JPH07126372A - Production of polycarbonate - Google Patents

Abstract

PURPOSE:To obtain a polycarbonate having a high molecular weight and an excellent quality by reacting a dihydroxy compound with a dialkenyl carbonate in the presence of a specified catalyst. CONSTITUTION:A dihydroxy compound (A) (e.g; bisphenol A) is mixed with a dialkenyl carbonate (B) of the formula [wherein R<1> to R<6> are each H, a halogen, 1-20C alkyl, alkoxycarbonyl or a 6-20C aryl, provided that they may be the same or different from each other and that they may be suitably combined with each other to form a ring or rings; Y is a residue derived by removing the two hydroxyl groups from the dihydroxy compound; and (n) is 0-20] (e.g. bisphenol A bisvinyl carbonate), a chain terminator (C) (e.g. o-n-butylphenol), and a compound (D) of a pH of 4 or below (e.g. LiOH) as a catalyst. The mixing ratio expressed in terms of component A is such that v. to, 1.5mol of component B, 0.05-10mol% component C and 10<-1> to 10<-8>mol of component D are used. The transesterification reaction is performed at 50-300 deg.C under a pressure of 1-50atm.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing polycarbonate. Specifically, when producing a polycarbonate by the transesterification method, under relatively mild reaction conditions,
The present invention relates to a production method capable of efficiently obtaining a high-quality polycarbonate.

[0002]

2. Description of the Related Art Generally, a method for producing a polycarbonate (hereinafter sometimes referred to as PC) is a method of directly reacting an aromatic dihydroxy compound such as bisphenol A with phosgene ( An interfacial polycondensation method) or a method (melting method) in which an aromatic dihydroxy compound such as bisphenol A and a carbonic acid diester such as diphenyl carbonate are transesterified in a molten state is known. In the interfacial polycondensation method in the production method of PC, toxic phosgene must be used, the production equipment is corroded by chlorine-containing compounds such as hydrogen chloride and sodium chloride produced as a by-product, and hydroxylation mixed in the resin. There are various problems such as difficulty in separating impurities such as sodium that adversely affect the physical properties of the polymer.

On the other hand, the melting method has the advantage that PC can be manufactured at a lower cost than the interfacial polycondensation method, but it is usually at 280 to 310 ° C. and 1 mmHg, under high temperature and high vacuum. Since the reaction is carried out for a long time, some leakage of oxygen cannot be prevented, and there is a big drawback that the problem of coloring the resin cannot be escaped. In such a melting method,
In order to reduce this coloring, various improved techniques have been proposed. For example, JP-B-61-39972 and JP-A-62-158719 disclose methods of adding an antioxidant in the latter stage of the reaction. Further, in JP-A-61-62522 and the like, a twin-screw vent type kneading extruder is used in the latter stage of the reaction, and in JP-A-2-153925 and the like, a horizontal stirring polymerization tank is used and the like. Improved techniques are disclosed. Furthermore, JP-A-2-175
Japanese Patent No. 722 discloses a method of reducing the content of hydrolyzable chlorine in a monomer to a certain amount or less, but the problem of quality has not been completely solved, and a satisfactory P
The reality is that C has not yet been obtained. Further, in order to moderate the reaction conditions, bis (o-alkoxycarbonylallyl) carbonate (US Pat. No. 4,323,66) is used.
No. 8), bis (o-nitroallyl) carbonate (US Pat. No. 4,363,905), and the like, a method using an active diallyl carbonate having an electron-withdrawing substituent, and an enol carbonate of acetoacetic ester (JP-A-56). -1
61353), enol carbonate of acetylacetone [Asahi Glass Industrial Technology Promotion Association Research Report, Vol 37, 33]
~ 48 (1980)], Journal of Pplymer Science: Part
C: Polymer Letters, Vol 27, 173-176, (1989) and other methods using enol carbonate are known.
However, the former is colored due to the electron-withdrawing group, and the latter is colored due to the catalyst, and a sufficiently satisfactory polycarbonate cannot be obtained.

[0004]

In view of the above situation, the inventor of the present invention has made P excellent in quality under relatively mild reaction conditions.
We have conducted intensive studies to develop a method for efficiently producing C. As a result, in the production of PC by the transesterification reaction, one of the reaction components in the transesterification reaction, a carbonic acid diester, is reacted with dialkenyl carbonates in the presence of a compound having a pK _b of 4 or less. It has been found that the above problems can be solved by doing so. The present invention has been completed based on such findings. That is, the present invention is
The present invention provides a method for producing a polycarbonate, which comprises reacting a (A) dihydroxy compound and a (B) dialkenyl carbonate in the presence of a compound having a pK _b of 4 or less.

First, in the present invention, there are various dihydroxy compounds used as the component (A).
For example, it is at least one compound selected from aromatic dihydroxy compounds and aliphatic dihydroxy compounds. The aromatic dihydroxy compound used as one of the components (A) has the general formula (II)

[0006]

[Chemical 2]

[Wherein R ⁷ is a halogen atom (for example, chlorine, bromine, fluorine, iodine) or a carbon number of 1 to 1)
8 alkyl groups (eg, methyl group, ethyl group, propyl group, n-butyl group, isobutyl group, amyl group, isoamyl group, hexyl group, etc.), and when R ⁷ is plural, they are the same. May be different or different, and m is an integer of 0 to 4. Z is a single bond, an alkylene group having 1 to 8 carbon atoms or an alkylidene group having 2 to 8 carbon atoms (for example, methylene group, ethylene group, propylene group, butylene group, penterylene group, hexylene group, ethylidene group, isopropylidene group). Or a cycloalkylene group having 5 to 15 carbon atoms or a cycloalkylidene group having 5 to 15 carbon atoms (eg, cyclopentylene group, cyclohexylene group, cyclopentylidene group, cyclohexylidene group), or S-, -SO-, -SO
_2- , -O-, -CO- bond or general formula (III) or (III ')

[0008]

[Chemical 3]

The bond represented by ] The aromatic dihydroxy compound represented by these is mentioned. Examples of such an aromatic dihydroxy compound include bis (4-hydroxyphenyl) methane; bis (3-methyl-4-hydroxyphenyl) methane; bis (3-chloro-4-hydroxyphenyl) methane; bis (3 , 5-dibromo-4
-Hydroxyphenyl) methane; 1,1-bis (4-hydroxyphenyl) ethane; 1,1-bis (2-t-butyl-4-hydroxy-3-methylphenyl) ethane;
1,1-bis (2-t-butyl-4-hydroxy-3-
Methylphenyl) ethane; 1-phenyl-1,1-bis (3-fluoro-4-hydroxy-3-methylphenyl) ethane; 2,2-bis (4-hydroxyphenyl)
Propane (commonly called bisphenol A: BPA); 2,2-
Bis (3-methyl-4-hydroxyphenyl) propane; 2,2-bis (2-methyl-4-hydroxyphenyl) propane; 2,2-bis (3,5-dimethyl-4-)
Hydroxyphenyl) propane; 1,1-bis (2-t
-Butyl-4-hydroxy-5-methylphenyl) propane; 2,2-bis (3-chloro-4-hydroxyphenyl) propane; 2,2-bis (3-fluoro-4-hydroxyphenyl) propane; 2, 2-bis (3-bromo-4-hydroxyphenyl) propane; 2,2-bis (3,5-difluoro-4-hydroxyphenyl) propane; 2,2-bis (3,5-dichloro-4-hydroxyphenyl) ) Propane; 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane; 2,2-bis (4-hydroxyphenyl) butane; 2,2-bis (4
-Hydroxyphenyl) octane; 2,2-bis (4-
Hydroxyphenyl) phenylmethane; 2,2-bis (4-hydroxy-1-methylphenyl) propane;
1,1-bis (4-hydroxy-t-butylphenyl)
Propane: 2,2-bis (4-hydroxy-3-bromophenyl) propane; 2,2-bis (4-hydroxy-)
3,5-dimethylphenyl) propane; 2,2-bis (4-hydroxy-3-chlorophenyl) propane;
2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane; 2,2-bis (4-hydroxy-3,2
5-dibromophenyl) propane; 2,2-bis (3-
Bromo-4-hydroxy-5-chlorophenyl) propane; 2,2-bis (3-phenyl-4-hydroxyphenyl) propane; 2,2-bis (4-hydroxyphenyl) butane; 2,2-bis (3- Methyl-4-hydroxyphenyl) butane; 1,1-bis (2-butyl-4-)
Hydroxy-5-methylphenyl) butane; 1,1-bis (2-t-butyl-4-hydroxy-5-methylphenyl) butane; 1,1-bis (2-t-butyl-4-hydroxy-5- Methylphenyl) isobutane; 1,1-
Bis (2-t-amyl-4-hydroxy-5-methylphenyl) butane; 2,2-bis (3,5-dichloro-4)
-Hydroxyphenyl) butane; 2,2-bis (3,5)
-Dibromo-4-hydroxyphenyl) butane; 4,4
-Bis (4-hydroxyphenyl) heptane; 1,1-
Bis (2-t-butyl-4-hydroxy-5-methylphenyl) heptane; 2,2-bis (4-hydroxyphenyl) octane; 1,1- (4-hydroxyphenyl)
Bis (hydroxyaryl) alkanes such as ethane;
1,1-bis (4-hydroxyphenyl) cyclopentane; 1,1-bis (4-hydroxyphenyl) cyclohexane; 1,1-bis (3-methyl-4-hydroxyphenyl) cyclohexane; 1,1-bis ( 3-cyclohexyl-4-hydroxyphenyl) cyclohexane;
1,1-bis (3-phenyl-4-hydroxyphenyl) cyclohexane; bis (hydroxyaryl) cycloalkanes such as 1,1-bis (4-hydroxyphenyl) -3,5,5-trimethylcyclohexane; bis ( 4-hydroxyphenyl) ether; bis (hydroxyaryl) ethers such as bis (4, -hydroxy-3-methylphenyl) ether; bis (4-hydroxyphenyl) sulfide; bis (3-methyl-4-hydroxyphenyl) Bis (hydroxyaryl) sulfides such as sulfides; bis (4-hydroxyphenyl) sulfoxide; bis (3-methyl-4-hydroxyphenyl) sulfoxide; bis (hydroxy) such as bis (3-phenyl-4-hydroxyphenyl) sulfoxide Aryl) sulfoki Bis (4hydroxyphenyl) sulfone; bis (3-methyl-4-hydroxyphenyl) sulfone; bis (3-phenyl-4-hydroxyphenyl) sulfone and other bis (hydroxyaryl) sulfones, 4,4 ′ -Dihydroxybiphenyl;
4,4'-dihydroxy-2,2'-dimethylbiphenyl;4,4'-dihydroxy-3,3'-dimethylbiphenyl;4,4'-dihydroxy-3,3'-dicyclohexylbiphenyl;3,3'- Difluoro-4,4 '
And dihydroxybiphenyls such as dihydroxybiphenyl.

Examples of aromatic dihydroxy compounds other than the above general formula (II) include dihydroxybenzenes, halogen- and alkyl-substituted dihydroxybenzenes. For example, resorcin, 3-methylresorcin, 3-ethylresorcin, 3-propylresorcin, 3-butylresorcin, 3-t-butylresorcin, 3-phenylresorcin, 3-cumylresorcin; 2,3,4,6- Tetrafluororesorcin; 2,3,4,6-tetrabromoresorcin; catechol, hydroquinone, 3-methylhydroquinone, 3-ethylhydroquinone, 3-propylhydroquinone, 3-butylhydroquinone, 3-
t-butylhydroquinone, 3-phenylhydroquinone, 3-cumylhydroquinone; 2,5-dichlorohydroquinone; 2,3,5,6-tetramethylhydroquinone; 2,3,4,6-tetra-t-butylhydroquinone; 2,3,5,6-tetrafluorohydroquinone; 2,3,5,6-tetrabromohydroquinone and the like.

There are various kinds of aliphatic dihydroxy compounds which are one of the components (A). For example,
Butane-1,4-diol; 2,2-dimethylpropane-1,3-diol; hexane-1,6-diol; diethylene glycol; triethylene glycol; tetraethylene glycol; octaethylene glycol; dipropylene glycol; N , N-methyldiethanolamine; cyclohexane-1,3-diol; cyclohexane-1,4-diol; 1,4-dimethylolcyclohexane; p-xylylene glycol; 2,2-bis-
Ethoxylated or propoxylated products of (4-hydroxycyclohexyl) -propane and dihydric alcohols or phenols such as bis-oxyethyl-bisphenol A; bis-oxyethyl-tetrachlorobisphenol A or bis-oxyethyl-tetrachlorohydroquinone. Can be mentioned. In the present invention, as the dihydroxy compound as the component (A), the above compounds are appropriately selected and used. Among these, it is preferable to use bisphenol A (BPA) which is an aromatic dihydroxy compound.

In the present invention, polycarbonate is used.
In manufacturing, the dihydroxy compound of the component (A)
And (B) component as dialkenyl carbonate
pK _bTransesterification in the presence of compounds with
It is characterized by making it. Here, the component (B) dialke
Nyl carbonates are not particularly limited, for example, general
Formula (I)

[0013]

[Chemical 4]

It is a compound represented by: In this general formula (I), R ^{1 to} R ⁶ each represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxycarbonyl group or an aryl group having 6 to 20 carbon atoms,
They may be the same or different.
In addition, R ^{1 to} R ⁶ may combine to form a cyclic structure. Examples of the alkyl group having 1 to 20 carbon atoms represented by R ^{1 to} R ⁶ include methyl group, ethyl group, propyl group, n-butyl group, isobutyl group, amyl group, isoamyl group, hexyl group, heptyl group. , Octyl group and the like. Further, as the aryl group having 6 to 20 carbon atoms,
Examples thereof include phenyl group and naphthyl group. And Y shows the residue which removed two hydroxyl groups from the dihydroxy compound, and n is an integer of 0-20.

On the other hand, there are various kinds of dialkenyl carbonates represented by the general formula (I) as the component (B). For example, in the general formula (I), when n is 0,
Divinyl carbonate [R ^{1 to} R ⁶ are all hydrogen atoms. ], Diisopropenyl carbonate [R ¹ , R
² and R ⁴ and R ⁵ are hydrogen atoms, and R ³ and R ⁶ are methyl groups. ]; Dipropenyl carbonate [R ² , R
³ and R ⁵ and R ⁶ are hydrogen atoms, and R ¹ and R ⁴ are methyl groups. ]; 2,2-dichloroethynylethynyl carbonate [R ¹ and R ² are chlorine atoms, and R ^{3 to} R ⁶
Is a hydrogen atom. ], 2,2'-bis (methoxycarbonyl) isopropenyl carbonate [R ¹ , R ⁴ are methoxycarbonyl groups, R ³ , R ⁵ are methyl groups and R ² ,
R ⁶ is a hydrogen atom. ] Etc. are mentioned. Also, n
Examples of the compound represented by the general formula (I) in the case of 1 to 20 include bisphenol A bisvinyl carbonate, bisphenol S bisvinyl carbonate,
Tetramethylbisphenol A bisvinyl carbonate, tetrabromobisphenol A bisvinyl carbonate, bis (4-ethenyloxycarbonyloxyphenyl) ether, hydroquinone bisvinyl carbonate, resorcin bisvinyl carbonate, bisphenol A bisisopropenyl carbonate, bisphenol S bisiso Examples thereof include propenyl carbonate, tetramethylbisphenol A bisisopropenyl carbonate, tetrabromobisphenol A bisisopropenyl carbonate, bis (4-isopropenyloxycarbonyloxyphenyl) ether, hydroquinone bisisopropenyl carbonate, resorcin bisisopropenyl carbonate. Others include 6-methyl-4-methylene-4H-1,3-dioxin-2-one. Among these, bisphenol A bisvinyl carbonate and bisisopropenyl carbonate are preferably used.

Various methods can be used to produce the dialkenyl carbonates represented by the above general formula (I). For example, divinyl carbonate or diisopropenyl carbonate is a tertiary amine. It can be synthesized by reacting phosgene with a corresponding mercury compound of an aldehyde or ketone in the presence. In addition, for example, bisphenol A bisvinyl carbonate can be synthesized by reacting isopropenyl chloroformate with a dihydroxy compound such as bisphenol A in the presence of a tertiary amine.
The above compounds can be easily synthesized by referring to US Pat. No. 2,574,699.

The production method of the present invention is to obtain a polycarbonate by transesterification in the presence of a specific compound using the components (A) and (B).
In order to produce a polycarbonate by this transesterification reaction, in addition to the above-mentioned components (A) and (B), if necessary, the following terminal terminator can be used.
Specific examples of such an end terminating agent include on-n-butylphenol; m-n-butylphenol; pn-butylphenol; o-isobutylphenol; m-isobutylphenol; p-isobutylphenol; ot
-Butylphenol; mt-butylphenol; p-
t-butylphenol; on-pentylphenol;
m-n-pentylphenol; p-n-pentylphenol; o-n-hexylphenol; m-n-hexylphenol; p-n-hexylphenol; o-cyclohexylphenol; m-cyclohexylphenol;
p-cyclohexylphenol; o-phenylphenol; m-phenylphenol; p-phenylphenol; on-nonylphenol; m-n-nonylphenol; p-n-nonylphenol; o-cumylphenol; m-cumylphenol; p-cumylphenol; o
-Naphthylphenol; m-naphthylphenol; p-
Naphthylphenol; 2,6-di-t-butylphenol; 2,5-di-t-butylphenol; 2,4-di-
t-butylphenol; 3,5-di-t-butylphenol; 2,5-dicumylphenol; 3,5-dicumylphenol; formula

[0018]

[Chemical 5]

Examples of the compound represented by

[0020]

[Chemical 6]

Examples include monohydric phenols such as Of these phenols, although not particularly limited in the present invention, pt-butylphenol; p-cumylphenol; p-phenylphenol and the like are preferable. Also, the formula

[0022]

[Chemical 7]

Examples thereof include compounds represented by Furthermore, in the present invention, phloroglucin; trimellitic acid; 1,1,1-tris (4-hydroxyphenyl) ethane; 1- [α-methyl-α- (4′-hydroxyphenyl) ethyl], if necessary. -4- [α ', α'-bis (4 "-hydroxyphenyl) ethyl] benzene; α,
α ′, α ″ -tris (4-hydroxyphenyl) -1,
3,5-triisopropylbenzene; isatin bis (o
-Cresol) or the like can be used as a branching agent.

In the present invention, a compound having a pK _b of 4 or less is used as a catalyst as a specific compound to be present in the reaction of the (A) dihydroxy compound and the (B) dialkenyl carbonate. Here, the compound having a pK _b of 4 or less is not particularly limited, and examples thereof include L
iOH, NaOH, KOH, Ca (OH) ₂ , Ba (O
H) ₂ , Sr (OH) ₂ and other alkali metal or alkaline earth metal hydroxides, tetramethylammonium hydroxide (Me ₄ NOH), tetraethylammonium hydroxide (Et ₄ NOH), tetrabutylammonium hydroxide ( Bu ₄ NOH), trimethylbenzylammonium hydroxide [C ₆ H ₅ CH ₂ (Me) ₃ NO
H] and the like, and ammonium hydroxides having an alkyl group, an aryl group, an aryl group and the like. In addition, tetramethylammonium borohydride (Me
₄ NBH _4), basic salts such as tetrabutylammonium borohydride (Bu ₄ NBH ₄₎ can be mentioned. Furthermore, 7-methyl-1,5,7-triazabicyclo [4.
4.0] dec-5-ene (MTBD); 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU)
Organic basic compounds such as Among the above compounds, tetramethylammonium hydroxide is preferably used.

The above catalysts may be used alone or in combination of two or more depending on the purpose. The amount of the catalyst added is usually 10 ^-1 to 10 relative to the dihydroxy compound as the component (A).
^-8 mol / mol, preferably 10 ^-2 to 10 ^-7 mol / mol. When the amount of this catalyst added is less than 10 ^-8 mol / mol,
The effect may not be realized. On the other hand, if it exceeds 10 ^-1 mol / mol, it leads to an increase in cost, and no more than this is added.

In the production method of the present invention, a polycarbonate is produced by the transesterification method using the above-mentioned components (A) and (B) and, if necessary, a terminal terminating agent or a branching agent as other components. Specifically, the reaction proceeds according to a known transesterification method. The procedure and conditions of the production method of the present invention will be specifically described below. First,
The dihydroxy compound as the component (A) and the dialkenyl carbonates as the component (B) are transesterified at a ratio of the component (B) to the component (A) at a ratio of 1 to 1.5 times. . Depending on the situation, the amount of the component (B) is 1.0, which is slightly excessive with respect to the component (A).
The molar amount is preferably 2 to 1.20 times. In the above transesterification reaction, the amount of the terminal terminator composed of the monohydric phenol or the like is the dihydroxy compound 1 which is the component (A).
When it is in the range of 0.05 mol% to 10 mol% with respect to mol, the hydroxyl group end or isopropenyl end of the obtained polycarbonate is sealed, and thus a polycarbonate having sufficiently excellent heat resistance and water resistance is obtained. And preferred.
The terminal terminating agent or dialkenyl carbonate composed of the above monohydric phenol may be added to the reaction system in advance. Further, it may be added in part to the reaction system in advance and the rest may be added as the reaction progresses. Further, in some cases, the total amount may be added to the reaction system after the transesterification reaction of the dihydroxy compound of the component (A) and the dialkenyl carbonate of the component (B) partially proceeds.

In carrying out the transesterification reaction according to the production method of the present invention, the reaction temperature is not particularly limited, but is usually in the range of 50 ° C. to 300 ° C., preferably 1
A method of gradually increasing the temperature to 00 ° C to 280 ° C, and more preferably to 180 ° C to 270 ° C as the reaction progresses is preferable. If the transesterification reaction is lower than 50 ° C., the progress of the reaction is slow, and if it exceeds 300 ° C., thermal deterioration or gelation of the polymer may occur, which is not preferable. The reaction pressure is set according to the vapor pressure of the monomer used and the reaction temperature. This is not limited as long as it is set so that the reaction is efficiently performed. Usually, in the initial stage of the reaction, 1 to 50 atm (760 to 38,
Up to 000 torr) at atmospheric pressure or pressure,
In the latter stage of the reaction, atmospheric pressure or reduced pressure is often used. The reaction time may be until the target molecular weight is reached, and is usually about 1 minute to 10 hours.

The above-mentioned transesterification reaction is carried out in the absence of an inert solvent, but if necessary, it may be carried out in the presence of an inert solvent in an amount of 1 to 150% by weight of the obtained PC. Here, as the inert solvent, for example, diphenyl ether, halogenated diphenyl ether, benzophenone, polyphenyl ether, dichlorobenzene,
Aromatic compounds such as methylnaphthalene, gases such as carbon dioxide, dinitrogen monoxide and nitrogen, chlorofluorohydrocarbons, alkanes such as ethane and propane, cyclohexane, tricyclo (5,2,10) -decane, cyclooctane, cyclodecane, etc. Examples thereof include cycloalkane, alkenes such as ethylene and propylene, and the like.

In the present invention, an antioxidant can be used if necessary. For example, as the phosphorus-based antioxidant, specifically, tri (nonylphenyl) phosphite, 2-ethylhexidiphenylphosphite, trimethylphosphite, triethylphosphite, tributylphosphite, trioctylphosphite can be used. , Trinonyl phosphite, tridecyl phosphite, trioctadecyl phosphite, distearyl pentaerythyl diphosphite, tris (2-chloroethyl) phosphite, tris (2,3-dichloropropyl) phosphite, etc. Fight; tricycloalkylphosphite such as tricyclohexylphosphite; triphenylphosphite, tricresylphosphite, tris (ethylphenyl) phosphite, tris (butylphenyl) phosphite, tris Triaryl phosphites such as nonylphenyl) phosphite and tris (hydroxyphenyl) phosphite; trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tridecyl phosphate, trioctadecyl phosphate, distearyl pentaerythrityl diphosphate, tris Trialkyl phosphates such as (2-chloroethyl) phosphate, tris (2,3-dichloropropyl) phosphate; tricycloalkyl phosphates such as tricyclohexyl phosphate; triphenyl phosphate, tricresyl phosphate, tris (nonylphenyl) phosphate, 2 Examples include triaryl phosphates such as ethylphenyldiphenyl phosphate.

In the present invention, as the transesterification reaction proceeds, the carbonyl compound corresponding to the dialkenyl carbonate used and the inert solvent are desorbed from the reactor. These desorbed substances can be separated, purified and recycled for use, and it is preferable to have a facility for removing them. And, the present invention can be carried out batchwise or continuously, and any equipment can be used. Here, in the case of continuous production, it is preferable to use at least two reactors and set the above reaction conditions. The material and structure of the reactor used in the present invention are not particularly limited, but it is sufficient that the reactor has a normal stirring function. However, since the viscosity increases in the latter stage of the reaction, it is preferable to have a high-viscosity stirring function. Further, the shape of the reactor is not limited to a tank type, and may be an extruder type reactor or the like.

The PC thus obtained may be granulated as it is, or may be molded by using an extruder or the like. Further, the PC obtained by the present invention can be used by blending well-known additives such as a plasticizer, a pigment, a lubricant, a release agent, a stabilizer and an inorganic filler. Further, the obtained PC can be blended with a polymer such as polyolefin, polystyrene, polyester, polysulfonate, polyamide and polyphenylene oxide. In particular, OH group, COOH group, NH ₂
It is effective to use a polyphenylene ether, a polyether nitrile, a terminal-modified polysiloxane compound, a modified polypropylene, a modified polystyrene, or the like having a group or the like at the end, in combination.

[0032]

The present invention will be further described in detail with reference to Examples and Comparative Examples. The present invention is not limited to the examples below. Synthesis Example 1 [Synthesis of bisphenol A bisisopropenyl carbonate] A separable flask (with a stirrer) having an internal volume of 1 liter was charged with 10 ml (0.0915 mol) of isopropenyl chloroformate and 100 ml of methylene chloride, and then, Bisphenol A 9.48
g (0.0416 mol), pyridine 7.4 ml (0.0.
(0915 mol), 50 ml of methylene chloride and 10 ml of acetone were added dropwise over 20 minutes while cooling with an ice bath. Then, the ice bath was removed, and the reaction was carried out at room temperature for 40 minutes. After completion of the reaction, the product was washed with 0.2N hydrochloric acid, and then water washing was repeated until the aqueous phase became neutral. After completion of washing, the organic phase was separated and concentrated to obtain crystals. The obtained crystals were recrystallized using methanol to obtain white needle crystals. ¹ H-N of the obtained white needle crystals
The result of MR is shown in FIG.

Examples 1 to 4 Bisphenol A bisisopropenyl carbonate synthesized in Synthesis Example 1 was placed in a 20 ml Schlenk tube.
0.208 g (0.525 mmol), bisphenol A 0.
114 g (0.5 mmol), a predetermined amount of the catalyst shown in Table 1 and a stirrer were put in, and the atmosphere was replaced with argon five times. This was reacted under an argon atmosphere at the reaction temperature and reaction time shown in Table 1. After completion of the reaction, 10 ml of methylene chloride was added to dissolve the reaction product, which was then transferred to a flask and the solvent was removed to obtain a reaction product. I of the obtained reaction product
From the R spectrum and ¹ H-NMR, it was confirmed that the reaction product was polycarbonate.

Example 5 The reaction product obtained by the same procedure as in Example 4 was dissolved in methylene chloride and crystallized with acetone. This was vacuum dried at room temperature and then reacted at 220 ° C. and 1 mmHg for 4 hours to obtain a polycarbonate.

Comparative Example 1 Example 3 was repeated except that diphenyl carbonate was used instead of bisphenol A bisisopropenyl carbonate. Comparative Example 2 The procedure of Example 3 was repeated except that bisphenol A bisphenyl carbonate was used instead of bisphenol A bisisopropenyl carbonate.

Comparative Example 3 In Example 2, the catalyst was replaced by 4% instead of LiOH.
-A procedure similar to that of Example 2 was performed except that dimethylaminopyridine (DMAP) was used. Comparative Example 4 The procedure of Example 4 was repeated, except that DMAP was used in place of Me ₄ NOH as the catalyst.

The reaction products obtained in Examples 1 to 5 and Comparative Examples 1 to 4 were dissolved in methylene chloride, and the weight average molecular weight (Mw) and glass transition temperature (Tg) were measured. Also, the appearance was checked. The measurement results are shown in Table 2. The weight average molecular weight and Tg were measured as follows. 1) Weight average molecular weight (Mw) It was measured by GPC (Gel Permeation Chromatography) (polystyrene standard) and converted into the value of polycarbonate. Measurement conditions Device: Waters ALC / GPS 150C Column: Tosoh Corp., TSK GEL GMH6
(60 cm column, PS gel) Solvent: Tetrahydrofuran Temperature: 40 ° C 2) Glass transition temperature (Tg) Measured at a heating rate of 20 ° C / min.

[0038]

[Table 1]

[0039]

[Table 2]

[Note] * 1: CRC Hand book of Chemistry and Physics 74th
From EDITION, P 8-45 * 2: The basicity of Me ₄ NOH is comparable to that of NaOH and KOH [Bunseki, Vol. 7, p. 504 (1991)], so N
From pK _a > 15 of a ⁺ (hydrate) and K ⁺ (hydrate) [see "Acid and Base", Motoharu Tanaka (Sokabo, page 25),
It was calculated using the "pK _b = pK _w -pK _a". * 3: From Macromolecules Vol. 26, 1503-1508 (1993)

[0041]

As described above, according to the present invention, in the transesterification reaction, by reacting the (A) dihydroxy compound with the (B) dialkenyl carbonate, the molecular weight of the polymer can be increased under relatively mild reaction conditions. It is possible to increase the production efficiency and efficiently produce a polycarbonate having excellent quality. Therefore, the present invention can be effectively and widely used as a method for industrially producing a polycarbonate by a transesterification method.

[Brief description of drawings]

FIG. 1 is a chart showing ¹ H-NMR results for bisphenol A bisisopropenyl carbonate obtained in Synthesis Example 1.

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[Procedure amendment]

[Submission date] October 7, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 2

[Correction method] Change

[Correction content]

[Chemical 1] [In the formula, R ^{1 to} R ⁶ are each a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, or an alkoxycarbonyl group.
Group or an aryl group having 6 to 20 carbon atoms, which may be the same or different, R ^{1 to} R
⁶ may combine with each other to form a ring structure. Y represents a residue obtained by removing two hydroxyl groups from a dihydroxy compound. n is 0
Is an integer of -20. ] The manufacturing method of the polycarbonate of Claim 1 represented by these.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0039

[Correction method] Change

[Correction content]

[0039]

[Table 2]

Claims (2)

[Claims] 1. A method for producing a polycarbonate, which comprises reacting a (A) dihydroxy compound with a (B) dialkenyl carbonate in the presence of a compound having a pK _b of 4 or less. 2. A dialkenyl carbonate is represented by the general formula (I): [In the formula, R ^{1 to} R ⁶ each represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxycarbonyl group or an aryl group having 6 to 20 carbon atoms, and they may be the same. Good or different, R ¹ ~
R ⁶ may be bonded to form a cyclic structure. Y represents a residue obtained by removing two hydroxyl groups from a dihydroxy compound. n is an integer of 0-20. ] The manufacturing method of the polycarbonate of Claim 1 represented by these.