JP7017662B1 - Thermosetting resin and its cured product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermosetting resin capable of obtaining a cured product having excellent dielectric properties. A thermosetting resin according to an embodiment has a repeating unit corresponding to a monovinyl aromatic compound and a repeating unit corresponding to a divinyl aromatic compound, and the content of the repeating unit corresponding to the divinyl aromatic compound. Is a linear vinyl copolymer having a content of 5.0 to 25.0 mol%. The end of the vinyl copolymer is represented by a structure derived from a polymerization initiator represented by the general formula (1): R1-N = N-R2, or a general formula (2): R3-O-O-R4. It has at least one of the structures derived from the polymerization initiator. In the general formulas (1) and (2), R1, R2, R3 and R4 independently represent a monovalent saturated hydrocarbon group or a monovalent aromatic hydrocarbon group, respectively. [Selection diagram] None

Description

Embodiments of the present invention relate to a thermosetting resin and a cured product thereof, and also to a thermosetting composition containing the thermosetting resin.

In recent years, the miniaturization and high performance of electronic devices have been progressing, and along with this, the required performance of various materials used has been improved. For example, there is a demand for a printed circuit board material having a low dielectric loss tangent that can be used for high-frequency communication.

Patent Document 1 discloses a vinyl compound in which the end of a bifunctional PPE (polyphenylene ether) oligomer is converted into a vinyl group as a thermosetting resin material having excellent heat resistance and electrical properties.

Patent Document 2 describes a curable resin composition for improving dielectric properties, long-term environmental reliability, heat resistance, and adhesion, which is derived from a repeating unit of 2 to 95 mol% derived from a divinyl aromatic compound and a monovinyl aromatic compound. A curable resin composition containing a polyfunctional vinyl aromatic copolymer containing 5 to 98 mol% of repeating units, a thermoplastic resin, and a thermosetting cross-linking agent is disclosed.

Japanese Unexamined Patent Publication No. 2004-06727 Japanese Unexamined Patent Publication No. 2019-178310

The thermosetting resins described in Patent Document 1 and Patent Document 2 have a relatively low dielectric loss tangent, but further improvement in dielectric properties is required.

In view of the above points, it is an object of the present invention to provide a thermosetting resin capable of obtaining a cured product having excellent dielectric properties.

The present invention includes embodiments shown below.
[1] It has a repeating unit corresponding to a monovinyl aromatic compound and a repeating unit corresponding to a divinyl aromatic compound, and the content of the repeating unit corresponding to the divinyl aromatic compound is 5.0 to 25.0 mol%. A linear vinyl copolymer having a structure derived from a polymerization initiator represented by the general formula (1): R1 ^- N = N- ^R2 at the end thereof, or the general formula (2). : It has at least one of the structures derived from the polymerization initiator represented by R ³ -O-O-R ⁴ , and R ¹ , R ² , R ³ and R ⁴ in the general formulas (1) and (2) have. , A thermocurable resin that independently represents a monovalent saturated or aromatic hydrocarbon group, respectively.
[2] A vinylbenzylphosphonium salt is copolymerized with a monovinyl aromatic compound using at least one of the polymerization initiator represented by the general formula (1) or the polymerization initiator represented by the general formula (2). The thermosetting resin according to [1], which has a structure obtained by reacting the obtained copolymer with formaldehyde.
[3] The thermosetting resin according to [1] or [2], which is a random copolymer having a repeating unit corresponding to the monovinyl aromatic compound and a repeating unit corresponding to the divinyl aromatic compound.
[4] The thermosetting resin according to any one of [1] to [3], wherein the number average molecular weight Mn and the weight average molecular weight Mw are 3,000 or more and 100,000 or less, respectively.
[5] A cured product obtained by curing the thermosetting resin according to any one of [1] to [4].
[6] A thermosetting composition containing the thermosetting resin according to any one of [1] to [4].
[7] The thermosetting composition according to [6], which is a printed circuit board material.

With the thermosetting resin according to the embodiment of the present invention, a cured product having excellent dielectric properties can be obtained.

The thermosetting resin according to the present embodiment is a vinyl copolymer having a repeating unit corresponding to a monovinyl aromatic compound and a repeating unit corresponding to a divinyl aromatic compound.

The repeating unit corresponding to the monovinyl aromatic compound is a structural unit of the vinyl copolymer, which has a structure formed by addition polymerization of the monovinyl aromatic compound as a monomer, and is the monovinyl aromatic compound. As long as it has a structure corresponding to the compound, it is not necessarily limited to the one obtained by polymerizing using the monovinyl aromatic compound, and the structure corresponding to the monovinyl aromatic compound is obtained by further reacting after the polymerization. But it may be.

Examples of the repeating unit corresponding to the monovinyl aromatic compound include a repeating unit having a structure in which the vinyl group of the monovinyl aromatic compound is single-bonded by addition polymerization as represented by the following general formula (3).

In formula (3), R ⁵ represents a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. More specifically, ^R5 may have a phenyl group which may have a substituent, a biphenyl group which may have a substituent, a naphthyl group which may have a substituent, and a substituent. Examples thereof include monovalent aromatic hydrocarbon groups having 6 to 30 carbon atoms (more preferably 6 to 20 carbon atoms) selected from the group consisting of good turphenyl groups. Here, the carbon number of ^R5 is the total number of carbon atoms of ^R5 including the number of carbon atoms contained in the substituent when it has a substituent.

The monovinyl aromatic compound forming such a repeating unit may be any aromatic compound having one vinyl group, for example, vinyl aromatic compounds such as styrene, vinylnaphthalene and vinylbiphenyl, and alkylstyrene (for example, o). -Methyl styrene, m-methyl styrene, p-methyl styrene, o-ethyl styrene, m-ethyl styrene, p-ethyl styrene), dialkyl styrene (eg 3,5-dimethyl styrene, 2,5-dimethyl styrene, 2) , 5-Diethylstyrene), alkyl vinyl biphenyl (eg ethyl vinyl biphenyl), nuclear alkyl substituted vinyl aromatic compounds such as alkyl vinyl naphthalene (eg ethyl vinyl naphthalene), etc., any one or more. Can be used in combination. Of these, styrene is preferable.

The repeating unit corresponding to the divinyl aromatic compound is a structural unit of the vinyl copolymer, and is a structural unit having a structure having one vinyl group formed by addition polymerization of the divinyl aromatic compound as a monomer. Is. The repeating unit is not necessarily limited to one polymerized using the divinyl aromatic compound as long as it has a structure corresponding to the divinyl aromatic compound, and the divinyl aromatic compound is further reacted after the polymerization. It may have a structure corresponding to the compound.

Examples of the repeating unit corresponding to the divinyl aromatic compound include a repeating unit having a structure in which one vinyl group of the divinyl aromatic compound is single-bonded by addition polymerization as represented by the following general formula (4). ..

In formula (4), R ⁶ represents a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. More specifically, R ⁶ has a phenylene group which may have a substituent, a biphenyldiyl group which may have a substituent, a naphthylene group which may have a substituent, and a substituent. Examples thereof include a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms (more preferably 6 to 20 carbon atoms) selected from the group consisting of a good terphenyldiyl group. Here, the carbon number of R ⁶ is the total carbon number of R ⁶ including the number of carbon atoms contained in the substituent when it has a substituent.

The divinyl aromatic compound forming such a repeating unit may be any aromatic compound having two vinyl groups, for example, divinylbenzene (including each position isomer or a mixture thereof), divinylnaphthalene (each). Examples thereof include position isomers (including position isomers or mixtures thereof) and divinylbiphenyl (including position isomers or mixtures thereof), which may be used alone or in combination of two or more. Among these, divinylbenzene (m-form, p-form or a mixture of these positional isomers) is preferable.

The thermosetting resin according to this embodiment is preferably a linear vinyl copolymer. Due to the linearity, the concentration of the terminal group derived from the polymerization initiator can be lowered and the dielectric property can be improved. Here, the linear shape means that the repeating units constituting the vinyl copolymer have a structure in which they are connected to each other in a one-dimensional chain shape, and have a structure having no crosslinked structure.

In the thermosetting resin according to the present embodiment, the order of the repeating units corresponding to the monovinyl aromatic compound and the repeating units corresponding to the divinyl aromatic compound may be regularly arranged or randomly arranged. good. The thermosetting resin is preferably a random copolymer in which repeating units corresponding to monovinyl aromatic compounds and repeating units corresponding to divinyl aromatic compounds are randomly arranged.

The thermosetting resin according to the present embodiment is a repeating unit corresponding to a monovinyl aromatic compound and a repeating unit corresponding to a divinyl aromatic compound, as well as a repeating unit corresponding to other monomers as long as its effect is not impaired. It may include a unit. Examples of such other monomers include trivinyl aromatic compounds, trivinyl aliphatic compounds, divinyl aliphatic compounds, monovinyl aliphatic compounds and the like.

In the thermosetting resin according to the present embodiment, the content of the repeating unit corresponding to the divinyl aromatic compound is preferably 5.0 to 25.0 mol%. That is, the content of the repeating unit corresponding to the divinyl aromatic compound is 5.0 mol% or more and 25.0 mol% or less, assuming that all the repeating units constituting the vinyl copolymer are 100 mol%. When the content of the repeating unit corresponding to the divinyl aromatic compound is 5.0 mol% or more, the thermosetting property can be enhanced and a good cured product can be obtained, and the content is 25.0 mol. When it is less than%, the residual amount of vinyl groups after thermosetting can be reduced. The content of the repeating unit corresponding to the divinyl aromatic compound is preferably 7.0 mol% or more, preferably 20.0 mol% or less, and may be 16.0 mol% or less.

In the thermosetting resin according to the present embodiment, the content of the repeating unit corresponding to the monovinyl aromatic compound is not particularly limited, but the total repeating unit constituting the vinyl copolymer is 100 mol%, and the content is 75.0 to 75.0. It is preferably 95.0 mol%. The content of the repeating unit corresponding to the monovinyl aromatic compound is more preferably 80.0 mol% or more, 74.0 mol% or more, and preferably 93.0 mol% or less.

The thermosetting resin according to the present embodiment has at least a structure derived from the polymerization initiator represented by the following general formula (1) or a structure derived from the polymerization initiator represented by the general formula (2) at the end thereof. It is preferable to have one. The polymerization initiator represented by the formula (1) is an azo-based initiator having no cyano group, unlike azobisisobutyronitrile (AIBN), which is a general-purpose azo-based initiator. The polymerization initiator represented by the formula (2) is an organic peroxide such as a dialkyl peroxide. Since these polymerization initiators do not have a polar group such as an active hydrogen group at the terminal, the dielectric loss tangent of the thermosetting resin can be reduced.
R ¹ -N = N-R ² (1)
R ³ -O-O-R ⁴ (2)

In formulas (1) and (2), R ¹ , R ² , R ³ and R ⁴ each independently represent a monovalent saturated hydrocarbon group or a monovalent aromatic hydrocarbon group and contain a heteroatom. do not have. The number of carbon atoms of the saturated hydrocarbon group is not particularly limited, but is preferably 1 to 23, and more preferably 4 to 13. The number of carbon atoms of the aromatic hydrocarbon group is not particularly limited, but is preferably 6 to 23, and more preferably 6 to 13.

The saturated hydrocarbon group may be a branched or linear saturated aliphatic hydrocarbon group (alkyl group) or a saturated alicyclic hydrocarbon group. Specific examples of the saturated hydrocarbon group include an alkyl group such as a tert-butyl group, a tert-pentyl group, a tert-hexyl group, a 1,1,3,3-tetramethylbutyl group, and a saturated fat such as a cyclohexyl group . Cyclic hydrocarbon groups can be mentioned.

Specific examples of the aromatic hydrocarbon group include an aryl group such as a phenyl group, a tolyl group and a naphthyl group , and an aralkyl group such as a cumyl group, a benzyl group and a phenethyl group .

In one embodiment, R ¹ , R ² , R ³ and R ⁴ may be independently represented by the following general formula (5).

In formula (5), R ⁷ , R ⁸ and R ⁹ independently represent a monovalent saturated hydrocarbon group or a monovalent aromatic hydrocarbon group, respectively. More preferably, R ⁷ is a monovalent saturated hydrocarbon group having 1 to 20 carbon atoms (more preferably 1 to 10 carbon atoms) or a monovalent element having 6 to 20 carbon atoms (more preferably 6 to 10 carbon atoms). It represents an aromatic hydrocarbon group, and R ⁸ and R ⁹ represent a methyl group. Saturated hydrocarbon groups for R ⁷ , R ⁸ and R ⁹ (preferably R ⁷ ) may be branched or straight chain, eg, methyl group, ethyl group, propyl group, butyl group, heptyl group, isopropyl group, Examples thereof include an alkyl group such as a tert-butyl group and a 2,2-dimethylpropyl group, and a saturated alicyclic hydrocarbon group such as a cyclohexyl group. Examples of the aromatic hydrocarbon for R ⁷ , R ⁸ and R ⁹ (preferably R ⁷ ) include a phenyl group, a tolyl group, a naphthyl group and the like.

When a vinyl copolymer is synthesized by radical polymerization using these polymerization initiators, both ends of the obtained vinyl copolymer usually have a structure derived from the polymerization initiator. When polymerization is carried out using the polymerization initiator of the above formula (1), a vinyl copolymer having the above R ¹ − and / or R ² − at both ends is obtained. That is, both ends of the vinyl copolymer may be R ¹ −, both may be R ² −, one end may be R ¹ −, and the other end may be R ² −.

In one embodiment, when a polymerization initiator in which ^R1 and ^R2 have a group represented by the above formula (5) is used as the polymerization initiator of the formula (1), both ends of the vinyl copolymer are described above. The group represented by the formula (5) is introduced. Therefore, the vinyl copolymer is represented by the following formula (6).

In formula (6), R ⁵ is as described above in formula (3), R ⁶ is as described above in formula (4), and R ⁷ , R ⁸ and R ⁹ are described above in formula (5). That's right. It should be noted that R ⁷ , R ⁸ and R ⁹ at both ends may be the same or different. m and n represent the number of repeating units corresponding to the monovinyl aromatic compound and the repeating unit corresponding to the divinyl aromatic compound, respectively, and the repeating units may be a random sequence or a block sequence, but a random sequence is preferable. Is.

On the other hand, when the polymerization is carried out using the polymerization initiator of the above formula (2), a vinyl copolymer having R ³ O- and / or R ⁴ O- at both ends is obtained. That is, both ends of the vinyl copolymer may be R ³ O-, both may be R ⁴ O-, and one end may be R ³ O- and the other end may be R ⁴ O-.

^In one embodiment, when a polymerization initiator in which R3 and ^R4 have a group represented by the above formula (5) is used as the polymerization initiator of the formula (2), the vinyl represented by the following formula (7) is used. A copolymer is obtained.

In formula (7), R ⁵ is as described above in formula (3), R ⁶ is as described above in formula (4), and R ⁷ , R ⁸ and R ⁹ are described above in formula (5). That's right. It should be noted that R ⁷ , R ⁸ and R ⁹ at both ends may be the same or different. m and n represent the number of repeating units corresponding to the monovinyl aromatic compound and the repeating unit corresponding to the divinyl aromatic compound, respectively, and the repeating units may be a random sequence or a block sequence, but a random sequence is preferable. Is.

The thermosetting resin according to this embodiment preferably has a number average molecular weight Mn of 3,000 or more and 100,000 or less. When the number average molecular weight Mn is 3,000 or more, the concentration of the terminal group derived from the polymerization initiator can be lowered and the dielectric property can be improved. Further, when the number average molecular weight Mn is 100,000 or less, it is possible to suppress the increase in viscosity when the thermosetting resin is used as a solution and improve the handleability. Further, the larger the molecular weight, the larger the residual amount of vinyl groups after heat curing tends to be. From the viewpoint of the dielectric property, the number average molecular weight Mn is more preferably 7,000 or more, further preferably 10,000 or more, further preferably 15,000 or more, and may be 20,000 or more. From the viewpoint of handleability and residual amount of vinyl groups, the number average molecular weight Mn is more preferably 50,000 or less, still more preferably 40,000 or less, and may be 30,000 or less.

The thermosetting resin according to this embodiment preferably has a weight average molecular weight Mw of 3,000 or more and 100,000 or less. When the weight average molecular weight Mw is 3,000 or more, the concentration of the terminal group derived from the polymerization initiator can be lowered and the dielectric property can be improved. Further, when the weight average molecular weight Mw is 100,000 or less, it is possible to suppress the increase in viscosity when the thermosetting resin is used as a solution, improve the handleability, and reduce the residual amount of vinyl groups. From the viewpoint of the dielectric property, the weight average molecular weight Mw is more preferably 10,000 or more, further preferably 20,000 or more, 30,000 or more, or 40,000 or more. From the viewpoint of handleability and residual amount of vinyl groups, the weight average molecular weight Mw is more preferably 90,000 or less, further preferably 80,000 or less, and may be 70,000 or less.

In the thermosetting resin according to the present embodiment, the molecular weight distribution Mw / Mn, which is the ratio of the weight average molecular weight Mw to the number average molecular weight Mn, is not particularly limited, but is preferably 4.0 or less, more preferably 1. It is .2 to 3.5, more preferably 1.5 to 3.0.

Here, the number average molecular weight Mn and the weight average molecular weight Mw are polystyrene-equivalent number average molecular weight and weight average molecular weight measured by gel permeation chromatography (GPC).

The method for producing a thermosetting resin according to this embodiment is not particularly limited. As a method for synthesizing a linear vinyl copolymer, in the production method according to a preferred embodiment, the polymerization initiator represented by the above formula (1) or the polymerization initiator represented by the formula (2) is used. The vinylbenzylphosphonium salt is copolymerized with a monovinyl aromatic compound using at least one of the above, and the obtained copolymer is reacted with formaldehyde. However, the method is not limited to this manufacturing method.

As the vinylbenzylphosphonium salt, it is preferable to use vinylbenzylphosphonium halide. Examples of the phosphonium group in the vinylbenzyl phosphonium salt include a quaternary phosphonium group such as trialkylphosphonium, triarylphosphonium, and triaralkylphosphonium. Examples of the halogen that forms a salt with the phosphonium group include chlorine and bromine.

As a method for copolymerizing the vinylbenzylphosphonium salt with the monovinyl aromatic compound, a known vinyl polymerization method can be used. By using the radical polymerization initiator represented by the above formula (1) and / or the above formula (2) as the polymerization initiator, a repeating unit derived from a vinylbenzylphosphonium salt and a repeating unit derived from a monovinyl aromatic compound can be used. The copolymer having is obtained.

As a method for reacting the obtained copolymer with formaldehyde, a known Wittig reaction can be used. By treating the copolymer with a base and reacting with formaldehyde, the phosphonium group is removed and vinyl is removed. The group is introduced.

In this production method, since the vinylbenzylphosphonium salt is monovinyl in the copolymerization step, a linear copolymer having no branch can be obtained, and after the copolymerization, vinyl is used as a repeating unit derived from the vinylbenzylphosphonium salt. Since the group is introduced, it is possible to obtain a linear vinyl copolymer having no branch while having a repeating unit corresponding to the divinyl aromatic compound.

The thermosetting composition according to the present embodiment contains the above-mentioned thermosetting resin. The content of the thermosetting resin in the thermosetting composition is not particularly limited as long as the composition has a property of being heat-curable. For example, with respect to 100% by mass of the solid content of the thermosetting composition (the amount excluding the organic solvent when the organic solvent described later is contained, and the total amount of the composition when the organic solvent is not contained). It may be 1 to 99% by mass, or 10 to 95% by mass.

In addition to the above thermosetting resin, the thermosetting composition includes, for example, other thermosetting resins (thermosetting cross-linking agents), thermoplastic resins, fillers, flame retardants, curing accelerators, and polymerization initiators. , Antifoaming agent, heat stabilizer, antistatic agent, ultraviolet absorber, colorant such as dye and pigment, lubricant, dispersant and the like may be contained.

Further, the thermosetting composition may contain an organic solvent in order to adjust its viscosity, and the thermosetting composition may be a solution containing the thermosetting resin. As the organic solvent, a solvent capable of dissolving the above-mentioned thermosetting resin is used, for example, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, esters such as ethyl acetate, propyl acetate and butyl acetate, dimethylacetamide and dimethyl. Examples thereof include amides such as formamide, aromatic hydrocarbons such as toluene and xylene, and any one of these or a combination of two or more thereof can be used.

Since the thermosetting resin or the thermosetting composition of the present embodiment has a vinyl group in the molecular chain of the vinyl copolymer, it can be crosslinked by polymerization, and a cured product can be obtained by thermosetting. Since the cured product has a low dielectric loss tangent and excellent dielectric properties, it can be used for electronic materials such as printed circuit board materials and semiconductor encapsulation materials. That is, the thermosetting composition according to one embodiment is a thermosetting composition for electronic materials.

Examples of the printed circuit board material include a rigid printed circuit board material such as a single-sided substrate, a double-sided substrate, a multilayer substrate, and a build-up substrate, and a film-shaped or sheet-shaped flexible printed circuit board material. Further, since it has a low dielectric loss tangent, it is suitably used as a high-frequency substrate material used in high-frequency communication equipment.

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

<Measurement / evaluation method>
[Mole ratio of styrene / divinylbenzene, divinylbenzene ratio]
The products obtained in Examples 1 to 13 and Comparative Examples 1 to 8 were dissolved in dehydrided chloroform, and ¹ H-NMR measurement was carried out with a nuclear magnetic resonance apparatus (manufactured by JEOL) to obtain a repeating unit corresponding to styrene. Obtain the molar ratio of the repeating unit corresponding to divinylbenzene, and determine the content of the repeating unit corresponding to styrene (styrene ratio) and the content of the repeating unit corresponding to divinylbenzene (divinylbenzene ratio) with respect to 100 mol% of all repeating units. Calculated.

[Number average molecular weight, weight average molecular weight]
Four columns (Shodex GPC columns KF-601, KF-602, KF-603, in which the products obtained in Examples 1 to 13 and Comparative Examples 1 to 8 were dissolved in tetrahydrofuran and the polystyrene gel was used as a filler. The polystyrene-equivalent number average molecular weight Mn and weight average molecular weight Mw were measured by gel permeation chromatography (GPC) (Prominence, manufactured by Shimadzu Corporation) in which KF-604 (manufactured by Showa Denko KK) was linked. The column oven temperature was 40 ° C., the THF flow rate was 0.6 mL / min, the sample concentration was 0.1% by mass, the sample injection amount was 10 μL, and a differential refractive index detector (Shodex RI-504, manufactured by Showa Denko) was used.

[Permittivity, dielectric loss tangent]
The products obtained in Examples 1 to 13 and Comparative Examples 1 to 8 were used as samples. Using a single-acting compression molding machine for testing (manufactured by Yasuda Seiki Seisakusho), 1.5 g of a sample was pressed at a pressure of 10 Pa and a temperature of 220 ° C. for 15 minutes to prepare a flat plate having a thickness of 30 mm × 30 mm × a thickness of 1 mm. The obtained flat plate is cut to prepare a test piece having a width of 2 mm, a thickness of 1 mm, and a length of 30 mm. Was measured.

[Thermosetting]
Using the products obtained in Examples 1 to 13 and Comparative Examples 1 to 8 as samples, the temperature was raised from room temperature to 350 ° C. using a differential scanning calorimetry device (manufactured by Rigaku) at a heating rate of 10 ° C./min. Those having a calorific value of 20 J / g or more at the exothermic peak were designated as “◯” (good thermosetting), and those having a calorific value of less than 20 J / g were designated as “x” (poor thermosetting).

[Residual amount of vinyl group]
A Fourier transform infrared spectrophotometer: Nicolet 6700 (manufactured by Thermo Fisher Scientific) was used as a sample of the products obtained in Examples 1 to 13 and Comparative Examples 1 to 8 and a flat plate prepared by [dielectric constant, dielectric loss tangent]. Then, the vinyl group peak area (1620-1640 cm ^-1 ) and the aromatic peak area (1420-1470 cm ^-1 ) of each of the product and the flat plate were measured. From the measured peak area, the vinyl group reaction rate of the product after pressing was measured by the following <Formula A>.
<Formula A>: Vinyl group reaction rate (%) = {1- (flat plate vinyl group peak area x product aromatic peak area) / (plate plate aromatic peak area x product vinyl group peak area)} × 100
From the divinylbenzene ratio and the vinyl group reaction rate, the residual amount of vinyl group was calculated by the following <Formula B>.
<Formula B>: Residual amount of vinyl group (mol%) = Divinylbenzene ratio (mol%) x (100-vinyl group reaction rate (%)) / 100
Generally, if the residual amount of vinyl groups is large, the durability of the product decreases due to the oxidation of vinyl groups. Therefore, those with a residual amount of vinyl groups of 9 mol% or more are marked with "x" (many residual vinyl groups) and less than 9 mol%. Those were marked with "○" (a small amount of residual vinyl group).

(Synthesis Example 1) Compound 1: Synthesis of triphenylvinylbenzylphosphonium chloride Vinyl benzyl chloride (trade name: CMS-14, manufactured by AGC Seimi Chemical Co., Ltd.) 1.5 mol (228.9 g), triphenylphosphine 1.8 mol (472.1 g) and 622.4 g of dimethylformamide were placed in a 2.0 L reactor and reacted at 70 ° C. for 3 hours under nitrogen conditions to precipitate a white solid. The solid was thoroughly washed with acetone and then dried under reduced pressure at 92 ° C. to recover 490 g of Compound 1.

(Synthesis Example 2) Synthesis of Copolymer A 45 g of styrene, 13.8 g of compound 1,2,2'-azobis (2,4,4-trimethylpentane) (trade name: VR-110, Fuji Film Wako Pure Chemical Industries, Ltd.) Manufactured by) 0.44 g and 137.3 g of dimethylformamide were put into a 500 mL reactor and reacted at 120 ° C. under nitrogen conditions for 3.5 hours to obtain copolymer A as a dimethylformamide solution.

(Synthesis Example 3) Synthesis of Copolymer B 22.5 g of styrene, 0.26 g of compound 1, 2,2'-azobis (2,4,4-trimethylpentane) of 14.9 g, and 87.4 g of dimethylformamide were added. , 300 mL was placed in a reactor and reacted at 120 ° C. under nitrogen conditions for 3 hours to obtain copolymer B as a dimethylformamide solution.

(Synthesis Example 4) Synthesis of Copolymer C 22.5 g of styrene, 32.4 g of compound 1, 2,2'-azobis (2,4,4-trimethylpentane) of 22.4 g, and 104.8 g of dimethylformamide were added. , 500 mL was placed in a reactor and reacted at 120 ° C. under nitrogen conditions for 3 hours to obtain the copolymer C as a dimethylformamide solution.

(Synthesis Example 5) Synthesis of Copolymer D 22.5 g of styrene, 2.1 g of compound 1, 2,2'-azobis (2,4,4-trimethylpentane) of 6.9 g, and 68.6 g of dimethylformamide were added. , 500 mL was placed in a reactor and reacted at 120 ° C. under nitrogen conditions for 2 hours to obtain the copolymer D as a dimethylformamide solution.

(Synthesis Example 6) Synthesis of Copolymer E 22.5 g of styrene, 15.0 g of compound 1,2,2'-azobis (2,4,4-trimethylpentane) 2.8 g, and dimethylformamide 87.4 g. , 500 mL was placed in a reactor and reacted at 120 ° C. under nitrogen conditions for 1.5 hours to obtain the copolymer E as a dimethylformamide solution.

(Synthesis Example 7) Synthesis of Copolymer F 525.0 g of styrene, 160.9 g of compound 1, 1.8 g of jittery butyl peroxide (trade name: Perbutyl D, manufactured by Nichiyu), and 1600.4 g of dimethylformamide were added. , 3.0 L was put into a reactor and reacted at 132 ° C. under nitrogen conditions for 7 hours to obtain the copolymer F as a dimethylformamide solution.

(Synthesis Example 8) Synthesis of Copolymer G 22.5 g of styrene, 15.0 g of compound 1, 0.12 g of jittery butyl peroxide, and 87.5 g of dimethylformamide were put into a 500 mL reactor, and nitrogen was added. The reaction was carried out at 132 ° C. for 6 hours under the conditions to obtain the copolymer G as a dimethylformamide solution.

(Synthesis Example 9) Synthesis of Copolymer H 343.6 g of styrene, 342.3 g of compound 1, 1.8 g of jittery butyl peroxide, and 1600.4 g of dimethylformamide were put into a 3.0 L reactor. , The reaction was carried out at 132 ° C. under nitrogen conditions for 6 hours to obtain the copolymer H as a dimethylformamide solution.

(Synthesis Example 10) Synthesis of Copolymer I 525.0 g of styrene, 160.9 g of compound 1, 15.1 g of jittery butyl peroxide, and 1600.4 g of dimethylformamide were put into a 3.0 L reactor. , The reaction was carried out at 132 ° C. under nitrogen conditions for 3 hours to obtain the copolymer I as a dimethylformamide solution.

(Synthesis Example 11) Synthesis of Copolymer J 22.5 g of styrene, 15.0 g of compound 1, 0.46 g of jittery butyl peroxide, and 87.4 g of dimethylformamide were put into a 500 mL reactor, and nitrogen was added. The reaction was carried out at 132 ° C. for 6 hours under the conditions to obtain the copolymer J as a dimethylformamide solution.

(Synthesis Example 12) Synthesis of Copolymer K 45 g of styrene, 13.8 g of compound 1, 0.20 g of jittery hexyl peroxide (trade name: Perhexyl D, manufactured by Nichiyu), and 137.2 g of dimethylformamide. Was put into a 500 mL reactor and reacted at 122 ° C. under nitrogen conditions for 7 hours to obtain the copolymer K as a dimethylformamide solution.

(Synthesis Example 13) Synthesis of Copolymer L 45 g of styrene, 13.8 g of compound 1, 0.17 g of jittery amyl peroxide (trade name: Luperox DTA, manufactured by Alchema Yoshitomi), and 137.2 g of dimethylformamide. , 500 mL was placed in a reactor and reacted at 125 ° C. under nitrogen conditions for 6 hours to obtain the copolymer L as a dimethylformamide solution.

(Synthesis Example 14) Synthesis of Copolymer M 20 g of styrene, 6.1 g of compound 1, 0.12 g of dicumyl peroxide (manufactured by Nacalai Tesque), and 61.0 g of dimethylformamide were put into a 300 mL reactor. , The reaction was carried out at 125 ° C. under nitrogen conditions for 3.5 hours to obtain the copolymer M as a dimethylformamide solution.

(Comparative Synthesis Example 1) Synthesis of Copolymer N 17.4 g of styrene, 2.7 g of compound 1, 2,2'-azobis (2,4,4-trimethylpentane) 0.16 g, and dimethylformamide 46.1 g Was put into a 300 mL reactor and reacted at 120 ° C. under nitrogen conditions for 3 hours to obtain copolymer N as a dimethylformamide solution.

(Comparative Synthesis Example 2) Synthesis of Copolymer O 20 g of styrene, 0.35 g of compound 1, 2,2'-azobis (2,4,4-trimethylpentane) of 26.6 g, and 108.7 g of dimethylformamide were added. It was put into a 500 mL reactor and reacted at 120 ° C. under nitrogen conditions for 2 hours to obtain the copolymer O as a dimethylformamide solution.

(Comparative Synthesis Example 3) Synthesis of Copolymer P 17.0 g of styrene, 2.7 g of compound 1, 0.08 g of jittery butyl peroxide, and 46.0 g of dimethylformamide were placed in a 500 mL reactor. The reaction was carried out at 132 ° C. under nitrogen conditions for 6 hours to obtain the copolymer P as a dimethylformamide solution.

(Comparative Synthesis Example 4) Synthesis of Copolymer Q 552.12 g of styrene, 16.92 g of compound 1, 3.27 g of azobisisobutyronitrile, and 1682.68 g of dimethylformamide were placed in a 3.0 L reactor. It was charged and reacted at 70 ° C. under nitrogen conditions for 9 hours. The reaction solution was concentrated under reduced pressure, then dissolved in dichloromethane and reprecipitated in a large excess of isopropyl alcohol. Next, the supernatant was decanted, and the remaining solid was dried under reduced pressure at 92 ° C. to recover 285.0 g of the copolymer Q.

(Comparative Synthesis Example 5) Synthesis of Copolymer R 110 g of styrene, 62.6 g of compound 1, 0.78 g of azobisisobutyronitrile, and 258.9 g of dimethylformamide were put into a 1.0 L reactor. , The reaction was carried out at 70 ° C. for 9 hours under nitrogen conditions to obtain the copolymer R as a dimethylformamide solution.

(Comparative Synthesis Example 6) Synthesis of Copolymer S 142.7 g of styrene, 21.2 g of compound 1, 0.75 g of azobisisobutyronitrile, and 245.9 g of dimethylformamide were placed in a 1.0 L reactor. It was charged and reacted at 70 ° C. under nitrogen conditions for 9 hours. The reaction solution was concentrated under reduced pressure, then dissolved in dichloromethane and reprecipitated in a large excess of isopropyl alcohol. Next, the supernatant was decanted, and the remaining solid was dried under reduced pressure at 92 ° C. to recover 102.4 g of the copolymer S.

(Comparative Synthesis Example 7) Synthesis of Copolymer T 55.2 g of styrene, 16.9 g of compound 1, 3.24 g of azobisisobutyronitrile, and 108.17 g of dimethylformamide were put into a 500 mL reactor. The copolymer T was obtained as a dimethylformamide solution by reacting under nitrogen conditions at 70 ° C. for 5 hours.

(Comparative Synthesis Example 8) Synthesis of copolymer U 50.2 g of styrene, 50.0 g of compound 1, 0.45 g of azobisisobutyronitrile, and 186.09 g of dimethylformamide were put into a 500 mL reactor. The copolymer U was obtained as a dimethylformamide solution by reacting at 68 ° C. for 8 and a half hours under nitrogen conditions.

(Example 1)
50.0 g of the dimethylformamide solution of the copolymer A obtained in Synthesis Example 2, 8.3 g of 37 mass% formalin, 10.2 g of the 28 mass% potassium hydroxide aqueous solution, and 71.8 g of tetrahydrofuran were placed in a 500 mL reactor. It was charged and reacted at room temperature for 3 hours. The reaction solution was reprecipitated in methanol, the solid was taken out by filtration, dissolved in dichloromethane, the organic layer was washed with distilled water, and reprecipitated to methanol / water = 7/3. Then, after taking out the solid by filtration, the product 1 was recovered by drying under reduced pressure at 92 ° C. The Mn of the product 1 was 25600, the Mw was 71300, the styrene ratio was 92.9 mol%, and the divinylbenzene ratio was 7.1 mol%.

(Example 2)
A 1.0 L reactor containing 120.0 g of a dimethylformamide solution of the copolymer B obtained in Synthesis Example 3, 32.0 g of 37 mass% formalin, 39.5 g of a 28 mass% potassium hydroxide aqueous solution, and 197.3 g of tetrahydrofuran. It was put into the inside and reacted at room temperature for 4 hours. The reaction solution was reprecipitated in methanol, the solid was taken out by filtration, dissolved in dichloromethane, the organic layer was washed with distilled water, and reprecipitated to methanol / water = 7/3. Then, after taking out the solid by filtration, the product 2 was recovered by drying under reduced pressure at 92 ° C. The Mn of the product 2 was 21,800, the Mw was 47700, the styrene ratio was 84.8 mol%, and the divinylbenzene ratio was 15.2 mol%.

(Example 3)
A 1.0 L reactor containing 150.0 g of a dimethylformamide solution of the copolymer C obtained in Synthesis Example 4, 50.5 g of 37 mass% formalin, 62.3 g of a 28 mass% potassium hydroxide aqueous solution, and 254.4 g of tetrahydrofuran. It was put into the inside and reacted at room temperature for 4 hours. The reaction solution was reprecipitated in methanol, the solid was taken out by filtration, dissolved in dichloromethane, the organic layer was washed with distilled water, and reprecipitated to methanol / water = 7/3. Then, the solid was taken out by filtration and then dried under reduced pressure at 92 ° C. to recover the product 3. The Mn of the product 3 was 21600, the Mw was 55500, the styrene ratio was 77.8 mol%, and the divinylbenzene ratio was 22.2 mol%.

(Example 4)
98.0 g of the dimethylformamide solution of the copolymer D obtained in Synthesis Example 5, 15.6 g of 37% by mass formalin, 19.2 g of a 28% by mass potassium hydroxide aqueous solution, and 159.8 g of tetrahydrofuran are placed in a 500 mL reactor. It was charged and reacted at room temperature for 4 hours. The reaction solution was reprecipitated in methanol, the solid was taken out by filtration, dissolved in dichloromethane, the organic layer was washed with distilled water, and reprecipitated to methanol / water = 7/3. Then, the solid was taken out by filtration and then dried under reduced pressure at 92 ° C. to recover the product 4. The Mn of the product 4 was 7800, the Mw was 24200, the styrene ratio was 92.1 mol%, and the divinylbenzene ratio was 7.9 mol%.

(Example 5)
A 1.0 L reactor containing 121.0 g of a dimethylformamide solution of the copolymer E obtained in Synthesis Example 6, 33.5 g of 37 mass% formalin, 41.3 g of a 28 mass% potassium hydroxide aqueous solution, and 204.0 g of tetrahydrofuran. It was put into the inside and reacted at room temperature for 4 hours. The reaction solution was reprecipitated in methanol, the solid was taken out by filtration, dissolved in dichloromethane, the organic layer was washed with distilled water, and reprecipitated to methanol / water = 7/3. Then, the solid was taken out by filtration and then dried under reduced pressure at 92 ° C. to recover the product 5. The Mn of the product 5 was 7100, the Mw was 19,900, the styrene ratio was 83.9 mol%, and the divinylbenzene ratio was 16.1 mol%.

(Example 6)
A 3.0 L reactor containing 1076.4 g of a dimethylformamide solution of the copolymer F obtained in Synthesis Example 7, 191.5 g of 37 mass% formalin, 236.4 g of a 28 mass% potassium hydroxide aqueous solution, and 1214.8 g of tetrahydrofuran. It was put into the inside and reacted at room temperature for 4 hours. Dichloromethane was added to the reaction solution and then reprecipitated in methanol. The solid was taken out by filtration, dissolved in dichloromethane, the organic layer was washed with distilled water, and reprecipitated to methanol / water = 7/3. Then, the solid was taken out by filtration and then dried under reduced pressure at 92 ° C. to recover the product 6. The Mn of the product 6 was 40,000, the Mw was 88,000, the styrene ratio was 91.1 mol%, and the divinylbenzene ratio was 8.9 mol%.

(Example 7)
118.1 g of a dimethylformamide solution of the copolymer G obtained in Synthesis Example 8, 26.6 g of 37 mass% formalin, 32.7 g of a 28 mass% potassium hydroxide aqueous solution, and 123.2 g of tetrahydrofuran were placed in a 500 mL reactor. It was charged and reacted at room temperature for 4 hours. The reaction solution was reprecipitated in methanol, the solid was taken out by filtration, dissolved in dichloromethane, the organic layer was washed with distilled water, and reprecipitated to methanol / water = 7/3. Then, the solid was taken out by filtration and then dried under reduced pressure at 92 ° C. to recover the product 7. The Mn of the product 7 was 35,000, the Mw was 65400, the styrene ratio was 81.1 mol%, and the divinylbenzene ratio was 18.9 mol%.

(Example 8)
A 5.0 L reactor containing 1400.0 g of a dimethylformamide solution of the copolymer H obtained in Synthesis Example 9, 329.0 g of 37 mass% formalin, 406.1 g of a 28 mass% potassium hydroxide aqueous solution, and 1000.0 g of tetrahydrofuran. It was put into the inside and reacted at room temperature for 4 hours. Dichloromethane was added to the reaction solution and then reprecipitated in methanol. The solid was taken out by filtration, dissolved in dichloromethane, the organic layer was washed with distilled water, and reprecipitated to methanol / water = 7/3. Then, the solid was taken out by filtration and then dried under reduced pressure at 92 ° C. to recover the product 8. The Mn of the product 8 was 39000, the Mw was 91000, the styrene ratio was 79.2 mol%, and the divinylbenzene ratio was 20.8 mol%.

(Example 9)
A 3.0 L reactor containing 1080.0 g of a dimethylformamide solution of the copolymer I obtained in Synthesis Example 10, 191.4 g of 37 mass% formalin, 256.4 g of a 28 mass% potassium hydroxide aqueous solution, and 1213.0 g of tetrahydrofuran. It was put into the inside and reacted at room temperature for 4 hours. Dichloromethane was added to the reaction solution and then reprecipitated in methanol. The solid was taken out by filtration, dissolved in dichloromethane, the organic layer was washed with distilled water, and reprecipitated to methanol / water = 7/3. Then, the solid was taken out by filtration and then dried under reduced pressure at 92 ° C. to recover the product 9. The Mn of the product 9 was 17,000, the Mw was 47,000, the styrene ratio was 92.5 mol%, and the divinylbenzene ratio was 7.5 mol%.

(Example 10)
124.9 g of the dimethylformamide solution of the copolymer J obtained in Synthesis Example 11, 28.2 g of 37 mass% formalin, 34.4 g of the 28 mass% potassium hydroxide aqueous solution, and 139.4 g of the tetrahydrofuran were placed in a 500 mL reactor. It was charged and reacted at room temperature for 4 hours. The reaction solution was reprecipitated in methanol, the solid was taken out by filtration, dissolved in dichloromethane, the organic layer was washed with distilled water, and reprecipitated to methanol / water = 7/3. The solid was then removed by filtration and then dried under reduced pressure at 92 ° C. to recover the product 10. The Mn of the product 10 was 18300, the Mw was 45100, the styrene ratio was 81.8 mol%, and the divinylbenzene ratio was 18.2 mol%.

(Example 11)
58.0 g of the dimethylformamide solution of the copolymer K obtained in Synthesis Example 12, 4.8 g of the 37 mass% formalin and 6.0 g of the 28 mass% potassium hydroxide aqueous solution were put into a 500 mL reactor, and 4 at room temperature. Reacted for time. The reaction solution was reprecipitated in methanol, the solid was taken out by filtration, dissolved in dichloromethane, the organic layer was washed with distilled water, and reprecipitated to methanol / water = 7/3. The solid was then removed by filtration and then dried under reduced pressure at 92 ° C. to recover the product 11. The Mn of the product 11 was 36000, the Mw was 64000, the styrene ratio was 92.2 mol%, and the divinylbenzene ratio was 7.8 mol%.

(Example 12)
A 1.0 L reactor containing 130.0 g of a dimethylformamide solution of the copolymer L obtained in Synthesis Example 13, 20.7 g of 37 mass% formalin, 25.5 g of a 28 mass% potassium hydroxide aqueous solution and 223.9 g of tetrahydrofuran. And reacted at room temperature for 4 hours. The reaction solution was reprecipitated in methanol, the solid was taken out by filtration, dissolved in dichloromethane, the organic layer was washed with distilled water, and reprecipitated to methanol / water = 7/3. The solid was then removed by filtration and then dried under reduced pressure at 92 ° C. to recover the product 12. The Mn of the product 12 was 24800, the Mw was 69000, the styrene ratio was 92.4 mol%, and the divinylbenzene ratio was 7.6 mol%.

(Example 13)
87.1 g of the dimethylformamide solution of the copolymer M obtained in Synthesis Example 14, 13.5 g of 37 mass% formalin, 16.7 g of the 28 mass% potassium hydroxide aqueous solution and 130.8 g of tetrahydrofuran were put into a 500 mL reactor. Then, the reaction was carried out at room temperature for 4 hours. The reaction solution was reprecipitated in methanol, the solid was taken out by filtration, dissolved in dichloromethane, the organic layer was washed with distilled water, and reprecipitated to methanol / water = 7/3. Then, the solid was taken out by filtration and then dried under reduced pressure at 92 ° C. to recover the product 13. The Mn of the product 13 was 16800, the Mw was 41800, the styrene ratio was 91.2 mol%, and the divinylbenzene ratio was 8.8 mol%.

(Comparative Example 1)
66.2 g of the dimethylformamide solution of the copolymer N obtained in Comparative Synthesis Example 1, 5.5 g of 37 mass% formalin, 7.7 g of the 28 mass% potassium hydroxide aqueous solution and 103.2 g of the tetrahydrofuran were placed in a 500 mL reactor. It was charged and reacted at room temperature for 4 hours. The reaction solution was reprecipitated in methanol, the solid was taken out by filtration, dissolved in dichloromethane, the organic layer was washed with distilled water, and reprecipitated to methanol / water = 7/3. The solid was then removed by filtration and then dried under reduced pressure at 92 ° C. to recover the product 14. The Mn of the product 14 was 22000, the Mw was 47500, the styrene ratio was 95.5 mol%, and the divinylbenzene ratio was 4.5 mol%.

(Comparative Example 2)
A reactor containing 151.0 g of a dimethylformamide solution of the copolymer O obtained in Comparative Synthesis Example 2, 59.8 g of 37 mass% formalin, 73.7 g of a 28 mass% potassium hydroxide aqueous solution and 269.4 g of tetrahydrofuran. It was put into the inside and reacted at room temperature for 5 hours. The reaction solution was reprecipitated in methanol, the solid was taken out by filtration, dissolved in dichloromethane, the organic layer was washed with distilled water, and reprecipitated to methanol / water = 7/3. The solid was then removed by filtration and then dried under reduced pressure at 92 ° C. to recover the product 15. The Mn of the product 15 was 12600, the Mw was 52200, the styrene ratio was 71.4 mol%, and the divinylbenzene ratio was 28.6 mol%.

(Comparative Example 3)
65.7 g of the dimethylformamide solution of the copolymer P obtained in Comparative Synthesis Example 3, 5.4 g of 37 mass% formalin, 7.1 g of the 28 mass% potassium hydroxide aqueous solution and 72.6 g of the tetrahydrofuran were placed in a 500 mL reactor. It was charged and reacted at room temperature for 5 hours. The reaction solution was reprecipitated in methanol, the solid was taken out by filtration, dissolved in dichloromethane, the organic layer was washed with distilled water, and reprecipitated to methanol / water = 7/3. The solid was then removed by filtration and then dried under reduced pressure at 92 ° C. to recover the product 16. The Mn of the product 16 was 19700, the Mw was 52000, the styrene ratio was 95.4 mol%, and the divinylbenzene ratio was 4.6 mol%.

(Comparative Example 4)
285.0 g of the copolymer Q, 37 mass% formalin 169.83 g, 28 mass% potassium hydroxide aqueous solution 209.66 g, and tetrahydrofuran 665.0 g obtained in Comparative Synthesis Example 4 were put into a 3 L reactor. Then, the reaction was carried out at room temperature for 4 hours. The reaction solution was reprecipitated in a large excess of methanol, the solid was removed by filtration, dissolved in dichloromethane, the organic layer was washed with distilled water, and reprecipitated to a large excess of methanol / water = 7/3. The solid was then removed by filtration and then dried under reduced pressure at 92 ° C. to recover the product 17. The Mn of the product 17 was 24700, the Mw was 39800, the styrene ratio was 92.1 mol%, and the divinylbenzene ratio was 7.9 mol%.

(Comparative Example 5)
20 g of the dimethylformamide solution of the copolymer R obtained in Comparative Synthesis Example 5, 3.8 g of 37 mass% formalin, 9.4 g of the 28 mass% potassium hydroxide aqueous solution, and 24 g of dimethylformamide were put into a 500 mL reactor. Then, the reaction was carried out at room temperature for 1 hour. The precipitated solid was dissolved in dichloromethane, reprecipitated in isopropyl alcohol, and the solid was removed by filtration. It was dissolved in dichloromethane again, the organic layer was washed with distilled water, and reprecipitated to methanol / water = 7/3. The solid was then removed by filtration and then dried under reduced pressure at 92 ° C. to recover the product 18. The Mn of the product 18 was 26600, the Mw was 48900, the styrene ratio was 85.3 mol%, and the divinylbenzene ratio was 14.7 mol%.

(Comparative Example 6)
6.00 g of the copolymer S obtained in Comparative Synthesis Example 6, 5.47 g of 37 mass% formalin, 6.00 g of a 28 mass% potassium hydroxide aqueous solution, and 150 g of tetrahydrofuran were placed in a 500 mL reactor. The reaction was carried out at room temperature for 4 hours. The reaction solution was reprecipitated in methanol, the solid was taken out by filtration, and then dried under reduced pressure at 92 ° C. to recover the product 19. The Mn of the product 19 was 24300, the Mw was 39200, the styrene ratio was 95.7 mol%, and the divinylbenzene ratio was 4.3 mol%.

(Comparative Example 7)
29.7 g of the dimethylformamide solution of the copolymer T obtained in Comparative Synthesis Example 7, 6.1 g of 37 mass% formalin, 7.6 g of the 28 mass% potassium hydroxide aqueous solution, and 70 g of tetrahydrofuran were placed in a 300 mL reactor. It was charged and reacted at room temperature for two and a half hours. The reaction solution was reprecipitated in methanol, the solid was taken out by filtration, dissolved in dichloromethane, the organic layer was washed with distilled water, and reprecipitated to methanol / water = 7/3. The solid was then removed by filtration and then dried under reduced pressure at 92 ° C. to recover the product 20. The Mn of the product 20 was 3400, the Mw was 8400, the styrene ratio was 91.9 mol%, and the divinylbenzene ratio was 8.1 mol%.

(Comparative Example 8)
In a 1 L reactor, 280.0 g of a dimethylformamide solution of the copolymer U obtained in Comparative Synthesis Example 8, 48.5 g of 37 mass% formalin, 59.5 g of a 28 mass% potassium hydroxide aqueous solution, and 93.8 g of tetrahydrofuran were added. And reacted at room temperature for 7 hours. Dichloromethane was added to the reaction solution and then reprecipitated in methanol. The solid was taken out by filtration, dissolved in dichloromethane, the organic layer was washed with distilled water, and reprecipitated to methanol / water = 7/3. The solid was then removed by filtration and then dried under reduced pressure at 92 ° C. to recover the product 21. The Mn of the product 21 was 24200, the Mw was 43300, the styrene ratio was 75.0 mol%, and the divinylbenzene ratio was 25.0 mol%.

The dielectric constant, dielectric loss tangent, thermosetting property and residual amount of vinyl groups were evaluated for the products obtained in Examples 1 to 13 and Comparative Examples 1 to 8. The results are shown in Tables 1 to 5 below.

As shown in Tables 4 and 5, in Comparative Examples 1 and 3 and Comparative Example 6, the divinylbenzene ratio was low, the thermosetting property was insufficient, and a test piece for evaluating the dielectric constant and the dielectric loss tangent could not be prepared. .. Therefore, the permittivity and the dielectric loss tangent are not measured, and the residual amount of vinyl groups is not evaluated.

In Comparative Example 2, the ratio of divinylbenzene was high, and therefore the residual amount of unreacted vinyl groups was inferior.

In Comparative Examples 4 and 5 and Comparative Examples 7 and 8, azobisisobutyronitrile was used as a polymerization initiator when synthesizing the copolymer, so that the dielectric loss tangent was inferior due to the presence of the cyano group in the product. ..

On the other hand, in the products of Examples 1 to 13, since the divinylbenzene ratio was within the specified range, the thermosetting property was excellent and the residual amount of vinyl groups was lower than that of Comparative Example 2. .. Further, since the products of Examples 1 to 13 are linear vinyl copolymers having a terminal structure derived from the polymerization initiator of the above formula (1) or the above formula (2) and have no cyano group at the terminal. , The dielectric loss tangent was lower than that of the products of Comparative Examples 4 and 5 and Comparative Examples 7 and 8, and the dielectric properties were excellent. Further, in the products of Examples 1 to 13, a sufficient sheet could be formed so as to be self-supporting without using a thermoplastic resin or a cross-linking agent, and the formability was excellent.

When Examples 1 to 5 using the polymerization initiator of the formula (1) and Examples 6 to 13 using the polymerization initiator of the formula (2) were compared, Examples 1 to 5 were more dielectric loss tangent. Showed a low tendency. It is considered that this is because when the polymerization initiator of the formula (2) is used, an ether bond is introduced at the terminal, whereas a hetero atom is not introduced in the formula (1).

It should be noted that the various numerical ranges described in the specification can be arbitrarily combined with the upper limit value and the lower limit value, respectively, and it is assumed that all combinations thereof are described in the present specification as a preferable numerical range. Further, the description of the numerical range of "X to Y" means X or more and Y or less.

Although some embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments, omissions, replacements, changes, etc. thereof are included in the scope and gist of the invention, as well as in the scope of the invention described in the claims and the equivalent scope thereof.

Claims (7)

It has a repeating unit corresponding to a monovinyl aromatic compound and a repeating unit corresponding to a divinyl aromatic compound, and the content of the repeating unit corresponding to the divinyl aromatic compound is 5.0 to 25.0 mol%. A chain-shaped vinyl copolymer having a structure derived from a polymerization initiator represented by the general formula (1): R1 ^- N = N- ^R2 at the end thereof, or the general formula ( ² ): R3. It has at least one of the structures derived from the polymerization initiator represented by —O— ^R4 , and ^R1 , ^{R2 ,} R3 and ^R4 in the general formulas (1) and (2) are independent of each other. A thermocurable resin that represents a monovalent saturated or aromatic hydrocarbon group. A copolymer obtained by copolymerizing a vinylbenzylphosphonium salt with a monovinyl aromatic compound using at least one of the polymerization initiator represented by the general formula (1) or the polymerization initiator represented by the general formula (2). The thermosetting resin according to claim 1, which has a structure obtained by reacting a polymer with formaldehyde. The thermosetting resin according to claim 1 or 2, which is a random copolymer having a repeating unit corresponding to the monovinyl aromatic compound and a repeating unit corresponding to the divinyl aromatic compound. The thermosetting resin according to any one of claims 1 to 3, wherein the number average molecular weight Mn and the weight average molecular weight Mw are 3,000 or more and 100,000 or less, respectively. A cured product obtained by curing the thermosetting resin according to any one of claims 1 to 4. A thermosetting composition comprising the thermosetting resin according to any one of claims 1 to 4. The thermosetting composition according to claim 6, which is a printed circuit board material.