Radical polymerizable group-containing ester compound

Abstract

Provided is a novel compound that can achieve both dielectric properties and desmearability after curing. A radical polymerizable group-containing ester compound according to an embodiment comprises: an ester bond-containing molecule that consists only of one or more first units which each have a structure derived from a polyphenylene ether having hydroxy groups at both terminals, and one or more second units which each have a structure derived from a bifunctional or trifunctional aromatic acid halide and which are bonded to the first units by ester bonds; and a radical polymerizable group that is added to each molecular terminal of the ester bond-containing molecule.

Description

Radical polymerizable group-containing ester compound

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

[0002] Conventionally, dielectric properties such as low dielectric loss tangent have been required for substrate materials such as printed wiring boards. Polyphenylene ether resins are known as compounds with excellent dielectric properties. 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 also discloses a terminally modified polymer compound that is a reaction product of the random copolymer compound with a compound having a substituent reactive with a hydroxyl group and an unsaturated double bond group.

[0004] WO2020 / 162537 WO2020 / 095829

[0005] While investigating substrate materials with excellent dielectric properties, the present inventors found that a terminal-modified compound in which radical polymerizable groups are introduced at both ends of a polyphenylene ether resin has excellent dielectric properties after curing but poor desmear properties. On the other hand, attempts to improve the desmear properties may result in a deterioration of the dielectric properties, and therefore it is desirable to achieve both excellent dielectric properties and desmear properties.

[0006] Here, desmearing property refers to the ease of removing smears in the desmearing process when manufacturing substrates such as printed wiring boards. Smears are resin residues that adhere to the inside of holes (via holes) when they are drilled in a substrate. If plating or other processes are applied as is, electrical continuity between the surface layer and the inner layer pattern will be lost, so they are removed by a desmearing process. The wet desmearing method, which uses an etching solution containing permanganate and alkali metal hydrate, is the mainstream desmearing method, and there is a need to efficiently remove smears without using special processes such as plasma methods.

[0007] An object of an embodiment of the present invention is to provide a novel compound that can achieve both excellent dielectric properties and desmear properties after curing when used as, for example, a substrate material.

[0008] The present invention includes the following embodiments: [1] A radically polymerizable group-containing ester compound having an ester bond-containing molecule consisting of one or more first units having a structure derived from polyphenylene ether having hydroxy groups at both ends and one or more second units having a structure derived from a difunctional or trifunctional aromatic acid halide and bonded to the first units via ester bonds, and a radically polymerizable group added to each molecular end of the ester bond-containing molecule.

[0009] [2] The following formula (1): In formula (1), R １ represents a divalent group obtained by removing hydrogen atoms from the hydroxy groups at both ends of 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 difunctional aromatic acid halide, R ３ represents a monovalent group obtained by removing an acid halide group from a compound having a radical polymerizable group and an acid halide group, p is the average number of repeating units and is a number of 1 or more, and R １ , R ２ and R ３ may be the same or different, the radical polymerizable group-containing ester compound according to [1].

[0010] [3] The following formula (2): In formula (2), R １ represents a divalent group obtained by removing hydrogen atoms from the hydroxy groups at both ends of 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 difunctional aromatic acid halide, R ４ represents a monovalent group obtained by removing a hydroxy group from a compound having a radical polymerizable group and a hydroxy group, q is the average number of repeating units and is a number of 1 or more, and R １ , R ２ and R ４may be the same or different, the radical polymerizable group-containing ester compound according to [1].

[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 radical polymerizable group-containing ester compound according to any one of [1] to [4], wherein the polyphenylene ether of the first unit has a number average molecular weight of 500 to 5,000.

[0013] [6] The R １ is expressed by the following formula (3): In formula (3), X represents a divalent group obtained by removing two phenolic hydroxy groups from a compound having two phenolic hydroxy groups, and R １１ and R １２ each independently represent a methyl group, an ethyl group, a propyl group, an allyl group, or a phenyl group; r and s each independently represent an integer of 0 to 4; t and u each independently represent an average number of repeating units and are a number of 1 to 100. The radically polymerizable group-containing ester compound according to any one of [2] to [5].

[0014] [7] The R ２ is a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenyldiyl group, a substituted or unsubstituted diphenyletherdiyl group, or a substituted or unsubstituted naphthylene group.

[0015] [8] The radical polymerizable group-containing ester compound according to any one of [1] to [7], which has a number average molecular weight of 700 to 50,000.

[0016] [9] Use of the radically polymerizable group-containing ester compound according to any one of [1] to [8] as a substrate material.

[0017] The radical polymerizable group-containing ester compound according to the embodiment of the present invention can achieve both excellent dielectric properties and desmear properties after curing when used as, for example, a substrate material.

[0018] The radically 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 radically polymerizable group attached to each molecular terminal of the ester bond-containing molecule. The first unit is a structural unit having a structure derived from polyphenylene ether with hydroxy groups at both terminals. The second unit is a structural unit having a structure derived from a difunctional 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 reaction between the hydroxy group of the first unit and the acid halide group of the second unit.

[0019] The radically polymerizable group-containing ester compound is a compound in which such an ester bond-containing molecule serves as a basic skeleton (i.e., a main portion) and a radically polymerizable group is added to the molecular terminal thereof. By introducing a second unit having a structure derived from an aromatic acid halide into the molecule in this manner, the excellent dielectric properties provided by the first unit can be maintained or improved, and the site of the introduced second unit can be hydrolyzed in the desmearing step, thereby improving desmearing properties.

[0020] The ester bond-containing molecule is composed 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 units and second units are alternately linked. For example, the ester bond-containing molecule may have a structure in which one first unit is linked to both sides of the first unit, or a structure in which a second unit is linked to the structure via a first unit, or a structure in which such linked structures are repeated in sequence. 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 a first unit is bonded to each of two second units, or in which a first unit is further linked to the second unit via the second unit, or in which such linked structures are sequentially repeated. In this case, each molecular terminal of the ester bond-containing molecule is a first unit.

[0022] The first unit is not necessarily limited to those derived from polyphenylene ether having hydroxy groups at both ends, as long as it has a structure derived from polyphenylene ether having hydroxy groups at both ends. The polyphenylene ether contains a repeating structure of optionally substituted phenyleneoxy units. The polyphenylene ether having hydroxy groups at both ends may be, for example, one having a repeating structure of substituted or unsubstituted phenyleneoxy units obtained by using a compound having two phenolic hydroxy groups as an initiator and polymerizing a phenolic monomer on both sides of the initiator.

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

[0024] The aromatic acid halide is preferably an aromatic acid chloride. Specific examples of the aromatic acid chloride include aromatic acid dichlorides such as 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)), and naphthalenedicarboxylic acid dichloride (e.g., 2,6-naphthalenedicarboxylic acid dichloride), and aromatic acid trichlorides such as trimesic acid trichloride.

[0025] The radical polymerizable group is a group containing a carbon-carbon double bond, and examples thereof include a vinyl group, a methacryloyl group, an acryloyl group, an allyl group, and an isopropenyl group. The radical polymerizable group is introduced into each molecular terminal of the ester bond-containing molecule, and is obtained by reacting an ester bond-containing molecule consisting of a first unit and a second unit with a compound having a radical polymerizable group and a functional group reactive with the functional group at the molecular terminal of the ester bond-containing molecule. The radical polymerizable group is introduced into all molecular terminals of the ester bond-containing molecule.

[0026] When the first unit of an ester bond-containing molecule is at the molecular end, the functional group at the molecular end is a hydroxy group. In this case, examples of functional groups that can react with the hydroxy group include acid halide groups such as acid chloride groups. Therefore, compounds that react with the ester bond-containing molecule to introduce radical polymerizability include compounds having an acid halide group and a radical polymerizable group, which are bonded to the first unit via an ester bond. Specific examples of compounds having an acid halide group and a radical polymerizable group include methacrylic acid halides such as methacrylic acid chloride and acrylic acid halides such as acrylic acid chloride.

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

[0028] Preferred examples of the radically polymerizable group-containing ester compound according to this embodiment include a compound represented by the following formula (1) or a compound represented by the following formula (2).

[0029]

[0030] In formula (1) and formula (2), R １ represents a divalent group obtained by removing hydrogen atoms from the hydroxy groups at both ends of a polyphenylene ether having hydroxy groups at both ends, and corresponds to the first unit described above. ２ represents a divalent group obtained by removing two acid halide groups from a difunctional aromatic acid halide, and corresponds to the second unit described above. 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. ４ represents a monovalent group obtained by removing the hydroxy group from a compound having a radical polymerizable group and a hydroxy 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 １ , R ２ and R ３ In formula (2), R １ , R ２ and R ４may be the same or different. １ may be the same or different, and R ２ may be the same or different, and R ３ may be the same or different, and R ４ may be the same or different.

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

[0032] R in the formula １ is preferably a divalent linking group represented by the following formula (3):

[0033] In formula (3), X represents a divalent group obtained by removing two phenolic hydroxy groups from a compound having two phenolic hydroxy groups. Examples of compounds having two phenolic hydroxy groups include bisphenol compounds such as bisphenol A, bisphenol E, bisphenol F, bisphenol B, and bisphenol C, and biphenol compounds such as 4,4'-dihydroxybiphenyl. The bisphenol compounds may have a substituent (e.g., an alkyl group such as a methyl group) on the aromatic ring, and examples thereof include tetramethylbisphenol A. The biphenol compounds may have a substituent (e.g., an alkyl group such as a methyl group) on the aromatic ring, and examples thereof include 4,4'-dihydroxy-3,3',5,5'-tetramethylbiphenyl and 4,4'-dihydroxy-2,2',3,3',5,5'-hexamethylbiphenyl.

[0034] In formula (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, and is preferably a methyl group. r and s each independently represent an integer of 0 to 4, preferably an integer of 1 to 4, and more preferably 2. In one embodiment, R１ is more preferably a divalent linking group represented by the following formula (3-1): X in formula (3-1) is the same as X in formula (3).

[0035] In formula (3) and formula (3-1), t and u are the average number of repeating units, and each independently represents a number from 1 to 100, preferably a number from 2 to 50, and more preferably a number 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 weights of each constituent component.

[0036] The number average molecular weight (Mn) of the polyphenylene ether of the first unit 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 are set so as to fall within this number average molecular weight range.

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

[0038] In formula (1) and formula (2), R ２ is a divalent linking group containing an aromatic ring, and specifically, is preferably a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenyldiyl group, a substituted or unsubstituted diphenyletherdiyl group, or a substituted or unsubstituted naphthylene group. Examples of the substituents include alkyl groups having 1 to 6 carbon atoms such as methyl groups and ethyl groups, alkoxy groups having 1 to 6 carbon atoms such as methoxy and ethoxy groups, aryl groups having 6 to 10 carbon atoms such as phenyl groups and tolyl groups, and aryloxy groups having 6 to 10 carbon atoms such as phenoxy groups. R ２is more preferably an unsubstituted or substituted phenylene group with at least one substituent selected from the group consisting of an alkyl group, an alkoxy group, an aryl group, and an aryloxy group.

[0039] In formula (1), R ３ represents a monovalent group that is a residue obtained by removing an acid halide group from a compound having one radically polymerizable group and one acid halide group in one molecule. ３ R contains a radical polymerizable group. As the radical polymerizable group, as described above, a vinyl group, a methacryloyl group, an acryloyl group, an allyl group, an isopropenyl group, etc. can be mentioned. ３ The number of carbon atoms is not particularly limited, and may be 2 to 20, 3 to 10, or 3 to 5.

[0040] The radical polymerizable group and the acid halide group may have some atoms overlapping. For example, when the compound having a radical polymerizable group and an acid halide group is a methacrylic acid halide or an acrylic acid halide, -C(=O)- in the (meth)acryloyl group forms part of the acid halide group. Therefore, the monovalent group excluding the acid halide group forms a radical polymerizable group, -C(-Z)=CH ３ (wherein Z represents a hydrogen atom or a methyl group).

[0041] In formula (2), R ４ represents a monovalent group that is a residue obtained by removing a hydroxy group from a compound having one radically polymerizable group and one hydroxy group in one molecule. ４ R contains a radical polymerizable group. As the radical polymerizable group, as described above, a vinyl group, a methacryloyl group, an acryloyl group, an allyl group, an isopropenyl group, etc. can be mentioned. ４ may or may not have an aromatic ring. ４ The number of carbon atoms is not particularly limited, and may be 2 to 30, 2 to 20, or 3 to 10.

[0042] In formula (1), p, which represents the average number of repeating units of the first unit and the second unit, 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 based on the number average molecular weight of the radically polymerizable group-containing ester compound and the molecular weights of each constituent component.

[0043] In formula (2), q, which represents the average number of repeating units of the first unit and the second unit, 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 based on the number average molecular weight of the radically polymerizable group-containing ester compound and the molecular weights of each constituent component.

[0044] In one embodiment, the compound of formula (1) is １ ~R ３ is preferably as follows: １ R: a divalent linking group represented by the above formula (3), where X in formula (3) represents a divalent group obtained by removing two phenolic hydroxy groups from a bisphenol compound or a biphenol compound. ２ R: a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenyldiyl group, a substituted or unsubstituted diphenyletherdiyl group, or a substituted or unsubstituted naphthylene group. ３ : A monovalent group obtained by removing an acid halide group from a compound having a vinyl group, a methacryloyl group, an acryloyl group, an allyl group, or an isopropenyl group and an acid halide group.

[0045] More preferably, the compound represented by formula (1) is １ ~R ３ is as follows: R １ R: 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 hydroxy groups from a bisphenol compound. ２ R: a substituted or unsubstituted phenylene group, or a substituted or unsubstituted diphenyletherdiyl group. ３ :-C(-Z)=CH ３(wherein Z represents a hydrogen atom or a methyl group).

[0046] More preferably, the compound represented by formula (1) is a compound represented by the following formula (4): In the formula, R ２ teeth, where p is the same as p in formula (1), t and u are the same as t and u in formula (3), and R ２ , t and u may be the same or different.

[0047] In one embodiment, the compound of formula (2) is １ , R ２ and R ４ is preferably as follows: １ R: a divalent linking group represented by the above formula (3), where X in formula (3) represents a divalent group obtained by removing two phenolic hydroxy groups from a bisphenol compound or a biphenol compound. ２ R: a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenyldiyl group, a substituted or unsubstituted diphenyletherdiyl group, or a substituted or unsubstituted naphthylene group. ４ : A monovalent group obtained by removing a hydroxy group from a compound having a vinyl group, a methacryloyl group, an acryloyl group, an allyl group, or an isopropenyl group and a hydroxy group.

[0048] More preferably, the compound represented by formula (2) is １ , R ２ and R ４ is as follows: R １ R: 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 hydroxy groups from a bisphenol compound. ２ R: a substituted or unsubstituted phenylene group, or a substituted or unsubstituted diphenyletherdiyl group. ４ : A monovalent group obtained by removing a hydroxy group from a compound having a vinyl group, an allyl group, or an isopropenyl group and a hydroxy group.

[0049] More preferably, the compound represented by formula (2) is a compound represented by the following formula (5): In the formula, R ２ teeth, where q is the same as q in formula (2), t and u are the same as t and u in formula (3), and R 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 radically 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. 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 designed molecular weight refers to the molecular weight of an ideal molecular structure calculated from the number of moles of raw material charged at the time of design. For example, in the case of Ester Compound 1 in Example 1 described below, the designed raw material charge molar ratio was SA90:terephthalic acid chloride:methacrylic acid chloride=2 mol:1 mol:2 mol, and the molecular weight of Ester Compound 1 calculated therefrom, taking into account hydrochloric acid released during the reaction, is 1680×2 mols+203.0×1 mol+104.5×2 mols−36.5×4=3626.

[0053] The aromatic ester group refers to an ester group bonded to an aromatic ring, as shown by the dotted line in the following chemical formula, and the number of aromatic ester group units refers to the number of aromatic ester groups contained in the designed molecular structure. 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.

[0054] The method for producing the radical polymerizable group-containing ester compound according to the present embodiment is not particularly limited. For example, a polyphenylene ether having hydroxy groups at both ends is reacted with a bifunctional or trifunctional aromatic acid halide in the presence of a basic compound to synthesize an ester bond-containing molecule, and a compound having a radical polymerizable group is reacted with the obtained ester bond-containing molecule to obtain the radical polymerizable group-containing ester compound.

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

[0056] More specifically, the compound represented by formula (1) may be synthesized as follows: A polyphenylene ether having hydroxy groups at both ends is reacted with a bifunctional aromatic acid halide under conditions where the molar ratio of polyphenylene ether is in excess to synthesize an ester bond-containing molecule having hydroxy groups at both ends. The resulting ester bond-containing molecule is then 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 represented by formula (1) where p = 1, a polyphenylene ether having hydroxy groups at both ends is charged in an amount set so that the molar ratio is twice that of a 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 charged in an amount set so that the molar ratio is twice or more that of the bifunctional aromatic acid halide, and the compound is reacted with the ester bond-containing molecule.

[0058] The compound represented by formula (2) may be synthesized as follows: A polyphenylene ether having hydroxy groups at both ends is reacted with a bifunctional aromatic acid halide under conditions where the molar ratio of the bifunctional aromatic acid halide is in excess to synthesize an ester bond-containing molecule having acid halide groups at both ends. The resulting ester bond-containing molecule is then reacted with a compound having a radical polymerizable group and a hydroxy group to obtain the compound represented by formula (2).

[0059] For example, when synthesizing a target substance represented by formula (2) where q = 1, a bifunctional aromatic acid halide is charged in an amount set so that the molar ratio is 2 times that of polyphenylene ether having hydroxy 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 hydroxy group is charged in an amount set so that the molar ratio is 2 times or more that of the polyphenylene ether, and is reacted with the ester bond-containing molecule.

[0060] The radical polymerizable group-containing ester compound according to this embodiment can be used as a substrate material for, for example, a printed wiring board, etc. A curable resin composition can be obtained by adding additives such as a crosslinking agent (curing agent), a curing accelerator, and a filler to the radical polymerizable group-containing ester compound, and the curable resin composition can be molded into a predetermined shape and polymerized and cured by heating, thereby obtaining a substrate having excellent dielectric properties and desmear resistance.

[0061] Examples will be described in detail below along with comparative examples, but 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. Polyphenylene ether having hydroxy groups at both ends, represented by the following formula (6). Number average molecular weight: 1600, hydroxyl group equivalent: 840 g / eq.

[0063] Low molecular weight polyphenylene ether: Synthesis was performed using the following method. (a) 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 to a 1 L flask equipped with a stirrer, a condenser, a thermometer, and an air inlet tube, 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) While controlling the temperature at 40°C, the mixture was reacted for 20 hours while bubbling air through the air inlet tube at a rate of 0.21 L / min. (c) Using a separate vessel, 18.09 g (0.04 mol) of ethylenediaminetetraacetate tetrahydrate was dissolved in 180.89 g of water. (d) After the reaction of (b), the solution of (c) was added to the product using a funnel, and the mixture was stirred for 30 minutes to stop the reaction, followed by standing and separation. (e) Then, 100 g of water was added to the upper layer, and the mixture was stirred at 60°C for 30 minutes, followed by standing and separation. (f) After standing and separation, the upper layer of (e) was subjected to solvent distillation under heating and reduced pressure, and concentrated to a solid content of approximately 50%. (g) The concentrated solution of (f) was transferred to a tray and dried in a vacuum dryer at 120°C for 8 hours to solidify. The solid was then pulverized into powder and then dried again in a vacuum dryer at 80°C for 24 hours to obtain 130 g of solid. The obtained solid was polyphenylene ether having hydroxy groups at both ends, represented by the above formula (6). The molecular weight was determined by the above GPC method, and 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: 1,400, functional group equivalent: 210 g / eq.

[0065] The number of moles shown in the following examples is the number of moles calculated from the functional group equivalent of the reactive functional group. For example, the above-mentioned SA90 has a hydroxyl group equivalent of 840 g / eq. If it is made into a bifunctional structure represented by the above formula (6), its molecular weight is 1680, and the number of moles was calculated based on this molecular weight. The number of moles for other raw materials was also calculated from the functional group equivalent in the same way.

[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, a condenser, and a 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) Using a separate vessel, 6.09 g (0.03 mol) of terephthaloyl chloride was dissolved in 93.44 g of methyl ethyl ketone. (c) While controlling the temperature at 40°C or less, solution (b) was added dropwise to solution (a) using a dropping funnel, and the mixture was 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 at 40°C or less, 7.84 g (0.075 mol) of methacrylic acid 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 of (d), 201.6 g of toluene, 100.8 g of isopropyl alcohol, and 100.8 g of water were added, heated, and stirred at 60°C for 30 minutes to stop the reaction, and then allowed to stand and separate. (f) Then, 20 g of isopropyl alcohol and 80 g of water were added to the upper layer, and the mixture was stirred at 60°C for 30 minutes, and then allowed to stand and separate. (g) The upper layer liquid of (f) was dropped into 2326 g of methanol, and 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 the molecular weight was determined by the above-mentioned GPC method, the number average molecular weight was 4700 and the weight average molecular weight was 12000. FT-IR measurement revealed that the 1740 cm －１ and 1264 cm －１ The absorption peak was confirmed. １H-NMR measurement confirmed signals at 5.32 ppm and 5.71 ppm derived from double bonds. The concentration of aromatic ester groups was 0.55 mmol / g. The ester compound 1 is a compound represented by the above formula (1), and R １ is expressed by the above (3-1).

[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, a condenser, and a thermometer, and dissolved. (b) Using a separate vessel, 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 13.91 g of triethylamine was added. (c) While controlling the temperature to 40°C or less, solution (b) was added dropwise to the solution of (a) using a dropping funnel, and the mixture was allowed to react at room temperature for 2 hours. (d) After the reaction of (c), 13.91 g of triethylamine was added, and then, while controlling the temperature to 40°C or less, 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 of (d), 184.8 g of toluene, 92.4 g of isopropyl alcohol, and 92.4 g of water were added, heated, and stirred at 60 ° C for 30 minutes to stop the reaction, and then allowed to stand and separate. (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, and then allowed to stand and separate. (g) The upper layer liquid of (f) was dropped into 2589.84 g of methanol, and 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). When the molecular weight was determined by the above-mentioned GPC method, the number average molecular weight was 3800 and the weight average molecular weight was 7800. FT-IR measurement revealed that the 1740 cm －１ and 1264 cm －１ The absorption peak was confirmed. １H-NMR measurement confirmed signals at 5.39 ppm and 5.78 ppm derived from double bonds. The concentration of aromatic ester groups was 1.81 mmol / g. The ester compound 2 is a compound represented by the above formula (2), and R １ is expressed by the above (3-1).

[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, a condenser, and a 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) Using a separate vessel, 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 at 40°C or less, solution (b) was added dropwise to the solution of (a) using a dropping funnel, and the mixture was allowed to react at room temperature for 2 hours. (d) After the reaction of (c), 7.59 g of triethylamine was added, and then, while controlling the temperature at 40°C or less, 7.84 g (0.075 mol) of methacrylic acid 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 of (d), 201.6 g of toluene, 100.8 g of isopropyl alcohol, and 100.8 g of water were added, heated, and stirred at 60°C for 30 minutes to stop the reaction, and then allowed to stand and separate. (f) Then, 20 g of isopropyl alcohol and 80 g of water were added to the upper layer, and the mixture was stirred at 60°C for 30 minutes, and then allowed to stand and separate. (g) The upper layer liquid of (f) was dropped into 2326 g of methanol, and 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), and when its molecular weight was determined by the above-mentioned GPC method, it had a number average molecular weight of 4700 and a weight average molecular weight of 12000. FT-IR measurement revealed that the 1740 cm －１ and 1264 cm －１ The absorption peak was confirmed. １H-NMR measurement confirmed signals at 5.32 ppm and 5.71 ppm derived from double bonds. The concentration of aromatic ester groups was 0.55 mmol / g. The ester compound 3 is a compound represented by the above formula (1), and R １ is expressed by the above (3-1).

[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, a condenser, and a 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) Using a separate vessel, 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 at 40°C or less, solution (b) was added dropwise to solution (a) using a dropping funnel, and the mixture was allowed to react at room temperature for 2 hours. (d) After the reaction of (c), 7.59 g of triethylamine was added, and then 7.84 g (0.075 mol) of methacrylic acid chloride was added dropwise using a dropping funnel while controlling the temperature to 40 ° C or less, and the reaction was allowed to proceed at room temperature for 2 hours. (e) After the reaction of (d), 201.6 g of toluene, 100.8 g of isopropyl alcohol, and 100.8 g of water were added, heated, and stirred at 60 ° C for 30 minutes to terminate the reaction, and then allowed to stand and separate. (f) Then, 20 g of isopropyl alcohol and 80 g of water were added to the upper layer, and the mixture was stirred at 60 ° C for 30 minutes, and then allowed to stand and separate. (g) The upper layer liquid of (f) was added dropwise to 2326 g of methanol, and the resulting solid was collected by filtration using a Kiriyama funnel and dried in a vacuum dryer at 60 ° C for 24 hours, yielding 93 g of solid.

[0073] The obtained solid was ester compound 4 represented by the following formula (10), and its molecular weight was determined by the above-mentioned GPC method, whereby it had a number average molecular weight of 4,600 and a weight average molecular weight of 11,000. FT-IR measurement revealed that it had a 1740 cm －１ and 1264 cm －１ The absorption peak was confirmed. １H-NMR measurement confirmed signals at 5.32 ppm and 5.71 ppm derived from double bonds. The concentration of aromatic ester groups was 0.53 mmol / g. The ester compound 4 is a compound represented by the above formula (1), and R １ is expressed by the above (3-1).

[0074] Example 5: Synthesis of Ester Compound 5 (a) 153.67 g of toluene and 97.58 g (0.12 mol; calculated molecular weight calculated as bifunctional from the hydroxyl value) of low-molecular-weight polyphenylene ether were added to a 1 L flask equipped with a stirrer, a condenser, and a 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) Using a separate vessel, 12.18 g (0.06 mol) of terephthalic acid chloride was dissolved in 65.85 g of methyl ethyl ketone. (c) While controlling the temperature at 40°C or less, solution (b) was added dropwise to solution (a) using a dropping funnel, and the mixture was allowed to react at room temperature for 2 hours. (d) After the reaction of (c), 15.18 g of triethylamine was added, and then 15.68 g (0.15 mol) of methacrylic acid chloride was added dropwise using a dropping funnel while controlling the temperature to 40 ° C or less, and the reaction was allowed to proceed at room temperature for 2 hours. (e) After the reaction of (d), 195.17 g of toluene, 97.58 g of isopropyl alcohol, and 97.58 g of water were added, heated, and stirred at 60 ° C for 30 minutes to terminate the reaction, and then allowed to stand and separate. (f) Then, 20 g of isopropyl alcohol and 80 g of water were added to the upper layer, and the mixture was stirred at 60 ° C for 30 minutes, and then allowed to stand and separate. (g) The upper layer liquid of (f) was added dropwise to 2571 g of methanol, and the resulting solid was collected by filtration using a Kiriyama funnel and dried in a vacuum dryer at 60 ° C for 24 hours, yielding 98 g of solid.

[0075] The obtained solid was ester compound 5 represented by the above formula (7), and when the molecular weight was determined by the above GPC method, it was found to have a number average molecular weight of 3,300 and a weight average molecular weight of 5,600. FT-IR measurement revealed that the 1740 cm －１ and 1264 cm －１ The absorption peak was confirmed. １H-NMR measurement confirmed signals at 5.32 ppm and 5.71 ppm derived from double bonds. The concentration of aromatic ester groups 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, a condenser, and a thermometer, and dissolved. (b) Using a separate vessel, 81.32 g (0.1 mol; the calculated molecular weight was calculated as bifunctional based on the hydroxyl value) of low-molecular-weight polyphenylene ether was added to 170.69 g of toluene, and the mixture was dissolved at 50-60°C. After dissolution, the mixture was cooled to room temperature, and then 25.30 g of triethylamine was added. (c) While maintaining the temperature at 40°C or below, solution (b) was added dropwise to solution (a) using a dropping funnel, and the mixture was allowed to react at room temperature for 2 hours. (d) After the reaction of (c), 25.30 g of triethylamine was added, and then 30.86 g (0.23 mol) of vinylbenzyl alcohol was added dropwise using a dropping funnel while controlling the temperature to 40 ° C or less, and the mixture was allowed to react 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, and the mixture was stirred at 60 ° C for 30 minutes to stop the reaction, and then the mixture was allowed to stand and separate. (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, and then the mixture was allowed to stand and separate. (g) The upper layer liquid of (f) was added dropwise to 2975.18 g of methanol, and the resulting solid was collected by filtration using a Kiriyama funnel and dried in a vacuum dryer at 60 ° C for 24 hours, yielding 119 g of solid.

[0077] The obtained solid was ester compound 6 represented by the above formula (8), and when the molecular weight was determined by the above GPC method, it was found to have a number average molecular weight of 2300 and a weight average molecular weight of 3800. FT-IR measurement revealed that the 1740 cm －１ and 1264 cm －１ The absorption peak was confirmed. １ H-NMR measurement confirmed signals at 5.39 ppm and 5.78 ppm derived from double bonds. The concentration of aromatic ester groups was 2.97 mmol / g.

[0078] [Comparative Example 1: Synthesis of vinylbenzylated polyphenylene ether compound] A 2 L four-neck flask equipped with a temperature controller, a stirrer, a cooling condenser, and a dropping funnel was charged with 158 g (0.1 mol) of SA90, 221 g of toluene, and 94.8 g of isopropyl alcohol to form a homogeneous solution, followed by 0.96 g of tetra-n-butylammonium bromide, and 33.6 g (0.22 mol) of vinylbenzyl chloride (meta / para = 50 / 50, trade name: CMSP, manufactured by AGC Seimi Chemical Co., Ltd.) and the temperature was raised to 75 ° C. To this, 53.3 g (0.64 mol) of 48% by weight aqueous sodium hydroxide solution was added dropwise every 2 hours in 1 / 4 amounts over 30 minutes, and the reaction was carried out at 75 ° C. for a total of 8 hours, and the reaction rate was 98% or more. The mixture was then cooled to 50°C, and 295 g of toluene, 31.6 g of isopropanol, and 79 g of water were added. The mixture was then neutralized with 66.7 g of a 35% by weight aqueous hydrochloric acid solution. The reaction solution was allowed to stand until it separated into two layers, and the lower aqueous solution layer was removed. The mixture was then washed five times with 15.8 g of isopropanol and 63.2 g of water. The organic layer was then removed at 70°C and 50 mmHg until the water content was 0.05% by weight or less, and the solution was filtered to obtain 345 g of a 50% by weight toluene solution of a vinylbenzylated polyphenylene ether compound (yield: 95% by weight based on polyphenylene ether). This solution was reprecipitated in a large excess of methanol, and the solid collected by filtration was dried under reduced pressure at 92°C. The resulting solid was a vinylbenzylated polyphenylene ether compound represented by the following formula (11). The molecular weight was determined by the above-mentioned GPC method, and the number average molecular weight was 2,200 and the weight average molecular weight was 4,000.

[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, a condenser, and a thermometer, and dissolved at 50-60°C. After dissolution, the solution was cooled to room temperature, and 17.71 g of triethylamine was added. (b) While controlling the temperature to 40°C or less, 18.29 g (0.175 mol) of methacrylic acid chloride was added dropwise to the solution (a) using a dropping funnel, and the mixture was allowed to react at room temperature for 2 hours. (c) After the reaction of (b), 98 g of toluene, 98 g of isopropyl alcohol, and 98 g of water were added, heated, and stirred at 60°C for 30 minutes to terminate the reaction, followed by standing to separate. (d) 20 g of isopropyl alcohol and 80 g of water were then added to the upper layer, and the mixture was stirred at 60°C for 30 minutes, followed by standing to separate. (e) The supernatant liquid of (d) was added dropwise to 2106.36 g of methanol, and the resulting solid was filtered using a Kiriyama funnel and dried in a vacuum dryer at 60°C for 24 hours to obtain 84 g of a solid, which is ester compound 7 represented by the following formula (12).

[0080] <Performance Evaluation 1 of Ester Compounds> The dielectric loss tangent Df as a dielectric property and the etching rate as a desmear property were evaluated for the ester compounds of Examples 1 and 2 and Comparative Example 2 and the vinylbenzylated polyphenylene ether compound of Comparative Example 1. The evaluation methods were as follows.

[0081] First, the components used in preparing the resin composition in this example will be described. (Curing 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 filler) Vinylsilane-treated silica: SC2300-SVJ (manufactured by Admatechs Co., Ltd.)

[0082] Next, a method for preparing the evaluation substrate will be described. (Resin Varnish) The resin components (components other than the inorganic filler) were added to a toluene solvent and mixed in the blending ratios (parts by mass) shown in Table 1 below so that the solids concentration was 50% by mass. The inorganic filler was added to the mixture, which was then stirred for 60 minutes and dispersed using a bead mill to obtain a resin varnish.

[0083] (Preparation of Evaluation Substrates 1 and 2) Resin-coated metal foil Each of the resin varnishes obtained above was applied to a metal foil ("MT18FL" manufactured by Mitsui Mining & Smelting Co., Ltd.), and then heated and dried at 100°C for 2 minutes to produce a resin-coated metal foil (resin-coated copper foil) with a resin layer thickness of approximately 20 μm.

[0084] Evaluation Substrate 1 Two sheets of the resin-coated metal foil obtained above were stacked together with their resin layers facing each other, and vacuum-molded at a temperature of 220°C for two hours under 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 as evaluation substrate 1.

[0085] Evaluation Board 2 A pseudo-four-layer board was produced by overlaying the above-mentioned resin-coated metal foil on both sides of a 0.2 mm thick unclad board, with the resin layers facing each other, and vacuum forming under the same conditions as for Evaluation Board 1. The copper foil was then removed from the pseudo-four-layer board by etching, resulting in Evaluation Board 2.

[0086] Using the evaluation substrates 1 and 2 prepared as described above, an evaluation test was carried out by the following method.

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

[0088] [Desmear Etching Rate] A 50 mm x 50 mm test piece was removed from the evaluation substrate 2 and dried in a thermostatic oven at 130°C for 30 minutes. It was then cooled at room temperature in a dry desiccator for 120 minutes. The initial weight was then measured using an electronic balance. Etching was then performed using the following procedures: 1. Swelling: Atotech Japan's "Swelling Dip Securigant P" (500 mL / L) + sodium hydroxide (3 g / L), 60°C, 5 minutes; 2. Hot water washing; 3. Microetching: Atotech Japan's "Concentrate Compact CP580" (580 mL / L) + sodium hydroxide (40 g / L), 80°C, 10 minutes; 4. Hot water washing; 5. Neutralization: Atotech Japan's "Reduction Solution Securigant P500" (100 mL / L) + sulfuric acid (98%) (50 mL / L), 40°C, 5 minutes; 6. After washing with water and etching, the test piece was dried with a dryer, then dried in a thermostatic oven at 130°C for 30 minutes, and then cooled at room temperature in a dry desiccator for 120 minutes. The weight after treatment was then measured with an electronic balance. The weight loss was calculated from the initial weight and the weight after treatment obtained above, and the treated area (50 cm) was calculated. ２ ) to obtain the etching rate (mg / cm ２ The values ​​shown in the table are the average values ​​(n=3) obtained from three samples.

[0089]

[0090] The results are shown in Table 1. The vinylbenzylated polyphenylene ether compound of Comparative Example 1 had excellent dielectric properties, but lacked the structure derived from the aromatic acid halide as the second unit, and therefore had poor desmear properties. Ester compound 7 of Comparative Example 2 had excellent desmear properties because it contained an ester bond, but lacked the structure derived from the polyphenylene ether as the first unit, and therefore had poor dielectric properties. In contrast, Examples 1 and 2 were able to achieve both excellent dielectric properties and desmear properties.

[0091] <Performance Evaluation 2 of Ester Compounds> The dielectric loss tangent Df was measured as an evaluation of the physical properties of the compounds alone for the ester compounds 1 to 7 of Examples 1 to 6 and Comparative Example 2 and the vinylbenzylated polyphenylene ether compound of Comparative Example 1. The measurement method is as follows.

[0092] [Dielectric loss tangent Df] Because ester compounds 1 to 7 alone cannot produce cured plates, samples were prepared by blending the vinyl benzylated polyphenylene ether compound with the ester compound at the following three levels of concentration (blending ratio): (1) Ester compound: vinyl benzylated polyphenylene ether compound: toluene = 5:95:100 (ester compound 5% by mass); (2) Ester compound: vinyl benzylated polyphenylene ether compound: toluene = 10:90:100 (ester compound 10% by mass); (3) Ester compound: vinyl benzylated polyphenylene ether compound: toluene = 15:85:100 (ester compound 15% by mass). The above three levels (1) to (3) were blended and dissolved, then poured into a tray and vacuum dried at 80°C for 24 hours in a reduced pressure dryer, and the resulting powder was used as a measurement sample. Note that the vinyl benzylated polyphenylene ether compound of Comparative Example 1 was not blended in this way and was used as a measurement sample alone.

[0093] Using a single-action compression molding machine (manufactured by Yasuda Seiki Seisakusho), 4 g of sample was pressed at a pressure of 10 Pa and a temperature of 200°C for 15 minutes to prepare a 100 mm x 100 mm x 0.5 mm thick flat plate. The obtained flat plate was cut to prepare test pieces with a width of 2 mm, a thickness of 0.5 mm, and a length of 100 mm, 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 mass% of the ester compound was calculated by extrapolating the dielectric loss tangent (Df) at each of the three concentrations described above, and this was used as the dielectric loss tangent (Df) of the compound alone.

[0094]

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

[0096] The various numerical ranges described in this specification can be arbitrarily combined with their respective upper and lower limit values, and all such combinations are considered to be preferred numerical ranges described in this specification. Furthermore, a numerical range described as "X to Y" means from X to Y.

[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, modifications, etc. are included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents.

Claims

1. A radically polymerizable group-containing ester compound having an ester bond-containing molecule consisting solely of one or more first units having a structure derived from polyphenylene ether with hydroxy groups at both ends and one or more second units having a structure derived from a difunctional or trifunctional aromatic acid halide and bonded to the first units via ester bonds, and a radically polymerizable group added to each molecular end of the ester bond-containing molecule.

2. The following formula (1): In formula (1), R １ represents a divalent group obtained by removing hydrogen atoms from the hydroxy groups at both ends of 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 difunctional aromatic acid halide, R ３ represents a monovalent group obtained by removing an acid halide group from a compound having a radical polymerizable group and an acid halide group, p is the average number of repeating units and is a number of 1 or more, and R １ , R ２ and R ３ The radical polymerizable group-containing ester compound according to claim 1 , wherein each of the radical polymerizable group-containing ester compounds may be the same or different.

3. The following formula (2): In formula (2), R １ represents a divalent group obtained by removing hydrogen atoms from the hydroxy groups at both ends of 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 difunctional aromatic acid halide, R ４ represents a monovalent group obtained by removing a hydroxy group from a compound having a radical polymerizable group and a hydroxy group, q is the average number of repeating units and is a number of 1 or more, and R １ , R ２ and R ４ The radical polymerizable group-containing ester compound according to claim 1 , wherein each of the radical polymerizable group-containing ester compounds may be the same or different.

4. The radically polymerizable group-containing ester compound according to any one of claims 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.

5. The radically polymerizable group-containing ester compound according to any one of claims 1 to 3, wherein the polyphenylene ether of the first unit has a number average molecular weight of 500 to 5,000.

6. The above R １ is expressed by the following formula (3): In formula (3), X represents a divalent group obtained by removing two phenolic hydroxy groups from a compound having two phenolic hydroxy groups, and R １１ and R １２ each independently represent a methyl group, an ethyl group, a propyl group, an allyl group, or a phenyl group; r and s each independently represent an integer of 0 to 4; and t and u each independently represent an average number of repeating units and are a number of 1 to 100.

7. The above R ２ is a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenyldiyl group, a substituted or unsubstituted diphenyletherdiyl group, or a substituted or unsubstituted naphthylene group.

8. The radically polymerizable group-containing ester compound according to any one of claims 1 to 3, which has a number average molecular weight of 700 to 50,000.

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

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