JP6435953B2 - Method for producing polycarbonate resin and polycarbonate resin - Google Patents

Description

  The present invention relates to a polycarbonate resin production method and a polycarbonate resin. More specifically, the present invention relates to a method for producing a polycarbonate resin having excellent color tone and a small amount of specific heterogeneous bonds, and a polycarbonate resin.

Polycarbonate resin is a resin with excellent heat resistance, mechanical properties, optical properties, and electrical properties. For example, it is widely used in automobile materials, electrical and electronic equipment materials, housing materials, and other parts manufacturing materials in industrial fields. ing.
As a method for producing such a polycarbonate resin, several methods are known. A raw material dihydroxy compound (for example, bisphenol A) and a carbonic acid diester (for example, a diaryl carbonate such as diphenyl carbonate) are mixed with an ester. There is a method (melting process) for producing a polycarbonate resin by transesterification in the presence of an exchange catalyst. Compared to other polycarbonate resin manufacturing processes, this manufacturing method has several advantages, such as not using an environmentally affecting solvent, less energy required for manufacturing, and less impurities such as contaminated chlorine in the product. Therefore, it is preferable as a commercial process, and various studies have been made in recent years.

  As the transesterification catalyst, a catalyst having a metal catalyst such as an alkali metal, an alkaline earth metal, or a transition metal is conventionally known. In addition, as a transesterification catalyst, Patent Document 1 discloses a method for producing a polycarbonate resin using a catalyst having a quaternary onium salt such as a phosphonium salt or an ammonium salt. , A method for producing a polycarbonate resin using an organic base catalyst such as a nitrogen-containing basic compound is disclosed, and Patent Document 3 and Patent Document 4 disclose a catalyst having both the metal catalyst and the organic base catalyst. A method for producing a polycarbonate resin using the above is disclosed.

Special table 2004-526839 gazette Japanese Unexamined Patent Publication No. 7-82363 Japanese Patent Laid-Open No. 5-1145 JP 7-109346 A

  In a method for producing a polycarbonate resin by a melt process, a raw material dihydroxy compound and a carbonic acid diester are brought into a molten state, and a transesterification catalyst is added to the mixture in the molten state to carry out a transesterification reaction. Polycarbonate as a polymer is produced by polycondensation while distilling off mono-hydroxy compounds such as phenol as a by-product generated in the reaction under high vacuum conditions. In the entire polymerization process, the reaction is carried out while maintaining a high temperature. By doing so, side reactions occur simultaneously. By that side reaction. There has been a problem that a coloring component for coloring the obtained polycarbonate resin and a specific by-product that adversely affects the weather resistance and fluidity of the obtained polycarbonate resin are produced.

Conventionally, when a metal catalyst is generally used as a transesterification catalyst in the production of polycarbonate resin, this problem is particularly prominent, and in addition, the thermal stability of the obtained polycarbonate resin, particularly during melt residence There were also problems of poor color tone stability and hydrolysis resistance at high temperatures.
On the other hand, the method for producing a polycarbonate resin using the organic base catalyst described in Patent Document 2 described above produces less by-products than the method for producing a polycarbonate resin using a metal catalyst. Although there is a tendency, since the color tone of the obtained polycarbonate resin tends to deteriorate, it was not a sufficiently satisfactory catalyst in the production method of polycarbonate resin at an industrial level. Moreover, in the method of producing a polycarbonate resin using the above organic base catalyst, since the organic base used for the catalyst is easily volatilized under reduced pressure, the compound is used as a catalyst until the final stage of the polymerization of the transesterification reaction. It could not continue to exist in the reaction system, resulting in a problem that the polymerization activity was lost and it was difficult to obtain a polycarbonate resin having a high molecular weight.

  In the method using the metal salt catalyst and the organic base catalyst described in Patent Document 3 and Patent Document 4 described above, when the blending amount of the metal salt catalyst is increased in order to increase the polymerization activity, the increase corresponds to the increase. As a by-product increases, the color tone of the obtained polycarbonate resin also deteriorates, so that the deterioration of the quality of the obtained polycarbonate resin can be suppressed while maintaining the polymerization activity. It wasn't possible.

  The present invention was devised in view of these problems, and is a polycarbonate production method capable of exhibiting sufficient polymerization activity up to the final polymerization stage and suppressing side reactions, and reducing specific by-products. At the same time, an object of the present invention is to provide an industrially advantageous method for producing a polycarbonate resin for obtaining a polycarbonate resin in which the color tone of the obtained polycarbonate resin is improved in a well-balanced manner.

As a result of intensive studies to solve the above-mentioned problems, the present inventors paid attention to the reactivity and side reaction suppression during the production of polycarbonate resin, the relationship between the volatility and the molecular structure of the compound constituting the transesterification catalyst, It has been found that the above-mentioned problems can be solved by combining an amine compound having a specific three-dimensional structure and a quaternary onium salt, and the present invention has been completed.
That is, the gist of the present invention resides in the following [1] to [4].
[1] A method for producing a polycarbonate resin, wherein the catalyst comprises hexamethylenetetramine and a quaternary onium salt in producing a polycarbonate resin by transesterification of a dihydroxy compound and a carbonic acid diester in the presence of a catalyst. .
[2] The amount of the hexamethylenetetramine is 0.01 to 10000 μmol with respect to 1 mol of the dihydroxy compound, and the amount of the quaternary onium salt is 0.01 with respect to 1 mol of the dihydroxy compound. The method for producing a polycarbonate resin according to [1], which is 10000 μmol.
[3] The method for producing a polycarbonate resin according to [1] or [2], wherein the quaternary onium salt is a quaternary phosphonium salt.
[4] A polycarbonate resin produced by the method for producing a polycarbonate resin according to any one of [1] to [3],
The total amount of the compounds represented by the following formulas (1) to (5) present in the compound obtained by hydrolyzing the polycarbonate resin is 100 ppm or more and 800 ppm or less with respect to the entire polycarbonate resin. Polycarbonate resin.

(In the formulas (1) to (5), R ^{1 to} R ⁵ and R ⁶ each independently represent a hydrogen atom or a methyl group. In the aromatic rings in the formulas (1) to (5), the aromatic ring One or more hydrogen atoms bonded to are substituted by an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a phenyl group, a vinyl group, a cyano group, an ester group, an amide group, a nitro group, or the like. May be.)

According to the present invention, by using a catalyst comprising an amine compound having a specific structure and a quaternary onium salt as a transesterification catalyst, side reactions can be suppressed while maintaining the reaction activity, and the color tone is improved. And polycarbonate with improved by-product reduction can be produced in a well-balanced manner.
Further, the polycarbonate resin obtained by the method for producing a polycarbonate resin of the present invention can be used as an automobile material, an electrical / electronic equipment material, a housing material, a material for manufacturing parts in other industrial fields, etc. It can also be suitably used when an additive is compounded.

Hereinafter, the present invention will be described in detail with reference to embodiments and examples, but the present invention is not limited to the embodiments and examples described below, and may be arbitrarily selected without departing from the scope of the present invention. It can be implemented by changing.
In the method for producing a polycarbonate resin according to the present invention, in the presence of a catalyst, a carbonic acid diester and a dihydroxy compound are polycondensed by a transesterification reaction to obtain a polycarbonate resin, and the catalyst has a specific structure. This is a method for producing a polycarbonate resin using a catalyst comprising an amine compound and a quaternary onium salt.

[1. Dihydroxy compound]
In the method for producing a polycarbonate resin of the present invention, one of the raw materials, the dihydroxy compound, is a compound having two hydroxyl groups in the molecule. Such a dihydroxy compound includes an aromatic dihydroxy compound having one or more aromatic rings in the molecule and two hydroxyl groups bonded to the aromatic ring, and two hydroxyl groups bonded to the aromatic ring. Aliphatic dihydroxy compounds which are ˜tertiary aliphatic alcohols. In the method for producing a polycarbonate resin of the present invention, the dihydroxy compound preferably contains at least one aromatic dihydroxy compound. Examples of the aromatic dihydroxy compound include the following.

Dihydroxybenzenes such as 1,2-dihydroxybenzene, 1,3-dihydroxybenzene (ie, resorcinol), 1,4-dihydroxybenzene;
Dihydroxybiphenyls such as 2,5-dihydroxybiphenyl, 2,2′-dihydroxybiphenyl, 4,4′-dihydroxybiphenyl, and the like;
2,2′-dihydroxy-1,1′-binaphthyl, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, , 7-dihydroxynaphthalene, dihydroxynaphthalene such as 2,7-dihydroxynaphthalene;
2,2′-dihydroxydiphenyl ether, 3,3′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether, 1,4-bis (3-hydroxyphenoxy) Dihydroxy diaryl ethers such as benzene and 1,3-bis (4-hydroxyphenoxy) benzene;

2,2-bis (4-hydroxyphenyl) propane (that is, bisphenol A, hereinafter sometimes abbreviated as “BPA”), 1,1-bis (4-hydroxyphenyl) propane, 2,2-bis ( 3-methyl-4-hydroxyphenyl) propane, 2,2-bis (3-methoxy-4-hydroxyphenyl) propane, 2- (4-hydroxyphenyl) -2- (3-methoxy-4-hydroxyphenyl) propane 1,1-bis (3-tert-butyl-4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (3-cyclohexyl-4) -Hydroxyphenyl) propane, 2- (4-hydroxyphenyl) -2- (3-cyclohexyl-4-hydroxyphenyl) propane, α α′-bis (4-hydroxyphenyl) -1,4-diisopropylbenzene, 1,3-bis [2- (4-hydroxyphenyl) -2-propyl] benzene, bis (4-hydroxyphenyl) methane, bis ( 4-hydroxyphenyl) cyclohexylmethane, bis (4-hydroxyphenyl) phenylmethane, bis (4-hydroxyphenyl) (4-propenylphenyl) methane, bis (4-hydroxyphenyl) diphenylmethane, bis (4-hydroxyphenyl) naphthyl Methane, 1,1-bis (4-hydroxyphenyl) ethane, 1,2-bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 1,1-bis (4-Hydroxyphenyl) -1-naphthylethane, 1,1-bis (4-hydride) Loxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) pentane, 1,1-bis (4-hydroxyphenyl) hexane, 2,2-bis ( 4-hydroxyphenyl) hexane, 1,1-bis (4-hydroxyphenyl) octane, 2,2-bis (4-hydroxyphenyl) octane, 1-bis (4-hydroxyphenyl) hexane, 2-bis (4- Hydroxyphenyl) hexane, 4,4-bis (4-hydroxyphenyl) heptane, 2,2-bis (4-hydroxyphenyl) nonane, 1,10-
Bis (4-hydroxyphenyl) decane, 1,1-bis (4-hydroxyphenyl) dodecane,
Bis (hydroxyaryl) alkanes such as;

  1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,4-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) ) -3,3-dimethylcyclohexane, 1,1-bis (4-hydroxyphenyl) -3,4-dimethylcyclohexane, 1,1-bis (4-hydroxyphenyl) -3,5-dimethylcyclohexane, 1,1 -Bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis (4-hydroxy-3,5-dimethylphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis (4-hydroxyphenyl) -3-propyl-5-methylcyclohexane, 1,1-bis (4-hydroxypheny ) -3-tert-butyl-cyclohexane, 1,1-bis (4-hydroxyphenyl) -4-tert-butyl-cyclohexane, 1,1-bis (4-hydroxyphenyl) -3-phenylcyclohexane, 1,1 Bis (hydroxyaryl) cycloalkanes such as bis (4-hydroxyphenyl) -4-phenylcyclohexane;

Cardostructure-containing bisphenols such as 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene;
Spirobiindene diols such as 2,2,2 ′, 2′-tetramethyl-1,1′-spirobi- [1H-indene] -6,6′-diol;
Dihydroxy diaryl sulfides such as 4,4′-dihydroxydiphenyl sulfide, 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfide;
Dihydroxydiaryl sulfoxides such as 4,4′-dihydroxydiphenyl sulfoxide, 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfoxide;
Dihydroxydiaryl sulfones such as 4,4′-dihydroxydiphenyl sulfone and 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfone:
In addition, 1 type may be used for an aromatic dihydroxy compound and it may use 2 or more types together by arbitrary combinations and a ratio.

Examples of the aliphatic dihydroxy compound include the following.
Ethane-1,2-diol, propane-1,2-diol, propane-1,3-diol, 2,2-dimethylpropane-1,3-diol, 2-methyl-2-propylpropane-1,3- Alkanediols such as diol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol, decane-1,10-diol;
Cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,4-diol, 1,4-cyclohexanedimethanol, 4- (2-hydroxyethyl) cyclohexanol, 2,2,4, Cycloalkanediols such as 4-tetramethyl-cyclobutane-1,3-diol;

Glycols such as 2,2′-oxydiethanol (ie, ethylene glycol), diethylene glycol, triethylene glycol, propylene glycol, spiro glycol, etc .;
1,2-benzenedimethanol, 1,3-benzenedimethanol, 1,4-benzenedimethanol, 1,4-benzenediethanol, 1,3-bis (2-hydroxyethoxy) benzene, 1,4-bis ( 2-hydroxyethoxy) benzene, 2,3-bis (hydroxymethyl) naphthalene, 1,6-bis (hydroxyethoxy) naphthalene, 4,4′-biphenyldimethanol, 4,4′-biphenyldiethanol, 1,4- Bis (2-hydroxyethoxy) biphenyl, bisphenol A bis (2-hydroxyethyl) ether,
Aralkyldiols such as bisphenol S bis (2-hydroxyethyl) ether;

1,2-epoxyethane (ie ethylene oxide), 1,2-epoxypropane (ie propylene oxide), 1,2-epoxycyclopentane, 1,2-epoxycyclohexane, 1,4-epoxycyclohexane, 1-methyl Cyclic ethers such as -1,2-epoxycyclohexane, 2,3-epoxynorbornane, and 1,3-epoxypropane;
In addition, 1 type may be used for an aliphatic dihydroxy compound, and it may use 2 or more types together by arbitrary combinations and a ratio.

  As the dihydroxy compound in the method for producing a polycarbonate resin of the present invention, among aromatic dihydroxy compounds, aromatic bis (hydroxyaryl) alkanes are more preferable from the viewpoint of impact resistance and heat resistance, and bis (4-hydroxyphenyl). ) Alkanes are more preferred, and 2,2-bis (4-hydroxyphenyl) propane (ie, bisphenol A) is most preferred.

[2. Carbonic acid diester]
The method for producing a polycarbonate resin according to the present invention uses a carbonic acid diester represented by the following formula (6).

In Formula (6), R ⁷ and R ⁸ each independently represent an alkyl group having 1 to 30 carbon atoms, an aryl group, or an arylalkyl group. Hereinafter, when R ⁷ and R ⁸ are an alkyl group or an arylalkyl group, they may be referred to as dialkyl carbonate, and when they are an aryl group, they may be referred to as diaryl carbonate.
Among these, from the viewpoint of reactivity with the dihydroxy compound, both R ⁷ and R ⁸ are preferably aryl groups, and more preferably diaryl carbonates represented by the following formula (7).

In formula (7), R ⁹ and R ¹⁰ each independently represent a halogen atom, a nitro group, a cyano group, an alkyl group having 1 to 20 carbon atoms, an alkoxycarbonyl group having 1 to 20 carbon atoms, or 4 to 20 carbon atoms. And an aryl group having 6 to 20 carbon atoms, m and n each independently represents an integer of 0 to 5.
Specific examples of such a carbonic acid diester include dialkyl carbonates such as dimethyl carbonate, diethyl carbonate, and di-t-butyl carbonate, diphenyl carbonate (hereinafter sometimes referred to as “DPC”), and bis (4-methyl). Phenyl) carbonate, bis (4-chlorophenyl) carbonate, bis (4-fluorophenyl) carbonate, bis (2-chlorophenyl) carbonate, bis (2,4-difluorophenyl) carbonate, bis (4-nitrophenyl) carbonate, bis (Substituted) diaryl carbonates such as (2-nitrophenyl) carbonate, bis (methylsalicylphenyl) carbonate, and ditolyl carbonate are exemplified, and among them, diphenyl carbonate is preferable. In addition, these carbonic acid diester can be used individually or in mixture of 2 or more types.

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

  These carbonic acid diesters (including the above-mentioned substituted dicarboxylic acid or dicarboxylic acid ester, the same shall apply hereinafter) are usually used in excess with respect to the dihydroxy compound. That is, the carbonic acid diester is used in an amount of 1.01-1.30 times (molar ratio), preferably 1.02-1.20 times (molar ratio), relative to the dihydroxy compound. When the molar ratio is too small, the terminal OH groups of the obtained polycarbonate resin increase, and the thermal stability of the resin tends to deteriorate. On the other hand, if the molar ratio is too large, the transesterification reaction rate decreases, and it becomes difficult to produce a polycarbonate resin having a desired molecular weight, or the residual amount of carbonic acid diester in the resin increases. May cause odor when used as a product.

[3. Transesterification catalyst]
In the method for producing a polycarbonate resin of the present invention, a catalyst comprising hexamethylenetetramine and a quaternary onium salt is used as a transesterification catalyst. An example of a specific structural formula of hexamethylenetetramine of the present invention is represented by the following formula (8). Although the quaternary onium salt can suppress the color tone deterioration of the polycarbonate resin obtained, it is easy to decompose and volatilize at high temperature and high vacuum in the final stage of polymerization, but it should be used in combination with hexamethylenetetramine. Thus, the polymerization activity can be maintained without decomposition and volatilization of hexamethylenetetramine having a stable molecular structure until the final stage of polymerization. Moreover, since hexamethylenetetramine has a large molecular size, it is presumed that side reactions can be suppressed at a high rate.

  In the method for producing a polycarbonate resin of the present invention, the quaternary onium salt, which is one of the essential components constituting the catalyst, has a compound having an electron pair that does not participate in a chemical bond, and other cation forms by the electron pair. A compound formed by coordination bond with the above compound. Preferred examples of the onium salt include ammonium salts, phosphonium salts, sulfonium salts, and the like. Among these, from the viewpoint that the polymerization reaction of the polycarbonate resin can be promoted while suppressing coloring of the product, the ammonium salt or A phosphonium salt is preferred, and a phosphonium salt is particularly preferred.

Examples of such ammonium salts or phosphonium salts include heteroaromatic ammonium salts, and aliphatic and aromatic ammonium salts, aliphatic and aromatic phosphonium salts represented by the following formula (9).

R ¹¹ , R ¹² , R ¹³ and R ¹⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, an aryl group having 6 to 20 carbon atoms or an alkylaryl group having 7 to 20 carbon atoms, These alkyl groups or aryl groups may contain a substituent containing O, N, S, etc., and two adjacent alkyl groups may be bonded to form a heterocycle. More specifically, a pyrrolidine ring, a piperidine ring, a piperazine ring and a morpholine ring are included. A represents a nitrogen atom or a phosphorus atom.

When R ¹¹ , R ¹² , R ^13, and R ¹⁴ are alkyl groups having 1 to 30 carbon atoms, a straight chain hydrocarbon group, a branched hydrocarbon group, an alicyclic hydrocarbon group, and an arylalkyl group are preferable. . More specifically, examples of the linear hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, an octyl group, a cetyl group, and an octadecyl group. Examples of the branched hydrocarbon group include an isopropyl group, an isobutyl group, a tertiary butyl group, and a neopentyl group. Examples of the alicyclic hydrocarbon group include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, and a cycloheptyl group. Examples of the arylalkyl group include a benzyl group, a 2-phenylethyl group, and a 3-phenylpropyl group.

When R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are aryl groups having 6 to 20 carbon atoms, preferably a phenyl group, o-methylphenyl group, m-methylphenyl group, p-methylphenyl group, p-ethyl Examples thereof include a phenyl group, a p-tert-butylphenyl group, an octylphenyl group, a nonylphenyl group, an octadecylphenyl group, and a naphthyl group.
These alkyl groups or aryl groups may each contain a substituent containing O, N, S, etc., such as an alkoxy group, a carbomethoxy group, a cyano group, a thioalkyl group, and an alkylamino group. More specifically, as these substituents, methoxymethyl group, methoxyethyl group, cyanoethyl group, methylthioethyl group, dimethylaminoethyl group, methoxyphenyl group, butoxyphenyl group, cyanophenyl group, methylthiophenyl group, dimethylaminophenyl Group and the like.

These alkyl groups or aryl groups are preferably those that do not change under the reaction conditions. In particular, from the viewpoint of dispersibility in polycarbonate resin and reactivity, an alkyl group having 2 to 20 carbon atoms and an aryl group are preferable, and an alkyl group having 3 to 6 carbon atoms and a phenyl group are more preferable.
In the above formula (9), X is not particularly limited as long as X is an anion capable of forming a salt by coordination with a corresponding cation, but OH, OR ¹⁵ , OCOR ¹⁶ , HCO ₃ , NO ₃ , R′SO ₃ , SO ₄ , HSO ₄ , ClO ₄ , BR ¹⁷ ₄ , or PR ¹⁸ ₆ is represented.

R ¹⁵ and R ¹⁶ represent an alkyl group or an aryl group, and may contain an alkyl group or an aryl group containing a substituent. More specifically, a linear hydrocarbon group, a branched hydrocarbon group, an alicyclic hydrocarbon group, an arylalkyl group, a fluoroalkyl group, a phenyl group, and a naphthyl group can be mentioned. Specific examples include a methyl group, an ethyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an octyl group, a trifluoromethyl group, a p-methylphenyl group, and a 2-naphthyl group.

R ¹⁷ and R ¹⁸ represent at least one selected from a hydrogen atom, a halogen atom, an alkyl group and an aryl group, and the alkyl group and the aryl group may include an alkyl group or an aryl group containing a substituent. good. More specifically, a linear hydrocarbon group, a branched hydrocarbon group, an alicyclic hydrocarbon group, an arylalkyl group, a fluoroalkyl group, a phenyl group, and a naphthyl group can be mentioned. Specific examples include a methyl group, an ethyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an octyl group, a trifluoromethyl group, a p-methylphenyl group, and a 2-naphthyl group. The four R ¹⁷ may be the same or different, and the six R ¹⁸ may be the same or different.

  Among such quaternary onium salts, examples of ammonium salts 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 Dorokisaido, methyltriphenylphosphonium ammonium hydroxide, such as butyl triphenyl ammonium hydroxide tetra (aryl or alkyl) ammonium hydroxides;

Tetramethylammonium chloride, tetra-n-butylammonium chloride, tetra-n-amylammonium bromide, n-tetradecyltrimethylammonium chloride, tetraethylammonium fluoride, tetra-n-hexylammonium iodide, tetra-n-octylammonium bromide , Trimethylstearylammonium chloride, trimethylvinylammonium bromide, dimethyldipalmitylammonium bromide, benzyltributylammonium chloride, carbamylcholine chloride, carnitine hydrochloride, chlorocholine chloride tetra-n-butylammonium azide, etc. ) Ammonium halides; and tetra-n-butylammonium borohydride, te Trabutylammonium hydrogen sulfate, tetramethylammonium sulfate, tetraethylammonium tetrafluoroborate, tetraethylammonium p-toluenesulfonate, tetraethylammonium trifluoromethanesulfonate, tetraethylammonium triflate, tetramethylammonium acetate, tetramethylammonium hexafluorophosphate, tetra And methyl ammonium perchlorate.

  Among such quaternary onium salts, phosphonium salts include, for example, tetramethylphosphonium hydroxide, tetraethylphosphonium hydroxide, tetrabutylphosphonium hydroxide, tetraphenylphosphonium hydroxide, tetranaphthylphosphonium hydroxide, tetra (chlorophenyl) ) Tetra (aryl or alkyl) phosphonium hydroxides such as phosphonium hydroxide, tetra (biphenyl) phosphonium hydroxide, tetratolylphosphonium hydroxide;

Tetra (aryl or alkyl) phosphonium alcoholates such as tetrabutylphosphonium phenolate, triphenylbutylphosphonium phenolate, tetraphenylphosphonium phenolate;
Tetrabutylphosphonium bromide, methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, n-butyltriphenylphosphonium bromide, methoxymethyltriphenylphosphonium chloride, benzyltriphenylphosphonium chloride, tetraphenylphosphonium chloride, tetraphenylphosphonium bromide, etc. (Aryl or alkyl) phosphonium halides;

  Tetramethylphosphonium tetraphenylborate, tritertiary butylphosphonium tetraphenylborate, tetraphenylphosphonium tetraphenylborate, methyltriphenylphosphonium tetraphenylborate, benzyltriphenylphosphonium tetraphenylborate, biphenyltriphenylphosphonium tetraphenylborate, tetratolylphosphonium Tetra (aryl or alkyl) phosphonium borates such as tetraphenylborate, tetraphenylphosphonium tetra-p-tolylborate;

Tetrabutylphosphonium acetate, tetrabutylphosphonium octylate,
Tetra (aryl or alkyl) phosphonium carboxylates such as tetrabutylphosphonium laurate;
Tetra (aryl or alkyl) diphosphonium salts such as tetra (pt-butylphenyl) phosphonium diphenyl phosphate;

  Among these, from the viewpoint of reaction activity and colorability of the polycarbonate resin, tetra (aryl or alkyl) ammonium hydroxides, tetra (aryl or alkyl) phosphonium hydroxides, tetra (aryl or alkyl) phosphonium alcoholates, tetra (Aryl or alkyl) phosphonium borates and tetra (aryl or alkyl) phosphonium carboxylates are preferred. Specifically, tetramethylammonium hydroxide, tetrabutylphosphonium hydroxide, tetrabutylphosphonium acetate, tetraphenylphosphonium tetraphenylborate, and tetraphenylphosphonium tetra-p-tolylborate are preferable.

  In the method for producing a polycarbonate resin of the present invention, the amount of hexamethylenetetramine used is preferably 0.01 μmol or more, more preferably 0.1 μmol or more, still more preferably 1 μmol, relative to 1 mol of the dihydroxy compound. Above, most preferably 10 μmol or more. On the other hand, the amount of hexamethylenetetramine used is preferably 10000 μmol or less, more preferably 1000 μmol or less, still more preferably 500 μmol or less, and most preferably 200 μmol or less with respect to 1 mol of the dihydroxy compound. When the amount of hexamethylenetetramine used is less than 0.01 μmol, polymerization activity cannot be obtained, and in order to obtain a desired high molecular weight polycarbonate resin, the residence time must be lengthened. There is a risk that the color tone will deteriorate. On the other hand, when the amount of hexamethylenetetramine used exceeds 10000 μmol, the generation of heterogeneous bond structures is accelerated, and there is a possibility that by-products are increased.

In addition, the amount of the quaternary onium salt used in the method for producing the polycarbonate resin of the present invention is preferably 0.01 μmol or more, more preferably 0.1 μmol or more, and even more based on 1 mol of the dihydroxy compound. Preferably it is 1 micromol or more, Most preferably, it is 10 micromol or more. On the other hand, the amount of the quaternary onium salt used is preferably 10000 μmol or less, more preferably 1000 μmol or less, even more preferably 500 μmol or less, and most preferably 200 μmol or less with respect to 1 mol of the dihydroxy compound. . When the amount of the quaternary onium salt used is less than 0.01 μmol, the desired polymerization activity cannot be obtained, and the residence time must be lengthened to reach the predetermined molecular weight, and the color tone deteriorates. Therefore, it is not preferable. On the other hand, when the amount of the quaternary onium salt used exceeds 10,000 μmol, the formation of heterogeneous bond structures is accelerated and the amount of by-products increases, which is also not preferable.

  In the method for producing a polycarbonate resin of the present invention, in addition to the above-described hexamethylenetetramine and quaternary onium salt as a transesterification catalyst within a range not significantly inhibiting the effects of the present invention, a compound other than these is further used as a catalyst component. It may be used. Specifically, a basic compound different from hexamethylenetetramine and a quaternary onium salt may be further added. As such a compound, at least one selected from the group consisting of compounds of Group 1 elements (excluding hydrogen), compounds of Group 2 elements, basic boron compounds, basic phosphorus compounds, and nitrogen-containing basic compounds. The above compounds are mentioned.

The group 1 element (excluding hydrogen) includes an inorganic compound such as a hydroxide, carbonate, hydrogen carbonate compound, etc. of the group 1 element (excluding hydrogen); Group 1 element (excluding hydrogen) Organic compounds such as salts with alcohols, phenols, and organic carboxylic acids. Here, as a group 1 element (except hydrogen), lithium, sodium, potassium, rubidium, and cesium are mentioned, for example. Among these group 1 elements (excluding hydrogen), cesium compounds are preferable, and cesium carbonate, cesium hydrogen carbonate, and cesium hydroxide are particularly preferable.

Examples of the Group 2 element compounds include hydroxides such as beryllium, magnesium, calcium, strontium, and barium; inorganic compounds such as carbonates; and alcohols, phenols, and organic carboxylic acids. Examples include salts.
Examples of the basic boron compound include sodium salts, potassium salts, lithium salts, calcium salts, magnesium salts, barium salts, and strontium salts 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 triethylphosphine, tri-n-propylphosphine, triisopropylphosphine, tri-n-butylphosphine, triphenylphosphine, tributylphosphine, triphenylphosphine, and tri-t-butyl. And trivalent phosphorus compounds such as phenylphosphine.
Examples of the nitrogen-containing basic compound include 4-aminopyridine, 2-aminopyridine, N, N-dimethyl-4-aminopyridine, 4-diethylaminopyridine, 2-hydroxypyridine, 2-methoxypyridine, and 4-methoxy. Examples include amine compounds such as pyridine, 2-dimethylaminoimidazole, 2-methoxyimidazole, imidazole, 2-mercaptoimidazole, 2-methylimidazole, and aminoquinoline.

  In the method for producing a polycarbonate resin of the present invention, the range of the ratio of the compound other than hexamethylenetetramine and quaternary onium salt that may be included as a catalyst component is the total amount of hexamethylenetetramine and quaternary onium salt: base It is usually in the range of 10000: 1 to 3: 1, preferably in the range of 5000: 1 to 5: 1, more preferably in the range of 1000: 1 to 10: 1. Deviating from the above range is not preferable because it may cause a problem that the amount of by-products increases.

  In the method for producing a polycarbonate resin of the present invention, the transesterification catalyst may be previously dissolved in a solvent and used as a diluted solution. Thus, by using it as a diluted solution, feed accuracy and dispersibility in the raw material can be improved. The solvent and concentration to be used are not particularly limited and may be appropriately selected depending on the solubility. Examples of the solvent include water, phenol, acetone, alcohol, toluene and the like. The properties of water when water is used as the solvent are not particularly limited as long as the type and concentration of impurities contained are constant, but usually distilled water, deionized water, and the like are preferably used.

[4. Production of polycarbonate resin]
In the method for producing a polycarbonate resin of the present invention, the dihydroxy compound as a raw material and a carbonic acid diester are mixed, and this raw material mixture is subjected to a polycondensation reaction in a polycondensation reaction apparatus in the presence of the transesterification reaction catalyst. Done. As the reaction system of this polycondensation step, a batch system, a continuous system, a combination thereof, or the like can be used. After the polycondensation step, the reaction is stopped and the unreacted raw materials and reaction by-products in the polymerization reaction solution are devolatilized and removed, the step of adding a thermal stabilizer, a release agent, etc. A polycarbonate resin is manufactured through the process of forming into a pellet.

The polycondensation step is usually carried out continuously in two or more stages, preferably in a multistage system of 3 to 7 stages. Specific reaction conditions are temperature: 150 ° C. to 320 ° C., pressure: normal pressure to 0.01 Torr (1.3 Pa), and average residence time: 5 minutes to 150 minutes.
In the multi-stage system, in order to more effectively remove by-product phenol as the polycondensation reaction proceeds in the polycondensation reaction apparatus, the temperature is gradually increased to a higher vacuum within the above reaction conditions. Set. In order to prevent quality deterioration such as hue of the obtained polycarbonate resin, it is preferable to set a low temperature and a short residence time as much as possible.

When the polycondensation step is performed in a multistage system, usually, a plurality of reactors including a vertical reactor are provided to increase the average molecular weight of the polycarbonate resin. Usually, 3 to 6 groups, preferably 4 to 5 groups are installed.
Examples of the reactor include a stirred tank reactor, a thin film reactor, a centrifugal thin film evaporation reactor, a surface renewal biaxial kneading reactor, a biaxial horizontal stirring reactor, a wet wall reactor, a free fall For example, a perforated plate reactor that polymerizes while being dropped, a perforated plate reactor with wire that polymerizes while being dropped along the wire, and the like are used.

As the types of the stirring blades of the vertical reactor, for example, turbine blades, paddle blades, fiddler blades, anchor blades, full zone blades (manufactured by Shinko Pantech Co., Ltd.), Sun Meller blades (manufactured by Mitsubishi Heavy Industries, Ltd.), Max. Examples thereof include blend blades (manufactured by Sumitomo Heavy Industries, Ltd.), helical ribbon blades, and twisted lattice blades (manufactured by Hitachi, Ltd.).
By the way, the horizontal reactor refers to a reactor in which a rotating shaft of a stirring blade is a horizontal type (horizontal direction). As a stirring blade of a horizontal reactor, for example, a single-shaft type 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 a biaxial stirring blade such as a spectacle blade or a lattice blade (manufactured by Hitachi, Ltd.).

[5. Polycarbonate resin]
The molecular weight of the polycarbonate resin obtained by the method for producing a polycarbonate resin of the present invention is arbitrary and may be appropriately selected and determined. The viscosity average molecular weight [Mv] converted from the solution viscosity is usually 5000 or more, preferably Is 10000 or more, more preferably 15000 or more. On the other hand, it is usually 40000 or less, preferably 30000 or less, more preferably 24000 or less. By setting the viscosity average molecular weight to be equal to or higher than the lower limit of the above range, the mechanical strength of the polycarbonate resin of the present invention can be further improved, which is more preferable when used for applications requiring high mechanical strength. On the other hand, by setting the viscosity average molecular weight to be equal to or lower than the upper limit of the above range, the polycarbonate resin of the present invention can be suppressed and improved in fluidity, and the molding processability can be improved and the molding process can be easily performed.

The viscosity average molecular weight [Mv] is obtained by using methylene chloride as a solvent and obtaining an intrinsic viscosity [η] (unit: dl / g) at a temperature of 20 ° C. using an Ubbelohde viscometer. , Η = 1.23 × 10 ⁻⁴ Mv ^0.83 . The intrinsic viscosity [η] is a value calculated from the following equation by measuring the specific viscosity [η _sp ] at each solution concentration [C] (g / dl).

  The terminal hydroxyl group concentration of the polycarbonate resin produced by the method for producing a polycarbonate resin of the present invention is not particularly limited, but is preferably 1500 ppm or less, more preferably 1000 ppm or less, still more preferably 800 ppm or less, and particularly preferably 600 ppm or less. . As this concentration decreases, the residence heat stability of the polycarbonate resin tends to be further improved. On the other hand, the terminal hydroxyl group concentration of the polycarbonate resin is preferably 50 ppm or more, more preferably 100 ppm or more, more preferably 150 ppm or more, and further preferably 200 ppm or more. As this density increases, the color tone tends to improve.

The unit of the terminal hydroxyl group concentration is the weight of the terminal hydroxyl group expressed in ppm relative to the weight of the polycarbonate resin. The measurement method is colorimetric determination (method described in Macromol. Chem. 88 215 (1965)) by the titanium tetrachloride / acetic acid method.
Moreover, when the polycarbonate resin obtained by the manufacturing method of the polycarbonate resin of this invention uses the dihydroxy compound containing bisphenol A as a raw material dihydroxy compound, when hydrolyzing the obtained polycarbonate resin, for example, following formula (1) ) To (5) may contain by-products, and the presence of these by-products includes hetero-bonded structural units derived from bisphenol A in the structural units of the resulting polycarbonate resin. It means that.

In formulas (1) to (5), R ^{1 to} R ⁵ and R ⁶ each independently represent a hydrogen atom or a methyl group. In the aromatic rings in the formulas (1) to (5), one or more hydrogen atoms bonded to the aromatic ring are an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a phenyl group, or a vinyl group. , A cyano group, an ester group, an amide group, a nitro group and the like.
The content of these by-products can be measured by analyzing the polycarbonate resin after hydrolysis. The total amount of the compounds shown in (1) to (5) is preferably 800 ppm or less, more preferably 600 ppm or less, more preferably 500 ppm or less, based on the total amount of the obtained polycarbonate resin before hydrolysis. More preferably. If the total amount of by-products exceeds 800 ppm, the polycarbonate resin may deteriorate in color tone or weather resistance. On the other hand, the total amount of the compounds shown in (1) to (5) is preferably 0 ppm. However, when trying to reduce it extremely, it is necessary to lower the polymerization activity and react for a long time. Since there exists a malfunction that a color tone deteriorates, it is preferable to set it as 100 ppm or more normally from a viewpoint of a product color tone.

  The polycarbonate resin obtained by the method for producing a polycarbonate resin of the present invention has a good color tone, but specifically, it is pellet YI, usually 15 or less, preferably 10 or less, more preferably 8 It is as follows. By using a polycarbonate resin in such a range, the color developability and brightness when colored are improved, and the degree of freedom in product design is improved.

[6. Polycarbonate resin composition]
The polycarbonate resin obtained by the method for producing a polycarbonate resin of the present invention,
If necessary, other components such as a polycarbonate resin obtained by a method other than the method for producing a polycarbonate resin of the present invention, a resin other than the polycarbonate resin, and various resin additives may be blended and used. One or more of the other components may be contained in any combination and ratio.

  Examples of other resins include thermoplastic polyester resins such as polyethylene terephthalate resin, polytrimethylene terephthalate, and polybutylene terephthalate resin; polyolefin resins such as polyethylene resin and polypropylene resin; polyamide resins; polyimide resins; polyetherimide resins; Resin; Polyphenylene ether resin; Polyphenylene sulfide resin; Polysulfone resin; Polymethacrylate resin.

In addition, 1 type may contain other resin and 2 or more types may contain it by arbitrary combinations and ratios.
Examples of the resin additive include thermal stability, antioxidant, ultraviolet absorber, release agent, lubricant, dye / pigment, antistatic agent, antifogging agent, antiblocking agent, fluidity improver, plasticizer, and dispersion. Agents, antibacterial agents, impact modifiers, flame retardants, reinforcing materials such as glass fibers and carbon fibers, and fillers such as talc, mica and silica. In addition, 1 type may contain resin additive and 2 or more types may contain it by arbitrary combinations and a ratio.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples, and can be arbitrarily modified and implemented without departing from the gist of the present invention.
First, measurement methods for each evaluation will be described.

<Evaluation method>
<Hue evaluation (pellet YI)>
The hue of the polycarbonate resin was evaluated by measuring the YI value (yellow index value) in the reflected light of the polycarbonate resin pellets 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. 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, and YI was −. It was confirmed 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 was used. The smaller the YI value, the less yellow the resin is, and the better the color tone.

<Measurement of By-Product Content Represented by Formulas (1), (2), (3), (4) and (5) contained in Polycarbonate Resin>
After 0.5 g of polycarbonate resin was dissolved in 5 ml of methylene chloride, 45 ml of methanol and 5 ml of 25 wt% aqueous sodium hydroxide solution were added, and the mixture was stirred at 70 ° C. for 30 minutes for hydrolysis (methylene chloride solution). Thereafter, 6N hydrochloric acid was added to the methylene chloride solution to adjust the pH of the solution to about 2 and adjusted to 100 ml with pure water.

Next, 20 μl of the prepared methylene chloride solution was injected into the liquid chromatography, and the content of the compounds represented by the formulas (1), (2), (3), (4) and (5) was measured (unit: : P
pm).
Liquid chromatography and measurement conditions are as follows.
Liquid chromatography: LC-10AD manufactured by Shimadzu Corporation
Column: YMC PACK ODS-AM M-307-3
4.6mmID × 75mmL
Detector: UV280nm
Eluent: (A) 0.05% trifluoroacetic acid aqueous solution (B) Methanol Gradient conditions: 0 minutes (B = 40%), 25 minutes (B-95%)

  The content of the compounds represented by the formulas (1), (2), (3), (4) and (5) was calculated from the respective peak areas based on a calibration curve created with bisphenol A. Table 2 shows the results of measuring the content of the compounds represented by the formulas (1), (2), (3), (4) and (5) for the polycarbonate resins obtained in Examples and Comparative Examples described later. In the column of “heterologous binding amount”.

In addition, about the compound represented by Formula (1), (2), (3), (4), and (5), molecular weight and the above-mentioned analysis by the liquid chromatography mass spectrometer of the adjusted methylene chloride solution were carried out. The molecular formula was determined. Moreover, the structure was determined by performing the NMR analysis of the component which fractionated each peak detected by the liquid chromatography analysis.
In Table 1 below, raw materials and abbreviations used in Examples and Comparative Examples are described.

<Polymerization of polycarbonate resin>
BPA 116.71 g (0.51 mol) and DPC 116.09 (0.54 mol) were charged into a 150 mL glass reactor equipped with a reactor stirrer, reactor heating device, and reactor pressure regulator. The mixture was prepared by adding the transesterification catalyst shown in (1) to an arbitrary molar ratio with respect to 1 mol of the dihydroxy compound (BPA). In addition, hexamethylenetetramine, potassium carbonate, and cesium carbonate were prepared by preparing a 2% aqueous solution in advance when preparing the mixture containing the above-described transesterification catalyst.

  Next, the operation of depressurizing the inside of the glass reactor to about 100 Pa (0.75 Torr) and then restoring the pressure to the atmospheric pressure with nitrogen was repeated three times to replace the inside of the reactor with nitrogen. After the nitrogen replacement, the reactor external temperature was set to 220 ° C., the reactor internal temperature was gradually raised, and the mixture was dissolved. Then, the stirrer was rotated at 100 rpm. Then, while distilling out phenol by-produced by the oligomerization reaction of BPA and DPC performed in the reactor, the pressure in the reactor is increased from 101.3 kPa (760 Torr) to 13.3 kPa in absolute pressure over 40 minutes. The pressure was reduced to (100 Torr).

At this time, the pressure at which phenol began to distill was observed. This pressure at which phenol begins to distill represents the magnitude of the activity of the catalyst at the initial stage of polymerization, and a larger number represents a higher activity of the catalyst, which is preferable as an effect of the present invention. In Table 2, it was described as the phenol distillation start pressure (unit: Torr).
Subsequently, the transesterification reaction was carried out for 80 minutes while maintaining the pressure in the reactor at 13.3 kPa and further distilling off the phenol. Thereafter, the temperature outside the reactor is raised to 250 ° C., and the pressure inside the reactor is reduced from 13.3 kPa (100 Torr) to 399 Pa (3 Torr) over 40 minutes, and the distilled phenol is removed from the system. Removed. Thereafter, the external temperature of the reactor was further raised to 280 ° C., and the absolute pressure in the reactor was reduced to 30 Pa (about 0.2 Torr) to carry out a polycondensation reaction. The polycondensation reaction was terminated when the agitator of the reactor reached a predetermined stirring power.

The reaction time from the start of the reaction to the end of the reaction was measured and listed in Table 2 as the polymerization time (unit: min).
Next, the inside of the reactor is restored to an absolute pressure of 101.3 kPa with nitrogen and increased to 0.2 MPa with a gauge pressure, and the polycarbonate resin is drawn out in the form of a strand from the bottom of the reactor tank. And then pelletized using a rotary cutter.

  In Table 2, “Mv” is the viscosity average molecular weight of the aromatic polycarbonate resin produced in each Example and each Comparative Example, and the measurement method was measured by the method described above. “OH” in Table 2 is the terminal hydroxyl group concentration of the aromatic polycarbonate resin produced in each Example and each Comparative Example, and the measurement method was measured by the method described above.

From the evaluation results shown in Table 2, the following can be said.
In Examples 1 and 2 using hexamethylenetetramine and a quaternary onium salt as a specific amount catalyst within the scope of the present application, a polycarbonate resin having a sufficient polymerization activity, a reduced amount of heterogeneous bonds, and a good hue is obtained. Can be obtained.
On the other hand, it can be seen that Comparative Examples 1 and 2 using only a quaternary onium salt without hexamethylenetetramine have a large amount of heterogeneous bonds and a large amount of by-products.
In Comparative Example 3 using an alkali metal as a catalyst, the phenol distillation start pressure is low, the polymerization activity is poor, and the amount of heterogeneous bonds is large.

In Comparative Example 4 in which the amount of the alkali metal catalyst was further increased, the amount of heterogeneous bonds was further increased although the polymerization activity was good. Therefore, it can be seen that the alkali metal catalyst conventionally used cannot balance the polymerization activity and the amount of different bonds.
In Comparative Example 5 containing only hexamethylenetetramine, the polymerization activity was insufficient and
Since the color tone also deteriorates, it is not preferable.

  From the above, it can be seen that Examples 1 and 2, which satisfy the constituent requirements of the present invention, can provide a polycarbonate excellent in the balance of polymerization activity, quality of the amount of different bonds, and color tone.

Claims (3)

A process for producing a polycarbonate resin, wherein the catalyst comprises hexamethylenetetramine and a quaternary onium salt in producing a polycarbonate resin by a transesterification reaction between a dihydroxy compound and a carbonic acid diester in the presence of a catalyst. The amount of the hexamethylenetetramine is 0 with respect to 1 mol of the dihydroxy compound.
. The method for producing a polycarbonate resin according to claim 1, wherein the amount of the quaternary onium salt is 0.01 to 10,000 μmol with respect to 1 mol of the dihydroxy compound. The method for producing a polycarbonate resin according to claim 1 or 2, wherein the quaternary onium salt is a quaternary phosphonium salt.