JPH0782364A - Production of polycarbonate - Google Patents

Abstract

PURPOSE:To efficiently produce a polycarbonate excellent in color tone at a high reaction rate without detriment to its hydrolysis resistance by subjecting a dihydroxy compd. and a carbonic diester to transesterification in the presence of a carbonylated org. nitrogen compd. CONSTITUTION:A polycarbonate is produced by the transesterification between a dihydroxy compd. and a carbonic diester in the presence of a carbonylated org. nitrogen compd. of the formula [wherein R<1> and R<2> are each H, 1-10C alkyl, or hydroxyl; R<3> is 1-8C alkylene or 6-40C arylene; and R<4> is H, 1-10C alkyl, hydroxyl, or -OR<5> (wherein R<5> is 1-10C alkyl or 6-40C aryl)].

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing polycarbonate. Specifically, in producing a polycarbonate from a dihydroxy compound and a carbonic acid diester by a transesterification method, by performing the transesterification reaction in the coexistence of a carbonyl group-containing nitrogen-containing organic compound, hydrolysis resistance is not significantly impaired, and remarkably The present invention relates to a method for efficiently producing a polycarbonate having an excellent color tone, which can improve the reaction rate.

[0002]

2. Description of the Related Art Generally, as a method for producing a polycarbonate (hereinafter sometimes referred to as PC), a method in which an aromatic dihydroxy compound such as bisphenol A is directly reacted 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 an advantage that PC can be manufactured at a lower cost than the interfacial polycondensation method, but usually, the reaction is carried out at a high temperature of 280 to 310 ° C. for a long time. In addition, it has a big drawback that it cannot escape from the coloring problem of the resin. In such a melting method, various improved techniques have been proposed in order to reduce this coloring. For example, JP-B-61-39972 and JP-A-63-223036 disclose a method of using a specific catalyst. Also, JP-A-61-151
Japanese Patent Laid-Open No. 236 and Japanese Patent Laid-Open No. 62-158719 disclose a method of adding an antioxidant in the latter stage of the reaction. And, in JP-A-61-62522, etc.,
In the latter stage of the reaction, a twin-screw vent type kneading extruder was used.
Japanese Patent Laid-Open No. 153925 discloses a process improvement technique such as using a horizontal stirring polymerization tank. Further, Japanese Patent Application Laid-Open No. 2-175722 discloses a method in which the content of hydrolyzable chlorine in a monomer is set to a certain level or less. Further, in order to improve the hydrolysis resistance of the obtained PC, it has been conventionally known that it is neutralized with a volatile acid such as dimethylsulfate, and recently, it has been neutralized with an acid such as p-toluenesulfonic acid. There is known a technique (Japanese Unexamined Patent Publication No. 4-175368) in which the oxidization is carried out and the excess acid is neutralized with epoxy. However, the problem of quality has not been completely solved yet, and the fact is that a satisfactory PC has not yet been obtained.

[0004]

Therefore, the present inventors have
In view of the above situation, the inventors have conducted earnest studies to solve the above-mentioned drawbacks of the conventional method and to develop a method capable of efficiently producing a PC having an excellent color tone by a transesterification method. As a result, it has been found that the above problem can be solved by carrying out the transesterification reaction in the coexistence of a specific nitrogen-containing organic compound when producing PC by the transesterification method. The present invention has been completed based on such findings. That is, the present invention is characterized in that, when a polycarbonate is produced from (A) a dihydroxy compound and (B) a carbonic acid diester by a transesterification method, the transesterification reaction is carried out in the coexistence of a carbonyl group-containing nitrogen-containing organic compound. The present invention provides a method for producing a polycarbonate.

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

[0006]

[Chemical 2]

[Wherein R is a halogen atom (for example, chlorine, bromine, fluorine, iodine) or an alkyl group having 1 to 8 carbon atoms (for example, methyl group, ethyl group, propyl group, n-butyl group, Isobutyl group, amyl group, isoamyl group, hexyl group, etc.) and when this R is plural,
They may be the same or different,
m is an integer of 0-4. 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). Ridene group, etc.), C5-15
Cycloalkylene group or cycloalkylidene group having 5 to 15 carbon atoms (for example, cyclopentylene group, cyclohexylene group, cyclopentylidene group, cyclohexylidene group, etc.), 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 aromatic dihydroxy compounds include bis (4-hydroxyphenyl) methane; 1,1-bis (4-hydroxyphenyl) ethane; 2,2-bis (4-hydroxyphenyl) propane (commonly called bisphenol A : BPA);
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-3,5-dibromophenyl) propane Such as bis (hydroxyaryl) alkanes; 1,1-bis (4-hydroxyphenyl) cyclopentane; 1,1-bis (4
-Hydroxyphenyl) cyclohexane; 1,1-bis (4-hydroxyphenyl) -3,5,5-trimethylcyclohexane and other bis (hydroxyaryl) cycloalkanes; 4,4-dihydroxydiphenyl ether; 4,4'-dihydroxy Dihydroxy aryl ethers such as -3,3'-dimethylphenyl ether;
4,4'-dihydroxydiphenyl sulfide; 4,
Dihydroxydiaryl sulfides such as 4'-dihydroxy-3,3'-dimethyldiphenyl sulfide;
4,4'-dihydroxydiphenyl sulfoxide; 4,
Dihydroxyaryl sulfoxides such as 4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide; 4,4'-dihydroxydiphenyl sulfone; 4,
Dihydroxydiarylsulfones such as 4'-dihydroxy-3,3'-dimethyldiphenylsulfone, dihydroxybenzene, halogen and alkyl substituted dihydroxybenzenes, for example 1,4-dihydroxy-2,5-
Dichlorobenzene; 1,4-dihydroxy-3-methylbenzene and the like can be mentioned.

There are various kinds of aliphatic dihydroxy compounds as the component (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. To be

Examples of the bisester of an aromatic dihydroxy compound, the bisester of an aliphatic dihydroxy compound, the carbonate of an aromatic dihydroxy compound, or the carbonate of an aliphatic dihydroxy compound used as the component (A) include The bisesters of the above compounds have the general formula (IV)

[0012]

[Chemical 4]

[Wherein R ⁶ represents a residue obtained by removing two hydroxyl groups from the above aliphatic dihydroxy compound, and R ⁷ represents an alkyl group having 1 to 6 carbon atoms or 4 to 4 carbon atoms.
A cycloalkyl group having 7 is shown. ] The compound represented by the general formula (V)

[0014]

[Chemical 5]

[In the formula, Ar ¹ represents a residue obtained by removing two hydroxyl groups from the aromatic dihydroxy compound, and R ⁷ has the same meaning as described above. ] The compound represented by the general formula (VI)

[0016]

[Chemical 6]

[In the formula, Ar ² represents an aryl group, and R ⁶ is the same as defined above. ] Or a compound represented by the general formula (VI
I)

[0018]

[Chemical 7]

[In the formula, Ar ¹ and Ar ² are the same as defined above. ] The compound represented by these is mentioned. Further, the carbonates of the above compounds have the general formula (VIII)

[0020]

[Chemical 8]

[In the formula, R ⁶ and R ⁷ are the same as defined above. ] The compound represented by the general formula (IX)

[0022]

[Chemical 9]

[In the formula, R ⁷ and Ar ¹ are the same as defined above. ] The compound represented by General formula (X)

[0024]

[Chemical 10]

[In the formula, R ⁶ and Ar ² are the same as defined above. ] Or a compound represented by the general formula (XI)

[0026]

[Chemical 11]

[In the formula, Ar ¹ and Ar ² are the same as defined above. ] The compound represented by these is 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 which is an aromatic dihydroxy compound. When bisphenol A is used, an adduct of bisphenol A and phenol or a mixture of the adduct and phenol can be used. By using the adduct as described above, bisphenol A having high purity can be obtained, which is effective.

On the other hand, in the present invention, there are various carbonic acid diesters used as the component (B). For example, it is at least one compound selected from diaryl carbonate compounds, dialkyl carbonate compounds or alkylaryl carbonate compounds. The diaryl carbonate compound used as one of the components (B) has the general formula (XII)

[0029]

[Chemical 12]

[In the formula, Ar ² is the same as described above. ] Or a compound represented by the general formula (XI)

[0031]

[Chemical 13]

[In the formula, Ar ¹ and Ar ² are the same as defined above. ] It is a compound represented by these. The dialkyl carbonate compound has the general formula (XIII)

[0033]

[Chemical 14]

[In the formula, R ⁷ is the same as defined above. ] Or a compound represented by the general formula (IX)

[0035]

[Chemical 15]

[In the formula, R ⁷ and Ar ¹ are the same as defined above. ] It is a compound represented by these. The alkyl aryl carbonate compound has the general formula (XIV)

[0037]

[Chemical 16]

[In the formula, R ⁷ and Ar ² are the same as defined above. ] Or a compound represented by the general formula (XV)

[0039]

[Chemical 17]

[In the formula, R ⁷ , Ar ¹ and Ar ² are the same as defined above. ] It is a compound represented by these. Here, examples of the carbonic acid diaryl compound include diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, bis (diphenyl) carbonate, and bisphenol A bisphenyl carbonate.
Examples of the dialkyl carbonate compound include diethyl carbonate, dimethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, bisphenol A bismethyl carbonate and the like. Examples of the alkyl aryl carbonate compound include methylphenyl carbonate, ethylphenyl carbonate, butylphenyl carbonate, cyclohexylphenyl carbonate, bisphenol A methylphenyl carbonate and the like. In the present invention, as the carbonic acid diester as the component (B), the above compounds are appropriately selected and used. Among these, diphenyl carbonate is preferably used.

The production method of the present invention is to obtain a polycarbonate by a transesterification reaction 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-butylphenol; mn-
Butylphenol; pn-butylphenol; o-isobutylphenol; m-isobutylphenol; p-
Isobutylphenol; ot-butylphenol; m
-T-butylphenol; pt-butylphenol;
nn-pentylphenol; mn-pentylphenol; pn-pentylphenol; nn-hexylphenol; mn-hexylphenol; pn-hexylphenol; o-cyclohexylphenol; m
-Cyclohexylphenol; p-cyclohexylphenol; o-phenylphenol; m-phenylphenol; p-phenylphenol; nn-nonylphenol; mn-nonylphenol; pn-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

[0042]

[Chemical 18]

Examples of the compound represented by

[0044]

[Chemical 19]

Examples include monohydric phenols such as compounds represented by: Of these phenols, although not particularly limited in the present invention, p-tert-butylphenol; p
-Cumylphenol; p-phenylphenol and the like are preferable. Also, the formula

[0046]

[Chemical 20]

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.
Further, although a catalyst is not particularly required in the present invention, a known catalyst may be used for promoting the transesterification reaction. Specific examples of such a catalyst include simple substance of alkali metal or alkaline earth metal, oxide, hydroxide, amide compound, alcoholate, phenolate, or Zn.
Basic metal oxides such as O, PbO and Sb ₂ O ₃ , organic titanium compounds, soluble manganese compounds, Ca, Mg,
Acetate of Zn, Pb, Sn, Mn, Cd, Co or nitrogen-containing basic compound and boron compound, nitrogen-containing basic compound and alkali (earth) metal compound, nitrogen-containing basic compound and alkali (earth) metal Examples thereof include a combined catalyst of a compound and a boron compound.

The production method of the present invention comprises the above-mentioned component (A),
When a polycarbonate is produced by a transesterification reaction using a terminal terminating agent, a branching agent or the like as the component (B) and other components, the transesterification reaction is represented by the general formula (I).

[0049]

[Chemical 21]

The major feature is that the carbonyl group-containing nitrogen-containing organic compound represented by Here, R ¹ and R ² in the formula (I) are each a hydrogen atom,
An alkyl group having 1 to 10 carbon atoms (for example, methyl group, ethyl group, propyl group, n-butyl group, isobutyl group, amyl group, isoamyl group, hexyl group, octyl group, nonyl group, tert-butyl group, tert- Amyl group, tert-octyl group, etc.) or hydroxyl group. R ³ has 1 to 8 carbon atoms.
Alkylene group (for example, methylene group, ethylene group, propylene group, butylene group, penterylene group, hexylene group, etc.) or C 6-40 arylene group (for example,
A phenylene group, a naphthalene group, a phenanthrene group, etc., or a group in which an alkylene group and an arylene group are connected). R ⁴ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms (eg, methyl group, ethyl group, propyl group, n
-Butyl group, isobutyl group, amyl group, isoamyl group,
Hexyl group, octyl group, nonyl group, tert-butyl group,
(tert-amyl group, tert-octyl group, etc.), hydroxyl group or —OR ⁵ is shown. Here, R ⁵ is an alkyl group having 1 to 10 carbon atoms (eg, methyl group, ethyl group, propyl group, n
-Butyl group, isobutyl group, amyl group, isoamyl group,
Hexyl group, octyl group, nonyl group, tert-butyl group,
tert-amyl group, tert-octyl group, etc.) or carbon number 6
To 40 aryl groups (for example, a phenyl group, a naphthyl group, a phenanthryl group, etc., or a group in which an alkylene group and an aryl group are connected).

There are various carbonyl group-containing nitrogen-containing organic compounds represented by the above general formula (I).
For example, 5-amino-2-pentanone, 5-dimethylamino-2-pentanone, 5-diethylamino-2-pentanone, 5-dipropyl-amino-2-pentanone, 5
-Dibutyl-amino-2-pentanone; 6-amino-2
-Hexanone, 6-dimethylamino-2-hexanone,
6-diethylamino-2-hexanone, 6-dipropylamino-2-hexanone, 6-dibutylamino-2-hexanone; 7-amino-2-heptanone, 7-dimethylamino-2-heptanone, 7-diethylamino-2- Heptanone, 7-dipropylamino-2-heptanone, 7
-Dibutylamino-2-heptanone; 6-amino-3-
Hexanone, 6-dimethylamino-3-hexanone, 6
-Diethylamino-3-hexanone, 6-dipropylamino-3-hexanone, 6-dibutylamino-3-hexanone; 7-amino-3-heptanone, 7-dimethylamino-3-heptanone, 7-diethylamino-3-heptanone , 7-dipropylamino-3-heptanone, 7-
Dibutylamino-3-heptanone; 8-amino-3-octanone, 8-dimethylamino-3-octanone, 8-
Examples include diethylamino-3-octanone, 8-dipropylamino-3-octanone, 8-dibutylamino-3-octanone and the like.

Further, 4-aminobutyric acid, 4-dimethylaminobutyric acid, 4-diethylaminobutyric acid, 4-dipropylaminobutyric acid, 4-dibutylaminobutyric acid; 5-aminovaleric acid,
5-Dimethylaminovaleric acid, 5-diethylaminovaleric acid, 5-dipropylaminovaleric acid, 5-dibutylaminovaleric acid; 6-aminocaproic acid, 6-dimethylaminocaproic acid, 6-diethylaminocaproic acid, 6-dipropylaminocaproic acid Acid, 6-dibutylaminocaproic acid; methyl 4-aminobutyrate, methyl 4-dimethylaminobutyrate, methyl 4-diethylaminobutyrate; methyl 5-aminovalerate, methyl 5-dimethylaminovalerate, methyl 5-diethylaminovalerate; 4 -Phenyl aminovalerate,
Examples thereof include phenyl 4-dimethylaminovalerate, phenyl 4-diethylaminovalerate, phenyl 5-aminovalerate, phenyl 5-dimethylaminovalerate and phenyl 5-diethylaminovalerate. These carbonyl group-containing nitrogen-containing organic compounds may be used alone or in combination of two or more.

When the transesterification reaction is carried out with the components (A) and (B) as the main components, the carbonyl group-containing nitrogen-containing organic compound is 1 to 10 relative to the dihydroxy compound of the component (A). ^-7 mol / mol, preferably 10 ^-2 to 10 ^-6 mol / mol, and added together. If the carbonyl group-containing nitrogen-containing organic compound is less than 10 ^-7 mol / mol, the effect aimed at by the present invention is not exhibited. Further, if it exceeds 1 mol / mol, the effect is not exhibited in the ratio to be added, which leads to an increase in cost, which is not preferable.

In the production method of the present invention, specifically, the reaction may be carried out under the above-mentioned conditions 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 of the component (A) and the carbonic acid diester of the component (B) are charged in a ratio such that the carbonic acid diester is 1 to 1.5 times the mol of the dihydroxy compound, and then the component (A) and A predetermined amount of the carbonyl group-containing nitrogen-containing organic compound is added to the total amount of the component (B), and a normal transesterification reaction is performed. Depending on the situation, the amount of the carbonic acid diester is preferably 1.02 to 1.20 times the molar amount of the dihydroxy compound, which is slightly excessive. In the above transesterification reaction, the amount of the terminal terminator composed of the monohydric phenol or the like is
With respect to 1 mol of the dihydroxy compound which is the component (A),
When the amount is in the range of 0.05 mol% to 10 mol%, the hydroxyl group terminal of the obtained polycarbonate is sealed, so that a polycarbonate having sufficiently excellent heat resistance and water resistance can be obtained. The total amount of such a terminal terminator composed of the 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 whole amount may be added to the reaction system after the transesterification reaction of the dihydroxy compound (A) and the carbonic acid diester (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 100 ° C to 330 ° C, preferably 180 ° C to 300 ° C, more preferably the reaction. It is better to gradually raise the temperature to 180 ° C to 300 ° C according to the progress of. If the transesterification reaction is lower than 100 ° C., the progress of the reaction is slow, and if it exceeds 330 ° C., thermal deterioration of the polymer may occur, which may not be 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 38,000)
It is often the case that the atmospheric pressure (normal pressure) up to the torr) or the pressurized state is kept, and in the latter stage of the reaction, the reduced pressure state, preferably finally 0.01 to 100 torr. Further, the reaction time may be carried out until the target molecular weight is reached, and usually,
It is about 0.2 to 10 hours.

In the present invention, an antioxidant can be used if necessary. Specific examples include phosphorus-based antioxidants such as tris (nonylphenyl) phosphite, trisphenylphosphite, 2-ethylhexyldiphenylphosphite, trimethylphosphite, triethylphosphite, tricresylphosphite, and triarylphosphite. There is.

In the present invention, as the reaction proceeds, phenols corresponding to the carbonic acid diester used,
Alcohols or their esters and 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. In the case of continuous production, it is preferable to use at least two reactors and set the above reaction conditions. The structure of the reactor used in the present invention is not particularly limited as long as it 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 when used in combination with a polyphenylene ether having a terminal group such as a group, a polyether nitrile, a terminal-modified polysiloxane compound, a modified polypropylene, and a modified polystyrene.

[0059]

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. Examples 1 to 5 and Comparative Examples 1 to 3 In a nickel steel autoclave (with a stirrer) having an internal volume of 1.4 liters, 228 g of bisphenol A (BPA)
(1.0 mol) and 225 g of diphenyl carbonate (1.0 mol)
5 mol) was charged, the carbonyl group-containing amine compound shown in Table 1 was added, and nitrogen substitution was performed 5 times. 1 mixture
The bisphenol A and diphenyl carbonate were melted by heating to 80 ° C. Next, the temperature is set to 220 ° C.,
At the same time, stirring was started and a small amount of nitrogen was passed through, and the produced phenol started to be distilled off. The temperature of the reactants is 220
It was kept at 0 ° C for 1 hour. Then set the temperature to 240 ℃,
The vacuum degree was gradually raised to 10 mmHg and the reaction was carried out for 1 hour. Then, the temperature was set to 270 ° C., the vacuum degree was set to 1 mmHg, and the reaction was performed for 1 hour. Finally, a viscous and transparent condensate (PC) was obtained in the autoclave. The viscous and transparent condensate obtained was dissolved in methylene chloride, and the viscosity average molecular weight was measured. The viscous and transparent condensate obtained is crushed,
Pelletized at 220-270 ° C using an extruder. The obtained pellets were injection-molded and the hydrolysis resistance was measured. Table 1 shows the measurement results of Examples 1 to 5 and Comparative Examples 1 to 3.

[0060]

[Table 1]

The viscosity average molecular weight and hydrolysis resistance were measured as follows. 1) Viscosity average molecular weight (Mv) The viscosity of a methylene chloride solution at 20 ° C was measured with an Ubbelohde type viscosity tube, and the intrinsic viscosity [η] was calculated from this, and then calculated by the following formula. [Η] = 1.23 × 10 ⁻⁵ × Mv ^0.83 2) Hydrolysis resistance The plate (thickness: 3 mm) was visually observed for a state after being exposed to 121 ° C. steam for 48 hours.

[0062]

As described above, according to the present invention, when the transesterification reaction is carried out in the presence of a carbonyl group-containing nitrogen-containing organic compound, the color tone can be improved without impairing the hydrolysis resistance. It is possible to efficiently produce excellent polycarbonate. Therefore, the present invention can be effectively and widely used as a method for industrially producing a polycarbonate by a transesterification method.

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[Procedure amendment]

[Submission date] June 30, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0060

[Correction method] Change

[Correction content]

[0060]

[Table 1]

Claims (2)

[Claims] 1. A method for producing a polycarbonate from a (A) dihydroxy compound and a (B) carbonic acid diester by a transesterification method, wherein the transesterification reaction is carried out in the coexistence of a carbonyl group-containing nitrogen-containing organic compound. Polycarbonate manufacturing method. 2. A carbonyl group-containing nitrogen-containing organic compound,
General formula (I) [In the formula, R ¹ and R ² are a hydrogen atom and a carbon number 1 respectively.
10 represents an alkyl group or a hydroxyl group, and R ³ has 1 carbon atom
To an alkylene group having 8 to 8 carbon atoms or an arylene group having 6 to 40 carbon atoms, R ⁴ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxyl group or —OR ⁵ (wherein R ⁵ is 1 to 1 carbon atoms).
It is an alkyl group of 0 or an aryl group of 6 to 40 carbon atoms. ) Is shown. ] It is represented by these, The Claim 1 characterized by the above-mentioned.
A method for producing the described polycarbonate.