JP2024061610A - Polymers, compositions, cured products, laminates, and electronic components - Google Patents

Abstract

[Problem] To provide a polymer having a low dielectric constant and a low dielectric dissipation factor, and to provide a composition and a laminate having a low dielectric constant and a low dielectric dissipation factor, and having a good balance of excellent curability, adhesion, heat resistance, and linear expansion coefficient. [Solution] A polymer (A) having a repeating structural unit represented by the following formula (1). TIFF2024061610000063.tif17170 [R11 represents a divalent substituted or unsubstituted nitrogen-containing heteroaromatic ring, R12 independently represents a divalent substituted or unsubstituted aromatic hydrocarbon group, R13 represents a hydrocarbon group having 1 to 20 carbon atoms to which at least one group represented by formula (a1) is bonded other than the two R12s, X1 independently represents -O-, -S-, or -N(R14)-, * represents a bond to R13, and ** represents a bond to another structural unit in the polymer (A). ] [Selected Figure] None

Description

One embodiment of the present invention relates to a polymer, a composition, a cured product, a laminate, or an electronic component.

In recent years, in the field of information and communications, the signal band of information and communications devices has become increasingly high-frequency in order to achieve high-speed, large-capacity transmission. To accommodate this increase in frequency, there is an increasing demand for low-dielectric and low-dielectric-tangent materials for the insulators used in printed wiring boards and semiconductor packages. In addition, since the insulators are in contact with metal wiring such as copper, it is desirable for the insulator material to have a linear expansion coefficient due to heat generation during electrical conduction that is close to that of the metal type of the wiring.

As materials that can handle this increased frequency, compositions using polyolefin resin, styrene resin, fluororesin, polyphenylene ether resin, vinylbenzyl ether resin, or polyphenylene ether resin have been proposed (Patent Documents 1 to 6).

Japanese Patent Application Laid-Open No. 7-188362 JP 2004-83680 A Japanese Patent No. 3414556 JP 2003-306591 A Patent No. 5649773 JP 2017-200997 A

However, although conventional materials such as the compositions described in Patent Documents 1 to 6 are somewhat excellent in terms of low dielectric constant and low dielectric tangent, they do not necessarily satisfy all of the requirements for properties necessary for electronic materials, such as heat resistance and adhesiveness.
For example, compositions using polyphenylene ether resins and fluororesins have low dielectric constant, low dielectric tangent, and excellent heat resistance, but the adhesion to low-roughened copper foil is insufficient, and the difference in linear expansion coefficient with copper is large. In addition, when copper wiring is formed due to the difference in linear expansion coefficient with copper, disconnection or connection failure may occur. In order to reduce the difference in linear expansion coefficient, a method of using an inorganic filler in combination is generally used, but if the amount added is too large, there is a problem that the adhesion with copper wiring is reduced. In this way, it is difficult to balance various physical properties with compositions using polyphenylene ether resins and fluororesins. In addition, the composition described in Patent Document 6 had room for improvement in terms of low dielectric properties.

One of the objectives of the present invention is to provide a polymer with a low dielectric constant and a low dielectric dissipation factor, and to provide a composition and a laminate that have a low dielectric constant and a low dielectric dissipation factor, and that have a good balance of curability, adhesion, heat resistance, and linear expansion coefficient.

As a result of intensive research into solving the above problems, the present inventors have found that the above problems can be solved by the following configuration examples.
[1]
A polymer (A) having a repeating structural unit represented by the following formula (1):

［前記式（１）において、
Ｒ¹¹は、２価の置換もしくは非置換の含窒素複素芳香族環を表し、
Ｒ¹²は、独立に２価の置換もしくは非置換の芳香族炭化水素基を表し、
Ｒ¹³は、２つのＲ¹²以外に下記式（ａ１）で表される基が少なくとも１つ結合した炭素数１～２０の炭化水素基を表し、
Ｘ¹は、独立に－Ｏ－、－Ｓ－、または－Ｎ（Ｒ¹⁴）－を表し、
Ｒ¹⁴は、水素原子、炭素数１～２０の１価の炭化水素基、炭素数１～２０の１価のハロゲン化炭化水素基、または、前記炭化水素基もしくはハロゲン化炭化水素基における一部が酸素原子および硫黄原子から選ばれる少なくとも１つで置換された基である。］

[In the formula (1),
R ¹¹ represents a divalent substituted or unsubstituted nitrogen-containing heteroaromatic ring;
R ¹² independently represents a divalent substituted or unsubstituted aromatic hydrocarbon group;
R ¹³ represents a hydrocarbon group having 1 to 20 carbon atoms to which at least one group represented by the following formula (a1) is bonded in addition to the two R ^12s :
X ¹ independently represents -O-, -S-, or -N(R ¹⁴ )-;
R ¹⁴ is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, or the above-mentioned hydrocarbon group or halogenated hydrocarbon group partially substituted with at least one atom selected from oxygen atoms and sulfur atoms.]

［前記式（ａ１）において、
＊は、前記Ｒ¹³への結合を表し、
＊＊は、前記重合体（Ａ）中の他の構造単位との結合手を表し、
Ｒ¹²およびＸ¹は、それぞれ前記式（１）中のＲ¹²およびＸ¹と同義である。］

[In the formula (a1),
* represents a bond to R ¹³ .
** represents a bond to another structural unit in the polymer (A),
R ¹² and X ¹ are the same as R ¹² and X ¹ in the formula (1), respectively.

[2]
The polymer (A) according to item [1], further comprising a repeating structural unit represented by the following formula (2):

［前記式（２）において、
Ｒ²¹は、２価の置換もしくは非置換の含窒素複素芳香族環を表し、
Ｒ²²は、主鎖に置換もしくは非置換の芳香族炭化水素基を含む２価の基を表し、
Ｘ²は、独立に－Ｏ－、－Ｓ－、または－Ｎ（Ｒ²⁴）－を表し、
Ｒ²⁴は、水素原子、炭素数１～２０の１価の炭化水素基、炭素数１～２０の１価のハロゲン化炭化水素基、または、前記炭化水素基もしくはハロゲン化炭化水素基における一部が酸素原子および硫黄原子から選ばれる少なくとも１つで置換された基である。］

[In the formula (2),
^R21 represents a divalent substituted or unsubstituted nitrogen-containing heteroaromatic ring;
R ²² represents a divalent group containing a substituted or unsubstituted aromatic hydrocarbon group in the main chain,
^X2 independently represents -O-, -S-, or -N( ^R24 )-;
R ²⁴ is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, or the above-mentioned hydrocarbon group or halogenated hydrocarbon group partially substituted with at least one atom selected from oxygen atoms and sulfur atoms.]

[3]
The polymer (A) according to item [1] or [2], having a group Y represented by the following formula (y) at its terminal:

［前記式（ｙ）において、Ｙは、炭素数３～５０のエチレン性不飽和二重結合を含有する基、炭素数６～５０の置換もしくは非置換の芳香族炭化水素基、炭素数６～５０の置換もしくは非置換の脂肪族炭化水素基、または、非置換含窒素複素芳香族環である。］

[In the formula (y), Y is a group containing an ethylenically unsaturated double bond having 3 to 50 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 50 carbon atoms, a substituted or unsubstituted aliphatic hydrocarbon group having 6 to 50 carbon atoms, or an unsubstituted nitrogen-containing heteroaromatic ring.]

[4]
When all structural units contained in the polymer (A) are taken as 100 mol%, the repeating structural unit represented by the formula (1) is contained in a range of 5 mol% to 95 mol%. The polymer (A) according to any one of items [1] to [3].

[5]
The polymer (A) according to any one of items [1] to [4], wherein —R ¹² — in the formulas (1) and (a1) is independently a structure represented by the following formula (5):

［前記式（５）において、
＊は、前記Ｒ¹³への結合を表し、
＊＊＊は、前記Ｘ¹との結合手を表し、
Ｒ⁵¹は、炭素数１～１０のアルキル基、炭素数１～１０のアルコキシ基、または炭素数３～１０のシクロアルキル基を表し、ｎ⁵²は０～４の整数を表し、ｎ⁵³は０～２の整数を表す。］

[In the formula (5),
* represents a bond to R ¹³ .
*** represents a bond to ^X1 ,
R ⁵¹ represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms, n ⁵² represents an integer of 0 to 4, and n ⁵³ represents an integer of 0 to 2.]

[6]
The polymer (A) according to item [5], wherein the structure represented by the formula (5) is the following formula (5-1) or the following formula (5-2):

［前記式（５－１）、式（５－２）において、
＊は、前記Ｒ¹³への結合を表し、
＊＊＊は、前記Ｘ¹との結合手を表し、
Ｒ⁵¹およびｎ⁵³は、式（５）中のＲ⁵¹およびｎ⁵³と同義であり、
ｎ⁵⁴は０～３の整数を表し、ｎ⁵⁵は０～２の整数を表し、
Ｒ⁵²は炭素数１～１０のアルキル基、炭素数１～１０のアルコキシ基、または炭素数３～１０のシクロアルキル基を表す。］

[In the formula (5-1) and formula (5-2),
* represents a bond to R ¹³ .
*** represents a bond to ^X1 ,
R ⁵¹ and n ⁵³ have the same meanings as R ⁵¹ and n ⁵³ in formula (5);
n ⁵⁴ represents an integer of 0 to 3, and n ⁵⁵ represents an integer of 0 to 2;
R ⁵² represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms.]

[7]
A composition comprising the polymer (A) according to item [1] and a curable compound (B) other than the polymer (A).

[8]
The curable compound (B) is at least one selected from the group consisting of vinyl compounds, maleimide compounds, allyl compounds, acrylic compounds, methacrylic compounds, thiol compounds, oxazine compounds, cyanate compounds, epoxy compounds, oxetane compounds, methylol compounds, benzocyclobutene compounds, propargyl compounds, and silane compounds. The composition according to item [7].

[9]
The composition according to item [7] or [8], further comprising at least one selected from the group consisting of hindered phenol compounds, phosphorus compounds, sulfur compounds, metal compounds, and hindered amine compounds.

[10]
A composition containing a polymer (A2) having a repeating structural unit represented by the following formula (3) and a repeating structural unit represented by the following formula (4), and a curable compound (B2) other than the polymer (A2).

［前記式（３）において、
Ｒ³¹は、炭素数３～１０の２価の有機基を表し、
Ｒ³²は、独立に２価の置換もしくは非置換の芳香族炭化水素基を表し、
Ｒ³³は、２つのＲ¹²と下記式（ａ２）で表される基が少なくとも１つ結合した炭素数１～２０の炭化水素基を表す。］

[In the formula (3),
R ³¹ represents a divalent organic group having 3 to 10 carbon atoms;
R ³² independently represents a divalent substituted or unsubstituted aromatic hydrocarbon group;
R ³³ represents a hydrocarbon group having 1 to 20 carbon atoms in which two R ¹² and at least one group represented by the following formula (a2) are bonded.]

［前記式（ａ２）において、
＊は、前記Ｒ³³への結合を表し、
＊＊は、前記重合体（Ａ２）中の他の構造単位との結合手を表し、
Ｒ³²は、前記式（３）中のＲ³²と同義である。］

[In the formula (a2),
* represents a bond to R ³³ ,
** represents a bond to another structural unit in the polymer (A2),
R ³² has the same meaning as R ³² in the formula (3).

［前記式（４）において、
Ｒ⁴¹は、炭素数３～１０の２価の有機基を表し、
Ｒ⁴²は、主鎖に置換もしくは非置換の芳香族炭化水素基を含む２価の基を表し、式中の酸素原子は前記芳香族炭化水素基に直接結合している。］

[In the formula (4),
R ⁴¹ represents a divalent organic group having 3 to 10 carbon atoms;
R ⁴² represents a divalent group containing a substituted or unsubstituted aromatic hydrocarbon group in the main chain, and the oxygen atom in the formula is directly bonded to the aromatic hydrocarbon group.

[11]
The composition according to item [10], wherein the polymer (A2) has a group Y represented by the following formula (y) at its terminal.

［前記式（ｙ）において、Ｙは、炭素数３～５０のエチレン性不飽和二重結合を含有する基、炭素数６～５０の置換もしくは非置換の芳香族炭化水素基、炭素数６～５０の置換もしくは非置換の脂肪族炭化水素基、または、非置換含窒素複素芳香族環である。］

[In the formula (y), Y is a group containing an ethylenically unsaturated double bond having 3 to 50 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 50 carbon atoms, a substituted or unsubstituted aliphatic hydrocarbon group having 6 to 50 carbon atoms, or an unsubstituted nitrogen-containing heteroaromatic ring.]

[12]
The curable compound (B2) is a vinyl compound, a maleimide compound, an allyl compound, an acrylic compound, a methacrylic compound, a thiol compound, an oxazine compound, a cyanate compound, an epoxy compound, an oxetane compound, a methylol compound, a benzocyclobutene compound, a propargyl compound, and a silane compound. The composition according to item [10] or [11], which includes at least one selected from the group consisting of silane compounds.

[13]
The composition according to any one of items [10] to [12], further comprising an antioxidant.
[14]
A cured product which is a cured product of the composition according to any one of items [7] to [13].
[15]
A laminate having a substrate and a cured layer formed using the composition according to any one of items [7] to [13].

[16]
Item [14] An electronic component having the cured product according to item [14].
[17]
An electronic component having the laminate according to item [15].

According to one embodiment of the present invention, it is possible to provide a polymer with a low dielectric constant and a low dielectric tangent, and to obtain a composition and a laminate that have a low dielectric constant and a low dielectric tangent, and also have a well-balanced excellent curability, adhesion, heat resistance, and linear expansion coefficient.

The following describes in detail preferred embodiments of the present invention. Note that the present invention is not limited to the embodiments described below, and should be understood to include various modifications that are implemented within the scope of the present invention.

In this specification, a numerical range described using "~" means that the numerical values before and after "~" are included as the lower and upper limits.

The polymer, composition, cured product, laminate, and electronic component according to one embodiment of the present invention will be described in detail below.

Polymer
A polymer according to one embodiment of the present invention (hereinafter also referred to as “polymer (A)”) has a repeating structural unit represented by the following formula (1) (hereinafter also referred to as “repeating unit (1)”).

［前記式（１）において、
Ｒ¹¹は、２価の置換もしくは非置換の含窒素複素芳香族環を表し、
Ｒ¹²は、独立に２価の置換もしくは非置換の芳香族炭化水素基を表し、
Ｒ¹³は、２つのＲ¹²以外に下記式（ａ１）で表される基が少なくとも１つ結合した炭素数１～２０の炭化水素基を表し、
Ｘ¹は、独立に－Ｏ－、－Ｓ－、または－Ｎ（Ｒ¹⁴）－を表し、
Ｒ¹⁴は、水素原子、炭素数１～２０の１価の炭化水素基、炭素数１～２０の１価のハロゲン化炭化水素基、または、前記炭化水素基もしくはハロゲン化炭化水素基における一部が酸素原子および硫黄原子から選ばれる少なくとも１つで置換された基である。］

[In the formula (1),
R ¹¹ represents a divalent substituted or unsubstituted nitrogen-containing heteroaromatic ring;
R ¹² independently represents a divalent substituted or unsubstituted aromatic hydrocarbon group;
R ¹³ represents a hydrocarbon group having 1 to 20 carbon atoms to which at least one group represented by the following formula (a1) is bonded in addition to the two R ^12s :
X ¹ independently represents -O-, -S-, or -N(R ¹⁴ )-;
R ¹⁴ is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, or the above-mentioned hydrocarbon group or halogenated hydrocarbon group partially substituted with at least one atom selected from oxygen atoms and sulfur atoms.]

［前記式（ａ１）において、
＊は、前記Ｒ¹³への結合を表し、
＊＊は、前記重合体（Ａ）中の他の構造単位との結合手を表し、
Ｒ¹²およびＸ¹は、それぞれ前記式（１）中のＲ¹²およびＸ¹と同義である。］

[In the formula (a1),
* represents a bond to R ¹³ .
** represents a bond to another structural unit in the polymer (A),
R ¹² and X ¹ are the same as R ¹² and X ¹ in the formula (1), respectively.

^R11 in the formula (1) represents a divalent substituted or unsubstituted nitrogen-containing heteroaromatic ring. Specific examples of the nitrogen-containing heteroaromatic ring include a pyrrole ring, a pyridine ring, a pyrimidine ring, a pyrazine ring, a pyridazine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, a phthalazine ring, a quinazoline ring, a naphthyridine ring, a carbazole ring, an acridine ring, and a phenazine ring.

As the nitrogen-containing heteroaromatic ring, a pyrimidine ring is preferred from the viewpoints that polymer (A) can be synthesized with good polymerization reactivity and that polymer (A) having excellent solubility in various organic solvents can be easily obtained.

The positions of the two bonds (bonds bonded to ^X1 , etc.) bonded to the nitrogen-containing heteroaromatic ring are not particularly limited, but from the viewpoint of synthesizing the polymer (A) with good polymerization reactivity, the meta positions are preferred.

Examples of the substituents in the nitrogen-containing heteroaromatic ring include halogen atoms, monovalent hydrocarbon groups having 1 to 20 carbon atoms, monovalent halogenated hydrocarbon groups having 1 to 20 carbon atoms, groups in which a portion of these hydrocarbon groups or halogenated hydrocarbon groups is substituted with at least one atom selected from oxygen atoms and sulfur atoms, nitro groups, cyano groups, amino groups, and salts of amino groups.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include a monovalent linear hydrocarbon group, a monovalent alicyclic hydrocarbon group, and a monovalent aromatic hydrocarbon group.

Examples of the chain hydrocarbon group include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, and n-pentyl; alkenyl groups such as ethenyl, propenyl, butenyl, and pentenyl; and alkynyl groups such as ethynyl, propynyl, butynyl, and pentynyl.

Examples of the monovalent alicyclic hydrocarbon group include monocyclic cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups; polycyclic cycloalkyl groups such as norbornyl and adamantyl groups; monocyclic cycloalkenyl groups such as cyclopropenyl, cyclobutenyl, cyclopentenyl, and cyclohexenyl groups; and polycyclic cycloalkenyl groups such as norbornenyl groups.

Examples of the monovalent aromatic hydrocarbon group include aryl groups such as phenyl, tolyl, xylyl, naphthyl, and anthryl; and aralkyl groups such as benzyl, phenethyl, phenylpropyl, and naphthylmethyl.

Examples of the monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms include groups in which some or all of the hydrogen atoms of the monovalent hydrocarbon group having 1 to 20 carbon atoms have been substituted with halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

Specific examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms or the monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms partially substituted with at least one selected from oxygen atoms and sulfur atoms include groups in which the hydrocarbon group or halogenated hydrocarbon group is partially substituted with -O-, -S-, an ester group, or a sulfonyl group.

The amino group is not particularly limited, and may be a primary amino group (-NH ₂ ), a secondary amino group (-NHR), or a tertiary amino group (-NR ₂ ).
The substituent (R) in the secondary amino group and tertiary amino group is not particularly limited, and examples thereof include the above-mentioned monovalent hydrocarbon groups having 1 to 20 carbon atoms.
The anion constituting the anion site in the salt of the amino group is not particularly limited, and examples thereof include known anions such as Cl ⁻ .

As the substituent in the nitrogen-containing heteroaromatic ring, from the viewpoint of synthesizing polymer (A) with good polymerization reactivity and improving the solubility of the monomers that are the raw materials of polymer (A), a halogen atom, a monovalent hydrocarbon group having 1 to 6 carbon atoms, a monovalent halogenated hydrocarbon group having 1 to 6 carbon atoms, a nitro group, a cyano group, an amino group, or a salt of an amino group is preferred, and a fluorine atom, a chlorine atom, a methyl group, a nitro group, a cyano group, a tert-butyl group, a phenyl group, or a primary amino group is more preferred.

Examples of monomers that can be used as raw materials for the moiety containing R ¹¹ include 4,6-dichloropyrimidine, 4,6-dibromopyrimidine, 2,4-dichloropyrimidine, 2,5-dichloropyrimidine, 2,5-dibromopyrimidine, 5-bromo-2-chloropyrimidine, 5-bromo-2-fluoropyrimidine, 5-bromo-2-iodopyrimidine, 2-chloro-5-fluoropyrimidine, and 2-chloro-5-iodopyrimidine. , 2-phenyl-4,6-dichloropyrimidine, 2-methylthio-4,6-dichloropyrimidine, 2-methylsulfonyl-4,6-dichloropyrimidine, 5-methyl-4,6-dichloropyrimidine, 2-amino-4,6-dichloropyrimidine, 5-amino-4,6-dichloropyrimidine, 2,5-diamino-4,6-dichloropyrimidine, 4-amino-2,6-dichloropyrimidine, 5-methoxy-4,6 pyrimidine compounds such as 2-dichloropyrimidine, 5-methoxy-2,4-dichloropyrimidine, 2-methyl-4,6-dichloropyrimidine, 6-methyl-2,4-dichloropyrimidine, 5-methyl-2,4-dichloropyrimidine, 5-nitro-2,4-dichloropyrimidine, 4-amino-2-chloro-5-fluoropyrimidine, 2-methyl-5-amino-4,6-dichloropyrimidine, and 5-bromo-4-chloro-2-methylthiopyrimidine; pyridazine compounds such as 3,6-dichloropyridazine, 3,5-dichloropyridazine, and 4-methyl-3,6-dichloropyridazine; and pyrazine compounds such as 2,3-dichloropyrazine, 2,6-dichloropyrazine, 2,5-dibromopyrazine, 2,6-dibromopyrazine, 2-amino-3,5-dibromopyrazine, and 5,6-dicyano-2,3-dichloropyrazine. These monomers may be used alone or in combination of two or more.

R ¹² in the formulas (1) and (a1) independently represents a divalent substituted or unsubstituted aromatic hydrocarbon group.

Examples of the divalent unsubstituted aromatic hydrocarbon group include aromatic hydrocarbon groups having 6 to 20 carbon atoms, such as a phenylene group, a naphthylene group, and an anthrylene group.

The substituent in the divalent substituted aromatic hydrocarbon group is not particularly limited, but examples include an allyl group, a halogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkylthio group having 1 to 20 carbon atoms, a nitro group, a cyano group, a carboxy group, a sulfonic acid group, a phosphonic acid group, a phosphoric acid group, a hydroxy group, a primary to tertiary amino group, a salt of a carboxy group, a salt of a sulfonic acid group, a salt of a phosphonic acid group, a salt of a phosphoric acid group, a salt of a hydroxy group, or a salt of a primary to tertiary amino group.

In order to improve the glass transition temperature (Tg) of the polymer (A), it is preferable that —R ¹² — in the formulas (1) and (a1) above is independently a structure represented by the following formula (5).

［前記式（５）において、
＊は、前記Ｒ¹³への結合を表し、
＊＊＊は、前記Ｘ¹との結合手を表し、
Ｒ⁵¹は、炭素数１～１０のアルキル基、炭素数１～１０のアルコキシ基、炭素数３～１０のシクロアルキル基、を表し、ｎ⁵²は０～４の整数を表し、ｎ⁵³は０～２の整数を表す。］

[In the formula (5),
* represents a bond to R ¹³ .
*** represents a bond to ^X1 ,
R ⁵¹ represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms, n ⁵² represents an integer of 0 to 4, and n ⁵³ represents an integer of 0 to 2.]

The structure represented by the formula (5) is preferably the following formula (5-1) or (5-2) from the viewpoint of maintaining a low dielectric constant and a low dielectric tangent and improving heat resistance (Tg of polymer (A)).

［前記式（５－１）、式（５－２）において、
＊は、前記Ｒ¹³への結合を表し、
＊＊＊は、前記Ｘ¹との結合手を表し、
Ｒ⁵¹およびｎ⁵³は、式（５）中のＲ⁵¹およびｎ⁵³と同義であり、
ｎ⁵⁴は０～３の整数を表し、ｎ⁵⁵は０～２の整数を表し、
Ｒ⁵²は炭素数１～１０のアルキル基、炭素数１～１０のアルコキシ基、または炭素数３～１０のシクロアルキル基を表す。］

[In the formula (5-1) and formula (5-2),
* represents a bond to R ¹³ .
*** represents a bond to ^X1 ,
R ⁵¹ and n ⁵³ have the same meanings as R ⁵¹ and n ⁵³ in formula (5);
n ⁵⁴ represents an integer of 0 to 3, and n ⁵⁵ represents an integer of 0 to 2;
R ⁵² represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms.]

Examples of the alkyl group having 1 to 10 carbon atoms in R ⁵¹ and R ⁵² include a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, and a n-pentyl group.

Examples of the alkoxy group having 1 to 10 carbon atoms in R ⁵¹ and R ⁵² include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, and an octyloxy group.

Examples of the cycloalkyl group having 3 to 10 carbon atoms in R ⁵¹ and R ⁵² include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group.

The n ⁵² represents an integer of 0 to 4, and preferably an integer of 1 to 3. The n ⁵³ represents an integer of 0 to 2, and preferably 0 or 1. The n ⁵⁴ represents an integer of 0 to 3, and preferably an integer of 0 to 2, and the n ⁵⁵ represents an integer of 0 to 2, and preferably 0 or 1.

R ¹³ in the formula (1) represents a hydrocarbon group having 1 to 20 carbon atoms to which at least one group represented by the formula (a1) is bonded in addition to the two R ^12. The structure of the hydrocarbon group is not particularly limited, and may contain an aromatic ring or an alicyclic ring.

When the portion of R ¹³ excluding the group represented by formula (a1) is represented by Z, the partial structure represented by -R ¹² -R ¹³ -R ¹² - in the repeating unit (1) can be represented by the following formula (1'): That is, the repeating unit (1) has a branched structure.
The branched structure is preferably formed by a tertiary or quaternary carbon in the Z.

［前記式（１'）において、ｎ¹は１以上の整数を表す。］

[In the formula (1'), ⁿ¹ represents an integer of 1 or more.]

An example of the monomer that is the raw material for the partial structure represented by -R ¹² -R ¹³ -R ¹² - is a compound represented by the following formula (6).

［前記式（６）において、
Ｚは、炭素数１～２０のｎ⁶¹価の炭化水素基を表し、
Ｒ⁶¹は、独立に炭素数１～１０のアルキル基、炭素数１～１０のアルコキシ基、または炭素数３～１０のシクロアルキル基を表し、
ｎ⁶¹は２以上４以下の整数を表し、
ｎ⁶²は独立して１～５の整数を表し、ｎ⁶³は０～４の整数を表し、１≦ｎ⁶²＋ｎ⁶³≦５である。］

[In the formula (6),
Z represents a hydrocarbon group having 1 to 20 carbon atoms and a valence of ⁿ⁶¹ ;
R ⁶¹ independently represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms;
n ⁶¹ represents an integer of 2 to 4,
n ⁶² independently represents an integer of 1 to 5, and n ⁶³ represents an integer of 0 to 4, and 1≦n ⁶² +n ⁶³ ≦5.]

The compound represented by formula (6) is preferably a compound represented by the following formula (6-1) or (6-2):

［前記式（６－１）および（６－２）において、Ｚ、Ｒ⁶¹およびｎ⁶¹は、前記式（６）中のＺ、Ｒ⁶¹およびｎ⁶¹と同義である。］

[In the formulas (6-1) and (6-2), Z, R ⁶¹ and n ⁶¹ have the same meanings as Z, R ⁶¹ and n ⁶¹ in the formula (6).]

Specific examples of the compound represented by formula (6) include the compounds shown below.

X ¹ in the formulas (1) and (a1) independently represents -O-, -S-, or -N( ^R )-. When X ¹ is -O-, it is preferable in terms of flexibility, solubility, and heat resistance. When X ¹ is -N( ^R )-, it is preferable in terms of adhesion, etc.

R ¹⁴ is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, or the above hydrocarbon group or halogenated hydrocarbon group partially substituted with at least one atom selected from oxygen atoms and sulfur atoms.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms and the monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms in R ¹⁴ include the monovalent hydrocarbon group having 1 to 20 carbon atoms and the monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms exemplified as the substituent in the nitrogen-containing heteroaromatic ring in R ^11. Specific examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms or the monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms in R ¹⁴ partially substituted with at least one atom selected from an oxygen atom and a sulfur atom include groups in which the hydrocarbon group or the halogenated hydrocarbon group is partially or entirely substituted with an ester group or a sulfonyl group.

From the viewpoint of enabling the synthesis of polymer (A) with good polymerization reactivity, R ¹⁴ is preferably a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms.
In addition, in formula (1), when two X's are both --N(R ¹⁴ )--, the two R ¹⁴ 's may be the same or different.

The ** in the formula (a1) represents a bond to another structural unit in the polymer (A). Here, the other structural unit may be another repeating unit (1), a repeating structural unit represented by the formula (2) described later, another structural unit, or a terminal group Y. When the ** in a certain repeating unit (1) represents a bond to another repeating unit (1), the ** is bonded to R ¹¹ in the other repeating unit (1) and is not bonded to X ¹ .

When all structural units contained in polymer (A) are taken as 100 mol%, the content of the repeating unit (1) is preferably in the range of 5 mol% to 95 mol%, more preferably 10 mol% to 90 mol%, and even more preferably 20 mol% to 80 mol%.

In addition to the repeating unit (1), the polymer (A) preferably further has a repeating structural unit represented by the following formula (2) (hereinafter also referred to as "repeating unit (2)").

［前記式（２）において、
Ｒ²¹は、２価の置換もしくは非置換の含窒素複素芳香族環を表し、
Ｒ²²は、主鎖に置換もしくは非置換の芳香族炭化水素基を含む２価の基を表し、
Ｘ²は、－Ｏ－、－Ｓ－、または－Ｎ（Ｒ²⁴）－を表し、
Ｒ²⁴は、水素原子、炭素数１～２０の１価の炭化水素基、炭素数１～２０の１価のハロゲン化炭化水素基、または、前記炭化水素基もしくはハロゲン化炭化水素基における一部が酸素原子および硫黄原子から選ばれる少なくとも１つで置換された基である。］

[In the formula (2),
^R21 represents a divalent substituted or unsubstituted nitrogen-containing heteroaromatic ring;
R ²² represents a divalent group containing a substituted or unsubstituted aromatic hydrocarbon group in the main chain,
^X2 represents -O-, -S-, or -N( ^R24 )-;
R ²⁴ is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, or the above-mentioned hydrocarbon group or halogenated hydrocarbon group partially substituted with at least one atom selected from oxygen atoms and sulfur atoms.]

In the formula (2), R ²¹ represents a divalent substituted or unsubstituted nitrogen-containing heteroaromatic ring.
Specific examples and preferred aspects of ^R21 are the same as those exemplified for ^R11 in the formula (1). In addition, the monomers that are the raw materials for the moiety containing ^R21 include the same monomers as those exemplified for ^R11 in the formula (1).

R ²² in the formula (2) represents a divalent group containing a substituted or unsubstituted aromatic hydrocarbon group in the main chain. The divalent group preferably contains a group represented by the following formula (2-1).

〔式（２－１）中、
Ａｒ¹及びＡｒ²はそれぞれ独立して、非置換若しくは置換の芳香族炭化水素基である。
Ｌは、単結合、－Ｏ－、－Ｓ－、－Ｎ（Ｒ⁸）－、－Ｃ（Ｏ）－、－Ｃ（Ｏ）－Ｏ－、－Ｃ（Ｏ）－ＮＨ－、－Ｓ（Ｏ）－、－Ｓ（Ｏ）₂－、－Ｐ（Ｏ）－、又は、２価の有機基である［Ｒ⁸は、水素原子、炭素数１～２０の１価の炭化水素基、又は、炭素数１～２０の１価のハロゲン化炭化水素基である。］。
ｙは、０～５の整数である。ｙが２以上の場合、複数のＡｒ¹及びＬは、それぞれ同一であっても異なっていてもよい。
Ｒ⁶及びＲ⁷はそれぞれ独立して、単結合、メチレン基又は炭素数２～４のアルキレン基である。〕

[In formula (2-1),
Ar ¹ and Ar ² each independently represent an unsubstituted or substituted aromatic hydrocarbon group.
L is a single bond, -O-, -S-, -N(R ⁸ )-, -C(O)-, -C(O)-O-, -C(O)-NH-, -S(O)-, -S(O) ₂ -, -P(O)-, or a divalent organic group [R ⁸ is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms.].
y is an integer of 0 to 5. When y is 2 or more, the multiple Ar ^1s and Ls may be the same or different.
R ⁶ and R ⁷ each independently represent a single bond, a methylene group, or an alkylene group having 2 to 4 carbon atoms.

The aromatic hydrocarbon groups represented by ^Ar1 and ^Ar2 are each independently preferably an aromatic hydrocarbon group having 6 to 30 carbon atoms, more preferably a phenyl group, a naphthyl group, or an anthryl group, and particularly preferably a phenyl group or a naphthyl group.

The aromatic hydrocarbon groups represented by Ar ¹ and Ar ² may each have 1 to 8 substituents. The number of substituents that the aromatic hydrocarbon groups represented by Ar ¹ and Ar ² have is preferably 0 to 8, more preferably 0 to 4, and even more preferably 0 to 2, from the viewpoint of enabling synthesis of polymer (A) with good polymerization reactivity, respectively.

The substituents in Ar ¹ and Ar ² are not particularly limited, and examples thereof include an allyl group, a halogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkylthio group having 1 to 20 carbon atoms, a nitro group, a cyano group, a carboxy group, a sulfonic acid group, a phosphonic acid group, a phosphoric acid group, a hydroxy group, a primary to tertiary amino group, a salt of a carboxy group, a salt of a sulfonic acid group, a salt of a phosphonic acid group, a salt of a phosphoric acid group, a salt of a hydroxy group, or a salt of a primary to tertiary amino group.

Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include monovalent chain hydrocarbon groups, monovalent alicyclic hydrocarbon groups, and monovalent aromatic hydrocarbon groups, with monovalent chain hydrocarbon groups being preferred in terms of the polymerizability and low dielectric properties of the polymer.

Examples of the chain hydrocarbon group include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, and n-pentyl; alkenyl groups such as ethenyl, propenyl, butenyl, and pentenyl; and alkynyl groups such as ethynyl, propynyl, butynyl, and pentynyl.

The divalent organic group in L is preferably a divalent organic group having 1 to 20 carbon atoms, such as a substituted or unsubstituted methylene group, an alkylene group having 2 to 20 carbon atoms, a halogenated alkylene group having 2 to 20 carbon atoms, a divalent cardo structure, or a group represented by the following formula (L1).

〔式（Ｌ１）中、Ｒ^cは、非置換若しくは置換の環員数５～３０の２価の脂環式炭化水素基である。〕

[In formula (L1), R ^c is an unsubstituted or substituted divalent alicyclic hydrocarbon group having 5 to 30 ring members.]

The substituted methylene group in L includes an alkyl group-substituted methylene group having 1 to 5 carbon atoms, such as 1-methylmethylene, 1-ethylmethylene, 1,1-dimethylmethylene, 1-ethyl-1-methylmethylene, and 1,1-bistrifluoromethylmethylene.

Examples of the alkylene group having 2 to 20 carbon atoms in L include an ethylene group, an n-propylene group, an isopropylene group, an n-butylene group, a sec-butylene group, a neopentylene group, a 4-methyl-pentane-2,2-diyl group, a nonane-1,9-diyl group, and a decane-1,1-diyl group.

Examples of halogenated methylene groups in L include groups in which some or all of the hydrogen atoms in a methylene group have been replaced with halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

Examples of halogenated alkylene groups having 2 to 20 carbon atoms in L include groups in which some or all of the hydrogen atoms in the alkylene group having 2 to 20 carbon atoms have been substituted with halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

The divalent cardo structure in L can be, for example, a divalent group derived from fluorene represented by the following formula (L2) (i.e., a group obtained by removing two hydrogen atoms from a compound having a fluorene skeleton).

〔式（Ｌ２）中、Ｒ₈及びＲ₉はそれぞれ独立して、水素原子、フッ素原子又は炭素数１～２０の１価の鎖状炭化水素基であり、ｋは独立して、０～４の整数である。〕

[In formula (L2), R ₈ and R ₉ each independently represent a hydrogen atom, a fluorine atom, or a monovalent chain hydrocarbon group having 1 to 20 carbon atoms, and k independently represents an integer of 0 to 4.]

The divalent cardo structure may be, for example, a structure derived from a compound represented by the following formula:

Examples of the unsubstituted or substituted divalent alicyclic hydrocarbon group having 5 to 30 ring members represented by R ^c include unsubstituted or substituted monocyclic alicyclic hydrocarbon groups having 5 to 15 ring members, unsubstituted or substituted monocyclic fluorinated alicyclic hydrocarbon groups having 5 to 15 ring members, unsubstituted or substituted polycyclic alicyclic hydrocarbon groups having 7 to 30 ring members, and unsubstituted or substituted polycyclic fluorinated alicyclic hydrocarbon groups having 7 to 30 ring members.

Examples of the unsubstituted or substituted monocyclic alicyclic hydrocarbon group having 5 to 15 ring members include cyclopentane-1,1-diyl group, cyclohexane-1,1-diyl group, 3,3,5-trimethylcyclohexane-1,1-diyl group, cyclopentene-3,3-diyl group, cyclohexene-3,3-diyl group, cyclooctane-1,1-diyl group, cyclodecane-1,1-diyl group, cyclododecane-1,1-diyl group, and groups in which some or all of the hydrogen atoms of these groups have been substituted with monovalent chain hydrocarbon groups having 1 to 20 carbon atoms.

Examples of the unsubstituted or substituted monocyclic fluorinated alicyclic hydrocarbon group having 5 to 15 ring members include groups in which some or all of the hydrogen atoms in the groups exemplified as the monocyclic alicyclic hydrocarbon group having 5 to 15 ring members are substituted with fluorine atoms.

Examples of the unsubstituted or substituted polycyclic alicyclic hydrocarbon group having 7 to 30 ring members include groups in which two hydrogen atoms bonded to one carbon atom of a polycyclic alicyclic hydrocarbon such as norbornane, norbornene, adamantane, tricyclo[5.2.1.0 ^2,6 ]decane, tricyclo[5.2.1.0 ^2,6 ]heptane, pinane, camphane, decalin, nortricyclane, perhydroanthracene, perhydroazulene, cyclopentanohydrophenanthrene, and bicyclo[2.2.2]-2-octene have been removed, and these groups have had some or all of the hydrogen atoms substituted with monovalent chain hydrocarbon groups having 1 to 20 carbon atoms.

Examples of the unsubstituted or substituted polycyclic fluorinated alicyclic hydrocarbon group having 7 to 30 ring members include groups in which some or all of the hydrogen atoms in the groups exemplified as the polycyclic alicyclic hydrocarbon group having 7 to 30 ring members are substituted with fluorine atoms.

R ⁸ in -N(R ⁸ )- is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms. Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms and the monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms include the monovalent hydrocarbon groups having 1 to 20 carbon atoms and the monovalent halogenated hydrocarbon groups having 1 to 20 carbon atoms exemplified above for Ar ¹ .

From the viewpoint of the structural stability of polymer (A), L is preferably a single bond, -O-, -S-, -C(O)-, -S(O)-, -S(O) _2- , -C(O)-NH-, -C(O)-O-, a methylene group, an alkyl group substituted with a methylene group having 1 to 5 carbon atoms, an alkylene group having 2 to 5 carbon atoms, a halogenated methylene group, a halogenated alkylene group having 2 to 10 carbon atoms, or a divalent cardo structure.
From the same viewpoint, y is preferably 0 to 4, more preferably 0 to 3, and particularly preferably 0 or 1.

Examples of the alkylene group having 2 to 4 carbon atoms for R ⁶ and R ⁷ include an ethylene group, an n-propylene group, an isopropylene group, an n-butylene group, and a sec-butylene group.
From the viewpoint of enabling the synthesis of the polymer (A) with good polymerization reactivity, R ⁶ and R ⁷ are preferably each independently a single bond, a methylene group, or an ethylene group.

Examples of monomers that can be used as raw materials for the portion containing R ²² include dihydroxyphenyl compounds such as hydroquinone, resorcinol, catechol, and phenylhydroquinone; 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 9,9-bis(4-hydroxy-3-phenylphenyl)fluorene, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, bis(4-hydroxyphenyl)diphenylmethane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-allylphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxy-3-phenylphenyl)propane, 4,4'-(1,3-dimethylbutylidene)bisphenol, 1,1-bis(4-hydroxyphenyl)-nonane, bis(4-hydroxyphenyl)diphenylmethane ... bisphenol compounds such as 1,4-bis[2-(4-hydroxyphenyl)-2-propyl]benzene, 1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene, 4,4'-cyclododecylidenebisphenol, 4,4'-decylidenebisphenol, and 4,4'-dihydroxy-2,2',3,3',5,5'-hexamethylbiphenyl; and diol compounds such as Priplast 1901, 1838, 3186, 3192, 3197, and 3199 (manufactured by Croda Japan Co., Ltd.). These monomers may be used alone or in combination of two or more.

X ² in the formula (2) is independently -O-, -S-, or -N(R ²⁴ )-. Specific examples and preferred aspects of X ² are the same as those exemplified for X ¹ in the formula (1).

When ** in the repeating unit (1) represents a bond to the repeating unit (2), the ** is bonded to R ²¹ in the repeating unit (2) and is not bonded to X ² .

When all structural units contained in polymer (A) are taken as 100 mol%, the content of repeating unit (2) is preferably in the range of 5 mol% to 95 mol%, more preferably 10 mol% to 90 mol%, and even more preferably 20 mol% to 80 mol%.

［前記式（ｙ）において、Ｙは、炭素数３～５０のエチレン性不飽和二重結合を含有する基、炭素数６～５０の置換もしくは非置換の芳香族炭化水素基、炭素数６～５０の置換もしくは非置換の脂肪族炭化水素基、または、非置換含窒素複素芳香族環である。］ The polymer (A) preferably has a group Y (hereinafter also referred to as "terminal group Y") represented by the following formula (y) at its terminal.

[In the formula (y), Y is a group containing an ethylenically unsaturated double bond having 3 to 50 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 50 carbon atoms, a substituted or unsubstituted aliphatic hydrocarbon group having 6 to 50 carbon atoms, or an unsubstituted nitrogen-containing heteroaromatic ring.]

When the terminal group Y is bonded to the repeating unit (1), for example, it is bonded to ^X1 but not to ^R11 . Similarly, when the terminal group Y is bonded to the repeating unit (2), it is bonded to ^X2 but not to ^R21 .

In order to improve the dielectric properties, the terminal group Y is preferably an aromatic or aliphatic hydrocarbon group or a nitrogen-containing heteroaromatic ring with low polarization, and if it further contains an ethylenically unsaturated double bond, the crosslink density can be improved, and heat resistance and curability can be expected.

Examples of the group containing an ethylenically unsaturated double bond having 3 to 50 carbon atoms include aromatic ring-containing groups such as 3-isopropenylphenyl group, 4-isopropenylphenyl group, 2-allylphenyl group, 2-methoxy-4-allylphenyl group, 4-(1-propenyl)-2-methoxyphenyl group, 4-vinylbenzyl group, 3-vinylbenzyl group, and 2-vinylbenzyl group, allyl group, acrylic group, methacrylic group, and methallyl group.

Examples of aromatic hydrocarbon groups having 6 to 50 carbon atoms include aryl groups such as phenyl, biphenyl, tolyl, xylyl, naphthyl, and anthryl; and aralkyl groups such as benzyl, phenethyl, phenylpropyl, and naphthylmethyl.

Examples of the aliphatic hydrocarbon group having 6 to 50 carbon atoms include monocyclic cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups; polycyclic cycloalkyl groups such as norbornyl and adamantyl groups; monocyclic cycloalkenyl groups such as cyclopropenyl, cyclobutenyl, cyclopentenyl, and cyclohexenyl groups; and polycyclic cycloalkenyl groups such as norbornenyl groups.

Examples of the unsubstituted nitrogen-containing heteroaromatic ring include the same rings as those exemplified for R ¹¹ above.

The substituent in the unsubstituted or substituted aromatic hydrocarbon group having 6 to 50 carbon atoms, the unsubstituted or substituted aliphatic hydrocarbon group having 6 to 50 carbon atoms, and the unsubstituted nitrogen-containing heteroaromatic ring is a group other than a hydroxy group, and specific examples thereof include the same groups as those exemplified as the substituent in Ar ¹ .

Polymer (A) having ^its ends capped with terminal group ^Y can be ^obtained by reacting, as raw materials, at least one monomer for forming terminal group Y selected from the group consisting of ^monohydric phenols, monohydric amines, monohydric thiols, monohydric aromatics, monohydric aliphatic halides, monohydric acid halides, and monohydric acid anhydrides in addition to the monomers that give R 11 and R 12 -R 13 -R 12 in formula (1).

When synthesizing a polymer (A) in which the terminal group Y contains a double bond, for example, in order to avoid gelation caused by reaction ^between double bonds in the monomer for forming the terminal group Y during polymerization of a monomer serving as a raw material for the portion containing R ¹¹ and a monomer serving as a raw material for the portion containing R ¹² and R ¹³ , the monomer for forming the terminal group Y may be added and reacted after polymerization of the monomer serving as a raw material for the portion containing R ¹¹ and the monomer serving as a raw material for the portion containing R 12 and R ¹³ .

Examples of monomers for forming the terminal group Y include monohydric phenol compounds such as t-butylphenol, nonylphenol, 4-isopropenylphenol, 4-vinylphenol, 2-allylphenol, isoeugenol, tocotrienol, α-tocophenol, 4-hydroxyphenylmaleimide, and 2-phenylphenol; monohydric amine compounds such as 4-hexylaniline and diallylamine; monohydric thiol compounds such as 1-octanethiol; monohydric aliphatic halides such as allyl chloride, 4-(chloromethyl)styrene, and 3-(chloromethyl)styrene; monohydric acid halides such as acryl chloride, methacryl chloride, crotonoyl chloride, and cinnamoyl chloride; and monohydric acid anhydrides such as acrylic anhydride, crotonic anhydride, and methacrylic anhydride. These monomers may be used alone or in combination of two or more.

The polymer (A) may have other structural units as necessary in addition to the repeating units (1) and (2) and the terminal group Y. Thus, the repeating units (1) may be bonded to each other, or to the repeating unit (2), the other structural units, or the terminal group Y, for example.

When the polymer (A) has a plurality of repeating units (1), the plurality of R ¹¹ may be the same or different from each other, and the same applies to R ¹² , R ¹³ , the repeating unit (2), and other structural units.

Examples of monomers that derive the other structural units include compounds that derive structural units containing a carbonate bond, a thiocarbonate bond, or a selenocarbonate bond, such as diphenyl carbonate, diphenyl thiocarbonate, diphenyl selenocarbonate, phosgene, thiophosgene, and selenophosgene; dihydroxy compounds such as benzene dimethanol and cyclohexane dimethanol; phosphine oxide compounds such as bis(fluorophenyl)phenylphosphine oxide, bis(fluorophenyl)naphthylphosphine oxide, and bis(fluorophenyl)anthrylphosphine oxide; and dihalides of dicarboxylic acids such as phthalic acid dichloride, isophthalic acid dichloride, and terephthalic acid dichloride. These monomers may be used alone or in combination of two or more.

<Method for synthesizing polymer (A)>
The synthesis method of the polymer (A) is not particularly limited, and a known method can be used. For example, the monomer that is the raw material of the portion containing R ¹¹ , the monomer that is the raw material of the portion containing R ¹² and R ¹³ , and, if necessary, the monomer that is the raw material of the portion containing R ²¹ , the monomer that is the raw material of the portion containing R ²² and R ¹³ , the monomer for forming the terminal group Y, and the monomer that derives the other structural unit can be synthesized by heating in an organic solvent together with a polymerization inhibitor, an alkali metal or an alkali metal compound, etc. The monomer that is the raw material of the portion containing R ²¹ , the monomer that is the raw material of the portion containing R ²² and R ¹³ , the monomer that derives the other structural unit, and the monomer for forming the terminal group Y may be reacted by polymerizing the monomer that is the raw material of the portion containing R ¹¹ and the monomer that is the raw material of the portion containing R ¹² , and then heating and mixing them.

Alkali Metal and Alkali Metal Compound When a compound having a hydroxy group, such as a phenol compound, is used as a raw material in the process of synthesizing the polymer (A), the alkali metal and alkali metal compound react with the compound having a hydroxy group to form an alkali metal salt.

Examples of such alkali metals and alkali metal compounds include:
Alkali metals such as lithium, sodium, potassium, etc.;
Alkali metal hydrides such as lithium hydride, sodium hydride, potassium hydride, etc.;
Alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, etc.
Alkali metal carbonates such as lithium carbonate, sodium carbonate, and potassium carbonate;
Examples of the hydrogen carbonate include alkali metal hydrogen carbonates such as lithium hydrogen carbonate, sodium hydrogen carbonate, and potassium hydrogen carbonate.
Of these, alkali metal carbonates are preferred, with potassium carbonate being more preferred.

When a compound having a hydroxyl group is used in the synthesis of polymer (A), the amount of alkali metal and alkali metal compound used is such that the lower limit of the ratio of the number of moles of alkali metal atoms to the number of moles of hydroxyl groups in all compounds used in the synthesis of polymer (A) is preferably 1, more preferably 1.1, and even more preferably 1.2, and the upper limit of said ratio is preferably 3, more preferably 2, and even more preferably 1.8.

Organic Solvent Examples of the organic solvent include
Ether solvents such as tetrahydrofuran (THF), dioxane, cyclopentyl methyl ether, anisole, phenetole, diphenyl ether, dialkoxybenzene, and trialkoxybenzene;
Nitrogen-containing solvents such as N,N-dimethylacetamide (DMAc), N,N-dimethylformamide, N-methyl-2-pyrrolidone, and 1,3-dimethyl-2-imidazolidinone;
ester solvents such as γ-butyrolactone;
Sulfur-containing solvents such as sulfolane, dimethyl sulfoxide, diethyl sulfoxide, dimethyl sulfone, diethyl sulfone, diisopropyl sulfone, and diphenyl sulfone;
Ketone solvents such as benzophenone, 2-heptanone, cyclohexanone, and methyl ethyl ketone;
Halogen-based solvents such as methylene chloride, chloroform, and chlorobenzene;
Examples of the solvent include aromatic hydrocarbon solvents such as benzene, toluene, and xylene.

Of these organic solvents, 2-heptanone, cyclohexanone, N-methyl-2-pyrrolidone, toluene, and xylene are preferred, and N-methyl-2-pyrrolidone, 2-heptanone, and cyclohexanone are more preferred.

The lower limit of the reaction temperature during the synthesis is preferably 50°C, more preferably 80°C, and the upper limit is preferably 300°C, more preferably 200°C.

The lower limit of the reaction time during the synthesis is preferably 1 hour, more preferably 2 hours, and even more preferably 3 hours, and the upper limit is preferably 100 hours, more preferably 50 hours, and even more preferably 24 hours.

In order to prevent the polymerization solution from gelling, the lower limit of the reaction temperature when the monomer for forming the terminal group Y is added after polymerization is preferably 0°C, more preferably 10°C, and the upper limit is preferably 130°C, more preferably 110°C.

The lower limit of the reaction time when the monomer for forming the terminal group Y is added after polymerization and reacted is preferably 1 hour, more preferably 2 hours, and even more preferably 3 hours, and the upper limit is preferably 48 hours, more preferably 24 hours, and even more preferably 10 hours.

Polymerization Inhibitor The polymerization inhibitor can be used for normal purposes such as obtaining a target molecular weight by controlling the polymerization reaction. For example, quinones include p-benzoquinone, 2-t-butyl-p-benzoquinone, 2,5-diphenyl-p-benzoquinone, chloranil, trimethylquinone, etc.

Hindered phenol compounds include 1,6-hexanediol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-3,5-triazine, pentaerythritol tetrakis[3-(3,5-t-butyl-4-hydroxyphenyl)propionate], 2,2-thio-diethylene bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, triazine, Examples include 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)-isocyanurate, 2,6-di-tert-butyl-p-cresol (BHT), 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione [manufactured by ADEKA Corporation, AO-020], and 1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenylmethyl)-2,4,6-trimethylbenzene [manufactured by ADEKA Corporation, AO-330].

Examples of hindered amine compounds include 4-cyclohexylcarbonyloxy-2,2,6,6-tetramethylpiperidinooxyl, 4-benzoyloxy-2,2,6,6-tetramethylpiperidinooxyl, 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxyl [ADEKA Corp., Adekastab LA-7RD], IRGASTAB UV 10 (4,4'-[1,10-dioxo-1,10-decanediyl)bis(oxy)]bis[2,2,6,6-tetramethyl]-1-piperidinyloxy), etc.

Examples of amine compounds include phenothiazine, 3,7-dicumylphenothiazine, N,N'-diphenyl-1,4-phenylenediamine, and N,N'-di-2-naphthyl-1,4-phenylenediamine.

[Physical Properties of Polymer (A)]
The lower limit of the polystyrene-equivalent weight average molecular weight (Mw) of the polymer (A) is preferably 1,000, more preferably 2,000, and even more preferably 3,000, and the upper limit is preferably 500,000, more preferably 100,000, even more preferably 50,000, and particularly preferably 30,000.

Polymer (A) having an Mw in the above range is preferred because it has a good balance of adhesion, heat resistance, impregnation into glass cloth, moldability such as resin flow, etc. Note that the Mw in the present invention is a value measured by gel permeation chromatography (GPC) under the conditions described in the examples below.

The dielectric loss tangent (tan δ) of polymer (A) is preferably 0.0025 or less, more preferably 0.0020 or less, and even more preferably 0.0012 or less, from the viewpoint of reducing transmission loss when a composition containing polymer (A) is prepared, and although there is no particular lower limit, it is preferably 0.0005 or more. Specifically, the dielectric loss tangent can be measured by the method described in the examples below.

<First composition>
The first composition according to one embodiment of the present invention (hereinafter also referred to as "the present composition (1)") is not particularly limited as long as it contains the polymer (A), but it is preferable that the composition (1) contains a curable compound (B) other than the polymer (A). The present composition (1) may further contain other components such as a curing assistant.

<Polymer (A)>
The polymer (A) used in the present composition (1) may be one type or two or more types. The present composition (1) may also be a mixture of two or more types of polymer (A).
When two or more kinds of polymers (A) are used, polymers (A) having different molecular weights within the molecular weight range of the polymer (A) can be mixed depending on the desired physical properties, for example.

The content of the polymer (A) in the present composition (1) is, for example, preferably 10 mass% or more, more preferably 20 mass% or more, even more preferably 50 mass% or more, and is preferably 99.95 mass% or less, more preferably 90 mass% or less, even more preferably 80 mass% or less, when the total solid content in the present composition (1) is 100 mass%.
It is preferable for the content of the polymer (A) to be within the above range, since this makes it possible to further improve the adhesiveness, heat resistance, curability, and electrical properties of the cured product obtained from the composition (1).

<Curable Compound (B)>
The curable compound (B) (hereinafter also referred to as "compound (B)") is a compound other than the polymer (A), which is cured by irradiation with heat or light (e.g. visible light, ultraviolet light, near infrared light, far infrared light), and may require a curing aid, which will be described later. Examples of such a compound (B) include vinyl compounds, maleimide compounds, allyl compounds, acrylic compounds, methacrylic compounds, thiol compounds, oxazine compounds, cyanate compounds, epoxy compounds, oxetane compounds, methylol compounds, benzocyclobutene compounds, propargyl compounds, and silane compounds. Among these, in terms of compatibility with the polymer (A), reactivity, and the like, it is particularly preferable to use at least one of vinyl compounds, maleimide compounds, and allyl compounds.
The compound (B) may be used alone or in combination of two or more kinds.

Examples of the vinyl compound include compounds represented by the following formulas (b-1-1) to (b-1-5).
Further examples of the vinyl compound include styrene-based thermoplastic elastomers, such as styrene butadiene styrene copolymer (SBS), hydrogenated styrene butadiene styrene copolymer (SEBS), styrene isoprene styrene copolymer (SIS), hydrogenated styrene isoprene styrene copolymer, styrene butadiene elastomer (SBR), tert-butylstyrene, and 2-vinyl-4,6-diamino-1,3,5-triazine, which contain a vinyl group.
Further examples of the vinyl compound include TA100 (manufactured by Mitsubishi Gas Chemical Co., Ltd.) and ULL-950S (manufactured by LONZA).

〔式（ｂ－１－２）及び（ｂ－１－４）中、ｎは独立して、１～５０００である。式（ｂ－１－５）中、ｌ、ｍ及びｎはそれぞれ独立して、１～５０００である。〕

[In formulas (b-1-2) and (b-1-4), n is independently 1 to 5000. In formula (b-1-5), l, m and n are each independently 1 to 5000.]

Examples of the maleimide compound include compounds represented by the following formulas (b-2-1) to (b-2-8).

〔式（ｂ－２－４）、（ｂ－２－５）、（ｂ－２－７）及び（ｂ－２－８）中、ｎは独立して、１～５０である。〕

[In formulas (b-2-4), (b-2-5), (b-2-7) and (b-2-8), n is independently 1 to 50.]

The allyl compound may, for example, be any of the compounds represented by the following formulas (b-3-1) to (b-3-6).

Examples of the acrylic compound include compounds represented by the following formulas (b-4-1) to (b-4-7).

〔式（ｂ－４－１）、（ｂ－４－２）、（ｂ－４－３）及び式（ｂ－４－６）中、ｎは独立して、１～５０である。式（ｂ－４－３）中、ｍは１～５０である。式（ｂ－４－６）中、Ｒは炭素数１～２０の２価の炭化水素基である。〕

[In formulas (b-4-1), (b-4-2), (b-4-3) and (b-4-6), n is independently 1 to 50. In formula (b-4-3), m is 1 to 50. In formula (b-4-6), R is a divalent hydrocarbon group having 1 to 20 carbon atoms.]

Examples of the methacrylic compound include bisphenol A type epoxy methacrylate, phenol novolac type epoxy methacrylate, trimethylolpropane methacrylate, dipentaerythritol hexamethacrylate, and SA-9000 (manufactured by Sabic).

Examples of the thiol compound include 1,4-bis(3-mercaptobutyryloxy)butane, 1,3,5-tris(2-(3-sulfanylbutanoyloxy)ethyl)-1,3,5-triazinane-2,4,6-trione, 2-(dibutylamino)-1,3,5-triazine-4,6-dithiol, and 6-diallylamino-1,3,5-triazine-2,4-dithiol.

Examples of the silane compound include KF-99 (manufactured by Shin-Etsu Chemical Co., Ltd.) and KF-9901 (manufactured by Shin-Etsu Chemical Co., Ltd.).

Examples of the oxazine compound include compounds represented by the following formulas (b-5-1) to (b-5-5).

Examples of the cyanate compound include compounds represented by the following formulas (b-6-1) to (b-6-7).

〔式（ｂ－６－６）及び（ｂ－６－７）中、ｎは独立して、０～３０である。〕

(In formulas (b-6-6) and (b-6-7), n is independently 0 to 30.)

Examples of the epoxy compound include compounds represented by the following formulas (b-7-1) to (b-7-5).
Further examples of the epoxy compound include polyglycidyl ether of dicyclopentadiene-phenol polymer, phenol novolac type liquid epoxy compound, cresol novolac type epoxy compound, epoxidized product of styrene-butadiene block copolymer, 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, XER-81 (manufactured by JSR Corporation, epoxy group-containing NBR particles), JP-100 (manufactured by Nippon Soda Co., Ltd.), and the like.

〔式（ｂ－７－５）中、ｎは０～５０００である。〕

[In formula (b-7-5), n is 0 to 5000.]

Examples of the oxetane compound include compounds represented by the following formulas (b-8-1) to (b-8-3).

〔式（ｂ－８－１）及び（ｂ－８－２）中、ｎはそれぞれ独立に、０～３０である。〕

(In formulas (b-8-1) and (b-8-2), n is each independently 0 to 30.)

Examples of the methylol compound include the methylol compounds described in JP-A-2006-178059 and JP-A-2012-226297. Specific examples include melamine-based methylol compounds such as polymethylolated melamine, hexamethoxymethylmelamine, hexaethoxymethylmelamine, hexapropoxymethylmelamine, and hexabutoxymethylmelamine; glycoluril-based methylol compounds such as polymethylolated glycoluril, tetramethoxymethylglycoluril, and tetrabutoxymethylglycoluril; guanamine-based methylol compounds such as 3,9-bis[2-(3,5-diamino-2,4,6-triazaphenyl)ethyl]-2,4,8,10-tetraoxospiro[5.5]undecane and 3,9-bis[2-(3,5-diamino-2,4,6-triazaphenyl)propyl]-2,4,8,10-tetraoxospiro[5.5]undecane, and compounds in which all or part of the active methylol groups in the compounds have been alkyl etherified.

Examples of the benzocyclobutene compound include the compounds described in JP-A-2005-60507.

Examples of the propargyl compound include compounds represented by the following formulas (b-9-1) to (b-9-2).

[Content of compound (B)]
The content ratio of compound (B) in composition (1) is, for example, preferably 0.05% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, and is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 50% by mass or less, when the total solid content in composition (1) is taken as 100% by mass.
It is preferable for the content of compound (B) to be within the above range, since this can further improve the strength and heat resistance of the cured product obtained from the present composition (1).

In addition, when the total solid content of the polymer (A) and the compound (B) in the composition (1) is taken as 100 mass%, the content of the compound (B) is preferably 1 mass% or more, more preferably 5 mass% or more, even more preferably 10 mass% or more, and is preferably 99 mass% or less, more preferably 95 mass% or less, even more preferably 90 mass% or less.
It is preferable for the content of compound (B) to be within the above range, since this can further improve the toughness and heat resistance of the cured product obtained from the present composition (1).

<Second Composition>
The second composition according to one embodiment of the present invention (hereinafter also referred to as "the present composition (2)") contains a polymer (A2) having a repeating structural unit represented by the following formula (3) (hereinafter also referred to as "repeating unit (3)") and a repeating structural unit represented by the following formula (4) (hereinafter also referred to as "repeating unit (4)"), and a curable compound (B2) other than the polymer (A2). The present composition (2) may further contain other components such as a curing assistant.

［前記式（３）において、
Ｒ³¹は、炭素数３～１０の２価の有機基を表し、
Ｒ³²は、独立に２価の置換もしくは非置換の芳香族炭化水素基を表し、
Ｒ³³は、２つのＲ³²と下記式（ａ２）で表される基が少なくとも１つ結合した炭素数１～２０の炭化水素基を表す。］

[In the formula (3),
R ³¹ represents a divalent organic group having 3 to 10 carbon atoms;
R ³² independently represents a divalent substituted or unsubstituted aromatic hydrocarbon group;
R ³³ represents a hydrocarbon group having 1 to 20 carbon atoms in which two R ³² are bonded to at least one group represented by the following formula (a2):

［前記式（ａ２）において、
＊は、前記Ｒ³³への結合を表し、
＊＊は、前記重合体（Ａ２）中の他の構造単位との結合手を表し、
Ｒ³²は、前記式（３）中のＲ³²と同義である。］

[In the formula (a2),
* represents a bond to R ³³ ,
** represents a bond to another structural unit in the polymer (A2),
R ³² has the same meaning as R ³² in the above formula (3).

［前記式（４）において、
Ｒ⁴¹は、炭素数３～１０の２価の有機基を表し、
Ｒ⁴²は、主鎖に置換もしくは非置換の芳香族炭化水素基を含む２価の基を表し、式中の酸素原子は前記芳香族炭化水素基に直接結合している。］

[In the formula (4),
R ⁴¹ represents a divalent organic group having 3 to 10 carbon atoms;
R ⁴² represents a divalent group containing a substituted or unsubstituted aromatic hydrocarbon group in the main chain, and the oxygen atom in the formula is directly bonded to the aromatic hydrocarbon group.

<Polymer (A2)>
The polymer (A2) has the repeating unit (3) and the repeating unit (4).
In the repeating unit (3), R ³¹ represents a divalent organic group having 3 to 10 carbon atoms. The divalent organic group having 3 to 10 carbon atoms is not particularly limited, and examples thereof include a phenyl group, a tolyl group, a xylyl group, and a naphthyl group. Of these, a xylyl group is preferred.

R ³² in the repeating unit (3) independently represents a divalent substituted or unsubstituted aromatic hydrocarbon group. Details of R ³² are the same as those of R ¹² in the repeating unit (1).

R ³³ in the repeating unit (3) represents a hydrocarbon group having 1 to 20 carbon atoms in which the two R ³² are bonded to at least one group represented by the following formula (a2): Details of R ³³ and the group represented by formula (a2) are the same as those of R ¹² in the repeating unit (1) and the group represented by formula (a1), respectively.

From the viewpoint of improving the glass transition temperature (Tg), it is preferable that polymer (A2) contains two or more of the repeating units (3).

In the repeating unit (4), R ⁴¹ represents a divalent organic group having 3 to 10 carbon atoms. The divalent organic group having 3 to 10 carbon atoms is not particularly limited, and examples thereof include a phenyl group, a tolyl group, a xylyl group, and a naphthyl group. Of these, a xylyl group is preferred.

R ⁴² in the repeating unit (4) represents a divalent group containing a substituted or unsubstituted aromatic hydrocarbon group in the main chain. Details of R ⁴² are the same as those of R ²² in the repeating unit (2).

When all structural units contained in polymer (A2) are taken as 100 mol%, the content of the repeating unit (3) is preferably in the range of 5 mol% to 95 mol%, more preferably 10 mol% to 90 mol%, and even more preferably 20 mol% to 80 mol%.

When all structural units contained in polymer (A2) are taken as 100 mol%, the content of repeating unit (4) is preferably in the range of 5 mol% to 95 mol%, more preferably 10 mol% to 90 mol%, and even more preferably 20 mol% to 80 mol%.

The polymer (A2) preferably has a group Y (terminal group Y) represented by the above-mentioned formula (y) at its terminal. Details of the terminal group Y are as described above.

When the terminal group Y is bonded to the repeating unit (3), for example, it is bonded to O (oxygen atom) but is not bonded to R ^31. Similarly, when the terminal group Y is bonded to the repeating unit (4), it is bonded to O (oxygen atom) but is not bonded to R ⁴¹ .

The polymer (A2) may have other structural units as necessary in addition to the repeating units (3) and (4) and the terminal group Y. Thus, the repeating units (3) may be bonded to each other, or to the repeating unit (4), the other structural units, or the terminal group Y, for example.

When the polymer (A2) has a plurality of repeating units (3), the plurality of R ³¹ may be the same or different from each other, and the same applies to R ³² , R ³³ , the repeating unit (4), and other structural units.

Examples of monomers that derive the other structural units include compounds that derive structural units containing a carbonate bond, a thiocarbonate bond, or a selenocarbonate bond, such as diphenyl carbonate, diphenyl thiocarbonate, diphenyl selenocarbonate, phosgene, thiophosgene, and selenophosgene; dihydroxy compounds such as benzene dimethanol and cyclohexane dimethanol; phosphine oxide compounds such as bis(fluorophenyl)phenylphosphine oxide, bis(fluorophenyl)naphthylphosphine oxide, and bis(fluorophenyl)anthrylphosphine oxide; and dihalides of dicarboxylic acids such as phthalic acid dichloride, isophthalic acid dichloride, and terephthalic acid dichloride. These monomers may be used alone or in combination of two or more.

The method for synthesizing the polymer (A2) is not particularly limited, and any known method can be used. For example, the polymer (A2) can be synthesized by the same method as that for the polymer (A) described above.
The physical properties of the polymer (A2) are preferably the same as those of the polymer (A) described above.

The polymer (A2) used in the present composition (2) may be one type or two or more types. Also, the present composition (2) may be a mixture of two or more types of polymer (A2).
When two or more kinds of polymers (A2) are used, polymers (A2) having different molecular weights within the molecular weight range of the polymer (A2) can be mixed depending on the desired physical properties, for example.

The content of the polymer (A2) in the present composition (2) is, for example, preferably 10 mass% or more, more preferably 20 mass% or more, even more preferably 50 mass% or more, and is preferably 99.95 mass% or less, more preferably 90 mass% or less, even more preferably 80 mass% or less, when the total solid content in the present composition (2) is 100 mass%.
It is preferable for the content of the polymer (A2) to be within the above range, since this makes it possible to further improve the adhesiveness, heat resistance, curability, and electrical properties of the cured product obtained from the composition (2).

<Curable Compound (B2)>
The curable compound (B2) (hereinafter also referred to as "compound (B2)") is a compound other than the polymer (A2), which is cured by irradiation with heat or light (e.g. visible light, ultraviolet light, near infrared light, far infrared light), and may require a curing aid, which will be described later. Examples of such a compound (B2) include vinyl compounds, maleimide compounds, allyl compounds, acrylic compounds, methacrylic compounds, thiol compounds, oxazine compounds, cyanate compounds, epoxy compounds, oxetane compounds, methylol compounds, benzocyclobutene compounds, propargyl compounds, and silane compounds. Among these, in terms of compatibility with the polymer (A2), reactivity, and the like, it is particularly preferable to use at least one of vinyl compounds, maleimide compounds, and allyl compounds.

Compound (B2) may be used alone or in combination of two or more. More specific examples of compound (B2) are the same as those of compound (B) described above.

[Content of compound (B2)]
The content ratio of compound (B2) in composition (2) is, for example, preferably 0.05% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, and is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 50% by mass or less, when the total solid content in composition (2) is 100% by mass.
It is preferable for the content of the compound (B2) to be within the above range, since this makes it possible to further improve the strength and heat resistance of the cured product obtained from the present composition (2).

In addition, when the total solid content of the polymer (A2) and the compound (B2) in the composition (2) is taken as 100 mass%, the content of the compound (B2) is preferably 1 mass% or more, more preferably 5 mass% or more, even more preferably 10 mass% or more, and is preferably 99 mass% or less, more preferably 95 mass% or less, even more preferably 90 mass% or less.
It is preferable for the content of the compound (B2) to be within the above range, since this makes it possible to further improve the toughness and heat resistance of the cured product obtained from the present composition (2).

<Other ingredients>
The present compositions (1) and (2) (hereinafter, collectively referred to simply as "the present compositions") may contain, in addition to the polymer (A) and the compound (B), further other components within the scope of not impairing the effects of the present invention.

The other components include, for example, a curing aid, a solvent, an additive for imparting various functions, an inorganic filler, an organic filler, and a polymer other than the polymer (A) or (A2). Each of these other components may be used alone or in combination of two or more.

[Curing aid]
The present composition may contain a curing aid, if necessary.
Examples of the curing aid include polymerization initiators such as thermal or photoradical initiators, cationic curing agents, and anionic curing agents.

Thermal radical initiators include organic peroxides such as dicumyl peroxide, 1,1-di(t-butylperoxy)cyclohexane, di(t-butylperoxyisopropyl)benzene, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, and benzoyl peroxide; and azo compounds such as azobisbutyronitrile, 1,1'-azobis(1-acetoxy-1-phenylethane), 2,2'-azobis(2,4-dimethylvaleronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), dimethyl-2,2'-azobis(isobutyrate), and 2,2'-azobis(2-methylbutyronitrile).

Examples of cationic curing agents include diallyliodonium salts having _BF4 , _PF6 , or _SbF6 as a counter anion, such as SP70, SP172, and CP66 manufactured by ADEKA CORPORATION, CI2855 and CI2823 manufactured by Nippon Soda Co., Ltd., and SI100 and SI150 manufactured by Sanshin Chemical Industry Co., Ltd., trialkylsulfonium salts, phosphonium salts such as butyltriphenylphosphonium thiocyanate, and boron trifluoride.

Examples of anionic curing agents include imidazole compounds such as 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-methylimidazolium isocyanurate, 2,4-diamino-6-[2-methylimidazoline-(1)]-ethyl-S-triazine, and 2,4-diamino-6-[2-ethyl-4-methylimidazoline-(1)]-ethyl-S-triazine; phosphorus compounds such as triphenylphosphine; and amine compounds such as 4,4'-diaminodiphenylmethane.

When a silane compound is used as compound (B) or (B2), examples of the curing aid include platinum black, platinic chloride, chloroplatinic acid, a reaction product of chloroplatinic acid with a monohydric alcohol, a complex of chloroplatinic acid with an olefin, platinum group metal catalysts such as platinum-based catalysts such as platinum bisacetoacetate, palladium-based catalysts, and rhodium-based catalysts, zinc benzoate, and zinc octoate.

When an oxazine compound is used as compound (B) or (B2), examples of the curing aid include phenol and its derivatives, cyanate esters, Bronsted acids such as p-toluenesulfonic acid, adipic acid, p-toluenesulfonic acid esters, 4,4'-diaminodiphenylsulfone, aromatic amine compounds such as melamine, bases such as 2-ethyl-4-methylimidazole, boron trifluoride, Lewis acids, and other curing agents.

When the present composition contains a curing aid, the content of the curing aid is preferably within a range in which the present composition cures well and a cured product is obtained. Specifically, the content is preferably 0.000001 parts by mass or more, more preferably 0.001 parts by mass or more, and preferably 20 parts by mass or less, more preferably 10 parts by mass or less, per 100 parts by mass of the total solid content of the polymer (A) or (A2) and the compound (B) or (B2).

[solvent]
The composition may contain a solvent, if necessary.
Examples of the solvent include amide solvents such as N,N-dimethylformamide, ester solvents such as γ-butyrolactone, butyl acetate, and the like, ketone solvents such as cyclopentanone, cyclohexanone, methyl ethyl ketone, 2-heptanone, and the like, ether solvents such as 1,2-methoxyethane, anisole, tetrahydrofuran, and the like, polyfunctional solvents such as 1-methoxy-2-propanol, propylene glycol methyl ether acetate, and the like, sulfone solvents such as dimethyl sulfoxide, methylene chloride, benzene, toluene, xylene, and trialkoxybenzene (number of carbon atoms in the alkoxy group: 1 to 4).

When the composition contains a solvent, the content of the solvent in the composition is not particularly limited, but is, for example, preferably 0 parts by mass or more and 2,000 parts by mass or less, more preferably 0 parts by mass or more and 1,000 parts by mass or less, relative to 100 parts by mass of the total of the solid contents of the polymer (A) or (A2) and the compound (B) or (B2).
In addition, when the polymer (A) or (A2) or the compound (B) or (B2) has high solubility in the solvent, the content of the solvent in the composition may be 50 parts by mass or more and 200 parts by mass or less.

[Additive]
The additives used for the purpose of imparting the various functions include antioxidants, flame retardants, and adhesion aids.Specific compounds include hindered phenol compounds, phosphorus compounds, sulfur compounds, metal compounds, and hindered amine compounds.Among these, hindered phenol compounds are preferred.

As the hindered phenol compound, a compound having a molecular weight of 500 or more is preferable. Examples of the hindered phenol compound having a molecular weight of 500 or more include triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-3,5-triazine, pentaerythritol tetrakis[3-(3,5-t-butyl-4-hydroxyphenyl)propionate], 1,1,3-tris[2 -Methyl-4-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxy]-5-t-butylphenyl]butane, 2,2-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, N,N-hexamethylenebis(3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tris -(3,5-di-t-butyl-4-hydroxybenzyl)-isocyanurate, 3,9-bis[2-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, 2,6-di-tert-butyl-p-cresol (BHT), 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione [manufactured by ADEKA Corporation, AO-020], 4,4',4''-(1-methylpropanyl-3-ylidene)tris(6-tert-butyl-m-cresol) [manufactured by ADEKA Corporation, AO-030], 6,6'-di-tert-butyl-4,4'-butylidenedi-m-cresol [manufactured by ADEKA Corporation, AO-040], 1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenylmethyl)-2,4,6-trimethylbenzene [manufactured by ADEKA Corporation, AO-330].

Examples of hindered amine compounds include 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxyl [ADEKA CORPORATION, Adeka STAB LA-7RD], IRGASTABUV 10 (4,4'-[1,10-dioxo-1,10-decanediyl)bis(oxy)]bis[2,2,6,6-tetramethyl]-1-piperidinyloxy) (CAS. 2516-92-9), TINUVIN 123 (4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl) (all manufactured by BASF), FA-711HM, FA-712HM (2,2,6,6-tetramethylpiperidinyl methacrylate, manufactured by Showa Denko Materials Co., Ltd.), TINUVIN 111FDL, TINUVIN 144, TINUVIN 152, TINUVIN 292, TINUVIN 765, TINUVIN 770DF, TINUVIN 5100, SANOLLS-2626, CHIMASSORB 119FL, CHIMASSORB 2020 FDL, CHIMASSORB 944 FDL, TINUVIN 622 LD (all manufactured by BASF), LA-52, LA-57, LA-62, LA-63P, LA-68LD, LA-77Y, LA-77G, LA-81, LA-82 (1,2,2,6,6-pentamethyl-4-piperidyl methacrylate), and LA-87 (all manufactured by ADEKA Corporation).

When the composition contains the above-mentioned additives, the content of the additives is, for example, preferably 0.001 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the total solid content of the polymer (A) or (A2) and the compound (B) or (B2).

[Inorganic filler]
Examples of the inorganic filler include silicas such as natural silica, fused silica, and amorphous silica, white carbon, titanium white, aerosil, alumina, talc, natural mica, synthetic mica, clay, barium sulfate, E-glass, A-glass, C-glass, L-glass, D-glass, S-glass, and M-glass G20.

When the composition contains an inorganic filler, the content of the inorganic filler is, for example, preferably 0.1 parts by mass or more and 300 parts by mass or less per 100 parts by mass of the total solid content of the polymer (A) or (A2) and the compound (B) or (B2). In addition, the inorganic filler may be in a state of being dispersed in the solvent by the polymer (A).

[Organic filler]
Examples of the organic filler include fluorine-based resins or fluorine-based particles such as polytetrafluoroethylene (PTFE), polyperfluoroalkoxy resins, polyfluorinated ethylene propylene resins, and polytetrafluoroethylene-polyethylene copolymers; polystyrene resins or particles; rubber-like resins or particles such as polybutadiene and styrene butadiene resins; and hollow particles having a shell of divinylbenzene or divinyl biphenyl.

When the composition contains an organic filler, the content of the organic filler is, for example, preferably 0.1 parts by mass or more and 300 parts by mass or less per 100 parts by mass of the total solid content of the polymer (A) or (A2) and the compound (B) or (B2). The organic filler may be in a state of being dispersed in the solvent by the polymer (A) or (A2).

[Method of preparing the present composition]
The composition can be prepared, for example, by uniformly mixing the polymer (A) or (A2), the compound (B) or (B2), and the other components. In this case, the order of mixing, mixing conditions, etc. are not particularly limited, and a conventionally known mixer may be used for mixing.

<Cured product>
A cured product according to one embodiment of the present invention (hereinafter also referred to as "present cured product") is a cured product of the present composition described above, and is obtained by curing the present composition described above.
The present cured product may be, for example, a partially cured product of the present composition obtained by drying the solvent from the present composition.

The method for curing the composition is not particularly limited, but typically involves a method of thermal curing by heating or a method of photocuring by irradiating light. These methods can also be used in combination.

In the case of thermal curing, the heating temperature is preferably 50° C. or higher, more preferably 100° C. or higher, and even more preferably 120° C. or higher, and is preferably 250° C. or lower, and more preferably 220° C. or lower. The heating time is preferably 0.1 hours or longer, more preferably 0.5 hours or longer, and is preferably 36 hours or shorter, and more preferably 5 hours or shorter.
In the case of photocuring, examples of the light to be irradiated include visible light, ultraviolet light, near infrared light, and far infrared light.

Glass transition temperature (Tg)
The lower limit of the Tg of the present cured product is preferably 100° C., more preferably 110° C., and the upper limit is, for example, 300° C. When the Tg is within the above range, melt molding can be more easily performed, and a cured product having excellent heat resistance can be easily obtained.

Tg was measured by preparing a test piece (width: 3 mm x length: 1 cm) and using a dynamic viscoelasticity measuring device (Seiko Instruments Inc., model number "EXSTAR4000"), measuring under nitrogen at a heating rate of 10°C/min from 50°C to 300°C at 1 Hz, and then at a heating rate of 10°C/min to 300°C at 1 Hz. The tan δ at this time was taken as the glass transition temperature (Tg). When two or more tan δ values exist, the lowest value was taken as Tg.

The dielectric loss tangent (tan δ) of the cured product is preferably 0.0025 or less, more preferably 0.0018 or less, and even more preferably 0.0015 or less, from the viewpoint of reducing transmission loss, and the lower limit is not particularly limited, but is preferably 0.0005 or more. Specifically, the dielectric loss tangent can be measured by the method described in the following examples.

The linear expansion coefficient (CTE) of the cured product is preferably less than 70 ppm/K, more preferably 50 ppm/K or less, and even more preferably 20 ppm/K or less. The lower limit is not particularly limited, but is preferably 17 ppm/K or more. Specifically, the linear expansion coefficient can be measured by the method described in the examples below. If the CTE is within the above range, the difference in linear expansion coefficient between the cured product and metal species such as copper wiring can be reduced.

The shape of the cured product is not particularly limited and may be any shape appropriate for the application or purpose, but may be, for example, a film. For example, the composition may be melt molded or cast molded to obtain a film-like cured product.

The thickness of the film is not particularly limited and may be appropriately selected depending on the desired application, but is, for example, 10 μm or more, preferably 30 μm or more, and, for example, 2 mm or less, preferably 1 mm or less.

<Laminate>
A laminate according to one embodiment of the present invention (hereinafter also referred to as "the present laminate") has, for example, a substrate and a cured layer formed using the present composition.
The laminate may have two or more substrate layers, may have two or more cured material layers, or may have other layers known in the art other than the substrate and the cured material layer. When the laminate has two or more substrate layers, cured material layers, or other layers, these may be the same layer (plate) or different layers (plates).

The laminate may be a prepreg made by impregnating a substrate such as glass cloth, aramid nonwoven fabric, or polyester nonwoven fabric with the composition and curing it.

From the viewpoints of adhesiveness and practicality, examples of the substrate include an inorganic substrate, a metal substrate, a resin substrate, etc. The substrate may also be a prepreg.
Examples of the inorganic substrate include inorganic substrates containing silicon, silicon carbide, silicon nitride, alumina, glass, gallium nitride, and the like as components.
Examples of the metal substrate include metal substrates containing copper, aluminum, gold, silver, nickel, palladium, and the like.
Examples of the resin substrate include resin substrates containing liquid crystal polymer, polyimide, polyphenylene sulfide, polyether ether ketone, polyamide (nylon), polyethylene terephthalate, polyethylene naphthalate, cycloolefin polymer, polyolefin, and the like.

The cured product layer can be formed, for example, by curing using the method described in the section on cured products.
The thickness of the cured material layer is not particularly limited, but is, for example, from 1 μm to 3 mm.

<Application>
The polymer (A), the composition, the cured product, and the laminate can be suitably used as structural materials used in the transportation industry such as the aircraft industry and the automobile industry, electrical and electronic materials used in the electrical and electronic industry, etc. Specifically, for example, they can be suitably used in sealing materials for electrical and electronic components, interlayer insulating films, and primers for stress relaxation; laminate plate applications (e.g., prepregs, copper-clad laminates, (multilayer) printed wiring boards, interlayer adhesives, solder resists, and solder pastes); adhesive applications (e.g., adhesive sheets for forming insulating layers, thermally conductive adhesives, and adhesive sheets); structural adhesives and prepregs used in various structural materials; various coatings, optical component applications (e.g., optical films such as wavelength plates and retardation plates, various special lenses such as conical lenses, spherical lenses, and cylindrical lenses, and lens arrays), and insulating films for printed wiring boards.

<Electronic Components>
An electronic component according to one embodiment of the present invention has the present cured product or the present laminate. The electronic component may have two or more present cured products or two or more present laminates, or may have one or more present cured products and one or more present laminates. When the electronic component has two or more present cured products or present laminates, they may be the same or different.

Examples of the electronic components include circuit boards, semiconductor packages, and display boards. The present cured product (cured film) can be used as a prepreg, copper-clad laminate, printed wiring board, adhesive sheet for forming an insulating layer, surface protection film, rewiring layer, or planarization film for these electronic components. Since the present cured product can maintain insulation even under high temperature and high humidity, the electronic components can protect the circuit patterns from external environments such as dust, heat, and moisture, and have excellent insulation reliability between circuit patterns, allowing them to operate stably for many years.

For example, the spaces between the patterns formed on the cured product (cured film) can be filled with metal by plating or the like, and if necessary, further cured products (cured films) can be stacked and metal can be filled repeatedly to form a rewiring layer, thereby manufacturing an electronic component having a substrate and a rewiring layer including metal wiring and an insulating film.

The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

[Synthesis Example 1]
In a four-necked separable flask equipped with a stirrer, 2,2-bis(4-hydroxy-3-methylphenyl)propane (51.27 g), α,α,α'-tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene (21.23 g), 4,6-dichloro-2-phenylpyrimidine (41.43 g), and potassium carbonate (51.31 g) were weighed out, N-methyl-2-pyrrolidone (113.92 g) was added, and the mixture was reacted at 130°C for 6 hours under a nitrogen atmosphere. After the reaction, the container was cooled to 10°C, and chloromethylstyrene (38.55 g) was added dropwise, and the mixture was reacted at 65°C for 6 hours. The resulting reaction solution was diluted with N-methyl-2-pyrrolidone (258.1 g), and the salt was removed by filtration, and the resulting solution was poured into methanol (4960 g). The precipitated solid was filtered off, washed with a small amount of methanol, and collected by filtration again. The solid was then dried under reduced pressure at 80° C. for 12 hours using a vacuum dryer to obtain a polymer (A-1) represented by the following formula (yield: 112.84 g, yield: 91%).

The above formula indicates that polymer (A-1) is a polymer having the above structural unit. In the above formula, * indicates bonding to any **, and polymer (A-1) has a group represented by the above formula (Y) at the polymer end. The same applies to the following synthesis examples.

[Synthesis Example 2]
A polymer (A-2) represented by the following formula was obtained (yield: 108.17 g, yield: 89%) in the same manner as in Synthesis Example 1, except that the raw materials used were changed to 2,2-bis(4-hydroxy-3-methylphenyl)propane (51.27 g), 4,4'-(2-hydroxybenzylidene)bis(2,3,6-trimethylphenol) (18.78 g), 4,6-dichloro-2-phenylpyrimidine (41.43 g), potassium carbonate (51.31 g), and chloromethylstyrene (38.55 g).

[Synthesis Example 3]
A polymer (A-3) represented by the following formula was obtained (yield: 106.28 g, yield: 90%) in the same manner as in Synthesis Example 1, except that the raw materials used were changed to 2,2-bis(4-hydroxy-3-methylphenyl)propane (51.27 g), 1,1,1-tris(4-hydroxyphenyl)ethane (15.32 g), 4,6-dichloro-2-phenylpyrimidine (41.43 g), potassium carbonate (51.31 g), and chloromethylstyrene (38.55 g).

[Synthesis Example 4]
A polymer (A-4) represented by the following formula was obtained (yield: 104.48 g, yield: 89%) in the same manner as in Synthesis Example 1, except that the raw materials used were changed to 2,2-bis(4-hydroxy-3-methylphenyl)propane (51.27 g), tris(4-hydroxyphenyl)methane (14.62 g), 4,6-dichloro-2-phenylpyrimidine (41.43 g), potassium carbonate (51.31 g), and chloromethylstyrene (38.55 g).

[Synthesis Example 5]
A polymer (A-5) represented by the following formula was obtained (yield: 118.31 g, yield: 91%) in the same manner as in Synthesis Example 1, except that the raw materials used were changed to 2,2-bis(4-hydroxy-3-methylphenyl)propane (51.27 g), 1,1,1-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane (27.24 g), 4,6-dichloro-2-phenylpyrimidine (41.43 g), potassium carbonate (51.31 g), and chloromethylstyrene (38.55 g).

[Synthesis Example 6]
Polymer (A-6) represented by the following formula was obtained in the same manner as in Synthesis Example 1, except that the raw materials used were changed to 2,2-bis(4-hydroxy-3-methylphenyl)propane (51.27 g), 4,4',4'',4'''-(propane-2,2-diylbis(cyclohexane-4,1,1-triyl)tetraphenol (28.84 g), 4,6-dichloro-2-phenylpyrimidine (41.43 g), potassium carbonate (55.98 g), and chloromethylstyrene (49.15 g). (Yield: 121.50 g, 88%).

[Synthesis Example 7]
Polymer (A-7) was obtained by synthesizing in the same manner as in Synthesis Example 1, except that the raw materials used were changed to 2,2-bis(4-hydroxy-3-methylphenyl)propane (57.68 g), 1,1,1-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane (13.62 g), 4,6-dichloro-2-phenylpyrimidine (41.43 g), potassium carbonate (48.98 g), and chloromethylstyrene (33.25 g) (yield: 110.00 g, 92%). Polymer (A-7) has the same structure as polymer (A-5), except that the content ratio of each repeating unit is different.

[Synthesis Example 8]
Polymer (A-8) was obtained by synthesizing in the same manner as in Synthesis Example 1, except that the raw materials used were changed to 2,2-bis(4-hydroxy-3-methylphenyl)propane (32.04 g), 1,1,1-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane (68.10 g), 4,6-dichloro-2-phenylpyrimidine (41.43 g), potassium carbonate (58.31 g), and chloromethylstyrene (54.45 g) (yield: 141.97 g, 88%). Polymer (A-8) has the same structure as polymer (A-5) except that the content ratio of each repeating unit is different.

[Synthesis Example 9]
A polymer (A-9) represented by the following formula was obtained in the same manner as in Synthesis Example 1, except that the raw materials used were changed to 4,4'-dihydroxy-2,2',3,3',5,5'-hexamethylbiphenyl (54.07 g), α,α,α'-tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene (21.23 g), 4,6-dichloro-2-phenylpyrimidine (41.43 g), potassium carbonate (51.31 g), and chloromethylstyrene (38.55 g). (Yield: 112.84 g, 89%).

[Synthesis Example 10]
A polymer (A-10) represented by the following formula was obtained (yield: 97.96 g, yield: 88%) in the same manner as in Synthesis Example 1, except that the raw materials used were changed to 9,9-bis(4-hydroxy-3-methylphenyl)fluorene (56.77 g), α,α,α'-tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene (15.92 g), 4,6-dichloro-2-phenylpyrimidine (31.07 g), potassium carbonate (38.48 g), and chloromethylstyrene (28.91 g).

[Synthesis Example 11]
A polymer (A-11) represented by the following formula was obtained (yield: 98.83 g, yield: 92%) in the same manner as in Synthesis Example 1, except that the raw materials used were changed to 4,4'-(cyclododecane-1,1-diyl)diphenol (52.88 g), α,α,α'-tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene (15.92 g), 4,6-dichloro-2-phenylpyrimidine (31.07 g), potassium carbonate (38.48 g), and chloromethylstyrene (28.91 g).

[Synthesis Example 12]
A polymer (A'-12) represented by the following formula was obtained (yield: 100.40 g, yield: 92%) in the same manner as in Synthesis Example 1, except that the raw materials used were changed to 2,2-bis(4-hydroxy-3-methylphenyl)propane (64.09 g), 4,6-dichloro-2-phenylpyrimidine (41.43 g), potassium carbonate (46.65 g), and chloromethylstyrene (27.95 g).

[Synthesis Example 13]
A polymer (A'-13) represented by the following formula was obtained (yield: 93.06 g, yield: 89%) in the same manner as in Synthesis Example 1, except that the raw materials used were changed to 2,2-bis(4-hydroxy-3-methylphenyl)propane (64.09 g), 4,6-dichloro-2-phenylpyrimidine (31.08 g), 4,6-dichloropyrimidine (6.86 g), potassium carbonate (46.65 g), and chloromethylstyrene (22.01 g).

[Synthesis Example 14]
A polymer (A'-14) represented by the following formula was obtained by synthesizing the polymer in the same manner as in the production example described in JP-A-2020-200425, except that the raw material used was changed to 1,1,1-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane.

[Synthesis Example 15]
A polymer (A-15) represented by the following formula was obtained (yield: 133.27 g, yield: 88%) in the same manner as in Synthesis Example 1, except that the raw materials used were changed to 2,2-bis(4-hydroxy-3-methylphenyl)propane (51.27 g), 4,4',4'',4'''-(propane-2,2-diylbis(cyclohexane-4,1,1-triyl)tetrakis(2-methylphenol) (31.63 g), 4,6-dichloro-2-phenylpyrimidine (41.43 g), potassium carbonate (55.98 g), and chloromethylstyrene (49.15 g).

[Weight average molecular weight (Mw), number average molecular weight (Mn)]
The weight average molecular weight (Mw) and number average molecular weight (Mn) of the polymers synthesized in Synthesis Examples 1 to 15 and the SA-9000 used in the following Comparative Examples were measured using a GPC apparatus ("HLC-8320" manufactured by Tosoh Corporation) under the following conditions. The results are shown in Table 1.
Column: "TSKgelα-M" manufactured by Tosoh Corporation and "TSKgelguardcolumnα" manufactured by Tosoh Corporation were connected. Developing solvent: N-methyl-2-pyrrolidone. Column temperature: 40°C.
Flow rate: 1.0 mL/min Sample concentration: 0.75% by mass
Sample injection volume: 50 μL
Detector: Refractometer Standard material: Monodisperse polystyrene Concentration of measurement sample: 0.1% by mass

<Glass transition temperature (Tg) of polymer>
A varnish for evaluation was prepared by mixing 100 parts by mass of the polymer to be measured (polymers synthesized in Synthesis Examples 1 to 15 and SA-9000), 0.5 parts by mass of Percumyl D (manufactured by NOF Corp.), and 100 parts by mass of toluene. Next, the prepared varnish for evaluation was applied to a copper foil (model number: CF-T49A-DS-HD2, manufactured by Fukuda Metals Co., Ltd.) using a Baker-type applicator (gap: 75 μm), and dried at 100 ° C. for 5 minutes to form a coating film. A copper foil (model number: CF-T49A-DS-HD2, manufactured by Fukuda Metals Co., Ltd.) was placed on the obtained coating film, and the resulting film was vacuum pressed at 150 ° C. for 5 minutes, and then baked at 200 ° C. under nitrogen for 2 hours to prepare a cured film with copper foil. The prepared cured film with copper foil was immersed in a 40 mass% iron chloride solution, and the copper foil was removed from the cured film with copper foil. The film was then washed with water and dried at 80°C for 30 minutes to prepare a 50 µm thick film for measuring the glass transition temperature (Tg).

A test piece (width: 3 mm x length: 1 cm) was cut out from the prepared film for Tg measurement, and measured using a dynamic viscoelasticity measuring device (Seiko Instruments Inc., model number "EXSTAR4000") at a heating rate of 10°C/min from 50°C to 300°C at 1 Hz, and tan δ at this time was taken as the glass transition temperature (Tg). The results are shown in Table 1.

<Dielectric tangent>
A test piece (width: 6 cm x length: 6 cm) was cut out from the cured film prepared in the same manner as the Tg measurement film, and the dielectric loss tangent of the test piece at 10 GHz was measured using a cavity resonator method (TE mode resonator, dielectric constant measurement system, manufactured by AET Corporation). A dielectric loss tangent of 0.0025 or less was marked as "good", and a loss tangent of more than 0.0025 was marked as "poor". The results are shown in Table 1.

<Peel strength of polymer>
A varnish for evaluation was prepared by mixing 100 parts by mass of the polymer to be measured (polymers synthesized in Synthesis Examples 1 to 15 and SA-9000), 0.5 parts by mass of Percumyl D (manufactured by NOF Corp.), and 100 parts by mass of toluene. Next, the prepared varnish for evaluation was applied to a copper foil (model number: CF-V9S-SV, manufactured by Fukuda Metals Co., Ltd.) using a Baker-type applicator (gap: 75 μm), heated at 100° C. for 5 minutes, and then dried at 130° C. for 5 minutes to form a coating film. A copper foil (model number: CF-V9S-SV, manufactured by Fukuda Metals Co., Ltd.) was placed on the obtained coating film, vacuum pressed at 150° C. for 5 minutes, and then baked at 200° C. under nitrogen for 2 hours to prepare a cured film with copper foil (copper foil: 18 μm, cured film 10 μm), which was used as a peel strength sample.

Test pieces (width: 5 mm x length: 10 cm) were cut from the prepared peel strength samples, and the copper foil with the cured film (one copper foil and cured film laminate in the peel strength sample) was pulled at 90 degrees at 500 mm/min using an Instron 5567 manufactured by Instron Corporation, and the peel strength was measured in accordance with IPC-TM-650 2.4.9. Peel strengths of 0.70 N/mm or more were marked "Good", and those less than 0.70 N/mm were marked "Poor". The results are shown in Table 1.

[Examples 1 to 23, Comparative Examples 1 to 8]
The components shown in the column for the composition type in Tables 2-1 and 2-2 (hereinafter collectively referred to as "Table 2") were mixed in a mixer rotor to obtain the ratio (parts by mass) shown in the column for the composition blend ratio, and the concentration was adjusted with toluene to obtain a solids concentration of 50 parts by mass, thereby preparing the composition.

<Preparation of cured film>
The compositions obtained in the above examples and comparative examples were applied onto copper foil (model number: CF-T49A-DS-HD2, manufactured by Fukuda Metals Co., Ltd.) using a Baker-type applicator (gap: 125 μm), and then heated at 100° C. for 5 minutes, and then dried at 140° C. for 5 minutes to form a coating film. Copper foil (model number: CF-T49A-DS-HD2, manufactured by Fukuda Metals Co., Ltd.) was placed on the obtained coating film, vacuum pressed at 160° C. for 10 minutes, and then baked at 200° C. under nitrogen for 2 hours to produce a cured film with copper foil (copper foil: 18 μm, cured film 50 to 100 μm). The obtained cured film with copper foil was immersed in a 40% by mass iron chloride solution, the copper foil was removed, and then washed with water and dried in an oven at 80° C. for 30 minutes to produce a cured film with a thickness of 50 μm.

<Glass transition temperature (Tg)>
A test piece (width: 3 mm x length: 1 cm) was cut out from the prepared cured film, and measured using a dynamic viscoelasticity measuring device (manufactured by Seiko Instruments Inc., "EXSTAR4000") at a heating rate of 10°C/min from 50°C to 300°C at 1 Hz, and tan δ at this time was taken as the glass transition temperature (Tg). The results are shown in Table 2. When two or more tan δ values were present, the lowest value was taken as Tg.

<Dielectric tangent>
A test piece (width: 6 cm x length: 6 cm) was cut out from the prepared cured film, and the dielectric loss tangent of the test piece at 10 GHz was measured using a cavity resonator method (dielectric constant measurement system TE mode resonator, manufactured by AET Corporation). A dielectric loss tangent of 0.0025 or less was marked as "good", and a dielectric loss tangent of more than 0.0025 was marked as "poor". The results are shown in Table 2.

<Peel strength>
A varnish for evaluation was prepared by mixing 70 parts by mass of polymer (polymers synthesized in Synthesis Examples 1 to 15 and SA-9000), 30 parts by mass of TAIC or DVB960, 0.5 parts by mass of Percumyl D (manufactured by NOF Corp.), and 100 parts by mass of toluene. Next, the prepared varnish for evaluation was applied to a copper foil (model number: CF-V9S-SV, manufactured by Fukuda Metals Co., Ltd.) using a Baker-type applicator (gap: 125 μm), heated at 100 ° C. for 5 minutes, and then dried at 130 ° C. for 5 minutes to form a coating film. A copper foil (model number: CF-V9S-SV, manufactured by Fukuda Metals Co., Ltd.) was placed on the obtained coating film, vacuum pressed at 150 ° C. for 5 minutes, and then baked at 200 ° C. under nitrogen for 2 hours to prepare a cured film with copper foil (copper foil: 18 μm, cured film 10 μm), which was used as a peel strength sample.

Test pieces (width: 5 mm x length: 10 cm) were cut from the prepared peel strength samples, and the copper foil with the cured film (one copper foil and cured film laminate in the peel strength sample) was pulled at 90 degrees at 500 mm/min using an Instron 5567 manufactured by Instron Corporation, and the peel strength was measured in accordance with IPC-TM-650 2.4.9. Peel strengths of 0.70 N/mm or more were marked "Good", and those less than 0.70 N/mm were marked "Poor". The results are shown in Table 2.

<Coefficient of Linear Expansion (CTE)>
A varnish for evaluation was prepared by mixing 70 parts by mass of polymer (polymers synthesized in Synthesis Examples 1 to 15 and SA-9000), 30 parts by mass of TAIC or DVB960, 0.5 parts by mass of Percumyl D (manufactured by NOF Corporation), and 100 parts by mass of toluene. Next, the prepared varnish for evaluation was applied to a copper foil (model number: CF-T49A-DS-HD2, manufactured by Fukuda Metals Co., Ltd.) using a Baker-type applicator (gap: 125 μm), heated at 100° C. for 5 minutes, and then dried at 140° C. for 5 minutes to form a coating film. A copper foil (model number: CF-T49A-DS-HD2, manufactured by Fukuda Metals Co., Ltd.) was placed on the obtained coating film, and the film was vacuum pressed at 160°C for 10 minutes, followed by baking under nitrogen at 200°C for 2 hours to produce a cured film with a copper foil (copper foil: 18 μm, cured film: 50-100 μm). The cured film with the copper foil thus produced was immersed in a 40% by mass iron chloride solution, and the copper foil was removed from the cured film with the copper foil. The film was then washed with water and dried at 80°C for 30 minutes to produce a film for CTE measurement.

The linear expansion coefficient of the prepared CTE measurement film was measured using a Seiko Instruments SSC-5200 TMA measurement device. The film was heated at 5°C/min to a temperature 20°C higher than its glass transition temperature, and the linear expansion coefficient was calculated from the gradient of the TMA curve from 80 to 120°C when the temperature was lowered. CTEs below 70 ppm/K were marked "○", and CTEs above 70 ppm were marked "×". The results are shown in Table 2.

The abbreviations used in Table 2 are explained below.

<Polymer>
SA-9000: Terminally modified polyphenylene ether manufactured by Sabic

<Curable Compound>
TAIC: triallyl isocyanurate manufactured by Mitsubishi Chemical Corporation DVB960: divinylbenzene (divinylbenzene 96% by mass) manufactured by Nippon Steel Chemical & Material Co., Ltd.

<Initiator>
DCP: Dicumyl peroxide, Percumyl D, manufactured by NOF Corporation

Claims (17)

A polymer (A) having a repeating structural unit represented by the following formula (1):

[In the formula (1),
R ¹¹ represents a divalent substituted or unsubstituted nitrogen-containing heteroaromatic ring;
R ¹² independently represents a divalent substituted or unsubstituted aromatic hydrocarbon group;
R ¹³ represents a hydrocarbon group having 1 to 20 carbon atoms to which at least one group represented by the following formula (a1) is bonded in addition to the two R ^12s :
X ¹ independently represents -O-, -S-, or -N(R ¹⁴ )-;
R ¹⁴ is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, or the above-mentioned hydrocarbon group or halogenated hydrocarbon group partially substituted with at least one atom selected from oxygen atoms and sulfur atoms.]

[In the formula (a1),
* represents a bond to R ¹³ .
** represents a bond to another structural unit in the polymer (A),
R ¹² and X ¹ are the same as R ¹² and X ¹ in the formula (1), respectively. The polymer (A) according to claim 1, further comprising a repeating structural unit represented by the following formula (2):

[In the formula (2),
^R21 represents a divalent substituted or unsubstituted nitrogen-containing heteroaromatic ring;
R ²² represents a divalent group containing a substituted or unsubstituted aromatic hydrocarbon group in the main chain,
^X2 independently represents -O-, -S-, or -N( ^R24 )-;
R ²⁴ is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, or the above-mentioned hydrocarbon group or halogenated hydrocarbon group partially substituted with at least one atom selected from oxygen atoms and sulfur atoms.] The polymer (A) according to claim 1, having a group Y represented by the following formula (y) at its terminal:

[In the formula (y), Y is a group containing an ethylenically unsaturated double bond having 3 to 50 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 50 carbon atoms, a substituted or unsubstituted aliphatic hydrocarbon group having 6 to 50 carbon atoms, or an unsubstituted nitrogen-containing heteroaromatic ring.] The polymer (A) according to claim 1, wherein the repeating structural unit represented by the formula (1) is contained in the polymer (A) in an amount ranging from 5 mol % to 95 mol %, assuming that all structural units contained in the polymer (A) are 100 mol %. 2. The polymer (A) according to claim 1, wherein —R ¹² — in the formulas (1) and (a1) is independently a structure represented by the following formula (5):

[In the formula (5),
* represents a bond to R ¹³ .
*** represents a bond to ^X1 ,
R ⁵¹ represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms, n ⁵² represents an integer of 0 to 4, and n ⁵³ represents an integer of 0 to 2.] The polymer (A) according to claim 5, wherein the structure represented by the formula (5) is the following formula (5-1) or the following formula (5-2):

[In the formula (5-1) and formula (5-2),
* represents a bond to R ¹³ .
*** represents a bond to ^X1 ,
R ⁵¹ and n ⁵³ have the same meanings as R ⁵¹ and n ⁵³ in formula (5);
n ⁵⁴ represents an integer of 0 to 3, and n ⁵⁵ represents an integer of 0 to 2;
R ⁵² represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms.] A composition containing the polymer (A) according to claim 1 and a curable compound (B) other than the polymer (A). The composition according to claim 7, wherein the curable compound (B) includes at least one selected from the group consisting of vinyl compounds, maleimide compounds, allyl compounds, acrylic compounds, methacrylic compounds, thiol compounds, oxazine compounds, cyanate compounds, epoxy compounds, oxetane compounds, methylol compounds, benzocyclobutene compounds, propargyl compounds, and silane compounds. The composition according to claim 7, further comprising at least one compound selected from the group consisting of hindered phenol compounds, phosphorus compounds, sulfur compounds, metal compounds, and hindered amine compounds. A composition containing a polymer (A2) having a repeating structural unit represented by the following formula (3) and a repeating structural unit represented by the following formula (4), and a curable compound (B2) other than the polymer (A2).

[In the formula (3),
R ³¹ represents a divalent organic group having 3 to 10 carbon atoms;
R ³² independently represents a divalent substituted or unsubstituted aromatic hydrocarbon group;
R ³³ represents a hydrocarbon group having 1 to 20 carbon atoms in which two R ¹² and at least one group represented by the following formula (a2) are bonded.]

[In the formula (a2),
* represents a bond to R ³³ ,
** represents a bond to another structural unit in the polymer (A2),
R ³² has the same meaning as R ³² in the formula (3).

[In the formula (4),
R ⁴¹ represents a divalent organic group having 3 to 10 carbon atoms;
R ⁴² represents a divalent group containing a substituted or unsubstituted aromatic hydrocarbon group in the main chain, and the oxygen atom in the formula is directly bonded to the aromatic hydrocarbon group. The composition according to claim 10 , wherein the polymer (A2) has a group Y represented by the following formula (y) at its terminal:

[In the formula (y), Y is a group containing an ethylenically unsaturated double bond having 3 to 50 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 50 carbon atoms, a substituted or unsubstituted aliphatic hydrocarbon group having 6 to 50 carbon atoms, or an unsubstituted nitrogen-containing heteroaromatic ring.] The composition according to claim 10, wherein the curable compound (B2) comprises at least one selected from the group consisting of vinyl compounds, maleimide compounds, allyl compounds, acrylic compounds, methacrylic compounds, thiol compounds, oxazine compounds, cyanate compounds, epoxy compounds, oxetane compounds, methylol compounds, benzocyclobutene compounds, propargyl compounds, and silane compounds. The composition according to claim 10, further comprising an antioxidant. A cured product that is a cured product of the composition described in claim 7 or 10. A laminate having a substrate and a cured layer formed using the composition according to claim 7 or 10. An electronic component having the cured product according to claim 14. An electronic component having the laminate according to claim 15.