WO2019208441A1

WO2019208441A1 - Polymer, molded body and article

Info

Publication number: WO2019208441A1
Application number: PCT/JP2019/016844
Authority: WO
Inventors: 遼祐一二三; 宮木　伸行; 育義冨田
Original assignee: Jsr株式会社; 国立大学法人東京工業大学
Priority date: 2018-04-26
Filing date: 2019-04-19
Publication date: 2019-10-31
Also published as: JPWO2019208441A1; TW201945434A

Abstract

One embodiment of the present invention pertains to a polymer, a molded body and an article, said polymer having a structural unit represented by formula (1) and at least one of structural units represented by formulae (2-1) and (2-2) [wherein: R¹ represents a C_1-20 hydrocarbon group; R¹¹'s and R¹²'s independently represent a halogen atom, a nitro group, a cyano group or a C_1-20 organic group; and x and y independently represent an integer of 0-4.] [wherein: a represents an integer of 0-2; R²'s independently represent a halogen atom, a nitro group, a cyano group or a C_1-20 organic group; and b represents an integer of 0-8.] [wherein: R³'s and R⁴'s independently represent a halogen atom, a nitro group, a cyano group or a C_1-20 organic group; c and d independently represent an integer of 0-8; e and f independently represent an integer of 0-2; and L represents a single bond, -SO₂- or a C_1-20 organic group.]

Description

Polymer, molded body and article

An embodiment of the present invention relates to a polymer, a molded body, and an article.

Optical components such as optical lenses and optical films are used in display devices such as liquid crystal display devices, camera module lenses such as digital cameras and mobile phone cameras, and optical sensors such as image sensors. In recent years, an optical component has been formed using a polymer having a high refractive index as a resin component from the viewpoint of thinning and high added value.
In addition, when an optical component such as an optical lens is used in an imaging system device such as a camera module, low birefringence is also required for high definition of images.

As a representative example of a low birefringence polymer, a polyether having a structure derived from a bisphenol compound such as a bisphenolfluorene derivative is known (see Patent Document 1). These polymers exhibit low birefringence because the refractive index in the main chain direction and the direction orthogonal to the main chain cancel each other due to the cardo structure of the fluorene skeleton. On the other hand, a polymer having a rigid and bulky skeleton such as a fluorene skeleton is generally known to be inferior in moldability because of its extremely high glass transition temperature.

On the other hand, various polymers having a phosphorus functional group are known, and polymers containing a phosphine sulfide moiety in the main chain have been studied as high heat resistant materials, flame retardant materials, and the like (see Non-Patent Documents 1 and 2). ). However, the optical properties of these polymers have not been investigated at all, and it is considered that the birefringence of these polymers is not low.

JP 2012-224863 A

So far, a polymer having a phosphine sulfide moiety which has a high refractive index and a low Abbe number and is excellent in low birefringence has not yet been known.

One embodiment of the present invention provides a polymer having a high refractive index and a low Abbe number and excellent in low birefringence.

As a result of intensive studies to solve the above problems, the present inventor has found that the above problems can be solved according to the following configuration example, and has completed the present invention.
A configuration example of the present invention is as follows.

[1] A polymer having a structural unit represented by the following formula (1) and at least one of structural units represented by the following formulas (2-1) and (2-2).

[In Formula (1), R ¹ is a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ¹¹ and R ¹² are each independently a halogen atom, a nitro group, a cyano group or a monovalent organic group having 1 to 20 carbon atoms. x and y are each independently an integer of 0 to 4. When x is 2 or more, the plurality of R ¹¹ are the same or different. When y is 2 or more, the plurality of R ¹² are the same or different. ]

[In the formula (2-1), a is an integer of 0 to 2. R ² is independently a halogen atom, a nitro group, a cyano group or a monovalent organic group having 1 to 20 carbon atoms. b is an integer of 0 to 8. When b is 2 or more, a plurality of R ² may be the same or different, and two or more of these groups may be bonded to each other to form a ring structure having 4 to 20 ring members. ]

[In Formula (2-2), R ³ and R ⁴ each independently represent a halogen atom, a nitro group, a cyano group, or a monovalent organic group having 1 to 20 carbon atoms. c and d are each independently an integer of 0 to 8. When c is 2 or more, the plurality of R ³ may be the same or different, and two or more of these groups may be bonded to each other to form a ring structure having 4 to 20 ring members. When d is 2 or more, the plurality of R ⁴ may be the same or different, and two or more of these groups may be bonded to each other to form a ring structure having 4 to 20 ring members. e and f are each independently an integer of 0-2. L is a single bond, —SO ₂ — or a divalent organic group having 1 to 20 carbon atoms. ]

[2] The polymer according to [1], wherein the absolute value of the stress optical coefficient measured at a temperature 20 ° C. higher than the glass transition temperature of the polymer is 3.0 × 10 ⁻⁹ Pa ⁻¹ or less.

[3] The polymer according to [1] or [2], wherein R ¹ in the formula (1) is an aromatic hydrocarbon group having 6 to 20 carbon atoms.

[4] The polymer according to any one of [1] to [3], which has a polystyrene-equivalent weight average molecular weight of 2,000 to 300,000.

[5] The polymer according to any one of [1] to [4], wherein the glass transition temperature is 100 ° C. or higher and 300 ° C. or lower.

[6] When the refractive indexes of the F-line (486 nm), D-line (589 nm), and C-line (656 nm) are nF, nD, and nC, respectively, the Abbe number (νD) obtained by the equation (A) is 25.0. The polymer according to any one of [1] to [5], which is:
νD = (nD−1) / (nF−nC) (A)
[7] The polymer according to any one of [1] to [6], wherein the refractive index nD of the D line is 1.60 or more.

[8] A molded article of the polymer according to any one of [1] to [7].
[9] An article selected from a film and an optical lens, comprising the molded article according to [8].

According to one embodiment of the present invention, a polymer having a high refractive index and a low Abbe number and excellent in low birefringence can be provided. Therefore, by using the polymer, a molded article having a high refractive index and a low Abbe number and excellent in low birefringence, particularly a film and an optical lens can be obtained conveniently and cost-effectively.

FIG. 1 is the ¹ H-NMR spectrum of polymer 3 obtained in Example 1.

≪Polymer≫
A polymer according to an embodiment of the present invention (hereinafter also referred to as “the present polymer”) includes a structural unit represented by formula (1) (hereinafter also referred to as “structural unit (I)”) and a formula ( 2-1) and (2-2) at least one of structural units (hereinafter, also referred to as “structural unit (II)”).
This polymer may have structural units other than structural unit (I) and (II).

[Structural unit (I)]
The structural unit (I) is represented by the following formula (1).
The present polymer may have one or more structural units (I).

In the formula (1), R ¹ is a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ¹¹ and R ¹² are each independently a halogen atom, a nitro group, a cyano group or a monovalent organic group having 1 to 20 carbon atoms. x and y are each independently an integer of 0 to 4. When x is 2 or more, the plurality of R ¹¹ are the same or different. When y is 2 or more, the plurality of R ¹² are the same or different.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms in R ¹ include, for example, a monovalent chain hydrocarbon group having 1 to 20 carbon atoms and a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms. And monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms.

Examples of the monovalent chain hydrocarbon group having 1 to 20 carbon atoms include:
Alkyl groups such as methyl, ethyl, propyl and butyl groups;
An alkenyl group such as an ethenyl group, a propenyl group, a butenyl group;
Examples include alkynyl groups such as ethynyl group, propynyl group, butynyl group.

Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include:
Monovalent monocyclic alicyclic saturated hydrocarbon groups such as a cyclopentyl group and a cyclohexyl group;
Monovalent monocyclic alicyclic unsaturated hydrocarbon groups such as a cyclopentenyl group and a cyclohexenyl group;
Norbornyl group, adamantyl group, tricyclo [5.2.1.0 ^2,6 ] decyl group, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] monovalent polycyclic alicyclic saturated hydrocarbon group such as dodecyl group;
Norbornenyl group, tricyclo [5.2.1.0 ^2,6 ] decenyl group, tetracyclo [4.4.0.1 ^2,5 . And monovalent polycyclic alicyclic unsaturated hydrocarbon groups such as 1 ^7,10 ] dodecenyl group.

Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms include:
Aryl groups such as phenyl, tolyl, xylyl, naphthyl and anthryl;
Examples include aralkyl groups such as benzyl group, phenethyl group, naphthylmethyl group, and anthrylmethyl group.

R ¹ is preferably an aromatic hydrocarbon group, more preferably an aryl group, and still more preferably a phenyl group.

Examples of the halogen atom in R ¹¹ and R ¹² include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. In these, a chlorine atom is preferable.

Examples of the monovalent organic group having 1 to 20 carbon atoms in R ¹¹ and R ¹² include a monovalent hydrocarbon group having 1 to 20 carbon atoms which may have a substituent. Examples of the hydrocarbon group having 1 to 20 carbon atoms include the same groups as those exemplified as the monovalent hydrocarbon group having 1 to 20 carbon atoms in R ¹ . Examples of the substituent include a halogen atom, a nitro group, a cyano group, a methoxy group, an acetyl group, a methylthio group, and a thioacetyl group.

R ¹¹ and R ¹² are preferably a chain hydrocarbon group, more preferably an alkyl group, and still more preferably a methyl group.

X and y are each independently preferably 0 and 1, more preferably 0.

The structural unit (I) is preferably a structural unit represented by the following formula (1 ′).

In Expression (1 '), R ¹ has the same meaning as R ¹ in formula (1). ]

As a monomer for deriving the structural unit (I), for example,
Bis (fluorophenyl) phenylphosphine sulfide, bis (fluorophenyl) naphthylphosphine sulfide, bis (fluorophenyl) anthrylphosphine sulfide, bis (fluorophenyl) tolylphosphine sulfide, bis (fluorophenyl) methylphosphine sulfide, bis (fluorophenyl) ) Difluorinated products of phosphine sulfides such as cyclohexylphosphine sulfide;
Bis (chlorophenyl) phenylphosphine sulfide, bis (chlorophenyl) naphthylphosphine sulfide, bis (chlorophenyl) anthrylphosphine sulfide, bis (chlorophenyl) tolylphosphine sulfide, bis (chlorophenyl) methylphosphine sulfide, bis (chlorophenyl) cyclohexylphosphine sulfide, etc. Examples include phosphine sulfide dichloroides.

In the case of synthesizing the present polymer by the following method 2, as a monomer that can be converted to the structural unit (I) by a functional group conversion reaction, for example,
Bis (fluorophenyl) phenylphosphine oxide, bis (fluorophenyl) naphthylphosphine oxide, bis (fluorophenyl) anthrylphosphine oxide, bis (fluorophenyl) tolylphosphine oxide, bis (fluorophenyl) methylphosphine oxide, bis (fluorophenyl) ) Difluorinated products of phosphine oxides such as cyclohexylphosphine oxide;
Bis (chlorophenyl) phenylphosphine oxide, bis (chlorophenyl) naphthylphosphine oxide, bis (chlorophenyl) anthrylphosphine oxide, bis (chlorophenyl) tolylphosphine oxide, bis (chlorophenyl) methylphosphine oxide, bis (chlorophenyl) cyclohexylphosphine oxide, etc. A phosphine oxide dichloro compound can be used.

As the monomer, difluorinated compounds are preferable, and bis (fluorophenyl) phenylphosphine sulfide and bis (fluorophenyl) phenylphosphine oxide are particularly preferable. The tolyl group is preferably a p-tolyl group.

The lower limit of the content ratio of the structural unit (I) in the present polymer is preferably 10 mol%, more preferably 30 mol%, further preferably 40 mol%, particularly preferably 45 mol%. As an upper limit of the said content rate, 90 mol% is preferable, 70 mol% is more preferable, 60 mol% is further more preferable, 55 mol% is especially preferable. When the content ratio of the structural unit (I) is in the above range, a polymer excellent in high refractive index, low Abbe number, and low birefringence can be obtained.

[Structural unit (II)]
The structural unit (II) is represented by at least one of the following formulas (2-1) and (2-2).
The present polymer may have one or more structural units (II). When the polymer has two or more types of structural units (II), it may have two or more types of structural units represented by the formula (2-1). 2) which may have a structural unit represented by 2) and one or more structural units represented by formula (2-1) and one or more structural units represented by formula (2-2) You may have.

In the formula (2-1), a is an integer of 0-2. R ² is independently a halogen atom, a nitro group, a cyano group or a monovalent organic group having 1 to 20 carbon atoms. b is an integer of 0 to 8. When b is 2 or more, a plurality of R ² may be the same or different, and two or more of these groups may be bonded to each other to form a ring structure having 4 to 20 ring members.

The structural unit represented by the formula (2-1) specifically means a structural unit represented by the following formulas (2-1-1) to (2-1-3). The following formula (2-2) has the same meaning.

Wherein (2-1-1) ~ (2-1-3), R ² is independently the same meaning as R ² in formula (2-1). In formula (2-1-1), b1 is an integer of 0 to 4. In formula (2-1-2), b2 is an integer from 0 to 2, and b3 is an integer from 0 to 4. In formula (2-1-3), b2 and b4 are each independently an integer of 0 to 2, and b5 is an integer of 0 to 4. ]

In formula (2-2), R ³ and R ⁴ are each independently a halogen atom, a nitro group, a cyano group, or a monovalent organic group having 1 to 20 carbon atoms. c and d are each independently an integer of 0 to 8. When c is 2 or more, the plurality of R ³ may be the same or different, and two or more of these groups may be bonded to each other to form a ring structure having 4 to 20 ring members. When d is 2 or more, the plurality of R ⁴ may be the same or different, and two or more of these groups may be bonded to each other to form a ring structure having 4 to 20 ring members. e and f are each independently an integer of 0-2. L is a single bond, —SO ₂ — or a divalent organic group having 1 to 20 carbon atoms.

Examples of the halogen atom in R ² , R ³ and R ⁴ include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. In these, a chlorine atom is preferable.

Examples of the monovalent organic group having 1 to 20 carbon atoms in R ² , R ³ and R ⁴ include monovalent hydrocarbon groups having 1 to 20 carbon atoms which may have a substituent. Examples of the hydrocarbon group having 1 to 20 carbon atoms include the same groups as those exemplified as the monovalent hydrocarbon group having 1 to 20 carbon atoms in R ¹ . Examples of the substituent include a halogen atom, a nitro group, a cyano group, a methoxy group, an acetyl group, a methylthio group, and a thioacetyl group. Among these, a chain hydrocarbon group is preferable, an alkyl group is more preferable, and a methyl group is more preferable.

Examples of the ring structure having 4 to 20 ring members formed by bonding two or more of a plurality of R ² , a plurality of R ³ or a plurality of R ⁴ groups to each other include:
Cyclobutene structure, cyclopentene structure, cyclohexene structure, norbornene structure, bicyclo [2.2.2] octene structure, dibenzobicyclo [2.2.2] octene structure, etc .; benzene structure, naphthalene structure, anthracene structure, etc. Hydrocarbon ring structures such as aromatic ring structures,
Aliphatic heterocyclic structures such as oxacyclohexene structure, azacyclohexene structure, and thiacyclohexene structure;
Aromatic heterocyclic structures such as furan structure, pyrrole structure, pyridine structure, thiophene structure, etc.

As a, e, and f, 0 and 1 are preferable and 0 is more preferable.
b, c and d are preferably 0 to 2, more preferably 0 and 1, and particularly preferably 0.

Examples of the divalent organic group having 1 to 20 carbon atoms represented by L include a divalent hydrocarbon group (α) having 1 to 20 carbon atoms, and a divalent valence between carbon and carbon of the divalent hydrocarbon group. Group (β) having a hetero atom-containing group, a group obtained by substituting a part or all of the hydrogen atoms of the group (α) or group (β) with a monovalent hetero atom or hetero atom-containing group, and the like. .

Examples of the hetero atom constituting the monovalent or divalent heteroatom-containing group include an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, a silicon atom, and a halogen atom.

Examples of the divalent heteroatom-containing group include —O—, —CO—, —S—, —CS—, —NR′—, —SO ₂ —, a group in which two or more of these are combined, and the like. It is done. R ′ is a hydrogen atom or a monovalent hydrocarbon group. Of these, —O— is preferable.

Examples of the monovalent hetero atom or hetero atom-containing group include a halogen atom, a hydroxy group, a carboxy group, a cyano group, an amino group, and a sulfanyl group.

Examples of the divalent organic group having 1 to 20 carbon atoms in L include groups represented by the following formulas (L-1) to (L-3) (hereinafter referred to as “group (L-1) to group (L— 3) ")) and the like.

[In formulas (L-1) to (L-3), * represents a site bonded to the aromatic ring in formula (2-2). ]

The lower limit of the carbon number of the divalent organic group in L is preferably 2, more preferably 3, and the upper limit is preferably 18, more preferably 16, more preferably 14, and particularly preferably 13.

L is preferably a single bond or a divalent organic group, more preferably a single bond or a group (L-1) to (L-3), particularly preferably a group (L-1) to a group (L-3). .

As the structural unit (II), structural units represented by the following formulas (2-A) to (2-G) (hereinafter also referred to as “structural units (II-A) to (II-G)”) Etc.

Of these, structural units (II-A), (II-F) and (II-G) are preferred.

As a monomer for deriving the structural unit (II), for example,
Dihydroxyphenyl compounds such as hydroquinone, resorcinol, catechol, phenylhydroquinone;
9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, 9,9-bis (4-hydroxy-3-phenylphenyl) fluorene, 1,1 -Bis (4-hydroxyphenyl) -1-phenylethane, bis (4-hydroxyphenyl) diphenylmethane, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3-methylphenyl) ) Propane, 2,2-bis (4-hydroxy-3-phenylphenyl) propane, bis (4-hydroxyphenyl) sulfone, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,4-bis [2- (4-Hydroxyphenyl) -2-propyl] benzene, 1,3-bis [2- (4-hydroxyphenyl) -2 Propyl] bisphenol compounds of benzene.

The lower limit of the content ratio of the structural unit (II) in the present polymer is preferably 10 mol%, more preferably 30 mol%, further preferably 40 mol%, particularly preferably 45 mol%. As an upper limit of the said content rate, 90 mol% is preferable, 70 mol% is more preferable, 60 mol% is further more preferable, 55 mol% is especially preferable. When the content ratio of the structural unit (II) is in the above range, a polymer having a higher refractive index, a lower Abbe number, and a lower birefringence can be obtained.

[Other structural units]
The other structural unit is not particularly limited as long as the effects of the present invention are not impaired.
The present polymer may have one or more of the other structural units.

Examples of the monomer for deriving the other structural unit include:
A compound that derives a structural unit containing a carbonate bond, thiocarbonate bond or selenocarbonate bond, such as diphenyl carbonate, diphenylthiocarbonate, diphenylselenocarbonate, phosgene, thiophosgene, selenophosgene;
Dihydroxy compounds such as benzenedimethanol and cyclohexanedimethanol;
Examples thereof include dihalides of dicarboxylic acids such as phthalic acid dichloride, isophthalic acid dichloride, and terephthalic acid dichloride.

When the present polymer has the other structural unit, the upper limit of the content of the other structural unit in the polymer is preferably 50 mol%, more preferably 30 mol%, still more preferably 20 mol%, 10 mol% is particularly preferred. As a minimum of the above-mentioned content rate, it is 1 mol%, for example.

[Physical properties of polymer]
-Weight average molecular weight (Mw)
As a minimum of the weight average molecular weight (Mw) of polystyrene conversion of this polymer, 2,000 is preferred, 10,000 is more preferred, 30,000 is still more preferred, and 40,000 is especially preferred. The upper limit of the Mw is preferably 300,000, more preferably 200,000, still more preferably 160,000, and particularly preferably 130,000.
The present polymer having Mw in the above range is preferable because it is excellent in mechanical properties and moldability.
Mw of the polymer in this specification is a value measured by gel permeation chromatography (GPC) under the conditions described in the following examples.

-Stress optical coefficient (CR) measured at a temperature 20 ° C higher than the glass transition temperature of the polymer
In this polymer, the absolute value of the stress optical coefficient (hereinafter also referred to as “CR”) measured at a temperature 20 ° C. higher than the glass transition temperature of the polymer is 3.0 × 10 ⁻⁹ Pa ⁻¹ or less. It is preferable.
CR is positive or negative, but when the refractive index in the direction parallel to the main chain of the polymer is compared with the refractive index in the direction perpendicular to the main chain, the refractive index in the direction parallel to the main chain Is large, CR is positive, and when the refractive index in the direction orthogonal to the main chain is larger, CR is negative.
Specifically, CR is measured by the method described in Examples.

The lower limit of the CR is preferably −3.0 × 10 ⁻⁹ Pa ^−1, more preferably −2.9 × 10 ⁻⁹ Pa ⁻¹ , and even more preferably −2.8 × 10 ⁻⁹ Pa ^−1. . The upper limit of the CR is preferably 3.0 × 10 ⁻⁹ Pa ^−1, more preferably 2.9 × 10 ⁻⁹ Pa ⁻¹ , and even more preferably 2.8 × 10 ⁻⁹ Pa ⁻¹ . A polymer having CR in the above range is a polymer excellent in low birefringence.

・ Glass transition temperature (Tg)
As a minimum of Tg of this polymer, 100 ° C is preferred, 120 ° C is more preferred, 130 ° C is still more preferred, and 140 ° C is especially preferred. The upper limit of Tg is, for example, 300 ° C. When Tg of this polymer exists in the said range, melt molding can be performed more easily and the molded object which is excellent in heat resistance can be obtained.
Tg is a value calculated from a thermogram obtained using a DSC measuring apparatus, and specifically, measured by the method described in the examples.

-Refractive index (nD)
The lower limit of the refractive index (nD) of the present polymer is preferably 1.60, more preferably 1.63, still more preferably 1.64, and particularly preferably 1.65. The upper limit of the refractive index is, for example, 1.80.
The refractive index in this specification refers to the refractive index of the D line unless otherwise specified.

・ Abbe number (νD)
The upper limit of the Abbe number (νD) of the polymer is preferably 25.0, more preferably 24.0, and particularly preferably 23.0. The lower limit of the Abbe number is 15.0, for example, and preferably 16.0.

Reduction in the thickness of molded articles such as lenses and films obtained by using the present polymer when the refractive index (nD) of the present polymer is 1.60 or more and the Abbe number (νD) is 25.0 or less. And it becomes easy to realize high added value.
Specifically, nD and νD are measured by the method described in the examples. The Abbe number in this specification means the Abbe number (νD) calculated by the following formula (A).

<Polymer synthesis method>
This polymer can be synthesized by a known method and is not particularly limited, but is preferably synthesized by the following method 1 or 2.

・ Method 1
The method 1 includes, for example, a monomer that derives a structural unit (I) such as a dihalogenated phosphine sulfide, a monomer that induces a structural unit (II) such as a bisphenol compound, and, if necessary, the other structure. This is a method of synthesizing a polymer by conducting a reaction 1 such as condensation polymerization in an organic solvent in the presence of an alkali metal compound or the like for a monomer that derives a unit. In the case of the reaction 1, for example, the reaction may be performed in the presence of an end-capping agent such as a monophenol compound such as 2-phenylphenol.
1 type may be used for the said monomer, an alkali metal compound, an organic solvent, and terminal blocker, respectively, and 2 or more types may be used for them.
In addition, it is preferable to use the said monomer in such an amount that the content rate of the structural unit formed from each monomer becomes the said range.

(Alkali metal compound)
The alkali metal compound reacts with an aromatic diol compound or the like in the course of synthesis of the present polymer to form an alkali metal salt. As such an alkali metal compound, for example,
Alkali metals such as lithium, sodium and potassium;
Alkali metal hydrides such as lithium hydride, sodium hydride, potassium hydride;
Alkali metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide;
Alkali metal carbonates such as lithium carbonate, sodium carbonate, potassium carbonate;
Examples thereof include alkali metal hydrogen carbonates such as lithium hydrogen carbonate, sodium hydrogen carbonate, and potassium hydrogen carbonate.
In these, an alkali metal carbonate is preferable and potassium carbonate is more preferable.

As the amount of the alkali metal compound used, the lower limit of the ratio of the number of moles of alkali metal atoms in the alkali metal compound to the number of moles of hydroxy groups in all compounds used in the synthesis of the present polymer is preferably 1. Is more preferable, and 1.2 is more preferable. The upper limit of the ratio is preferably 3, more preferably 2, and even more preferably 1.5.

(Organic solvent)
As an organic solvent used in the method 1, for example,
Ether solvents such as tetrahydrofuran (THF), dioxane, cyclopentyl methyl ether, anisole, phenetole, diphenyl ether, dialkoxybenzene, trialkoxybenzene;
Nitrogen-containing solvents such as N, N-dimethylacetamide (DMAc), N, N-dimethylformamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone;
ester solvents such as lactone solvents such as γ-butyrolactone;
Sulfur-containing solvents such as sulfolane, dimethyl sulfoxide, diethyl sulfoxide, dimethyl sulfone, diethyl sulfone, diisopropyl sulfone, diphenyl sulfone;
Ketone solvents such as benzophenone;
Halogen solvents such as methylene chloride, chloroform, chlorobenzene;
Aromatic hydrocarbon solvents such as benzene, toluene, xylene and the like can be mentioned.
Among these organic solvents, DMAc, N, N-dimethylformamide and N-methyl-2-pyrrolidone are preferable, and N-methyl-2-pyrrolidone is more preferable.

(Conditions for Method 1)
As a minimum of reaction temperature in the above-mentioned method 1, 50 ° C is preferred and 100 ° C is more preferred. The upper limit of the reaction temperature is preferably 300 ° C, more preferably 200 ° C.
The lower limit of the reaction time in Method 1 is preferably 1 hour, more preferably 2 hours, and even more preferably 3 hours. The upper limit of the reaction time is preferably 100 hours, more preferably 50 hours, and even more preferably 24 hours.

・ Method 2
Method 2 includes, for example, a monomer that can be converted into the structural unit (I) by a functional group conversion reaction such as dihalogenated phosphine oxide, and a monomer that derives the structural unit (II) such as a bisphenol compound, If necessary, a polymer obtained by polymerizing a monomer derived from the other structural unit in an organic solvent in the presence of an alkali metal compound or the like is converted into a functional group in the organic solvent in the presence of a sulfurizing agent or the like. Etc. to synthesize the present polymer.
In the case of the method 2, the reaction may be carried out using a reducing agent such as chlorosilanes.

The polymerization reaction in Method 2 may be performed in the same manner as Reaction 1 in Method 1. Each of the monomer, alkali metal compound, organic solvent, and end-capping agent used in this reaction may be used alone or in combination of two or more.
In addition, it is preferable to use the said monomer in such an amount that the content rate of the structural unit formed from each monomer becomes the said range.

(Sulfurizing agent)
The sulfurizing agent is preferably a material capable of forming a phosphine sulfide moiety by reacting with a phosphine moiety, a phosphine oxide moiety, or the like in the course of synthesis of the present polymer.
As such a sulfurizing agent, for example,
Simple sulfur;
Alkali sulfide metals such as lithium sulfide, sodium sulfide and potassium sulfide;
Phosphorous sulfide compounds such as niolin pentasulfide;
Examples include 1,3,2,4-dithiadiphosphetan-2,4-disulfide compounds such as Lawson's reagent, Davy reagent, Japanese reagent, and Belleo reagent.
Of these, 1,3,2,4-dithiadiphosphetane-2,4-disulfide compounds are preferred, and Lawesson's reagent is more preferred.

(Organic solvent)
As the organic solvent used in the functional group conversion, for example,
Halogen solvents such as methylene chloride, chloroform, chlorobenzene;
Ether solvents such as THF, dioxane, cyclopentyl methyl ether, anisole, phenetole, diphenyl ether, dialkoxybenzene, trialkoxybenzene;
Aromatic hydrocarbon solvents such as benzene, toluene, xylene and the like can be mentioned.
Among these organic solvents, methylene chloride, chloroform, dioxane, cyclopentyl methyl ether, and toluene are preferable, and toluene is more preferable.
1 type (s) or 2 or more types can be used for this organic solvent.

(Reducing agent)
By using the reducing agent, a phosphine oxide site or the like can be reduced to give a phosphine site, and the subsequent sulfurization reaction can be facilitated.
Examples of such a reducing agent include chlorosilanes such as dichlorosilane and trichlorosilane. Of these chlorosilanes, trichlorosilane is preferred.
One or more reducing agents can be used.

(conditions)
As a minimum of reaction temperature in the case of the above-mentioned functional group conversion, 0 ° C is preferred and 20 ° C is more preferred. The upper limit of the reaction temperature is preferably 200 ° C., more preferably 180 ° C.
As a minimum of reaction time in the case of the above-mentioned functional group conversion, 1 hour is preferred, 2 hours are more preferred, and 3 hours are still more preferred. The upper limit of the reaction time is preferably 100 hours, more preferably 50 hours, and even more preferably 30 hours.

≪Molded body≫
The polymer can be molded into a molded body by a molding method such as a melt molding method or a solvent casting method. When forming a molded body such as an optical component from this polymer, the molding method is melt molding from the viewpoint that a molded body excellent in characteristics such as low birefringence, mechanical strength and dimensional accuracy can be easily obtained. The method is preferred.
Examples of the melt molding method include a press molding method, an extrusion molding method, and an injection molding method. Among these, the injection molding method is preferable from the viewpoints of moldability and productivity.

The molding conditions in the molding process may be appropriately selected depending on the purpose of use or molding method, but the lower limit of the temperature in the injection molding method is preferably 150 ° C, more preferably 180 ° C, and even more preferably 200 ° C. As an upper limit of the said temperature, 400 degreeC is preferable, 350 degreeC is more preferable, and 330 degreeC is further more preferable. By setting the temperature at the time of injection molding within the above range, thermal decomposition and yellowing of the polymer can be effectively suppressed.

As the usage of the molded article, an optical component utilizing characteristics excellent in high refractive index, low Abbe number and low birefringence is preferable. Examples of the optical component include an optical disc, an optical lens, a prism, a light diffusion plate, an optical card, an optical fiber, an optical mirror, a liquid crystal display element substrate, a light guide plate, a polarizing film, and a retardation film.

≪Optical lens≫
The optical lens according to an embodiment of the present invention preferably includes a molded body of the polymer and is formed of the molded body.
The optical lens can be obtained, for example, by injection-molding the polymer into a lens shape by a molding machine such as an injection molding machine or an injection compression molding machine. When obtaining an optical lens, it is preferable that the molding environment is a low dust environment in order to avoid contamination of foreign matters as much as possible.

The optical lens can be used as various lenses such as a pickup lens, an f-θ lens, and a spectacle lens. Further, since the optical lens has a high refractive index and a low Abbe number, it can be particularly suitably used as a chromatic aberration correction lens. Specifically, it can be suitably used as a lens for a single lens reflex camera, a digital still camera, a video camera, a camera-equipped mobile phone, a lens-equipped film, a telescope, a binocular, a microscope, a projector, or the like.

The optical lens may be a convex lens or a concave lens. In the case of a concave lens, it can be suitably used as an optical lens system with little chromatic aberration in combination with other high Abbe number convex lenses.

≪Film≫
The film according to an embodiment of the present invention preferably includes a molded body of the present polymer and is formed of the molded body.
The film can be obtained, for example, by forming the polymer into a film shape by melt molding or solvent casting.

The film is not particularly limited, but can be suitably used as an optical film. Specifically, it can be suitably used as a liquid crystal display element substrate, a light guide plate, a polarizing film, a retardation film, and the like.

The thickness of the film is not particularly limited and may be appropriately selected depending on the desired use. For example, the thickness is 10 μm to 2 mm, preferably 30 μm to 1 mm.

Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to the following examples. Each physical property value was measured by the following method.

[Weight average molecular weight (Mw)]
The Mw of the polymer was measured using a GPC apparatus (“HLC-8320 type” manufactured by Tosoh Corporation) under the following conditions.
Column: Tosoh Co., Ltd. “TSKgel α-M” and Tosoh Co., Ltd. “TSKgel guardcylum α” linked together Developing solvent: N-methyl-2-pyrrolidone with LiBr concentration of 10 mM Column temperature: 40 ° C
Flow rate: 1.0 mL / min Sample concentration: 0.33 mass%
Sample injection volume: 50 μL
Detector: UV-Vis spectrophotometer Standard material: Monodisperse polystyrene

[ ¹ H-NMR analysis]
In order to determine the content ratio of each structural unit in the polymer, ¹ H-NMR analysis was performed. ¹ H-NMR analysis was performed using a nuclear magnetic resonance apparatus (“ECX400” manufactured by JEOL Ltd.) and deuterated chloroform as a measurement solvent.

[Comparative Example 1]
A nitrogen inlet tube, a Dean-Stark tube and a condenser tube were attached, and a 2-mL (4-hydroxyphenyl) propane (9.13 g, 40.0 mmol), (4-Fluorophenyl) phenylphosphine oxide (13.1 g, 41.7 mmol) and potassium carbonate (7.95 g, 57.5 mmol) were weighed into which N-methyl-2-pyrrolidone (50 ml) was added, The reaction was performed at 180 ° C. for 14 hours under a nitrogen atmosphere.
After completion of the reaction, N-methyl-2-pyrrolidone (50 ml) was added for dilution, and the salt was removed by filtration. An appropriate amount of ion exchange resins (“Diaion RCP160M” and “Diaion WA21J” manufactured by Mitsubishi Chemical Corporation) were added to the filtrate, and the mixture was stirred for 4.5 hours with a mix rotor. After removing the ion exchange resin by filtration, the remaining solution was poured into ion exchange water (2.0 kg) to precipitate a solid. The precipitated solid was separated by filtration, washed twice with ion exchange water (600 ml), three times with acetone (600 ml) and once with ion exchange water (1200 ml), and again collected by filtration. Then, the polymer 1 shown to a following formula (A1) was obtained by drying at 120 degreeC under pressure reduction using a vacuum dryer (yield 18.5g, yield 89.4%).

[Comparative Example 2]
1,1-bis (4-hydroxyphenyl) -1-phenylethane (2.90 g, 10.0 mmol), bis (4-fluorophenyl) phenylphosphine oxide (3.30 g, 10.5 mmol), potassium carbonate (2 0.01 g, 14.5 mmol) and N-methyl-2-pyrrolidone (14 ml) were used in the same manner as in Comparative Example 1 to obtain a powder of polymer 2 represented by the following formula (A2). (Yield 5.15 g, Yield 88.8%).

[Example 1]
In a round bottom flask equipped with a stir bar and a reflux tube, the polymer of Comparative Example 1 (10.0 g, 20.0 mmol) and Lawson's reagent (6.85 g, 16.9 mmol) were weighed, and toluene (260 ml) was added thereto. ) Was added and allowed to react under reflux conditions for 24 hours under an argon atmosphere. After completion of the reaction, the solvent was removed with a rotary evaporator. Thereto, chloroform (150 ml) was added to redissolve the polymer, and the precipitate was removed by filtration. The remaining solution was poured into acetone (1500 ml), and the precipitated solid was filtered off, washed with a small amount of acetone, filtered again and collected (precipitation operation in acetone). Using the solution obtained by dissolving the obtained solid in tetrahydrofuran (150 ml), the same precipitation operation as acetone was performed. The solid obtained after the second precipitation operation in acetone was dried at 120 ° C. under reduced pressure for 14 hours using a vacuum dryer to obtain a polymer 3 represented by the following formula (A3) (yield: 9. 5 g, yield 92%). The ¹ H-NMR spectrum of the obtained polymer is shown in FIG.

[Example 2]
The same operation as in Example 1 was carried out except that the polymer of Comparative Example 2 (2.61 g, 4.6 mmol), Lawesson's reagent (1.59 g, 3.9 mmol) and toluene (100 ml) were used. A powder of polymer 4 shown in (A4) was obtained (yield 2.22 g, yield 82.7%).

<Evaluation>
For the polymers 1 to 4 obtained in Examples 1 and 2 and Comparative Examples 1 and 2, the glass transition temperature (Tg), the refractive index (nD), the Abbe number (νD) and the glass transition temperature of 20 were obtained according to the following method. The stress optical coefficient (CR) measured at a high temperature was evaluated. The evaluation results are shown in Table 1.

[Glass transition temperature (Tg) [° C]]
The Tg of the polymer was determined from a thermogram obtained using a DSC apparatus (“Thermo Plus DSC8230” manufactured by Rigaku). DSC measurement was performed under nitrogen at a rate of temperature increase of 20 ° C./min. Specifically, in the DSC temperature rising curve in the thermogram, the temperature corresponding to the intersection of the baseline and the tangent at the inflection point was defined as Tg. The inflection point was a temperature corresponding to a peak in a thermogram DDSC (DSC differential value) curve. In addition, the DDSC curve was referred to as appropriate for confirming the DSC baseline.
Tg can be evaluated as “good” when it is 100 ° C. or more and 300 ° C. or less, and can be evaluated as “bad” when it is less than 100 ° C. or exceeds 300 ° C.

[Refractive index (nD) [−] and Abbe number (νD) [−]]
A solution obtained by dissolving the polymer in an appropriate amount of methylene chloride was cast on a glass plate, and dried overnight at room temperature and normal pressure. Next, the residual methylene chloride was removed with a vacuum dryer to obtain a polymer film. The refractive index of this film was measured with a prism coupler (“Model 2010” manufactured by Metricon). The refractive index was measured at three wavelengths of 408 nm, 633 nm, and 828 nm, and the refractive index (nD) of the D line (589 nm) was determined using the Cauchy equation. The refractive index (nF) of the F line (486 nm) and the refractive index (nC) of the C line (656 nm) were determined in the same manner, and the Abbe number (νD) was calculated by the following formula (A).
νD = (nD−1) / (nF−nC) (A)
When the refractive index (nD) is 1.65 or more, it can be evaluated as “good”.
When the Abbe number (νD) is 25.0 or less, it can be evaluated as “good”, and when it exceeds 25.0, it can be evaluated as “bad”.

[Stress optical coefficient (CR) [10 ^-9 Pa ^-1 ]]
The stress optical coefficient (CR) measured at a temperature 20 ° C. higher than the glass transition temperature of the polymer was determined by a known method (NIHON REOROJI GAKKAISHI, Vol. 24, No. 3, 129-132, 1996). The film formed for evaluation of the refractive index was cut into strips, applied with several kinds of loads, heated and stretched under a temperature condition of Tg + 20 ° C., and slowly cooled with the loads applied. The relationship between the stress applied to the film and the resulting birefringence (measurement wavelength 598 nm) was determined, and the proportionality coefficient was taken as CR. For measurement of birefringence, “RETS100” manufactured by Otsuka Electronics Co., Ltd. was used. In addition, the positive / negative of CR was evaluated by measuring the retardation value by overlapping the obtained stretched film and the stretched polycarbonate film (CR is positive) so that the stretch directions are parallel or perpendicular to each other. CR is positive when the measured retardation value is greater when parallelly stacked than when vertically stacked, and CR is negative when vertically stacked is greater than when stacked in parallel.
CR can be evaluated as “good” when the absolute value (| CR |) is 3.0 × 10 ⁻⁹ Pa ⁻¹ or less, and “bad” when it exceeds 3.0 × 10 ⁻⁹ Pa ^−1. Can be evaluated.

As is apparent from Table 1, the polymers obtained in Examples 1 and 2 are good in evaluation of glass transition temperature (Tg), refractive index (nD), Abbe number (νD), and birefringence (CR). Results were obtained.

This polymer has a high refractive index and a low Abbe number, and is excellent in low birefringence. Therefore, according to the present polymer, a molded product having a high refractive index and a low Abbe number and excellent in low birefringence can be obtained conveniently and cost-effectively. In addition, an optical lens and a film having a high refractive index, a low Abbe number, and excellent low birefringence characteristics can be obtained.

Claims

A polymer having a structural unit represented by the formula (1) and at least one of the structural units represented by the formulas (2-1) and (2-2):

In formula (1), R 1 is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and R 11 and R 12 are each independently a halogen atom, a nitro group, a cyano group or 1 to 20 carbon atoms. And x and y are each independently an integer of 0 to 4, when x is 2 or more, a plurality of R 11 are the same or different, and when y is 2 or more, a plurality of R 12 of the same or different;

In formula (2-1), a is an integer of 0 to 2, R 2 is independently a halogen atom, a nitro group, a cyano group, or a monovalent organic group having 1 to 20 carbon atoms, b Is an integer of 0 to 8, and when b is 2 or more, a plurality of R 2 are the same or different, and two or more of these groups are bonded to each other to form a ring structure having 4 to 20 ring members May be;

In formula (2-2), R 3 and R 4 are each independently a halogen atom, a nitro group, a cyano group or a monovalent organic group having 1 to 20 carbon atoms, and c and d are each independently , An integer of 0 to 8, and when c is 2 or more, the plurality of R 3 are the same or different and two or more of these groups are bonded to each other to form a ring structure having 4 to 20 ring members And when d is 2 or more, the plurality of R 4 are the same or different and two or more of these groups are bonded to each other to form a ring structure having 4 to 20 ring members. E and f are each independently an integer of 0 to 2, and L is a single bond, —SO 2 — or a divalent organic group having 1 to 20 carbon atoms.
The polymer according to claim 1, wherein the absolute value of the stress optical coefficient measured at a temperature 20 ° C. higher than the glass transition temperature of the polymer is 3.0 × 10 −9 Pa −1 or less.
The polymer according to claim 1 or 2, wherein R 1 in the formula (1) is an aromatic hydrocarbon group having 6 to 20 carbon atoms.
The polymer according to any one of claims 1 to 3, wherein the polystyrene-reduced weight average molecular weight is 2,000 or more and 300,000 or less.
The polymer according to any one of claims 1 to 4, wherein the glass transition temperature is 100 ° C or higher and 300 ° C or lower.
6. The Abbe number νD obtained by the formula (A) is 25.0 or less when the refractive indexes of the F-line, D-line, and C-line are nF, nD, and nC, respectively. The polymer described in 1.
νD = (nD−1) / (nF−nC) (A)
The polymer according to any one of claims 1 to 6, wherein the refractive index nD of the D line is 1.60 or more.
A molded article of the polymer according to any one of claims 1 to 7.
An article selected from a film and an optical lens, comprising the molded article according to claim 8.