Novel heterocyclic ring-containing monomer

Abstract

To provide a radically polymerizable compound which is used as a transparent resin ingredient suitable for optical applications and which not only exhibits excellent curability but also has a low viscosity and, when cured, yields a polymer that has excellent flexibility and a high refractive index.SOLUTION: Provided is a (meth)acrylic acid ester having a thiadiazole ring represented by the general formula (1) in the figure. (In the general formula (1), A denotes an oxygen atom or a sulfur atom, n denotes an integer from 1 to 6, R1 denotes a linear or branched alkyl group having 1 to 6 carbon atoms, and R2 denotes a hydrogen atom or a methyl group.)SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a (meth)acrylic acid ester and a polymerization method thereof, and more particularly to a (meth)acrylic acid ester having a thiadiazole ring and a polymerization method thereof. [Background technology]

[0002] (Meth)acrylic acid esters are known as representative radical polymerizable compounds. Such (meth)acryloyl groups have double bonds activated by conjugation with adjacent carbonyl groups, and these double bonds polymerize by radical polymerization to produce polymers. (Meth)acrylic acid esters are excellent in terms of polymerization speed, internal curing properties, durability of the chemical bonds formed, and economy, and are therefore used in a wide range of applications, such as photosensitive resins, coating materials, adhesives, sealants, adhesives, pressure sensitive adhesives, paints, inks, rubber vulcanizing agents, resists, dental materials, optical lenses, molding materials, and reactive diluents.

[0003] In addition, the polymer is widely used in various fields such as optical materials, vehicle parts, lighting materials, and building materials due to its excellent transparency, dimensional stability, and weather resistance. In recent years, in electronic materials, particularly in display-related fields, it has been proposed to use optical films such as light extraction films as substrates in order to further increase the light-emitting efficiency, and (meth)acrylic acid esters are used as monomers for such films. By including this (meth)acrylic acid ester polymer, it is possible to provide the polymer with excellent shapeability, processability, and moldability, adhesion, and flexibility in addition to high transparency.

[0004] Such optical films are often made up of several types of laminated films, or an inorganic film is laminated in contact with the optical film. In such cases, if there is a large difference in the refractive index between the films or between the films and the adhesive, light will be reflected at the interface between the layers, causing halation and poor visibility. For this reason, it is important to minimize the difference in refractive index between each layer or adhesive. In addition, since these optical films are generally often laminated with inorganic layers that have a high refractive index, there is a demand for the refractive index of the film itself to be high. For example, the refractive index (n D ) is about 2.1.

[0005] On the other hand, various high refractive index glasses have been developed, but they are fragile and difficult to use as optical films, and high refractive index materials containing inorganic particles have problems such as transparency and the difficulty of maintaining a high dispersion state without the inorganic particles agglomerating. Therefore, expectations are high for a polymerized film of (meth)acrylic acid ester that has the same transparency as glass, but the refractive index (n D For example, the refractive index (n D ) is known to be around 1.49. Therefore, there is a demand for a method to increase the refractive index of (meth)acrylic esters and their polymers while taking advantage of the properties of acrylic resins, such as transparency, adhesion, flexibility, and processability.

[0006] Attempts to increase the refractive index of (meth)acrylic esters include the introduction of aromatic rings and the introduction of heavy atoms such as sulfur atoms and bromine atoms as a means of generally increasing the refractive index of organic substances. However, monomers having polycyclic aromatic rings such as biphenyl, naphthalene, fluorene, and anthracene in their molecular structure are expected to have a high refractive index, but in most cases they become high-viscosity liquids or crystalline solids, which causes a problem of reduced handling properties such as solubility. Generally, compounds with high refractive indexes are often solid or highly viscous compounds, and there are few compounds that have both, and it is difficult to know whether a compound has both properties without synthesizing it. As one of these attempts, many attempts to introduce sulfur atoms and the like have been considered. For example, Patent Document 1 aims to increase the refractive index by introducing an aromatic ring via a sulfur atom. Patent Document 2 discloses a polymerizable composition mainly composed of a thio(meth)acrylate monomer, and discloses bis[(4-methacryloylthio)phenyl] sulfide and the like. Patent Document 3 discloses a compound having a methylthiophenyl group as a novel (meth)acrylic acid ester for dilution, which has a low viscosity, a high refractive index, and a homopolymer with high heat resistance. Patent Document 4 discloses a polymerizable composition that uses a (meth)acrylate compound containing a sulfide compound and a sulfur compound, and uses zirconium oxide nanocrystals as metal compound nanocrystals, as a liquid curable ink composition that can form a cured product with a high refractive index and is applicable to the inkjet method.

[0007] Furthermore, Patent Document 5 discloses a (meth)acrylic acid ester having a condensed ring selected from the group consisting of a naphthalene ring, an anthracene ring, a benzothiazole ring, a benzoxazole ring, a benzimidazole ring, a fluorene ring, and a phenanthrene ring, as a polymerizable compound having a high refractive index, high solubility in a polymerizable compound having an aromatic ring, and high visible light transmittance of the cured product. Patent Document 6 discloses a (meth)acrylic acid ester having an aryl group or a heteroaryl group as a method for producing a high refractive index symmetrical (meth)acrylic acid ester, and a compound having a mercaptobenzothiazole group as the heteroaryl group. Similarly, Patent Document 7 discloses a (meth)acrylic acid ester compound having a benzothiazole ring as a sulfur atom-containing (meth)acrylic acid ester. The structure of any of these compounds is different from that of the compound of the present invention.

[0008] Furthermore, Patent Document 8 discloses a compound in which an aromatic ring or an aromatic heterocycle is introduced into three of the four molecular chains of a quaternary carbon of a pentaerythritol skeleton, and a (meth)acrylic group is introduced into the remaining one. As aromatic heterocycles, benzoxazole ring, thienoxazole ring, thiazolooxazole ring, oxazolooxazole ring, oxazoloimidazole ring, oxazolopyridine ring, oxazolopyridazine ring, oxazolopyrimidine ring, oxazolopyrazine ring, naphthoxazole ring, quinolinoxazole ring, dioxazolopyrazine ring, phenoxazine ring, benzothiazole ring, furothiazole ring, thienothiazole ring, thiazolothiazole ring, thiazoloimidazole ring, thienothiadiazole ring, thiazolothiadiazole ring, thiazolopyridine ring, thiazolopyridazine ring, thiazolopyrimidine ring, thiazolopyrazine ring, naphthothiazole ring, quinolinothiazole ring, and phenothiazine ring are disclosed. Among them, thiazolothiadiazole ring is disclosed, but no specific compound is disclosed, and no physical properties are described. In addition, since it is based on a pentaerythritol skeleton, its basic structure is different from that of the compound of the present invention.

[0009] Patent Document 9 discloses a low-viscosity curable resin composition capable of producing a cured product with excellent impact resistance, and discloses a compound having a (meth)acryloyl group and a heterocycle as a radically polymerizable compound having a radically polymerizable functional group, and discloses residues of thiazole, isothiazole, thiadiazole, benzothiazole, thiatriazole, phenothiazine, thiazine, etc. as a heterocycle group containing a nitrogen atom, an oxygen atom, and a sulfur atom as heteroatoms. However, although thiadiazole is disclosed, there are no examples of specific compounds, no description of its physical properties, and no description of characteristics specific to thiadiazole.

[0010] Patent Document 10 discloses an adduct of dimercaptothiadiazole with acrylate as an additive for wear resistance / oxidation resistance, but the adduct has a structure in which a mercapto group is added to the double bond of the acrylate, and is not an acrylate ester.

[0011] Patent Documents 11 and 12 disclose a polyfunctional (meth)acrylate having a heteroarylene group, which is a monofunctional acrylate and a monomer having a high refractive index, and a high refractive index composition is prepared by combining the polyfunctional (meth)acrylate with a heteroarylene group. The document discloses a compound (1,3,4-thiadiazole-2,5-diyl)bis(sulfanediyl)bis(ethane-2,1-diyl)diacrylate) in which two acrylate groups are substituted on a thiadiazole ring. This polyfunctional (meth)acrylate has a lower refractive index than para-thiophenylbenzyl acrylate, and the refractive index of the composition is reduced by adding the polyfunctional (meth)acrylate. For this reason, as described in the document, the polyfunctional (meth)acrylate functions as a crosslinking agent and is used to prevent the polymer from becoming non-flexible. In addition, 1,3,4-thiadiazole-2,5-diyl)bis(sulfanediyl)bis(ethane-2,1-diyl)diacrylate cannot be added in large amounts due to its high viscosity, and as described in the document, it is used in an amount of 10% by weight or less of the curable composition. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] JP 2020-37693 A [Patent Document 2] Japanese Patent Application Publication No. 9-25321 [Patent Document 3] JP 2017-190326 A [Patent Document 4] JP 2021-31669 A [Patent Document 5] JP 2018-104696 A [Patent Document 6] JP 2012-82145 A [Patent Document 7] JP 2023-32499 A [Patent Document 8] JP 2017-14213 A [Patent Document 9] JP 2021-172823 A [Patent Document 10] Japanese Patent Application Publication No. 6-505276 [Patent Document 11] JP 2020-506251 A [Patent Document 12] Patent Publication No. 2021-523281 Summary of the Invention [Problem to be solved by the invention]

[0013] The present invention provides a radically polymerizable compound which is used as a transparent resin raw material suitable for optical applications, and which not only has excellent curability but also has low viscosity, and gives a polymer obtained by curing which has excellent flexibility and a high refractive index. [Means for solving the problem]

[0014] As a result of extensive research, the inventors discovered that by using a (meth)acrylic acid ester having a specific structure as a resin raw material, it is possible to achieve both the contradictory properties of a high refractive index and low viscosity, and thus completed the present invention.

[0015] A first aspect of the present invention resides in a (meth)acrylic acid ester having a thiadiazole ring, represented by the following general formula (1).

[0016] [ka]

[0017] In the general formula (1), A represents an oxygen atom or a sulfur atom, n represents an integer of 1 to 6, and R 1 represents a linear or branched alkyl group having 1 to 6 carbon atoms; R 2 represents a hydrogen atom or a methyl group.

[0018] The second invention relates to a compound represented by the general formula (1), in which A is an oxygen atom, n is 2, and R 1 is a methyl group.

[0019] A third invention resides in a radically polymerizable composition comprising the (meth)acrylic acid ester having a thiadiazole ring according to the first or second invention, and a radical polymerization initiator.

[0020] A fourth invention resides in the radical polymerizable composition according to the third invention, further comprising a compound having an unsaturated bond other than the (meth)acrylic acid ester having a thiadiazole ring represented by general formula (1).

[0021] A fifth invention resides in the radically polymerizable composition according to the fourth invention, characterized in that the compound having an unsaturated bond is a compound having one or more unsaturated bonds selected from the group consisting of monofunctional (meth)acrylates, monofunctional (meth)acrylamides, polyfunctional (meth)acrylates, and polyfunctional (meth)acrylamides.

[0022] A sixth invention resides in the radical polymerizable composition according to the fourth invention, characterized in that the content of the (meth)acrylic acid ester having a thiadiazole ring represented by general formula (1) is 20% by weight or more.

[0023] A seventh invention resides in a method for producing a (meth)acrylic acid ester having a thiadiazole ring represented by general formula (1), comprising a first step of reacting a 1,3,4-thiadiazole compound having a thiol group represented by general formula (3) with a halogenated alcohol or a halogenated thioalcohol in the presence of a base to synthesize a compound represented by general formula (5), and a second step of (meth)acrylating the obtained compound represented by general formula (5).

[0024] [ka]

[0025] In the general formula (3), R 1 represents a straight or branched alkyl group having 1 to 6 carbon atoms.

[0026] [ka]

[0027] In the general formula (5), A represents an oxygen atom or a sulfur atom, n represents an integer of 1 to 6, and R 1 represents a straight or branched alkyl group having 1 to 6 carbon atoms.

[0028] [ka]

[0029] In the general formula (1), A represents an oxygen atom or a sulfur atom, n represents an integer of 1 to 6, and R 1 represents a linear or branched alkyl group having 1 to 6 carbon atoms; R 2 represents a hydrogen atom or a methyl group.

[0030] The eighth invention resides in a polymerization method comprising irradiating the radically polymerizable composition according to the third invention with active energy rays.

[0031] A ninth aspect of the present invention resides in the polymerization method according to the eighth aspect of the present invention, wherein the active energy rays to be irradiated have a peak wavelength in the wavelength range of 350 nm to 420 nm.

[0032] The tenth aspect of the present invention is a polymer obtained by polymerizing the radically polymerizable composition according to the first or second aspect of the present invention, and the refractive index (n D ) is present in polymers having a molecular weight of 1.55 or more.

[0033] In the present invention, (meth)acrylate means acrylate or methacrylate, (meth)acryloyl means acryloyl or methacryloyl, and (meth)acrylic means acrylic or methacrylic. In addition, the refractive index in the present invention is the refractive index (n D Furthermore, the viscosity in the present invention means a value measured at 25° C. using an E-type viscometer, unless otherwise specified. Effect of the Invention

[0034] The (meth)acrylic acid ester having a thiadiazole ring of the present invention and the radical polymerizable composition containing the (meth)acrylic acid ester having the thiadiazole ring are not only excellent in curability but also have low viscosity, and the polymer obtained by curing the radical polymerizable composition has a high refractive index. In addition, the (meth)acrylic acid ester having a thiadiazole ring of the present invention is highly compatible with various radical polymerizable compounds, and by mixing and copolymerizing with various radical polymerizable compounds, it is possible to adjust the refractive index of the polymer. Therefore, it is extremely useful in the field of optical materials as a high refractive index material and a refractive index adjuster. [Brief description of the drawings]

[0035] [Figure 1] 1H-NMR chart of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole synthesized in Synthesis Example 2. [Diagram 2] A graph showing the relationship between the ratio of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole added in a copolymer composition of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole and trimethylolpropane triacrylate and the refractive index and viscosity of the composition. The smooth line smoothly connects each of the plotted points. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] The present invention will be described in detail below.

[0037] ((Meth)acrylic acid ester having a thiadiazole ring represented by general formula (1)) The present invention relates to a (meth)acrylic acid ester having a thiadiazole ring represented by the following general formula (1).

[0038] [ka]

[0039] In the general formula (1), A represents an oxygen atom or a sulfur atom, n represents an integer of 1 to 6, and R 1 represents a linear or branched alkyl group having 1 to 6 carbon atoms; R 2 represents a hydrogen atom or a methyl group.

[0040] In the general formula (1), R 1 Specific examples of the linear or branched alkyl group having 1 to 6 carbon atoms represented by the formula (I) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, an n-pentyl group, an isopentyl group, a 2-methylbutyl group, a neopentyl group, a 1-ethylpropyl group, an n-hexyl group, a 4-methylpentyl group, a 3-methylpentyl group, a 2-methylpentyl group, a 1-methylpentyl group, a 3,3-dimethylbutyl group, a 2,2-dimethylbutyl group, a 1,1-dimethylbutyl group, and a 1,2-dimethylbutyl group.

[0041] Specific examples of the (meth)acrylic acid ester represented by the general formula (1) include 2-acryloxymethylthio-5-methylthio-1,3,4-thiadiazole, 2-methacryloxymethylthio-5-methylthio-1,3,4-thiadiazole, 2-acryloxymethylthio-5-ethylthio-1,3,4-thiadiazole, 2-methacryloxymethylthio-5-ethylthio-1,3,4-thiadiazole, 2-acryloxymethylthio-5-n-propylthio-1,3,4-thiadiazole, and 2-methacryloxymethylthio-5-n-propylthio-1,3,4-thiadiazole. ,3,4-thiadiazole, 2-acryloxymethylthio-5-isopropylthio-1,3,4-thiadiazole, 2-methacryloxymethylthio-5-isopropylthio-1,3,4-thiadiazole, 2-acryloxymethylthio-5-n-butylthio-1,3,4-thiadiazole, 2-methacryloxymethylthio-5-n-butylthio-1,3,4-thiadiazole, 2-acryloxymethylthio-5-n-pentylthio-1,3,4-thiadiazole, 2-methacryloxymethylthio-5-n-pentylthio-1,3,4-thiadiazole , 2-acryloxymethylthio-5-n-hexylthio-1,3,4-thiadiazole, 2-methacryloxymethylthio-5-n-hexylthio-1,3,4-thiadiazole, 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole, 2-methacryloxyethylthio-5-methylthio-1,3,4-thiadiazole, 2-acryloxyethylthio-5-ethylthio-1,3,4-thiadiazole, 2-methacryloxyethylthio-5-ethylthio-1,3,4-thiadiazole, 2-acryloxyethylthio-5-n- Propylthio-1,3,4-thiadiazole, 2-methacryloxyethylthio-5-n-propylthio-1,3,4-thiadiazole, 2-acryloxyethylthio-5-isopropylthio-1,3,4-thiadiazole, 2-methacryloxyethylthio-5-isopropylthio-1,3,4-thiadiazole, 2-acryloxyethylthio-5-n-butylthio-1,3,4-thiadiazole, 2-methacryloxyethylthio-5-n-butylthio-1,3,4-thiadiazole, 2-acryloxyethylthio-5-n-pentylthio-1,3,4-Thiadiazole, 2-methacryloxyethylthio-5-n-pentylthio-1,3,4-thiadiazole, 2-acryloxyethylthio-5-n-hexylthio-1,3,4-thiadiazole, 2-methacryloxyethylthio-5-n-hexylthio-1,3,4-thiadiazole, 2-acryloxy-n-propylthio-5-methylthio-1,3,4-thiadiazole, 2-methacryloxy-n-propylthio-5-methylthio-1,3,4-thiadiazole, 2-acryloxy-n-propylthio-5-ethylthio-1,3,4-thiadiazole , 2-methacryloxy-n-propylthio-5-ethylthio-1,3,4-thiadiazole, 2-acryloxy-n-propylthio-5-n-propylthio-1,3,4-thiadiazole, 2-methacryloxy-n-propylthio-5-n-propylthio-1,3,4-thiadiazole, 2-acryloxy-n-propylthio-5-isopropylthio-1,3,4-thiadiazole, 2-methacryloxy-n-propylthio-5-isopropylthio-1,3,4-thiadiazole, 2-acryloxy-n-propylthio-5-n-butylthio-1,3,4- Thiadiazole, 2-methacryloxy-n-propylthio-5-n-butylthio-1,3,4-thiadiazole, 2-acryloxy-n-propylthio-5-n-pentylthio-1,3,4-thiadiazole, 2-methacryloxy-n-propylthio-5-n-pentylthio-1,3,4-thiadiazole, 2-acryloxy-n-propylthio-5-n-hexylthio-1,3,4-thiadiazole, 2-methacryloxy-n-propylthio-5-n-hexylthio-1,3,4-thiadiazole, 2-acryloxy-n-butylthio-5-methylthio- 1,3,4-thiadiazole, 2-methacryloxy-n-butylthio-5-methylthio-1,3,4-thiadiazole, 2-acryloxy-n-butylthio-5-ethylthio-1,3,4-thiadiazole, 2-methacryloxy-n-butylthio-5-ethylthio-1,3,4-thiadiazole, 2-acryloxy-n-butylthio-5-n-propylthio-1,3,4-thiadiazole, 2-methacryloxy-n-butylthio-5-n-propylthio-1,3,4-thiadiazole, 2-acryloxy-n-butylthio-5-isopropylthio-1,3,4-Thiadiazole, 2-methacryloxy-n-butylthio-5-isopropylthio-1,3,4-thiadiazole, 2-acryloxy-n-butylthio-5-n-butylthio-1,3,4-thiadiazole, 2-methacryloxy-n-butylthio-5-n-butylthio-1,3,4-thiadiazole, 2-acryloxy-n-butylthio-5-n-pentylthio-1,3,4-thiadiazole, 2-methacryloxy-n-butylthio-5-n-pentylthio-1,3,4-thiadiazole, 2-acryloxy-n-butylthio-5-n-hexylthio-1,3,4-thiadiazole, xylthio-1,3,4-thiadiazole, 2-methacryloxy-n-butylthio-5-n-hexylthio-1,3,4-thiadiazole, 2-acryloxy-n-pentylthio-5-methylthio-1,3,4-thiadiazole, 2-methacryloxy-n-pentylthio-5-methylthio-1,3,4-thiadiazole, 2-acryloxy-n-pentylthio-5-ethylthio-1,3,4-thiadiazole, 2-methacryloxy-n-pentylthio-5-ethylthio-1,3,4-thiadiazole, 2-acryloxy-n-pentylthio- 5-n-propylthio-1,3,4-thiadiazole, 2-methacryloxy-n-pentylthio-5-n-propylthio-1,3,4-thiadiazole, 2-acryloxy-n-pentylthio-5-isopropylthio-1,3,4-thiadiazole, 2-methacryloxy-n-pentylthio-5-isopropylthio-1,3,4-thiadiazole, 2-acryloxy-n-pentylthio-5-n-butylthio-1,3,4-thiadiazole, 2-methacryloxy-n-pentylthio-5-n-butylthio-1,3,4-thiadiazole, 2- Acryloxy-n-pentylthio-5-n-pentylthio-1,3,4-thiadiazole, 2-methacryloxy-n-pentylthio-5-n-pentylthio-1,3,4-thiadiazole, 2-acryloxy-n-pentylthio-5-n-hexylthio-1,3,4-thiadiazole, 2-methacryloxy-n-pentylthio-5-n-hexylthio-1,3,4-thiadiazole, 2-acryloxy-n-hexylthio-5-methylthio-1,3,4-thiadiazole, 2-methacryloxy-n-hexylthio-5-methylthio-1,3,4-Thiadiazole, 2-acryloxy-n-hexylthio-5-ethylthio-1,3,4-thiadiazole, 2-methacryloxy-n-hexylthio-5-ethylthio-1,3,4-thiadiazole, 2-acryloxy-n-hexylthio-5-n-propylthio-1,3,4-thiadiazole, 2-methacryloxy-n-hexylthio-5-n-propylthio-1,3,4-thiadiazole, 2-acryloxy-n-hexylthio-5-isopropylthio-1,3,4-thiadiazole, 2-methacryloxy-n-hexylthio-5-isopropylthio-1,3,4-thiadiazole o-1,3,4-thiadiazole, 2-acryloxy-n-hexylthio-5-n-butylthio-1,3,4-thiadiazole, 2-methacryloxy-n-hexylthio-5-n-butylthio-1,3,4-thiadiazole, 2-acryloxy-n-hexylthio-5-n-pentylthio-1,3,4-thiadiazole, 2-methacryloxy-n-hexylthio-5-n-pentylthio-1,3,4-thiadiazole, 2-acryloxy-n-hexylthio-5-n-pentylthio-1,3,4-thiadiazole, 2-acryloxy-n-hexylthio-5-n-hexylthio-1,3,4-thiadiazole, 2-acryloxy-n-hexylthio-5-n-hexylthio-1,3,4-thiadiazole, 2-methacryloxy-n-hexylthio- 5-n-hexylthio-1,3,4-thiadiazole, 2-acryloylthiomethylthio-5-methylthio-1,3,4-thiadiazole, 2-methacryloylthiomethylthio-5-methylthio-1,3,4-thiadiazole, 2-acryloylthiomethylthio-5-ethylthio-1,3,4-thiadiazole, 2-methacryloylthiomethylthio-5-ethylthio-1,3,4-thiadiazole, 2-acryloylthiomethylthio-5-n-propylthio-1,3,4-thiadiazole, 2-methacryloylthiomethylthio-5-n-propylthio-1,3,4-thiadiazole ,3,4-thiadiazole, 2-acryloylthiomethylthio-5-isopropylthio-1,3,4-thiadiazole, 2-methacryloylthiomethylthio-5-isopropylthio-1,3,4-thiadiazole, 2-acryloylthiomethylthio-5-n-butylthio-1,3,4-thiadiazole, 2-methacryloylthiomethylthio-5-n-butylthio-1,3,4-thiadiazole, 2-acryloylthiomethylthio-5-n-pentylthio-1,3,4-thiadiazole, 2-methacryloylthiomethylthio-5-n-pentylthio-1,3,4-Thiadiazole, 2-Acryloylthiomethylthio-5-n-hexylthio-1,3,4-thiadiazole, 2-Methacryloylthiomethylthio-5-n-hexylthio-1,3,4-thiadiazole, 2-Acryloylthioethylthio-5-methylthio-1,3,4-thiadiazole, 2-Methacryloylthioethylthio-5-methylthio-1,3,4-thiadiazole, 2-Acryloylthioethylthio-5-ethylthio-1,3,4-thiadiazole, 2-Methacryloylthioethylthio-5-ethylthio-1,3,4-thiadiazole, 2-A 2-Acryloylthioethylthio-5-n-propylthio-1,3,4-thiadiazole, 2-Methacryloylthioethylthio-5-n-propylthio-1,3,4-thiadiazole, 2-Acryloylthioethylthio-5-isopropylthio-1,3,4-thiadiazole, 2-Methacryloylthioethylthio-5-isopropylthio-1,3,4-thiadiazole, 2-Acryloylthioethylthio-5-n-butylthio-1,3,4-thiadiazole, 2-Methacryloylthioethylthio-5-n-butylthio-1,3,4-thiadiazole, 2-Acryloylthioethylthio-5-n-butylthio-1,3,4-thiadiazole 2-Acryloylthioethylthio-5-n-pentylthio-1,3,4-thiadiazole, 2-Methacryloylthioethylthio-5-n-pentylthio-1,3,4-thiadiazole, 2-Acryloylthioethylthio-5-n-hexylthio-1,3,4-thiadiazole, 2-Methacryloylthioethylthio-5-n-hexylthio-1,3,4-thiadiazole, 2-Acryloylthio-n-propylthio-5-methylthio-1,3,4-thiadiazole, 2-Methacryloylthio-n-propylthio-5-methylthio-1,3,4-thiadiazole, 2-Acryloylthioethylthio-5-n-pentylthio-1,3,4-thiadiazole, 2-methacryloylthio-n-propylthio-5-ethylthio-1,3,4-thiadiazole, 2-acryloylthio-n-propylthio-5-n-propylthio-1,3,4-thiadiazole, 2-methacryloylthio-n-propylthio-5-isopropylthio-1,3,4-thiadiazole, 2-methacryloylthio-n-propylthio-5-isopropylthio-1,3,4-thiadiazole, 2-acryloylthio-n-propylthio-5-isopropylthio-1,3,4-thiadiazole, 2-methacryloylthio-n-propylthio-5-isopropylthio-1,3,4-Thiadiazole, 2-Acryloylthio-n-propylthio-5-n-butylthio-1,3,4-thiadiazole, 2-Methacryloylthio-n-propylthio-5-n-butylthio-1,3,4-thiadiazole, 2-Acryloylthio-n-propylthio-5-n-pentylthio-1,3,4-thiadiazole, 2-Methacryloylthio-n-propylthio-5-n, -pentylthio-1,3,4-thiadiazole, 2-acryloylthio-n-propylthio-5-n-hexylthio-1,3,4-thiadiazole, 2-methacryloylthio-n-propylthio-5-n-hexylthio-1,3,4-thiadiazole, 2-acryloylthio-n-butylthio-5-methylthio-1,3,4-thiadiazole, 2-methacryloylthio-n-butylthio-5-methylthio-1,3,4-thiadiazole, 2-acryloylthio-n-butylthio-5-ethylthio-1,3,4-thiadiazole, 2-methacryloylthio-n-butylthio-5-ethylthio-1,3,4-thiadiazole, 2-Acryloylthio-n-butylthio-5-n-propylthio-1,3,4-thiadiazole, 2-Methacryloylthio-n-butylthio-5-n-propylthio-1,3,4-thiadiazole, 2-Acryloylthio-n-butylthio-5-isopropylthio-1,3,4-thiadiazole, 2-Methacryloylthio-n-butylthio-5-isopropylthio-1,3,4-thiadiazole, 2-Acryloylthio-n-butylthio-5-n-butylthio- 1,3,4-Thiadiazole, 2-Methacryloylthio-n-butylthio-5-n-butylthio-1,3,4-thiadiazole, 2-Acryloylthio-n-butylthio-5-n-pentylthio-1,3,4-thiadiazole, 2-Methacryloylthio-n-butylthio-5-n-pentylthio-1,3,4-thiadiazole, 2-Acryloylthio-n-butylthio-5-n-hexylthio-1,3,4-thiadiazole, 2-Methacryloylthio-n-butylthio-5-n-hexylthio-1,3,4-thiadiazole, 2-Acryloylthio-n-butylthio-5-n-hexylthio-1,3,4-thiadiazole, 2-methacryloylthio-n-pentylthio-5-methylthio-1,3,4-thiadiazole, 2-acryloylthio-n-pentylthio-5-ethylthio-1,3,4-thiadiazole, 2-methacryloylthio-n-pentylthio-5-ethylthio-1,3,4-thiadiazole, 2-acryloylthio-n-pentylthio-5-n-propylthio-1,3,4-thiadiazole, 2-methacryloylthio-n-pentylthio-5-n-propylthio-1,3,4-Thiadiazole, 2-Acryloylthio-n-pentylthio-5-isopropylthio-1,3,4-thiadiazole, 2-Methacryloylthio-n-pentylthio-5-isopropylthio-1,3,4-thiadiazole, 2-Acryloylthio-n-pentylthio-5-n-butylthio-1,3,4-thiadiazole, 2-Methacryloylthio-n-pentylthio-5-n-butylthio-1,3,4-thiadiazole, 2-Acryloylthio-n-pentylthio-5-n-pentylthio-1,3,4-thiadiazole, 2-Methacryloylthio -n-pentylthio-5-n-pentylthio-1,3,4-thiadiazole, 2-acryloylthio-n-pentylthio-5-n-hexylthio-1,3,4-thiadiazole, 2-methacryloylthio-n-pentylthio-5-n-hexylthio-1,3,4-thiadiazole, 2-acryloylthio-n-hexylthio-5-methylthio-1,3,4-thiadiazole, 2-methacryloylthio-n-hexylthio-5-methylthio-1,3,4-thiadiazole, 2-acryloylthio-n-hexylthio-5-ethylthio-1,3,4-thiadiazole 2-methacryloylthio-n-hexylthio-5-ethylthio-1,3,4-thiadiazole, 2-acryloylthio-n-hexylthio-5-n-propylthio-1,3,4-thiadiazole, 2-methacryloylthio-n-hexylthio-5-n-propylthio-1,3,4-thiadiazole, 2-acryloylthio-n-hexylthio-5-isopropylthio-1,3,4-thiadiazole, 2-methacryloylthio-n-hexylthio-5-iso ... xylthio-5-n-butylthio-1,3,4-thiadiazole, 2-methacryloylthio-n-hexylthio-5-n-butylthio-1,3,4-thiadiazole, 2-acryloylthio-n-hexylthio-5-n-pentylthio-1,3,4-thiadiazole, 2-methacryloylthio-n-hexylthio-5-n-pentylthio-1,3,4-thiadiazole, 2-acryloylthio-n-hexylthio-5-n-hexylthio-1,3,4-thiadiazole, 2-methacryloylthio-n-hexylthio-5-n-hexylthio-1,3,4-Thiadiazole, etc.

[0042] In the (meth)acrylic acid ester having a thiadiazole ring of the present invention, the 1,3,4-thiadiazole ring in which sulfur atoms are substituted at the 2- and 5-positions serves as a skeleton that exhibits a high refractive index, and an increase in viscosity is suppressed by attaching an acrylic group, which is a polymerizable group, to the sulfur atom of the ring via an alkylene group. Furthermore, by substituting an alkyl group instead of an acrylic group on the other sulfur atom, the viscosity is further reduced to a practical level.

[0043] The (meth)acrylic acid ester having a thiadiazole ring of the present invention is characterized by a high refractive index and a low viscosity. 1 In terms of viscosity, R is preferably a methyl group or an ethyl group, and n is preferably 2, 3 or 4. 1 A compound represented by the following general formula (2), in which is a methyl group, n is 2, and A is an oxygen atom, is most preferred in terms of ease of synthesis and physical properties.

[0044] [ka]

[0045] In the general formula (2), R 2 represents a hydrogen atom or a methyl group.

[0046] Specifically, 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole and 2-methacryloxyethylthio-5-methylthio-1,3,4-thiadiazole are preferred, and 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole is particularly preferred.

[0047] (Synthesis method) The compound of general formula (1) of the present invention can be obtained by synthesizing a compound of general formula (5) in a first step by reacting a 1,3,4-thiadiazole compound having a thiol group represented by general formula (3) with a halogenated alcohol or a halogenated thioalcohol in the presence of a base, and then reacting the obtained compound of general formula (5) with a (meth)acrylic acid halide of general formula (6) in a second step.

[0048] [ka]

[0049] In the above reaction formula, A represents an oxygen atom or a sulfur atom, n represents an integer from 1 to 6, and R 1 represents a linear or branched alkyl group having 1 to 6 carbon atoms, and X represents a chlorine atom or a bromine atom.

[0050] [ka]

[0051] In the above reaction formula, A represents an oxygen atom or a sulfur atom, n represents an integer from 1 to 6, and R 1 represents a linear or branched alkyl group having 1 to 6 carbon atoms; R 2 represents a hydrogen atom or a methyl group.

[0052] (First step) Examples of the 1,3,4-thiadiazole compound having a thiol group represented by general formula (3) used as a raw material include 2-mercapto-5-methylthio-1,3,4-thiadiazole, 2-mercapto-5-ethylthio-1,3,4-thiadiazole, 2-mercapto-5-n-propylthio-1,3,4-thiadiazole, 2-mercapto-5-n-butylthio-1,3,4-thiadiazole, 2-mercapto-5-n-pentylthio-1,3,4-thiadiazole, and 2-mercapto-5-n-hexylthio-1,3,4-thiadiazole.

[0053] Examples of halogenated alcohols that can be used in the reaction include chloromethanol, bromomethanol, 2-chloroethanol, 2-bromoethanol, 3-chloropropanol, 3-bromopropanol, 4-chlorobutanol, 4-bromobutanol, 5-chloropentanol, and 5-bromopentanol. Examples of halogenated thioalcohols that can be used in the reaction include chloromethanethiol, bromomethanethiol, 2-chloroethanethiol, 2-bromoethanethiol, 3-chloropropanethiol, 3-bromopropanethiol, 4-chlorobutanethiol, 4-bromobutanethiol, 5-chloropentanethiol, 5-bromopentanethiol, 6-chlorohexanethiol, and 6-bromohexanethiol.

[0054] The amount of halogenated alcohol or halogenated thioalcohol used relative to the 1,3,4-thiadiazole compound having a thiol group represented by general formula (3) is, for example, 0.1 to 5 mol, and preferably 0.5 to 1.5 mol, relative to 1 mol of the 1,3,4-thiadiazole compound having a thiol group represented by general formula (3).

[0055] In the reaction of a 1,3,4-thiadiazole compound having a thiol group represented by general formula (3) with a halogenated alcohol or halogenated thioalcohol, it is desirable to add a basic compound as a catalyst. Examples of basic compounds include triethylamine, N,N-diisopropylethylamine, N-methylmorpholine, imidazole, pyridine, N,N-dimethylaminopyridine, 2,6-dimethylpyridine, 1-methylimidazole, and 1,8-diazabicyclo[5.4.0]undec-7-ene. One or more of these can be used.

[0056] In the first step, it is preferable to use a reaction solvent, such as polyhydric alcohol ethers, cyclic ethers, polyhydric alcohol esters, ketones, alkyl esters, sulfoxides, etc.

[0057] Examples of polyhydric alcohol ethers include glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monopentyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl methyl ether, and ethylene glycol monophenyl ether. Examples of cyclic ethers include 1,3-dioxane, 1,4-dioxane, and tetrahydrofuran. Examples of polyhydric alcohol esters include glycol esters such as ethylene glycol acetate. Examples of ketones include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Examples of alkyl esters include ethyl acetate, propyl acetate, and butyl acetate. Examples of sulfoxides include dimethyl sulfoxide and diethyl sulfoxide. Among these, cyclic ethers are preferably used.

[0058] The reaction temperature in the first step is usually in the range of 0 to 100° C., preferably 40 to 80° C. If the reaction temperature is too low, the reaction time may become long, whereas if the reaction temperature is too high, it is undesirable because it promotes the production of reaction by-products.

[0059] After the reaction of the first step is completed, the base catalyst is removed and the solution containing the product is separated. The method of removing the catalyst includes a method of filtering off the neutralized salt precipitated after neutralization treatment. The solution containing the obtained product can be used as it is in the next step. If a different solvent is used in the next step, the solvent can be distilled off, isolated, and used in the next step.

[0060] <Second process> In the second step, the compound of general formula (5) obtained in the first step is (meth)acrylated. Various methods can be used for (meth)acrylation, and first, a halogenated (meth)acryl represented by general formula (6) can be used as a (meth)acrylation agent.

[0061] Examples of halogenated acrylics that can be used include acryloyl chloride, acryloyl bromide, etc. Examples of halogenated methacrylics that can be used include methacryloyl chloride, methacryloyl bromide, etc.

[0062] The amount of the halogenated (meth)acrylic used relative to the compound of general formula (5) is, for example, 1 to 10 mol, and preferably 1 to 5 mol, relative to 1 mol of the compound of general formula (5).

[0063] In the reaction of the compound of general formula (5) with the halogenated (meth)acrylic acid, it is desirable to add a basic compound as a catalyst. Examples of the basic compound include triethylamine, N,N-diisopropylethylamine, N-methylmorpholine, imidazole, pyridine, N,N-dimethylaminopyridine, 2,6-dimethylpyridine, 1-methylimidazole, and 1,8-diazabicyclo[5.4.0]undec-7-ene. One or more of these can be used.

[0064] In the second step, it is preferable to use a reaction solvent. As the reaction solvent, for example, polyhydric alcohol ethers, cyclic ethers, polyhydric alcohol esters, ketones, alkyl esters, sulfoxides, etc. can be used. The same solvent as in the first step can be used, and the compound of general formula (5) obtained in the first step can be dissolved in the solvent and used in the second step without being isolated.

[0065] Examples of polyhydric alcohol ethers include glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monopentyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl methyl ether, and ethylene glycol monophenyl ether. Examples of cyclic ethers include 1,3-dioxane, 1,4-dioxane, and tetrahydrofuran. Examples of polyhydric alcohol esters include glycol esters such as ethylene glycol acetate. Examples of ketones include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Examples of alkyl esters include ethyl acetate, propyl acetate, and butyl acetate. Examples of sulfoxides include dimethyl sulfoxide and diethyl sulfoxide. Among these, cyclic ethers are preferably used.

[0066] The reaction temperature in the second step is usually in the range of 0 to 100° C., preferably 5 to 60° C. If the reaction temperature is too low, the reaction time may become long, whereas if the reaction temperature is too high, it is undesirable because it promotes the production of reaction by-products.

[0067] After the reaction of the second step is completed, the base catalyst is removed and the solution containing the product is separated. The catalyst can be removed by, for example, filtering off the neutralized salt precipitated after neutralization treatment. The solvent is removed from the solution containing the product obtained, and the compound of general formula (1) can be isolated and purified by purification using column chromatography or the like.

[0068] As the (meth)acrylation agent in the second step, in addition to the (meth)acrylic halide, (meth)acrylic anhydride, (meth)acrylic acid, etc. can also be used.

[0069] In addition to the above-mentioned synthesis methods, the compound of general formula (1) of the present invention can be synthesized by a method in which the compound of general formula (5) obtained in the first step is reacted with thionyl chloride or the like to chlorinate the terminals, followed by reaction with a (meth)acrylate salt such as potassium acrylate, or by changing the halogenated alcohol in the first step to a dihalogenated alkyl such as bromochloroethane or dibromoethane to make the reactive terminals of the compound of general formula (5) halogenated, followed by reaction with a (meth)acrylate salt.

[0070] The (meth)acrylic acid ester having a thiadiazole ring and represented by general formula (1) synthesized by the above method is a compound with low viscosity and high refractive index. For example, the compound of structural formula (2) is a liquid compound, and its viscosity at 25°C is low at about 50 mPa·s, and its refractive index at 25°C (n D ) has a high refractive index of 1.61. The refractive index (n D ) is greater than 1.595.

[0071] It is believed that the (meth)acrylic acid ester having a thiadiazole ring represented by general formula (1) achieves a high refractive index and low viscosity by introducing an acrylic group, which is a polymerizable group, via a flexible alkyl chain to the thiadiazole ring having a thiomethyl group, which exhibits a high refractive index.

[0072] In addition, the (meth)acrylic acid ester having a thiadiazole ring represented by general formula (1) has a high compatibility with other radical polymerizable compounds such as acrylic acid esters due to its characteristic structure, and the radical polymerizable composition produced by mixing with other radical polymerizable compounds is also radically polymerized and cured, and the refractive index of the cured product can be made higher than that of the cured product of other radical polymerizable compounds, making it possible to adjust the refractive index of the cured product. In addition, the (meth)acrylic acid ester represented by general formula (1) of the present invention has a low viscosity, so that it is difficult to increase the viscosity by mixing with other radical polymerizable compounds, and it is easy to apply, and can be used for applications such as inkjet ink.

[0073] (Radically polymerizable composition) The (meth)acrylic acid ester having a thiadiazole ring of the present invention exhibits good radical polymerizability, and can be copolymerized by mixing with various compounds having unsaturated bonds other than the (meth)acrylic acid ester monomer having a thiadiazole ring.

[0074] Examples of compounds having an unsaturated bond that can be used include organic compounds having a double bond, such as styrene, vinyl acetate, acrylonitrile, methacrylonitrile, acrylamide, acrylic acid ester, methacrylic acid ester, vinyl ether, vinyl sulfide, etc. Among these radical polymerizable compounds, the compound of the present invention has an acrylic structure, and therefore has excellent compatibility with monofunctional (meth)acrylates, monofunctional (meth)acrylamides, polyfunctional (meth)acrylates, polyfunctional (meth)acrylamides, etc., and has the same polymerizable group, making it a preferred combination for copolymerization.

[0075] Examples of monofunctional (meth)acrylates that can be used include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, hydroxyethyl acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, tridecyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, propoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, methoxydiethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, methoxytetraethylene glycol (meth)acrylate, 2-(2-ethoxyethoxy)ethyl acrylate, phenoxyethyl (meth)acrylate, methyl acrylate, ethyl ... ethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxytetraethylene glycol (meth)acrylate, phenoxyhexaethylene glycol (meth)acrylate, methoxydipropylene glycol (meth)acrylate, methoxytripropylene glycol (meth)acrylate, cyclohexyl (meth)acrylate, tert-butylcyclohexyl (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, bornyl (meth)acrylate, isobornyl (meth)acrylate, tetrahydrofurfuryl acrylate, 2-methyl-2-adamantyl (meth)acrylate, allyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxyhexyl (meth)acrylate, and the like.

[0076] Further examples include hydroxyl group-containing (meth)acrylic monomers, carboxyl group-containing (meth)acrylic monomers, amino group-containing (meth)acrylic monomers, acetoacetyl group-containing (meth)acrylic monomers, isocyanate group-containing (meth)acrylic monomers, glycidyl group-containing (meth)acrylic monomers, and (meth)acrylic monomers having an aromatic hydrocarbon group.

[0077] Examples of hydroxyl group-containing (meth)acrylic monomers include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and 8-hydroxyoctyl (meth)acrylate; hydroxyalkyl (meth)acrylamides such as N-hydroxyethyl (meth)acrylamide and N-hydroxypropyl (meth)acrylamide; and 2-acryloyloxyethyl-2-hydroxyethyl phthalate. Examples of the monomers include primary hydroxyl group-containing (meth)acrylic monomers such as N-methylol (meth)acrylamide, secondary hydroxyl group-containing (meth)acrylic monomers such as 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, and 2-hydroxy-3-phenoxypropyl (meth)acrylate, and tertiary hydroxyl group-containing (meth)acrylic monomers such as 2,2-dimethyl 2-hydroxyethyl (meth)acrylate. Among these, hydroxyalkyl (C1-C6, linear or branched) (meth)acrylates are preferably used.

[0078] Examples of the carboxyl group-containing (meth)acrylic monomer include monocarboxylic acids such as (meth)acrylic acid and crotonic acid, and dicarboxylic acids such as maleic acid, maleic anhydride, fumaric acid, citraconic acid, and itaconic acid, and among these, (meth)acrylic acid is preferably used.

[0079] Examples of the amino group-containing (meth)acrylic monomer include aminoalkyl (meth)acrylates such as N,N-dimethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, N,N-di-t-butylaminoethyl (meth)acrylate, and N,N-diethylaminoethyl (meth)acrylate; and aminoalkyl (C1 to C6, linear or branched) (meth)acrylamides such as N,N-dimethylaminoethyl (meth)acrylamide, N,N-diethylaminoethyl (meth)acrylamide, and N,N-dimethylaminopropyl (meth)acrylamide.

[0080] Examples of the acetoacetyl group-containing (meth)acrylic monomer include 2-(acetoacetoxy)ethyl (meth)acrylate.

[0081] Examples of the isocyanate group-containing (meth)acrylic monomer include 2-acryloyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate, and alkylene oxide adducts thereof.

[0082] Examples of the glycidyl group-containing (meth)acrylic monomer include glycidyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, N-2-hydroxyethyl (meth)acrylamide glycidyl ether, and N-methyl-N-2-hydroxyethyl (meth)acrylamide glycidyl ether.

[0083] Examples of the (meth)acrylic monomer having an aromatic hydrocarbon group include (meth)acrylic monomers having a benzene ring group, such as benzyl (meth)acrylate, phenyl (meth)acrylate, benzyl phenyl (meth)acrylate, p-phenyl benzyl acrylate, pt-butyl phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxypropyl (meth)acrylate, phenoxy diethylene glycol (meth)acrylate, ethylene oxide modified nonylphenol (meth)acrylate, ethylene oxide modified cresol (meth)acrylate, phenol ethylene oxide modified (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, methoxybenzyl (meth)acrylate, m-phenoxybenzyl (meth)acrylate, and chlorobenzyl (meth)acrylate. Examples of the monomers include (meth)acrylic monomers having a naphthalene ring group, such as 4-methoxy-1-naphthoxy)ethyl (meth)acrylate, 1-naphthylmethyl (meth)acrylate, and 2-naphthylmethyl acrylate; and also (meth)acrylic monomers having a biphenyl ring group, such as p-biphenyl (meth)acrylate, ethoxylated-p-biphenyl (meth)acrylate, o-phenylphenol (meth)acrylate, and ethoxylated-o-phenylphenol (meth)acrylate; and also fluorenyl (meth)acrylate, 9-fluorenylmethyl (meth)acrylate (9-(meth)acryloyloxymethylfluorene), and the like. In addition to the compounds exemplified here, examples of the aromatic hydrocarbon group include (meth)acrylic monomers having an azulene ring group, an anthracene ring group, a phenanthrene ring group, a pyrene ring group, a chrysene ring group, a naphthacene ring group, a triphenylene ring group, an o-terphenyl ring group, an m-terphenyl ring group, a p-terphenyl ring group, a fluorene ring group, or the like.Many of these (meth)acrylic monomers having an aromatic hydrocarbon group have a high refractive index but also have a high viscosity. By forming a copolymer composition with a (meth)acrylic acid ester having a thiadiazole ring represented by the general formula (1) of the present invention, a photoradical polymerizable composition having a high refractive index but low viscosity can be obtained.

[0084] Examples of monofunctional (meth)acrylamides include N-alkyl (C1 to C18, linear or branched) (meth)acrylamides, N-alkoxy (C1 to C6, linear or branched) alkyl (C1 to C18, linear or branched) (meth)acrylamides, N-hydroxyalkyl (C1 to C18, linear or branched) (meth)acrylamides, N,N-dihydroxyalkyl (C1 to C18, linear or branched) (meth)acrylamides, N- ... Examples of the monomer include C18, linear or branched)-N-alkyl (C1 to C18, linear or branched) (meth)acrylamide, N-vinylpyrrolidone, N-vinylcaprolactam, N-(dialkyl (C1 to C6, linear or branched) amino) alkyl (C1 to C18, linear or branched) (meth)acrylamide, N,N-dialkyl (C1 to C18, linear or branched) (meth)acrylamide, N-acryloylmorpholine, and diacetone (meth)acrylamide. In particular, from the viewpoint of easy availability as a high-purity industrial product, N,N-dimethylacrylamide, N,N-diethylacrylamide, N-isopropylacrylamide, N-acryloylmorpholine, diacetone acrylamide, N-(dimethylamino)propyl (meth)acrylamide, and N-hydroxyethylacrylamide are more preferable. These monofunctional monomers may be used alone or in combination of two or more.

[0085] Examples of polyfunctional (meth)acrylates include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, ditetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, ) acrylate, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,7-heptanediol di(meth)acrylate, 1,8-octanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate ) acrylate, ethylene oxide modified phosphoric acid di(meth)acrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol tetra(meth)acrylate, trimethylolethane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, ethylene oxide modified bisphenol A di(meth)acrylate, propylene oxide modified bisphenol A di(meth)acrylate, cyclohexane dimethanol di(meth)acrylate, acrylate ester (dioxane glycol diacrylate), alkoxylated hexanediol di(meth)acrylate, alkoxylated cyclohexane dimethanol di(meth)acrylate, epoxy (meth)acrylate, urethane (meth)acrylate and other monomers and oligomers.From the viewpoint of commercial availability, examples of polyfunctional (meth)acrylates include, for example, trade names CN2203 and CN2270 manufactured by SARTOMER, and trade names M-6100 and M-8060 manufactured by Toa Gosei Co., Ltd.; examples of urethane acrylates include, for example, trade names UV-3200B, UV-3000B, UV-6640B, UV-3700B, UV-3310B, and UV-7000B manufactured by Nippon Synthetic Chemical Industry Co., Ltd.; trade names U-4HA and U-200PA manufactured by Shin-Nakamura Chemical Co., Ltd.; and trade names EBECRYL245, EBECRYL1259, and EBECRYL245 manufactured by Daicel-Cytec Co., Ltd. ECRYL8210, EBECRYL284, EBECRYL8402, SARTOMER's trade names CN944, CN969, CN9002, CN9029, Negami Chemical Industries' trade names UN1255, UN-5507, Kyoeisha Chemical's trade names AH-600, UA-306I, etc. can be used, and epoxy (meth)acrylates can be Daicel-Cytec's trade names EBECRYL1259, EBECRYL605, EBECRYL1606, SARTOMER's trade names CN110, CN120, CN153, etc. Furthermore, from the viewpoint of the viscosity of the resin composition and ease of handling, etc., urethane acrylate UV-6640B or U-200PA is more preferable. These polyfunctional (meth)acrylates may be used alone or in combination of two or more.

[0086] Also included are high refractive index polyfunctional (meth)acrylic esters such as bis(4-methacryloylthiophenyl)sulfide and bis(4-acryloylthiophenyl)sulfide.

[0087] Examples of polyfunctional (meth)acrylamides include methylene bis(meth)acrylamide, ethylene bis(meth)acrylamide, diallyl (meth)acrylamide, and urethane di(meth)acrylamide.

[0088] When the (meth)acrylic acid ester having a thiadiazole ring of the present invention is copolymerized with a compound having an unsaturated bond other than (meth)acrylic acid ester, the mixing ratio depends on the desired physical properties, but in terms of being a refractive index adjuster, the (meth)acrylic acid ester having a thiadiazole ring of the present invention is preferably used in an amount of 5% by weight or more relative to the radical polymerizable composition, more preferably 10% by weight or more, and particularly preferably 20% by weight or more in terms of a high refractive index. The (meth)acrylic acid ester having a thiadiazole ring of the present invention has a low viscosity, so that the refractive index can be adjusted without significantly increasing the viscosity of the polymerizable composition.

[0089] (Radical polymerization initiator) A radical polymerization initiator is added to the radical polymerizable composition of the present invention. The radical polymerization initiator is not particularly limited, but may be, for example, a thermal radical polymerization initiator, a photoradical polymerization initiator, etc. In addition, the radical polymerization initiator may be either a thermal radical polymerization initiator or a photoradical polymerization initiator, or both a thermal radical polymerization initiator and a photoradical polymerization initiator may be used.

[0090] Examples of the thermal radical polymerization initiator include organic peroxides, inorganic peroxides, and azo compounds. Examples of organic peroxides include hydroperoxides, dialkyl peroxides, peroxy esters, diacyl peroxides, peroxydicarbonates, peroxyketals, and ketone peroxides (benzoyl peroxide, t-butylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di(2-ethylhexanoyl)peroxyhexane, t-butylperoxybenzoate, t-butyl peroxide, cumene hydroperoxide, dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-dibutylperoxyhexane, 2,4-dichlorobenzoyl peroxide, 1,4-di(2-t-butylperoxyisopropyl)benzene, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, methyl ethyl ketone peroxide, and 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate). Examples of inorganic peroxides include hydrogen peroxide and persulfates (potassium persulfate, ammonium persulfate, etc.). Examples of azo compounds include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2-hydroxymethylpropionitrile), 1,1'-azobiscyclohexane-1-carbonitrile, 4,4'-azobis(4-cyanovaleric acid), 2-(carbamoylazo)isobutyronitrile, 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile, 2,2'-azobis(2-methylpropane), 2,2'-azobis(2,4,4-trimethylpentane), and dimethyl 2,2'-azobisisobutyrate.

[0091] As the photoradical polymerization initiator, any commonly used one can be used without any particular limitation. For example, a benzyl methyl ketal-based polymerization initiator, an α-hydroxyalkylphenone-based polymerization initiator, an oxime ester-based polymerization initiator, an α-aminoacetophenone-based polymerization initiator, an acylphosphine oxide-based polymerization initiator, a biimidazole-based polymerization initiator, a triazine-based polymerization initiator, a thioxanthone-based polymerization initiator, etc. can be used.

[0092] Examples of benzyl methyl ketal polymerization initiators include 2,2-dimethoxy-1,2-diphenylethan-1-one (trade name "Omnirad651" manufactured by IGM Group B.V., (Omnirad is a registered trademark of IGM Group B.V.)), and examples of α-hydroxyalkylphenone radical polymerization initiators include 2-hydroxy-2-methyl-1-phenylpropan-1-one (trade name "Omnirad1173" manufactured by IGM Group B.V.), 1-hydroxycyclohexyl phenyl ketone (trade name "Omnirad184" manufactured by IGM Group B.V.), 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one (trade name "Omnirad2959" manufactured by IGM Group B.V.), and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)-benzyl]phenyl}-2-methyl-1-one (trade name "Omnirad127" manufactured by IGM Group B.V.).

[0093] In particular, the benzyl methyl ketal polymerization initiator 2,2-dimethoxy-1,2-diphenylethan-1-one (trade name "Omnirad651" manufactured by IGM Group B.V.), the α-hydroxyalkylphenone radical polymerization initiator 2-hydroxy-2-methyl-1-phenylpropan-1-one (trade name "Omnirad1173" manufactured by IGM Group B.V.), and 1-hydroxycyclohexyl phenyl ketone (trade name "Omnirad184" manufactured by IGM Group B.V.) are preferred.

[0094] Also usable are acetophenone-based polymerization initiators such as acetophenone, 2-hydroxy-2-phenylacetophenone, 2-ethoxy-2-phenylacetophenone, 2-methoxy-2-phenylacetophenone, 2-isopropoxy-2-phenylacetophenone, and 2-isobutoxy-2-phenylacetophenone, benzyl-based polymerization initiators such as benzyl and 4,4'-dimethoxybenzyl, and anthraquinone-based polymerization initiators such as 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-phenoxyanthraquinone, 2-(phenylthio)anthraquinone, and 2-(hydroxyethylthio)anthraquinone.

[0095] Examples of the biimidazole polymerization initiator include 2,4,5-triarylimidazole dimers such as 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-chlorophenyl)-4,5-di(methoxyphenyl)imidazole dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazole dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer, and 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer.

[0096] Examples of the α-aminoacetophenone polymerization initiator include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one (trade name "Omnirad907" manufactured by IGM Group B.V.), 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone (trade name "Omnirad369" manufactured by IGM Group B.V.), and 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholino-4-yl-phenyl)butan-1-one (trade name "Omnirad379" manufactured by IGM Group B.V.).

[0097] Examples of the acylphosphine oxide polymerization initiator include 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (trade name "OmniradTPO" manufactured by IGM Group B.V.) and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (trade name "Omnirad819" manufactured by IGM Group B.V.).

[0098] Examples of the oxime ester polymerization initiator include 1,2-octanedione, 1-[4-(phenylthio)phenyl]-, 2-(o-benzoyloxime) (trade name "IrgacureOXE01" manufactured by BASF, Irgacure is a registered trademark of BASF), ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(o-acetyloxime) (trade name "IrgacureOXE02" manufactured by BASF), [8-[[(acetyloxy)imino][2-(2,2,3,3-tetrafluoropropoxy)phenyl]methyl]-11-(2-ethylhexyl)-11H-benzo[a]carbazol-5-yl]-, (2,4,6-trimethylphenyl) (trade name "IrgacureOXE03" manufactured by BASF), and the like.

[0099] Examples of the triazine-based polymerization initiator include 2-(3,4-methylenedioxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine and 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine.

[0100] Examples of the thioxanthone-based polymerization initiator include 2,4-diethylthioxanthone and 2-isopropylthioxanthone.

[0101] The benzyl methyl ketal-based polymerization initiator, α-hydroxyalkylphenone-based polymerization initiator, oxime ester-based photopolymerization initiator, α-aminoacetophenone-based photopolymerization initiator, acylphosphine oxide-based photopolymerization initiator, biimidazole-based polymerization initiator, triazine-based polymerization initiator, and thioxanthone-based polymerization initiator that can be used in the present invention can each be used alone, or two or more types can be used in combination depending on the application, etc.

[0102] Among the above-listed photoradical polymerization initiators, biimidazole-based photopolymerization initiators, alkylphenone-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, and oxime-based photopolymerization initiators are preferred. In terms of activity, acylphosphine oxide-based photopolymerization initiators and oxime ester-based photopolymerization initiators are particularly preferred.

[0103] From the viewpoints of ease of production of a cured product, resolution, and pattern formability, polymerization and curing by light irradiation is preferred, and in this sense, a radically polymerizable composition using a photoradical polymerization initiator is preferred.

[0104] The amount of the photopolymerization initiator added is preferably 0.1% by weight or more and 10% by weight or less based on the radical polymerizable composition.

[0105] (Photoradical polymerization sensitizer) Conventionally, high pressure mercury lamps have been used as light sources in photoradical polymerization, but due to problems such as high energy consumption, curing devices using LED light sources, which have low running costs and little impact on the natural environment, have come to be used. However, these LED light sources emit light with long wavelengths such as 365nm, 385nm, 395nm, and 405nm, and unlike high pressure mercury lamps, they emit light of a single wavelength, so there is a problem that the irradiation energy is weak. With such LED lamps, it is often the case that conventional photoradical polymerization initiators cannot cure sufficiently. In order to deal with such long wavelength, single light LED lamps, it is preferable to further add a photoradical polymerization sensitizer. By adding a photoradical polymerization sensitizer that absorbs long wavelength light, the radical generation reaction of the photoradical polymerization initiator can be promoted, and the reactivity of the radical polymerization can be improved.

[0106] The photoradical polymerization sensitizer can be any commonly used one that is active to light of the irradiation wavelength and can be used without any particular limitation. For example, thioxanthone-based sensitizers such as isopropylthioxanthone and diethylthioxanthone, benzophenone-based sensitizers such as 4,4'-bis(diethylamino)benzophenone, anthracene-based sensitizers such as 9,10-diethoxyanthracene, 9,10-dibutoxyanthracene, 9,10-bisheptanoyloxyanthracene and 9,10-bisoctanoyloxyanthracene, coumarin-based sensitizers such as coumarin and ketocoumarin, acridine orange, camphorquinone, etc. can be used.

[0107] The amount of the photoradical polymerization sensitizer added is preferably 0.1% by weight or more and 10% by weight or less based on the radical polymerizable composition.

[0108] The radical polymerizable composition of the present invention may contain a polymerization accelerator depending on the photoradical polymerization initiator used. Examples of the polymerization accelerator include amine compounds such as ethyl p-dimethylaminobenzoate, 2-ethylhexyl p-dimethylaminobenzoate, methyl p-dimethylaminobenzoate, 2-dimethylaminoethyl benzoate, and butoxyethyl p-dimethylaminobenzoate.

[0109] The radical polymerizable composition of the present invention may contain a polymerization inhibitor to enhance the stability of the composition. Examples of the polymerization inhibitor include at least one compound selected from the group consisting of hydroquinone, hydroquinone monomethyl ether, 1,4-benzoquinone, tert-butylhydroquinone, and 4-tert-butylpyrocatechol.

[0110] Furthermore, the radical polymerization composition of the present invention may contain a surfactant, and the surfactant is preferably a nonionic surfactant. By containing a nonionic surfactant, the coating property when the radical polymerization composition is applied to a substrate to obtain a resin film is improved, and a coating film of uniform thickness can be obtained. The nonionic surfactant is, for example, a compound containing a fluorine group (for example, a fluorinated alkyl group) or a silanol group, or a compound having a siloxane bond as the main skeleton. It is preferable to use one containing a fluorine-based surfactant or a silicone-based surfactant. Examples of fluorine-based surfactants include, but are not limited to, Megafac F-171, F-173, F-444, F-470, F-471, F-475, F-482, F-477, F-554, F-556, and F-557 manufactured by DIC Corporation, and Novec FC4430 and FC4432 manufactured by Sumitomo 3M Limited. Examples of silicone-based surfactants include surfactants having a siloxane bond in the molecule. Specifically, examples of the surfactants include Toray Silicone DC3PA, SH7PA, DC11PA, SH21PA, SH28PA, SH29PA, SH30PA, and SH8400 (trade name: manufactured by Toray Dow Corning Co., Ltd.), KP321, KP322, KP323, KP324, KP326, KP340, and KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), TSF400, TSF401, TSF410, TSF4300, TSF4440, TSF4445, TSF4446, TSF4452, and TSF4460 (manufactured by Momentive Performance Materials Japan, LLC). Examples of the silicone surfactants having fluorine atoms include surfactants having siloxane bonds and fluorocarbon chains in the molecule. Specific examples include Megafac (registered trademark) R08, Megafac BL20, Megafac F475, Megafac F477, and Megafac F443 (manufactured by DIC Corporation).

[0111] In addition to the above, the radical polymerizable composition of the present invention may contain various resin additives such as pigments, dyes, diluents, organic or inorganic fillers, leveling agents, surfactants, dispersants, defoamers, thickeners, flame retardants, surface modifiers, penetration promoters, moisture absorbents, moisturizing agents, fixing agents, antifungal agents, preservatives, antioxidants, ultraviolet absorbers, chelating agents, pH adjusters, stabilizers, lubricants, and plasticizers, as long as the effects of the present invention are not impaired.

[0112] (Polymerization method) A cured product can be obtained by polymerizing the radical polymerizable composition of the present invention by applying heat or irradiating light. For example, when the radical polymerizable composition is irradiated with light to polymerize and photocure, the radical polymerizable composition can be molded into a film and photocure, or can be molded into a block and photocure. When the composition is molded into a film and photocure, the liquid radical polymerizable composition is applied to a substrate such as a polyester film using a bar coater or the like to a thickness of 5 to 300 microns. On the other hand, the composition can be applied to a thinner or thicker thickness by spin coating or screen printing. The (meth)acrylic acid ester having a thiadiazole ring and the radical polymerizable composition containing the (meth)acrylic acid ester having a thiadiazole ring of the present invention have a low viscosity, so that the composition may be used as an ink for inkjet printing.

[0113] The coating film made of the radically polymerizable composition thus prepared is irradiated with energy rays (ultraviolet rays) having a wavelength range of 300 nm to 500 nm at 1 to 1000 mW / cm 2A cured product can be obtained by irradiating light with an intensity of about 100 nm. Examples of light sources used include high pressure mercury lamps, ultra-high pressure mercury lamps, metal halide lamps, xenon lamps, gallium-doped lamps, black lights, 405 nm ultraviolet LEDs, 395 nm ultraviolet LEDs, 385 nm ultraviolet LEDs, 365 nm ultraviolet LEDs, semiconductor lasers, blue LEDs, white LEDs, D bulbs and V bulbs manufactured by Fusion Co., Ltd., and the like. Natural light such as sunlight can also be used. In particular, 405 nm ultraviolet LEDs, 395 nm ultraviolet LEDs, 385 nm ultraviolet LEDs, 375 nm ultraviolet LEDs, and 365 nm ultraviolet LEDs are characterized by having a sensitizing effect even with light having a long wavelength range such as 365 nm to 405 nm, and ultraviolet LEDs or semiconductor lasers with central wavelengths of 365 nm, 375 nm, 385 nm, 395 nm, and 405 nm are preferred as irradiation sources.

[0114] Since the radical polymerizable composition of the present invention has a high refractive index, its polymer can be preferably used for a film for optical applications. In addition, since it is highly compatible with other radical polymerizable compounds and can produce a copolymer, it is also possible to adjust the refractive index of the produced copolymer. In addition, when used for optical applications, light transmittance and yellowness (YI value) are generally problems. In general, this light transmittance is preferably 90% or more for optical applications, and a high transmittance makes it possible to improve the visibility and save power when used in a display. In addition, in optical applications, the YI value is preferably 10 or less, more preferably 8 or less, and even more preferably 5 or less. An optical laminate having a YI value of this upper limit or less has good transparency, and can contribute to high visibility when used, for example, as a front panel of a display. A film obtained by polymerizing and curing the radical polymerizable composition of the present invention not only has an ultra-high refractive index, but also shows a high transmittance and a low YI value, making it an optimal radical polymerizable composition for optical applications. EXAMPLES

[0115] Hereinafter, specific embodiments of the present invention will be described in further detail with reference to examples. However, the present invention is not limited to these examples as long as it does not depart from the gist of the present invention.

[0116] (Compound Identification) The identity of the obtained compound was determined using the following instruments. (1) 1 H-NMR analysis: Nuclear magnetic resonance apparatus (NMR), manufactured by JEOL Ltd., model: JNM ECS 400 type FT NMR Spectrator) (2) Mass spectrum: Measured using a mass spectrometer, model GCMS-QP2000, manufactured by Shimadzu Corporation.

[0117] (Physical property measurement of compounds) Measurement of physical properties of the obtained compound (1) Viscosity: E-type viscometer (Toki Sangyo, TVE-35H) (2) Refractive index: Refractometer (measurement conditions: 25°C, nD) For liquids (1.50≦nD≦1.70) Model name: ERMA, ER-7MW-H For liquids / films / thin films (1.30≦nD≦1.70) Model name: Anton Paar Japan, AbbematMw (3) Transmittance: SHIMADZU, UV-2600

[0118] (Viscosity measurement of compounds) The viscosity was measured using an E-type viscometer TVE35H. A cone rotor of 1°34'×R24 was used, and after adjusting the gap between the sample cup and the cone rotor, 1.1 mL of sample was injected into the center of the sample cup using a syringe. The sample cup was then set in the viscometer body, and the cone rotor was rotated at 25°C and 20 rpm. The value at which the viscosity became constant was taken as the viscosity value.

[0119] (Refractive index measurement method) Liquid (1.50≦n D≦1.70), the measurements were performed at 25° C. using a refractometer ER-7MW-H manufactured by ERMA. Liquid / film / thin film (1.30≦n D ≦1.70), measurements were performed at 25°C using AbbematMw manufactured by Anton Paar Japan.

[0120] (Method of measuring transmittance) The transmittance at 430 nm of the thin film obtained on the glass substrate was measured using a UV-VIS SPECTROPHOTOMETER (Shimazu Corporation, "UV-2600").

[0121] (Method of measuring YI value) As with the transmittance, the YI value was calculated using a UV-VIS SPECTROPHOTOMETER (Shimazu Corporation, "UV-2600") and color measurement software.

[0122] (Tack-free test) As a method for determining whether the radical polymerizable composition of the present invention has been photocured, there is a tack-free test (finger touch test). That is, when the radical polymerizable composition is irradiated with light, it cures and the tack (stickiness) of the surface disappears, so whether it has cured or not is confirmed by whether the tack (stickiness) has disappeared after irradiation with light.

[0123] (UV exposure machine) Model name: MATSUO, UV-LED CURE M / C, JVC-200-SC-N-POWER

[0124] [Synthesis Example 1] Synthesis of 2-(2-hydroxyethyl)thio-5-methylthio-1,3,4-thiadiazole (compound of general formula (5)) 2-mercapto-5-methylthio-1,3,4-thiadiazole (14.75g, 0.090mol), triethylamine (9.54g, 0.094mol), and 4-methyltetrahydrofuran (147.5g) were placed in a three-neck flask and stirred at room temperature for several minutes. Then, 2-bromoethanol (11.22g, 0.090mol) was added dropwise, and after the dropwise addition was completed, the mixture was reacted at 70°C for 8 hours. Then, the mixture was cooled to room temperature, and triethylamine hydrochloride was removed by vacuum filtration, and the organic layer was washed with pure water. Then, the organic layer was dehydrated with magnesium sulfate and suction filtration was performed to obtain a tetrahydrofuran solution of the intermediate 2-(2-hydroxyethyl)thio-5-methylthio-1,3,4-thiadiazole.

[0125] [Synthesis Example 2] Synthesis of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole (compound of general formula (1)) The tetrahydrofuran solution of 2-(2-hydroxyethyl)thio-5-methylthio-1,3,4-thiadiazole obtained in Synthesis Example 1 and triethylamine (9.36 g, 0.092 mol) were placed in a three-neck flask, stirred and mixed at room temperature, and then ice-cooled so that the internal temperature was 0 to 5°C. Then, acryloyl chloride (10.45 g, 0.115 mol) was slowly dropped so that the internal temperature was in the range of 5 to 15°C, and after the dropwise addition was completed, the reaction was carried out at room temperature for 3.5 hours. Then, triethylamine hydrochloride was removed by filtration under reduced pressure, and the organic layer was washed with a 5% aqueous sodium bicarbonate solution and pure water in that order, dehydrated and filtered with anhydrous magnesium sulfate, and the solvent was distilled off with an evaporator. Then, purification was carried out by column chromatography to obtain the target product, 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole, as a pale yellow liquid. The yield was 7.5 g. Yield 32%.

[0126] (1) Viscosity (25℃): 45mPa·s (2)n D =1.61 (3) 1H-NMR (CDCl3, ppm): δ = 2.8 (s, 3H, methyl), 3.6 (t, 2H, methylene), 4.5 (t, 2H, methylene), 5.9 (d, 1H, vinyl), 6.1 (dd, 1H, vinyl), 6.4 (d, 1H, vinyl). (4) Mass spectrum: (EI-MS) m / z=262 (M + )

[0127] [Example 1] Photoradical polymerization of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole 1 To 100 parts of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole obtained by the same method as in Synthesis Example 2, 3 parts of OmniradTPO as a photoradical polymerization initiator and 1 part of a fluorosurfactant Megafac F-477 (Megafac is a registered trademark of DIC Corporation) were added, and the mixture was dissolved by applying ultrasonic waves. This radically polymerizable composition was formed into a film of 10 μm on a glass substrate using a bar coater (OSP-10), and after replacing the inside of the exposure machine with nitrogen, light with a wavelength of 365 nm was applied at an exposure dose of 30 J / cm with an illuminance of 100 mW. 2 The surface was checked for tackiness after exposure and found to have no tackiness. The refractive index (n D The refractive index (n D ) was measured and found to be 1.64. The transmittance of the film was 92%, and the YI value was 3.4. The results are shown in Tables 1 and 2. Furthermore, this film was highly flexible, and even when folded in half on a glass substrate, no cracks were observed in the film at the folded portion.

[0128] [Example 2] Photoradical polymerization of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole 2 To 100 parts of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole obtained by the same method as in Synthesis Example 2, 3 parts of OmniradTPO as a photoradical polymerization initiator and 1 part of a fluorosurfactant Megafac F-477 (Megafac is a registered trademark of DIC Corporation) were added, and dissolved by applying ultrasonic waves. Thereafter, the prepared radical polymerizable composition was formed into a film of 25 μm on a glass substrate using a bar coater (OSP-25), and after replacing the inside of the exposure machine with nitrogen, light with a wavelength of 365 nm was applied at an exposure dose of 30 J / cm with an illuminance of 100 mW. 2 The surface was checked for tackiness after exposure and found to have no tackiness. The refractive index (n D The refractive index (n D ) was measured and found to be 1.64. The results are shown in Table 1. The film had a transmittance of 90% and a YI value of 4.7. Furthermore, this film was highly flexible, and no cracks were observed in the film at the folded portion even when it was folded in half on a glass substrate.

[0129] [Example 3] Photoradical polymerization of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole 3 To 100 parts of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole obtained by the same method as in Synthesis Example 2, 3 parts of OmniradTPO as a photoradical polymerization initiator and 1 part of fluorosurfactant Megafac F-477 (Megafac is a registered trademark of DIC Corporation) were added, and dissolved by applying ultrasonic waves. Thereafter, the prepared radical polymerizable composition was formed into a film of 10 μm on a glass substrate using a bar coater (OSP-10), and after replacing the inside of the exposure machine with nitrogen, light with a wavelength of 405 nm was applied at 30 J / cm. 2 The surface was checked for tackiness after exposure and found to have no tackiness. The refractive index (n D The refractive index (n D) was measured and found to be 1.64. The transmittance of the film was 98%, and the YI value was 0.8. The results are shown in Table 1. Furthermore, this film was highly flexible, and even when folded in half on a glass substrate, no cracks were observed in the film at the folded portion.

[0130] [Comparative Example 1] Photoradical polymerization of trimethylolpropane triacrylate (TMPTA) A radical polymerizable composition was prepared in the same manner as in Example 1, except that 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole was replaced with trimethylolpropane triacrylate (TMPTA), and the composition was irradiated with light and cured in the same manner. After exposure, the surface was checked for tackiness, and no tackiness was found. The refractive index (n D The refractive index (n D ) was measured and found to be 1.52. The film's transmittance was 100%, and its YI value was 0.2. The results are shown in Tables 1, 2, and 3. However, when this film was folded in half on a glass substrate, it was found to have low flexibility and cracks were observed in the film at the folded portion.

[0131] [Comparative Example 2] Photoradical polymerization of trimethylolpropane triacrylate (TMPTA) A radical polymerizable composition was prepared in the same manner as in Example 2, except that 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole was replaced with trimethylolpropane triacrylate (TMPTA), and the composition was irradiated with light and cured in the same manner. After exposure, the surface was checked for tackiness, and no tackiness was found. The refractive index (n D The refractive index (n D ) was measured and found to be 1.52. The film's transmittance was 100%, and its YI value was 0.4. The results are shown in Table 1. However, when this film was folded in half on a glass substrate, it was found to have low flexibility and cracks were observed in the film at the folded portion.

[0132] [Table 1]

[0133] As is clear from Examples 1 to 3 and Comparative Examples 1 and 2 and Table 1 summarizing the results, the compound of the present invention, 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole, has a low viscosity and can be easily polymerized even with light of a long single wavelength such as 365 nm or 405 nm. In addition, the refractive index (n D ) is 1.64, exceeding 1.60, indicating a very high refractive index. Furthermore, the obtained polymerized film is highly flexible, does not crack at the folded portion even when folded, has a high transmittance of 90% or more at 430 nm, and a low YI value of 5 or less. In particular, the film polymerized and cured at 405 nm has a transmittance of 98%, and its YI value is an extremely low 0.8, indicating that it is particularly suitable for optical applications.

[0134] [Example 4] Photoradical copolymerization of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole and multifunctional (meth)acrylate 1 50 parts of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole obtained by the same method as in Synthesis Example 2 and 50 parts of trimethylolpropane triacrylate (TMPTA) were mixed, 3 parts of Omnirad TPO and 1 part of Megafac F-477 were added, and the mixture was dissolved by applying ultrasonic waves. The dissolution rate of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole in trimethylolpropane triacrylate was extremely fast, and the mixture was easily mixed to form a uniform liquid phase. Thereafter, the prepared radical polymerizable composition was formed into a film of 10 μm on a glass substrate using a bar coater (OSP-25), and after replacing the inside of the exposure machine with nitrogen, light with a wavelength of 365 nm was applied at 30 J / cm. 2 The surface was checked for tackiness after exposure and found to have no tackiness. The refractive index (n D The refractive index (n D) was measured and found to be 1.58. The film had a transmittance of 96% and a YI value of 1.0. The results are shown in Table 2.

[0135] [Example 5] Photoradical copolymerization of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole and multifunctional (meth)acrylate 2 50 parts of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole obtained by the same method as in Synthesis Example 2 and 50 parts of trimethylolpropane triacrylate (TMPTA) were mixed, 3 parts of Omnirad TPO and 1 part of Megafac F-477 were added, and the mixture was dissolved by applying ultrasonic waves. The dissolution rate of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole in trimethylolpropane triacrylate was extremely fast, and the mixture was easily mixed to form a uniform liquid phase. Thereafter, the prepared radical polymerizable composition was formed into a film of 25 μm on a glass substrate using a bar coater (OSP-25), and after replacing the inside of the exposure machine with nitrogen, light with a wavelength of 365 nm was applied at 30 J / cm. 2 The surface was checked for tackiness after exposure and found to have no tackiness. The refractive index (n D The refractive index (n D ) was measured and found to be 1.58. The film had a transmittance of 96% and a YI value of 1.8.

[0136] [Example 6] Photoradical copolymerization of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole and multifunctional (meth)acrylate 3 50 parts of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole obtained by the same method as in Synthesis Example 2 and 50 parts of bis(4-methacryloylthiophenyl)sulfide (BMTPS) were mixed, 3 parts of OmniradTPO and 1 part of Megafac F-477 were added, and the mixture was dissolved by applying ultrasonic waves. Although bis(4-methacryloylthiophenyl)sulfide is a solid, it was dissolved in 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole to form a uniform liquid phase. Thereafter, the prepared radical polymerizable composition was formed into a film of 10 μm on a glass substrate using a bar coater (OSP-25), and after replacing the inside of the exposure machine with nitrogen, light with a wavelength of 365 nm was applied at 30 J / cm. 2 The surface was checked for tackiness after exposure and found to have no tackiness. The refractive index (n D The refractive index (n D ) was measured and found to be 1.67. The transmittance of the film was 92%, and the YI value was 2.6. The results are shown in Table 2. Bis(4-methacryloylthiophenyl)sulfide (BMTPS) manufactured by Tokyo Chemical Industry Co., Ltd. was used. The reagent is a white solid, and was dissolved in ethyl benzoate at several concentrations to measure the viscosity at 25°C. The refractive index (nD) of BMTPS was calculated to be 1.645 by extrapolation.

[0137] [Comparative Example 3] Photoradical copolymerization of TMPTA and BMTPS 1 70 parts of trimethylolpropane triacrylate (TMPTA) and 30 parts of bis(4-methacryloylthiophenyl) sulfide (BMTPS) were mixed, 3 parts of OmniradTPO and 1 part of Megafac F-477 were added, and the mixture was dissolved by applying ultrasonic waves. After that, a film was formed on a glass substrate to a thickness of 10 μm using a bar coater, and after replacing the inside of the exposure machine with nitrogen, light with a wavelength of 365 nm was applied at 30 J / cm. 2 The surface was checked for tackiness after exposure and found to have no tackiness. The refractive index (n D The refractive index (nD ) was measured and found to be 1.57. The film had a transmittance of 98% and a YI value of 0.8. The results are shown in Table 2.

[0138] [Comparative Example 4] Photoradical copolymerization of TMPTA and BMTPS 2 Trimethylolpropane triacrylate (TMPTA) and bis(4-methacryloylthiophenyl) sulfide (BMTPS) were mixed together at 50 parts each, and 3 parts of Omnirad TPO and 1 part of Megafac F-477 were added. Ultrasonic waves were applied, but BMTPS did not dissolve in TMPTA at room temperature. It was dissolved by heating to 40°C, but solid matter precipitated during film formation, and a polymerization test could not be performed. The refractive index (n D ) was 1.56.

[0139] [Comparative Example 5] Photoradical copolymerization of TMPTA and BMTPS 3 30 parts of trimethylolpropane triacrylate (TMPTA) and 70 parts of bis(4-methacryloylthiophenyl) sulfide (BMTPS) were mixed, 3 parts of OmniradTPO and 1 part of Megafac F-477 were added, and the mixture was sonicated to dissolve, but it did not dissolve and remained in a suspended state even when heated.

[0140] [Table 2]

[0141] As is clear from the results of Examples 1, 4 and Comparative Example 1 and Table 2, trimethylolpropane triacrylate (TMPTA) and 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole of the present invention can be copolymerized at any ratio, and the refractive index of the copolymer is additive with the ratio of the added 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole. Therefore, by adjusting the amount of the added 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole of the present invention and changing the copolymerization composition, it is possible to achieve a desired refractive index between 1.52 and 1.64. In addition, as is clear from Example 6, it is also compatible with solid monomers having a structure such as bis(4-methacryloylthiophenyl)sulfide, and the obtained 1:1 copolymer shows a very high refractive index of 1.67. This bis(4-methacryloylthiophenyl) sulfide also copolymerizes with trimethylolpropane triacrylate. However, as is clear from Comparative Examples 3 to 5, at a 1:1 mixing ratio, dissolution is difficult and solids precipitate during film formation, making it impossible to produce a uniform film. It is also clear that the solubility limit of BMTPS in the copolymer composition is 30% by weight.

[0142] [Example 7] Preparation of photoradical copolymerization composition of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole and multifunctional (meth)acrylate 1 90 parts of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole obtained in the same manner as in Synthesis Example 2 and 10 parts of trimethylolpropane triacrylate (TMPTA) were mixed and dissolved by applying ultrasonic waves. The dissolution rate of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole and trimethylolpropane triacrylate was extremely fast, and they were easily mixed together to form a uniform liquid phase. The refractive index (n D ) was 1.59 and the viscosity was 48 mPa·s.

[0143] [Example 8] Preparation of photoradical copolymerization composition of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole and multifunctional (meth)acrylate 2 50 parts of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole obtained in the same manner as in Synthesis Example 2 and 50 parts of trimethylolpropane triacrylate (TMPTA) were mixed and dissolved by applying ultrasonic waves. The dissolution rate of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole and trimethylolpropane triacrylate was extremely fast, and they were easily mixed together to form a uniform liquid phase. The refractive index (n D ) was 1.53 and the viscosity was 58 mPa·s.

[0144] [Example 9] Preparation of photoradical copolymerization composition of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole and multifunctional (meth)acrylate 3 10 parts of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole obtained in the same manner as in Synthesis Example 2 and 90 parts of trimethylolpropane triacrylate (TMPTA) were mixed and dissolved by applying ultrasonic waves. The dissolution rate of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole and trimethylolpropane triacrylate was extremely fast, and they were easily mixed together to form a uniform liquid phase. The refractive index (n D ) was 1.49 and the viscosity was 92 mPa·s.

[0145] [Example 10] Preparation of photoradical copolymerization composition of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole and multifunctional (meth)acrylate 4 50 parts of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole obtained in the same manner as in Synthesis Example 2 and 50 parts of bis(4-methacryloylthiophenyl)sulfide (BMTPS) were mixed and dissolved by applying ultrasonic waves. The dissolution rate of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole and bis(4-methacryloylthiophenyl)sulfide was extremely fast, and they were easily mixed together to form a uniform liquid phase. The refractive index (n D ) was 1.63 and the viscosity was 110 mPa·s.

[0146] [Table 3]

[0147] As is clear from Table 3, Examples 1 to 10, and Comparative Example 1, the refractive index n D is easily dissolved and mixed with trimethylolpropane triacrylate, a polyfunctional (meth)acrylate, in any composition to form a copolymer composition. As is clear from FIG. 2, there is an additivity between the composition ratio and the refractive index, and it is possible to adjust the refractive index of the composition. In terms of viscosity adjustment, the viscosity reducing effect of the amount of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole, a compound of the present invention, added to a copolymer composition of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole, a compound of the present invention, and trimethylolpropane triacrylate, a polyfunctional (meth)acrylate, is large, and the viscosity of the copolymer composition can be greatly reduced by adding a small amount. For example, it is understood that in order to suppress the viscosity of the copolymer composition to 60 mPa·s or less, 45 wt % or more of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole should be added.

Claims

1. A (meth)acrylic acid ester having a thiadiazole ring represented by the following general formula (1): 【Chemistry 1】 In the general formula (1), A represents an oxygen atom or a sulfur atom, n represents an integer of 1 to 6, and R １ represents a linear or branched alkyl group having 1 to 6 carbon atoms; R ２ represents a hydrogen atom or a methyl group.)

2. In the general formula (1), A is an oxygen atom, n is 2, and R １ is a methyl group, R ２ The (meth)acrylic acid ester having a thiadiazole ring according to claim 1 , wherein is a hydrogen atom.

3. A radically polymerizable composition comprising the (meth)acrylic acid ester having a thiadiazole ring according to claim 1 or 2, and a radical polymerization initiator.

4. 4. The radically polymerizable composition according to claim 3, further comprising a compound having an unsaturated bond other than the (meth)acrylic acid ester having a thiadiazole ring represented by general formula (1).

5. 5. The radical polymerizable composition according to claim 4, wherein the compound having an unsaturated bond is a compound having one or more unsaturated bonds selected from the group consisting of monofunctional (meth)acrylates, monofunctional (meth)acrylamides, polyfunctional (meth)acrylates, and polyfunctional (meth)acrylamides.

6. 5. The radical polymerizable composition according to claim 4, wherein the content of the (meth)acrylic acid ester having a thiadiazole ring is 20% by weight or more.

7. A method for producing a (meth)acrylic acid ester having a thiadiazole ring represented by general formula (1), comprising a first step of synthesizing a compound represented by general formula (5) by reacting a 1,3,4-thiadiazole compound having a thiol group represented by general formula (3) with a halogenated alcohol or a halogenated thioalcohol in the presence of a base, and a second step of (meth)acrylating the obtained compound represented by general formula (5). 【Chemistry 2】 (In the general formula (2), R １ represents a straight or branched alkyl group having 1 to 6 carbon atoms. 【Chemistry 3】 In the general formula (5), A represents an oxygen atom or a sulfur atom, n represents an integer of 1 to 6, and R １ represents a straight or branched alkyl group having 1 to 6 carbon atoms. 【Chemistry 4】 In the general formula (1), A represents an oxygen atom or a sulfur atom, n represents an integer of 1 to 6, and R １ represents a linear or branched alkyl group having 1 to 6 carbon atoms; R ２ represents a hydrogen atom or a methyl group.)

8. A polymerization method comprising irradiating the radically polymerizable composition according to claim 3 with active energy rays.

9. 9. The polymerization method according to claim 8, wherein the active energy rays to be irradiated have a peak wavelength in the wavelength range of 350 nm to 420 nm.

10. A polymer obtained by polymerizing the radically polymerizable composition according to claim 1 or 2, which has a refractive index (n Ｄ ) is 1.55 or more.

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