Radical polymerizable group-containing ester compounds

Abstract

This invention provides a novel compound that can achieve both dielectric properties and desmear properties after curing. [Solution] The radical polymerizable group-containing ester compound according to the embodiment comprises one or more first units having a structure derived from polyphenylene ether with hydroxyl groups at both ends, and one or more second units having a structure derived from a bifunctional or trifunctional aromatic acid halide and bonded to the first unit by an ester bond, and a radical polymerizable group attached to each molecular end of the ester bond-containing molecule.

Description

Technical Field

[0001] The present invention relates to a radical polymerizable group-containing ester compound.

Background Art

[0002] Conventionally, for substrate materials such as printed wiring boards, dielectric properties such as a low dielectric tangent have been required. As a compound having excellent dielectric properties, polyphenylene ether resin is known. For example, Patent Document 1 discloses an ester compound having a phenylene ether oligomer structure in the main chain and polycyclic aromatic ring carbonyloxy groups at both ends.

[0003] Patent Document 2 discloses a random copolymer compound of a polyphenylene ether resin having phenolic hydroxyl groups at both ends, an aliphatic polymer having alcoholic hydroxyl groups at both ends, and an acid dichloride compound as a binder, and a terminal-modified polymer compound which is a reaction product of the random copolymer compound and a compound having a substituent capable of reacting with a hydroxyl group and an unsaturated double bond group.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] While investigating substrate materials with excellent dielectric properties, the inventors found that end-modified compounds, in which radical polymerizable groups are introduced at both ends of a polyphenylene ether resin, exhibit excellent dielectric properties after curing, but poor desmear properties. Conversely, attempts to improve desmear properties can sometimes worsen dielectric properties; therefore, it is desirable to achieve a balance between dielectric properties and desmear properties.

[0006] Here, desmear properties refer to the ease of removing smear during the desmear process when manufacturing substrates such as printed circuit boards. Smear is resin residue that adheres to the inside of holes (vias) when they are drilled in the substrate. If plating or other processes are applied as is, electrical conductivity between the surface layer and the inner layer pattern cannot be achieved, so it is removed by desmearing. The wet desmearing method, which uses an etching solution containing permanganate and alkali metal hydrate, is the mainstream method for desmearing, and it is required to efficiently remove smear without using special processes such as plasma methods.

[0007] The embodiments of the present invention aim to provide a novel compound that can achieve both dielectric properties and desmear properties after curing, for example, when used as a substrate material. [Means for solving the problem]

[0008] The present invention includes embodiments shown below. [1] A radical polymerizable group-containing ester compound comprising one or more first units having a structure derived from a polyphenylene ether with hydroxyl groups at both ends, and one or more second units having a structure derived from a bifunctional or trifunctional aromatic acid halide and bonded to the first unit by an ester bond, and a radical polymerizable group attached to each molecular end of the ester bond-containing molecule.

[0009] [2] The following formula (1): [ka] It is expressed as, and in equation (1), R 1represents a divalent group obtained by removing the hydrogen atoms of the hydroxy groups at both ends from a polyphenylene ether having hydroxy groups at both ends, and R 2 represents a divalent group obtained by removing two acid halide groups from a bifunctional aromatic acid halide, and R 3 represents a monovalent group obtained by removing an acid halide group from a compound having a radically polymerizable group and an acid halide group, p represents an average value of the number of repeating units and represents a number of 1 or more, and R in the same molecule 1 、R 2 and R 3 are each independently the radically polymerizable group-containing ester compound according to [1], which may be the same or different from each other.

[0010] [3] The following formula (2):

Chemical formula

[0011] [4] The radically polymerizable group-containing ester compound according to any one of [1] to [3], wherein the radically polymerizable group is a vinyl group, a methacryloyl group, an acryloyl group, an allyl group, or an isopropenyl group.

[0012] [5] The radically polymerizable group-containing ester compound according to any one of [1] to [4], wherein the number average molecular weight of the polyphenylene ether in the first unit is 500 to 5000.

[0013] [6] The R 1 The following equation (3): [ka] It is expressed as follows, where in formula (3), X represents a divalent group obtained by removing two phenolic hydroxyl groups from a compound having two phenolic hydroxyl groups, and R 11 and R 12 The radical polymerizable group-containing ester compound according to any one of [2] to [5], wherein each of the following independently represents a methyl group, an ethyl group, a propyl group, an allyl group, or a phenyl group; each of the following independently represents an integer from 0 to 4; and each of the following independently represents an average value of the number of repeating units, from 1 to 100.

[0014] [7] The R 2 The radical polymerizable group-containing ester compound according to any one of [2] to [6], wherein the group is a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenyldiyl group, a substituted or unsubstituted diphenyl etherdiyl group, or a substituted or unsubstituted naphthylene group.

[0015] [8] A radical polymerizable group-containing ester compound according to any one of items [1] to [7], having a number average molecular weight of 700 to 50000.

[0016] [9] Use as a substrate material for any one of the radical polymerizable group-containing ester compounds described in any one of the items [1] to [8]. [Effects of the Invention]

[0017] When the radical polymerizable group-containing ester compound according to the embodiment of the present invention is used, for example, as a substrate material, it is possible to achieve both dielectric properties and desmear properties after curing. [Modes for carrying out the invention]

[0018] The radical polymerizable group-containing ester compound according to this embodiment comprises an ester bond-containing molecule consisting of at least one first unit and at least one second unit, and a radical polymerizable group attached to each molecular end of the ester bond-containing molecule. The first unit is a structural unit having a structure derived from polyphenylene ether with hydroxyl groups at both ends. The second unit is a structural unit having a structure derived from a bifunctional or trifunctional aromatic acid halide, and is bonded to the first unit by an ester bond. That is, the ester bond-containing molecule has a structure in which the first unit and the second unit are bonded by an ester bond formed by the reaction of the hydroxyl group of the first unit and the acid halide group of the second unit.

[0019] Radical polymerizable group-containing ester compounds are compounds in which a molecule containing such ester bonds serves as the basic framework (i.e., the main part), with radical polymerizable groups added to its molecular ends. In this way, by introducing a second unit with a structure derived from aromatic acid halides into the molecule, the excellent dielectric properties of the first unit can be maintained or improved, while the desmear properties can be enhanced by hydrolysis of the introduced second unit during the desmear process.

[0020] The above-described ester bond-containing molecule consists only of one or more first units and one or more second units, and does not contain any other monomers as constituent components. The ester bond-containing molecule has a structure in which first and second units are alternately linked. For example, the ester bond-containing molecule may have a structure in which one first unit is bonded to both sides of a second unit, or a structure in which second units are further linked to this structure via first units, or a structure in which this linked structure is sequentially repeated. In this case, each molecular end of the ester bond-containing molecule is a second unit.

[0021] Alternatively, the ester bond-containing molecule may have a structure in which, for example, one second unit is bonded to both sides of the first unit, or a structure in which the first unit is further linked to the said structure via the second unit, or a structure in which the linked structure is repeated sequentially. In this case, each molecular end of the ester bond-containing molecule is a first unit.

[0022] The first unit is not necessarily limited to being derived from a polyphenylene ether having hydroxyl groups at both ends, as long as it has a structure derived from a polyphenylene ether having hydroxyl groups at both ends. The polyphenylene ether contains a repeating structure of substituted or unsubstituted phenylene oxy units. The polyphenylene ether having hydroxyl groups at both ends may be, for example, obtained by polymerizing a phenolic monomer on both sides of a compound having two phenolic hydroxyl groups as an initiator, thereby giving it a repeating structure of substituted or unsubstituted phenylene oxy units.

[0023] The second unit is not necessarily limited to being derived from a bifunctional or trifunctional aromatic acid halide, as long as it has a structure derived from a bifunctional or trifunctional aromatic acid halide. Aromatic acid halides are aromatic carboxylic acid halides, and in this embodiment, examples include bifunctional halides having two acid halide groups (-C(=O)-Y, where Y represents a halogen atom) and trifunctional halides having three acid halide groups. When the structure is derived from a bifunctional aromatic acid halide, the ester bond-containing molecule is linear, and radical polymerizable groups are attached to both ends. When the structure is derived from a trifunctional aromatic acid halide, the ester bond-containing molecule is branched, has three or more molecular ends, and radical polymerizable groups are attached to these three or more molecular ends.

[0024] Aromatic acid chlorides are preferred as aromatic acid halides. Specific examples of aromatic acid chlorides include terephthalic acid chloride, isophthalic acid chloride, phthalic acid chloride, methoxyterephthalic acid chloride (e.g., 2-methoxyterephthalic acid chloride), phenoxyterephthalic acid chloride (e.g., 2-phenoxyterephthalic acid chloride), biphenyl dicarbonyl chloride (e.g., 4,4'-biphenyl dicarbonyl chloride), oxybis(benzoyl chloride) (e.g., 4,4'-oxybis(benzoyl chloride)), naphthalenedicarboxylic acid dichloride (e.g., 2,6-naphthalenedicarboxylic acid dichloride), and other aromatic acid trichlorides such as trimesic acid trichloride.

[0025] The radical polymerizable groups described above are groups containing a carbon-carbon double bond, such as vinyl groups, methacryloyl groups, acryloyl groups, allyl groups, and isopropenyl groups. The radical polymerizable groups are introduced at the molecular ends of the ester bond-containing molecules described above, and are obtained by reacting a compound having a functional group that can react with the functional group at the molecular end of the ester bond-containing molecule and a radical polymerizable group with an ester bond-containing molecule consisting of a first unit and a second unit. The radical polymerizable groups are introduced at all molecular ends of the ester bond-containing molecule.

[0026] In ester bond-containing molecules, if the first unit is at the molecular terminal, the functional group at that molecular terminal is a hydroxyl group. In this case, functional groups that can react with the hydroxyl group include, for example, acid halide groups such as acid chloride groups. Therefore, compounds that react with ester bond-containing molecules to introduce radical polymerizability include compounds having an acid halide group and a radical polymerizable group, which are bonded to the first unit by an ester bond. Specific examples of compounds having an acid halide group and a radical polymerizable group include methacrylate halides such as methacrylate chloride and acrylic acid halides such as acrylate chloride.

[0027] In ester-bond-containing molecules, if the second unit is at the molecular terminal, the functional group at that terminal is an acid halide group. In this case, a functional group that can react with the acid halide group is, for example, a hydroxyl group. Therefore, compounds that react with ester-bond-containing molecules to introduce radical polymerizability include compounds having a hydroxyl group and a radical polymerizable group, which are bonded to the second unit by an ester bond. Specific examples of compounds having a hydroxyl group and a radical polymerizable group include vinylbenzyl alcohol, allyl alcohol, allylbenzyl alcohol, allylphenol, 2-methylallyl alcohol, 2-hydroxyethyl acrylate, and 2-hydroxymethyl methacrylate.

[0028] Examples of radical polymerizable group-containing ester compounds according to this embodiment include compounds represented by the following formula (1) or compounds represented by the following formula (2).

[0029] [ka] [ka]

[0030] In equations (1) and (2), R 1 This represents a divalent group obtained by removing the hydrogen atoms from the hydroxyl groups at both ends of a polyphenylene ether that has hydroxyl groups at both ends, and corresponds to the first unit described above. 2 This represents a divalent group obtained by removing two acid halide groups from a bifunctional aromatic acid halide, and corresponds to the second unit described above. 3 R represents a monovalent group obtained by removing the acid halide group from a compound having both a radical polymerizable group and an acid halide group. 4 R represents a monovalent group obtained by removing the hydroxyl group from a compound having a radical polymerizable group and a hydroxyl group. p represents the average number of repeating units and is a number of 1 or more. q represents the average number of repeating units and is a number of 1 or more. In formula (1), R in the same molecule 1 , R 2and R 3 These may be the same or different. In equation (2), R in the same molecule 1 , R 2 and R 4 These may be the same or different. That is, R in the same molecule 1 The R molecules may be the same or different, and within the same molecule... 2 The R molecules may be the same or different, and within the same molecule... 3 The R molecules may be the same or different, and within the same molecule... 4 They may be the same or different.

[0031] In both formulas (1) and (2), the second unit has a structure derived from a bifunctional aromatic acid halide; therefore, the radical polymerizable group-containing ester compounds of formulas (1) and (2) have radical polymerizable groups at their two molecular ends.

[0032] R in the formula 1 Preferably, it is a divalent linking group represented by the following formula (3). [ka]

[0033] In formula (3), X represents a divalent group obtained by removing two phenolic hydroxyl groups from a compound having two phenolic hydroxyl groups. Preferably, the compound having two phenolic hydroxyl groups is a bisphenol compound such as bisphenol A, bisphenol E, bisphenol F, bisphenol B, bisphenol C, or a biphenol compound such as 4,4'-dihydroxybiphenyl. The bisphenol compound may have substituents (such as alkyl groups such as methyl groups) on its aromatic ring, for example, tetramethylbisphenol A. The biphenol compound may also have substituents (such as alkyl groups such as methyl groups) on its aromatic ring, for example, 4,4'-dihydroxy-3,3',5,5'-tetramethylbiphenyl, 4,4'-dihydroxy-2,2',3,3',5,5'-hexamethylbiphenyl, and the like.

[0034] In equation (3), R 11 and R 12 Each independently represents a methyl group, an ethyl group, a propyl group, an allyl group, or a phenyl group, preferably a methyl group. Each independently represents an integer from 0 to 4, preferably an integer from 1 to 4, and more preferably 2. In one embodiment, R 1 It is more preferable that the linking group is a divalent linking group represented by the following formula (3-1). In formula (3-1), X is the same as X in formula (3). [ka]

[0035] In formulas (3) and (3-1), t and u are the average values ​​of the number of repeating units, each independently representing a number from 1 to 100, preferably from 2 to 50, and more preferably from 3 to 20. Here, t and u can be calculated from the number-average molecular weight of the polyphenylene ether based on the molecular weight of each component.

[0036] The number-average molecular weight (Mn) of the polyphenylene ether in the first unit described above is preferably 500 to 5000, more preferably 600 to 3000, and even more preferably 700 to 2000. It is preferable that t and u in the above formula be set to fall within this range of number-average molecular weight.

[0037] In this specification, the number-average molecular weight (Mn) and weight-average molecular weight (Mw) are values ​​obtained by GPC (gel permeation chromatography) and calculated using a calibration curve with standard polystyrene. Specifically, the GPC conditions are as follows: Column: Shodex GPC columns KF-601, KF-602, KF-603, KF-604 (4 linked) manufactured by Resonaq Corporation; Mobile phase: THF (tetrahydrofuran); Mobile phase flow rate: 0.6 mL / min; Column temperature: 40°C; Sample injection volume: 10 μL; Sample concentration: 0.1% by mass.

[0038] In equations (1) and (2), R 2 The compound is a divalent linking group containing an aromatic ring, and is preferably a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenyldiyl group, a substituted or unsubstituted diphenyl etherdiyl group, or a substituted or unsubstituted naphthylene group. Examples of substituents include C1-C6 alkyl groups such as methyl and ethyl groups, C1-C6 alkoxy groups such as methoxy and ethoxy groups, C6-C10 aryl groups such as phenyl and tolyl groups, and C6-C10 aryloxy groups such as phenoxy groups. 2 It is more preferable that the phenylene group is substituted with at least one substituent selected from the group consisting of alkyl groups, alkoxy groups, aryl groups, and aryloxy groups, or is an unsubstituted phenylene group.

[0039] In equation (1), R 3 R represents a monovalent group, which is a residue obtained by removing the acid halide group from a compound that has one radical polymerizable group and one acid halide group in one molecule. Therefore, R 3 It contains radical polymerizable groups. Examples of radical polymerizable groups include vinyl groups, methacryloyl groups, acryloyl groups, allyl groups, and isopropenyl groups, as mentioned above. 3 The number of carbon atoms is not particularly limited and can be 2 to 20, 3 to 10, or 3 to 5.

[0040] Note that the radical polymerizable group and the acid halide group may have some overlapping atoms. For example, in the case of methacrylate halide or acrylic acid halide, the -C(=O)- in the (meth)acryloyl group forms part of the acid halide group. Therefore, the monovalent group excluding the acid halide group may include -C(-Z)=CH3 (where Z represents a hydrogen atom or a methyl group) as the radical polymerizable group.

[0041] In equation (2), R 4 R represents a monovalent group, which is a residue obtained by removing the hydroxyl group from a compound that has one radical polymerizable group and one hydroxyl group in one molecule. Therefore, R4 It contains radical polymerizable groups. Examples of radical polymerizable groups include vinyl groups, methacryloyl groups, acryloyl groups, allyl groups, and isopropenyl groups, as mentioned above. 4 It may or may not have an aromatic ring. 4 The number of carbon atoms is not particularly limited and can be 2 to 30, 2 to 20, or 3 to 10.

[0042] In formula (1), p, which represents the average value of the number of repeating units of the first and second units, is preferably 1 to 10, more preferably 1 to 5, more preferably 1 to 3, and even more preferably 1 to 2. Here, p can be calculated from the number average molecular weight of the radical polymerizable group-containing ester compound based on the molecular weight of each component.

[0043] In formula (2), q, which represents the average number of repeating units of the first and second units, is preferably 1 to 10, more preferably 1 to 5, more preferably 1 to 3, and even more preferably 1 to 2. Here, q can be calculated from the number average molecular weight of the radical polymerizable group-containing ester compound based on the molecular weight of each component.

[0044] In one embodiment, the compound represented by formula (1) is R in the formula 1 ~R 3 It is preferable that the following conditions are met. R 1 : A divalent linking group represented by the above formula (3). Here, X in formula (3) represents a bisphenol compound or a divalent group obtained by removing two phenolic hydroxyl groups from a biphenol compound. R 2 : A substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenyldiyl group, a substituted or unsubstituted diphenyl etherdiyl group, or a substituted or unsubstituted naphthylene group. R 3 : A monovalent group obtained by removing the acid halide group from a compound having a vinyl group, methacryloyl group, acryloyl group, allyl group, or isopropenyl group and an acid halide group.

[0045] More preferably, the compound represented by formula (1) is R in the formula. 1 ~R 3 The following applies: R 1 : A divalent linking group represented by the above formula (3-1). Here, X in formula (3-1) represents a divalent group obtained by removing two phenolic hydroxyl groups from a bisphenol compound. R 2 A substituted or unsubstituted phenylene group, or a substituted or unsubstituted diphenyl ether diyl group. ·R 3 :-C(-Z)=CH3 (where Z represents a hydrogen atom or a methyl group).

[0046] More preferably, the compound represented by formula (1) is the compound represented by the following formula (4). [ka] In the formula, R 2 teeth, [ka] This represents that p is the same as p in equation (1), t and u are the same as t and u in equation (3), and R in the same molecule 2 t and u may be the same or different.

[0047] In one embodiment, the compound represented by formula (2) is R in the formula 1 , R 2 and R 4 It is preferable that the following conditions are met. R 1 : A divalent linking group represented by the above formula (3). Here, X in formula (3) represents a bisphenol compound or a divalent group obtained by removing two phenolic hydroxyl groups from a biphenol compound. R 2 : A substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenyldiyl group, a substituted or unsubstituted diphenyl etherdiyl group, or a substituted or unsubstituted naphthylene group. R 4A monovalent group obtained by removing a hydroxyl group from a compound having a vinyl group, methacryloyl group, acryloyl group, allyl group, or isopropenyl group and a hydroxyl group.

[0048] More preferably, the compound represented by formula (2) is R in the formula 1 , R 2 and R 4 The following applies: R 1 : A divalent linking group represented by the above formula (3-1). Here, X in formula (3-1) represents a divalent group obtained by removing two phenolic hydroxyl groups from a bisphenol compound. R 2 A substituted or unsubstituted phenylene group, or a substituted or unsubstituted diphenyl ether diyl group. ·R 4 A monovalent group obtained by removing a hydroxyl group from a compound having a vinyl group, an allyl group, or an isopropenyl group and a hydroxyl group.

[0049] More preferably, the compound represented by formula (2) is the compound represented by the following formula (5). [ka] In the formula, R 2 teeth, [ka] This represents that q is the same as q in equation (2), t and u are the same as t and u in equation (3), and R in the same molecule 2 t and u may be the same or different.

[0050] The number-average molecular weight (Mn) of the radical polymerizable group-containing ester compound according to this embodiment is not particularly limited, but is preferably 700 to 50,000, more preferably 700 to 20,000, more preferably 800 to 10,000, and even more preferably 1,000 to 8,000. The weight-average molecular weight (Mw) of the radical polymerizable group-containing ester compound is not particularly limited, but is preferably 1,000 to 100,000, more preferably 1,000 to 50,000, more preferably 1,500 to 30,000, and even more preferably 2,000 to 20,000.

[0051] The aromatic ester group concentration of the radical polymerizable group-containing ester compound is not particularly limited, but is preferably 0.2 to 10.0 mmol / g, and more preferably 0.4 to 5.0 mmol / g. Here, the aromatic ester group concentration is calculated from the number of moles of raw materials charged using the following formula. Aromatic ester group concentration (mmol / g) = Number of aromatic ester group units (mol) / Design molecular weight × 1000

[0052] Here, the design molecular weight refers to the molecular weight of the ideal molecular structure calculated from the number of moles of raw materials used during the design phase. For example, in the case of ester compound 1 in Example 1, which will be described later, the molar ratio of raw materials used during the design phase is SA90:terephthalic acid chloride:methacrylate chloride = 2 moles:1 mole:2 moles. The molecular weight of ester compound 1 calculated from this, taking into account the hydrochloric acid released during the reaction, is 1680 × 2 moles + 203.0 × 1 mole + 104.5 × 2 moles - 36.5 × 4 = 3626.

[0053] An aromatic ester group is an ester group bonded to an aromatic ring, as shown in the dotted line structure of the chemical formula below. The number of aromatic ester group units refers to the number of aromatic ester groups contained in the molecular structure at the time of design. For example, in the case of ester compound 1 of Example 1, the number of aromatic ester group units contained is 2. Therefore, the aromatic ester group concentration of ester compound 1 is 2 / 3626 × 1000 = 0.55 mmol / g. [ka]

[0054] The method for producing the radical polymerizable group-containing ester compound according to this embodiment is not particularly limited. For example, a radical polymerizable group-containing ester compound can be obtained by reacting a polyphenylene ether having hydroxyl groups at both ends with a bifunctional or trifunctional aromatic acid halide in the presence of a base compound to synthesize an ester bond-containing molecule, and then reacting the obtained ester bond-containing molecule with a compound having a radical polymerizable group.

[0055] The above reaction may be carried out in a solution dissolved in an organic solvent. The organic solvent is not particularly limited and includes, for example, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexane, N-methylpyrrolidone, and dimethylformamide. Examples of the base compound include organic base compounds such as triethylamine, tripopenylamine, and pyridine.

[0056] More specifically, when synthesizing the compound represented by formula (1) above, it may be synthesized as follows: A polyphenylene ether having hydroxyl groups at both ends and a bifunctional aromatic acid halide are reacted under conditions in which the molar ratio of polyphenylene ether is in excess to synthesize an ester bond-containing molecule having hydroxyl groups at both ends. Then, the obtained ester bond-containing molecule is reacted with a compound having a radical polymerizable group and an acid halide group to obtain the compound represented by formula (1).

[0057] For example, when synthesizing a target substance in formula (1) where p=1, a polyphenylene ether having hydroxyl groups at both ends is added in an amount that is twice the molar ratio of the bifunctional aromatic acid halide, and the two are reacted to synthesize an ester bond-containing molecule. Next, a compound having a radical polymerizable group and an acid halide group is added in an amount that is more than twice the molar ratio of the bifunctional aromatic acid halide, and the ester bond-containing molecule is reacted with the compound.

[0058] When synthesizing the compound represented by formula (2) above, the following method may be used: A polyphenylene ether having hydroxyl groups at both ends is reacted with a difunctional aromatic acid halide under conditions in which the molar ratio of the difunctional aromatic acid halide is in excess to synthesize an ester bond-containing molecule having acid halide groups at both ends. Then, the obtained ester bond-containing molecule is reacted with a compound having a radical polymerizable group and a hydroxyl group to obtain the compound represented by formula (2).

[0059] For example, when synthesizing a target substance where q=1 in formula (2), a bifunctional aromatic acid halide is added in a molar ratio of twice that of a polyphenylene ether having hydroxyl groups at both ends, and the two are reacted to synthesize an ester bond-containing molecule. Next, a compound having a radical polymerizable group and a hydroxyl group is added in a molar ratio of more than twice that of the polyphenylene ether, and the ester bond-containing molecule is reacted with the compound.

[0060] The radical polymerizable group-containing ester compound according to this embodiment can be used, for example, as a substrate material for printed circuit boards. By adding additives such as a crosslinking agent (curing agent), a curing accelerator, and a filler to the radical polymerizable group-containing ester compound, a curable resin composition can be obtained. By molding the curable resin composition into a predetermined shape and polymerizing and curing it by heating, a substrate with excellent dielectric properties and desmear can be obtained. [Examples]

[0061] Examples are described in detail below, along with comparative examples. However, the present invention is not limited to these examples.

[0062] Details of the raw materials used in the examples and comparative examples are as follows. • SA90: "NORYL(registered trademark) SA90" manufactured by SABIC. A polyphenylene ether with hydroxyl groups at both ends, represented by the following formula (6). Number average molecular weight 1600, hydroxyl group equivalent 840 g / eq. [ka]

[0063] • Low molecular weight polyphenylene ether: Synthesized by the following method. (a) In a 1 L flask equipped with a stirrer, condenser, thermometer, and air inlet, 267.76 g of toluene, 114.75 g of methanol, 56.88 g (0.2 mol) of tetramethylbisphenol A, and 134.38 g (1.1 mol) of 2,6-dimethylphenol were added and dissolved at room temperature. After dissolution, 0.89 g (0.004 mol) of cupric bromide and 11.63 g (0.09 mol) of dibutylamine were added. (b) The reaction was carried out for 20 hours while controlling the temperature to 40°C and bubbling with 0.21 L / min of air through an air inlet tube. (c) In a separate container, 18.09 g (0.04 mol) of ethylenediaminetetraacetate tetrahydrate was dissolved in 180.89 g of water. After the reaction in (d)(b), the solution in (c) was added to the product using a funnel, and the reaction was stopped by stirring for 30 minutes, after which the product was allowed to stand and separate. (e) Then, 100g of water was added to the upper layer, stirred at 60°C for 30 minutes, and then allowed to stand and separate. (f) The upper layer of (e) after static separation was heated under reduced pressure to remove the solvent and concentrated to a solid content of approximately 50%. The concentrated liquids of (g) and (f) were transferred to a tray and dried in a vacuum dryer at 120°C for 8 hours until solidified. After that, they were crushed into a powder and dried again in a vacuum dryer at 80°C for 24 hours to obtain 130 g of solid. The obtained solid was a polyphenylene ether with hydroxyl groups at both ends, represented by formula (6) above. When its molecular weight was determined by the GPC method described above, the number-average molecular weight was 930 and the weight-average molecular weight was 1420. The hydroxyl value was 138 mgKOH / g.

[0064] • V575: "Unifiner (registered trademark) V575" manufactured by Unitika Ltd. Polyarylate resin. Number average molecular weight 1400, functional group equivalent 210 g / eq.

[0065] The mole counts shown in the following examples are calculated from the functional group equivalents of the reacting functional groups. For example, in the case of SA90 mentioned above, the hydroxyl group equivalent is 840 g / eq, and assuming the bifunctional structure shown in formula (6) above, its molecular weight is 1680, and the mole count was calculated based on this molecular weight. The mole counts for other raw materials were similarly calculated from the functional group equivalents.

[0066] [Example 1: Synthesis of Ester Compound 1] (a) 149.6 g of toluene and 100.8 g (0.06 mol) of SA90 were added to a 1 L flask equipped with a stirrer, condenser, and thermometer, and dissolved at 50-60°C. After dissolution, the mixture was cooled to room temperature, and 7.59 g of triethylamine was added. (b) In a separate container, 6.09 g (0.03 mol) of terephthalate chloride was dissolved in 93.44 g of methyl ethyl ketone. (c) While controlling the temperature to 40°C or below, solution (b) was added dropwise to solution (a) using a dropping funnel and allowed to react at room temperature for 2 hours. (d) After the reaction in (c), 7.59 g of triethylamine was added, and then, while controlling the temperature to below 40°C, 7.84 g (0.075 mol) of methacrylate chloride was added dropwise using a dropping funnel, and the mixture was allowed to react at room temperature for 2 hours. (e) After the reaction in (d), 201.6 g of toluene, 100.8 g of isopropyl alcohol, and 100.8 g of water were added and heated, then stirred at 60°C for 30 minutes to stop the reaction, and then separated by standing. (f) Then, 20 g of isopropyl alcohol and 80 g of water were added to the upper layer, stirred at 60°C for 30 minutes, and then allowed to stand and separate. (g) The upper layer of (f) was added dropwise to 2326 g of methanol, the resulting solid was filtered using a Kiriyama funnel, and dried in a vacuum dryer at 60°C for 24 hours to obtain 90 g of solid.

[0067] The obtained solid was ester compound 1 represented by the following formula (7). When its molecular weight was determined by the GPC method described above, its number-average molecular weight was 4700 and its weight-average molecular weight was 12000. FT-IR measurement revealed that 1740 cm³ of the aromatic ester group was present. -1 and 1264cm -1 An absorption peak was observed. 1 ¹H-NMR measurements revealed signals originating from double bonds at 5.32 ppm and 5.71 ppm. The aromatic ester group concentration was 0.55 mmol / g. Ester compound 1 is the compound represented by formula (1) above, and R in formula (1) 1 This is represented by (3-1) above. [ka]

[0068] [Example 2: Synthesis of Ester Compound 2] (a) 68.84 g of methyl ethyl ketone and 22.33 g (0.11 mol) of terephthalic acid chloride were added to a 1 L flask equipped with a stirrer, condenser, and thermometer, and dissolved. (b) In a separate container, 92.4 g (0.055 mol) of SA90 was added to 160.63 g of toluene and dissolved at 50-60°C. After dissolution, the mixture was cooled to room temperature, and then 13.91 g of triethylamine was added. (c) While controlling the temperature to 40°C or below, solution (b) was added dropwise to solution (a) using a dropping funnel and allowed to react at room temperature for 2 hours. (d) After the reaction in (c), 13.91 g of triethylamine was added, and then, while controlling the temperature to 40°C or below, 16.97 g (0.1265 mol) of vinylbenzyl alcohol was added dropwise using a dropping funnel, and the mixture was allowed to react at room temperature for 2 hours. (e) After the reaction in (d), 184.8 g of toluene, 92.4 g of isopropyl alcohol, and 92.4 g of water were added and heated, then stirred at 60°C for 30 minutes to stop the reaction, and then separated by standing. (f) Then, 23.36 g of isopropyl alcohol and 200.2 g of water were added to the upper layer, and the mixture was stirred at 60°C for 30 minutes, after which it was allowed to stand and separate. (g) The upper layer of (f) was added dropwise to 2589.84 g of methanol, the resulting solid was filtered using a Kiriyama funnel, and dried in a vacuum dryer at 60°C for 24 hours to obtain 104 g of solid.

[0069] The obtained solid was ester compound 2 represented by the following formula (8). The molecular weight was determined by the GPC method described above, and it was found to have a number-average molecular weight of 3800 and a weight-average molecular weight of 7800. FT-IR measurement revealed that 1740 cm³ of the aromatic ester group was present. -1 and 1264cm -1 An absorption peak was observed. 1 ¹H-NMR measurements revealed signals originating from double bonds at 5.39 ppm and 5.78 ppm. The aromatic ester group concentration was 1.81 mmol / g. Ester compound 2 is the compound represented by formula (2) above, and R in formula (2) 1 This is represented by (3-1) above. [ka]

[0070] [Example 3: Synthesis of Ester Compound 3] (a) 149.6 g of toluene and 100.8 g (0.06 mol) of SA90 were added to a 1 L flask equipped with a stirrer, condenser, and thermometer, and dissolved at 50-60°C. After dissolution, the mixture was cooled to room temperature, and 7.59 g of triethylamine was added. (b) In a separate container, 6.09 g (0.03 mol) of isophthalic acid chloride was dissolved in 93.44 g of methyl ethyl ketone. (c) While controlling the temperature to 40°C or below, solution (b) was added dropwise to solution (a) using a dropping funnel and allowed to react at room temperature for 2 hours. (d) After the reaction in (c), 7.59 g of triethylamine was added, and then, while controlling the temperature to below 40°C, 7.84 g (0.075 mol) of methacrylate chloride was added dropwise using a dropping funnel, and the mixture was allowed to react at room temperature for 2 hours. (e) After the reaction in (d), 201.6 g of toluene, 100.8 g of isopropyl alcohol, and 100.8 g of water were added and heated, then stirred at 60°C for 30 minutes to stop the reaction, and then separated by standing. (f) Then, 20 g of isopropyl alcohol and 80 g of water were added to the upper layer, stirred at 60°C for 30 minutes, and then allowed to stand and separate. (g) The upper layer of (f) was added dropwise to 2326 g of methanol, the resulting solid was filtered using a Kiriyama funnel, and dried in a vacuum dryer at 60°C for 24 hours to obtain 90 g of solid.

[0071] The obtained solid was an ester compound 3 represented by the following formula (9). When its molecular weight was determined by the GPC method described above, the number-average molecular weight was 4700 and the weight-average molecular weight was 12000. FT-IR measurement revealed a 1740 cm³ compound originating from the aromatic ester group. -1 and 1264cm -1 An absorption peak was observed. 1 ¹H-NMR measurements revealed signals originating from double bonds at 5.32 ppm and 5.71 ppm. The aromatic ester group concentration was 0.55 mmol / g. Ester compound 3 is the compound represented by formula (1) above, and R in formula (1) 1 This is represented by (3-1) above. [ka]

[0072] [Example 4: Synthesis of Ester Compound 4] (a) 149.6 g of toluene and 100.8 g (0.06 mol) of SA90 were added to a 1 L flask equipped with a stirrer, condenser, and thermometer, and dissolved at 50-60°C. After dissolution, the mixture was cooled to room temperature, and 7.59 g of triethylamine was added. (b) In a separate container, 8.85 g (0.03 mol) of 4,4'-oxybis(benzoyl chloride) was dissolved in 93.44 g of methyl ethyl ketone. (c) While controlling the temperature to 40°C or below, solution (b) was added dropwise to solution (a) using a dropping funnel and allowed to react at room temperature for 2 hours. (d) After the reaction in (c), 7.59 g of triethylamine was added, and then, while controlling the temperature to below 40°C, 7.84 g (0.075 mol) of methacrylate chloride was added dropwise using a dropping funnel, and the mixture was allowed to react at room temperature for 2 hours. (e) After the reaction in (d), 201.6 g of toluene, 100.8 g of isopropyl alcohol, and 100.8 g of water were added and heated, then stirred at 60°C for 30 minutes to stop the reaction, and then separated by standing. (f) Then, 20 g of isopropyl alcohol and 80 g of water were added to the upper layer, stirred at 60°C for 30 minutes, and then allowed to stand and separate. (g) The upper layer of (f) was added dropwise to 2326 g of methanol, the resulting solid was filtered using a Kiriyama funnel, and dried in a vacuum dryer at 60°C for 24 hours to obtain 93 g of solid.

[0073] The obtained solids consisted of ester compounds represented by the following formula (10). Molecular weights were determined by the GPC method described above, with a number-average molecular weight of 4600 and a weight-average molecular weight of 11000. FT-IR measurement revealed a concentration of 1740 cm³ originating from the aromatic ester group. -1 and 1264cm -1 An absorption peak was observed. 1 ¹H-NMR measurements revealed signals originating from double bonds at 5.32 ppm and 5.71 ppm. The aromatic ester group concentration was 0.53 mmol / g. The ester compound 4 is the compound represented by formula (1) above, and R in formula (1) 1 This is represented by (3-1) above. [ka]

[0074] [Example 5: Synthesis of Ester Compound 5] (a) 153.67 g of toluene and 97.58 g (0.12 moles, calculated molecular weight converted from hydroxyl value as a bifunctional compound) of low molecular weight polyphenylene ether were added to a 1 L flask equipped with a stirrer, condenser, and thermometer, and dissolved at 50-60°C. After dissolution, the mixture was cooled to room temperature and 15.18 g of triethylamine was added. (b) In a separate container, 12.18 g (0.06 mol) of terephthalate chloride was dissolved in 65.85 g of methyl ethyl ketone. (c) While controlling the temperature to 40°C or below, solution (b) was added dropwise to solution (a) using a dropping funnel and allowed to react at room temperature for 2 hours. (d) After the reaction in (c), 15.18 g of triethylamine was added, and then, while controlling the temperature to 40°C or below, 15.68 g (0.15 mol) of methacrylate chloride was added dropwise using a dropping funnel, and the mixture was allowed to react at room temperature for 2 hours. (e) After the reaction in (d), 195.17 g of toluene, 97.58 g of isopropyl alcohol, and 97.58 g of water were added and heated, then stirred at 60°C for 30 minutes to stop the reaction, and then separated by standing. (f) Then, 20 g of isopropyl alcohol and 80 g of water were added to the upper layer, stirred at 60°C for 30 minutes, and then allowed to stand and separate. (g) The upper layer of (f) was added dropwise to 2571 g of methanol, the resulting solid was filtered using a Kiriyama funnel, and dried in a vacuum dryer at 60°C for 24 hours to obtain 98 g of solid.

[0075] The obtained solid was ester compound 5 represented by formula (7) above. When its molecular weight was determined by the GPC method described above, its number-average molecular weight was 3300 and its weight-average molecular weight was 5600. FT-IR measurement revealed that 1740 cm³ of the aromatic ester group was present. -1 and 1264cm -1 An absorption peak was observed. 1 1H-NMR measurements revealed signals originating from double bonds at 5.32 ppm and 5.71 ppm. The aromatic ester group concentration was 1.05 mmol / g.

[0076] [Example 6]: Synthesis of ester compound 6 (a) 73.15 g of methyl ethyl ketone and 40.60 g (0.2 mol) of terephthalic acid chloride were added to a 1 L flask equipped with a stirrer, condenser, and thermometer, and dissolved. (b) Using another container, 81.32 g (0.1 mol, calculated molecular weight converted to difunctional based on the hydroxyl value) of low molecular weight polyphenylene ether was added to 170.69 g of toluene, dissolved at 50 - 60 °C, cooled to room temperature after dissolution, and then 25.30 g of triethylamine was added. (c) While controlling the temperature below 40 °C, the solution of (b) was added dropwise to the solution of (a) using a dropping funnel, and the reaction was carried out at room temperature for 2 hours. (d) After the reaction of (c), 25.30 g of triethylamine was added. Then, while controlling the temperature below 40 °C, 30.86 g (0.23 mol) of vinylbenzyl alcohol was added dropwise using a dropping funnel, and the reaction was carried out at room temperature for 2 hours. (e) After the reaction of (d), 162.6 g of toluene, 81.3 g of isopropyl alcohol, and 81.3 g of water were added and heated, stirred at 60 °C for 30 minutes to stop the reaction, and then allowed to stand for separation. (f) Then, 23.36 g of isopropyl alcohol and 200.2 g of water were added to the upper layer, stirred at 60 °C for 30 minutes, and then allowed to stand for separation. (g) The upper layer solution of (f) was added dropwise into 2975.18 g of methanol, the obtained solid was filtered with a Toyama funnel, and dried in a vacuum dryer at 60 °C for 24 hours to obtain 119 g of a solid.

[0077] The obtained solid was the ester compound 6 represented by the above formula (8). When the molecular weight was determined by the above GPC method, the number average molecular weight was 2300 and the weight average molecular weight was 3800. By FT - IR measurement, absorption peaks at 1740 cm -1 (b) Using another container, 81.32 g (0.1 mol, calculated molecular weight converted to difunctional based on the hydroxyl value) of low molecular weight polyphenylene ether was added to 170.69 g of toluene, dissolved at 50 - 60 °C, cooled to room temperature after dissolution, and then 25.30 g of triethylamine was added. (c) While controlling the temperature below 40 °C, the solution of (b) was added dropwise to the solution of (a) using a dropping funnel, and the reaction was carried out at room temperature for 2 hours. (d) After the reaction of (c), 25.30 g of triethylamine was added. Then, while controlling the temperature below 40 °C, 30.86 g (molecular weight converted to difunctional based on the hydroxyl value) of vinylbenzyl alcohol was added dropwise using a dropping funnel, and the reaction was carried out at room temperature for 2 hours. (e) After the reaction of (d), 〔amount of toluene〕g of toluene, 〔amount of isopropyl alcohol〕g of isopropyl alcohol, and 〔amount of water〕g of water were added and heated, stirred at 60 °C for 30 minutes to stop the reaction, and then allowed to stand for separation. (f) Then, 〔amount of isopropyl alcohol〕g of isopropyl alcohol and 〔amount of water〕g of water were added to the upper layer, stirred at 60 °C for 30 minutes, and then allowed to stand for separation. (g) The upper layer solution of (f) was added dropwise into 〔amount of methanol〕g of methanol, the obtained solid was filtered with a Toyama funnel, and dried in a vacuum dryer at 60 °C for 24 hours to obtain 〔amount of solid〕g of a solid. The obtained solid was the ester compound 6 represented by the above formula (8). When the molecular weight was determined by the above GPC method, the number average molecular weight was 2300 and the weight average molecular weight was 3800. By FT - IR measurement, absorption peaks at 1740 cm -1 and 1264 cm (g) The upper layer solution of (f) was added dropwise into 2975.18 g of methanol, the obtained solid was filtered with a Toyama funnel, and dried in a vacuum dryer at 60 °C for 2 hours to obtain 119 g of a solid.

[0077] The obtained solid was the ester compound 6 represented by the above formula (8). When the molecular weight was determined by the above GPC method, the number average molecular weight was 2300 and the weight average molecular weight was 3800. By FT - IR measurement, absorption peaks at 1740 cm -1 and 1264 cm -1 of the absorption peaks were confirmed. Also, 1 H - NMR measurement confirmed signals derived from double bonds at 5.39 ppm and 5.78 ppm. The aromatic ester group concentration was 2.97 mmol / g.

[0078] [Comparative Example ①: Synthesis of Vinylbenzylated Polyphenylene Ether Compound] It should be noted that there seems to be some inconsistent or incorrect numbering and formatting in the original text, especially in the repeated parts. The above translation tries to make sense of the text as accurately as possible based on the given rules.In a 2L four-necked flask equipped with a temperature controller, stirrer, cooling condenser, and dropping funnel, 158g (0.1 mol) of SA90, 221g of toluene, and 94.8g of isopropyl alcohol were charged to form a homogeneous solution. Subsequently, 0.96g of tetra-n-butylammonium bromide and 33.6g (0.22 mol) of vinyl benzyl chloride (meth / para isomer = 50 / 50, trade name: CMSP, manufactured by AGC Seimi Chemical Co., Ltd.) were added, and the temperature was raised to 75°C. To this, 53.3g (0.64 mol) of 48% by mass sodium hydroxide aqueous solution was added dropwise at a rate of 1 / 4 every 2 hours over 30 minutes, and the reaction was carried out at 75°C for a total of 8 hours, with a reaction rate of over 98%. After that, the solution was cooled to 50°C, and 295g of toluene, 31.6g of isopropanol, and 79g of water were added, and the mixture was neutralized with 66.7g of 35% by mass hydrochloric acid aqueous solution. The reaction solution was allowed to stand until it separated into two layers, and the lower aqueous layer was removed. Furthermore, it was washed five times with 15.8 g of isopropanol and 63.2 g of water. The organic layer was dried at 70°C and 50 mmHg until the moisture content was reduced to less than 0.05% by mass. This solution was then filtered to obtain 345 g of a 50% by mass toluene solution of the vinyl benzylated polyphenylene ether compound (95% by mass yield based on polyphenylene ether). This solution was reprecipitation in a large excess of methanol, and the solid, separated by filtration, was dried under reduced pressure at 92°C. The obtained solid was a vinyl benzylated polyphenylene ether compound represented by the following formula (11). Molecular weight was determined by the GPC method described above, and the number-average molecular weight was 2200, and the weight-average molecular weight was 4000. [ka]

[0079] [Comparative Example 2: Synthesis of Ester Compound 7] (a) 232.59 g of toluene and 98 g (0.07 mol) of V575 were added to a 1 L flask equipped with a stirrer, condenser, and thermometer, and dissolved at 50-60°C. After dissolution, the mixture was cooled to room temperature, and then 17.71 g of triethylamine was added. (b) While controlling the temperature to 40°C or below, 18.29 g (0.175 mol) of methacrylate chloride was added dropwise to the solution from (a) using a dropping funnel, and the mixture was allowed to react at room temperature for 2 hours. (c) After the reaction in (b), 98 g of toluene, 98 g of isopropyl alcohol, and 98 g of water were added and heated, then stirred at 60°C for 30 minutes to stop the reaction, and then separated by standing. (d) Then, 20 g of isopropyl alcohol and 80 g of water were added to the upper layer, stirred at 60°C for 30 minutes, and then allowed to stand and separate. (e) The upper layer of (d) was added dropwise to 2106.36 g of methanol, and the resulting solid was filtered using a Kiriyama funnel. The solid was dried in a vacuum dryer at 60°C for 24 hours to obtain 84 g of solid. The obtained solid is ester compound 7, represented by the following formula (12). [ka]

[0080] <Performance Evaluation of Ester Compounds 1> The dielectric properties, specifically the dielectric loss tangent Df and desmear properties, were evaluated for the ester compounds of Examples 1 and 2, Comparative Example 2, and the vinyl benzylated polyphenylene ether compound of Comparative Example 1. The evaluation method is as follows.

[0081] First, the components used in preparing the resin composition in this embodiment will be described. (Hardening agent) • TAIC: Triallyl isocyanurate (TAIC manufactured by Mitsubishi Chemical Corporation) (Curing accelerator) • Peroxide initiator: PBP (1,3-bis(butylperoxyisopropyl)benzene) (Perbutyl P manufactured by NOF Corporation) (Inorganic fillers) • Vinylsilane-treated silica: SC2300-SVJ (manufactured by Admatex Co., Ltd.)

[0082] Next, we will explain the method for fabricating the evaluation board. (Resin varnish) The resin components (components other than the inorganic filler) were added to toluene solvent in the proportions (parts by mass) shown in Table 1 below, so that the solid content concentration was 50% by mass, and then mixed. The inorganic filler was added to the mixture, stirred for 60 minutes, and then dispersed using a bead mill to obtain a resin varnish.

[0083] (Fabrication of evaluation boards 1 and 2) • Resin-coated metal foil After applying each of the resin varnishes obtained above to metal foil (MT18FL manufactured by Mitsui Mining & Smelting Co., Ltd.), the foil was heated and dried at 100°C for 2 minutes to produce resin-coated metal foil (resin-coated copper foil) with a resin layer thickness of approximately 20 μm.

[0084] • Evaluation board 1 Two of the resin-coated metal foils obtained above were stacked with their resin layers facing each other, and vacuum-formed at a temperature of 220°C for 2 hours and a pressure of 3 MPa to produce a double-sided metal-clad laminate (double-sided copper-clad laminate) with an insulating layer thickness of approximately 40 μm, which was used as evaluation substrate 1.

[0085] • Evaluation board 2 A pseudo-four-layer board was manufactured by layering the resin-coated metal foil described above onto both sides of an unclad board with a thickness of 0.2 mm, with resin layers facing each other, and then vacuum forming it under the same conditions as for evaluation board 1. Subsequently, the copper foil was removed from the pseudo-four-layer board by etching to obtain evaluation board 2.

[0086] Using the evaluation boards 1 and 2 prepared as described above, evaluation tests were conducted using the method shown below.

[0087] [Dielectric Loss Tangent Df] The dielectric loss tangent at 10 GHz was measured using evaluation board 1 by the cavity resonator perturbation method. Specifically, the dielectric loss tangent (Df) of the evaluation board at 10 GHz was measured using a network analyzer (N5230A manufactured by Keysight Technologies, Inc.).

[0088] [Desmear etching rate] A 50mm x 50mm test specimen was removed from evaluation substrate 2, dried in a constant-temperature drying oven at 130°C for 30 minutes, and then cooled in a dry desiccator at room temperature for 120 minutes. The initial weight was then measured using an electronic balance. Etching was then performed according to the following procedure: 1. Swelling: Atotech Japan's "Swelling Dip Securigant P" (500 mL / L) + sodium hydroxide (3 g / L), 60°C, 5 minutes 2. Hot water wash 3. Micro-etching: Atotec Japan's "Concentrate Compact CP580" (580 mL / L) + sodium hydroxide (40 g / L), 80°C, 10 minutes 4. Hot water wash 5. Neutralization: Atotech Japan's "Reduction Solution Securigant P500" (100 mL / L) + sulfuric acid (98%) (50 mL / L), 40°C, 5 minutes 6.Washing After the etching process described above, the specimen was dried in a dryer, then dried in a constant-temperature oven at 130°C for 30 minutes, and then cooled in a dry desiccator at room temperature for 120 minutes. The weight after treatment was then measured using an electronic balance. From the initial weight and the weight after treatment obtained above, the weight loss was calculated and the treatment area (50 cm²) was determined. 2 By dividing by ), the etching rate (mg / cm²) can be calculated. 2 The following values ​​were calculated. Note that the values ​​shown in the table are the average values ​​(n=3) obtained from three samples.

[0089] [Table 1]

[0090] The results are shown in Table 1. The vinyl benzylated polyphenylene ether compound of Comparative Example 1 exhibited excellent dielectric properties, but lacked the structure derived from the aromatic acid halide, which is the second unit, and therefore exhibited poor desmear properties. The ester compound 7 of Comparative Example 2, containing an ester bond, exhibited excellent desmear properties, but lacked the structure derived from the polyphenylene ether, which is the first unit, and therefore exhibited poor dielectric properties. In contrast, Examples 1 and 2 were able to achieve both excellent dielectric properties and good desmear properties.

[0091] <Performance Evaluation of Ester Compounds 2> For the ester compounds 1-7 of Examples 1-6 and Comparative Example 2, and the vinyl benzylated polyphenylene ether compound of Comparative Example 1, the dielectric loss tangent Df was measured as an evaluation of the physical properties of each compound individually. The measurement method is as follows.

[0092] [Dielectric Loss Tangent Df] Since ester compounds 1-7 alone could not produce cured plates, samples were prepared by blending the ester compounds with vinyl benzylated polyphenylene ether compounds at the following three levels of concentration (blending ratio). (1) Ester compound: vinyl benzylated polyphenylene ether compound: toluene = 5:95:100 (5% by mass of ester compound) (2) Ester compound: vinyl benzylated polyphenylene ether compound: toluene = 10:90:100 (10% by mass of ester compound) (3) Ester compound: vinyl benzylated polyphenylene ether compound: toluene = 15:85:100 (15% by mass of ester compound) The above three levels (1) to (3) were blended, dissolved, poured into a tray, and vacuum-dried in a vacuum dryer at 80°C for 24 hours. The resulting powder was used as the measurement sample. In Comparative Example 1, the vinyl benzylated polyphenylene ether compound was used as the measurement sample alone without such blending.

[0093] Using a single-acting compression molding machine (manufactured by Yasuda Seiki Seisakusho), 4g of the sample was pressed for 15 minutes at a pressure of 10 Pa and a temperature of 200°C to produce a 100mm x 100mm x 0.5mm thick flat plate. The obtained flat plate was cut to prepare test pieces with a width of 2mm, a thickness of 0.5mm, and a length of 100mm, and the dielectric loss tangent (Df) at 10 GHz was measured using a cavity resonator dielectric constant measuring device (manufactured by KEYSIGHT). For ester compounds 1 to 7, the dielectric loss tangent (Df) at 100% by mass of the ester compound was extrapolated from the dielectric loss tangent (Df) at each of the three concentrations mentioned above to calculate the dielectric loss tangent (Df) of the compound alone.

[0094] [Table 2]

[0095] The results are shown in Table 2. Ester compounds 1 to 6 of Examples 1 to 6 exhibited superior dielectric properties compared to ester compound 7 of Comparative Example 2.

[0096] Furthermore, the various numerical ranges described in this specification can be any combination of their upper and lower limits, and all such combinations are described herein as preferred numerical ranges. Also, the description of a numerical range as "X~Y" means X or greater and Y or less.

[0097] Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their omissions, substitutions, and modifications are included in the scope and spirit of the invention, as well as in the claims and their equivalents.

Claims

1. A radical polymerizable group-containing ester compound comprising one or more first units having a structure derived from a polyphenylene ether with hydroxyl groups at both ends, and one or more second units having a structure derived from a bifunctional or trifunctional aromatic acid halide and bonded to the first unit by an ester bond, and a radical polymerizable group attached to each molecular end of the ester bond-containing molecule.

2. The following formula (1): 【Chemistry 1】 It is expressed as, and in equation (1), R １ R represents a divalent group obtained by removing the hydrogen atoms from the hydroxyl groups at both ends of a polyphenylene ether which has hydroxyl groups at both ends. ２ R represents a divalent group obtained by removing two acid halide groups from a bifunctional aromatic acid halide. ３ represents a monovalent group obtained by removing the acid halide group from a compound having a radical polymerizable group and an acid halide group, p is the average value of the number of repeating units and represents a number of 1 or more, and R in the same molecule １ , R ２ and R ３ The radical polymerizable group-containing ester compound according to claim 1, wherein each of these may be the same or different.

3. The following formula (2): 【Chemistry 2】 represented by, in formula (2), R １ represents a divalent group obtained by removing the hydrogen atoms of the hydroxy groups at both ends from a polyphenylene ether having hydroxy groups at both ends, R ２ represents a divalent group obtained by removing two acid halide groups from a bifunctional aromatic acid halide, R ４ represents a monovalent group obtained by removing a hydroxy group from a compound having a radically polymerizable group and a hydroxy group, q represents an average value of the number of repeating units and represents a number of 1 or more, and R １ , R ２ and R ４ may be the same or different from each other, the radically polymerizable group-containing ester compound according to claim 1.

4. The radical polymerizable group-containing ester compound according to any one of claims 1 to 3, wherein the radical polymerizable group is a vinyl group, a methacryloyl group, an acryloyl group, an allyl group, or an isopropenyl group.

5. The radical polymerizable group-containing ester compound according to any one of claims 1 to 3, wherein the number average molecular weight of the polyphenylene ether of the first unit is 500 to 5000.

6. The aforementioned R １ The following equation (3): 【Transformation 3】 It is expressed as follows, where in formula (3), X represents a divalent group obtained by removing two phenolic hydroxyl groups from a compound having two phenolic hydroxyl groups, and R １１ and R １２ The radical polymerizable group-containing ester compound according to claim 2 or 3, wherein each of the following independently represents a methyl group, an ethyl group, a propyl group, an allyl group, or a phenyl group; r and s each independently represent an integer from 0 to 4; and t and u are the average values ​​of the number of repeating units and each independently represent a number from 1 to 100.

7. The aforementioned R ２ The radical polymerizable group-containing ester compound according to claim 2 or 3, wherein the group is a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenyldiyl group, a substituted or unsubstituted diphenyl etherdiyl group, or a substituted or unsubstituted naphthylene group.

8. A radical polymerizable group-containing ester compound according to any one of claims 1 to 3, wherein the number average molecular weight is 700 to 50,000.

9. Use of a radical polymerizable group-containing ester compound as a substrate material according to any one of claims 1 to 3.

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