:

[0019] In the formula, R represents an aromatic hydrocarbon group which may have a substituent. The number of carbon atoms in the aromatic hydrocarbon group is not particularly limited, but is preferably 18 or less, more preferably 10 or less, and even more preferably 6 or less. Specific examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and an anthracenyl group. Among these, a phenyl group is preferred.

[0020] When the aromatic hydrocarbon group has a substituent, the substituent is not particularly limited, and examples thereof include hydrocarbon groups, oxygen-containing groups, nitrogen-containing groups, sulfur-containing groups, phosphorus-containing groups, halogens, etc. Among these, hydrocarbon groups, oxygen-containing groups, nitrogen-containing groups, and sulfur-containing groups are preferred, and hydrocarbon groups are more preferred.

[0021] The hydrocarbon group is not particularly limited, but examples thereof include saturated or unsaturated aliphatic hydrocarbon groups, saturated or unsaturated alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and hydrocarbon groups that are combinations thereof. The hydrocarbon group preferably has 1 to 22 carbon atoms. Among these, saturated aliphatic hydrocarbon groups are preferred. The saturated aliphatic hydrocarbon group may be linear or branched.

[0022] When component (A) acts as a polymerization initiator, the number of carbon atoms in the linear or branched saturated aliphatic hydrocarbon group as the substituent of R is preferably 1 to 18, more preferably 1 to 12, even more preferably 1 to 8, particularly preferably 1 to 4, especially preferably 2 to 4, and most preferably 3 or 4, from the viewpoint of efficiently proceeding with photopolymerization. Of the linear or branched saturated aliphatic hydrocarbon groups, branched saturated aliphatic hydrocarbon groups are preferred. For example, 1-methylethan-1-yl, 1-methylpropan-1-yl, 2-methylpropan-1-yl, and 2-methylpropan-2-yl groups are preferred. Furthermore, the number of substituents in R may be 1 to 5, preferably 1 to 3, and more preferably 1 or 2.

[0023] When component (A) acts as a photosensitizer, the carbon number of the linear or branched saturated aliphatic hydrocarbon group as the substituent of R is preferably 1 to 18, more preferably 1 to 12, even more preferably 1 to 8, and particularly preferably 1 to 4. Of the linear or branched saturated aliphatic hydrocarbon groups, branched saturated aliphatic hydrocarbon groups are preferred. The number of substituents of R may be 1 to 5, preferably 1 to 3, and more preferably 1 or 2.

[0024] The benzophenone derivative of component (A) may have a substituent at any of the 2- to 6- and 2'- to 6'-positions of the benzophenone skeleton, other than the sulfide group to which the aromatic hydrocarbon group, which may have a substituent, is bonded. The number of such substituents is preferably four or less, more preferably two or less, and even more preferably zero. The substituent is not particularly limited, but examples include hydrocarbon groups, oxygen-containing groups, nitrogen-containing groups, sulfur-containing groups, phosphorus-containing groups, and halogens. Specific examples of these substituents include those described above as the substituents of the aromatic hydrocarbon group in R, and reference is made to the descriptions thereof.

[0025] In a preferred example, the benzophenone derivative of component (A) is represented by the following formula (1):

[0026] In the formula, R 1 and R 2 each independently represents an aromatic hydrocarbon group which may have a saturated aliphatic hydrocarbon group.

[0027] Specific examples of the aromatic hydrocarbon group in the aromatic hydrocarbon group which may have a saturated aliphatic hydrocarbon group include those mentioned above as the aromatic hydrocarbon group for R, and reference is made to the description thereof.

[0028] In terms of photopolymerization reactivity, absorption of long wavelength ultraviolet light (molar absorption coefficient at 365 nm), heat resistance, and compatibility with monomers or solvents, R 1 and R 2 are each independently an aromatic hydrocarbon group having a saturated aliphatic hydrocarbon group, which is a preferred embodiment. The saturated aliphatic hydrocarbon group is preferably a linear or branched saturated aliphatic hydrocarbon group having 1 to 18 carbon atoms, more preferably 1 to 12 carbon atoms, even more preferably 1 to 8 carbon atoms, particularly preferably 1 to 4 carbon atoms, even more preferably 2 to 4 carbon atoms, and most preferably 3 or 4 carbon atoms. Of the linear or branched saturated aliphatic hydrocarbon groups, branched saturated aliphatic hydrocarbon groups are preferred. 1 and R 2A preferred embodiment of R is an aromatic hydrocarbon group having two saturated aliphatic hydrocarbon groups, more preferably the two saturated aliphatic hydrocarbon groups each have 1 to 8 carbon atoms, and even more preferably at least one of the two groups is a butyl group. 1 and R 2 Another preferred embodiment of the above is an aromatic hydrocarbon group having one saturated aliphatic hydrocarbon group, and more preferably, the saturated aliphatic hydrocarbon group has 3 or 4 carbon atoms.

[0029] When component (A) of the present invention has the above structure, that is, when it has two or more sulfide groups bonded to aromatic hydrocarbon groups which may have a substituent, it has a higher molar absorption coefficient, particularly a higher molar absorption coefficient for light including 365 nm, compared to conventional structures having one sulfide group bonded to an aromatic hydrocarbon group or structures having two sulfide groups bonded to saturated aliphatic hydrocarbon groups, and therefore photopolymerization can be carried out efficiently, making it useful as a photopolymerization initiator and / or photosensitizer.

[0030] The polymerization initiator or photosensitizer of the present invention preferably has a molar absorption coefficient of 30,000 L / (mol cm) or more at the maximum absorption wavelength of component (A). A large molar absorption coefficient for ultraviolet light with a longer wavelength is useful, and for example, the molar absorption coefficient at 365 nm is preferably 3,000 L / (mol cm) or more, more preferably 4,000 L / (mol cm) or more, and even more preferably 5,000 L / (mol cm) or more.

[0031] The component (A) of the present invention may remain in the resin even after the photopolymerization reaction. In such a case, if the component (A) has low heat resistance (low thermal decomposition temperature), the component (A) in the resin composition containing the component (A) will thermally decompose at high temperatures, causing problems such as bleeding out of the decomposed product and discoloration or coloring of the resin. Therefore, a component (A) having high heat resistance (high thermal decomposition temperature) is preferred from the viewpoint of heat resistance. 1 and R 2is preferably a branched saturated aliphatic hydrocarbon group having 2 to 6 carbon atoms. The thermal decomposition temperature can be determined using the 5% weight loss temperature as an index, and in terms of the molding temperature of the resin described below, the 5% weight loss temperature of component (A) is preferably 300°C or higher, more preferably 320°C or higher, and even more preferably 335°C or higher.

[0032] The following resin molding temperatures are known, but are not particularly limited to, for example, styrene-based resins (polystyrene: PS, molding temperature 100°C), cycloolefin-based resins (molding temperature 100°C), (meth)acrylic resins (polymethyl methacrylate, molding temperature 160°C), and acrylonitrile-butadiene-styrene copolymers (acrylonitrile-butadiene-styrene copolymers: ABS, molding temperature 220°C).

[0033] The above disclosure also applies to a method of using component (A) to initiate a polymerization reaction of a monomer, and a method of using component (A) for photosensitization in which excitation energy is transferred to another photopolymerization initiator to initiate a polymerization reaction of a monomer.

[0034] (Polymerization Initiator Composition) The polymerization initiator composition of the present invention contains the following components (A) and (B): Component (A): a benzophenone derivative having two or more sulfide groups bonded to aromatic hydrocarbon groups which may have a substituent; and Component (B): an amine compound having one or more hydrogen atoms on the carbon atom adjacent to the nitrogen atom.

[0035] The polymerization initiator composition of the present invention contains the following components (A) and (C): Component (A): a benzophenone derivative having two or more sulfide groups bonded to an aromatic hydrocarbon group which may have a substituent; and Component (C): a polymerization initiator selected from an intramolecular cleavage-type radical polymerization initiator, a cationic polymerization initiator, and an anionic polymerization initiator.

[0036] Here, component (A) is the same as described above as the polymerization initiator or photosensitizer of the present invention, and the specific description of component (A) is to be referred to for the embodiments of the polymerization initiator composition of the present invention. In the polymerization initiator composition of the present invention containing components (A) and (B), component (A) can act mainly as a polymerization initiator. In the polymerization initiator composition of the present invention containing components (A) and (C), component (A) can act mainly as a photosensitizer.

[0037] The polymerization initiator composition of the present invention, which contains components (A) and (B), generates radical species through a bimolecular reaction between components (A) and (B). Specifically, the benzophenone derivative of component (A) becomes excited upon irradiation with light, and this excited state interacts with the amine compound of component (B), which serves as a hydrogen donor, abstracting hydrogen from the amine compound to generate an active radical in the amine compound. Subsequent polymerization is typically initiated by the radical generated from the amine compound.

[0038] In the amine compound of component (B), the carbon atom adjacent to the nitrogen atom has one or more hydrogen atoms. The phrase "the carbon atom adjacent to the nitrogen atom has one or more hydrogen atoms" means that at least one of the carbon atoms adjacent to the nitrogen atom has one or more hydrogen atoms. Therefore, this does not preclude the compound from having a carbon atom adjacent to the nitrogen atom that does not have a hydrogen atom, other than the at least one carbon atom. Furthermore, the atom bonded to the nitrogen atom is not limited to carbon atoms, and other atoms such as hydrogen atoms may also be bonded.

[0039] Such amine compounds are not particularly limited, but examples include aminobenzoic acid compounds, amine compounds in which an aliphatic hydrocarbon group and / or a hydroxyl-containing saturated aliphatic hydrocarbon group is bonded to a nitrogen atom, amine compounds in which an aliphatic hydrocarbon group and an aromatic group are bonded to a nitrogen atom, amine compounds in which an aliphatic hydrocarbon group and an aliphatic hydrocarbon group containing an unsaturated group are bonded to a nitrogen atom, amine compounds with two or more nitrogen atoms, and heterocyclic compounds containing a nitrogen atom. These amine compounds may contain two or more nitrogen atoms per molecule. The amino group contained in the amine compound may be a primary amino group, a secondary amino group, or a tertiary amino group, with amine compounds having a tertiary amino group being preferred. The carbon atom adjacent to the nitrogen atom of the amine compound may be bonded to another atom via a double bond or a triple bond, but it is preferred that at least one carbon atom be bonded to another carbon atom via a single bond. For example, when the amine compound is a tertiary amine compound, two or less of the three carbon atoms adjacent to the nitrogen atom may have unsaturated bonds, but it is preferred that one or more do not have unsaturated bonds.

[0040] Among these, aminobenzoic acid compounds; amine compounds in which an aliphatic hydrocarbon group and a hydroxyl group-containing saturated aliphatic hydrocarbon group are bonded to a nitrogen atom; amine compounds in which a hydroxyl group-containing saturated aliphatic hydrocarbon group is bonded to a nitrogen atom; amine compounds in which an aliphatic hydrocarbon group and an aliphatic hydrocarbon group having a carbon-carbon double bond-containing group are bonded to a nitrogen atom; amine compounds in which an aliphatic hydrocarbon group is bonded to a nitrogen atom; amine compounds in which an aliphatic hydrocarbon group and an aromatic group are bonded to a nitrogen atom; amine compounds in which an aliphatic hydrocarbon group is bonded to a nitrogen atom and has two or more nitrogen atoms; and amine compounds containing a six-membered heterocycle having a nitrogen atom are preferred. More preferred are amine compounds in which a hydrocarbon group is bonded to a nitrogen atom; amine compounds in which a hydroxy group-containing saturated aliphatic hydrocarbon group is bonded to a nitrogen atom; amine compounds in which an aliphatic hydrocarbon group and an aliphatic hydrocarbon group having a carbon-carbon double bond-containing group are bonded to a nitrogen atom; amine compounds in which an aliphatic hydrocarbon group is bonded to a nitrogen atom and the nitrogen atom is filled with two or more nitrogen atoms; and amine compounds in which an aliphatic hydrocarbon group and an aromatic group are bonded to a nitrogen atom. Further preferred are aminobenzoic acid compounds; amine compounds in which an aliphatic hydrocarbon group and an aliphatic hydrocarbon group having a carbon-carbon double bond-containing group is bonded to a nitrogen atom; and amine compounds in which an aliphatic hydrocarbon group is bonded to a nitrogen atom and the nitrogen atom is filled with two or more nitrogen atoms, with aminobenzoic acid compounds being particularly preferred.

[0041] In the above, the amine compounds having an aliphatic hydrocarbon group and / or a hydroxyl group-containing saturated aliphatic hydrocarbon group bonded to the nitrogen atom, the amine compounds having an aliphatic hydrocarbon group and a hydroxyl group-containing saturated aliphatic hydrocarbon group bonded to the nitrogen atom, the amine compounds having a hydroxyl group-containing saturated aliphatic hydrocarbon group bonded to the nitrogen atom, and the amine compounds having an aliphatic hydrocarbon group bonded to the nitrogen atom preferably include amine compounds having only the groups shown here bonded to the nitrogen atom, but this does not necessarily prevent a hydrogen atom from being bonded to the nitrogen atom. The groups shown here are mainly monovalent groups. However, this does not necessarily prevent a divalent group, such as a divalent aliphatic hydrocarbon group having another group such as an aromatic group bonded to the terminal. The amine compounds having an aliphatic hydrocarbon group and an aromatic group bonded to the nitrogen atom preferably include amine compounds having only the groups shown here bonded to the nitrogen atom, but this does not necessarily prevent a hydrogen atom from being bonded to the nitrogen atom. Here, the aromatic group may be an aromatic group consisting of hydrocarbons alone, or a heterocyclic aromatic group containing a heteroatom such as a nitrogen atom. The groups shown here are mainly monovalent groups. However, this does not necessarily preclude the group from being a divalent group, such as a divalent aliphatic hydrocarbon group having another group bonded to the terminal. Amine compounds in which an aliphatic hydrocarbon group and an aliphatic hydrocarbon group having an unsaturated group-containing group are bonded to the nitrogen atom, and amine compounds in which an aliphatic hydrocarbon group and an aliphatic hydrocarbon group having a carbon-carbon double bond-containing group are bonded to the nitrogen atom, preferably include amine compounds in which only the groups shown here are bonded to the nitrogen atom, but this does not necessarily preclude a hydrogen atom from being bonded to the nitrogen atom. The groups shown here are primarily monovalent groups. However, this does not necessarily preclude a divalent group, such as a divalent aliphatic hydrocarbon group having another group bonded to the terminal. Amine compounds in which an aliphatic hydrocarbon group is bonded to the nitrogen atom and the compound has two or more nitrogen atoms preferably include amine compounds containing a nitrogen atom to which only aliphatic hydrocarbon groups are bonded, but this does not necessarily preclude a hydrogen atom from being bonded to at least one nitrogen atom. The aliphatic hydrocarbon group is a monovalent or divalent group. Divalent groups include aliphatic hydrocarbon groups having nitrogen atoms bonded to both terminals.

[0042] Preferred embodiments of component (B) include an aminobenzoic acid compound represented by the following formula (2) or an amine compound represented by the following formula (3) in which an aliphatic hydrocarbon group or a hydroxyl group-containing saturated aliphatic hydrocarbon group is bonded to a nitrogen atom:

[0043] In the formula, R 3 and R 4 represents a saturated aliphatic hydrocarbon group, and R 5 represents a hydrocarbon group.

[0044] In the formula, R 6 When n is 2 or more, each independently represents an aliphatic hydrocarbon group or a hydroxyl group-containing saturated aliphatic hydrocarbon group, and R 7 represents an aromatic group, and n is an integer of 1 to 3. The aliphatic hydrocarbon group may have a phenyl group as a substituent.

[0045] In the formula (2), R 3 and R 4 The saturated aliphatic hydrocarbon group preferably has a carbon number of 1 to 12, more preferably 1 to 8, still more preferably 1 to 4, and particularly preferably 1 or 2. Specific examples include a methyl group, an ethane-1-yl group, a propan-1-yl group, a 1-methylethane-1-yl group, a butan-1-yl group, a 1-methylpropan-1-yl group, a 2-methylpropan-1-yl group, a 2-methylpropan-2-yl group, a pentan-1-yl group, a pentan-2-yl group, a hexane-1-yl group, a heptan-1-yl group, an octan-1-yl group, a nonan-1-yl group, a decan-1-yl group, an undecane-1-yl group, and a dodecane-1-yl group.

[0046] R 5 The hydrocarbon group is not particularly limited as long as it is a group consisting of carbon and hydrogen, but is preferably a saturated or unsaturated aliphatic hydrocarbon group, more preferably a saturated aliphatic hydrocarbon group, preferably having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, and even more preferably 1 to 4 carbon atoms. 3 and R 4 Examples include the following.

[0047] In a particularly preferred example, R3 , R 4 , R 5 are each independently a saturated aliphatic hydrocarbon group having 1 to 4 carbon atoms.

[0048] Specific examples of the aminobenzoic acid compound represented by the formula (2) include, but are not limited to, ethyl dimethylaminobenzoate, ethyl methylethylaminobenzoate, and ethyl diethylaminobenzoate.

[0049] In the formula (3), R 6 The aliphatic hydrocarbon group of R is a saturated or unsaturated aliphatic hydrocarbon group, and is preferably a saturated aliphatic hydrocarbon group. 6 The aliphatic hydrocarbon group preferably has 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 carbon atom. 6 The aliphatic hydrocarbon group may have a phenyl group as a substituent. 6 Among the aliphatic hydrocarbon groups, saturated aliphatic hydrocarbon groups include those listed above under R 3 and R 4 Examples of the compounds are as follows: 6 The hydroxy group-containing saturated aliphatic hydrocarbon group preferably has 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 2 carbon atoms. The number of hydroxy groups is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1. Specific examples include a hydroxymethyl group, a hydroxyethan-1-yl group, a hydroxypropan-1-yl group, a hydroxybutan-1-yl group, a hydroxypentan-1-yl group, a hydroxyhexan-1-yl group, a hydroxyheptan-1-yl group, and a hydroxyoctan-1-yl group, with a hydroxymethyl group, a hydroxyethan-1-yl group, a hydroxypropan-1-yl group, and a hydroxybutan-1-yl group being preferred, and a hydroxyethan-1-yl group being more preferred.

[0050] R 7 The aromatic group preferably has 4 to 10 carbon atoms. The aromatic group may contain a nitrogen atom or a sulfur atom, preferably a nitrogen atom. Examples of the aromatic group include a phenyl group, a naphthyl group, a pyrrolyl group, a pyridyl group, and an azepinyl group, with a phenyl group and a pyridyl group being preferred.7 The amine compound in which is an aromatic group is not particularly limited, but examples thereof include dimethylaminopyridine, dimethylaniline, and N,N-dimethylbenzylamine.

[0051] In the formula (3), n is preferably 3, and n R 6 Preferably, at least one of the groups is a hydroxy group-containing saturated aliphatic hydrocarbon group, and the others are aliphatic hydrocarbon groups. Specific examples of such amine compounds include, but are not limited to, dimethylethanolamine, methyldiethanolamine, triethanolamine, triethylamine, triisopropylamine, dimethylaminopyridine, and dimethylaniline, with dimethylethanolamine, methyldiethanolamine, and triethanolamine being preferred.

[0052] Among the amine compounds listed above as component (B), the amine compounds in which an aliphatic hydrocarbon group and an aliphatic hydrocarbon group having an unsaturated group-containing group are bonded to a nitrogen atom include, but are not limited to, amine compounds containing 1 to 4 nitrogen atoms and an unsaturated group-containing group having 18 or less carbon atoms. Preferred are amine compounds in which an unsaturated group-containing group is bonded to a divalent aliphatic hydrocarbon group at one end and a nitrogen atom is bonded to the other end of the divalent aliphatic hydrocarbon group. Examples of unsaturated group-containing groups include, but are not limited to, groups containing a double or triple bond between carbon atoms or a double or triple bond between a carbon atom and a heteroatom, with groups containing a carbon-carbon double bond being preferred. Examples of groups containing a carbon-carbon double bond include, but are not limited to, groups containing a vinyl group, an allyl group, a (meth)acryloyl group, a (meth)acryloyloxy group, an acrylamide group, or the like. Specific examples of such amine compounds include, but are not limited to, 2-dimethylaminoethyl acrylate.

[0053] Among the amine compounds listed above as component (B), amine compounds having two or more nitrogen atoms include, but are not limited to, amine compounds containing 2 to 5 nitrogen atoms, in which the nitrogen atoms are linked via a divalent saturated aliphatic hydrocarbon, and polyalkyleneimines. Specific examples of such amine compounds include, but are not limited to, ethylenediamine, dimethylethylenediamine, tetramethylethylenediamine, diethylenetriamine, pentamethyldiethylenetriamine, triethyltetramine, hexamethyltriethylenetetramine, tetraethylpentamine, piperazine, dimethylpiperazine, and polyethyleneimines having a molecular weight of 200 to 100,000. The polyethyleneimines may have a linear, branched, or cyclic structure, or may be mixtures thereof. The nitrogen atoms contained in the polyethyleneimines may be primary, secondary, or tertiary amino groups, or may be mixtures thereof. The amine compound having two or more nitrogen atoms in which an aliphatic hydrocarbon group is bonded to a nitrogen atom is preferably a linear and / or branched compound, more preferably a branched compound.

[0054] Among the amine compounds listed above as component (B), the heterocyclic compound having a nitrogen atom is not particularly limited, but a preferred embodiment is, for example, a compound having a saturated or unsaturated heterocycle containing 1 to 4 nitrogen atoms and 2 to 12 carbon atoms. Heterocyclic compounds containing a 6-membered heterocycle containing a nitrogen atom are more preferred, and heterocyclic compounds containing two nitrogen atoms and 4 to 10 carbon atoms are even more preferred. Specific examples of heterocyclic compounds having a nitrogen atom include, but are not particularly limited to, diazabicyclooctane, diazabicycloundecene, diazabicyclononene, pyrrolizidine, quinuclidine, hexamine, indolizidine, etc.

[0055] In the polymerization initiator composition of the present invention, the molar ratio of component (A) to component (B) can be 10:1 to 1:10, preferably 5:1 to 1:5, more preferably 3:1 to 1:3, and even more preferably 1:1 to 1:3.

[0056] The blending amounts of the polymerization initiator composition of the present invention relative to the monomers are not particularly limited; however, from the viewpoint of efficiently proceeding the reaction, the blending amounts of the components (A) and (B) are preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.2% by mass or more, respectively.

[0057] The blending amounts of the polymerization initiator composition of the present invention relative to the monomers are not particularly limited. However, from the viewpoint of efficiently proceeding the reaction, the blending amounts of the components (A) and (B) are preferably 0.001 mol % or more, more preferably 0.01 mol % or more, and even more preferably 0.1 mol % or more, respectively.

[0058] The polymerization initiator composition of the present invention may contain other components in addition to the components (A) and (B) within the range that does not impair the effects of the present invention. The other components are not particularly limited, but examples thereof include a solvent, a sensitizer, a silane coupling agent, a resin additive, an antistatic agent, an ultraviolet absorber, an antioxidant, etc.

[0059] The polymerization initiator composition of the present invention, which contains component (A) and component (C), generates radical species, cation species, or anion species through a bimolecular reaction between component (A) and component (C). That is, the benzophenone derivative of component (A) becomes excited upon irradiation with light, and component (C) receives the excitation energy, causing component (C) to generate radical species, cation species, or anion species. The subsequent polymerization is usually initiated by the radical species, cation species, or anion species generated from component (C).

[0060] The polymerization initiator of component (C) is selected from an intramolecular cleavage type radical polymerization initiator, a cationic polymerization initiator, and an anionic polymerization initiator.

[0061] The intramolecular cleavage type radical polymerization initiator is not particularly limited, but examples thereof include benzyl ketal compounds, hydroxyacetophenone compounds, aminoacetophenone compounds, and acylphosphine oxides.

[0062] The benzyl ketal compound is not particularly limited, but examples thereof include 2,2-dimethoxy-2-phenylacetophenone.

[0063] The hydroxyacetophenone compound is not particularly limited, but examples thereof include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropanone, 1-(4-(2-hydroxyethoxy)-phenyl)-2-hydroxy-methylpropanone, 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one, and the like.

[0064] The aminoacetophenone compound is not particularly limited, but examples thereof include 2-benzyl-2-(dimethylamino)-1-[4-(morpholino)phenyl]-1-butanone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, and the like.

[0065] The acylphosphine oxide is not particularly limited, but examples thereof include phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and ethyl(2,4,6-trimethylbenzoyl)-phenylphosphineate.

[0066] The cationic polymerization initiator is not particularly limited, but examples thereof include photoacid generators. The photoacid generator is not particularly limited, but examples thereof include iodonium salt compounds and sulfonium salt compounds. The iodonium salt compounds are not particularly limited, but examples thereof include diphenyliodonium hexafluorophosphate and 4-methoxyphenylphenyliodonium trifluoroacetate. The sulfonium salt compounds are not particularly limited, but examples thereof include triphenylsulfonium hexafluorophosphate, triphenylsulfonium trifluoromethanesulfonate, and diphenyl[4-(phenylthio)phenyl]sulfonium hexafluorophosphate. The cation moiety of these compounds can be a variety of cations and is not limited to the above examples.

[0067] The anionic polymerization initiator is not particularly limited, but examples thereof include photobase generators, such as 1,2-dicyclohexyl-4,4,5,5-tetramethylbiguanidinium n-butyltriphenylborate and 1,2-diisopropyl-3-[bis(dimethylamino)methylene]guanidinium 2-(3-benzoylphenyl)propionate.

[0068] In the polymerization initiator composition of the present invention, the molar ratio of component (A) to component (C) can be 10:1 to 1:100, preferably 1:1 to 1:100, more preferably 1:5 to 1:25, and even more preferably 1:5 to 1:10.

[0069] The blending amounts of the polymerization initiator composition of the present invention relative to the monomers are not particularly limited; however, from the viewpoint of efficiently proceeding the reaction, the blending amounts of the components (A) and (C) are preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, respectively.

[0070] The blending amounts of the polymerization initiator composition of the present invention relative to the monomers are not particularly limited. However, from the viewpoint of efficiently proceeding the reaction, the blending amounts of the components (A) and (C) are preferably 0.001 mol % or more, more preferably 0.01 mol % or more, and even more preferably 0.1 mol % or more, respectively.

[0071] The polymerization initiator composition of the present invention may contain other components besides component (A) and component (C) within the range that does not impair the effects of the present invention. The other components are not particularly limited, but examples thereof include a solvent, a sensitizer other than component (C), a silane coupling agent, a resin additive, an antistatic agent, an ultraviolet absorber, an antioxidant, etc.

[0072] The polymerization initiator composition of the present invention exhibits excellent reaction rates in the production of resins by photopolymerization. It is particularly suitable for photopolymerization reactions using an LED light source. In recent years, devices irradiating longer wavelengths of UV light, particularly LED light sources, have come into use due to the need to prevent UV contamination and the increasing size of curing equipment. Among these, LEDs with wavelengths ranging from 295 to 410 nm, preferably 295 to 390 nm, more preferably 340 to 390 nm, even more preferably 360 to 370 nm, and particularly preferably 365 nm, are the most commonly used long-wavelength UV light sources, and there is a demand for the development of polymerization initiators compatible with these wavelengths. A combination of a benzophenone derivative incorporating two or more thioethers as sulfide groups bonded to an aromatic hydrocarbon skeleton and an amine compound exhibits greater sensitivity to long-wavelength UV light than conventional hydrogen abstraction polymerization initiators, enhancing the reactivity of unsaturated monomers.

[0073] From the above-mentioned viewpoints, the polymerization initiator composition of the present invention preferably has a molar absorption coefficient of 30,000 L / (mol cm) or more at the maximum absorption wavelength of component (A). A large molar absorption coefficient for ultraviolet light with a longer wavelength is useful, and for example, the molar absorption coefficient at 365 nm is preferably 3,000 L / (mol cm) or more, more preferably 4,000 L / (mol cm) or more, and even more preferably 5,000 L / (mol cm) or more.

[0074] The above disclosure also applies to a method of using a composition comprising component (A) and component (B) to initiate a polymerization reaction of a monomer, and also to a method of using a composition comprising component (A) and component (C) to initiate a polymerization reaction of a monomer.

[0075] (Method for producing resin) The polymerization initiator or photosensitizer of the present invention, particularly the polymerization initiator composition of the present invention containing the same, is added to a resin raw material containing a monomer, and the monomer is polymerized by photopolymerization by irradiating the raw material with light having a wavelength of 365 nm. The mechanism of the polymerization reaction is not particularly limited, and examples thereof include radical polymerization, ionic polymerization (cationic polymerization, anionic polymerization), etc.

[0076] The polymerization initiator or photosensitizer of the present invention, particularly the polymerization initiator composition of the present invention containing the same, can be used as a monomer (a raw material for a resin) containing the polymerization initiator or photosensitizer of the present invention. Examples of the compound having a polymerizable unsaturated bond include, but are not limited to, (meth)acrylate monomers, styrene monomers, vinyl monomers, allyl monomers, maleimide monomers, acrylamide monomers, olefin monomers, and cyclic olefin monomers. Mixtures of these monomers (raw materials for copolymers) can also be used. Examples of the compound having a polymerizable cyclic structure include, but are not limited to, heterocyclic compounds such as ethylene oxide, propylene oxide, ethyleneimine, and ethylene sulfide. Mixtures of these monomers (raw materials for copolymers) can also be used.

[0077] When a resin is produced using the polymerization initiator or photosensitizer of the present invention, particularly the polymerization initiator composition of the present invention containing the same, a resin raw material containing the same and a monomer can be irradiated with light having a wavelength of 365 nm to cause photopolymerization.

[0078] Furthermore, photopolymerization can be carried out in a solvent as needed. The solvent is not particularly limited, but examples thereof include solvents used in general chemical reactions, such as water, alcohols, and organic solvents. The polymerization initiator or photosensitizer of the present invention, particularly the polymerization initiator composition of the present invention containing the same, is useful in that it has excellent affinity with the solvent and can efficiently proceed with photopolymerization. In particular, it is preferable that the initiator or photosensitizer can be mixed with the solvent to produce a transparent mixture.

[0079] In terms of solubility in monomers, solvents, etc., the component (A) of the present invention is preferably a benzophenone derivative having two sulfide groups bonded to an aromatic hydrocarbon group which may have a substituent, more preferably a benzophenone derivative having two sulfide groups bonded to an aromatic hydrocarbon group which has a saturated aliphatic hydrocarbon group, and 1 and R 2 is a branched saturated aliphatic hydrocarbon group. Another preferred embodiment is a benzophenone derivative in which two saturated aliphatic hydrocarbon groups are bonded to the aromatic hydrocarbon group. Furthermore, when the aromatic hydrocarbon group is a residue of benzene, it is preferable that the saturated aliphatic hydrocarbon group is bonded to a position other than the para position of the carbon atom to which the sulfur atom is bonded.

[0080] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. 1. Benzophenone Derivatives The benzophenone derivatives of component (A) were obtained as follows: (1) 4,4'-diphenylthiobenzophenone

[0081] 4,4'-Dichlorobenzophenone (5.0 g), potassium carbonate (12 g), potassium iodide (1.0 g), and DMF (15 g) were mixed and stirred, to which benzenethiol (5.7 g) was added, and the mixture was heated at 110°C for 12 hours. After that, the mixture was cooled to 70°C, ion-exchanged water was added, and the mixture was further cooled to room temperature. After cooling, the precipitated solid was separated, heated and dissolved in toluene at 80°C, and a 37% aqueous hydrogen chloride solution was added, followed by heating for 15 minutes. The aqueous layer was then separated, and the toluene solution was washed with water. Methanol was added to the toluene solution, and recrystallization was carried out to obtain 4,4'-diphenylthiobenzophenone. IR (KBr): 2360 cm -1 , 1645 cm -1 , 1588 cm -1 , 1310 cm -1 , 1278 cm -1 , 1080 cm -1 , 928 cm -1 , 740 cm -1 . 1 HNMR (CDCl3, 400 MHz): 7.21-7.24 (d, 4H, Ph), 7.38-7.42 (d, 4H, Ph), 7.50-7.52 (d, 4H, Ph), 7.64-7.67 (d, 4H, Ph). 13 CNMR (CDCl3, 100 MHz): 127.6, 128.8, 129.8, 130.7, 132.2, 133.7, 134.8, 144.1, 194.8.

[0082] (2) 4,4'-ditolylthiobenzophenone

[0083] 4,4'-Dichlorobenzophenone (5.0 g), potassium carbonate (12 g), potassium iodide (1.0 g), and DMF (15 g) were mixed and stirred, and p-toluenethiol (6.5 g) was added and heated at 110°C for 12 hours. After that, the mixture was cooled to 70°C, ion-exchanged water was added, and the mixture was further cooled to room temperature. After cooling, the precipitated solid was separated and dissolved in toluene by heating at 80°C, and a 37% aqueous hydrogen chloride solution was added and heated for 15 minutes. The aqueous layer was then separated, and the toluene solution was washed with water. Methanol was added to the toluene solution and recrystallization was carried out to obtain 4,4'-ditolylthiobenzophenone. IR (KBr): 2363 cm -1 , 1652 cm -1 , 1586 cm -1 , 1491 cm -1 , 1308 cm -1 , 1274 cm -1 , 1081 cm -1 , 1081 cm -1 , 925 cm -1 , 825 cm -1 , 803 cm -1 , 754 cm -1 , 487 cm -1 . 1 HNMR (CDCl3, 400 MHz): 2.40 (s, 6H, Me), 7.15-7.18 (d, 4H, Ph), 7.21-7.23 (d, 4H, Ph), 7.41-7.43 (d, 4H, Ph), 7.60-7.62 (d, 4H, Ph). 13 CNMR (CDCl3, 100 MHz): 21.3 (Me), 126.5, 128.1, 130.5, 130.6, 134.4, 134.6, 139.3, 145.0 (Ph), 194.8 (C=O).

[0084] (3) 4,4'-bis(p-isopropylphenylthio)benzophenone

[0085] 4,4'-Dichlorobenzophenone (5.0 g), potassium carbonate (12 g), potassium iodide (1.0 g), and DMF (15 g) were added, mixed, and stirred. p-Isopropylbenzenethiol (7.3 g) was added, and the mixture was heated at 110°C for 12 hours. After that, the mixture was cooled to 70°C, ion-exchanged water was added, and the mixture was further cooled to room temperature. After cooling, the precipitated solid was separated, heated and dissolved in toluene at 80°C, and a 37% aqueous hydrogen chloride solution was added, followed by heating for 15 minutes. The aqueous layer was then separated, and the toluene solution was washed with water. Methanol was added to the toluene solution, and recrystallization was carried out to obtain 4,4'-bis(p-isopropylphenylthio)benzophenone. IR (KBr): 2960 cm -1 , 2360 cm -1 , 1652 cm -1 , 1586 cm -1 , 1486 cm -1 , 1285 cm -1 , 1079 cm -1 , 827 cm -1 , 753 cm -1 . 1 HNMR (CDCl3, 400 MHz): 1.27-1.28 (d, 6H, Me), 2.91-2.98 (m, 1H, -CHMe2), 7.17-7.19 (d, 2H, Ph), 7.26-7.28 (d, 2H, Ph), 7.43-7.46 (d, 2H, Ph), 7.63-7.65 (d, 2H, Ph). 13 CNMR (CDCl3, 100 MHz): 23.7 (Me), 34.1 (-CHMe2), 126.5, 127.9, 128.4, 130.5, 134.3, 134.6, 150.0, 197.8 (Ph).

[0086] (4) 4,4'-bis(p-tert-butylphenylthio)benzophenone

[0087] 4,4'-Dichlorobenzophenone (5.0 g), potassium carbonate (12 g), potassium iodide (1.0 g), and DMF (15 g) were added, mixed, and stirred. p-tert-butylbenzenethiol (8.0 g) was added and heated at 110°C for 12 hours. After that, the mixture was cooled to 70°C, ion-exchanged water was added, and the mixture was further cooled to room temperature. After cooling, the precipitated solid was separated and dissolved in toluene by heating at 80°C. A 37% aqueous hydrogen chloride solution was added, and the mixture was heated for 15 minutes. The aqueous layer was then separated, and the toluene solution was washed with water. Methanol was added to the toluene solution, and recrystallization was carried out to obtain 4,4'-bis(p-tert-butylphenylthio)benzophenone. IR (KBr): 2959 cm -1 , 2360 cm -1 , 1644 cm -1 , 1587 cm -1 , 1309 cm -1 , 1287 cm -1 , 834 cm -1 . 1 HNMR (CDCl3, 400 MHz): 1.34 (s, 9H, -CMe3), 7.18-7.20 (d, 4H, Ph), 7.43-7.45 (d, 8H, Ph), 7.63-7.65 (d, 4H, Ph). 13 CNMR (CDCl3, 100 MHz): 31.1 (Me), 34.8 (-CMe3), 126.5, 127.0, 128.2, 130.4, 133.8, 134.6, 144.8, 152.4 (Ph), 194.9 (C=O).

[0088] (5) 4-(p-Tolylthio)benzophenone

[0089] 4-Chlorobenzophenone (4.3 g), potassium carbonate (6.0 g), potassium iodide (0.5 g), and DMF (13 g) were added, mixed, and stirred, and p-toluenethiol (3.0 g) was added and heated at 110°C for 12 hours. After that, it was cooled to 70°C, ion-exchanged water was added, and the mixture was further cooled to room temperature. After cooling, the precipitated solid was separated and dissolved in toluene by heating at 80°C, and a 37% aqueous hydrogen chloride solution was added and heated for 15 minutes. The aqueous layer was then separated, and the toluene solution was washed with water. Methanol was added to the toluene solution and recrystallization was carried out to obtain 4-(p-tolylthio)benzophenone. IR (KBr): 2959 cm -1 , 2360 cm -1 , 1644 cm -1 , 1587 cm -1 , 1309 cm -1 , 1287 cm -1 , 834 cm -1 . 1 HNMR (CDCl3, 400 MHz): 2.40 (s, 3H, Me), 7.16-7.24 (m, 4H, Ph), 7.42-7.48 (m, 4H, Ph), 7.55-7.58 (t, 1H, Ph), 7.67-7.68 (d, 2H, Ph), 7.74-7.77 (d, 2H, Ph). 13 CNMR (CDCl3, 100 MHz): 21.3 (Me), 126.5, 128.0, 128.3, 129.9, 130.5, 130.7, 132.2, 134.4, 134.5, 137.7, 139.3, 145.3 (Ph), 195.8 (C=O).

[0090] (6) 4,4'-bis(methylthio)benzophenone

[0091] 4,4'-Dichlorobenzophenone (5.0 g), potassium carbonate (12 g), potassium iodide (1.0 g), and DMF (30 g) were mixed and stirred, and then 15% aqueous sodium methanethiolate solution (20 g) was added and heated at 110°C for 12 hours. After that, the mixture was cooled to 70°C, ion-exchanged water was added, and the mixture was further cooled to room temperature. After cooling, the precipitated solid was separated and dissolved in toluene by heating at 80°C, and a 37% aqueous hydrogen chloride solution was added and heated for 15 minutes. The aqueous layer was then separated, and the toluene solution was washed with water. Methanol was added to the toluene solution and recrystallization was carried out to obtain 4,4'-bis(methylthio)benzophenone. IR (KBr): 2357 cm -1 , 1650 cm -1 , 1276 cm -1 , 804 cm -1 , 726 cm -1 , 695 cm -1 , 474 cm -1 . 1 HNMR (CDCl3, 400 MHz): 2.55 (s, 6H, Me), 7.28-7.31 (d, 4H, Ph), 7.71-7.73 (d, 4H, Ph). 13 CNMR (CDCl3, 100 MHz): 14.9 (Me), 124.5, 130.5, 136.2, 145.0 (Ph), 194.9 (C=O).

[0092] (7) 4,4'-bis(octylthio)benzophenone

[0093] 4,4'-Dichlorobenzophenone (5.0 g), potassium carbonate (12 g), potassium iodide (1.0 g), and DMF (15 g) were added, mixed, and stirred, and octanethiol (12 g) was added and heated at 110°C for 12 hours. After that, it was cooled to 70°C, ion-exchanged water was added, and the mixture was further cooled to room temperature. After cooling, the precipitated solid was separated and dissolved in toluene by heating at 80°C, and a 37% aqueous hydrogen chloride solution was added and heated for 15 minutes. The aqueous layer was then separated, and the toluene solution was washed with water. Methanol was added to the toluene solution and recrystallization was carried out to obtain 4,4'-bis(octylthio)benzophenone. IR (KBr): 2923 cm -1, 2852 cm -1 , 1634 cm -1 , 1590 cm -1 , 1398 cm -1 , 1293 cm -1 , 1090 cm -1 , 729 cm -1 . 1 HNMR (CDCl3, 400 MHz): 0.87-0.91 (t, 3H, Me), 1.23-1.37 (m, 16H, -CH2-), 1.43-1.50 (m, 4H, -CH2-), 1.68-1.76 (m, 4H, -CH2-), 2.98-3.03 (t, 4H, -SCH2-), 7.31-7.34 (d, 4H, Ph), 7.70-7.72 (d, 4H, Ph). 13 CNMR (CDCl3, 100 MHz): 14.1, 22.6, 28.8, 28.9, 29.1, 31.8, 32.0, 32.1 (fatty chain), 126.1, 130.5, 131.2, 144.0 (Ph), 195.0 (C=O).

[0094] (9) 4,4'-Dithio(4-tert-butyl-2-methylphenyl)benzophenone

[0095] 4,4'-Dichlorobenzophenone (5.0 g), potassium carbonate (12 g), potassium iodide (1.0 g), and DMF (15 g) were added, mixed, and stirred. 5-tert-butyl-2-methylbenzenethiol (8.7 g) was added and heated at 100°C for 12 hours. After that, it was cooled to 70°C, ion-exchanged water was added, and the mixture was further cooled to room temperature. After cooling, the precipitated solid was separated and dissolved in toluene by heating at 80°C. A 37% aqueous solution of hydrogen chloride was added, and the mixture was heated for 15 minutes. The aqueous layer was then separated, and the toluene solution was washed with water. Methanol was added to the toluene solution, and recrystallization was carried out to obtain 4,4'-dithio(4-tert-butyl-2-methylphenyl)benzophenone. IR (KBr): 2963 cm -1 , 2362 cm -1 , 1640 cm -1 , 1586 cm -1, 1287 cm -1 , 1082 cm -1 , 926 cm -1 , 754 cm -1 . 1 HNMR (CDCl3, 400 MHz): 1.30 (s, 18H, tBu), 2.33 (s, 6H, Me), 7.05-7.07 (d, 4H, Ph), 7.25-7.28 (d, 2H, Ph), 7.36-7.37 (d, 2H, Ph), 7.56 (s, 2H, Ph), 7.61-7.63 (d, 4H, Ph). 13 CNMR (CDCl3, 100 MHz): 20.1(Ph-CH3), 31.3 (C(CH3)3), 34.5 (C(CH3)3), 125.7, 126.9, 129.5, 130.6, 130.8, 133.2, 134.2, 139.3, 144.6, 150.4 (Ph), 194.9 (C=O).

[0096] (10) 4,4'-dithio(3-methylphenyl)benzophenone

[0097] 4,4'-Dichlorobenzophenone (5.0 g), potassium carbonate (12 g), potassium iodide (1.0 g), and DMF (15 g) were added, mixed, and stirred, and m-toluenethiol (6.0 g) was added and heated at 100°C for 12 hours. After that, it was cooled to 70°C, ion-exchanged water was added, and it was further cooled to room temperature. After cooling, the precipitated solid was separated and dissolved in toluene by heating at 80°C, and a 37% aqueous hydrogen chloride solution was added and heated for 15 minutes. Then, the aqueous layer was separated, and the toluene solution was washed with water. Methanol was added to the toluene solution and recrystallization was carried out to obtain 4,4'-dithio(3-methylphenyl)benzophenone. IR (KBr): 2358 cm -1 , 1642 cm -1 , 1310 cm -1 , 1282 cm -1 , 1077 cm -1 , 927 cm -1 , 846 cm -1 , 781 cm -1 , 750 cm -1. 1 HNMR (CDCl3, 400 MHz): 2.37 (s, 6H, Me), 7.21-7.23 (m, 6H, Ph), 7.27-7.31 (t, 4H, Ph), 7.34 (s, 2H, Ph), 7.64-7.66 (d, 4H, Ph). 13 CNMR (CDCl3, 100 MHz): 21.3 (Me), 127.3, 129.5, 129.6, 130.6, 130.9, 131.8, 134.4, 134.8, 139.6, 144.3 (Ph), 194.8 (C=O).

[0098] (11) 4,4'-Dithio(2,4-dimethylphenyl)benzophenone

[0099] 4,4'-Dichlorobenzophenone (5.0 g), potassium carbonate (12 g), potassium iodide (1.0 g), and DMF (15 g) were added, mixed, and stirred. 2,4-dimethylbenzenethiol (6.0 g) was added and heated at 100°C for 12 hours. After that, it was cooled to 70°C, ion-exchanged water was added, and the mixture was further cooled to room temperature. After cooling, the precipitated solid was separated and dissolved in toluene by heating at 80°C. A 37% aqueous solution of hydrogen chloride was added, and the mixture was heated for 15 minutes. The aqueous layer was then separated, and the toluene solution was washed with water. Methanol was added to the toluene solution, and recrystallization was carried out to obtain 4,4'-dithio(2,4-dimethylphenyl)benzophenone. IR (KBr): 2361 cm -1 , 1644 cm -1 , 1588 cm -1 , 1399 cm -1 , 1311 cm -1 , 1285 cm -1 , 1079 cm -1 , 928 cm -1 , 809 cm -1 , 753 cm -1 . 1HNMR (CDCl3, 400 MHz): 2.34 (s, 6H, Me), 2.37 (s, 6H, Me), 7.03-7.07 (m, 6H, Ph), 7.16 (s, 2H, Ph), 7.42-7.44 (d, 2H, Ph), 7.59-7.61 (d, 4H, Ph). 13 CNMR (CDCl3, 100 MHz): 20.6, 21.2 (Me), 125.6, 126.6, 128.0, 130.6, 134.2, 136.3, 140.1, 142.3, 144.8 (Ph), 194.8 (C=O).

[0100] (12) 4,4'-Dithio(2,5-dimethylphenyl)benzophenone

[0101] 4,4'-Dichlorobenzophenone (5.0 g), potassium carbonate (12 g), potassium iodide (1.0 g), and DMF (15 g) were added, mixed, and stirred, and 2,5-dimethylbenzenethiol (6.0 g) was added and heated at 100°C for 12 hours. After that, it was cooled to 70°C, ion-exchanged water was added, and it was further cooled to room temperature. After cooling, the precipitated solid was separated and dissolved in toluene by heating at 80°C, and a 37% aqueous hydrogen chloride solution was added and heated for 15 minutes. Then, the aqueous layer was separated, and the toluene solution was washed with water. Methanol was added to the toluene solution, and recrystallization was carried out to obtain 4,4'-dithio(2,5-dimethylphenyl)benzophenone. IR (KBr): 2919 cm -1 , 1650 cm -1 , 1585 cm -1 , 1488 cm -1 , 1284 cm -1 , 1083 cm -1 , 924 cm -1 , 754 cm -1 . 1 HNMR (CDCl3, 400 MHz): 2.32 (s, 3H, Me), 2.33 (s, 3H, Me), 7.05-7.08 (s, 4H, Ph), 7.13-7.24 (m, 6H, Ph), 7.35 (s, 2H, Me), 7.61-7.63 (d, 4H, Ph).13 CNMR (CDCl3, 100 MHz): 20.2, 20.8 (Me), 125.9, 128.2, 128.6, 129.1, 130.6, 130.9, 134.3, 136.5, 136.8, 139.1, 144.4 (Ph), 194.8 (C=O).

[0102] 2. UV absorption characteristics of component (A) A 100 μM chloroform solution of each benzophenone derivative was prepared and placed in a 10 mm quartz cell. The absorption spectrum was measured using an ultraviolet-visible spectrophotometer (V-550, manufactured by JASCO Corporation). The maximum absorption wavelength, its molar absorption coefficient, and the molar absorption coefficient at 365 nm are shown in Table 1.

[0103] When component (A) was used in Examples A-1 to A-4 and A-9 to A-12, the molar absorption coefficient at the maximum absorption wavelength was 30,000 L / (mol cm) or more, confirming that it could efficiently absorb light. In particular, from the molar absorption coefficient at 365 nm, when component (A) was used in Examples A-1 to A-4 and A-9 to A-12, it was 3,000 L / (mol cm) or more, confirming that it had better ability to absorb light at a wavelength of 365 nm than Comparative Examples A-5 to A-7. This suggests that the polymerization initiator composition containing component (A) of the present invention is useful for photoradical polymerization using an LED as a light source.

[0104] Among the examples, benzophenone derivatives having two sulfide groups bonded to an aromatic hydrocarbon group having one saturated aliphatic hydrocarbon group as a substituent, such as A-2 to A-4 and A-10, have a molar absorption coefficient at 365 nm of 4000 L / (mol cm) or more, and in particular, benzophenone derivatives having R in the above formula (1), such as A-3 and A-4, have a molar absorption coefficient at 365 nm of 4000 L / (mol cm) or more. 1 and R 2 It has been confirmed that when is a branched saturated aliphatic hydrocarbon group, the molar absorption coefficient at 365 nm is 5000 L / (mol·cm) or more, and this is more useful.

[0105] 3. Heat Resistance of Component (A) The 5% weight loss temperature of each benzophenone derivative was measured as follows: Using a simultaneous thermogravimetric and differential thermal analyzer (TG / DTA6200, manufactured by SII), the samples were heated at a rate of 10°C / min over a measurement range of 25°C to 550°C, and the temperature at which the weight change (TG) decreased by 5% by weight was read. The results are shown in Table 1.

[0106] These results confirm that when component (A) was any of Examples A-1 to A-4 and A-9 to A-12, the 5% weight loss temperature was 300°C or higher, and that these had better heat resistance than Comparative Examples A-5 to A-7. This suggests that the polymerization initiator composition containing component (A) of the present invention does not decompose even during high-temperature molding of the resin when component (A) is present in the resin after the polymerization reaction, and that problems such as bleed-out of decomposition products and discoloration / coloration of the resin are improved.

[0107] Among the examples, benzophenone derivatives having two sulfide groups bonded to an aromatic hydrocarbon group having a saturated aliphatic hydrocarbon group as a substituent, such as A-2 to A-4 and A-9 to A-12, have a 5% weight loss temperature of 300°C or higher, and in particular, benzophenone derivatives having R in the above formula (1), such as A-3, A-4, and A-9, have a 5% weight loss temperature of 300°C or higher. 1 and R 2 When is a branched saturated aliphatic hydrocarbon group, the 5% weight loss temperature is 335° C. or higher, and it is therefore useful for application to higher molding temperatures.

[0108]

[0109] 4. Reactivity of Polymerization Initiator Composition (1) In the combinations shown in Tables 2A, 2B, 3A, 3B, and 3C, 0.15 g of component (A) (benzophenone derivative) and 0.15 g of component (B) (amine compound) were dissolved as monomers in 3.0 g of butyl acrylate. This reaction solution was irradiated with 365 nm light using an LED light source to carry out a polymerization reaction. After 5 minutes of light irradiation (cumulative light dose 500 mJ / cm), 2 ), 10 minutes (accumulated light amount 1000 mJ / cm 2The viscous solid of butyl acrylate (20%) was dissolved in a 0.05 wt % solution of dibutylhydroxytoluene (BHT) in deuterated chloroform to terminate the polymerization reaction and prepare a sample for NMR measurement. The reaction rate was calculated from the reduction rate of the olefin-derived peak of butyl acrylate measured by NMR (BRUKER: ULTRASHILDE 400PLUS) when the butyl acrylate before the reaction was set at 100.

[0110] Tables 2A and 2B confirm that the polymerization reaction proceeds when a polymerization initiator composition containing component (A) and component (B) is used, but does not proceed with the use of either component alone, as in Comparative Examples 4 and 5. When component (B) is B-1, Examples 5 to 8 and 28 to 31, in which component (A) is A-1 to A-4 and A-9 to A-12, showed a reaction rate of 90% or more 5 minutes after the start of the reaction, compared to Comparative Examples 6 to 9, in which A-5 to A-8 were used, demonstrating superior reactivity. This suggests that the polymerization initiator composition of the present invention is capable of efficiently proceeding with photopolymerization.

[0111] Among the examples, when component (A) is A-3, A-4, A-9, A-11, or A-12, it has been confirmed that photopolymerization proceeds more efficiently, and is therefore useful.

[0112] It was confirmed from Tables 3A, 3B, and 3C that when component (A) was A-1, and component (B) was B-1 to B-20 as in the examples, the photopolymerization reaction proceeded. This suggests that the polymerization initiator composition of the present invention can efficiently cause photopolymerization to proceed.

[0113] Among the examples, when component (B) was B-1 (aminobenzoic acid compound), B-2 and B-4 (amine compounds in which an aliphatic hydrocarbon group and a hydroxyl group-containing saturated aliphatic hydrocarbon group are bonded to a nitrogen atom), B-3 (amine compound in which a hydroxyl group-containing saturated aliphatic hydrocarbon group is bonded to a nitrogen atom), B-5 ​​(amine compound containing a 6-membered heterocycle having a nitrogen atom), B-10 (amine compound in which an aliphatic hydrocarbon group and an aliphatic hydrocarbon group containing an unsaturated group are bonded to a nitrogen atom), B-11 to B-13, B-16 to B-18 (amine compounds in which an aliphatic hydrocarbon group is bonded to a nitrogen atom and has two or more nitrogen atoms), B-14 (amine compound in which an aliphatic hydrocarbon group and an aromatic group are bonded to a nitrogen atom), or B-15 (amine compound in which an aliphatic hydrocarbon group is bonded to a nitrogen atom), the reaction rate after 5 minutes was 80% or more, and the compound was effective for photopolymerization. Furthermore, when component (B) is B-1, B-2, B-3, B-4, B-10, B-11 to B-13, or B-14, the reaction rate after 5 minutes is 90% or more, which is useful. In particular, when component (B) is B-1, B-10, or B-12, the reaction rate after 5 minutes is 95% or more, which is useful.

[0114]

[0115]

[0116]

[0117]

[0118]

[0119] Table 4 shows the results of a test to determine the effect of the amount (mass%) of the polymerization initiator composition in the reaction solution on the reaction rate. The reaction solution contained 3 g (100 mass%) of butyl acrylate as a monomer and the amounts of component (A) and component (B) shown in Table 4. These results confirmed that when the polymerization initiator composition of the present invention was used in an amount of 0.1 mass% or more of component (A) and component (B) relative to the mass of the reaction solution (component (A): 0.04 mol% and component (B): 0.07 mol% relative to the monomer), the reaction rate after 5 minutes was 40% or more. Furthermore, when the polymerization initiator composition of the present invention was used in an amount of 0.25 mass% or more of component (A) and component (B) relative to the monomer (component (A): 0.1 mol% and component (B): 0.17 mol%, respectively), the reaction rate after 5 minutes was 80% or more. Furthermore, when the amounts of component (A) and component (B) of the present invention were 0.5% by mass or more (component (A): 0.2 mol % and component (B): 0.35 mol % relative to the monomer), the reaction rate after 5 minutes was 95% or more, and it was confirmed that the photopolymerization reaction proceeded efficiently. It was also confirmed that the photopolymerization reaction proceeded efficiently even when component (A) and component (B) were not the same mass, as in Examples 43 and 44. This suggests that the polymerization initiator composition containing component (A) and component (B) of the present invention is useful for the polymerization reaction of various monomers.

[0120]

[0121] 5. Solubility of component (A) in monomers and solvents Component (A) A-1 to A-4 and A-9 to A-12 (0.1 g) were added to butyl acrylate (1.0 g) or toluene (1.0 g) and stirred, and the appearance of the mixture was visually confirmed, and the solubility was evaluated as follows (Table 5). Solubility evaluation ◎: Dissolved transparently ○: Dissolved almost transparently, but turbidity was observed △: Not dissolved

[0122] As shown in Examples 20 to 23 and 45 to 48 in Table 5, it was confirmed that when component (A) was A-2 to A-4 and A-9 to A-12, the components were well soluble in butyl acrylate or toluene. This suggests that when component (A) contained in the polymerization initiator composition of the present invention has an aromatic hydrocarbon group to which a saturated aliphatic hydrocarbon group is bonded, it is well soluble in monomers and solvents and is useful for photopolymerization reactions.

[0123] Among the examples, benzophenone derivatives having two sulfide groups bonded to an aromatic hydrocarbon group having a saturated aliphatic hydrocarbon group as a substituent, such as A-2 to A-4 and A-9 to A-12, have good solubility in toluene, and A-3, A-4, and A-9 to A-12 in particular have good solubility in butyl acrylate and toluene, and are therefore useful.

[0124]

[0125] 6. Reactivity of Polymerization Initiator Composition (2) As shown in Table 6, A-3 (0.15 g) as component (A) (benzophenone derivative) and B-1 (0.15 g) as component (B) (amine compound) were dissolved in 3.0 g of each monomer to prepare a reaction solution. This reaction solution was irradiated with 365 nm light using an LED light source to carry out a polymerization reaction. After 5 minutes of light irradiation (cumulative light dose 500 mJ / cm), 2 ), 10 minutes (accumulated light amount 1000 mJ / cm 2 The viscous solid of 100% by mass of the copolymer was dissolved in a 0.05% by mass solution of dibutylhydroxytoluene (BHT) in deuterated chloroform to terminate the polymerization reaction, and the resulting mixture was used as a sample for NMR measurement. Using an NMR (BRUKER: ULTRASHILDE 400PLUS), the reaction rate was determined from the rate of decrease in the olefin-derived peaks of the various monomers, relative to the values ​​of the various monomers before the reaction, which were taken as 100.

[0126] As shown in Examples 8 and 49 to 52 in Table 6, the reaction rates after 5 minutes of light irradiation were more than 99% for (meth)acrylate monomers and acrylamide monomers, confirming high reactivity. This suggests that the polymerization initiator composition of the present invention is useful for the polymerization reactions of various monomers.

[0127]

[0128] 7. Sensitizer Test Component (A) (0.3 g) and component (C) (0.03 g) shown in Tables 7A, 7B, and 7C were dissolved in butyl acrylate (3.0 g) to prepare a reaction solution. This reaction solution was irradiated with 365 nm light using an LED light source to carry out a polymerization reaction. After 1 minute of light irradiation (accumulated light dose 100 mJ / cm), 2 ), 2 minutes (accumulated light intensity 200 mJ / cm 2 ), 3 minutes (accumulated light intensity 300 mJ / cm 2 The viscous solid of butyl acrylate was dissolved in a 0.05% by mass solution of dibutylhydroxytoluene (BHT) in deuterated chloroform to terminate the polymerization reaction, and the resulting solid was used as a sample for NMR measurement. The reaction rate was determined from the rate of decrease in the olefin-derived peaks of butyl acrylate measured using an NMR (BRUKER: ULTRASHILDE 400PLUS) with the butyl acrylate before the reaction taken as 100.

[0129] As shown in Examples 53 to 58 in Tables 7A, 7B, and 7C, it was confirmed that the polymerization reaction of butyl acrylate proceeded more smoothly than in the comparative examples even when component (A) was used as a photosensitizer and combined with a polymerization initiator of component (C) to form a polymerization initiator composition. This suggests that the photosensitizer of the present invention is useful for the polymerization reaction of various monomers when combined with a polymerization initiator to form a polymerization initiator composition.

[0130]

[0131]

[0132]

Claims

1. A polymerization initiator or photosensitizer comprising the following component (A): Component (A): A benzophenone derivative having two or more sulfide groups bonded to aromatic hydrocarbon groups which may have a substituent.

2. The benzophenone derivative of component (A) is represented by the following formula (1): (In the formula, R 1 and R 2 each independently represents an aromatic hydrocarbon group which may have a saturated aliphatic hydrocarbon group.

3. The above R 1 and R 2 and each independently represent an aromatic hydrocarbon group having a saturated aliphatic hydrocarbon group having 1 to 18 carbon atoms.

4. The polymerization initiator or photosensitizer according to claim 1, wherein the molar absorption coefficient of the component (A) at 365 nm is 3000 L / (mol cm) or more.

5. The polymerization initiator or photosensitizer according to claim 1, wherein the 5% weight loss temperature of said component (A) is 300°C or higher.

6. A polymerization initiator composition comprising the following components (A) and (B): Component (A): a benzophenone derivative having two or more sulfide groups bonded to aromatic hydrocarbon groups which may have a substituent; Component (B): an amine compound having one or more hydrogen atoms on the carbon atom adjacent to the nitrogen atom.

7. The polymerization initiator composition according to claim 6, wherein the amine compound of component (B) is at least one selected from the group consisting of aminobenzoic acid compounds, amine compounds having an aliphatic hydrocarbon group and / or a hydroxyl group-containing saturated aliphatic hydrocarbon group bonded to a nitrogen atom, amine compounds having an aliphatic hydrocarbon group and an aromatic group bonded to a nitrogen atom, amine compounds having an aliphatic hydrocarbon group and an aliphatic hydrocarbon group having an unsaturated group-containing group bonded to a nitrogen atom, amine compounds having two or more nitrogen atoms, and heterocyclic compounds having a nitrogen atom.

8. The amine compound of the component (B) is represented by the following formula (2): (In the formula, R 3 and R 4 represents a saturated aliphatic hydrocarbon group, R 5 The polymerization initiator composition according to claim 6 , wherein the formula (I) is a hydrocarbon group.

9. A polymerization initiator composition comprising the following components (A) and (C): Component (A): a benzophenone derivative having two or more sulfide groups bonded to an aromatic hydrocarbon group which may have a substituent; Component (C): a polymerization initiator selected from an intramolecular cleavage type radical polymerization initiator, a cationic polymerization initiator, and an anionic polymerization initiator.

10. A method for producing a resin, comprising adding the polymerization initiator or photosensitizer according to any one of claims 1 to 5 to a resin raw material containing a monomer, and irradiating the raw material with light having a wavelength of 365 nm to polymerize the monomer by photopolymerization.

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