JP2020204004A - Polystyrene compound - Google Patents

Abstract

To provide a novel polystyrene compound.SOLUTION: The polystyrene compound has a first constituent unit represented by the following formula (1) and a second constituent unit having a carboxyl group. The proportion of the second constituent unit in the total of the first constituent unit and the second constituent unit is 20-80 mol%. [In the formula (1), R1 represents a hydrogen atom or a methyl group.]SELECTED DRAWING: None

Description

The present invention relates to polystyrene compounds.

Compounds containing styrene-derived structural units such as polystyrene (hereinafter referred to as "polystyrene compounds") are highly transparent, lightweight, and have excellent moldability, electrical properties, weather resistance, chemical resistance, and the like. It is used for various purposes depending on the manufacturing method. For example, it is widely used as a material for household electric appliances, office equipment, household products, packaging products, toys, furniture, synthetic paper and other industrial materials.

An object of the present invention is to provide a novel polystyrene compound.

［式中、Ｔｇは２成分の共重合体のガラス転移温度を示し、Ｔｇ^１及びＴｇ^２は、それぞれ第１成分の単独重合体のガラス転移温度及び第２成分の単独重合体のガラス転移温度を示し、Ｗ_１及びＷ_２は、それぞれ第１成分の重量割合及び第２成分の重量割合を示す。］ Generally, a glass transition point (Tg) is mentioned as one of the indexes indicating heat resistance. For the Tg of the multi-component copolymer, the Tg of the homopolymer of each component and the weight ratio W (unit: weight%) of each component in the copolymer are calculated, and the FOX formula (theoretical formula) is used. Can be easily predicted. For example, the formula of FOX in the two-component copolymer is represented by the following formula.

[In the formula, Tg indicates the glass transition temperature of the two-component copolymer, and Tg ¹ and Tg ² are the glass transition temperature of the homopolymer of the first component and the glass transition temperature of the homopolymer of the second component, respectively. ₁ and W ₂ indicate the weight ratio of the first component and the weight ratio of the second component, respectively. ]

On the other hand, as a result of the studies by the present inventors, it has been found that in a polystyrene compound containing a constituent unit having a carboxyl group at a specific ratio, a polystyrene compound having a Tg sufficiently higher than Tg predicted from the FOX formula can be obtained. The heading has completed the present invention.

［式（１）中、Ｒ^１は、水素原子又はメチル基を示す。］ That is, one aspect of the present invention has a first structural unit represented by the following formula (1) and a second structural unit having a carboxyl group, and has a first structural unit and a second configuration. The present invention relates to a polystyrene compound in which the ratio of the second constituent unit to the total with the unit is 20 to 80 mol%.

[In formula (1), R ¹ represents a hydrogen atom or a methyl group. ]

The polystyrene compound of one aspect of the present invention is a novel polystyrene compound showing a Tg sufficiently higher than the Tg predicted from the FOX formula, and has high heat resistance as compared with a homopolymer of styrene. Further, a material for introducing a structural unit having a carboxyl group, such as vinyl benzoate, is expensive and the amount used may be limited. However, according to the present invention, such an expensive material A polystyrene compound having excellent heat resistance can be obtained even when the amount used is reduced. That is, the polystyrene compound of one aspect of the present invention is a polystyrene compound that can be produced at low cost and has high heat resistance.

The reason why the above effect is obtained is not clear, but the above effect can be obtained by forming hydrogen bonds between the carboxyl groups contained in the polystyrene compound and by forming an appropriate amount of hydrogen bonds. The present inventors speculate.

［式（３）中、Ｒ^２は、水素原子又はメチル基を示し、Ｒ^４はハロゲン原子、炭素原子、酸素原子、窒素原子、硫黄原子、リン原子、セレン原子、ケイ素原子及び錫原子からなる群より選択される少なくとも一種を含む置換基（但し、カルボキシル基を含む基を除く）を示し、ｍは０以上４以下の整数を示す。ｍが２以上である場合、複数のＲ^４は同一であっても異なっていてもよい。］

［式（４）中、Ｒ^２は、水素原子又はメチル基を示す。］ The second structural unit is preferably at least one selected from the group consisting of the structural unit represented by the following formula (3) and the structural unit represented by the following formula (4).

[In formula (3), R ² represents a hydrogen atom or a methyl group, and R ⁴ consists of a halogen atom, a carbon atom, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, a selenium atom, a silicon atom and a tin atom. A substituent containing at least one selected from the group (excluding a group containing a carboxyl group) is shown, and m is an integer of 0 or more and 4 or less. When m is 2 or more, the plurality of R ^4s may be the same or different. ]

[In formula (4), R ² represents a hydrogen atom or a methyl group. ]

Polystyrene compounds preferably do not have a functional group containing at least one selected from the group consisting of hydroxy and carbonyl groups, except for the carboxyl group of the second building block.

The number average molecular weight of the polystyrene compound is preferably 10,000 or more and 500,000 or less.

According to the present invention, there is provided a novel polystyrene compound having a Tg sufficiently higher than the Tg predicted from the FOX formula.

It is a graph which shows the Tg of the polymer of an experimental example, and the Tg calculated from the FOX formula. It is a graph which shows the Tg of the polymer of an experimental example, and the Tg calculated from the FOX formula. It is a graph which shows the Tg of the polymer of an experimental example, and the Tg calculated from the FOX formula.

Hereinafter, preferred embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments. In addition, in this specification, "(meth) acrylic acid" means at least one of acrylic acid and methacrylic acid corresponding thereto. The same applies to other similar expressions such as "(meth) acryloyl" and "(meth) acryloyl". In addition, the numerical range indicated by using "~" indicates a range including the numerical values before and after "~" as the minimum value and the maximum value, respectively. Further, the upper limit value and the lower limit value individually described as the numerical range can be arbitrarily combined.

［式（１）中、Ｒ^１は、水素原子又はメチル基を示す。］ <Polystyrene compound>
The polystyrene compound of the present embodiment has a structural unit represented by the following formula (1) (first structural unit) and a structural unit having a carboxyl group (second structural unit). The polystyrene compound may have one kind of structural unit as the first structural unit, or may have two or more kinds of structural units. Further, the polystyrene compound may have one kind of structural unit as the second structural unit, or may have two or more kinds of structural units.

[In formula (1), R ¹ represents a hydrogen atom or a methyl group. ]

The content ratio of the first structural unit in the polystyrene compound is from the viewpoint that the performance (transparency, light weight, moldability, electrical characteristics, weather resistance, chemical resistance, etc.) peculiar to the styrene homopolymer can be easily obtained, and From the viewpoint of more sufficiently obtaining the effect of improving heat resistance, the content may be 20 mol% or more, 30 mol% or more, 40 mol% or more, or 50 mol% or more based on the total amount of the constituent units contained in the polystyrene compound. The content ratio of the first structural unit in the polystyrene compound is 80 mol% or less, 70 mol% or less, 60 mol% or less, based on the total amount of the structural units contained in the polystyrene compound, from the viewpoint of more sufficiently obtaining the effect of improving heat resistance. Alternatively, it may be 50 mol% or less. The content ratio of the first structural unit can be measured by a Fourier transform infrared spectrophotometer (FT-IR), a nuclear magnetic resonance apparatus (NMR), or the like.

［式（２）中、Ｒ^２及びＲ^３は、それぞれ独立して、水素原子又はメチル基を示し、Ｘは単結合又は２価の連結基を示す。］ The second structural unit is preferably a structural unit having one carboxyl group, and is, for example, a structural unit represented by the following formula (2).

[In formula (2), R ² and R ³ independently represent a hydrogen atom or a methyl group, and X represents a single bond or a divalent linking group. ]

In the structural unit represented by the formula (2), when one of R ² and R ³ is a methyl group, the other is preferably a hydrogen atom. The divalent linking group represented by X is, for example, a substituted or unsubstituted divalent hydrocarbon group. The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. When the hydrocarbon group is an aliphatic hydrocarbon group, the hydrocarbon group may be linear, branched or cyclic. X is free of carboxyl groups, preferably free of hydroxy and carbonyl groups. X is more preferably a single bond or a substituted or unsubstituted divalent aromatic hydrocarbon group. In a polystyrene compound, the plurality of R ^2s may be the same or different, the plurality of R ^3s may be the same or different, and the plurality of Xs may be the same or different. ..

［式（３）中、Ｒ^２は、水素原子又はメチル基を示し、Ｒ^４はハロゲン原子、炭素原子、酸素原子、窒素原子、硫黄原子、リン原子、セレン原子、ケイ素原子及び錫原子からなる群より選択される少なくとも一種を含む置換基（但し、カルボキシル基を含む基を除く）を示し、ｍは０以上４以下の整数を示す。ｍが２以上である場合、複数のＲ^４は同一であっても異なっていてもよい。］

［式（４）中、Ｒ^２は、水素原子又はメチル基を示す。］ The structural unit represented by the formula (2) is preferably a structural unit represented by the following formula (3) or a structural unit represented by the following formula (4). In other words, the second structural unit is preferably at least one selected from the group consisting of the structural unit represented by the following formula (3) and the structural unit represented by the following formula (4). In this case, the effect of improving heat resistance can be more sufficiently obtained.

[In formula (3), R ² represents a hydrogen atom or a methyl group, and R ⁴ consists of a halogen atom, a carbon atom, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, a selenium atom, a silicon atom and a tin atom. Indicates a substituent containing at least one selected from the group (excluding a group containing a carboxyl group), and m represents an integer of 0 or more and 4 or less. When m is 2 or more, the plurality of R ^4s may be the same or different. ]

[In formula (4), R ² represents a hydrogen atom or a methyl group. ]

The R ⁴ in the formula (3), for example, an alkyl group, an aryl group, hydroxy group, an amino group or a nitro group (excluding the group containing the carboxyl group). The alkyl group may be either substituted or unsubstituted. The alkyl group has, for example, 1 to 6 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group and a propyl group. The aryl group may be either substituted or unsubstituted. The aryl group has, for example, 6 to 10 carbon atoms. Examples of the aryl group include a phenyl group and a naphthyl group. In the formula (3), m is preferably 0.

The content ratio of the second structural unit in the polystyrene compound is 20 mol% or more, 30 mol% or more, 40 mol% or more based on the total amount of the structural units contained in the polystyrene compound from the viewpoint of more sufficiently obtaining the effect of improving heat resistance. Alternatively, it may be 50 mol% or more. The content ratio of the second structural unit in the polystyrene compound is 80 mol% based on the total amount of the structural units contained in the polystyrene compound from the viewpoint of cheaper production and the more sufficient effect of improving heat resistance. Hereinafter, it may be 70 mol% or less, 60 mol% or less, or 50 mol% or less. The content ratio of the second structural unit can be measured by a Fourier transform infrared spectrophotometer (FT-IR), a nuclear magnetic resonance apparatus (NMR), or the like.

In the polystyrene compound of the present embodiment, the ratio of the second structural unit to the total of the first structural unit and the second structural unit is 20 to 80 mol%. When the above ratio is 20 to 80 mol%, the polystyrene compound exhibits a Tg that is sufficiently higher than the Tg predicted from the FOX formula. That is, the difference (ΔTg: Tg _{actual measurement-} Tg _FOX ) between the actual measurement value of Tg (Tg _{actual measurement} ) and the Tg (Tg _FOX ) predicted from the FOX equation is large.

The ratio of the second constituent unit to the total of the first constituent unit and the second constituent unit is 70 mol% or less from the viewpoint that ΔTg becomes larger and the effect of improving heat resistance can be more sufficiently obtained. It may be 60 mol% or less or 50 mol% or less. The ratio of the second structural unit may be 30 mol% or more from the viewpoint that ΔTg becomes larger and the effect of improving heat resistance can be more sufficiently obtained. From these viewpoints, the proportion of the second structural unit is, for example, 20 to 70 mol%, 20 to 60 mol%, 20 to 50 mol%, 30 to 80 mol%, 30 to 70 mol%, 30 to 60 mol% or 30 to 50 mol. May be%. The ratio of the second structural unit may be 30 mol% or more, 40 mol% or more, or 50 mol% or more from the viewpoint that the _{actual measurement} of Tg becomes larger and more excellent heat resistance can be obtained.

［式（５）中、Ｒ^５及びＲ^６は、それぞれ独立して、水素原子又はメチル基を示し、Ｒ^７はハロゲン原子、炭素原子、酸素原子、窒素原子、硫黄原子、リン原子、セレン原子、ケイ素原子及び錫原子からなる群より選択される少なくとも一種を含む置換基（但し、カルボキシル基を含む基を除く）を示し、ｎは０以上４以下の整数を示す。ｎが２以上である場合、複数のＲ^７は同一であっても異なっていてもよい。］ The polystyrene compound may further have a first structural unit and a third structural unit different from the second structural unit. The polystyrene compound may have one kind of structural unit as the third structural unit, and may have two or more kinds of structural units. Examples of the third structural unit include a structural unit represented by the following formula (5).

[In formula (5), R ⁵ and R ⁶ each independently represent a hydrogen atom or a methyl group, and R ⁷ is a halogen atom, a carbon atom, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, or a selenium atom. , A substituent containing at least one selected from the group consisting of a silicon atom and a tin atom (excluding a group containing a carboxyl group), and n indicates an integer of 0 or more and 4 or less. When n is 2 or more, the plurality of R ^7s may be the same or different. ]

The specific example of R ⁷ in the formula (5) is the same as the specific example of R ⁴ in the formula (3).

The content ratio of the third structural unit in the polystyrene compound is 10 mol% or less, 5 mol% or less, or 1 mol% or less based on the total amount of the structural units contained in the polystyrene compound from the viewpoint that the effect of improving heat resistance can be more sufficiently obtained. It may be. The polystyrene compound preferably does not have a third structural unit from the viewpoint of more sufficiently obtaining the effect of improving heat resistance.

The polystyrene compound has a functional group containing at least one selected from the group consisting of a hydroxy group and a carbonyl group, excluding the carboxyl group of the second structural unit, from the viewpoint of more sufficiently obtaining the effect of improving heat resistance. It is preferable not to do so. That is, it is preferable that the functional group containing at least one selected from the group consisting of a hydroxy group and a carbonyl group of the polystyrene compound of the present embodiment is only the carboxyl group of the second structural unit.

［式（６）中、＊は結合手を示す。］ The structural unit located at the end of the polystyrene compound may have a group derived from a polymerization initiator or a chain transfer agent described later. That is, the polystyrene compound may have a partial structure derived from a polymerization initiator or a chain transfer agent at its terminal. For example, when azobisisobutyronitrile is used as the polymerization initiator and the structural unit located at the end of the polystyrene compound is the first structural unit, the polystyrene compound has a terminal structure represented by the following formula (6). You can do it.

[In equation (6), * indicates a bond. ]

The arrangement of the first structural unit, the second structural unit, and the third structural unit in the polystyrene compound is not particularly limited, but the polystyrene compound has a random copolymer weight from the viewpoint of more sufficiently obtaining the effect of improving heat resistance. It is preferably coalesced. The polystyrene compound may have a block structure composed of repetitions of the first structural unit, may have a block structure composed of repetitions of the second structural unit, and may have a third structural unit. It may have a block structure composed of the repetition of.

The number average molecular weight (Mn) of the polystyrene compound is preferably 10,000 or more, and may be 15,000 or more or 20,000 or more, from the viewpoint of improving heat resistance and moldability. The number average molecular weight (Mn) is preferably 500,000 or less, and may be 250,000 or less or 100,000 or less from the viewpoint of improving moldability. The number average molecular weight (Mn) can be measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.

The polystyrene compound of the present embodiment described above can be widely used in applications requiring heat resistance.

<Manufacturing method of polystyrene compound>
The polystyrene compound of the present embodiment includes, for example, styrene (first compound), a group having an ethylenically unsaturated bond (hereinafter referred to as "ethylenically unsaturated group"), and a second compound having a carboxyl group. In some cases, it is obtained by polymerizing a monomer component containing a third compound having an ethylenically unsaturated group (excluding the first compound and the second compound) by a known method. In this case, the first structural unit in the polystyrene compound is the structural unit derived from the first compound, the second structural unit is the structural unit derived from the second compound, and the third structural unit is the third compound. It is a structural unit of origin. The form of polymerization may be, for example, radical polymerization.

Examples of the ethylenically unsaturated group in the second compound include a (meth) acryloyl group, a vinyl group, an allyl group and the like. Specific examples of the second compound include 4-vinylbenzoic acid, 3-vinylbenzoic acid, 2-vinylbenzoic acid, (meth) acrylic acid, 2- (meth) acryloxyethyl hexahydrophthalic acid, 2-( Meta) acryloxypropyl hexahydrophthalic acid, 2- (meth) acryloxiethyl tetrahydrophthalic acid, 2- (meth) acryloxipropyl tetrahydrophthalic acid, 5-methyl-2- (meth) acryloxiethyl hexahydrophthalic acid , 2- (meth) acryloxyethyl phthalic acid, 2- (meth) acryloxipropyl phthalic acid, 2- (meth) acryloxyethyl phthalic acid, 2- (meth) acryloxypropyl phthalic acid, crotonic acid, sorbic acid And so on. Among these, 4-vinylbenzoic acid, 3-vinylbenzoic acid, 2-vinylbenzoic acid and (meth) acrylic acid are preferably used. These compounds can be used alone or in combination of two or more.

Examples of the ethylenically unsaturated group in the third compound include a (meth) acryloyl group, a vinyl group, an allyl group and the like. Examples of the third compound include p-methylstyrene; o-methylstyrene; m-methylstyrene; 2,4-dimethylstyrene; 2,5-dimethylstyrene; 3,4-dimethylstyrene; 3,5-dimethyl. Styrene; Alkyl styrene such as p-terchary butyl styrene, p-chlorostyrene; m-chlorostyrene; o-chlorostyrene; p-bromostyrene; m-bromostyrene; o-bromostyrene; p-fluorostyrene; m- Fluorostyrene; o-fluorostyrene; halogenated styrene such as o-methyl-p-fluorostyrene, 4-vinylbiphenyl; 3-vinylbiphenyl; vinylbiphenyls such as 2-vinylbiphenyl, 1- (4-vinylphenyl) -Naphthalene; 2- (4-vinylphenyl) -naphthalene; 1- (3-vinylphenyl) -naphthalene; 2- (3-vinylphenyl) -naphthalene; 1- (2-vinylphenyl) -naphthalene; 2-( Vinylphenyl naphthalenes such as 2-vinylphenyl) naphthalene, 1- (4-vinylphenyl) -anthracene; 2- (4-vinylphenyl) -anthracene; 9- (4-vinylphenyl) -anthracene; 1- (3) -Vinylphenyl) -anthracene; 2- (3-vinylphenyl) -anthracene; 9- (3-vinylphenyl) -anthracene; 1- (2-vinylphenyl) -anthracene; 2- (2-vinylphenyl) -anthracene Vinylphenyl anthracenes such as 9- (2-vinylphenyl) -anthracene, 1- (4-vinylphenyl) -phenanthrene; 2- (4-vinylphenyl) -phenanthrene; 3- (4-vinylphenyl) -phenanthrene 4- (4-Vinylphenyl) -phenanthrene; 9- (4-vinylphenyl) -phenanthrene; 1- (3-vinylphenyl) -phenanthrene; 2- (3-vinylphenyl) -phenanthrene; 3- (3- (3-) Vinylphenyl) -phenanthrene; 4- (3-vinylphenyl) -phenanthrene; 9- (3-vinylphenyl) -phenanthrene; 1- (2-vinylphenyl) -phenanthrene; 2- (2-vinylphenyl) -phenanthrene; 3- (2-Vinylphenyl) -phenanthrene; 4- (2-vinylphenyl) -phenanthrene; vinylphenyl phenanthrenes such as 9- (2-vinylphenyl) -phenanthrene, 1- (4-vinylphenyl) -pyrene; 2- (4-Vinyl Phenyl) -pyrene; 1- (3-vinylphenyl) -pyrene; 2- (3-vinylphenyl) -pyrene; 1- (2-vinylphenyl) -pyrene; 2- (2-vinylphenyl) -pyrene, etc. Vinylphenylpyrenes, 4-vinyl-p-terphenyl; 4-vinyl-m-terphenyl; 4-vinyl-o-terphenyl; 3-vinyl-p-terphenyl; 3-vinyl-m-terphenyl; 3-Vinyl-o-terphenyl; 2-vinyl-p-terphenyl; 2-vinyl-m-terphenyl; vinyl terphenyls such as 2-vinyl-o-terphenyl, 4- (4-vinylphenyl) Vinylphenyl terphenyls such as -p-terphenyl, 4-vinyl-4'-methylbiphenyl; 4-vinyl-3'-methylbiphenyl; 4-vinyl-2'-methylbiphenyl; 2-methyl-4-vinyl Biphenyls; vinylalkyl biphenyls such as 3-methyl-4-vinyl biphenyls, 4-vinyl-4'-fluorobiphenyls; 4-vinyl-3'-fluorobiphenyls; 4-vinyl-2'-fluorobiphenyls; 4-vinyl -2-Fluorobiphenyl; 4-vinyl-3-fluorobiphenyl; 4-vinyl-4'-chlorobiphenyl; 4-vinyl-3'-chlorobiphenyl; 4-vinyl-2'-chlorobiphenyl; 4-vinyl-2 −Chlorobiphenyl; 4-vinyl-3-chlorobiphenyl; 4-vinyl-4'-bromobiphenyl; 4-vinyl-3'-bromobiphenyl; 4-vinyl-2'-bromobiphenyl; 4-vinyl-2-bromo Biphenyls; vinyl halides such as 4-vinyl-3-bromobiphenyl, trialkylsilylvinylbiphenyls such as 4-vinyl-4'-trimethylsilylbiphenyl, 4-vinyl-4'-trimethylstannylbiphenyl; 4- Trialkylstannyl vinylbiphenyls such as vinyl-4'-tributylstannylbiphenyl, trialkylsilylmethylvinylbiphenyls such as 4-vinyl-4'-trimethylsilylmethylbiphenyl, 4-vinyl-4'-trimethylstannylmethyl Biphenyl; trialkylstannyl methylvinyl biphenyls such as 4-vinyl-4'-tributylstannylmethylbiphenyl, p-chloroethylstyrene; m-chloroethylstyrene; halogen-substituted alkylstyrenes such as o-chloroethylstyrene, p. -Trimethylsilylstyrene; m-trimethylsilylstyrene O-trimethylsilylstyrene; p-triethylsilylstyrene; m-triethylsilylstyrene; o-triethylsilylstyrene; alkylsilylstyrenes such as p-dimethyltersary-butylsilylstyrene, p-dimethylphenylsilylstyrene; p-methyl Diphenylsilylstyrene; phenyl group-containing silylstyrenes such as p-triphenylsilylstyrene, p-dimethylchlorosilylstyrene; p-methyldichlorosilylstyrene; p-trichlorosilylstyrene; p-dimethylbromosilylstyrene; p-dimethyliodo Examples thereof include halogen-containing silylstyrenes such as silylstyrene and silyl group-containing silylstyrenes such as p- (p-trimethylsilyl) dimethylsilylstyrene. These compounds may be used alone or as a mixture of two or more.

The blending amount of the first compound, the blending amount of the second compound, and the blending amount of the third compound are the content ratio of the first structural unit, the content ratio of the second structural unit, and the third composition in the polystyrene compound. The content ratio of the unit may be adjusted so as to be within the above-mentioned range.

In the step of polymerizing the monomer component, a polymerization initiator may be used. The polymerization initiator may be a known polymerization initiator, for example, a known radical polymerization initiator. Specific examples of the polymerization initiator include azobisisobutyronitrile (AIBN), 1,1'-azobis (cyclohexanecarbonitrile), 2,2'-azobis (2-methylpropionitrile), 4,4'. -Radiopolymerization initiator of azo compounds such as azobis (4-cyanopropionic acid), (2RS, 2'RS) -azobis (4-methoxy-2,4-dimethylvaleronitrile); peroxides such as benzoyl peroxide Examples of the radical polymerization initiator of the above.

A chain transfer agent may be used in the step of polymerizing the monomer component. The polystyrene compound may be synthesized by a living radical polymerization reaction. Examples of the chain transfer agent include 2-cyano-2-benzodithioate, 4-cyano-4- (phenylcarbonothioilthio) pentanoic acid, 2-cyano-2-propyldodecyltrithiocarbonate, 4-cyano-4. -[(Dodecylsulfanylthiocarbonyl) sulfanyl] pentanoic acid, 2- (dodecylthiocarbonotioilthio) -2-methylpropionic acid, cyanomethyldodecyltrithiocarbonate, cyanomethylmethyl (phenyl) carbamodithioate, bis Dithioester compounds such as (thiobenzoyl) disulfide, bis (dodecylsulfanylthiocarbonyl) disulfide, cumyldithiobenzoate, and [1- (O-ethylzantyl) ethyl] benzene are preferably used.

The ratio of the monomer component, the radical polymerization initiator, and the chain transfer agent at the time of radical polymerization may be appropriately determined in consideration of the degree of polymerization of the block structure to be formed, the reactivity of the monomer component, and the like. : Radical polymerization initiator: The chain transfer agent is preferably 1000: 0.5 to 50: 10 to 100 (mol ratio), and more preferably 1000: 0.5: 10 (mol ratio).

Hereinafter, the content of the present invention will be described in more detail with reference to experimental examples, but the present invention is not limited to the following experimental examples.

(Experimental Example 1)
[Synthesis of Polymer 1]
1.78 g of 4-vinylbenzoic acid (hereinafter referred to as "VBA"), 0.624 g of styrene (hereinafter referred to as "St"), and azobisisobutyronitrile (hereinafter referred to as "AIBN") in a 10 mL polymerization tube. ) And 6.0 mL of tetrahydrofuran (hereinafter referred to as "THF") were added and stirred to obtain a uniform solution. Then, freeze degassing was performed 4 times, and the mixture was stirred at 70 ° C. for 48 hours. As a result, VBA and St were polymerized. The obtained reaction solution was rapidly cooled with pre-cooled methanol to stop the reaction. Reprecipitation was carried out using 300 mL of chloroform, and the solid recovered by suction filtration was dried under reduced pressure to obtain polymer 1 (random copolymer of VBA and St) as a white powder solid.

[Principal component analysis]
Ratio of VBA-derived structural units and St-derived structural units to the total of VBA-derived structural units and St-derived structural units in the obtained polymer 1 using a nuclear magnetic resonance apparatus (NMR). Asked. The results are shown in Table 1.

[Measurement of molecular weight]
The number average molecular weight Mn and the weight average molecular weight Mw of the polymer were measured by gel permeation chromatography (GPC) using polystyrene as a standard substance, and the molecular weight distribution Mn / Mw was determined. The results are shown in Table 1.

[Measurement of glass transition temperature (Tg)]
The polymer 1 was weighed in a closed aluminum pan, and the Tg ( _measured Tg) of the polymer 1 was measured using a differential scanning calorimetry device (DSC) (trade name: EXSTAR6000 DSC6200) manufactured by Seiko Instruments Inc. Further, the theoretical value (Tg _FOX ) of Tg of the polymer 1 was calculated based on the formula of _FOX , and ΔTg (Tg _{actual measurement-} Tg _FOX ) was obtained. The results are shown in Table 1 and FIG. The horizontal axis of FIG. 1 shows the ratio (unit: mol%) of the VBA-derived structural unit to the total of the VBA-derived structural unit and the St-derived structural unit, and the vertical axis of FIG. 1 is a polymer. Tg (unit: ° C.) is shown.

(Experimental Example 2)
Except that the amount of VBA was changed to 1.11 g, the amount of St was changed to 0.782 g, the amount of AIBN was changed to 24.1 mg, and the amount of THF was changed to 5.0 mL. , Polymer 2 (random copolymer of VBA and St) was obtained in the same manner as in Experimental Example 1. Further, the obtained polymer 2 was subjected to component analysis, molecular weight measurement and Tg measurement in the same manner as in Experimental Example 1. The results are shown in Table 1 and FIG.

(Experimental Example 3)
The amount of VBA was changed to 0.741 g, the amount of St was changed to 1.04 g, the amount of AIBN was changed to 24.7 mg, and the amount of THF was changed to 5.0 mL. Polymer 3 (random copolymer of VBA and St) was obtained in the same manner as in Experimental Example 1 except for the above. Further, the obtained polymer 3 was subjected to component analysis, molecular weight measurement and Tg measurement in the same manner as in Experimental Example 1. The results are shown in Table 1 and FIG.

(Experimental Example 4)
Except for changing the amount of VBA to 0.667g, the amount of St to 1.09g, the amount of AIBN to 24.7mg, and the amount of THF to 5.0mL. , Polymer 4 (random copolymer of VBA and St) was obtained in the same manner as in Experimental Example 1. Further, the obtained polymer 4 was subjected to component analysis, molecular weight measurement and Tg measurement in the same manner as in Experimental Example 1. The results are shown in Table 1 and FIG.

(Experimental Example 5)
Experimental examples except that the amount of VBA was changed to 1.48 g, the amount of AIBN was changed to 16.4 mg, the amount of THF was changed to 3.3 mL, and St was not used. Polymer 5 (a homopolymer of VBA) was obtained in the same manner as in 1. Further, the obtained polymer 5 was subjected to component analysis, molecular weight measurement and Tg measurement in the same manner as in Experimental Example 1. The results are shown in Table 1 and FIG.

(Experimental Example 6)
Experimental examples except that VBA was not used, the St compounding amount was changed to 1.46 g, the AIBN compounding amount was changed to 23.3 mg, and the THF compounding amount was changed to 4.7 mL. Polymer 6 (St homopolymer) was obtained in the same manner as in 1. Further, the obtained polymer 6 was subjected to component analysis, molecular weight measurement and Tg measurement in the same manner as in Experimental Example 1. The results are shown in Table 1 and FIG.

(Experimental Example 7)
In a 10 mL polymerization tube, 0.646 g of methacrylic acid (hereinafter referred to as "MA"), 0.751 g of St, 24.9 mg of AIBN, and 5 of N, N-dimethylformamide (hereinafter referred to as "DMF"). 0.0 mL was added and stirred to obtain a uniform solution. Then, freeze degassing was performed 4 times, and the mixture was stirred at 70 ° C. for 48 hours. As a result, MA and St were polymerized. The obtained reaction solution was rapidly cooled with pre-cooled methanol to stop the reaction. Reprecipitation was carried out using 300 mL of chloroform, and the solid recovered by suction filtration was dried under reduced pressure to obtain polymer 7 (random copolymer of MA and St) as a white powder solid.

The obtained polymer 7 is subjected to component analysis using a nuclear magnetic resonance apparatus (NMR), and the ratio of the constituent units derived from MA and the constituent units derived from St to the total of the constituent units derived from MA and the constituent units derived from St are derived. The ratio of the constituent units of was calculated. Further, the obtained polymer 7 was subjected to molecular weight measurement and Tg measurement in the same manner as in Experimental Example 1. The results are shown in Table 2 and FIG. The horizontal axis of FIG. 2 shows the ratio (unit: mol%) of the structural unit derived from MA to the total of the structural unit derived from MA and the structural unit derived from St, and the vertical axis of FIG. 2 is the polymer. Tg (unit: ° C.) is shown.

(Experimental Example 8)
Except that the amount of MA was changed to 0.861 g, the amount of St was changed to 0.522 g, the amount of AIBN was changed to 24.6 mg, and the amount of DMF was changed to 5.0 mL. , Polymer 8 (random copolymer of MA and St) was obtained in the same manner as in Experimental Example 7. Further, the obtained polymer 8 was subjected to component analysis, molecular weight measurement and Tg measurement in the same manner as in Experimental Example 7. The results are shown in Table 2 and FIG.

(Experimental Example 9)
Except that the amount of MA was changed to 0.259 g, the amount of St was changed to 1.25 g, the amount of AIBN was changed to 25.2 mg, and the amount of DMF was changed to 5.0 mL. , Polymer 9 (random copolymer of MA and St) was obtained in the same manner as in Experimental Example 7. Further, the obtained polymer 9 was subjected to component analysis, molecular weight measurement and Tg measurement in the same manner as in Experimental Example 7. The results are shown in Table 2 and FIG.

(Experimental Example 10)
Experimental examples except that the amount of MA was changed to 1.03 g, the amount of AIBN was changed to 19.9 mg, the amount of DMF was changed to 6.0 mL, and St was not used. Polymer 10 (a homopolymer of MA) was obtained in the same manner as in 7. Further, the obtained polymer 10 was subjected to component analysis, molecular weight measurement and Tg measurement in the same manner as in Experimental Example 7. The results are shown in Table 2 and FIG.

(Experimental Example 11)
To a 10 mL polymerization tube, 1.11 g of VBA, 0.751 g of methyl methacrylate (hereinafter referred to as "MMA"), 24.6 mg of AIBN, and 5.0 mL of THF were added and stirred to obtain a uniform solution. .. Then, freeze degassing was performed 4 times, and the mixture was stirred at 70 ° C. for 24 hours. As a result, VBA and MMA were polymerized. The obtained reaction solution was rapidly cooled with pre-cooled methanol to stop the reaction. Reprecipitation was carried out using 300 mL of chloroform, and the solid recovered by suction filtration was dried under reduced pressure to obtain polymer 11 (random copolymer of VBA and MMA) as a white powder solid.

The obtained polymer 11 is subjected to component analysis using a nuclear magnetic resonance apparatus (NMR), and the ratio of the VBA-derived structural units and the MMA-derived structural units to the total of the VBA-derived structural units and the MMA-derived structural units. The ratio of the constituent units of was calculated. Further, the obtained polymer 11 was subjected to molecular weight measurement and Tg measurement in the same manner as in Experimental Example 1. The results are shown in Table 3 and FIG. The horizontal axis of FIG. 3 shows the ratio (unit: mol%) of the VBA-derived structural unit to the total of the VBA-derived structural unit and the MMA-derived structural unit, and the vertical axis of FIG. 3 is the polymer. Tg (unit: ° C.) is shown.

(Experimental Example 12)
Except that the amount of VBA was changed to 1.48 g, the amount of MMA was changed to 0.50 g, the amount of AIBM was changed to 24.5 mg, and the amount of THF was changed to 5.0 mL. , Polymer 12 (random copolymer of VBA and MMA) was obtained in the same manner as in Experimental Example 11. Further, the obtained polymer 12 was subjected to component analysis, molecular weight measurement and Tg measurement in the same manner as in Experimental Example 11. The results are shown in Table 3 and FIG.

(Experimental Example 13)
Except that the amount of VBA was changed to 0.667g, the amount of MMA was changed to 1.05g, the amount of AIBN was changed to 24.5mg, and the amount of THF was changed to 5.0mL. , Polymer 13 (random copolymer of VBA and MMA) was obtained in the same manner as in Experimental Example 11. Further, the obtained polymer 13 was subjected to component analysis, molecular weight measurement and Tg measurement in the same manner as in Experimental Example 11. The results are shown in Table 3 and FIG.

(Experimental Example 14)
Experimental examples except that VBA was not used, the amount of MMA was changed to 1.50 g, the amount of AIBN was changed to 24.6 mg, and the amount of THF was changed to 5.0 mL. Polymer 14 (a homopolymer of MMA) was obtained in the same manner as in 11. Further, the obtained polymer 14 was subjected to component analysis, molecular weight measurement and Tg measurement in the same manner as in Experimental Example 11. The results are shown in Table 3 and FIG.

As shown in Tables 1 to 3 and FIGS. 1 to 3, the polymers (polystyrene compounds) of Experimental Examples 1 to 4 and 7 to 9 containing a structural unit having a carboxyl group in a specific ratio were _measured by Tg from Tg _FOX. It was confirmed that the value was sufficiently high.

Claims (4)

It has a first structural unit represented by the following formula (1) and a second structural unit having a carboxyl group.
A polystyrene compound in which the ratio of the second structural unit to the total of the first structural unit and the second structural unit is 20 to 80 mol%.

[In formula (1), R ¹ represents a hydrogen atom or a methyl group. ] The polystyrene according to claim 1, wherein the second structural unit is at least one selected from the group consisting of the structural unit represented by the following formula (3) and the structural unit represented by the following formula (4). Compound.

[In formula (3), R ² represents a hydrogen atom or a methyl group, and R ⁴ represents an alkyl group, an aryl group, a hydroxy group, an amino group or a nitro group (excluding a group containing a carboxyl group). m represents an integer of 0 or more and 4 or less. When m is 2 or more, the plurality of R ^4s may be the same or different. ]

[In formula (4), R ² represents a hydrogen atom or a methyl group. ] The polystyrene compound according to claim 1 or 2, which does not have a functional group containing at least one selected from the group consisting of a hydroxy group and a carbonyl group, except for the carboxyl group contained in the second structural unit. The polystyrene compound according to any one of claims 1 to 3, wherein the polystyrene compound has a number average molecular weight of 10,000 or more and 500,000 or less.

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