Polymers and methods for producing the same

Abstract

Provided are a copolymer capable of achieving both high heat resistance and high transparency (or light transmittance), and a method for producing the same and its use. 【Solution means】A copolymer of a fluorene compound represented by the following formula (1) and a (meth)acrylate ester is prepared. TIFF2026050205000008.tif36154 (In the formula, R 2b represents a substituent, k represents an integer of 0 to 2, the double line of the solid line and the broken line represents a single bond or a double bond, R 2a and R 2b independently represent a non-polymerizable substituent, m1 represents an integer of 0 to 3, m2 represents an integer of 0 to 4, R 3 , R 4 and R 5 independently represent a hydrogen atom or a non-polymerizable substituent.)

Description

[Technical Field]

[0001] This disclosure relates to copolymers (resins or copolymers) of specific fluorene compounds (fluorenyl vinyl ketone compounds) having an acryloyl (or vinyl ketone) skeleton with (meth)acrylic acid esters, as well as methods for producing the same and its applications. [Background technology]

[0002] Fluorene, derived from coal tar, is a unique hydrocarbon with a π-conjugated aromatic system, possessing a rigid, highly symmetrical chemical structure and high reactivity. Due to these characteristics, it is used as a starting material for various fine chemical materials, with diverse applications including liquid crystal materials, photo-functional materials (or optical materials), and organic EL dyes, often as a monomer. Polyfluorenes, in which the fluorene skeleton repeatedly appears in the main chain, are used as organic semiconductors or light-emitting materials. Furthermore, fluorene compounds with two aromatic rings at the 9th position are also useful as functional monomers, and the resulting polymers (resins or polymers) exhibit excellent optical properties and heat resistance, making them suitable for use in optical materials or optical components.

[0003] Japanese Patent Publication No. 2023-122572 (Patent Document 1) discloses a fluorene compound represented by the following formula as a compound capable of forming a resin exhibiting high heat resistance, and also discloses a resin containing this fluorene compound as a polymerization component.

[0004] [ka]

[0005] (In the formula, R 1 The 'x' represents a substituent, k is an integer between 0 and 2, and the double line (solid and dashed) indicates a single or double bond. R 2a and R 2bThese independently represent nonpolymerizable substituents, where m1 is an integer from 0 to 3, and m2 is an integer from 0 to 4. R 3 , R 4 and R 5 (Each represents either a hydrogen atom or a nonpolymerizable substituent.) [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2023-122572 [Overview of the project] [Problems that the invention aims to solve]

[0007] In the examples described in Patent Document 1, 2-acryloyl-9,9-dimethylfluorene and its homopolymer were synthesized, and it was stated that this homopolymer exhibited high heat resistance, and that the cast film prepared using the homopolymer had excellent transparency. However, no specific transmittance is indicated, and the homopolymer was obtained as a pale yellow solid, which may make it difficult to use in applications requiring higher transparency (or light transmittance).

[0008] Therefore, the object of this disclosure is to provide copolymers that can achieve both high heat resistance (especially high weight loss temperature) and high transparency (or light transmittance), as well as methods for producing the same and applications thereof. [Means for solving the problem]

[0009] As a result of diligent research to achieve the above objectives, the present inventors discovered that when a fluorene compound having a specific chemical structure (fluorenyl vinyl ketone skeleton) is polymerized in combination with a (meth)acrylic acid ester, the resulting copolymer exhibits both high heat resistance and high transparency, thus completing this disclosure (or the present invention).

[0010] That is, the present disclosure may include the following aspects.

[0011] Aspect [1]: A copolymer of a fluorene compound represented by the following formula (1) and a (meth)acrylate.

[0012] [Chemical formula]

[0013] (In the formula, R 1 represents a substituent, k represents an integer from 0 to 2, the double line of the solid line and the dashed line represents a single bond or a double bond, R 2a and R 2b each independently represent a non-polymerizable substituent, m1 represents an integer from 0 to 3, m2 represents an integer from 0 to 4, R 3 , R 4 and R 5 each independently represent a hydrogen atom or a non-polymerizable substituent.)

[0014] Aspect [2]: In the formula (1), R 1 represents a hydrocarbon group or an oxygen atom, R 2a and R 2b each independently represent a hydrocarbon group, m1 represents an integer from 0 to 2, m2 represents an integer from 0 to 2, R 3 , R 4 and R 5 each independently represent a hydrogen atom or a hydrocarbon group, the copolymer according to Aspect [1].

[0015] Aspect [3]: In the formula (1), R 1 represents an alkyl group, k is 0 or 2, R <000002​​​​​​​​​5 The copolymer according to embodiment [1] or [2], wherein is independently a hydrogen atom or an alkyl group.

[0016] Appearance [4]: The copolymer according to any one of embodiments [1] to [3], wherein the (meth)acrylic acid ester is an alkyl (meth)acrylic acid ester.

[0017] Appearance [5]: The copolymer according to any one of embodiments [1] to [4], wherein the ratio of constituent units derived from the fluorene compound represented by formula (1) to constituent units derived from the (meth)acrylic acid ester is the former / latter (molar ratio) = 5 / 95 to 50 / 50.

[0018] Appearance [6]: 5% weight loss temperature T d5 However, the temperature is above 200℃, The copolymer according to any one of embodiments [1] to [5], wherein the light transmittance at 550 nm at a thickness of 0.8 mm is 50% or more.

[0019] Appearance [7]: The copolymer according to any one of embodiments [1] to [6], wherein the light transmittance at 450 nm at a thickness of 0.8 mm is 50% or more.

[0020] Appearance [8]: The glass transition temperature Tg is 100-200°C. The number-average molecular weight Mn is between 5,000 and 500,000. The refractive index nd is 1.55 to 1.65. The Abbe number νd is between 16 and 25. The birefringence of a uniaxially stretched film obtained under the stretching conditions of a stretching temperature (glass transition temperature Tg+10) °C, a stretching speed of 25 mm / min, and a stretching ratio of 3 times is -200 × 10⁻¹⁰ at a wavelength of 600 nm. -4 A copolymer according to any of embodiments [1] to [7], wherein the coefficient is ~0.

[0021] Appearance [9]: A method for producing a copolymer according to any one of embodiments [1] to [8], comprising a polymerization step of polymerizing a polymerization component comprising a fluorene compound represented by formula (1) and the (meth)acrylic acid ester.

[0022] Appearance

[10] : A molded article comprising the copolymer described in any of embodiments [1] to [8].

[0023] Appearance

[11] : A molded article according to the embodiment

[10] which is an optical component.

[0024] Appearance

[12] : A molded article according to embodiment

[10] or

[11] , wherein the molded article is in the form of a film, a sheet, or a lens.

[0025] Furthermore, this disclosure may achieve (or solve) the following secondary objectives.

[0026] In other words, another object of this disclosure is to provide copolymers that exhibit a lower Abbe number even at a refractive index comparable to that of polymers used for general optical components (e.g., optical lenses), as well as methods for producing them and their applications.

[0027] Another object of this disclosure is to provide copolymers that can satisfy a good balance of high heat resistance, high transparency, high refractive index, low Abbe number and low birefringence (absolute value of small birefringence), as well as methods for producing them and their applications.

[0028] In this specification and the claims, the number of carbon atoms in a substituent is defined as C1, C6, C 10 It is sometimes indicated in such ways. For example, "C1 alkyl group" means an alkyl group with 1 carbon atom, and "C 6-10 The term "aryl group" refers to an aryl group with 6 to 10 carbon atoms.

[0029] In this specification and in the claims, “independently” means that the two components are independent components, for example, R 2a and R2b In the case of R 2a and R 2b This means that the two groups may be the same group (non-polymerizable substituent) or they may be different groups.

[0030] In this specification and in the claims, the numerical range indicated by "X~Y" may include the numbers X and Y at both ends.

[0031] In this specification and in the claims, the “constituent unit” of a copolymer (resin or polymer) may be a unit of chemical structure formed in the resin by originating from (or corresponding to) a polymerization component. [Effects of the Invention]

[0032] This disclosure provides copolymers that can achieve both high heat resistance and high transparency (or light transmittance), as well as methods for producing the same and applications. [Brief explanation of the drawing]

[0033] [Figure 1] Figure 1 is a graph showing the relationship between the conversion rate of polymerization components and polymerization time when the copolymer obtained in Example 1 was polymerized. [Figure 2] Figure 2 is a graph showing the relationship between the conversion rate of polymerization components and polymerization time when the copolymer obtained in Example 2 was polymerized. [Figure 3] Figure 3 is a graph showing the relationship between the conversion rate of polymerization components and polymerization time when the copolymer obtained in Example 3 was polymerized. [Figure 4] Figure 4 is a graph showing the relationship between the conversion rate of polymerization components and polymerization time when the copolymer obtained in Example 4 was polymerized. [Figure 5] Figure 5 is a graph showing the relationship between the conversion rate of polymerization components and polymerization time when the copolymer obtained in Example 5 was polymerized. [Figure 6] Figure 6 is a chart of the size exclusion chromatography (SEC) results of the copolymer obtained in Example 1. [Figure 7]Figure 7 is a chart of the size exclusion chromatography (SEC) results of the copolymer obtained in Example 2. [Figure 8] Figure 8 is a chart of the size exclusion chromatography (SEC) results of the copolymer obtained in Example 3. [Figure 9] Figure 9 is a chart of the size exclusion chromatography (SEC) results of the copolymer obtained in Example 4. [Figure 10] Figure 10 is a chart of the size exclusion chromatography (SEC) results of the copolymer obtained in Example 5. [Figure 11] Figure 11 is a chart of the size exclusion chromatography (SEC) results of the polymer obtained in Comparative Example 1. [Figure 12] Figure 12 is a chart of the thermogravimetric differential thermal analysis (TG-DTA) of the copolymer obtained in Example 1. [Figure 13] Figure 13 is a chart of the thermogravimetric differential thermal analysis (TG-DTA) of the copolymer obtained in Example 2. [Figure 14] Figure 14 is a chart of the thermogravimetric differential thermal analysis (TG-DTA) of the copolymer obtained in Example 3. [Figure 15] Figure 15 is a chart of the thermogravimetric differential thermal analysis (TG-DTA) of the copolymer obtained in Example 4. [Figure 16] Figure 16 is a chart of the thermogravimetric differential thermal analysis (TG-DTA) of the copolymer obtained in Example 5. [Figure 17] Figure 17 is a chart of the thermogravimetric differential thermal analysis (TG-DTA) results for the polymer obtained in Comparative Example 1. [Figure 18] Figure 18 is a chart of differential scanning calorimetry (DSC) of the copolymer obtained in Example 1. [Figure 19] Figure 19 is a chart of differential scanning calorimetry (DSC) results for the copolymer obtained in Example 2. [Figure 20] Figure 20 is a chart of differential scanning calorimetry (DSC) of the copolymer obtained in Example 3. [Figure 21]Figure 21 is a chart of differential scanning calorimetry (DSC) of the copolymer obtained in Example 4. [Figure 22] Figure 22 is a chart of differential scanning calorimetry (DSC) of the copolymer obtained in Example 5. [Figure 23] Figure 23 is a chart of differential scanning calorimetry (DSC) results for the polymer obtained in Comparative Example 1. [Figure 24] Figure 24 shows the UV-Vis spectra of the copolymers obtained in Examples 3-4 and the polymer obtained in Comparative Example 1 before and after the lightfastness test. [Modes for carrying out the invention]

[0034] The copolymer of this disclosure is a resin (polymer) containing a fluorene compound represented by formula (1) and a (meth)acrylic acid ester as polymerization components (monomer components), and can achieve both high heat resistance and high transparency (or light transmittance). Furthermore, the copolymer of this disclosure can exhibit a lower Abbe number even with a refractive index similar to that of polymers used for general optical components (e.g., optical lenses). The copolymer of this disclosure can also satisfy high heat resistance, high transparency, high refractive index, low Abbe number, and low birefringence (absolute value of small birefringence) in a balanced manner.

[0035] The copolymers disclosed herein have ethylenically unsaturated bonds of monomer components [e.g., a vinyl ketone skeleton of formula (1) [-C(=O)-CR 3 =CR 4 R 5 It can be prepared by addition polymerization utilizing [such as] the ethylenically unsaturated bond in the (meth)acryloyl group of (meth)acrylic acid esters.

[0036] [Fluorene compounds represented by formula (1)] Acryloyl skeleton (or vinyl ketone skeleton, i.e., the group [-C(=O)-CR 3 =CR 4 R 5 Fluorene compounds (fluorenyl vinyl ketone compounds) having ]) are represented by the following formula (1).

[0037] In this disclosure, the fluorene compound represented by formula (1) below, when combined with a (meth)acrylic acid ester, tends to produce copolymers that not only exhibit high heat resistance and high refractive index, but also effectively reduce the Abbe number with respect to the refractive index. Furthermore, the copolymers tend to exhibit negative birefringence, and the birefringence can be increased in the negative direction depending on the application.

[0038] [ka]

[0039] [In the formula, R 1 The '' indicates a substituent (monovalent or divalent group), k is an integer between 0 and 2, and the double line (solid and dashed) indicates a single or double bond. R 2a and R 2b These independently represent nonpolymerizable substituents, where m1 is an integer from 0 to 3, and m2 is an integer from 0 to 4. R 3 , R 4 and R 5 [This independently represents a hydrogen atom or a non-polymerizable substituent.]

[0040] In the above equation (1), R 1 Examples of monovalent or divalent substituents (or non-radical polymerizable substituents) represented by include monovalent groups such as hydrocarbon groups, hydroxyl groups, hydroxyaryl groups, hydroxy(poly)alkoxyaryl groups, carboxyl groups, alkoxycarbonyl groups, substituted amino groups (mono or disubstituted amino groups), and halogen atoms, as well as divalent groups such as oxygen atoms (or oxo groups [=O]).

[0041] Examples of hydrocarbon groups include alkyl groups, cycloalkyl groups, aryl groups, and groups formed by combining (bonding) two or more of these hydrocarbon groups, and saturated hydrocarbon groups are preferred.

[0042] Examples of alkyl groups (linear or branched alkyl groups) include linear or branched C groups such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-hexyl, n-octyl, 2-ethylhexyl, n-decyl, and n-dodecyl. 1-20 Examples include alkyl groups, preferably linear or branched C 1-12 Alkyl alkyl groups, more preferably linear or branched C 1-6 Alkyl groups are examples.

[0043] Examples of cycloalkyl groups include cyclopentyl groups, cyclohexyl groups, and other C groups. 5-10 Examples include cycloalkyl groups, preferably C 5-8 Examples include cycloalkyl groups.

[0044] Examples of aryl groups include phenyl, naphthyl (1-naphthyl, 2-naphthyl), biphenylyl, anthryl, and phenanthryl groups. 6-14 Aryl group, preferably C 6-10 An example is the aryl group.

[0045] Examples of groups formed by combining (bonding) two or more hydrocarbon groups include alkylaryl groups and aralkyl groups. Examples of alkylaryl groups include mono- or di-C groups such as methylphenyl (tolyl) and dimethylphenyl (xylyl) groups. 1-6 Alkyl C 6-10 Examples include aryl groups. Aralkyl groups include, for example, phenylmethyl group (benzyl group), 2-phenylethyl group (phenethyl group), etc. 6-10 Aryl C 1-6 Examples include alkyl groups.

[0046] Examples of hydroxyaryl groups include hydroxyphenyl groups, alkylhydroxyphenyl groups, arylhydroxyphenyl groups, hydroxynaphthyl groups, and other substituted hydroxy C groups. 6-12Examples of substituents include aryl groups, and examples of substituents include alkyl groups, hydrocarbon groups such as aryl groups, etc.

[0047] Examples of hydroxyphenyl groups include the 4-hydroxyphenyl group.

[0048] Examples of alkylhydroxyphenyl groups include (mono or di)C groups such as 4-hydroxy-3-methylphenyl and 4-hydroxy-3,5-dimethylphenyl. 1-4 Examples include alkylhydroxyphenyl groups.

[0049] Examples of arylhydroxyphenyl groups include phenylhydroxyphenyl groups (or hydroxybiphenylyl groups) such as the 4-hydroxy-3-phenylphenyl group (or 6-hydroxy-3-biphenylyl group).

[0050] Examples of hydroxynaphthyl groups include the 6-hydroxy-2-naphthyl group and the 5-hydroxy-1-naphthyl group.

[0051] Examples of hydroxy(poly)alkoxyaryl groups include, for example, groups in which the hydroxyl group is replaced with a hydroxy(poly)alkoxy group, corresponding to the specific groups exemplified above for hydroxyaryl groups, i.e., substituted hydroxy(poly)C groups such as hydroxy(poly)alkoxyphenyl groups, alkylhydroxy(poly)alkoxyphenyl groups, arylhydroxy(poly)alkoxyphenyl groups, and hydroxy(poly)alkoxynaphthyl groups. 2-4 Alkoxy C 6-12 Examples of substituents include aryl groups. Examples of substituents include alkyl groups and hydrocarbon groups such as aryl groups.

[0052] Examples of hydroxy(poly)alkoxyphenyl groups include hydroxy(mono or deca)C groups such as 4-(2-hydroxyethoxy)phenyl, 4-(2-hydroxypropoxy)phenyl, and 4-(2-(2-hydroxyethoxy)ethoxy)phenyl. 2-3 Examples include alkoxyphenyl groups.

[0053] Examples of alkylhydroxy(poly)alkoxyphenyl groups include (mono or di)C groups such as 4-(2-hydroxyethoxy)-3-methylphenyl group and 4-(2-hydroxyethoxy)-3,5-dimethylphenyl group. 1-4 Alkyl-hydroxy(mono or deca)C 2-3 Examples include alkoxyphenyl groups.

[0054] Examples of arylhydroxy(poly)alkoxyphenyl groups include phenyl-hydroxy(mono or deca)C groups such as 4-(2-hydroxyethoxy)-3-phenylphenyl group [or 6-(2-hydroxyethoxy)-3-biphenylyl group]. 2-3 Alkoxyphenyl group [or hydroxy(mono or deca)C] 2-3 Examples include alkoxy-biphenylyl groups.

[0055] Examples of hydroxy(poly)alkoxynaphthyl groups include hydroxy(mono or deca)C groups such as 6-(2-hydroxyethoxy)-2-naphthyl and 5-(2-hydroxyethoxy)-1-naphthyl. 2-3 Examples include alkoxy-naphthyl groups.

[0056] Examples of alkoxycarbonyl groups include C such as the methoxycarbonyl group. 2-6 Examples include alkoxy-carbonyl groups.

[0057] Examples of substituted amino groups (mono- or disubstituted amino groups) include alkylamino groups and acylamino groups. Examples of alkylamino groups include mono- or dialkylamino groups such as dimethylamino groups, and examples of acylamino groups include mono- or diacylamino groups such as diacetylamino groups.

[0058] Examples of halogen atoms include chlorine, bromine, and iodine atoms.

[0059] R 1 Preferred substituents represented by are monovalent hydrocarbon groups, particularly saturated hydrocarbon groups such as alkyl groups (especially saturated aliphatic hydrocarbon groups), and more preferably C groups such as methyl, hexyl, octyl, and decyl groups. 1-12 Alkyl alkyl groups, more preferably in the following steps, C 1-10 Alkyl alkyl group, C 1-8 Alkyl alkyl group, C 1-6 Alkyl alkyl group, C 1-4 Alkyl alkyl group, C 1-3 Alkyl alkyl group, C 1-2 These are alkyl groups and methyl groups.

[0060] Note, R 1 If R is the aforementioned divalent group, 1 It is double-bonded to the 9-position of the fluorene ring (or fluorene skeleton), where k is 1; R 1 If is a monovalent group, R 1 A single bond is attached to the 9-position of the fluorene ring, where k is 1 or 2; if k is 0 (unsubstituted), a hydrogen atom is attached to the 9-position of the fluorene ring. Also, if k is 2, two R atoms are attached. 1 The types of (monovalent groups) may be different from each other, but it is preferable that they be the same.

[0061] R 1 The coefficient k may be any integer between 0 and 2, preferably 0 or 2, and more preferably 2.

[0062] R 2a and R2b Examples of the non-polymerizable substituent (non-radical polymerizable substituent having no ethylenically unsaturated bond) represented by are substituents different from the group [-C(=O)-CR 3 =CR 4 R 5 , and examples thereof include hydrocarbon groups such as an alkyl group (linear or branched alkyl group) and an aryl group, a cyano group, halogen atoms such as a fluorine atom, a chlorine atom, and a bromine atom. Examples of the alkyl group include C 1-6 alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, and a t-butyl group, and examples of the aryl group include C 6-10 aryl groups such as a phenyl group.

[0063] R 2a ,R 2b Preferred non-polymerizable substituents represented by are saturated hydrocarbon groups such as an alkyl group (particularly, saturated aliphatic hydrocarbon group), a cyano group, and a halogen atom, and more preferably an alkyl group such as C 1-4 alkyl group, particularly an alkyl group such as a methyl group. 1-3 is preferred.

[0064] R 2a and R 2b The substitution numbers m1 and m2 of are, for example, integers of about 0 to 2, preferably 0 or 1, and more preferably 0. m1 and m2 may be different from each other, and are preferably the same. Also, R 2a and R 2b The types of may be the same as or different from each other; when m1 is 2 or more, the types of two or more R 2a may be the same as or different from each other; when m2 is 2 or more, the types of two or more R 2b may be the same as or different from each other. Also, R 2a ,R 2b The substitution positions of are not particularly limited, and for R 2a , with respect to the group [-C(=O)-CR 3 =CR 4 R 5The substitution only needs to be made at a position other than the substitution location of ].

[0065] R 3 Examples of nonpolymerizable substituents represented by (non-radical polymerizable substituents that do not have an ethylenically unsaturated bond) include hydrocarbon groups such as alkyl groups, halogen atoms, and groups [-CHR 6 -OH] or group [-CHR] 6 -OC(=O)-R 7 ](In each formula, R 6 and R 7 Examples include (where represents a hydrogen atom or an optionally substituted hydrocarbon group).

[0066] R 3 If R is a hydrocarbon group or a halogen atom, specifically, 1 Examples include hydrocarbon groups and halogen atoms similar to those exemplified above. 3 When is a hydrocarbon group, it may be a hydrocarbon group such as a linear or branched alkyl group (saturated hydrocarbon group, especially a saturated aliphatic hydrocarbon group), preferably in the following steps: 1-6 Alkyl alkyl group, C 1-4 Alkyl alkyl group, C 1-3 It is an alkyl group, especially a methyl group or other C 1-2 Alkyl alkyl groups are preferred.

[0067] Also, the base [-CHR 6 -OH], group [-CHR 6 -OC(=O)-R 7 In ], R 6 and R 7 R is independently a hydrogen atom or a substituted monovalent hydrocarbon group, and this hydrocarbon group is R 1 Examples of hydrocarbon groups similar to those exemplified above include linear or branched alkyl groups, cycloalkyl groups, aryl groups, and groups formed by combining two or more of these. Furthermore, examples of substituents that this hydrocarbon group may have include halogen atoms, substituted amino groups (mono or disubstituted amino groups), and nitro groups, where R is an example of a halogen atom or substituted amino group. 1Examples include halogen atoms and substituted amino groups similar to those exemplified above. Note that the group [-CHR 6 -OC(=O)-R 7 In ], R 6 and R 7 The types may be the same or different from each other.

[0068] Preferred R 6 This is a hydrogen atom, a linear or branched alkyl group. Preferably, this alkyl group is C in the following steps: 1-6 Alkyl alkyl group, C 1-4 Alkyl alkyl group, C 1-3 Alkyl alkyl group, C 1-2 These are alkyl groups and methyl groups. Among them, R is particularly preferred. 6 It is a hydrogen atom.

[0069] Preferred R 7 is a hydrogen atom, a linear or branched alkyl group, more preferably a linear or branched alkyl group, and even more preferably C in the following steps. 1-6 Alkyl alkyl group, C 1-4 Alkyl alkyl group, C 1-3 It is an alkyl group, especially a methyl group or other C 1-2 Alkyl alkyl groups are preferred.

[0070] Typical group [-CHR 6 Examples of -OH groups include 1-hydroxyalkyl groups such as hydroxymethyl, 1-hydroxyethyl, and 1-hydroxyhexyl groups; 1-hydroxycycloalkylmethyl groups such as 1-hydroxycyclohexylmethyl groups; and 1-hydroxyarylmethyl groups such as 1-hydroxyphenylmethyl (1-hydroxybenzyl) groups. Preferred group [-CHR 6 The -OH] is a 1-hydroxyalkyl group, and more preferably, in the following steps, 1-hydroxyC 1-6 Alkyl alkyl, 1-hydroxyC 1-4 Alkyl alkyl, 1-hydroxyC 1-3 It is an alkyl group, and in particular, a 1-hydroxyC group such as a hydroxymethyl group. 1-2It is an alkyl group.

[0071] Typical group [-CHR 6 -OC(=O)-R 7 Examples of preferred groups include acetyloxymethyl group, 1-acetyloxyethyl group, 1-acetyloxyhexyl group, propionyloxymethyl group, (cyclohexylcarbonyloxy)methyl group, (benzoyloxy)methyl group, and other 1-(acyloxy)alkyl groups. 6 -OC(=O)-R 7 ] proceeds in the following steps: 1-(C 1-12 Acyloxy)C 1-6 Alkyl, 1-(C 1-8 Acyloxy)C 1-4 Alkyl, 1-(C 1-7 Acyloxy)C 1-3 The alkyl group is more preferably an acetyloxymethyl group, propionyloxymethyl group, (cyclohexylcarbonyloxy)methyl group, (benzoyloxy)methyl group, etc., and is a 1-(C 1-7 Acyloxy)methyl group, especially 1-(C) 1-4 It is an acyloxymethyl group.

[0072] Preferred R 3 Examples include hydrogen atoms, hydrocarbon groups (or saturated hydrocarbon groups), halogen atoms, and groups [-CHR] 6 -OH] or group [-CHR] 6 -OC(=O)-R 7 ], more preferably a hydrogen atom, alkyl group, group [-CHR 6 -OH] or group [-CHR] 6 -OC(=O)-R 7 ], and more preferably a hydrogen atom or an alkyl group, particularly preferably a hydrogen atom.

[0073] Note, R 3 The type is R 4 ~R 5 The types may be the same as or different from each other.

[0074] R4 or R 5 Examples of nonpolymerizable substituents represented by (non-radical polymerizable substituents that do not have an ethylenically unsaturated bond) include hydrocarbon groups such as linear or branched alkyl groups, halogen atoms, and specifically, R 1 Examples include hydrocarbon groups and halogen atoms, as exemplified above, and similar groups.

[0075] Also, R 4 ,R 5 When the group represented by is a substituent, it may be a hydrocarbon group (saturated hydrocarbon group) such as an alkyl group or a halogen atom, preferably in the following steps: hydrocarbon group (saturated hydrocarbon group, in particular saturated aliphatic hydrocarbon group), linear or branched alkyl group, C 1-6 Alkyl alkyl group, C 1-4 Alkyl alkyl group, C 1-3 It is an alkyl group, especially a methyl group or other C 1-2 It is an alkyl group.

[0076] Preferred R 4 and R 5 These include hydrogen atoms, hydrocarbon groups, and halogen atoms, and more preferably hydrogen atoms or hydrocarbon groups (or saturated hydrocarbon groups), particularly hydrogen atoms or alkyl groups, and especially hydrogen atoms. 4 and R 5 The types may be different from each other, but it is preferable that they be the same.

[0077] Base [-C(=O)-CR 3 =CR 4 R 5 The substitution position of ] is not particularly restricted, but is preferably at position 2 (or position 7).

[0078] Typical fluorene compounds represented by the above formula (1) include: R 1 This indicates a hydrocarbon group or an oxygen atom. R 2a and R 2bm1 independently represents a hydrocarbon group (such as a saturated aliphatic hydrocarbon group), m2 represents an integer from 0 to 2, and m1 represents an integer from 0 to 2. R 3 , R 4 and R 5 Examples include fluorene compounds that independently exhibit a hydrogen atom or a hydrocarbon group (such as a saturated aliphatic hydrocarbon group);

[0079] Preferably, In the above equation (1), R 1 is an alkyl group (C 1-6 It represents an alkyl group, etc., and k is 0 or 2. R 2a and R 2b These are independently alkyl groups (C 1-6 (e.g., alkyl group), m1 represents 0 or 1, m2 represents 0 or 1, R 3 , R 4 and R 5 These are independently hydrogen atoms or alkyl groups (C 1-6 Examples include fluorene compounds exhibiting alkyl groups, etc.;

[0080] More preferably, In the above equation (1), R 1 is C 1-4 Alkyl groups (such as methyl groups) 1-3 It represents an alkyl group, etc., and k is 0 or 2 (in particular, 2), R 2a and R 2b C is independent 1-4 Alkyl groups (such as methyl groups) 1-3 (e.g., alkyl group), m1 represents 0 or 1, m2 represents 0 or 1, R 3 , R 4 and R 5 These are independently hydrogen atoms or C 1-4 Alkyl groups (such as methyl groups) 1-3 Examples include fluorene compounds exhibiting alkyl groups (especially hydrogen atoms).

[0081] A specific fluorene compound (fluorenyl vinyl ketone compound) represented by formula (1) is R 3 is a hydrogen atom or alkyl group, R 4 and R 5 Examples include fluorene compounds in which the hydrogen atom is present, such as (meth)acryloylfluorenes like 2-acryloylfluorene and 2-methacryloylfluorene; and (meth)acryloyl-9,9-dialkylfluorenes like 2-acryloyl-9,9-dimethylfluorene and 2-methacryloyl-9,9-dimethylfluorene.

[0082] Furthermore, the copolymer of this disclosure contains at least one structural unit represented by the following formula (1P) as a structural unit derived from the fluorene compound represented by formula (1).

[0083] [ka]

[0084] (In the formula, R 1 ,k,R 2a and R 2b , m1, m2, R 3 , R 4 and R 5 Furthermore, the double lines, including both solid and dashed lines, are the same as those in formula (1), including preferred embodiments.

[0085] [(meth)acrylic acid ester] Examples of (meth)acrylic acid esters [or monofunctional (meth)acrylates] include aliphatic monofunctional (meth)acrylates, alicyclic monofunctional (meth)acrylates, aromatic monofunctional (meth)acrylates, and monofunctional (meth)acrylates containing sulfur atoms.

[0086] Aliphatic monofunctional (meth)acrylates include linear or branched alkyl (meth)acrylates [or alkyl (meth)acrylate esters], such as methyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, etc. 1-20 Examples include alkyl (meth)acrylates.

[0087] Examples of alicyclic monofunctional (meth)acrylates include C636 5-10 Examples include cross-linked cyclic (meth)acrylates such as cycloalkyl (meth)acrylates, dicyclopentenyl (meth)acrylates, and isobornyl (meth)acrylates.

[0088] Examples of aromatic monofunctional (meth)acrylates include aryl (meth)acrylates such as phenyl (meth)acrylate; aralkyl (meth)acrylates such as benzyl (meth)acrylate; and aryloxyalkyl (meth)acrylates, specifically C2-phenoxyethyl (meth)acrylate, 2-(2-naphthoxy)ethyl (meth)acrylate, and 2-(o-phenylphenoxy)ethyl (meth)acrylate. 6-12 Aryloxy C 2-4 Examples include alkyl (meth)acrylates; mono(meth)acrylates of bi or bisphenols (or their alkylene oxide adducts), such as mono(meth)acrylates of ethylene oxide adducts of bisphenol A; and (meth)acrylates having a fluorene skeleton, such as 9-(meth)acryloyloxymethylfluorene.

[0089] Examples of monofunctional (meth)acrylates containing sulfur atoms include alkylthio(meth)acrylates, arylthio(meth)acrylates, aralkylthio(meth)acrylates, and arylthioalkyl(meth)acrylates. Examples of alkylthio(meth)acrylates include methylthio(meth)acrylates. 1-6Examples include alkylthio(meth)acrylates. Examples of arylthio(meth)acrylates include phenylthio(meth)acrylate and other C3 6-10 Examples include arylthio(meth)acrylates. Examples of arylthio(meth)acrylates include benzylthio(meth)acrylate. 6-10 Aryl C 1-6 Examples include alkylthio(meth)acrylates. Examples of arylthioalkyl(meth)acrylates include phenylthioethyl(meth)acrylate. 6-10 Arylthio C 2-4 Examples include alkyl (meth)acrylates.

[0090] (meth)acrylic acid esters may be used alone or in combination of two or more. Preferred (meth)acrylic acid esters include aliphatic or alicyclic monofunctional (meth)acrylates; more preferably are aliphatic monofunctional (meth)acrylates such as alkyl (meth)acrylates [or alkyl (meth)acrylates]; and even more preferably, (meth)acrylic acid C 1-12 Alkyl esters, (meth)acrylate C 1-8 Alkyl esters, (meth)acrylate C 1-6 Alkyl esters, (meth)acrylate C 1-4 Alkyl esters, (meth)acrylate C 1-3 Alkyl esters, (meth)acrylate C 1-2 It is an alkyl ester; most preferably methyl (meth)acrylate (especially MMA).

[0091] In this disclosure, because a (meth)acrylic acid ester [preferably an aliphatic or alicyclic monofunctional (meth)acrylate, particularly an alkyl (meth)acrylic acid ester such as MMA] is combined with the fluorene compound represented by formula (1), the resulting copolymer tends to have improved transparency (or light transmittance) and lightfastness, and is also easy to adjust to low birefringence (reduce the absolute value of birefringence).

[0092] [Composition ratio (copolymerization ratio)] In the copolymer of the present disclosure, the ratio (composition ratio or copolymerization ratio) of constituent units derived from the fluorene compound represented by formula (1) to constituent units derived from the (meth)acrylic acid ester [preferably aliphatic or alicyclic monofunctional (meth)acrylate, in particular alkyl (meth)acrylate such as MMA] may be, for example, about 0.1 / 99.9 to 90 / 10, and preferably in the following increments: 1 / 99 to 80 / 20, 2 / 98 to 70 / 30, 4 / 96 to 60 / 40, 5 / 95 to 50 / 50, 6 / 94 to 40 / 60, 7 / 93 to 30 / 70, 8 / 92 to 25 / 75, 9 / 91 to 20 / 80, and 10 / 90 to 15 / 85. When the proportion of constituent units derived from the fluorene compound represented by formula (1) is within a moderate range and not too low, it tends to be easier to improve heat resistance and refractive index, and to reduce the Abbe number. Furthermore, by increasing the proportion of constituent units derived from the fluorene compound represented by formula (1), the copolymer tends to exhibit negative birefringence, and the birefringence can be increased in the negative direction depending on the application. On the other hand, when the proportion of constituent units derived from the (meth)acrylic acid ester is within a moderate range and not too low, it tends to be easier to improve transparency (or light transmittance) and light resistance. Furthermore, by increasing the proportion of constituent units derived from the fluorene compound represented by formula (1), it tends to be easier to reduce birefringence (reduce the absolute value of birefringence) depending on the application.

[0093] In the copolymer of this disclosure, even if the proportion of constituent units derived from the fluorene compound represented by formula (1) is relatively small, it appears that heat resistance (especially the weight loss temperature) can be effectively improved. Therefore, it is possible to achieve a higher degree of compatibility between high heat resistance and high transparency (light transmittance).

[0094] In this specification and in the claims, the proportion of constituent units in the copolymer (composition ratio or copolymerization ratio) can be determined based on the NMR spectrum of the copolymer.

[0095] In the copolymer of the present disclosure, the total proportion of constituent units derived from the fluorene compound represented by formula (1) [constituent units represented by formula (1P)] and the (meth)acrylic acid ester [preferably aliphatic or alicyclic monofunctional (meth)acrylate, particularly alkyl (meth)acrylate such as MMA] is, for example, 10 mol% or more (for example, 30 to 100 mol%) with respect to the total amount of constituent units of the copolymer (total amount of constituent units derived from all polymer components), preferably in stages, 50 mol% or more, 70 mol% or more, 80 mol% or more, 90 mol% or more, 95 mol% or more, and particularly preferably substantially 100 mol%. When the total proportion of constituent units derived from the fluorene compound represented by formula (1) and the (meth)acrylic acid ester is within a moderate range that is not too small, it tends to be easier to achieve both high heat resistance (especially high weight loss temperature) and high transparency (or light transmittance).

[0096] [Other copolymer components] The copolymers of this disclosure may contain, as polymerization components (monomer components), other copolymer components different from the fluorene compound represented by formula (1) and the (meth)acrylic acid ester. The other copolymer components may be monofunctional or polyfunctional.

[0097] Other monofunctional copolymer components may include any compound having one polymerizable group (ethylenically unsaturated bond or polymerizable unsaturated bond), such as a vinyl group, an alkenyl group such as an allyl group, or a (meth)acryloyl group. Specifically, these include monofunctional vinyl monomers and monofunctional (meth)acrylic monomers [excluding (meth)acrylic acid esters]. Examples of monofunctional vinyl monomers include α-olefin monomers such as ethylene and propylene; styrene monomers such as styrene, α-methylstyrene, and vinyltoluene; vinyl ester monomers such as vinyl acetate; and N-vinylpyrrolidone. Examples of monofunctional (meth)acrylic monomers include (meth)acrylic acid; (meth)acrylamide; N-substituted (meth)acrylamides such as N-methylol(meth)acrylamide and N,N-dimethyl(meth)acrylamide; and (meth)acrylonitrile.

[0098] Other polyfunctional copolymer components can have multiple (two or more) polymerizable groups, and polyfunctional (meth)acrylates having multiple (two or more) (meth)acryloyl groups are commonly used. The number of (meth)acryloyl groups per molecule is, for example, 2 to 10, preferably 2 to 6, more preferably 2 to 4, most preferably 2 to 3, and especially 2.

[0099] Examples of polyfunctional (meth)acrylates include epoxy (vinyl ester resins) such as aliphatic epoxy (meth)acrylates, alicyclic epoxy (meth)acrylates, aromatic epoxy (meth)acrylates, and poly(meth)acrylates of novolac-type epoxy resins; urethane (meth)acrylates; polyester (meth)acrylates (poly(meth)acrylates of polyester polyols having two or more hydroxyl groups); (poly)alkylene glycol di(meth)acrylates; di(meth)acrylates of alicyclic diols; di(meth)acrylates of biphenols or bisphenols or their alkylene oxide (alkylene carbonate or haloalkanol) adducts; and poly(meth)acrylates of low molecular weight polyol compounds having about 3 to 6 hydroxyl groups or their alkylene oxide (alkylene carbonate or haloalkanol) adducts.

[0100] Examples of the aliphatic epoxy (meth)acrylate include di(meth)acrylates of (poly)alkylene glycol diglycidyl ethers, such as di(meth)acrylate of 1,6-hexanediol diglycidyl ether and di(meth)acrylate of polypropylene glycol diglycidyl ether.

[0101] Examples of the alicyclic epoxy (meth)acrylate include cyclohexanediol, cyclohexanedimethanol, dicyclopentadienedimethanol, norbornanediol, norbornanedimethanol, adamantanediol, adamantanedimethanol, tricyclodecanediol, tricyclodecanedimethanol, and other C3 5-15Examples include di(meth)acrylates of epoxy compounds (diglycidyl ethers) corresponding to diols having an aliphatic hydrocarbon ring; di(meth)acrylates of bisphenols or biphenols, or hydrogenated diglycidyl ethers of their alkylene oxide (alkylene carbonate or haloalkanol) adducts, as described in the aromatic epoxy (meth)acrylate section below.

[0102] Examples of the aromatic epoxy (meth)acrylate include di(meth)acrylates of bisphenols or biphenols or their alkylene oxide (alkylene carbonate or haloalkanol) adducts, such as di(meth)acrylate of bisphenol A diglycidyl ether. Examples of bisphenols include bisphenol A, bisphenol F, bisphenol AD, and bisphenol S. Examples of biphenols include p,p'-biphenol, m,m'-biphenol, and o,o'-biphenol.

[0103] Examples of the (poly)alkylene glycol di(meth)acrylate include ethylene glycol di(meth)acrylate, butanediol di(meth)acrylate, and other C 2-10 Alkylene glycol di(meth)acrylate; diethylene glycol di(meth)acrylate, etc., di or hexa C 2-10 Examples include alkylene glycol di(meth)acrylate.

[0104] Examples of di(meth)acrylates of the alicyclic diols include cyclohexanediol, cyclohexanedimethanol, dicyclopentadienedimethanol, norbornanediol, norbornanedimethanol, adamantanediol, adamantanedimethanol, tricyclodecanediol, tricyclodecanedimethanol, and other C13 5-15Examples include di(meth)acrylates corresponding to diols having an aliphatic hydrocarbon ring; di(meth)acrylates of bisphenols or biphenols described in the above aromatic epoxy(meth)acrylates, such as di(meth)acrylate of hydrogenated bisphenol A, or hydrogenated di(meth)acrylates of their alkylene oxide (alkylene carbonate or haloalkanol) adducts.

[0105] Examples of poly(meth)acrylates of low molecular weight polyol compounds having approximately 3 to 6 hydroxyl groups or their alkylene oxide (alkylene carbonate or haloalkanol) adducts include glycerin tri(meth)acrylate, diglycerin tetra(meth)acrylate, trimethylolethane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and sorbitol tri or hexa(meth)acrylate.

[0106] Other copolymerization components may be used alone or in combination of two or more.

[0107] Furthermore, if the polymerization component includes other polyfunctional copolymers, the copolymer of this disclosure may be a three-dimensional network cured product (a cured product of a heat-curable or photocurable resin). That is, the copolymer of this disclosure may be formed by curing a curable composition that further includes at least another polyfunctional copolymer in addition to the fluorene compound and (meth)acrylic acid ester represented by formula (1). The monofunctional polymerization component in the curable composition may be a reactive diluent. The copolymer of this disclosure may also be a thermoplastic resin having a substantially linear chemical structure formed mainly of monofunctional polymerization components, and is preferably a thermoplastic resin.

[0108] The proportion of other copolymer components may be, for example, 50 mol% or less relative to the total amount of copolymer components (total amount of constituent units derived from all copolymer components), and preferably in stages, 30 mol% or less, 20 mol% or less, 10 mol% or less (0.1 to 5 mol%, etc.), and 1 mol% or less.

[0109] [Method for producing copolymers] The copolymer according to this disclosure may include a polymerization step of polymerizing a polymerization component comprising the fluorene compound represented by formula (1) and the (meth)acrylic acid ester. Specifically, the copolymer can be prepared by subjecting a polymerizable composition (or curable composition) containing the polymerization component to addition polymerization. The method of addition polymerization is not particularly limited and may be ionic polymerization, but radical polymerization is preferred. Examples of radical polymerization include bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization, with solution polymerization being preferred.

[0110] A polymerizable composition (or curable composition) for forming a copolymer may contain at least the polymerization component, and may further contain a polymerization initiator, solvent, additives, etc., as needed.

[0111] The polymerization initiator is not particularly limited, and since radical polymerization is often used as an addition polymerization, it may be a thermal polymerization initiator (thermal radical generator) or a photopolymerization initiator (photoradical generator).

[0112] Examples of thermal polymerization initiators include organic peroxides and azo compounds. Examples of organic peroxides include dialkyl peroxides such as di-t-butyl peroxide; diacyl peroxides such as lauroyl peroxide and benzoyl peroxide; peracids (or peracid esters) such as t-butyl hydroperoxide, cumene hydroperoxide, and t-butyl peracetate; ketone peroxides; peroxycarbonates; and peroxyketals. Examples of azo compounds include azonitrile compounds such as 2,2'-azobis(isobutyronitrile) (or AIBN), azoamide compounds, and azoamidine compounds. These thermal polymerization initiators may be used alone or in combination of two or more. Of these, azo compounds such as AIBN are preferred.

[0113] Examples of photopolymerization initiators include benzoins, specifically benzoin alkyl ethers such as benzoin and benzoin ethyl ether; acetophenones such as acetophenone and 2-hydroxy-2-methyl-1-phenylpropan-1-one; aminoacetophenones such as 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinoaminopropanone-1; anthraquinones such as anthraquinone and 2-methylanthraquinone; thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, and 2-chlorothioxanthone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenones such as benzophenone; and xanthones. These photopolymerization initiators may be used individually or in combination of two or more.

[0114] The proportion of polymerization initiator (thermal and / or photopolymerization initiator) may be, for example, about 0.1 to 15 parts by mass per 100 parts by mass of the total amount of polymerization components, preferably 0.5 to 10 parts by mass, more preferably 1 to 8 parts by mass, and even more preferably 2 to 6 parts by mass. Alternatively, the proportion of polymerization initiator (thermal and / or photopolymerization initiator) may be, for example, about 0.1 to 10 moles per 100 moles of the total amount of polymerization components, preferably 1 to 8 moles, more preferably 2 to 6 moles, and even more preferably 3 to 5 moles.

[0115] Furthermore, the photopolymerization initiator may be combined with a photosensitizer. Typical photosensitizers include tertiary amines, such as trialkylamines; trialcanolamines such as triethanolamine; alkyl dialkylaminobenzoates, specifically N,N-dimethylaminobenzoate ethyl such as p-(dimethylamino)benzoate ethyl, N,N-dimethylaminobenzoate amyl such as p-(dimethylamino)benzoate amyl; bis(dialkylamino)benzophenone such as 4,4-bis(diethylamino)benzophenone; and dialkylaminobenzophenone such as 4-(dimethylamino)benzophenone. These photosensitizers may be used alone or in combination of two or more. The proportion of the photosensitizer is 1 to 200 parts by mass, preferably 5 to 150 parts by mass, and more preferably 10 to 100 parts by mass, per 100 parts by mass of the polymerization initiator.

[0116] Polymerizable compositions (or curable compositions) do not necessarily contain a solvent, but may contain a solvent depending on the polymerization method, such as solution polymerization, or to adjust handling properties. The solvent is not particularly limited and includes, for example, hydrocarbons, specifically aliphatic hydrocarbons such as hexane and heptane, alicyclic hydrocarbons such as cyclohexane, aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons, specifically methylene chloride, chloroform, 1,2-dichloroethane, chlorobenzene, etc.; ethers, specifically linear ethers such as diethyl ether, cyclic ethers such as tetrahydrofuran and 1,4-dioxane, etc.; ketones, specifically dialkyl ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexa Examples of solvents include cyclic ketones such as ethanol; esters, specifically acetic acid esters such as methyl acetate, ethyl acetate, and butyl acetate; glycol ether acetates, specifically (poly)alkylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate and diethylene glycol monobutyl ether acetate; sulfoxides, specifically dimethyl sulfoxide; amides, specifically dimethylformamide, dimethylacetamide, and N-methyl-2-pyrrolidone; and nitriles, specifically acetonitrile. These solvents can be used individually or as mixed solvents in combination of two or more. Of these solvents, hydrocarbons are preferred, and aromatic hydrocarbons such as toluene are even more preferred.

[0117] The proportion of the solvent is not particularly limited, and the concentration of solids (components other than the solvent) may be such that it is, for example, about 0.1 to 50% by mass relative to the entire polymerizable composition (or curable composition); for example, the solvent may be in a ratio of 50 to 200 mL, preferably 80 to 120 mL, per 100 moles of total polymerizing components.

[0118] The polymerizable composition (or curable composition) may contain conventional additives, such as colorants, stabilizers (e.g., heat stabilizers, antioxidants, UV absorbers, etc.), fillers, antistatic agents, flame retardants, surfactants, plasticizers, curing agents, polymerization inhibitors, etc. These additives may be used individually or in combination of two or more.

[0119] The total proportion of additives is, for example, 30% by mass or less, preferably in stages, 20% by mass or less (0.001 to 15% by mass, etc.), 10% by mass or less, and 5% by mass or less (0.01 to 3% by mass, etc.) relative to the entire polymerizable composition.

[0120] These additives do not necessarily have to be included in the polymerizable composition; they may be added or blended into the copolymer after polymerization.

[0121] The copolymer may be easily polymerized by imparting active energy (or active energy rays) to the polymerizable composition (or curable composition). The active energy may be thermal energy and / or light energy.

[0122] When heat treatment is performed using thermal energy, the heating temperature (polymerization temperature) can be selected according to the polymerization method, for example, 20 to 200°C, preferably in stages, 30 to 150°C, 40 to 100°C, 50 to 80°C, and 60 to 70°C. The polymerization time is not particularly limited, for example, 1 to 24 hours, preferably 3 to 12 hours, and more preferably 4 to 6 hours.

[0123] While light energy such as ultraviolet rays and X-rays may also be used, it is preferable to use thermal energy.

[0124] Polymerization may be carried out in an atmosphere of an inert gas, such as nitrogen gas; or a noble gas such as helium or argon. The reaction can also be carried out under normal pressure, reduced pressure, or pressurized pressure.

[0125] After the reaction is complete, the resulting resin may be separated and purified by conventional methods, such as washing, extraction, concentration, drying, reprecipitation, centrifugation, filtration, column chromatography, adsorption, or a combination thereof.

[0126] [Properties of copolymers] Temperature T of the copolymer of the present disclosure at 5% weight loss d5 The temperature may be, for example, 200°C or higher (for example, 230°C or higher), specifically 250-350°C, and preferably in stages, 260-330°C, 270-320°C, 275-310°C, and 280-300°C. In the copolymer of the present disclosure, even if the proportion of the constituent unit represented by formula (1) is relatively small, T d5 It tends to have a high coefficient of heat, making it easy to improve heat resistance.

[0127] The glass transition temperature Tg of the copolymers of this disclosure may be, for example, around 100 to 200°C (e.g., 100 to 180°C), and preferably in the following steps: 105 to 160°C, 108 to 150°C, 110 to 140°C, 112 to 130°C, and 115 to 120°C.

[0128] The copolymer of this disclosure may be crystalline or amorphous resin.

[0129] The transmittance (light transmittance) of the copolymer of this disclosure at a wavelength of 550 nm is, for example, 50% or more at a thickness of 0.8 mm, preferably in stages, 55% or more, 60% or more, 65% or more, and 70% or more.

[0130] The transmittance (light transmittance) of the copolymer of this disclosure at a wavelength of 450 nm is, for example, 40% or more at a thickness of 0.8 mm, preferably in stages as follows: 45% or more, 50% or more, 55% or more, and 60% or more.

[0131] The transmittance (light transmittance) of the copolymer of this disclosure at a wavelength of 650 nm is, for example, 50% or more at a thickness of 0.8 mm, preferably in stages as follows: 55% or more, 60% or more, 65% or more, 70% or more, and 75% or more.

[0132] The number-average molecular weight Mn of the copolymer in this disclosure may be, for example, around 5,000 to 500,000, and preferably in the following increments: 7,000 to 200,000, 8,000 to 100,000, 9,000 to 50,000, and 10,000 to 30,000. The molecular weight dispersion D (Mw / Mn) of the resin may be, for example, around 1 to 10, and preferably in the following increments: 1.5 to 5, 1.8 to 4, and 2 to 3. The number-average molecular weight Mn and molecular weight dispersion D (Mw / Mn) may be appropriately adjusted depending on the application of the copolymer.

[0133] The refractive index nd of the copolymer of this disclosure may be, for example, about 1.55 to 1.65 at a temperature of 20°C and a wavelength of 587.6 nm, preferably 1.56 to 1.63 (e.g., 1.57 to 1.61), and more preferably 1.56 to 1.6 (e.g., 1.58 to 1.59).

[0134] The Abbe number νd of the copolymers of this disclosure may be, for example, 25 or less (e.g., 16 to 25) at a temperature of 20°C, preferably 24 or less (e.g., 17 to 23), and more preferably 22 or less (e.g., 18 to 21.5). Compared to general polymers for optical components, the copolymers of this disclosure tend to have a lower Abbe number with respect to refractive index.

[0135] The birefringence of the copolymers of this disclosure may be evaluated by the birefringence (3x birefringence or birefringence at 3x stretching) of a stretched film obtained by uniaxially stretching a film formed from the resin alone three times. The absolute value of the 3x birefringence is, for example, 0 to 200 × 10 at a measurement temperature of 25°C and a wavelength of 600 nm. -4 It may be within a range of degree, and when used in applications such as optical lenses, preferably in the following steps: 100 × 10 -4 Below, 80 x 10 -4 Below, 50 x 10 -4 Below, 40 x 10 -4 Below, 30 x 10 -4 Below, 25 x 10 -4 Below, 20 x 10 -4 Below, 10 x 10 -4The following applies: The copolymers of this disclosure tend to easily achieve a good balance between high refractive index and low birefringence (absolute value of small birefringence), which are optical properties that are trade-offs with each other. The lower limit of the absolute value range of the 3x birefringence can be 0 or greater, but depending on the application, for example, 0.1 × 10 -4 The above is 1 x 10 -4 The above 5 x 10 -4 The above is 10 x 10 -4 The above may also be acceptable. Note that the 3x birefringence may be a negative value, for example, -200 × 10⁻⁶. -4 ~0 (for example, -100 × 10) -4 ~0), preferably -80 × 10 -4 ~0 (for example, -50 × 10) -4 ~0), more preferably -30 × 10 -4 ~0 (for example, -20 × 10) -4 It is ~0).

[0136] In this specification and in the claims, the 5% weight loss temperature T d5 The glass transition temperature Tg, transmittance, number-average molecular weight Mn, molecular weight dispersion D(Mw / Mn), refractive index nd, Abbe number νd, and triple birefringence can be measured by the method described in the examples below.

[0137] [Resin compositions and molded articles] The resin composition of the present disclosure comprises at least the copolymer of the present disclosure, and may optionally contain other components different from the copolymer of the present disclosure. Examples of other components include other polymers (other resins) different from the copolymer of the present disclosure, conventional additives, and so on.

[0138] Other resins different from the copolymers of this disclosure include curable resins (thermo- or photo-curable resins) and thermoplastic resins.

[0139] Examples of curable resins (thermal or photocurable resins) include phenolic resins (resol type, novolac type, etc.); amino resins (urea resin, melamine resin, guanamine resin, etc.); furan resins; unsaturated polyester resins; diallyl phthalate resins; vinyl ester resins [or epoxy (meth)acrylate resins]; polyfunctional (meth)acrylate resins; epoxy resins; urethane resins; polyimide resins; and silicone resins.

[0140] Examples of thermoplastic resins include polyolefin resins (such as chain or cyclic olefin resins); styrene resins [polystyrene (PS) or styrene copolymers (including high-impact polystyrene (HIPS), rubber-containing styrene resins such as ABS resin (or rubber-grafted styrene copolymers))]; (meth)acrylic resins [such as (meth)acrylic monomers alone or copolymers]; vinyl acetate resins [including polyvinyl alcohol (PVA) and polyvinyl acetal]; vinyl chloride resins (such as vinyl chloride and / or vinylidene chloride alone or copolymers); fluororesins; polyester resins [polyalkylene arylate resins, polyarylate resins, liquid crystalline polyesters, polycarbonate resins (PC) (for example, bisphenol A type, etc.)] Examples include: bisphenol-type polycarbonate resins, etc.; polyamide resins (PA) [aliphatic polyamide resins, aromatic polyamide resins (aramid resins), etc.]; polyacetal resins (POM); polyphenylene ether resins (PPE); polyphenylene sulfide resins (PPS); polysulfone resins [polysulfone resins (PSF), polyethersulfone (PES), etc.]; polyetherketone resins [polyetherketone resins (PEK), polyetheretherketone resins (PEEK), polyetherketone etherketone ketone (PEKEKK), etc.]; phenoxy resins; polyketone resins; cellulose derivatives (cellulose esters, cellulose ethers, etc.); thermoplastic polyimide resins; polyethernitrile resins; thermoplastic elastomers (TPE), etc.

[0141] Other resins may be included individually or in combination of two or more. Furthermore, if necessary, the copolymers of this disclosure may form polymer alloys with other resins.

[0142] The proportion of the copolymer of the present disclosure may be, for example, about 10% by mass or more, relative to the total amount of resin components in the resin composition (total amount of the copolymer of the present disclosure and other resins), and preferably in the following in stages: 30% by mass or more, 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, and 100% by mass.

[0143] The resin composition may or may not contain conventional additives as needed. Examples of additives include fillers or reinforcing agents, colorants such as dyes and pigments, conductive agents, flame retardants, flame retardant aids, plasticizers, lubricants, stabilizers (antioxidants, UV absorbers, heat stabilizers, etc.), mold release agents, antistatic agents, dispersants, compatibilizers, flow regulators, leveling agents, defoamers, surface modifiers, stress reducers, and carbon materials. Additives may be used individually or in combination of two or more.

[0144] The total proportion of additives is, for example, 50 parts by mass or less, preferably 30 parts by mass or less, 0 to 10 parts by mass, and may be about 0.1 to 5 parts by mass, based on 100 parts by mass of the resin component in the resin composition.

[0145] The resin composition can be prepared by mixing the copolymer of the present disclosure with other components as needed by conventional methods such as dry or wet mixing or melt kneading, and the resin composition may be in the form of pellets or the like.

[0146] This disclosure includes molded articles comprising at least one copolymer (or resin composition) of the disclosure. The shape of the molded article is not particularly limited and may be selected according to the application. For example, it may be pellet-shaped, linear (fibrous or thread-shaped), rod-shaped, or other one-dimensional shapes; film-shaped, sheet-shaped, or plate-shaped, or lenticular-shaped, or hollow (tubular or tubular) shapes; or a composite or complex shape combining these shapes. Because the molded article has a good balance of excellent optical properties, it can be used particularly effectively as an optical component such as an optical film (optical sheet) or optical lens.

[0147] The molded articles can be manufactured using conventional molding methods, such as injection molding, compression molding, transfer molding, lamination molding, FRP molding, casting, powder molding, extrusion molding, blow molding, lamination, casting, calendering, foam molding, and 3D printing.

[0148] Furthermore, the molded article may be a composite molded article comprising the copolymer (or resin composition) of the present disclosure and other constituent members. The proportion of the resin composition of the present disclosure in the molded article is not particularly limited and may be, for example, 10 to 100% by mass or 20 to 80% by mass. [Examples]

[0149] The present disclosure will be described in more detail below based on examples, but the present disclosure is not limited to these examples. The evaluation methods in the examples are as follows.

[0150] [Evaluation Method] ( 1 (H NMR spectrum) Measurements were performed at 25°C using a nuclear magnetic resonance (NMR) spectrometer (Bruker "AVANCE NEO"). Deuterated chloroform was used as the measurement solvent, and the chemical shift values ​​were calibrated using tetramethylsilane (TMS) and solvent signals.

[0151] (molecular weight) The molecular weight (number-average molecular weight Mn) and molecular weight dispersion D (Mw / Mn) of the polymer were determined by loading two HK-404L size exclusion columns (manufactured by Showa Denko K.K.) heated to 40°C into a high-performance liquid chromatograph (EXTREMA Chromatograph, manufactured by JASCO Corporation) in series. Chloroform (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., for GPC, with amylene added) was flowed as the eluent at 0.6 mL / min, and the chromatogram detected by a differential refractometer (RI-4035, manufactured by JASCO Corporation) was used to obtain the standard polymethyl methacrylate (Mn: 6.48 × 10⁻⁶). 5 , 2.52 × 10 5 , 1.42 × 10 5 , 2.91 × 10 4 , 8.59×10 3 , 4.25×10 3 , 1.46 × 10 3 , 8.30×10 2 The results were evaluated by calibrating with a cubic curve () (using ).

[0152] (Glass transition temperature Tg and 5% weight decomposition temperature T) d5 ) Using a thermogravimetric differential scanning calorimetry (TG-DTA, Rigaku Corporation's "Rigaku Differential Thermal Balance Thermo plus EVO2 Sample Observation TG-DTA"), the temperature was raised from room temperature to 500°C at a heating rate of 10°C / min under a nitrogen stream to obtain the glass transition temperature Tg and the 5% gravimetric decomposition temperature (5% mass loss temperature; T). 5d or T d5 (Also known as) was measured.

[0153] (transmittance) A 0.8 mm thick test specimen was formed by hot-pressing the sample at 200-240°C. The transmittance of this test specimen was measured at wavelengths of 300-900 nm using a UV-Vis spectrophotometer (Shimadzu Corporation "UV2600i").

[0154] (Lightfastness test) The test specimens used for transmittance measurement were irradiated with 405 nm wavelength light at an output of 50 mW for 100 hours using a laser irradiator (manufactured by Ricoh Optical). The transmittance of the test specimens obtained after irradiation was measured, and their light resistance was evaluated.

[0155] (Refractive index) A test specimen approximately 1 mm thick was formed by hot-pressing the sample at 200-240°C. The refractive index nd of this specimen was measured using a Carnu precision refractometer [(Shimadzu Devices Mfg. Ltd. "KPR-2000")] at a measurement temperature of 20°C, using a contact fluid with a refractive index of 1.60, at a wavelength of 587.6 nm (d-line). Similarly, the refractive indices nC and nF were measured in the same manner as for the refractive index nd, except that the measurement wavelengths were changed to 656.3 nm (C-line) and 486.1 nm (F-line).

[0156] (Abbe number νd) The Abbe number νd was calculated from the refractive indices nF, nd, and nC using the following formula.

[0157] Abbe number νd = (nd-1) / (nF-nC)

[0158] (3x birefringence (birefringence when stretched 3 times)) A film with a thickness of 200 to 600 μm was formed by hot pressing the sample at 200 to 240°C. This film was cut into strips of 10 mm x 50 mm, and test specimens were obtained by uniaxial stretching (free-end uniaxial stretching) at a rate of 25 mm / min under the temperature condition of glass transition temperature Tg + 10°C to achieve a stretch ratio of 3. The retardation of the obtained test specimens was measured using a phase difference film / optical material inspection device (RETS-100, manufactured by Otsuka Electronics Co., Ltd.) under the conditions of a measurement temperature of 25°C and a measurement wavelength of 600 nm, using the parallel nicol rotation method. The birefringence (3x birefringence) was calculated by dividing the value by the thickness of the measurement area.

[0159] [Synthesis Example 1] According to Example 1 of JP-A-2023-122572, 2-acryloyl-9,9-dimethylfluorene (or 9,9-dimethylfluorenyl vinyl ketone; hereinafter also referred to as FVK) was prepared.

[0160] [Example 1] (Charge ratio: [FVK] / [MMA]=10 / 90) FVK (1.37 g, 5.52 mmol), methyl methacrylate (MMA, 4.96 g, 49.5 mmol), and 2,2'-azobisisobutyronitrile (AIBN, 0.361 g, 2.20 mmol) were dissolved in toluene (55 mL). Of the obtained monomer solution, 50 mL was taken, freeze-degassed under a nitrogen atmosphere, heated at 65 °C, and polymerized for 6 hours. Then, it was added to methanol (1.0 L) to cause precipitation, and this precipitate was recovered by filtration. The recovered precipitate was dissolved in dichloromethane (30 mL) and reprecipitated twice with ether (600 mL). The solid obtained by reprecipitation was vacuum-dried at 60 °C to obtain a copolymer (yield: 2.97 g, yield rate: 51.7%).

[0161] In addition, reaction tracking was performed using the remaining portion (5 mL) of the separated monomer solution. That is, the monomer solution was divided into five 1-mL portions as tracking samples, polymerized under the same conditions as above, and one tracking sample was recovered at polymerization times of 15 minutes, 30 minutes, 60 minutes, 120 minutes, and 360 minutes. Each recovered tracking sample was dissolved in deuterated chloroform 1 and the conversion rate of the polymerization components at a predetermined polymerization time was tracked by measuring 1H NMR.

[0162] [Example 2] (Charge ratio: [FVK] / [MMA]=20 / 80) A monomer solution was prepared using FVK (2.73 g, 11.0 mmol) and MMA (4.41 g, 44.0 mmol) as polymerization components, and polymerization was carried out while tracking the reaction in the same manner as in Example 1 to obtain a copolymer. The yield of the copolymer obtained using 50 mL of the monomer solution was 3.88 g, and the yield rate was 54.4%. Reaction tracking was performed using the remaining 5 mL of the monomer solution.

[0163] [Example 3] (Charge ratio: [FVK] / [MMA] = 30 / 70) A copolymer was obtained by carrying out polymerization while tracking the reaction in the same manner as in Example 1, except that FVK (4.10 g, 16.5 mmol) and MMA (3.85 g, 38.5 mmol) were used as the polymerization components. The yield of the copolymer obtained using 50 mL of the monomer solution was 5.18 g, and the yield was 65.2%. The reaction was tracked using the remaining 5 mL of the monomer solution.

[0164] [Example 4] (Charge ratio: [FVK] / [MMA] = 50 / 50) A copolymer was obtained by carrying out polymerization in the same manner as in Example 1, except that FVK (6.83 g, 27.5 mmol) and MMA (2.75 g, 27.5 mmol) were used as the polymerization components and the reaction tracking was carried out separately. The yield of the copolymer obtained using 55 mL of the monomer solution was 6.42 g, and the yield was 67.0%.

[0165] The reaction tracking was carried out in the same manner as in Example 1 using a monomer solution obtained by dissolving FVK (0.621 g, 2.50 mmol), MMA (0.250 g, 2.50 mmol), and AIBN (0.033 g, 0.2 mmol) in toluene (5 mL).

[0166] [Example 5] (Charge ratio: [FVK] / [MMA] = 75 / 25) A copolymer was obtained by carrying out polymerization while tracking the reaction in the same manner as in Example 1, except that FVK (4.656 g, 18.75 mmol), MMA (0.625 g, 6.24 mmol), and AIBN (0.164 g, 0.999 mmol) were dissolved in toluene (25 mL) to prepare a monomer solution. The yield of the copolymer obtained using 20 mL of the monomer solution was 3.47 g, and the yield was 65.7%. The reaction was tracked using the remaining 5 mL of the monomer solution.

[0167] [Comparative Example 1] (Charge ratio: [FVK] / [MMA] = 100 / 0) Polymerization was carried out in the same manner as in Example 5, except that only FVK (6.21 g, 25.0 mmol) was used as the polymerization component without using MMA, and reaction tracking was not performed, to obtain a copolymer (yield: 4.44 g, yield: 71.4%).

[0168] [Comparative Example 2] (Ingredient ratio: [FVK] / [MMA]=0 / 100) Polymerization was carried out in the same manner as in Example 5, except that only MMA (2.50 g, 25.0 mmol) was used as the polymerization component without using FVK, and reaction tracking was not performed, to obtain a copolymer (yield: 0.74 g, yield: 30%).

[0169] [Tracking the copolymerization reaction between FVK and MMA] Figures 1-5 show the results of reaction tracking using follow-up samples in each example. In all examples, more than 60% of FVK was consumed after 2 hours of reaction, and almost completely consumed after 6 hours. The tracking results show that while FVK is consumed faster than MMA in terms of monomer consumption rate, the difference is not significant. Considering the polymer composition ratio and the reactivity of FVK and MMA, it is expected that copolymerization proceeded in a statistically random manner.

[0170] [Molecular weight and thermophysical properties of copolymers] The resulting polymer (copolymer) was subjected to size exclusion chromatography (SEC) and 1 The structural analysis was performed using 1H NMR, and the thermophysical properties were measured using TG-DTA and DSC. The results are shown in Table 1 and Figures 6-23 below.

[0171] [Table 1]

[0172] In all examples, the molecular weight of the polymer was Mn > 10000, confirming that polymerization was progressing. Furthermore, although the proportion of FVK in the polymer composition ratio obtained in the examples was slightly higher than the initial ratio, there was no significant dissociation. As the proportion of FVK increased, T 5d Both Tg tend to increase, suggesting that the introduction of the rigid fluorene skeleton improved the heat resistance of the polymer. In particular, T 5d Even when the proportion of FVK was relatively low, as in Example 1, the improvement was unexpectedly significant.

[0173] [Transmittance and lightfastness] Using the polymers obtained in Examples 3-4 and Comparative Example 1, films with a thickness of 0.8 mm were prepared, and their transmittance and light resistance (transmittance after a light resistance test involving 100 hours of irradiation at a wavelength of 405 nm) were evaluated. The results are shown in Figure 24.

[0174] As is clear from Figure 24, as the proportion of FVK increased, the transmittance before and after the lightfastness test decreased in both cases, and the appearance also tended to become more yellow. Therefore, the examples had superior transparency (or light transmittance). Furthermore, when comparing the transmittance and appearance before and after the lightfastness test of the polymer in the examples, no significant degradation was observed after the lightfastness test, indicating superior lightfastness.

[0175] [Refractive index, Abbe number, birefringence] The refractive index (nd), Abbe number (νd), and triple birefringence of the polymers obtained in Examples 3-4 and Comparative Example 1 were evaluated. The results are shown in Table 2 below.

[0176] [Table 2]

[0177] As the proportion of FVK increased, the refractive index increased and the Abbe number tended to decrease. Usually, although the Abbe number tends to decrease as the refractive index increases, the obtained polymer showed a lower Abbe number even with the same refractive index compared to general optical lens polymers, and it was confirmed that the relationship between the refractive index and the Abbe number was very peculiar. Also, the obtained polymer tended to show negative birefringence, and as the proportion of FVK increased, the birefringence decreased (increased in the negative direction).

Industrial Applicability

[0178] The copolymer (or resin) of the present disclosure exhibits excellent optical properties such as high heat resistance and transparency, and thus can be used in various applications in addition to heat-resistant members and optical members. The shape of the optical material may be, for example, film or sheet form, plate form, lens form, tubular form, etc.

[0179] Typical applications include graphitization precursors; gas separation membranes such as CO2 gas separation membranes; membranes for fuel cells; light-emitting materials such as light-emitting materials for organic EL; organic semiconductors; adhesives or adhesives such as optical adhesives and optical tacks; coating agents, specifically optical overcoats or hardcoats such as coating agents for LED (light-emitting diode) elements, ink materials, etc.; lenses, specifically pickup lenses such as pickup lenses for DVDs (digital versatile discs), microlenses such as microlenses for liquid crystal projectors, eyeglass lenses, etc.; films or sheets, especially optical films or optical sheets, specifically liquid Polarizing films such as polarizing films for crystal displays, anti-reflective films (or anti-reflective coatings) such as anti-reflective films for display devices, films for touch panels, films for flexible substrates, films for displays, and more specifically, filters and protective films, prism sheets, etc., in thin displays, especially in displays such as PDP (plasma displays), LCD (liquid crystal displays), VFD (vacuum fluorescent displays), SED (surface conduction electron emission displays), FED (field emission displays), NED (nano-emissive displays), cathode ray tubes, and electronic paper; optical fibers; optical waveguides; holograms, etc.

Claims

1. A copolymer of a fluorene compound represented by the following formula (1) and a (meth)acrylic acid ester. 【Chemistry 1】 (In the formula, R １ The '' indicates a substituent, k is an integer between 0 and 2, and the double line (solid and dashed) indicates a single or double bond. R ２ａ and R ２ｂ m1 independently represents a nonpolymerizable substituent, m1 represents an integer from 0 to 3, and m2 represents an integer from 0 to 4. R ３ , R ４ and R ５ (Each represents either a hydrogen atom or a non-polymerizable substituent.)

2. In the above formula (1), R １ This indicates a hydrocarbon group or an oxygen atom. R ２ａ and R ２ｂ each independently represents a hydrocarbon group, m1 represents an integer of 0 to 2, m2 represents an integer of 0 to 2, R ３ , R ４ and R ５ The copolymer according to claim 1, wherein each independently represents a hydrogen atom or a hydrocarbon group.

3. In the above formula (1), R １ represents an alkyl group, where k is 0 or 2. R ２ａ and R ２ｂ Each independently represents an alkyl group, where m1 represents 0 or 1, and m2 represents 0 or 1. R ３ , R ４ and R ５ The copolymer according to claim 1, wherein is independently a hydrogen atom or an alkyl group.

4. The copolymer according to any one of claims 1 to 3, wherein the (meth)acrylic acid ester is an alkyl (meth)acrylic acid ester.

5. The copolymer according to any one of claims 1 to 3, wherein the ratio of constituent units derived from the fluorene compound represented by formula (1) to constituent units derived from the (meth)acrylic acid ester is the former / latter (molar ratio) = 5 / 95 to 50 / 50.

6. 5% weight loss temperature T ｄ５ However, the temperature is above 200°C. The copolymer according to any one of claims 1 to 3, wherein the light transmittance at 550 nm at a thickness of 0.8 mm is 50% or more.

7. The copolymer according to claim 6, wherein the light transmittance at 450 nm at a thickness of 0.8 mm is 50% or more.

8. The glass transition temperature Tg is 100 to 200°C. The number-average molecular weight Mn is between 5,000 and 500,000. The refractive index nd is 1.55 to 1.

65. The Abbe number νd is between 16 and 25. The birefringence of a uniaxially stretched film obtained under the stretching conditions of a stretching temperature (glass transition temperature Tg + 10) °C, a stretching speed of 25 mm / min, and a stretching ratio of 3 times is -200 × 10⁻¹⁰ at a wavelength of 600 nm. －４ The copolymer according to any one of claims 1 to 3, wherein the coefficient is ~0.

9. A method for producing a copolymer according to any one of claims 1 to 3, comprising a polymerization step of polymerizing a polymerization component comprising the fluorene compound represented by formula (1) and the (meth)acrylic acid ester.

10. A molded article comprising the copolymer according to any one of claims 1 to 3.

11. The molded article according to claim 10, which is an optical component.

12. The molded article according to claim 10, which is in the form of a film, a sheet, or a lens.

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