JP6349849B2 - Polycarbonate resin - Google Patents

Description

  The present invention relates to a polycarbonate resin which is excellent in hue and molded appearance and has a small amount of residual low molecular components.

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 plastic.
Conventional polycarbonate resins are manufactured using raw materials derived from petroleum resources. However, in recent years, there is a concern about the exhaustion of petroleum resources, and there is a need to provide polycarbonate resins using raw materials obtained from biomass resources such as plants. It has been demanded. In addition, since there is concern that global warming due to an increase and accumulation of carbon dioxide emissions will lead to climate change, polycarbonate resin made from carbon-neutral plant-derived monomers as raw materials even after disposal after use Development is required.

  Under such circumstances, isosorbide, which is a dihydroxy compound obtained from biomass resources (hereinafter sometimes abbreviated as ISB), is used as a monomer component, and the monohydroxy compound produced as a by-product is distilled under reduced pressure by transesterification with a carbonic acid diester. A method for obtaining a polycarbonate resin has been proposed (see, for example, Patent Documents 1 to 4). Polycarbonate resins obtained from ISB are being studied for use in optical applications and glass replacement applications by making use of excellent optical properties in addition to their use as molding materials that take advantage of heat resistance.

  However, dihydroxy compounds such as ISB have lower thermal stability than bisphenols used in conventional aromatic polycarbonate resins, and are thermally decomposed during polycondensation reactions, molding and processing at high temperatures. There was a problem of coloring. In order to solve this problem, improvement of polymerization reaction conditions and polymerization catalyst, and addition by adding a heat stabilizer or the like to the polycarbonate resin have been studied (for example, see Patent Documents 5 to 8).

Patent Document 9 describes that when ISB is used as the dihydroxy compound, the ratio of the terminal phenyl group to the terminal group is maintained at a certain level or more to prevent deterioration in color tone after extrusion kneading or stay molding. Has been.
Furthermore, Patent Document 10 describes that a non-defective polycarbonate resin can be obtained by setting the conditions for extrusion and filtering within a certain range of manufacturing conditions.

  Patent Document 11 discloses that the water absorption of the resin can be suppressed by setting the terminal OH of the dihydroxy compound polycarbonate resin using ISB as a raw material to be within a certain range.

International Publication No. 2004/111106 Pamphlet Japanese Patent Laid-Open No. 2006-232897 JP 2006-28441 A JP 2008-24919 A JP 2009-161745 A WO 2011/065505 pamphlet JP 2009-91405 A JP 2009-144020 A JP 2011-21172 A JP 2012-214728 A International Publication No. 2011-096089 Pamphlet

However, in the invention described in Patent Document 9, these are for the purpose of preventing deterioration of the color tone after extrusion kneading or stay molding, and the color tone when extrusion kneading or stay molding is not performed is not mentioned. The means for suppressing the color tone in the original polymerization stage is not described and is insufficient.
Further, in the invention described in Patent Document 10, evaluation as an actual molded body has not been made, and an injection molded product using a resin actually obtained by these methods has a poor appearance such as so-called silver. In the extruded product, fine bubbles are generated, which is not satisfactory.

  Furthermore, in the invention described in Patent Document 11, severe polymerization conditions are required to lower the terminal OH, and as a result, only the color tone is deteriorated and the appearance is poor. Further, when the terminal OH is extremely reduced, a specific oligomer component tends to be generated and tends to remain in the polycarbonate resin. These oligomer components tend to cause poor appearance during molding. However, neither a problem nor a solution was disclosed about these, and problem solving was necessary.

  Therefore, a polycarbonate resin using a dihydroxy compound such as ISB is relatively low in thermal stability and polymerized at a lower temperature than conventional aromatic polycarbonate resins in order to improve color tone. As a result, the residual amount of desorption components by-produced by the polycondensation reaction increases, causing problems such as equipment contamination and odor during injection molding and extrusion molding, and the surface appearance of molded products is impaired, resulting in molding yield. May worsen. These are problems that become more apparent as the production volume increases. Further, according to the study by the present inventors, unless the terminal group ratio of the polycarbonate resin is controlled to a certain level, there is a problem that silver is likely to be generated by injection molding or fine bubbles are generated by extrusion molding. It was done. Furthermore, a problem has also been found in that appearance defects frequently occur unless the specific oligomer component is made a certain amount or less.

In addition, in fields where high transparency, hue, and good appearance are required, such as optical applications and glass replacement applications, further improvements in color tone and quality are required. Performance required by conventional methods Not satisfied.
An object of the present invention is to solve the above-mentioned problems, and particularly to provide a polycarbonate resin which is excellent in hue and appearance and has few remaining low molecular components.

[1] A polycarbonate resin containing a structural unit derived from a dihydroxy compound represented by the following formula (1):
The ratio (A / B) of the number of terminal groups (A) represented by the following structural formula (2) to the total number of terminals (B) is 75% or more and less than 98%,
The content of the compound represented by the following formula (3) is 10 to 700 ppm by weight,
A polycarbonate resin, wherein the content of a monohydroxy compound derived from a carbonic acid diester is 700 ppm by weight or less.

[2] The polycarbonate resin according to [1], wherein the polycarbonate resin pellet has a YI of 15 or less.
[3] At least one phosphorous selected from the group consisting of phosphoric acid, phosphorous acid, hypophosphorous acid, polyphosphoric acid, phosphonic acid, phosphonic acid ester, acidic phosphoric acid ester, and aliphatic cyclic phosphorous acid ester The polycarbonate resin according to [1] or [2], wherein the compound contains 0.7 ppm by weight or less of phosphorus atom.
[4] The polycarbonate resin according to any one of [1] to [3],
A polycarbonate resin in which the reaction time at 210 ° C. or higher and 240 ° C. or lower is less than 3 hours in the reaction step of polycarbonate resin production.
[5] Polycarbonate resin is
The dihydroxy compound represented by the following formula (4), the dihydroxy compound represented by (5), the dihydroxy compound represented by the following formula (6), the dihydroxy compound represented by the following formula (7) and the following formula (8) The polycarbonate resin according to any one of [1] to [4], comprising a structural unit derived from one or more dihydroxy compounds selected from the group consisting of dihydroxy compounds represented by:

HO—R ⁵ —OH (5)
(In the above formula (5), R ⁵ represents a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms.)
HO—CH ₂ —R ⁶ —CH ₂ —OH (6)
(In the above formula (6), R ⁶ represents a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms.)
_{^{H- (O-R 7) p}} -OH (7)
(In the above formula (7), ^{R 7} represents a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, p is an integer from 2 to 100.)
HO—R ⁸ —OH (8)
(In the formula (8), ^{R 8} is a substituted or unsubstituted alkylene group having 2 to 20 carbon atoms.
)
[6]
[1] A molded product formed by molding the polycarbonate resin according to any one of [5].

  According to the present invention, it is possible to obtain a polycarbonate resin that is particularly excellent in hue and appearance and has a small amount of low molecular components, and the polycarbonate resin has hue, transparency, heat resistance, weather resistance, appearance, and mechanical properties. Excellent strength, injection molding field such as electrical / electronic parts, automotive parts, glass replacement, film, sheet field, bottle, container field, and lens applications such as camera lens, finder lens, CCD and CMOS lens To a wide range of fields such as retardation films, diffusion sheets, polarizing films, and other films, sheets, optical disks, optical materials, optical components, dyes, charge transfer agents, and other binders used for liquid crystal and organic EL displays Applicable polycarbonate resin can be provided. Furthermore, since the appearance defects in molding can be greatly reduced, productivity, workability, and product quality can be improved.

  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.

[Polycarbonate resin]
It is a polycarbonate resin containing a structural unit derived from a dihydroxy compound represented by the following formula (1).

[Polycarbonate resin pellets]
Polycarbonate resin obtained by polycondensation is usually extracted in the form of a strand from an extraction port provided at the bottom of the polycondensation tank, and is cooled with water or after water cooling and then cut with a cutter to form pellets, chips, etc. It is assumed to be a body. Here, in the present invention, “pellet” means a resin cut into granular bodies. Further, as will be described later, pellets in the present invention include pellets, chips, and the like that are formed after various additives are added to the polycarbonate resin and melt-kneaded.

  The hue of the polycarbonate resin pellet was measured with reflected light using a spectrocolorimeter CM-5 manufactured by Konica Minolta Co., Ltd. according to ASTM D1925. As measurement conditions, a measurement diameter of 30 mm and SCE were selected. Petri dish calibration glass CM-A212 was fitted into the measurement part, and zero calibration was performed by placing a zero calibration box CM-A124 thereon, followed by white calibration using a built-in white calibration plate. Measurement was performed using a white calibration plate CM-A210. L * was 99.40 ± 0.05, a * was 0.03 ± 0.01, b * was −0.43 ± 0.01, and YI was −. It was confirmed to be 0.58 ± 0.01. The YI of the pellet was measured by packing the pellet in a cylindrical glass container having an inner diameter of 30 mm and a height of 50 mm to a depth of about 40 mm. The operation of taking out the pellet from the glass container and then performing the measurement again is repeated twice, and the average value of the three times of measurement values is used.

  In the polycarbonate resin of the present invention, the YI of the pellet is preferably 15 or less, more preferably 13 or less, further preferably 10 or less, particularly preferably 9 or less, and most preferably 8 or less. If the YI of the pellet is larger than 10, the color of the obtained injection-molded product or extruded product tends to deteriorate.

(End group structure of polycarbonate resin)
As described above, in the method for producing a polycarbonate resin, it is preferable to use diphenyl carbonate as the carbonic acid diester. In this case, the total number of terminals (B) of the number of existing terminal groups (A) of the terminal group represented by the following structural formula (2) (hereinafter sometimes referred to as “phenyl group terminal”) of the polycarbonate resin to be produced. The ratio (A / B) to is in the range of 75% or more and less than 98%.

In addition, the ratio (A / B) of the number (A) of phenyl group terminals present in the polycarbonate resin to the total number of terminals (B) is preferably in the range of 76% or more, and in the range of 77% or more. Particularly preferred. Moreover, it is preferable that it is the range of 96% or less, and it is especially preferable that it is the range of 95% or less.
If the ratio (A / B) of the number of phenyl group terminals (A) to the total number of terminals (B) is less than 75%, the molded product has a poor appearance called silver during injection molding, and bubbles in extrusion molding. Is likely to occur. Further, when the ratio (A / B) of the number of phenyl group terminals (A) to the total number of terminals (B) is more than 98%, appearance defects in injection molding and extrusion molding tend to decrease. Further, if it is attempted to obtain more than 98% polycarbonate resin, the polymerization conditions may be harsh or a long reaction will be required. As a result, the polycarbonate resin may be deteriorated, and only a poor color tone may be obtained. Very expensive.

  The method for adjusting the ratio (A / B) of the number of phenyl group terminals (A) in the polycarbonate resin to the total number of terminals (B) is not particularly limited, but for example, carbonic acid with respect to all dihydroxy compounds used in the reaction. Adjust the amount ratio of diester within a range where a desired high molecular weight product can be obtained, remove residual monomer from the reaction system by degassing at the latter stage of the polymerization reaction, increase the stirring efficiency of the reactor at the latter stage of the polymerization reaction, etc. Thus, by increasing the reaction rate, the ratio (A / B) of the number of existing phenyl groups (A) to the total number of terminals (B) can be adjusted to the above-described range.

The proportion of the phenyl group terminal in the polycarbonate resin can be calculated by measuring ¹ H-NMR spectrum using deuterated chloroform to which TMS is added as a measurement solvent with an NMR spectrometer.
In addition, the usage rate of the dihydroxy compound which has the coupling | bonding structure of Structural formula (1), an alicyclic dihydroxy compound, and the other dihydroxy compound used as needed is each which comprises the polycarbonate resin used by this invention. It adjusts suitably according to the ratio of the structural unit originating in a dihydroxy compound.

(Amount of Compound Represented by Formula (3) and Reduction Method)
The polycarbonate resin of the present invention contains a special oligomer component represented by the following structural formula (3). If the amount is too small, it is necessary to apply excessive heat or increase the reaction residence time in the purification stage, which may cause deterioration of the color tone of the polymer, and the above range is preferable. When the amount is too large, there is a problem of contamination of the apparatus at the time of molding or a problem of appearance defect of the molded product.

The residual amount of the compound represented by the following structural formula (3) in the polycarbonate resin of the present invention is 10 ppm to 700 ppm by weight, and the lower limit is preferably 15 ppm by weight, and particularly preferably 20 ppm. It is preferably at least ppm.
Further, it is preferably 650 ppm by weight or less, particularly preferably 600 ppm by weight or less. If the remaining amount of the compound represented by the following structural formula (3) in the polycarbonate resin is in the above range, there is no dirt or odor during molding, the molding appearance is good, and the plate YI is also good. preferable. In order to adjust the content of the compound represented by the following structural formula (3), during the polycarbonate resin production, the ratio of the number of phenyl group terminals (A) to the number of all terminals (B) (A / B) By making the content 98% or less, generation of a compound represented by the following structural formula (3) can be suppressed. Furthermore, generation | occurrence | production can be suppressed by making the pressure in a final polymerization tank into 600 Pa or less, or making polymerization time in temperature higher than 220 degreeC into less than 2 hours. In particular, the devolatilization efficiency can be drastically improved by making the final polymerization tank a horizontal reaction tank. Moreover, the compound represented by Structural formula (3) can be reduced by performing devolatilization from a vacuum vent with an extruder, or performing water injection in the case of devolatilization.

  The polycarbonate resin of the present invention is usually obtained by polycondensation of a dihydroxy compound, a carbonic acid diester and a catalyst under melting as described later. In this polycondensation reaction, a monohydroxy compound is generated as a leaving component from the carbonic acid diester. For example, when diphenyl carbonate is used as the carbonic acid diester, the monohydroxy compound produced is phenol. At this time, if the residual amount of the monohydroxy compound in the obtained polycarbonate resin is large, there may be a problem of contamination of the apparatus and odor during molding. The upper limit of the residual amount of the monohydroxy compound in the polycarbonate resin of the present invention is 700 ppm by weight or less, more preferably 500 ppm by weight or less, and particularly preferably 300 ppm by weight or less. At the time of production of the polycarbonate resin, by using an appropriate amount of a specific phosphorus compound that becomes a catalyst deactivator as described later, and further sufficiently performing devolatilization treatment, the residual amount of the monohydroxy compound in the polycarbonate resin is reduced, And generation | occurrence | production under a heating can be suppressed. Details of the method for measuring the amount of the monohydroxy compound in the polycarbonate resin are described in the Examples section. In addition, the lower limit is not limited, but is usually 0.01 ppm by weight or less, more preferably 0.1 ppm by weight or less, and particularly preferably 1 ppm by weight or less. If the amount is too small, it is necessary to apply excessive heat or increase the reaction residence time in the purification stage, which may cause deterioration of the color tone of the polymer, and the above range is preferable.

[Production method of polycarbonate resin]
Hereinafter, the method for producing the polycarbonate resin of the present invention will be described in detail.
<Raw material>
(Dihydroxy compound)
The polycarbonate resin of the present invention is a polycarbonate resin containing a structural unit derived from a dihydroxy compound represented by the following formula (1).

(However, the site represented by the above formula (1) unless a portion constituting a part of _-CH 2 -OH.)
In the present invention, the polycarbonate resin is represented by the dihydroxy compound represented by the following formula (4), (5), in addition to the structural unit derived from the dihydroxy compound represented by the above formula (1). One or more dihydroxy compounds selected from the group consisting of a dihydroxy compound represented by the following formula (6), a dihydroxy compound represented by the following formula (7), and a dihydroxy compound represented by the following formula (8) Structural units derived from the compound can be included.

HO—R ⁵ —OH (5)
(In the above formula (5), R ⁵ represents a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms.)
HO—CH ₂ —R ⁶ —CH ₂ —OH (6)
(In the above formula (6), R ⁶ represents a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms.)
_{^{H- (O-R 7) p}} -OH (7)
(In the above formula (7), ^{R 7} represents a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, p is an integer from 2 to 100.)
HO—R ⁸ —OH (8)
(In the above formula (8), R ⁸ represents a substituted or unsubstituted alkylene group having 2 to 20 carbon atoms.)
In the following, the carbon number of various groups means the total number of carbon atoms including the carbon number of the substituent when the group has a substituent.

[Dihydroxy Compound Represented by Formula (1)]
The polycarbonate resin in the present invention contains a structural unit derived from the dihydroxy compound represented by the above formula (1).
Examples of the dihydroxy compound represented by the above formula (1) include anhydrous sugar alcohols such as isosorbide, isomannide and isoidet which are in a stereoisomeric relationship. These may be used individually by 1 type and may be used in combination of 2 or more type. Among these dihydroxy compounds, isosorbide obtained by dehydrating condensation of sorbitol produced from various starches that are abundant as resources and are readily available is easy to obtain and manufacture, optical properties, moldability From the viewpoint of the above, it is most preferable.
When the polycarbonate resin simultaneously contains structural units derived from the dihydroxy compound represented by the above (1) and (2), the ratio is not particularly limited, and may be set as appropriate according to the required performance of the polycarbonate resin. .

[Dihydroxy compounds represented by formulas (4) to (8)]
In the present invention, the polycarbonate resin is optionally dihydroxy compound represented by the above formula (4), dihydroxy compound represented by the following formula (5), dihydroxy compound represented by the following formula (6), A structural unit derived from one or more dihydroxy compounds selected from the group consisting of a dihydroxy compound represented by the formula (7) and a dihydroxy compound represented by the following formula (8) can be included.

<Dihydroxy compound represented by Formula (4)>
The dihydroxy compound represented by the formula (4) has a cyclic ether structure in the molecule, and is a compound called spiroglycol.
<Dihydroxy compound represented by Formula (5)>
The dihydroxy compound represented by the formula (5) is an alicyclic dihydroxy compound having a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms, preferably 4 to 18 carbon atoms, in R ⁵ . Here, when R ⁵ has a substituent, examples of the substituent include substituted or unsubstituted alkyl groups having 1 to 12 carbon atoms. When the alkyl group has a substituent, examples of the substituent include an alkoxy group such as a methoxy group, an ethoxy group, and a propoxy group, and an aryl group such as a phenyl group and a naphthyl group.

Since this dihydroxy compound has a ring structure, it is possible to increase the toughness of a molded product when the obtained polycarbonate resin is molded, and in particular, the toughness when molded into a film can be increased.
The cycloalkylene group for R ⁵ is not particularly limited as long as it is a hydrocarbon group having a ring structure, and may be a bridge structure having a bridgehead carbon atom. From the viewpoint that production of the dihydroxy compound is easy and the amount of impurities can be reduced, the dihydroxy compound represented by the formula (5) is a compound containing a 5-membered ring structure or a 6-membered ring structure, that is, R ⁵ is A dihydroxy compound which is a substituted or unsubstituted cyclopentylene group or a substituted or unsubstituted cyclohexylene group is preferred. If it is such a dihydroxy compound, the heat resistance of the polycarbonate resin obtained can be made high by including a 5-membered ring structure or a 6-membered ring structure. The 6-membered ring structure may be fixed in a chair shape or a boat shape by a covalent bond.

Among them, the dihydroxy compound represented by the formula (5) is preferably various isomers in which R ⁵ is represented by the following formula (9). Here, in formula (9), R ¹¹ represents a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms. When R ¹¹ is a C 1-12 alkyl group having a substituent, examples of the substituent include alkoxy groups such as a methoxy group, an ethoxy group, and a propoxy group, and aryl groups such as a phenyl group and a naphthyl group. It is done.

More specifically, as the dihydroxy compound represented by the formula (5), 2, 2, 4, 4
-Tetramethyl-1,3-cyclobutanediol, 1,2-cyclopentanediol, 1,3-cyclopentanediol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 2- Examples include, but are not limited to, methyl-1,4-cyclohexanediol, tricyclodecanediols, and pentacyclodiols.
These may be used alone or in combination of two or more.

<Dihydroxy compound represented by formula (6)>
The dihydroxy compound represented by the formula (6) is an alicyclic dihydroxy compound having a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms, preferably 3 to 18 carbon atoms, in R ⁶ . Here, when R ⁶ has a substituent, examples of the substituent include a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms. When the alkyl group has a substituent, the substituent includes , Alkoxy groups such as methoxy group, ethoxy group and propoxy group, and aryl groups such as phenyl group and naphthyl group.
Since this dihydroxy compound has a ring structure, it is possible to increase the toughness of a molded product when the obtained polycarbonate resin is molded, and in particular, the toughness when molded into a film can be increased.

The cycloalkylene group for R ⁶ is not particularly limited as long as it is a hydrocarbon group having a ring structure, and may be a bridge structure having a bridgehead carbon atom. From the viewpoint that production of the dihydroxy compound is easy and the amount of impurities can be reduced, the dihydroxy compound represented by the formula (6) is a compound having a 5-membered ring structure or a 6-membered ring structure, that is, R ⁶ is A dihydroxy compound which is a substituted or unsubstituted cyclopentylene group or a substituted or unsubstituted cyclohexylene group is preferred. If it is such a dihydroxy compound, the heat resistance of the polycarbonate resin obtained can be made high by including a 5-membered ring structure or a 6-membered ring structure. The 6-membered ring structure may be fixed in a chair shape or a boat shape by a covalent bond. Among the dihydroxy compounds represented by the formula (6), it is preferable that R ⁶ is various isomers represented by the formula (9).

More specifically, as the dihydroxy compound represented by the formula (6), 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 3,8-bis (hydroxy) Methyl) tricyclo [5.2.1.0 ^2.6 ] decane, 3,9-bis (hydroxymethyl) tricyclo [5.2.1.0 ^2.6 ] decane, 4,8-bis (hydroxymethyl) Examples include tricyclo [5.2.1.0 ^2.6 ] decane, 4,9-bis (hydroxymethyl) tricyclo [5.2.1.0 ^2.6 ] decane, and the like, but are not limited thereto. It is not a thing.

These may be used alone or in combination of two or more. That is, although these dihydroxy compounds may be obtained as a mixture of isomers for production reasons, they can be used as they are as an isomer mixture. For example, 3,8-bis (hydroxymethyl) tricyclo [5.2.1.0 ^2.6 ] decane, 3,9-bis (hydroxymethyl) tricyclo [5.2.1.0 ^2.6 ] decane, 4,8-bis (hydroxymethyl) tricyclo [5.2.1.0 ^2.6 ] decane and a mixture of 4,9-bis (hydroxymethyl) tricyclo [5.2.1.0 ^2.6 ] decane Can be used.

  Of the specific examples of the dihydroxy compound represented by the formula (6), cyclohexanedimethanols are particularly preferable. From the viewpoint of easy availability and ease of handling, 1,4-cyclohexanedimethanol, 1 1,3-cyclohexanedimethanol and 1,2-cyclohexanedimethanol are preferred.

<Dihydroxy compound represented by Formula (7)>
The dihydroxy compound represented by the formula (7) is a compound having a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, preferably 2 to 5 carbon atoms, in R ⁷ . p is an integer of 2 to 100, preferably 6 to 50, more preferably 12 to 40.
Specific examples of the dihydroxy compound represented by the formula (7) include diethylene glycol, triethylene glycol, and polyethylene glycol (molecular weight: 150 to 4000), but are not limited thereto. The dihydroxy compound represented by the formula (7) is preferably polyethylene glycol having a molecular weight of 300 to 2000, and particularly preferably polyethylene glycol having a molecular number of 600 to 1500.
These may be used alone or in combination of two or more.

<Dihydroxy compound represented by formula (8)>
The dihydroxy compound represented by the formula (8) is a substituted or unsubstituted alkylene group having 2 to 20 carbon atoms, preferably 2 to 10 carbon atoms, for R ⁸ . When the alkylene group for R ⁸ has a substituent, examples of the substituent include an alkyl group having 1 to 5 carbon atoms.
Among the dihydroxy compounds represented by the above formula (8), specific examples of the dihydroxy compound in which R ⁸ is a substituted or unsubstituted alkylene group having 2 to 20 carbon atoms include ethylene glycol, propylene glycol, 1, Examples include 4-butanediol and 1,6-hexanediol, but are not limited thereto.

  Among these dihydroxy compounds, 1,3-propanediol, 1,6-propanediol are preferred from the viewpoint of availability, ease of handling, high reactivity during polymerization, and hue of the obtained polycarbonate resin. Hexanediol is preferred. From the viewpoint of heat resistance, spiroglycol having an acetal ring is preferable. These may be used alone or in combination of two or more depending on the required performance of the polycarbonate resin to be obtained.

  In the present invention, the polycarbonate resin is a structural unit derived from the dihydroxy compound represented by the formula (4), a structural unit derived from the dihydroxy compound represented by the formula (5), and the formula (6). Among the structural units derived from the dihydroxy compound represented, the structural unit derived from the dihydroxy compound represented by the formula (7), and the structural unit derived from the dihydroxy compound represented by the formula (8), the above formula ( It is preferable that the structural unit derived from the dihydroxy compound represented by 6) and / or the structural unit derived from the dihydroxy compound represented by the formula (7) is included. Since there is little decomposition | disassembly, it is more preferable that the structural unit derived from the dihydroxy compound represented by said Formula (6) is included.

[Other dihydroxy compounds]
In the present invention, in the polycarbonate resin, the structural unit derived from the dihydroxy compound represented by the above formulas (4) to (8) may be replaced with a structural unit derived from another dihydroxy compound as necessary.
Examples of other dihydroxy compounds include bisphenols, ethylene oxide (EO) additions of bisphenols, and fluorene compounds.

Examples of bisphenols include 2,2-bis (4-hydroxyphenyl) propane (= bisphenol A), 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, and 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) 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'- Dihydroxydiphenyl sulfone, bis (4-hydroxyphenyl) sulfide, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3′-dichlorodiphenyl ether, 4,4′-dihydroxy-2,5-diethoxydiphenyl ether Etc.
Examples of the ethylene oxide (EO) additions of bisphenols include those obtained by adding ethylene oxide (EO) to the aforementioned bisphenol compounds.

<Fluorene compound>
9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, 9,9-bis (4-hydroxy-3-ethylphenyl) fluorene, 9,9 -Bis (4-hydroxy-3-n-propylphenyl) fluorene, 9,9-bis (4-hydroxy-3-isopropylphenyl) fluorene, 9,9-bis (4-hydroxy-3-n-butylphenyl) Fluorene, 9,9-bis (4-hydroxy-3-sec-butylphenyl) fluorene, 9,9-bis (4-hydroxy-3-tert-propylphenyl) fluorene, 9,9-bis (4-hydroxy-) 3-cyclohexylphenyl) fluorene, 9,9-bis (4-hydroxy-3-phenylphenyl) fluorene, 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-hydro Shietokishi) -3-tert-butyl-6-methylphenyl) fluorene, 9,9-bis (4- (3-hydroxy-2,2-dimethyl) phenyl) fluorene, and the like.

  These may be used alone or in combination of two or more. However, since a dihydroxy compound having an aromatic ring in the structure other than that represented by the formula (1) may adversely affect the optical properties, the structural unit derived from such a dihydroxy compound is polycarbonate. It is preferably used in an amount of 50 mol% or less, more preferably 20 mol% or less, and further preferably 5 mol% or less, based on the total of structural units derived from the dihydroxy compound in the resin, particularly polycarbonate. The resin preferably does not contain a structural unit derived from a dihydroxy compound having an aromatic ring in the structure other than that represented by the formula (1).

[Content ratio of structural unit derived from dihydroxy compound]
In the present invention, the content ratio of the structural unit derived from the dihydroxy compound represented by the formula (1) contained in the polycarbonate resin is preferably 20% by weight or more with respect to the total of the structural units derived from the dihydroxy compound. More preferably, it is 25% by weight or more, more preferably 30% by weight or more, and usually 95% by weight or less, preferably 90% by weight or less. When the content ratio of the structural unit is too small, the heat resistance is small and the surface hardness may be inferior. Moreover, when there is too much content rate of this structural unit, the glass transition temperature of polycarbonate resin may become high too much, and shaping | molding may become difficult, or a water absorption rate may deteriorate.

The polycarbonate resin is represented by the dihydroxy compound represented by the formula (4), the dihydroxy compound represented by the formula (5), the dihydroxy compound represented by the formula (6), and the formula (7). In the case of containing a structural unit derived from one or more dihydroxy compounds selected from the group consisting of the dihydroxy compound represented by the formula (8) and the dihydroxy compound represented by the formula (8), 0.1 wt% or more and less than 20 wt%, preferably 0.1 wt% or more and 18 wt% or less, more preferably 0.2 wt% or more and 15 wt% or less with respect to the total of derived structural units. is there. When the structural unit derived from the dihydroxy compound represented by the above formulas (4) to (8) is contained in the polycarbonate resin in the above lower limit value or more, when the polycarbonate resin is melted and molded, foreign matters and bubbles due to heat Generation of the resin can be prevented, and coloring of the polycarbonate resin can be prevented. However, when the number of structural units is excessively large, light resistance tends to be lowered when formed into a molded product.

  All dihydroxy compounds used in the production of the polycarbonate resin of the present invention contain stabilizers such as reducing agents, antioxidants, oxygen scavengers, light stabilizers, antacids, pH stabilizers or heat stabilizers. May be. In particular, since the specific dihydroxy compound of the present invention is easily altered under acidic conditions, it is preferable to include a basic stabilizer.

  Examples of the basic stabilizer include hydroxides, carbonates, phosphates, phosphites, hypophosphites of group 1 or group 2 metals in the long-period periodic table (Nomenclature of Inorganic Chemistry IUPAC Recommendations 2005). Acid salts, borates and fatty acid salts, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylethylammonium hydroxide, trimethylbenzylammonium hydroxide, trimethylphenylammonium hydroxide, Triethylmethylammonium hydroxide, triethylbenzylammonium hydroxide, triethylphenylammonium Basic ammonium compounds such as nium hydroxide, tributylbenzylammonium hydroxide, tributylphenylammonium hydroxide, tetraphenylammonium hydroxide, benzyltriphenylammonium hydroxide, methyltriphenylammonium hydroxide and butyltriphenylammonium hydroxide, diethylamine , Dibutylamine, triethylamine, morpholine, N-methylmorpholine, pyrrolidine, piperidine, 3-amino-1-propanol, ethylenediamine, N-methyldiethanolamine, diethylethanolamine, 4-aminopyridine, 2-aminopyridine, N, N- Dimethyl-4-aminopyridine, 4-diethylaminopyridine, 2-hydroxypyridine, 2-methoxy Amine compounds such as pyridine, 4-methoxypyridine, 2-dimethylaminoimidazole, 2-methoxyimidazole, imidazole, 2-mercaptoimidazole, 2-methylimidazole and aminoquinoline, and di- (tert-butyl) amine and 2, Examples include hindered amine compounds such as 2,6,6-tetramethylpiperidine. Among these stabilizers, tetramethylammonium hydroxide, imidazole or hindered amine compounds are preferable from the viewpoint of stabilization effect.

The content of these basic stabilizers in all the dihydroxy compounds used in the present invention is not particularly limited, but the specific dihydroxy compounds used in the present invention are unstable in an acidic state. It is preferable to add a stabilizer so that the pH of the aqueous solution containing the specific dihydroxy compound is around 7.
If the amount of the stabilizer is too small, the effect of preventing the alteration of the specific dihydroxy compound may not be obtained. If the amount is too large, the specific dihydroxy compound may be modified. On the other hand, it is preferably 0.0001% by weight to 1% by weight, and more preferably 0.001% by weight to 0.1% by weight.

When these basic stabilizers are included in the dihydroxy compound used in the present invention and used as a raw material for the production of polycarbonate resin, the basic stabilizer itself becomes a polymerization catalyst, and it becomes difficult to control the polymerization rate or quality. The hue will be deteriorated.
Therefore, for specific dihydroxy compounds or other dihydroxy compounds containing a basic stabilizer, the basic stabilizer should be removed by ion exchange resin or distillation before using it as a raw material for producing polycarbonate resin. Is preferred.
In addition, since the specific dihydroxy compound used in the present invention is gradually oxidized by oxygen, in order to prevent decomposition due to oxygen during storage or handling during manufacture, water should not be mixed and deoxygenated. It is preferable to use an agent or to put it in a nitrogen atmosphere.

(Carbonated diester)
The polycarbonate resin of the present invention can be obtained by polycondensation by a transesterification reaction using a dihydroxy compound containing the above-mentioned specific dihydroxy compound and a carbonic acid diester as raw materials. As a carbonic acid diester used, what is represented by following formula (10) is mentioned normally. These carbonic acid diesters may be used alone or in combination of two or more.

In the above formula (10), A ¹ and A ² are each a substituted or unsubstituted aliphatic hydrocarbon group having 1 to 18 carbon atoms or a substituted or unsubstituted aromatic hydrocarbon 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.

Examples of the carbonic acid diester represented by the formula (10) include substituted diphenyl carbonates such as diphenyl carbonate (DPC) and ditolyl carbonate, dimethyl carbonate, diethyl carbonate, and di-t-butyl carbonate. Among them, preferred is diphenyl carbonate or substituted diphenyl carbonate, and particularly preferred is diphenyl carbonate.
In addition, carbonic acid diester may contain impurities such as chloride ions, and the impurities may hinder the polymerization reaction or deteriorate the hue of the resulting polycarbonate resin. It is preferable to use a product purified by the above.

<Transesterification reaction catalyst>
The polycarbonate resin of the present invention is produced by transesterification of the above-described dihydroxy compound and carbonic acid diester. More specifically, it can be obtained by transesterification and removing by-product monohydroxy compounds and the like out of the system.
In the transesterification reaction, polycondensation is performed in the presence of a transesterification reaction catalyst. The transesterification reaction catalyst (hereinafter simply referred to as a catalyst or a polymerization catalyst) that can be used in the production of the polycarbonate resin of the present invention may be used. ) Can greatly affect the reaction rate or the quality of the polycarbonate resin obtained by polycondensation.

The catalyst used is not limited as long as it can satisfy the transparency, hue, heat resistance, weather resistance, and mechanical strength of the produced polycarbonate resin. For example, metal compounds of Group 1 or Group 2 (hereinafter simply referred to as “Group 1” or “Group 2”) in the long-period periodic table, as well as basic boron compounds, basic phosphorus compounds, and basic ammonium compounds And basic compounds such as amine compounds. Preferably, Group 1 metal compounds and / or Group 2 metal compounds are used.

  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, potassium carbonate, and carbonic acid. Lithium, cesium carbonate, sodium acetate, potassium acetate, lithium acetate, cesium acetate, sodium stearate, potassium stearate, lithium stearate, cesium stearate, sodium borohydride, potassium borohydride, lithium borohydride, hydrogenated Cesium boron, sodium phenide boron, potassium phenide boron, lithium phenide boron, cesium phenide boron, sodium benzoate, potassium benzoate, lithium benzoate, cesium benzoate, hydrogen phosphate 2 Thorium, 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, lithium, Examples include cesium alcoholate, phenolate, disodium salt of bisphenol A, dipotassium salt, dilithium salt, and dicesium salt. Among these, lithium compounds are preferable from the viewpoint of polymerization activity and the hue of the obtained polycarbonate resin.

  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, carbonic acid. Examples thereof include magnesium, strontium carbonate, calcium acetate, barium acetate, magnesium acetate, strontium acetate, calcium stearate, barium stearate, magnesium stearate, and strontium stearate. Among these, a magnesium compound, a calcium compound or a barium compound is preferable, and a magnesium compound and / or a calcium compound is more preferable, and a calcium compound is most preferable from the viewpoint of polymerization activity and the hue of the obtained polycarbonate resin.

In addition, a basic compound such as a basic boron compound, a basic phosphorus compound, a basic ammonium compound, and an amine compound can be used in combination with the above-mentioned Group 1 metal compound and / or Group 2 metal compound. However, it is particularly preferred to use only Group 1 metal compounds and / or Group 2 metal compounds.
Examples of the basic phosphorus compound include triethylphosphine, tri-n-propylphosphine, triisopropylphosphine, tri-n-butylphosphine, triphenylphosphine, tributylphosphine, and quaternary phosphonium salts.

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

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

The amount of the polymerization catalyst used is preferably 0.1 μmol to 300 μmol, more preferably 0.5 μmol to 100 μmol, and particularly preferably 1 μmol to 50 μmol per 1 mol of all dihydroxy compounds used in the polymerization.
In particular, when a compound containing at least one metal selected from the group consisting of Group 2 and lithium in the long-period periodic table is used, particularly when a magnesium compound and / or a calcium compound is used, the amount of metal is The amount is preferably 0.1 μmol or more, more preferably 0.3 μmol or more, particularly preferably 0.5 μmol or more per 1 mol of the dihydroxy compound. Moreover, as an upper limit, 20 micromol or less is preferable, More preferably, it is 10 micromol or less, More preferably, it is 5 micromol or less, Most preferably, it is 3 micromol or less.

  If the amount of the catalyst is too small, the polymerization rate is slowed down. Therefore, in order to obtain a polycarbonate resin having a desired molecular weight, the polymerization temperature must be increased accordingly. Therefore, there is a high possibility that the hue of the obtained polycarbonate resin is deteriorated, and the unreacted raw material volatilizes during the polymerization, and the molar ratio of the dihydroxy compound and the carbonic acid diester collapses, and the desired molecular weight may not be reached. There is sex. On the other hand, if the amount of the polymerization catalyst used is too large, undesirable side reactions may occur, and the resulting polycarbonate resin may be deteriorated in hue or colored during molding.

  However, if a large amount of sodium, potassium or cesium is included in the polycarbonate resin, the hue may be adversely affected. And these metals may mix not only from the catalyst to be used but from a raw material or a reaction apparatus. Regardless of the source, the total amount of the compounds of these metals in the polycarbonate resin is preferably 1 ppm by weight or less, more preferably 0.5 ppm by weight or less as the amount of metal.

<Production method of polycarbonate resin>
The polycarbonate resin of the present invention can be obtained by polycondensing a dihydroxy compound containing a specific dihydroxy compound and a carbonic acid diester by a transesterification reaction.
The raw material dihydroxy compound and carbonic acid diester are preferably mixed uniformly before the transesterification reaction. The mixing temperature is usually 80 ° C. or higher, preferably 90 ° C. or higher, and the upper limit is usually 250 ° C. or lower, preferably 200 ° C. or lower, more preferably 150 ° C. or lower. Among these, 100 ° C. or higher and 120 ° 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. May adversely affect the hue and thermal stability of the polycarbonate resin obtained.

  The operation of mixing the dihydroxy compound containing the specific dihydroxy compound which is the raw material of the polycarbonate resin of the present invention and the carbonic acid diester is an oxygen concentration of 10 vol% or less, further 0.0001 vol% to 10 vol%, and more preferably 0.0001 vol% to 5 vol%. It is particularly preferable to carry out in an atmosphere of 0.0001 vol% to 1 vol% from the viewpoint of preventing hue deterioration.

In order to obtain the polycarbonate resin of the present invention, it is preferable to use a carbonic acid diester in a molar ratio of 0.94 to 1.04, more preferably 0 to all dihydroxy compounds including the specific dihydroxy compound used in the reaction. The molar ratio is .98 to 1.02, more preferably 1.00 to 1.01. When this molar ratio becomes small, the terminal phenyl group of the produced polycarbonate resin is reduced, and appearance defects during molding are likely to occur.

  Moreover, when this molar ratio becomes large, the rate of transesterification may decrease, or it may be difficult to produce a polycarbonate resin having a desired molecular weight. The decrease in the transesterification reaction rate may increase the heat history during the polymerization reaction, and may deteriorate the hue and weather resistance of the resulting polycarbonate resin. Furthermore, when the molar ratio of the carbonic acid diester is increased with respect to all the dihydroxy compounds including the specific dihydroxy compound, the amount of the residual carbonic diester and the compound (3) in the obtained polycarbonate resin are increased. There may be a problem of appearance defects.

In the present invention, the method of polycondensing a dihydroxy compound and a carbonic acid diester is usually carried out in multiple stages using a plurality of reactors in the presence of the above-mentioned catalyst. The form of reaction
Any method of a batch method, a continuous method, or a combination of a batch method and a continuous method may be used, but a continuous method in which a polycarbonate resin can be obtained with less heat history and excellent in productivity is preferable.

  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. Appropriate selection of the internal temperature and pressure in the reaction system is important from the viewpoint of controlling the polymerization rate and the quality of the polycarbonate resin obtained. 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 may not 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 not impairing the hue of the final polycarbonate resin, it is important to select the kind and amount of the catalyst described above. The polycarbonate resin of the present invention is preferably produced by polymerizing in a multistage using a plurality of reactors using a catalyst, but the reason for carrying out the polymerization in a plurality of reactors is that at the initial stage of the polymerization reaction, Since there are many monomers contained in the reaction solution, it is important to suppress the volatilization of the monomers while maintaining the necessary polymerization rate. In the late stage of the polymerization reaction, in order to shift the equilibrium to the polymerization side, This is because it is important to sufficiently distill off the produced monohydroxy compound. 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 production of the polycarbonate resin of the present invention may be at least two. However, from the viewpoint of production efficiency, three or more, preferably 3 to 5, particularly preferably. There are four. In the present invention, if there are two or more reactors, a plurality of reaction stages having different conditions may be provided in the reactor, or the temperature and pressure may be continuously changed.

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 supplied to the polymerization tank. A catalyst supply line is installed in the middle of the raw material line before being fed, and preferably supplied as an aqueous solution.
If the temperature of the polymerization reaction is too low, the productivity is lowered and the thermal history of the product is increased. If it is too high, not only the monomer is volatilized but also decomposition and coloring of the polycarbonate resin may be promoted. Specifically, in the first stage reaction, the internal temperature of the polymerization reactor is 130 to 210 ° C, preferably 150 to 205 ° C, and more preferably 170 to 200 ° C.
The reaction system pressure is 1-110 kPa, preferably 5-70 kPa, more preferably 7-30 kPa (absolute pressure), and the reaction time is 0.1-10 hours, preferably 0.5-3. It is carried out while distilling off the monohydroxy compound generated over time.

  In the second and subsequent stages, the pressure in the reaction system is gradually reduced from the pressure in the first stage, and subsequently generated monohydroxy compounds are removed from the reaction system. In particular, in order to remove the compound (3), the second and subsequent stages are set to 15 KPa or less, and finally the reaction system pressure (absolute pressure) is set to 600 Pa or less, and the maximum internal temperature is 190 to 240 ° C., preferably Is 1950 to 235 ° C., usually for 0.1 to 5 hours, preferably 1 to 4 hours, particularly preferably 0.5 to 3 hours.

  In order to obtain a polycarbonate resin having a predetermined molecular weight, if the polymerization temperature is high and the polymerization time is too long, the color tone tends to deteriorate. In particular, in order to obtain a polycarbonate resin that suppresses coloring and thermal deterioration of the polycarbonate resin and has a good hue and a low content of the compound (3), the maximum internal temperature in all reaction steps is less than 240 ° C., particularly 210 to 235. It is preferable that it is ° C.

In addition, the reaction time when the internal temperature in all reaction stages is 210 ° C. or higher and 240 ° C. or lower is less than 3 hours, so that the polycarbonate resin can be prevented from being colored or thermally deteriorated to obtain a polycarbonate resin having a good hue. It is preferable because the amount of compound (3) generated can be suppressed, and is particularly preferably within 2.5 hours.
In addition, in order to suppress a decrease in the polymerization rate in the latter half of the polymerization reaction and to minimize deterioration due to thermal history, it is excellent in plug flow property and interfacial renewability at the final stage of polymerization, and excellent in removing compound (3). It is preferable to use a horizontal reactor.

The monohydroxy compound produced as a by-product is preferably reused as a raw material for diphenyl carbonate, bisphenol A, etc. after purification as necessary from the viewpoint of effective utilization of resources.
The polycarbonate resin of the present invention is usually cooled and solidified after polycondensation as described above, and pelletized with a rotary cutter or the like. The method of pelletization is not limited, but it is extracted from the final polymerization reactor in a molten state, cooled and solidified in the form of a strand, and pelletized, or from the final polymerization reactor in a molten state, uniaxial or biaxial extrusion. The resin is supplied to the machine, melt-extruded, cooled and solidified into pellets, or extracted from the final polymerization reactor in a molten state, cooled and solidified in the form of strands, once pelletized, and then uniaxially again Alternatively, a method may be mentioned in which resin is supplied to a biaxial extruder, melt-extruded, cooled and solidified, and pelletized.

When an extruder is used, in the extruder, the residual monomer is devolatilized under reduced pressure, and generally known thermal stabilizers, neutralizers, UV absorbers, light stabilizers, mold release agents, colorants, antistatic agents Further, a lubricant, a lubricant, a plasticizer, a compatibilizer, a flame retardant and the like can be added and kneaded.
The melt kneading temperature in the extruder depends on the glass transition temperature and molecular weight of the polycarbonate resin, but is usually 200 to 300 ° C, preferably 210 to 280 ° C, and more preferably 220 to 2.
70 ° C. When the melt kneading temperature is lower than 200 ° C., the melt viscosity of the polycarbonate resin is high, the load on the extruder is increased, and the productivity is lowered. When the temperature is higher than 300 ° C., the polycarbonate resin is severely deteriorated by heat, resulting in a decrease in mechanical strength due to a decrease in molecular weight, coloring, generation of gas, and generation of compound (3).

  The molecular weight of the polycarbonate resin of the present invention thus obtained can be expressed by a reduced viscosity, and the reduced viscosity is usually 0.30 dL / g or more, preferably 0.35 dL / g or more, The upper limit is more preferably 1.20 dL / g or less and 1.00 dL / g or less, and still more preferably 0.80 dL / g or less. If the reduced viscosity of the polycarbonate resin is too low, the mechanical strength of the molded product may be small. If it is too large, the fluidity at the time of molding tends to decrease, and the productivity and moldability tend to decrease. The reduced viscosity of the polycarbonate resin was measured using a Ubbelohde viscosity tube at a temperature of 20.0 ° C. ± 0.1 ° C., using methylene chloride as a solvent and adjusting the polycarbonate resin concentration to 0.6 g / dL precisely. The Details of the method for measuring the reduced viscosity are described in the Examples section.

[Polycarbonate resin additive]
<Phosphorus compounds>
The polycarbonate resin of the present invention preferably contains a phosphorus compound added to deactivate the polymerization catalyst and further suppress coloring of the polycarbonate resin at high temperatures. The phosphorus compound is at least one selected from the group consisting of phosphoric acid, phosphorous acid, hypophosphorous acid, polyphosphoric acid, phosphonic acid, phosphonic acid ester, acidic phosphoric acid ester, and aliphatic cyclic phosphite ester. It is preferable to use seeds. Among them, phosphorous acid, phosphonic acid, and phosphonic acid ester are more excellent in catalyst deactivation and coloring suppression effects, and phosphonic acid ester is particularly preferable.

  Examples of phosphonic acid include phosphonic acid (phosphorous acid), methylphosphonic acid, ethylphosphonic acid, vinylphosphonic acid, decylphosphonic acid, phenylphosphonic acid, benzylphosphonic acid, aminomethylphosphonic acid, methylenediphosphonic acid, 1-hydroxyethane- Examples include 1,1-diphosphonic acid, 4-methoxyphenylphosphonic acid, nitrilotris (methylenephosphonic acid), and propylphosphonic anhydride.

  Examples of phosphonic acid esters include dimethyl phosphonate, diethyl phosphonate, bis (2-ethylhexyl) phosphonate, dilauryl phosphonate, dioleyl phosphonate, diphenyl phosphonate, dibenzyl phosphonate, dimethyl methylphosphonate, diphenyl methylphosphonate, and ethylphosphonic acid. Diethyl, diethyl benzylphosphonate, dimethyl phenylphosphonate, diethyl phenylphosphonate, dipropyl phenylphosphonate, diethyl (methoxymethyl) phosphonate, diethyl vinylphosphonate, diethyl hydroxymethylphosphonate, dimethyl (2-hydroxyethyl) phosphonate, p-methylbenzylphosphonate diethyl, diethylphosphonoacetic acid, diethylphosphonoacetic acid ethyl, diethylphosphonoacetic acid tert-butyl, (Robenzyl) diethyl phosphonate, diethyl cyanophosphonate, diethyl cyanomethylphosphonate, diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, diethylphosphonoacetaldehyde diethyl acetal, diethyl (methylthiomethyl) phosphonate Can be mentioned.

  Acid phosphate esters include dimethyl phosphate, diethyl phosphate, divinyl phosphate, dipropyl phosphate, dibutyl phosphate, bis (butoxyethyl) phosphate, bis (2-ethylhexyl) phosphate, diisotridecyl phosphate, phosphate Examples include phosphoric acid diesters such as dioleyl, distearyl phosphate, diphenyl phosphate, and dibenzyl phosphate, or mixtures of diesters and monoesters, diethyl chlorophosphate, and zinc stearyl phosphate.

An aliphatic cyclic phosphite is defined as a phosphite compound that does not contain an aromatic group in a cyclic structure containing a phosphorus atom. For example, bis (decyl) pentaerythritol diphosphite, bis (tridecyl) pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, bis (2,6-tert-butylphenyl) pentaerythritol diphosphite, bis (nonyl) Phenyl) pentaerythritol diphosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, Examples thereof include a polymer type compound composed of a dihydroxy compound such as hydrogenated bisphenol A / pentaerythritol phosphite polymer and pentaerythritol diphosphite.
These may be used alone or in a combination of two or more in any combination and ratio.

  If the content of the phosphorus compound is too small, the effect of catalyst deactivation and coloring suppression is insufficient, and if it is too much, the polycarbonate resin may be colored, or coloring under wet heat conditions may occur. The content of the phosphorus compound is not particularly limited, but the content of phosphorus atom in the polycarbonate resin is preferably 0.02 ppm by weight or more and 0.7 ppm by weight or less, more preferably 0.05 ppm by weight. As mentioned above, 0.65 weight ppm or less is preferable, and 0.07 weight ppm or more and 0.60 weight ppm or less are particularly preferable.

  Since the phosphorus compound is usually phosphorus trichloride as a starting material, unreacted substances and chlorine-containing components derived from detached hydrochloric acid may remain, but the chlorine atom contained in the phosphorus compound may remain. The amount is preferably 5% by weight or less. When the residual amount of chlorine atoms is large, there is a concern that the metal part of the production facility to which the phosphorus compound is added is corroded, the thermal stability of the polycarbonate resin is lowered, and the molecular weight reduction due to coloring or thermal deterioration is promoted.

  As described above, the phosphorus compound is preferably added and kneaded to the polycarbonate resin using an extruder. In particular, it is most effective to supply the polycarbonate resin to the extruder in a molten state after polymerization and immediately add the phosphorus compound to the resin. Further, when the catalyst is deactivated and devolatilization is performed by a vacuum vent with an extruder, low molecular components can be efficiently devolatilized.

<Hindered phenol compounds>
The polycarbonate resin of the present invention can be expected to further improve the color tone of the polycarbonate resin by containing a hindered phenol compound in addition to the phosphorus compound.
Specific examples of hindered phenol compounds include 2,6-di-tert-butylphenol, 2,4-di-tert-butylphenol, 2-tert-butyl-4-methoxyphenol, and 2-tert-butyl- 4,6-dimethylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,5-di-tert-butylhydroquinone, n- Octadecyl-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate, 2-t
ert-butyl-6- (3′-tert-butyl-5′-methyl-2′-hydroxybenzyl) -4-methylphenyl acrylate, 2,2′-methylene-bis- (4-methyl-6-tert- Butylphenol), 2,2'-methylene-bis- (6-cyclohexyl-4-methylphenol), 2,2'-ethylidene-bis- (2,4-di-tert-butylphenol), tetrakis- [methylene-3 -(3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate] -methane, n-octadecyl-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, 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], pentaerythritol-tetrakis [3- (3,5- Di-tert-butyl-4-hydroxyphenyl) propionate] and the like.

These may be used alone or in a combination of two or more in any combination and ratio.
The content of the hindered phenol compound in the polycarbonate resin of the present invention is preferably 0.001 to 1 part by weight, and 0.005 to 0.5 part by weight when the polycarbonate resin is 100 parts by weight. Is more preferable, and 0.01 part by weight to 0.3 part by weight is further preferable.
In addition, it is preferable that a hindered phenol compound and the following antioxidants are added and kneaded to the polycarbonate resin using an extruder, similarly to the phosphorus compound.

<Antioxidant>
For the purpose of antioxidation, a generally known antioxidant can be added to the polycarbonate resin of the present invention.
Specific examples of the antioxidant 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, 2,2-methylenebis (4 6-di-tert-butylphenyl) octyl phosphite, tris (2,4-di-tert-butylphenyl) phosphite, tributyl phosphate, triethyl phosphate, trimethyl phosphate, trimethyl phosphate Phenyl phosphate, diphenyl monoorthoxenyl phosphate, dibutyl phosphate, dioctyl phosphate, diisopropyl phosphate, 4,4′-biphenylenediphosphinic acid tetrakis (2,4-di-tert-butylphenyl), pentaerythritol tetrakis (3-mercaptopropio Nate), pentaerythritol tetrakis (3-lauryl thiopropionate), glycerol-3-stearyl thiopropionate, N, N-hexamethylene bis (3,5-di-tert-butyl-4-hydroxy-hydrocinna Mido), 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-2- [β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl} -2,4,8,10-tetraoxaspiro (5,5) Undecane and the like can be mentioned.

These antioxidants may be used alone or in combination of two or more.
The blending amount of these antioxidants is preferably 0.0001 parts by weight to 0.1 parts by weight, more preferably 0.0005 parts by weight to 0.08 parts by weight, when the polycarbonate resin is 100 parts by weight. More preferred is 0.001 to 0.05 parts by weight.

[Bluing agent]
The polycarbonate resin of the present invention may contain a bluing agent.
The bluing agent used in the present invention is appropriately selected from the bluing agents usually used in polycarbonate resin compositions, and may be used by adjusting the blending amount. Good.
The content of the bluing agent in the polycarbonate resin of the present invention is preferably 0.1 × 10 ^{−4 to} 10.0 × when the polycarbonate resin (A) is usually 100 parts by weight.
10 ⁻⁴ parts by weight, more preferably 0.3 × 10 ^{−4 to} 5.0 × 10 ⁻⁴ parts by weight, and particularly preferably 0.3 × 10 ^{−4 to} 2.0 × 10 ⁻⁴ parts by weight.

If the content of the bluing agent is 0.1 × 10 ⁻⁴ parts by weight or more, the YI value before and after the accelerated light resistance test of the polycarbonate resin plate of the present invention is set to a specific range, or the b * value is 3 Since it becomes easy to make it below, it is preferable. On the other hand, if the content of the bluing agent is 10.0 × 10 ⁻⁴ parts by weight or less, the brightness does not decrease, and therefore, it is preferable to make the L * value 90 or more.

As the bluing agent used in the present invention, those used in the polycarbonate resin composition can be suitably used. From the viewpoint of the absorption wavelength, the maximum absorption wavelength is preferably 520 to 600 nm, more preferably 540. A dye of ˜580 nm is used.
Specific examples of preferable anthraquinone-based bluing agents for use in the present invention include, for example, the general name Solvent Violet 13 [CA. No. (Color Index No) 60725; Trademarks “Malexex Violet B” manufactured by LANXESS, “Diaresin Blue G” manufactured by Mitsubishi Chemical Corporation, “Sumiplast Violet B” manufactured by Sumitomo Chemical Co., Ltd.], Solvent Violet 14 , Generic name Solvent Violet 31 [CA. No. 68210; Trade names “Diaresin Violet D” manufactured by Mitsubishi Chemical Corporation], Solvent Violet 33 [CA. No. 60725; trade name “Diaresin Blue J” manufactured by Mitsubishi Chemical Corporation], Solvent Violet 36 [CA. No. 68210; brand name “Macrolex Violet 3R” manufactured by LANXESS, Solvent Blue 45 [CA. No. 61110; trade name “Tetrazole Blue RLS” manufactured by Sand Corp.], generic name Solvent Blue 94 [CA. No. 61500; trade name “Diaresin Blue N” manufactured by Mitsubishi Chemical Corporation, generic name Solvent Blue 97 [“Macrolex Blue RR” manufactured by LANXESS, Inc.], generic name Solvent Blue 45, generic name Solvent Blue 87, and generic name Disperse Violet 28. It is done.

  Among these, the general name Solvent Violet 13 (“Macrolex Violet B” manufactured by LANXESS), the general name Solvent Violet 36 [“Macrolex Violet 3R” manufactured by LANXESS, Inc.], the general name Solvent Blue97 [“Macrolex Blue RR” manufactured by LANXESS, Inc. The general name Solvent Violet 13 [“Macrolex Violet B” manufactured by LANXESS, Inc.] is more preferable. In particular, a dye having a structure represented by the following formula (7), that is, the general name Solvent Violet 13 [CA. No. (Color Index No.) 60725; trade names “Malexex Violet B” manufactured by LANXESS, “Diaresin Blue G” manufactured by Mitsubishi Chemical Corporation, and “Sumiplast Violet B” manufactured by Sumitomo Chemical Co., Ltd.] are preferable.

In the present invention, as the bluing agent, a pigment having a maximum absorption wavelength of preferably 520 to 600 nm, more preferably 540 to 580 nm can be used, and the above dye and pigment can be used in combination.
In the present invention, one type of bluing agent may be used alone, or two or more types may be used in combination, but the amount of bluing agent used is preferably small, and the type of bluing agent used is also Less is preferable.

  In the present invention, the blending time and blending method of the above bluing agent to be blended with the polycarbonate resin (A) are not particularly limited. As the blending time, for example, a method of adding together with the raw material before the polymerization reaction and performing the polymerization as it is, a method of blending with a pipe or an extruder at the end of the polymerization reaction, a method of blending when the polycarbonate resin and other compounding agents are melt kneaded However, it is preferable to mix by kneading after the completion of the polymerization reaction because the dispersion of the bluing agent is improved and the b * value and the L * value are easily adjusted. In particular, a method of introducing into a extruder in a molten state after completion of the polycondensation reaction, blending a bluing agent and melt-kneading is preferable because the influence of heat history and oxygen mixing can be minimized.

[Polycarbonate resin composition]
The polycarbonate resin of the present invention includes, for example, aromatic polycarbonate resin, aromatic polyester, aliphatic polyester, polyamide, polystyrene, polyolefin, acrylic, amorphous polyolefin, ABS, AS, and other synthetic resins, polylactic acid, polybutylene succinate, etc. It can also be used as a polymer alloy by kneading with one or more of biodegradable resins and rubbers.

Furthermore, the polycarbonate resin of the present invention includes a nucleating agent, a flame retardant, a flame retardant aid, an inorganic filler, an impact modifier, a hydrolysis inhibitor, a foaming agent, which are usually used in the resin composition together with these other resin components. A dyeing pigment or the like can be added to obtain a polycarbonate resin composition.
[Molding method of polycarbonate resin]
The polycarbonate resin of the present invention and the resin composition containing the polycarbonate resin can be formed into a molded product by a generally known method such as an injection molding method, an extrusion molding method, a compression molding method, etc., and hue, transparency, weather resistance, A molded product having excellent heat resistance and mechanical strength can be obtained.

  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.

[Evaluation method]
In the following, the physical properties and characteristics of the polycarbonate resin were evaluated by the following methods.

(1) Measurement of reduced viscosity A polycarbonate resin sample was dissolved in methylene chloride to prepare a polycarbonate resin 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. From the solvent passage time t ₀ and the solution passage time t, the relative viscosity η _The relative viscosity η _sp was determined from the relative viscosity η _rel by the following formula (ii).

η _rel = t / t ₀ (i)
η _sp = (η−η ₀ ) / η ₀ = η _rel −1 (ii)
The reduced viscosity η _sp / c was determined by dividing the specific viscosity η _sp by the concentration c (g / dL). The higher this value, the higher the molecular weight.

About 30 mg of polycarbonate resin pellets are weighed and dissolved in about 0.7 mL of deuterated chloroform to give a solution, and a known amount of 1,1,2,2-tetrabromoethane is added as an internal standard, and this is an NMR tube with an inner diameter of 5 mm. The ¹ H NMR spectrum was measured at room temperature using JNM-AL400 (resonance frequency 400 MHz) manufactured by JEOL Ltd., and determined from the signal intensity ratio based on the internal standard, the terminal phenyl group, and the terminal double bond.

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.

Phenyl group terminal ratio (%) = [terminal group formula (α) existence number / total terminal existence number] × 100
Device: JNM-AL400 (resonance frequency 400 MHz) manufactured by JEOL Ltd.
・ Measurement temperature: normal temperature ・ Relaxation time: 6 seconds ・ Number of integrations: 512 times

(2) Molding of polycarbonate resin and measurement of color tone The polycarbonate resin pellets were vacuum-dried at 90 ° C for 5 hours or more. The dried polycarbonate resin pellets are supplied to an injection molding machine (J75EII type manufactured by Nippon Steel Co., Ltd.), and the final cylinder temperature is 250 ° C. and the molding cycle is 23 seconds. Plate-type injection molded pieces (width 60 mm × length) The operation of molding (60 mm × thickness 3 mm) was repeated. After the 10th shot, the residence time of the resin in the cylinder is 4 minutes. The yellow index (YI) value in the transmitted light in the thickness direction of the injection molded pieces obtained in the 10th to 60th shots was measured as described below, and the average value was calculated.

  The color tone of the obtained molded body (plate) was measured according to ASTM D1925 using a spectrocolorimeter CM-5 manufactured by Konica Minolta. The plate obtained by the above-described injection molding was placed in a measurement chamber, and the YI value of transmitted light was measured. The smaller the YI value, the better the quality without yellowness. Since the color tone of the plate is unstable immediately after molding, the color tone measurement is performed after one day or more after molding. The plates used for comparison are stored under the same conditions, and the values measured simultaneously are used.

(3) Measurement of color tone of polycarbonate resin pellet The hue of the polycarbonate resin pellet was measured with reflected light using a spectrocolorimeter CM-5 manufactured by Konica Minolta Co., Ltd. according to ASTM D1925. As measurement conditions, a measurement diameter of 30 mm and SCE were selected. Petri dish calibration glass CM-A212 was fitted into the measurement part, and zero calibration was performed by placing a zero calibration box CM-A124 thereon, followed by white calibration using a built-in white calibration plate. Measurement was performed using a white calibration plate CM-A210. L * was 99.40 ± 0.05, a * was 0.03 ± 0.01, b * was −0.43 ± 0.01, and YI was −. It was confirmed to be 0.58 ± 0.01. The YI of the pellet was measured by packing the pellet in a cylindrical glass container having an inner diameter of 30 mm and a height of 50 mm to a depth of about 40 mm. The operation of taking out the pellet from the glass container and then performing the measurement again was repeated twice, and the average value of the measurement values of three times in total was used.

(4) Number of defective appearances The appearance of 50 plates injection-molded in the above (2) was visually observed to count the number of silver and bubbles generated.

(5) Measurement of the content of the monohydroxy compound and the compound represented by the following formula (3) About 1 g of a polycarbonate resin sample is precisely weighed and dissolved in 5 mL of methylene chloride to obtain a solution, so that the total amount becomes 25 mL. Acetone was added to the solution for reprecipitation. Subsequently, the treatment liquid was filtered through a 0.2 μm disk filter and quantified by liquid chromatography.

[Raw materials]
The abbreviations and manufacturers of the compounds used in the following Examples and Comparative Examples are as follows.
<Dihydroxy compound>
・ ISB: Isosorbide (Rocket Fleure)
CHDM: 1,4-cyclohexanedimethanol [manufactured by SK Chemical Co.]
TCDDM: Tricyclodecane dimethanol [manufactured by OXEA]
<Carbonated diester>
・ DPC: Diphenyl carbonate [Mitsubishi Chemical Corporation]
<Hindered phenol compounds>
Irganox 1010: pentaerythritol-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] [manufactured by BASF]
<Phosphorus compounds>
・ Phosphorous acid [manufactured by Taihei Chemical Industry Co., Ltd.] (molecular weight 82.0)
AS2112: Tris (2,4-di-tert-butylphenyl) phosphite [manufactured by ADEKA Corporation] (molecular weight 646.9) Adeka Stub PEP-36: Bis (2,6-t-butyl-4-methyl Phenyl) pentaerythrityl diphosphite) (manufactured by Adeka)
Those having a chlorine atom content of 5% by weight or less were used.

[ Reference Example 1]
Polycarbonate resin was polymerized using a continuous polymerization facility comprising three vertical stirring reactors, one horizontal stirring reactor, and a twin screw extruder. ISB, CHDM, and DPC were melted in tanks, respectively, and the molar ratio ISB / CHDM / DPC = 0.700 / 0.300 / 1.01
0 was continuously fed to the first vertical stirred reactor. At the same time, an aqueous solution of calcium acetate monohydrate as a catalyst was supplied to the first vertical stirring reactor so as to be 1.5 μmol with respect to 1 mol of all dihydroxy compounds. The average residence time in the first vertical stirring reactor is 90 minutes,
The liquid level was kept constant while controlling the opening degree of the valve provided in the transfer pipe at the bottom of the reactor. The reaction liquid discharged from the bottom of the reactor is successively successively supplied to the second vertical stirring reactor, the third vertical stirring reactor, and the fourth horizontal stirring reactor [2-axis glasses blade manufactured by Hitachi Plant Technologies, Ltd.]. Continuously supplied. The first vertical stirring reactor and the second vertical stirring reactor were equipped with a reflux condenser, and the distillation of unreacted dihydroxy compound and DPC was suppressed by adjusting the reflux ratio.

  The reaction temperature, internal pressure and residence time of each reactor are as follows: first vertical stirring reactor: 190 ° C., 25 kPa, 90 minutes, second vertical stirring reactor: 195 ° C., 10 kPa, 45 minutes, third vertical type Stirring reactor: 210 ° C., 3 kPa, 45 minutes, fourth horizontal stirring reactor: 230 ° C., 0.5 kPa, 90 minutes. The operation was carried out while finely adjusting the internal pressure of the fourth horizontal stirring reactor so that the reduced viscosity of the obtained polycarbonate resin was 0.61 dL / g to 0.64 dL / g.

  The polycarbonate resin was continuously extracted from the fourth horizontal stirring reactor, and then the resin was supplied in a molten state to a twin-screw extruder [TEX30α manufactured by Nippon Steel Works, Ltd.]. The extruder had three vacuum vents, and the remaining low molecular components in the resin were removed by devolatilization. Before the second vent, water was added in an amount of 2000 ppm by weight with respect to the resin, and water injection devolatilization was performed. The extruder (total 10 barrels) was set to a cylinder temperature of 220 ° C. and a screw rotation speed of 230 rpm. The resin temperature at the exit of the extruder was 262 ° C.

  The polycarbonate resin that passed through the extruder was continuously filtered through a filter in a molten state, then discharged from the die into a strand, cooled with water, solidified, and pelletized with a rotary cutter.

[Example 2]
The same as Reference Example 1 except that master pellets coated with phosphorous acid were supplied from the front of the first vent port and 0.65 ppm (0.2 ppm as the amount of phosphorus atoms) of phosphorous acid was added to the polycarbonate resin. Went to.
By adding phosphorous acid, there was an improvement in color tone (reduction in YI), and residual phenol could also be reduced.

[Example 3]
The temperature of the fourth horizontal stirring reactor was set to 225 ° C., master pellets coated with phosphorous acid were supplied from the front of the first vent port, and phosphorous acid was 0.65 ppm relative to the polycarbonate resin.
(0.2 ppm as the amount of phosphorus atoms) was added, and the same procedure as in Reference Example 1 was carried out except that the amount of water injected in the extruder was 4000 ppm by weight.
By increasing the amount of water injected, the residual phenol could be reduced, and the occurrence of poor appearance could be reduced.

[ Reference Example 4]
The same procedure as in Reference Example 1 was conducted except that the molar ratio ISB / CHDM / DPC = 0.700 / 0.300 / 1.012 was continuously supplied to the first vertical stirring reactor.
Although the compound represented by the formula (3) was slightly increased, the proportion of the terminal phenyl group was high.

[Example 5]
A master pellet coated with phosphorous acid from before the first vent port was continuously supplied to the first vertical stirring reactor at a molar ratio of ISB / CHDM / DPC = 0.500 / 0.500 / 1.004. The same procedure as in Reference Example 1 was conducted except that 1.50 ppm of phosphorous acid (0.6 ppm as the amount of phosphorus atoms) was added to the polycarbonate resin.
The effect was obtained even if the ratio of ISB / CHDM / DPC was changed.

[Example 6]
A master pellet coated with phosphorous acid from the front side of the first vent port was continuously supplied to the first vertical stirring reactor at a molar ratio of ISB / CHDM / DPC = 0.500 / 0.500 / 1.006. The same procedure as in Reference Example 1 was conducted except that 0.65 ppm of phosphorous acid (0.2 ppm as the amount of phosphorus atoms) was added to the polycarbonate resin.
Due to the increase in terminal phenyl, it was possible to further suppress the appearance defect as compared with Example 5.

[Example 7]
A master pellet coated with phosphorous acid from the front of the first vent port was continuously supplied to the first vertical stirring reactor at a molar ratio of ISB / CHDM / DPC = 0.600 / 0.400 / 1.008. The same procedure as in Reference Example 1 was conducted except that 0.65 ppm of phosphorous acid (0.2 ppm as the amount of phosphorus atoms) was added to the polycarbonate resin.
The effect was obtained even if the ratio of ISB / CHDM / DPC was changed.

[Example 8]
A master pellet coated with phosphorous acid from the front side of the first vent port was continuously supplied to the first vertical stirring reactor at a molar ratio of ISB / TCDDM / DPC = 0.700 / 0.300 / 1.004. The same procedure as in Reference Example 1 was conducted except that 0.65 ppm of phosphorous acid (0.2 ppm as the amount of phosphorus atoms) was added to the polycarbonate resin.
The same effect was obtained even when the dihydroxy compound copolymerized with ISB was changed to TCDDM.

[Comparative Example 1]
The molar ratio ISB / CHDM / DPC = 0.700 / 0.300 / 1.000, and an aqueous solution of calcium acetate monohydrate as a catalyst was 1.25 μm with respect to 1 mol of all dihydroxy compounds.
The reaction temperature, the internal pressure, and the residence time of each reactor are respectively the first vertical stirring reactor: 188 ° C., 24.2 kPa, 90 Minute, second
Vertical stirring reactor: 194 ° C., 19.9 kPa, 60 minutes, third vertical stirring reactor: 214 ° C.
9.9 kPa, 60 minutes, 4th horizontal stirring reactor: 225 ° C., 0.1 kPa, 120 minutes,
The extruder has a cylinder temperature of 240 ° C for the first four barrels, 195 ° C for the last six barrels,
The same procedure as in Reference Example 1 was performed except that the screw rotation speed was set to 225 rpm.

Compared to Reference Example 1, the degree of vacuum in the second and third tanks was low, and DPC was difficult to distill out. As a result, the polymer could be obtained with a large amount of terminal phenyl. However, since the residence time was as long as 120 minutes in the fourth polymerization tank, the color tone deteriorated and the amount of the compound represented by the formula (3) increased. As a result, appearance defects were likely to occur even in molded products, and the color tone was poor.

[Comparative Example 2]
The molar ratio of ISB / CHDM / DPC is 0.500 / 0.500 / 1.000, and an aqueous solution of calcium acetate monohydrate as a catalyst is 1.25 μm with respect to 1 mol of all dihydroxy compounds.
The reaction temperature, internal pressure, and residence time of each reactor are respectively the first vertical stirring reactor: 190 ° C., 25 kPa, 90 minutes, and the second vertical stirring type. Stirring reactor: 196 ° C., 17.7 kPa, 60 minutes, third vertical stirring reactor: 215 ° C., 6.9 kPa,
60 minutes, 4th horizontal stirred reactor: 225 ° C, 0.9 kPa, 120 minutes, extruder set cylinder temperature to 240 ° C for the first 4 barrels, 180 ° C for the 6 barrels in the second half, screw speed to 225rpm The same procedure as in Reference Example 1 was performed except that.

  Since the terminal OH was less than 75%, appearance defects in the molded product were likely to occur, and the residence time in the fourth polymerization tank was as long as 120 minutes, so that a large amount of the compound represented by formula (3) remained. However, since the set temperature in the extruder was lowered to 180 ° C., the color tone was good.

[Comparative Example 3]
Continuously fed to the first vertical stirring reactor at a molar ratio ISB / CHDM / DPC = 0.500 / 0.500 / 1.050, the temperature of the fourth horizontal stirring reactor was 235 ° C., 120 minutes, First
Performed in the same manner as Reference Example 1 except that master pellets coated with phosphorous acid were supplied from the front of the vent and phosphoric acid was added to the polycarbonate resin in an amount of 0.65 ppm (0.2 ppm as the amount of phosphorus atoms). It was.

Since the DPC molar ratio was set to be high, polymerization could not be performed unless the residence time of the fourth polymerization tank was increased. The obtained polycarbonate resin pellets also had a poor color tone, and the residual amount of the compound represented by formula (3) was large, so that appearance defects in molded articles were likely to occur, and the color tone was also poor.

[Comparative Example 4]
The molar ratio ISB / CHDM / DPC = 0.500 / 0.500 / 1.000 was continuously supplied to the first vertical stirring reactor, and the temperature of the fourth horizontal stirring reactor was 220 ° C. for 190 minutes. Except that, the same procedure as in Reference Example 1 was performed.
Since the DPC molar ratio was set to a small value, the generation of the compound represented by the formula (3) was suppressed, but the color tone deteriorated due to the long residence time, and the number of phenyl ends was small, so that the molding was difficult. Appearance defects are likely to occur.

[Comparative Example 5]
Polycarbonate resin was polymerized using a batch polymerization equipment consisting of a vertical stirring reactor and a twin screw extruder. ISB, TCDDM, and DPC were respectively melted in tanks, and ISB was supplied to the first vertical stirring reactor at a molar ratio ISB / TCDDM / DPC = 0.700 / 0.300 / 1.058. At the same time, an aqueous solution of cesium carbonate as a catalyst was supplied to the first vertical stirring reactor so that cesium carbonate was 1.25 μmol with respect to 1 mol of all dihydroxy compounds. As the first step of the reaction, the heating bath temperature is heated to 150 ° C., while stirring, the raw materials are dissolved for 15 minutes, the pressure is reduced from normal pressure to 13.3 kPa over 40 minutes, and the heating bath temperature is changed to While increasing the temperature to 190 ° C. over 40 minutes, the generated phenol was extracted out of the reaction vessel.

After maintaining the entire reaction vessel at 190 ° C. for 15 minutes, as a second step, the heating bath temperature was increased to 240 ° C. over 30 minutes. Ten minutes after entering the temperature rise, the pressure in the reaction vessel was reduced to 0.200 kPa or less in 30 minutes, and the generated phenol was distilled off. 120 minutes later, after reaching a predetermined stirring torque, the reaction was stopped, the polycarbonate resin was continuously extracted from the reactor, and then the twin-screw extruder [TEX30α manufactured by Nippon Steel Works, Ltd.] with the resin in a molten state. Supplied to. Master pellets coated with butyl p-toluenesulfonate are supplied from the front of the first vent port, 6 ppm of butyl p-toluenesulfonate is added to the polycarbonate resin, Irganox 1010 1000 ppm, PEP-36 100 ppm
AS2112 500 ppm was added. The extruder had three vacuum vents, and the remaining low molecular components in the resin were removed by devolatilization. The extruder (total 10 barrels) was set to a cylinder temperature of 220 ° C. and a screw rotation speed of 230 rpm. The resin temperature at the exit of the extruder was 262 ° C.

The polycarbonate resin that passed through the extruder was continuously filtered through a filter in a molten state, then discharged from the die into a strand, cooled with water, solidified, and pelletized with a rotary cutter.
Since the polymerization was performed at a high temperature of 240 ° C. for 120 minutes in the final stage, the color tone was worse than that of Example 8 using the same TCDDM. Furthermore, since it is a vertical polymerization tank, a large amount of phenol and the compound represented by the formula (3) remain, and the color tone (YI) of the molded product deteriorates and appearance defects tend to occur.

According to the present invention, it is excellent in hue, transparency, heat resistance, weather resistance, and mechanical strength, and it is an injection molding field such as electrical / electronic parts, automotive parts, glass replacement applications, films, sheet fields, bottles, containers. Fields, lens applications such as camera lenses, viewfinder lenses, CCD and CMOS lenses, retardation films used for liquid crystal and organic EL displays, films such as diffusion sheets and polarizing films, sheets, optical disks, optical materials , Polycarbonate resin applicable to a wide range of fields such as binders that immobilize optical components, dyes and charge transfer agents, etc., and further, molding of products as described above due to low residual low molecular components In doing so, dirt and odor of the molding machine are suppressed, and it becomes possible to improve productivity and workability.

Claims (2)

A method for producing a polycarbonate resin containing a structural unit derived from a dihydroxy compound represented by the following formula (1):
Polycarbonate resin is fed to the extruder in a molten state after polymerization, and phosphoric acid, phosphorous acid, hypophosphorous acid, polyphosphoric acid, phosphonic acid, phosphonic acid ester, acidic phosphoric acid ester, and aliphatic cyclic sublimation are added to the polycarbonate resin. At least one phosphorus compound selected from the group consisting of phosphate esters is added in an amount of 0.7 ppm by weight or less as the amount of phosphorus atoms, kneaded, and devolatilized by a vacuum vent,
In the polycarbonate resin production reaction step, the reaction time at 210 ° C. or higher and 230 ° C. or lower is 2.5 hours or less,
The ratio (A / B) of the number of terminal groups (A) represented by the following structural formula (2) to the total number of terminals (B) is 75% or more and less than 98%,
The content of the compound represented by the following formula (3) is 10 to 700 ppm by weight,
A method for producing a polycarbonate resin, wherein the content of a monohydroxy compound derived from a carbonic acid diester is 700 ppm by weight or less.

Polycarbonate resin
The dihydroxy compound represented by the following formula (4), the dihydroxy compound represented by (5), the dihydroxy compound represented by the following formula (6), the dihydroxy compound represented by the following formula (7) and the following formula (8) 2. The method for producing a polycarbonate resin according to claim 1 , comprising a structural unit derived from one or more dihydroxy compounds selected from the group consisting of dihydroxy compounds represented by formula ( 1 ):

HO—R ⁵ —OH (5)
(In the above formula (5), R5 represents a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms.)
HO—CH ₂ —R ⁶ —CH ₂ —OH (6)
(In the above formula (6), R6 represents a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms.)
H- (O-R < ⁷ >) p-OH (7)
(In said formula (7), R7 shows a C2-C10 substituted or unsubstituted alkylene group, and p is an integer of 2-100.)
HO—R ⁸ —OH (8)
(In the above formula (8), R8 represents a substituted or unsubstituted alkylene group having 2 to 20 carbon atoms.)