JP6213025B2 - Polycarbonate resin and polycarbonate resin composition - Google Patents

Description

  The present invention relates to a polycarbonate resin and a polycarbonate resin composition.

  Polycarbonate resins are excellent in mechanical strength, electrical characteristics, transparency and the like, and are widely used as engineering plastics in various fields such as electric / electronic equipment fields and automobile fields. In recent years, in these fields of application, molding products have become thinner, smaller, and lighter, and further improvements in the performance of molding materials are required. Among them, the development of polycarbonate resins that are thin but have high hardness is desired. Some proposals have been made.

  For example, Patent Document 1 or Patent Document 2 discloses polycarbonates and copolycarbonates having excellent surface hardness produced using bisphenols different from conventional bisphenol A as a raw material. Patent Document 3 discloses hardness and fluidity by blending a polycarbonate having a structural unit derived from 1,1-bis (4-hydroxy-3-methylphenyl) cyclohexane and a polycarbonate having a structural unit derived from bisphenol A. A polycarbonate resin composition having a good balance of properties is described.

JP-A-64-069625 Japanese Patent Laid-Open No. 08-183852 International Publication No. 2009/083933 Pamphlet

However, a conventionally known technique cannot obtain a polycarbonate resin or a polycarbonate resin composition having high surface hardness and excellent transparency.
An object of the present invention is to provide a polycarbonate resin or a polycarbonate resin composition having a high surface hardness, high flame retardancy, few foreign substances, and excellent transparency.

The present inventor has intensively studied to solve the above problems, and in a polycarbonate resin having a specific structural unit, the compound obtained by alkaline hydrolysis of the polycarbonate resin contains the specific compound, When the content of the compound is in a specific range, it has been found that a polycarbonate resin having high surface hardness, high flame retardancy, few foreign substances, and excellent transparency can be obtained, and the present invention has been completed. . That is, the gist of the present invention resides in a polycarbonate resin, a polycarbonate resin composition, and a molded product thereof according to the following [1] to [6].
[1]
A polycarbonate resin having at least a structural unit represented by the following formula (1), which is obtained by alkaline hydrolysis of the polycarbonate resin, includes a compound represented by the following formula (2) and the following formula (3) ), And the amount of the compound represented by the following formula (3) is 2000 ppm by weight or more and 10,000 ppm by weight or less based on the total amount of the compound obtained by alkaline hydrolysis of the polycarbonate resin. Polycarbonate resin.

(In Formula (1), Formula (2) or Formula (3), R ¹ , R ² and R ³ are each independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted group. A substituted aryl group, and X represents a single bond, a carbonyl group, a substituted or unsubstituted alkylidene group, a substituted or unsubstituted sulfur atom, or an oxygen atom.)
[2]
The compound obtained by alkaline hydrolysis of the polycarbonate resin contains a compound represented by the following formula (4), and the amount of the compound represented by the following formula (4) alkali-hydrolyzes the polycarbonate resin. The polycarbonate resin according to [1], which is in a range of 500 ppm to 7000 ppm by weight with respect to the total amount of the compound obtained.

(In formula (4), R ⁴ , R ⁵ and R ⁶ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group, Represents a single bond, a carbonyl group, a substituted or unsubstituted alkylidene group, a substituted or unsubstituted sulfur atom, or an oxygen atom.)
[3]
The polycarbonate resin according to [1] or [2], wherein the polycarbonate resin has a viscosity average molecular weight of 15000 or more and 35000 or less.
[4]
[1] A polycarbonate resin composition comprising the polycarbonate resin according to any one of [3] and a flame retardant.
[5]
The polycarbonate resin composition according to [4], wherein the content of the flame retardant is 0.1 part by weight or more and 30 parts by weight or less with respect to 100 parts by weight of the polycarbonate resin composition.
[6]
A molded product formed by molding the polycarbonate resin according to any one of [1] to [3] or the polycarbonate resin composition according to [4] or [5].

    According to the present invention, it is possible to obtain a polycarbonate resin and a polycarbonate resin composition having a good surface height and having greatly improved transparency.

  Hereinafter, embodiments of the present invention will be described in detail. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary.

<Polycarbonate resin>
The polycarbonate resin of this invention is a polycarbonate resin which has a structural unit represented by following formula (1), Comprising: The compound obtained by carrying out alkali hydrolysis of this polycarbonate resin is represented by following formula (2). A compound and a compound represented by the following formula (3) are contained.

(In Formula (1), Formula (2) or Formula (3), R ¹ , R ² and R ³ are each independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted group. A substituted aryl group, and X represents a single bond, a carbonyl group, a substituted or unsubstituted alkylidene group, a substituted or unsubstituted sulfur atom, or an oxygen atom.)
Examples of the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms of R ¹ , R ² and R ³ include, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and an 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. Examples of the substituted or unsubstituted aryl group include a phenyl group, a benzyl group, a tolyl group, a 4-methylphenyl group, and a naphthyl group.

Among these, a methyl group, an ethyl group, an n-propyl group, and a 4-methylphenyl group are preferable, and a methyl group is more preferable.
Here, the bonding position of R ¹ , R ² and R ^{3 to} the phenyl ring is an arbitrary position selected from the 2-position, 3-position, 5-position and 6-position with respect to X on each phenyl ring. Among these, the third and fifth positions with respect to X are preferred.

Of X, the substituted or unsubstituted sulfur atom, for example, -S -, - SO ₂ -, and the like.
A substituted or unsubstituted alkylene group and a substituted or unsubstituted alkylidene group are shown below.

Here, R ⁷ and R ⁸ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group, and Z is substituted or unsubstituted. Represents an alkylene group or a polymethylene group having 4 to 20 carbon atoms. n represents an integer of 1 to 10.
Examples of the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms of R ⁷ and R ⁸ include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec- Examples thereof include a butyl group, a tert-butyl group, an n-pentyl group, a sec-pentyl group, an n-hexyl group, an n-heptyl group, and an n-octyl group. Examples of the substituted or unsubstituted aryl group include a phenyl group, a benzyl group, a tolyl group, a 4-methylphenyl group, and a naphthyl group.

Among these, a methyl group, an ethyl group, an n-propyl group, or a 4-methylphenyl group is preferable, a methyl group is more preferable, in particular, both R ⁷ and R ⁸ are methyl groups, and n is 1, More preferably, X is an isopropylidene group.
Z is bonded to carbon bonded to two phenyl groups to form a substituted or unsubstituted divalent carbocycle. Examples of the divalent carbocycle include a cycloalkylidene group such as a cyclopentylidene group, a cyclohexylidene group, a cycloheptylidene group, a cyclododecylidene group, an adamantylidene group (preferably a carbon number of 5 8 or less). Examples of the substituted ones include those having these methyl substituents and ethyl substituents. Among these, a methyl-substituted product of a cyclohexylidene group, a cyclohexylidene group, or a cyclododecylidene group is preferable.

  The compound represented by the above formula (2) obtained by alkaline hydrolysis of the polycarbonate resin of the present invention is preferably a compound represented by the following formula (6).

In the formula (6), R ¹ and R ² are the same as R ¹ and R ^{2 in} the formula (2).
Among them, 2,2-bis (3-methyl-4-hydroxyphenyl) propane is preferable.
More preferred.
In the polycarbonate resin of the present invention, the amount of the compound represented by the formula (2) obtained by alkali hydrolysis of the polycarbonate resin is 50% by weight or more based on the total amount of the compound obtained by alkali hydrolysis. More preferably, it is 70 weight% or more, More preferably, it is 90 weight% or more. When the amount of the compound represented by the formula (2) is excessively small, surface hardness and fluidity tend to be inferior.

In the polycarbonate resin of the present invention, the amount of the compound represented by the formula (3) obtained by alkaline hydrolysis of the polycarbonate resin is based on the total amount of compounds obtained by alkaline hydrolysis of the polycarbonate resin. , 2000 ppm to 10,000 ppm by weight. The upper limit is preferably 7000 ppm by weight, and more preferably 5000 ppm by weight. The lower limit is preferably 2500 ppm by weight. If the amount of the compound represented by the formula (3) is too small, the transparency may be lowered. If the amount of the compound represented by the formula (3) is too large, the hardness / fluidity may be lowered.
The compound represented by the above formula (3) obtained by alkaline hydrolysis of the polycarbonate resin of the present invention is preferably a compound represented by the following formula (7).

In the formula (7), R ³ is the same as R ^{3 in the} formula (3).
Among them, 2,2-bis (3-methyl-4-hydroxyphenyl) propane (hereinafter sometimes referred to as “monomethyl BPA”) is more preferable.
In the polycarbonate resin of the present invention, the compound obtained by alkaline hydrolysis of the polycarbonate resin contains a compound represented by the following formula (4), and the amount of the compound represented by the following formula (4) is It is preferably 500 ppm to 7000 ppm by weight, and the upper limit is more preferably 5000 ppm by weight, and still more preferably 4500 ppm by weight, based on the total amount of compounds obtained by alkaline hydrolysis of the resin. The lower limit is more preferably 1000 ppm by weight, and even more preferably 2500 ppm by weight. If the amount of the compound represented by the following formula (4) is too small, flame retardancy may be reduced, and if it is too large, the amount of foreign matter may increase.

(In formula (4), R ⁴ , R ⁵ and R ⁶ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group, Represents a single bond, a carbonyl group, a substituted or unsubstituted alkylidene group, a substituted or unsubstituted sulfur atom, or an oxygen atom.)
Examples of the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms of R ⁴ , R ⁵ and R ⁶ include, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group,
Examples include isobutyl, sec-butyl, tert-butyl, n-pentyl, sec-pentyl, n-hexyl, n-heptyl, and n-octyl. Examples of the substituted or unsubstituted aryl group include a phenyl group, a benzyl group, a tolyl group, a 4-methylphenyl group, and a naphthyl group.

Among these, a methyl group, an ethyl group, an n-propyl group, and a 4-methylphenyl group are preferable, and a methyl group is more preferable.
Here, the bonding position of R ⁴ , R ⁵ and R ^{6 to} the phenyl ring is an arbitrary position selected from the 2-position, 3-position, 5-position and 6-position with respect to X on each phenyl ring. Among these, the third and fifth positions with respect to X are preferred.
Of X, the substituted or unsubstituted sulfur atom, for example, -S -, - SO ₂ -, and the like.
A substituted or unsubstituted alkylene group and a substituted or unsubstituted alkylidene group are shown below.

Here, R ⁹ and R ¹⁰ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group, and Z is substituted or unsubstituted. Represents an alkylene group or a polymethylene group having 4 to 20 carbon atoms. n represents an integer of 1 to 10.
Examples of the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms of R ⁹ and R ¹⁰ include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec- Examples thereof include a butyl group, a tert-butyl group, an n-pentyl group, a sec-pentyl group, an n-hexyl group, an n-heptyl group, and an n-octyl group. Examples of the substituted or unsubstituted aryl group include a phenyl group, a benzyl group, a tolyl group, a 4-methylphenyl group, and a naphthyl group.

Among these, a methyl group, an ethyl group, an n-propyl group, or a 4-methylphenyl group is preferable, a methyl group is more preferable, both R ⁹ and R ¹⁰ are methyl groups, n is 1, that is, X is More preferably, it is an isopropylidene group.
Z is bonded to carbon bonded to two phenyl groups to form a substituted or unsubstituted divalent carbocycle. Examples of the divalent carbocycle include a cycloalkylidene group such as a cyclopentylidene group, a cyclohexylidene group, a cycloheptylidene group, a cyclododecylidene group, an adamantylidene group (preferably a carbon number of 5 To 8). Examples of the substituted ones include those having these methyl substituents and ethyl substituents. Among these, a methyl-substituted product of a cyclohexylidene group, a cyclohexylidene group, or a cyclododecylidene group is preferable.
The compound represented by the above formula (4) obtained by alkaline hydrolysis of the polycarbonate resin of the present invention is preferably a compound represented by the following formula (9).

In the formula ^(9), R 4, ^{R 5} and ^{R 6} are the same as ^R 4, ^{R 5} and ^{R 6} in the formula (4).
In the polycarbonate resin of the present invention, the compound obtained by alkaline hydrolysis of the polycarbonate resin preferably contains a compound represented by the following formula (10), and the amount of the compound represented by the following formula (10) is The total amount of the compounds obtained by alkaline hydrolysis of the polycarbonate resin is preferably 20 ppm by weight or more and 2000 ppm by weight or less, and the upper limit is more preferably 1300 ppm by weight, and still more preferably 800 ppm by weight. The lower limit is more preferably 100 ppm by weight. If the amount of the compound represented by the following formula (10) is too small, flame retardancy may be reduced, and if it is too large, the amount of foreign matter may increase.

In said formula (10), R < ¹ >, R < ² > and X show the same group as R < ¹ >, R < ² > and X of said Formula (2), R < ¹¹ > is a hydrogen atom, a substituted or unsubstituted carbon number 1 It represents an alkyl group having 20 or less or a substituted or unsubstituted aryl group.
The compound represented by the formula (10) obtained by alkaline hydrolysis of the polycarbonate resin of the present invention is preferably a compound represented by the following formula (11).

  In the polycarbonate resin of the present invention, the compound obtained by alkali hydrolysis of the polycarbonate resin preferably contains a compound represented by the following formula (12), and the amount of the compound represented by the following formula (12) is The total amount of the compounds obtained by alkaline hydrolysis of the polycarbonate resin is preferably 100 ppm to 2000 ppm, and the upper limit is more preferably 10,000 ppm, and even more preferably 600 ppm. The lower limit is more preferably 200 ppm by weight and even more preferably 300 ppm by weight. If the amount of the compound represented by the following formula (12) is too small, flame retardancy may be reduced, and if it is too large, the amount of foreign matter may increase.

In the above formula (12), R ¹ and X, the equation (2) and R ¹ and X represent the same ^{group, R 12} is a hydrogen atom, a substituted or unsubstituted C 1 to 20 alkyl group carbon, Or a substituted or unsubstituted aryl group;
The compound represented by the formula (12) obtained by alkaline hydrolysis of the polycarbonate resin of the present invention is preferably a compound represented by the following formula (13).

<Quantitative method by alkali hydrolysis>
The method for alkali hydrolysis of the polycarbonate resin of the present invention and the quantitative determination of the alkali hydrolyzed compound can be carried out by the following method.
Dissolve 0.5 g of polycarbonate resin in 5 ml of methylene chloride to make a solution. Next, 45 ml of methanol and 5 ml of 25% by weight aqueous sodium hydroxide solution are added to the solution, and then the compound hydrolyzed from the solution obtained by stirring at 70 ° C. for 30 minutes is quantified by liquid chromatography.

Measurement conditions by liquid chromatography are as follows.
(Analysis conditions)
Liquid chromatography device: manufactured by Shimadzu Corporation
System controller: CBM-20A
Pump: LC-10AD
Column oven: CTO-10ASvp
Detector: SPD-M20A
Analytical column: YMC-Pack ODS-AM 75 mm × Φ4.6 mm
Oven temperature: 40 ° C
Detection wavelength: 280 nm
Eluent: A solution: 0.1% trifluoroacetic acid aqueous solution, B solution: acetonitrile
From A / B = 60/40 (vol%) to A / B = 95/5 (vol%)
Gradient in 50 minutes Flow rate: 1 mL / min
Sample injection volume: 20 μl
Identification of the alkali-hydrolyzed compound was carried out by fractionating the portion corresponding to the peak observed at the above retention time, and ¹ H NMR, ¹³ C NMR, mass spectrometry (MS), infrared absorption spectrum of the collected sample. (IR spectrum) or the like.

<Physical properties of polycarbonate resin>
The viscosity average molecular weight of the polycarbonate resin of the present invention is preferably 15000 or more and 350.
00 or less. The upper limit is more preferably 30000 or less, and still more preferably 28000 or less. The lower limit is more preferably 18000 or more and even more preferably 20000 or more. If the viscosity average molecular weight is too low, flame retardancy or mechanical properties may be reduced. On the other hand, if the viscosity average molecular weight is too high, the fluidity is lowered and the amount of foreign matter may be increased.

  In the polycarbonate resin of the present invention, the ratio (Mw / Mn) of polystyrene-equivalent weight average molecular weight Mw and number average molecular weight Mn measured by gel permeation chromatography (GPC) is 3.0 or more and 5.0 or less. A range is preferable. Furthermore, (Mw / Mn) is more preferably in the range of 3.0 or more and 4.0 or less. When (Mw / Mn) is too small, the fluidity in the molten state increases and the moldability tends to decrease. On the other hand, if (Mw / Mn) is excessively large, the melt viscosity tends to increase and molding tends to be difficult.

The polycarbonate resin of the present invention preferably has a pencil hardness according to JIS K5400 of HB or higher. Further, the pencil hardness of the polycarbonate resin is preferably F or more, more preferably H or more. However, it is usually 3H or less. A polycarbonate resin having a pencil hardness of less than HB may damage the surface.
The terminal hydroxyl group concentration of the polycarbonate resin of the present invention is not particularly limited, but when the transesterification method described later is adopted as the production method, the terminal hydroxyl group concentration of the polycarbonate resin is usually 100 ppm or more, preferably 200 ppm or more, more preferably. , 300 ppm or more. Moreover, it is 2000 ppm or less normally, Preferably it is 1800 ppm or less, More preferably, it is 1200 ppm or less. If the terminal hydroxyl group concentration of the polycarbonate resin is too small, the initial hue at the time of molding tends to deteriorate. When the terminal hydroxyl group concentration is excessively large, the residence heat stability tends to decrease.

<Production method of polycarbonate resin>
Next, the manufacturing method of the polycarbonate resin of this invention is demonstrated. There is no restriction | limiting in particular in the manufacturing method of the polycarbonate resin of this invention, It is a polycarbonate resin which has a structural unit represented by said Formula (1), Comprising: The compound obtained by carrying out alkali hydrolysis of this polycarbonate resin is the said formula. The compound represented by (2) and the compound represented by the formula (3) are contained, and the amount of the compound represented by the formula (3) is based on the total amount of compounds obtained by alkaline hydrolysis. As long as it can be manufactured so as to include a specific amount, it may be manufactured by any method. A polycarbonate resin is usually obtained by polymerizing a dihydroxy compound and a carbonate-forming compound. The production method is large. For example, carbonyl chloride (hereinafter sometimes referred to as “CDC” or “phosgene”) is used as a dihydroxy compound and a carbonate-forming compound at the interface between an organic phase and an aqueous phase that are not arbitrarily mixed. An interfacial polycondensation method for producing a polycarbonate resin by reaction (hereinafter sometimes referred to as “interface method”) and a dihydroxy compound and a carbonate-forming compound such as a carbonic acid diester are melted in the presence of a transesterification reaction catalyst. There is a melt polycondensation method (hereinafter sometimes referred to as “melting method”) in which a polycarbonate resin is produced by transesterification in a state.

  As the production method, the amount of the compound represented by the above formula (2) and the compound represented by the above formula (3) obtained by alkali hydrolysis of the produced polycarbonate resin is determined by a specific amount. It is preferable in that it can be easily controlled.

<Dihydroxy compound component>
The dihydroxy compound preferably contains a compound represented by the following formula (14) in both the melting method (transesterification method) and the interface method.

(In the formula ^(14), R 1, ^{R 2} and X are the same as ^R 1, ^{R 2} and X in the formula (2).)
Specific examples of the compound represented by the formula (14) include 2,2-bis (3-methyl-4-hydroxyphenyl) propane and 2,2-bis (3,5-dimethyl-4-hydroxy). Phenyl) propane, 1,1-bis (4-hydroxy-3-methylphenyl) cyclohexane, 1,1-bis (4-hydroxy-3-methylphenyl) -3,5,5-trimethylcyclohexane, 1,1- Bis (4-hydroxy-3-methylphenyl) adamantane, 1,4-bis (4-hydroxy-3-methylphenyl) adamantane, 2,2-bis (4-hydroxy-3-ethylphenyl) propane, 2,2 -Bis (4-hydroxy-3-tert-butylphenyl) propane, 2,2-bis (4-hydroxy-3-cyclohexylphenyl) propane, 2 2-bis (4-hydroxy-3-phenylphenyl) propane, 5,5-bis (4-hydroxy-3-methylphenyl) hexahydro-4,7-methanoindane, 2,2-bis (4-hydroxy-3- Methylphenyl) sulfone, 2,2-bis (4-hydroxy-3-methylphenyl) sulfide, 3,3′-dimethylbiphenol, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 1 , 1-bis (4-hydroxy-3,5-dimethylphenyl) cyclohexane, 1,1-bis (4-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylcyclohexane, 1,1-bis (4-hydroxy-3,5-dimethylphenyl) adamantane, 1,4-bis (4-hydroxy-3,5-dimethylphenyl) adama Tan, 2,2-bis (3-ethyl-4-hydroxy-5-methylphenyl) propane, 2,2-bis (3-tert-butyl-4-hydroxy-5-methylphenyl) propane, 2,2- Bis (3-cyclohexyl-4-hydroxy-5-methylphenyl) propane, 2,2-bis (4-hydroxy-3-methyl-5-phenylphenyl) propane, 2,2-bis (3,5-diethyl- 4-hydroxyphenyl) propane, 2,2-bis (3,5-di-tert-butyl-4-hydroxyphenyl) propane, 2,2-bis (3,5-dicyclohexyl-4-hydroxyphenyl) propane 2,2-bis (4-hydroxy-3,5-diphenylphenyl) propane, 5,5-bis (4-hydroxy-3,5-dimethylphenyl) hexa Dro-4,7-methanoindane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) sulfone, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) sulfide, 3,3 ′ , 5,5'-tetramethylbiphenol, 2,2-bis (4-hydroxy-3-methylphenyl) cyclododecane, and the like.

  Among these, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 1,1-bis (4-hydroxy-3-methylphenyl) cyclohexane, 1,1-bis (4-hydroxy-3-) Methylphenyl) -3,5,5-trimethylcyclohexane, 5,5-bis (4-hydroxy-3-methylphenyl) hexahydro-4,7-methanoindane, 3,3′-dimethylbiphenol, 2,2-bis ( 4-hydroxy-3,5-dimethylphenyl) propane, 1,1-bis (4-hydroxy-3,5-dimethylphenyl) cyclohexane, 1,1-bis (4-hydroxy-3,5-dimethylphenyl)- 3,5,5-trimethylcyclohexane, 5,5-bis (4-hydroxy-3,5-dimethylphenyl) hexahydro-4,7-me Noindan, 3,3 ', 5,5'-tetramethyl-biphenol, 2,2-bis (4-hydroxy-3-methylphenyl) cyclododecane, and the like.

  Further, among these, 2,2-bis (3-methyl-4-hydroxyphenyl) propane (hereinafter sometimes referred to as BPC), 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) Propane, 1,1-bis (4-hydroxy-3-methylphenyl) cyclohexane, 1,1-bis (4-hydroxy-3-methylphenyl) -3,5,5-trimethylcyclohexane are preferred, and 2,2 -Bis (3-methyl-4-hydroxyphenyl) propane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, 1,1-bis (4-hydroxy-3-methylphenyl) cyclohexane, 2,2-bis (4-hydroxy-3-methylphenyl) cyclododecane is preferred.

The compounds represented by the formula (14) can be used alone or in combination of two or more.
Furthermore, the dihydroxy compound preferably contains a compound represented by the following formula (15). Among them, 2,2-bis (3-methyl-4-hydroxyphenyl) propane (hereinafter sometimes referred to as “monomethyl BPA”) is more preferable. In the dihydroxy compound, the content of the following formula (15) is preferably 15000 ppm by weight or less and 2000 ppm by weight or more, and the upper limit is more preferably 11000 ppm by weight, and still more preferably 8000 ppm by weight or less. . The lower limit is preferably 2700 ppm by weight, more preferably 3400 ppm by weight. When there is too little content of the compound represented by following formula (15), the transparency of the manufactured polycarbonate resin may become low. If the amount of the compound represented by the following formula (15) is too large, the hardness / fluidity of the produced polycarbonate resin may be lowered.

(In formula (15), R ³ is the same as R ^{3 in} formula (3).)
As the dihydroxy compound other than the compound represented by the formula (14) and the compound represented by the formula (15), 2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as “bisphenol A”) Aromatic dihydroxy compounds such as), alicyclic dihydroxy compounds such as anhydrous sugar alcohol, and dihydroxy compounds having a cyclic ether group such as spiroglycol.

(Melting method: transesterification method)
In the melting method, a dihydroxy compound containing a compound represented by the formula (14) and a compound represented by the formula (15) as raw materials, and a carbonic acid diester as a carbonate-forming compound are used, and preferably a transesterification catalyst. A polycarbonate resin is produced by a melt polycondensation reaction carried out continuously in the presence.

(Carbonated diester)
Examples of the carbonic acid diester used in the present invention include a carbonic acid diester compound represented by the following formula (16).

  Here, in the above formula (16), A ′ is a linear, branched or cyclic monovalent hydrocarbon group having 1 to 10 carbon atoms which may have a substituent. Two A's may be the same or different from each other. Examples of the substituent on A ′ include a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a phenyl group, a phenoxy group, a vinyl group, a cyano group, an ester group, and an amide. Examples thereof include a group and a nitro group.

Specific examples of the carbonic acid diester compound include substituted diphenyl carbonates such as diphenyl carbonate and ditolyl carbonate, and dialkyl carbonates such as dimethyl carbonate, diethyl carbonate, and di-t-butyl carbonate.
Among these, diphenyl carbonate (hereinafter sometimes abbreviated as DPC) and substituted diphenyl carbonate are preferable. These carbonic acid diesters can be used alone or in admixture of two or more.

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

In the melting method, these carbonic acid diester compounds (including the above-mentioned substituted dicarboxylic acid or dicarboxylic acid ester; the same applies hereinafter) are used in excess relative to the dihydroxy compound.
That is, the carbonic acid diester compound is usually used in the range of 1.01 mol to 1.30 mol, preferably 1.02 mol to 1.20 mol, relative to 1 mol of the dihydroxy compound. When the usage-amount of the said carbonic acid diester compound is too small, the terminal hydroxyl group density | concentration of the obtained polycarbonate resin will become high, and it will become the tendency for thermal stability to deteriorate. In addition, if the amount of carbonic acid diester compound used is excessively large, the transesterification reaction rate decreases, and it becomes difficult to produce a polycarbonate resin having a desired molecular weight, and the carbonic acid diester compound remains in the resin. The amount is increased, which may cause odors during molding or molding.

(Transesterification catalyst)
In the melting method, it is preferable to polymerize the polycarbonate resin in the presence of a transesterification catalyst. Examples of the transesterification catalyst include, but are not particularly limited to, catalysts used when producing a polycarbonate resin by a transesterification method. In general, for example, a compound of a long-period periodic table group 1 element (excluding hydrogen) (hereinafter sometimes referred to as “Group 1 element (excluding hydrogen)”), a long-period periodic table At least one selected from the group consisting of compounds of Group 2 elements (hereinafter sometimes referred to as “Group 2 elements”), basic boron compounds, basic phosphorus compounds, basic ammonium compounds, and amine compounds. Compounds. Among these transesterification catalysts, practically, at least one compound selected from the group consisting of compounds of group 1 elements (excluding hydrogen) and compounds of group 2 elements is preferable. These transesterification catalysts may be used alone or in combination of two or more.

The amount of the transesterification catalyst used is usually in the range of 1 × 10 ⁻⁹ to 1 × 10 ⁻¹ mol with respect to 1 mol of all dihydroxy compounds, in order to obtain a polycarbonate resin excellent in molding characteristics and transparency. In the case of using at least one compound selected from the group consisting of compounds of Group 1 elements (excluding hydrogen) and Group 2 elements, the amount of the transesterification catalyst is 1 mol of all dihydroxy compounds. On the other hand, it is preferably in the range of 1.0 × 10 ^{−7 to} 5 × 10 ⁻⁶ mol, more preferably in the range of 0.5 × 10 ⁻⁶ to 4 × 10 ⁻⁶ mol, and still more preferably 1 Within the range of 0.0 × 10 ^{−6 to} 3 × 10 ⁻⁶ mol. If it is less than the lower limit, the viscosity average molecular weight of the produced polycarbonate resin may be lowered. Further, the amount of the compound represented by the above formula (4), the amount of the compound represented by the above formula (10), and the compound represented by the above formula (12) obtained by alkaline hydrolysis of the produced polycarbonate resin. The amount may decrease and flame retardancy may deteriorate. When the amount is larger than the above upper limit, the amount of the compound represented by the formula (4) obtained by alkaline hydrolysis of the produced polycarbonate resin, the amount of the compound represented by the formula (10), and the formula There is a possibility that the amount of the compound represented by (12) becomes excessively large, and a gel-like substance or a foreign substance insoluble in the solvent is generated, resulting in poor appearance and transparency of the polycarbonate resin.

  Group 1 elements (excluding hydrogen) include inorganic metal compounds such as metal hydroxides, carbonates, hydrogen carbonate compounds; salts of the metals with alcohols, phenols, organic carboxylic acids, etc. And organometallic compounds. Here, as a group 1 element (except hydrogen), lithium, sodium, potassium, rubidium, cesium etc. are mentioned, for example. Among these metal compounds, cesium compounds are preferable, and cesium carbonate, cesium hydrogen carbonate, and cesium hydroxide are particularly preferable.

Examples of Group 2 element compounds include inorganic metal compounds such as metal hydroxides and carbonates; salts of the metals with alcohols, phenols, and organic carboxylic acids. Here, examples of the Group 2 element include calcium, strontium, barium and the like.
Examples of the beryllium compound and magnesium compound include inorganic metal compounds such as metal hydroxides and carbonates; salts of the metals with alcohols, phenols, and organic carboxylic acids.

  Examples of basic boron compounds include sodium salts, potassium salts, lithium salts, calcium salts, magnesium salts, barium salts, strontium salts, and the like of boron compounds. Here, as the boron compound, for example, tetramethylboron, tetraethylboron, tetrapropylboron, tetrabutylboron, trimethylethylboron, trimethylbenzylboron, trimethylphenylboron, triethylmethylboron, triethylbenzylboron, triethylphenylboron, tributyl Examples include benzylboron, tributylphenylboron, tetraphenylboron, benzyltriphenylboron, methyltriphenylboron, and butyltriphenylboron.

Examples of the basic phosphorus compound include trivalent phosphine compounds such as triethylphosphine, tri-n-propylphosphine, triisopropylphosphine, tri-n-butylphosphine, triphenylphosphine, and tributylphosphine, or derivatives thereof. And quaternary phosphonium salts.
Examples of the basic ammonium compound include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylethylammonium hydroxide, trimethylbenzylammonium hydroxide, trimethylphenylammonium hydroxide, Triethylmethylammonium hydroxide, triethylbenzylammonium hydroxide, triethylphenylammonium hydroxide, tributylbenzylammonium hydroxide, tributylphenylammonium hydroxide, tetraphenylammonium hydroxide, benzyltriphenylammonium hydroxide, methyltriphenylammonium hydroxide Sid, butyl triphenyl ammonium hydroxide, and the like.

  Examples of the amine compound include 4-aminopyridine, 2-aminopyridine, N, N-dimethyl-4-aminopyridine, 4-diethylaminopyridine, 2-hydroxypyridine, 2-methoxypyridine, 4-methoxypyridine, 2 -Dimethylaminoimidazole, 2-methoxyimidazole, imidazole, 2-mercaptoimidazole, 2-methylimidazole, aminoquinoline and the like.

(Catalyst deactivator)
After completion of the transesterification reaction, a catalyst deactivator for neutralizing and deactivating the transesterification catalyst may be added. The heat resistance and hydrolysis resistance of the polycarbonate resin obtained by such treatment are improved.
As such a catalyst deactivator, an acidic compound having a pKa of 3 or less, such as sulfonic acid and sulfonic acid ester, is preferable. Specifically, benzenesulfonic acid, p-toluenesulfonic acid, methyl benzenesulfonate, benzenesulfone Examples include ethyl acetate, propyl benzenesulfonate, butyl benzenesulfonate, methyl p-toluenesulfonate, ethyl p-toluenesulfonate, propyl p-toluenesulfonate, and butyl p-toluenesulfonate.

Among these, p-toluenesulfonic acid or butyl p-toluenesulfonate is preferably used.
The production of polycarbonate resin by a melting method is to prepare a raw material mixed melt of a raw material dihydroxy compound and a carbonic acid diester (original preparation process), and the raw material mixed melt is melted in the presence of a transesterification reaction catalyst. It is carried out by performing a polycondensation reaction in multiple stages using a plurality of reaction vessels (polycondensation step). The reaction system may be any of a batch system, a continuous system, or a combination of a batch system and a continuous system. As the reaction tank, a plurality of vertical stirring reaction tanks and, if necessary, at least one horizontal stirring reaction tank subsequent thereto are used. Usually, these reaction tanks are installed in series and processed continuously.

After the polycondensation process, the reaction is stopped, the unreacted raw materials and reaction byproducts in the polycondensation reaction liquid are devolatilized and removed, the process of adding a thermal stabilizer, mold release agent, colorant, etc., polycarbonate resin You may add suitably the process etc. which form in a predetermined particle size.
Next, each process of the manufacturing method will be described.

(Primary process)
The dihydroxy compound and the carbonic acid diester compound used as the raw material of the polycarbonate resin are usually raw materials using a batch type, semi-batch type or continuous type stirring tank type apparatus in an atmosphere of an inert gas such as nitrogen or argon. Prepared as a mixed melt. For example, when BPC is mainly used as the dihydroxy compound and diphenyl carbonate is used as the carbonic acid diester compound, the melt mixing temperature is usually selected from the range of 120 ° C. to 180 ° C., preferably 125 ° C. to 160 ° C.

Hereinafter, the case where BPC is mainly used as a dihydroxy compound and diphenyl carbonate is used as a raw material as a carbonic acid diester compound will be described as an example.
At this time, the ratio of the dihydroxy compound and the carbonic acid diester compound is adjusted so that the carbonic acid diester compound becomes excessive. The carbonic acid diester compound is usually 1.01 mol to 1.30 mol with respect to 1 mol of the dihydroxy compound. Preferably, it is adjusted to a ratio of 1.02 mol to 1.20 mol.

(Polycondensation process)
The polycondensation by the transesterification reaction between the dihydroxy compound and the carbonic acid diester compound is usually carried out continuously in a multistage system of two or more stages, preferably 3 to 7 stages. Specific reaction conditions for each stage include temperature: 150 ° C. to 330 ° C., pressure: normal pressure to 0.01 Torr (1.3 Pa), and average residence time: 5 minutes to 150 minutes.

In each multi-stage reactor, in order to more effectively remove monohydroxy compounds such as phenol as a by-product from the system as the transesterification progresses, the reaction temperature is increased stepwise in the above reaction conditions. Set to high vacuum.
In particular, the maximum temperature of the final polymerization tank is usually 250 ° C to 330 ° C, preferably 270 ° C to 320 ° C, more preferably 280 ° C to 300 ° C. If the maximum temperature of the final polymerization tank is too low, the viscosity average molecular weight of the produced polycarbonate resin may be lowered. Further, the amount of the compound represented by the above formula (4), the amount of the compound represented by the above formula (10), and the compound represented by the above formula (12) obtained by alkaline hydrolysis of the produced polycarbonate resin. The amount may be reduced. On the other hand, if the maximum temperature of the final polymerization tank is too high, the hue of the polycarbonate resin deteriorates, and the amount of the compound represented by the formula (4) obtained by alkaline hydrolysis of the produced polycarbonate resin, The amount of the compound represented by the formula (10) and the amount of the compound represented by the formula (12) are excessively increased, resulting in the formation of a gel-like substance or foreign matter insoluble in the solvent, resulting in poor appearance and mechanical properties of the polycarbonate resin. May be reduced.

  The average residence time in the final polymerization tank is usually 5 minutes to 150 minutes, preferably 30 minutes to 120 minutes, and more preferably 60 minutes to 90 minutes. When the average residence time in the final polymerization tank is too short, the amount of the compound represented by the formula (3) obtained by alkaline hydrolysis of the produced polycarbonate resin is decreased, and the transparency may be decreased. In some cases, the polymerization reaction does not proceed sufficiently, and only a polycarbonate having a low viscosity average molecular weight can be obtained. On the other hand, if the average residence time in the final polymerization tank is too long, the amount of the compound represented by the formula (4) obtained by alkaline hydrolysis of the produced polycarbonate resin becomes excessively large and insoluble in the solvent. There is a possibility that a gel-like material or a foreign substance is generated, resulting in poor appearance and mechanical properties of the polycarbonate resin.

When the polycondensation step is performed in a multistage manner, usually, a plurality of reaction vessels including a vertical stirring reaction vessel are provided to increase the viscosity average molecular weight of the polycarbonate resin. The reaction tank is usually installed in 2 to 6 groups, preferably 4 to 5 groups.
Here, as a reaction tank, for example, a stirring tank type reaction tank, a thin film reaction tank, a centrifugal thin film evaporation reaction tank, a surface renewal type biaxial kneading reaction tank, a biaxial horizontal type stirring reaction tank, a wet wall reaction tank, a free tank A perforated plate type reaction vessel that polycondenses while dropping, a perforated plate type reaction vessel with wire that polycondenses while dropping along a wire, and the like are used.

The types of stirring blades in the vertical stirring reaction tank include, for example, turbine blades, paddle blades, fiddler blades, anchor blades, full zone blades (manufactured by Shinko Environmental Solution Co., Ltd.), Sun Meller blades (manufactured by Mitsubishi Heavy Industries, Ltd.), Max blend blades (manufactured by Sumitomo Heavy Industries, Ltd.), helical ribbon blades, twisted lattice blades (manufactured by Hitachi Plant Technology Co., Ltd.), and the like.
Moreover, a horizontal stirring reaction tank means that the rotating shaft of a stirring blade is a horizontal type (horizontal direction). As a stirring blade of a horizontal stirring reaction tank, for example, a uniaxial stirring blade such as a disk type or a paddle type, HVR, SCR, N-SCR (manufactured by Mitsubishi Heavy Industries, Ltd.), Vivolak (Sumitomo Heavy Industries, Ltd.) )), Or biaxial stirring blades such as spectacle blades and lattice blades (manufactured by Hitachi Plant Technology Co., Ltd.).

In addition, the transesterification catalyst used for the polycondensation of a dihydroxy compound and a carbonic acid diester compound may usually be prepared as a solution in advance. The concentration of the catalyst solution is not particularly limited, and is adjusted to an arbitrary concentration according to the solubility of the catalyst in the solvent. As the solvent, acetone, alcohol, toluene, phenol, water and the like can be appropriately selected.
When water is selected as the solvent for the catalyst, the nature of the water is not particularly limited as long as the type and concentration of impurities contained are constant, but usually distilled water or deionized water is preferably used.

(Interface method)
The polycarbonate resin production method by the interfacial method usually involves preparing an aqueous solution of a group 1 element (excluding hydrogen) and / or a group 2 element salt of a dihydroxy compound in the presence of an amine compound used as a polymerization catalyst. Then, an interfacial polycondensation reaction between a dihydroxy compound and a carbonyl chloride (hereinafter sometimes referred to as CDC) which is a carbonate-forming compound is performed, and then a polycarbonate resin is obtained through neutralization, water washing and drying steps.

  CDC is usually used in liquid or gaseous form. The preferred amount of CDC used is appropriately selected depending on the reaction conditions, particularly the reaction temperature and the concentration of the metal salt of the dihydroxy compound in the aqueous phase, and is not particularly limited. Usually, the amount of CDC is 1 mol to 2 mol, preferably 1.05 mol to 1.5 mol, per 1 mol of the dihydroxy compound. When the amount of CDC used is excessively large, unreacted CDC increases and the basic unit tends to be extremely deteriorated. On the other hand, if the amount of CDC used is excessively small, the amount of chloroformate group is insufficient and proper molecular weight elongation tends not to be performed.

In the interface method, an organic solvent is usually used. Examples of the organic solvent include inert organic solvents that dissolve reaction products such as carbonyl chloride, carbonate oligomer, and polycarbonate resin and are incompatible with water (or do not form a solution with water).
Examples of such inert organic solvents include aliphatic hydrocarbons such as hexane and n-heptane; chlorinations such as dichloromethane, chloroform, carbon tetrachloride, dichloroethane, trichloroethane, tetrachloroethane, dichloropropane, and 1,2-dichloroethylene. Aliphatic hydrocarbons; aromatic hydrocarbons such as benzene, toluene and xylene; chlorinated aromatic hydrocarbons such as chlorobenzene, o-dichlorobenzene and chlorotoluene; and other substituted aromatic hydrocarbons such as nitrobenzene and acetophenone It is done.

Among these, for example, chlorinated hydrocarbons such as dichloromethane or chlorobenzene are preferably used. These inert organic solvents can be used alone or as a mixture with other solvents.
The condensation catalyst can be arbitrarily selected from many condensation catalysts used in the two-phase interfacial condensation method. For example, trialkylamine, N-ethylpyrrolidone, N-ethylpiperidine, N-ethylmorpholine, N-isopropylpiperidine, N-isopropylmorpholine and the like can be mentioned. Of these, triethylamine and N-ethylpiperidine are preferable.

  Monophenol is used as the chain terminator. Examples of the monophenol include phenols; alkylphenols having 1 to 20 carbon atoms such as pt-butylphenol and p-cresol; halogenated phenols such as p-chlorophenol and 2,4,6-tribromophenol. It is done. The usage-amount of monophenol is suitably selected according to the molecular weight of the carbonate oligomer obtained, and is 0.5 mol%-10 mol% normally with respect to a dihydroxy compound.

In the interface method, the molecular weight of the polycarbonate resin is determined by the addition amount of a chain terminator such as monophenol. For this reason, from the viewpoint of controlling the molecular weight of the polycarbonate resin, the chain stopper is preferably added immediately after the consumption of the carbonate-forming compound is completed and before the molecular weight elongation starts.
When monophenol is added in the presence of a carbonate-forming compound, a large amount of condensates (diphenyl carbonates) of monophenols are produced, and it is difficult to obtain a polycarbonate resin having a target molecular weight. If the addition time of monophenol is extremely delayed, it becomes difficult to control the molecular weight, and furthermore, the resin has a specific shoulder on the low molecular weight side of the molecular weight distribution, and there is a tendency that problems such as dripping occur during molding.

  In the interface method, any branching agent can be used. Examples of such a branching agent include 2,4-bis (4-hydroxyphenylisopropyl) phenol, 2,6-bis (2-hydroxy-5-methylbenzyl) -4-methylphenol, 2- (4- Hydroxyphenyl) -2- (2,4-dihydroxyphenyl) propane, 1,4-bis (4,4′-dihydroxytriphenylmethyl) benzene and the like. In addition, 2,4-dihydroxybenzoic acid, trimesic acid, cyanuric chloride and the like can also be used. Among these, a branching agent having at least three phenolic hydroxyl groups is preferable. The amount of branching agent used is appropriately selected according to the degree of branching of the carbonate oligomer obtained, and is usually 0.05 mol% to 2 mol% with respect to the dihydroxy compound.

(Manufacture of polycarbonate resin by interface method)
The production of polycarbonate resin by the interfacial method usually involves preparing an aqueous solution of a group 1 element (excluding hydrogen) of a dihydroxy compound and, as a condensation catalyst, for example, interfacial polycondensation of the dihydroxy compound and phosgene in the presence of an amine compound. Reaction is performed, and then a polycarbonate resin is obtained through neutralization, washing with water, and drying. Specifically, the polycarbonate resin production process by the interfacial method includes a raw material process for preparing raw materials such as monomer components, an oligomerization process in which an oligomerization reaction is performed, a polycondensation process in which a polycondensation reaction using an oligomer is performed, A washing step for washing the reaction solution after the polycondensation reaction by alkali washing, acid washing and water washing, a polycarbonate resin isolation step for pre-concentrating the washed reaction solution and isolating the polycarbonate resin after granulation, It has at least a drying step for drying the polycarbonate resin particles. Hereinafter, each step will be described.

(Primary process)
In the primary control process, an aqueous solution of a dihydroxy compound and a compound of a Group 1 element (except hydrogen) such as sodium hydroxide (NaOH) or an aqueous solution of a Group 2 element such as magnesium hydroxide is added to the primary tank. An aqueous solution of a salt of a Group 1 element (excluding hydrogen) and / or a Group 2 element of a dihydroxy compound containing demineralized water (DMW) and a reducing agent such as hydrosulfite (HS) as necessary. Raw materials are prepared.

(Group 1 elements (excluding hydrogen) and / or Group 2 elements)
As the compound of Group 1 element (excluding hydrogen) and / or the compound of Group 2 element, a hydroxide is usually preferable. For example, sodium hydroxide, lithium hydroxide, potassium hydroxide, magnesium hydroxide, water Examples include calcium oxide. Among these, sodium hydroxide is preferable.

The ratio of the total amount of the compound of Group 1 element (excluding hydrogen) and / or the compound of Group 2 element to the amount of dihydroxy compound is usually 1.0 to 1.5 (equivalent ratio), preferably 1 0.02 to 1.04 (equivalent ratio). When the ratio of the total amount of the compound of the Group 1 element (excluding hydrogen) and / or the compound of the Group 2 element is excessively large or excessively small, the terminal group of the carbonate oligomer obtained in the oligomerization step described later is used. Affecting the polycondensation reaction as a result.

(Oligomerization process)
Next, in the oligomerization step, an aqueous solution of a group 1 element (excluding hydrogen) and / or a group 2 element salt of the dihydroxy compound prepared in the original preparation step and CDC in a predetermined reactor.
And a phosgenation reaction of a dihydroxy compound in the presence of an organic solvent such as methylene chloride (CH ₂ Cl ₂ ).

Subsequently, a condensation catalyst such as triethylamine (TEA) and a chain terminator such as pt-butylphenol (pTBP) are added to the mixed solution in which the phosgenation reaction of the dihydroxy compound is performed, and the oligomerization reaction of the dihydroxy compound Is done.
Next, the oligomerization reaction liquid of the dihydroxy compound was introduced into a predetermined stationary separation tank after further oligomerization reaction, and the organic phase containing the carbonate oligomer and the aqueous phase were separated and separated. The organic phase is fed to the polycondensation process.
Here, from the time when the aqueous solution of the group 1 element (excluding hydrogen) and / or the group 2 element salt of the dihydroxy compound is supplied to the reactor in which the phosgenation reaction of the dihydroxy compound is performed, it enters the stationary separation tank The residence time in the oligomerization step is usually 120 minutes or less, preferably 30 to 60 minutes.

(CDC)
The CDC used in the oligomerization step is usually used in liquid or gaseous form. The preferred amount of CDC used in the oligomerization step is appropriately selected depending on the reaction conditions, particularly the reaction temperature and the concentration of the dihydroxy compound in the aqueous phase, and is not particularly limited. Usually, the amount of CDC is 1 mol to 2 mol, preferably 1.05 mol to 1.5 mol, per 1 mol of the dihydroxy compound. When the amount of CDC used is excessively large, unreacted CDC increases and the basic unit tends to be extremely deteriorated. On the other hand, if the amount of CDC used is excessively small, the amount of chloroformate group is insufficient and proper molecular weight elongation tends not to be performed.

(Organic solvent)
In the oligomerization step, an organic solvent is usually used. As the organic solvent, any reaction product that dissolves reaction products such as CDC, carbonate oligomer, and polycarbonate resin at the reaction temperature and reaction pressure in the oligomerization step and is incompatible with water (or does not form a solution with water). An active organic solvent is mentioned.

Examples of such inert organic solvents include aliphatic hydrocarbons such as hexane and n-heptane; chlorinations such as dichloromethane, chloroform, carbon tetrachloride, dichloroethane, trichloroethane, tetrachloroethane, dichloropropane, and 1,2-dichloroethylene. Aliphatic hydrocarbons; aromatic hydrocarbons such as benzene, toluene and xylene; chlorinated aromatic hydrocarbons such as chlorobenzene, o-dichlorobenzene and chlorotoluene; and other substituted aromatic hydrocarbons such as nitrobenzene and acetophenone It is done.
Among these, chlorinated hydrocarbons such as dichloromethane or chlorobenzene are preferably used. These inert organic solvents can be used alone or as a mixture with other solvents.

(Condensation catalyst)
The oligomerization reaction can be performed in the presence of a condensation catalyst. The addition timing of the condensation catalyst is preferably after CDC is consumed. The condensation catalyst can be arbitrarily selected from many condensation catalysts used in the two-phase interfacial condensation method. For example, trialkylamine, N-ethylpyrrolidone, N-ethylpiperidine, N-ethylmorpholine, N-isopropylpiperidine, N-isopropylmorpholine and the like can be mentioned. Of these, triethylamine and N-ethylpiperidine are preferable.

(Chain terminator)
In the present embodiment, monophenol is usually used as a chain terminator in the oligomerization step. Examples of the monophenol include phenols; alkylphenols having 1 to 20 carbon atoms such as pt-butylphenol and p-cresol; halogenated phenols such as p-chlorophenol and 2,4,6-tribromophenol. It is done. The usage-amount of monophenol is suitably selected according to the molecular weight of the carbonate oligomer obtained, and is 0.5 mol%-10 mol% normally with respect to a dihydroxy compound.

In the interface method, the molecular weight of the polycarbonate resin is determined by the addition amount of a chain terminator such as monophenol. For this reason, from the viewpoint of controlling the molecular weight of the polycarbonate resin, the chain stopper is preferably added immediately after the consumption of the carbonate-forming compound is completed and before the molecular weight elongation starts.
When monophenol is added in the presence of a carbonate-forming compound, a large amount of condensates (diphenyl carbonates) of monophenols are produced, and it is difficult to obtain a polycarbonate resin having a target molecular weight. When the addition time of monophenol is extremely delayed, it becomes difficult to control the molecular weight, and furthermore, the resin has a specific shoulder on the low molecular weight side of the molecular weight distribution, and there is a tendency that problems such as dripping occur during molding.

(Branching agent)
In the oligomerization step, any branching agent can be used. Examples of such a branching agent include 2,4-bis (4-hydroxyphenylisopropyl) phenol, 2,6-bis (2-hydroxy-5-methylbenzyl) -4-methylphenol, 2- (4- Hydroxyphenyl) -2- (2,4-dihydroxyphenyl) propane, 1,4-bis (4,4′-dihydroxytriphenylmethyl) benzene and the like. In addition, 2,4-dihydroxybenzoic acid, trimesic acid, cyanuric chloride and the like can also be used. Among these, a branching agent having at least three phenolic hydroxyl groups is preferable. The amount of branching agent used is appropriately selected according to the degree of branching of the carbonate oligomer obtained, and is usually 0.05 mol% to 2 mol% with respect to the dihydroxy compound.

In the oligomerization step, when the two-phase interfacial condensation method is employed, prior to contacting the phosgene with the Group 1 element (excluding hydrogen) compound aqueous solution and / or the Group 2 element compound aqueous solution of the dihydroxy compound, It is particularly preferable to form an emulsion by bringing an organic phase containing an aqueous solution containing a Group 1 element (excluding hydrogen) compound aqueous solution or an aqueous Group 2 element compound solution into contact with an organic phase that is not arbitrarily mixed with water. preferable.

Examples of means for forming such an emulsion include a stirrer having a predetermined stirring blade, a homogenizer, a homomixer, a colloid mill, a flow jet mixer, a dynamic mixer such as an ultrasonic emulsifier, a static mixer, and the like. It is preferable to use a mixer. The emulsion usually has a droplet diameter of 0.01 μm to 10 μm and has emulsion stability.
The emulsion state of the emulsion is usually represented by the Weber number or P / q (load power value per unit volume). The Weber number is preferably 10,000 or more, more preferably 20,000 or more, and most preferably 35,000 or more. Also, the upper limit is about 1,000,000 or less. P / q is preferably 200 kg · m / L or more, more preferably 500 kg · m / L or more, and most preferably 1,000 kg · m / L or more.

The contact between the emulsion and the CDC is preferably carried out under a mixing condition that is weaker than the emulsification conditions described above in order to suppress the dissolution of CDC in the organic phase. The Weber number is less than 10,000, preferably less than 5,000, and more preferably less than 2,000. Further, P / q is less than 200 kg · m / L, preferably less than 100 kg · m / L, and more preferably less than 50 kg · m / L. CDC contact can be achieved by introducing CDC into a tubular reactor or tank reactor.

  The reaction temperature in the oligomerization step is usually 80 ° C. or lower, preferably 60 ° C. or lower, more preferably 10 ° C. to 50 ° C. The reaction time is appropriately selected depending on the reaction temperature, and is usually 0.5 minutes to 10 hours, preferably 1 minute to 2 hours. If the reaction temperature is excessively high, side reactions cannot be controlled and the CDC basic unit tends to deteriorate. If the reaction temperature is excessively low, this is a favorable situation in terms of reaction control, but the refrigeration load increases and the cost tends to increase.

The concentration of the carbonate oligomer in the organic phase may be in a range in which the obtained carbonate oligomer is soluble, and is specifically about 10 wt% to 40 wt%. The proportion of the organic phase is preferably a volume ratio of 0.2 to 1.0 with respect to the aqueous phase containing a group 1 element (excluding hydrogen) compound aqueous solution and / or a group 2 element compound aqueous solution of a dihydroxy compound. .

(Polycondensation process)
Next, in the polycondensation step, the organic phase containing the carbonate oligomer separated from the aqueous phase in the stationary separation tank is transferred to an oligomer storage tank having a stirrer. A condensation catalyst such as triethylamine (TEA) is further added to the oligomer storage tank.
Subsequently, the organic phase stirred in the oligomer storage tank is introduced into a predetermined polycondensation reaction tank. Subsequently, an organic solvent such as demineralized water (DMW) or methylene chloride (CH ₂ Cl ₂ ) is added to the polycondensation reaction tank. Then, an aqueous sodium hydroxide solution is supplied and mixed with stirring to carry out a polycondensation reaction of the carbonate oligomer.
Thereafter, the polycondensation reaction liquid in the polycondensation reaction tank is successively introduced successively into a plurality of polycondensation reaction tanks, and the polycondensation reaction of the carbonate oligomer is completed.

Here, in the polycondensation step, the residence time in the polycondensation reaction tank in which the polycondensation reaction of the carbonate oligomer is continuously performed is usually 12 hours or less, preferably 0.5 to 5 hours.
As a preferred embodiment of the polycondensation step, first, an organic phase containing a carbonate oligomer and an aqueous phase are separated, and an inert organic solvent is added to the separated organic phase as necessary to adjust the concentration of the carbonate oligomer. In this case, the amount of the inert organic solvent is adjusted so that the concentration of the polycarbonate resin in the organic phase obtained by the polycondensation reaction is 5% by weight to 30% by weight. Next, an aqueous solution containing water and a Group 1 element (excluding hydrogen) compound and / or a Group 2 element compound is added, and in order to further adjust the polycondensation conditions, a condensation catalyst is preferably added, A polycondensation reaction is performed according to the polycondensation method. The ratio of the organic phase to the aqueous phase in the polycondensation reaction is preferably about volume ratio of organic phase: aqueous phase = 1: 0.2 to 1: 1.

  Examples of the Group 1 element (excluding hydrogen) compound and / or the Group 2 element compound include the same compounds as those used in the oligomerization step described above. Of these, sodium hydroxide is preferred industrially. The amount of the Group 1 element (excluding hydrogen) compound and / or the Group 2 element compound may be more than the amount that the reaction system is always kept basic during the polycondensation reaction. Sometimes, the whole amount may be added all at once, or may be added in divided portions appropriately during the polycondensation reaction.

When the amount of the Group 1 element (excluding hydrogen) compound and / or the Group 2 element compound is excessively large, the hydrolysis reaction as a side reaction tends to proceed. Therefore, the concentration of the Group 1 element (excluding hydrogen) compound or the Group 2 element compound contained in the aqueous phase after the completion of the polycondensation reaction is 0.05N or more, preferably about 0.05N to 0.3N. It is good to make it.
The temperature of the polycondensation reaction in the polycondensation step is usually around room temperature. The reaction time is about 0.5 to 5 hours, preferably about 1 to 3 hours.

(Washing process)
Next, after the polycondensation reaction in the polycondensation reaction tank is completed, the polycondensation reaction solution is subjected to alkali washing with an alkali washing solution, acid washing with an acid washing solution, and water washing with washing water by a known method. In addition, the total residence time of the washing step is usually 12 hours or less, preferably 0.5 to 6 hours.

(Polycarbonate resin isolation process)
In the polycarbonate resin isolation step, first, the polycondensation reaction solution containing the polycarbonate resin washed in the washing step is prepared as a concentrated solution concentrated to a predetermined solid content concentration. The solid content concentration of the polycarbonate resin in the concentrate is usually 5% to 35% by weight, preferably 10% to 30% by weight.

Next, the concentrate is continuously supplied to a predetermined granulation tank, and stirred and mixed with demineralized water (DMW) at a predetermined temperature. And the granulation process which evaporates an organic solvent is performed, maintaining a suspended state in water, and the water slurry containing a polycarbonate resin granular material is formed.
Here, the temperature of the demineralized water (DMW) is usually 37 ° C to 67 ° C, preferably 40 ° C to 50 ° C. Moreover, the solidification temperature of polycarbonate resin by the granulation process performed in a granulation tank is 37 to 67 degreeC normally, Preferably, it is 40 to 50 degreeC.
The water slurry containing the polycarbonate resin powder continuously discharged from the granulation tank is then continuously introduced into a predetermined separator, and water is separated from the water slurry.

(Drying process)
In the drying process, in the separator, the polycarbonate resin powder from which water has been separated from the water slurry is continuously supplied to a predetermined dryer, retained for a predetermined residence time, and then continuously extracted. . Examples of the dryer include a fluidized bed dryer. A plurality of fluidized bed dryers may be connected in series to continuously perform the drying process.

Here, the dryer usually has a heating means such as a heat medium jacket, for example, with water vapor, usually 0.1 MPa-G to 1.0 MPa-G, preferably 0.2 MPa-G to 0. .6 MPa-G. As a result, the temperature of nitrogen (N ₂ ) flowing through the dryer is
Usually, it is maintained at 100 ° C to 200 ° C, preferably 120 ° C to 180 ° C.
The polycarbonate resin obtained by the above-mentioned interface method usually has a small amount of the compound represented by the formula (4) obtained by alkali hydrolysis of the produced polycarbonate resin. Therefore, the following method is used.

By heat-treating the polycarbonate resin obtained by the interface method, it becomes possible to appropriately adjust the amount of the compound represented by the above formula (4) obtained by alkali hydrolysis of the polycarbonate resin. Any method may be used for the heat treatment. Specifically, a method of heating the polycarbonate resin in a tank by a batch method, a method of heating the polycarbonate resin in a tank by a continuous method, a method of heating the polycarbonate resin by an extruder, etc. Can be mentioned. Of these, heating by a single screw extruder or a twin screw extruder is more preferable, and heating by a twin screw extruder with a vent port is more preferable. The heat treatment temperature is preferably 200 ° C to 400 ° C, more preferably 260 ° C to 390 ° C, further preferably 270 ° C to 380 ° C, and most preferably 280 ° C to 370 ° C as the polycarbonate resin temperature. If the polycarbonate resin temperature is too low, the amount of the compound represented by the formula (4) obtained by alkali hydrolysis of the polycarbonate resin, the amount of the compound represented by the formula (10), and the formula (12) May reduce the amount of compound. On the other hand, if the polycarbonate resin temperature is too high, the polymer hue deteriorates, and the amount of the compound represented by the formula (4) obtained by alkaline hydrolysis of the polycarbonate resin, the compound represented by the formula (10) The amount of the compound represented by the formula (12) is excessively large, and a gel-like substance or a foreign substance insoluble in the solvent may be generated, which may cause poor appearance and mechanical properties of the polycarbonate resin. .

The polycarbonate resin temperature is the polycarbonate resin temperature at the exit of the extruder if it is an extruder, and the polycarbonate resin temperature in the tank if it is a tank.
The heat treatment time is preferably 0.5 minutes to 2 hours, more preferably 1 minute to 1 hour, further preferably 1.5 minutes to 30 minutes, and most preferably 2 minutes to 10 minutes. If the heat treatment time is too short, the amount of the compound represented by the formula (4) obtained by alkali hydrolysis of the polycarbonate resin, the amount of the compound represented by the formula (10), and the formula (12) The amount of the compound may be reduced. On the other hand, if the heat treatment time is too long, the polymer hue deteriorates, and the amount of the compound represented by the formula (4) obtained by alkaline hydrolysis of the polycarbonate resin, the amount of the compound represented by the formula (10). The amount of the compound represented by the formula (12) is excessively increased, and a gel-like material or a foreign substance that is insoluble in the solvent may be generated, which may cause poor appearance and decrease the mechanical properties of the polycarbonate resin. In the case of heat treatment by an extruder, the heat treatment time is calculated from the extrusion speed and the volume in the barrel.

  The polycarbonate resin of this invention can be made into the polycarbonate resin composition which further added the polycarbonate resin which has as a main component the structural unit derived from the compound represented by following formula (17). The polycarbonate resin composition is preferable because the heat resistance is further improved.

Here, in Formula (17), X is the same as X in Formula (1).
Specific examples of the compound represented by the formula (17) include 2,2-bis (4-hydroxyphenyl) propane (bisphenol A).
In the polycarbonate resin composition, the content of the polycarbonate resin of the present invention is preferably 10% by weight or more, more preferably 20% by weight or more, and further preferably 30% by weight or more. Moreover, 99 weight% or less is preferable and 90 weight% or less is more preferable. If the content of the polycarbonate resin of the present invention is too large, the impact resistance may be lowered. If the content is too small, the transparency may be deteriorated and the surface hardness may be lowered.

  When the polycarbonate resin is a polycarbonate resin composition further containing a flame retardant, the polycarbonate resin exhibits a more remarkable effect and flame retardancy is improved. Examples of the flame retardant to be used include at least one selected from the group consisting of sulfonic acid metal salt flame retardants, halogen-containing compound flame retardants, phosphorus-containing compound flame retardants, and silicon-containing compound flame retardants. Among these, a sulfonic acid metal salt flame retardant is preferable.

  The content of the flame retardant is preferably 0.01 to 30 parts by weight, more preferably 0.05 to 30 parts by weight, in 100 parts by weight of the polycarbonate resin composition. If the flame retardant content is excessively small, the flame retardant effect may be reduced. When the content of the flame retardant is excessively large, the mechanical strength of the molded article formed with the polycarbonate resin composition tends to decrease.

Examples of the sulfonic acid metal salt flame retardant include aliphatic sulfonic acid metal salts and aromatic sulfonic acid metal salts. Examples of the metal of these metal salts include group 1 elements of sodium, lithium, potassium, rubidium and cesium (excluding hydrogen); beryllium and magnesium magnesium; group 2 elements such as calcium, strontium and barium. . A sulfonic acid metal salt can also be used 1 type or in mixture of 2 or more types. Examples of the sulfonic acid metal salt include aromatic sulfonesulfonic acid metal salts and perfluoroalkane-sulfonic acid metal salts.

The content of the sulfonic acid metal salt-based flame retardant is preferably 0.01 parts by weight to 1 part by weight, more preferably 0.04 parts by weight to 0.3 parts by weight, in 100 parts by weight of the polycarbonate resin composition. Preferably they are 0.05 weight part-0.2 weight part.
Specific examples of the aromatic sulfonesulfonic acid metal salt include, for example, sodium diphenylsulfone-3-sulfonate, potassium diphenylsulfone-3-sulfonate, sodium 4,4′-dibromodiphenyl-sulfone-3-sulfonate, 4 , 4′-Dibromodiphenyl-sulfone-3-sulfone potassium, 4-chloro-4′-nitrodiphenylsulfone-3-calcium sulfonate, disodium diphenylsulfone-3,3′-disulfonate, diphenylsulfone-3,3 Examples include dipotassium di-sulfonate.

  Specific examples of perfluoroalkane-sulfonic acid metal salt include perfluorobutane-sodium sulfonate, perfluorobutane-potassium sulfonate, perfluoromethylbutane-sodium sulfonate, perfluoromethylbutane-potassium sulfonate, perfluoro Examples include octane-sodium sulfonate, potassium perfluorooctane-sulfonate, and tetraethylammonium salt of perfluorobutane-sulfonic acid.

Specific examples of the halogen-containing compound flame retardant include, for example, tetrabromobisphenol A, tribromophenol, brominated aromatic triazine, tetrabromobisphenol A epoxy oligomer, tetrabromobisphenol A epoxy polymer, decabromodiphenyl oxide, tribromo Examples include allyl ether, tetrabromobisphenol A carbonate oligomer, ethylene bistetrabromophthalimide, decabromodiphenylethane, brominated polystyrene, hexabromocyclododecane and the like.
The content of the halogen-containing compound flame retardant is preferably 5 to 30 parts by weight, more preferably 10 to 25 parts by weight, in 100 parts by weight of the polycarbonate resin composition.

  Examples of the phosphorus-containing compound flame retardant include red phosphorus, coated red phosphorus, polyphosphate compound, phosphate ester compound, and phosphazene compound. Among these, specific examples of the phosphate ester compound include, for example, trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate, triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl. Phosphate, diisopropylphenyl phosphate, tris (chloroethyl) phosphate, tris (dichloropropyl) phosphate, tris (chloropropyl) phosphate, bis (2,3-dibromopropyl) -2,3-dichloropropyl phosphate, tris (2,3- Dibromopropyl) phosphate, bis (chloropropyl) monooctyl phosphate, bisphenol A bisphosphate, hydro Non bisphosphate, resorcinol bisphosphate, trioxybenzene phosphate.

The content of the phosphorus-containing compound flame retardant is preferably 3 to 25 parts by weight, more preferably 5 to 25 parts by weight, and most preferably 10 to 12 parts by weight in 100 parts by weight of the polycarbonate resin composition. Parts by weight.
Examples of the silicon-containing compound flame retardant include silicone varnish, a silicone resin in which a substituent bonded to a silicon atom is an aromatic hydrocarbon group and an aliphatic hydrocarbon group having 2 or more carbon atoms, and a main chain having a branched structure. And a silicone compound having an aromatic group in the organic functional group contained therein, a silicone powder carrying a polydiorganosiloxane polymer which may have a functional group on the surface of the silica powder, and an organopolysiloxane-polycarbonate copolymer Etc.

<Additives>
Various additives are blended in the polycarbonate resin or the polycarbonate resin composition as necessary. Examples of additives include stabilizers, ultraviolet absorbers, mold release agents, colorants, antistatic agents, thermoplastic resins, thermoplastic elastomers, glass fibers, glass flakes, glass beads, carbon fibers, wollastonite, silicic acid. Examples thereof include calcium and aluminum borate whiskers.

  The mixing method of the polycarbonate resin or the polycarbonate resin composition and additives is not particularly limited. For example, a method of mixing a solid state polycarbonate resin or a polycarbonate resin composition such as pellets or powder and an additive and then kneading with an extruder, a method of mixing a molten polycarbonate resin and an additive, a melting method Or the method etc. of adding an additive etc. in the middle of the polymerization reaction of the raw material monomer in an interface method, or the completion | finish of polymerization reaction are mentioned.

<Molded body>
A molded body is prepared using the polycarbonate resin or the polycarbonate resin composition of the present invention. A molding method of the molded body is not particularly limited, and examples thereof include a method of molding using a conventionally known molding machine such as an injection molding machine.
The molded body of the present invention has a high hardness on the surface of the molded body, excellent transparency, and few foreign matters.

The molded body of the present invention includes, for example, a casing for precision equipment such as a mobile phone and a PC; a housing for home appliances such as a TV; a film for a screen; an exterior member of a multicolor molded resin molded product of two or more colors such as glazing; It is useful as a raw material for resin members that require high dimensional accuracy, such as multilayer extruded products with two or more surface layers of building materials such as ports, agricultural houses, and soundproof boards.
Moreover, from the polycarbonate resin and the polycarbonate resin composition of the present invention, it is possible to prepare a fat molded body having high hardness and improved workability, and the molded body includes a lamp lens, a protective cover, a diffusion plate, and the like. It is suitably used for lighting-related resin molded products such as LEDs; glasses lenses, vending machine buttons, keys for portable devices, and the like.

EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example, this invention is not limited to a following example. In addition, the physical property of the polycarbonate resin used in the Example and a polycarbonate resin composition was evaluated by the following method.
(1) Viscosity average molecular weight (Mv)
The polycarbonate resin was dissolved in methylene chloride (concentration 6.0 g / L), the specific viscosity (ηsp) at 20 ° C. was measured using an Ubbelohde viscosity tube, and the viscosity average molecular weight (Mv) was calculated by the following formula.
ηsp / C = [η] (1 + 0.28ηsp)
[η] = 1.23 × 10 ⁻⁴ Mv ^0.83
(2) Terminal hydroxyl group concentration of polycarbonate (OH)
The terminal hydroxyl group concentration of the polycarbonate was measured by colorimetric determination according to the titanium tetrachloride / acetic acid method (see Makromol. Chem. 88, 215 (1965)).

(3) Alkaline hydrolysis method and determination of alkali hydrolyzate 0.5 g of polycarbonate resin was dissolved in 5 ml of methylene chloride to prepare a solution. Next, 45 ml of methanol and 5 ml of 25% by weight aqueous sodium hydroxide solution were added to the solution, followed by stirring at 70 ° C. for 30 minutes. The obtained solution was analyzed by liquid chromatography according to the following measurement conditions, and the hydrolyzate was quantified.

Liquid chromatography measurement was performed by the following method.
Device: manufactured by Shimadzu Corporation System controller: CBM-20A
Pump: LC-10AD
Column oven: CTO-10ASvp
Detector: SPD-M20A
Analytical column: YMC-Pack ODS-AM 75 mm × Φ4.6 mm
Oven temperature: 40 ° C
Detection wavelength: 280 nm
Eluent: A solution: 0.1% trifluoroacetic acid aqueous solution, B solution: acetonitrile
From A / B = 60/40 (vol%) to A / B = 95/5 (vol%)
Gradient in 50 minutes Flow rate: 1 mL / min
Sample injection volume: 20 μl
For identification of each hydrolyzate, a portion corresponding to the peak observed at the retention time was fractionated, and ¹ H NMR, ¹³ C NMR, two-dimensional NMR method, mass spectrometry (MS), It carried out by the infrared absorption spectrum method (IR spectrum).

(4) Pellet YI
The transparency of the polycarbonate resin was evaluated by measuring the YI value (yellowness index value) in the reflected light of the polycarbonate resin pellet in accordance with ASTM D1925. As the apparatus, a spectrocolorimeter CM-5 manufactured by Konica Minolta Co., Ltd. was used, and the measurement conditions were a measurement diameter of 30 mm and SCE. Petri dish calibration glass CM-A212 was fitted into the measurement part, and zero calibration was performed by placing a zero calibration box CM-A124 thereon, followed by white calibration using a built-in white calibration plate. Next, measurement was performed using a white calibration plate CM-A210. L ^* was 99.40 ± 0.05, a ^* was 0.03 ± 0.01, b ^* was −0.43 ± 0.01, YI Was found to be −0.58 ± 0.01. The pellets were measured by packing them into a cylindrical glass container having an inner diameter of 30 mm and a height of 50 mm to a depth of about 40 mm. The operation of taking out the pellet from the glass container and then performing the measurement again was repeated twice, and the average value of the measurement values of three times in total was used. The smaller the YI value, the better the transparency of the polycarbonate resin.

(5) Determination of presence or absence of methylene chloride insoluble matter 0.5 g of polycarbonate resin was immersed in 5 ml of methylene chloride, stirred for 30 minutes, and then filtered through a glass filter. The glass filter was vacuum-dried at room temperature for 2 hours, and when the weight increase was 0.01 g or more compared to before filtration, it was determined that the methylene chloride insoluble matter was “present”. Further, when the weight increase was less than 0.01 g, it was determined that the methylene chloride insoluble matter was “none”.

[Example 1]
6.7 kg of dihydroxy compound (made by Honshu Chemical Industry Co., Ltd.) containing 4890 ppm by weight of monomethyl BPA and the other being BPC and 5.8 kg of diphenyl carbonate (DPC), stirrer, heating medium jacket, vacuum pump, reflux condenser Was added to the first reactor having an internal volume of 40 L. Next, an aqueous solution of cesium carbonate was added so that the amount of cesium carbonate was 1.5 μmol per mol of the dihydroxy compound to prepare a mixture.

  Next, the operation of depressurizing the inside of the first reactor to 1.33 kPa (10 Torr) and then restoring the pressure to the atmospheric pressure with nitrogen was repeated five times to replace the inside of the first reactor with nitrogen. After nitrogen substitution, the internal temperature of the first reactor was gradually raised through a heat medium having a temperature of 230 ° C. through the heat medium jacket to dissolve the mixture. Then, the stirrer was rotated at 330 rpm, the temperature in the heating medium jacket was controlled, and the internal temperature of the first reactor was kept at 220 ° C. The pressure in the first reactor was 101.3 kPa (760 Torr) in absolute pressure over 40 minutes while distilling off phenol produced as a by-product by the oligomerization reaction of BPC and DPC performed in the first reactor. To 13.3 kPa (100 Torr).

  Subsequently, a transesterification reaction was performed for 80 minutes while maintaining the pressure in the first reactor at 13.3 kPa and further distilling off phenol. The inside of the system was restored to absolute pressure of 101.3 kPa with nitrogen, the gauge pressure was increased to 0.2 MPa, and the oligomer in the first reactor was passed through a transfer pipe heated to 200 ° C. or higher in advance. Two reactors were pumped. The second reactor had an internal volume of 30 L and was equipped with a stirrer, a heating medium jacket, a vacuum pump and a reflux condenser, and the internal pressure was controlled to atmospheric pressure and the internal temperature was controlled to 240 ° C.

Next, the oligomer fed into the second reactor was stirred at 33 rpm, the internal temperature was raised with a heating medium jacket, and the inside of the second reactor was absolute pressure from 101.3 kPa to 13.3 kPa over 40 minutes. The pressure was reduced to. Thereafter, the temperature increase was continued, and the internal pressure was reduced from 13.3 kPa to 399 Pa (3 Torr) as an absolute pressure over an additional 40 minutes, and phenol distilled out was removed out of the system. Further, the temperature was continuously raised, and after the absolute pressure in the second reactor reached 70 Pa (about 0.5 Torr), the pressure was maintained at 70 Pa, and a polycondensation reaction was performed. When the stirrer of the second reactor has reached a predetermined predetermined stirring power (viscosity average molecular weight is equivalent to 25,000), the polycondensation reaction is completed, and then the polymerization reaction in the second reactor is made into pellets The time was about 174 minutes. The maximum temperature of the second reactor was 285 ° C.
Each evaluation was carried out on this polycarbonate resin according to the above-mentioned procedure. The results are shown in Table 1.

[Example 2]
The same procedure as in Example 1 was performed except that the polymerization reaction time in the second reactor was 178 minutes. Each evaluation was carried out on this polycarbonate resin according to the above-mentioned procedure. The results are shown in Table 1.
[Comparative Example 1]
The same procedure as in Example 1 was performed except that the monomethyl BPA content in the dihydroxy compound was 1480 ppm by weight and the maximum temperature of the second reactor was 286 ° C. Each evaluation was carried out on this polycarbonate resin according to the above-mentioned procedure. The results are shown in Table 1.
[Comparative Example 2]
The same operation as in Comparative Example 1 was performed except that the maximum temperature of the second reactor was 283 ° C. Each evaluation was carried out on this polycarbonate resin according to the above-mentioned procedure. The results are shown in Table 1.

[Comparative Example 3]
The same operation as in Comparative Example 1 was performed except that the maximum temperature of the second reactor was 285 ° C. Each evaluation was carried out on this polycarbonate resin according to the above-mentioned procedure. The results are shown in Table 1.
[Comparative Example 4]
Adding cesium carbonate to 2.0 μmol per 1 mol of the dihydroxy compound, stopping the polycondensation reaction when the stirring power of the stirrer of the second reactor is equivalent to a viscosity average molecular weight of 35,000, It carried out similarly to the comparative example 1 except the maximum temperature of the reactor having been 300 degreeC. Each evaluation was carried out on this polycarbonate resin according to the above-mentioned procedure. The results are shown in Table 1.

  Since the polycarbonate resin of Examples 1 and 2 has a specific amount of monomethyl BPA after alkali hydrolysis, the pellet YI is low (good transparency) compared to the polycarbonate resins of Comparative Examples 1 to 3. Recognize.

  According to the present invention, it is possible to obtain a polycarbonate resin composition and a molded product having excellent transparency and surface hardness, high flame retardancy, and few foreign substances by a simple method. It is possible to expand the field of application to applications that require surface hardness, such as the field of equipment, the field of automobiles such as headlamp lenses and vehicle windows, and the field of building materials such as lighting and exterior.

Claims (6)

A polycarbonate resin having at least a structural unit represented by the following formula (1), which is obtained by alkaline hydrolysis of the polycarbonate resin, includes a compound represented by the following formula (2) and the following formula (3) ), And the amount of the compound represented by the following formula (3) is 2000 ppm by weight or more and 10,000 ppm by weight or less based on the total amount of the compound obtained by alkaline hydrolysis of the polycarbonate resin. Polycarbonate resin characterized by being.

(In Formula (1), Formula (2) or Formula (3), R ¹ , R ² and R ³ are each independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted group. A substituted aryl group, and X represents a single bond, a carbonyl group, a substituted or unsubstituted alkylidene group, a substituted or unsubstituted sulfur atom, or an oxygen atom.) The compound obtained by alkaline hydrolysis of the polycarbonate resin contains a compound represented by the following formula (4), and the amount of the compound represented by the following formula (4) alkali-hydrolyzes the polycarbonate resin. The polycarbonate resin according to claim 1, wherein the polycarbonate resin is in a range of 500 ppm to 7000 ppm by weight with respect to the total amount of the compound obtained.

(In formula (4), R ⁴ , R ⁵ and R ⁶ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group, Represents a single bond, a carbonyl group, a substituted or unsubstituted alkylidene group, a substituted or unsubstituted sulfur atom, or an oxygen atom.)   The polycarbonate resin according to claim 1 or 2, wherein the polycarbonate resin has a viscosity average molecular weight of 15000 or more and 35000 or less.   A polycarbonate resin composition comprising the polycarbonate resin according to any one of claims 1 to 3 and a flame retardant.   5. The polycarbonate resin composition according to claim 4, wherein the content of the flame retardant is from 0.1 parts by weight to 30 parts by weight with respect to 100 parts by weight of the polycarbonate resin composition.   A molded article formed by molding the polycarbonate resin according to any one of claims 1 to 3 or the polycarbonate resin composition according to claim 4 or 5.