JP7516885B2 - Polycarbonate resin composition - Google Patents

Description

The present invention relates to a polycarbonate resin composition that has excellent heat resistance, mechanical strength, and moldability, as well as a low relative dielectric constant and a low dielectric loss tangent. The present invention also relates to a molded article and a cover for a millimeter wave radar that use this polycarbonate resin composition.

Polycarbonate resin has excellent mechanical strength, heat resistance, electrical properties, transparency, etc., and is widely used in various fields as an engineering plastic.

In recent years, high-frequency radio waves have come to be used in the fields of electrical and electronic equipment and automobiles, and as a result, materials with both low dielectric constant and low dielectric loss tangent are required. However, conventional polycarbonate resins made from bisphenol A have not been able to fully meet these requirements.

Using polycarbonate resin made from aliphatic diols is expected to lower the dielectric constant, but there is an issue of reduced heat resistance.

Patent Document 1 discloses a polycarbonate copolymer with improved optical properties and heat resistance by copolymerizing an aliphatic diol, a cyclic acetal diol, with an aromatic diol. In addition, Patent Document 2 discloses a polycarbonate copolymer with a low photoelastic constant and improved thermal stability by copolymerizing an aliphatic diol, a cyclic acetal diol, with an aromatic diol.

Patent Document 3 proposes a cover for millimeter wave radar that uses a polycarbonate resin made from a bisphenol having a specific substituent group, thereby lowering the dielectric tangent and improving millimeter wave transmittance.

Japanese Patent Application Publication No. 9-268225 International Publication No. 2012/063965 JP 2019-197048 A

As the volume of information and communication traffic increases in recent years, there is a strong demand for faster communication speeds in information and communication devices such as mobile phones. High-frequency radio waves are ideal for high-speed communication, and the market for next-generation (5G) communications in the 28 GHz band is expected to take off.

The use of such high frequency bands is expected to be used not only for mobile phone and other communications but also in a wide range of fields. For example, in automotive applications, social infrastructure applications, and medical and nursing applications, millimeter wave radars are becoming higher in frequency to increase the distance from detectable objects and improve maximum resolution.

In addition, there is an increasing demand for higher performance in the housings of information and communication devices that are expected to use high-frequency bands. High-frequency band radio waves have larger transmission losses and poorer permeability through materials than lower-frequency band radio waves. Therefore, it is desirable for housings used for high-frequency communications to have better radio wave permeability than before.

The transmission loss is proportional to the square root of the dielectric constant ( _εr ) and the dielectric loss tangent (tan δ) of the dielectric. Therefore, in order to increase the radio wave permeability of the housing, it is necessary to reduce the dielectric constant _εr and the dielectric loss tangent tan δ of the material used for the housing.

In addition, materials used in such fields desirably have not only a low dielectric constant and a low dielectric tangent, but also appropriate heat resistance, mechanical strength, and moldability, and there is a strong demand for materials that meet these conditions. However, conventional materials have not been able to meet these requirements.

Patent Document 1 discloses a polycarbonate copolymer with improved heat resistance, but makes no mention of its dielectric properties. Patent Document 2 discloses a polycarbonate copolymer with improved thermal stability, but makes no mention of its dielectric properties.

Patent Document 3 proposes a cover for millimeter wave radar that uses a polycarbonate resin made from a bisphenol having a specific substituent group, thereby lowering the dielectric tangent and improving millimeter wave transparency. However, no significant improvement in the relative dielectric constant was observed compared to conventional polycarbonate resin made from bisphenol A.

The present invention has been made in consideration of the above problems, and aims to provide a polycarbonate resin composition that has excellent heat resistance, mechanical strength, and moldability, as well as a low relative dielectric constant and a low dielectric loss tangent.

As a result of intensive research conducted by the inventors to solve the above problems, they discovered that a polycarbonate resin composition containing two specific types of repeating units can be produced that meets the above objectives, and thus completed the present invention.

That is, the gist of the present invention lies in the following [1] to [17].

[1] A polycarbonate resin composition comprising a polycarbonate resin containing a repeating unit (A) represented by the following formula (1) and a repeating unit (B) represented by the following formula (2), in which the sum of the proportion of the repeating unit (C) represented by the following formula (3) and the proportion of the repeating unit (D) represented by the following formula (4) contained in the repeating unit (B) is 40 mol % or more.

In formula (1), ^W1 is an organic group containing a cyclic structure and may contain a heteroatom. ^R1 to ^R4 are each independently an alkyl group having 1 to 10 carbon atoms and may contain a heteroatom, and may be bonded to ^W1 to form a ring.
In formula (2), R ⁵ to R ⁸ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a group containing an aryl group and having 6 to 12 carbon atoms, and W ² represents at least one selected from a single bond, an oxygen atom, a sulfur atom, and a divalent organic group.
In formula (3), R ⁹ and R ¹⁰ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a group containing an aryl group and having 6 to 12 carbon atoms, and R ¹¹ and R ¹² are each independently an alkyl group having 1 to 10 carbon atoms, or a group containing an aryl group and having 6 to 12 carbon atoms.
In formula (4), R ¹³ to R ¹⁶ each independently represent an alkyl group having 1 to 10 carbon atoms, or a group containing an aryl group and having 6 to 12 carbon atoms.

[2] The polycarbonate resin composition according to [1], characterized in that the amount of terminal hydroxyl groups measured by a colorimetric method using the titanium tetrachloride/acetic acid method is 100 to 2,500 ppm.

[3] The polycarbonate resin composition according to [1] or [2], characterized in that the amount of residual phenol is 250 ppm or less.

[4] The polycarbonate resin composition according to any one of [1] to [3], wherein W ¹ in the formula (1) is selected from the following formula (5) or (6):

[In formula (6), R ¹⁷ and R ¹⁸ each independently represent a hydrogen atom, a group containing a heteroatom, a group containing a halogen atom, an alkyl group having 1 to 10 carbon atoms, or a group containing an aryl group and having 6 to 12 carbon atoms.]

[5] The polycarbonate resin composition according to any one of [1] to [4], wherein R ⁹ and R ¹⁰ in the formula (3) each independently represent a hydrogen atom or a methyl group.

[6] The polycarbonate resin composition according to any one of [1] to [5], wherein R ¹³ to R ¹⁶ in the formula (4) are methyl groups.

[7] The polycarbonate resin composition according to any one of [1] to [6], wherein R ⁹ and R ¹⁰ in the formula (3) are methyl groups.

[8] The polycarbonate resin composition according to any one of [1] to [7], characterized in that the repeating unit (A) is a repeating unit represented by the following formula (7) or (8):

[9] The polycarbonate resin composition according to any one of [1] to [8], wherein ^W2 in the formula (2) is selected from a single bond, a methylene group, an ethylidene group, and an isopropylidene group.

[10] The polycarbonate resin composition according to any one of [1] to [9], characterized in that the sum of the repeating units (C) and (D) contained in the repeating units (B) is 80 mol % or more relative to the total repeating units (B).

[11] A polycarbonate resin composition according to any one of [1] to [10], characterized in that the amount of terminal hydroxyl groups measured by a colorimetric method using titanium tetrachloride/acetic acid is 130 to 1,000 ppm.

[12] The polycarbonate resin composition according to any one of [1] to [11], characterized in that the ratio of the repeating unit (A) to the repeating unit (B) is 1:99 to 90:10.

[13] The polycarbonate resin composition according to any one of [1] to [12], wherein the viscosity average molecular weight (Mv) of the polycarbonate resin is in the range of 16,000 to 32,000.

[14] A molded article obtained using the polycarbonate resin composition described in any one of [1] to [13].

[15] An injection-molded article obtained using the polycarbonate resin composition described in any one of [1] to [13].

[16] An extrusion molded product obtained using the polycarbonate resin composition described in any one of [1] to [13].

[17] A cover for a millimeter wave radar obtained using the polycarbonate resin composition described in any one of [1] to [13].

The polycarbonate resin composition of the present invention has excellent heat resistance and mechanical strength, as well as a low dielectric constant and a low dielectric tangent, and therefore can provide a polycarbonate resin composition with low transmission loss and high transmission rate of high-frequency radio waves. Such a polycarbonate resin composition can be widely used in housings for mobile phones and the like that use radio waves in the high-frequency band, millimeter-wave radars for various in-vehicle sensors, millimeter-wave radars for railways and aircraft, millimeter-wave radars in the fields of transportation, medical care and nursing, security, and information content transmission.

The present invention will be described in detail below with reference to embodiments and examples, but the present invention should not be construed as being limited to the embodiments and examples shown below.

In this specification, unless otherwise specified, "~" is used to mean that the numbers before and after it are included as the lower and upper limits.

[Polycarbonate resin]
The polycarbonate resin composition of the present invention is a polycarbonate resin composition comprising a polycarbonate resin containing a repeating unit (A) represented by the following formula (1) and a repeating unit (B) represented by the following formula (2), wherein the sum of the proportions of the repeating unit (C) represented by the following formula (3) and the repeating unit (D) represented by the following formula (4) contained in the repeating unit (B) is 40 mol % or more based on the total repeating units (B):
The polycarbonate resin composition contains a polycarbonate resin containing a repeating unit (A) represented by the following formula (1) and a repeating unit (B) represented by the following formula (2), and the sum of the proportions of the repeating unit (C) represented by the following formula (3) and the repeating unit (D) represented by the following formula (4) contained in the repeating unit (B) is 40 mol % or more, whereby the polycarbonate resin composition has excellent heat resistance and mechanical strength, and can achieve a low relative dielectric constant and a low dielectric dissipation factor.

In formula (1), ^W1 is an organic group containing a cyclic structure and may contain a heteroatom. ^R1 to ^R4 are each independently an alkyl group having 1 to 10 carbon atoms and may contain a heteroatom, and may be bonded to ^W1 to form a ring.
In formula (2), R ⁵ to R ⁸ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a group containing an aryl group and having 6 to 12 carbon atoms, and W ² represents at least one selected from a single bond, an oxygen atom, a sulfur atom, and a divalent organic group.
In formula (3), R ⁹ and R ¹⁰ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a group containing an aryl group and having 6 to 12 carbon atoms, and R ¹¹ and R ¹² are each independently an alkyl group having 1 to 10 carbon atoms, or a group containing an aryl group and having 6 to 12 carbon atoms.
In formula (4), R ¹³ to R ¹⁶ each independently represent an alkyl group having 1 to 10 carbon atoms, or a group containing an aryl group and having 6 to 12 carbon atoms.

The polycarbonate resin composition of the present invention may contain a polycarbonate resin mixture of a polycarbonate resin containing a repeating unit (A) and a polycarbonate resin containing a repeating unit (B), may contain a copolymer polycarbonate resin containing a repeating unit (A) and a repeating unit (B), or may contain a polycarbonate resin containing a repeating unit (A) and/or a polycarbonate resin containing a repeating unit (B) and a copolymer polycarbonate resin containing a repeating unit (A) and a repeating unit (B).

<Repeating unit (A) represented by formula (1)>
In the polycarbonate resin composition of the present invention, in the formula (1), ^W1 is an organic group containing a cyclic structure, which may contain a heteroatom. ^R1 to ^R4 are each independently an alkyl group having 1 to 10 carbon atoms, which may contain a heteroatom, and which may be bonded to ^W1 to form a ring. Examples of the heteroatom include an oxygen atom, a sulfur atom, and a nitrogen atom. An oxygen atom is preferable.

In the formula (1), W ¹ is not particularly limited as long as it is an organic group containing a cyclic structure, but preferably contains a heteroatom.

In the formula (1), more preferred specific examples of ^W1 include the following formula (5) or (6).

[In formula (6), R ¹⁷ and R ¹⁸ each independently represent a hydrogen atom, a group containing a heteroatom, a group containing a halogen atom, an alkyl group having 1 to 10 carbon atoms, or a group containing an aryl group and having 6 to 12 carbon atoms.]

When ^W1 is represented by formula (6), it is preferable that ^R1 or ^R2 in formula (1) is bonded to position *1 and ^R3 or ^R4 is bonded to position *2 to form a ring, as shown in formula (6B) below.

R ¹⁷ and R ¹⁸ are each preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and particularly preferably a hydrogen atom.

Specific examples of particularly suitable repeating units (A) include repeating units represented by the following general formula (7) or (8). By using repeating units represented by the following formula (7) or (8) as repeating units (A), the thermal stability of the polycarbonate resin composition of the present invention can be improved and the relative dielectric constant can be effectively reduced.

<Repeating unit (B) represented by formula (2)>
In the polycarbonate resin composition of the present invention, in the formula (2), R ⁵ to R ⁸ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a group containing an aryl group and having 6 to 12 carbon atoms, and W ² represents at least one selected from a single bond, an oxygen atom, a sulfur atom, and a divalent organic group.

Specific examples of the alkyl group having 1 to 10 carbon atoms for R ⁵ to R ⁸ include a methyl group, an ethyl group, a n-propyl group, a n-butyl group, a n-pentyl group, a n-hexyl group, a n-heptyl group, a n-octyl group, a n-nonyl group, and a n-decyl group;
A methylethyl group, a methylpropyl group, a methylbutyl group, a methylpentyl group, a methylhexyl group, a methylheptyl group, a methyloctyl group, and a methylnonyl group;
dimethylethyl group, dimethylpropyl group, dimethylbutyl group, dimethylpentyl group, dimethylhexyl group, dimethylheptyl group, dimethyloctyl group;
A trimethylpropyl group, a trimethylbutyl group, a trimethylpentyl group, a trimethylhexyl group, a trimethylheptyl group;
Ethylbutyl group, ethylpentyl group, ethylhexyl group, ethylheptyl group, ethyloctyl group;
Examples of the cyclohexyl group include a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a trimethylcyclohexyl group, a tetramethylcyclohexyl group, an ethylcyclohexyl group, a diethylcyclohexyl group, and a methylethylcyclohexyl group.

Specific examples of the aryl-containing group having 6 to 12 carbon atoms for R ⁵ to R ⁸ include a phenyl group, a tolyl group, and a naphthyl group.

Among these, it is preferable that R ⁵ to R ⁸ are each independently a hydrogen atom or a methyl group, and it is more preferable that all of R ⁵ to R ⁸ are hydrogen atoms or all of R ⁵ to R ⁸ are methyl groups.

In the formula (2), ^W2 represents at least one selected from a single bond, an oxygen atom, a sulfur atom, and a divalent organic group.
The divalent organic group for ^W2 is not particularly limited as long as it is a conventionally known divalent organic group and can be appropriately selected and used. Specific examples include organic groups represented by the following formulae (9a) to (9h).

In the above formula (9a), R ¹⁹ and R ²⁰ each independently represent a hydrogen atom, a monovalent hydrocarbon group having 1 to 24 carbon atoms, or an alkoxy group having 1 to 24 carbon atoms, and among these, a monovalent hydrocarbon group having 1 to 24 carbon atoms is preferable.
Examples of the monovalent hydrocarbon group having 1 to 24 carbon atoms include an alkyl group having 1 to 24 carbon atoms, an alkenyl group having 2 to 24 carbon atoms, an aryl group having 6 to 24 carbon atoms which may have a substituent, and an arylalkyl group having 7 to 24 carbon atoms.

Examples of alkyl groups having 1 to 24 carbon atoms include linear and branched alkyl groups and alkyl groups having a partial ring structure, with linear alkyl groups being preferred. Examples of such alkyl groups having 1 to 24 carbon atoms include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, and n-octyl groups.

Examples of alkenyl groups having 2 to 24 carbon atoms include linear and branched alkenyl groups and alkenyl groups having a partial ring structure, with linear alkenyl groups being preferred. Examples of such alkenyl groups having 2 to 24 carbon atoms include vinyl groups, n-propenyl groups, n-butenyl groups, n-pentenyl groups, n-hexenyl groups, n-heptenyl groups, and n-octenyl groups.

Examples of the aryl group having 6 to 24 carbon atoms include aryl groups which may have a substituent, such as an alkyl group, such as a phenyl group, a naphthyl group, a methylphenyl group, a dimethylphenyl group, and a trimethylphenyl group.
Examples of the arylalkyl group having 7 to 24 carbon atoms include a benzyl group.

Examples of alkoxy groups having 1 to 24 carbon atoms include linear, branched, and partially cyclic alkoxy groups, with linear alkoxy groups being preferred. Specific examples include methoxy, ethoxy, propoxy, and butoxy groups.

In the above formula (9b), ^X1 represents an oxygen atom or NRa, where Ra has the same definition as ^R19 and ^R20 above.

In the above formula (9c), ^X2 represents a divalent hydrocarbon group having 3 to 18 carbon atoms, such as a propylene group, butylene group, pentylene group, hexylene group, heptylene group, octylene group, nonylene group, decylene group, undecylene group, and dodecynylene group, each of which may further have a substituent. Examples of the substituent include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a phenyl group. The group may further have a partial crosslinked structure.

In the above formula (9h), two ^X3 each independently represent an alkylene group having 1 to 7 carbon atoms. Such an alkylene group may be linear or branched, and may have a cyclic structure, and examples thereof include a methylene group, an ethylene group, a propylene group, and a butylene group. Furthermore, m represents an integer of 1 to 500, and is preferably 5 to 300, and more preferably 10 to 100.

Among these, ^W2 is more preferably a single bond, a methylene group, an ethylidene group, or an isopropylidene group.

<Repeating unit (C) represented by formula (3)>
In the polycarbonate resin composition of the present invention, in the formula (3), R ⁹ and R ¹⁰ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a group containing an aryl group and having 6 to 12 carbon atoms, and R ¹¹ and R ¹² each independently represent an alkyl group having 1 to 10 carbon atoms, or a group containing an aryl group and having 6 to 12 carbon atoms.

Specific examples of the alkyl group having 1 to 10 carbon atoms for R ⁹ and R ¹⁰ include a methyl group, an ethyl group, a n-propyl group, a n-butyl group, a n-pentyl group, a n-hexyl group, a n-heptyl group, a n-octyl group, a n-nonyl group, and a n-decyl group;
A methylethyl group, a methylpropyl group, a methylbutyl group, a methylpentyl group, a methylhexyl group, a methylheptyl group, a methyloctyl group, and a methylnonyl group;
dimethylethyl group, dimethylpropyl group, dimethylbutyl group, dimethylpentyl group, dimethylhexyl group, dimethylheptyl group, dimethyloctyl group;
A trimethylpropyl group, a trimethylbutyl group, a trimethylpentyl group, a trimethylhexyl group, a trimethylheptyl group;
Ethylbutyl group, ethylpentyl group, ethylhexyl group, ethylheptyl group, ethyloctyl group;
Examples of the cyclohexyl group include a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a trimethylcyclohexyl group, a tetramethylcyclohexyl group, an ethylcyclohexyl group, a diethylcyclohexyl group, and a methylethylcyclohexyl group.

Specific examples of the group containing an aryl group and having 6 to 12 carbon atoms for R ⁹ and R ¹⁰ include a phenyl group, a tolyl group, and a naphthyl group.

It is preferable that R ⁹ and R ¹⁰ are each independently a hydrogen atom or a methyl group. It is more preferable that at least one of them is a methyl group, and it is most preferable that both R ⁹ and R ¹⁰ are methyl groups.

Specific examples of the alkyl group having 1 to 10 carbon atoms for R ¹¹ and R ¹² are the same as those for R ⁹ and R ¹⁰ .

Specific examples of the aryl-containing group having 6 to 12 carbon atoms for R ¹¹ and R ¹² are the same as those for R ⁹ and R ¹⁰ .

R ¹¹ and R ¹² each independently preferably represent an alkyl group having 1 to 10 carbon atoms, and most preferably a methyl group.

<Repeating unit (D) represented by formula (4)>
In the polycarbonate resin composition of the present invention, in the formula (4), R ¹³ to R ¹⁶ are each independently an alkyl group having 1 to 10 carbon atoms, or a group containing an aryl group and having 6 to 12 carbon atoms.

Specific examples of the alkyl group having 1 to 10 carbon atoms for R ¹³ to R ¹⁶ are the same as R ⁹ and R ¹⁰ in the above formula (3).

Specific examples of the aryl-containing group having 6 to 12 carbon atoms for R ¹³ to R ¹⁶ are the same as R ⁹ and R ¹⁰ in the above formula (3).

It is preferable that at least one of R ¹³ to R ¹⁶ is a methyl group, and it is most preferable that all of R ¹³ to R ¹⁶ are methyl groups.

<Suitable repeating unit (B)>
The repeating unit (B) of the polycarbonate resin composition of the present invention is most preferably a repeating unit represented by the following formula (10) and/or the following formula (11). That is, the repeating unit (B) preferably contains a repeating unit represented by the following formula (10) as the repeating unit (C), and preferably contains a repeating unit represented by the following formula (11) as the repeating unit (D). By using the repeating unit represented by the following formula (10) and/or the following formula (11) as the repeating unit (B), the mechanical properties including surface hardness and heat resistance of the polycarbonate resin composition of the present invention become more excellent.

<Repeating Units (A) and (B)>
The polycarbonate resin composition of the present invention contains a repeating unit (A) represented by the formula (1) and a repeating unit (B) represented by the formula (2), and the sum of the proportions of the repeating unit (C) represented by the formula (3) and the repeating unit (D) represented by the formula (4) contained in the repeating unit (B) is 40 mol % or more based on the total repeating units (B).

The ratio of repeating units (A) and (B) in the polycarbonate resin contained in the polycarbonate resin composition of the present invention is not particularly limited, but the ratio (molar ratio) of repeating units (A) and repeating units (B) is preferably 1:99 to 90:10, particularly 10:90 to 80:20, and especially 15:85 to 70:30. From the viewpoint of improving dielectric properties, the polycarbonate resin composition of the present invention preferably contains 10% by mass or more, particularly 15% by mass or more of repeating units (A), and from the viewpoint of improving heat resistance and dielectric properties, the polycarbonate resin composition of the present invention preferably contains 10% by mass or more, particularly 20% by mass or more, and especially 30% by mass or more of repeating units (B).
In the polycarbonate resin contained in the polycarbonate resin composition of the present invention, the sum of the content of the repeating unit (A) and the content of the repeating unit (B) is preferably 80 mass % or more, more preferably 85 mass % or more, and particularly preferably 90 mass % or more, from the viewpoint of improving dielectric properties.

The ratio of the repeating units (A) and (B) in the polycarbonate resin contained in the polycarbonate resin composition can be calculated by measuring ^1H -NMR of the polycarbonate resin dissolved in deuterated chloroform. In the present invention, a deuterated chloroform solution of the polycarbonate resin was prepared so that the polycarbonate resin concentration was 50 mg/mL, and the temperature was 30°C, the relaxation time was 6 seconds, and the cumulative number was 128.

In addition, in the polycarbonate resin contained in the polycarbonate resin composition of the present invention, the sum of the repeating units (C) represented by formula (3) and the repeating units (D) represented by formula (4) among the repeating units (B) is 40 mol% or more, more preferably 60 mol% or more, even more preferably 80 mol% or more, and particularly preferably 100 mol% based on the total repeating units (B).

The ratio of the sum of the repeating units (C) and (D) in the repeating unit (B) in the polycarbonate resin contained in the polycarbonate resin composition of the present invention can be calculated by measuring ^1H -NMR of the polycarbonate resin dissolved in deuterated chloroform. In the present invention, a deuterated chloroform solution of the polycarbonate resin was prepared so that the polycarbonate resin concentration was 50 mg/mL, and the temperature was 30°C, the relaxation time was 6 seconds, and the number of accumulations was 128.

The proportions of repeating units (A), (B) and repeating units (C), (D) in repeating unit (B) in the polycarbonate resin contained in the polycarbonate resin composition can also be calculated from the charge composition ratio of the dihydroxy compound when the polycarbonate resin is produced, and in the examples shown below, they are determined from this charge composition ratio.

The polycarbonate resin contained in the polycarbonate resin composition of the present invention may contain only one type of repeating unit (A), or may contain two or more types. That is, it may contain two or more types of repeating units (A) represented by the above formula (1). Also, it may contain only one type of repeating unit (B), or may contain two or more types. That is, it may contain two or more types of repeating units (B) represented by the above formula (2). The same applies to repeating units (C) and repeating units (D).

[Polycarbonate resin composition]
The polycarbonate resin composition of the present invention may contain components other than the repeating units (A) and (B) described above, provided that the characteristics of the present invention are not impaired. However, in order to ensure the effects of the present invention, the sum of the repeating units (A) and (B) is preferably contained in the polycarbonate resin composition of the present invention at 65% by mass or more, more preferably at 70% by mass or more, and particularly preferably at 75% by mass or more.

[0043] Examples of components of the polycarbonate resin composition of the present invention other than the repeating units (A) and (B) include a repeating unit (E) other than the repeating units (A) and (B), various resin additives, and resins other than polycarbonate resins.
In order to effectively bring out the features of the present invention, the content of the polycarbonate resin in the polycarbonate resin composition of the present invention is preferably 80% by mass or more, more preferably 85% by mass or more, and particularly preferably 90% by mass or more, based on 100% by mass of the polycarbonate resin composition of the present invention.

<Other repeating units>
The polycarbonate resin composition of the present invention may contain a repeating unit (E) other than the repeating units (A) and (B) described above, as long as the characteristics of the present invention are not impaired. Examples of the repeating unit (E) include a repeating unit represented by the following formula (12).

In the above formula (12), R ²¹ to R ²⁶ are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, of which an alkyl group having 1 to 6 carbon atoms is preferred. Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, and a propyl group. As such another repeating unit (E), a repeating unit in which R ²¹ to R ²⁴ are methyl groups and R ²⁵ and R ²⁶ are hydrogen atoms is preferred.

Specific examples of other repeating units (E) include structural units derived from aromatic dihydroxy compounds such as 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 2,2-bis(4-hydroxyphenyl)cyclohexane, 2,2-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, and 6,6'-dihydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindane. As aromatic dihydroxy compounds, 2,2-bis(4-hydroxyphenyl)propane (bisphenol A) and 6,6'-dihydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindane are more preferred.

<Seed resin additives>
Examples of resin additives that may be contained in the polycarbonate resin composition of the present invention include heat stabilizers, antioxidants, mold release agents, light resistance agents (HALS), flame retardants, antistatic agents, antifogging agents, lubricants, antiblocking agents, flow improvers, plasticizers, dispersants, antibacterial agents, dyes, pigments, etc. The resin additives may be contained alone or in any combination and ratio of two or more kinds.

<Other resins>
Examples of other resins that may be contained in the polycarbonate resin composition of the present invention include thermoplastic polyester resins such as polyethylene terephthalate resin, polytrimethylene terephthalate, and polybutylene terephthalate resin; styrene-based resins such as polystyrene resin, high impact polystyrene resin (HIPS), acrylonitrile-styrene copolymer (AS resin), acrylonitrile-styrene-acrylic rubber copolymer (ASA resin), and acrylonitrile-ethylene propylene rubber-styrene copolymer (AES resin); polyolefin resins such as polyethylene resin and polypropylene resin; polyamide resin; polyimide resin; polyetherimide resin; polyurethane resin; polyphenylene ether resin; polyphenylene sulfide resin; polysulfone resin; and polymethacrylate resin.
Incidentally, one type of the other resin may be contained, or two or more types may be contained in any combination and ratio.

<Amount of terminal hydroxyl groups measured by colorimetric method>
The amount of terminal hydroxyl groups measured by colorimetry using titanium tetrachloride/acetic acid in the polycarbonate resin composition of the present invention is not particularly limited, but is preferably 2,500 ppm or less, more preferably 2,000 ppm or less, even more preferably 1,500 ppm or less, and particularly preferably 1,000 ppm or less. By making the amount of terminal hydroxyl groups measured by colorimetry below the above upper limit, the relative dielectric constant of the polycarbonate resin composition of the present invention can be effectively reduced. In addition, the amount of terminal hydroxyl groups measured by colorimetry in the polycarbonate resin composition of the present invention is preferably 100 ppm or more, more preferably 110 ppm or more, even more preferably 120 ppm or more, and particularly preferably 130 ppm or more. By making the amount of terminal hydroxyl groups measured by colorimetry above the above lower limit, the color, thermal stability, and wet heat stability of the polycarbonate resin composition of the present invention can be further improved.

The amount of terminal hydroxyl groups in the polycarbonate resin composition of the present invention, as measured by colorimetry, can be adjusted to a preferred value by controlling the molar ratio of the raw materials, the amount of catalyst, the temperature during the reaction, and the degree of vacuum.

The unit of the amount of terminal hydroxyl groups measured by colorimetry of the polycarbonate resin composition of the present invention is the mass of terminal hydroxyl groups relative to the mass of the polycarbonate resin composition of the present invention expressed in ppm. The measurement method is as described in the Examples, which is a colorimetry method using titanium tetrachloride/acetic acid. By this measurement method, terminal hydroxyl groups derived from aromatic diols can be detected without detecting terminal hydroxyl groups derived from aliphatic diols.
For polycarbonate resin compositions consisting of multiple structures, samples are prepared by mixing the corresponding raw dihydroxy compounds according to the copolymerization ratio at least at three levels of concentration, and a calibration curve is drawn from the data of the three or more points, after which the amount of terminal hydroxyl groups is measured. The detection wavelength is 546 nm.

<Viscosity average molecular weight>
The molecular weight of the polycarbonate resin contained in the polycarbonate resin composition of the present invention is not particularly limited, but is preferably 16,000 to 32,000 in terms of viscosity average molecular weight (Mv) calculated from the solution viscosity. By setting the viscosity average molecular weight within the above range, the features of the present invention can be effectively brought out. That is, if the viscosity average molecular weight of the polycarbonate resin contained in the polycarbonate resin composition of the present invention is equal to or higher than the above lower limit, the relative dielectric constant and dielectric loss tangent of the polycarbonate resin composition of the present invention are lowered, which is preferable. In addition, if the viscosity average molecular weight of the polycarbonate resin contained in the polycarbonate resin composition of the present invention is equal to or lower than the above upper limit, the flowability of the polycarbonate resin composition of the present invention is favorable, which is preferable. From this viewpoint, the viscosity average molecular weight (Mv) of the polycarbonate resin composition of the present invention is more preferably 17,000 or more, and even more preferably 18,000 or more. In addition, it is more preferably 31,000 or less, and even more preferably 30,000 or less.

The viscosity average molecular weight (Mv) of a polycarbonate resin refers to a value calculated from the Schnell viscosity formula, i.e., η = 1.23 × 10 ^-4 Mv ^0.83 , by determining the intrinsic viscosity (limiting viscosity) [η] (unit: dL/g) at a temperature of 20°C using methylene chloride as a solvent and an Ubbelohde viscometer. The intrinsic viscosity (limiting viscosity) [η] is a value calculated from the following formula by measuring the specific viscosity [ηsp] at each solution concentration [C] (g/dL).

<Pencil hardness>
The pencil hardness of the polycarbonate resin composition of the present invention is measured by a method conforming to ISO 15184. There is no particular limitation on the pencil hardness, but it is preferable that the pencil hardness has high hardness characteristics such as HB or higher. It is more preferable that the pencil hardness is F or higher.
The pencil hardness of the polycarbonate resin composition is measured using a pencil hardness tester on a polycarbonate resin test piece having a thickness of 3 mm, a length of 25 mm, and a width of 25 mm, under a load of 750 g. The test piece can be obtained by injection molding using an injection molding machine.

<Glass transition temperature>
The glass transition temperature (Tg) of the polycarbonate resin composition of the present invention is not particularly limited, but is preferably 100 to 200° C. If the Tg is 100° C. or higher, high heat resistance can be obtained. On the other hand, if the Tg is 200° C. or lower, good fluidity can be obtained, and high moldability can be obtained.
The Tg of the polycarbonate resin composition was measured by heating about 10 mg of a polycarbonate resin composition sample at a heating rate of 20° C./min using a differential scanning calorimeter, measuring the calorific value, and determining an extrapolated glass transition onset temperature, which is the temperature of the intersection between a straight line extending from the low-temperature side baseline to the high-temperature side and a tangent drawn at the point where the gradient of the curve of the stepwise change in the glass transition is maximum, in accordance with ISO 3146. This extrapolated glass transition temperature was taken as the glass transition temperature (Tg).

<Relative dielectric constant (ε _r ), dielectric loss tangent (tan δ)>
The polycarbonate resin composition of the present invention preferably has a relative dielectric constant (ε _r ) of 2.47 or less, more preferably 2.45 or less, and particularly preferably 2.43 or less, measured at a temperature of 23° C. and a frequency of 10 GHz. The dielectric loss tangent (tan δ) is preferably 4.00×10 ⁻³ or less, more preferably 3.00×10 ⁻³ or less, and particularly preferably 2.50×10 ⁻³ or less. By having the relative dielectric constant and dielectric loss tangent below the above upper limit, the transmittance of radio waves in the high frequency band is good.
The relative dielectric constant (ε _r ) and dielectric loss tangent (tan δ) of the polycarbonate resin composition are measured by cutting a rectangular film having a length of 70 mm and a width of 2 mm from a film having a thickness of 30 to 250 μm molded using this polycarbonate resin composition, conditioning the film for 48 hours under conditions of a room temperature of 23° C. and a humidity of 50%, and then using a cavity resonator at a frequency of 10 GHz.

<Residual phenol content>
The amount of residual phenol in the polycarbonate resin composition of the present invention is not particularly limited, but is preferably 250 ppm or less, more preferably 230 ppm or less, and even more preferably 200 ppm or less. By adjusting the amount of residual phenol to the above upper limit or less, the relative dielectric constant of the polycarbonate resin composition of the present invention can be reduced. In addition, the amount of residual phenol in the polycarbonate resin composition of the present invention is preferably 5 ppm or more. By adjusting the amount of residual phenol to the above lower limit or more, the amount of foreign matter in the polycarbonate resin composition of the present invention can be reduced.
The amount of phenol remaining in the polycarbonate resin composition is preferably adjusted by the pressure, temperature and amount of catalyst during the reaction.
The amount of phenol remaining in the polycarbonate resin composition may be adjusted after the reaction is completed. For example, a method of removing the phenol by volatilization using a commonly used kneading device such as a single-screw or twin-screw extruder or various kneaders at a pressure of 133 to 13.3 Pa and a temperature of 200 to 320° C. may be used.
The amount of residual phenol in the polycarbonate resin composition can be quantified by dissolving 1.25 g of the polycarbonate resin composition in 7 mL of methylene chloride, adding 30 mL of acetonitrile to the solution while stirring to cause reprecipitation, diluting the solution to 50 mL with acetonitrile, and measuring the supernatant by liquid chromatography (column: reverse phase, detector: UV 210 nm).

[Production method of polycarbonate resin]
The polycarbonate resin in the polycarbonate resin composition of the present invention can be produced by a conventionally known polymerization method, and the polymerization method is not particularly limited.Examples of the polymerization method include interfacial polymerization method, melt transesterification method, pyridine method, ring-opening polymerization method of cyclic carbonate compound, solid-phase transesterification method of prepolymer, etc.The following will specifically explain the particularly suitable method among these methods.

<Interfacial Polymerization Method>
In the interfacial polymerization method, a dihydroxy compound as a raw material and a carbonate-forming compound are reacted in the presence of an organic solvent and an alkaline aqueous solution that are inert to the reaction, usually at a pH of 9 or more, and then interfacial polymerization is carried out in the presence of a polymerization catalyst to obtain a polycarbonate resin. Note that a molecular weight regulator (terminal terminator) may be present in the reaction system as necessary, and an antioxidant may be present to prevent oxidation of the dihydroxy compound as a raw material.

The organic solvent inert to the reaction is not particularly limited, but examples thereof include chlorinated hydrocarbons such as dichloromethane, 1,2-dichloroethane, chloroform, monochlorobenzene, and dichlorobenzene; aromatic hydrocarbons such as benzene, toluene, and xylene; and the like. Note that one type of organic solvent may be used, or two or more types may be used in any combination and ratio.

The alkaline compound contained in the alkaline aqueous solution is not particularly limited, but examples thereof include alkali metal compounds and alkaline earth metal compounds such as sodium hydroxide, potassium hydroxide, lithium hydroxide, and sodium hydrogen carbonate. Among these, sodium hydroxide and potassium hydroxide are preferred. The alkaline compounds may be used alone or in any combination and ratio of two or more.

There is no limit to the concentration of the alkaline compound in the alkaline aqueous solution, but the alkaline compound concentration is usually 5 to 10 mass % in order to control the pH of the alkaline aqueous solution to 10 to 12. In addition, for example, when blowing in phosgene, in order to control the pH of the aqueous phase to 10 to 12, preferably 10 to 11, it is preferable that the molar ratio of the raw material dihydroxy compound to the alkaline compound is usually 1:1.9 or more, preferably 1:2.0 or more, and usually 1:3.2 or less, preferably 1:2.5 or less.

As the carbonate-forming compound, carbonyl halides are preferably used, and among these, phosgene is preferably used, and the method using phosgene is specifically called the phosgene method.

The polymerization catalyst is not particularly limited, but examples thereof include aliphatic tertiary amines such as trimethylamine, triethylamine, tributylamine, tripropylamine, and trihexylamine; alicyclic tertiary amines such as N,N'-dimethylcyclohexylamine and N,N'-diethylcyclohexylamine; aromatic tertiary amines such as N,N'-dimethylaniline and N,N'-diethylaniline; quaternary ammonium salts such as trimethylbenzylammonium chloride, tetramethylammonium chloride, and triethylbenzylammonium chloride; pyridine; guanine; salts of guanidine; and the like. Note that one type of polymerization catalyst may be used, or two or more types may be used in any combination and ratio.

The molecular weight regulator is not particularly limited, but examples thereof include aromatic phenols having a monovalent phenolic hydroxyl group; aliphatic alcohols such as methanol and butanol; mercaptans; and phthalic acid imides, among which aromatic phenols are preferred. Specific examples of such aromatic phenols include phenol, o-n-butylphenol, m-n-butylphenol, p-n-butylphenol, o-isobutylphenol, m-isobutylphenol, p-isobutylphenol, o-t-butylphenol, m-t-butylphenol, p-t-butylphenol, o-n-pentylphenol, m-n-pentylphenol, p-n-pentylphenol, o-n-hexylphenol, m-n-hexylphenol, p-n-hexylphenol, p-t-octylphenol, o-cyclohexylphenol, m-cyclohexylphenol, p-cyclohexylphenol, o-phenylphenol, m-phenylphenol, p-phenylphenol, o-n-nonylphenol, m-n-nonylphenol, p Examples of such phenols include n-nonylphenol, o-cumylphenol, m-cumylphenol, p-cumylphenol, o-naphthylphenol, m-naphthylphenol, p-naphthylphenol, 2,5-di-t-butylphenol, 2,4-di-t-butylphenol, 3,5-di-t-butylphenol, 2,5-dicumylphenol, 3,5-dicumylphenol, p-cresol, bromophenol, tribromophenol, monoalkylphenols having a linear or branched alkyl group having an average of 12 to 35 carbon atoms at the ortho, meta or para position, 9-(4-hydroxyphenyl)-9-(4-methoxyphenyl)fluorene, 9-(4-hydroxy-3-methylphenyl)-9-(4-methoxy-3-methylphenyl)fluorene, 4-(1-adamantyl)phenol, etc. Among these, p-t-butylphenol, p-phenylphenol and p-cumylphenol are preferably used. The molecular weight regulator may be used alone or in any combination and ratio of two or more kinds.

The amount of molecular weight regulator used is not particularly limited, but is usually 0.5 moles or more, preferably 1 mole or more, and usually 50 moles or less, preferably 30 moles or less, per 100 moles of the dihydroxy compound raw material.

Antioxidants are not particularly limited, but examples include hindered phenol-based antioxidants. Specific examples thereof include pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, thiodiethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], 2,4-dimethyl-6-(1-methylpentadecyl)phenol, diethyl[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]phosphate, 3,3',3",5,5',5"-hexa-tert-butyl-a,a',a"-(mesitylene-2,4,6- triyl)tri-p-cresol, 4,6-bis(octylthiomethyl)-o-cresol, ethylene bis(oxyethylene)bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], hexamethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazin-2-ylamino)phenol, 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate, etc.

Among these, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are preferred. Commercially available products of such phenolic antioxidants include "Irganox 1010" and "Irganox 1076" manufactured by BASF, and "Adekastab AO-50" and "Adekastab AO-60" manufactured by ADEKA.

The antioxidant may be used alone or in any combination of two or more in any ratio.

The amount of the antioxidant used is not particularly limited, but is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, and even more preferably 0.1 parts by mass or more, per 100 parts by mass of the raw dihydroxy compound. By using the antioxidant in the above range, the antioxidant's effect is sufficient. In addition, the amount of the antioxidant used is preferably 1 part by mass or less, more preferably 0.5 parts by mass or less, per 100 parts by mass of the raw dihydroxy compound. By using the antioxidant in the above range, gas generation during injection molding can be suppressed.

During the reaction, the order in which the reaction substrate (reaction raw material), reaction solvent (organic solvent), catalyst, additives, etc. are mixed can be any order as long as the desired polycarbonate resin composition is obtained, and any appropriate order can be set. For example, when phosgene is used as the carbonate-forming compound, the molecular weight modifier can be mixed at any time between the reaction of the raw material dihydroxy compound with phosgene (phosgenation) and the start of the polymerization reaction.

The reaction temperature is not particularly limited, but is preferably 0 to 40°C. The reaction time is not particularly limited, but is preferably several minutes (e.g., 10 minutes) to several hours (e.g., 6 hours).

<Melt transesterification method>
In the melt transesterification method, for example, a transesterification reaction is carried out between a carbonate ester and a raw material dihydroxy compound.
The starting dihydroxy compound is the same as that used in the interfacial polymerization method.

The carbonate ester may be, for example, a compound represented by the following formula (13), and examples thereof include aryl carbonates, dialkyl carbonates, biscarbonates of dihydroxy compounds, monocarbonates of dihydroxy compounds, and carbonates of dihydroxy compounds such as cyclic carbonates.

In the above general formula (13), R ²⁷ and R ²⁸ each independently represent an alkyl group, an aryl group, or an arylalkyl group having 1 to 30 carbon atoms. Hereinafter, when R ²⁷ and R ²⁸ are an alkyl group or an arylalkyl group, they may be referred to as a dialkyl carbonate, and when they are an aryl group, they may be referred to as a diaryl carbonate. In particular, from the viewpoint of reactivity with dihydroxy compounds, it is preferable that R ²⁷ and R ²⁸ are both aryl groups, and it is more preferable that they are diaryl carbonates represented by the following general formula (14).

In the above general formula (14), R ²⁹ and R ³⁰ each independently represent a halogen atom, a nitro group, a cyano group, an alkyl group having 1 to 20 carbon atoms, an alkoxycarbonyl group having 1 to 20 carbon atoms, a cycloalkyl group having 4 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and p and q each independently represent an integer of 0 to 5.

Specific examples of such carbonate esters include dialkyl carbonates such as dimethyl carbonate, diethyl carbonate, and di-t-butyl carbonate, diphenyl carbonate (hereinafter sometimes abbreviated as "DPC"), bis(4-methylphenyl)carbonate, bis(4-chlorophenyl)carbonate, bis(4-fluorophenyl)carbonate, bis(2-chlorophenyl)carbonate, bis(2,4-difluorophenyl)carbonate, bis(4-nitrophenyl)carbonate, bis(2-nitrophenyl)carbonate, bis(methylsalicylphenyl)carbonate, and diaryl carbonates (which may have a substituent) such as ditolyl carbonate, with diphenyl carbonate being preferred. These carbonate esters may be used alone or in combination of two or more.

The carbonate ester may be replaced with a dicarboxylic acid or a dicarboxylic acid ester, preferably in an amount of 50 mol % or less, more preferably 30 mol % or less. Representative dicarboxylic acids or dicarboxylic acid esters include terephthalic acid, isophthalic acid, diphenyl terephthalate, diphenyl isophthalate, etc. When replaced with such a dicarboxylic acid or dicarboxylic acid ester, a polyester carbonate is obtained.

The ratio of the raw dihydroxy compound and the carbonate ester is arbitrary as long as the desired polycarbonate resin composition is obtained, but it is preferable to use these carbonate esters in excess of the raw dihydroxy compound when polymerizing with the dihydroxy compound. That is, the carbonate ester is preferably 1.01 times (molar ratio) or more relative to the dihydroxy compound, and more preferably 1.02 or more. By setting the molar ratio in the above range, the thermal stability of the obtained polycarbonate resin composition is good. In addition, the carbonate ester is preferably 1.30 times (molar ratio) or less relative to the dihydroxy compound, and more preferably 1.20 times or less. By setting the molar ratio in the above range, the reactivity is improved, the productivity of the polycarbonate resin composition having the desired molecular weight is good, and the amount of residual carbonate ester in the resin is reduced, which is preferable because it is possible to suppress odor generation during molding processing or when the molded product is formed.

When producing a polycarbonate resin composition by the melt transesterification method, a transesterification catalyst is usually used. The transesterification catalyst is not particularly limited, and any conventionally known catalyst can be used. For example, it is preferable to use an alkali metal compound and/or an alkaline earth metal compound. In addition, a basic compound such as a basic boron compound, a basic phosphorus compound, a basic ammonium compound, or an amine compound may be used in combination as an auxiliary. Note that one type of transesterification catalyst may be used, or two or more types may be used in any combination and ratio.

In the melt transesterification method, the reaction temperature is not particularly limited, but is usually 100 to 320°C. The pressure during the reaction is not particularly limited, but is usually reduced pressure of 2 mmHg or less. The specific operation is to carry out the melt polycondensation reaction under the above conditions while removing by-products.

Here, in the presence of an alkaline catalyst, the polycarbonate resin composition of the present invention is significantly affected by thermal history and oxidation, leading to a deterioration in color. Therefore, it is preferable to set the reaction temperature to 320°C or lower, and to select reduced pressure conditions with a lower limit of approximately 0.05 mmHg to prevent oxygen from leaking from the equipment due to excessive reduced pressure.

The reaction can be carried out in either a batch or continuous manner. When the reaction is carried out in a batch manner, the order in which the reaction substrate, reaction solvent, catalyst, additives, etc. are mixed can be any order as long as the desired polycarbonate resin composition is obtained, and any appropriate order can be set.

In the melt transesterification method, a catalyst deactivator may be used as necessary. Any compound that neutralizes the transesterification catalyst may be used as the catalyst deactivator. Examples of such a catalyst deactivator include sulfur-containing acidic compounds and their derivatives, and phosphorus-containing acidic compounds and their derivatives. The catalyst deactivator may be used alone or in any combination and ratio of two or more.

The amount of catalyst deactivator used is not particularly limited, but is usually 0.5 equivalents or more, preferably 1 equivalent or more, more preferably 3 equivalents or more, and usually 50 equivalents or less, preferably 10 equivalents or less, more preferably 8 equivalents or less, relative to the transesterification catalyst. The amount of catalyst deactivator used is usually 1 ppm or more, 100 ppm or less, and preferably 50 ppm or less, relative to the polycarbonate resin composition.

[Method of manufacturing molded products]
To produce the molded article of the present invention from the polycarbonate resin composition of the present invention, a conventional extruder or injection molding machine is used.

The molding temperature when molding the polycarbonate resin composition of the present invention is preferably 200°C or higher, more preferably 250°C or higher, and most preferably 280°C or higher. By setting the molding temperature within the above range, the flowability and moldability are improved. Furthermore, the molding temperature when molding the polycarbonate resin composition of the present invention is preferably 350°C or lower, and particularly preferably 320°C or lower. By setting the molding temperature within the above range, the color tone of the obtained molded product can be made good.

When performing injection molding or extrusion molding, pigments, dyes, mold release agents, heat stabilizers, etc. can be appropriately added to the polycarbonate resin composition of the present invention within the scope that does not impair the object of the present invention.

<Injection molded products>
To produce an injection molded article from the polycarbonate resin composition of the present invention, a conventional injection molding machine is used.

When using an injection molding machine or the like, the mold temperature is preferably 150°C or less, more preferably 120°C or less, and most preferably 100°C or less. By keeping the mold temperature within the above range, the cooling time during molding can be shortened, shortening the production cycle of molded products and improving productivity. Furthermore, when using an injection molding machine or the like, the mold temperature is preferably 30°C or more, and particularly preferably 50°C or more. By keeping the mold temperature within the above range, it is possible to obtain uniform molded products, which is preferable.

<Extrusion molded products>
To produce an extrusion molded product from the polycarbonate resin composition of the present invention, a conventional extrusion molding machine is used. The extrusion molding machine is generally equipped with a T-die, a round die, or the like, and can produce extrusion molded products of various shapes. Examples of the extrusion molded products include sheets, films, plates, tubes, pipes, and the like. Among these, sheets and films are preferred.

The extrusion molded product of the polycarbonate resin composition of the present invention may be laminated with a hard coat layer on both sides or one side of the extrusion molded product to improve adhesion, paintability, and printability, or a film for improving weather resistance and/or scratch resistance may be heat laminated on both sides or one side of the extrusion molded product. In addition, the surface may be subjected to a graining process or a semi-transparent or opaque process.

The polycarbonate resin composition of the present invention has excellent heat resistance and mechanical strength, as well as a low dielectric constant and a low dielectric loss tangent. For this reason, it is expected to be used in a wide range of fields, and can be suitably used, for example, as a module for millimeter-wave radar mounted on vehicles, railways, and aviation. It can also be suitably used as a housing for information and communication devices such as mobile phones and smartphones.

[Millimeter wave radar cover]
The molded article of the present invention using the polycarbonate resin composition of the present invention, which has excellent heat resistance, mechanical strength, and moldability, as well as a low dielectric constant and a low dielectric tangent, is particularly suitable as a cover for a millimeter wave radar.

There are no particular limitations on the method for processing the polycarbonate resin composition of the present invention into a cover for a millimeter wave radar, but injection molding is preferred because it provides excellent dimensional accuracy and mass productivity. The injection molding method is also not particularly limited, and any molding method generally used for thermoplastic resins can be used. Examples include ultra-high speed injection molding, injection compression molding, two-color molding, gas-assisted and other hollow molding methods, molding methods using insulating molds, molding methods using rapid heating and cooling molds, foam molding (including supercritical fluids), insert molding, and IMC (in-mold coating molding) molding. A molding method using a hot runner system can also be used.

The millimeter-wave radar module equipped with the millimeter-wave radar cover of the present invention obtained in this way can be suitably used for in-vehicle millimeter-wave radars used in automatic brake control devices, vehicle distance control devices, steering devices for reducing pedestrian accidents, erroneous transmission suppression control devices, devices for suppressing acceleration when pedaling is misapplied, devices for warning of approaching vehicles, lane keeping assist devices, collision prevention warning devices, parking assist devices, devices for warning of obstacles around the vehicle, etc.; railway and aviation millimeter-wave radars used in platform monitoring/railroad crossing obstacle detection devices, content transmission devices within trains, tram/railroad collision prevention devices, foreign object detection devices within runways, etc.; millimeter-wave radars for transportation infrastructure such as intersection monitoring devices and elevator monitoring devices; millimeter-wave radars for various security devices; millimeter-wave radars for medical and nursing care such as child and elderly monitoring systems; millimeter-wave radars for transmitting various information content; etc.

The present invention will be described in more detail below with reference to examples. Note that the present invention is not limited to the following examples.

The physical properties of the polycarbonate resin compositions obtained in the following examples and comparative examples were evaluated by the following methods.

(1) Amount of terminal hydroxyl groups measured by colorimetric determination The amount of terminal hydroxyl groups measured by colorimetric determination was measured by a colorimetric method using titanium tetrachloride/acetic acid. Specifically, it was measured by the method described below. This allows the amount of terminal hydroxyl groups measured by a colorimetric method using titanium tetrachloride/acetic acid in the present examples and comparative examples to be measured.
(a) Preparation of 5 v/v % Acetic Acid Solution 50 ml of acetic acid was added to a 1000 ml measuring flask, and the mixture was made up to volume with methylene chloride and mixed to prepare a 5 v/v % acetic acid solution.
(b) Preparation of titanium tetrachloride solution 90 mL of methylene chloride was placed in a 300 mL flask using a measuring cylinder, and 10 mL of 5 v/v % acetic acid solution was added using a measuring cylinder. A stirrer was added and while stirring with a magnetic stirrer, 2.5 mL of titanium tetrachloride solution and 2.0 mL of methanol were slowly added using a 5 mL measuring pipette to prepare a titanium tetrachloride solution.
(c) Preparation of calibration curve samples A methylene chloride solution was prepared so that the amount of terminal hydroxyl groups of the raw material dihydroxy compound was 10 ppm by weight, and 0, 3, and 5 mL were added to a 25 mL measuring flask. Then, 5 mL of 5 v/v % acetic acid and 10 mL of titanium tetrachloride solution were added. Each was made up to 10 mL with methylene chloride and mixed well.
(d) Preparation of a calibration curve The absorbance of each of the prepared calibration samples was measured at a detection wavelength of 546 nm. The obtained absorbance was plotted against the concentration of the calibration curve sample. The reciprocal of this slope was used as a factor.
(e) Preparation of measurement sample and absorbance measurement 0.2 g of the polycarbonate resin composition and 5 mL of methylene chloride were added to a 25 mL measuring flask and dissolved. Next, 5 mL of 5 v/v % acetic acid solution and 10 mL of titanium tetrachloride solution were added, and the mixture was made up to 10 mL with methylene chloride and mixed well. The absorbance of the solution thus prepared was measured at a detection wavelength of 546 nm.
(f) Calculation of the Amount of Terminal Hydroxyl Groups The amount of terminal hydroxyl groups in the polycarbonate resin composition was calculated by dividing the product of the measured absorbance and the factor by the concentration of the measurement sample.
In the case of a polycarbonate resin composition in which the raw material dihydroxy compound has a plurality of structures, samples are prepared by mixing the corresponding raw material dihydroxy compounds according to the copolymerization ratio at least at three levels of concentration, and the amount of terminal hydroxyl groups is measured after drawing a calibration curve from the data of the three or more points. The detection wavelength is 546 nm.

(2) Residual Phenol Amount 1.25 g of a polycarbonate resin composition was dissolved in 7 mL of methylene chloride, and 30 mL of acetonitrile was added thereto with stirring to cause reprecipitation. The mixture was then diluted with acetonitrile to 50 mL, and the supernatant was subjected to liquid chromatography under the following conditions to determine the amount of residual phenol.
Equipment: Shimadzu Corporation LC-20AD
Column: SUPELCO Ascentis Express C18 5 cm x 3.0 mm, 2.7 μm
Analysis temperature: 40°C
Eluent composition:
Solution A: 0.1% by weight phosphoric acid aqueous solution: acetonitrile = 5:1
B solution: acetonitrile Gradient program:
At analysis time 0 minutes, solution A:solution B=84:16 (volume ratio, same below).
During the analysis time from 0 to 18 minutes, the eluent composition was gradually changed to A:B = 0:100.
Analysis time: 18 to 25 minutes, solution A: solution B = 0:100 Flow rate: 1.0 mL/min Detection wavelength: 210 nm

(3) Viscosity average molecular weight (Mv)
Polycarbonate resin was dissolved in methylene chloride (concentration: 6.0 g/L), and the intrinsic viscosity (limiting viscosity) [η] (unit: dL/g) at 20°C was measured using an Ubbelohde viscosity tube (manufactured by Moritomo Rika Kogyo Co., Ltd.). The viscosity average molecular weight (Mv) was calculated from the Schnell viscosity formula (the following formula).
η=1.23×10 ⁻⁴ Mv ⁰ . ⁸³

(4) Glass transition temperature (Tg)
Using a differential scanning calorimeter (DSC6220 manufactured by SII), about 10 mg of a sample of the polycarbonate resin composition was heated at a heating rate of 20° C./min to measure the calorific value, and in accordance with ISO 3146, an extrapolated glass transition onset temperature was determined, which is the temperature of the intersection between a straight line extending the baseline on the low temperature side to the high temperature side and a tangent drawn at the point where the gradient of the curve of the stepwise change in the glass transition is maximum, and this extrapolated glass transition temperature was designated as the glass transition temperature (Tg).

(5) Film Formability During film forming for measuring the relative dielectric constant (ε _r ) and dielectric loss tangent (tan δ) below, the film formability was evaluated as either OK (◯) or not (×).

(6) Relative dielectric constant (ε _r ) and dielectric tangent (tan δ)
The polycarbonate resin composition vacuum dried at 80°C for 5 hours was molded into a film shape using a heat press molding machine to produce a film having a thickness of 30 to 250 μm. The molding conditions of the heat press molding machine were appropriately adjusted within the range of a temperature of 150 to 250°C and a pressure of 10 to 15 MPa. A strip-shaped film having a length of 70 mm and a width of 2 mm was cut out from this film, and after 48 hours of humidity control under conditions of room temperature of 23°C and humidity of 50%, the relative dielectric constant (ε r ) and the dielectric loss tangent (tan _δ ) were measured at a frequency of 10 GHz using a cavity resonator (CP-531 manufactured by Kanto Applied Electronics Development Co., Ltd.) and a series network analyzer (E8361A PNA manufactured by Keysight Technologies, Inc.).

(7) Pencil Hardness A plate of the polycarbonate resin composition having a thickness of 3 mm, a length of 25 mm, and a width of 25 mm was molded using a small injection molding machine (Shinko Selvic C, Mobile Co., Ltd.) to obtain a test piece. The pencil hardness of the test piece was measured at a load of 750 g using a pencil hardness tester (manufactured by Toyo Seiki Co., Ltd.) in accordance with ISO 15184.

[Example 1]
A raw material mixture was prepared by adding 39.36 g (approximately 0.129 mol) of 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane (hereinafter sometimes abbreviated as "SPG") (manufactured by Mitsubishi Gas Chemical Co., Inc.), 77.35 g (approximately 0.302 mol) of 2,2-bis(4-hydroxy-3-methylphenyl)propane (hereinafter sometimes abbreviated as "BPC") (manufactured by Honshu Chemical Co., Ltd.), 94.65 g (approximately 0.442 mol) of diphenyl carbonate (hereinafter sometimes abbreviated as "DPC"), and a 4.0 mass% aqueous solution of cesium carbonate as a catalyst to a glass reactor having a capacity of 150 ml and equipped with a reactor stirrer, a reactor heating device, and a reactor pressure adjusting device.

Next, the pressure inside the glass reactor was reduced to about 50 Pa (0.38 Torr), and then the pressure was returned to atmospheric pressure with nitrogen, and this operation was repeated three times to replace the inside of the reactor with nitrogen. After nitrogen replacement, the temperature outside the reactor was set to 220°C, and the temperature inside the reactor was gradually raised to dissolve the mixture. Then, the stirrer was rotated at 100 rpm. Then, while distilling off the phenol by-product of the oligomerization reaction of the dihydroxy compound and DPC that takes place inside the reactor, the pressure inside the reactor was reduced from 101.3 kPa (760 Torr) to 13.3 kPa (100 Torr) absolute pressure over 40 minutes.

Then, the pressure inside the reactor was kept at 13.3 kPa, and the transesterification reaction was carried out for 80 minutes while further distilling off the phenol. After that, the temperature outside the reactor was raised to 250°C, and the pressure inside the reactor was reduced from 13.3 kPa (100 Torr) to 399 Pa (3 Torr) absolute pressure over 40 minutes, and the distilled phenol was removed from the system. Furthermore, the temperature outside the reactor was raised to 285°C, and the absolute pressure inside the reactor was reduced to 30 Pa (approximately 0.2 Torr), and the polycondensation reaction was carried out. The polycondensation reaction was terminated when the reactor agitator reached a predetermined stirring power.

Next, the pressure inside the reactor was restored to 101.3 kPa absolute pressure with nitrogen, and then the gauge pressure was increased to 0.2 MPa. The polycarbonate resin was extracted in the form of strands from the bottom of the reactor to obtain strand-shaped polycarbonate resin, which was then pelletized using a rotary cutter.
The polycarbonate resin thus obtained was subjected to the various evaluations according to the procedures described above. The results are shown in Table 1.

[Example 2]
The procedure of Example 1 was repeated, except that a raw material mixture was prepared by adding 39.36 g (about 0.129 mol) of SPG (manufactured by Mitsubishi Gas Chemical Company, Inc.), 77.35 g (about 0.302 mol) of BPC (manufactured by Honshu Chemical Company, Inc.), 96.03 g (about 0.448 mol) of DPC, and a 4.0 mass% aqueous solution of cesium carbonate as a catalyst such that the amount of cesium carbonate was 25 μmol per 1 mol of the total dihydroxy compounds.
The polycarbonate resin thus obtained was subjected to the various evaluations according to the procedures described above. The results are shown in Table 1.

[Example 3]
The procedure of Example 1 was repeated, except that a raw material mixture was prepared by adding 39.36 g (about 0.129 mol) of SPG (manufactured by Mitsubishi Gas Chemical Company, Inc.), 77.35 g (about 0.302 mol) of BPC (manufactured by Honshu Chemical Company, Inc.), 90.49 g (about 0.422 mol) of DPC, and a 4.0 mass% aqueous solution of cesium carbonate as a catalyst such that the amount of cesium carbonate was 25 μmol per 1 mol of the total dihydroxy compounds.
The polycarbonate resin thus obtained was subjected to the various evaluations according to the procedures described above. The results are shown in Table 1.

[Example 4]
A raw material mixture was prepared by adding 39.36 g (about 0.129 mol) of SPG (manufactured by Mitsubishi Gas Chemical Company, Inc.), 77.35 g (about 0.302 mol) of BPC (manufactured by Honshu Chemical Company, Inc.), 93.45 g (about 0.436 mol) of DPC, and a 4.0 mass% aqueous solution of cesium carbonate as a catalyst to a glass reactor having a capacity of 150 ml and equipped with a reactor stirrer, a reactor heating device, and a reactor pressure adjusting device.

Next, the pressure inside the glass reactor was reduced to about 50 Pa (0.38 Torr), and then the pressure was returned to atmospheric pressure with nitrogen, and this operation was repeated three times to replace the inside of the reactor with nitrogen. After nitrogen replacement, the temperature outside the reactor was set to 220°C, and the temperature inside the reactor was gradually raised to dissolve the mixture. Then, the stirrer was rotated at 100 rpm. Then, while distilling off the phenol by-product of the oligomerization reaction of the dihydroxy compound and DPC that takes place inside the reactor, the pressure inside the reactor was reduced from 101.3 kPa (760 Torr) to 13.3 kPa (100 Torr) absolute pressure over 40 minutes.

Next, the pressure in the reactor was kept at 13.3 kPa, and the transesterification reaction was carried out for 80 minutes while further distilling off phenol. Thereafter, the temperature outside the reactor was raised to 250°C, and the pressure inside the reactor was reduced from 13.3 kPa (100 Torr) to 399 Pa (3 Torr) in absolute pressure over 40 minutes, and the distilled phenol was removed from the system. Furthermore, the temperature outside the reactor was raised to 280°C, and the absolute pressure inside the reactor was reduced to 80 Pa (about 0.6 Torr), and a polycondensation reaction was carried out. When the agitator of the reactor reached a predetermined stirring power, the polycondensation reaction was terminated.
The polycarbonate resin thus obtained was subjected to the various evaluations according to the procedures described above. The results are shown in Table 1.

[Example 5]
The procedure of Example 1 was repeated except that a raw material mixture was prepared by adding 63.35 g (about 0.208 mol) of SPG (manufactured by Mitsubishi Gas Chemical Company, Inc.), 53.36 g (about 0.208 mol) of BPC (manufactured by Honshu Chemical Company, Inc.), 92.30 g (about 0.431 mol) of DPC, and a 4.0 mass% aqueous solution of cesium carbonate as a catalyst such that the amount of cesium carbonate was 25 μmol per 1 mol of the total dihydroxy compounds.
The polycarbonate resin thus obtained was subjected to the various evaluations according to the procedures described above. The results are shown in Table 1.

[Example 6]
The procedure of Example 1 was repeated, except that a raw material mixture was prepared by adding 85.76 g (about 0.282 mol) of SPG (manufactured by Mitsubishi Gas Chemical Company, Inc.), 30.95 g (about 0.121 mol) of BPC (manufactured by Honshu Chemical Company, Inc.), 89.24 g (about 0.417 mol) of DPC, and a 4.0 mass% aqueous solution of cesium carbonate as a catalyst such that the amount of cesium carbonate was 30 μmol per 1 mol of the total dihydroxy compounds.
The polycarbonate resin thus obtained was subjected to the various evaluations according to the procedures described above. The results are shown in Table 1.

[Example 7]
The procedure of Example 1 was repeated except that a raw material mixture was prepared by adding 39.36 g (approximately 0.129 mol) of SPG (manufactured by Mitsubishi Gas Chemical Company, Inc.), 77.35 g (approximately 0.302 mol) of 4,4-methylenebis(2,6-dimethylphenol) (hereinafter, sometimes abbreviated as "TmBPF") (manufactured by Deepak Novochem Technologies Limited), 95.57 g (approximately 0.446 mol) of DPC, and a 4.0 mass% aqueous solution of cesium carbonate as a catalyst such that the amount of cesium carbonate was 35 μmol per 1 mol of the total dihydroxy compounds.
The polycarbonate resin thus obtained was subjected to the various evaluations according to the procedures described above. The results are shown in Table 1.

[Example 8]
The procedure of Example 1 was repeated, except that a raw material mixture was prepared by adding 106.72 g (about 0.351 mol) of SPG (manufactured by Mitsubishi Gas Chemical Company, Inc.), 9.99 g (about 0.039 mol) of BPC (manufactured by Honshu Chemical Company, Inc.), 85.13 g (about 0.397 mol) of DPC, and a 4.0 mass% aqueous solution of cesium carbonate as a catalyst such that the amount of cesium carbonate was 25 μmol per 1 mol of the total dihydroxy compounds.
The polycarbonate resin thus obtained was subjected to the various evaluations according to the procedures described above. The results are shown in Table 1.

[Comparative Example 1]
The procedure described in Example 1 was repeated, except that a raw material mixture was prepared by adding 34.92 g (about 0.115 mol) of SPG (manufactured by Mitsubishi Gas Chemical Company, Inc.), 29.41 g (about 0.115 mol) of BPC (manufactured by Honshu Chemical Company, Inc.), 52.38 g (about 0.229 mol) of 2,2-bis(4-hydroxyphenyl)propane (hereinafter, sometimes abbreviated as "BPA") (manufactured by Mitsubishi Chemical Corporation), 101.75 g (about 0.475 mol) of DPC, and a 4.0 mass% aqueous solution of cesium carbonate as a catalyst such that the amount of cesium carbonate was 25 μmol per 1 mol of the total dihydroxy compounds.
The polycarbonate resin thus obtained was subjected to the various evaluations according to the procedures described above. The results are shown in Table 2.

[Comparative Example 2]
The procedure of Example 1 was repeated except that a raw material mixture was prepared by adding 42.44 g (about 0.139 mol) of SPG (manufactured by Mitsubishi Gas Chemical Company, Inc.), 74.27 g (about 0.325 mol) of BPA (manufactured by Mitsubishi Chemical Corporation), 96.03 g (about 0.448 mol) of DPC, and a 4.0 mass% aqueous solution of cesium carbonate as a catalyst such that the amount of cesium carbonate was 20 μmol per 1 mol of the total dihydroxy compounds.
The polycarbonate resin thus obtained was subjected to the various evaluations according to the procedures described above. The results are shown in Table 2.

[Comparative Example 3]
The procedure of Example 1 was repeated except that a raw material mixture was prepared by adding 119.77 g (about 0.393 mol) of SPG (manufactured by Mitsubishi Gas Chemical Company, Inc.), 84.29 g (about 0.393 mol) of DPC, and a 4.0 mass% aqueous solution of cesium carbonate as a catalyst such that the amount of cesium carbonate was 500 μmol per 1 mol of the total dihydroxy compounds.
The polycarbonate resin thus obtained was subjected to the various evaluations according to the procedures described above. The results are shown in Table 2.

[Comparative Example 4]
The procedure of Example 1 was repeated except that a raw material mixture was prepared by adding 116.71 g (about 0.511 mol) of BPA (manufactured by Mitsubishi Chemical Corporation), 117.18 g (about 0.547 mol) of DPC, and a 0.04 mass% aqueous solution of cesium carbonate as a catalyst such that the amount of cesium carbonate was 0.5 μmol per 1 mol of the total dihydroxy compounds.
The polycarbonate resin thus obtained was subjected to the various evaluations according to the procedures described above. The results are shown in Table 2.

[Comparative Example 5]
The procedure of Example 1 was repeated except that a raw material mixture was prepared by adding 100.00 g (about 0.390 mol) of BPC (manufactured by Honshu Chemical Co., Ltd.), 86.08 g (about 0.402 mol) of DPC, and a 0.4 mass% aqueous solution of cesium carbonate as a catalyst such that the amount of cesium carbonate was 4.5 μmol per mol of the total dihydroxy compounds.
The polycarbonate resin thus obtained was subjected to the various evaluations according to the procedures described above. The results are shown in Table 2.

In Tables 1 and 2, the sum of the proportion of repeating unit (C) and the proportion of repeating unit (D) in repeating unit (B) is expressed as "((C) + (D))/(B) [mol %]."

[Discussion]
From the above results, the following can be seen:
Examples 1 to 8, which contain the repeating unit (A) and the repeating unit (C) or the repeating unit (D) as the repeating unit (B), have lower dielectric constants (ε _r ) and dielectric loss tangents (tan δ) and therefore have superior dielectric properties compared to Comparative Example 4, which does not contain either the repeating unit (A) or the repeating unit (B). Comparative Example 5, which contains only the repeating unit (C), has a dielectric loss tangent (tan δ) at the same level as Examples 1 to 8, but has a higher dielectric constant (ε _r ) and inferior dielectric properties compared to Examples 1 to 8. In Comparative Examples 1 to 3, a film having a thickness of 30 to 250 μm was produced using a hot press molding machine, and when the film was cut into a strip having a length of 70 mm and a width of 2 mm, the film was brittle and difficult to cut out, and the dielectric constant (ε _r ) and dielectric loss tangent (tan δ) could not be measured. That is, Comparative Examples 1 and 2, in which "((C)+(D))/(B) [mol %]" does not satisfy the requirement of the present invention, and Comparative Example 3, which contains only the repeating unit (A), are inferior in mechanical strength and moldability to Examples 1 to 8.
Furthermore, Examples 1 to 8 are superior to Comparative Examples 1, 2 and 4 in pencil hardness.

From the above, it can be seen that the polycarbonate resins of Examples 1 to 8, which are the polycarbonate resin compositions of the present invention, have excellent mechanical strength and moldability, as well as a low relative dielectric constant (ε _r ) and a low dielectric tangent (tan δ), compared to the polycarbonate resins of Comparative Examples 1 to 5, and therefore have excellent dielectric properties.

Claims (16)

A polycarbonate resin composition comprising a polycarbonate resin containing a repeating unit (A) represented by the following formula (1) and a repeating unit (B) represented by the following formula (2):
the content of the repeating unit (A) in the polycarbonate resin composition is 10% by mass or more, and the content of the repeating unit (B) is 10% by mass or more,
the sum of the content of the repeating unit (A) and the content of the repeating unit (B) in the polycarbonate resin is 80 mass% or more;
The polycarbonate resin composition according to claim 1, wherein the sum of the proportion of the repeating unit (C) represented by the following formula (3) and the proportion of the repeating unit (D) represented by the following formula (4) contained in the repeating unit (B) is 80 mol % or more:

In formula (1), W ¹ is any one selected from the following formulas (5) and (6):
In formula (2), R ⁵ to R ⁸ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a group containing an aryl group and having 6 to 12 carbon atoms, and W ² represents at least one selected from a single bond, an oxygen atom, a sulfur atom, and a divalent organic group.
In formula (3), R ⁹ and R ¹⁰ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a group containing an aryl group and having 6 to 12 carbon atoms, and R ¹¹ and R ¹² are each independently an alkyl group having 1 to 10 carbon atoms, or a group containing an aryl group and having 6 to 12 carbon atoms.
In formula (4), R ¹³ to R ¹⁶ each independently represent an alkyl group having 1 to 10 carbon atoms, or a group containing an aryl group and having 6 to 12 carbon atoms.

[In formula (6), R ¹⁷ and R ¹⁸ each independently represent a hydrogen atom, a group containing a heteroatom, a group containing a halogen atom, an alkyl group having 1 to 10 carbon atoms, or a group containing an aryl group and having 6 to 12 carbon atoms.] The polycarbonate resin composition according to claim 1, characterized in that the amount of terminal hydroxyl groups measured by a colorimetric method using the titanium tetrachloride/acetic acid method is 100 to 2,500 ppm. The polycarbonate resin composition according to claim 1 or 2, characterized in that the amount of residual phenol is 250 ppm or less. The polycarbonate resin composition according to any one of claims 1 to 3, wherein the polycarbonate resin composition has a relative dielectric constant (εr) of 2.45 or less, measured at a temperature of 23°C and a frequency of 10 GHz. 5. The polycarbonate resin composition according to claim 1, wherein R ⁹ and R ¹⁰ in the formula (3) each independently represent a hydrogen atom or a methyl group. The polycarbonate resin composition according to any one of claims 1 to 5, wherein R ¹³ to R ¹⁶ in the formula (4) are methyl groups. The polycarbonate resin composition according to any one of claims 1 to 6, wherein R ⁹ and R ¹⁰ in the formula (3) are methyl groups. The polycarbonate resin composition according to any one of claims 1 to 7, wherein the repeating unit (A) is a repeating unit represented by the following formula (7) or (8):

The polycarbonate resin composition according to any one of claims 1 to 8, wherein ^W2 in the formula (2) is selected from a single bond, a methylene group, an ethylidene group, and an isopropylidene group. 10. The polycarbonate resin composition according to claim 1, wherein the amount of terminal hydroxyl groups is 130 to 1,000 ppm as measured by a colorimetric method using titanium tetrachloride/acetic acid. The polycarbonate resin composition according to any one of claims 1 to 10 , characterized in that a ratio of the repeating unit (A) to the repeating unit (B) is from 1:99 to 90:10. The polycarbonate resin composition according to any one of claims 1 to 11 , wherein the polycarbonate resin has a viscosity average molecular weight (Mv) in the range of 16,000 to 32,000. A molded article obtained by using the polycarbonate resin composition according to any one of claims 1 to 12 . An injection-molded article obtained by using the polycarbonate resin composition according to any one of claims 1 to 12 . An extrusion molded product obtained by using the polycarbonate resin composition according to any one of claims 1 to 12 . A cover for a millimeter wave radar obtained by using the polycarbonate resin composition according to any one of claims 1 to 12 .