JP2012031298A - Production method of polycarbonate resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method for producing an aromatic polycarbonate resin and a nonaromatic polycarbonate resin while favorably maintaining their color tones.SOLUTION: The production method of the polycarbonate resin produces a plurality of the polycarbonate resins containing the aromatic polycarbonate resins and the nonaromatic polycarbonate resins by using the same production equipment. The inside of the production equipment is cleaned by using an aromatic monohydroxy compound after producing the aromatic polycarbonate resin, and after that, the nonaromatic polycarbonate resin is produced.

Description

  The present invention relates to a method for producing a polycarbonate resin, and more particularly to a method for producing an aromatic polycarbonate resin and a non-aromatic polycarbonate resin by switching them in the same production facility.

Polycarbonate resins are excellent in mechanical properties such as impact resistance, heat resistance, transparency and the like, and are widely used for various mechanical parts, optical disks, automobile parts and the like.
As a method for producing such a polycarbonate resin, an aqueous alkaline solution of dihydroxy compounds represented by 2,2-bis (4-hydroxyphenylpropane) (hereinafter referred to as “bisphenol A”) and carbonyl chloride are organically used. A method of reacting at a phase interface in the presence of a solvent (interface method) and a method of subjecting a dihydroxy compound and a carbonic acid diester represented by diphenyl carbonate to a polycondensation reaction in the presence of a transesterification catalyst in a molten state (melting) Law) is known. Among these, the melting method based on the transesterification has an advantage that a polycarbonate resin can be produced at a lower cost than that of the interface method, and many types of dihydroxy compounds can be handled.

In general, since polycarbonate resins are used in many applications, it is necessary to produce a plurality of types of polycarbonate resins. On the other hand, when the polycarbonate resin is produced by the above-described melting method, since it is usually made in a production facility in which a plurality of reaction vessels are connected in series under reduced pressure, the reaction conditions such as the starting molar ratio of starting materials are changed. Switching loss occurs until the desired type of polycarbonate resin is obtained. Even in the batch method, although switching loss is reduced, in order to prevent deterioration of quality such as contamination and coloring of the previous raw material when it cannot be manufactured in large quantities or the type of dihydroxy compound itself is changed. However, there is a problem that a cleaning operation is required.
As a method of reducing such switching loss and quality deterioration, in a plurality of manufacturing apparatuses each connected with a plurality of reaction vessels, polycondensation of bisphenol A and diphenyl carbonate is performed in the preceding reaction vessel (preliminary polymerization step), and the subsequent step A method for continuously producing a plurality of types of aromatic polycarbonate resins by polycondensation (late polymerization step) in the reaction tank is reported (see Patent Document 1). In addition, using a plurality of polymerization equipment with a single raw material mixing tank, by adding additional diphenyl carbonate before the first reaction tank of the plurality of polymerization equipment, a plurality of aromatic polycarbonates having different molecular weights A method for continuously producing a resin has been reported (see Patent Document 2).
In addition, for the purpose of preventing coloring of the aromatic polycarbonate resin, a production method using a stainless steel reactor washed with a liquid containing an aromatic monohydroxy compound (see Patent Document 3), or after stopping the melt polycondensation reaction, And a method of dissolving and washing the resin remaining in the reaction tank or the like with a cleaning solution containing an aromatic monohydroxy compound, aromatic dihydroxy compound, carbonic acid diester, etc. within 24 hours (see Patent Document 4) has been reported. .

JP 2004-26916 A International Publication No. 2008/12987 Pamphlet Japanese Patent Application Laid-Open No. 6-056884 JP 2004-197004 A

  In the method for producing an aromatic polycarbonate resin in Patent Documents 1 and 2, a plurality of polycarbonate resins can be produced, but the aromatic polycarbonate resin and the non-aromatic polycarbonate resin can be efficiently switched using the same production facility. There was a problem that could not be manufactured. Also in the manufacturing method of the aromatic polycarbonate resin in patent document 3 and 4, sufficient effect is suppressed for mixing of the crystallized foreign material at the time of manufacturing by switching an aromatic polycarbonate resin and a non-aromatic polycarbonate resin, and deterioration of a color tone. There was a problem not to give.

  In particular, an aromatic polycarbonate resin comprising a structural unit derived from an aromatic dihydroxy compound and a non-aromatic polycarbonate comprising at least a structural unit derived from a non-aromatic dihydroxy compound such as an aliphatic dihydroxy compound and / or an alicyclic dihydroxy compound When the resin is produced in the same production facility, the aromatic polycarbonate resin and the non-aromatic polycarbonate resin may have different production temperature zones. In the case of producing an aromatic polycarbonate resin, there is a possibility that a crystallized foreign matter formed by crystallization of the aromatic polycarbonate resin remaining in the production facility becomes a problem. In addition, when an aromatic polycarbonate resin is subsequently produced after the production of the non-aromatic polycarbonate resin, the non-aromatic polycarbonate resin remaining in the production facility may become a color-causing substance due to thermal decomposition. There is a possibility that the aromatic polycarbonate resin is colored.

  An object of the present invention is to provide a production method for co-producing aromatic polycarbonate resin and non-aromatic polycarbonate resin while maintaining good color tone in the same production facility.

According to this invention, the manufacturing method of the polycarbonate resin which concerns on following (1) thru | or (3) is provided.
(1) A polycarbonate resin production method for producing a plurality of types of polycarbonate resins, including an aromatic polycarbonate resin and a non-aromatic polycarbonate resin, in the same production facility, wherein the aromatic polycarbonate resin is produced, A method for producing a polycarbonate resin, wherein the production facility is cleaned with a monohydroxy compound and then a non-aromatic polycarbonate resin is produced.
(2) After washing the inside of the production facility with the aromatic monohydroxy compound, a melt mixture of a dihydroxy compound containing a non-aromatic dihydroxy compound and a carbonic acid diester and / or a melt viscosity at 240 ° C. is a shear rate. The method for producing a polycarbonate resin according to (1), wherein the inside of the production facility is washed with a non-aromatic polycarbonate resin that is 1000 Pa · s or less under a condition of 912 sec ⁻¹ .
(3) A polycarbonate resin production method for producing a plurality of types of polycarbonate resins, including an aromatic polycarbonate resin and a non-aromatic polycarbonate resin, using the same production equipment, wherein the aromatic resin is produced after the non-aromatic polycarbonate resin is produced. The production facility is cleaned with an aromatic monohydroxy compound, and then a molten mixture of an aromatic dihydroxy compound and a carbonic acid diester and / or a melt viscosity at 300 ° C. of 400 Pa · s or less under a shear rate of 912 sec ^−1. The manufacturing method of the polycarbonate resin which wash | cleans the said manufacturing equipment inside with the aromatic polycarbonate resin which is and then manufactures aromatic polycarbonate resin.

  According to the present invention, in the same production facility, it is possible to suppress the mixing of crystallized foreign matters and the deterioration of color tone when switching between an aromatic polycarbonate resin and a non-aromatic polycarbonate resin, and stably. In addition, it is possible to produce a polycarbonate resin excellent in color tone.

It is a figure which shows the one aspect | mode of the polycarbonate resin manufacturing equipment which concerns on this invention.

  The present invention is a method for producing a plurality of types of polycarbonate resins, including an aromatic polycarbonate resin and a non-aromatic polycarbonate resin, in the same production facility, and continuously producing the plurality of types of polycarbonate resins by switching production. In addition, the present invention relates to a method for producing a polycarbonate resin in which the inside of a production facility is washed with an aromatic monohydroxy compound before switching between the aromatic polycarbonate resin and the non-aromatic polycarbonate resin.

  The “production equipment” as used in the present invention means equipment capable of consistently performing from raw material preparation to polymerization, and may be a batch reaction system or a continuous reaction system. Further, a plurality of reaction vessels may be provided as long as they are continuously connected by piping or the like. In addition, even if it is understood that the polymerization process generally has a plurality of series such that the reaction solution branches into a plurality of systems during the polymerization, it is included in the “production equipment” of the present invention.

The “aromatic polycarbonate resin” of the present invention is a polycarbonate resin composed of a structural unit derived from an aromatic dihydroxy compound, and can be produced by reacting the aromatic dihydroxy compound with a carbonate compound such as a carbonic acid diester. it can.
The “non-aromatic polycarbonate resin” of the present invention is a polycarbonate resin containing at least a structural unit derived from a non-aromatic dihydroxy compound such as an aliphatic dihydroxy compound or an alicyclic dihydroxy compound, and the non-aromatic dihydroxy compound The content ratio of the structural unit derived from is preferably 30 mol% or more, more preferably 50 mol% or more. The non-aromatic dihydroxy compound can be produced by reacting a dihydroxy compound containing at least a non-aromatic dihydroxy compound such as an aliphatic dihydroxy compound or an alicyclic dihydroxy compound with a carbonate compound such as a carbonic acid diester.

  The aromatic dihydroxy compound of the present invention is a compound having one or more aromatic rings in the molecule and two hydroxyl groups bonded to the aromatic ring. The non-aromatic dihydroxy compound of the present invention is a dihydroxy compound other than the aromatic dihydroxy compound, and an aliphatic dihydroxy compound and an alicyclic dihydroxy compound are preferred.

  In addition, “plurality of polycarbonate resins” in the present invention means that there are a plurality of types of polycarbonate resins having different structural units, and “production switching” means a change in a raw material dihydroxy compound, reaction conditions, catalyst, etc. Is to produce polycarbonate resins having different structural units.

In the production method of the present invention, when a plurality of types of polycarbonate resins including an aromatic polycarbonate resin and a non-aromatic polycarbonate resin are continuously produced by production switching, the aromatic polycarbonate resin and the non-aromatic polycarbonate resin are In the mutual switching, the production facility is washed with an aromatic monohydroxy compound before switching to the production of a non-aromatic polycarbonate resin after the production of the aromatic polycarbonate resin. Further, after washing the production facility with the aromatic monohydroxy compound, a melt mixture of a dihydroxy compound containing a non-aromatic dihydroxy compound and a carbonic acid diester, and / or a melt viscosity at 240 ° C. having a shear rate of 912 sec ⁻¹ It is preferable to wash the inside of the production facility with a non-aromatic polycarbonate resin having a pressure of 1000 Pa · s or less under the conditions, and a non-fragrance having a melt viscosity at 240 ° C. of 1000 Pa · s or less under the conditions of a shear rate of 912 sec ^−1. More preferably, the inside of the production facility is washed with a group polycarbonate resin.
When the production is switched, by washing with the aromatic monohydroxy compound, the aromatic polycarbonate resin for the pre-production remaining in the production facility can be dissolved and removed out of the system. Further, after washing the inside of the production facility with the aromatic monohydroxy compound, the melt is a molten mixture of a dihydroxy compound containing a non-aromatic dihydroxy compound and a carbonic acid diester, and / or a non-aromatic polycarbonate resin having a low melt viscosity. By washing the inside of the production facility, the following non-aromatic polycarbonate resin can be produced smoothly. Particularly, the non-aromatic polycarbonate having a melt viscosity at 240 ° C. of 1000 Pa · s or less under the condition of a shear rate of 912 sec ^−1. Since the aromatic polycarbonate resin is similar to the non-aromatic polycarbonate resin to be produced next, the following non-aromatic polycarbonate resin can be more smoothly produced by washing the inside of the production facility with the non-aromatic polycarbonate resin.
The “molten mixture of a dihydroxy compound containing a non-aromatic dihydroxy compound and a carbonic acid diester” is preferably a molten mixture of raw materials of a non-aromatic polycarbonate resin produced after washing. Further, the “non-aromatic polycarbonate resin having a melt viscosity at 240 ° C. of 1000 Pa · s or less under the condition of a shear rate of 912 sec ⁻¹ ” has the same structural unit as the non-aromatic polycarbonate resin produced after washing. Is preferred. When the structural unit of the non-aromatic polycarbonate resin to be subjected to cleaning is different from the structural unit of the non-aromatic polycarbonate resin to be manufactured after cleaning, there is a possibility of causing foreign matter.
Further, the non-aromatic polycarbonate resin used for washing has a melt viscosity at 240 ° C. of preferably 1000 Pa · s or less, more preferably 900 Pa · s or less, and preferably 100 Pa · s or more under the condition of a shear rate of 912 sec ^−1. 200 Pa · s or more is more preferable. When the melt viscosity of the non-aromatic polycarbonate resin is excessively high, the non-aromatic polycarbonate resin tends to remain in the production facility after washing, and may become a foreign matter in the non-aromatic polycarbonate resin produced after washing. Further, if the melt viscosity of the non-aromatic polycarbonate resin is excessively low, there is a possibility that the residue after washing of the monohydroxy compound cannot be removed from the production facility.

In addition, in the present invention, after the production of non-aromatic polycarbonate resin from the production of non-aromatic polycarbonate resin to the production of aromatic polycarbonate resin, the inside of the production equipment is washed with an aromatic monohydroxy compound, Further, after washing the inside of the production facility with a molten mixture of an aromatic dihydroxy compound and a carbonic acid diester and / or an aromatic polycarbonate resin having a melt viscosity at 300 ° C. of 400 Pa · s or less under the condition of a shear rate of 912 sec ^−1. An aromatic polycarbonate resin is produced. In particular, at the time of the switching, it is preferable to produce an aromatic polycarbonate resin after washing the production facility with an aromatic polycarbonate resin having a melt viscosity at 300 ° C. of 400 Pa · s or less under conditions of a shear rate of 912 sec ^−1. .

When switching to production, in addition to washing with an aromatic monohydroxy compound, washing with a molten mixture of an aromatic dihydroxy compound and a carbonic acid diester and / or an aromatic polycarbonate resin having a low melt viscosity results in the production facility. It is possible to smoothly remove the non-aromatic polycarbonate resin remaining in the pre-manufacturing and to produce the next aromatic polycarbonate resin smoothly. In particular, a non-aromatic polycarbonate resin having a melt viscosity at 300 ° C. of 1000 Pa · s or less under conditions of a shear rate of 912 sec ⁻¹ is similar to the non-aromatic polycarbonate resin to be produced next. When the production facility is cleaned, the following non-aromatic polycarbonate resin can be produced more smoothly.
The “molten mixture of aromatic dihydroxy compound and carbonic acid diester” is preferably a molten mixture of raw materials for the aromatic polycarbonate resin produced after washing. The “aromatic polycarbonate resin having a melt viscosity at 300 ° C. of 400 Pa · s or less under the condition of a shear rate of 912 sec ⁻¹ ” preferably has the same structural unit as the aromatic polycarbonate resin produced after washing. . When the structural unit of the aromatic polycarbonate resin used for washing differs from the structural unit of the aromatic polycarbonate resin produced after washing, there is a possibility of causing foreign matter.
Further, the aromatic polycarbonate resin subjected to washing has a melt viscosity at 300 ° C. of preferably 400 Pa · s or less, more preferably 300 Pa · s or less, and particularly preferably 200 Pa · s or less under the condition of a shear rate of 912 sec ^−1. It is preferably 80 Pa · s or more, more preferably 100 Pa · s or more. If the melt viscosity of the aromatic polycarbonate resin is excessively high, the aromatic polycarbonate resin tends to remain in the production facility after washing, and may become a foreign substance in the aromatic polycarbonate resin produced after washing. Moreover, when the melt viscosity of the aromatic polycarbonate resin is excessively low, there is a possibility that the residue after washing of the monohydroxy compound cannot be removed from the production facility.

As described above, according to the present invention, even when different types of polycarbonate resin are continuously manufactured using the same manufacturing equipment, the contamination of the polycarbonate resin manufactured previously is not mixed into the polycarbonate resin manufactured later. It can be suppressed to a level that does not impair the physical properties such as mixing and hue.
As a result, it is possible to continuously produce a plurality of types of polycarbonate resins without temporarily stopping the production facility and performing a washing operation with a special solvent.

  Hereafter, the general manufacturing method of the polycarbonate resin concerning this invention is demonstrated.

(Aromatic dihydroxy compounds)
The aromatic dihydroxy compound according to the present invention is a compound having one or more aromatic rings in the molecule and two hydroxyl groups bonded to the aromatic ring. Examples thereof include compounds represented by the following general formula (1) and the following general formula (2).

Here, in the general formula (2), R ₁ and R ₂ each independently represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms or a substituted or unsubstituted aryl group, and R ₃ And R ₄ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group.
Examples of the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms of R ₁ and R ₂ include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec -Butyl group, tert-butyl group, n-pentyl group, sec-pentyl group, n-hexyl group, n-heptyl group, n-octyl group and the like. Examples of the substituted or unsubstituted aryl group include: A phenyl group, a benzyl group, a tolyl group, 4-methylphenyl group, a naphthyl group, etc. are mentioned.
Examples of the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms of R ₃ and R ₄ include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec -Butyl group, tert-butyl group, n-pentyl group, sec-pentyl group, n-hexyl group, n-heptyl group, n-octyl group and the like. Examples of the substituted or unsubstituted aryl group include: A phenyl group, a benzyl group, a tolyl group, 4-methylphenyl group, a naphthyl group, etc. are mentioned.
Among these, R ₁ and R ₂ are preferably a methyl group, an ethyl group, an n-propyl group, or a 4-methylphenyl group, and particularly preferably a methyl group. R ₃ and R ₄ are preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, or a 4-methylphenyl group, and particularly preferably a hydrogen atom or a methyl group.

In General Formula (1) or General Formula (2), X represents a single bond, a carbonyl group, a substituted or unsubstituted alkylidene group, a substituted or unsubstituted sulfur atom, or an oxygen atom. Examples of the substituted or unsubstituted sulfur atom include —S— and —SO ₂ —. In addition, a substituted or unsubstituted alkylidene group is

Indicates. Here, R ₅ and R ₆ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group, and Z is substituted or unsubstituted. A substituted alkylene group having 4 to 20 carbon atoms is shown.
Examples of the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms of R ₅ and R ₆ include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec -Butyl group, tert-butyl group, n-pentyl group, sec-pentyl group, n-hexyl group, n-heptyl group, n-octyl group and the like. Examples of the substituted or unsubstituted aryl group include a phenyl group, a benzyl group, a tolyl group, a 4-methylphenyl group, and a naphthyl group.
Among these, R ₅ and R ₆ are preferably a methyl group, an ethyl group, an n-propyl group, or a 4-methylphenyl group, and particularly preferably a methyl group.
Z is bonded to the carbon to which two phenyl groups are bonded in the general formula (1) or the general formula (2) to form a substituted or unsubstituted divalent carbocycle. Examples of the divalent carbocycle include a cycloalkylidene group such as a cyclopentylidene group, a cyclohexylidene group, a cycloheptylidene group, a cyclododecylidene group, an adamantylidene group (preferably a carbon number of 5 To 12 carbon atoms). Examples of the substituted ones include those having these methyl substituents and ethyl substituents. Among these, a methyl-substituted product of a cyclohexylidene group, a cyclododecylidene group, or a cyclohexylidene group is preferable.

  Specific examples of the aromatic dihydroxy compound represented by the general formula (1) include, for example, 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) and 1,1-bis (4-hydroxyphenyl) cyclohexane. 1,1-bis (4-hydroxyphenyl) -3,5,5-trimethylcyclohexane, 1,1-bis (4-hydroxyphenyl) adamantane, 1,1-bis (4-hydroxyphenyl) cyclododecane, , 4-bis (4-hydroxyphenyl) adamantane, 5,5-bis (4-hydroxyphenyl) hexahydro-4,7-methanoindane, 2,2-bis (4-hydroxyphenyl) sulfone, 2,2-bis ( 4-hydroxyphenyl) sulfide, 9,9-bis (4-hydroxyphenyl) fluorene, etc.

  Among these, 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) is preferably used. In addition, the aromatic dihydroxy compound represented by General formula (1) can be used 1 type or in mixture of 2 or more types.

  Specific examples of the aromatic dihydroxy compound represented by the general formula (2) include 2,2-bis (4-hydroxy-3-methylphenyl) propane and 1,1-bis (4-hydroxy-3-). Methylphenyl) cyclohexane, 1,1-bis (4-hydroxy-3-methylphenyl) -3,5,5-trimethylcyclohexane, 1,1-bis (4-hydroxy-3-methylphenyl) adamantane, 1,1 -Bis (4-hydroxy-3-methylphenyl) cyclododecane, 1,4-bis (4-hydroxy-3-methylphenyl) adamantane, 2,2-bis (4-hydroxy-3-ethylphenyl) propane, 2 , 2-bis (4-hydroxy-3-tert-butylphenyl) propane, 2,2-bis (4-hydroxy-3-cyclohexylphenyl) ) Propane, 2,2-bis (4-hydroxy-3-phenylphenyl) propane, 5,5-bis (4-hydroxy-3-methylphenyl) hexahydro-4,7-methanoindane, 2,2-bis (4 -Hydroxy-3-methylphenyl) sulfone, 2,2-bis (4-hydroxy-3-methylphenyl) sulfide, 3,3'-dimethylbiphenol, 2,2-bis (4-hydroxy-3,5-dimethyl) Phenyl) propane, 1,1-bis (4-hydroxy-3,5-dimethylphenyl) cyclohexane, 1,1-bis (4-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylcyclohexane, 1,1-bis (4-hydroxy-3,5-dimethylphenyl) adamantane, 1,1-bis (4-hydroxy-3,5-dimethyl) Phenyl) cyclododecane, 1,4-bis (4-hydroxy-3,5-dimethylphenyl) adamantane, 2,2-bis (3-ethyl-4-hydroxy-5-methylphenyl) propane, 2,2-bis (3-tert-butyl-4-hydroxy-5-methylphenyl) propane, 2,2-bis (3-cyclohexyl-4-hydroxy-5-methylphenyl) propane, 2,2-bis (4-hydroxy-3) -Methyl-5-phenylphenyl) propane, 2,2-bis (3,5-diethyl-4-hydroxyphenyl) propane, 2,2-bis (3,5-di-tert-butyl-4-hydroxyphenyl) Propane, 2,2-bis (3,5-di-cyclohexyl-4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3,5-diph Enylphenyl) propane, 5,5-bis (4-hydroxy-3,5-dimethylphenyl) hexahydro-4,7-methanoindane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) sulfone, 2 , 2-bis (4-hydroxy-3,5-dimethylphenyl) sulfide, 3,3 ′, 5,5′-tetramethylbiphenol, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, 9 , 9-bis (4-hydroxy-3-ethylphenyl) fluorene, 9,9-bis (4-hydroxy-3-n-propylphenyl) fluorene, 9,9-bis (4-hydroxy-3-isopropylphenyl) Fluorene, 9,9-bis (4-hydroxy-3-n-butylphenyl) fluorene, 9,9-bis (4-hydroxy-3-sec) Butylphenyl) fluorene, 9,9-bis (4-hydroxy-3-tert-propylphenyl) fluorene, 9,9-bis (4-hydroxy-3-cyclohexylphenyl) fluorene, 9,9-bis (4-hydroxy) -3-phenylphenyl) fluorene and the like.

  Among these, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 1,1-bis (4-hydroxy-3-methylphenyl) cyclohexane, 1,1-bis (4-hydroxy-3-) Methylphenyl) cyclododecane, 1,1-bis (4-hydroxy-3-methylphenyl) -3,5,5-trimethylcyclohexane, 5,5-bis (4-hydroxy-3-methylphenyl) hexahydro-4, 7-methanoindane, 3,3′-dimethylbiphenol, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 1,1-bis (4-hydroxy-3,5-dimethylphenyl) cyclohexane, 1,1-bis (4-hydroxy-3,5-dimethylphenyl) cyclododecane, 1,1-bis (4-hydroxy-3,5- Methylphenyl) -3,5,5-trimethylcyclohexane, 5,5-bis (4-hydroxy-3,5-dimethylphenyl) hexahydro-4,7-methanoindane, 3,3 ′, 5,5′-tetramethyl Biphenol, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene and the like are preferable.

  Among these, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, and 1,1-bis (4- Hydroxy-3-methylphenyl) cyclohexane, 1,1-bis (4-hydroxy-3-methylphenyl) cyclododecane, 1,1-bis (4-hydroxy-3,5-dimethylphenyl) cyclododecane, 1,1 -Bis (4-hydroxy-3-methylphenyl) -3,5,5-trimethylcyclohexane is more preferred, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (4- Hydroxy-3,5-dimethylphenyl) propane, 1,1-bis (4-hydroxy-3-methylphenyl) cyclohexane, 1,1-bis (4-hydride) Xy-3,5-dimethylphenyl) cyclohexane, 1,1-bis (4-hydroxy-3-methylphenyl) cyclododecane, and 1,1-bis (4-hydroxy-3,5-dimethylphenyl) cyclododecane Most preferred. In addition, the aromatic dihydroxy compound represented by General formula (3) can be used 1 type or in mixture of 2 or more types.

(Non-aromatic dihydroxy compound)
The non-aromatic dihydroxy compound of the present invention is a dihydroxy compound in which at least one of the two hydroxyl groups is not bonded to an aromatic ring, such as alicyclic dihydroxy compounds, aliphatic dihydroxy compounds, oxyalkylene glycols, and the like. Is mentioned.
(Alicyclic dihydroxy compound)
The alicyclic dihydroxy compound of the present invention is a dihydroxy compound having a saturated hydrocarbon cyclic structure. The number of rings is not particularly limited, regardless of whether the cyclic structure is a monocyclic structure or a multicyclic structure. Specifically, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, tricyclodecane dimethanol, pentacyclopentadecane dimethanol, 2,6-decalin dimethanol, , 5-decalin dimethanol, 2,3-decalin dimethanol, 2,3-norbornane dimethanol, 2,5-norbornane dimethanol, 1,3-adamantane dimethanol. Furthermore, dihydroxy compounds having a heterocyclic structure such as an anhydrous sugar alcohol represented by the following general formula (3) and a cyclic ether compound represented by the following general formula (4) are also alicyclic dihydroxy compounds of the present invention. .

Examples of the alicyclic dihydroxy compound represented by the general formula (3) include isosorbide, isomannide, and isoide which are in a stereoisomeric relationship.
The dihydroxy compound having a heterocyclic structure may be 3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2 as the alicyclic dihydroxy compound represented by the general formula (4). , 4,8,10-tetraoxaspiro (5.5) undecane (common name: spiroglycol), 3,9-bis (1,1-diethyl-2-hydroxyethyl) -2,4,8,10- Tetraoxaspiro (5.5) undecane, 3,9-bis (1,1-dipropyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro (5.5) undecane, dioxane glycol, etc. Is mentioned.
These may be used alone or in combination of two or more.

  Of these alicyclic dihydroxy compounds, isosorbide, isomannide and isoidet are particularly preferred, and they are also abundant as plant-derived resources and are obtained by dehydrating condensation of sorbitol produced from readily available glucose. However, it is particularly preferable from the viewpoints of availability and production, optical characteristics, moldability, and carbon neutral.

(Aliphatic dihydroxy compound)
The aliphatic dihydroxy compound of the present invention is not particularly limited, and examples thereof include ethylene glycol, 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, 1,3-butanediol, 1 , 2-butanediol, 1,5-heptanediol, 1,6-hexanediol and the like.

(Oxyalkylene glycol)
The oxyalkylene glycol of the present invention is not particularly limited, and examples thereof include diethylene glycol, triethylene glycol, and tetraethylene glycol.

（一般式（５）中、Ｒ₁〜Ｒ₄はそれぞれ独立に、水素原子、置換若しくは無置換の炭素数１〜炭素数２０のアルキル基、置換若しくは無置換の炭素数６〜炭素数２０のシクロアルキル基、又は、置換若しくは無置換の炭素数６〜炭素数２０のアリール基を表し、Ｘは置換若しくは無置換の炭素数２〜炭素数１０のアルキレン基、置換若しくは無置換の炭素数６〜炭素数２０のシクロアルキレン基、又は、置換若しくは無置換の炭素数６〜炭素数２０のアリーレン基を表し、ｍ及びｎはそれぞれ独立に１〜５の整数である。） (Other dihydroxy compounds)
The non-aromatic dihydroxy compound of the present invention includes a dihydroxy compound having an aromatic ring in the molecule but having no hydroxyl group bonded to the aromatic ring. For example, the compound etc. which are represented with following General formula (5) are mentioned.

(In General Formula (5), R _{1 to} R ₄ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted carbon group having 6 to 20 carbon atoms. Represents a cycloalkyl group or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, and X represents a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, a substituted or unsubstituted carbon number of 6; Represents a cycloalkylene group having 20 carbon atoms, or a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, and m and n are each independently an integer of 1 to 5).

  Specific examples of the dihydroxy compound represented by the general formula (5) include 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene and 9,9-bis (4- (2-hydroxy). Ethoxy) -3-methylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-isopropylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-isobutyl Phenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-tert-butylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-cyclohexylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-phenylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethyl) Xyl) -3,5-dimethylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-tert-butyl-6-methylphenyl) fluorene, and the like, preferably 9,9 -Bis (4- (2-hydroxyethoxy) phenyl) fluorene and 9,9-bis (4- (2-hydroxyethoxy) -3-methylphenyl) fluorene, particularly preferably 9,9-bis (4 -(2-Hydroxyethoxy) phenyl) fluorene.

(Carbonated diester)
As a carbonic acid diester of this invention, the compound shown by following General formula (6) is mentioned.

Here, in the general formula (6), A ′ is an optionally substituted linear, branched or cyclic monovalent hydrocarbon group having 1 to 10 carbon atoms. Two A ′ may be the same or different from each other.
In addition, as a substituent on A ′, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a phenyl group, a phenoxy group, a vinyl group, a cyano group, and an ester group Amide group, nitro group and the like.

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

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

  In the production method of the present invention, the amount of these carbonic acid diesters (including the above-mentioned substituted dicarboxylic acid or dicarboxylic acid ester; the same shall apply hereinafter) is usually such that the carbonic acid diester compound is 1. It is used in a ratio of 00 mol to 1.30 mol, preferably 1.00 mol to 1.20 mol. If the molar ratio of the carbonic acid diester is excessively small, the transesterification rate decreases, making it difficult to produce a polycarbonate resin having a desired molecular weight, or increasing the terminal hydroxyl group concentration of the resulting polycarbonate resin, resulting in thermal stability. Tend to get worse. In addition, if the molar ratio of the carbonic acid diester is excessively large, the reaction rate of the transesterification decreases, and it becomes difficult to produce a polycarbonate resin having a desired molecular weight, and the residual amount of the carbonic acid diester compound in the resin. Is unfavorable because it may cause odor when being molded or formed into a molded product.

(Transesterification catalyst)
Examples of the transesterification catalyst used in the production method of the present invention include a catalyst usually used in producing a polycarbonate resin by an ester exchange method, and are not particularly limited.
In general, for example, basic compounds such as alkali metal compounds, alkaline earth metal compounds, beryllium compounds, magnesium compounds, basic boron compounds, basic phosphorus compounds, basic ammonium compounds, and amine compounds can be used. Among these, alkali metal compounds, alkaline earth metal compounds, beryllium compounds, and magnesium compounds are desirable for practical use. These transesterification catalysts may be used alone or in combination of two or more.

The amount of the transesterification catalyst used is usually in the range of 1 × 10 ⁻⁹ to 1 × 10 ⁻³ mol per 1 mol of all dihydroxy compounds. In order to obtain a polycarbonate resin excellent in molding characteristics and hue. In the case of using an alkali metal compound and / or an alkaline earth metal compound, the amount of the transesterification catalyst is preferably 1.0 × 10 ⁻⁸ to 1 × 10 ^{−4 with} respect to 1 mol of the wholly aromatic dihydroxy compound. Within the range of mol, more preferably within the range of 1.0 × 10 ⁻⁸ to 1 × 10 ⁻⁵ mol, particularly preferably within the range of 1.0 × 10 ^{−7 to} 5.0 × 10 ⁻⁶ mol. It is. If the amount is less than the above lower limit amount, the polymerization activity necessary for producing a polycarbonate resin having a desired molecular weight cannot be obtained. If the amount is more than this amount, the polymer hue deteriorates, the amount of branching components is too large, and the fluidity is low. Decreasing, and the polycarbonate resin having excellent target melting characteristics cannot be produced.

Examples of the alkali metal compound include inorganic alkali metal compounds such as alkali metal hydroxides, carbonates and hydrogencarbonate compounds; organic alkali metal compounds such as salts with alkali metal alcohols, phenols and organic carboxylic acids. It is done. Here, as an alkali metal, lithium, sodium, potassium, rubidium, cesium etc. are mentioned, for example.
Among these alkali metal compounds, calcium compounds and / or cesium compounds are preferable, and calcium acetate, calcium carbonate, calcium hydroxide, cesium carbonate, cesium hydrogen carbonate, and cesium hydroxide are particularly preferable.

  Examples of the alkaline earth metal compound include inorganic alkaline earth metal compounds such as alkaline earth metal hydroxides and carbonates; alkaline earth metal alcohols, phenols, salts with organic carboxylic acids, and the like. It is done. Here, examples of the alkaline earth metal include calcium, strontium, barium and the like.

  Examples of the beryllium compound and the magnesium compound include inorganic metal compounds such as hydroxides and carbonates of the metals; salts of the metals with alcohols, phenols, and organic carboxylic acids.

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

  Examples of the basic phosphorus compound include trivalent phosphine compounds such as triethylphosphine, tri-n-propylphosphine, triisopropylphosphine, tri-n-butylphosphine, triphenylphosphine, and tributylphosphine, or derivatives thereof. And quaternary phosphonium salts.

  Examples of the basic ammonium compound include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylethylammonium hydroxide, trimethylbenzylammonium hydroxide, trimethylphenylammonium hydroxide, Triethylmethylammonium hydroxide, triethylbenzylammonium hydroxide, triethylphenylammonium hydroxide, tributylbenzylammonium hydroxide, tributylphenylammonium hydroxide, tetraphenylammonium hydroxide, benzyltriphenylammonium hydroxide, methyltriphenylammonium hydroxide Sid, butyl triphenyl ammonium hydroxide, and the like.

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

<Manufacturing process of polycarbonate resin>
Next, a specific manufacturing process of the polycarbonate resin to which the manufacturing method of the present invention is applied will be described.
The reaction conditions such as reaction temperature, reaction pressure, reaction time, etc. are the type of polycarbonate resin to be produced (for example, aromatic polycarbonate resin or non-aromatic polycarbonate resin) and the grade to be produced even if the structural unit is the same (for example, It is appropriately selected depending on the difference in melt viscosity and viscosity average molecular weight.
Hereinafter, the production of an aromatic polycarbonate resin by a melting method using an aromatic dihydroxy compound and a carbonic acid diester compound as raw materials will be described as an example.

The polycarbonate resin production process involves preparing a raw material mixed melt of an aromatic dihydroxy compound as a raw material and a carbonic acid diester (original tone process), and in the presence of a transesterification catalyst, the raw material mixed melt is melted. It is carried out by performing a polycondensation reaction in multiple stages using a plurality of reaction vessels (polycondensation step). The reaction system may be any of a batch system, a continuous system, or a combination of a batch system and a continuous system. As the reaction tank, a plurality of vertical stirring reaction tanks and, if necessary, at least one horizontal stirring reaction tank subsequent thereto are used. Usually, these reaction tanks are installed in series and processed continuously.
After the polycondensation process, the reaction is stopped, the unreacted raw materials and reaction byproducts in the polycondensation reaction liquid are devolatilized and removed, the process of adding a thermal stabilizer, mold release agent, colorant, etc., polycarbonate resin You may add suitably the process etc. which form in a predetermined particle size.
Next, each process of the manufacturing method will be described.

(Primary process)
The aromatic dihydroxy compound and carbonic acid diester compound used as the raw material for the polycarbonate resin are usually used in a batch, semi-batch or continuous stirring tank type apparatus in an atmosphere of an inert gas such as nitrogen or argon. It is prepared as a raw material mixed melt. For example, when bisphenol A is used as the aromatic dihydroxy compound and diphenyl carbonate is used as the carbonic acid diester, the temperature of the melt mixing is usually selected from the range of 120 ° C to 180 ° C, preferably 125 ° C to 160 ° C.
Hereinafter, the case where bisphenol A is used as an aromatic dihydroxy compound and diphenyl carbonate is used as a raw material as a carbonic acid diester will be described as an example.
At this time, the ratio of the aromatic dihydroxy compound and the carbonic acid diester is adjusted so that the carbonic acid diester becomes excessive. The carbonic acid diester is usually 1.01 mol to 1.30 mol with respect to 1 mol of the aromatic dihydroxy compound. , Preferably adjusted to a ratio of 1.02 mol to 1.20 mol.

(Polycondensation process)
The polycondensation by the transesterification reaction between the aromatic dihydroxy compound and the carbonic acid diester is usually carried out continuously in a multistage system of two or more stages, preferably 3 to 7 stages. Specific reaction conditions for each stage 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 each multi-stage reaction tank, in order to more effectively remove aromatic monohydroxy compounds such as phenol as a by-product from the system as the polycondensation reaction proceeds, the temperature is increased stepwise in the above reaction conditions. Set to a higher vacuum. 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 manner, usually, a plurality of reaction vessels including a vertical stirring reaction vessel are provided to increase the average molecular weight of the polycarbonate resin. The reaction tank is usually installed in 2 to 6 groups, preferably 4 to 5 groups.
Here, as a reaction tank, for example, a stirring tank type reaction tank, a thin film reaction tank, a centrifugal thin film evaporation reaction tank, a surface renewal type biaxial kneading reaction tank, a biaxial horizontal type stirring reaction tank, a wet wall reaction tank, a free tank A perforated plate type reaction vessel that polycondenses while dropping, a perforated plate type reaction vessel with wire that polycondenses while dropping along a wire, and the like are used.

  The types of stirring blades in the vertical stirring reaction tank include, for example, turbine blades, paddle blades, fiddler blades, anchor blades, full zone blades (manufactured by Shinko Environmental Solution Co., Ltd.), Sun Meller blades (manufactured by Mitsubishi Heavy Industries, Ltd.), Max blend blades (manufactured by Sumitomo Heavy Industries, Ltd.), helical ribbon blades, twisted lattice blades (manufactured by Hitachi Plant Technology Co., Ltd.), and the like.

  Moreover, a horizontal stirring reaction tank means that the rotating shaft of a stirring blade is a horizontal type (horizontal direction). As a stirring blade of a horizontal stirring reaction tank, for example, a uniaxial stirring blade such as a disk type or a paddle type, HVR, SCR, N-SCR (manufactured by Mitsubishi Heavy Industries, Ltd.), Vivolak (Sumitomo Heavy Industries, Ltd.) )), Or biaxial stirring blades such as spectacle blades and lattice blades (manufactured by Hitachi Plant Technology Co., Ltd.).

  In addition, the transesterification catalyst used for the polycondensation of the aromatic dihydroxy compound and the carbonic acid diester may be usually prepared in advance as an aqueous solution. The concentration of the catalyst aqueous solution is not particularly limited, and is adjusted to an arbitrary concentration according to the solubility of the catalyst in water. Moreover, it can replace with water and other solvents, such as acetone, alcohol, toluene, and phenol, can also be selected.

  The properties of water used for dissolving the catalyst 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.

<Polycarbonate resin>
(Aromatic polycarbonate resin)
Next, the aromatic polycarbonate resin produced by the production method of the present invention (hereinafter sometimes referred to as “the aromatic polycarbonate resin according to the present invention”) will be described.

  As an aromatic polycarbonate resin which concerns on this invention, the polycarbonate resin which consists of a structural unit represented by following General formula (7), General formula (8) etc. is mentioned, for example.

In General Formula (8), R ₁ and R ₂ each independently represent a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms or a substituted or unsubstituted aryl group, and R ₃ and R ₄ Each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group.
In General Formula (7) or General Formula (8), X represents a single bond, a carbonyl group, a substituted or unsubstituted alkylidene group, a substituted or unsubstituted sulfur atom, or an oxygen atom. In addition, a substituted or unsubstituted alkylidene group is

Indicates. Here, R ₅ and R ₆ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group, and Z is substituted or unsubstituted. A substituted alkylene group having 4 to 20 carbon atoms is shown.
Examples of the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms of R ₅ and R ₆ include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec -Butyl group, tert-butyl group, n-pentyl group, sec-pentyl group, n-hexyl group, n-heptyl group, n-octyl group and the like. Examples of the substituted or unsubstituted aryl group include a phenyl group, a benzyl group, a tolyl group, a 4-methylphenyl group, and a naphthyl group.
Among these, R ₅ and R ₆ are preferably a methyl group, an ethyl group, an n-propyl group, or a 4-methylphenyl group, and particularly preferably a methyl group.
Z is bonded to the carbon to which two phenyl groups are bonded in general formula (7) or general formula (8) to form a substituted or unsubstituted divalent carbocycle. Examples of the divalent carbocycle include cycloalkylidene groups such as a cyclopentylidene group, a cyclohexylidene group, a cycloheptylidene group, a cyclododecylidene group, and an adamantylidene group.

As a preferable example of the aromatic polycarbonate resin containing the structural unit represented by the general formula (7), a bisphenol A type polycarbonate resin made from 2,2-bis (4-hydroxyphenyl) propane (BPA) is used. Can be mentioned.
As a preferable example of the polycarbonate resin containing the structural unit represented by the general formula (8), 2,2-bis (4-hydroxy-3-methylphenyl) propane (hereinafter abbreviated as “bisphenol C”). Bisphenol C-type polycarbonate resin, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 1,1-bis (4-hydroxy-3-methylphenyl) cyclohexane, 1,1-bis (4-hydroxy-3,5-dimethylphenyl) cyclohexane, 1,1-bis (4-hydroxy-3-methylphenyl) cyclododecane, and / or 1,1-bis (4-hydroxy- And polycarbonate resin made from 3,5-dimethylphenyl) cyclododecane.

  The aromatic polycarbonate resin to which this embodiment is applied may have structural units having both structures of the general formula (7) and the general formula (8) as long as the object of the present invention is not hindered. The ratio of the general formula (8) in the general formula (7) depends on the type and use of the polycarbonate resin as a product, but is generally 30% by weight or more, more preferably 50% by weight or less, and still more preferably 70% by weight or more.

(Non-aromatic polycarbonate resin)
Next, the non-aromatic polycarbonate resin produced by the production method of the present invention will be described. The non-aromatic polycarbonate resin according to the present invention is a polycarbonate resin containing at least a structural unit derived from a non-aromatic dihydroxy compound such as an aliphatic dihydroxy compound or an alicyclic dihydroxy compound, and is derived from the non-aromatic dihydroxy compound. The content ratio of the structural unit is preferably 30 mol% or more, more preferably 50 mol% or more. The non-aromatic dihydroxy compound can be produced by reacting a dihydroxy compound containing at least a non-aromatic dihydroxy compound such as an aliphatic dihydroxy compound or an alicyclic dihydroxy compound with a carbonate compound such as a carbonic acid diester.

  The non-aromatic polycarbonate resin according to the present invention is preferably a polycarbonate resin containing at least a structural unit derived from an aliphatic dihydroxy compound and / or an alicyclic dihydroxy compound, and a structural unit derived from a structural unit derived from an alicyclic dihydroxy compound. More preferably, the polycarbonate resin contains at least a structural unit derived from the alicyclic dihydroxy compound represented by the general formula (3) because it has excellent transparency, heat resistance, and low refractive index. It is particularly preferred.

<Manufacturing switching method>
The present invention, when producing a plurality of types of polycarbonate resin, including an aromatic polycarbonate resin and a non-aromatic polycarbonate resin, in the same production facility, when switching between the aromatic polycarbonate resin and the non-aromatic polycarbonate resin, This is a method for continuously producing a plurality of types of polycarbonate resins in which the production facility is washed with an aromatic monohydroxy compound before switching.

(Aromatic monohydroxy compounds)
Examples of the aromatic monohydroxy compound used for washing in the present invention include phenol and cresol. Among these, phenol is preferably used. These are not only purchased products, but also those produced as a by-product during the production of the polycarbonate resin of the present invention can be recovered, purified and reused.

Cleaning of the production facility with the aromatic monohydroxy compound is performed by washing the reaction vessel and the by-product distillation line by heating and holding the reaction apparatus above the boiling point of the aromatic monohydroxy compound used and refluxing the compound. Is preferred. Insufficient washing often causes residual by-products, oligomers, and raw materials to be denatured and colored due to heat history, and is mixed into the reaction solution after switching and causes coloring. The reflux cleaning described above is preferably performed at least once.
The “production equipment” in the present invention means a reaction tank, piping connecting the reaction tank, a valve, a liquid feed pump, a byproduct distillation line, and the like.

Next, switching and manufacturing of a plurality of types of polycarbonate resins will be specifically described.
The aromatic polycarbonate resin and the non-aromatic polycarbonate resin can be switched to each other as follows by washing with an aromatic monohydroxy compound at the time of switching.
1) A method for producing a polycarbonate resin, in which after the production of an aromatic polycarbonate resin, the inside of the production facility is washed with an aromatic monohydroxy compound, and then a non-aromatic polycarbonate resin is produced.
2) A method for producing a polycarbonate resin, comprising producing a non-aromatic polycarbonate resin, washing the inside of the production facility with an aromatic monohydroxy compound, and then producing an aromatic polycarbonate resin.
Therefore, it is possible to continuously produce an aromatic polycarbonate resin and a non-aromatic polycarbonate resin by washing with an aromatic monohydroxy compound at the time of switching.
In addition, the aromatic monohydroxy compound used for washing | cleaning is recycled after refine | purifying by distillation etc. after collection | recovery.

By the way, in addition to the washing of the production facility with the aromatic monohydroxy compound, the subsequent washing is continuously performed, whereby the continuous production of a polycarbonate resin having further excellent hue can be suitably carried out. In particular, in the case of producing an aromatic polycarbonate resin subsequent to the production of a non-aromatic polycarbonate resin, the non-aromatic polycarbonate resin may become a color-causing substance due to thermal decomposition, and the aromatic polycarbonate resin may be colored. The following cleaning is effective after cleaning with an aromatic monohydroxy compound.
(1) Washing with a molten mixture of a dihydroxy compound and a carbonic acid diester (2) Washing with a low melt viscosity aromatic or non-aromatic polycarbonate resin These may be carried out alone or in combination.

The washing with the molten mixture of (1) dihydroxy compound and carbonic acid diester can be performed as follows.
(1a) After the production of the aromatic polycarbonate resin, before switching to the production of the non-aromatic polycarbonate resin, the inside of the production facility with the aromatic monohydroxy compound is washed, and subsequently, before the production of the desired non-aromatic polycarbonate resin, The inside of the production facility is washed with a molten mixture of a dihydroxy compound containing a non-aromatic dihydroxy compound and a carbonic acid diester.
This washing is usually performed by circulating a molten mixture of a dihydroxy compound and a carbonic acid diester not containing a catalyst under conditions for producing a polycarbonate resin.
(1b) Washing with a molten mixture of an aromatic dihydroxy compound and a carbonic acid diester involves washing the inside of a production facility with an aromatic monohydroxy compound before switching to production of an aromatic polycarbonate resin after producing a non-aromatic polycarbonate resin. Then, before the production of the desired aromatic polycarbonate resin, the inside of the production facility is washed with a molten mixture of the aromatic dihydroxy compound and the carbonic acid diester.
This washing is usually performed by circulating a molten mixture of an aromatic dihydroxy compound and a carbonic acid diester not containing a catalyst under the conditions for producing a polycarbonate resin.

In addition, (2) washing with an aromatic or non-aromatic polycarbonate resin having a low melt viscosity can be performed as follows.
(2a) After the production of the aromatic polycarbonate resin, when switching the production to the non-aromatic polycarbonate resin, the inside of the production facility with the aromatic monohydroxy compound is washed, and subsequently before the production of the desired non-aromatic polycarbonate resin, By manufacturing a non-aromatic polycarbonate resin having a similar structure and low melt viscosity, the inside of the manufacturing facility is cleaned.
Specifically, it is preferable to clean the inside of the production facility with a non-aromatic polycarbonate resin having a melt viscosity at 240 ° C. of 1000 Pa · s or less under the condition of a shear rate of 912 sec ⁻¹ .
(2b) After the production of the non-aromatic polycarbonate resin, when switching to the production of the aromatic polycarbonate resin, the inside of the production facility with the aromatic monohydroxy compound is washed, and the same before the production of the target aromatic polycarbonate resin. By manufacturing an aromatic polycarbonate resin having a low melt viscosity with a simple structure, the production facility is cleaned.
Specifically, it is preferable to clean the inside of the production facility with an aromatic polycarbonate resin having a melt viscosity at 300 ° C. of 400 Pa · s or less under the condition of a shear rate of 912 sec ⁻¹ .

Thus, before moving from a non-aromatic polycarbonate resin to an aromatic polycarbonate resin, or before moving from an aromatic polycarbonate resin to a non-aromatic polycarbonate resin, a cleaning polycarbonate resin having a lower melt viscosity is used in the production facility. By washing the polycarbonate resin before washing, the polycarbonate resin before washing can be removed to a level that does not impair the physical properties of the changed polycarbonate resin.
In addition, the polycarbonate resin used for washing | cleaning can also be collect | recovered as an off grade.

  Hereinafter, the present invention will be described more specifically based on examples. In addition, this invention is not limited to a following example. The physical properties of the polycarbonate resin used in the examples were evaluated by the following methods.

(1) Melt viscosity The polycarbonate resin dried at 120 ° C. for 5 hours is heated to 240 ° C. or 300 ° C. using a capillary rheometer (manufactured by Toyo Seiki Co., Ltd.) having a die diameter of 1 mmφ × 10 mmL, and the shear rate γ = The melt viscosity was measured between 9.12 and 1824 (sec ⁻¹ ). From the measurement results, the melt viscosity η ^* ₉₁₂ at a shear rate of ₉₁₂ sec ⁻¹ was read.

(2) Viscosity average molecular weight (Mv)
A methylene chloride solution (concentration (C) 0.6 g / dl) of polycarbonate resin was prepared, and the specific viscosity (η _sp ) at a temperature of 20 ° C. was measured using an Ubbelohde viscometer. Average molecular weight (Mv) was calculated.
η _sp /C=[η](1+0.28η _sp)
[Η] = 1.23 × 10 ⁻⁴ Mv ^0.83

(3) Hue Using an injection molding machine J100SS-2 (manufactured by Nippon Steel Works), a plate having a thickness of 3 mm, a length of 100 mm, and a width of 100 mm under conditions of a barrel temperature of 280 ° C. and a mold temperature of 90 ° C. Injection molded. About this injection-molded plate, the tristimulus value XYZ which is the absolute value of the color is measured with a color tester (SC-1-CH manufactured by Suga Test Instruments Co., Ltd.), and the YI value which is an index of yellowness by the following relational expression Was calculated. The larger this YI value, the more yellow it is colored.

Example 1
In the production facility shown in FIG. 1, an aqueous solution of cesium carbonate is added per mole of BPA to 6,700 g of bisphenol A (hereinafter referred to as “BPA”) and 6,539 g of diphenyl carbonate (hereinafter referred to as “DPC”). It added so that it might become 1 micromol as a metal amount, and prepared the mixture. Next, the mixture has an internal temperature of 80 ° C. or less and an internal volume of 40 L from the raw material inlet 1, a stirring motor 6 a, a heat medium jacket (not shown), a vacuum pump (not shown), and a reflux condenser. The first reaction tank 2 equipped with 7a was charged.

  Subsequently, the operation of depressurizing the inside of the first reaction tank 2 to 133 Pa (10 torr) and then restoring the pressure to the atmospheric pressure with nitrogen was repeated five times, and the inside of the first reaction tank 2 was replaced with nitrogen. After nitrogen substitution, the internal temperature of the first reaction tank 2 was gradually raised through a heating medium at a temperature of 230 ° C. through the heating medium jacket to dissolve the contents. Then, it stirred at 300 rpm, the temperature in a heat-medium jacket was controlled, and the internal temperature of the 1st reaction tank 2 was maintained at 220 degreeC. And while distilling off the phenol by-produced by the oligomerization reaction of BPA and DPC performed in the first reaction tank 22, the pressure in the first reaction tank 2 is 101.3 kPa (absolute pressure) over 40 minutes. The pressure was reduced from 760 Torr to 13.3 kPa (100 Torr).

  Subsequently, the pressure in the first reaction tank 2 was maintained at 13.3 kPa, and an oligomerization reaction was performed for 80 minutes while further distilling off phenol. After completion of the oligomerization reaction, the inside of the system was returned to 101.3 kPa in absolute pressure with nitrogen, further increased to 0.2 MPa (gauge pressure), and oligomerized via a transfer pipe heated to 200 ° C. or higher in advance. The oligomer obtained by the reaction was equipped with a stirring motor 6b having an internal volume of 40 L controlled to an internal temperature of 240 ° C., a heat medium jacket (not shown), a vacuum pump (not shown), and a reflux condenser 7b. 2 It pumped to the reaction tank 3 (internal pressure: atmospheric pressure).

  Next, the oligomer fed into the second reaction tank 3 was stirred at 38 rpm, the internal temperature was raised with a heat medium jacket, and the inside of the second reaction tank 3 was increased from 101.3 kPa to 13 in absolute pressure over 40 minutes. The pressure was reduced to 3 kPa. Thereafter, the temperature increase was continued, and the internal pressure was reduced from 13.3 kPa to 399 Pa (3 Torr) as an absolute pressure over an additional 40 minutes, and the distilled phenol was removed out of the system. Further, the temperature was increased and the pressure was reduced. After the absolute pressure in the second reaction tank 3 reached 70 Pa (about 0.5 torr), the pressure was maintained at 70 Pa, and a polycondensation reaction was performed. The final internal temperature in the second reaction tank 3 was 285 ° C.

  In the present embodiment, the stirring power of the stirring motor provided in the second reaction tank 3 is used as an index of the molecular weight of the polycarbonate resin. The polycondensation reaction was completed when the stirring motor of the second reaction tank 3 reached a predetermined stirring power. Next, after the internal pressure of the second reaction tank 3 was restored to 101.3 kPa in absolute pressure with nitrogen, the pressure was further increased to 0.2 MPa (gauge pressure), and the aromatic polycarbonate resin A was introduced from the bottom of the second reaction tank 3. Was extracted in the form of a strand and pelletized using a rotary tip cutter 5 while being cooled in a strand cooling tank 4. It was Mv = 26,000 and YI = 2.0 of the obtained aromatic polycarbonate resin A.

  In parallel with the pelletization, 4,000 g of phenol is added to the first reaction tank 2 whose internal temperature is 50 ° C. or less in advance, the inside of the first reaction tank 2 is made 10 torr, and then the pressure is restored to atmospheric pressure with nitrogen. The operation was repeated 5 times, and the inside of the first reaction tank 2 was replaced with nitrogen. After nitrogen replacement, the internal pressure in the first reaction tank 2 is increased to 0.02 MPa (gauge pressure) with nitrogen, and the internal temperature of the first reaction tank 2 is gradually increased through a heat medium having a temperature of 230 ° C. in the heat medium jacket. The phenol was refluxed at 140 ° C. for 60 minutes.

  Next, the phenol solution is sent to the second reaction tank 3 through the transfer pipe, and the internal temperature in the reaction tank 3 is 220 ° C. and the internal pressure is 0.3 MPa (gauge) by controlling the vacuum pump and the heat medium jacket. Pressure), phenol was refluxed for 60 minutes.

  After 60 minutes, the degree of vacuum in the system was increased, 1,000 g of phenol (25% of the supply amount) was recovered from the gas phase, and the residue was purged from the bottom of the tank.

  After the washing operation using phenol was performed twice in total, isosorbide (hereinafter referred to as “ISB”) 4,448 g, 1,4-cyclohexane was added to the first reaction tank 2 which had been cooled to 60 ° C. in advance. First reaction was performed by adding 1.25 μmol of calcium acetate monohydrate as a catalyst to 1,881 g of dimethanol (hereinafter referred to as “CHDM”) and 9,315 g of DPC with respect to 1 mol of dihydroxy compound. The operation of setting the inside of the tank 2 to 10 torr and then returning to atmospheric pressure with nitrogen was repeated 5 times, and the inside of the first reaction tank 2 was replaced with nitrogen. After nitrogen substitution, the internal temperature of the first reaction tank 2 was gradually raised through a heating medium at a temperature of 230 ° C. through the heating medium jacket to dissolve the contents. Then, it stirred at 300 rpm, the temperature in a heat-medium jacket was controlled, and the internal temperature of the 1st reaction tank 2 was maintained at 210 degreeC. Then, the pressure in the first reaction tank 2 is increased to an absolute pressure of 101. over 90 minutes while distilling off phenol by-produced by the oligomerization reaction of ISB and CHDM and DPC performed in the first reaction tank 2. The pressure was reduced from 3 kPa (760 Torr) to 13.3 kPa (100 torr).

  Subsequently, the pressure in the first reaction tank 2 was maintained at 13.3 kPa, and an oligomerization reaction was performed for 30 minutes while further distilling off phenol. After completion of the oligomerization reaction, the inside of the system was returned to 101.3 kPa in absolute pressure with nitrogen, further increased to 0.2 MPa (gauge pressure), and oligomerized via a transfer pipe heated to 200 ° C. or higher in advance. The oligomer obtained by the reaction was pumped to a second reaction tank 3 (internal pressure: atmospheric pressure) equipped with a stirrer having an internal volume of 40 L controlled to an internal temperature of 220 ° C., a heat medium jacket, a vacuum pump and a reflux condenser.

  Next, the oligomer fed into the second reaction tank 3 was stirred at 38 rpm, the internal temperature was raised with a heat medium jacket, and the inside of the second reaction tank 3 was increased from 101.3 kPa to 13 in absolute pressure over 40 minutes. The pressure was reduced to 3 kPa. Thereafter, the temperature increase was continued, and the internal pressure was reduced from 13.3 kPa to 399 Pa (3 Torr) as an absolute pressure over an additional 40 minutes, and the distilled phenol was removed out of the system. Further, the temperature was increased and the pressure was reduced. After the absolute pressure in the second reaction tank 3 reached 70 Pa (about 0.5 torr), the pressure was maintained at 70 Pa, and a polycondensation reaction was performed. The final internal temperature in the second reaction tank 3 was 220 ° C.

  The polycondensation reaction was terminated when the stirring motor 6b of the second reaction tank 3 reached a predetermined stirring power. Next, after the internal pressure of the second reaction tank 3 is restored to 101.3 kPa as an absolute pressure with nitrogen, the pressure is further increased to 0.2 MPa (gauge pressure), and a non-aromatic polycarbonate resin is introduced from the bottom of the second reaction tank 3. A was extracted as a strand and pelletized using a chip cutter 5 while being cooled in a water bath. The obtained non-aromatic polycarbonate resin A had Mv = 19,500 and YI = 2.5, and in the non-aromatic polycarbonate resin A, there was no crystallized foreign matter derived from the aromatic polycarbonate resin A.

(Example 2)
In Example 1, a polycarbonate resin was produced in the same manner as in Example 1 except that after the aromatic polycarbonate resin A was produced, phenol was washed once to produce a non-aromatic polycarbonate resin A. As a result, the hue of the non-aromatic polycarbonate resin A was the same as that of Example 1, but a slight amount of crystallized foreign matter derived from the aromatic polycarbonate resin A was present in the resin.

(Comparative Example 1)
In Example 1, after producing the aromatic polycarbonate resin A, a polycarbonate resin was produced in the same manner as in Example 1 except that the non-aromatic polycarbonate resin A was produced without washing with phenol. As a result, the hue of the non-aromatic polycarbonate resin A was equivalent to that of Example 1, but a large amount of crystallized foreign matter derived from the aromatic polycarbonate resin A was present in the resin.

(Example 3)
In Example 1, after the production of the aromatic polycarbonate resin A, the washing operation in the production facility with phenol was performed twice, and then the non-aromatic melt viscosity was 900 Pa · s at 240 ° C. under a shear rate of 912 sec ^−1. A polycarbonate resin was produced in the same manner as in Example 1 except that the inside of the production facility was further washed with the polycarbonate resin A and a non-aromatic polycarbonate resin A having a predetermined Mv = 19,500 was produced. The obtained non-aromatic polycarbonate resin A had Mv = 19,500 and YI = 2.0, and in the non-aromatic polycarbonate resin A, there was no crystallization foreign matter derived from the aromatic polycarbonate resin A.

Example 4
Isosorbide (hereinafter referred to as “ISB”) 4,448 g, 1,4-cyclohexanedimethanol (hereinafter referred to as “CHDM”) 1,881 g, DPC 9 in the first reaction tank 2 having an internal temperature of 60 ° C. in advance. , 315 g of calcium acetate monohydrate added as a catalyst with 1.25 μmol of metal added to 1 mol of dihydroxy compound as a catalyst, the inside of the first reaction tank 2 is depressurized to 10 torr, and then a large amount of nitrogen is added. The operation of returning to atmospheric pressure was repeated 5 times, and the inside of the first reaction tank 2 was replaced with nitrogen. After nitrogen substitution, the internal temperature of the first reaction tank 2 was gradually raised through a heating medium at a temperature of 230 ° C. through the heating medium jacket to dissolve the contents. Then, it stirred at 300 rpm, the temperature in a heat-medium jacket was controlled, and the internal temperature of the 1st reaction tank 2 was maintained at 210 degreeC. Then, the pressure in the first reaction tank 2 is increased to an absolute pressure of 101. over 90 minutes while distilling off phenol by-produced by the oligomerization reaction of ISB and CHDM and DPC performed in the first reaction tank 2. The pressure was reduced from 3 kPa (760 Torr) to 13.3 kPa (100 torr).

  Subsequently, the pressure in the first reaction tank 2 was maintained at 13.3 kPa, and an oligomerization reaction was performed for 30 minutes while further distilling off phenol. After completion of the oligomerization reaction, the inside of the system was returned to 101.3 kPa in absolute pressure with nitrogen, further increased to 0.2 MPa (gauge pressure), and oligomerized via a transfer pipe heated to 200 ° C. or higher in advance. The oligomer obtained by the reaction was pumped to a second reaction tank 3 (internal pressure: atmospheric pressure) equipped with a stirrer having an internal volume of 40 L controlled to an internal temperature of 220 ° C., a heat medium jacket, a vacuum pump and a reflux condenser.

  Next, the oligomer fed into the second reaction tank 3 was stirred at 38 rpm, the internal temperature was raised with a heat medium jacket, and the inside of the second reaction tank 3 was increased from 101.3 kPa to 13 in absolute pressure over 40 minutes. The pressure was reduced to 3 kPa. Thereafter, the temperature increase was continued, and the internal pressure was reduced from 13.3 kPa to 399 Pa (3 Torr) as an absolute pressure over an additional 40 minutes, and the distilled phenol was removed out of the system. Further, the temperature was increased and the pressure was reduced. After the absolute pressure in the second reaction tank 3 reached 70 Pa (about 0.5 torr), the pressure was maintained at 70 Pa, and a polycondensation reaction was performed. The final internal temperature in the second reaction tank 3 was 220 ° C.

  The polycondensation reaction was terminated when the stirring motor 6b of the second reaction tank 3 reached a predetermined stirring power. Next, after the internal pressure of the second reaction tank 3 is restored to 101.3 kPa as an absolute pressure with nitrogen, the pressure is further increased to 0.2 MPa (gauge pressure), and a non-aromatic polycarbonate resin is introduced from the bottom of the second reaction tank 3. B was extracted as a strand and pelletized using a rotary tip cutter 5 while being cooled in a water bath. The obtained non-aromatic polycarbonate resin B had Mv = 19,500 and YI = 2.5.

  In parallel with the pelletization, 4,000 g of phenol is charged into the first reaction tank 2 whose internal temperature is 50 ° C. or lower in advance, the inside of the first reaction tank 2 is made 10 torr, and then the pressure is restored to atmospheric pressure with nitrogen. The operation was repeated 5 times, and the inside of the first reaction tank 2 was replaced with nitrogen. After nitrogen replacement, the internal pressure in the first reaction tank 2 is increased to 0.02 MPa (gauge pressure) with nitrogen, and the internal temperature of the first reaction tank 2 is gradually increased through a heat medium having a temperature of 230 ° C. in the heat medium jacket. The phenol was refluxed at 140 ° C. for 60 minutes.

  Next, the phenol solution is fed to the second reaction tank 3 through a transfer pipe, and the internal temperature of the reaction tank is 220 ° C. and the internal pressure is 0.3 MPa (gauge pressure) by controlling the vacuum pump and the heat medium jacket. ) And refluxing phenol for 60 minutes.

  After 60 minutes, the degree of vacuum in the system was increased, 1,000 g of phenol (25% of the supply amount) was recovered from the gas phase, and the residue was purged from the bottom of the tank.

  After performing the washing operation using phenol, the first reaction tank 2 cooled to 80 ° C. in advance was charged with 6,700 g of BPA, 6,583 g of DPC, and an aqueous solution of cesium carbonate in an amount of 0. The mixture added and mixed so as to be 5 μmol was charged, the inside of the first reaction tank 2 was depressurized to 10 torr, and then the pressure was restored to atmospheric pressure with nitrogen five times. Replaced. After nitrogen substitution, the internal temperature of the first reaction tank 2 was gradually raised through a heating medium at a temperature of 230 ° C. through the heating medium jacket to dissolve the contents. Then, it stirred at 300 rpm, the temperature in a heat-medium jacket was controlled, and the internal temperature of the 1st reaction tank 2 was maintained at 220 degreeC. And while distilling off the phenol by-produced by the oligomerization reaction of BPA and DPC performed in the first reaction tank 2, the pressure in the first reaction tank 2 is 101.3 kPa (absolute pressure) over 40 minutes. The pressure was reduced from 760 Torr to 13.3 kPa (100 Torr).

  Subsequently, the pressure in the first reaction tank 2 was maintained at 13.3 kPa, and the oligomerization reaction and the cleaning in the first reaction tank 2 were performed for 80 minutes while further distilling off the phenol. Then, after the internal pressure of the system is restored to 101.3 kPa in absolute pressure with nitrogen, the pressure is further increased to 0.2 MPa (gauge pressure), and is obtained by an oligomerization reaction through a transfer pipe heated to 200 ° C. or higher in advance. The oligomer was pumped to a second reaction tank 3 (internal pressure: atmospheric pressure) equipped with a stirrer having an internal volume of 40 L controlled to an internal temperature of 240 ° C., a heat medium jacket, a vacuum pump and a reflux condenser.

  Next, the oligomer fed into the second reaction tank 3 was stirred at 38 rpm, the internal temperature was raised with a heat medium jacket, and the inside of the second reaction tank 3 was increased from 101.3 kPa to 13 in absolute pressure over 40 minutes. The pressure was reduced to 3 kPa. Thereafter, the temperature increase was continued, and the internal pressure was reduced from 13.3 kPa to 399 Pa (3 Torr) as an absolute pressure over an additional 40 minutes, and the distilled phenol was removed out of the system. Further, the temperature was increased and the pressure was reduced. After the absolute pressure in the second reaction tank 3 reached 70 Pa (about 0.5 torr), the pressure was maintained at 70 Pa, and the polycondensation reaction and the cleaning in the second reaction tank 3 were performed. The final internal temperature in the second reaction tank 3 was 285 ° C.

When the stirring motor of the second reaction tank 3 became stirring power corresponding to Mv = 15,000, the polycondensation reaction and the cleaning in the second reaction tank 3 were completed. Next, after the internal pressure of the second reaction tank 3 is restored to 101.3 kPa in absolute pressure with nitrogen, the pressure is further increased to 0.2 MPa (gauge pressure), and the aromatic polycarbonate resin is removed from the bottom of the second reaction tank 3. Purged. When the melt viscosity of the aromatic polycarbonate resin was measured, it was 105 Pa · s under the condition of a shear rate of 912 sec ⁻¹ at 300 ° C.

  After carrying out the purge operation, 6,700 g of BPA is added to the first reaction tank 2 cooled to 80 ° C. in advance, an aqueous solution of cesium carbonate is added to 6,583 g of DPC, and the metal amount is 0.5 μmol per mol of BPA. The operation of charging the mixture so that the inside of the first reaction tank 2 was brought to 10 torr and then returning to atmospheric pressure with nitrogen was repeated five times to replace the inside of the first reaction tank 2 with nitrogen. After nitrogen substitution, the internal temperature of the first reaction tank 2 was gradually raised through a heating medium at a temperature of 230 ° C. through the heating medium jacket to dissolve the contents. Then, it stirred at 300 rpm, the temperature in a heat-medium jacket was controlled, and the internal temperature of the 1st reaction tank 2 was maintained at 220 degreeC. And while distilling off the phenol by-produced by the oligomerization reaction of BPA and DPC performed in the first reaction tank 2, the pressure in the first reaction tank 2 is 101.3 kPa (absolute pressure) over 40 minutes. The pressure was reduced from 760 Torr to 13.3 kPa (100 Torr).

  Subsequently, the pressure in the first reaction tank 2 was maintained at 13.3 kPa, and an oligomerization reaction was performed for 80 minutes while further distilling off phenol. After completion of the oligomerization reaction, the inside of the system was returned to 101.3 kPa in absolute pressure with nitrogen, further increased to 0.2 MPa (gauge pressure), and oligomerized via a transfer pipe heated to 200 ° C. or higher in advance. The oligomer obtained by the reaction was pumped to a second reaction tank 3 (internal pressure: atmospheric pressure) equipped with a stirrer having an internal volume of 40 L controlled to an internal temperature of 240 ° C., a heat medium jacket, a vacuum pump and a reflux condenser.

  Next, the oligomer fed into the second reaction tank 3 was stirred at 38 rpm, the internal temperature was raised with a heat medium jacket, and the inside of the second reaction tank 3 was increased from 101.3 kPa to 13 in absolute pressure over 40 minutes. The pressure was reduced to 3 kPa. Thereafter, the temperature increase was continued, and the internal pressure was reduced from 13.3 kPa to 399 Pa (3 Torr) as an absolute pressure over an additional 40 minutes, and the distilled phenol was removed out of the system. Further, the temperature was increased and the pressure was reduced. After the absolute pressure in the second reaction tank 3 reached 70 Pa (about 0.5 torr), the pressure was maintained at 70 Pa, and a polycondensation reaction was performed. The final internal temperature in the second reaction tank 3 was 285 ° C.

  The polycondensation reaction was completed when the stirring motor of the second reaction tank 3 reached a predetermined stirring power. Next, after the internal pressure of the second reaction tank 3 is restored to 101.3 kPa in absolute pressure with nitrogen, the pressure is further increased to 0.2 MPa (gauge pressure), and the aromatic polycarbonate resin B is introduced from the bottom of the second reaction tank 3. Was extracted in the form of a strand and pelletized using a rotary cutter while cooling in a water bath. It was Mv = 21,000 and YI = 2.5 of the obtained aromatic polycarbonate resin B.

(Comparative Example 2)
In Example 4, the same procedure as in Example 4 was performed, except that the production facility was washed with phenol and the production facility was not washed with a low-viscosity aromatic polycarbonate resin. The aromatic polycarbonate resin finally obtained had a very poor color tone with Mv = 21,000 and YI = 4.5.

  According to the present invention, it is possible to suppress mixing of crystallized foreign matters and deterioration of color tone when continuously producing by switching between an aromatic polycarbonate resin and a non-aromatic polycarbonate resin in the same production facility. A method for efficiently producing a polycarbonate resin having a stable and excellent color tone is provided.

DESCRIPTION OF SYMBOLS 1 Raw material inlet 2 1st reaction tank 3 2nd reaction tank 4 Strand cooling tank 5 Chip cutter 6a, 6b Stirring motor 7a, 7b Reflux cooler

Claims (3)

  A method for producing a polycarbonate resin, comprising an aromatic polycarbonate resin and a non-aromatic polycarbonate resin, wherein a plurality of types of polycarbonate resins are produced with the same production equipment, wherein the aromatic monohydroxy compound is produced after the production of the aromatic polycarbonate resin. A method for producing a polycarbonate resin, comprising: washing the inside of the production facility, and then producing a non-aromatic polycarbonate resin. After washing the production facility with the aromatic monohydroxy compound, a melt mixture of a dihydroxy compound containing a non-aromatic dihydroxy compound and a carbonic acid diester and / or a melt viscosity at 240 ° C. has a shear rate of 912 sec ^−1. 2. The method for producing a polycarbonate resin according to claim 1, wherein the inside of the production facility is washed with a non-aromatic polycarbonate resin having a pressure of 1000 Pa · s or less under the above conditions. A method for producing a polycarbonate resin comprising producing an aromatic polycarbonate resin and a non-aromatic polycarbonate resin at the same production facility, wherein the aromatic monohydroxy is produced after the non-aromatic polycarbonate resin is produced. The inside of the production facility is washed with a compound, and then a molten mixture of an aromatic dihydroxy compound and a carbonic acid diester and / or a fragrance having a melt viscosity at 300 ° C. of 400 Pa · s or less under conditions of a shear rate of 912 sec ^−1. A method for producing a polycarbonate resin, comprising washing the inside of the production facility with an aromatic polycarbonate resin and then producing an aromatic polycarbonate resin.

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