JP2021147516A - Polymerization initiator mixture, polymerizable composition, cured product, and method for producing cured product - Google Patents

Abstract

To provide a polymerization initiator mixture that has a photopolymerizable property and can efficiently absorb light with a wavelength of 365 nm and the like, radiated from lamps such as a high-pressure mercury lamp and an LED lamp to generate radicals.SOLUTION: A polymerization initiator mixture has a dialkyl peroxide having a thioxanthone skeleton represented by general formula (1), and a photopolymerization initiator excluding the dialkyl peroxide having the thioxanthone skeleton.SELECTED DRAWING: None

Description

The present invention relates to a method for producing a polymerization initiator mixture, a polymerizable composition, a cured product, and a cured product.

In order to synthesize a polymer or the like, a polymerization initiator capable of generating active species such as radicals, cations and anions by heat, light or oxidation-reduction is widely used. In particular, the photopolymerization initiator can generate an active species by absorbing active energy rays such as light, and is used as a polymerization initiator of a polymerizable compound.

Since the photopolymerizable composition composed of the above-mentioned photopolymerization initiator and polymerizable compound is rapidly cured by light irradiation, from the viewpoint of quick curing and low VOC, a coating agent, a paint, a printing ink, and a photosensitive composition are used. It is applied to applications such as sex printing plates, adhesives, and various photoresists.

In recent years, in the above-mentioned photopolymerization technology field, there is a demand for a photopolymerization initiator that is highly reactive, easy to manufacture, and easy to handle. For example, in the use of printing inks typified by offset inks, highly colored inks are required for quality improvement, but as the pigment content increases, it becomes more difficult to cure the inks. The same applies to the curing of coating agents, paints, photosensitive printing plates, adhesives, various photoresists, etc., which also have pigments added. Therefore, there is a need for photoinitiators that have higher sensitivity and better resolution properties than current initiator systems.

On the other hand, Patent Document 1 discloses that the above-mentioned mixture of the photoinitiator and the selected oxime ester compound can be carried out better than the case where only the known photoinitiator compound is used.

Special Table 2012-507571

However, the polymerization initiator mixture described in Patent Document 1 does not sufficiently absorb light having a wavelength longer than 365 nm emitted from a high-pressure mercury lamp or an LED lamp, and thus has the most important basic characteristics of the photopolymerization initiator. The sensitivity is not sufficient, and further improvement of the sensitivity is mentioned as an issue.

Therefore, in order to solve the above problems, the present invention is a photopolymerizable polymerization initiator capable of efficiently absorbing light having a wavelength of 365 nm or the like emitted from a lamp such as a high-pressure mercury lamp or an LED lamp to generate an active species. It provides a mixture.

Furthermore, the present invention provides a polymerizable composition containing the above-mentioned polymerization initiator mixture and a polymerizable compound, a cured product thereof, and a method for producing the cured product.

（式（１）中、Ｒ^１、Ｒ^２、Ｒ^３およびＲ^４は独立してメチル基またはエチル基を表し、Ｒ^５は炭素数１〜６のアルキル基、またはフェニル基を表し、Ｒ^６は独立した置換基であって、炭素数１〜４のアルキル基、炭素数１〜４のアルコキシ基、または塩素原子を表し、ｎは０から２の整数を表す。）で表されるチオキサントン骨格を有するジアルキルペルオキシドと、前記チオキサントン骨格を有するジアルキルペルオキシド以外の光重合開始剤を含有する重合開始剤混合物に関する。 That is, the present invention has the general formula (1):

(In formula (1), R ¹ , R ² , R ³ and R ⁴ independently represent a methyl group or an ethyl group, R ⁵ represents an alkyl group or a phenyl group having 1 to 6 carbon atoms, and R ⁶ Is an independent substituent and represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a chlorine atom, and n represents an integer from 0 to 2). The present invention relates to a mixture of a dialkyl peroxide having a thioxanthone skeleton and a photopolymerization initiator other than the dialkyl peroxide having the thioxanthone skeleton.

The present invention relates to a polymerizable composition containing the above-mentioned polymerization initiator mixture and a polymerizable compound.

The present invention relates to a cured product formed from the polymerizable composition.

The present invention relates to a method for producing a cured product, which comprises a step of irradiating the polymerizable composition with an active energy ray.

The details of the mechanism of action of the effect in the polymerization initiator mixture according to the present invention are unknown, but it is presumed as follows. However, the present invention is not limited to this mechanism of action.

The polymerization initiator mixture of the present invention can efficiently absorb light having a wavelength of 365 nm or the like emitted from a lamp such as a high-pressure mercury lamp or an LED lamp to generate a radical, and the absorbed light energy can be used as another polymerization initiator. Dialkyl peroxide having a thioxanthone skeleton capable of generating an active species and light having a wavelength shorter than 365 nm emitted from a lamp such as a high-pressure mercury lamp or an LED lamp are efficiently absorbed to absorb radicals. It contains a photopolymerization initiator other than the dialkyl peroxide having the thioxanthone skeleton that can be generated. Therefore, the polymerizable composition containing the polymerization initiator mixture and the polymerizable compound can be satisfactorily cured by irradiation with light.

The polymerization initiator mixture of the present invention contains a dialkyl peroxide having a thioxanthone skeleton represented by the following general formula (1) and a photopolymerization initiator other than the dialkyl peroxide having the thioxanthone skeleton.

（式（１）中、Ｒ^１、Ｒ^２、Ｒ^３およびＲ^４は独立してメチル基またはエチル基を表し、Ｒ^５は炭素数１〜６のアルキル基、またはフェニル基を表し、Ｒ^６は独立した置換基であって、炭素数１〜４のアルキル基、炭素数１〜４のアルコキシ基、または塩素原子を表し、ｎは０から２の整数を表す。） <Dialkyl peroxide with thioxanthone skeleton>
The dialkyl peroxide having the thioxanthone skeleton of the present invention can be represented by the following general formula (1). The dialkyl peroxide having a thioxanthone skeleton may be used alone or in combination of two or more.

(In formula (1), R ¹ , R ² , R ³ and R ⁴ independently represent a methyl group or an ethyl group, R ⁵ represents an alkyl group or a phenyl group having 1 to 6 carbon atoms, and R ⁶ Is an independent substituent and represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a chlorine atom, and n represents an integer of 0 to 2).

In the general formula (1), R ¹ , R ² , R ³ and R ⁴ independently represent a methyl group or an ethyl group. R ¹ , R ² , R ³ and R ⁴ are preferably methyl groups from the viewpoint of increasing the storage stability of the polymerizable composition because the decomposition temperature of the dialkyl peroxide having the thioxanthone skeleton is high.

In the general formula (1), ^{R 5} is an alkyl group or a phenyl group, having 1 to 6 carbon atoms. The alkyl group may be a straight chain or a branched chain. Specific examples of R ⁵ include a methyl group, an ethyl group, a propyl group, a 2,2-dimethylpropyl group and a phenyl group. Among these, a methyl group, an ethyl group, and a propyl group are preferable from the viewpoint of facilitating the synthesis of the dialkyl peroxide having the thioxanthone skeleton. Since the decomposition temperature of the dialkyl peroxide having a thioxanthone skeleton is high, the storage stability of the polymerizable composition is high, and the sensitivity to the light of the lamp is high, so that the methyl group and the ethyl group are more preferable.

In the general formula (1), the substitution position of the dialkyl peroxide with respect to thioxanthone is not particularly limited, but it is substituted with the 2-position, 3-position, or 4-position of the thioxanthone skeleton from the viewpoint of high sensitivity to the light of the lamp. Is preferable, and from the viewpoint of easy synthesis, it is more preferable that the thioxanthone skeleton is substituted at the 2- or 3-position.

In the general formula (1), R ⁶ is an independent substituent and represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a chlorine atom. The light absorption characteristics of the dialkyl peroxide having the thioxanthone skeleton can be adjusted by the push-pull effect applied to these substituents with respect to the emission wavelength of the lamp to be used, and the light of the lamp can be efficiently absorbed. can.

In the general formula (1), n represents an integer from 0 to 2. From the viewpoint of facilitating the synthesis of the dialkyl peroxide having a thioxanthone skeleton, n is preferably an integer of 0 to 1, and more preferably 0.

In the general formula (1), when n is an integer of 1 to 2, ^{the substitution position of R 6} is not particularly limited, but is set to the 6th or 7th position of the thioxanthone skeleton from the viewpoint of high sensitivity to the light of the lamp. It is preferably substituted, and it is more preferable that it is substituted at the 7-position of the thioxanthone skeleton from the viewpoint of facilitating the synthesis of the dialkyl peroxide having the thioxanthone skeleton.

Specific examples of the R ⁶ include alkyl groups such as methyl group, ethyl group, isopropyl group and n-butyl group; methoxy group, ethoxy group, n-propyloxy group, sec-butyloxy group and tert-butyloxy group. Alkyl groups such as; chlorine atoms and the like. A methoxy group or an ethoxy group is more preferable because the lamp has high sensitivity to light.

Specific examples of the dialkyl peroxide having the thioxanthone skeleton of the present invention are shown below, but the present invention is not limited thereto.

Examples of the dialkyl peroxide having a thioxanthone skeleton include compounds 1 to 9, and more preferably compounds 1, compound 2, compound 3, compound 7, and compound 8.

（上記反応式において、Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４、Ｒ^５、Ｒ^６およびｎは前記一般式（１）と同じである。） <Method for producing dialkyl peroxide having a thioxanthone skeleton>
The method for producing a dialkyl peroxide having a thioxanthone skeleton represented by the general formula (1) is, for example, a step of reacting an isoalkyl group-substituted thioxanthone derivative with a hydroperoxide in the presence of a metal complex, as shown in the following reaction formula. Hereinafter, a method including the step (A)) can be mentioned. After the reaction, a step of distilling off (removing) excess raw materials under reduced pressure and a purification step may be included.

(In the above reaction formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and n are the same as the general formula (1).)

In the step (A), a commercially available product can be used as the isoalkyl group-substituted thioxanthone derivative. If there is no commercially available product, for example, J.A. Chem. Soc. As described in 99,645 (1911), it can be synthesized by reacting 2,2'-dithiodibenzoic acid with an aromatic compound in sulfuric acid.

In the step (A), the hydroperoxide is preferably reacted with 1.0 mol of the isoalkyl group-substituted thioxanthone derivative in an amount of 0.8 mol or more, preferably 1.0 mol, from the viewpoint of increasing the yield of the target product. The above reaction is more preferable, the reaction is preferably 10.0 mol or less, and the reaction is more preferably 6.0 mol or less. As the hydroperoxide, a commercially available product can be used, and if there is no commercially available product, the hydroperoxide can be synthesized according to a known synthesis method described in JP-A-58-72557 and the like.

In the step (A), as the metal complex, a metal complex of a metal selected from the transition metals of the 4th and 5th periods can be used. Examples of the metal of the metal complex include copper, cobalt, manganese, iron, chromium, zinc and the like, and examples of the ligand include halogens such as bromine and chlorine, and ores such as sulfuric acid, phosphoric acid, nitrate and carbon dioxide. Examples thereof include organic acids such as acid, formic acid, acetic acid, naphthenic acid, octenoic acid and gluconic acid, cyanide and acetylacetonate. The metal complex is preferably used in an amount of 0.0001 mol or more, more preferably 0.001 mol or more, and more preferably 0.001 mol or more, based on 1.0 mol of hydroperoxide, from the viewpoint of increasing the yield of the target product. It is preferable to use 1.0 mol or less, and more preferably 0.1 mol or less.

In the step (A), the reaction temperature is preferably 0 ° C. or higher, more preferably 20 ° C. or higher, and 100 ° C. or lower from the viewpoint of increasing the yield of the target product. It is preferably 80 ° C. or lower, more preferably 80 ° C. or lower. The reaction time cannot be unconditionally determined because it varies depending on the raw material, the reaction temperature, and the like, but is usually preferably 1 hour to 60 hours from the viewpoint of increasing the yield of the target product.

In the step (A), it is preferable to use an organic solvent, and as the organic solvent, for example, benzene, toluene, chlorobenzene, o-dichlorobenzene, nitrobenzene and the like can be used. The organic solvent may be used alone or in combination of two or more. The amount of the organic solvent used is usually about 50 to 1000 parts by mass with respect to 100 parts by mass of the total amount of the raw materials. By distilling off the organic solvent after the step (A), the dialkyl peroxide having a thioxanthone skeleton may be taken out, and in order to improve the handleability and reduce the risk at the time of thermal decomposition, the dialkyl peroxide derivative is used as the organic solvent. It may be used as a diluted product.

The step (A) can be carried out under any of the conditions of normal pressure, pressurization and reduced pressure, but it is preferably carried out in an atmosphere of an inert gas such as nitrogen.

In the purification step, in order to remove excess raw materials and by-products, for example, a basic aqueous solution such as sodium hydrogen carbonate, potassium hydrogen carbonate, sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, sodium sulfite, etc. , The step of purifying the target product by washing with an acidic aqueous solution such as hydrochloric acid or sulfuric acid, ion-exchanged water or the like.

<Photopolymerization initiator other than dialkyl peroxide having a thioxanthone skeleton>
The photopolymerization initiator other than the dialkyl peroxide having a thioxanthone skeleton of the present invention can be used without limitation as long as it generates an active species by light having a wavelength shorter than 365 nm. For example, a radical photopolymerization initiator and a cation. Examples thereof include a system photopolymerization initiator and an anion system photopolymerization initiator. The photopolymerization initiator other than the dialkyl peroxide having a thioxanthone skeleton may be used alone or in combination of two or more.

Examples of the radical photopolymerization initiator include an α-hydroxyketone-based photopolymerization initiator, an α-aminoalkylketone-based photopolymerization initiator, an acylphosphine oxide-based photopolymerization initiator, and an oxime ester-based photopolymerization initiator. Can be mentioned.

Examples of the α-hydroxyketone-based photopolymerization initiator include 1-hydroxycyclohexylphenylketone, 2-hydroxy-2-methyl-propiophenone, and 4'-(2F-hydroxyethoxy) -2-hydroxy-2-. Examples thereof include α-hydroxyketone derivatives such as methylpropiophenone and 2-hydroxy-1- (4- (4- (2-hydroxy-2-methylpropionyl) benzyl) phenyl) -2-methylpropan-1-one. ..

Examples of the α-aminoalkylketone-based photopolymerization initiator include 2-methyl-4'-methylthio-2-morpholinopropiophenone and 2-benzyl-2- (N, N-dimethylamino) -1-(. Examples include α-aminoalkyl ketone derivatives such as 4-morpholinophenyl) butane-1-one and 2- (dimethylamino) -2- (4-methylbenzyl) -1- (4-morpholinophenyl) butane-1-one. Be done.

Examples of the acylphosphine oxide-based photopolymerization initiator include diphenyl-2,4,6-trimethylbenzoylphosphine oxide, phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide, and ethyl (mesitylcarbonyl) phenylphosphine. Acylphosphine oxide derivatives such as finale can be mentioned.

Examples of the oxime ester-based photopolymerization initiator include 1- [4- (phenylthio) phenyl] octane-1,2-dione-2- (O-benzoyloxime) and 1-[({1- [9-]. Examples thereof include oxime ester derivatives such as ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl] ethylidene} amino) oxy] etanone.

Examples of the cationic photopolymerization initiator include a diazonium salt of Lewis acid, an iodonium salt of Lewis acid, a sulfonium salt of Lewis acid, a phosphonium salt of Lewis acid, other halides, a triazine-based initiator, and a borate-based initiator. And so on.

Examples of the anionic photopolymerization initiator include acetophenone O-benzoyloxime, cyclohexylcarbamic acid 1,2-bis (4-methoxyphenyl) -2-oxoethyl, nifedipine, cyclohexylcarbamic acid 2-nitrobenzyl, 2-( 9-oxoxanthen-2-yl) propionic acid 1,5,7-triazabicyclo [4,4,0] deca-5-ene and the like can be mentioned.

The mass ratio of the dialkyl peroxide having the thioxanthone skeleton to the photopolymerization initiator other than the dialkyl peroxide having the thioxanthone skeleton (dialkyl peroxide having the thioxanthone skeleton / photopolymerization initiator other than the dialkyl peroxide having the thioxanthone skeleton) has a wavelength of 365 nm. From the viewpoint of the absorption efficiency of light such as 1/100 or more, more preferably 1/10 or more, and from the viewpoint of the absorption efficiency of light having a wavelength shorter than 365 nm, 100 / It is preferably 1 or less, and more preferably 10/1 or less.

The polymerization initiator mixture of the present invention may contain a sensitizer. The sensitizer may be used alone or in combination of two or more.

<Sensitizer>
The sensitizer of the present invention can be used without limitation as long as it transfers the absorbed light energy to the polymerization initiator by irradiation with active energy rays, for example, 4,4'-bis (diethylamino) benzophenone and the like. Benzophenone derivatives; Thioxanthone derivatives such as isopropylthioxanthone and diethylthioxanthone; Anthracene derivatives such as 9,10-dibutoxyanthracene; Kumarin derivatives such as coumarin and ketocumarin; Examples thereof include benzoic acid ester derivatives such as ethyl acid, isoamyl 4-dimethylaminobenzoate, and ethyl benzoate (2-dimethylamino); alkylamine derivatives such as triethanolamine and methyldiethanolamine; phenylquinone and the like.

The sensitizer is emitted from a lamp such as a high-pressure mercury lamp or an LED lamp with respect to a total of 100 parts by mass of the dialkyl peroxide having the thioxanthone skeleton and the photopolymerization initiator other than the dialkyl peroxide having the thioxanthone skeleton. From the viewpoint of efficiently absorbing light and efficiently generating radicals, it is preferably 1 part by mass or more, more preferably 10 parts by mass or more, and from the viewpoint of preventing coloring of the cured product, 500. It is preferably less than or equal to parts by mass, and more preferably less than or equal to 100 parts by mass.

<Polymerizable composition>
The polymerizable composition of the present invention contains the above-mentioned polymerization initiator mixture and a polymerizable compound.

The polymerizable compound can be used without particular limitation as long as it is a polymerizable compound depending on the active species, and examples thereof include radical polymerizable compounds, cationically polymerizable compounds, and anionic polymerizable compounds.

<Radical polymerizable compound>
As the radically polymerizable compound, a compound having an ethylenically unsaturated group can be preferably used. Examples of the radically polymerizable compound include (meth) acrylic acid esters, styrenes, maleic acid esters, fumaric acid esters, itaconic acid esters, cinnamic acid esters, crotonic acid esters, vinyl ethers, and vinyl. Examples thereof include esters, vinyl ketones, allyl ethers, allyl esters, N-substituted maleimides, N-vinyl compounds, unsaturated nitriles, olefins and the like. Among these, it is preferable to contain highly reactive (meth) acrylic acid esters. The radically polymerizable compound may be used alone or in combination of two or more.

As the (meth) acrylic acid esters, monofunctional compounds and polyfunctional compounds can be used. Examples of the monofunctional compound include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, and stearyl. Alkyl (meth) acrylates such as (meth) acrylate; cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylicate, dicyclopentenyl (meth) acrylicate, dicyclopentenyloxyethyl Ester compounds of (meth) acrylic acid such as (meth) acrylicate and 2-ethyl-2-adamantyl (meth) acrylate and alicyclic alcohol; aryl such as phenyl (meth) acrylate and benzyl (meth) acrylate (meth) Meta) acrylate; 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 3-hydroxy-1-adamantyl (meth) acrylate, polyethylene glycol mono Monomers having a hydroxy group such as (meth) acrylate and polypropylene glycol mono (meth) acrylate; methoxyethyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, 2-phenylphenoxyethyl (meth). ) Acrylate, tetrahydrofurfuryl (meth) acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl) methyl (meth) acrylate, (3-ethyloxetane-3-yl) methyl (meth) Monomer having a chain or cyclic ether bond such as acrylate, cyclic trimethylolpropaneformal (meth) acrylate; N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethyl (meth) acrylamide, N-methylol. (Meta) acrylamide, N-isopropyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, diacetone (meth) acrylamide, (meth) acryloylmorpholine, N- (meth) acryloyloxyethyl hexahydrophthalimide, etc. Monomer having a nitrogen atom; Monomer having an isocyanate group such as 2- (meth) acryloyloxyethyl isocyanate; Glysidyl (meth) acrylic Monomers with epoxy groups such as relate, 4-hydroxybutyl (meth) acrylate glycidyl ether; Monomers with phosphorus atoms such as 2-((meth) acryloyloxy) ethyl phosphate; 3- (meth) acryloxypropyltrimethoxy Monomers with silicon atoms such as silane; 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3,3-pentafluoropropyl (meth) acrylate, 2- (perfluorohexyl) ethyl ( Monomers having a fluorine atom such as meta) acrylate; (meth) acrylic acid, monosuccinate (2- (meth) acryloyloxyethyl), mono-phthalate (2- (meth) acryloyloxyethyl), mono (2) maleate. Examples thereof include monomers having a carboxyl group such as − (meth) acryloyloxyethyl) and ω-carboxy-polycaprolactone mono (meth) acrylate.

Examples of the polyfunctional compound include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, and 1,4-butanediol di (meth). Acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, glycerin di (meth) acrylate, glycerin tri (meth) acrylate, glycerin propoxytri (meth) acrylate, trimethylol Etantri (meth) acrylate, trimethylolpropantri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol di (meth) acrylate monostearate, dipentaerythritol penta (meth) Acrylate, dipentaerythritol hexa (meth) acrylate, neopentyl glycol di (meth) acrylate of hydroxypivalate, tricyclodecanedimethanol di (meth) acrylate, 2,2-bis (4- (meth) acryloxiethoxyphenyl) Propane, 2,2-bis (4- (meth) acryloxypolyethoxyphenyl) propane, 9,9-bis (4- (2- (meth) acryloyloxyethoxy) phenyl) fluorene, 9,9-bis (4) -Ester compound of polyhydric alcohol such as 2- (2- (2- (meth) acryloyloxyethoxy) ethoxy) phenyl) fluorene and (meth) acrylic acid; bis (4- (meth) acryloyloxyphenyl) sulfide, bis ( 4- (Meta) acryloylthiophenyl) sulfide, tris (2- (meth) acryloyloxyethyl) isocyanurate, ethylenebis (meth) acrylamide, zinc (meth) acrylate, zirconium (meth) acrylate, aliphatic urethane acrylate , Aromatic urethane acrylate, epoxy acrylate, polyester acrylate and the like.

The (meth) acrylic acid esters are used from the viewpoints of improving the sensitivity of the polymerizable composition, reducing oxygen inhibition, and improving the mechanical strength, hardness, heat resistance, durability, and chemical resistance of the coating film of the cured product. Therefore, the ester compound of the polyhydric alcohol and (meth) acrylic acid is preferable, and in particular, trimethylol ethanetriacrylate, trimethylol propantriacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol pentaacrylate. Pentaerythritol hexaacrylate is preferred.

A copolymer obtained from the polymerizable compound can be added to the polymerizable composition.

The content of the polymerization initiator mixture is preferably 0.1 to 40 parts by mass, more preferably 0.5 to 20 parts by mass, and 1 to 20 parts by mass with respect to 100 parts by mass of the polymerizable compound. It is more preferably 15 parts by mass. The content of the polymerization initiator mixture is not preferable if it is less than 0.1 parts by mass with respect to 100 parts by mass of the polymerizable compound because the curing reaction does not proceed. When the content of the polymerization initiator mixture is more than 40 parts by mass with respect to 100 parts by mass of the polymerizable compound, the solubility in the polymerizable compound reaches saturation, and when the polymerizable composition is formed, the solubility is reached. It is preferable because crystals of the polymerization initiator mixture may precipitate and the surface of the film may be roughened, or the strength of the coating film of the cured product may decrease due to an increase in the decomposition residue of the polymerization initiator mixture. No.

<Pigment>
By blending a pigment, the polymerizable composition can be suitably used as a coating agent, a paint, a printing ink, a photosensitive printing plate, an adhesive, various photoresists such as a color resist and a black resist, and the like. The pigments include yellow pigments, blue pigments, and red pigments that are generally used in applications such as coating agents, paints, printing inks, photosensitive printing plates, adhesives, and various photo resists such as color resists and black resists. , White pigment, black pigment, carbon black and the like can be used and are not particularly limited. The pigment may be used alone or in combination of two or more.

When the pigment is used, the proportion of the pigment is preferably about 10 to 90% by mass, more preferably about 20 to 50% by mass, based on the total solid content of the polymerizable composition. If the content of the pigment is too small, sufficient colorability may not be obtained, and conversely, if the content of the pigment is too large, the strength of the cured film and the image forming property may be deteriorated.

<Alkali-soluble resin>
The polymerizable composition can be suitably used as a negative resist by blending an alkali-soluble resin. As the alkali-soluble resin, those generally used for negative resists can be used, and the resin is not particularly limited as long as it is soluble in an aqueous alkali solution, but a resin containing a carboxyl group is preferable. The alkali-soluble resin may be used alone or in combination of two or more.

As the alkali-soluble resin, for example, a carboxyl group-containing (meth) acrylic acid ester copolymer, a carboxyl group-containing epoxy acrylate resin, or the like is preferably used.

The carboxyl group-containing (meth) acrylic acid ester copolymer includes at least one selected from the monofunctional compounds of the (meth) acrylic acid esters (excluding the monomer having the carboxyl group) and (meth). ) Acrylic acid, (meth) acrylic acid dimer, itaconic acid, crotonic acid, maleic acid, fumaric acid, vinyl benzoic acid, cinnamic acid, monosuccinate (2- (meth) acryloyloxyethyl), monophthalate Ethyl unsaturated groups such as (2- (meth) acryloyloxyethyl), mono (2- (meth) acryloyloxyethyl), ω-carboxy-polycaprolactone mono (meth) acrylate, and their acid anhydrides. It is a copolymer containing at least one selected from the contained carboxylic acids.

Examples of the carboxyl group-containing (meth) acrylic acid ester copolymer include a copolymer of methyl methacrylate, cyclohexyl methacrylate, and methacrylic acid. Further, styrene, α-methylstyrene, N-vinyl-2-pyrrolidone, N-methylmaleimide, N-phenylmaleimide, N-cyclohexylmaleimide, diethyl fumarate, diethyl itaconic acid and the like may be copolymerized.

Further, the carboxyl group-containing (meth) acrylic acid ester copolymer is a reaction of an ethylenically unsaturated group or the like from the viewpoint of achieving both the developability of a negative resist and the coating properties such as heat resistance, hardness and chemical resistance. Carboxyl group-containing (meth) acrylic acid ester copolymers in which a sex group is introduced into the side chain are also preferably used. As a method for introducing an ethylenically unsaturated group into the above side chain, for example, a part of the carboxyl group of the carboxyl group-containing (meth) acrylic acid ester copolymer has an epoxy group in the molecule such as glycidyl (meth) acrylate. And a method of adding a compound having an ethylenically unsaturated group, or a method of adding an ethylenically unsaturated group-containing monocarboxylic acid such as methacrylic acid to an epoxy group and a carboxyl group-containing (meth) acrylic acid ester copolymer. , A method of adding a compound having an isocyanate group and an ethylenically unsaturated group in a molecule such as 2- (meth) acryloyloxyethyl isocyanate to a (meth) acrylic acid ester copolymer containing a hydroxyl group and a carboxyl group can be mentioned. ..

As the carboxyl group-containing epoxy acrylate resin, a compound obtained by further reacting an acid anhydride with an epoxy acrylate resin which is a reaction product of an epoxy compound and the ethylenically unsaturated group-containing carboxylic acid is preferable.

Examples of the epoxy resin include (o, m, p-) cresol novolac type epoxy resin, phenol novolac type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, trisphenol methane type epoxy resin, and bisphenyl fluorene. Examples include type epoxy resins. The epoxy resin may be used alone or in combination of two or more.

Examples of the acid anhydride include maleic anhydride, succinic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, and chloreindic anhydride. , Trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic acid dianhydride, biphenyltetracarboxylic acid dianhydride, itaconic anhydride and the like.

Further, in the synthesis of the carboxyl group-containing epoxy acrylate resin, if necessary, a tricarboxylic acid anhydride such as trimellitic anhydride is used to hydrolyze the acid anhydride group remaining after the reaction to obtain a carboxyl group. Can be increased. Further, the ethylenically double bond can be further increased by using maleic anhydride containing an ethylenically unsaturated group.

The acid value of the alkali-soluble resin is preferably 20 to 300 mgKOH / g, more preferably 40 to 180 mg / KOH. When the acid value is less than 20 mgKOH / g, the solubility in an alkaline aqueous solution is poor, which makes it difficult to develop the unexposed portion, which is not preferable. Further, when the acid value is more than 300 mgKOH / g, the exposed portion tends to be easily separated from the substrate during development, which is not preferable.

The weight average molecular weight of the alkali-soluble resin is preferably 1,000 to 100,000, preferably 1,500 to 30,000. If the weight average molecular weight is smaller than 1,000, the heat resistance and hardness of the exposed portion are poor, which is not preferable. If the weight average molecular weight is larger than 100,000, it may be difficult to develop the unexposed portion, which is not preferable. The weight average molecular weight can be measured by a gel permeation chromatography (GPC) method. As an example, using HLC-8220GPC (manufactured by Tosoh) as a GPC device and three TSKgelHZM-M (manufactured by Tosoh) as columns, tetrahydrofuran as a developing solvent, column temperature 40 ° C., flow velocity 0.3 ml / min. , RI detector, sample injection concentration 0.5% by mass, injection amount 10 microliters, chromatography can be performed to obtain the weight average molecular weight in terms of polystyrene.

The proportion of the alkali-soluble resin is preferably 10 to 70% by mass, more preferably 15 to 60% by mass, based on the total solid content of the polymerizable composition. If the ratio is less than 10% by mass, the developability is poor, which is not preferable. If the ratio is more than 70% by mass, the reproducibility of the pattern shape and the heat resistance are lowered, which is not preferable.

As the alkali-soluble resin, an alkali-soluble resin which is an active ingredient after the synthesis reaction can be isolated and purified, or a reaction solution obtained by the synthesis reaction, a dried product thereof, or the like can be used as it is. ..

<Other ingredients>
By using a curing accelerator as the other component, the polymerizable composition can be cured by heating at a low temperature. As the curing accelerator, for example, an amine compound, a thiourea compound, a 2-mercaptobenzimidazole compound, an orthobenzoixulfimide, a fourth period transition metal compound and the like can be used. The curing accelerator may be used alone or in combination of two or more.

The amine compound is preferably a tertiary amine, for example, N, N-dimethylaniline, N, N-dimethyltoluidine, N, N-diethylaniline, N, N-bis (2-hydroxyethyl) -p-. Examples thereof include toluidine, ethyl 4- (dimethylamino) benzoate, ethyl 4-dimethylaminobenzoate (2-methacryloyloxy) and the like.

Examples of the thiourea include acetylthiourea, N, N'dibutylthiourea and the like.

Examples of the 2-mercaptobenzimidazole compound include 2-mercaptobenzimidazole, 2-mercaptomethylbenzimidazole, 2-mercaptomethoxybenzimidazole and the like.

The fourth cycle transition metal compound can be selected from organic acid salts such as vanadium, cobalt and copper or metal chelate compounds, for example, cobalt octylate, cobalt naphthenate, copper naphthenate, vanadium naphthenate and copper. Examples thereof include acetylacetonate, manganese acetylacetonate, vanadylacetylacetonate and the like.

The curing accelerator is preferably blended immediately before using the polymerizable composition. The content of the curing accelerator is preferably 0.1 to 20 parts by mass, and more preferably 0.2 to 10 parts by mass with respect to 100 parts by mass of the polymerizable compound.

As the other components, the polymerizable composition is generally used in applications such as coating agents, paints, printing inks, photosensitive printing plates, adhesives, and various photoresists such as color resists and black resists. Additives can be added. Examples of the additive include a polymerization inhibitor (p-methoxyphenol, hydroquinone, 2,6-di-t-butyl-4-methylphenol, phenothiazine, etc.), an ultraviolet absorber, an infrared absorber, a chain transfer agent, and light. Stabilizers, antioxidants, leveling agents, surface conditioners, surfactants, thickeners, defoaming agents, adhesion promoters, plasticizers, epoxy compounds, thiol compounds, resins with ethylenically unsaturated bonds, saturated resins , Coloring dyes, fluorescent dyes, carbon-based materials (carbon fibers, carbon black, graphite, graphitized carbon black, activated carbon, carbon nanotubes, fullerene, graphene, carbon microcoils, carbon nanohorns, carbon aerogels, etc.), metal oxides (oxidation) Examples include titanium, iridium oxide, zinc oxide, alumina, silica, etc.), metals (silver, copper, etc.), inorganic compounds (glass powder, layered viscous minerals, mica, talc, calcium carbonate, etc.), dispersants, flame retardants, etc. .. The additive may be used alone or in combination of two or more.

The content of the additive is appropriately selected according to the purpose of use and is not particularly limited, but is usually preferably 500 parts by mass or less with respect to 100 parts by mass of the polymerizable compound, and 100 parts by mass. It is more preferable that the content is parts by mass or less.

A solvent may be further added to the polymerizable composition in order to improve the viscosity, coatability, and smoothness of the cured film. The solvent is one that can dissolve or disperse components such as the polymerization initiator mixture and the polymerizable compound, and is not particularly limited as long as it is a solvent that volatilizes at a drying temperature.

Examples of the solvent include water, alcohol-based solvent, carbitol-based solvent, ester-based solvent, ketone-based solvent, ether-based solvent, lactone-based solvent, unsaturated hydrocarbon-based solvent, cellosolve acetate-based solvent, and carbitol acetate-based solvent. Examples thereof include a solvent, propylene glycol monomethyl ether acetate, and diethylene glycol dimethyl ether. The solvent may be used alone or in combination of two or more.

The amount of the solvent used is preferably 10 to 1000 parts by mass, more preferably 20 to 500 parts by mass, based on 100 parts by mass of the solid content of the polymerizable composition.

<Method for preparing polymerizable composition>
When preparing the polymerizable composition, components such as the polymerization initiator mixture, the polymerizable compound, and if necessary, the pigment are charged into a storage container, and a paint shaker, a bead mill, a sand grind mill, etc. It may be dissolved or dispersed according to a conventional method using a ball mill, an attritor mill, a two-roll mill, a three-roll mill, or the like. Further, if necessary, it may be filtered through a mesh or a membrane filter or the like.

In the preparation of the polymerizable composition, the polymerization initiator mixture may be added to the polymerizable composition from the beginning, but it is used when the polymerizable composition is stored for a relatively long time. Immediately before, the polymerization initiator mixture is preferably dissolved or dispersed in the composition containing the polymerizable compound.

<Manufacturing method of cured product>
The cured product of the present invention is formed from the polymerizable composition. The method for producing a cured product includes one of a step of applying the polymerizable composition on a substrate and then irradiating the polymerizable composition with an active energy ray, and a step of heating the polymerizable composition. The method. Further, a step including both the step of irradiating with the active energy ray and the step of heating is also referred to as a dual cure step.

Examples of the coating method include spin coating method, bar coating method, spray coating method, dip coating method, flow coating method, slit coating method, doctor blade coating method, gravure coating method, screen printing method, offset printing method, and inkjet. Various methods such as a printing method and a dispenser printing method can be mentioned. Further, examples of the substrate include films and sheets such as glass, silicon wafers, metals and plastics, and three-dimensional molded products, and the shape of the substrate is not limited.

In the step of irradiating the above polymerizable composition with an active energy ray, the polymerization initiator mixture is decomposed by irradiation with an active energy ray such as an electron beam, ultraviolet rays, visible light, or radiation to polymerize the polymerizable compound. Therefore, a cured product can be obtained.

The active energy ray is preferably light having a wavelength of 250 to 450 nm, and more preferably 350 to 410 nm from the viewpoint of rapid curing.

Examples of the light source for irradiating the light include solid-state lasers such as low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, ultraviolet electrode-free lamps, LED lamps, xenon arc lamps, carbon arc lamps, sunlight, and YAG lasers. , A gas laser such as a semiconductor laser or an argon laser can be used. When visible light to infrared light that absorbs less of the polymerization initiator mixture is used, curing can be performed by using a sensitizer that absorbs the light as the additive.

The exposure amount of the active energy ray should be appropriately set according to the wavelength and intensity of the active energy ray and the composition of the polymerizable composition. As an example, the exposure amount in the UV-A region ^{is preferably 10 to 5,000 mJ / cm 2} , and more preferably 30 to 1,000 mJ / cm ² . When the dual cure step is applied as the method for producing the cured product and the step of heating is performed after the step of irradiating with the active energy rays, the polymerization initiator mixture is completely decomposed by the active energy rays. The exposure amount should be set appropriately so as not to cause this.

In the step of heating the above-mentioned polymerizable composition, a cured product can be obtained by decomposing the polymerization initiator mixture by heat and polymerizing the polymerizable compound.

In the step of heating the polymerizable composition, examples of the heating method include heating, ventilation heating and the like. The heating method is not particularly limited, and examples thereof include an oven, a hot plate, infrared irradiation, and electromagnetic wave irradiation. Further, as a method of ventilation heating, for example, a ventilation type drying oven or the like can be mentioned.

In the step of heating the polymerizable composition, the higher the heating temperature, the faster the decomposition rate of the polymerization initiator mixture. However, if the decomposition rate is too fast, the decomposition residue of the polymerizable compound tends to increase. On the other hand, the lower the heating temperature, the slower the decomposition rate of the polymerization initiator mixture, and therefore a longer time is required for curing. Therefore, the heating temperature and the heating time should be appropriately set according to the composition of the polymerizable composition. As an example, the heating temperature is preferably 50 to 230 ° C, more preferably 100 to 200 ° C. When the curing accelerator is added to the polymerizable composition, the heating temperature can be arbitrarily adjusted from room temperature to 160 ° C. depending on the type and amount of the curing accelerator. On the other hand, the heating time is preferably 1 to 180 minutes, more preferably 5 to 120 minutes.

When the dual cure step is applied as a method for producing the cured product, in particular, a step of heating the polymerizable composition after the step of irradiating the polymerizable composition with an active energy ray is a coloring pigment that absorbs or scatters light. It is preferable because it is possible to efficiently cure the deep part of the coating film of the polymerization composition containing a high concentration of light and the portion where the light is blocked and the light does not reach.

When the polymerization composition contains the solvent, the method for producing the cured product can include a drying step. In particular, when the step of irradiating the polymerizable composition on the substrate and then irradiating with the active energy ray is applied, it is preferable to provide a drying step before the step of irradiating with the active energy ray.

Examples of the method for drying the solvent in the drying step include heat drying, ventilation heating drying, and vacuum drying. The heat-drying method is not particularly limited, and examples thereof include an oven, a hot plate, infrared irradiation, and electromagnetic wave irradiation. Further, as a method of ventilation heating and drying, for example, a ventilation type drying oven and the like can be mentioned.

Further, in the drying step, the temperature of the polymerizable composition becomes lower than the set temperature of drying due to the latent heat of vaporization of the solvent, so that a long time until the polymerizable composition gels can be secured. Since the time until gelation is affected by the drying method, film thickness, etc., the drying temperature and time should be appropriately set including the selection of the solvent. As an example, the drying temperature is preferably 20 to 120 ° C, more preferably 40 to 100 ° C. The drying time is preferably 1 to 60 minutes, more preferably 1 to 30 minutes. Further, by using the polymerization inhibitor, it is possible to secure a long time until gelation.

The dry film thickness (film thickness of the cured product) of the polymerizable composition is appropriately set depending on the intended use, but is preferably 0.05 to 500 μm, more preferably 0.1 to 100 μm. ..

<Pattern formation method>
When the polymerizable composition contains the alkali-soluble resin, a pattern can be formed by a photolithography method. The polymerizable composition is applied to the substrate in the same manner as described above, and if necessary, dried to form a dry film. Then, by irradiating the dry film with active energy rays through a mask, the polymerizable compound is polymerized in the exposed portion to form a cured film. On the other hand, it is also possible to produce a highly accurate pattern shape without using a mask by direct drawing using a laser.

After the above exposure, the unexposed portion is developed and removed with an alkaline developer such as 0.3 to 3% by mass of sodium carbonate aqueous solution to obtain a patterned cured film. Further, for the purpose of improving the adhesion between the cured film and the base material, post-baking is performed at 180 to 250 ° C. and 20 to 90 minutes as post-drying. In this way, a desired pattern based on the cured film is formed.

The polymerization initiator mixture of the present invention is a printing ink such as offset printing ink, gravure printing ink, screen printing ink, inkjet printing ink, conductive ink, insulating ink, light guide plate ink; photosensitive printing plate; nanoimprint material; Resins for 3D printers; hard coating agents, coating agents for optical disks, coating agents for optical fibers, paints for mobile terminals, paints for home appliances, paints for cosmetic containers, paints for woodwork, internal antireflection paints for optical elements, high / low refractive index Paints / coating agents such as coating agents, heat-shielding coating agents, heat-dissipating coating agents, antifogging agents; holographic recording materials; dental materials; waveguide materials; black stripes for lens sheets; green sheets and electrode materials for capacitors; FPD Adhesives for, HDD adhesives, optical pickup adhesives, image sensor adhesives, organic EL sealants, touch panel OCA, touch panel OCR adhesives / sealants; color resists, black resists, color filters Protective film, photo spacer, black column spacer, frame resist, photoresist for TFT wiring, resist for FPD such as interlayer insulating film; resist for printed substrate such as liquid solder resist, dry film resist; semiconductor resist, buffer coat film, etc. It can be used for various purposes such as materials for semiconductors, and there is no particular limitation on the application.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(1) Preparation of polymerizable composition <Preparation of polymerizable composition (A)>
The amount of the polymerizable compound (b) shown in Table 1 and the mixture of the (a) polymerization initiator were added and stirred well to obtain the polymerizable compositions (A) of Examples 1 to 7 and Comparative Examples 1 to 6. Prepared.

In Table 1, DPGDA indicates dipropylene glycol diacrylate (Wako Pure Chemical Industries, Ltd. reagent);

<Preparation of polymerizable composition (B)>
The amounts of (b) polymerizable compound and (c) pigment shown in Table 2 were mixed and stirred, and (a) a mixture of polymerization initiators was added and stirred well. A polymerizable composition (B) was prepared.

In Table 2, the black pigments are 3,7-bis (2-oxo-1H-indole-3 (2H) -iriden) benzo [1,2-b: 4,5-b'] difuran-2,6- (3H, 7H) -dione; is shown.

<Preparation of polymerizable composition (C)>
The amounts of (b) the polymerizable compound, (d) the alkali-soluble resin, and other components shown in Table 3 were mixed and stirred, and (a) the polymerization initiator mixture was added and stirred well. And the polymerizable composition (C) of Comparative Example 13 was prepared.

In Table 3, DPHA is a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (trade name: Aronix M-402, manufactured by Toagosei Co., Ltd.);
RD200 is a copolymer of methyl methacrylate / methacrylic acid / cyclohexyl maleimide (mass%: 61/14/25), weight average molecular weight: 17,000, acid value: 90 (synthetic product);
F-477 is a fluorine-based leveling agent (trade name: Megafuck F-477, manufactured by DIC Corporation);
PGMEA represents propylene glycol monomethyl ether acetate (Wako Pure Chemical Industries, Ltd. reagent);

(2) Evaluation of sensitivity by LED lamp with wavelength of 385 nm (clear coating)
<Examples 1 to 7, Comparative Examples 1 to 6>
The polymerizable composition (A) prepared above was applied to a PET film (Cosmo Shine A4300, manufactured by Toyobo Co., Ltd.) that had been subjected to an easy-adhesion treatment using a bar coater (# 6) to a thickness of 10 μm. A uniform coating film was prepared. Next, an LED lamp having a wavelength of 385 nm (UniJet E110III, manufactured by Ushio, Inc.) was used to irradiate light at ^{1000 mJ / cm 2.} The degree of curing (%) of the cured film portion was measured by attenuated total reflection infrared spectroscopy (ATR-IR). At that time, using the peak areas of the absorption spectrum of the out-of-plane variable angle vibration of the double bond group (810 cm ^-1 ) and the absorption spectrum of the carbonyl group that does not change before and after exposure (1740 cm ^-1 ), based on the following equation. The curing rate (curing degree) was calculated. The results are shown in Table 4.

(3) Evaluation of sensitivity by LED lamp with wavelength of 385 nm (black ink)
<Examples 8 to 14, Comparative Examples 7 to 12>
The polymerizable composition (B) prepared above was applied to a PET film (Cosmo Shine A4300, manufactured by Toyobo Co., Ltd.) that had been subjected to an easy-adhesion treatment using a bar coater (# 6) to a thickness of 10 μm. A uniform coating film was prepared. Next, an LED lamp having a wavelength of 385 nm (UniJet E110III, manufactured by Ushio, Inc.) was used to irradiate light at ^{1000 mJ / cm 2.} The degree of curing (%) of the cured film portion was measured by attenuated total reflection infrared spectroscopy (ATR-IR). The curing rate (curing degree) was calculated based on the above formula. The results are shown in Table 5.

(3) Evaluation of Sensitivity by Ultra High Pressure Mercury Lamp <Examples 15 to 16, Comparative Example 13>
The polymerizable composition (C) prepared above was applied onto an aluminum substrate using a spin coater. After coating, the aluminum substrate was dried in a clean oven at 90 ° C. for 2.5 minutes to dry the solvent to prepare a uniform coating film having a thickness of 1.5 μm. Next, stepwise exposure was performed in the range of ^{10 to 1000 mJ / cm 2} via a mask pattern using a proximity exposure machine using an ultra-high pressure mercury lamp as a light source. The exposed aluminum substrate was immersed in a 1.0 mass% sodium carbonate aqueous solution at 23 ° C. for 60 seconds to remove the unexposed portion by development. Subsequently, it was washed with pure water for 30 seconds to obtain a pattern shape. The minimum exposure amount at which the pattern shape was formed was evaluated as "sensitivity". The evaluation results of each (a) polymerization initiator mixture are shown in Table 6.

In Table 7 above, HK is 1-hydroxycyclohexylphenyl ketone;
BAPO is a phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide;
MAPO is diphenyl-2,4,6-trimethylbenzoylphosphine oxide;
AK1 is 2-methyl-4'-methylthio-2-morpholinopropiophenone;
AK2 is 2-benzyl-2- (N, N-dimethylamino) -1- (4-morpholinophenyl) butane-1-one;
AK3 is 2- (dimethylamino) -2- (4-methylbenzyl) -1- (4-morpholinophenyl) butane-1-one;
OXIME is 1- [4- (phenylthio) phenyl] octane-1,2-dione-2- (O-benzoyloxime);
TX is the following compound 1 (2- (1-tert-butylperoxy-1-methylethyl) -9H-thioxanthene-9-one);
EMK represents 4,4'-bis (diethylamino) benzophenone;

<Synthesis of dialkyl peroxide with thioxanthone skeleton>
[Synthesis Example 1: Synthesis of Compound 1]
30 mL of benzene, 6.10 g (24.0 mmol) of 2-isopropylthioxanthone, and 0.0238 g (0.24 mmol) of copper (I) chloride were placed in a 200 mL four-necked flask and stirred at room temperature. 15.7 g (120 mmol) of a 69 mass% tert-butyl hydroperoxide aqueous solution was gradually added. The mixture was heated to 65 ° C. under a nitrogen stream and reacted for 60 hours. The reaction mixture was cooled, 20 mL of ethyl acetate was added, and then the aqueous phase was separated. The oil phase was washed with 5% by mass hydrochloric acid, 5% by mass aqueous sodium hydroxide solution and ion-exchanged water, and dried over anhydrous magnesium sulfate. After filtration, the oil phase was concentrated under reduced pressure to obtain a crude product. The crude product was purified by silica gel column chromatography (n-hexane / ethyl acetate = 5/1) to obtain 2.55 g (yield 31%) of Compound 1. Table 8 shows the analysis results of the obtained compound 1 by EI-MS and ^{1 1 H-NMR.}

Claims (8)

General formula (1):

(In formula (1), R ¹ , R ² , R ³ and R ⁴ independently represent a methyl group or an ethyl group, R ⁵ represents an alkyl group or a phenyl group having 1 to 6 carbon atoms, and R ⁶ Is an independent substituent and represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a chlorine atom, and n represents an integer from 0 to 2). With dialkylperoxide having
A polymerization initiator mixture containing a photopolymerization initiator other than the dialkyl peroxide having a thioxanthone skeleton. A claim, wherein the photopolymerization initiator is at least one photopolymerization initiator selected from the group consisting of a radical-based photopolymerization initiator, a cationic photopolymerization initiator, and an anionic photopolymerization initiator. 1. The polymerization initiator mixture according to 1. The polymerization initiator mixture according to claim 1 or 2, which comprises a sensitizer. A polymerizable composition containing the polymerization initiator mixture according to any one of claims 1 to 3 and a polymerizable compound. The polymerizable composition according to claim 4, further comprising a pigment. A cured product, which is formed from the polymerizable composition according to claim 4 or 5. The method for producing a cured product according to claim 6, further comprising a step of irradiating the polymerizable composition with an active energy ray. The method for producing a cured product according to claim 7, further comprising a step of heating after the step of irradiating with the active energy ray.