JP2007332273A - Soluble polyfunctional vinyl aromatic copolymer and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a soluble polyfunctional vinyl aromatic copolymer having improvement in resistance to heat and thermal decomposition, solvent solubility, and processability. <P>SOLUTION: The solvent-soluble polyfunctional vinyl aromatic copolymer having a controlled molecular distribution is obtained by carrying out polymerization at a temperature of 20-120°C in a homogeneous solution where monomer components comprising 20-99 mol% of a divinyl aromatic compound (a) and 80-1 mol% of a monovinyl aromatic compound (b) are dissolved into a solvent having a dielectric constant of 2.0-15.0, in the presence of (A) a Lewis acid catalyst, (B) one or more promoter selected from the group consisting of an ester compound, a thioester compound, a carboxylic acid compound, a carboxylic acid anhydride compound, an ether compound, and a thioether compound, and one or more polymerization additives selected from the group consisting of (C) an alcohol compound and a mercaptan compound. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a soluble polyfunctional vinyl aromatic polymer having improved heat discoloration resistance, heat decomposability and processability, and a method for producing the same.

  Many of the monomers having a reactive active unsaturated bond can generate a multimer by selecting an appropriate reaction condition and a catalyst that causes a chain reaction by cleavage of the unsaturated bond. In general, the types of monomers having an unsaturated bond are extremely diverse, so the variety of types of resins obtained is also remarkable. However, there are relatively few types of monomers that can obtain a high molecular weight compound having a molecular weight of 10,000 or more, generally called a high molecular compound. For example, ethylene, substituted ethylene, propylene, substituted propylene, styrene, alkyl styrene, alkoxy styrene, norbornene, various acrylic esters, butadiene, cyclopentadiene, dicyclopentadiene, isoprene, maleic anhydride, maleimide, fumaric acid ester, allyl compound And the like as typical monomers. A wide variety of resins have been synthesized by using these monomers alone or copolymerizing them.

  The applications of these resins are mainly limited to the field of relatively inexpensive consumer equipment, and there is almost no application in advanced technology fields such as those related to electronic substrates. The reason is that heat resistance, heat decomposition resistance, solvent solubility or processability cannot be achieved at the same time.

  As a method for solving the disadvantages of such a vinyl polymer, a resin such as strength is obtained by adding a very small amount of an aromatic polyfunctional vinyl compound such as an aromatic divinyl compound and an aromatic trivinyl compound to the vinyl monomer. Improvements in properties have been made. For example, in JP-A-2-170806, an aromatic polyfunctional vinyl compound and a styrene monomer are copolymerized with heat or an initiator to obtain a styrene polymer having a wide molecular weight distribution. It is disclosed that the coalescence exhibits high impact strength. However, if the polymerization conversion rate is increased according to the technique disclosed herein, the cross-linking reaction with the aromatic polyfunctional vinyl compound occurs rapidly. Therefore, when there is a large amount of aromatic polyfunctional vinyl compound, the gelation of the resin occurs. , Workability and appearance are significantly impaired. Therefore, the conventional modification of the resin with the aromatic polyfunctional vinyl compound can suppress the addition amount of the aromatic polyfunctional vinyl compound as low as 50 to 250 ppm. Therefore, the modification with the aromatic polyfunctional vinyl compound is performed. There was a drawback that the effect was not sufficient for application in advanced technology fields.

  Further, JP 2000-128908 A discloses a styrene polymer having a controlled degree of branching using a polyfunctional chain transfer agent in combination with an aromatic polyfunctional vinyl polymer and a method for producing the same. The amount of polyfunctional vinyl polymer added to the styrene monomer was only 1 to 700 ppm. In addition, polymers obtained by blending and polymerizing a large amount of aromatic polyfunctional vinyl compounds usually have a highly crosslinked structure and often become insoluble / infusible gel-like polymers with no workability. .

  On the other hand, multi-branched polymers consisting of highly branched (branched) polymer chains are less entangled with molecular chains, have a lower viscosity than linear polymers of the same molecular weight, and introduce many reactive groups into the branches. It has been attracting attention as a highly functional material. JP-T-2001-512752 discloses a monofunctional vinyl monomer: 50 to 99.9 parts by weight and an aromatic polyfunctional vinyl compound 0.1 to 50 parts by weight in the presence of a radical polymerization initiator at 250 to 400 ° C. Discloses a method for producing a multi-branched polymer. However, when looking at the results disclosed in this example, since a crosslinking reaction is likely to occur during the polymerization, the molecular weight of the polymer obtained when the added amount of the aromatic polyfunctional vinyl compound is 6 to 25% is used. The distribution value is an extremely large value of 60 or more. Therefore, since the technique disclosed herein cannot increase the amount of polyfunctional vinyl compound added, the modification effect of the aromatic polyfunctional vinyl compound is not sufficient for application in the advanced technology field. I can't say that.

  Further, US Pat. No. 5,767,211 discloses a production method for synthesizing a multi-branched polymer having no crosslinked structure by polymerizing a bi- and trifunctional vinyl compound in the presence of an azo radical polymerization initiator and a cobalt chain transfer catalyst. Has been. However, in this polymerization method, since a chain transfer catalyst that promotes β-hydrogen elimination is used to generate a branched structure, a structure having a double bond in the vicinity of the branched structure in the generated polymer. Will have. For this reason, even if a thermosetting operation is performed to increase the heat resistance of the produced polymer, the effect of improving the heat resistance is small because the reactivity of the polymer is low, and it is not suitable for application in the advanced technology field. There were drawbacks. Furthermore, in this production method, since the chain transfer reaction relies exclusively on the chain transfer ability of the cobalt chain transfer catalyst, it is necessary to add a large amount of the chain transfer catalyst to the polymerization system, which significantly slows down the polymerization rate. Furthermore, there have been problems in practical use such as difficulty in removing the catalyst when recovering the polymer.

  Makromol.Chem., 1978, 179, 2069-2073, a solvent-soluble divinylbenzene polymer can be obtained by anionic polymerization of divinylbenzene using di-iso-propylamine and butyllithium as catalysts. Is disclosed. However, since the divinylbenzene polymer disclosed therein does not have an indane structure in the main chain skeleton, the heat resistance is not sufficient, and the characteristics are not sufficient as a material used in the advanced technology field. There were drawbacks. Also, the polymerization method is industrially carried out such that the selectivity of the vinyl group at the time of polymerization is not sufficient so that gelation is likely to occur, the monomer concentration cannot be increased, and the polymerization temperature cannot be raised above 0 ° C. It was a problematic way to do. Further, Makromol. Chem., 1988, 189, 723-731, a solvent-soluble divinylbenzene-styrene copolymer is obtained by anionic polymerization of divinylbenzene and styrene using lithium di-iso-propylamide as a catalyst. It is disclosed that it can be obtained. However, since this copolymer does not have an indane structure in its main chain skeleton, it has a drawback that its heat resistance is not sufficient, and the properties are not sufficient as a material used in the advanced technology field. In addition, this polymerization method is also susceptible to gelation because the selectivity of the vinyl group during polymerization is not sufficient, and it is necessary to perform polymerization at a low monomer concentration and at a polymerization temperature as low as 0 ° C. or less. It was a problematic way to do.

  Macromolecules, 1980, 13, pp. 1350-1354 and Macromolecules, 1982, 15, pp. 1212-1225 are solvent-soluble divinylbenzene polymers by cationic polymerization of divinylbenzene using acetyl perchlorate as a catalyst. Is disclosed. However, this divinylbenzene polymer does not contain an indane structure in the main chain skeleton, and is a polymer consisting only of the structure represented by the formula (a2). As a material used for the above, there is a drawback that the characteristics are not sufficient.

  As a method for solving the problems of the existing technology, JP 2004-123873 A discloses divinyl aromatic compound (a) and monovinyl aromatic compound (b) in an organic solvent, Lewis acid catalyst, and initiation of a specific structure. A soluble polyfunctional vinyl aromatic copolymer obtained by polymerizing at a temperature of 20 to 100 ° C. in the presence of an agent is disclosed. Japanese Patent Application Laid-Open No. 2005-213443 discloses a single amount containing 20 to 100 mol% of a divinyl aromatic compound (a) in the presence of a quaternary ammonium salt with a Lewis acid catalyst and an initiator having a specific structure. A method for producing a soluble polyfunctional vinyl aromatic copolymer having a controlled molecular weight distribution, characterized in that a body component is cationically polymerized at a temperature of 20 to 120 ° C. The soluble polyfunctional vinyl aromatic copolymer easily obtained by the techniques disclosed in these two patents is excellent in solvent solubility and processability, and by using this, a cured product excellent in heat resistance and heat decomposition resistance. Can be obtained. However, although the soluble polyfunctional vinyl aromatic copolymer obtained by these techniques is a polymer excellent in heat resistance in terms of giving a cured product having a high glass transition temperature, it is resistant to heat discoloration and outgassing. In terms of generation of heat, the thermal decomposition resistance to high process temperatures corresponding to recent lead-free solders is not sufficient, and there are cases where defects such as blistering and discoloration occur due to a high thermal history near 300 ° C.

  Therefore, it solves the above-mentioned various problems of the prior art, has excellent thermal decomposition resistance against a high heat history, has a pendant vinyl group with excellent curability, and is controlled to have excellent processability. Until now, there has been no production method for producing a polyfunctional vinyl aromatic polymer having both molecular weight distribution and solvent solubility with high efficiency.

JP-A-2-170806 JP 2000-128908 A JP-T-2001-512752 US Patent No. 5,767,211 JP 2004-123873 A Japanese Patent Laying-Open No. 2005-213443 Makromol. Chem., 1978, 179, 2069-2073 Makromol.Chem., 1988, 189, 723-731 Macromolecules, 1980, Volume 13, pages 1350-1354 Macromolecules, 1982, Volume 15, pp. 1221-1225

  The present invention has an excellent thermal decomposition resistance against a high heat history, has a pendant vinyl group with excellent curability, and has a controlled molecular weight distribution with excellent processability and solvent solubility. An object of the present invention is to provide a vinyl aromatic copolymer and a production method for producing the copolymer with high efficiency.

（式中、Ｒ¹は炭素数６〜３０の芳香族炭化水素基を示し、Ｒ²は炭素数６〜３０の芳香族炭化水素基を示す。）で表されるジビニル芳香族化合物（ａ）由来のビニル基を含有する構造単位のモル分率が次式、
（ａ１）／［（ａ１）＋（ａ２）］≧０．５
を満足し、更に、可溶性多官能ビニル芳香族重合体の数平均分子量Ｍｎが３００〜１０００００であり、重量平均分子量Ｍｗと数平均分子量Ｍｎの比で表される分子量分布（Ｍｗ／Ｍｎ）が１０．０以下であり、トルエン、キシレン、テトラヒドロフラン、ジクロロエタン又はクロロホルムに可溶である可溶性多官能ビニル芳香族共重合体である。 The present invention is a copolymer obtained by copolymerizing a divinyl aromatic compound (a) and a monovinyl aromatic compound (b), and a chain-like structure having an ether bond or a thioether bond in part of its end group It has a hydrocarbon group or an aromatic hydrocarbon group, and has the following formulas (a1) and (a2)

(Wherein R ¹ represents an aromatic hydrocarbon group having 6 to 30 carbon atoms, and R ² represents an aromatic hydrocarbon group having 6 to 30 carbon atoms) (a) The molar fraction of structural units containing a vinyl group derived from
(A1) / [(a1) + (a2)] ≧ 0.5
Furthermore, the number average molecular weight Mn of the soluble polyfunctional vinyl aromatic polymer is 300 to 100,000, and the molecular weight distribution (Mw / Mn) represented by the ratio of the weight average molecular weight Mw to the number average molecular weight Mn is 10 It is a soluble polyfunctional vinyl aromatic copolymer that is not more than 0.0 and is soluble in toluene, xylene, tetrahydrofuran, dichloroethane, or chloroform.

（式中、Ｒ³は炭素数１〜３０の鎖状炭化水素基又は芳香族炭化水素基を示す。Ｙは酸素若しくはイオウを示す。）で表される構造の末端基のモル分率が次式を満足すること、
（ｂ１）／［（ｂ１）＋（ｂ２）］≧０．５
2） 可溶性多官能ビニル芳香族重合体の末端へのエーテル結合及びチオエーテル結合のいずれかを介した鎖状炭化水素基又は芳香族炭化水素基の導入量（ｃ１）が次式を満足すること。
（ｃ１）≧１．５（個／分子） Here, it is desirable that the soluble polyfunctional vinyl aromatic polymer satisfies one or more of the following requirements.
1) Among the end groups of the soluble polyfunctional vinyl aromatic polymer, the following formulas (b1) and (b2)

(Wherein R ³ represents a chain hydrocarbon group having 1 to 30 carbon atoms or an aromatic hydrocarbon group; Y represents oxygen or sulfur). Satisfying the formula,
(B1) / [(b1) + (b2)] ≧ 0.5
2) The introduction amount (c1) of the chain hydrocarbon group or aromatic hydrocarbon group through either an ether bond or a thioether bond to the terminal of the soluble polyfunctional vinyl aromatic polymer satisfies the following formula.
(C1) ≧ 1.5 (pieces / molecule)

  The present invention also includes (A) a Lewis acid catalyst, (B) one or more promoters selected from the group consisting of ester compounds, thioester compounds, carboxylic acid compounds, carboxylic acid anhydride compounds, ether compounds and thioether compounds, and (C) 20-99 mol% of divinyl aromatic compound (a) and 80-1 of monovinyl aromatic compound (b) in the presence of one or more polymerization additives selected from the group consisting of alcohol compounds and mercaptan compounds. The above-mentioned soluble polyfunctional vinyl aromatic copolymer is polymerized at a temperature of 20 to 120 ° C. in a homogeneous solution in which a monomer component containing mol% is dissolved in a solvent having a dielectric constant of 2.0 to 15.0. It is a manufacturing method of coalescence.

Here, in the method for producing the soluble polyfunctional vinyl aromatic polymer, it is desirable to satisfy any one or more of the following requirements.
1) the Lewis acid catalyst is a metal fluoride or a complex thereof,
2) The (B) component promoter is one or more compounds selected from the group consisting of ester compounds, thioester compounds, carboxylic acid compounds and carboxylic anhydride compounds,
3) With respect to 1 mol of the polymerization additive of the component (C), the Lewis acid catalyst of the component (A) is used in the range of 0.001 to 10 mol, and the promoter of the component (B) is used in the range of 0.001 to 10 mol. thing

  Hereinafter, the soluble polyfunctional vinyl aromatic copolymer of the present invention and the production method thereof will be described in detail.

  The soluble polyfunctional vinyl aromatic copolymer of the present invention is a copolymer obtained by copolymerizing a divinyl aromatic compound (a) and a monovinyl aromatic compound (b), which is toluene, xylene, tetrahydrofuran, dichloroethane. Alternatively, it is a soluble polyfunctional vinyl aromatic copolymer that is soluble in chloroform.

  The number average molecular weight Mn (in terms of standard polystyrene obtained using gel permeation chromatography) of this soluble polyfunctional vinyl aromatic polymer is preferably 300 to 100,000, more preferably 400 to 50,000, and still more preferably. 500-20000. If Mn is less than 300, the viscosity of the soluble polyfunctional vinyl aromatic polymer is too low, so that it is difficult to form a thick film and the workability is lowered, which is not preferable. Further, if Mn is 100,000 or more, gel is likely to be formed, and when formed into a film or the like, the appearance is deteriorated, which is not preferable. The value of molecular weight distribution (Mw / Mn) obtained from Mn and weight average molecular weight Mw is 10.0 or less, preferably 5.0 or less. When Mw / Mn exceeds 10.0, problems such as deterioration of processing characteristics of the soluble polyfunctional vinyl aromatic polymer and generation of gel occur.

  Furthermore, the polyfunctional vinyl aromatic copolymer of the present invention has a molar fraction (a1) / [((2) containing a vinyl group derived from the divinyl aromatic compound represented by the above formulas (a1) and (a2). a1) + (a2)] needs to satisfy ≧ 0.5. The molar fraction is preferably 0.7 or more, particularly preferably 0.9 or more. When the molar fraction is 0.5 or more, it is possible to obtain a molded article that is rich in thermosetting and excellent in heat resistance and mechanical properties after curing.

The soluble polyfunctional vinyl aromatic copolymer of the present invention has a chain hydrocarbon group or an aromatic hydrocarbon group via an ether bond or a thioether bond in a part of its end group, and the above formula (a1) and The molar fraction of the structural unit containing the vinyl group derived from the divinyl aromatic compound (a) represented by (a2) satisfies the following formula. In formulas (a1) and (a2), R ¹ represents an aromatic hydrocarbon group having 6 to 30 carbon atoms, and R ² represents an aromatic hydrocarbon group having 6 to 30 carbon atoms.
(A1) / [(a1) + (a2)] ≧ 0.5

  The soluble polyfunctional vinyl aromatic copolymer of the present invention preferably contains 25 to 95 mol%, more preferably 30 to 90 mol% of a structural unit derived from the divinyl aromatic compound (a). If the structural unit derived from the divinyl aromatic compound (a) is less than 20 mol%, the heat resistance of the cured product is insufficient, and if it exceeds 99 mol%, the moldability is lowered.

The soluble polyfunctional vinyl aromatic copolymer of the present invention contains a chain hydrocarbon group or an aromatic hydrocarbon group via an ether bond or a thioether bond, and these are represented by the above formulas (b1) and (b2). It is preferable to be included as a copolymer molecule having a terminal group. In formulas (b1) and (b2), R ³ represents a chain hydrocarbon group having 1 to 30 carbon atoms or an aromatic hydrocarbon group, and Y represents oxygen or sulfur. Polymer represents a main chain (including a branched chain) obtained by removing a terminal group portion from a copolymer molecule. The soluble polyfunctional vinyl aromatic copolymer of the present invention may contain copolymer molecules other than those represented by the formulas (b1) and (b2).

  And it is preferable that the molar fraction (b1) / [(b1) + (b2)] of the terminal group of the said structure is 0.5 or more, More preferably, it is 0.7 or more. If the molar fraction is less than 0.5, the heat discoloration of the copolymer of the present invention is lowered.

  When the soluble polyfunctional vinyl aromatic copolymer of the present invention has a chain hydrocarbon group or aromatic hydrocarbon group as an end group via an ether bond or a thioether bond to the terminal of the polymer, the amount introduced ( It is preferable that c1) satisfies 1.5 (pieces / molecule) or more. More preferably, it is 2.0 (pieces / molecule) or more. If it is less than 1.5 (pieces / molecule), the solution viscosity increases and the molding processability decreases.

For example, the case where the terminal group via an ether bond or a thioether bond is a benzyl group will be described by the chemical formula as follows.
When the polymer is a linear polymer, since there are two ends (start end and stop end) as shown in formula (I), for example, only one end group having an ether bond is contained. However, when one branch is formed, as shown in the formula (II), there are four ends (two start ends and two stop ends), and therefore, for example, two end groups having an ether bond are included. Thus, as the number of branches increases, the number of terminals increases, so that two or more terminal groups via an ether bond or thioether bond also enter one molecule, and the number increases as the number of branches increases. Therefore, (c1) being 1.5 (pieces / molecule) or more also means that there is a branch.

  End group calculation via an ether bond or a thioether bond is performed by the following method. The copolymer composition of the divinyl aromatic compound (a) and the monovinyl aromatic compound (b) is determined by NMR, and the average molecular weight of the repeating unit is calculated. The apparent average degree of polymerization is calculated by dividing the number average molecular weight in terms of standard polystyrene by the average molecular weight of this repeating unit. On the other hand, the number of ether groups and hydroxyl groups per repeating unit is calculated from the results of elemental analysis and NMR analysis. From the apparent average degree of polymerization and the number of moles of ether groups and hydroxyl groups, the number of terminal groups via an apparent ether bond or thioether bond per molecule in the copolymer is calculated.

  As for the method for introducing the terminal group via an ether bond or a thioether bond, it is considered that the terminal group exists at the end of the polymer by the reaction mechanism shown in the formula (III). For example, taking benzyl alcohol as an example, the carbon cation at the end of the growing polymer chain undergoes a chain transfer reaction with benzyl alcohol to form a benzyl ether bond. If methanol is used instead of benzyl alcohol, it becomes methyl ether. As will be described in the description of the production method, it is possible to introduce a terminal group via ether (or thioter) into the polymer terminal by the polymerization additive of component (C).

  As described above, the soluble polyfunctional vinyl aromatic copolymer of the present invention has a terminal hydrocarbon group or aromatic hydrocarbon group via an ether bond or a thioether bond as a part of the terminal group. Contained as. By introducing such end groups, the heat discoloration resistance and heat decomposition resistance of the copolymer are greatly improved. Specific examples of such terminal groups are not particularly limited, and a chain hydrocarbon group having 1 to 30 carbon atoms via an ether bond such as a methyl ether group, an ethyl ether group, a propyl ether group, a butyl ether group and a benzyl ether group, and Aromatic hydrocarbon groups, chain hydrocarbon groups having 1 to 30 carbon atoms and aromatic hydrocarbons via thioether bonds such as methylthioether group, ethylthioether group, propylthioether group, butylthioether group and benzylthioether group The group can be mentioned.

（式中、芳香族環にはビニル基、その他の脂肪族炭化水素基、及び、その他の芳香族炭化水素基等の置換基、縮合した芳香族環、縮合した置換芳香族環を有していてもよい）で表されるインダン構造を有することが好ましい。インダン構造単位の含有量は０〜２０モル％の範囲であることがよい。 In the polyfunctional vinyl aromatic polymer of the present invention, the following general formula (2) is contained in the main chain skeleton.

(In the formula, the aromatic ring has a substituent such as a vinyl group, other aliphatic hydrocarbon groups, and other aromatic hydrocarbon groups, a condensed aromatic ring, and a condensed substituted aromatic ring. It may preferably have an indane structure represented by: The content of the indane structural unit is preferably in the range of 0 to 20 mol%.

  The indane structure represented by the general formula (2) is a structural unit that further enhances the heat resistance and the solubility in a solvent of the copolymer of the present invention. The indane structure is formed by attacking the aromatic ring of the structural unit derived from the divinyl aromatic compound and the monovinyl aromatic compound at the active site of the growing polymer chain end, and the polyfunctional vinyl aromatic is produced by the production method of the present invention. When the polymer is produced, the production of this structure is promoted by carrying out the production in the presence of one or more polymerization additives selected from the group consisting of the alcohol compounds and mercaptan compounds described in the present invention. The properties of the copolymer are improved. The indane structure is preferably present in an amount of 0.01 mol% or more based on the structural units of all monomers. More preferably, it is 0.02 mol% or more, More preferably, it is 0.1 mol% or more. If the indane structure is not present in the main chain skeleton of the polyfunctional vinyl aromatic copolymer of the present invention, heat resistance and solubility in a solvent are insufficient.

  The soluble polyfunctional vinyl aromatic copolymer of the present invention can be obtained by copolymerizing 20 to 99 mol% of a divinyl aromatic compound (a) and 1 to 80 mol% of a monovinyl aromatic compound (b). In this case, another monomer (c) can be used if necessary.

  The divinyl aromatic compound as component (a) is preferably used in an amount of 20 to 98 mol%, more preferably 25 to 95 mol%, still more preferably 30 to 85 mol%, based on all monomers. When the amount of the divinyl aromatic compound (a) used is less than 15 mol%, the resulting soluble polyfunctional vinyl aromatic copolymer tends to be lowered when it is cured, such being undesirable.

  The monovinyl aromatic compound as the component (b) is preferably 2 to 80 mol%, more preferably 5 to 75 mol%, still more preferably 15 to 70 mol%, most preferably 30 with respect to all monomers. ˜60 mol% is used. When the amount of the ethyl vinyl aromatic compound (b) used is large, the heat resistance tends to decrease when the soluble polyfunctional vinyl aromatic copolymer is cured.

  Moreover, when using the other monomer as (c) component, it is 0-80 mol% with respect to the sum total of a monomer, Preferably it is 0-50 mol%, More preferably, it is 0-30 mol%, Most preferably 3 to 30 mol% is used. When the amount used is large, the heat resistance tends to decrease when the produced soluble polyfunctional vinyl aromatic copolymer is cured.

  When the soluble polyfunctional vinyl aromatic copolymer of the present invention exhibits heat resistance by thermosetting, the divinyl aromatic compound (a) as a component that gives a structural unit that plays a major role as a crosslinking component, For example, m-divinylbenzene, p-divinylbenzene, 1,2-diisopropenylbenzene, 1,3-diisopropenylbenzene, 1,4-diisopropenylbenzene, 1,3-divinylnaphthalene, 1,8- Divinylnaphthalene, 1,4-divinylnaphthalene, 1,5-divinylnaphthalene, 2,3-divinylnaphthalene, 2,7-divinylnaphthalene, 2,6-divinylnaphthalene, 4,4′-divinylbiphenyl, 4,3 ′ -Divinylbiphenyl, 4,2'-divinylbiphenyl, 3,2'-divinylbiphenyl, 3,3'-divinylbiphenyl Enyl, 2,2′-divinylbiphenyl, 2,4-divinylbiphenyl, 1,2-divinyl-3,4-dimethylbenzene, 1,3-divinyl-4,5,8-tributylnaphthalene, 2,2′- Divinyl-4-ethyl-4′-propylbiphenyl and the like can be used, but are not limited thereto. These can be used alone or in combination of two or more.

  Here, preferred specific examples of the component (a) include divinylbenzene (both m- and p-isomers) and divinylbiphenyl (including each isomer) in terms of cost and heat resistance of the obtained polymer. And divinylnaphthalene (including each isomer). More preferred are divinylbenzene (both m- and p-isomers) and divinylbiphenyl (including each isomer). In particular, divinylbenzene (both m- and p-isomers) is most preferably used from the viewpoints of cost and availability. Particularly in fields where high heat resistance is required, divinylbiphenyl (including each isomer) and divinylnaphthalene (including each isomer) are preferably used.

  The component (b) that improves the solvent solubility and processability of the soluble polyfunctional vinyl aromatic copolymer of the present invention is a monovinyl aromatic compound. Examples of monovinyl aromatic compounds include styrene, nuclear alkyl-substituted monovinyl aromatic compounds such as methylstyrene and ethylstyrene, α-alkyl-substituted monovinyl aromatic compounds such as α-methylstyrene, β-alkyl-substituted styrene, alkoxy-substituted styrene, and indene. Examples thereof include, but are not limited to, derivatives and acenaphthylene derivatives. Also, o-ethylvinylbenzene, m-ethylvinylbenzene, p-ethylvinylbenzene, 3-vinyl-3′-ethylbiphenyl, 3-vinyl-4′-ethylbiphenyl, 4-vinyl-4′-ethylbiphenyl 2 -Vinyl-6-ethylnaphthalene, 2-vinyl-7-ethylnaphthalene and the like can be used, but are not limited thereto. By introducing structural units derived from these components into the polyfunctional vinyl aromatic polymer, not only can the gelation of the polymer be prevented and the solubility in the solvent can be increased, but also the polyfunctional vinyl aromatic Processability at the time of application of the group polymer can be improved. Preferred examples include styrene, ethyl vinyl benzene (both m- and p-isomers) and ethyl vinyl biphenyl (including each isomer) in terms of cost, prevention of gelation and moldability of the resulting polymer. And the like.

  Further, in the method for producing the soluble polyfunctional vinyl aromatic copolymer of the present invention, other methods such as a trivinyl aromatic compound, a trivinyl aliphatic compound, a divinyl aliphatic compound, and a monovinyl aliphatic compound are provided as long as the effects of the present invention are not impaired. The monomer component (c) can be used. Specific examples of the trivinyl aromatic compound include, for example, 1,2,4-trivinylbenzene, 1,3,5-trivinylbenzene, 1,2,4-triisopropenylbenzene, 1,3,5-triiso Examples include propenylbenzene, 1,3,5-trivinylnaphthalene, 3,5,4′-trivinylbiphenyl, and the like. Specific examples of the trivinyl aliphatic compound include 1,2,4-trivinylcyclohexane. Specific examples of the divinyl aliphatic compound include diallyl ether compounds such as ethylene glycol bisallyl ether, and diene compounds such as butadiene and isoprene. Examples of the monovinyl aliphatic compound include olefin compounds such as isobutene and diisobutylene, but are not limited thereto.

  The monomers (a) to (c) can be used alone or in combination of two or more.

  In the method for producing a soluble polyfunctional aromatic vinyl copolymer of the present invention, (A) Lewis acid catalyst, (B) ester compound, thioester compound, carboxylic acid compound, carboxylic anhydride compound, ether compound And one or more compounds selected from the group consisting of thioether compounds and (C) one or more polymerization additives selected from the group consisting of alcohol compounds and mercaptan compounds are subjected to cationic copolymerization.

  The Lewis acid catalyst of the component (A) used in the present invention is a compound composed of a metal ion (acid) and a ligand (base), and has the ability to accept an electron pair. There is no particular limitation, and it can be used. Among the Lewis acid catalysts, metal fluorides and complexes thereof are preferred from the viewpoints of the heat decomposability and heat discoloration of the copolymer of the present invention. Examples of the metal fluoride include fluorides of divalent to hexavalent metals such as B, Al, Ga, In, Ta, Si, Ge, Sn, Pb, Sb, Bi, Ti, W, Zn, Fe, and V. It is done. Specific examples include aluminum fluoride (III), indium fluoride (III), thallium fluoride (III), silicon fluoride (IV), tin fluoride (IV), lead fluoride (IV), fluoride Mention may be made of metal fluorides such as antimony (V), bismuth fluoride (III), boron fluoride (III) and their complexes. Said catalyst is not specifically limited, It can use individually or in combination of 2 or more types. Of the above-mentioned catalysts, boron (III) fluoride and its complex are preferable in view of thermal decomposition resistance and polymerization activity of the polymer. Specifically, water complexes of boron trifluoride, alcohols (methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, etc.) ) Complexes, ether (diethyl ether, dimethyl ether, etc.) complexes, phenol complexes, acetic acid complexes, and the like. Among these, boron trifluoride ether (diethyl ether, dimethyl ether, etc.) complexes are most preferably used in terms of availability and ease of polymerization control.

  As the co-catalyst as component (B), 1) ester compounds such as ethyl acetate and methyl propionate, 2) thioester compounds such as methyl mercaptopropionic acid and ethyl mercaptopropionic acid, 3) acetic acid, propionic acid and butyric acid 4) Carboxylic anhydride compounds such as acetic anhydride and succinic anhydride, 5) Ether compounds such as diethyl ether and tetrahydrolane, and 6) Thioether compounds such as diethyl sulfide and diphenyl sulfide. One or more promoters selected from the group consisting of: Among these, ester compounds and carboxylic acid anhydride compounds are preferably used because they can synergize with the Lewis acid catalyst of component (A) to easily control the polymerization rate and the molecular weight distribution of the polymer. .

  Component (C), a polymerization additive, undergoes a chain transfer reaction with a polymerization active species during the polymerization reaction, and is excellent in thermal stability and heat discoloration at the end group, which is a feature of the copolymer of the present invention. Is a compound that plays a role of forming a chain hydrocarbon group or an aromatic hydrocarbon group via an ether bond or a thioether bond, specifically, having 1 to 1 carbon atoms having an alcoholic hydroxyl group or a thioalcohol mercapto group One or more compounds selected from the group consisting of 30 chain hydrocarbon compounds and aromatic hydrocarbon compounds may be mentioned.

  Specific examples of the polymerization additive as component (C) include C1-C30 chain hydrocarbons having alcoholic hydroxyl groups such as methanol, ethanol, n-butanol, sec-butanol, n-decanol, and benzyl alcohol. Examples thereof include C 1-30 chain hydrocarbon compounds and aromatic hydrocarbon compounds having a thioalcoholic mercapto group such as compounds, aromatic hydrocarbon compounds, methyl mercaptan, ethyl mercaptan, butyl mercaptan, and benzyl mercaptan. Among these, methanol, ethanol, iso-propanol, n-butanol, sec-butanol, n-decanol, benzyl alcohol, butyl mercaptan and benzyl mercaptan are particularly preferable in terms of reactivity and availability. And as for these (A)-(C) components, all can use 1 or more types.

  The amount of the Lewis acid catalyst used as the component (A) is 0.0001 to 10 times the mole of the total of the divinyl aromatic compound (a), the monovinyl aromatic compound (b) and the other monomer component (c). However, the preferred use amount is in the range of 0.0005 to 5 times mol. Especially preferably, it is 0.001-0.5 times mole. When the amount of the Lewis acid catalyst used is less than 0.0001 times the moles of all monomers, the polymerization rate is significantly reduced, and when it is 10 times the moles or more, the polymerization rate becomes too high, and the polymerization reaction is controlled. It becomes difficult.

  Moreover, although the usage-amount of the co-catalyst of (B) component is normally used in the range of 0.001-20 times mole with respect to a Lewis' acid catalyst, a preferable usage-amount is the range of 0.003-10 times mole. Most preferably, it is 0.01-5 times mole. When the amount of the cocatalyst used is less than 0.001 times mol of the Lewis acid catalyst, it becomes difficult to control the molecular weight distribution, and when it exceeds 20 times mol, the polymerization rate is greatly reduced.

  (C) Although the usage-amount of the polymerization additive of a component is used in the range of 0.01-100 times mole with respect to a Lewis' acid catalyst, a preferable usage-amount is the range of 0.1-50 times mole. Especially preferably, it is 0.5-10 times mole. When the amount of the component (C) used is less than 0.01 times mol, it becomes difficult to control the molecular weight distribution, and when it exceeds 100 times mol, the polymerization rate is greatly reduced. The amount of component (C) used relative to component (B) is suitably about 0.05 to 20 moles.

  In addition, the polymerization reaction is performed in one or more organic solvents having a dielectric constant of 2 to 15 for dissolving the soluble polyfunctional vinyl aromatic copolymer to be formed. The organic solvent is a compound that does not essentially inhibit cationic polymerization, and dissolves the Lewis acid catalyst, promoter, initiator, monomer, and polyfunctional vinyl aromatic copolymer of the present invention to form a homogeneous solution. It is formed and used as a polymerization solvent alone or in combination of two or more so that the dielectric constant is in the range of 2-15.

  Compounds that can be used as the organic solvent include aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, propylbenzene, and butylbenzene; direct compounds such as ethane, propane, butane, pentane, hexane, heptane, octane, nonane, and decane. Chain aliphatic hydrocarbons; branched aliphatic hydrocarbons such as 2-methylpropane, 2-methylbutane, 2,3,3-trimethylpentane, 2,2,5-trimethylhexane; cyclohexane, methylcyclohexane, ethyl Examples include cycloaliphatic hydrocarbons such as cyclohexane; paraffin oil obtained by hydrorefining a petroleum fraction. Among these, toluene, xylene, pentane, hexane, heptane, octane, 2-methylpropane, 2-methylbutane, cyclohexane, methylcyclohexane and ethylcyclohexane are preferable. Toluene, xylene, n-hexane, cyclohexane, methylcyclohexane, and ethylcyclohexane are more preferable from the viewpoints of the balance between polymerizability and solubility and availability.

  These compounds are used alone or in combination of two or more in consideration of the dielectric constant being 2 to 15. In consideration of the viscosity of the resulting polymer solution and the ease of heat removal, the amount of the solvent used is usually such that the concentration of the polymer is 1 to 50 wt%, preferably 5 to 35 wt% after completion of the polymerization. It is determined. If the dielectric constant is less than 2, the polymerization solution tends to be non-uniform, resulting in low polymerization activity and a wide molecular weight distribution, which is not preferable. If the dielectric constant exceeds 15, gelation tends to occur during polymerization. Therefore, it is not preferable.

  In this polymerization, it is preferable that the volume A of the monomer component containing the aromatic divinyl compound and the volume B of the organic solvent satisfy 0.1 ≦ A / (A + B) ≦ 0.95. When the volume fraction of the monomer component is less than 0.1, the production efficiency of the copolymer is lowered, which causes an increase in cost in terms of industrial implementation, which is not preferable. On the other hand, if it exceeds 0.95, gelation tends to occur during production, which is not preferable.

  In the production method of the present invention, the polymerization is carried out in a temperature range of 20 to 120 ° C. When the polymerization reaction is carried out at a temperature lower than 20 ° C., the heat resistance of the produced copolymer is lowered, which is not preferable. When the temperature exceeds 120 ° C., the selectivity of the reaction is lowered, so that the reaction is difficult to control and insoluble due to crosslinking. This is not preferable because the formation of a gel easily occurs.

  The method for recovering the copolymer after the termination of the polymerization reaction is not particularly limited. For example, a commonly used method such as a steam stripping method or precipitation with a poor solvent may be used.

  Furthermore, the metal ion content of the soluble polyfunctional vinyl aromatic polymer obtained by the production method of the present invention is preferably 100 ppm or less for each metal ion. More preferably, it is 50.0 ppm or less. Most preferably, it is 10.0 ppm or less. If the metal ion content is 100 ppm or more, the electrical characteristics of the polymer deteriorate, which is not preferable.

  The soluble polyfunctional vinyl aromatic copolymer of the present invention or the soluble polyfunctional vinyl aromatic copolymer obtained by the production method of the present invention can be processed into a molding material, sheet or film, and has a low dielectric constant, low Semiconductor-related materials or optical materials that can satisfy characteristics such as water absorption and high heat resistance, as well as paints, photosensitive materials, adhesives, sewage treatment agents, heavy metal scavengers, ion exchange resins, antistatic agents, oxidation Can be applied to anti-fogging agents, anti-fogging agents, anti-corrosive agents, anti-dyeing agents, bactericides, insect repellents, medical materials, flocculants, surfactants, lubricants, binders for solid fuels, conductive treatment agents, etc. . Furthermore, examples of the optical component include a CD pickup lens, a DVD pickup lens, a Fax lens, an LBP lens, an oligon mirror, and a prism.

  According to the present invention, a soluble polyfunctional vinyl aromatic copolymer having improved heat discoloration resistance, heat decomposability and processability can be produced with high efficiency.

  EXAMPLES Next, the present invention will be described with reference to examples, but the present invention is not limited thereto. In addition, all the parts in each example are parts by weight. Moreover, the measurement of the softening temperature etc. in an Example performed sample preparation and a measurement with the method shown below.

1) Molecular weight and molecular weight distribution of polymer GPC (manufactured by Tosoh Corporation, HLC-8120GPC) was used for measuring the molecular weight and molecular weight distribution of the soluble polyfunctional vinyl aromatic copolymer, solvent: tetrahydrofuran (THF), flow rate: 1.0 ml / min, column temperature: 40 ° C. The molecular weight of the copolymer was measured as a molecular weight in terms of polystyrene using a calibration curve with monodisperse polystyrene.

2) Polymer structure Determined by ¹³ C-NMR and ¹ H-NMR analysis using a JNM-LA600 nuclear magnetic resonance spectrometer manufactured by JEOL. Using chloroform -d ₁ as a solvent, was used resonance line of tetramethylsilane as an internal standard.

3) Sample preparation and measurement of glass transition temperature (Tg) and softening temperature measurement A soluble polyfunctional vinyl aromatic copolymer solution was uniformly applied to a glass substrate so that the thickness after drying was 20 μm, and then hot The plate was heated at 90 ° C. for 30 minutes and dried. The obtained resin film on the glass substrate is set in a TMA (thermomechanical analyzer) measuring device together with the glass substrate, heated to 220 ° C. at a temperature rising rate of 10 ° C./min under a nitrogen stream, and further 220 ° C. The remaining solvent was removed by heat treatment for 20 minutes. After allowing the glass substrate to cool to room temperature, the measurement probe is brought into contact with the sample in the TMA measuring apparatus, and measurement is performed by scanning from 30 ° C. to 360 ° C. at a temperature rising rate of 10 ° C./min under a nitrogen stream. The softening temperature was determined by the tangential method. If the probe does not penetrate the resin film due to the heat resistance of the sample and does not show a probe penetration depth smaller than the film thickness, in addition to the softening temperature, the penetration rate for the probe penetration temperature and film thickness is expressed as a percentage. displayed.

4) Measurement of thermal decomposition temperature and carbonization yield Measurement of thermal decomposition temperature and heat discoloration resistance of soluble polyfunctional vinyl aromatic copolymer was performed by placing the sample on a TGA (thermobalance) measuring device and raising the temperature in a nitrogen stream. Measurement is performed by scanning from 30 ° C. to 320 ° C. at a rate of 10 ° C./min, the weight loss at 300 ° C. is obtained, and the amount of color change of the sample after measurement is visually confirmed. The heat discoloration property was evaluated by classifying none, ○: pale yellow, Δ: brown, and x: black.

  Divinylbenzene 28.5 mol (4059 ml), ethyl vinylbenzene 1.5 mol (213.7 ml), styrene 10.0 mol (1145.8 ml), benzyl alcohol 16 mol (1655.7 ml), ethyl acetate 4.80 mol (468.9 ml), 7111 ml of toluene (dielectric constant: 2.3) and 6222 ml of cyclohexane (dielectric constant: 2.02) were put into a 30 L reactor, and 6.4 mol of boron trifluoride was added at 30 ° C. Diethyl ether complex was added and allowed to react for 5 hours. The polymerization reaction was stopped with 2845 g of calcium hydroxide, followed by filtration and washing with 5 L of distilled water three times. After 8.0 g of butylhydroxytoluene was dissolved in the polymerization solution, the solution was concentrated using an evaporator at 40 ° C. for 1 hour. The reaction mixture was poured into a large amount of methanol at room temperature to precipitate a polymer. The obtained polymer was washed with methanol, filtered, dried and weighed to obtain 3356 g of copolymer A (yield: 67.8 wt%).

Mw of the obtained copolymer A was 6230, Mn was 2100, and Mw / Mn was 2.97. By performing ¹³ C-NMR and ¹ H-NMR analyses, in the copolymer A, resonance lines derived from the ether end, the indane end and the alcohol end were observed. The proportion of ether terminals in all oxygen-containing terminals calculated from the NMR measurement results was 79.4 mol%. As a result of conducting elemental analysis of the copolymer A, it was C: 90.5 wt%, H: 7.6 wt%, and O: 2.4 wt%. Introduction amount of chain hydrocarbon group or aromatic hydrocarbon group via ether bond or thioether bond to soluble polyfunctional vinyl aromatic polymer calculated from elemental analysis result and number average molecular weight in terms of standard polystyrene (c1) Was 3.4 (pieces / molecule). Further, the total structural units derived from divinylbenzene were 45.3 mol%, and the structural units derived from styrene, benzyl alcohol, and ethylvinylbenzene were included in total 54.7 mol%. Further, the indane structure contained in the copolymer A was present at 5.5 mol% with respect to the total of the structural units of all the monomers. Furthermore, the molar fraction of the structural unit represented by the general formula (a1) in the total amount of the structural units represented by the general formulas (a1) and (a2) was 1.00. As a result of TMA measurement, Tg was 289 ° C. and softening temperature was 300 ° C. or higher. As a result of TGA measurement, the weight loss at 300 ° C. was 0.3 wt%, and the heat discoloration was ◎.
Copolymer A was soluble in toluene, xylene, THF, dichloroethane, dichloromethane, and chloroform, and no gel was formed. The cast film of copolymer A was a transparent film without fogging.

Comparative Example 1
Divinylbenzene 9.98 mol (1420.8 ml), ethyl vinylbenzene 0.53 mol (74.8 ml), styrene 10.5 mol (1203.1 ml), 1-chlorobutane 4.0 mol (419.9 ml), acetic acid 15.0 mol (1465.2 ml) of ethyl and 10000 ml of toluene (dielectric constant: 2.3) are put into a 30 L reactor, and 10.0 mol of titanium tetrachloride is added at 30 ° C. and reacted for 40 minutes. It was. The polymerization reaction was stopped with 4691 g of methanol and then washed 3 times with 5 L of distilled water. After 8.0 g of butylhydroxytoluene was dissolved in the polymerization solution, the solution was concentrated using an evaporator at 40 ° C. for 1 hour. The reaction mixture was poured into a large amount of methanol at room temperature to precipitate a polymer. The obtained polymer was washed with methanol, filtered, dried and weighed to obtain 1279.1 g of copolymer B (yield: 52.0 wt%).

Mw of the obtained copolymer B was 3770, Mn was 1800, and Mw / Mn was 2.09. ^{According to 13} C-NMR and ¹ H-NMR analysis, copolymer B has a total of 27.2 mol% of structural units derived from divinylbenzene, and a total of 72.8 structural units derived from styrene and ethylvinylbenzene. It contained mol%. On the other hand, the copolymer B was found to have an indane structure. The indane structure was present in an amount of 4.8 mol% with respect to the total of all monomer structural units. Furthermore, the molar fraction of the structural unit represented by the general formula (a1) in the total amount of the structural units represented by the general formulas (a1) and (a2) was 0.99. As a result of TMA measurement, Tg was 281 ° C. and softening temperature was 300 ° C. or higher. As a result of TGA measurement, the weight loss at 300 ° C. was 12.1 wt%, and the heat discoloration resistance was x.
Copolymer B was soluble in toluene, xylene, THF, dichloroethane, dichloromethane, and chloroform, and no gel was formed. Further, the cast film of the copolymer B was a transparent film without fogging.

  Divinylbenzene 32.41 mol (4616 ml), ethyl vinylbenzene 1.35 mol (192.4 ml), styrene 11.26 mol (1290 ml), benzyl alcohol 5.4 mol (558.8 ml), ethyl acetate 3.60 mol (351.7 ml) and 15000 ml of toluene (dielectric constant: 2.3) were charged into a 30 L reactor, 1.2 mol of boron trifluoride diethyl ether complex was added at 50 ° C. for 5 hours. The reaction was allowed to proceed for 15 minutes. The polymerization reaction was stopped with 533.5 g of calcium hydroxide, filtered, and washed 3 times with 5 L of distilled water. 8.0 g of butylhydroxytoluene was dissolved in the polymerization solution, and then concentrated at 60 ° C. for 1 hour using an evaporator. The reaction mixture was poured into a large amount of methanol at room temperature to precipitate a polymer. The obtained polymer was washed with methanol, filtered, dried and weighed to obtain 3619 g of copolymer C (yield: 65.0 wt%).

Mw of the obtained copolymer C was 5980, Mn was 1960, and Mw / Mn was 3.05. By performing ¹³ C-NMR and ¹ H-NMR analyses, in the copolymer C, resonance lines derived from the ether end, the indane end and the alcohol end were observed. The proportion of ether terminals in all oxygen-containing terminals calculated from the NMR measurement results was 76.5 mol%. As a result of conducting elemental analysis, they were C: 89.9 wt%, H: 7.4 wt%, and O: 2.7 wt%. Introduction amount of chain hydrocarbon group or aromatic hydrocarbon group via ether bond or thioether bond to soluble polyfunctional vinyl aromatic polymer calculated from elemental analysis result and number average molecular weight in terms of standard polystyrene (c1) Was 3.6 (pieces / molecule). Further, the structural unit was derived from a total of 43.4 mol% of structural units derived from divinylbenzene, and a total of 56.6 mol% of structural units derived from styrene, a structure derived from benzyl alcohol, and a structural unit derived from ethylvinylbenzene. Further, the indane structure contained in the copolymer C was present at 3.2 mol% with respect to the total of the structural units of all the monomers. Furthermore, the molar fraction of the structural unit represented by the general formula (a1) in the total amount of the structural units represented by the general formulas (a1) and (a2) was 1.00. As a result of TMA measurement, Tg was 288 ° C., and softening temperature was 300 ° C. or higher. As a result of TGA measurement, the weight loss at 300 ° C. was 0.2 wt%, and the heat discoloration was ◎.
Copolymer C was soluble in toluene, xylene, THF, dichloroethane, dichloromethane, and chloroform, and no gel was formed. The cast film of copolymer C was a transparent film without cloudiness.

  Divinylbenzene 0.2138 mol (30.5 ml), ethylvinylbenzene 0.0113 mol (1.61 ml), styrene 0.0751 mol (8.6 ml), t-butyl alcohol 0.036 mol (3.29 ml), 0.024 mol (2.34 ml) of ethyl acetate and 100 ml of toluene (dielectric constant: 2.3) were put into a 200 mL reactor, and 0.008 mol of boron trifluoride diethyl ether complex at 50 ° C. Was added and reacted for 2 hours 30 minutes. The polymerization reaction was stopped with 3.56 g of calcium hydroxide, followed by filtration and washing with 50 ml of distilled water three times. After 0.04 g of butylhydroxytoluene was dissolved in the polymerization solution, it was concentrated using an evaporator at 60 ° C. for 1 hour. The reaction mixture was poured into a large amount of methanol at room temperature to precipitate a polymer. The obtained polymer was washed with methanol, filtered, dried and weighed to obtain 4.452 g of copolymer D (yield: 12.0 wt%).

Mw of the obtained copolymer D was 4940, Mn was 2950, and Mw / Mn was 1.68. By performing ¹³ C-NMR and ¹ H-NMR analyses, in the copolymer D, resonance lines derived from the ether end, the indane end and the alcohol end were observed. The ratio of the ether terminal to the total oxygen-containing terminal calculated from the NMR measurement result was 82.8 mol%. As a result of conducting elemental analysis of the copolymer D, it was C: 91.1 wt%, H: 7.7 wt%, and O: 1.2 wt%. Introduction amount of chain hydrocarbon group or aromatic hydrocarbon group via ether bond or thioether bond to soluble polyfunctional vinyl aromatic polymer calculated from elemental analysis result and number average molecular weight in terms of standard polystyrene (c1) Was 2.3 (pieces / molecule). Further, the total structural units derived from divinylbenzene were 48.6 mol%, and the total structural units derived from styrene, benzyl alcohol, and ethyl vinyl benzene were 51.4 mol%. Further, the indane structure contained in the copolymer D was present at 1.6 mol% with respect to the total of the structural units of all the monomers. Furthermore, the molar fraction of the structural unit represented by the general formula (a1) in the total amount of the structural units represented by the general formulas (a1) and (a2) was 1.00. As a result of the TMA measurement, Tg was 280 ° C., and the softening temperature was 300 ° C. or higher. As a result of TGA measurement, the weight loss at 300 ° C. was 0.4 wt%, and the heat discoloration was ◎.
Copolymer D was soluble in toluene, xylene, THF, dichloroethane, dichloromethane, and chloroform, and no gel was observed. The cast film of copolymer D was a transparent film without fogging.

  Divinylbenzene 0.2138 mol (30.5 ml), ethyl vinylbenzene 0.0113 mol (1.61 ml), styrene 0.0751 mol (8.6 ml), methyl alcohol 0.016 mol (0.65 ml), ethyl acetate 0.012 mol (1.17 ml) and 100 ml of toluene (dielectric constant: 2.3) are put into a 200 mL reactor, and 0.008 mol of boron trifluoride diethyl ether complex is added at 50 ° C. And reacted for 1 hour 30 minutes. The polymerization reaction was stopped with 3.56 g of calcium hydroxide, followed by filtration and washing with 50 ml of distilled water three times. After 0.04 g of butylhydroxytoluene was dissolved in the polymerization solution, it was concentrated using an evaporator at 60 ° C. for 1 hour. The reaction mixture was poured into a large amount of methanol at room temperature to precipitate a polymer. The obtained polymer was washed with methanol, filtered, dried, and weighed to obtain 11.361 g of a copolymer E (yield: 29.1 wt%).

Mw of the obtained copolymer E was 7890, Mn was 3210, and Mw / Mn was 2.46. By performing ¹³ C-NMR and ¹ H-NMR analyses, in the copolymer E, resonance lines derived from the ether end, the indane end and the alcohol end were observed. The proportion of ether terminals in all oxygen-containing terminals calculated from the NMR measurement results was 81.1 mol%. As a result of conducting elemental analysis of the copolymer E, it was C: 90.4 wt%, H: 7.2 wt%, and O: 2.4 wt%. Introduction amount of chain hydrocarbon group or aromatic hydrocarbon group via ether bond or thioether bond to soluble polyfunctional vinyl aromatic polymer calculated from elemental analysis result and number average molecular weight in terms of standard polystyrene (c1) Was 3.5 (pieces / molecule). Further, the structural unit was derived from a total of 49.9 mol% of structural units derived from divinylbenzene and 51.1 mol% of a structural unit derived from styrene, a structure derived from benzyl alcohol, and a structural unit derived from ethylvinylbenzene. Further, the indane structure contained in the copolymer E was 1.7 mol% with respect to the total of the structural units of all the monomers. Furthermore, the molar fraction of the structural unit represented by the general formula (a1) in the total amount of the structural units represented by the general formulas (a1) and (a2) was 1.00. As a result of the TMA measurement, Tg was 283 ° C., and the softening temperature was 300 ° C. or higher. As a result of TGA measurement, the weight loss at 300 ° C. was 0.5 wt%, and the heat discoloration was ◎.
Copolymer E was soluble in toluene, xylene, THF, dichloroethane, dichloromethane, and chloroform, and no gel was observed. Moreover, the cast film of the copolymer E was a transparent film without cloudiness.

  Divinylbenzene 17.1 mol (2436 ml), ethyl vinylbenzene 0.9 mol (128.2 ml), styrene 18.0 mol (2062.4 ml), benzyl alcohol 9.6 mol (888.7 ml), ethyl acetate 4. 80 mol (468.9 ml), 6400 ml of toluene (dielectric constant: 2.3) and 5600 ml of cyclohexane (dielectric constant: 2.02) were put into a 30 L reactor, and 4.8 mol of trifluoride at 30 ° C. Boron diethyl ether complex was added and allowed to react for 5 hours. The polymerization reaction was stopped with 2134 g of calcium hydroxide, followed by filtration and washing with 5 L of distilled water three times. 8.0 g of butylhydroxytoluene was dissolved in the polymerization solution, and then concentrated at 60 ° C. for 1 hour using an evaporator. The reaction mixture was poured into a large amount of methanol at room temperature to precipitate a polymer. The obtained polymer was washed with methanol, filtered, dried, and weighed to obtain a copolymer F1071 g (yield: 25.4 wt%).

Mw of the obtained copolymer F was 5730, Mn was 1710, and Mw / Mn was 3.36. By conducting ¹³ C-NMR and ¹ H-NMR analyses, resonance lines derived from the ether end, the indane end and the alcohol end of the copolymer F were observed. The ratio of the ether terminal to the total oxygen-containing terminal calculated from the NMR measurement result was 78.8 mol%. As a result of conducting elemental analysis of the copolymer F, they were C: 90.8 wt%, H: 7.4 wt%, and O: 1.8 wt%. Introduction amount of chain hydrocarbon group or aromatic hydrocarbon group via ether bond or thioether bond to soluble polyfunctional vinyl aromatic polymer calculated from elemental analysis result and number average molecular weight in terms of standard polystyrene (c1) Was 3.4 (pieces / molecule). Further, 34.7 mol% in total of structural units derived from divinylbenzene and 65.3 mol% in total of structural units derived from styrene, a structure derived from benzyl alcohol, and a structural unit derived from ethyl vinyl benzene were contained. Further, the indane structure contained in the copolymer F was present in an amount of 3.4 mol% with respect to the total of the structural units of all the monomers. Furthermore, the molar fraction of the structural unit represented by the general formula (a1) in the total amount of the structural units represented by the general formulas (a1) and (a2) was 1.00. As a result of the TMA measurement, Tg was 284 ° C., and the softening temperature was 300 ° C. or higher. As a result of TGA measurement, the weight loss at 300 ° C. was 0.2 wt%, and the heat discoloration was ◎.
Copolymer F was soluble in toluene, xylene, THF, dichloroethane, dichloromethane, and chloroform, and no gel was formed. The cast film of copolymer A was a transparent film without fogging.

Claims (7)

A copolymer obtained by copolymerizing a divinyl aromatic compound (a) and a monovinyl aromatic compound (b), a chain hydrocarbon group having an ether bond or a thioether bond in part of its end group, or It has an aromatic hydrocarbon group and has the following formulas (a1) and (a2)

(Wherein R ¹ represents an aromatic hydrocarbon group having 6 to 30 carbon atoms, and R ² represents an aromatic hydrocarbon group having 6 to 30 carbon atoms) (a) The molar fraction of structural units containing a vinyl group derived from
(A1) / [(a1) + (a2)] ≧ 0.5
Furthermore, the number average molecular weight Mn of the soluble polyfunctional vinyl aromatic polymer is 300 to 100,000, and the molecular weight distribution (Mw / Mn) represented by the ratio of the weight average molecular weight Mw to the number average molecular weight Mn is 10 A soluble polyfunctional vinyl aromatic copolymer that is not more than 0.0 and is soluble in toluene, xylene, tetrahydrofuran, dichloroethane, or chloroform. Of the terminal groups of the soluble polyfunctional vinyl aromatic polymer, the following formulas (b1) and (b2)

(Wherein R ³ represents a chain hydrocarbon group having 1 to 30 carbon atoms or an aromatic hydrocarbon group; Y represents oxygen or sulfur). formula,
(B1) / [(b1) + (b2)] ≧ 0.5
The soluble polyfunctional vinyl aromatic copolymer according to claim 1, wherein: The introduction amount (c1) of the chain hydrocarbon group or the aromatic hydrocarbon group through either an ether bond or a thioether bond to the terminal of the soluble polyfunctional vinyl aromatic polymer is represented by the following formula (c1) ≧ 1.5 (Individual / molecule)
The soluble polyfunctional vinyl aromatic copolymer according to claim 1 or 2, wherein: (A) Lewis acid catalyst,
(B) one or more promoters selected from the group consisting of ester compounds, thioester compounds, carboxylic acid compounds, carboxylic anhydride compounds, ether compounds and thioether compounds,
(C) one or more polymerization additives selected from the group consisting of alcohol compounds and mercaptan compounds,
In the presence of a monomer component containing 20 to 99 mol% of divinyl aromatic compound (a) and 80 to 1 mol% of monovinyl aromatic compound (b), a dielectric constant of 2.0 to 15. The method for producing a soluble polyfunctional vinyl aromatic copolymer according to claim 1, wherein the polymerization is carried out at a temperature of 20 to 120 ° C. in a homogeneous solution dissolved in 0 solvent.   The method for producing a soluble polyfunctional vinyl aromatic copolymer according to claim 4, wherein the Lewis acid catalyst is a metal fluoride or a complex thereof.   The soluble catalyst according to claim 4 or 5, wherein the co-catalyst of component (B) is one or more compounds selected from the group consisting of ester compounds, thioester compounds, carboxylic acid compounds and carboxylic anhydride compounds. A method for producing a polyfunctional vinyl aromatic copolymer.   (C) The component (A) Lewis acid catalyst is used in an amount of 0.001 to 10 mol and the component (B) promoter is used in an amount of 0.001 to 10 mol with respect to 1 mol of the polymerization additive of the component (C). The method for producing a soluble polyfunctional vinyl aromatic copolymer according to any one of claims 4 to 6.