Novel heterocyclic ring-containing monomer

Abstract

[Problem] To provide a radical-polymerizable compound which is used as a raw material of a transparent resin suitable for optical applications and which not only exhibits excellent curing properties but also has a low viscosity and, when cured, yields a polymer that exhibits excellent flexibility and has a high refractive index. [Solution] Provided is a (meth)acrylic acid ester having a thiadiazole ring represented by general formula (1). (In general formula (1), A denotes an oxygen atom or a sulfur atom, n denotes an integer between 1 and 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.)

Description

Novel heterocyclic monomers

[0001] The present invention relates to a (meth)acrylic acid ester and a method for polymerizing the same, and more particularly to a (meth)acrylic acid ester having a thiadiazole ring and a method for polymerizing the same.

[0002] (Meth)acrylic acid esters are known as representative radically polymerizable compounds. Such (meth)acryloyl groups have double bonds activated by conjugation with adjacent carbonyl groups, and these double bonds polymerize via radical polymerization to form polymers. (Meth)acrylic acid esters are excellent in terms of polymerization rate, internal curing properties, durability of the chemical bonds formed, and economy, and are therefore used in a wide range of applications, including 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] Furthermore, due to their excellent transparency, dimensional stability, and weather resistance, their polymers are widely used in various fields, such as optical materials, vehicle parts, lighting materials, and building materials. In recent years, in electronic materials, particularly in display-related fields, the use of optical films such as light extraction films as substrates has been proposed to further improve light-emitting efficiency, and (meth)acrylic acid esters have been used as monomers for such films. By including a polymer of this (meth)acrylic acid ester, it is possible to impart not only high transparency but also excellent shapeability, processability, and moldability to the polymer, as well as adhesion and flexibility.

[0004] Such optical films are often laminated with several types of films, or an inorganic film is laminated in contact with the optical film. In such cases, if there is a large difference in refractive index between the films or between the films and the adhesive, light is reflected at the interface of the layers, causing halation and poor visibility. Therefore, 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 having a high refractive index, it is required to increase the refractive index of the film itself. For example, the refractive index (nＤ ) is about 2.1.

[0005] On the other hand, various high refractive index glasses have been developed, but they are easily broken and difficult to apply as optical films, and high refractive index materials containing inorganic particles have problems such as transparency and difficulty in maintaining a highly dispersed state without the inorganic particles agglomerating. Therefore, a polymer film of (meth)acrylic acid ester having transparency similar to that of glass is expected, but the refractive index (n Ｄ For example, the refractive index (n Ｄ ) is known to be around 1.49. Therefore, there is a need for a method for increasing the refractive index of (meth)acrylic acid 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 generally involve the introduction of aromatic rings or heavy atoms such as sulfur or bromine atoms, as a means of increasing the refractive index of organic materials. However, while monomers containing polycyclic aromatic rings such as biphenyl, naphthalene, fluorene, and anthracene in their molecular structure are expected to have a high refractive index, they almost always become high-viscosity liquids or crystalline solids, resulting in problems such as poor solubility and handling. Generally, compounds with high refractive indexes are often solids or high-viscosity compounds, while compounds that possess both properties are rare. Currently, it is difficult to determine whether a compound possesses both properties without first synthesizing it. One such attempt involves the introduction of sulfur atoms, for example. For example, Patent Document 1 attempts to increase the refractive index by introducing an aromatic ring via a sulfur atom. Patent Document 2 discloses polymerizable compositions primarily composed of thio(meth)acrylate monomers, including bis[(4-methacryloylthio)phenyl] sulfide. Furthermore, 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 thereof 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 an inkjet method.

[0007] Furthermore, Patent Document 5 discloses a (meth)acrylic acid ester having a fused 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 polymerizable compounds 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 differs 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 specific compounds are not disclosed, and its physical properties are not described. Furthermore, since it is based on a pentaerythritol skeleton, it has a fundamental structure 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 heterocyclic groups 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 combined with para-thiophenylbenzyl acrylate, a monofunctional acrylate and a high refractive index monomer, to prepare a high refractive index composition. One of the polyfunctional (meth)acrylates having a heteroarylene group disclosed in these documents is a compound in which two acrylate groups are substituted on a thiadiazole ring (1,3,4-thiadiazole-2,5-diyl)bis(sulfanediyl)bis(ethane-2,1-diyl)diacrylate). This polyfunctional (meth)acrylate has a lower refractive index than para-thiophenylbenzyl acrylate, and its addition reduces the refractive index of the composition. For this reason, as described in these documents, this polyfunctional (meth)acrylate functions as a crosslinking agent and is used to prevent the polymer from becoming inflexible. Furthermore, 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.

[0012] JP 2020-37693 A JP 9-25321 A JP 2017-190326 A JP 2021-31669 A JP 2018-104696 A JP 2012-82145 A JP 2023-32499 A JP 2017-14213 A JP 2021-172823 A JP 6-505276 A JP 2020-506251 A JP 2021-523281 A

[0013] To provide a radical polymerizable compound which is used as a transparent resin raw material suitable for optical applications, which not only has excellent curing properties but also has low viscosity, and which gives a polymer obtained by curing that has excellent flexibility and a high refractive index.

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

[0017] In 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 is a compound represented by the general formula (1), wherein 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 radically 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, 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.

[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]

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

[0026]

[0027] In 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]

[0029] In general formula (1), A represents an oxygen atom or a sulfur atom, n represents an integer of 1 to 6, and R１ 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 invention is a polymer obtained by polymerizing the radically polymerizable composition according to the first or second invention, wherein 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 refers to acrylate or methacrylate, (meth)acryloyl refers to acryloyl or methacryloyl, and (meth)acrylic refers to acrylic or methacrylic. Furthermore, unless otherwise specified, the refractive index in the present invention refers to 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.

[0034] The (meth)acrylic acid ester having a thiadiazole ring of the present invention and the radically polymerizable composition containing the (meth)acrylic acid ester having the thiadiazole ring not only have excellent curability but also low viscosity, and the polymer obtained by curing the radically polymerizable composition has a high refractive index. Furthermore, the (meth)acrylic acid ester having a thiadiazole ring of the present invention is highly compatible with various radically polymerizable compounds, and by mixing and copolymerizing it with various radically polymerizable compounds, the refractive index of the polymer can be adjusted. Therefore, it is extremely useful in the field of optical materials as a high refractive index material or a refractive index adjuster.

[0035] The objects, features and advantages of the present invention will become more apparent from the following detailed description.

[0036] 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole synthesized in Synthesis Example 2 １ H-NMR chart. A diagram showing the relationship between the addition ratio of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole 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 the plotted points.

[0037] The present invention will be described in detail below.

[0038] ((Meth)acrylic acid ester having a thiadiazole ring represented by general formula (1)) The present invention is a (meth)acrylic acid ester having a thiadiazole ring represented by the following general formula (1).

[0039]

[0040] In 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.

[0041] In 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.

[0042] 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, 2-methacryloxymethylthio-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 thiol, 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-pentylthio-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 thio-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-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, 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-acryloylthioethylthio-5-ethylthio-1,3,4-thiadiazole, 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 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-n-propylthio-5-methylthio-1,3,4-thiadiazole 2-acryloylthio-n-propylthio-5-ethylthio-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-n-propylthio-1,3,4-thiadiazole, 2-acryloylthio-n-propylthio-5-isopropylthio-1,3,4-thiadiazole, 2-methacryloylthio-n-propylthio-5-isopropylthio-1,3,4-thiadiazole,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-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-methacryloyl Thio-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-pentylthio-5-methylthio-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-ethylthio-1,3,4-thiadiazole thio-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-isopropylthio-1,3,4-thiadiazole, 2-acryloylthio-n-hexylthio-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, and the like.

[0043] In the (meth)acrylic acid ester having a thiadiazole ring of the present invention, the 1,3,4-thiadiazole ring substituted with sulfur atoms at the 2- and 5-positions forms 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.

[0044] 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 The 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.

[0045]

[0046] In general formula (2), R ２ represents a hydrogen atom or a methyl group.

[0047] 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.

[0048] (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.

[0049]

[0050] In the above reaction formula, 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, and X represents a chlorine atom or a bromine atom.

[0051]

[0052] In the above reaction formula, 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.

[0053] (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.

[0054] 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.

[0055] The amount of halogenated alcohol or halogenated thioalcohol used relative to 1 mole of the 1,3,4-thiadiazole compound having a thiol group represented by general formula (3) is, for example, 0.1 to 5 moles, and preferably 0.5 to 1.5 moles, relative to 1 mole of the 1,3,4-thiadiazole compound having a thiol group represented by general formula (3).

[0056] 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 compounds can be used.

[0057] In the first step, it is preferable to use a reaction solvent, such as a polyhydric alcohol ether, a cyclic ether, a polyhydric alcohol ester, a ketone, an alkyl ester, or a sulfoxide.

[0058] 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.

[0059] 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, the production of reaction by-products is promoted, which is undesirable.

[0060] After the reaction in the first step is completed, the base catalyst is removed and the solution containing the product is separated. For example, a method for removing the catalyst may be used, such as a method of performing a neutralization treatment and then filtering off the precipitated neutralized salt. The resulting solution containing the product can be used directly 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.

[0061] <Second Step> In the second step, the compound of general formula (5) obtained in the first step is (meth)acrylated. Various methods can be used for the (meth)acrylation, but first, as a (meth)acrylation agent, a (meth)acrylic halide represented by general formula (6) can be mentioned.

[0062] Usable halogenated acrylic compounds include acryloyl chloride, acryloyl bromide, etc. Usable halogenated methacrylic compounds include methacryloyl chloride, methacryloyl bromide, etc.

[0063] The amount of the (meth)acrylic halide used relative to 1 mole of the compound of general formula (5) is, for example, 1 to 10 moles, preferably 1 to 5 moles, per mole of the compound of general formula (5).

[0064] In the reaction of the compound of general formula (5) with the (meth)acrylic halide, 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.

[0065] In the second step, it is preferable to use a reaction solvent. Examples of the reaction solvent that can be used include polyhydric alcohol ethers, cyclic ethers, polyhydric alcohol esters, ketones, alkyl esters, sulfoxides, etc. 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 isolation.

[0066] 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.

[0067] 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, the production of reaction by-products is promoted, which is undesirable.

[0068] After the reaction of the second step is completed, the base catalyst is removed and the solution containing the product is separated. For example, the catalyst can be removed by neutralizing the product and then filtering off the precipitated neutralized salt. The solvent is removed from the resulting solution containing the product, and the product is purified by column chromatography or the like to isolate and purify the compound of general formula (1).

[0069] As the (meth)acrylation agent in the second step, (meth)acrylic anhydride, (meth)acrylic acid, etc. can also be used in addition to (meth)acrylic halide.

[0070] In addition to the above-mentioned synthesis methods, the compound of general formula (1) of the present invention can also 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 a method in which the halogenated alcohol in the first step is replaced with an alkyl dihalide such as bromochloroethane or dibromoethane to convert the reactive terminals of the compound of general formula (5) into halogens, followed by reaction with a (meth)acrylate salt.

[0071] 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 as low as about 50 mPa·s, and its refractive index (n Ｄ The refractive index of 1-naphthyl methyl acrylate at 25°C (n Ｄ ) is greater than 1.595.

[0072] It is believed that the (meth)acrylic acid ester having a thiadiazole ring represented by general formula (1) achieves a high refractive index and a low viscosity by introducing an acrylic group, which is a polymerizable group, via a flexible alkyl chain to a thiadiazole ring having a thiomethyl group, which exhibits a high refractive index.

[0073] Furthermore, due to its characteristic structure, the (meth)acrylic acid ester having a thiadiazole ring represented by general formula (1) is highly compatible with other radically polymerizable compounds such as acrylic acid esters, and a radically polymerizable composition produced by mixing it with other radically polymerizable compounds also undergoes radical polymerization curing, making it possible to increase the refractive index of the cured product to be higher than the refractive index of the cured product of other radically polymerizable compounds, thereby making it possible to adjust the refractive index of the cured product. Furthermore, the (meth)acrylic acid ester represented by general formula (1) of the present invention has a low viscosity, so that it is less likely to increase in viscosity when mixed with other radically polymerizable compounds, making it easy to apply, and it can also be used in applications such as inkjet inks.

[0074] (Radical 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.

[0075] 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, in particular, monofunctional (meth)acrylates, monofunctional (meth)acrylamides, polyfunctional (meth)acrylates, polyfunctional (meth)acrylamides, etc., and since the polymerizable groups are the same, this is a preferred combination for copolymerization.

[0076] Examples of usable monofunctional (meth)acrylates 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 ... methyl (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.

[0077] 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.

[0078] 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 suitable 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 to C6, linear or branched) (meth)acrylates are preferred.

[0079] 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.

[0080] 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.

[0081] Examples of the acetoacetyl group-containing (meth)acrylic monomer include 2-(acetoacetoxy)ethyl (meth)acrylate.

[0082] Examples of the isocyanate group-containing (meth)acrylic monomer include 2-acryloyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate, and alkylene oxide adducts thereof.

[0083] 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.

[0084] 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, benzylphenyl (meth)acrylate, p-phenylbenzyl acrylate, p-t-butylphenyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxypropyl (meth)acrylate, phenoxydiethylene 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 monomer include (meth)acrylic monomers having a naphthalene ring group, such as 4-methoxy-1-naphthoxyethyl (meth)acrylate, 1-naphthylmethyl (meth)acrylate, and 2-naphthylmethyl acrylate; (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 fluorenyl (meth)acrylate and 9-fluorenylmethyl (meth)acrylate (9-(meth)acryloyloxymethylfluorene). In addition to the compounds exemplified here, examples include (meth)acrylic monomers having, as aromatic hydrocarbon groups, 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 a high viscosity, and by forming a copolymer composition with a (meth)acrylic acid ester having a thiadiazole ring represented by general formula (1) of the present invention, a photoradical polymerizable composition having a high refractive index but a low viscosity can be obtained.

[0085] 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-hydroxyalkyl (C1 to C18, linear or branched) (meth)acrylamides, and N-hydroxyalkyl (C1 to C18). Examples of suitable monofunctional monomers include N-(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, diacetoneacrylamide, N-(dimethylamino)propyl(meth)acrylamide, and N-hydroxyethylacrylamide are more preferred. These monofunctional monomers may be used alone or in combination of two or more.

[0086] 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, cyclohexanedimethanol di(meth)acrylate, acrylate ester (dioxane glycol diacrylate), alkoxylated hexanediol di(meth)acrylate, alkoxylated cyclohexanedimethanol di(meth)acrylate, epoxy (meth)acrylate, urethane (meth)acrylate, and other monomers and oligomers.From the viewpoint of easy availability as a commercially available product, examples of polyfunctional (meth)acrylates include, for example, CN2203 and CN2270 manufactured by SARTOMER Co., Ltd., and M-6100 and M-8060 manufactured by Toagosei Co., Ltd.; examples of urethane acrylates include, for example, UV-3200B, UV-3000B, UV-6640B, UV-3700B, UV-3310B, and UV-7000B manufactured by Nippon Synthetic Chemical Industry Co., Ltd.; U-4HA and U-200PA manufactured by Shin-Nakamura Chemical Co., Ltd.; and EBECRYL245, EBECRYL1259, and EBECRYL245 manufactured by Daicel-Cytec Co., Ltd. Examples of epoxy (meth)acrylates that can be used include ECRYL8210, EBECRYL284, EBECRYL8402, SARTOMER products under the trade names CN944, CN969, CN9002, and CN9029, Negami Chemical Industrial Co., Ltd. products under the trade names UN1255 and UN-5507, and Kyoeisha Chemical Co., Ltd. products under the trade names AH-600 and UA-306I. Examples of epoxy (meth)acrylates that can be used include Daicel-Cytec products under the trade names EBECRYL1259, EBECRYL605, and EBECRYL1606, and SARTOMER products under the trade names CN110, CN120, and CN153. Furthermore, from the viewpoint of the viscosity of the resin composition, ease of handling, and the like, urethane acrylate UV-6640B or U-200PA is more preferred. These polyfunctional (meth)acrylates may be used singly or in combination of two or more.

[0087] Also included are high refractive index polyfunctional (meth)acrylic esters such as bis(4-methacryloylthiophenyl)sulfide and bis(4-acryloylthiophenyl)sulfide.

[0088] Examples of polyfunctional (meth)acrylamides include methylenebis(meth)acrylamide, ethylenebis(meth)acrylamide, diallyl(meth)acrylamide, and urethanedi(meth)acrylamide.

[0089]

[0033] 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 a (meth)acrylic acid ester, the mixing ratio thereof depends on the desired physical properties, but in terms of acting as 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, more preferably 10% by weight or more, relative to the radical polymerizable composition, and in terms of achieving a high refractive index, it is particularly preferably used in an amount of 20% by weight or more. Since the (meth)acrylic acid ester having a thiadiazole ring of the present invention has a low viscosity, the refractive index of the polymerizable composition can be adjusted without significantly increasing the viscosity thereof.

[0090] (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 examples thereof include a thermal radical polymerization initiator, a photoradical polymerization initiator, and the like. Furthermore, the radical polymerization initiator may be either a thermal radical polymerization initiator or a photoradical polymerization initiator, or may be both a thermal radical polymerization initiator and a photoradical polymerization initiator.

[0091] Examples of the thermal radical polymerization initiator include organic peroxides, inorganic peroxides, and azo compounds. Examples of organic peroxides include hydroperoxides, dialkyl peroxides, peroxyesters, 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.

[0092] The photoradical polymerization initiator can be any commonly used one without any particular limitation, and examples thereof include benzyl methyl ketal-based polymerization initiators, α-hydroxyalkylphenone-based polymerization initiators, oxime ester-based polymerization initiators, α-aminoacetophenone-based polymerization initiators, acylphosphine oxide-based polymerization initiators, biimidazole-based polymerization initiators, triazine-based polymerization initiators, and thioxanthone-based polymerization initiators.

[0093] Examples of benzyl methyl ketal polymerization initiators include 2,2-dimethoxy-1,2-diphenylethan-1-one (trade name "Omnirad 651" 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 "Omnirad 1173" manufactured by IGM Group B.V.), 1-hydroxycyclohexyl phenyl ketone (trade name "Omnirad 184" manufactured by IGM Group B.V.), 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one (trade name "Omnirad 2959" manufactured by IGM Group B.V.), and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)-benzyl]phenyl}-2-methyl-1-one (trade name "Omnirad 127" manufactured by IGM Group B.V.).

[0094] In particular, 2,2-dimethoxy-1,2-diphenylethan-1-one (trade name "Omnirad 651" manufactured by IGM Group B.V.), which is a benzyl methyl ketal polymerization initiator, 2-hydroxy-2-methyl-1-phenylpropan-1-one (trade name "Omnirad 1173" manufactured by IGM Group B.V.), which is an α-hydroxyalkylphenone radical polymerization initiator, and 1-hydroxycyclohexyl phenyl ketone (trade name "Omnirad 184" manufactured by IGM Group B.V.) are preferred.

[0095] 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.

[0096] 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.

[0097] Examples of the α-aminoacetophenone polymerization initiator include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one (trade name "Omnirad 907" manufactured by IGM Group B.V.), 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone (trade name "Omnirad 369" manufactured by IGM Group B.V.), and 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholino-4-yl-phenyl)butan-1-one (trade name "Omnirad 379" manufactured by IGM Group B.V.).

[0098] Examples of the acylphosphine oxide polymerization initiator include 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (trade name "Omnirad TPO" manufactured by IGM Group B.V.) and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (trade name "Omnirad 819" manufactured by IGM Group B.V.).

[0099] Examples of oxime ester polymerization initiators 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.

[0100] 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.

[0101] Examples of the thioxanthone-based polymerization initiator include 2,4-diethylthioxanthone and 2-isopropylthioxanthone.

[0102] 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 be used alone or in combination of two or more types depending on the application, etc.

[0103] 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, with acylphosphine oxide-based photopolymerization initiators and oxime ester-based photopolymerization initiators being particularly preferred in terms of activity.

[0104] From the viewpoints of ease of production of the cured product, resolution, and pattern formability, polymerization and curing by light irradiation is preferred, and in this sense, a radical polymerizable composition using a photoradical polymerization initiator is preferred.

[0105] 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.

[0106] (Photoradical Polymerization Sensitizer) High-pressure mercury lamps have traditionally been used as light sources in photoradical polymerization. However, due to issues such as their high energy consumption, curing devices using LED light sources have become more popular due to their low running costs and environmental impact. However, these LED light sources emit long-wavelength light, such as those with central wavelengths of 365 nm, 385 nm, 395 nm, or 405 nm. Unlike high-pressure mercury lamps, LED light emits light with a single wavelength, resulting in weak irradiation energy. Such LED lamps often fail to sufficiently cure products using conventional photoradical polymerization initiators. To accommodate such long-wavelength, single-beam LED lamps, it is preferable to further add a photoradical polymerization sensitizer. The addition of a photoradical polymerization sensitizer that absorbs long-wavelength light promotes the radical generation reaction of the photoradical polymerization initiator, thereby improving the reactivity of radical polymerization.

[0107] The photoradical polymerization sensitizer can be any commonly used one that is active to light of the irradiation wavelength and is not particularly limited. 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.

[0108] 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.

[0109] The radically 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.

[0110] 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.

[0111] Furthermore, the radical polymerization composition of the present invention may contain a surfactant, preferably a nonionic surfactant. The inclusion of a nonionic surfactant improves the coatability of the radical polymerization composition when applied to a substrate to obtain a resin film, enabling the production of a coating film of uniform thickness. Nonionic surfactants include, for example, compounds containing fluorine groups (e.g., fluorinated alkyl groups) or silanol groups, or compounds having a siloxane bond as their main skeleton. It is preferable to use those containing a fluorine-based surfactant or a silicone-based surfactant. Examples of fluorine-based surfactants include 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, but are not limited thereto. Silicone-based surfactants include surfactants having a siloxane bond within the molecule. Specific examples include Toray Silicone DC3PA, SH7PA, DC11PA, SH21PA, SH28PA, SH29PA, SH30PA, and SH8400 (trade names: manufactured by Dow Corning Toray Co., Ltd.), KP321, KP322, KP323, KP324, KP326, KP340, and KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), and TSF400, TSF401, TSF410, TSF4300, TSF4440, TSF4445, TSF4446, TSF4452, and TSF4460 (manufactured by Momentive Performance Materials Japan, LLC). Examples of silicone surfactants having fluorine atoms include surfactants having a siloxane bond and a fluorocarbon chain in the molecule. Specific examples include Megafac (registered trademark) R08, Megafac BL20, Megafac F475, Megafac F477, and Megafac F443 (manufactured by DIC Corporation).

[0112] 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, antifoaming agents, thickeners, flame retardants, surface modifiers, penetration enhancers, moisture absorbers, humectants, 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.

[0113] (Polymerization Method) A cured product can be obtained by polymerizing the radically polymerizable composition of the present invention by applying heat or irradiating it with light. For example, when irradiating the radically polymerizable composition with light to polymerize and photocure it, the radically polymerizable composition can be molded into a film and then photocured, or it can be molded into a block and then photocured. When molded into a film and then photocured, the liquid radically polymerizable composition is applied to a substrate such as a polyester film using a bar coater or the like to a film thickness of 5 to 300 microns. Alternatively, it can be applied to a thinner or thicker film thickness by spin coating or screen printing. The (meth)acrylic acid ester having a thiadiazole ring and the radically polymerizable composition containing the (meth)acrylic acid ester having a thiadiazole ring of the present invention have low viscosity and can therefore be used as an ink for inkjet printing.

[0114] 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 at an intensity of about 100 nm. Examples of light sources that can be used include high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, xenon lamps, gallium-doped lamps, black lights, 405 nm UV LEDs, 395 nm UV LEDs, 385 nm UV LEDs, 365 nm UV LEDs, semiconductor lasers, blue LEDs, white LEDs, and Fusion's D-bulb and V-bulb bulbs. Natural light such as sunlight can also be used. In particular, 405 nm UV LEDs, 395 nm UV LEDs, 385 nm UV LEDs, 375 nm UV LEDs, and 365 nm UV LEDs are characterized by their sensitizing effect even with light in the long wavelength range of 365 nm to 405 nm, such as 405 nm UV LEDs, 395 nm UV LEDs, 385 nm UV LEDs, 375 nm UV LEDs, and 365 nm UV LEDs. UV LEDs or semiconductor lasers with center wavelengths of 365 nm, 375 nm, 385 nm, 395 nm, or 405 nm are preferred as irradiation sources.

[0115] Because the radical polymerizable composition of the present invention has a high refractive index, its polymers can be preferably used in films for optical applications. Furthermore, it is highly compatible with other radical polymerizable compounds, making it possible to produce copolymers, thereby enabling the refractive index of the resulting copolymer to be adjusted. Furthermore, when used in optical applications, light transmittance and yellowness index (YI value) are generally important. For optical applications, a light transmittance of 90% or more is generally preferred. High transmittance can improve visibility and reduce power consumption when used in displays. For optical applications, the YI value is preferably 10 or less, more preferably 8 or less, and even more preferably 5 or less. Optical laminates with a YI value below this upper limit have good transparency and can contribute to high visibility when used, for example, as the front panel of a display. Films polymerized and cured from the radical polymerizable composition of the present invention not only have an ultra-high refractive index but also exhibit high transmittance and a low YI value, making them ideal radical polymerizable compositions for optical applications.

[0116] Specific embodiments of the present invention will be further described below with reference to examples, but the present invention is not limited to these examples unless it exceeds the gist of the invention. That is, the following examples are not intended to be exhaustive or to limit the present invention to the exact form described. Therefore, the present invention is not limited to the following described examples unless it exceeds the gist of the invention. Furthermore, unless otherwise specified, all parts and percentages are by weight.

[0117] (Identification of Compound) The identification of the obtained compound was measured using the following equipment: (1) １ H-NMR analysis: Nuclear magnetic resonance apparatus (NMR), manufactured by JEOL Ltd., Model: JNM ECS 400 FT NMR Spectrometer) (2) Mass spectrum: Measured using a mass spectrometer, Model GCMS-QP2000, manufactured by Shimadzu Corporation.

[0118] (Measurement of physical properties of compounds) Measurement of physical properties of the obtained compounds (1) Viscosity: E-type viscometer (Toki Sangyo, TVE-35H) (2) Refractive index: Refractometer (measurement conditions: 25°C, nD) In ​​the case of liquid (1.50≦nD≦1.70) Model name: ERMA, ER-7MW-H In the case of liquid / film / thin film (1.30≦nD≦1.70) Model name: Anton Paar Japan, AbbematMw (3) Transmittance: SHIMADZU, UV-2600

[0119] (Viscosity Measurement of Compound) The viscosity was measured using an E-type viscometer TVE35H. A cone rotor of 1°34' x 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.

[0120] (Refractive index measurement method) Liquid (1.50≦n Ｄ ≦1.70), the measurement was carried out at 25°C using a refractometer ERMA ER-7MW-H. Ｄ≦1.70), the measurement was carried out at 25° C. using Abbemat Mw manufactured by Anton Paar Japan.

[0121] (Method for 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").

[0122] (Method of Measuring YI Value) As with the transmittance, the YI value was calculated using a UV-VIS SPECTROPHOPHOTOMETER (Shimazu Corporation, "UV-2600") and color measurement software.

[0123] (Tack-Free Test) A method for determining whether the radical polymerizable composition of the present invention has been photocured is the tack-free test (touch test). That is, when the radical polymerizable composition is irradiated with light, it cures and the tack (stickiness) of the surface disappears, and whether it has been cured or not is confirmed by whether the tack (stickiness) has disappeared after light irradiation.

[0124] (UV exposure machine) Model name: MATSUO, UV-LED CURE M / C, JVC-200-SC-N-POWER

[0125] 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 (14.75 g, 0.090 mol), triethylamine (9.54 g, 0.094 mol), and 4-methyltetrahydrofuran (147.5 g) were placed in a three-neck flask and stirred at room temperature for several minutes. 2-Bromoethanol (11.22 g, 0.090 mol) was then added dropwise, and after the completion of the dropwise addition, the mixture was reacted at 70°C for 8 hours. The mixture was then cooled to room temperature, and the triethylamine hydrochloride was removed by filtration under reduced pressure. The organic layer was washed with pure water. The organic layer was then dehydrated over magnesium sulfate and subjected to suction filtration to obtain a tetrahydrofuran solution of the intermediate 2-(2-hydroxyethyl)thio-5-methylthio-1,3,4-thiadiazole.

[0126] Synthesis Example 2 Synthesis of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole (Compound of General Formula (1)) A three-necked flask was charged with 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), and the mixture was stirred and mixed at room temperature, followed by ice cooling so that the internal temperature was 0 to 5°C. Thereafter, acryloyl chloride (10.45 g, 0.115 mol) was slowly added dropwise so that the internal temperature was within the range of 5 to 15°C, and after completion of the addition, the mixture was allowed to react at room temperature for 3.5 hours. Thereafter, triethylamine hydrochloride was removed by filtration under reduced pressure, and the organic layer was washed with a 5% aqueous sodium hydrogencarbonate solution and then pure water, dehydrated over anhydrous magnesium sulfate, filtered, and then the solvent was removed by evaporation using an evaporator. Thereafter, 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 in an amount of 7.5 g (yield: 32%).

[0127] (1) Viscosity (25℃): 45mPa・s (2)n Ｄ = 1.61 (3) １ H-NMR (CDCl ３ , 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 ＋ )

[0128] 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 Omnirad TPO as a photoradical polymerization initiator and 1 part of the fluorosurfactant Megafac F-477 (Megafac is a registered trademark of DIC Corporation) were added, and the mixture was dissolved by applying ultrasound. This radically polymerizable composition was formed into a film of 10 μm on a glass substrate using a bar coater (OSP-10). After replacing the atmosphere inside the exposure machine with nitrogen, the film was exposed to light of 365 nm wavelength at an illuminance of 100 mW and an exposure dose of 30 J / cm.２ After the 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 1.64. 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 portions.

[0129] 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 Omnirad TPO as a photoradical polymerization initiator and 1 part of the fluorosurfactant Megafac F-477 (Megafac is a registered trademark of DIC Corporation) were added, and the mixture was dissolved by applying ultrasound. Thereafter, the prepared radical polymerizable composition was formed into a film of 25 μm on a glass substrate using a bar coater (OSP-25). After replacing the atmosphere inside the exposure machine with nitrogen, the film was exposed to light of 365 nm wavelength at an illuminance of 100 mW and an exposure dose of 30 J / cm. ２ After the 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 1.64. The results are shown in Table 1. The transmittance of the film was 90%, and the YI value was 4.7. 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 portions.

[0130] 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 Omnirad TPO as a photoradical polymerization initiator and 1 part of the fluorosurfactant Megafac F-477 (Megafac is a registered trademark of DIC Corporation) were added, and the mixture was 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). After replacing the atmosphere inside the exposure machine with nitrogen, light with a wavelength of 405 nm was applied at 30 J / cm. ２ After the 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 1.64. 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.

[0131] Comparative Example 1 Photoradical Polymerization of Trimethylolpropane Triacrylate (TMPTA) A radically 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 then 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 transmittance of the film was 100%, and the 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.

[0132] Comparative Example 2 Photoradical polymerization of trimethylolpropane triacrylate (TMPTA) A radically 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 then 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 transmittance of the film was 100%, and the 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.

[0133]

[0134] 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. Furthermore, the refractive index (n Ｄ ) is 1.64, exceeding 1.60, indicating a very high refractive index. Furthermore, the obtained polymer 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 polymerized and cured film has a transmittance of 98% at 405 nm, and its YI value is an extremely low 0.8, indicating that it is particularly suitable for optical applications.

[0135] Example 4 Photoradical Copolymerization of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole and Polyfunctional (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, and 3 parts of Omnirad TPO and 1 part of Megafac F-477 were added, followed by sonication to dissolve. 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 homogeneous liquid phase. Thereafter, the prepared radically polymerizable composition was formed into a 10 μm film on a glass substrate using a bar coater (OSP-25). After replacing the atmosphere inside the exposure machine with nitrogen, the film was exposed to light with a wavelength of 365 nm at 30 J / cm. ２ After the exposure, the surface was checked for tackiness, and no tackiness was found. The refractive index (n Ｄ The refractive index (n Ｄ The measured value of YI was 1.58. The transmittance of the film was 96%, and the YI value was 1.0. The results are shown in Table 2.

[0136] Example 5 Photoradical Copolymerization of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole with Polyfunctional (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, and 3 parts of Omnirad TPO and 1 part of Megafac F-477 were added, followed by sonication to dissolve. 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 homogeneous liquid phase. Thereafter, the prepared radically polymerizable composition was formed into a film of 25 μm on a glass substrate using a bar coater (OSP-25). After replacing the atmosphere inside the exposure machine with nitrogen, the film was exposed to light of 365 nm wavelength at 30 J / cm. ２After the exposure, the surface was checked for tackiness, and no tackiness was found. The refractive index (n Ｄ The refractive index (n Ｄ The measured value of YI was 1.58. The transmittance of the film was 96%, and the YI value was 1.8.

[0137] Example 6 Photoradical Copolymerization of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole and Polyfunctional (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, and 3 parts of Omnirad TPO and 1 part of Megafac F-477 were added, followed by sonication to dissolve. Although bis(4-methacryloylthiophenyl) sulfide is a solid, it dissolved in 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole to form a homogeneous liquid phase. The prepared radically polymerizable composition was then formed into a 10 μm film on a glass substrate using a bar coater (OSP-25). After replacing the atmosphere inside the exposure machine with nitrogen, the film was exposed to light with a wavelength of 365 nm at 30 J / cm. ２ After the 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 1.67. 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) used was manufactured by Tokyo Chemical Industry Co., Ltd. This reagent is a white solid, and was dissolved in ethyl benzoate at several concentrations to measure the viscosity at 25°C. By extrapolation, the refractive index (nD) of BMTPS was calculated to be 1.645.

[0138] 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, to which 3 parts of Omnirad TPO and 1 part of Megafac F-477 were added, and the mixture was dissolved by applying ultrasonic waves. A film of 10 μm thickness was then formed on a glass substrate using a bar coater, and after replacing the atmosphere in the exposure machine with nitrogen, light of 365 nm wavelength was applied at 30 J / cm. ２ After the exposure, the surface was checked for tackiness, and no tackiness was found. The refractive index (n Ｄ The refractive index (n Ｄ The measured value of YI was 1.57. The transmittance of the film was 98%, and the YI value was 0.8. The results are shown in Table 2.

[0139] Comparative Example 4 Photoradical Copolymerization of TMPTA and BMTPS 2 50 parts each of trimethylolpropane triacrylate (TMPTA) and bis(4-methacryloylthiophenyl) sulfide (BMTPS) were mixed, to which 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. Although it was dissolved by heating to 40°C, solid matter precipitated during film formation, and a polymerization test could not be carried out. The refractive index (n Ｄ ) was 1.56.

[0140] 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, and 3 parts of Omnirad TPO and 1 part of Megafac F-477 were added. The mixture was sonicated to dissolve, but the mixture did not dissolve and remained in a suspended state even when heated.

[0141]

[0142] As is evident from the results of Examples 1 and 4, Comparative Example 1, and Table 2, trimethylolpropane triacrylate (TMPTA) and the 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole of the present invention can be copolymerized in any ratio, and the refractive index of the resulting copolymer exhibits additive properties with the proportion of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole added. Therefore, by adjusting the amount of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole added and varying the copolymer composition, it is possible to achieve a desired refractive index between 1.52 and 1.64. Furthermore, as is evident from Example 6, the copolymer is also compatible with solid monomers having a structure such as bis(4-methacryloylthiophenyl) sulfide, and the resulting 1:1 copolymer exhibits 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, solids precipitate during film formation, and a uniform film cannot be produced. It is also clear that the solubility limit of BMTPS in preparing the copolymer composition is 30% by weight.

[0143] Example 7 Preparation of a Photoradical Copolymerization Composition of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole and Polyfunctional (Meth)acrylate 1 90 parts of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole obtained by the same method as in Synthesis Example 2 and 10 parts of trimethylolpropane triacrylate (TMPTA) were mixed and dissolved by applying ultrasound. The dissolution rates of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole and trimethylolpropane triacrylate were extremely fast and they easily mixed together to form a homogeneous liquid phase. The refractive index (n Ｄ ) was 1.59 and the viscosity was 48 mPa·s.

[0144] Example 8 Preparation of Photoradical Copolymerization Composition of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole and Polyfunctional (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 and dissolved by applying ultrasound. The dissolution rates of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole and trimethylolpropane triacrylate were extremely fast and easily mixed to form a homogeneous liquid phase. The refractive index (n Ｄ ) was 1.53 and the viscosity was 58 mPa·s.

[0145] Example 9 Preparation of Photoradical Copolymerization Composition of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole and Polyfunctional (Meth)acrylate 3 10 parts of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole obtained by the same method as in Synthesis Example 2 and 90 parts of trimethylolpropane triacrylate (TMPTA) were mixed and dissolved by applying ultrasound. The dissolution rates of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole and trimethylolpropane triacrylate were extremely fast and they easily mixed together to form a homogeneous liquid phase. The refractive index (n Ｄ ) was 1.49 and the viscosity was 92 mPa·s.

[0146] Example 10: Preparation of a photoradical copolymerization composition of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole and polyfunctional (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 ultrasound. The dissolution rate of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole and bis(4-methacryloylthiophenyl) sulfide was extremely fast, and they easily mixed to form a homogeneous liquid phase. The refractive index (n Ｄ ) was 1.63 and the viscosity was 110 mPa·s.

[0147]

[0148] As is clear from Table 3, Examples 1 to 10, and Comparative Example 1, the refractive index n Ｄ The compound 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole is easily dissolved and mixed with the polyfunctional (meth)acrylate trimethylolpropane triacrylate in any desired composition to form a copolymer composition. As is clear from Figure 2, there is an additivity relationship between the composition ratio and the refractive index, indicating that the refractive index of the composition can be adjusted. Furthermore, in terms of viscosity adjustment, the viscosity-reducing effect of the amount of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole added to a copolymer composition of the compound of the present invention and the polyfunctional (meth)acrylate trimethylolpropane triacrylate is significant, and even a small amount can significantly reduce the viscosity of the copolymer composition. For example, it is found that adding 45 wt % or more of 2-acryloxyethylthio-5-methylthio-1,3,4-thiadiazole is sufficient to maintain the viscosity of the copolymer composition at 60 mPa·s or less.

[0149] The compound of the present invention represented by general formula (1) is a radical polymerizable compound used as a transparent resin raw material suitable for optical applications, and is a radical polymerizable compound that not only has excellent curability but also low viscosity, and the polymer obtained by curing has excellent flexibility and a high refractive index.

Claims

1. A (meth)acrylic acid ester having a thiadiazole ring represented by the following general formula (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 ester having a thiadiazole ring according to claim 1 or 2, and a radical polymerization initiator.

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. The radical polymerizable composition according to claim 4, 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.

6. The radical polymerizable composition according to claim 4, characterized in that 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 compound represented by general formula (5) thus obtained. (In the general formula (2), R １ represents a straight or branched alkyl group having 1 to 6 carbon atoms. 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. 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. 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, the refractive index (n Ｄ ) is 1.55 or more.

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