JP5407207B2 - Polycarbonate resin and method for producing the same - Google Patents

Description

  The present invention relates to a polycarbonate resin and a method for producing the same, and more particularly to a polycarbonate resin having reduced volatile impurities such as phenol and a method for producing the same.

  Polycarbonate resins are excellent in mechanical properties such as heat resistance and impact resistance and dimensional stability, and are also excellent in transparency, and are used in various applications.

  By the way, as a method for producing a polycarbonate resin, there are a melting method (transesterification method), a phosgene method (interfacial polymerization method), etc. In any method, unreacted raw materials, low molecular weight products, reaction solvents, etc. Obtained as a crude polycarbonate resin containing volatile impurities. Examples of the low molecular weight product include phenol in a melting method. That is, in the melting method, phenol produced in the transesterification reaction is distilled off under reduced pressure, but phenol remains in the reaction liquid and is contained in the polycarbonate resin as an equilibrium relationship between the reaction liquid phase and the gas phase. The

  Conventionally, as a method for producing a purified polycarbonate resin by removing volatile impurities, for example, when a polycarbonate resin is melted and extruded into pellets, nitrogen and water are supplied to an extrusion kneading part of a melt extruder to perform a decompression process. (Patent Documents 1 and 2), a method of adding saturated aliphatic hydrocarbons or aromatic hydrocarbons (Patent Documents 3 and 4), a method of supplying carbon dioxide in a pressurized state and performing a decompression process (Patent Document 5) Also known is a method (Patent Document 6) in which a polycarbonate resin and water are kneaded at 0.3 to 10 MPa using a multistage vent type melt extruder and subjected to reduced pressure treatment.

JP-A-9-59367 JP-A-9-59368 JP-A-9-67433 JP-A-9-157375 JP 2000-302879 A JP 2001-31753 A

  An object of the present invention is to provide a polycarbonate resin having a very low content of volatile impurities such as phenol and a method for producing the same.

  As a result of intensive studies, the present inventors have obtained the following surprising findings. That is, when a polycarbonate resin is produced from a dihydroxy compound and a carbonic acid diester by a transesterification method using a polycarbonate resin production apparatus including at least one reactor and at least one extruder, a specific temperature condition is used in the extruder. In other words, the present inventors have found that it is possible to efficiently remove volatile impurities by suppressing the decomposition reaction of the polycarbonate resin, and to obtain a novel polycarbonate resin which has not been conventionally known. The present invention has been completed through further studies based on such findings, and the gist of each invention is as follows.

That is, the first gist of the present invention is obtained by a melting method that by the ester exchange reaction between an aromatic dihydroxy compound and a carbonic acid diester, which satisfies the conditions described in the following (1) to (3) It exists in the characteristic aromatic polycarbonate resin.
(1) The viscosity average molecular weight is 13,000 to 30,000.
(2) The amount of the aromatic monohydroxy compound and the amount of the aromatic dihydroxy compound remaining in the resin are each 20 ppm or less.
(3) One or more structural units of structural formulas (1) to (5) are contained, and the total amount of the structural units is 1,000 to 6,000 ppm.

The second aspect of the present invention, the apparatus for producing a polycarbonate resin containing at least one group reactor and at least 1 group extruder, polycarbonate melt method that by the transesterification method and a dihydroxy compound and a carbonic acid diester A method for producing a polycarbonate resin for producing a resin, wherein T2 is 370 ° C. or lower when the extruder inlet resin temperature is T1 (° C.) and the extruder outlet resin temperature is T2 (° C.). The present invention resides in a method for producing a polycarbonate resin, wherein ΔT indicated by (I) is 70 ° C. or less.

  According to the present invention, there is provided a polycarbonate resin having a very low content of volatile impurities such as phenol and having excellent thermal stability at the time of molding and a method for producing the same.

  Hereinafter, the present invention will be described in detail.

  First, for convenience of explanation, a method for producing a polycarbonate resin according to the present invention will be described.

  In the present invention, a polycarbonate resin is produced from a dihydroxy compound and a carbonic acid diester by a transesterification method. According to the transesterification method, a polycarbonate resin in which the amount of OH groups at the end groups is adjusted can be obtained.

  Examples of the dihydroxy compound used as a raw material include 2,2-bis (4-hydroxyphenyl) propane (alias: bisphenol A), 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane (alias: Tetrabromobisphenol A), bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxy) Phenyl) octane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 1,1-bis (3-tert-butyl-4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-) 3,5-dimethylphenyl) propane, 2,2-bis (3-bromo-4-hydroxyphenyl) propane, 2,2 Bis (3,5-dichloro-4-hydroxyphenyl) propane, 2,2-bis (3-phenyl-4-hydroxyphenyl) propane, 2,2-bis (3-cyclohexyl-4-hydroxyphenyl) propane, 1 , 1-bis (4-hydroxyphenyl) -1-phenylethane, bis (4-hydroxyphenyl) diphenylmethane, 2,2-bis (4-hydroxyphenyl) -1,1,1-trichloropropane, 2,2- Bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexachloropropane, 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane Bis (hydroxyaryl) alkanes such as 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxy) Enyl) cyclohexane, bis (hydroxyaryl) cycloalkanes such as 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 9,9-bis (4-hydroxyphenyl) fluorene, Cardiostructure-containing bisphenols such as 9-bis (4-hydroxy-3-methylphenyl) fluorene; dihydroxydiaryl ethers such as 4,4′-dihydroxydiphenyl ether and 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether Dihydroxydiaryl sulfides such as 4,4′-dihydroxydiphenyl sulfide and 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfide; 4,4′-dihydroxydiphenyl sulfoxide, 4,4′-dihydroxy-3, 3'-dimethyldiphenyl Dihydroxydiaryl sulfoxides such as sulfoxide; dihydroxydiaryl sulfones such as 4,4′-dihydroxydiphenylsulfone, 4,4′-dihydroxy-3,3′-dimethyldiphenylsulfone; hydroquinone, resorcin, 4,4′-dihydroxydiphenyl Etc. Among these, bis (4-hydroxyphenyl) alkanes are preferable, and bisphenol A is particularly preferable from the viewpoint of impact resistance. Furthermore, for the purpose of enhancing flame retardancy, a compound in which one or more tetraalkylphosphonium sulfonates are bonded to the above-mentioned dihydroxy compound can also be used. These dihydroxy compounds may be used in combination of two or more.

  In the melting method, a branched polycarbonate resin can be obtained by adjusting the reaction temperature and the amount of the catalyst. As a part of the dihydroxy compound, phloroglucin, 4,6-dimethyl-2,4,6-tris ( 4-hydroxyphenyl) heptene-2,4,6-dimethyl-2,4,6-tris (4-hydroxyphenyl) heptane, 2,6-dimethyl-2,4,6-tris (4-hydroxyphenyl) heptene -3,1,3,5-tris (4-hydroxyphenyl) benzene, polyhydroxy compounds such as 1,1,1-tris (4-hydroxyphenyl) ethane, 3,3-bis (4-hydroxyaryl) oxy Indole (also known as isatin bisphenol), 5-chloruisatin, 5,7-dichloroisatin, 5-bromoisatin, etc. It may be used as agents.

  On the other hand, examples of the carbonic acid diester as a raw material include compounds represented by the following general formula (a).

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

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

  The carbonic acid diester may be partially substituted with dicarboxylic acid or dicarboxylic acid ester, and the ratio is usually 50 mol% or less, preferably 30 mol% or less. Examples of typical dicarboxylic acid or dicarboxylic acid ester include terephthalic acid, isophthalic acid, diphenyl terephthalate, and diphenyl isophthalate. When substituted with such a dicarboxylic acid or dicarboxylic acid ester, a polyester carbonate is obtained.

  In the transesterification method, carbonic acid diester (including the above-mentioned substituted dicarboxylic acid or dicarboxylic acid ester; the same shall apply hereinafter) is used in excess relative to the dihydroxy compound. That is, the ratio (molar ratio) of the carbonic acid diester to the dihydroxy compound is usually 1.00 to 1.30, preferably 1.01 to 1.20, and more preferably 1.03 to 1.20. When the molar ratio is excessively small, the terminal OH groups of the obtained polycarbonate resin increase, and the thermal stability of the resin tends to deteriorate. In addition, when the molar ratio is excessively large, the transesterification reaction rate decreases, and it becomes difficult to produce a polycarbonate resin having a desired molecular weight, and the residual amount of carbonic acid diester in the resin increases. It may cause odors during molding and molding.

  Generally, a polycarbonate having a desired molecular weight and a terminal hydroxyl group amount can be obtained by adjusting the mixing ratio of the carbonic acid diester and the dihydroxy compound or adjusting the degree of vacuum during the reaction. As a more aggressive method, there is a well-known adjustment method in which a terminal terminator is added separately during the reaction. In this case, examples of the terminal terminator include monohydric phenols, monovalent carboxylic acids, and carbonic acid diesters. The amount of terminal hydroxyl groups greatly affects the thermal stability, hydrolysis stability, color tone, etc. of the product polycarbonate. The amount of terminal hydroxyl groups is usually 1,000 ppm or less, preferably 700 ppm or less in order to give practical physical properties although it depends on the use.

Usually, a transesterification catalyst is used in the transesterification process. The transesterification catalyst is not particularly limited, but an alkali metal compound and / or an alkaline earth metal compound is preferable. In addition, a basic compound such as a basic boron compound, a basic phosphorus compound, a basic ammonium compound, or an amine compound can be used in combination. Among these transesterification catalysts, alkali metal compounds are preferable from a practical viewpoint. These transesterification catalysts may be used in combination of two or more. The amount of the transesterification catalyst used is usually 1 × 10 ⁻⁹ to 1 × 10 ⁻¹ mol, preferably 1 × 10 ⁻⁷ to 1 × 10 ⁻³ mol, more preferably 1 × 10 to 1 mol of the dihydroxy compound. It is in the range of ⁻⁷ to 1 × 10 ⁻⁵ mol.

  Examples of the alkali metal compound include inorganic alkali metal compounds such as alkali metal hydroxides, carbonates and hydrogencarbonate compounds; organic alkali metal compounds such as alkali metal alcohols (or phenols) and salts with organic carboxylic acids. Can be mentioned. Here, examples of the alkali metal include lithium, sodium, potassium, rubidium, and cesium. Among these alkali metal compounds, cesium compounds are preferable, and cesium carbonate, cesium hydrogen carbonate, or cesium hydroxide is particularly preferable.

  The transesterification reaction between the dihydroxy compound and the carbonic acid diester can be carried out as follows.

  First, as a raw material preparation step, a batch, semi-batch or continuous stirring tank type apparatus is used in an inert gas atmosphere such as nitrogen or argon to prepare a raw material mixed melt. For example, when bisphenol A is used as the dihydroxy compound and diphenyl carbonate is used as the carbonic acid diester, the melt mixing temperature is usually in the range of 120 ° C. to 180 ° C., preferably 125 ° C. to 160 ° C.

  Next, as a polycondensation step, an ester exchange reaction between the dihydroxy compound and the carbonic acid diester compound is performed. The transesterification reaction is usually carried out continuously in a multistage system of two or more stages, preferably 3 to 7 stages. Specific reaction conditions for each tank are temperature: 150 to 320 ° C., pressure: normal pressure to reduced pressure (0.01 Torr: 1.3 Pa), and average residence time: 5 to 150 minutes.

  And in each multi-stage reactor, in order to more effectively remove the by-produced phenol out of the system as the polycondensation reaction proceeds, the reaction conditions are set to higher temperature and higher vacuum step by step. Finally, the pressure is reduced to 2 Torr (266.6 Pa) or less. Thereby, a melt polycondensation reaction can be performed while removing by-products such as aromatic hydroxy compounds. In addition, in order to prevent deterioration in quality such as hue of the obtained polycarbonate resin, it is preferable to set the temperature and the residence time as short as possible within the above range.

  As a catalyst deactivator in the transesterification polycarbonate, a compound that neutralizes the catalyst, for example, a sulfur-containing acidic compound or a derivative formed therefrom can be used. The usage-amount of the compound which neutralizes a catalyst is 0.5-10 equivalent normally with respect to the alkali metal which the said catalyst contains, Preferably it is the range of 1-5 equivalent. In addition, the ratio of the compound that neutralizes the catalyst to the polycarbonate is usually in the range of 1 to 100 ppm, preferably 1 to 20 ppm.

  The viscosity average molecular weight of the polycarbonate resin is not particularly limited, but is usually 13,000 to 30,000, preferably 20,000 to 30,000, and more preferably 23,000 to 30,000. When the viscosity average molecular weight exceeds 30,000, the fluidity at the time of molding deteriorates, and when it is less than 13,000, the workability may be impaired. In addition, said viscosity average molecular weight means the value converted from the solution viscosity measured at the temperature of 20 degreeC, using a methylene chloride as a solvent.

  The present invention is a method for producing a polycarbonate resin, wherein a polycarbonate resin is produced from a dihydroxy compound and a carbonic acid diester by a transesterification method using a polycarbonate resin production apparatus comprising at least one reactor and at least one extruder. When the extruder inlet resin temperature is T1 (° C.) and the extruder outlet resin temperature is T2 (° C.), T2 is 370 ° C. or lower, and ΔT represented by the following formula (I) is 70 ° C. or lower. It is characterized by that.

  In the case of a production apparatus including one extruder, the extruder inlet resin temperature T1 and the extruder outlet resin temperature T2 indicate the one extruder inlet resin temperature (final reactor outlet resin temperature) and the outlet resin temperature. In the case of a production apparatus including two extruders, it refers to the first extruder inlet resin temperature (final reactor outlet resin temperature) and the second extruder outlet resin temperature.

  When the extruder outlet resin temperature T2 exceeds 370 ° C. or ΔT exceeds 70 ° C., it is difficult to remove volatile components. This is presumably due to the thermal decomposition of the polycarbonate resin and the decomposition of the raw material components. The extruder outlet resin temperature T2 is preferably 250 to 350 ° C., and ΔT in the above formula (I) is preferably 50 ° C. or less.

  In the present invention, for the same purpose as described above, the difference between the maximum set temperature (Tmax) and the minimum set temperature (Tmin) of the barrel temperature in the extruder preferably satisfies the following formula (I I).

  In the above formula (I I), Tmin is preferably 200 to 240 ° C. The difference between the maximum set temperature (Tmax) and the minimum set temperature (Tmin) is preferably 60 to 120 ° C.

  In the present invention, it is preferable that at least one of the extruders is a vent-type melt extruder, and it is more preferable that the final extruder of the extruders is a vent-type melt extruder. The type of the vent-type melt extruder is not particularly limited, and may be either a single-shaft type or a multi-axis type, and a different direction screw rotation type, a partially meshed different direction screw rotation type, or the like can be used as appropriate. The number of vents is not limited and is appropriately selected from a range of 1 to 10 stages.

  When performing devolatilization melt extrusion using a vent type melt extruder, the following two embodiments (i) and (ii) are recommended.

(I) When the polymer filter is not used after the devolatilization melt extrusion of the resin, the extruder outlet resin temperature T2 satisfies the formula (1) and the extruder screw peripheral speed V (m / min) is the formula ( Volatilization melt extrusion is performed under the conditions satisfying 2). The peripheral speed of the screw in (2) means the peripheral speed at the maximum outer diameter portion of the screw.

（式（１）中、［η］は、ウベローデ粘度計を使用し、塩化メチレン溶液（ポリカーボネート樹脂の濃度０．６ｇ／ｄＬ）として、２０℃で測定したポリカーボネート樹脂の極限粘度を表す。）

(In formula (1), [η] represents the intrinsic viscosity of the polycarbonate resin measured at 20 ° C. as a methylene chloride solution (polycarbonate resin concentration 0.6 g / dL) using an Ubbelohde viscometer)

  Formula (1) is an empirical formula that defines the extruder outlet resin temperature (molten resin temperature) employed in the present invention by the extruder outlet resin temperature (melted resin temperature) and the intrinsic viscosity (function of viscosity average molecular weight) of the polycarbonate resin. Yes, with the following significance.

  The resin temperature at the outlet of the extruder needs to be appropriately selected according to the intrinsic viscosity of the molten resin flowing through the extruder. Generally, the higher the viscosity of the extruder, the higher the resin temperature at the exit of the extruder, and it is thought that mixing with additives and removal of volatile components will be carried out effectively. Surprisingly, when the resin temperature at the outlet of the extruder exceeds a predetermined temperature, it becomes difficult to remove the volatile components. This is presumably due to the thermal decomposition of the polycarbonate resin and the decomposition of the raw material components. On the other hand, when the resin temperature at the exit of the extruder is lower than a predetermined temperature, not only the melt viscosity of the resin increases and it becomes difficult to remove volatile components, but the supply pressure to the cylinder increases and crystallization occurs. To do. The above equation (1) is an empirical equation representing the optimum range of the relationship between the extruder outlet resin temperature and the intrinsic viscosity of the polycarbonate resin, which is obtained based on the above various phenomena.

  Formula (2) means that the peripheral speed V of the screw of the extruder needs to be appropriately selected according to the extruder outlet resin temperature (T) defined by Formula (1). When the peripheral speed V of the screw of the extruder is less than the range specified by the above formula (2), it becomes difficult to remove the volatile component, and when it exceeds the range specified by the above formula (2), it is applied to the resin. The shear stress becomes excessively high, thereby increasing the resin temperature, and as described above, due to the thermal decomposition of the polycarbonate resin and the decomposition of the raw material components, it becomes difficult to remove the volatile components.

  In the case of (i), a preferable range of the extruder outlet resin temperature T2 (° C.) is a range shown in the formula (10), and a preferable range of the peripheral speed V (m / min) of the screw of the extruder is a formula ( 20).

（式（１０）中、［η］は式（１）の［η］と同義である。）

(In formula (10), [η] is synonymous with [η] in formula (1).)

(Ii) When devolatilizing and extruding the resin and processing with a polymer filter, the extruder outlet resin temperature T2 satisfies the formula (3) and the screw peripheral speed V (m / min) is the formula Volatilization melt extrusion is performed under the conditions satisfying (4).

（式（３）中、［η］は式（１）の［η］と同義である。）

(In formula (3), [η] is synonymous with [η] in formula (1).)

  The technical significance of the formulas (3) and (4) is the same as the above formulas (1) and (2). And in order to prevent the pressure loss at the time of processing with a polymer filter, it is necessary to make the extruder exit resin temperature high, and allowable conditions differ compared with the case where it does not process with a polymer filter.

  In the case of (ii) above, the preferred range of the extruder outlet resin temperature T2 (° C.) is the range shown in the formula (30), and the preferred range of the peripheral speed V (m / min) of the screw of the extruder is the formula ( 40).

（式（３０）中、［η］は式（１）の［η］と同義である。）

(In formula (30), [η] is synonymous with [η] in formula (1).)

  The polymer filter is a filter that filters out foreign substances present in the polycarbonate resin, and the form thereof is generally known in the form of a candle type, a pleat type, a leaf disk type, etc. A leaf disk polymer filter is preferred. The leaf disk type is usually a disk shape, and one or more layers of woven wire meshes having various wire diameters and aperture ratios are used. The types of weaving include plain weave, twill weave, plain tatami weave, twill tatami weave, and may be non-woven fabric. As the material, stainless steel such as SUS-316 or SUS-316L is usually used, but sintered metal or resin can also be used. The absolute filtration accuracy is usually 0.5 μm to 50 μm, preferably 0.5 μm to 20 μm.

  In the present invention, water can be used as a devolatilization aid. The water supplied to the extruder is not particularly limited as long as it does not affect the quality of the polycarbonate resin, but water having a low electrical conductivity is preferable. The electrical conductivity of water is usually 1 mS / cm or less, preferably 1 μS / cm or less. The amount of water supplied to the extruder is usually 5 to 5000 ppm, preferably 5 to 3000 ppm, more preferably 5 to 2000 ppm with respect to the polycarbonate resin.

  The polycarbonate resin obtained by the production method of the present invention is usually pelletized according to a conventional method. In the case of using cooling water for cooling / cutting the polycarbonate resin during pelletization, the electric conductivity of the cooling water is preferably low, and is usually 1 mS / cm or less, preferably 1 μS / cm or less, as described above. . According to the present invention, it is possible to produce a polycarbonate resin having a sufficiently reduced content of volatile impurities, and the amount of aromatic monohydroxy compound and amount of aromatic dihydroxy compound is usually 20 ppm or less, respectively. The amount of monohydroxy compound is preferably 10 ppm or less.

  Next, the aromatic polycarbonate resin of the present invention will be described.

  The aromatic polycarbonate resin of the present invention is obtained by a transesterification reaction between an aromatic dihydroxy compound and a carbonic acid diester, and satisfies the conditions described in the following (1) to (3).

(1) The viscosity average molecular weight is 13,000 to 30,000.
(2) The amount of the aromatic monohydroxy compound and the amount of the aromatic dihydroxy compound remaining in the resin are each 20 ppm or less.
(3) One or more structural units of structural formulas (1) to (5) are contained, and the total amount of the structural units is 1,000 to 6,000 ppm.

  The viscosity average molecular weight of the aromatic polycarbonate resin of the present invention is 13,000 to 30,000, preferably 20,000 to 30,000, more preferably 23,000 to 30,000. The measurement method of the viscosity average molecular weight and the significance of the numerical range are as described above.

  Further, the amount of the aromatic monohydroxy compound and the amount of the aromatic dihydroxy compound remaining in the resin are each 20 ppm or less, and the amount of the aromatic monohydroxy compound is particularly preferably 10 ppm or less. By satisfying such conditions, the aromatic polycarbonate resin of the present invention is excellent in thermal stability during molding.

  The total amount of the structural units in the aromatic polycarbonate resin of the present invention is 1,000 to 6,000 ppm, preferably 2,500 to 5,500 ppm, and more preferably 3,000 to 5,500 ppm. When the total amount of structural units is less than 1,000 ppm, for example, dripping occurs during blow molding, and when it exceeds 6,000 ppm, fluidity is impaired. In addition, the measuring method of the said structural unit is demonstrated in the below-mentioned Example.

  The aromatic polycarbonate resin of the present invention can be obtained by the above-described production method using a polycarbonate resin production apparatus including at least one reactor and at least one extruder.

  The content of the structural unit in the aromatic polycarbonate resin of the present invention can be adjusted by appropriately selecting the conditions for the transesterification reaction between the aromatic dihydroxy compound and the carbonic acid diester. Recommended transesterification conditions are as follows.

That is, in order to form a specific amount of the structural units (1) to (5), the amount of catalyst at the time of transesterification and the temperature (internal temperature) of the final reactor are important, and the amount of catalyst is 1 mol of dihydroxy compound. Is selected from the range of usually 1 × 10 ⁻⁷ to 1 × 10 ⁻³ mol, preferably 1 × 10 ⁻⁷ to 1 × 10 ⁻⁵ mol, and the temperature of the final reactor is usually 260 to 300 ° C., Preferably, it selects from the range of 270-290 degreeC.

  The resulting resin is devolatilized and melt extruded in an extruder. At this time, in accordance with the present invention, by devolatilizing and melt extruding at specific temperature conditions, only volatile impurities are removed and produced by transesterification. The above-mentioned structural unit can maintain the above-mentioned content without substantially damaging it.

  For the polycarbonate resin according to the present invention, conventionally known additives such as other thermoplastic resins, flame retardants, impact resistance improvers, antistatic agents, slip agents, antiblocking agents, lubricants, antibacterial agents are used depending on applications. Clouding agents, natural oils, synthetic oils, waxes, organic fillers and inorganic fillers can be appropriately selected and used.

  The polycarbonate resin according to the present invention is a building material such as a sheet, a container such as a water bottle, an optical lens such as an automotive headlamp lens and glasses, an optical recording material such as an optical disk, a light guide plate such as a liquid crystal display, etc. Can be suitably used.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to a following example, unless the summary is exceeded. In the following examples, the above-mentioned structural units (1) to (5) were measured as follows.

  In a flask, 0.5 g of polycarbonate was precisely weighed, dissolved in 5 mL of methylene chloride, 45 mL of methanol and 5 mL of 25 wt% aqueous sodium hydroxide solution were added, and the mixture was stirred at 70 ° C. for 30 minutes while being dry-distilled in a condenser. After allowing to cool, the condenser is washed with 5 mL of methanol, and the washing solution is added to the above solution. Then, the pH is about 2 with about 7 mL of 6N hydrochloric acid, and the total amount of the solution becomes 100 mL in a 100 mL volumetric flask. So that it was adjusted with pure water.

  Then, 20 μL of the above solution was subjected to liquid chromatography (“LC-10AD” manufactured by Shimadzu, column; “YMC-PackODS-AM AM-307-3” 4.6 mm ID × 75 mmL, detector; UV 280 nm, eluent; (A) 0.05% TFA aqueous solution / (B) methanol, gradient; measured at 0 minutes (B = 40%), 25 minutes (B = 95%)), and quantified the structural units (1) to (5). . Note that the structural units (3) and (4) were quantified as the total content of the two because there was an overlap of peaks and quantification of complete separation was not possible.

Example 1:
An aromatic polycarbonate resin was produced under the following conditions by a continuous production apparatus having 4 vertical stirring reactors and 4 horizontal stirring reactors.

(First vertical stirring reactor): 220 ° C., 13.3 kPa
(Second vertical stirring reactor): 240 ° C., 2 kPa
(Third vertical stirring reactor): 270 ° C., 67 Pa
(4th vertical stirring reactor): 270 ° C., 67 Pa
(Fifth horizontal stirring reactor): 270 ° C., 67 Pa

  First, bisphenol A (BPA) and diphenyl carbonate (DPC) are mixed at a constant molar ratio (DPC / BPA = 1.030) in a nitrogen gas atmosphere in the original preparation step, and heated to 140 ° C., A raw material mixed melt was obtained. Subsequently, the raw material mixed melt is continuously fed into the first vertical stirring reactor through the raw material introduction pipe heated to 140 ° C., and the average bottom residence time is 60 minutes. The liquid level was kept constant while controlling the opening degree of the valve provided in the discharge line. Simultaneously with the start of the supply of the raw material mixed melt, an aqueous cesium carbonate solution as a catalyst was continuously fed into the first vertical stirring reactor from the catalyst introduction tube at a ratio of 1 μmol with respect to 1 mol of bisphenol A.

  The polymerization reaction liquid discharged from the bottom of the first vertical stirring reactor is continuously used as the second vertical stirring reactor, the third vertical stirring reactor, the fourth vertical stirring reactor, and the fifth horizontal stirring reaction. The vessel was fed continuously and continuously. During the polymerization reaction, the liquid level was controlled so that the average residence time of each reactor was 60 minutes, and phenol produced as a by-product was distilled off simultaneously with the polymerization reaction. The production rate of the aromatic polycarbonate resin is 15 kg / Hr. The aromatic polycarbonate resin thus obtained had a viscosity average molecular weight of 25,800, bisphenol A content 24 ppm, diphenyl carbonate content 39 ppm, phenol content 33 ppm, structural unit (1) content 1754 ppm, structural unit (2) content 1286 ppm, structural unit ( 3) and (4) The total content was 1092 ppm, and the structural unit (5) content was 145 ppm.

  Subsequently, said aromatic polycarbonate resin was supplied to the extruder connected to the 5th horizontal stirring reactor, and devolatilization melt extrusion was performed in the following way.

  The above aromatic polycarbonate resin was supplied to a twin screw extruder “JSW TEX30” (manufactured by Nippon Steel) with a supply amount of 12.5 kg / hr and pelletized. The conditions of the extruder are a resin temperature of 270 ° C. at the extruder inlet (fifth horizontal stirring reactor outlet), an extruder outlet resin temperature of 284 ° C., a rotation speed of 100 rpm (peripheral speed: 9 m / min), and a vacuum degree of 60 Pa. The strand-like resin discharged from the extruder die was cooled and cut into pellets. The obtained resin pellets had a phenol content of 4 ppm and a bisphenol A content of 18 ppm. The contents of the structural units (1) to (5) were the same as described above.

  The amount of each monomer was measured as follows. That is, 1.2 g of the polymer was dissolved in 7 ml of methylene chloride, and 23 ml of acetone was added thereto while stirring to reprecipitate, and the supernatant was subjected to liquid chromatography (“LC-10AT” manufactured by Shimadzu, column; “MCI GEL ODS”). 5 μm 4.6 mm ID × 150 mm L, detector: UV219 nm, eluent: acetonitrile / water = 4/6), and the amounts of phenol and bisphenol A in the polymer were quantified.

Example 2:
In Example 1, except that the amount of resin supplied to the extruder was 15 kg / hr, the resin temperature at the outlet of the extruder was 314 ° C., the rotation speed was 150 rpm (peripheral speed: 14 m / min), and the degree of vacuum was changed to 90 Pa, The same operation as in Example 1 was performed. The obtained resin pellets had a phenol content of 14 ppm and a bisphenol A content of 17 ppm.

Comparative Example 1:
In Example 1, except that the amount of resin supplied to the extruder was 15 kg / hr, the extruder outlet resin temperature was 342 ° C., the rotation speed was 150 rpm (peripheral speed: 14 m / min), and the degree of vacuum was changed to 90 Pa, The same operation as in Example 1 was performed. The resin pellets obtained had a phenol content of 24 ppm and a bisphenol A content of 18 ppm.

  The results of Examples 1 and 2 and Comparative Example 1 are shown together with the melt extrusion conditions in Table 1.

Example 3:
In Example 1, four leaf disk polymer filters (absolute filtration accuracy 20 μm) manufactured by Nippon Pole Co., Ltd. were installed at the exit of the extruder, the amount of resin supplied was 15 kg / hr, and the resin temperature at the exit of the extruder was 340 ° C. , Except that the rotation speed was 150 rpm (peripheral speed: 14 m / min), the degree of vacuum was changed to 60 Pa, and water with an electrical conductivity of 0.5 μS / cm was supplied to the 2000 ppm extruder as a devolatilization aid. Was carried out in the same manner as in Example 1. The obtained resin pellets had a phenol content of 19 ppm and a bisphenol A content of 24 ppm.

Comparative Example 2:
In Example 1, four leaf disk polymer filters (absolute filtration accuracy 20 μm) manufactured by Nihon Pall Co., Ltd. were installed at the exit of the extruder, the amount of resin supplied was 15 kg / hr, and the resin temperature at the exit of the extruder was 355 ° C. The same procedure as in Example 1 was performed except that the rotation speed was changed to 150 rpm (peripheral speed: 14 m / min) and the degree of vacuum was changed to 90 Pa. The obtained resin pellets had a phenol content of 27 ppm and a bisphenol A content of 30 ppm.

  The results of Example 3 and Comparative Example 2 are shown together with melt extrusion conditions in Table 2.

Claims (8)

The apparatus for manufacturing a polycarbonate resin containing at least one group reactor of at least 1 group extruder, obtained by a melting method that by the ester exchange reaction between an aromatic dihydroxy compound and a carbonic acid diester, the following (1) - ( An aromatic polycarbonate resin characterized by satisfying the conditions described in 3).
(1) The viscosity average molecular weight is 13,000 to 30,000.
(2) The amount of the aromatic monohydroxy compound and the amount of the aromatic dihydroxy compound remaining in the resin are each 20 ppm or less.
(3) One or more structural units of structural formulas (1) to (5) are contained, and the total amount of the structural units is 1,000 to 6,000 ppm.

The apparatus for manufacturing a polycarbonate resin containing at least one group reactor of at least 1 group extruder, a method of manufacturing the polycarbonate resin to produce a polycarbonate resin by the melting method that by the transesterification method and a dihydroxy compound and a carbonic acid diester When the extruder inlet resin temperature is T1 (° C.) and the extruder outlet resin temperature is T2 (° C.), T2 is 370 ° C. or lower, and ΔT shown in the following formula (I) is 70 ° C. or lower. A method for producing a polycarbonate resin.

The manufacturing method of Claim 2 with which the difference of the maximum setting temperature (Tmax) and minimum setting temperature (Tmin) of the barrel temperature in the said extruder satisfies the following formula | equation (II).

  The manufacturing method according to claim 3, wherein Tmin = 200 to 240 ° C.   The manufacturing method according to any one of claims 2 to 4, wherein at least one of the extruders is a vent-type melt extruder.   The manufacturing method according to claim 5, wherein a final extruder of the extruders is a vent type melt extruder.   The manufacturing method of any one of Claims 2-6 which uses a devolatilization adjuvant with an extruder.   The method according to any one of claims 2 to 7, wherein the polycarbonate resin has a viscosity average molecular weight of 13,000 to 30,000.