JP2012214768A - Method for manufacturing polycarbonate resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently and stably manufacture a polycarbonate resin excellent in thermostability, hue and mechanical strength with less foreign matter.SOLUTION: The polycarbonate is manufactured by supplying a polycarbonate resin, which is obtained by using a dihydroxy compound having -CH-O- group and a diester carbonate as raw material dihydroxy compounds and polycondensing them by transesterification reaction, to an extruder in which at least one set temperature of the constituent barrel is 100°C or higher and lower than 250°C.

Description

  The present invention relates to a method for efficiently and stably producing a polycarbonate resin which is excellent in thermal stability, hue, and mechanical strength and has few foreign matters.

  Polycarbonate resins generally contain bisphenols as monomer components and take advantage of transparency, heat resistance, mechanical strength, etc., so-called electrical and electronic parts, automotive parts, optical recording media, optical fields such as lenses, etc. Widely used as engineering plastics. However, for optical compensation film applications such as flat panel displays, which have been rapidly spreading recently, more advanced optical properties such as low birefringence and low photoelastic coefficient have been required, and conventional bisphenols are used as monomers. The aromatic polycarbonate resin as a component cannot meet the demand.

  In addition, conventional polycarbonate resins are manufactured using raw materials derived from petroleum resources. However, in recent years, there is a concern about the depletion of petroleum resources, and polycarbonate resins using raw materials obtained from biomass resources such as plants are used. Offer is required. In addition, it is feared that global warming due to the increase and accumulation of carbon dioxide emissions will lead to climate change, etc., so that carbon-neutral plant-derived monomers are used as raw materials even after disposal after use. There is a need for the development of such polycarbonate resins.

  Under such circumstances, there has been proposed a method for obtaining a polycarbonate resin while using a special dihydroxy compound as a monomer component and distilling off a monohydroxy compound by-produced by transesterification with a carbonic acid diester under reduced pressure (for example, Patent Document 1). To 6).

  Before making polycarbonate resin pellets, add or disperse a catalyst deactivator to stop the progress of polymerization, remove residual monomers and other volatile components under reduced pressure, heat stabilizers, release agents, etc. It is required to add and / or disperse the additive in order to impart performance according to the intended use, and in the conventional polycarbonate resin containing bisphenol A as a monomer component, an extruder is used. It has been proposed to use these operations. (For example, refer to Patent Document 7).

International Publication No. 04/111106 Pamphlet Japanese Patent Laid-Open No. 2006-232897 JP 2006-28441 A JP 2008-24919 A JP 2009-91404 A JP 2009-91417 A JP-A-5-239333

  However, since polycarbonate resins containing special dihydroxy compounds other than bisphenols as monomer components start to decompose at a lower temperature than conventional polycarbonate resins containing bisphenols as monomer components, low molecular weight components can be removed or additives When mixing to an extruder with the same heater temperature as before, the resin is decomposed and deteriorated inside the extruder because it is too hot, the hue deteriorates, and the strand is broken by the decomposition gas. In order to suppress the deterioration of the resin and the hue as described above, the heater temperature of the extruder is set too low. And the melt viscosity of polycarbonate resin increases, the load on the extruder increases and the extrusion operation becomes unstable, Extruder there is a problem in that or got stopped at the overload.

  On the other hand, in order to suppress the deterioration of the resin and the hue as described above, if the supply temperature of the resin is lowered too much, or if the heater temperature of the extruder is set too low for the same purpose, the polycarbonate resin will melt. There is also a problem that the viscosity increases, the load on the extruder increases, the extrusion operation becomes unstable, and the extruder stops due to overload.

  On the other hand, when trying to lower the melt viscosity of the polycarbonate resin, it is necessary to lower the molecular weight of the polycarbonate resin itself or raise the extrusion temperature. However, lowering the molecular weight causes a decrease in mechanical strength and heat resistance. When the temperature of extrusion is increased, the resin is decomposed and deteriorated, and not only a resin satisfying the physical properties such as mechanical strength can be obtained, but also the coloration is promoted, or the strand is out of gas by the decomposition gas, There was a problem that pellets could not be obtained stably.

  It is an object of the present invention to provide a method for efficiently and stably producing a polycarbonate resin that solves the above-mentioned conventional problems and is excellent in thermal stability, hue, and mechanical strength.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor extruded a polycarbonate resin produced by polycondensation by a transesterification reaction using a catalyst and a specific dihydroxy compound and a carbonic acid diester as raw material monomers. In a method for producing a polycarbonate resin by supplying to a machine, by setting at least one heater set temperature of the extruder of the extruder having a plurality of heaters to 100 ° C. or more and less than 250 ° C., excellent mechanical strength and hue are obtained. It was found that a polycarbonate resin can be stably produced.

（但し、上記一般式（１）で表される部位が−ＣＨ_２−Ｏ−Ｈの一部である場合を除く。） That is, the gist of the present invention resides in the following [1] to [17].
[1] A method for producing a polycarbonate resin by polycondensation by a transesterification reaction using a catalyst and a dihydroxy compound and a carbonic acid diester as raw materials, and supplying the produced polycarbonate resin to an extruder,
The dihydroxy compound includes at least a dihydroxy compound having a site represented by the following general formula (1) in a part of the structure;
The dihydroxy compound having a site represented by the following general formula (1) includes a compound having a cyclic ether structure,
A method for producing a polycarbonate resin, characterized in that a barrel constituting the extruder includes a plurality of heaters, and at least one heater set temperature among these heaters is set to 100 ° C. or higher and lower than 250 ° C.

(However, the site represented by the above general formula (1) unless it is part of _-CH 2 -O-H.)

[2] The method for producing a polycarbonate resin according to [1], wherein a set temperature of the heater is not higher than a heater set temperature adjacent to a polycarbonate resin supply side of the extruder.

[3] The method for producing a polycarbonate resin according to [1] or [2], wherein set temperatures of all the heaters are 100 ° C. or higher and lower than 250 ° C.

[4] The method for producing a polycarbonate resin according to any one of [1] to [3], wherein the polycarbonate resin obtained by polycondensation by a transesterification reaction is supplied to the extruder in a molten state.

[5] The screw of the extruder is composed of a plurality of elements, at least one of the elements is a kneading disk, and the total length of the kneading disk is 20% of the total length of the screw. The method for producing a polycarbonate resin according to any one of [1] to [4].

[6] When the weight of the resin extruded per hour by the extruder is W (kg / h) and the sectional area of the barrel of the extruder is S (m ² ), the following formula (5) is satisfied: [1] A process for producing a polycarbonate resin according to any one of [5].
12000 ≦ W / S ≦ 60000 (5)

[7] The reduced viscosity (η _sp / c) of the polycarbonate resin obtained through the extruder measured in methylene chloride at a concentration of 0.6 g / dL and a temperature of 20.0 ° C. ± 0.1 ° C. The method for producing a polycarbonate resin according to any one of [1] to [6], which is 0.3 dL / g or more and 1.2 dL / g or less.

[8] The method for producing a polycarbonate resin according to any one of [1] to [7], wherein the polycarbonate resin obtained through the extruder has a glass transition temperature of 80 ° C. or higher and lower than 145 ° C.

[9] The polycarbonate resin according to any one of [1] to [8], wherein the content of the aromatic monohydroxy compound contained in the polycarbonate resin obtained through the extruder is less than 0.1 wt%. Production method.

[10] The method for producing a polycarbonate resin according to any one of [1] to [9], wherein the raw material monomer is filtered with a raw material filter before polycondensation.

[11] The method for producing a polycarbonate resin according to any one of [1] to [10], wherein an operation of kneading a heat stabilizer is performed using the extruder.

[12] The method for producing a polycarbonate resin according to any one of [1] to [11], wherein the catalyst is at least one compound selected from the group consisting of a metal of Group 2 of the long-period periodic table and lithium. .

[13] The method for producing a polycarbonate resin according to any one of [1] to [12], wherein the dihydroxy compound having a site represented by the general formula (1) is isosorbide.

[14] The method for producing a polycarbonate resin according to any one of [1] to [13], wherein an alicyclic dihydroxy compound is further used as the dihydroxy compound.

[15] A polycarbonate resin having a yellow index value of 30 or less obtained by the production method according to any one of [1] to [14].

[16] A polycarbonate resin obtained by the production method according to any one of [1] to [14] or a film having a thickness of 35 μm ± 5 μm obtained by extrusion molding of the polycarbonate resin according to [15] A polycarbonate resin film having a maximum length of 25 μm or more contained in the film of 1000 / m ² or less.

[17] A polycarbonate resin film having a thickness of 20 μm to 200 μm obtained by molding the polycarbonate resin according to [15] or [16].

  According to the present invention, it is excellent in mechanical strength and hue, and has few foreign substances. Electric / electronic parts, automotive parts and other injection molding fields, films, sheet fields, bottles, container fields, camera lenses, viewfinder lenses Films such as CCD and CMOS lenses, retardation films used for liquid crystals and plasma displays, films such as diffusion sheets and polarizing films, sheets, optical disks, optical materials, optical components, dyes, charge transfer agents, etc. It becomes possible to efficiently and stably produce a polycarbonate resin having performance applicable to a wide range of fields such as a binder application to be fixed.

FIG. 1 is a process diagram showing an example of a manufacturing process according to the present invention.

DESCRIPTION OF EMBODIMENTS Embodiments of the present invention will be described in detail below. However, the description of the constituent elements described below is an example (representative example) of an embodiment of the present invention. It is not limited to the contents. In addition, when the expression “to” is used in the present specification, it is used in a sense including numerical values or physical values before and after the expression.
In the present specification, “mass%” and “wt%”, “mass ppm” and “weight ppm”, and “mass part” and “part by weight” have the same meaning. In addition, when “ppm” is simply described, it indicates “weight ppm”.

The method for producing a polycarbonate resin according to the present invention comprises polycondensation by a transesterification reaction using a catalyst, a dihydroxy compound and a carbonic acid diester as raw material monomers, and the obtained polycarbonate resin is supplied to an extruder set at a specific temperature. , A method for producing a polycarbonate resin. More specifically, the dihydroxy compound includes at least a dihydroxy compound having a site represented by the following general formula (1) in a part of the structure, and represented by the following general formula (1). The dihydroxy compound having a portion to be formed contains a compound having a cyclic ether structure, and the heater setting temperature of at least one of the heaters of the extruder is set to 100 ° C. or more and less than 250 ° C. .

（但し、上記一般式（１）で表される部位が−ＣＨ_２−Ｏ−Ｈの一部である場合を除く。）

(However, the site represented by the above general formula (1) unless it is part of _-CH 2 -O-H.)

<Raw material monomers and polymerization catalyst>
(Dihydroxy compound)
In the method for producing a polycarbonate resin of the present invention, a carbonic acid diester and a dihydroxy compound are used as raw material monomers, but at least one of the dihydroxy compounds has a part of the structure having a site represented by the above general formula (1) It is a dihydroxy compound (hereinafter sometimes referred to as “dihydroxy compound of the present invention”), and the dihydroxy compound includes a compound having a cyclic ether structure. The dihydroxy compound of the present invention refers to a compound containing at least two hydroxyl groups and at least the structural unit of the above general formula (1).

  The dihydroxy compound of the present invention is not particularly limited as long as it has a portion represented by the general formula (1) in a part of its structure, and specifically, diethylene glycol, triethylene Oxyalkylene glycols such as glycol, tetraethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol; 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, 9,9-bis (4- ( 2-hydroxyethoxy) -3-methylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-isopropylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy)- 3-isobutylphenyl) 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-hydroxyethoxy) -3,5-dimethylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-tert- Butyl-6-methylphenyl) fluorene, 9,9-bis (4- (3-hydroxy-2,2-dimethylpropoxy) phenyl) fluorene, etc., have an aromatic group in the side chain and an aromatic group in the main chain A compound having an ether group bonded to an anhydrosugar alcohol represented by a dihydroxy compound represented by the following general formula (2), the following general formula (3) Compounds having a cyclic ether structure of spiroglycol, etc. represented the like. Of these, compounds having a cyclic ether structure, particularly compounds having two cyclic ether structures, such as isosorbide and spiroglycol, are preferred from the viewpoints of heat resistance, imparting phase difference during stretching, and low photoelastic coefficient. From the viewpoints of handling, reactivity during polymerization, hue of the polycarbonate resin obtained, and imparting toughness when formed into a film, diethylene glycol, triethylene glycol, and polyethylene glycol are preferred. In this invention, although the compound which has a cyclic ether structure is included as a dihydroxy compound of this invention, as above-mentioned, advantages, such as heat resistance and phase difference provision at the time of extending | stretching, are acquired. Here, particularly from the viewpoint of heat resistance, anhydrous sugar alcohols typified by dihydroxy compounds represented by the following general formula (2) and compounds having a cyclic ether structure represented by the following general formula (3) are preferred. The compound having a cyclic ether structure is rigid and can increase the mechanical properties of the obtained polycarbonate resin, but is easy to be colored at a high temperature. However, according to the method of the present invention, an effect of suppressing coloring can be obtained. . In particular, when a compound having two cyclic ether structures is used, the effect is further increased. These dihydroxy compounds may be used alone or in combination of two or more depending on the required performance of the polycarbonate resin to be obtained.

  Examples of the dihydroxy compound represented by the general formula (2) include isosorbide, isomannide, and isoidet, which have a stereoisomeric relationship, and these may be used alone or in combination of two or more. You may use it in combination.

  Of these dihydroxy compounds, it is preferable to use a dihydroxy compound having no aromatic ring structure from the viewpoint of the hue of the polycarbonate resin. Among them, it is produced from various starches that are abundant as plant-derived resources and are easily available. Isosorbide obtained by dehydrating and condensing sorbitol is most preferable from the viewpoints of availability and production, light resistance, optical properties, moldability, heat resistance, and carbon neutral.

  In the method for producing a polycarbonate resin of the present invention, a constituent unit derived from a dihydroxy compound other than the above-described dihydroxy compound of the present invention (hereinafter sometimes referred to as “other dihydroxy compound”) is included as a raw material monomer. As other dihydroxy compounds, ethylene glycol, 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 1,5 -Aliphatic dihydroxy compounds such as heptanediol and 1,6-hexanediol; 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, tricyclodecane dimethanol, pentacyclo Pentadecane dimethanol, 2,6- Alicyclic dihydroxy such as carindimethanol, 1,5-decalindimethanol, 2,3-decalindimethanol, 2,3-norbornanedimethanol, 2,5-norbornanedimethanol, 1,3-adamantandimethanol, etc. Compound; 2,2-bis (4-hydroxyphenyl) propane [= bisphenol A], 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-3) , 5-diethylphenyl) propane, 2,2-bis (4-hydroxy- (3,5-diphenyl) phenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2, 2-bis (4-hydroxyphenyl) pentane, 2,4′-dihydroxy-diphenylmethane, bis (4-hydroxyphenyl) Nyl) methane, bis (4-hydroxy-5-nitrophenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 3,3-bis (4-hydroxyphenyl) pentane, 1,1-bis (4 -Hydroxyphenyl) cyclohexane, bis (4-hydroxyphenyl) sulfone, 2,4'-dihydroxydiphenylsulfone, bis (4-hydroxyphenyl) sulfide, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3, 3'-dichlorodiphenyl ether, 9,9-bis (4- (2-hydroxyethoxy-2-methyl) phenyl) fluorene, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy Aromatic bisphenols such as 2-methylphenyl) fluorene .

  Among these other dihydroxy compounds, from the viewpoint of the hue of the polycarbonate resin, it is selected from the group consisting of dihydroxy compounds having no aromatic ring structure in the molecular structure, that is, aliphatic dihydroxy compounds and alicyclic dihydroxy compounds. It is preferable to use at least one compound, and as the aliphatic dihydroxy compound, 1,3-propanediol, 1,4-butanediol, and 1,6-hexanediol are particularly preferable. As the alicyclic dihydroxy compound, In particular, 1,4-cyclohexanedimethanol and tricyclodecane dimethanol are preferred, and 1,4-cyclohexanedimethanol is particularly preferred from the viewpoint of improving polymerization reactivity and toughness.

  By using these other dihydroxy compounds, it is possible to obtain effects such as improvement in flexibility of polycarbonate resin, improvement in heat resistance, improvement in moldability, but structural units derived from other dihydroxy compounds. When the content ratio is too large, mechanical properties and heat resistance may be lowered. Therefore, the ratio of the structural unit derived from the dihydroxy compound of the present invention to the structural unit derived from all dihydroxy compounds is 20 mol. % Or more, preferably 30 mol% or more, particularly preferably 50 mol% or more. That is, the proportion of structural units derived from other dihydroxy compounds is preferably 80 mol% or less, preferably 70 mol% or less, and 50 mol% or less with respect to the structural units derived from all dihydroxy compounds. And particularly preferred. When the amount of the monomer having a structural unit derived from the dihydroxy compound of the present invention is too large, the resulting polycarbonate resin has a high melt viscosity, which makes it difficult to filter using a filter having a small opening, resulting in an increase in foreign matter. Or pelletization and film formation may be difficult. Preferably it is 90 mol% or less, preferably 85 mol% or less, particularly preferably 80 mol% or less.

  The dihydroxy compound of the present invention may contain a stabilizer such as a reducing agent, antioxidant, oxygen scavenger, light stabilizer, antacid, pH stabilizer, heat stabilizer and the like. In particular, since the dihydroxy compound of the present invention is easily altered under acidic conditions, it is preferable to contain a basic stabilizer when stored before use. Basic stabilizers include group 1 or group 2 metal hydroxides, carbonates, phosphates, phosphites, hypophosphites in the long-period periodic table (Nomenclature of Inorganic Chemistry IUPAC Recommendations 2005). Salts, borates, fatty acid salts, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylethylammonium hydroxide, trimethylbenzylammonium hydroxide, trimethylphenylammonium hydroxide, Triethylmethylammonium hydroxide, triethylbenzylammonium hydroxide, triethylphenylammonium hydroxide Basic ammonium compounds such as roxide, tributylbenzylammonium hydroxide, tributylphenylammonium hydroxide, tetraphenylammonium hydroxide, benzyltriphenylammonium hydroxide, methyltriphenylammonium hydroxide, butyltriphenylammonium hydroxide; 4-amino Pyridine, 2-aminopyridine, N, N-dimethyl-4-aminopyridine, 4-diethylaminopyridine, 2-hydroxypyridine, 2-methoxypyridine, 4-methoxypyridine, 2-dimethylaminoimidazole, 2-methoxyimidazole, imidazole Amine compounds such as 2-mercaptoimidazole, 2-methylimidazole and aminoquinoline. Of these, Na or K phosphates and phosphites are preferred, and hydrogen phosphate 2Na and hydrogen phosphite 2Na are particularly preferred, because of their effects and ease of distillation removal described below.

  The content of these stabilizers in the dihydroxy compound of the present invention is not particularly limited, but if it is too small, the effect of preventing alteration of the dihydroxy compound of the present invention may not be obtained. Since modification of the compound may be caused, it is usually 0.0001% by weight to 1% by weight, preferably 0.001% by weight to 0.1% by weight, based on the dihydroxy compound of the present invention.

  In addition, when the dihydroxy compound of the present invention has a cyclic ether structure such as isosorbide, it is easily oxidized by oxygen. Therefore, during storage and production, in order to prevent decomposition by oxygen, do not mix moisture, In addition, it is important to use an oxygen scavenger or the like and handle under a nitrogen atmosphere. In particular, when isosorbide is oxidized, decomposition products such as formic acid may be generated. If isosorbide containing these decomposition products is used as a raw material for the production of polycarbonate resin, it may lead to coloration of the resulting polycarbonate resin, and may not only significantly deteriorate the physical properties but also affect the polymerization reaction. In some cases, a high molecular weight polymer cannot be obtained.

  In order to obtain the dihydroxy compound of the present invention which does not contain the above oxidatively decomposed product and to remove the above basic stabilizer, distillation purification can be performed before use as a raw material after storage. The distillation in this case may be batch distillation or continuous distillation, and is not particularly limited. As distillation conditions, it is preferable to carry out distillation under reduced pressure in an inert gas atmosphere such as argon or nitrogen. In order to completely remove oxygen, the inert gas is introduced into the distillate before or during distillation. It can also be distributed. In order to suppress denaturation due to heat, it is preferably 250 ° C. or lower, preferably 200 ° C. or lower, particularly 180 ° C. or lower.

  By such distillation purification, the formic acid content in the dihydroxy compound of the present invention is 20 ppm by weight or less, preferably 10 ppm by weight or less, and particularly preferably 5 ppm by weight or less includes the dihydroxy compound of the present invention. When a dihydroxy compound is used as a raw material for producing a polycarbonate resin, it is effective in producing a polycarbonate resin excellent in hue and thermal stability without impairing polymerization reactivity. In addition, the value of said formic acid content is a value measured by ion chromatography.

(Carbonated diester)
In the present invention, a polycarbonate resin can be obtained by polycondensation by a transesterification reaction using a dihydroxy compound containing the dihydroxy compound of the present invention described above and a carbonic acid diester as raw materials. Examples of the carbonic acid diester used in the present invention include those represented by the following general structural formula (4). These carbonic acid diesters may be used alone or in combination of two or more.

（Ａ^１、Ａ^２は、それぞれ置換もしくは無置換の炭素数１〜１８の脂肪族または置換もしくは無置換の芳香族基であり、Ａ^１とＡ^２は同一であっても異なっていてもよい。）
Ａ^１およびＡ^２の好ましいものは置換もしくは無置換の芳香族炭化水素基であり、より好ましいのは無置換の芳香族炭化水素基である。尚、脂肪族炭化水素基の置換基としては、エステル基、エーテル基、カルボン酸、アミド基、ハロゲンが挙げられ、芳香族炭化水素基の置換基としては、メチル基、エチル基等のアルキル基が挙げられる。

(A ¹ and A ² are each a substituted or unsubstituted aliphatic group having 1 to 18 carbon atoms or a substituted or unsubstituted aromatic group, and A ¹ and A ² may be the same or different. .)
A preferable example of A ¹ and A ² is a substituted or unsubstituted aromatic hydrocarbon group, and a more preferable example is an unsubstituted aromatic hydrocarbon group. In addition, examples of the substituent of the aliphatic hydrocarbon group include an ester group, an ether group, a carboxylic acid, an amide group, and a halogen. Examples of the substituent of the aromatic hydrocarbon group include an alkyl group such as a methyl group and an ethyl group. Is mentioned.

  Examples of the carbonic acid diester represented by the general formula (4) include diphenyl carbonate (hereinafter sometimes referred to as “DPC”), substituted diphenyl carbonate such as ditolyl carbonate, dimethyl carbonate, diethyl carbonate, and di-t-. Although butyl carbonate etc. are illustrated, Diphenyl carbonate and substituted diphenyl carbonate are preferable, and diphenyl carbonate is particularly preferable. Carbonic acid diesters may contain impurities such as chloride ions, which may hinder the polymerization reaction or worsen the hue of the resulting polycarbonate resin. It is preferable to use what was done.

  In the method of the present invention, a polycarbonate resin can be obtained by polycondensation of a dihydroxy compound containing the dihydroxy compound of the present invention and a carbonic acid diester by an ester exchange reaction. The dihydroxy compound and carbonic acid diester as raw materials can be transesterified even if they are dropped independently into the reaction vessel, but they can also be mixed uniformly before the transesterification. The mixing temperature is preferably 80 ° C. or higher, and preferably 90 ° C. or higher. On the other hand, the upper limit is preferably 250 ° C. or lower, preferably 200 ° C. or lower, more preferably 150 ° C. or lower. Among these, 100 ° C. or higher and 130 ° C. or lower is preferable. If the mixing temperature is too low, the dissolution rate may be slow or the solubility may be insufficient, often causing problems such as solidification, and if the mixing temperature is too high, the dihydroxy compound may be thermally deteriorated. As a result, the hue of the polycarbonate resin obtained is deteriorated, which may adversely affect light resistance and heat resistance.

  In the method of the present invention, the oxygen concentration in the operating environment in which the dihydroxy compound containing the dihydroxy compound of the present invention as a raw material and the carbonic acid diester are mixed is preferably 10 vol% or less, more preferably 0.0001 vol% to 10 vol%, and in particular, 0 From the viewpoint of preventing deterioration of hue, it is preferable to carry out in an atmosphere of 0.0001 vol% to 5 vol%, particularly 0.0001 vol% to 1 vol%.

  In the present invention, the carbonic acid diester may be used in a molar ratio of 0.90 to 1.20, preferably 0.95 to 1.10, based on all dihydroxy compounds including the dihydroxy compound of the present invention used in the reaction. More preferably, it is 0.97 to 1.03, and particularly preferably 0.99 to 1.02. When this molar ratio is decreased, the terminal hydroxyl group of the produced polycarbonate resin is increased, the thermal stability of the polymer is deteriorated, coloring occurs during molding, the rate of transesterification reaction is reduced, and the desired high molecular weight. The body may not be obtained. On the other hand, when this molar ratio is increased, the rate of transesterification reaction decreases, the production of polycarbonate having a desired molecular weight becomes difficult, the amount of residual carbonic diester in the polycarbonate resin increases, and during extrusion and molding In some cases, gas may be generated. The decrease in the transesterification reaction rate may increase the heat history during the polymerization reaction and may deteriorate the hue of the resulting polycarbonate resin.

  Furthermore, when the molar ratio of the carbonic diester is increased with respect to all the dihydroxy compounds including the dihydroxy compound of the present invention, the amount of residual carbonic diester in the obtained polycarbonate resin increases, which becomes a gas at the time of molding and causes molding defects. Bleed out from the product, which is not preferable. The concentration of the carbonic acid diester remaining in the polycarbonate resin obtained by the method of the present invention is preferably 200 ppm by weight or less, more preferably 100 ppm by weight or less, particularly preferably 60 ppm by weight or less, and particularly preferably 30 ppm by weight or less. .

(catalyst)
In the method of the present invention, as described above, when a polycarbonate resin is produced by polycondensation of a dihydroxy compound containing the dihydroxy compound of the present invention and a carbonic acid diester by a transesterification reaction, a transesterification catalyst (hereinafter simply referred to as “catalyst”). Or “polymerization catalyst”).

  In the method of the present invention, the transesterification catalyst (catalyst) can particularly affect the thermal stability of the polycarbonate resin and the yellow index (YI) value representing the hue. The transesterification catalyst used is not limited as long as it satisfies the thermal stability and hue of the polycarbonate resin, but is not limited to Group 1 or Group 2 in the long-period periodic table (hereinafter simply referred to as “1”). Group compounds ”and“ group 2 ”), and basic compounds such as basic boron compounds, basic phosphorus compounds, basic ammonium compounds, and amine compounds. Preferably, at least one of a Group 1 metal compound and a Group 2 metal compound is used, more preferably at least one metal compound selected from the group consisting of a metal of Group 2 of the long-period periodic table and lithium is used. .

  The group 1 metal compound and the group 2 metal compound are usually used in the form of a hydroxide or a salt such as carbonate, carboxylate or phenol salt, but are easily available and easy to handle. From the viewpoints of hue and polymerization activity, acetates are preferred.

  Specific examples of the group 1 metal compound include sodium hydroxide, potassium hydroxide, lithium hydroxide, cesium hydroxide, sodium hydrogen carbonate, potassium hydrogen carbonate, lithium hydrogen carbonate, cesium hydrogen carbonate, sodium carbonate, and carbonic acid. Potassium, lithium carbonate, cesium carbonate, sodium acetate, potassium acetate, lithium acetate, cesium acetate, sodium stearate, potassium stearate, lithium stearate, cesium stearate, sodium borohydride, potassium borohydride, lithium borohydride Cesium borohydride, sodium borohydride, potassium borohydride, lithium phenyl borohydride, cesium phenyl borohydride, sodium benzoate, potassium benzoate, lithium benzoate, cesium benzoate, phosphorus 2 sodium hydrogen, 2 potassium hydrogen phosphate, 2 lithium hydrogen phosphate, 2 cesium hydrogen phosphate, 2 sodium phenyl phosphate, 2 potassium phenyl phosphate, 2 lithium phenyl phosphate, 2 cesium phenyl phosphate, sodium, potassium, Examples thereof include lithium, cesium alcoholate, phenolate, bisphenol A disodium salt, 2 potassium salt, 2 lithium salt, 2 cesium salt, etc. Among them, lithium compounds are preferred.

  Specific examples of the Group 2 metal compound include calcium hydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide, calcium hydrogen carbonate, barium hydrogen carbonate, magnesium hydrogen carbonate, strontium hydrogen carbonate, calcium carbonate. , Barium carbonate, magnesium carbonate, strontium carbonate, calcium acetate, barium acetate, magnesium acetate, strontium acetate, calcium stearate, barium stearate, magnesium stearate, strontium stearate, etc., among which magnesium compounds, calcium compounds, barium compounds And at least one metal selected from the group consisting of magnesium compounds and calcium compounds from the viewpoint of polymerization activity and hue of the polycarbonate resin obtained More preferably compounds, most preferably a calcium compound.

  In addition, a basic compound such as a basic boron compound, a basic phosphorus compound, a basic ammonium compound, or an amine compound is used in combination with at least one of the group 1 metal compound and the group 2 metal compound. However, since it may volatilize during the polymerization reaction and cause troubles, it is particularly preferable to use at least one of the Group 1 metal compound and the Group 2 metal compound.

  Examples of the basic boron compound that can be used in combination include tetramethyl boric acid, tetraethyl boric acid, tetrapropyl boric acid, tetrabutyl boric acid, trimethylethyl boric acid, trimethylbenzyl boric acid, trimethylphenyl boric acid, and triethylmethyl. Sodium salt such as boric acid, triethylbenzyl boric acid, triethylphenyl boric acid, tributylbenzyl boric acid, tributylphenyl boric acid, tetraphenyl boric acid, benzyltriphenyl boric acid, methyltriphenyl boric acid, butyltriphenyl boric acid, A potassium salt, a lithium salt, a calcium salt, a barium salt, a magnesium salt, a strontium salt, or the like can be given.

  Examples of the basic phosphorus compound that can be used in combination include triethylphosphine, tri-n-propylphosphine, triisopropylphosphine, tri-n-butylphosphine, triphenylphosphine, tributylphosphine, or a quaternary phosphonium salt. It is done.

  Examples of the basic ammonium compound that can be used in combination include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylethylammonium hydroxide, trimethylbenzylammonium hydroxide, and trimethyl. Phenylammonium hydroxide, triethylmethylammonium hydroxide, triethylbenzylammonium hydroxide, triethylphenylammonium hydroxide, tributylbenzylammonium hydroxide, tributylphenylammonium hydroxide, tetraphenylammonium hydroxide, benzyltriphenylammonium hydroxide, methyltrimethyl Phenyla Mode onium hydroxide, butyl triphenyl ammonium hydroxide, and the like.

  Examples of the amine compound that can be used in combination 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.

  The amount of the catalyst used is preferably 0.1 μmol to 300 μmol, preferably 0.5 μmol to 100 μmol, preferably 0.5 μmol to 50 μmol, more preferably 0.5 μmol to 20 μmol, in particular, per 1 mol of all dihydroxy compounds used. Preferably it is 1 micromol-5 micromol. In particular, when using at least one metal compound selected from the metals of Group 2 of the long-period periodic table and lithium, the amount of metal is usually 0.1 μmol or more, preferably 0.5 μmol, per 1 mol of all dihydroxy compounds used. As described above, particularly preferably 0.7 μmol or more. Further, the upper limit is usually 20 μmol, preferably 10 μmol, more preferably 3 μmol, particularly preferably 1.5 μmol, and most preferably 1.0 μmol.

  If the amount of the catalyst used is too small, the polycondensation reaction will not proceed easily, and a polycarbonate resin having a desired molecular weight may not be obtained. On the other hand, if the amount of the catalyst used is too large, the hue or thermal stability of the polycarbonate resin obtained by an undesired side reaction may be deteriorated or foreign matter may be caused. In addition, Group 1 metals, especially sodium, potassium, and cesium, especially sodium, may adversely affect the hue when contained in a large amount in the polycarbonate resin. The metal is not only from the catalyst used, but also from raw materials and reactors. The total amount of these compounds in the polycarbonate resin is usually 1 ppm by weight or less, preferably 0.8 ppm by weight or less, more preferably 0.7 ppm by weight or less as the amount of metal. . The amount of metal in the polycarbonate resin can be measured using a method such as atomic emission, atomic absorption, Inductively Coupled Plasma (ICP) after recovering the metal in the polycarbonate resin by a method such as wet ashing. I can do it.

  The catalyst may be added directly to the reactor, or may be added to a raw material adjusting tank in which a dihydroxy compound and a carbonic acid diester are mixed in advance, and then present in the reactor. You may add in the piping which supplies a raw material. If the amount of the catalyst used is too small, sufficient polymerization activity cannot be obtained and the progress of the polymerization reaction is delayed, so that it is difficult to obtain a polycarbonate resin having a desired molecular weight, and a long-term heat history is caused. Can get worse.

<Manufacturing method>
(Polycondensation method)
In the method of the present invention, the method for obtaining a polycarbonate resin by polycondensation of the dihydroxy compound and the carbonic acid diester may be carried out in multiple stages using a plurality of reactors in the presence of the catalyst. The type of reaction may be any of a batch method, a continuous method, or a combination of a batch method and a continuous method, but among these, a continuous method is preferable from the viewpoint of stabilizing quality. In the initial stage of polymerization, it is preferable to obtain a prepolymer at a relatively low temperature and low vacuum, and in the latter stage of polymerization, it is preferable to increase the molecular weight to a predetermined value at a relatively high temperature and high vacuum, but the jacket temperature at each molecular weight stage. It is important from the viewpoints of hue and thermal stability to appropriately select the internal temperature and pressure in the reaction system. For example, if either the temperature or the pressure is changed too quickly before the polymerization reaction reaches a predetermined value, the unreacted monomer will be distilled, causing the molar ratio of the dihydroxy compound and the carbonic acid diester to change, resulting in a decrease in the polymerization rate. Or a polymer having a predetermined molecular weight or terminal group cannot be obtained, and as a result, the object of the present invention may not be achieved.

  Furthermore, it is effective to use a reflux condenser for the polymerization reactor in order to suppress the amount of the monomer to be distilled off, and the effect is particularly great in a reactor at the initial stage of polymerization where there are many unreacted monomer components. The temperature of the refrigerant introduced into the reflux condenser can be appropriately selected according to the monomer used, but the temperature of the refrigerant introduced into the reflux condenser is usually 45 to 180 ° C. at the inlet of the reflux condenser. Yes, preferably 80 to 150 ° C, particularly preferably 100 to 130 ° C. If the temperature of the refrigerant is too high, the amount of reflux decreases and the effect is reduced. On the other hand, if the temperature is too low, the distillation efficiency of the monohydroxy compound that should be distilled off tends to decrease. As the refrigerant, hot water, steam, heat medium oil or the like is used, and steam or heat medium oil is preferable.

  In order to maintain the polymerization rate appropriately and suppress the distillation of the monomer while suppressing the occurrence of foreign matter in the final polycarbonate resin and not impairing the hue and thermal stability, Selection of type and quantity is important. The reason for carrying out the polymerization in a plurality of reactors in the present invention is that, in the initial stage of the polymerization reaction, since there are many monomers contained in the reaction solution, the volatilization of the monomers can be suppressed while maintaining the necessary polymerization rate. It is important that, in the latter stage of the polymerization reaction, it is important to sufficiently distill off the by-product monohydroxy compound in order to shift the equilibrium to the polymerization side, and desirable polymerization reaction conditions are different in the early and late stages. . Thus, in order to set different polymerization reaction conditions, it is preferable from the viewpoint of production efficiency to use a plurality of polymerization reactors arranged in series.

  As described above, the number of reactors used in the polymerization in the present invention may be at least two. However, from the viewpoint of production efficiency, three or more, preferably 3 to 5, particularly preferably. Is four. In the present invention, if there are two or more reactors, different reaction conditions can be set in each reactor, and the temperature and pressure are continuously changed in each reactor. However, it is preferable that the temperature is increased stepwise and the pressure is decreased stepwise for each reactor.

  In the present invention, the polymerization catalyst can be added to the raw material preparation tank, the raw material storage tank, or can be added directly to the polymerization tank. From the viewpoint of supply stability and polymerization control, the polymerization catalyst is added to the polymerization tank. A catalyst supply pipe may be installed in the middle of the raw material pipe before being supplied, and is preferably supplied as an aqueous solution.

  If the temperature of the polymerization reaction is too low, it causes a decrease in productivity and an increase in the thermal history of the product, and if it is too high, it not only causes the vaporization of monomers but also may promote the decomposition and coloring of the polycarbonate resin. .

  The specific temperature is as follows. In the first stage reaction, the maximum internal temperature of the polymerization reactor is preferably 140 to 270 ° C., preferably 170 to 240 ° C., more preferably 180 to 210 ° C., and preferably 110 to 1 kPa, preferably 70 to 5 kPa, more preferably 30 to 10 kPa (absolute pressure) for 0.1 to 10 hours, preferably 0.5 to 3 hours, while distilling off the by-produced monohydroxy compound out of the reaction system Is done. The reaction in the first stage in the present invention refers to a reaction in a reactor at the uppermost stream of the process in a reactor in which 5% by weight or more of a monohydroxy compound distilled through the entire polymerization reaction is distilled. .

  In the second and subsequent stages, the pressure in the reaction system is gradually reduced from the pressure in the first stage, and the monohydroxy compound that is subsequently generated is removed from the reaction system. 2 kPa or less, preferably 1 kPa or less, 210 ° C. or higher, preferably 220 ° C. or higher and 270 ° C. or lower, preferably 250 ° C. or lower, more preferably 240 ° C. or lower, preferably 0.1 to 10 hours, 1 to 6 hours, particularly preferably 0.5 to 3 hours.

  In particular, in order to suppress the coloring and thermal deterioration of the polycarbonate resin and obtain a polycarbonate resin having a good hue and thermal stability, the maximum internal temperature in all reaction stages is less than 260 ° C., preferably less than 250 ° C., particularly 245 It is preferable that it is less than ° C. The internal temperature here refers to the temperature of the process liquid, and is usually measured by a thermometer using a thermocouple or the like provided in the reactor. In order to suppress the decrease in the polymerization rate after the polymerization reaction and minimize deterioration due to thermal history, it is necessary to use a horizontal reactor with excellent plug flow and interface renewability at the final stage of polymerization. preferable. However, in order to obtain a polycarbonate resin having a predetermined molecular weight, it is necessary to note that the yellow index (YI) value representing the hue tends to increase if the polymerization temperature is increased or the polymerization time is excessively increased.

  The monohydroxy compound distilled off as a by-product in the reaction is preferably used as a raw material for fuels and chemicals from the viewpoint of effective utilization of resources. In particular, it is preferable to recycle as raw materials such as diphenyl carbonate and bisphenol A after purification as necessary.

(Process after polycondensation reaction)
The polycarbonate resin of the present invention is preferably filtered using a filter after the polycondensation reaction described above. In particular, the polycarbonate resin obtained by polycondensation is introduced into an extruder and then discharged from the extruder in order to remove low molecular weight components contained in the polycarbonate resin and to add and knead a heat stabilizer and the like. The resin is preferably filtered using a filter.

Examples of the method of supplying the polycarbonate resin obtained by polycondensation as described above to an extruder and filtering it using a filter to form pellets include the following methods.
A method of extracting polycarbonate resin in a molten state from a final polymerization reactor using a gear pump or a screw in order to generate a pressure necessary for filtration, and filtering with the filter;
After the polycarbonate resin is supplied from the final polymerization reactor to a uniaxial or biaxial extruder in a molten state, and melt-extruded, an operation such as filtering with a filter is performed as necessary, and then cooled and solidified in the form of a strand. , Pelletizing with a rotary cutter, etc .;
Polycarbonate resin is supplied to a single-screw or twin-screw extruder in a molten state without being solidified from the final polymerization reactor, melt-extruded, then cooled and solidified in the form of a strand, pelletized, and the pellet is extruded again. A method of introducing into a machine and performing an operation such as filtering with a filter as necessary, and then cooling and solidifying in the form of a strand to pelletize;
A method in which polycarbonate resin is discharged from the final polymerization reactor in a molten state, once cooled and solidified in the form of strands, pelletized, the pellets are introduced into an extruder, cooled and solidified in the form of strands, and pelletized ;
Etc.
Above all, in order to minimize heat history and suppress thermal degradation such as deterioration of hue and molecular weight, the polycarbonate resin obtained by polycondensation by transesterification reaction is not solidified from the final polymerization reactor. Polycarbonate resin is supplied to a single-screw or twin-screw extruder in a molten state, melt-extruded, directly filtered through the filter, discharged from a die, cooled and solidified in the form of a strand, and rotated with a rotary cutter, etc. A method of pelletizing is preferred.

(Example of manufacturing equipment)
An example of an apparatus for carrying out the present invention for obtaining a polycarbonate resin from the raw material monomers described above is shown in the process diagram of FIG. Isosorbide (ISB) is used as the raw material monomer of the present invention as dihydroxy compound of the present invention, 1,4-cyclohexanedimethanol (CHDM) is used as the other dihydroxy compound, diphenyl carbonate (DPC) is used as the carbonic acid diester, and calcium acetate is used as the polymerization catalyst. It shall be.

  First, in the raw material preparation step, a DPC melt prepared at a predetermined temperature in a nitrogen gas atmosphere is continuously supplied from the raw material supply port 1a to the raw material mixing tank 2a. Also, the ISB melt and the CHDM melt measured in a nitrogen gas atmosphere are continuously supplied to the raw material mixing tank 2a from the raw material supply ports 1b and 1c, respectively. And these are mixed by the stirring blade 3a in the raw material mixing tank 2a, and a uniform raw material mixing melt is obtained.

  Next, the obtained raw material mixed melt is continuously supplied to the first vertical stirring reactor 6a via the raw material supply pump 4a and the raw material filtration filter 5a. Moreover, calcium acetate aqueous solution is continuously supplied as a raw material catalyst from the catalyst supply port 1d in the middle of the transfer piping of the raw material mixed melt.

  In the polycondensation step of the production apparatus of FIG. 1, a first vertical stirring reactor 6a, a second vertical stirring reactor 6b, a third vertical stirring reactor 6c, and a fourth horizontal stirring reactor 6d are provided in series. It is done. In each reactor, the liquid level is kept constant, the polycondensation reaction is continuously performed, and the polymerization reaction liquid discharged from the bottom of the first vertical stirring reactor 6a is sent to the second vertical stirring reactor 6b. Then, the polycondensation reaction proceeds sequentially by sequentially supplying the third vertical stirring reactor 6c and the fourth horizontal stirring reactor 6d. The reaction conditions in each reactor are preferably set so as to become high temperature, high vacuum, and low stirring speed as the polycondensation reaction proceeds.

  The first vertical stirring reactor 6a, the second vertical stirring reactor 6b, and the third vertical stirring reactor 6c are provided with Max Blend blades 7a, 7b, 7c, respectively. The fourth horizontal stirring reactor 6d is provided with a biaxial glasses-type stirring blade 7d. Since the reaction liquid to be transferred becomes highly viscous after the third vertical stirring reaction tank 6c, a gear pump 4b is provided.

  In the first vertical stirring reactor 6a and the second vertical stirring reactor 6b, the amount of heat supplied may be particularly large, so that the internal heat exchangers 8a and 8b are respectively provided so that the heat medium temperature does not become excessively high. Is provided.

  These four reactors are respectively equipped with distillation tubes 11a, 11b, 11c, and 11d for discharging by-products generated by the polycondensation reaction. As for the first vertical stirring reactor 6a and the second vertical stirring reactor 6b, reflux condensers 9a and 9b and reflux pipes 10a and 10b are provided in order to return a part of the distillate to the reaction system. The reflux ratio can be controlled by appropriately adjusting the pressure of the reactor and the heat medium temperature of the reflux condenser.

  The distillation pipes 11a, 11b, 11c, and 11d are connected to condensers 12a, 12b, 12c, and 12d, respectively, and each reactor is in a predetermined depressurized state by a decompression device 13a, 13b, 13c, and 13d. To be kept.

  In addition, by-products such as phenol (monohydroxy compound) are continuously liquefied and recovered from the condensers 12a, 12b, 12c, and 12d attached to each reactor. In addition, cold traps (not shown) are provided downstream of the condensers 12c and 12d attached to the third vertical reactor 6c and the fourth horizontal reactor 6d, respectively, so that by-products are continuously present. Solidified and recovered.

The reaction liquid raised to a predetermined molecular weight is withdrawn from the fourth horizontal stirring reactor 6d and transferred to the extruder 15a by the gear pump 4c. The pipe connecting the gear pump 4c and the extruder 15a is preferably a jacket type double pipe through which the heat medium flows to the outside. The temperature of the heat medium is the viscosity of the polycarbonate resin, the pressure loss of the pipe, and the heat stability of the polycarbonate resin. However, it is usually 300 ° C. or lower, preferably 280 ° C. or lower, more preferably 260 ° C. or lower, particularly preferably. Is optimally 250 ° C or lower, particularly 240 ° C or lower. On the other hand, if the pressure is too low, the pressure loss in the pipe becomes large and the pipe diameter needs to be increased, but at the same time, the residence time in the pipe of the polycarbonate resin may become long and may cause thermal deterioration. Above, preferably 180 ° C. or higher, more preferably 200 ° C. or higher, particularly preferably 210 ° C. or higher, and most preferably 220 ° C. or higher.
The extruder 15a is equipped with a vacuum vent to remove residual low molecular components in the polycarbonate. Further, an antioxidant, a light stabilizer, a colorant, a release agent, and the like are added as necessary.

Resin is supplied to the filter 15b by the gear pump 4d from the extruder 15a, and foreign matter is filtered. The resin that has passed through the filter 15b is extracted in the form of a strand from the die 15c, and after cooling and solidifying the resin with water in the strand cooling tank 16a, the resin is pelletized by the strand cutter 16b. The polycarbonate resin pellets thus obtained are pneumatically transported by the air blower 16c and sent to the product hopper 16d. A predetermined amount of product is packed in the product bag 16f by the measuring instrument 16e.
There are no restrictions on the types of gear pumps 4c and 4d, but in particular, there is a circuit that introduces some polymer from the discharge side of the gear pump to the gland through the valve, applies a certain pressure to the shaft seal, and returns it to the suction port. A self-circulating seal type gear pump that does not use a gland packing at the seal portion is preferable from the viewpoint of reducing foreign matter.

<Details of pellet manufacturing process after polymerization reaction>
(Extruder)
In the present invention, the form of the extruder is not limited, but a plurality of heaters are connected in order to adjust the temperature of the barrel (sometimes called a cylinder), and a single or twin screw is installed inside the barrel. An equipped extruder is preferred.
Among them, a twin screw extruder is preferable for improving the devolatilization performance described later and for uniform kneading of the additive. In this case, the rotation direction of the shaft may be different or the same, but the same direction is preferable from the viewpoint of kneading performance. Usually known in this extruder, heat stabilizer, neutralizer, UV absorber, mold release agent, colorant, antistatic agent, lubricant, lubricant, plasticizer, compatibilizer, flame retardant, etc. Can be added and kneaded.

  Examples of the heat stabilizer include triphenyl phosphite, tris (nonylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, tridecyl phosphite, trioctyl phosphite, trioctadecyl phosphite, Didecyl monophenyl phosphite, dioctyl monophenyl phosphite, diisopropyl monophenyl phosphite, monobutyl diphenyl phosphite, monodecyl diphenyl phosphite, monooctyl diphenyl phosphite, bis (2,6-di-tert-butyl-4 -Methylphenyl) pentaerythrityl diphosphite, 2,2-methylenebis (4,6-di-tert-butylphenyl) octyl phosphite, bis (nonylphenyl) pentaerythrityl diphosphite, bi Phosphorus heat stabilizers such as (2,4-di-tert-butylphenyl) pentaerythrityl diphosphite, distearyl pentaerythrityl diphosphite; triethylene glycol-bis [3- (3-tert-butyl- 5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], pentaerythrityltetrakis [3- ( 3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 1,3,5-trimethyl-2, 4,6-tris (3,5-di-tert-bul-4-hydroxybenzyl) benzene, , N-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamide), 3,5-di-tert-butyl-4-hydroxy-benzylphosphonate-diethyl ester, tris (3 5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 4,4′-biphenylenediphosphinic acid tetrakis (2,4-di-tert-butylphenyl), 3,9-bis {1,1-dimethyl- Hindered phenols such as 2- [β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl} -2,4,8,10-tetraoxaspiro (5,5) undecane Thermal stabilizer; dilauryl-3,3′-thiodipropionic acid ester, ditridecyl-3,3′-thiodipropionic acid ester Ter, dimyristyl-3,3′-thiodipropionic acid ester, distearyl-3,3′-thiodipropionic acid ester, laurylstearyl-3,3′-thiodipropionic acid ester, pentaerythrityl tetrakis (3- Mercaptopropionate), pentaerythrityltetrakis (3-laurylthiopropionate), glycerol-3-stearylthiopropionate, bis [2-methyl-4- (3-laurylthiopropionyloxy) -5-tert In addition to sulfur-based heat stabilizers such as -butylphenyl] sulfide, octadecyl disulfide, mercaptobenzimidazole, 2-mercapto-6-methylbenzimidazole, 1,1'-thiobis (2-naphthol), hindered amine heat stabilizers Can be used, these are In Germany, or in combination they are used.

Phosphorus heat stabilizers include tris (nonylphenyl) phosphite, trimethyl phosphate, tris (2,4-di-tert-butylphenyl) phosphite, bis (2,4-di-tert-butylphenyl) pentaerythris Lithyl diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythrityl diphosphite is preferably used. These compounds can be used alone or in combination of two or more.
Here, the content of the phosphite heat stabilizer is 0.0001 part by weight or more and 1 part by weight or less, preferably 0.001 part by weight or more and 0.1 part by weight, based on 100 parts by weight of the polycarbonate resin (a). Hereinafter, it is more preferably 0.003 parts by weight or more and 0.01 parts by weight or less.
When the content is excessively small, the coloring suppression effect may be insufficient. In addition, if the content is excessively large, deposits increase on the surface of the cooling roll in the case of a mold surface or film molding, and the appearance of the surface of the product may be impaired. May be reduced.

  As the hindered phenol-based heat stabilizer, a compound having an aromatic monohydroxy skeleton substituted with one or more alkyl groups having 5 or more carbon atoms is preferable. Specifically, octadecyl-3- (3,5-di- -Tert-butyl-4-hydroxyphenyl) propionate, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) Benzene and the like are preferred, and pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) pro Onato is more preferable.

Here, the content of the phenolic antioxidant (d) is preferably 0.0001 part by weight or more and 1 part by weight or less, more preferably 0.001 part by weight or more with respect to 100 parts by weight of the polycarbonate resin (a). 0.3 parts by weight or less, more preferably 0.005 parts by weight or more and 0.1 parts by weight or less.
When the content is excessively small, the coloring suppression effect may be insufficient. Moreover, when there is too much said content, in the case of a metal mold | die surface or film shaping | molding, there exists a possibility that a deposit may increase on the surface of a cooling roll, and the surface external appearance of a product may be impaired. When the phosphite heat stabilizer and the hindered phenol heat stabilizer are used in combination, the effect is great.

  Release agents include higher fatty acids, higher fatty acid esters of mono- or polyhydric alcohols, natural animal waxes such as beeswax, natural plant waxes such as carnauba wax, natural petroleum waxes such as paraffin wax, and montan wax. Natural coal wax, olefin wax, silicone oil, organopolysiloxane and the like can be mentioned, and higher fatty acid and higher fatty acid ester of monohydric or polyhydric alcohol are particularly preferable.

  The higher fatty acid ester is preferably a partial ester or a total ester of a substituted or unsubstituted monovalent or polyhydric alcohol having 1 to 20 carbon atoms and a substituted or unsubstituted saturated fatty acid having 10 to 30 carbon atoms. . Such partial esters or total esters of monohydric or polyhydric alcohols and saturated fatty acids include stearic acid monoglyceride, stearic acid diglyceride, stearic acid triglyceride, stearic acid monosorbate, stearyl stearate, behenic acid monoglyceride, behenyl behenate, Pentaerythrityl monostearate, pentaerythrityl tetrastearate, pentaerythrityl tetrapelargonate, propylene glycol monostearate, stearyl stearate, palmityl palmitate, butyl stearate, methyl laurate, isopropyl palmitate, biphenyl biphenyl Examples include phenate, sorbitan monostearate, 2-ethylhexyl stearate and the like. Of these, stearic acid monoglyceride, stearic acid triglyceride, pentaerythrityl tetrastearate, and behenyl behenate are preferably used.

  As the higher fatty acid, a substituted or unsubstituted saturated fatty acid having 10 to 30 carbon atoms is preferable. Examples of such saturated fatty acids include myristic acid, lauric acid, palmitic acid, stearic acid, behenic acid and the like. One of these release agents (e) may be used alone, or two or more thereof may be mixed and used. The content of the release agent (e) is 0.0001 to 2 parts by weight, preferably 0.01 to 1 part by weight, more preferably 100 parts by weight of the polycarbonate resin (a). Is 0.1 to 0.5 parts by weight. If the content of the release agent is small, the effect tends to be small, and if it is excessively large, in the case of mold surface or film molding, the deposit on the cooling roll surface increases and the surface appearance of the product is impaired. There is a fear.

  In addition, in the polycarbonate resin obtained by polycondensation as described above, hue, heat stability, raw material monomers that may adversely affect the product due to bleed-out, etc. Low molecular weight compounds such as hydroxy compounds and polycarbonate oligomers often remain, but those having a vent port as the extruder are preferably used by reducing the pressure from the vent port using a vacuum pump or the like. It is also possible to devolatilize and remove. Moreover, volatile liquids, such as water, can be introduce | transduced in the said extruder, and devolatilization can also be accelerated | stimulated. The amount of water introduced is usually 0.01 parts by weight to 0.5 parts by weight, preferably 0.1 parts by weight to 0.3 parts by weight, when the polycarbonate resin to be treated is 100 parts by weight. The number of vent ports may be one or plural, but preferably two or more.

  Furthermore, in order to suppress thermal deterioration of the polycarbonate resin in the extruder, the rotational speed of a shaft (hereinafter sometimes referred to as a screw) provided in the extruder is 300 rpm or less, preferably 250 rpm or less, more preferably 200 rpm or less. When the rotation speed of the screw exceeds 300 rpm, shear heat generation of the polycarbonate resin increases, and there is a tendency to cause deterioration in hue and molecular weight. On the other hand, if the number of rotations of the screw is too small, not only may the devolatilization performance deteriorate and the additive kneading performance deteriorates, but the processing amount per unit time decreases, leading to deterioration in productivity. Therefore, it is preferably 50 rpm or more, more preferably 70 rpm or more.

  And the peripheral speed of the screw is appropriately determined by the screw diameter and the number of rotations of the extruder, but in order to suppress thermal deterioration such as coloring and molecular weight reduction due to heat generation due to shearing of the polycarbonate resin, Usually 1.0 m / sec or less, preferably 0.6 m / sec or less, particularly preferably 0.4 m / sec or less. On the other hand, if the peripheral speed becomes too low, venting up during vacuum devolatilization tends to occur, and devolatilization performance and additive dispersion performance tend to decrease. 1 m / sec or more.

  Usually, the screw of an extruder is composed of a plurality of elements (screw elements) in order to give various functions, and generally only a spiral screw (flight) mainly for the purpose of transporting resin. Consists of a full flight consisting of a kneading disk for resin kneading, a seal ring for resin sealing, etc., depending on the purpose, reverse flight with a screw in the direction opposite to the resin transport direction is also used It is done. There are two- and three-row types depending on how the screw is cut. In the present invention, a double-row type deep groove type that can take a large amount of processing with respect to the screw diameter of the extruder and can suppress shearing heat generated by screw rotation. Is preferred.

  In the present invention, the configuration of these screw elements is not limited, but it is preferable to have a kneading disk. Among them, the total length of the kneading disk is 20% of the total length of the screw. % Or less, more preferably 15% or less, and most preferably 10% or less. If the total length of the kneading disk is too long, local heat generation due to the shearing of the resin increases, and problems such as deterioration of the hue and molecular weight of the polycarbonate resin tend to occur. On the other hand, if the total length of the kneading disk is too short, the performance at the time of devolatilization and kneading of the additive may be deteriorated. It is preferably 3% or more of the length, and more preferably 5% or more.

  The kneading disk includes a forward feed type, an orthogonal type, and a reverse feed type with respect to the resin transport direction, and can be appropriately selected according to the viscosity of the resin used and the required performance.

  As the material of the screw element, it is preferable to increase the surface nickel content or the like to keep the iron content low, or to treat the surface hardness with TiN or CrN.

  In the present invention, the temperature of the resin when supplying the polycarbonate resin in a molten state to the extruder is preferably 180 ° C. or higher, more preferably 200 ° C. or higher, particularly 215 ° C. or higher, especially 220 degreeC or more is suitable. The upper limit is preferably less than 250 ° C., more preferably less than 245 ° C., more preferably less than 240 ° C., and particularly preferably less than 235 ° C. If the temperature of the polycarbonate resin supplied to the extruder is too low, the load on the extruder may increase and the extrusion operation may become unstable, or the extruder may stop due to overload. There is a possibility that the heat generation in the machine increases, resulting in deterioration of the polycarbonate resin. If the temperature is too high, the polycarbonate resin is liable to deteriorate, the hue is deteriorated, the molecular weight is lowered, and the associated machine. There is a tendency to cause a decrease in mechanical strength.

  The temperature of the polycarbonate resin supplied to the extruder is a method of controlling the internal temperature of the final polymerization reactor, controlling the temperature of the piping for supplying the polycarbonate resin to the extruder, or providing a heat exchanger. Can be controlled.

  Also, when the polycarbonate resin obtained by polycondensation is once cooled and then heated and melted again and then supplied to the extruder, the temperature of the polycarbonate resin at the time of supply satisfies the same temperature condition as above. It is necessary.

  The temperature of the polycarbonate resin supplied to the extruder is a method of controlling the internal temperature of the final polymerization reactor, controlling the temperature of the piping for supplying the polycarbonate resin to the extruder, or providing a heat exchanger. Can be controlled.

Furthermore, the polycarbonate resin supplied to the extruder preferably has a glass transition temperature of 80 ° C. or higher, more preferably 85 ° C. or higher, and particularly preferably 90 ° C. or higher. When the glass transition temperature is too low, the heat resistance is inferior, and the field of use is limited when forming the obtained polycarbonate resin into a molded product.
On the other hand, if the glass transition temperature is high, the melt viscosity becomes too high, and in an industrial reactor having a practically upper limit of temperature, a polycarbonate resin having practical mechanical properties cannot be obtained, or thermal stability In the case of a polycarbonate resin that is inferior to the above, if the polymerization temperature is increased, the decomposition reaction may emerge and a polycarbonate resin having practical mechanical properties may not be obtained.

Moreover, even if a polycarbonate resin is obtained by a polymerization reaction, a polycarbonate resin having a high glass transition temperature has a high melt viscosity in a region having a practical molecular weight. Therefore, the polycarbonate resin in the present invention preferably has a glass transition temperature of less than 145 ° C., more preferably 140 ° C. or less, and particularly preferably 135 ° C. or less.
The glass transition temperature of the present invention means that the temperature is raised from room temperature to a temperature sufficiently exceeding the glass transition temperature at a heating rate of 20 ° C./min in a nitrogen stream, and after maintaining the temperature for 3 minutes, it is 20 ° C. to 30 ° C. Obtained by heating at a rate of 20 ° C./min to a temperature well above the glass transition temperature (obtained by the second temperature increase). This refers to the extrapolated glass transition start temperature obtained from DSC data.

  In addition, since the glass transition temperature of the polycarbonate resin discharged from the extruder and, if necessary, obtained through a filter does not substantially change due to processing in the extruder and the filter, the glass transition of the polycarbonate resin supplied to the extruder The temperature is generally inherited. Moreover, the measurement of the glass transition temperature is simpler and more realistic when the polycarbonate resin finally obtained through an extruder is used than when the polycarbonate supplied to the extruder is used. Therefore, in the present invention, the glass transition temperature of the polycarbonate resin supplied to the extruder can be replaced with the glass transition temperature of the polycarbonate resin obtained through the extruder as in the examples described later. In this case, the preferable glass transition temperature of the polycarbonate resin obtained through the extruder is naturally the same as the preferable range of the glass transition temperature of the polycarbonate resin supplied to the extruder.

As the form of the extruder used in the present invention, an extruder having a plurality of heaters connected to adjust the temperature of a barrel (also called a cylinder) and having a single or twin screw inside the barrel. Is preferred.
The polycarbonate resin supplied under the above conditions is extruded while heating or cooling a continuous barrel surrounding the screw from the outside with a plurality of heaters. In the present invention, it is necessary that at least one heater set temperature is lower than 250 ° C., preferably 240 ° C. or lower, more preferably 220 ° C. or lower, particularly preferably 200 ° C. or lower. By setting the heater in this way, when the resin is heated to a temperature higher than that, it is cooled there, and the polycarbonate resin is prevented from being deteriorated by heat. Although the present invention can be implemented even if a part of the heater exceeds the upper limit of the above temperature, in order to prevent overheating more thoroughly, it is more preferable that all the heaters are below the above 250 ° C.

  On the other hand, the heater set to less than 250 ° C for the purpose of preventing overheating needs to be at least 100 ° C or higher. If there is a part that is too cold in the extruder barrel, the polycarbonate resin is rapidly cooled at the part that comes into contact with the barrel, increasing the viscosity and increasing the heat generated by shearing, which promotes deterioration of the polycarbonate resin or rotates the screw. The motor load may increase. The set temperature of the heater is preferably 120 ° C. or higher, more preferably 140 ° C. or higher, and particularly preferably 160 ° C. or higher. In addition, it is preferable that all the heaters are 100 degreeC or more for the same reason as the above.

  Due to shear heat generation in the extruder, the resin tends to become hot as it approaches the outlet. For this reason, it is preferable that a low temperature part exists in an exit side more. That is, each heater is preferably the same or lower set temperature as the adjacent heater on the polycarbonate resin supply side. In other words, it is preferably not higher than the heater adjacent to the polycarbonate resin supply side. Specifically, it is preferably 5 ° C. or more, more preferably 10 ° C. or more lower than the heater set temperature adjacent to the polycarbonate resin supply side of the extruder. However, since the viscosity of the polycarbonate resin increases and may cause local overheating if it is excessively cooled, the temperature difference with respect to the heater adjacent to the supply side is preferably 50 ° C. or less. However, since the viscosity of the polycarbonate resin increases and may cause local overheating if it is excessively cooled, the temperature difference with respect to the heater adjacent to the supply side is preferably 50 ° C. or less.

  Particularly preferably, the set temperature of the heater on the most inlet side is 200 ° C. or more and less than 250 ° C., and the set temperature of the heater on the most exit side is 100 ° C. or more and 220 ° C. or less.

  Incorporating shear heat generation due to screw rotation, excessively lowering the temperature of the supplied polycarbonate resin, or excessively lowering the heater setting temperature of the extruder to lower the temperature of the supplied polycarbonate resin in the extruder In the method of the present invention, since the load on the extruder increases and screw rotation becomes unstable or the motor is overloaded, the temperature of the polycarbonate resin introduced into the extruder and the die are The difference in the temperature of the discharged polycarbonate resin is preferably within 50 ° C, more preferably within 30 ° C, and particularly preferably within 20 ° C.

In the present invention, when the weight of the resin extruded per hour by the extruder is W (kg / h) and the sectional area of the barrel of the extruder is S (m ² ), the following formula (5) It is preferable to satisfy.
12000 ≦ W / S ≦ 60000 (5)
If W / S is too small, not only will the size of the extruder be excessive with respect to the amount of polycarbonate resin to be processed, but also the residence time in the extruder will increase, reducing the molecular weight of the polycarbonate resin and deterioration such as coloring. The lower limit is preferably 15000, more preferably 20000, and particularly preferably 25000. On the other hand, if it is too large, an excessively large polycarbonate resin is supplied with respect to the size of the extruder, which may lead to a decrease in devolatilization efficiency and deterioration of the polycarbonate resin due to shearing heat generation. Therefore, the upper limit is preferably 50000, More preferably, it is 40000, particularly preferably 35000.

  Furthermore, in the present invention, the temperature of the polycarbonate resin discharged from the extruder is preferably less than 280 ° C, more preferably less than 270 ° C, particularly preferably less than 260 ° C. When the polycarbonate resin discharged from the extruder is 280 ° C. or higher, the polycarbonate resin is likely to be deteriorated, which tends to cause a deterioration in hue, a decrease in molecular weight, and a decrease in mechanical strength associated therewith. Conversely, if the temperature of the polycarbonate resin discharged from the extruder becomes too low, the melt viscosity of the polycarbonate resin is high, the load on the extruder increases, screw rotation becomes unstable, and the motor is overloaded. Therefore, it is preferably 220 ° C. or higher, more preferably 230 ° C. or higher, and particularly preferably 240 ° C. or higher. Usually, in an extruder, heat is generated by shearing of the resin accompanying the rotation of the screw, and generally the temperature of the discharged polycarbonate resin tends to be higher than the temperature of the supplied polycarbonate resin. This tendency becomes significant when the molecular weight is high and the melt viscosity is high. Increasing the temperature of the polycarbonate resin tends to reduce the melt viscosity, and the amount of shear heat generation can be suppressed by that amount. Since there is a tendency to cause a decrease in mechanical strength, it is not easy to perform extrusion by preventing deterioration of a polycarbonate resin having high viscosity that is inferior in thermal stability.

  The temperature of the polycarbonate resin discharged from the extruder is preferably controlled by the temperature of the polycarbonate resin supplied to the extruder or the temperature of a heater attached to the barrel, but the polycarbonate resin is supplied to the extruder. Since it may vary depending on the amount, the screw rotation speed of the extruder, and the configuration of the screw element, it is preferable to control these conditions together.

  Especially in the case of polycarbonate resin with high viscosity, shear heat generation due to screw rotation increases, and the temperature of the discharged resin tends to rise with respect to the temperature of the supplied resin. Therefore, dispersion of additives, devolatilization performance, and productivity In order to suppress the deterioration of the polycarbonate resin due to the shear heat generation while maintaining the above, it is important to select the rotation speed and peripheral speed of the screw and the element configuration together with the setting of the heater temperature.

(filter)
In the present invention, after the polycarbonate resin obtained by polycondensation is devolatilized and mixed with additives in the extruder, the filter is used to remove foreign matters such as burns and gels contained in the resin. It is preferable to filter. Above all, it is possible to remove residual monomer and by-product phenol by vacuum devolatilization and to extrude polycarbonate resin with an extruder and filter with a filter in order to mix additives such as heat stabilizer and mold release agent. preferable.

  As the form of the filter, known ones such as a candle type, a pleat type, a leaf disk type can be used. Among them, a leaf disk type that can take a large filtration area with respect to the storage container of the filter is preferable, and a large filtration area can be taken. Thus, it is preferable to use a plurality of combinations. The leaf disk type filter is configured by combining a holding member (also referred to as a retainer) and a filtering member (hereinafter also referred to as media), and storing these filters (in some cases, a plurality or plural). It is used in the form of a unit (sometimes called a filter unit) stored in a container.

  In the present invention, a type in which a plurality of aperture media are overlapped so that the differential pressure (pressure loss) of the filter is small and the apertures become finer in order from the resin intrusion direction is preferable. For the purpose of crushing the gel, it is also possible to use a type obtained by sintering metal powder.

In the present invention, the aperture of the filter is preferably not more than 50 μm, more preferably not more than 30 μm, still more preferably not more than 20 μm, and preferably not more than 15 μm in order to reduce foreign matters. If the opening is reduced, the pressure loss in the filter increases, and the filter may be damaged or the polycarbonate resin may be deteriorated by shearing heat generation. Therefore, the filtration accuracy of 99% is 1 μm or more. It is preferable. Here, the opening defined as 99% filtration accuracy means the value of χ when the βχ value represented by the following formula (5) determined in accordance with ISO 16889 is 100.
βχ = (number of particles on the primary side larger than χ μm) / (number of particles on the secondary side larger than χ μm) (5)
(Here, the primary side is before filtration with a filter, and the secondary side is after filtration.)

  The material of the filter medium is not limited as long as it has the strength and heat resistance necessary for resin filtration, but stainless steel such as SUS316 and SUS316L, which has a low content of metal, especially iron, is preferable. In addition, as the type of weaving, non-woven fabric types can be used in addition to regular weaving portions such as plain weave, twill weave, plain tatami mat, twill mat weave, etc. In the present invention, a non-woven fabric type having a high gel-capturing ability, particularly a type in which steel wires constituting the non-woven fabric are sintered and fixed is preferable.

  In addition, if the filter contains an iron component, the resin tends to be deteriorated during filtration at a high temperature exceeding 200 ° C. Therefore, as described above, the content of iron components is small in the case of stainless steel. In addition, it is preferable to passivate it before use. Passivation treatment is a method in which the filter is immersed in an acid such as nitric acid, or an acid is passed through the filter to form a passive state on the surface, which is roasted (heated) in the presence of water vapor or oxygen. Examples thereof include a method and a method using these in combination, and it is preferable to perform both nitric acid treatment and roasting.

  The temperature when the filter is roasted is usually 350 ° C. to 500 ° C., preferably 350 ° C. to 450 ° C., and the roasting time is usually 3 hours to 200 hours, preferably 5 hours to 100 hours. If the roasting temperature is too low or the time is too short, the formation of the passive state becomes insufficient, and the polycarbonate resin tends to deteriorate during filtration. On the other hand, if the temperature of roasting is too high or the time is too long, the filter media may be severely damaged and the required filtration accuracy may not be achieved.

  The concentration of nitric acid when the filter is treated with nitric acid is usually 5% to 50% by weight, preferably 10% to 30% by weight, and the temperature during treatment is usually 5 ° C to 100 ° C, preferably 50 ° C. to 90 ° C., and the treatment time is usually 5 minutes to 120 minutes, preferably 10 minutes to 60 minutes. If the concentration of nitric acid is too low, the processing temperature is too low, or the processing time is too short, the formation of passives will be insufficient, the concentration of nitric acid will be too high, the processing temperature will be too high, or the processing time will be If it is too long, the filter media will be severely damaged and the required filtration accuracy may not be achieved.

  It is preferable that the filter is stored in a storage container because it facilitates filtration by applying pressure. The material of the containment vessel is not limited as long as it has strength and heat resistance that can withstand resin filtration, but is preferably a stainless steel such as SUS316 or SUS316L with a low iron content. If the iron content is large, the polycarbonate resin may be deteriorated as described above.

  The storage container of the filter may be arranged such that the supply port and the discharge port of polycarbonate resin are arranged substantially horizontally, arranged substantially vertically, or arranged obliquely. In order to prevent gas and polycarbonate resin from staying in the container and prevent deterioration of the polycarbonate resin, the polycarbonate resin supply port is arranged at the bottom of the filter storage container, and the discharge port is arranged at the top. It is preferable that the polycarbonate resin supplied from the lower part of the storage container of the filter is discharged from the upper part of the storage container.

Moreover, if the value obtained by dividing the internal volume (m ³ ) of the filter storage container by the polycarbonate resin flow rate (m ³ / min) is too small, the differential pressure of the filter may increase and the filter may be damaged. If it is too large, the polycarbonate resin is deteriorated at the time of filtration, so it is preferably 1 minute to 20 minutes, preferably 2 minutes to 10 minutes, more preferably 2 minutes to 5 minutes.

  In the method of the present invention, the temperature of the polycarbonate resin before filtration in the filter is preferably less than 280 ° C, more preferably less than 270 ° C, particularly preferably less than 265 ° C, and particularly preferably less than 260 ° C. When the temperature before filtering with the filter is 280 ° C. or higher, thermal deterioration in the filter unit is likely to occur, and there is a tendency to cause deterioration in hue, molecular weight, and accompanying mechanical strength. Conversely, if the temperature before filtering with the filter becomes too low, the polycarbonate has a high melt viscosity, and the load on the filter increases and may cause damage to the filter. Above, more preferably 230 ° C or higher, particularly preferably 240 ° C or higher.

  In the method of the present invention, the filter unit is usually provided with a heater composed of a plurality of blocks outside thereof to control the temperature. However, if the set temperature is too high, the polycarbonate resin may be deteriorated. Hereinafter, it is preferably set to 260 ° C. or less, particularly preferably 250 ° C. or less. On the other hand, if the set temperature is too low, the melt viscosity becomes high and it is difficult to filter with a filter, so that the temperature is usually 150 ° C. or higher, preferably 180 ° C. or higher, particularly preferably 200 ° C. or higher.

  Also, the piping for guiding the polycarbonate resin discharged from the filter unit to the die is usually provided with a heater outside, but if the set temperature is too high, the polycarbonate resin may be deteriorated. Hereinafter, it is preferably set to 260 ° C. or less, particularly preferably 250 ° C. or less. On the other hand, if the set temperature is too low, the melt viscosity becomes high and the pressure loss in the pipe increases, so that the temperature is usually 150 ° C. or higher, preferably 180 ° C. or higher, particularly preferably 200 ° C. or higher. Furthermore, if the residence time of the polycarbonate resin from the outlet of the filter unit to the die is long, the polycarbonate resin may be deteriorated. Therefore, the time is usually 1 to 30 minutes, preferably 3 to 20 minutes.

  In the method of the present invention, the temperature of the polycarbonate resin discharged from the die after devolatilization and mixing in the extruder, preferably through filtration with the filter, is preferably 200 ° C. or more, preferably 220. The upper limit is preferably less than 280 ° C, preferably less than 270 ° C, more preferably less than 265 ° C, and particularly preferably less than 260 ° C. If the temperature of the polycarbonate resin discharged from the die is too low, the melt viscosity becomes high and the extruded strand is not stable and may be difficult to be pelletized with a rotary cutter or the like. . On the other hand, when the temperature is too high, the polycarbonate resin is likely to be thermally deteriorated, which may cause gas generation, hue deterioration, molecular weight reduction, and accompanying mechanical strength reduction.

  The die is usually provided with a heater, but if the set temperature is too high, the polycarbonate resin may be deteriorated. Therefore, the die is usually set to 280 ° C. or less, preferably 260 ° C. or less, particularly preferably 250 ° C. or less. . On the other hand, if the set temperature is too low, the melt viscosity becomes high and the pressure loss in the pipe increases, so that the temperature is usually 150 ° C. or higher, preferably 180 ° C. or higher, particularly preferably 200 ° C. or higher.

  Normally, when polycarbonate resin is mixed with the extruder, shear heat is generated due to screw rotation, and when using a filter, if the filter is filtered with a small mesh, the temperature rises due to shear heat and is discharged from the die. To control the temperature of the polycarbonate resin, the throughput of the polycarbonate resin in the extruder, barrel temperature setting, screw rotation speed and peripheral speed, element configuration, etc., opening of the filter, filtration area, temperature It is important to comprehensively control the setting, the temperature setting of the pipe through which the die and polymer flow, the molecular weight of the polycarbonate resin, and the like.

In the method of the present invention, the terminal double bond of the polycarbonate resin before introduction into the extruder obtained by polycondensation by the transesterification reaction is kneaded with the extruder at Xμeq / g, and in some cases, the filter When the terminal double bond of the polycarbonate resin constituting the polycarbonate resin pellet obtained by using a cutter after cooling is Yμeq / g, it is discharged as follows. It is preferable to satisfy Expression (6).
Y−X ≦ 50 (6)
More preferably, YX ≦ 30, still more preferably YX ≦ 15, particularly preferably YX ≦ 10, and most preferably YX ≦ 5. When Y-X exceeds 30, not only does it tend to produce a colored component that is thought to be derived from the double bond, but it facilitates gas generation in and around the filter, and strand discharge is unstable. It may become difficult to pelletize with a cutter.

In the method of the present invention, when the filter is used, the terminal double bond of the polycarbonate resin before being introduced into the filter is discharged in the form of a strand from the die, xμeq / g, and after cooling, using a cutter When the terminal double bond of the polycarbonate resin which comprises the obtained polycarbonate resin pellet is set to Yμeq / g, it is preferred to satisfy the following formula (7).
Y−x ≦ 10 (7)
More preferably, Y−x ≦ 8, and particularly preferably Y−x ≦ 5. When Y-x exceeds 10, not only tends to produce a colored component that is considered to be derived from the double bond, but also promotes the generation of gas in and around the filter, and the strand discharge is unstable. It may become difficult to pelletize with a cutter.

  In the method of the present invention, x-X indicates an increase in the terminal double bond in the extruder, and the value is preferably 30 μeq / g or less, more preferably 20 μeq / g or less, particularly preferably 10 μeq / g. g or less, preferably 5 μeq / g or less. When x-X exceeds 30 μeq / g, not only tends to produce colored components in the extruder, but also facilitates the generation of gas in the filter and the surrounding piping, making the strand discharge unstable. Therefore, it may be difficult to pelletize with a cutter.

In the method of the present invention, when the reduced viscosity (η _sp / c) of the polycarbonate resin supplied to the extruder obtained by polycondensation by the transesterification reaction is kneaded with the extruder, Depending on the case, the reduced viscosity (η _sp / c) of the polycarbonate resin constituting the polycarbonate resin pellet obtained by filtering using the filter, discharging from the die in the form of a strand, and using a cutter after cooling is B and When it does, it is preferable to satisfy | fill following formula (8).
0.8 <B / a <1.1 (8)
More preferably, B / a> 0.85, still more preferably B / a> 0.9, and particularly preferably B / a> 0.95. When B / a is 0.8 or less, there is a tendency that a colored component considered to be generated by a side reaction or a component that becomes a colored precursor is generated, which is not preferable. On the other hand, when the reduced viscosity rises in the extruder, the generation of foreign matters such as gels and burns rises, so it is preferable that B / a ≦ 1.0. A method for measuring the reduced viscosity will be described later.

Further, when a filter is installed on the downstream side of the extruder in the method of the present invention, the reduced viscosity (η _sp / c) of the polycarbonate resin supplied to the filter is filtered using A, the filter, and then from the die. When the reduced viscosity (η _sp / c) of the polycarbonate resin constituting the polycarbonate resin pellet obtained by discharging in the form of a strand and cooling using a cutter is B, the following formula (9) is satisfied. preferable.
0.8 <B / A <1.1 (9)
More preferably, B / A> 0.85, still more preferably B / A> 0.9, and particularly preferably B / A> 0.95. When B / A is 0.8 or less, there is a tendency that a coloring component that is considered to be generated by a side reaction or a component that becomes a coloring precursor is generated. On the other hand, when the reduced viscosity increases in the polymer filter, the generation of foreign matters such as gels and burns rises, so it is preferable that B / A ≦ 1.0.

  Furthermore, it is preferable to arrange a gear pump between the extruder and the filter in order to stabilize the supply amount of the polycarbonate resin to the filter. Although there is no restriction | limiting about the kind of gear pump, Especially the self-circulation type which does not use a gland packing for a seal | sticker part is preferable from a viewpoint of foreign material reduction.

  In the present invention, in the case of stranding or pelletization in which the polycarbonate resin is in direct contact with the outside air, it is preferably class 7 as defined in JIS B 9920 (2002), more preferably, in order to prevent contamination by foreign matter from the outside air. It is desirable to carry out in a clean room with higher cleanliness than class 6.

  Further, the polycarbonate resin devolatilized and mixed by the extruder and optionally filtered by the filter is cooled and solidified, and pelletized by a rotary cutter or the like. It is preferred to use a cooling method. As the air used for air cooling, it is desirable to use air from which foreign substances in the air have been removed in advance with a hepa filter or the like to prevent reattachment of foreign substances in the air. When using water cooling, it is desirable to use water from which metal in water has been removed with an ion exchange resin or the like, and further, foreign matter in water has been removed with the filter. The opening of the filter to be used is preferably 10 to 0.45 μm as a filtration accuracy of 99.9% removal.

(Filtration before polymerization)
On the other hand, in the method of the present invention, in order to further reduce foreign substances contained in the finally obtained polycarbonate resin, it is also effective to filter the raw material monomer through a raw material filtration filter in advance before the polycondensation reaction. .

  The shape of the raw material filtration filter may be any type such as basket type, disc type, leaf disc type, tube type, flat cylindrical type, pleated cylindrical type, etc. A pleated type that can be taken is preferred. Further, the filter medium constituting the raw material filter may be any of metal wind, laminated metal mesh, metal nonwoven fabric, porous metal plate, etc., but from the viewpoint of filtration accuracy, a laminated metal mesh or metal nonwoven fabric is preferable, among which metal A type in which a nonwoven fabric is sintered and fixed is preferable.

  There are no particular restrictions on the material of the raw material filter, and metal and resin ceramics can be used. From the viewpoint of heat resistance and color reduction, a metal filter having an iron content of 80% or less. Of these, stainless steel such as SUS304, SUS316, SUS316L, and SUS310S is preferable.

  In addition, when filtering the raw material monomer, it is preferable to use a plurality of filter units in order to extend the life of the raw material filtration filter while ensuring the filtration performance, and in particular, the filter in the unit on the upstream side is preferably used. When the aperture is C μm and the aperture of the filter in the downstream unit is D μm, C is preferably larger than D (C> D) in at least one combination. When this condition is satisfied, the raw material filtration filter is less likely to be blocked, and the replacement frequency of the raw material filtration filter can be reduced.

  The opening of the raw material filtration filter is not particularly limited, but in at least one of the raw material filtration filters, the filtration accuracy of 99.9% is preferably 10 μm or less, and the filter unit constituting the raw material filtration filter includes In the case of a plurality of arrangements, it is preferably 8 μm or more, more preferably 10 μm or more on the most upstream side, and preferably 2 μm or less, more preferably 1 μm or less on the most downstream side. In addition, the opening of the said raw material filtration filter said here is also determined based on ISO16889 mentioned above.

  In the present invention, the temperature of the raw material fluid when the raw material is passed through the raw material filtration filter is not limited. However, if the raw material is too low, the raw material is solidified. If the raw material is too high, there is a problem such as thermal decomposition. ° C, preferably 100 ° C to 150 ° C.

  In the present invention, any of the raw materials to be used may be filtered, or all of the raw materials may be filtered. The method is not limited, and the dihydroxy compound and the carbonic acid diester are not limited. The raw material mixture may be filtered, or may be mixed after separately filtering. Moreover, in the manufacturing method of this invention, the reaction liquid in the middle of a polycondensation reaction can also be filtered with the filter similar to the said raw material filtration filter.

(Polycarbonate resin obtained)
The yellow index value of the polycarbonate resin obtained by the method of the present invention is preferably 70 or less, more preferably 30 or less, particularly preferably 15 or less, and most preferably 10 or less. In order to lower the yellow index value, it is necessary to appropriately select monomer preparation conditions, polymerization reaction conditions, filtration conditions, extrusion conditions, screw elements, thermal stabilizers, mold release agents and the like as described above.

Further, the molecular weight of the polycarbonate resin obtained in the method of the present invention can be represented by a reduced viscosity (η _sp / c), and the reduced viscosity is usually 0.3 dL / g or more, preferably 0.35 dL / g or more. The upper limit of the reduced viscosity is usually 1.2 dL / g or less, preferably 0.8 dL / g or less, and particularly preferably 0.7 dL / g or less. If the reduced viscosity is too low, the mechanical strength of the molded product may be small, and when the film is formed into a film and then subjected to a stretching operation, the film may be stretched. On the other hand, if it is too large, not only the fluidity at the time of molding will decrease and the productivity and moldability will tend to be lowered, but also there is a possibility that the deterioration will be severe due to shear heat generation during filtration and extrusion. The reduced viscosity is precisely measured by using a Ubbelohde viscosity tube at a temperature of 20.0 ° C. ± 0.1 ° C. by accurately measuring polycarbonate resin pellets, using methylene chloride as a solvent, and preparing precisely at 0.6 g / dL. To do.

The melt viscosity at a shear rate of 91.2 sec ⁻¹ of the polycarbonate resin obtained by the method of the present invention measured at 240 ° C. is usually 500 Pa · s or more, preferably 800 Pa · s or more, particularly preferably 1000 Pa · s or more. The upper limit is usually 3000 Pa · s or less, preferably 2000 Pa · s or less, particularly preferably 1500 Pa · s or less. If the melt viscosity is too low, the mechanical strength of the molded product tends to be inferior. If it is too high, as described above, the shear heat generated by the filter or the extruder increases, and the deterioration during filtration or extrusion may become severe. There is. In addition, since the melt viscosity varies depending on the molecular structure in addition to the molecular weight, it is important to select these according to the required performance and control them within the above range.

  The concentration of the terminal group represented by the following structural formula (10) of the polycarbonate resin obtained in the present invention is preferably 20 μeq / g or more, more preferably 40 μeq / g or more, and particularly preferably 50 μeq / g or more. . When the concentration of the terminal group is too low, coloring tends to increase during filtration. If it is too high, gas tends to be generated at the time of filtration, and there is a possibility of causing problems such as running out of gas in the strand. Therefore, it is preferably 200 μeq / g or less, more preferably 150 μeq / g or less, particularly preferably. 100 μeq / g or less.

  In order to control the concentration of the terminal group represented by the structural formula (10), in addition to controlling the molar ratio of the dihydroxy compound containing the dihydroxy compound of the present invention as the raw material to the carbonic acid diester, the polymerization pressure during the transesterification reaction And a method of controlling the polymerization temperature, the temperature of the reflux condenser, etc. according to the ease of volatilization of the monomer, among which the use of a reactor having a reflux condenser at the initial stage of polymerization stabilizes the concentration of the above end groups. It is effective for.

  In the transesterification reaction carried out in this invention, when the polycarbonate resin of the present invention is produced using a substituted diphenyl carbonate such as diphenyl carbonate or ditolyl carbonate as the carbonic acid diester represented by the general formula (4), phenol It is inevitable that aromatic monohydroxy compounds such as substituted phenols are by-produced and remain in the polycarbonate resin. Since these may cause generation of gas during filtration and odor during molding, it is preferably less than 0.1% by weight, more preferably 0.05% by weight using an extruder with a vacuum vent. It is preferable to make it less than, especially less than 0.03% by weight. However, it is difficult to remove these compounds completely industrially, and the lower limit of the content of the aromatic monohydroxy compound is usually 0.0001% by weight.

  These aromatic monohydroxy compounds may naturally have a substituent depending on the raw material used, and may have, for example, an alkyl group having 5 or less carbon atoms. When diphenyl carbonate is used as the carbonic acid diester, the aromatic monohydroxy compound is phenol.

  The polycarbonate resin obtained by the method of the present invention can be formed into a molded product by a generally known method such as an injection molding method, an extrusion molding method, or a compression molding method. Additives such as heat stabilizers, neutralizers, UV absorbers, mold release agents, colorants, antistatic agents, lubricants, lubricants, plasticizers, compatibilizers, flame retardants to the polycarbonate resin as necessary Can be kneaded with the extruder. Moreover, it can also mix using a tumbler, a super mixer, a floater, a V-type blender, a Nauta mixer, a Banbury mixer, another extruder, etc.

According to the method of the present invention, a polycarbonate resin with little coloring and less foreign matter can be stably obtained. Therefore, a foreign matter having a thickness of 25 μm or more contained in a film having a thickness of 35 μm ± 5 μm formed using the resin is preferably 1000 μm. Pieces / m ² or less, more preferably 500 pieces / m ² or less, still more preferably 400 pieces / m ² or less, and most preferably 200 pieces / m ² or less. Thus, the characteristic that there are few foreign substances is especially suitable when using polycarbonate resin for an optical use. Although the thickness of the film obtained by shape | molding the polycarbonate resin of this invention is not specifically limited according to a use, Usually, it is about 20 micrometers-about 200 micrometers.

  Polycarbonate resins obtained by the method of the present invention include, for example, aromatic polycarbonate, aromatic polyester, aliphatic polyester, polyamide, polystyrene, polyolefin, acrylic resin, amorphous polyolefin, ABS, AS, and other synthetic resins, polylactic acid, polybutylene. It can also be used as a polymer alloy by kneading with one or more of biodegradable resins such as succinate and rubber.

  According to the present invention, it is possible to provide a polycarbonate resin that is excellent in thermal stability, hue, and mechanical strength and has few foreign matters. In the production of polycarbonate resin film, the polycarbonate resin pellets are manufactured not only by using the pellets after the above procedure, but also by molding into a film without going through the pellet state. May be.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by a following example, unless the summary is exceeded. In the following, the physical properties and characteristics of polycarbonate were evaluated by the following methods.

(1) Measurement of oxygen concentration The oxygen concentration in the polymerization reaction apparatus was measured using an oxygen meter (AMI: 1000RS).

(2) Measurement of reduced viscosity Polycarbonate resin pellets were dissolved using methylene chloride as a solvent to prepare a polycarbonate solution having a concentration of 0.6 g / dL. Measured at a temperature of 20.0 ° C. ± 0.1 ° C. using an Ubbelohde viscometer manufactured by Moriyu Rika Kogyo Co., Ltd., and the relative viscosity η _rel is obtained from the following equation from the solvent passage time t ₀ and the solution passage time t. ,
η _rel = t / t ₀
From the relative viscosity, the specific viscosity η _sp was determined from the following equation.
η _sp = (η _rel −η ₀ ) / η ₀ = η _rel −1
The reduced viscosity η _sp / c was determined by dividing the specific viscosity by the concentration c (g / dL). The higher this value, the higher the molecular weight.

(3) Measurement of terminal phenyl group concentration and terminal double bond concentration About 30 mg of polycarbonate resin pellets are weighed and dissolved in about 0.7 mL of deuterated chloroform to make a solution, and 1,1,2,2-tetrabromoethane is contained inside. Add a known amount as a standard, put it in an NMR tube with an inner diameter of 5 mm, measure ¹ HNMR spectrum at room temperature using JNM-AL400 (resonance frequency 400 MHz) manufactured by JEOL Ltd. The signal intensity ratio based on the terminal double bond was determined.
30 mg of polycarbonate was weighed and dissolved in about 0.7 mL of deuterated chloroform, and this was put into an NMR tube having an inner diameter of 5 mm, and a ¹ H NMR spectrum was measured. The amounts of terminal phenyl groups, terminal hydroxy groups, and terminal double bonds were determined from the intensity ratio of signals based on the structural units derived from each terminal group and each dihydroxy compound. The equipment and conditions used are as follows.
Device: JNM-AL400 (resonance frequency 400 MHz) manufactured by JEOL Ltd.
・ Measurement temperature: normal temperature ・ Relaxation time: 6 seconds ・ Number of integrations: 512 times

Analysis of ¹ H NMR in the case of the copolymer polycarbonate of ISB and CHDM exemplified in the present invention is performed as follows. Calculate the integrated value of the next peak.
(A): 5.6-4.8 ppm: derived from all ISB structural units (proton number: 3, molecular weight: 172.14)
(B): 2.2-0.5 ppm: derived from all CHDM structural units (proton number: 10, molecular weight: 170.21)
(C): 4.4 ppm: derived from ISB terminal hydroxy group (proton number: 1, molecular weight: 173.14)
(D): 3.6-3.5 ppm: derived from ISB terminal hydroxy group (proton number: 1, molecular weight: 173.14) and CHDM terminal hydroxy group (proton number: 2, molecular weight: 171.21)
(E): 3.5-3.4 ppm: derived from terminal hydroxyl group of CHDM (proton number: 2, molecular weight: 171.21) and derived from ISB terminal double bond (proton number: 1, molecular weight: 155.13)
(F): 2.6 ppm: derived from terminal hydroxyl group of ISB (proton number: 1, molecular weight: 173.14)
(G): 6.7-6.5 ppm: derived from terminal double bond of ISB (proton number: 1, molecular weight: 155.13)
(H) 2.3 ppm: derived from terminal double bond of CHDM (proton number: 2, molecular weight: 153.20)
(I): 7.5-7.3 ppm: derived from terminal phenyl group (proton number: 2, molecular weight: 93.10)
<Value corresponding to the number of moles of each structure>
All ISB structural units: (a) integral value / 3 = (a ′)
All CHDM structural units: (b) integral value / 10 = (b ′)
ISB terminal hydroxy group: (c) integral value + (f) integral value = (c ′)
CHDM terminal hydroxy group: {(d) integral value− (f) integral value} / 2 + {(e) integral value− (g) integral value)} / 2 = (d ′)
ISB terminal double bond: (g) integrated value = (e ′)
CHDM terminal double bond: (h) integral value / 2 = (f ′)
Terminal phenyl group: (i) integral value / 2 = (g ′)
<Amount of each end group (unit: μeq / g)>
ISB terminal hydroxy group amount: (c ′) / (i ′) × 1000000
-Terminal hydroxyl group amount of CHDM: (δ ') / (i') x 1000000
ISB terminal double bond amount: (e ′) / (i ′) × 1000000
CHDM terminal double bond amount: (f ′) / (i ′) × 1000000
-Terminal phenyl group amount: (g ') / (i') x 1000000
However, (i ′) = (a ′) × 172.14 + (b ′) × 170.21.

(4) Measurement of phenol content and DPC content About 1.25 g of polycarbonate resin pellets are precisely weighed and dissolved in 7 ml of methylene chloride to prepare a solution, and then acetone is added so that the total amount becomes 25 ml and reprecipitation treatment is performed. Went. Next, the treatment liquid was filtered through a 0.2 μm disk filter and quantified by liquid chromatography.

(5) Measurement of glass transition temperature Using a differential scanning calorimeter (DSC 6220 manufactured by SII Nanotechnology), about 10 mg of polycarbonate resin pellets cut into an appropriate size are placed in the company's aluminum pan and sealed. The temperature was raised from room temperature to 250 ° C. at a heating rate of 20 ° C./min under a nitrogen stream of 50 mL / min. After maintaining the temperature for 3 minutes, it was cooled to 30 ° C. at a rate of 20 ° C./min. The temperature was maintained at 30 ° C. for 3 minutes, and the temperature was increased again to 200 ° C. at a rate of 20 ° C./min. From the DSC data obtained at the second temperature increase, the extrapolated glass transition start temperature was determined.

(6) Hue of polycarbonate resin pellet The resin pellet obtained was packed in a 1 cm cell, and the yellow index (YI) value in reflected light was measured three times using a color tester (CM-3700d manufactured by Konica Minolta Co., Ltd.). Was calculated. The smaller the YI value, the better the quality without yellowness.

(7) Quantitative determination of foreign matter in polycarbonate resin pellets The barrel set temperature of a 20 mm diameter single screw extruder equipped with a T-die is 210 ° C, 220 ° C, 230 ° C, 230 ° C, 220 ° C from the pellet supply side, and cooled. A film having a thickness of 35 μm ± 5 μm was formed using a roll, and the number of foreign matters of 25 μm or more per 1 m ² was measured using an optical control system (Film Quality Testing System (model FSA100)).

(8) Injection Molding Evaluation The polycarbonate resin pellets were dried for 24 hours in a nitrogen atmosphere at a temperature 20 ° C. lower than the glass transition temperature. Next, the dried polycarbonate resin pellets are supplied to an injection molding machine (J75EII type manufactured by Nippon Steel Co., Ltd.), and an injection molded piece (width 60 mm × length 60 mm × thickness 3 mm) at a resin temperature of 220 to 230 ° C. Molded.

(9) Hot water immersion test The injection molded product obtained in the above (7) was immersed in warm water at 80 ° C. for 6 hours, and the behavior was observed.

(10) Measurement of melt viscosity (Pa · s) A sample dried at 120 ° C. for 6 hours was heated to a constant temperature using a capillary rheometer (manufactured by Toyo Seiki Co., Ltd.) equipped with a die diameter of 1 mmφ × 10 mmL. measured between shear rate γ = 9.12~1824 ^{(sec -1)} Te was read melt viscosity at 91.2sec ^-1.

The abbreviations of the compounds used in the description of the following examples are as follows.
ISB: Isosorbide (Rocket Fleure, trade name POLYSORB)
CHDM: 1,4-cyclohexanedimethanol (trade name SKY CHDM manufactured by Shin Nippon Rika Co., Ltd.)
・ 1,6-HD: 1,6-hexanediol (manufactured by BASF)
・ DPC: Diphenyl carbonate (Mitsubishi Chemical Corporation)

The detailed conditions of Examples 1 to 10 and Comparative Examples 1 to 2 are shown in Table 1 below.
[Example 1]
In the raw material preparation tank sufficiently substituted with nitrogen (oxygen concentration 0.0005 vol% to 0.001 vol%), the raw material prepared so that the ISB / CHDM / DPC molar ratio is 50/50/100 is used as the heat medium. To the first polymerization reactor equipped with a heat medium jacket, a heat medium internal coil, a stirring blade, a distillation pipe connected to a vacuum pump and a condenser, and at the same time, a raw material supply pipe From the connected catalyst supply pipe, calcium acetate monohydrate in an aqueous solution was continuously supplied so as to be 1.25 × 10 ⁻⁶ mol (calcium metal atom equivalent) per 1 mol of all dihydroxy compounds. After mixing the raw material and catalyst aqueous solution by piping, install two pleated cylindrical type raw material filtration filters in the flow path to enter the first reactor, the upstream raw material filtration filter opening is 10 μm, downstream The mesh opening was 1 μm. In the first polymerization reactor, the distillation pipe is provided with a reflux condenser using oil (inlet temperature 130 ° C.) as a refrigerant, and phenol and the like that are not condensed in the reflux condenser. In addition, a condenser using warm water (inlet temperature 45 ° C.) as a refrigerant was disposed. While keeping the rotation speed of the stirring blade of the first polymerization reactor constant, the internal temperature is controlled to be constant at 185 ° C., the pressure is 25 kPa, and the residence time is 1.5 hours, and the reaction solution is continuously extracted from the bottom of the reaction tank. To the second polymerization reactor. Similar to the first polymerization reactor, the second polymerization reactor includes a heat medium jacket, a heat medium internal coil, a stirring blade, a distillation pipe connected to a vacuum pump, and a distillation pipe having a reflux condenser and a condenser. The inner temperature was 213 ° C., the pressure was 14 kPa, and the residence time was controlled to be constant at 1 hour, and the reaction solution was continuously withdrawn from the bottom of the reaction vessel and supplied to the third polymerization reactor. The third polymerization reactor is controlled so as to be constant at an internal temperature of 229 ° C., a pressure of 6 kPa, and a residence time of 1 hour. The polycondensation reaction proceeds while distilling off the by-produced phenol, and the reaction solution is transferred to the reaction vessel. It was continuously extracted from the bottom and supplied to a horizontal stirring reactor (fourth polymerization reactor) having two horizontal rotating shafts and mutually discontinuous stirring blades mounted substantially perpendicular to the horizontal shaft. The fourth polymerization reactor was controlled so that the internal temperature near the inlet was 228 ° C., the internal temperature near the outlet was 240 ° C., the pressure was 0.07 kPa, and the residence time was 2 hours, and the polycondensation reaction was further advanced. . The obtained polycarbonate resin has an additive supply port and three vent ports, L / D = 42, and the kneading disk occupies 6% of the length of the elements constituting the entire screw of the extruder. The twin screw extruder was continuously fed (the other screw elements of the kneading disc consisted of full flight and seal ring). In the extruder, 0.1% of water was supplied to the polycarbonate resin to be treated, and the vent port was connected to a vacuum pump to remove volatile components contained in the polycarbonate resin. A side feeder is installed downstream of the water supply nozzle and the subsequent vent port, and pentaerythrityl tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (trade name: IRGANOX 1010) 0.1 parts by weight of 100 parts by weight of polycarbonate resin, 0.05 parts by weight of tris (2,4-di-t-butylphenyl) phosphite (trade name: ADK STAB 2112), stearic acid monoglyceride (RIKEN) (Manufactured by Vitamin Co., Ltd.) was also continuously supplied to 0.3 parts by weight.
As for the heater temperature of the barrel of the extruder, the upstream 4 blocks (C1 to C4) were set to 245 ° C., the downstream 6 blocks (C5 to C10) were set to 225 ° C., and the screw rotation speed was 250 rotations. At this time, the polycarbonate resin supplied to the extruder was temporarily extracted, and temperature measurement and various analyzes were performed. The results are shown in Table 1.

The polycarbonate resin processed by the extruder was supplied to a filter unit having a resin inlet at the bottom and an outlet at the top through a gear pump installed at the outlet. Table 1 shows the temperature of the resin sampled before the filter unit and various measured values. A leaf disk filter (manufactured by Nippon Pole Co., Ltd.) having a mesh size of 7 μm was mounted inside the filter unit to remove foreign substances in the polycarbonate resin. Before use, the filter was roasted at 310 ° C. for 40 hours in a water vapor atmosphere and then at 420 ° C. for 52 hours in an air atmosphere, cooled to room temperature, and then immersed in a 30% by weight nitric acid aqueous solution for 30 minutes. Then, an oxide film was formed, washed and dried. The filter unit was provided with a heater composed of a plurality of blocks, and each temperature was set to 230 to 240 ° C. On the outlet side of the filter unit, a die was installed through a polymer pipe equipped with a heater composed of a plurality of blocks. The set temperature of the heater of the polymer pipe was set to 220 to 230 ° C, and the heater of the dice was set to 220 ° C. The polycarbonate resin was extracted in the form of a strand in a room maintained at a class 10000 cleanness from the die, solidified in a water tank, and pelletized with a rotary cutter.
The obtained pellets were injection molded and subjected to a hot water immersion test, but no abnormality such as deformation was observed. The analytical values are shown in Table 1.

[Example 2]
In Example 1, pentaerythrityl tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] and tris (2,4-di-t-butylphenyl) phosphite were added. The procedure was the same as in Example 1 except that this was not done.

[Example 3]
The internal temperature of the first polymerization reactor is 194 ° C., the pressure is 27 kPa, the internal temperature of the second polymerization reactor is 190 ° C., the pressure is 19 kPa, the internal temperature of the third polymerization reactor is 213 ° C., the pressure is 7.5 kPa, The same procedure as in Example 1 was performed except that the inner temperature near the inlet of the fourth polymerization reactor was 214 ° C., the inner temperature near the outlet was 228 ° C., the pressure was 0.7 kPa, and the die heater was set to 230 ° C. It was. The temperature at the time of supplying to an extruder became 230 degreeC, and the pellet YI fell compared with Example 1. FIG.

[Example 4]
The internal temperature of the first polymerization reactor is 190 ° C., the pressure is 25 kPa, the internal temperature of the second polymerization reactor is 196 ° C., the pressure is 17.7 kPa, the internal temperature of the third polymerization reactor is 215 ° C., and the pressure is 6. 9 kPa, the internal temperature near the inlet of the fourth polymerization reactor is 218 ° C., the internal temperature near the outlet is 232 ° C., the pressure is 0.9 kPa, the heater temperature of the barrel of the extruder is set to 240 ° C. for the upstream 4 blocks The same procedure as in Example 1 was performed except that the downstream 6 blocks were set to 185 ° C.

[Example 5]
In the raw material preparation tank, the molar ratio of ISB / CHDM / DPC is adjusted to 70/30/100, the internal temperature of the first polymerization reactor is 188 ° C., the pressure is 24.2 kPa, and the second polymerization reactor The internal temperature was 194 ° C., the pressure was 19.9 kPa, the internal temperature of the third polymerization reactor was 214 ° C., the pressure was 9.9 kPa, the internal temperature near the inlet of the fourth polymerization reactor was 218 ° C., and the internal temperature near the outlet Was 232 ° C., the pressure was 0.1 kPa, the heater temperature of the extruder barrel was set to 240 ° C. for the upstream 4 blocks and 195 ° C. for the 6 blocks downstream.

[Example 6]
The same operation as in Example 2 was performed except that the aperture of the filter was changed to 22 μm. The pressure loss in the polymer filter was reduced, the decrease in molecular weight and the increase in double bond ends were in a tendency to be suppressed, and the color tone of the obtained polycarbonate resin was improved, but the amount of foreign matter was increased.

[Comparative Example 1]
The internal temperature of the third polymerization reactor is 240 ° C., the pressure is 4 kPa, the internal temperature near the inlet of the fourth polymerization reactor is 240 ° C., the internal temperature near the outlet is 252 ° C., and the pressure is 0.02 kPa. Supply temperature is 251 ° C, the heater temperature of the barrel of the extruder is 250 ° C for the upstream 4 blocks, 245 ° C for the 6 blocks downstream, the screw speed is 280rpm, and the heater set temperature of the filter unit is 270-280 The same procedure as in Example 1 was performed except that the temperature of the polymer pipe heater was set to 270 to 280 ° C., and the die heater was set to 280 ° C. Although the pressure loss in the polymer filter tended to be suppressed, the temperature of the polycarbonate resin discharged from the die was 285 ° C., and it was remarkably colored. Further, gas was generated from the die, the strands were disturbed, and pellets could not be obtained.

[Example 7]
The same procedure as in Example 1 was performed except that the molar ratio of ISB / DPC was adjusted to 100/100 in the raw material preparation tank. The obtained polycarbonate resin had a glass transition temperature of 160 ° C. YI of the obtained polycarbonate resin pellet was 46 and better than Example 2. However, when injection molding was performed using the obtained polycarbonate resin pellets, cracks were generated by the extrusion pins for release, and no molded product was obtained. Further, the film has insufficient toughness, and it was difficult to form a film for measuring foreign matter.

[Example 8]
The same procedure as in Example 1 was conducted except that the molar ratio of ISB / 1,6-HD / DPC was adjusted to 65/35/100 in the raw material preparation tank. The obtained polycarbonate resin had a glass transition temperature of 77 ° C. YI of the obtained polycarbonate resin pellet was 30, which was better than that of Example 2. However, when injection molding was performed using the obtained polycarbonate resin pellets, the releasability from the mold was poor. When the hot water immersion test was performed, deformation was observed.

[Comparative Example 2]
In Example 1, the internal temperature of the third polymerization reactor was 240 ° C., the pressure was 4 kPa, the internal temperature near the inlet of the fourth polymerization reactor was 240 ° C., the internal temperature near the outlet was 252 ° C., and the pressure was 0.02 kPa. The extruder resin supply temperature is 251 ° C., the extruder barrel heater temperature is set to 260 ° C. for the upstream 4 blocks, the downstream 6 blocks to 250 ° C., and the heater set temperature for the filter unit is 240 to 250. The same procedure as in Example 1 was carried out except that the temperature of the polymer pipe heater was set to 240 to 250 ° C., and the die heater was set to 240 ° C. The reduced viscosity at the filter inlet was lowered, the polycarbonate resin pellets were remarkably colored, gas was generated from the dies, the strands were disturbed, and the pelletization loss was large.

[Example 9]
The same operation as in Example 6 was performed except that the ratio of the kneading element of the extruder was 12%.

[Example 10]
The same procedure as in Example 9 was performed, except that a part of the polycarbonate resin was extracted from the piping for supplying the polycarbonate resin to the extruder from the fourth polymerization reactor, and the amount of the resin supplied to the extruder was reduced.

  The results of each Example and Comparative Example are shown in Table 1 below.

1a Raw material (carbonic acid diester) supply port 1b, 1c Raw material (dihydroxy compound) supply port 1d Catalyst supply port 2a Raw material mixing tank 3a Anchor type stirring blade 4a Raw material mixed liquid transfer pump 4b, 4c, 4d Gear pump 5a Raw material filtration filter 6a First Vertical stirring reaction tank 6b Second vertical stirring reaction tank 6c Third vertical stirring reaction tank 6d Fourth horizontal stirring reactor 7a, 7b, 7c Max blend blade 7d Biaxial glasses-type stirring blade 8a, 8b Internal heat exchanger 9a, 9b Reflux coolers 10a, 10b Reflux tubes 11a, 11b, 11c, 11d Distillate tubes 12a, 12b, 12c, 12d Condensers 13a, 13b, 13c, 13d Decompressor 14a Distillate recovery tank 15a Extruder 15b ( Polymer) Filter 15c Die 16a Strand cooling tank 16b Strand cutter 16c Air blower 6d product hopper 16e meter 16f product bag (paper bag, such as a flexible container)

Claims (17)

A catalyst and a method for producing a polycarbonate resin by using a dihydroxy compound and a carbonic acid diester as a raw material monomer, polycondensing by a transesterification reaction, and supplying the produced polycarbonate resin to an extruder,
The dihydroxy compound includes at least a dihydroxy compound having a site represented by the following general formula (1) in a part of the structure;
The dihydroxy compound having a site represented by the following general formula (1) includes a compound having a cyclic ether structure,
A method for producing a polycarbonate resin, characterized in that a barrel constituting the extruder includes a plurality of heaters, and at least one heater set temperature among these heaters is set to 100 ° C. or higher and lower than 250 ° C.

(However, the site represented by the above general formula (1) unless it is part of _-CH 2 -O-H.)   The method for producing a polycarbonate resin according to claim 1, wherein the set temperature of the heater is not higher than the set temperature of the heater adjacent to the polycarbonate resin supply side of the extruder.   The method for producing a polycarbonate resin according to claim 1 or 2, wherein a set temperature of all the heaters is 100 ° C or higher and lower than 250 ° C.   The method for producing a polycarbonate resin according to any one of claims 1 to 3, wherein the polycarbonate resin obtained by polycondensation by an ester exchange reaction is supplied to the extruder in a molten state.   The screw of the extruder is composed of a plurality of elements, at least one of the elements is a kneading disk, and the total length of the kneading disks is 20% or less of the total length of the screw. The manufacturing method of the polycarbonate resin of any one of Claims 1 thru | or 4. Claim 1 thru | or satisfy | filling following formula (5) when the weight of the resin extruded per hour with the said extruder is set to W (kg / h) and the cross-sectional area of the barrel of the said extruder is set to S (m < ² >). 6. The method for producing a polycarbonate resin according to any one of 5 above.
12000 ≦ W / S ≦ 60000 (5) The polycarbonate resin obtained through the extruder has a reduced viscosity (η _sp / c) of 0.3 dL measured in methylene chloride at a concentration of 0.6 g / dL and at a temperature of 20.0 ° C. ± 0.1 ° C. 7. The method for producing a polycarbonate resin according to any one of claims 1 to 6, wherein the production method is at least 1.2 gL / g.   The method for producing a polycarbonate resin according to any one of claims 1 to 7, wherein a glass transition temperature of the polycarbonate resin obtained through the extruder is 80 ° C or higher and lower than 145 ° C.   The method for producing a polycarbonate resin according to any one of claims 1 to 8, wherein the content of the aromatic monohydroxy compound contained in the polycarbonate resin obtained through the extruder is less than 0.1 wt%.   The method for producing a polycarbonate resin according to any one of claims 1 to 9, wherein the raw material monomer is filtered with a raw material filter before polycondensation.   The method for producing a polycarbonate resin according to any one of claims 1 to 10, wherein an operation of kneading a heat stabilizer is performed using the extruder.   The method for producing a polycarbonate resin according to any one of claims 1 to 11, wherein the catalyst is at least one compound selected from the group consisting of a metal of Group 2 of the long-period periodic table and lithium.   The method for producing a polycarbonate resin according to any one of claims 1 to 12, wherein the dihydroxy compound having a site represented by the general formula (1) is isosorbide.   The method for producing a polycarbonate resin according to any one of claims 1 to 13, wherein an alicyclic dihydroxy compound is further used as the dihydroxy compound.   A polycarbonate resin having a yellow index value of 30 or less obtained by the production method according to any one of claims 1 to 14. When the polycarbonate resin obtained by the production method according to any one of claims 1 to 14 or the polycarbonate resin according to claim 15 is molded into a film having a thickness of 35 µm ± 5 µm. A polycarbonate resin film having a maximum length of 25 μm or more contained in the film of 1000 / m ² or less.   The polycarbonate resin film whose thickness obtained by shape | molding the polycarbonate resin of Claim 15 or 16 is 20 micrometers-200 micrometers.

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