Allyl group-containing polycarbonate resin and curable resin composition

Abstract

To provide a polycarbonate resin which exhibits a low dielectric constant and a low dielectric loss tangent, and a curable resin composition which includes the polycarbonate resin and exhibits a low dielectric constant and a low dielectric loss tangent.SOLUTION: A polycarbonate resin is provided, which contains a specific bisphenol-based constitutional unit (A) having a substituent and a specific bisphenol-based constitutional unit (B) having an allyl group, has a ratio of the (A) in the total constitutional unit of 70 mol% or more, and satisfies the following (a) to (c). (a) A weight average molecular weight obtained by measuring the polycarbonate resin by a gel permeation chromatography method is 15,000 to 45,000. (b) A relative dielectric constant at a frequency of 10 GHz obtained by measuring the polycarbonate resin according to a cavity resonator perturbation method is 2.3 to 2.7, and a dielectric loss tangent is 0.0001 to 0.0030. (c) A ratio of the (B) in the total constitutional unit of the polycarbonate resin is 1 mol% or more and 10 mol% or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an allyl group-containing polycarbonate resin exhibiting a low dielectric constant and a low dielectric loss tangent. The present invention also relates to a curable resin composition exhibiting a low dielectric constant and a low dielectric loss tangent, which uses the allyl group-containing polycarbonate resin as a curing agent. [Background technology]

[0002] Mobile wireless communication services, typified by mobile phones, which were previously used for voice calls, are now being used as a means of accessing the Internet thanks to advances in communication and information processing technology. Furthermore, communication between people and machines and objects is about to begin full-scale operation for purposes of control, sensing, and monitoring. To address the significant increase in network traffic, the next-generation wireless communication standard, 5G systems (hereafter referred to as 5G), has begun operation. While previous communication systems (e.g., 4G LTE) used low-frequency bands below 2.5 GHz, 5G will use high-frequency bands above 6 GHz. Therefore, future 5G-compatible devices will need to be compatible with high-frequency signals. For example, reducing transmission loss in printed circuit boards (hereafter referred to as PCBs) is one way to address high-frequency signals. Transmission loss here refers to conductor loss originating in the conductors (e.g., copper circuits) that make up the PCB, and dielectric loss originating in the dielectric (insulating material surrounding the circuit). While smoothing the conductor surface is one way to address the former, it is difficult to expect significant improvement. Specifically, because dielectric loss depends on the frequency of the current and the dielectric constant and dielectric dissipation factor of the insulating material around the circuit, there is a demand for lower dielectric constant insulating materials. In addition, there is a need for insulating materials that have the same processability and physical properties (e.g., heat resistance, adhesiveness, insulating properties, etc.) as conventional circuit board materials.

[0003] PCBs are divided into package substrates located directly under chips such as mobile processors, rigid mainboard substrates that mount these package substrates, and flexible printed circuit boards (FPCBs) used for LCD drivers, camera modules, and film antennas. These insulating materials are made of thermosetting resins, whose composition consists of (i) thermosetting and crosslinking components such as epoxy resins and maleimide resins, (ii) filler components that provide flame retardancy, heat resistance, and a low linear expansion coefficient, and (iii) polymers used to improve flexibility and adhesion. Polymers used as PCB insulating materials generally require heat resistance, adhesion, processability, flexibility, and compatibility. Traditional polymers used for PCBs include carboxyl-modified acrylonitrile-butadiene copolymer rubber, acrylic polymers, and urethane polymers. However, none of these materials possess the low dielectric properties required for high-frequency applications, and new materials are currently needed.

[0004] Therefore, curable resin compositions containing a predetermined amount of polycarbonate resin have been investigated for the purpose of reducing dielectric constant and improving flexibility and adhesion. For example, Patent Document 1 discloses a resin composition containing an epoxy resin, a curing agent, a polycarbonate resin, and an inorganic filler. However, even if a polycarbonate resin is added to a curable resin composition, the composition becomes incompatible upon curing, making it difficult to achieve the desired effect of adding the polycarbonate resin, and there is a problem that the amount added is limited. Furthermore, Patent Documents 2, 3, and 4 disclose methods of adding an allyl group-containing aliphatic polycarbonate resin to a curable resin composition. However, although the inclusion of an allyl group improves the compatibility of the curable resin composition, the copolymerization of an aliphatic diol increases the dielectric loss tangent. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-35056 [Patent Document 2] Japanese Patent Application Publication No. 2019-89965 [Patent Document 3] Japanese Patent Application Publication No. 2019-89966 [Patent Document 4] Japanese Patent Application Publication No. 2019-89967 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a polycarbonate resin that exhibits a low dielectric constant and a low dielectric dissipation factor. Another object of the present invention is to provide a curable resin composition containing the polycarbonate resin that exhibits a low dielectric constant and a low dielectric dissipation factor, and a cured product thereof. [Means for solving the problem]

[0007] As a result of extensive research, the present inventors have surprisingly found that the above object can be achieved by using an allyl group-containing polycarbonate resin containing a specific structural unit. Based on this finding, further investigations have led to the completion of the present invention.

[0008] That is, according to the present invention, the following (Configuration 1) to (Configuration 12) are provided. (Configuration 1) A polycarbonate resin comprising a structural unit (A) represented by the following formula (1) and a structural unit (B) represented by the following formula (2), wherein the proportion of the structural unit (A) in all structural units is 70 mol % or more, and wherein the following (a) to (c) are satisfied: (a) the weight-average molecular weight of the polycarbonate resin measured by gel permeation chromatography is in the range of 15,000 to 45,000; (b) The relative permittivity of polycarbonate resin at a frequency of 10 GHz measured in accordance with the cavity resonator perturbation method is in the range of 2.3 to 2.7, and the dielectric loss tangent is in the range of 0.0001 to 0.0030; (c) The proportion of the structural unit (B) in all structural units of the polycarbonate resin is 1 mol % or more and 10 mol % or less.

[0009] [ka]

[0010] (In formula (1), R1 and R2 each independently represent a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 6 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms; R3 and R4 each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 6 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms; and X represents a single bond, a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted alkylidene group having 2 to 20 carbon atoms, a substituted or unsubstituted sulfur atom, or an oxygen atom.)

[0011] [ka]

[0012] (In general formula (2), R5 to R8 each independently represent a hydrogen atom or an allyl group having 3 to 20 carbon atoms, provided that at least one of R5 to R8 is an allyl group having 3 to 20 carbon atoms. Y represents a single bond, a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted alkylidene group having 2 to 20 carbon atoms, a substituted or unsubstituted sulfur atom, or an oxygen atom.)

[0013] (Configuration 2) A polycarbonate resin according to configuration 1, wherein the terminal structure of the polycarbonate resin contains a structure (C) derived from a monohydroxy compound represented by the following formula (3), and the structure (C) accounts for 10 mol % or more of all terminal structures constituting the polycarbonate resin:

[0014] [ka]

[0015] (In formula (3), R9 is a hydrogen atom, a linear or branched alkyl group having 1 to 9 carbon atoms, a linear or branched alkoxy group having 1 to 10 carbon atoms, or a linear or branched phenyl-substituted alkyl group having 1 to 20 carbon atoms; R 10 is an allyl group having 3 to 20 carbon atoms.

[0016] (Configuration 3) 3. The polycarbonate resin according to claim 1, wherein X in the formula (1) is at least one group selected from the group consisting of the following formula (4):

[0017] [ka]

[0018] (R 11 and R 12 each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, and Z represents a substituted or unsubstituted alkylene group having 4 to 12 carbon atoms.

[0019] (Configuration 4) The polycarbonate resin according to any one of configurations 1 to 3, wherein Y in the formula (2) is a substituted or unsubstituted alkylene group having 1 to 12 carbon atoms, a substituted or unsubstituted alkylidene group having 2 to 12 carbon atoms, or a substituted or unsubstituted sulfur atom. (Configuration 5) 5. The polycarbonate resin according to any one of configurations 1 to 4, wherein the proportion of the structural unit (A) in all structural units of the polycarbonate resin is 80 mol % or more. (Configuration 6) 6. The polycarbonate resin according to any one of configurations 1 to 5, wherein the proportion of the structural unit (B) in all structural units of the polycarbonate resin is from 2 mol % to 8 mol %. (Configuration 7) 7. The polycarbonate resin according to any one of configurations 1 to 6, wherein R1 and R2 in formula (1) are each at least one group selected from the group consisting of a methyl group, an isopropyl group, a tert-butyl group, a cyclohexyl group, and a phenyl group, and R3 and R4 are each a hydrogen atom or a methyl group. (Configuration 8) 8. The polycarbonate resin according to any one of configurations 1 to 7, wherein R5 and R6 in the formula (2) are allyl groups having 3 to 10 carbon atoms, and R7 and R8 are hydrogen atoms. (Configuration 9) 9. The polycarbonate resin according to any one of aspects 1 to 8, wherein Y in the formula (2) is a sulfide group, a sulfone group, or an isopropyl group. (Configuration 10) 10. The polycarbonate resin according to any one of configurations 1 to 9, wherein the polycarbonate resin is a polycarbonate resin produced by an interfacial polycondensation method between a dihydroxy compound and carbonyl chloride. (Configuration 11) 11. A curable resin composition comprising the polycarbonate resin according to any one of Aspects 1 to 10, a maleimide compound, and an inorganic filler. (Configuration 12) 12. The resin composition according to aspect 11, which is used to form an insulating layer of a printed wiring board. [Effects of the Invention]

[0020] The allyl group-containing polycarbonate resin of the present invention exhibits a low dielectric constant and a low dielectric loss tangent, and a curable resin composition using such an allyl group-containing polycarbonate resin as a curing agent can give a cured product with a low linear expansion coefficient and high strength, and is suitable for use as a material for high-frequency substrates. DETAILED DESCRIPTION OF THE INVENTION

[0021] The present invention will be described in detail below.

[0022] <Polycarbonate resin> The polycarbonate resin of the present invention contains a structural unit (A) represented by the following formula (1).

[0023] [ka]

[0024] In formula (1), R1 and R2 each independently represent a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 6 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms; and R3 and R4 each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 6 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms.

[0025] In R1 and R2, examples of the substituted or unsubstituted alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, a sec-pentyl group, and an n-hexyl group. Examples of the substituted or unsubstituted cycloalkyl group having 6 to 20 carbon atoms include a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the substituted or unsubstituted aryl group having 6 to 20 carbon atoms include a phenyl group, a benzyl group, a tolyl group, a 4-methylphenyl group, and a naphthyl group.

[0026] Among these, R1 and R2 are preferably a methyl group, an isopropyl group, a tert-butyl group, a cyclohexyl group, or a phenyl group, and particularly preferably a methyl group.

[0027] In R3 and R4, examples of the substituted or unsubstituted alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, a sec-pentyl group, and an n-hexyl group. Examples of the substituted or unsubstituted cycloalkyl group having 6 to 20 carbon atoms include a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the substituted or unsubstituted aryl group having 6 to 20 carbon atoms include a phenyl group, a benzyl group, a tolyl group, a 4-methylphenyl group, and a naphthyl group.

[0028] Among these, R3 and R4 are preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, or a 4-methylphenyl group, and particularly preferably a hydrogen atom or a methyl group. Here, the bonding positions of R1, R2, R3, and R4 in formula (1) are any positions selected from the 2-, 3-, 5-, and 6-positions relative to X on each phenyl ring, and preferably the 3- and 5-positions.

[0029] In formula (1), X represents a single bond, a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted alkylidene group having 2 to 20 carbon atoms, a substituted or unsubstituted sulfur atom, or an oxygen atom. Examples of the substituted or unsubstituted sulfur atom include -S- and -SO2-. The substituted or unsubstituted alkylidene group having 2 to 20 carbon atoms is preferably at least one group selected from the group consisting of the following formula (4):

[0030] [ka]

[0031] R 11 and R 12 each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, and Z represents a substituted or unsubstituted alkylene group having 4 to 12 carbon atoms.

[0032] R 11 and R 12 In the formula (I), examples of the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, a sec-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, etc. Examples of the substituted or unsubstituted aryl group having 6 to 20 carbon atoms include a phenyl group, a benzyl group, a tolyl group, a 4-methylphenyl group, a naphthyl group, etc.

[0033] Among these, R 11 and R 12 is preferably a methyl group, an ethyl group, an n-propyl group or a 4-methylphenyl group, and particularly preferably a methyl group.

[0034] In formula (1), Z bonds to the carbon atom connecting the two phenyl groups to form a substituted or unsubstituted divalent carbocyclic ring. Examples of divalent carbocyclic rings include cycloalkylidene groups (preferably having 5 to 8 carbon atoms) such as a cyclopentylidene group, a cyclohexylidene group, a cycloheptylidene group, a cyclododecylidene group, or an adamantylidene group. Substituted groups include those having a methyl substituent or an ethyl substituent. Among these, a cyclohexylidene group and a methyl-substituted cyclohexylidene group are preferred.

[0035] The polycarbonate resin of the present invention must contain the structural unit (A) represented by formula (1). The proportion of the structural unit (A) in all structural units of the polycarbonate resin is 70 mol% or more, preferably 80 mol% or more, more preferably 90 mol% or more, and even more preferably 95 mol% or more. If the structural unit (A) of formula (1) is less than 70 mol%, the dielectric properties will be poor, which is not preferred.

[0036] The polycarbonate resin of the present invention contains a structural unit (B) represented by the following formula (2).

[0037] [ka]

[0038] In formula (2), R5 to R8 each independently represent a hydrogen atom or an allyl group having 3 to 20 carbon atoms. However, it is preferable that at least one of R5 to R8 is an allyl group, and that two or more are allyl groups. It is particularly preferable that R5 and R6 are allyl groups having 3 to 10 carbon atoms, and R7 and R8 are hydrogen atoms. Here, the bonding positions of R5 to R8 in formula (2) are any positions selected from the 2nd, 3rd, 5th, and 6th positions relative to Y on each phenyl ring, and preferably the 3rd and 5th positions.

[0039] Y represents a single bond, a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted alkylidene group having 2 to 20 carbon atoms, a substituted or unsubstituted sulfur atom, or an oxygen atom.

[0040] The specific structure of Y is the same as the specific structure of X described above for X in formula (1). Among these, Y is preferably a sulfide group, a sulfone group, or an isopropyl group.

[0041] Examples of dihydroxy compounds from which structural unit (B) is derived include 2,2-bis(3-allyl-4-hydroxyphenyl)propane, 2,2-bis(3-allyl-4-hydroxyphenyl)methane, and 2,2-bis(3-allyl-4-hydroxyphenyl)sulfone, with 2,2-bis(3-allyl-4-hydroxyphenyl)propane and 2,2-bis(3-allyl-4-hydroxyphenyl)sulfone being preferred. These may be used alone or in combination.

[0042] The polycarbonate resin of the present invention must contain the structural unit (B) represented by formula (2). The proportion of the structural unit (B) in all structural units of the polycarbonate resin is 1 mol% or more and 10 mol% or less, preferably 2 mol% or more and 8 mol% or less, and more preferably 2 mol% or more and 5 mol% or less. If the proportion of the structural unit (B) is less than 1 mol%, the reactivity of the polycarbonate resin with the maleimide compound will be poor, and if it exceeds 10 mol%, the dielectric properties will be poor, which is undesirable.

[0043] The polycarbonate resin used in the present invention can usually be obtained by reacting a dihydroxy compound with a carbonyl compound. Examples of reaction methods include interfacial polycondensation, melt transesterification, solid-phase transesterification of carbonate prepolymers, and ring-opening polymerization of cyclic carbonate compounds. In the case of interfacial polycondensation, a monohydric phenol end-stopper is usually used. The polycarbonate resin may also be a branched polycarbonate obtained by polymerizing a trifunctional component, or a copolymer polycarbonate obtained by copolymerizing an aliphatic dicarboxylic acid, an aromatic dicarboxylic acid, and a vinyl monomer.

[0044] The polycarbonate resin of the present invention is produced by a reaction method known per se for producing ordinary polycarbonate resins, for example, a method of reacting a dihydroxy compound with a carbonyl compound such as carbonyl chloride (phosgene) or a carbonic acid diester. The basic means for these production methods will now be briefly described.

[0045] In reactions using carbonyl chloride (phosgene) as the carbonyl compound, the reaction is usually carried out in the presence of an acid binder and a solvent. Examples of acid binders include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and amine compounds such as pyridine. Examples of solvents include halogenated hydrocarbons such as methylene chloride and chlorobenzene. To promote the reaction, a catalyst such as a tertiary amine or a quaternary ammonium salt can also be used. The reaction temperature is usually 0 to 40°C, and the reaction time is several minutes to 5 hours.

[0046] The polycarbonate resin of the present invention may contain a structure (C) derived from a monohydroxy compound represented by the following formula (3), which is used as a terminal terminator in the polymerization reaction.

[0047] [ka]

[0048] In formula (3), R9 is a hydrogen atom, a linear or branched alkyl group having 1 to 9 carbon atoms, a linear or branched alkoxy group having 1 to 10 carbon atoms, or a linear or branched phenyl-substituted alkyl group having 1 to 20 carbon atoms; 10 is an allyl group having 3 to 20 carbon atoms. 10 The bonding position of is any position selected relative to the OH group on each phenyl ring, preferably the ortho position.

[0049] Specific examples of the monohydroxy compound include 2-allylphenol, chavicol, eugenol, etc. These may be used alone or in combination of two or more kinds.

[0050] The terminal structures derived from these monohydroxy compounds preferably account for 10 mol % or more, more preferably 30 mol % or more, and even more preferably 50 mol % or more of all terminal structures constituting the obtained polycarbonate resin. By introducing terminal structures derived from these monohydroxy compounds into the terminals, the reactivity between the polycarbonate resin and the maleimide compound becomes even better.

[0051] Furthermore, the polycarbonate resin of the present invention can use commonly used monofunctional phenols as a terminal terminator. Particularly in the case of a reaction using phosgene as a carbonate precursor, monofunctional phenols are commonly used as terminal terminators for molecular weight control, and the resulting polycarbonate resin has excellent thermal stability compared to polycarbonate resins that are not terminated at the terminals with groups based on monofunctional phenols.

[0052] Such monofunctional phenols may be any that can be used as a terminal terminator for polycarbonate resins, and are generally phenol or lower alkyl-substituted phenols, and can include monofunctional phenols represented by the following formula (5):

[0053] [ka]

[0054] In formula (5), A is a linear or branched alkyl group or arylalkyl group having 1 to 9 carbon atoms, and r is an integer of 1 to 5, preferably 1 to 3.

[0055] Specific examples of the monofunctional phenols include phenol, p-tert-butylphenol, p-cumylphenol, and isooctylphenol.

[0056] Other monofunctional phenols that can be used include phenols or benzoic acid chlorides having a long-chain alkyl group or aliphatic ester group as a substituent, or long-chain alkylcarboxylic acid chlorides. When these are used to cap the ends of polycarbonate polymers, they not only function as end terminators or molecular weight regulators, but also improve the melt fluidity of the resin, facilitating molding and processing, and are effective in reducing the physical properties of the molded product, particularly the water absorption rate of the resin, and in reducing the birefringence of the molded product, so are preferably used. Among these, phenols having a long-chain alkyl group as a substituent, represented by the following formulas (6) and (7), are preferably used.

[0057] [ka]

[0058] [ka]

[0059] In formula (7), Z is -RO-, -R-CO-O-, or -RO-CO-, where R represents a single bond or a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms, and n represents an integer of 10 to 50.

[0060] The substituted phenols of the formula (6) are preferably those in which n is 10 to 30, particularly 10 to 26, and specific examples thereof include decylphenol, dodecylphenol, tetradecylphenol, hexadecylphenol, octadecylphenol, eicosylphenol, docosylphenol, and triacontylphenol.

[0061] Furthermore, as the substituted phenols of the formula (7), compounds in which Z is -R-CO-O- and R is a single bond are preferred, and those in which n is 10 to 30, particularly 10 to 26, are preferred, and specific examples thereof include decyl hydroxybenzoate, dodecyl hydroxybenzoate, tetradecyl hydroxybenzoate, hexadecyl hydroxybenzoate, eicosyl hydroxybenzoate, docosyl hydroxybenzoate, and triacontyl hydroxybenzoate.

[0062] These monofunctional phenols are preferably introduced into the terminals of the resulting polycarbonate resin in an amount of at least 5 mol %, more preferably at least 10 mol %, based on the total terminals of the resulting polycarbonate resin. The monofunctional phenols may be used alone or in combination of two or more.

[0063] The amount of terminal OH groups relative to all structural units of the polycarbonate resin is preferably 300 ppm or less, more preferably 100 ppm or less, and even more preferably 50 ppm or less. When it is 300 ppm or less, the polycarbonate resin has excellent thermal stability.

[0064] The melt polymerization reaction is typically a transesterification reaction between a dihydric phenol and a carbonate ester. The reaction is carried out by mixing the dihydric phenol and carbonate ester under heating in the presence of an inert gas, and then distilling off the resulting alcohol or phenol. The reaction temperature varies depending on the boiling point of the resulting alcohol or phenol, but is typically in the range of 120 to 350°C. Toward the end of the reaction, the system is reduced in pressure to approximately 10 to 0.1 Torr (1,300 Pa to 13 Pa) to facilitate distillation of the resulting alcohol or phenol. The reaction time is typically approximately 1 to 4 hours.

[0065] Examples of carbonate esters include esters of an aryl group or aralkyl group having 6 to 10 carbon atoms, which may have a substituent, or an alkyl group having 1 to 4 carbon atoms. Specific examples include diphenyl carbonate, ditolyl carbonate, bis(chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, bis(diphenyl) carbonate, dimethyl carbonate, diethyl carbonate, and dibutyl carbonate, with diphenyl carbonate being preferred.

[0066] A polymerization catalyst can be used to increase the polymerization rate. Examples of such a polymerization catalyst include alkali metal compounds such as sodium hydroxide, potassium hydroxide, and sodium and potassium salts of dihydric phenols; alkaline earth metal compounds such as calcium hydroxide, barium hydroxide, and magnesium hydroxide; nitrogen-containing basic compounds such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, trimethylamine, and triethylamine; alkali metal and alkaline earth metal alkoxides; organic acid salts of alkali metals and alkaline earth metals; and other catalysts typically used in esterification and transesterification reactions, such as zinc compounds, boron compounds, aluminum compounds, silicon compounds, germanium compounds, organotin compounds, lead compounds, osmium compounds, antimony compounds, manganese compounds, titanium compounds, and zirconium compounds. The catalysts may be used alone or in combination. The amount of these polymerization catalysts used is preferably 1 × 10 per mole of the starting dihydric phenol. -8 ~1×10 -3 equivalent, more preferably 1 x 10 -7 ~5×10 -4 It is selected within the range of equivalents.

[0067] In order to reduce the number of phenolic terminal groups in such polymerization reactions, it is preferable to add compounds such as bis(chlorophenyl)carbonate, bis(bromophenyl)carbonate, bis(nitrophenyl)carbonate, bis(phenylphenyl)carbonate, chlorophenylphenylcarbonate, bromophenylphenylcarbonate, nitrophenylphenylcarbonate, phenylphenylcarbonate, methoxycarbonylphenylphenylcarbonate, and ethoxycarbonylphenylphenylcarbonate in the latter stages of the polycondensation reaction or after its completion. Among these, 2-chlorophenylphenylcarbonate, 2-methoxycarbonylphenylphenylcarbonate, and 2-ethoxycarbonylphenylphenylcarbonate are preferred, with 2-methoxycarbonylphenylphenylcarbonate being particularly preferred.

[0068] In the polycarbonate resin of the present invention, the structural units (A) and (B) preferably account for 75 mol % or more of all structural units, more preferably 80 mol % or more, even more preferably 85 mol % or more, and even more preferably 90 mol % or more.

[0069] A structural unit (Z) other than the structural unit (A) and the structural unit (B) may be contained in an amount of preferably 25 mol % or less, more preferably 20 mol % or less, even more preferably 15 mol % or less, and particularly preferably 10 mol % or less, within a range that does not impair the effects of the present invention.

[0070] Other dihydroxy components from which the structural unit (Z) is derived include, for example, hydroquinone, resorcinol, 4,4'-biphenol, 4,4'-bis(2,6-dimethyl)diphenol, 2,4'-dihydroxydiphenylmethane, bis(2-hydroxyphenyl)methane, bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)cyclohexylmethane, bis(4-hydroxyphenyl)diphenylmethane, 1,1-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxy-2-chlorophenyl)ethane, 2,2-bis(4-hydroxyphenyl)-1-phenylpropane, 1,1-bis(4-hydroxyphenyl)dec ... Examples of suitable hydroxybenzoates include bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4'-(p-phenylenediisopropylidene)diphenol, 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 1,1-bis(4-hydroxyphenyl)-4-isopropylcyclohexane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, 4,4'-dihydroxydiphenyl sulfone, 2,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl sulfoxide, and 4,4'-dihydroxydiphenyl sulfide. These may be used alone or in combination of two or more.

[0071] Other diol components from which the structural unit (Z) is derived include, for example, isosorbide:1,4:3,6-dianhydro-D-sorbitol, tricyclodecane dimethanol (TCDDM), 4,8-bis(hydroxymethyl)tricyclodecane, tetramethylcyclobutanediol (TMCBD), 2,2,4,4-tetramethylcyclobutane-1,3-diol, mixed isomers, cis / trans-1,4-cyclohexanedimethanol (CHDM), cis / trans-1,4-bis(hydroxymethyl)cyclohexane, cyclohex-1,4- Examples of suitable cyclohexanedimethanol include cyclohexanediol, ...

[0072] (Properties of polycarbonate resin) The number-average molecular weight and weight-average molecular weight of the polycarbonate resin of the present invention can be measured by gel permeation chromatography using standard polystyrene as the standard. The weight-average molecular weight of the polycarbonate resin of the present invention is in the range of 15,000 to 45,000, preferably 18,000 to 42,000, more preferably 20,000 to 35,000, and even more preferably 23,000 to 33,000. Within this range, compatibility with maleimide compounds is improved, the strength of the cured resin composition is improved, and the resin exhibits a low dielectric constant and a low dielectric dissipation factor. The number-average molecular weight of the polycarbonate resin of the present invention is preferably in the range of 5,000 to 15,000, more preferably 8,000 to 14,000, and even more preferably 9,000 to 12,000.

[0073] The polycarbonate resin of the present invention has a relative dielectric constant at a frequency of 10 GHz, measured by a perturbation method using a cavity resonator, in the range of 2.3 to 2.7, preferably 2.40 to 2.68, and more preferably 2.45 to 2.66. The dielectric loss tangent at a frequency of 10 GHz, measured by the same method, is in the range of 0.0001 to 0.0030, preferably 0.0005 to 0.0025. It is preferable for the relative dielectric constant and dielectric loss tangent to be within the above ranges, as this reduces the dielectric loss of the insulating material.

[0074] The allyl group equivalent of the polycarbonate resin of the present invention is preferably in the range of 50 to 1000 eq / ton, more preferably 100 to 700 eq / ton, even more preferably 130 to 500 eq / ton, and particularly preferably 150 to 400 eq / ton. When the allyl group equivalent is equal to or greater than the lower limit, the dielectric properties are more excellent. When the allyl group equivalent is equal to or less than the upper limit, the reactivity with maleimide compounds is more excellent.

[0075] (Curable resin composition) The polycarbonate resin of the present invention has an allyl group, and therefore can be used as a curing agent (maleimide curing agent) for curing a maleimide compound, which can be cured by heating.

[0076] Furthermore, a cured product obtained by curing a maleimide compound with the polycarbonate resin of the present invention exhibits a high glass transition temperature, a high thermal decomposition temperature, and a low coefficient of linear thermal expansion due to the use of the maleimide compound.

[0077] The curable resin composition of the present invention contains a polycarbonate resin. Polycarbonate resins have excellent impact resistance and therefore excellent mechanical strength, which contributes to enhancing the toughness of the cured product.

[0078] The content of the polycarbonate resin component is preferably 0.1% by weight or more, more preferably 1% by weight or more, and even more preferably 2% by weight or more, based on 100% by weight of the resin component of the resin composition. The upper limit is preferably 30% by weight or less, more preferably 20% by weight or less, and even more preferably 10% by weight or less. By keeping the content of the polycarbonate resin component within the above range, the toughness of the cured product can be improved.

[0079] Furthermore, since the polycarbonate resin of the present invention is used, the cured product obtained from the curable resin composition of the present invention has a lower dielectric constant and a lower dielectric dissipation factor than a cured product obtained by curing a maleimide compound with an allylphenol resin or a cured product obtained by curing an epoxy resin with a phenol novolac resin.

[0080] When the maleimide compound is cured using the polycarbonate resin of the present invention, it is believed that the curing occurs through the following reactions (1) to (3). (1) Reaction of a maleimide group with an allyl group. (2) Reaction between maleimide groups. (3) Reaction between allyl groups.

[0081] Furthermore, the polycarbonate resin of the present invention has excellent solubility in solvents that are generally used to dissolve maleimide compounds, and therefore a resin varnish can be obtained in which the polycarbonate resin of the present invention, the maleimide compound, and, if necessary, an epoxy resin described below are all dissolved in a solvent.

[0082] The solvent is generally a polar solvent such as methyl ethyl ketone. The polycarbonate resin of the present invention can be cured by itself through the reaction (3) without being combined with a maleimide compound. However, by combining it with a maleimide compound, the curing temperature can be lowered and thermal properties such as the glass transition temperature can be improved compared to when the resin is cured alone. Therefore, it is preferable to combine it with a maleimide compound or an epoxy resin and subject it to a curing reaction.

[0083] The uses of the curable resin composition of the present invention are not particularly limited. For example, the uses may be similar to those of known thermosetting molding materials, such as encapsulating materials, film materials, and laminate materials. More specific examples of uses include interlayer insulating layers for printed wiring boards, semiconductor encapsulating materials, encapsulating resin materials for electronic components, electrical insulating materials, resin materials for copper-clad laminates, build-up laminate materials, resist materials, resin materials for liquid crystal color filters, paints, various coating agents, adhesives, and fiber-reinforced plastic (FRP) materials.

[0084] <Maleimide compounds> The maleimide compound is not particularly limited as long as it is a compound having two or more maleimide groups, and examples thereof include bismaleimide compounds and polyphenylmethane maleimide. Examples of bismaleimide compounds include 4,4'-diphenylmethane bismaleimide (e.g., BMI-1100 manufactured by Daiwa Chemical Industry Co., Ltd.), alkyl bismaleimide, diphenylmethane bismaleimide, phenylene bismaleimide, bisphenol A diphenyl ether bismaleimide (e.g., BMI-4000 manufactured by Daiwa Chemical Industry Co., Ltd.), 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide (e.g., BMI-5100 manufactured by Daiwa Chemical Industry Co., Ltd.), 4-methyl-1,3-phenylene bismaleimide, 1,6'-bismaleimide-(2,2,4-trimethyl)hexane, 4,4'-diphenyl ether bismaleimide, 4,4'-diphenylsulfone bismaleimide, 1,3-bis(3-maleimidophenoxy)benzene, and 1,3-bis(4-maleimidophenoxy)benzene.

[0085] Polyphenylmethane maleimide is a polymer in which three or more benzene rings substituted with maleimide groups are bonded via methylene groups, and an example thereof is BMI-2300 manufactured by Daiwa Chemical Industry Co., Ltd. These maleimide compounds may be used alone or in combination of two or more.

[0086] The content of the maleimide compound in the curable resin composition of the present invention is preferably 10 to 300 parts by weight, more preferably 15 to 200 parts by weight, and even more preferably 20 to 150 parts by weight, per 100 parts by weight of the polycarbonate resin. When the content of the maleimide compound is within the above range, the gelation temperature of the curable resin composition can be reduced, for example, to 200°C or lower. Furthermore, the cured product of the curable resin composition exhibits a higher glass transition temperature, a higher thermal decomposition temperature, a lower linear expansion coefficient, a lower dielectric constant, and a lower dielectric loss tangent.

[0087] <Epoxy resin> The curable resin composition of the present invention may contain an epoxy resin as needed. The polycarbonate resin used in the present invention may have a phenolic hydroxyl group, and therefore may also be used as a curing agent (epoxy resin curing agent) for curing the epoxy resin. The epoxy resin can be cured by heating.

[0088] When an epoxy resin is cured using the polycarbonate resin of the present invention, it is believed that the curing occurs through the reaction (3) described above and the following reactions (4) and (5). (4) Reaction of epoxy groups with hydroxyl groups. (5) Reaction between epoxy groups.

[0089] Examples of epoxy resins include bixylenol-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, bisphenol AF-type epoxy resins, dicyclopentadiene-type epoxy resins, trisphenol-type epoxy resins, naphthol novolac-type epoxy resins, phenol novolac-type epoxy resins, tert-butyl-catechol-type epoxy resins, naphthalene-type epoxy resins, naphthol-type epoxy resins, anthracene-type epoxy resins, glycidylamine-type epoxy resins, glycidyl ester-type epoxy resins, cresol novolac-type epoxy resins, biphenyl-type epoxy resins, linear aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, spiro ring-containing epoxy resins, cyclohexane-type epoxy resins, cyclohexanedimethanol-type epoxy resins, naphthylene ether-type epoxy resins, trimethylol-type epoxy resins, and tetraphenylethane-type epoxy resins. Epoxy resins may be used alone or in combination of two or more.

[0090] <Solvent> The solvent is not particularly limited as long as it dissolves the components contained in the curable resin composition of the present invention (the polycarbonate resin of the present invention, the maleimide compound, and, if necessary, the epoxy resin and curing reaction catalyst, etc.). Typically, a polar solvent is used as the solvent. Examples of polar solvents include ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diethyl ketone, methyl propyl ketone, methyl amyl ketone, isophorone, diisobutyl ketone, diacetone alcohol, and cyclohexanone, as well as N,N-dimethylformamide, N-methyl-2-pyrrolidone, methanol, ethanol, butanol, ethyl acetate, butyl acetate, methyl cellosolve, ethyl diglycol acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and tetrahydrofuran. Any one of these solvents may be used alone, or two or more may be used in combination. Among these solvents, ketone-based solvents are preferred, and methyl ethyl ketone is more preferred.

[0091] <Curing reaction catalyst> The curing reaction catalyst (curing accelerator) preferably contains a catalyst (hereinafter also referred to as "catalyst (1)") that has the effect of accelerating the reaction between an allyl group and a maleimide group. Examples of catalyst (1) include imidazole compounds and organic peroxides. Examples of the imidazole compound include 2-ethyl-4-methylimidazole, 2-methylimidazole, 2-ethylimidazole, 2,4-dimethylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 1-vinyl-2-methylimidazole, 1-propyl-2-methylimidazole, 2-isopropylimidazole, 1-cyanomethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, and 1-cyanoethyl-2-phenylimidazole. Examples of organic peroxides include ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxydicarbonates, and peroxyesters. In the dialkyl peroxides, the alkyl group may be substituted with a phenyl group or the like. An example of such a dialkyl peroxide is dicumyl peroxide.

[0092] When the curable resin composition of the present invention contains an epoxy resin, it may contain a catalyst (hereinafter also referred to as "catalyst (2)") that has the effect of accelerating the reaction between a hydroxyl group and an epoxy group as a curing reaction catalyst. Examples of catalyst (2) include phosphorus-based compounds, tertiary amines, imidazole compounds, organic acid metal salts, Lewis acids, and amine complex salts. Examples of phosphorus-based compounds include triphenylphosphine, tris-2,6-dimethoxyphenylphosphine, tri-p-tolylphosphine, and triphenyl phosphite. Examples of tertiary amines include 2-dimethylaminomethylphenol, benzyldimethylamine, α-methylbenzyldimethylamine, and 1,8-diazabicyclo[5.4.0]undecene-7. Examples of imidazole compounds include those similar to those described above.

[0093] <Inorganic filler> The curable resin composition of the present invention contains an inorganic filler, which can reduce the linear expansion coefficient of the cured product of the curable resin composition.

[0094] The inorganic filler material is not particularly limited as long as it is an inorganic compound, but examples thereof include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium titanate zirconate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silica is particularly preferred. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Spherical silica is preferred. The inorganic fillers may be used alone or in combination of two or more.

[0095] The average particle size of the inorganic filler is usually 5 μm or less, preferably 2.5 μm or less, more preferably 1.5 μm or less, and even more preferably 1 μm or less. The lower limit of the average particle size is not particularly limited, but may be 1 nm (0.001 μm) or more, 5 nm or more, or 10 nm or more, for example. The average particle size of the inorganic filler can be measured by a laser diffraction / scattering method based on the Mie scattering theory.

[0096] The inorganic filler is preferably treated with a surface treatment agent, more preferably with one or more surface treatment agents such as a fluorine-containing silane coupling agent, an aminosilane coupling agent, an epoxysilane coupling agent, a mercaptosilane coupling agent, a silane coupling agent, an alkoxysilane compound, an organosilazane compound, or a titanate coupling agent, and even more preferably with an aminosilane silane coupling agent. The surface treatment agent preferably has a functional group that reacts with other components, such as a resin, such as an epoxy group, an amino group, or a mercapto group, and more preferably the functional group is bonded to the terminal group.

[0097] From the viewpoint of reducing the average linear expansion coefficient of the cured resin composition and improving the dielectric performance, the content of the inorganic filler component is preferably 45 parts by weight or more, more preferably 50 parts by weight or more, and even more preferably 60 parts by weight or more, based on 100 parts by weight of the nonvolatile content in the resin composition. The upper limit is not particularly limited, but is preferably 85 parts by weight or less, more preferably 80 parts by weight or less, and even more preferably 75 parts by weight or less.

[0098] <Flame retardant> The curable resin composition of the present invention may contain a flame retardant. Examples of the flame retardant include phosphazene compounds, organic phosphorus flame retardants, organic nitrogen-containing phosphorus compounds, nitrogen compounds, silicone flame retardants, and metal hydroxides. The flame retardants may be used alone or in combination of two or more.

[0099] When the curable resin composition contains a flame retardant, the content of the flame retardant is preferably 0.3 parts by weight or more, more preferably 0.5 parts by weight or more, and even more preferably 0.7 parts by weight or more, based on 100 parts by weight of the nonvolatile content in the resin composition. This allows the resin composition and its cured product to have significant flame retardancy. The upper limit is preferably 5 parts by weight or less, more preferably 4 parts by weight or less, and even more preferably 3 parts by weight or less.

[0100] <Optional additives> The resin composition of the present invention may contain other additives as needed. Examples of such other additives include thermoplastic resins, organic fillers, organometallic compounds such as organocopper compounds, organozinc compounds, and organocobalt compounds, as well as resin additives such as thickeners, antifoaming agents, leveling agents, adhesion promoters, and colorants.

[0101] Examples of thermoplastic resins include phenoxy resins, polyvinyl acetal resins, polyolefin resins, polybutadiene resins, polyimide resins, polyamideimide resins, polyetherimide resins, polysulfone resins, polyethersulfone resins, polyphenylene ether resins, polyetheretherketone resins, polyester resins, etc. However, the thermoplastic resins referred to here do not include the polycarbonate resins of the present invention.

[0102] As the organic filler, any organic filler that can be used when forming an insulating layer of a printed wiring board may be used, and examples thereof include rubber particles, polyamide fine particles, silicone particles, and the like. [Example]

[0103] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the following examples and comparative examples, the methods for measuring the various properties are as follows.

[0104] (1) Weight average molecular weight (Mw) The resulting polycarbonate resin was used as a measurement sample, and the weight-average molecular weight (Mw) was measured by gel permeation chromatography (GPC) and calculated using the polystyrene equivalent method. A calibration curve was prepared using standard polystyrenes with known molecular weights (12 types, from Tosoh PS Oligomer Kit A-500 to F-128). Measurements were performed using a Tosoh HLC-8220GPC column with three Tosoh TSK-gel SuperHZ4000 / 3000 / 2000 columns. The sample was prepared by dissolving 10 mg of polycarbonate copolymer in 5 mL of chloroform (containing 0.05% toluene as an internal standard) and filtering using a Millipore Millex LG4 column. Measurements were performed at 40°C and a flow rate of 0.35 mL / min. Chloroform for high-performance liquid chromatography (Wako Pure Chemical Industries, Ltd.) was used as the eluent.

[0105] (2) Allyl group equivalent and terminal ratio of structure (C) The obtained polycarbonate resin was used as a measurement sample, and the JNM-AL400 (resonance frequency 400 MHz) manufactured by JEOL Ltd. was used to measure the 1 H-NMR spectra were measured, and the allyl group equivalent weight in the polymer was calculated from the signal intensity ratio based on the structural units derived from each compound. The allyl group equivalent weight values ​​in the table show the total value of the backbone and terminal portions.

[0106] Furthermore, the signal intensity ratios based on the allyl group-containing monohydroxy group constituting the terminal, the structural unit derived from the monohydroxy group not containing an allyl group, and the OH group which is the unreacted terminal were calculated, and the sum of the signal intensity ratios at the terminals was taken as the total terminals, and the proportion of the signal intensity ratios of the allyl group-containing monohydroxy group was calculated as the terminal ratio (mol %). Polymer amount: 40mg Solvent: 0.6 mL of deuterated chloroform Accumulation count: 256 times

[0107] (3) Glass transition temperature The obtained polycarbonate resin was used as a measurement sample and measured using a thermal analysis system DSC-2910 manufactured by TA Instruments under conditions of a nitrogen atmosphere (nitrogen flow rate: 40 ml / min) and a heating rate of 20°C / min according to JIS K7121.

[0108] (4) Creating a laminate To 100 g of the obtained polycarbonate resin, BMI-2300 (polyphenylmethane maleimide, maleimide equivalent: 186.0 g / eq) manufactured by Daiwa Chemical Industry Co., Ltd. was added as a maleimide compound in an amount calculated by the following formula (1), and 1.2 g (1% of the total resin amount) of dicumyl peroxide as a curing reaction catalyst was dissolved in methyl ethyl ketone to a solid content of 60%, to obtain a resin varnish.

[0109] The resulting resin varnish was impregnated into glass cloth (E-glass) to a resin content of 40% by weight, and then dried at 100°C for 10 minutes to remove the solvent, yielding a prepreg. Six of these prepregs were stacked and press-molded at 180°C, then post-baked at 230°C for 5 hours to yield a molded product (laminate) with a thickness of 1.5 mm. The resin content refers to the proportion of resin (cured product) relative to the total weight of the molded product. Amount of maleimide compound (g) = maleimide equivalent (g / eq) ÷ allyl group equivalent of polycarbonate resin (eq / ton) × 10 6 ×100g÷5×10 -6 (Formula 1)

[0110] (5) Linear expansion coefficient A test piece measuring 5 mm square and 1.5 mm thick was cut out from the laminate. The linear expansion coefficient at 30°C was measured using a linear expansion coefficient measuring device "TMA4000SE" manufactured by NETZSCH at a heating rate of 2°C / min.

[0111] (6) Dielectric constant and dielectric loss tangent The polycarbonate resin and the laminate produced in (4) above were used as samples, and the relative permittivity and dielectric loss tangent at a frequency of 10 GHz were measured using a dielectric constant meter (Anritsu Network Analyzer MS46122B, AET Cavity Resonator for 10 GHz).

[0112] [Example 1] A reactor equipped with a thermometer, stirrer, and reflux condenser was charged with 4190 parts of 25% aqueous sodium hydroxide solution and 8754 parts of ion-exchanged water, to which 1820 parts of bisphenol C (S-BOC, manufactured by Honshu Chemical Industry Co., Ltd., designated BPC in the table), 115 parts of diallyl bisphenol A (BPA-CA, manufactured by Konishi Chemical Industry Co., Ltd., designated DAL-A in the table), and 3.9 parts of sodium hydrosulfite (manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.) were dissolved. 8904 parts of methylene chloride was added, and 1000 parts of phosgene was blown in over approximately 75 minutes at 15 to 25°C with stirring. After completion of the phosgene blowing, 599 parts of 25% aqueous sodium hydroxide solution and 73 parts of p-tert-butylphenol (PTBP, manufactured by DIC Co., Ltd., designated PTBP in the table) were added, stirring was resumed, and after emulsification, 2.6 parts of triethylamine was added. The mixture was further stirred at 26 to 33°C for 1 hour to complete the reaction.

[0113] After the reaction was complete, the product was diluted with methylene chloride and washed with water, then acidified with hydrochloric acid and washed with water. This process was repeated until the conductivity of the aqueous phase was nearly the same as that of ion-exchanged water, yielding a methylene chloride solution of polycarbonate resin. This solution was then passed through a 0.3 μm filter and added dropwise to warm water in a kneader with an isolation chamber and a foreign matter outlet in the bearing section. The methylene chloride was distilled off while the polycarbonate resin was flaked. The liquid-impregnated flakes were then crushed and dried to obtain a powder. The properties were measured, and the results are shown in Table 1.

[0114] [Example 2] A polycarbonate resin powder was obtained in the same manner as in Example 1, except that 1,858 parts of bisphenol C was used and 74 parts of diallyl bisphenol S (referred to as DAL-S in the table, TG-SH(H) manufactured by Nippon Kayaku Kogyo Co., Ltd.) was used instead of diallyl bisphenol A. Each property was measured, and the results are shown in Table 1.

[0115] [Example 3] A polycarbonate resin powder was obtained in the same manner as in Example 1, except that 1,858 parts of bisphenol C were used, 74 parts of diallyl bisphenol S (TG-SH(H) manufactured by Nippon Kayaku Kogyo Co., Ltd.) was used instead of diallyl bisphenol A, and 82 parts of o-allylphenol (referred to as o-AP in the table, manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of p-tert-butylphenol. Each property was measured, and the results are shown in Table 1.

[0116] [Example 4] A polycarbonate resin powder was obtained in the same manner as in Example 1, except that 2038 parts of 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane (referred to as BP-OCZ in the table, manufactured by Honshu Chemical Industry Co., Ltd.) were used, 184 parts of diallyl bisphenol A, and 67 parts of p-tert-butylphenol were used instead of bisphenol C. The properties were measured, and the results are shown in Table 1.

[0117] [Example 5] A reactor equipped with a thermometer, a stirrer, and a reflux condenser was charged with 5016 parts of a 25% aqueous sodium hydroxide solution and 4013 parts of ion-exchanged water, and 115 parts of diallyl bisphenol S, 1894 parts of 2,2-bis(4-hydroxy-3-tert-butylphenyl)propane (referred to as BP-OTBPA in the table, manufactured by Honshu Chemical Industry Co., Ltd.), 296 parts of 1,1-bis(4-hydroxy-3-methylphenyl)-3,3,5-trimethylcyclohexane (referred to as BP-TMC in the table, manufactured by Honshu Chemical Industry Co., Ltd.), and 4.6 parts of sodium hydrosulfite were dissolved therein. Then, 17760 parts of methylene chloride and 112 g of tetrabutylammonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.) were added, and 1000 parts of phosgene was blown into the mixture at 15 to 25°C over approximately 75 minutes with stirring. After the phosgene injection was completed, 317 parts of a 25% aqueous sodium hydroxide solution, 31 parts of p-tert-butylphenol, and 30 parts of o-allylphenol were added, stirring was resumed, and after emulsification, 4.8 parts of triethylamine was added, followed by further stirring at 26 to 33°C for 1 hour to complete the reaction.

[0118] After the reaction was complete, the product was diluted with methylene chloride and washed with water, then acidified with hydrochloric acid and washed with water. This process was repeated until the conductivity of the aqueous phase was nearly the same as that of ion-exchanged water, yielding a methylene chloride solution of polycarbonate resin. This solution was then passed through a 0.3 μm filter and added dropwise to warm water in a kneader with an isolation chamber and a foreign matter outlet in the bearing section. The methylene chloride was distilled off while the polycarbonate resin was flaked. The liquid-impregnated flakes were then crushed and dried to obtain a powder. The properties were measured, and the results are shown in Table 1.

[0119] [Example 6] A polycarbonate resin powder was obtained by the same procedure as in Example 5, except that 69 parts of diallyl bisphenol S were used, 303 parts of bisphenol C were used instead of 2,2-bis(4-hydroxy-3-tert-butylphenyl)propane, 2184 parts of 2,2-bis(4-hydroxy-3-cyclohexylphenyl)propane (referred to as BP-OCHPA in the table, manufactured by Honshu Chemical Industry Co., Ltd.) were used instead of 1,1-bis(4-hydroxy-3-methylphenyl)-3,3,5-trimethylcyclohexane, 2062 parts of 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane (manufactured by Honshu Chemical Industry Co., Ltd.), and 65 parts of o-AP were used without adding p-tert-butylphenol. The properties were measured, and the results are shown in Table 1.

[0120] [Comparative Example 1] A reactor equipped with a thermometer, a stirrer, and a reflux condenser was charged with 4190 parts of a 25% aqueous sodium hydroxide solution and 8754 parts of ion-exchanged water, and 1915 parts of bisphenol C and 4.4 parts of sodium hydrosulfite were dissolved therein. Then, 8904 parts of methylene chloride was added, and 1000 parts of phosgene was blown in over about 75 minutes at 15 to 25° C. with stirring. After completion of the phosgene blowing, 599 parts of a 25% aqueous sodium hydroxide solution and 71 parts of p-tert-butylphenol were added, stirring was resumed, and after emulsification, 2.6 parts of triethylamine was added. The mixture was further stirred at 26 to 33° C. for 1 hour to complete the reaction.

[0121] After the reaction was complete, the product was diluted with methylene chloride and washed with water, then acidified with hydrochloric acid and washed with water. This process was repeated until the conductivity of the aqueous phase reached nearly the same level as that of ion-exchanged water, yielding a methylene chloride solution of polycarbonate resin. This solution was then passed through a 0.3 μm filter and added dropwise to warm water in a kneader equipped with an isolation chamber and a foreign matter outlet in the bearing section. The methylene chloride was distilled off while the polycarbonate resin was flaked. The liquid-impregnated flakes were then crushed and dried to obtain a powder. The properties were measured, and the results are shown in Table 2.

[0122] Comparative Example 2 A polycarbonate resin powder was obtained in the same manner as in Example 1, except that 1628 parts of bisphenol C and 346 parts of diallyl bisphenol A were used. Each property was measured, and the results are shown in Table 2.

[0123] Comparative Example 3 A polycarbonate resin powder was obtained in the same manner as in Example 1, except that the amount of bisphenol C was 1858 parts, diallyl bisphenol S was used instead of diallyl bisphenol A (74 parts), and o-allyl phenol was used instead of p-tert-butyl phenol (31 parts). Each property was measured, and the results are shown in Table 2.

[0124] Comparative Example 4 A polycarbonate resin powder was obtained in the same manner as in Example 1, except that 1,535 parts of bisphenol A (referred to as BPA in the table, manufactured by Nippon Steel Chemical Co., Ltd.), 227 parts of diallyl bisphenol A, and 58 parts of p-tert-butylphenol were used instead of bisphenol C. Each property was measured, and the results are shown in Table 2.

[0125] [Table 1]

[0126] [Table 2] [Industrial Applicability]

[0127] According to the present invention, a polycarbonate resin having a low dielectric constant and a low dielectric loss tangent can be obtained. Furthermore, a cured product having a low linear expansion coefficient and high strength can be obtained using the polycarbonate resin. Such a cured product is extremely useful as a highly functional polymer material, and as an electrically and thermally excellent material, it can be used in a wide range of applications, such as interlayer insulating layers for printed wiring boards, semiconductor encapsulants, electrical insulating materials, resins for copper-clad laminates, resists, encapsulating resins for electronic components, resins for liquid crystal color filters, paints, various coating agents, adhesives, build-up laminate materials, and FRP.

Claims

1. A polycarbonate resin comprising a structural unit (A) represented by the following formula (1) and a structural unit (B) represented by the following formula (2), wherein the proportion of the structural unit (A) in all structural units is 70 mol % or more, and wherein the following (a) to (c) are satisfied: (a) the weight average molecular weight of the polycarbonate resin measured by gel permeation chromatography is in the range of 15,000 to 45,000; (b) the relative dielectric constant of the polycarbonate resin at a frequency of 10 GHz measured in accordance with a cavity resonator perturbation method is in the range of 2.3 to 2.7, and the dielectric loss tangent is in the range of 0.0001 to 0.0030; (c) The proportion of the structural unit (B) in all structural units of the polycarbonate resin is 1 mol % or more and 10 mol % or less. 【Chemistry 1】 (In formula (1), R １ and R ２ each independently represents at least one group selected from the group consisting of a methyl group, an isopropyl group, a tert-butyl group, and a cyclohexyl group; R ３ and R ４ each independently represents a hydrogen atom or a methyl group, and X represents at least one group selected from the group consisting of the following formula (4): 【Chemistry 2】 (R 11 and R 12 each independently represent a methyl group, an ethyl group, an n-propyl group, or a 4-methylphenyl group, and Z bonds to the carbon atom connecting the two phenyl groups to form a cyclohexylidene group or a methyl-substituted cyclohexylidene group.) 【Transformation 3】 (In general formula (2), R ５ ~R ８ are each independently a hydrogen atom or an allyl group. ５ ~R ８ At least two of the groups are allyl groups. Y represents a sulfide group, a sulfone group, or an isopropyl group.

2. 2. The polycarbonate resin according to claim 1, wherein the terminal structure of the polycarbonate resin contains a structure (C) derived from a monohydroxy compound represented by the following formula (3), and the structure (C) accounts for 10 mol % or more of all terminal structures constituting the polycarbonate resin: 【Chemistry 4】 (In formula (3), R ９ is a hydrogen atom, a linear or branched alkyl group having 1 to 9 carbon atoms, a linear or branched alkoxy group having 1 to 10 carbon atoms, or a linear or branched phenyl-substituted alkyl group having 1 to 20 carbon atoms; R １０ is an allyl group having 3 to 20 carbon atoms.

3. 3. The polycarbonate resin according to claim 1, wherein the proportion of the structural unit (A) in all structural units of the polycarbonate resin is 80 mol % or more.

4. 4. The polycarbonate resin according to claim 1, wherein the proportion of the structural unit (B) in all structural units of the polycarbonate resin is 2 mol % or more and 8 mol % or less.

5. 5. The polycarbonate resin according to claim 1, which is produced by an interfacial polycondensation method between a dihydroxy compound and carbonyl chloride.

6. A curable resin composition comprising the polycarbonate resin according to any one of claims 1 to 5, a maleimide compound, and an inorganic filler.

7. The resin composition according to claim 6, which is used to form an insulating layer of a printed wiring board.

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