JP7624704B2 - Optical Materials - Google Patents

Description

The present disclosure particularly relates to optical materials containing iodine-containing polymers for use in high refractive index polymer materials.

Conventionally, the introduction of sulfur atoms into the molecule has been considered effective in increasing the refractive index of polymeric materials, and one such high refractive index polymeric material is a sulfur-containing acrylic resin obtained by polymerizing an acrylic compound having a (meth)acryloylthio group and an aromatic ring with a styrene derivative and a mercapto compound (Patent Document 1).

Japanese Patent Application Publication No. 10-130339

However, the refractive index of conventional polymer materials is not necessarily sufficient. Also, from the perspective of versatility, the development of new polymer materials with high refractive index is desired.

The present disclosure has been made in light of such circumstances. Rather than addressing the issue by simply extending the conventional technology, the present inventors attempted to achieve the above-mentioned objective by addressing the issue in a new direction. As a result, the present inventors discovered that the above-mentioned main objective could be achieved by using a specific raw material, which led to the present disclosure. One embodiment of the present disclosure is as follows:
[Item 1]
An optical material comprising an iodine-containing polymer which contains a repeating unit derived from a triiodophenyl group-containing acrylate monomer (1).
[Item 2]
The monomer (1) is represented by the following formula:
CH ₂ =C(-X ¹ )-C(=O)Y ¹ -L-TIP
[In the formula, TIP is the triiodophenyl group,
^X1 is a hydrogen atom, a methyl group or a halogen atom;
^Y1 is -O- or -NH-;
L is a direct bond or a divalent organic group.
Item 2. The optical material according to item 1, represented by the formula:
[Item 3]
The iodine-containing polymer is CH ₂ ═C(—X ² )—C(═O)Y ² —R
[Wherein ,
X2 is ^a hydrogen atom, a methyl group or a halogen atom;
^Y2 is -O- or -NH-;
R is an organic group having 2 to 30 carbon atoms.
3. The optical material according to item 1 or 2, having a repeating unit derived from a triiodophenyl group-free acrylate monomer (2) represented by the following formula:
[Item 4]
Item 4. The optical material according to item 3, wherein R is an alkylene group or an oxyalkylene group.
[Item 5]
The R is -(R ¹ O) _q -R ²
[In the formula, R ¹ is independently an alkylene group having 1 to 10 carbon atoms, R ² is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and q is 1 to 100.]
Item 4. The optical material according to item 3, wherein the oxyalkylene group is represented by the following formula:
[Item 6]
Item 6. The optical material according to any one of Items 3 to 5, wherein in the iodine-containing polymer, a content of the repeating unit derived from the monomer (2) is 0.02 parts by mole or more per 1 part by mole of the repeating unit derived from the monomer (1).
[Item 7]
Item 7. The optical material according to any one of items 1 to 6, wherein the triiodophenyl group is a 2,3,5-triiodophenyl group or a 2,4,6-triiodophenyl group.
[Item 8]
Item 8. The optical material according to any one of items 1 to 7, wherein the iodine-containing polymer has a structure derived from a molecular weight control agent.
[Item 9]
Item 9. The optical material according to item 8, wherein the molecular weight control agent is at least one selected from the group consisting of a monothiol compound, a dithiol compound, and a RAFT agent.
[Item 10]
An optical component formed from the optical material according to any one of claims 1 to 9, and selected from a coating, a film, a sheet, a prism, a lens and a fiber.
[Item 11]
An optical article comprising the optical component according to claim 10.

According to the present disclosure, an optical material is provided that is a novel high refractive index polymer material. The optical material of the present disclosure can be excellent not only in refractive index but also in solubility, film-forming properties, heat resistance, etc.

1 shows the results of TGA measurement of an iodine-containing polymer in Example 17 of the present disclosure.

<Optical materials>
The optical material in the present disclosure is a material that is a raw material for various optical components, and is particularly used in optical components that utilize its high refractive index. The optical material in the present disclosure includes an iodine-containing polymer that includes a repeating unit derived from a triiodophenyl group-containing acrylate monomer (1).

[Iodine-containing polymer]
The iodine-containing polymer in the present disclosure is a polymer containing a repeating unit derived from a triiodophenyl group-containing acrylate monomer (1). The iodine-containing polymer may be linear or branched, but is preferably linear.

(Triiodophenyl Group-Containing Acrylate Monomer (1))
The acrylate monomer (1) is an acrylate monomer (1) having at least one triiodophenyl group. The triiodophenyl group may be a 2,3,5-triiodophenyl group or a 2,4,6-triiodophenyl group, and is preferably a 2,4,6-triiodophenyl group. In the past, iodine-containing monomers had problems in molecular weight controllability, solubility, and/or film-forming properties, and their applications had not been considered. The present inventors have unexpectedly found that by selecting a triiodophenyl group-containing acrylate monomer (1) from among iodine-containing monomers, it is possible to solve these problems while having a high refractive index.

The acrylate monomer (1) in the present disclosure has the following formula:
CH ₂ =C(-X ¹ )-C(=O)Y ¹ -L-TIP
[In the formula, TIP is the triiodophenyl group,
^X1 is a hydrogen atom, a methyl group or a halogen atom;
Y ¹ is —O— or —NH—
L is a direct bond or a divalent organic group.
It may be expressed as:

^X1 is preferably a hydrogen atom or a methyl group.

It is preferred that ^Y1 is --O--.

The organic group in L may be an aliphatic group or an aromatic group, preferably an aliphatic group, and in particular an alkylene group or a (poly)oxyalkylene group.

When L is an alkylene group, the number of carbon atoms in L may be 1 or more, 2 or more, 3 or more, 5 or more, or 10 or more, and may be 30 or less, 25 or less, 20 or less, 15 or less, or 10 or less.

When L is a (poly)oxyalkylene group, the number of oxygen atoms in L may be 1 or more, 2 or more, or 3 or more, and may be 25 or less, 7 or less, or 5 or less.

When L is a (poly)oxyalkylene group, L has the formula:
-(L ¹ O) _p -
[In the formula, each L ¹ is independently an alkylene group having 1 to 10 carbon atoms, and p is 1 to 100.]
It may be expressed as:

L ¹ may have 1 or more, 2 or more, 3 or more, or 5 or more carbon atoms, and may have 10 or less, 7 or less, 5 or less, or 3 or less carbon atoms.

p may be 1 or more, 3 or more, 5 or more, 10 or more, 25 or more, or 50 or more, and may be 100 or less, 80 or less, 60 or less, 40 or less, 20 or less, or 10 or less.

Specific examples of -L ¹ O-, which is a repeating unit of -(L ¹ O) _p -, include:
-CH ₂ CH ₂ O-
_-CH2CH ( _CH3 )O-
_-CH2CH ( _{C2H5 )} O-
-CH ₂ C(CH ₃ ) ₂ O-
-CH ₂ CH ₂ CH ₂ CH ₂ O-
etc.

(Non-triiodophenyl group-containing acrylate monomer (2))
The iodine-containing polymer in the present disclosure may contain a repeating unit derived from a non-triiodophenyl group-containing acrylate monomer (2).

The triiodophenyl group-free acrylate monomer (2) does not have a triiodophenyl group. The triiodophenyl group-free acrylate monomer (2) may not have an iodophenyl group, and may not have an iodine atom.

The acrylate monomer (2) in the present disclosure has the following formula:
CH ₂ =C(-X ² )-C(=O)Y ² -R
[Wherein,
^X2 is a hydrogen atom, a methyl group or a halogen atom;
^Y2 is -O- or -NH-
R is a hydrogen atom, a hydroxyl group, or an organic group having 1 to 30 carbon atoms.
It may be expressed as:

^X2 is preferably a hydrogen atom or a methyl group.

It is preferred that ^Y2 is --O--.

R may be an aliphatic or aromatic group, preferably an aliphatic group, and in particular an alkyl or (poly)oxyalkylene group.

When R is an alkyl group, the number of carbon atoms in R may be 1 or more, 2 or more, 3 or more, 5 or more, or 10 or more, and may be 30 or less, 25 or less, 20 or less, 15 or less, or 10 or less.

When R is a (poly)oxyalkylene group, the number of oxygen atoms in R may be 1 or more, 2 or more, or 3 or more, and may be 25 or less, 7 or less, or 5 or less.

When R is a (poly)oxyalkylene group, R has the formula:
-(R ¹ O) _q -R ²
[In the formula, R ¹ is independently an alkylene group having 1 to 10 carbon atoms, R ² is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and q is 1 to 100.]
It may be expressed as:

The number of carbon atoms in R ¹ may be 1 or more, 2 or more, 3 or more, or 5 or more, and may be 10 or less, 7 or less, 5 or less, or 3 or less.

q may be 1 or more, 3 or more, 5 or more, 10 or more, 25 or more, or 50 or more, and may be 100 or less, 80 or less, 60 or less, 40 or less, 20 or less, or 10 or less.

Specific examples of the repeating unit -R ¹ O- in -(R ¹ O) _q - include:
-CH ₂ CH ₂ O-
_-CH2CH ( _CH3 )O-
_-CH2CH ( _{C2H5 )} O-
-CH ₂ C(CH ₃ ) ₂ O-
-CH ₂ CH ₂ CH ₂ CH ₂ O-
etc.

When ^R2 is an alkyl group, the number of carbon atoms in ^R2 may be 1 or more, 2 or more, 3 or more, or 5 or more, and may be 10 or less, 7 or less, 5 or less, or 3 or less.

(Sulfur-containing structure)
The iodine-containing polymer in the present disclosure may have a sulfur atom. The refractive index of the iodine-containing polymer may be improved by having a sulfur atom. The sulfur atom may be present in the main chain or in a side chain, and is preferably present in the main chain.

(Structure derived from molecular weight control agent)
The iodine-containing polymer in the present disclosure may have a structure derived from a molecular weight control agent. The molecular weight control agent is an additive that can suppress polymerization and control the molecular weight range, and is typically a chain transfer agent. The molecular weight control agent is preferably an aromatic compound. By being aromatic, the refractive index of the iodine-containing polymer can be improved. Examples of the molecular weight control agent include various chain transfer agents, RAFT agents, NMP agents, ATRP agents, and TERP agents, and sulfur-containing chain transfer agents such as thiol-type chain transfer agents and RAFT agents are preferred.

The thiol-type chain transfer agent may be a monothiol compound, a dithiol compound, a trithiol compound, or a polythiol compound having a tetrathiol or higher, but is preferably a monothiol compound or a dithiol compound. The thiol-type chain transfer agent may be a thiol compound having a sulfur atom in addition to the thiol group. The thiol compound may be a molecule consisting of only carbon, hydrogen, and sulfur.

Specific examples of thiol-type chain transfer agents include aliphatic monothiol compounds such as methanethiol, ethanethiol, propanethiol, butanethiol, and cyclohexanethiol;

Methanedithiol, 1,2-ethanedithiol, 1,1-propanedithiol, 1,2-propanedithiol, 1,3-propanedithiol, 2,2-propanedithiol, 1,6-hexanedithiol, 1,2,3-propanetrithiol, 1,1-cyclohexanedithiol, 1,2-cyclohexanedithiol, 2,2-dimethylpropane-1,3-dithiol, 3,4-dimethoxybutane-1,2-dithiol, 2-methylcyclohexane-2,3-dithiol, 1,1-bis(mercaptomethyl)cyclohexane, thiomalic acid bis(2-mercaptoethyl ester), 2,3-dimercapto-1-propanol(2-mercaptoacetate), 2,3-dimercapto-1-propanol(3-mercaptopropionate), diethylene glycol bis( Aliphatic polythiol compounds such as 1,2-dimercaptopropyl methyl ether, 2,3-dimercaptopropyl methyl ether, 2,2-bis(mercaptomethyl)-1,3-propanedithiol, bis(2-mercaptoethyl)ether, ethylene glycol bis(2-mercaptoacetate), ethylene glycol bis(3-mercaptopropionate), trimethylolpropane bis(2-mercaptoacetate), trimethylolpropane bis(3-mercaptopropionate), pentaerythritol tetrakis(2-mercaptoacetate), pentaerythritol tetrakis(3-mercaptopropionate), and tetrakis(mercaptomethyl)methane;

Bis(mercaptomethyl)sulfide, bis(mercaptoethyl)sulfide, bis(mercaptopropyl)sulfide, bis(mercaptomethylthio)methane, bis(2-mercaptoethylthio)methane, bis(3-mercaptopropyl)methane, 1,2-bis(mercaptomethylthio)ethane, 1,2-(2-mercaptoethylthio)ethane, 1,2-(3-mercaptopropyl)ethane, 1,3-bis(mercapto 1,3-bis(2-mercaptoethylthio)propane, 1,3-bis(3-mercaptopropylthio)propane, 1,2-bis(2-mercaptoethylthio)-3-mercaptopropane, 2-mercaptoethylthio-1,3-propanedithiol, 1,2,3-tris(mercaptomethylthio)propane, 1,2,3-tris(2-mercaptoethylthio)propane, 1,2,3-tris(3-mercaptopropylthio)propane, mercaptopropylthio)propane, tetrakis(mercaptomethylthiomethyl)methane, tetrakis(2-mercaptoethylthiomethyl)methane, tetrakis(3-mercaptopropylthiomethyl)methane, bis(2,3-dimercaptopropyl)sulfide, 2,5-dimercapto-1,4-dithiane, bis(mercaptomethyl)disulfide, bis(mercaptoethyl)disulfide, bis(mercaptopropyl)disulfide, 4-mercaptomethyl-3,6-dithiaoctane-1,8-dithiol, bis(mercaptomethyl)-3,6,9-trithia-1,11-undecanedithiol, bis(1,3-dimercapto-2-propyl)sulfide, hydroxymethylsulfide bis(2-mercaptoacetate), hydroxymethylsulfide bis(3-mercaptopropionate), hydroxyethylsulfide bis(2-mercaptoacetate) ester), hydroxyethyl sulfide bis(3-mercaptopropionate), hydroxypropyl sulfide bis(2-mercaptoacetate), hydroxypropyl sulfide bis(3-mercaptopropionate), hydroxymethyl disulfide bis(2-mercaptoacetate), hydroxymethyl disulfide bis(3-mercaptopropionate), hydroxyethyl disulfide bis(2-mercaptoacetate), hydroxyethyl disulfide bis(3-mercaptopropionate), hydroxypropyl disulfide bis(2-mercaptoacetate), hydroxypropyl disulfide bis(3-mercaptopropionate), 2-mercaptoethyl ether bis(2-mercaptoacetate), 2-mercaptoethyl ether bis(3-mercaptopropionate), 1,4-dithiane-2,5-diol bis(2 -mercaptoacetate), 1,4-dithiane-2,5-diol bis(3-mercaptopropionate), thioglycolic acid bis(2-mercaptoethyl ester), thiodipropionic acid bis(2-mercaptoethyl ester), 4,4'-thiodibutyric acid bis(2-mercaptoethyl ester), dithiodiglycolic acid bis(2-mercaptoethyl ester), dithiodipropionic acid bis(2-mercaptoethyl ester), 4,4'-dithiodibutyric acid bis(2-mercaptoethyl ester), thiodiglycolic acid bis(2,3-dimercaptopropyl ester), thiodipropionic acid bis(2,3-dimercaptopropyl ester), dithiodiglycolic acid bis(2,3-dimercaptopropyl ester), dithiodipropionic acid bis(2,3-dimercaptopropyl ester); aliphatic thiols containing sulfur atoms in addition to mercapto groups, such as bis(2,3-dimercaptopropyl ester);

Aromatic monothiol compounds such as benzenethiol, o-methyl-α-toluenethiol, o-toluenethiol, m-toluenethiol, p-toluenethiol, 1-naphthalenethiol, and 2-naphthalenethiol;

1,2-dimercaptobenzene, 1,3-dimercaptobenzene, 1,4-dimercaptobenzene, 1,2-bis(mercaptomethyl)benzene, 1,3-bis(mercaptomethyl)benzene, 1,4-bis(mercaptomethyl)benzene, 1,2-bis(mercaptoethyl)benzene, 1,3-bis(mercaptoethyl)benzene, 1,4-bis(mercaptoethyl)benzene, 1,2,3-trimercaptobenzene, 1,2,4-trimercaptobenzene, 1,3,5-trimercaptobenzene, 1,2,3-tris(mercaptomethyl)benzene, 1,2, Aromatic polythiols such as 4-tris(mercaptomethyl)benzene, 1,3,5-tris(mercaptomethyl)benzene, 1,2,3-tris(mercaptoethyl)benzene, 1,2,4-tris(mercaptoethyl)benzene, 1,3,5-tris(mercaptoethyl)benzene, 2,5-toluenedithiol, 3,4-toluenedithiol, 1,3-di(p-methoxyphenyl)propane-2,2-dithiol, 1,3-diphenylpropane-2,2-dithiol, phenylmethane-1,1-dithiol, and 2,4-di(p-mercaptophenyl)pentane;

1,2-bis(mercaptomethylenethio)benzene, 1,3-bis(mercaptomethylenethio)benzene, 1,4-bis(mercaptomethylenethio)benzene, 1,2-bis(mercaptoethylenethio)benzene, 1,3-bis(mercaptoethylenethio)benzene, 1,4-bis(mercaptoethylenethio)benzene, 1,2-bis(mercaptopropylenethio)benzene, 1,3-bis(mercaptopropylenethio)benzene, 1,4-bis(mercaptopropylenethio)benzene, 1,2-bis(mercaptoethylenethiomethylene)benzene, 1, 3-bis(mercaptoethylenethiomethylene)benzene, 1,4-bis(mercaptoethylenethiomethylene)benzene, 1,2-bis(mercaptopropylenethiomethylene)benzene, 1,3-bis(mercaptopropylenethiomethylene)benzene, 1,4-bis(mercaptopropylenethiomethylene)benzene, bis(4-mercaptophenyl)sulfide, bis(3-mercaptophenyl)sulfide, 4,4'-oxybisbenzenethiol, 4,4'-biphenyldithiol, 1,2-bis(mercaptomethyleneoxy)benzene, 1,3-bis(methylphenyl)sulfide 1,4-bis(mercaptomethyleneoxy)benzene, 1,2-bis(mercaptoethyleneoxy)benzene, 1,3-bis(mercaptoethyleneoxy)benzene, 1,4-bis(mercaptoethyleneoxy)benzene, 1,2-bis(mercaptoethyleneoxymethylene)benzene, 1,3-bis(mercaptoethyleneoxymethylene)benzene, 1,4-bis(mercaptoethyleneoxymethylene)benzene, 1,2-bis(mercaptopropyleneoxymethylene)benzene, 1,3-bis(mercaptopropylene Aromatic polythiol compounds containing sulfur atoms in addition to mercapto groups, such as 1,4-bis(mercaptopropyleneoxymethylene)benzene, 1,3,5-trimercaptobenzene, 1,2,3-tris(mercaptomethylthio)benzene, 1,2,4-tris(mercaptomethylthio)benzene, 1,3,5-tris(mercaptomethylthio)benzene, 1,2,3-tris(mercaptoethylthio)benzene, 1,2,4-tris(mercaptoethylthio)benzene, and 1,3,5-tris(mercaptoethylthio)benzene;

Heterocyclic compounds containing a sulfur atom in addition to a mercapto group, such as 3,4-thiophenedithiol and 2,5-dimercapto-1,3,4-thiadiazole;

2-mercaptoethanol, 3-mercapto-1,2-propanediol, glycerin di(mercaptoacetate), 1-hydroxy-4-mercaptocyclohexane, 2,4-dimercaptophenol, 2-mercaptohydroquinone, 4-mercaptophenol, 3,4-dimercapto-2-propanol, 1,3-dimercapto-2-propanol, 2,3-dimercapto-1-propanol, 1,2-dimercapto-1,3-butanediol, pentaerythritol tris(3-mercaptoprop pentaerythritol pentakis(3-mercaptopropionate), pentaerythritol mono(3-mercaptopropionate), pentaerythritol bis(3-mercaptopropionate), pentaerythritol tris(thioglycolate), dipentaerythritol pentakis(3-mercaptopropionate), hydroxymethyl-tris(mercaptoethylthiomethyl)methane, 1-hydroxyethylthio-3-mercaptoethylthiobenzene, and other compounds that contain a hydroxy group in addition to a mercapto group, as well as derivatives thereof. These may be used alone or in combination of two or more.

Specific examples of RAFT agents include dithioesters such as 2-cyano-2-propyl benzodithioate and 4-cyano-4-(phenylcarbonothioylthio)pentanoic acid; trithiocarbonates such as 2-cyano-2-propyl dodecyl trithiocarbonate, 4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid, 2-(dodecylthiocarbonothioylthio)-2-methylpropionic acid, and cyanomethyl dodecyl trithiocarbonate; dithiocarbamates such as cyanomethyl methyl(phenyl)carbamodithioate; and disulfides such as bis(thiobenzoyl) disulfide and bis(dodecylsulfanylthiocarbonyl) disulfide. These may be used alone or in combination of two or more.

(Structures derived from other raw materials)
The iodine-containing polymer of the present disclosure may have a structure derived from other raw materials in addition to the above. Specific examples of other raw materials include styrene-based monomers such as styrene, p-methylstyrene, α-methylstyrene, halogenated styrene, vinylbenzoic acid, 4-vinylbenzenesulfonic acid, 4-vinylbenzenesulfonic acid ester, and 4-vinylbenzenesulfonic acid amide; amide group-containing vinyl monomers such as (meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N,N-dimethyl(meth)acrylamide, and N,N-dimethylaminopropyl(meth)acrylamide; methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, butyl(meth)acrylate, and 2-ethyl(meth)acrylate. Examples of such monomers include (meth)acrylates and (meth)acrylamide monomers such as ethylhexyl, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, glycidyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, N-t-butylaminoethyl (meth)acrylate, and polyethylene glycol (meth)acrylate; nitrile group-containing vinyl monomers such as (meth)acrylonitrile; and other monomers such as vinyl halides, vinylidene halides, and vinyl acetate. These monomers may be used alone or in combination of two or more.

(Molecular Weight of Iodine-Containing Polymer)
The number average molecular weight of the iodine-containing polymer in the present disclosure may be 300 or more, 500 or more, 1000 or more, 1500 or more, 3000 or more, 5000 or more, or 10000 or more, preferably 3000 or more. The number average molecular weight of the iodine-containing polymer in the present disclosure may be 100000 or less, 50000 or less, 25000 or less, 15000 or less, 12500 or less, or 10000 or less, preferably 50000 or less. By being in the above range, the solubility, film-forming property, heat resistance and transparency of the iodine-containing polymer can be excellent in a moderate balance. The number average molecular weight may be a polystyrene-equivalent molecular weight.

The dispersion index (Mw/Mn) of the iodine-containing polymer in this disclosure may be 1.5 or more, 2 or more, 3 or more, or 4 or more. The dispersion index (Mw/Mn) of the iodine-containing polymer in this disclosure may be 7.5 or less, 5 or less, 4 or less, or 3 or less.

(Composition of iodine-containing polymer)
The content of the repeating unit derived from the monomer (1) in the iodine-containing polymer may be 20% by weight or more, 30% by weight or more, 40% by weight or more, 50% by weight or more, 60% by weight or more, 70% by weight or more, or 80% by weight or more. The content of the repeating unit derived from the monomer (1) in the iodine-containing polymer may be 95% by weight or less, 85% by weight or less, 75% by weight or less, 65% by weight or less, 55% by weight or more, or 45% by weight or less. From the viewpoint of improving the refractive index, the larger the amount of the monomer (1), the more preferable.

The content of the repeating units derived from monomer (2) in the iodine-containing polymer may be 2.0% by weight or more, 4.0% by weight or more, 6.0% by weight or more, 8.0% by weight or more, 10% by weight or more, 15% by weight or more, or 20% by weight or more. The content of the repeating units derived from monomer (2) in the iodine-containing polymer may be 50% by weight or less, 40% by weight or less, 30% by weight or less, 20% by weight or less, 10% by weight or less, or 7.5% by weight or less. The presence of the repeating units derived from monomer (2) particularly improves film-forming properties.

The content of the structure derived from the molecular weight control agent in the iodine-containing polymer may be 1.0% by weight or more, 3.0% by weight or more, 5.0% by weight or more, or 10% by weight or more, and is preferably 3% by weight or more. The content of the structure derived from the molecular weight control agent in the iodine-containing polymer may be 50% by weight or less, 40% by weight or less, 30% by weight or less, or 25% by weight or less, and is preferably 40% by weight or less.

The content of structures derived from other raw materials in the iodine-containing polymer may be 1.0% by weight or more, 3.0% by weight or more, 5.0% by weight or more, or 10% by weight or more. The content of structures derived from other raw materials in the iodine-containing polymer may be 30% by weight or less, 20% by weight or less, or 10% by weight or less.

The iodine content in the iodine-containing polymer may be 10% by weight or more, 25% by weight or more, 30% by weight or more, 35% by weight or more, 40% by weight or more, or 45% by weight or more, and is preferably 30% by weight or more. The iodine content in the iodine-containing polymer may be 55% by weight or less, 50% by weight or less, or 45% by weight or less.

The sulfur content in the iodine-containing polymer may be 1.0% by weight or more, 2.0% by weight or more, 3.0% by weight or more, 4.0% by weight or more, 5.0% by weight or more, or 7.5% by weight or more, and is preferably 2.0% by weight or more. The sulfur content in the iodine-containing polymer may be 30% by weight or less, 20% by weight or less, 15% by weight or less, or 10% by weight or less, and is preferably 10% by weight or less.

The content of the repeating unit derived from monomer (1) may be 2.0 molar parts or more, 3.0 molar parts or more, 5.0 molar parts or more, 10 molar parts or more, 15 molar parts or more, or 20 molar parts or more, and preferably 3 molar parts or more, per 1 molar part of the structure derived from the molecular weight control agent in the iodine-containing polymer. The content of the repeating unit derived from monomer (1) may be 50 molar parts or less, 45 molar parts or less, 40 molar parts or less, 35 molar parts or less, 30 molar parts or less, or 25 molar parts or less, and preferably 40 molar parts or less, per 1 molar part of the structure derived from the molecular weight control agent.

The content of the repeating unit derived from monomer (2) in the iodine-containing polymer may be 0.2 molar parts or more, 0.3 molar parts or more, 0.5 molar parts or more, 1.0 molar parts or more, 1.5 molar parts or more, or 2 molar parts or more, preferably 0.3 molar parts or more, per 1 molar part of the structure derived from the molecular weight control agent. The content of the repeating unit derived from monomer (1) may be 5.0 molar parts or less, 4.5 molar parts or less, 4.0 molar parts or less, 3.5 molar parts or less, 3.0 molar parts or less, or 2.5 molar parts or less, preferably 4.0 molar parts or less, per 1 molar part of the structure derived from the molecular weight control agent.

The content of the repeating unit derived from monomer (2) may be 0.02 molar parts or more, 0.03 molar parts or more, 0.05 molar parts or more, 0.1 molar parts or more, 0.15 molar parts or more, or 0.2 molar parts or more, preferably 0.03 molar parts or more, for example 0.1 molar parts or more, relative to 1 molar part of the repeating unit derived from monomer (1) in the iodine-containing polymer. The amount of monomer (2) used may be 0.5 molar parts or less, 0.45 molar parts or less, 0.4 molar parts or less, 0.35 molar parts or less, 0.3 molar parts or less, or 0.25 molar parts or less, preferably 0.4 molar parts or less, relative to 1 molar part of monomer (1). The presence of the repeating unit derived from monomer (2) particularly improves film-forming properties.

By containing each component in the above range, the iodine-containing polymer can have a high refractive index while providing a good balance of excellent solubility, film-forming properties, heat resistance, and transparency.

(Refractive index of iodine-containing polymer)
The refractive index of the iodine-containing polymer in the present disclosure may be 1.65 or more, 1.70 or more, 1.72 or more, 1.76 or more, 1.78 or more, 1.80 or more, or 1.82 or more, preferably 1.72 or more, and more preferably 1.78 or more.

(Heat resistance of iodine-containing polymer)
The heat resistance temperature of the iodine-containing polymer in the present disclosure (the temperature at which a 5% weight loss is observed when the temperature is increased at a heating rate of 10° C./min in a nitrogen gas atmosphere) may be 250° C. or higher, 260° C. or higher, 270° C. or higher, 280° C. or higher, 290° C. or higher, 300° C. or higher, 310° C. or higher, or 320° C. or higher, preferably 260° C. or higher, and more preferably 280° C. or higher.

(Method for producing iodine-containing polymer)
In the method for producing the iodine-containing polymer of the present disclosure, the iodine-containing polymer can be obtained by a step of polymerizing the above-mentioned monomers as raw materials.
The method for producing an iodine-containing polymer according to the present disclosure includes the steps of:
The method may include a step of polymerizing the monomer in the presence of a molecular weight control agent. By polymerizing the monomer in the presence of a molecular weight control agent, it becomes easy to control the molecular weight within the above-mentioned range.

The amount of the raw materials used can be appropriately changed so that the above-mentioned iodine-containing polymer can be obtained. The amount of monomer (1) used can be 2.0 molar parts or more, 3.0 molar parts or more, 5.0 molar parts or more, 10 molar parts or more, 15 molar parts or more, or 20 molar parts or more, and is preferably 3 molar parts or more, for example 10 molar parts or more, relative to 1 molar part of the molecular weight control agent. The amount of monomer (1) used can be 50 molar parts or less, 45 molar parts or less, 40 molar parts or less, 35 molar parts or less, 30 molar parts or less, or 25 molar parts or less, and is preferably 40 molar parts or less, relative to 1 molar part of the molecular weight control agent. For example, by increasing the amount of the molecular weight control agent, polymerization can be suppressed and an increase in molecular weight can be suppressed.

The amount of monomer (2) used may be 0.2 molar parts or more, 0.3 molar parts or more, 0.5 molar parts or more, 1.0 molar parts or more, 1.5 molar parts or more, or 2 molar parts or more relative to 1 molar part of molecular weight control agent, and is preferably 0.3 molar parts or more, for example 1 molar part or more. The amount of monomer (2) used may be 5.0 molar parts or less, 4.5 molar parts or less, 4.0 molar parts or less, 3.5 molar parts or less, 3.0 molar parts or less, or 2.5 molar parts or less relative to 1 molar part of molecular weight control agent, and is preferably 4.0 molar parts or less. For example, by increasing the amount of molecular weight control agent, polymerization can be suppressed and an increase in molecular weight can be suppressed.

The amount of monomer (2) used may be 0.02 molar parts or more, 0.03 molar parts or more, 0.05 molar parts or more, 0.1 molar parts or more, 0.15 molar parts or more, or 0.2 molar parts or more, and is preferably 0.03 molar parts or more, for example 0.1 molar parts or more, relative to 1 molar part of monomer (1). The amount of monomer (2) used may be 0.5 molar parts or less, 0.45 molar parts or less, 0.4 molar parts or less, 0.35 molar parts or less, 0.3 molar parts or less, or 0.25 molar parts or less, and is preferably 0.4 molar parts or less, relative to 1 molar part of monomer (1). The presence of monomer (2) particularly improves film-forming properties.

In the present disclosure, the polymerization method is not particularly limited, and can be performed by a known polymerization method such as bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, etc., but solution polymerization is preferred. Also, a known polymerization method such as radical polymerization, anionic polymerization, cationic polymerization, etc. can be selected, but radical polymerization is preferably selected. An appropriate polymerization method can be selected depending on the type of monomer, polymerization temperature, etc.

In the present disclosure, an appropriate polymerization initiator can be selected and used depending on the type of monomer, polymerization temperature, etc. Examples of polymerization initiators include azo-based initiators such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,2-dimethylvaleronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), and 2,2'-azobis(2-amidinopropane)dihydrochloride; and peroxide-based initiators such as benzoyl peroxide, di-t-butyl hydroperoxide, t-butyl hydroperoxide, cumyl peroxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, benzoyl peroxide, dicumyl peroxide, ethyl 3,3-di(t-amylperoxy)butyrate, potassium sulfate, and ammonium persulfate. These may be used alone or in combination of two or more types.

When polymerization is carried out by solution polymerization, an appropriate solvent is selected taking into consideration the solubility of the monomer and radical initiator, the polymerization temperature, etc., and the polymerization can be carried out in that solvent. Examples of solvents include DMF, N-methyl-2-pyrrolidone, acetone, THF, benzene, toluene, ethylbenzene, xylene, chlorobenzene, methyl ethyl ketone, ethyl lactate, isopropyl alcohol, etc. These may be used alone or in combination of two or more.

The polymerization temperature may be any temperature at which the polymerization initiator decomposes and polymerization begins, and may be, for example, 0°C or higher, 20°C or higher, 40°C or higher, 60°C or higher, or 70°C or higher, and is preferably 40°C or higher and may be 100°C or lower, 90°C or lower, 80°C or lower, or 70°C or lower.

The optimal polymerization time can be determined depending on the selected monomer, polymerization initiator, polymerization temperature, etc., but may be, for example, 1 hour or more, 5 hours or more, 10 hours or more, 15 hours or more, or 20 hours or more, and may be 72 hours or less, 60 hours or less, 48 hours or less, 36 hours or less, or 24 hours or less.

The amount of polymerization initiator used may vary depending on the type of monomer and the type of initiator, but may be, for example, 0.1 mol% or more, 1 mol% or more, 3 mol% or more, 5 mol% or more, 10 mol% or more, 15 mol% or more, 20 mol% or more, or 25 mol% or more, and may be 50 mol% or less, 40 mol% or less, 30 mol% or less, 20 mol% or less, or 10 mol% or less, based on the total amount of monomers used.

The amount of polymerization solvent used is not particularly limited, but may be in a range such that the raw material concentration is 5% by weight or more, 10% by weight or more, 15% by weight or more, or 20% by weight or more, and 50% by weight or less, 40% by weight or less, 30% by weight or less, or 20% by weight or less.

<Optical components>
The optical material in the present disclosure may be used as an optical component such as a coating, a film, a sheet, a prism, a lens, a fiber, etc. (hereinafter, referred to as a coating, etc.). When used for these applications, the optical material may be formed by applying the optical material to a substrate. The type of substrate is not particularly limited, and may be a resin, glass, metal, ceramic, etc.

When applying the optical material of the present disclosure to a substrate, the optical material may be a non-solvent type, but may be used as a solution containing, in addition to the iodine-containing polymer, a solvent that dissolves the iodine-containing polymer. The type of solvent is not particularly limited as long as it dissolves the iodine-containing polymer, but for example, organic solvents such as THF, chloroform, DMF, and DMSO can be used. The concentration of the iodine-containing polymer in the coating liquid may be 0.01 wt% or more, 0.1 wt% or more, 0.5 wt% or more, or 1 wt% or more, and may be 5 wt% or less, 3 wt% or less, 1.5 wt% or less, or 0.5 wt% or less.

A coating or the like may be obtained by applying a solution containing an iodine polymer to a base and removing the solvent as necessary. Application methods that can be used include dip coating, spray coating, flow coating, shower coating, roll coating, spin coating, gravure coating, microgravure coating, comma roll coating, Mayer bar coating, slot bicoat, air knife coating, lip coating, kiss coating, brush coating, and other commonly used application methods. The temperature for removing the solvent is not particularly limited, but can be, for example, 0 to 200°C.

The type of substrate is not particularly limited and may be resin, glass, metal, ceramic, etc.

The coating thickness may be 0.1 μm or more, 1 μm or more, or 3 μm or more, and may be 1 m or less, 500 μm or less, or 200 μm or less.

<Optical article having optical component>
Examples of optical articles having optical components such as the above-mentioned coatings are not particularly limited, but preferred examples include optical devices such as high refractive index light emitting diodes (LEDs) and image sensors, high refractive index materials such as anti-reflection films, lens materials, and lens coatings, and optical instruments such as telescopes, binoculars, microscopes, cameras, endoscopes (fiberscopes), planetariums, length measuring instruments, comparators, range finders, spectrometers, interferometers, and polarimeters.

The following describes in detail the embodiments of the present disclosure with reference to examples, but the present disclosure is not limited to these examples.

The test method is as follows.
<IR Measurement>
The FT/IR 4600 manufactured by JASCO Corporation was used.

<NMR Measurement>
400 MHz-NMR JOEL ECS-400K manufactured by JEOL Ltd. or 400 MHz-NMR JOEL ECZ-400 manufactured by JEOL Ltd. was used.

<SEC Measurement>
The experiment was carried out using the following equipment and conditions.
Tosoh Corporation HLC-8320GPC
Column: TSKgel SuperMultiporeHZ-M x 2 (4.6mmI.D. x 15cm x 2)
Standard: Polystyrene SRM706 (NIST)
Eluent: THF
Detector: RI; Polarity (+), Response (0.5s)
UV; wavelength (254nm), polarity (+), response (0.5s)

<Heat resistance>
Using a TGA measuring device (Shimadzu Model TGA-50/50H), measurements were performed in a nitrogen gas atmosphere at a temperature increase rate of 10° C./min in the temperature range from 25° C. to 450° C. The temperature _Td at which a 5% weight loss was observed is shown in Table 2.

<Solubility>
2 mg of the obtained iodine-containing polymer was added to 2 ml of each organic solvent and left overnight at 25° C. The solubility was evaluated according to the following criteria. The results are shown in Table 2.
○: Dissolved with no residue left behind △: Some parts remain undissolved ×: Most parts remain undissolved

<Refractive index>
The refractive index of the iodine-containing polymer was measured by forming a film of the iodine-containing polymer on a silicon wafer, measuring 30 points with a laser having a wavelength of 632 nm using an ellipsometer (SE-101 manufactured by Photonic Lattice Co., Ltd.), and averaging the measurements. The results are shown in Table 2.

200mlのナスフラスコに、2,4,6-triiodephenol 14.4g(30mmol), TEA 6ml, THF60mlを入れ、氷浴でAcryloyl chloride 4.07g(45mmol) を10～15分間かけて加え室温で24h攪拌した。黄色固体を得た。Evapoして酢エチを加えた。濾過して塩を取り除き、分液操作（1N HCl, sat NaHCO₃, sat NaCl）を各3回行った。有機層にMgSO₄を入れて脱水をして減圧乾燥し、黄色粉末固体を12.58g得た。¹H-NMR、¹³C-NMR,IR測定より物性評価を行った。展開溶媒を（クロロホルム：ヘキサン＝1：1）にし、カラムクロマトグラフィーを行った。その後、減圧乾燥して白色固体を得た。ヘキサン、クロロホルムを用いて再結晶を行い、元素分析を行い、得られた化合物がTriiodophenyl acrylate(TIP-AC)であることを確認した。収量は12.58g収率87%であった。 [Synthesis of monomer (TIP-AC)]

In a 200ml eggplant flask, 14.4g (30mmol) of 2,4,6-triiodephenol, 6ml of TEA, and 60ml of THF were added, and 4.07g (45mmol) of acrylic chloride was added over 10-15 minutes in an ice bath and stirred at room temperature for 24h. A yellow solid was obtained. Evaporation was performed and ethyl acetate was added. The salt was removed by filtration, and separation operations ( ^1N HCl, sat NaHCO ₃ , sat NaCl) were performed three times each. MgSO ₄ was added to the organic layer, dehydrated, and dried under reduced pressure, obtaining 12.58g of a yellow powder solid. The physical properties were evaluated by 1H-NMR, ^13C -NMR, and IR measurements. The developing solvent was changed to (chloroform:hexane = 1:1) and column chromatography was performed. After drying under reduced pressure, a white solid was obtained. The compound was recrystallized using hexane and chloroform, and elemental analysis was performed, confirming that the compound obtained was triiodophenyl acrylate (TIP-AC). The yield was 12.58 g, 87%.

重合管にTIP-AC 0.52g(1mmol), DMF 0.3ml, 表１に示す量のAIBN (TIP-ACに対して3 mol%)を入れて脱気封管を行い60℃オイルバス中で20h攪拌した。メタノールで再沈殿してメンブレン濾過した後、減圧乾燥して、含ヨウ素ポリマーを得た。¹H-NMR、IR測定、及びGPC測定により組成及び分子量を決定した。得られた含ヨウ素ポリマーについて、熱重量測定、溶解性試験、屈折率測定を行った。結果を表１～４に示す。 [Example 1]
Synthesis of poly(TIP-AC)

0.52g (1mmol) of TIP-AC, 0.3ml of DMF, and the amount of AIBN shown in Table 1 (3 mol% relative to TIP-AC) were placed in a polymerization tube, which was then degassed and sealed, and stirred for 20 hours in a 60°C oil bath. The mixture was reprecipitated in methanol, filtered through a membrane, and dried under reduced pressure to obtain an iodine-containing polymer. The composition and molecular weight were determined by ^1H -NMR, IR, and GPC measurements. The obtained iodine-containing polymer was subjected to thermogravimetry, solubility tests, and refractive index measurements. The results are shown in Tables 1 to 4.

重合管にTIP-AC 0.52g(1mmol), DMF 0.3ml, 4,4'-Thiobisbenzenethiol（TBBT）(TIP-ACに対して1.5 mol%), AIBN (TIP-ACに対して3 mol%) を入れて脱気封管を行い60℃オイルバス中で20h攪拌した。メタノールで再沈殿してメンブレン濾過した後、減圧乾燥して、含ヨウ素ポリマーを得た。¹H-NMR、IR測定、及びGPC測定により組成及び分子量を決定した。得られた含ヨウ素ポリマーについて、熱重量測定、溶解性試験、屈折率測定を行った。結果を表１～４に示す。表１中、ｎは含ヨウ素ポリマーにおけるTBBTから誘導された構造１モル部に対するTIP-ACから誘導された繰り返し単位の量（モル部）の１／２を示している。 [Example 2]
Synthesis of TBBT-poly(TIP-AC)

0.52g (1mmol) of TIP-AC, 0.3ml of DMF, 4,4'-Thiobisbenzenethiol (TBBT) (1.5 mol% relative to TIP-AC), and AIBN (3 mol% relative to TIP-AC) were placed in a polymerization tube, degassed, sealed, and stirred in a 60°C oil bath for 20h. The mixture was reprecipitated with methanol, filtered through a membrane, and dried under reduced pressure to obtain an iodine-containing polymer. The composition and molecular weight were determined by ^1H -NMR, IR, and GPC measurements. Thermogravimetry, solubility tests, and refractive index measurements were performed on the obtained iodine-containing polymer. The results are shown in Tables 1 to 4. In Table 1, n indicates 1/2 of the amount (mol parts) of repeating units derived from TIP-AC relative to 1 mol part of the structure derived from TBBT in the iodine-containing polymer.

[Example 3]
Synthesis of TBBT-poly(TIP-AC) 0.52g (1mmol) of TIP-AC, 0.3ml of DMF, TBBT (15mol% relative to TIP-AC) and AIBN (30mol% relative to TIP-AC) were placed in a polymerization tube, degassed and sealed, and stirred in a 60℃ oil bath for 20h. A yellow liquid and a viscous solid were obtained. The mixture was reprecipitated with methanol, filtered through a membrane, and then dried under reduced pressure. Thermogravimetry, solubility test, and refractive index measurement were performed on the obtained iodine-containing polymer. The results are shown in Tables 1 to 4. In Table 1, n indicates 1/2 of the amount (mol parts) of repeating units derived from TIP-AC relative to 1 mol part of the structure derived from TBBT in the iodine-containing polymer.

[Example 4]
Synthesis of TBBT-poly(TIP-AC) The synthesis and testing were carried out in the same manner as in Example 3, except that the weighing temperature was 65° C. The results are shown in Tables 1 to 4.

[Example 5]
Synthesis of TBBT-poly(TIP-AC) The synthesis and testing were carried out in the same manner as in Example 3, except that the weighing temperature was 70° C. The results are shown in Tables 1 to 4.

[Example 6]
Synthesis of TBBT-poly(TIP-AC) The synthesis and testing were carried out in the same manner as in Example 3, except that the weighing temperature was 75° C. The results are shown in Tables 1 to 4.

[Example 7]
Synthesis of TBBT-poly(TIP-AC) The synthesis and testing were carried out in the same manner as in Example 3, except that the weighing temperature was 80° C. The results are shown in Tables 1 to 4.

重合管にTIP-AC (0.95mmol 、0.50g), 2-(2-Ethoxyethoxy)ethyl Acrylate(EEA) (0.05mmol、0.009g), DMF 0.3ml, AIBN (TIP-ACとEEAの合計量に対して30mol%、0.05g), TBBT(TIP-ACとEEAの合計量に対して15mol%、0.037g)を入れて脱気封管を行い75℃オイルバス中で20h攪拌した。メタノールで再沈殿してメンブレン濾過した後、減圧乾燥して含ヨウ素ポリマーを得た。得られた含ヨウ素ポリマーについて、熱重量測定、溶解性試験、屈折率測定を行った。結果を表１～４に示す。表１中、ｎは含ヨウ素ポリマーにおけるTBBTから誘導された構造１モル部に対するTIP-ACから誘導された繰り返し単位の量（モル部）の１／２を示し、ｍは含ヨウ素ポリマーにおけるTBBTから誘導された構造１モル部に対するEEAから誘導された繰り返し単位の量（モル部）の１／２を示している。 [Example 8]
Synthesis of TBBT-poly(TIP-AC-co-EEA)

TIP-AC (0.95mmol, 0.50g), 2-(2-Ethoxyethoxy)ethyl Acrylate (EEA) (0.05mmol, 0.009g), 0.3ml of DMF, AIBN (30mol% based on the total amount of TIP-AC and EEA, 0.05g), and TBBT (15mol% based on the total amount of TIP-AC and EEA, 0.037g) were placed in a polymerization tube, degassed and sealed, and stirred in a 75℃ oil bath for 20h. The mixture was reprecipitated with methanol, filtered through a membrane, and dried under reduced pressure to obtain an iodine-containing polymer. The obtained iodine-containing polymer was subjected to thermogravimetry, solubility test, and refractive index measurement. The results are shown in Tables 1 to 4. In Table 1, n represents half the amount (by mole) of the repeating unit derived from TIP-AC relative to 1 mole part of the structure derived from TBBT in the iodine-containing polymer, and m represents half the amount (by mole) of the repeating unit derived from EEA relative to 1 mole part of the structure derived from TBBT in the iodine-containing polymer.

[Example 9]
Synthesis of TBBT-poly(TIP-AC-co-EEA)
The synthesis and testing were carried out in the same manner as in Example 8, except that 0.90 mol of TIP-AC and 0.10 mol of EEA were used. The results are shown in Tables 1 to 4.

[Example 10]
Synthesis of TBBT-poly(TIP-AC-co-EEA)
The synthesis and testing were carried out in the same manner as in Example 8, except that 0.80 mol of TIP-AC and 0.20 mol of EEA were used. The results are shown in Tables 1 to 4.

重合管にTIP-AC (0.8mmol 、0.42g), 2-(2-Ethoxyethoxy)ethyl Acrylate(EEA) (0.2mmol、0.037g) ,DMF 0.3ml, AIBN(TIP-ACとEEAの合計量に対して7.5 mol%), Benzenethiol(BT) (TIP-ACとEEAの合計量に対して7.5 mol%) を入れて脱気封管を行い60℃オイルバス中で20h攪拌した。メタノールで再沈殿してメンブレン濾過した後、減圧乾燥して含ヨウ素ポリマーを得た。¹H-NMR、IR測定、及びGPC測定により求まった組成及び分子量の結果を表１に示す。表１中、ｎは含ヨウ素ポリマーにおけるBTから誘導された構造１モル部に対するTIP-ACから誘導された繰り返し単位の量（モル部）を示し、ｍは含ヨウ素ポリマーにおけるTBBTから誘導された構造１モル部に対するEEAから誘導された繰り返し単位の量（モル部）を示している。得られた含ヨウ素ポリマーについて、熱重量測定、溶解性試験、屈折率測定を行った結果を表１～４に示す。 [Example 11]
Synthesis of BT-poly(TIP-AC-co-EEA)

TIP-AC (0.8mmol, 0.42g), 2-(2-Ethoxyethoxy)ethyl Acrylate (EEA) (0.2mmol, 0.037g), 0.3ml DMF, AIBN (7.5 mol% based on the total amount of TIP-AC and EEA), and Benzenethiol (BT) (7.5 mol% based on the total amount of TIP-AC and EEA) were placed in a polymerization tube, degassed and sealed, and stirred in a 60°C oil bath for 20h. The mixture was reprecipitated with methanol, filtered through a membrane, and dried under reduced pressure to obtain an iodine-containing polymer. The composition and molecular weight determined by ^1H -NMR, IR, and GPC measurements are shown in Table 1. In Table 1, n indicates the amount (molar parts) of repeating units derived from TIP-AC relative to 1 mol part of the structure derived from BT in the iodine-containing polymer, and m indicates the amount (molar parts) of repeating units derived from EEA relative to 1 mol part of the structure derived from TBBT in the iodine-containing polymer. The obtained iodine-containing polymer was subjected to thermogravimetry, a solubility test and a refractive index measurement, and the results are shown in Tables 1 to 4.

[Example 12]
Synthesis of BT-poly(TIP-AC-co-EEA)
The synthesis and testing were carried out in the same manner as in Example 10, except that the amount of AIBN was 15 mol% based on the total amount of TIP-AC and EEA, and the amount of BT was 15 mol% based on the total amount of TIP-AC and EEA. The results are shown in Tables 1 to 4.

[Example 13]
Synthesis of BT-poly(TIP-AC-co-EEA)
The synthesis and testing were carried out in the same manner as in Example 10, except that the amount of AIBN was 30 mol% based on the total amount of TIP-AC and EEA, and the amount of BT was 30 mol% based on the total amount of TIP-AC and EEA. The results are shown in Tables 1 to 4.

重合管にTIP-AC (0.95mmol、0.50g), 2-(2-Ethoxyethoxy)ethyl Acrylate(EEA) (0.05mmol、0.009g) ,DMF 0.3ml, AIBN (3mol%、0.005g), を入れて脱気封管を行い60℃オイルバス中で20h攪拌した。メタノールで再沈殿してメンブレン濾過した後、減圧乾燥して含ヨウ素ポリマーを得た。¹H-NMR、IR測定、及びGPC測定により求まった組成及び分子量の結果を表１に示す。得られた含ヨウ素ポリマーについて、熱重量測定、溶解性試験、屈折率測定を行った。結果を表１～４に示す。表１中、ｎとｍは含ヨウ素ポリマーにおけるTIP-ACから誘導された繰り返し単位の量（モル部）と、EEAから誘導された繰り返し単位の量（モル部）との比率を示している。 [Example 14 ]
Synthesis of poly (TIP-AC-co-EEA)

TIP-AC (0.95mmol, 0.50g), 2-(2-Ethoxyethoxy)ethyl Acrylate (EEA) (0.05mmol, 0.009g), 0.3ml of DMF, and AIBN (3mol%, 0.005g) were placed in a polymerization tube, which was then degassed and sealed, and stirred in a 60°C oil bath for 20h. The mixture was reprecipitated with methanol, filtered through a membrane, and dried under reduced pressure to obtain an iodine-containing polymer. The composition and molecular weight determined by ^1H -NMR, IR, and GPC measurements are shown in Table 1. The obtained iodine-containing polymer was subjected to thermogravimetry, solubility testing, and refractive index measurement. The results are shown in Tables 1 to 4. In Table 1, n and m indicate the ratio of the amount of repeating units derived from TIP-AC (parts by mole) to the amount of repeating units derived from EEA (parts by mole) in the iodine-containing polymer.

[Example 15 ]
Synthesis of poly (TIP-AC-co-EEA)
The synthesis and testing were carried out in the same manner as in Example 14, except that the amount of TIP-AC was 0.9 mmol and the amount of EEA was 0.1 mmol. The results are shown in Tables 1 to 4.

[Example 16 ]
Synthesis of poly (TIP-AC-co-EEA)
The synthesis and testing were carried out in the same manner as in Example 14, except that the amount of TIP-AC was 0.9 mmol and the amount of EEA was 0.15 mmol. The results are shown in Tables 1 to 4.

[Example 17 ]
Synthesis of poly (TIP-AC-co-EEA)
The synthesis and testing were carried out in the same manner as in Example 14, except that the amount of TIP-AC was 0.9 mmol and the amount of EEA was 0.2 mmol. The results are shown in Tables 1 to 4.

The iodine-containing polymer of the present disclosure can be used in optical devices such as high refractive index light-emitting diodes (LEDs) and image sensors, high refractive index materials such as anti-reflection films, lens materials, high refractive index polymer materials such as lens coatings, and optical instruments such as telescopes, binoculars, microscopes, cameras, endoscopes (fiberscopes), planetariums, length measuring instruments, comparators, range finders, spectrometers, interferometers, and polarimeters. In particular, the iodine-containing polymer of the present disclosure can be used preferably in applications requiring not only a high refractive index but also solubility, film-forming properties, heat resistance, transparency, and the like.

Claims (11)

An optical material comprising an iodine-containing polymer including a repeating unit derived from a triiodophenyl group-containing acrylate monomer (1),
The iodine-containing polymer has a number average molecular weight of 50,000 or less, and satisfies at least one of the following (I) and (II) :
(I) The iodine-containing polymer is
formula:
CH ₂ =C(-X ² )-C(=O)Y ² -R
[Wherein,
X2 is a hydrogen atom, a methyl group or a halogen atom ^;
Y2 is -O- or -NH- ^;
R is an organic group having 2 to 30 carbon atoms.
The repeating unit is derived from a triiodophenyl group-free acrylate monomer (2) represented by the formula:
The R is an alkyl group, or
-(R ¹ O) _q -R ²
[In the formula, R ¹ is independently an alkylene group having 1 to 10 carbon atoms, R ² is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and q is 1 to 100.]
It is a (poly)oxyalkylene group represented by the following formula:
(II) The iodine-containing polymer has a structure derived from a molecular weight control agent. The monomer (1) is represented by the following formula:
CH ₂ =C(-X ¹ )-C(=O)Y ¹ -L-TIP
[Wherein,
TIP is the triiodophenyl group;
^X1 is a hydrogen atom, a methyl group or a halogen atom;
^Y1 is -O- or -NH-;
L is a direct bond or a divalent aliphatic or aromatic group .
The optical material according to claim 1 , The iodine-containing polymer has the following formula:
CH ₂ =C(-X ² )-C(=O)Y ² -R
[Wherein,
^X2 is a hydrogen atom, a methyl group or a halogen atom;
^Y2 is -O- or -NH-;
R is an organic group having 2 to 30 carbon atoms.
The repeating unit is derived from a triiodophenyl group-free acrylate monomer (2) represented by the formula :
The R is an alkyl group, or
-(R ¹ O) _q -R ²
[In the formula, R ¹ is independently an alkylene group having 1 to 10 carbon atoms, R ² is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and q is 1 to 100.]
The optical material according to claim 1 or 2, wherein the (poly)oxyalkylene group is represented by the following formula : The optical material according to claim 3 , wherein R is an alkyl group . The optical material according to claim 3 , wherein R is the (poly) oxyalkylene group. The optical material according to any one of claims 3 to 5, wherein the content of the repeating unit derived from monomer (2) in the iodine-containing polymer is 0.02 molar parts or more per 1 molar part of the repeating unit derived from monomer (1). The optical material according to any one of claims 1 to 6, wherein the triiodophenyl group is a 2,3,5-triiodophenyl group or a 2,4,6-triiodophenyl group. The optical material according to any one of claims 1 to 7, wherein the iodine-containing polymer has a structure derived from a molecular weight control agent. The optical material according to claim 8, wherein the molecular weight control agent is at least one selected from the group consisting of monothiol compounds, dithiol compounds, and RAFT agents. An optical component formed from the optical material according to any one of claims 1 to 9 and selected from a coating, a film, a sheet, a prism, a lens and a fiber. An optical article comprising the optical component according to claim 10.

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