JP2022067467A - Housing for communication equipment - Google Patents

Abstract

To provide a housing for communication equipment that has a low dielectric loss tangent and is free of appearance defects and thin.SOLUTION: The invention provides a housing for communication equipment including a micro- and/or milliwave antenna employing a polycarbonate resin composition. A polycarbonate resin in the polycarbonate resin composition has a structural unit represented by the specified formula (1-1), and is subjected to alkaline hydrolysis to form a compound represented by the specified formula (2-1). The polycarbonate resin has a terminal hydroxyl group content from 200 mass ppm to 400 mass ppm inclusive, and a viscosity-average molecular weight from 21000 to 25500 inclusive.SELECTED DRAWING: None

Description

The present invention relates to a housing for a communication device having a built-in microwave and / or millimeter wave antenna, particularly a thin-walled communication device housing having a low dielectric loss tangent and few appearance defects. The present invention also relates to a polycarbonate resin composition capable of obtaining such a housing for communication equipment and a molded product thereof.

High-frequency communication equipment is required to reduce transmission loss and improve signal propagation speed in wiring, housing, and the like, and for that purpose, materials having low dielectric characteristics are required. Further, materials having low dielectric properties are required in various fields such as devices using so-called millimeter-wave radar used for detecting obstacles in automobiles and the like.

Patent Document 1 proposes a cover made of a polycarbonate resin material having excellent millimeter-wave transparency. However, the polycarbonate resin having a specific structure disclosed herein has relatively poor thermal stability, and when a thin-walled molded product is obtained, the appearance of the molded product is poor (black foreign matter) due to shear heat generation during molding. There was a problem that occurred. Further, further reduction of dielectric loss tangent is required.

Japanese Unexamined Patent Publication No. 2019-197048

Under such circumstances, an object of the present invention is a housing for communication equipment having a built-in microwave and / or millimeter wave antenna, which has a lower dielectric loss tangent and has almost no appearance defects. To provide the body.

As a result of diligent research to solve the above problems, the present inventor is a polycarbonate resin containing a carbonate structural unit derived from a specific aromatic dihydroxy compound, and has a specific range of terminal hydroxyl groups and viscosity average molecular weight. We have found that the above problems can be solved by using a controlled polycarbonate resin, and have reached the present invention.

That is, the gist of the present invention lies in the following [1] to [8].

[1] A housing for a communication device having a built-in microwave and / or millimeter wave antenna obtained by using the polycarbonate resin composition, and the polycarbonate resin composition is represented by at least the following formula (1). The alkaline hydrolyzate containing a polycarbonate resin having a structural unit and obtained by alkaline hydrolysis of the polycarbonate resin includes a compound represented by the following formula (2) and a compound represented by the following formula (3). The amount of the compound contained in the alkaline hydrolyzate represented by the following formula (3) is 1500 mass ppm or more and 6000 with respect to the amount of the compound represented by the following formula (2) in the alkaline hydrolyzate. A housing for communication equipment having a weight of ppm or less, a terminal hydroxyl group of the polycarbonate resin of 200 mass ppm or more and 400 mass ppm or less, and a viscosity average molecular weight of the polycarbonate resin of 21,000 or more and 25,500 or less.

(In the formula (1), the formula (2) and the formula (3), R ¹ , R ² and R ³ are independently substituted or unsubstituted alkyl groups having 1 or more and 20 or less carbon atoms, or substituted or absent. A substituted aryl group is indicated, where X indicates a single bond, a carbonyl group, a substituted or unsubstituted alkylidene group, a substituted or unsubstituted sulfur atom, or an oxygen atom.)

[2] The housing for communication equipment according to [1], which has a thickness of 1.5 mm or less.

[3] The structural unit represented by the formula (1) is the structural unit represented by the following formula (1-1), and the compound represented by the formula (2) is the following formula (2-1). The housing for a communication device according to [1] or [2], wherein the compound represented by the above formula (3) is a compound represented by the following formula (3-1).

[4] The housing for a communication device according to any one of [1] to [3], wherein the antenna is used for a radio wave in a frequency band of 3.5 to 30 GHz.

[5] The housing for a communication device according to any one of [1] to [4], wherein the communication device is a notebook computer, a tablet terminal, a smartphone, or a router device.

[6] A communication device having a built-in microwave and / or millimeter wave antenna, which is obtained by using the communication device housing according to any one of [1] to [5].

[7] A polycarbonate resin composition containing a polycarbonate resin having at least a structural unit represented by the following formula (1), wherein the alkaline hydrolyzate obtained by alkaline hydrolysis of the polycarbonate resin has the following formula. The amount of the compound represented by the following formula (3) in the alkaline hydrolyzate containing the compound represented by (2) and the compound represented by the following formula (3) is the amount in the alkaline hydrolyzate. The amount of the terminal hydroxyl group of the polycarbonate resin is 200 mass ppm or more and 400 mass ppm or less, and the viscosity of the polycarbonate resin is 1500 mass ppm or more and 6000 mass ppm or less with respect to the amount of the compound represented by the following formula (2). A polycarbonate resin composition having an average molecular weight of 21,000 or more and 25,500 or less.

(In the formula (1), the formula (2) and the formula (3), R ¹ , R ² and R ³ are independently substituted or unsubstituted alkyl groups having 1 or more and 20 or less carbon atoms, or substituted or absent. A substituted aryl group is indicated, where X indicates a single bond, a carbonyl group, a substituted or unsubstituted alkylidene group, a substituted or unsubstituted sulfur atom, or an oxygen atom.)

[8] A molded product obtained by using the polycarbonate resin composition according to [7].

The housing for communication equipment incorporating the microwave and / or millimeter wave antenna of the present invention is a thin-walled communication equipment housing having a lower dielectric loss tangent and almost no appearance defects, and is a housing for microwave and / or communication equipment. It has excellent radio wave transmission in the millimeter wave band, and is thin and has an excellent product appearance.
Further, the polycarbonate resin composition of the present invention has excellent low dielectric properties and thin-wall formability, and incorporates a member of a communication device that requires low dielectric properties, specifically, a microwave and / or millimeter wave antenna. It can be widely used as a housing for a communication device such as a notebook computer, a tablet terminal, a smartphone, or a router device. Furthermore, it can be used in a wide range of fields such as automobiles, medical care / nursing care, and railways / aviation.

Hereinafter, the present invention will be described in detail by showing embodiments and examples, but the present invention is not limited to the embodiments and examples shown below.
In addition, in this specification, "-" is used in the meaning which includes the numerical values described before and after it as the lower limit value and the upper limit value, unless otherwise specified.

[Polycarbonate resin composition]
The polycarbonate resin composition of the present invention has at least a polycarbonate resin having a structural unit represented by the following formula (1) (hereinafter, may be referred to as “structural unit (1)”) (hereinafter, “polycarbonate of the present invention”. It is a polycarbonate resin composition containing "resin"), and the polycarbonate resin of the present invention satisfies the following requirements <1> to <3>.
<1> The alkaline hydrolyzate obtained by alkaline hydrolysis of the polycarbonate resin of the present invention includes a compound represented by the following formula (2) (hereinafter, may be referred to as "compound (2)") and. It contains a compound represented by the following formula (3) (hereinafter, may be referred to as "compound (3)"), and the amount of the compound (3) in the alkaline hydrolyzate is contained in the alkaline hydrolyzate. 1500 mass ppm or more and 6000 mass ppm or less with respect to the amount of the compound (2) of.
<2> The amount of terminal hydroxyl groups is 200 mass ppm or more and 400 mass ppm or less.
<3> The viscosity average molecular weight is 21,000 or more and 25,500 or less.

(In the formula (1), the formula (2) and the formula (3), R ¹ , R ² and R ³ are independently substituted or unsubstituted alkyl groups having 1 or more and 20 or less carbon atoms, or substituted or absent. A substituted aryl group is indicated, where X indicates a single bond, a carbonyl group, a substituted or unsubstituted alkylidene group, a substituted or unsubstituted sulfur atom, or an oxygen atom.)

<Polycarbonate resin>
First, the polycarbonate resin of the present invention contained in the polycarbonate resin composition of the present invention will be described.

(Structural unit (1) / compound (2))
The structural unit (1) is a structural unit introduced into the polycarbonate resin by using the compound (2) as the raw material dihydroxy compound in the method for producing a polycarbonate resin described later.
In the formula (1) representing the structural unit (1) and the formula (2) representing the compound (2), R ¹ and R ² are independently substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms or substituted, respectively. Alternatively, an unsubstituted aryl group is shown.

Examples of the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms of R ¹ and R ² in the formulas (1) and (2) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and n-. Butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, sec-pentyl group, n-hexyl group, n-heptyl group, n-octyl group and the like can be mentioned and are substituted or unsubstituted. Examples of the aryl group include a phenyl group, a benzyl group, a tolyl group, a 4-methylphenyl group, a naphthyl group and the like.

Among these, R ¹ and R ² are preferably a methyl group, an ethyl group, an n-propyl group and a 4-methylphenyl group, and a methyl group is particularly preferable.

Further, the bonding position of R ¹ and R ² in the equations (1) and (2) is preferably the third position with respect to X.

In formulas (1) and (2), X represents a single bond, a carbonyl group, a substituted or unsubstituted alkylidene group, a substituted or unsubstituted sulfur atom, or an oxygen atom. As the substituted or unsubstituted alkylidene group, a substituted or unsubstituted alkrylden group having 1 to 20 carbon atoms is preferable, and the alkylidene group may be linear, branched or cyclic.
As X, a single-bonded, substituted or unsubstituted alkylidene group is preferable from the viewpoint of thermal stability and heat resistance, and among these, a substituted or unsubstituted alkylidene group having 1 to 12 carbon atoms is more preferable from the viewpoint of fluidity. In particular, a methylidene group, an ethylidene group, and a propylidene group are preferable, and a 2,2-propyridene group is particularly preferable.

As a preferable specific example of the compound (2), 2,2-bis (4-hydroxy-3-methylphenyl) propane represented by the following formula (2-1) (hereinafter, may be abbreviated as "BPC"). , 2,2-Bis (2-hydroxy-5-biphenylyl) propane represented by the following formula (2-2), 1,1-bis (4) represented by the following formula (2-3). -Hydroxy-3-methylphenyl) cyclododecane, 4,4-ethylidenebis (2-methylphenol) represented by the following formula (2-4), 4,4-represented by the following formula (2-5) (Octahydro-4,7-methano-5H-inden-5-iriden) bis (2-methylphenol), 1,1-bis (4-hydroxy-3-methylphenyl) represented by the following formula (2-6) ) Cyclohexane and the like.

From the viewpoint of thermal stability and fluidity, the structural unit (1) is preferably a structural unit represented by the following formula (1-1), and the compound (2) is preferably a structural unit represented by the following formula (2-1). The compound represented is preferably 2,2-bis (4-hydroxy-3-methylphenyl) propane (BPC).

The polycarbonate resin of the present invention may contain only one type of the structural unit (1), or may contain two or more types. Therefore, the alkaline hydrolyzate obtained by alkaline hydrolysis of the polycarbonate resin of the present invention may contain only one kind of compound (2) or may contain two or more kinds.

<Compound (3)>
In formula (3) representing compound (3), R ³ represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms or a substituted or unsubstituted aryl group.

Examples of the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms of R3 in the formula ( ³ ) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group and sec. -Butyl group, tert-butyl group, n-pentyl group, sec-pentyl group, n-hexyl group, n-heptyl group, n-octyl group and the like can be mentioned, and examples of the substituted or unsubstituted aryl group include. Examples thereof include a phenyl group, a benzyl group, a trill group, a 4-methylphenyl group, and a naphthyl group.

Among these ^, R3 is preferably a methyl group, an ethyl group, an n-propyl group, or a 4-methylphenyl group, and a methyl group is particularly preferable.

Further, the binding position of R3 in the formula ( ³ ) is preferably the third position with respect to X.

In formula (3), X represents a single bond, a carbonyl group, a substituted or unsubstituted alkylidene group, a substituted or unsubstituted sulfur atom, or an oxygen atom. As the substituted or unsubstituted alkylidene group, a substituted or unsubstituted alkrylden group having 1 to 20 carbon atoms is preferable, and the alkylidene group may be linear, branched or cyclic.
As X, a single-bonded, substituted or unsubstituted alkylidene group is preferable from the viewpoint of thermal stability and heat resistance, and among these, a substituted or unsubstituted alkylidene group having 1 to 12 carbon atoms is more preferable from the viewpoint of fluidity. In particular, a methylidene group, an ethylidene group, and a propylidene group are preferable, and a 2,2-propyridene group is particularly preferable.

As a suitable specific example of the compound (3), 2- (4-hydroxyphenyl) -2- (3-methyl-4-hydroxyphenyl) propane represented by the following formula (3-1) (hereinafter, “monomethyl”). It may be referred to as "BPA"), 2- (4-hydroxyphenyl) -2- (3-phenyl-4-hydroxyphenyl) propane represented by the following formula (3-2), and the following formula (3-3). 1- (4-Hydroxyphenyl) -1- (3-methyl-4-hydroxyphenyl) cyclododecane represented by), 1- (4-hydroxyphenyl) -1 represented by the following formula (3-4) -(3-Methyl-4-hydroxyphenyl) ethane, 4- (4-hydroxyphenyl) -4- (3-methyl-4-hydroxyphenyl) (octahydro-4, represented by the following formula (3-5). 7-methano-5H-inden-5-iriden), 1- (4-hydroxyphenyl) -1- (3-methyl-4-hydroxyphenyl) cyclohexane represented by the following formula (3-6), and the like can be mentioned. ..

From the viewpoint of thermal stability and fluidity, the compound (3) is a 2- (4-hydroxyphenyl) -2- (3-methyl-4-hydroxyphenyl) propane represented by the following formula (3-1). It is preferably monomethyl BPA).

The alkaline hydrolyzate obtained by alkaline hydrolysis of the polycarbonate resin of the present invention may contain only one kind of compound (3) or may contain two or more kinds.

Further, R ¹ and R ² in the formula (2) representing the compound (2) and R ³ in the formula (3) representing the compound (3) do not necessarily have to be the same and may be different. Further, the X in the formula (2) and the X in the formula (3) may be the same or different.
However, from the viewpoint of thermal stability and fluidity, it is preferable that at least one of R ¹ and R ² in the formula (2) and R ³ in the formula (3) are the same, and X and the formula in the formula (2). It is preferable that X in (3) is the same.

<Structural unit of polycarbonate resin>
The polycarbonate resin of the present invention containing the structural unit (1) produces the compound (2) by alkaline hydrolysis.
Further, the fact that the compound (3) is contained in the alkaline hydrolyzate obtained by alkaline hydrolysis of the polycarbonate resin of the present invention means that the polycarbonate resin of the present invention is a structural unit derived from the compound (3). Specifically, it means having a structural unit represented by the following formula (4) (hereinafter, may be referred to as "structural unit (4)").

(In equation (4), R3 and X are synonymous with equation ( ³ ).)

That is, the polycarbonate resin of the present invention contains at least one or more of the structural unit (1) and one or more of the structural unit (4), but the polycarbonate resin of the present invention has a structure. It may contain a structural unit other than the unit (1) and the structural unit (4).
The other structural units are not particularly limited, and examples thereof include structural units derived from the following dihydroxy compounds.

Biphenols such as 2,2,6,6-tetramethyl-4,4-biphenol, 4,4-biphenol, 2,5-biphenol, 2,2-biphenol;
2,2'-Dihydroxydiphenyl ether, 3,3'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, 1,4-bis (3-hydroxyphenoxy) Dihydroxydiaryl ethers such as benzene and 1,3-bis (4-hydroxyphenoxy) benzene;
2,2-Bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) propane, 2,2-bis (3-methoxy-4-hydroxyphenyl) propane, 2- (4-hydroxyphenyl) )-2- (3-methoxy-4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, α, α'-bis (4-hydroxyphenyl) -1, 4-Diisopropylbenzene, 1,3-bis [2- (4-hydroxyphenyl) -2-propyl] benzene, bis (4-hydroxyphenyl) methane, bis (4-hydroxy-3,5-dimethylphenyl) methane, Bis (4-hydroxyphenyl) phenylmethane, bis (4-hydroxyphenyl) (4-propenylphenyl) methane, bis (4-hydroxyphenyl) diphenylmethane, bis (4-hydroxyphenyl) naphthylmethane, 1,1-bis ( 4-Hydroxyphenyl) ethane, 2-bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 1,1-bis (4-hydroxyphenyl) -1-naphthyl Etan, 1-bis (4-hydroxyphenyl) butane, 2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) pentane, 1,1-bis (4-hydroxyphenyl) hexane, 2,2-Bis (4-hydroxyphenyl) hexane, 1-bis (4-hydroxyphenyl) octane, 2-bis (4-hydroxyphenyl) octane, 1-bis (4-hydroxyphenyl) hexane, 2-bis ( 4-Hydroxyphenyl) hexane, 4,4-bis (4-hydroxyphenyl) heptane, 2,2-bis (4-hydroxyphenyl) nonane, 10-bis (4-hydroxyphenyl) decane, 1-bis (4-bis) Bis (hydroxyaryl) alkanes such as hydroxyphenyl) dodecane;
1-bis (4-hydroxyphenyl) cyclopentane, 1-bis (4-hydroxyphenyl) cyclohexane, 4-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3- Dimethylcyclohexane, 1-bis (4-hydroxyphenyl) -3,4-dimethylcyclohexane, 1,1-bis (4-hydroxyphenyl) -3,5-dimethylcyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis (4-hydroxy-3,5-dimethylphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis (4-hydroxyphenyl) -3 -Propyl-5-methylcyclohexane, 1,1-bis (4-hydroxyphenyl) -3-tert-butyl-cyclohexane, 1,1-bis (4-hydroxyphenyl) -3-tert-butyl-cyclohexane, 1, Bis (hydroxyaryl) cycloalkanes such as 1-bis (4-hydroxyphenyl) -3-phenylcyclohexane and 1,1-bis (4-hydroxyphenyl) -4-phenylcyclohexane;
Cardo-structure-containing bisphenols such as 9,9-bis (4-hydroxyphenyl) fluorene and 9,9-bis (4-hydroxy-3-methylphenyl) fluorene;
Dihydroxydiaryl sulfides such as 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide;
Dihydroxydiaryl sulfoxides such as 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide;
Dihydroxydiaryl sulfones such as 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone:

The polycarbonate resin of the present invention may contain only one type of structural unit other than the structural units (1) and (4), or may contain two or more types.

From the viewpoint that the polycarbonate resin of the present invention effectively obtains the effect of the present invention by containing the structural unit (1), the polycarbonate resin of the present invention is contained in the structural unit derived from all the dihydroxy compounds in the polycarbonate resin of the present invention. , The structural unit (1) is preferably contained in an amount of 20 mol% or more, particularly 50 mol% or more, and the polycarbonate resin of the present invention particularly contains a structural unit (1) and a structural unit (4) as structural units derived from all dihydroxy compounds. ) Only.

(Requirement <1>)
The requirement <1> of the polycarbonate resin of the present invention is that the amount of the compound (3) in the alkaline hydrolyzate obtained by alkaline hydrolysis of the polycarbonate resin of the present invention is 1500 to 6000 mass ppm with respect to the amount of the compound (2). It is in the range of. Hereinafter, the amount of compound (3) with respect to the amount of compound (2) in the alkaline hydrolyzate obtained by alkaline hydrolysis of the polycarbonate resin is referred to as "compound (3) / compound (2) amount".

When the amount of compound (3) / compound (2) is 1500 mass ppm or more, lower dielectric properties can be achieved. The dielectric property tends to be lower as the amount of compound (3) / compound (2) is larger, although it depends on other requirements <2> and <3>. However, if the amount of the compound (3) / compound (2) is too large, the appearance of the thin-walled molded product is deteriorated, so that the amount of the compound (3) / compound (2) is 6000 mass ppm or less. From these viewpoints, the amount of the compound (3) / compound (2) of the polycarbonate resin of the present invention is preferably 1700 to 5500 mass ppm, more preferably 2000 to 5200 mass ppm.

The amount of the compound (3) / compound (2) of the polycarbonate resin can be determined according to the method for alkaline hydrolysis of the polycarbonate resin and the quantification method of the alkaline hydrolyzate described in the section of Examples described later.

(Requirement <2>)
The requirement <2> of the polycarbonate resin of the present invention is that the amount of terminal hydroxyl groups is 200 to 400 mass ppm.
Since the amount of terminal hydroxyl groups is in a very limited range of 200 to 400 mass ppm, it is possible to achieve both low dielectric properties and good appearance. The amount of terminal hydroxyl groups of the polycarbonate resin of the present invention is preferably 210 to 370 mass ppm, more preferably 220 to 350 mass ppm.

The amount of the terminal hydroxyl group of the polycarbonate resin represents the total amount M of the terminal hydroxyl groups represented by the following formula (5), and the unit of the amount of the terminal hydroxyl group is the mass of the terminal hydroxyl group expressed in ppm with respect to the mass of the polycarbonate resin. be. The measuring method is colorimetric quantification by the titanium tetrachloride / acetic acid method (method described in Macromol. Chem. 88 215 (1965)).

In formula (5), R ⁴ independently has 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, and a cyclo having 4 to 20 carbon atoms. It is an alkyl group and an aryl group having 6 to 20 carbon atoms, and r represents an integer of 0 to 2).

The amount of terminal hydroxyl groups in the polycarbonate resin can be adjusted to a preferable value by controlling the molar ratio of raw materials charged at the time of manufacturing the polycarbonate resin, the amount of catalyst, the temperature during the reaction, and the degree of vacuum.

As the polycarbonate resin of the present invention, two or more types of polycarbonate resins having different amounts of terminal hydroxyl groups may be mixed and used. In this case, the polycarbonate resin having the amount of terminal hydroxyl groups outside the above suitable range may be used. It may be mixed using and controlled to the amount of terminal hydroxyl groups in the above range.

(Requirement <3>)
The requirement <3> of the polycarbonate resin of the present invention is that the viscosity average molecular weight is 21000 to 25500.
Since the viscosity average molecular weight is in a very limited range of 21000 to 25500, it is possible to achieve both low dielectric properties and good appearance. If the viscosity average molecular weight is less than the above lower limit, low dielectric properties cannot be obtained, and if it exceeds the above upper limit, a good appearance cannot be obtained in a thin-walled molded product. The viscosity average molecular weight of the polycarbonate resin of the present invention is preferably 21500 to 25000, more preferably 22000 to 24500.

For the viscosity average molecular weight (Mv) of the polycarbonate resin, the intrinsic viscosity (extreme viscosity) [η] (unit: dL / g) at a temperature of 20 ° C. was determined using a Ubbelohde viscometer using methylene chloride as a solvent. It means the viscosity formula, that is, the value calculated from η = 1.23 × 10 ^-4 Mv ^0.83 . The intrinsic viscosity (extreme viscosity) [η] is a value calculated by the following formula by measuring the specific viscosity [ηsp] at each solution concentration [C] (g / dL).

The polycarbonate resin of the present invention may be used by mixing two or more types of polycarbonate resins having different viscosity average molecular weights. In this case, a polycarbonate resin having a viscosity average molecular weight outside the above-mentioned suitable range is used. It may be mixed and controlled to have a viscosity average molecular weight in the above range.

<Manufacturing method of polycarbonate resin>
The polycarbonate resin of the present invention can be produced by a conventionally known polymerization method using a raw material dihydroxy compound described later, and the polymerization method is not particularly limited. Examples of the polymerization method include an interfacial polymerization method, a melt transesterification method, a pyridine method, a ring-opening polymerization method of a cyclic carbonate compound, a solid phase transesterification method of a prepolymer, and the like. Hereinafter, particularly suitable of these methods will be specifically described.

(Interfacial polymerization method)
In the interfacial polymerization method, the pH is usually kept at 9 or higher in the presence of an organic solvent and an alkaline aqueous solution inert to the reaction, the dihydroxy compound as a raw material is reacted with the carbonate-forming compound, and then in the presence of a polymerization catalyst. A polycarbonate resin is obtained by performing interfacial polymerization. If necessary, a molecular weight modifier (terminal terminator) may be present in the reaction system, or an antioxidant may be present to prevent oxidation of the raw material dihydroxy compound.

The organic solvent inert to the reaction is not particularly limited, and is, for example, chlorinated hydrocarbons such as dichloromethane, 1,2-dichloroethane, chloroform, monochlorobenzene, dichlorobenzene and the like; aromatic hydrocarbons such as benzene, toluene and xylene. Hydrogen; etc. As the organic solvent, one kind may be used, or two or more kinds may be used in any combination and ratio.

The alkaline compound contained in the alkaline aqueous solution is not particularly limited, and examples thereof include alkali metal compounds such as sodium hydroxide, potassium hydroxide, lithium hydroxide, and sodium hydrogencarbonate, and alkaline earth metal compounds. Of these, sodium hydroxide and potassium hydroxide are preferable. As the alkaline compound, one kind may be used, or two or more kinds may be used in any combination and ratio.

Although the concentration of the alkaline compound in the alkaline aqueous solution is not limited, the alkaline compound concentration is usually 5 to 10% by mass in order to control the pH of the alkaline aqueous solution to 10 to 12. Further, for example, when injecting phosgene, the mol ratio of the raw material dihydroxy compound to the alkaline compound is usually 1: 1.9 in order to control the pH of the aqueous phase to be 10 to 12, preferably 10 to 11. Above, above all, it is preferably 1: 2.0 or more, and usually 1: 3.2 or less, and above all, 1: 2.5 or less is preferable.

As the raw material dihydroxy compound, at least compound (2) is used. Further, compound (3) may be used as a raw material dihydroxy compound as needed so as to satisfy the requirement <1>.
However, the compound (2) used for producing the polycarbonate resin is usually produced by condensation of a ketone or aldehyde with an aromatic alcohol according to the following reaction formula.

(In the above formula, R ^a corresponds to R ¹ and R ² in the formula (2), and R ^b and R ^c are concatenations corresponding to X in the formula (2) with -R ^b -C-R ^c . It is the basis.)

In such a condensation reaction between a ketone or aldehyde and an aromatic alcohol, the substituent R ^a of the aromatic alcohol is removed during the reaction, and the compound (3) having the substituent R ^a on only one benzene ring is secondary. May be produced as a living organism. Further, the aromatic alcohol used as ^a raw material for producing the compound (2) may contain phenol having no substituent Ra as an impurity in the product, and in this case, it is substituted with only one benzene ring. A compound (3) having ^a group Ra is produced.

Therefore, since the compound (3) may be contained as an impurity in the compound (2) produced by the condensation reaction as described above, the compound (2) contained as an impurity (2). By purifying 3) as necessary and adjusting the amount to obtain a polycarbonate resin satisfying the requirement <1>, the required amount of the compound (3) can be used as the raw material dihydroxy compound.

As the carbonate-forming compound, a carbonyl halide is preferably used, and among them, phosgene is preferably used, and the method when phosgene is used is particularly called a phosgene method.

The polymerization catalyst is not particularly limited, but is, for example, an aliphatic tertiary amine such as trimethylamine, triethylamine, tributylamine, tripropylamine, trihexylamine; N, N'-dimethylcyclohexylamine, N, N'-diethylcyclohexyl. Alicyclic tertiary amines such as amines; aromatic tertiary amines such as N, N'-dimethylaniline, N, N'-diethylaniline; trimethylbenzylammonium chloride, tetramethylammonium chloride, triethylbenzylammonium chloride and the like. Tetra-ammonium salts and the like; pyridines; guanines; guanidine salts; etc. As the polymerization catalyst, one kind may be used, or two or more kinds may be used in any combination and ratio.

The molecular weight adjusting agent is not particularly limited, and examples thereof include aromatic phenols having a monovalent phenolic hydroxyl group; fatty alcohols such as methanol and butanol; mercaptans; phthalic acid imides, and the like, among which aromatic phenols are used. preferable. Specific examples of such aromatic phenols include phenol, on-butylphenol, mn-butylphenol, pn-butylphenol, o-isobutylphenol, m-isobutylphenol, p-isobutylphenol, o. -T-butylphenol, mt-butylphenol, pt-butylphenol, on-pentylphenol, mn-pentylphenol, pn-pentylphenol, on-hexylphenol, mn-hexyl Phenol, pn-hexylphenol, pt-octylphenol, o-cyclohexylphenol, m-cyclohexylphenol, p-cyclohexylphenol, o-phenylphenol, m-phenylphenol, p-phenylphenol, on-nonylphenol , Mn-nonylphenol, pn-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, tri Bromophenol, monoalkylphenol having linear or branched alkyl groups with an average carbon number of 12 to 35 at the ortho-position, meta-position or para-position, 9- (4-hydroxyphenyl) -9- (4-methoxyphenyl) Examples thereof include fluorene, 9- (4-hydroxy-3-methylphenyl) -9- (4-methoxy-3-methylphenyl) fluorene, 4- (1-adamantyl) phenol and the like. Among these, pt-butylphenol, p-phenylphenol and p-cumylphenol are preferably used. As the molecular weight adjusting agent, one type may be used, or two or more types may be used in combination in any combination and ratio.

The amount of the molecular weight adjusting agent used is not particularly limited, but is usually 0.5 mol or more, preferably 1 mol or more, and usually 50 mol or less, preferably 30 mol or less, with respect to 100 mol of the raw material dihydroxy compound.

The antioxidant is not particularly limited, and examples thereof include a hindered phenolic antioxidant. Specific examples thereof include pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl). ) Propionate, thiodiethylenebis [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] Phosphoate, 3,3', 3'', 5,5', 5''-Hexa-tert-butyl-a, a', a''-(mesitylen-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-triazine- Examples thereof include 2-ylamino) phenol and 2- [1- (2-hydroxy-3,5-di-tert-pentylphenyl) ethyl] -4,6-di-tert-pentylphenyl acrylate.

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

It should be noted that one type of antioxidant may be used, or two or more types may be used in any combination and ratio.

The amount of the antioxidant used is not particularly limited, but is usually 0.001 part by mass or more, preferably 0.01 part by mass or more, and more preferably 0.1 part by mass or more with respect to 100 parts by mass of the raw material dihydroxy compound. It is usually 1 part by mass or less, preferably 0.5 part by mass or less. If the amount of the antioxidant used is less than the lower limit of the above range, the effect as the antioxidant may be insufficient, and if the amount of the antioxidant used exceeds the upper limit of the above range, the effect as the antioxidant may be insufficient. There is a possibility that gas will be easily emitted during injection molding.

The order in which the reaction substrate (reaction raw material), reaction solvent (organic solvent), catalyst, additives, etc. are mixed at the time of the reaction is arbitrary as long as the desired polycarbonate resin can be obtained, and an appropriate order can be arbitrarily set. Just do it. For example, when phosgene is used as the carbonate-forming compound, the molecular weight adjusting agent can be mixed at any time from the reaction (phosgenation) between the raw material dihydroxy compound and phosgene to the start of the polymerization reaction. ..
The reaction temperature is not particularly limited, but is preferably 0 to 40 ° C., and the reaction time is not particularly limited, but is preferably several minutes (for example, 10 minutes) to several hours (for example, 6 hours).

(Melted transesterification method)
In the melt transesterification method, for example, a transesterification reaction between a carbonate ester and a raw material dihydroxy compound is performed.
The raw material dihydroxy compound is the same as in the interfacial polymerization method.

The carbonate ester may be, for example, a compound represented by the following general formula (6), and is a dihydroxy such as an aryl carbonate, a dialkyl carbonate, a biscarbonate of a dihydroxy compound, a monocarbonate of a dihydroxy compound, or a cyclic carbonate. Examples thereof include carbonated compounds.

In the above general formula (6), R ²¹ and R ²² independently represent an alkyl group, an aryl group, or an arylalkyl group having 1 to 30 carbon atoms, respectively. Hereinafter, when R ²¹ and R ²² are an alkyl group or an arylalkyl group, they may be referred to as dialkyl carbonate, and when they are aryl groups, they may be referred to as diaryl carbonate. Among them, from the viewpoint of reactivity with the dihydroxy compound, both R ²¹ and R ²² are preferably aryl groups, and more preferably diaryl carbonate represented by the following general formula (7).

In the above general formula (7), R ²³ and R ²⁴ independently have 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, and 4 carbon atoms. It is a cycloalkyl group of about 20 or an aryl group of 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 dit-butyl carbonate, diphenyl carbonate (hereinafter, may be abbreviated as "DPC"), and 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, Examples thereof include diaryl carbonates (which may have a substituent) such as bis (2-nitrophenyl) carbonate, bis (methylsalitylphenyl) carbonate, and ditril carbonate, and diphenyl carbonate is preferable. These carbonate esters can be used alone or in admixture of two or more.

Further, the carbonate ester may be replaced with a dicarboxylic acid or a dicarboxylic acid ester in an amount of preferably 50 mol% or less, more preferably 30 mol% or less. Typical dicarboxylic acids or dicarboxylic acid esters include terephthalic acid, isophthalic acid, diphenyl terephthalate, diphenyl isophthalic acid and the like. When substituted with such a dicarboxylic acid or a dicarboxylic acid ester, a polyester carbonate is obtained.

The ratio of the raw material dihydroxy compound to the carbonate ester is arbitrary as long as the desired polycarbonate resin can be obtained, but it is preferable to use these carbonate esters in excess with respect to the raw material dihydroxy compound when polymerizing with the dihydroxy compound. That is, the amount of the carbonate ester is preferably 1.01 times (mol ratio) or more, and more preferably 1.02 times or more with respect to the dihydroxy compound. By setting the mol ratio in the above range, the thermal stability of the obtained polycarbonate resin becomes good. The amount of the carbonate ester is preferably 1.30 times (mol ratio) or less, and more preferably 1.20 times or less with respect to the dihydroxy compound. By setting the mol ratio within the above range, the reactivity is improved, the productivity of the polycarbonate resin having a desired molecular weight is improved, and the amount of residual carbonate ester in the resin is reduced, so that the molding process is performed. It is suitable because it can suppress the generation of odor when it is used or when it is made into a molded product.

When producing a polycarbonate resin by the transesterification method, a transesterification catalyst is usually used. The transesterification catalyst is not particularly limited, and conventionally known ones can be used. For example, it is preferable to use an alkali metal compound and / or an alkaline earth metal compound. Further, as an auxiliary, 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 the transesterification catalyst, one type 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 preferably 100 to 320 ° C. The pressure during the reaction is not particularly limited, but a reduced pressure condition of 2 mmHg or less is preferable. As a specific operation, the melt polycondensation reaction may be carried out while removing by-products under the above conditions.

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

The reaction form can be either a batch method or a continuous method. In the case of batch method, the order of mixing the reaction substrate, reaction solvent, catalyst, additives and the like is arbitrary as long as the desired polycarbonate resin can be obtained, and an appropriate order may be set arbitrarily.

In the melt transesterification method, a catalyst deactivating agent may be used if necessary. As the catalyst deactivating agent, a compound that neutralizes the transesterification catalyst can be arbitrarily used. Examples thereof include sulfur-containing acidic compounds and derivatives thereof, phosphorus-containing acidic compounds and derivatives thereof, and the like. As the catalyst deactivating agent, one type may be used, or two or more types may be used in combination in any combination and ratio.

The amount of the catalyst deactivating agent 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, relative to the transesterification catalyst. Hereinafter, it is preferably 10 equivalents or less, more preferably 8 equivalents or less. The amount of the catalyst deactivating agent used is usually 1 mass ppm or more, 100 mass ppm or less, and preferably 50 mass ppm or less with respect to the polycarbonate resin.

<Other ingredients>
The polycarbonate resin composition of the present invention may contain other components in addition to the polycarbonate resin of the present invention, if necessary, as long as the desired physical properties are not significantly impaired. Examples of other components include polycarbonate resins other than the polycarbonate resin of the present invention (that is, polycarbonate resins that do not meet the requirements <1> to <3> of the polycarbonate resin of the present invention), resins other than the polycarbonate resin, and various resins. Additives and the like can be mentioned.

However, in order to surely obtain the effect of the present invention by containing the polycarbonate resin of the present invention, the polycarbonate resin composition of the present invention contains the polycarbonate resin of the present invention in 100% by mass of the polycarbonate resin composition in total. It is preferably contained in an amount of 65% by mass or more, particularly 70% by mass or more, and particularly preferably 75% by mass or more.
Further, the content of the polycarbonate resin in the polycarbonate resin composition of the present invention is preferably 80% by mass or more with respect to 100% by mass of the polycarbonate resin composition of the present invention in order to effectively bring out the features of the present invention. It is more preferably 85% by mass or more, and particularly preferably 90% by mass or more.

Examples of the resin additive include a heat stabilizer, an antioxidant, a mold release agent, a light resistant agent (HALS), a flame retardant, an antistatic agent, an antifogging agent, a lubricant, an antiblocking agent, a fluidity improving agent, and a plasticizer. , Dispersants, antibacterial agents, dyes, pigments and the like. In addition, 1 type may be contained in the resin additive, and 2 or more types may be contained in arbitrary combinations and ratios.

Examples of other resins include thermoplastic polyester resins such as polyethylene terephthalate resin, polytrimethylene terephthalate, and polybutylene terephthalate resin; polystyrene resin, high impact polystyrene resin (HIPS), acrylonitrile-styrene copolymer (AS resin), and the like. Styre resin such as acrylonitrile-styrene-acrylic rubber copolymer (ASA resin), acrylonitrile-ethylene propylene rubber-styrene copolymer (AES resin); polyolefin resin such as polyethylene resin and polypropylene resin; polyamide resin; polyimide resin ; Polyetherimide resin; Polyurethane resin; Polyphenylene ether resin; Polyphenylene sulfide resin; Polysulfone resin; Polymethacrylate resin and the like.
As the other resin, one type may be contained, or two or more types may be contained in any combination and ratio.

<Polycarbonate resin molding method>
In order to produce a polycarbonate resin molded product from the polycarbonate resin composition of the present invention, an ordinary extrusion molding machine or injection molding machine is used.

The molding temperature at the time of 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 to the above lower limit or higher, the fluidity is improved and the moldability is improved. 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 to be equal to or lower than the above upper limit, the color tone of the polycarbonate resin composition can be improved.

In injection molding or extrusion molding, pigments, dyes, mold release agents, heat stabilizers and the like can be appropriately added to the polycarbonate resin composition of the present invention as long as the object of the present invention is not impaired.

<Polycarbonate resin molded product>
The polycarbonate resin composition of the present invention can be suitably used as a molded product by heat processing such as injection molding and extrusion molding. There are no restrictions on the shape, pattern, color, dimensions, etc. of such a polycarbonate resin molded product, and it can be appropriately selected depending on the intended use of the molded product, for example, plate-shaped, plate-shaped, rod-shaped, sheet-shaped, etc. Various shapes such as film-shaped, cylindrical, annular, circular, elliptical, polygonal, deformed, hollow, frame-shaped, box-shaped, panel-shaped, and special shapes are listed. Be done. Further, for example, the surface may have irregularities or a three-dimensional shape having a three-dimensional curved surface.

(Injection molded product)
The polycarbonate resin composition of the present invention can be suitably used as an injection-molded product by injection molding. The injection molding method is not particularly limited, and a molding method generally used for thermoplastic resins can be arbitrarily adopted. Examples include ultra-high-speed injection molding, injection compression molding, two-color molding, hollow molding such as gas assist, molding using a heat insulating mold, molding using a rapid heating mold, and foaming. Examples include molding (including supercritical fluid), insert molding, and IMC (in-mold coating molding) molding method. Further, a molding method using a hot runner method can also be used.

When using an injection molding machine or the like, the mold temperature is preferably 150 ° C. or lower, more preferably 120 ° C. or lower, and most preferably 100 ° C. or lower. By setting the mold temperature to the above upper limit or less, the cooling time at the time of molding can be shortened, and the manufacturing cycle of the molded product is shortened, so that the productivity is improved. Further, when using an injection molding machine or the like, the mold temperature is preferably 30 ° C. or higher, particularly preferably 50 ° C. or higher. By setting the mold temperature to the above lower limit or higher, a uniform molded product can be obtained, which is preferable.

(Extruded product)
The polycarbonate resin composition of the present invention can be suitably used as an extruded product by extrusion molding. An extrusion molding machine is usually used for producing an extrusion molded product from the polycarbonate resin composition of the present invention, although there is no particular limitation. Generally, the extruder is equipped with a T-die, a round die, or the like, and extrusion-molded products having various shapes can be obtained. Examples of the extruded product include sheets, films, plates, tubes, pipes and the like. Among these, a sheet or a film is preferable.

In the extruded product of the polycarbonate resin composition of the present invention, a hard coat layer may be laminated on both sides or one side of the extruded product in order to improve adhesiveness, coatability and printability, and weather resistance and / or scratch resistance may be obtained. The property improving film may be heat-laminated on both sides or one side of the extruded product. Further, the surface may be subjected to a wrinkling process, a translucent process, an opaque process, or the like.

(Use)
The molded product of the polycarbonate resin composition of the present invention is, for example, various automobile parts, electric / electronic equipment, information terminal equipment, OA equipment, mechanical parts, home appliances, vehicle parts, building parts, various containers, leisure goods / miscellaneous goods, etc. It can be used as parts for lighting equipment, in particular, housings for electronic devices such as smartphones and computers, antenna covers, covers for routers and switches that are wired communication devices, and covers for millimeter-wave radar.

Among these, the polycarbonate resin composition of the present invention is a communication device having a built-in microwave and / or millimeter wave antenna, particularly because of the low dielectric property of the polycarbonate resin composition of the present invention and the good appearance characteristics of the thin-walled molded product. It can be effectively used as a molding material for a housing.

(Thickness of molded product)
The thickness of the molded product using the polycarbonate resin composition of the present invention, particularly in the case of a housing for communication equipment incorporating a microwave and / or millimeter wave antenna described later, is preferably 1.5 mm or less. 1.2 mm or less is more preferable, and 1.0 mm or less is most preferable. Here, the thickness of the molded product refers to a portion that occupies an area portion of 50% or more of the entire molded product, for example, the thickness of the main plate surface.
If the thickness of the molded product is not more than the above upper limit, the transmission loss can be reduced. When the thickness of the molded product is not less than the above lower limit, the mechanical strength and the like for maintaining the structure of the molded product can be sufficiently sufficient.
When the thickness of the molded product is thicker than 1.5 mm, poor appearance is unlikely to occur, but when the thickness is 1.5 mm or less, shear heat generation in injection molding becomes large, and black foreign matter is generated in particular. It will be easier. According to the polycarbonate resin composition of the present invention, a good appearance can be obtained in a thin-walled molded product which tends to be accompanied by such poor appearance.

[Case for communication equipment]
The molded product obtained by using the polycarbonate resin composition of the present invention has a low dielectric positive contact, a thin wall and a good appearance, and is excellent in radio wave transmission in the microwave and / or millimeter wave band, and therefore these characteristics are strictly required. It is useful as a housing for communication equipment with a built-in microwave and / or millimeter wave antenna.

There are no restrictions on the shape, pattern, color, dimensions, etc. of the housing for communication equipment that incorporates such a microwave and / or millimeter wave antenna, and for communication equipment that incorporates the microwave and / or millimeter wave antenna. It can be appropriately selected according to the application of the housing.

In the present invention, the microwave is a radio wave having a frequency of 3.0 to 30 GHz, and the millimeter wave is a radio wave having a frequency of 30 to 300 GHz. Therefore, microwaves and / or millimeter waves are radio waves of 3.0 to 300 GHz. That is, a communication device having a built-in microwave and / or millimeter wave antenna is a communication device having a built-in antenna for transmitting and receiving radio waves having a frequency of 3.0 to 300 GHz. Specific examples of the communication device include a notebook computer, a tablet terminal, a smartphone, a router device, and the like that transmit and receive radio waves having a frequency of 3.0 to 300 GHz.

The frequency transmitted and received by the microwave and / or millimeter wave antenna of the housing for communication equipment incorporating the microwave and / or millimeter wave antenna of the present invention is not particularly limited as long as it is 3.0 to 300 GHz. 3. It is more suitable for radio waves in the frequency band of 3.2 to 250 GHz, and further suitable for radio waves in the frequency band of 3.4 to 200 GHz.

In particular, the housing for communication equipment incorporating the microwave and / or millimeter wave antenna of the present invention is used for radio waves in the frequency band of 3.5 to 30 GHz used in 5G (5th generation mobile communication system). It can be suitably used.

Radio waves in the microwave and / or millimeter wave band tend to have poor radio transmission. From this point of view, a housing for a communication device having a built-in antenna for transmitting and receiving radio waves in the microwave and / or millimeter wave band is required to have high radio wave transparency.
Further, the housing for communication equipment having a built-in microwave and / or millimeter wave antenna is required to be thin and have a good appearance because of its compactness and design as a commercial product.

The polycarbonate resin of the present invention contained in the polycarbonate resin composition of the present invention used for a housing for a communication device having an antenna for transmitting and receiving radio waves in the microwave and / or millimeter wave band of the present invention has a low dielectrically tangent. It has both high thin-wall formability and good appearance. Therefore, the polycarbonate resin composition of the present invention containing such a polycarbonate resin of the present invention has a low relative permittivity, a high thin-wall formability and a good appearance, and transmits and receives radio waves in the microwave and / or millimeter wave band. It is suitable for use in the housing of communication equipment.

Specific examples of a housing for a communication device having a built-in microwave and / or millimeter wave antenna include a housing such as a notebook computer, a tablet terminal, a smartphone, or a router device. The molded article of the present invention made of the polycarbonate resin composition of the present invention is particularly suitable for these uses.

Hereinafter, the present invention will be described in more detail based on Examples. The present invention is not limited to the following examples.

The physical characteristics of the polycarbonate resins obtained in the following Examples and Comparative Examples were evaluated by the following methods.

(1) Viscosity average molecular weight (Mv)
The polycarbonate resin is dissolved in methylene chloride (concentration 6.0 g / L), and the intrinsic viscosity (extreme viscosity) [η] (unit: dL / g) at 20 ° C. is determined using an Ubbelohde viscosity tube (manufactured by Moriyu Rika Kogyo Co., Ltd.). The viscosity average molecular weight (Mv) was calculated from the viscosity formula (following formula) of Schnell.
η = 1.23 × 10 ^-4 Mv ^0.83

(2) Amount of terminal hydroxyl groups The amount of terminal hydroxyl groups of the polycarbonate resin is determined by colorimetric quantification according to the colorimetric quantification by the titanium tetrachloride / acetic acid method (method described in Macromol. Chem. 88 215 (1965)). It was measured.
In the case of a polycarbonate resin copolymer composed of a plurality of dihydroxy compounds, a sample in which the corresponding dihydroxy compounds are mixed according to the copolymerization ratio is prepared at a concentration of at least 3 levels, and a calibration curve is obtained from the data of 3 points or more. After subtracting, measure the amount of terminal hydroxyl groups in the polycarbonate resin.
The detection wavelength is 546 nm.

(3) Alkaline Hydrolysis and Quantification of Alkaline Hydrolyzate 0.5 g of polycarbonate resin was dissolved in 5 mL of methylene chloride to prepare a solution. Then, 45 mL of methanol and 5 mL of a 25 mass% sodium hydroxide aqueous solution were added to the solution, and the mixture was stirred at 70 ° C. for 30 minutes. The obtained solution was analyzed by liquid chromatography according to the following measurement conditions, the hydrolyzate was quantified, and the amount of compound (3) / compound (2) (ratio of monomethyl BPA to BPC) was calculated.
Equipment: Shimadzu Corporation System controller: CBM-20A
Pump: LC-10AD
Column oven: CTO-10ASvp
Detector: SPD-M20A
Analytical column: YMC-Pack ODS-AM 75 mm x φ4.6 mm
Oven temperature: 40 ° C
Detection wavelength: 280 nm
Eluent: Solution A: 0.1% aqueous solution of trifluoroacetic acid, solution B: acetonitrile A / B = 60/40 (vol%) to A / B = 95/5 (vol%) Gradient flow rate: 1 mL in 50 minutes / Min
Sample injection amount: 20 μL
For identification of each hydrolyzate, the portion corresponding to the peak observed at the retention time is fractionated, and ¹ HNMR, ¹³ CNMR, two-dimensional NMR method, mass spectrometry (MS), infrared absorption of the fractionated sample are performed. It was carried out by the spectral method (IR spectrum).

(4) Number of black foreign matter generating plates After drying the polycarbonate resin pellets at 100 ° C for 5 hours using a hot air dryer, a mold was used at a cylinder temperature of 290 ° C using a J75EII type injection molding machine manufactured by Japan Steel Works. Injection molding was performed under the conditions of a temperature of 70 ° C. and a molding cycle of 40 seconds to obtain 10 plate-shaped molded bodies of polycarbonate resin having a thickness of 0.8 mm, a length of 100 mm, and a width of 100 mm.
The appearance of the 10 plate-shaped molded bodies was visually observed, and the number of plates in which one or more black foreign substances having a size of 30 μm or more were confirmed was examined as a black foreign substance generating plate.

(5) Relative permittivity (ε _r ) / dielectric loss tangent (tan δ)
The polycarbonate resin vacuum-dried at 80 ° C. for 5 hours was formed into a film by a hot press molding machine to prepare a film having a thickness of 80 to 120 μm. The molding conditions of the hot press molding machine were appropriately adjusted in the range of a temperature of 150 to 250 ° C. and a pressure of 10 to 15 MPa. A strip-shaped film with a length of 70 mm and a width of 2 mm was cut out from this film, and the humidity was adjusted for 48 hours under the conditions of room temperature of 23 ° C. and humidity of 50%. The relative permittivity (ε _r ) and the dielectric loss tangent (tan δ) were measured at a frequency of 10 GHz using an E8631A PNA series network analyzer manufactured by Keysight Technology.

[Raw material dihydroxy compound]
As the raw material dihydroxy compound, BPC: 2,2-bis (4-hydroxy-3-methylphenyl) propane (manufactured by Honshu Chemical Industry Co., Ltd.) containing monomethyl BPA as an impurity in the amounts shown in Table 1 below was used.

[Example 1]
6.6 kg of BPC-a and 5.8 kg of diphenyl carbonate (DPC) were added to a first reactor having a content of 40 L equipped with a stirrer, a heat medium jacket, a vacuum pump and a reflux condenser. Then, an aqueous solution of cesium carbonate was added so that the amount of cesium carbonate was 1.5 μmol per 1 mol of the dihydroxy compound (BPC-a) to prepare a mixture.

Next, the inside of the first reactor was depressurized to 1.33 kPa (10 Torr), and then the operation of repressurizing to atmospheric pressure with nitrogen was repeated 5 times to replace the inside of the first reactor with nitrogen. After the nitrogen substitution, the internal temperature of the first reactor was gradually raised by passing a heat medium having a temperature of 230 ° C. through a heat medium jacket to dissolve the mixture. Then, the stirrer was rotated at 330 rpm to control the temperature inside the heat medium jacket to keep the internal temperature of the first reactor at 220 ° C. Then, while distilling off the phenol by-produced by the oligomerization reaction of BPC-a and DPC performed inside the first reactor, the pressure inside the first reactor was increased to 101.3 kPa (absolute pressure) over 40 minutes. The pressure was reduced from 760 Torr) to 13.3 kPa (100 Torr).

Next, the transesterification reaction was carried out for 80 minutes while maintaining the pressure in the first reactor at 13.3 kPa and further distilling off phenol. After restoring the absolute pressure of the system to 101.3 kPa with nitrogen, the pressure is increased to 0.2 MPa with a gauge pressure, and the oligomer in the first reactor is passed through a transfer pipe that has been preheated to 200 ° C or higher. 2 Pumped into the reactor. The second reactor had an internal capacity of 30 L, was equipped with a stirrer, a heat medium jacket, a vacuum pump, and a reflux condenser, and controlled the internal pressure to atmospheric pressure and the internal temperature to 240 ° C.

Next, the oligomer pressure-fed into the second reactor was stirred at 33 rpm, the internal temperature was raised with a heat medium jacket, and the inside of the second reactor was passed through the second reactor at an absolute pressure of 101.3 kPa to 13.3 kPa over 40 minutes. The pressure was reduced to. Then, the temperature was continuously raised, and the internal pressure was reduced from 13.3 kPa to 399 Pa (3 Torr) in absolute pressure over another 40 minutes, and the distilled phenol was removed from the system. Further, the temperature was continuously raised, and after the absolute pressure in the second reactor reached 70 Pa (about 0.5 Torr), 70 Pa was maintained and the polycondensation reaction was carried out. When the stirrer of the second reactor reached a predetermined stirring power (corresponding to a viscosity average molecular weight of 23,000 to 25,000), the polycondensation reaction was terminated, and then pellets were obtained. The polymerization reaction time in the reactor was about 194 minutes. The maximum temperature of the second reactor was 286 ° C.
Each evaluation was carried out using the obtained polycarbonate resin according to the above procedure. The results are shown in Table 2.

[Example 2]
It was carried out in the same manner as in Example 1 except that BPC-b was used instead of BPC-a. The evaluation results are shown in Table 2.

[Example 3]
It was carried out in the same manner as in Example 1 except that BPC-c was used instead of BPC-a. The evaluation results are shown in Table 2.

[Example 4]
The same procedure as in Example 1 was carried out except that BPC-a 3.3 kg and BPC-d 3.3 kg were used instead of BPC-a 6.6 kg. The evaluation results are shown in Table 2.

[Comparative Example 1]
It was carried out in the same manner as in Example 1 except that BPC-d was used instead of BPC-a. The evaluation results are shown in Table 2.

[Comparative Example 2]
It was carried out in the same manner as in Example 1 except that BPC-e was used instead of BPC-a. The evaluation results are shown in Table 2.

[Comparative Example 3]
It was carried out in the same manner as in Example 1 except that 6.5 kg of BPC-a was used. The evaluation results are shown in Table 2.

[Comparative Example 4]
It was carried out in the same manner as in Example 1 except that 6.7 kg of BPC-a was used. The evaluation results are shown in Table 2.

[Comparative Example 5]
The same procedure as in Example 1 was carried out except that 6.7 kg of BPC-a was used and the reaction was stopped when the predetermined stirring power target in the stirrer of the second reactor reached the viscosity average molecular weight of 20,000. bottom. The evaluation results are shown in Table 2.

[Comparative Example 6]
The reaction was carried out in the same manner as in Example 1 except that the reaction was stopped when the predetermined stirring power target in the stirrer of the second reactor was equivalent to the viscosity average molecular weight of 26,000. The evaluation results are shown in Table 2.

[Comparative Example 7]
Examples except that 6.8 kg of BPC-e was used instead of BPC-a and the reaction was stopped when the predetermined stirring power target in the stirrer of the second reactor was equivalent to the viscosity average molecular weight of 26,500. It was carried out in the same manner as in 1. The evaluation results are shown in Table 2.

In Table 2 below, whether or not the polycarbonate resin produced in each example satisfies the requirements <1> to <3> (○) or not (×) is also described in the remarks column.

[Discussion]
From the above results, the following can be understood.
In Comparative Examples 1 to 4 that do not satisfy the requirements <1> or <2>, a low dielectric loss tangent cannot be achieved. Further, in Comparative Example 5 in which the molecular weight is small and the requirement <3> is not satisfied even if the requirements <1> and the requirement <2> are satisfied, the dielectric loss tangent is high, and conversely, the molecular weight is large and the requirement <3> is not satisfied. In Example 6, black foreign matter is generated in a relatively thin molded body of 0.8 mm. Comparative Example 7, which does not satisfy all of the requirements <1> to <3>, is significantly inferior in dielectric properties and appearance.
On the other hand, in Examples 1 to 4 satisfying the requirements <1> to <3>, the dielectric loss tangent is low, and even a thin plate with a thickness of 0.8 mm suppresses the generation of black foreign matter, resulting in an excellent appearance. Molded product can be obtained.

Claims (8)

A housing for a communication device having a built-in microwave and / or millimeter wave antenna obtained by using a polycarbonate resin composition.
The polycarbonate resin composition contains at least a polycarbonate resin having a structural unit represented by the following formula (1).
The alkaline hydrolyzate obtained by alkaline hydrolysis of the polycarbonate resin contains a compound represented by the following formula (2) and a compound represented by the following formula (3), and is contained in the alkaline hydrolyzate. The amount of the compound represented by the following formula (3) is 1500 mass ppm or more and 6000 mass ppm or less with respect to the amount of the compound represented by the following formula (2) in the alkaline hydrolyzate.
The amount of terminal hydroxyl groups of the polycarbonate resin is 200 mass ppm or more and 400 mass ppm or less.
A housing for communication equipment having a viscosity average molecular weight of 21,000 or more and 25,500 or less of the polycarbonate resin.

(In the formula (1), the formula (2) and the formula (3), R ¹ , R ² and R ³ are independently substituted or unsubstituted alkyl groups having 1 or more and 20 or less carbon atoms, or substituted or absent. Indicates a substituted aryl group, where X indicates a single bond, a carbonyl group, a substituted or unsubstituted alkylidene group, a substituted or unsubstituted sulfur atom, or an oxygen atom.) The housing for communication equipment according to claim 1, wherein the thickness is 1.5 mm or less. The structural unit represented by the formula (1) is a structural unit represented by the following formula (1-1), and the compound represented by the formula (2) is represented by the following formula (2-1). The housing for communication equipment according to claim 1 or 2, wherein the compound represented by the above formula (3) is a compound represented by the following formula (3-1).

The housing for a communication device according to any one of claims 1 to 3, wherein the antenna is used for a radio wave in a frequency band of 3.5 to 30 GHz. The housing for a communication device according to any one of claims 1 to 4, wherein the communication device is a notebook computer, a tablet terminal, a smartphone, or a router device. A communication device having a built-in microwave and / or millimeter wave antenna, which is obtained by using the communication device housing according to any one of claims 1 to 5. A polycarbonate resin composition containing at least a polycarbonate resin having a structural unit represented by the following formula (1).
The alkaline hydrolyzate obtained by alkaline hydrolysis of the polycarbonate resin contains a compound represented by the following formula (2) and a compound represented by the following formula (3).
The amount of the compound represented by the following formula (3) in the alkaline hydrolyzate is 1500 mass ppm or more and 6000 mass ppm or less with respect to the amount of the compound represented by the following formula (2) in the alkaline hydrolyzate. And
The amount of terminal hydroxyl groups of the polycarbonate resin is 200 mass ppm or more and 400 mass ppm or less.
A polycarbonate resin composition having a viscosity average molecular weight of 21,000 or more and 25,500 or less.

(In the formula (1), the formula (2) and the formula (3), R ¹ , R ² and R ³ are independently substituted or unsubstituted alkyl groups having 1 or more and 20 or less carbon atoms, or substituted or absent. A substituted aryl group is indicated, where X indicates a single bond, a carbonyl group, a substituted or unsubstituted alkylidene group, a substituted or unsubstituted sulfur atom, or an oxygen atom.) A molded product obtained by using the polycarbonate resin composition according to claim 7.