JP2016188376A - Polycarbonate resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polycarbonate resin having excellent light resistance, transparency, color tone, heat resistance, thermal stability, and mechanical strength.SOLUTION: A polycarbonate resin is obtained by polycondensation of a dihydroxy compound including a dihydroxy compound having in a portion of its structure, a moiety represented by the following general formula (1) and a carbonic diester represented by the following general formula (2) in the presence of a catalyst. The catalyst is a compound including at least one metal selected from the group consisting of lithium and the group 2 in the long-period periodic table. An amount of the compound including the metal is, as an amount of the metal, 20 μmol or less per 1 mol of the dihydroxy compound, and further an aromatic monohydroxy compound is contained in an amount of 700 weight ppm or less.SELECTED DRAWING: None

Description

  The present invention relates to a polycarbonate resin excellent in light resistance, transparency, hue, heat resistance, thermal stability, and mechanical strength.

Polycarbonate resins are generally composed of bisphenols as monomer components, taking advantage of transparency, heat resistance, mechanical strength, etc., and electrical / electronic parts, automotive parts, medical parts, building materials, films, sheets, bottles It is widely used as so-called engineering plastics in the fields of optical recording media and lenses.
However, conventional polycarbonate resins are limited in use outdoors or in the vicinity of lighting devices, because their hue, transparency, and mechanical strength deteriorate when used in places exposed to ultraviolet rays or visible light for a long time. .

In order to solve such problems, a method of adding a benzophenone ultraviolet absorber, a benzotriazole ultraviolet absorber, or a benzoxazine ultraviolet absorber to a polycarbonate resin is widely known (for example, Non-Patent Document 1).
However, when such an ultraviolet absorber is added, although the hue after UV irradiation is improved, the hue, heat resistance, and transparency of the resin are deteriorated in the first place. There were problems such as contamination of the mold.

  Since the bisphenol compound used in the conventional polycarbonate resin has a benzene ring structure, it absorbs a large amount of ultraviolet rays. This causes a deterioration in the light resistance of the polycarbonate resin. Therefore, an aliphatic dihydroxy compound having no benzene ring structure in the molecular skeleton. If a cyclic dihydroxy compound monomer unit having an ether bond in the molecule, such as a compound, an alicyclic dihydroxy compound, or isosorbide, is used, it is expected that light resistance is improved in principle. Among them, a polycarbonate resin using isosorbide obtained from biomass resources as a monomer is excellent in heat resistance and mechanical strength, so that many studies have been made in recent years (for example, Patent Documents 1 to 6). .

  However, cyclic dihydroxy compounds having an ether bond in the molecule, such as the above aliphatic dihydroxy compounds, alicyclic dihydroxy compounds, and isosorbide, do not have phenolic hydroxyl groups, and thus are widely known as methods for producing polycarbonate resins using bisphenol A as a raw material. It is difficult to polymerize by the conventional interface method, and it is usually produced by a method called a transesterification method or a melting method. In this method, the dihydroxy compound and a carbonic acid diester such as diphenyl carbonate are transesterified at a high temperature of 200 ° C. or higher in the presence of a basic catalyst, and the polymerization proceeds by removing by-product phenol and the like out of the system, A polycarbonate resin is obtained. However, a polycarbonate resin obtained using a monomer having no phenolic hydroxyl group as described above is inferior in thermal stability to a polycarbonate resin obtained using a monomer having a phenolic hydroxyl group such as bisphenol A. In addition, there is a problem that coloring occurs during polymerization or molding that is exposed to high temperatures, and as a result, ultraviolet light and visible light are absorbed, resulting in deterioration of light resistance. In particular, when a monomer having an ether bond in the molecule, such as isosorbide, is used, the hue is remarkably deteriorated and a great improvement has been demanded.

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

Polycarbonate resin handbook (issued by Seiichi Honma, published by Nikkan Kogyo Shimbun, August 28, 1992)

  An object of the present invention is to solve the above-mentioned conventional problems and provide a polycarbonate resin excellent in light resistance, transparency, hue, heat resistance, thermal stability, and mechanical strength.

  As a result of intensive studies to solve the above problems, the present inventor has found that a dihydroxy compound containing a dihydroxy compound having a part of the structure represented by the following general formula (1) and the following general formula (2) A polycarbonate resin obtained by polycondensation in the presence of a catalyst that is a compound containing lithium and at least one metal selected from the group consisting of two groups in the long-period periodic table. The amount of the compound containing the metal is 20 μmol or less per 1 mol of the dihydroxy compound as the metal amount, and the polycarbonate resin containing 700 ppm by weight or less of the aromatic monohydroxy compound has only excellent light resistance. The present invention has been found by having excellent transparency, hue, heat resistance, thermal stability, and mechanical strength.

(However, the case where the site represented by the general formula (1) is —CH ₂ —O—H is excluded.)

(In General Formula (2), A ¹ and A ² are each independently a substituted or unsubstituted aliphatic group having 1 to 18 carbon atoms, or a substituted or unsubstituted aromatic group.)
That is, the gist of the present invention resides in the following [1] to [18].
[1] A dihydroxy compound containing a dihydroxy compound having a site represented by the following general formula (1) in a part of the structure and a carbonic acid diester represented by the following general formula (2) are combined with each other in the presence of a catalyst. A polycarbonate resin obtained by condensation, wherein the catalyst is a compound containing at least one metal selected from the group consisting of lithium and group 2 in the long-period periodic table, and the amount of the compound containing the metal is the amount of metal A polycarbonate resin characterized in that it is 20 μmol or less per 1 mol of the dihydroxy compound and contains 700 ppm by weight or less of an aromatic monohydroxy compound.

(However, the case where the site represented by the general formula (1) is —CH ₂ —O—H is excluded.)

(In General Formula (2), A ¹ and A ² are each independently a substituted or unsubstituted aliphatic group having 1 to 18 carbon atoms, or a substituted or unsubstituted aromatic group.)
[2] The compound according to [1], wherein the compound containing at least one metal selected from the group consisting of lithium and the group 2 of the long-period periodic table is a magnesium compound and / or a calcium compound. Polycarbonate resin.
[3] The polycarbonate resin according to [1] or [2], wherein the total amount of sodium, potassium, and cesium in the polycarbonate resin is 1 ppm by weight or less as a metal amount.
[4] The polycarbonate resin according to any one of [1] to [3], wherein a total amount of lithium, sodium, potassium, and cesium in the polycarbonate resin is 1 ppm by weight or less as a metal amount.
[5] The polycarbonate resin contains 6 carbonic acid diesters represented by the general formula (2).
The polycarbonate resin according to any one of [1] to [4], which is contained in an amount of 0 ppm by weight or less.
[6] A dihydroxy compound having a site represented by the general formula (1) in a part of the structure,
The polycarbonate resin according to any one of [1] to [5], which is a compound represented by the following general formula (3).

[7] The polycarbonate resin is selected from the group consisting of a structural unit derived from a dihydroxy compound having a portion represented by the general formula (1) in a part of the structure, an aliphatic dihydroxy compound, and an alicyclic dihydroxy compound. The polycarbonate resin according to any one of [1] to [6], comprising a structural unit derived from at least one kind of compound.
[8] The concentration of the end group represented by the following general formula (4) in the polycarbonate resin is 2
The polycarbonate resin according to any one of [1] to [7], which is 0 μeq / g or more and 160 μeq / g or less.

[9] When the mole number of H bonded to the aromatic ring in the polycarbonate resin is (A) and the mole number of H bonded to other than the aromatic ring is (B), A / (A + B) ≦ 0.05 The polycarbonate resin according to any one of [1] to [8], wherein
[10] Any one of [1] to [9], wherein the polycarbonate resin has a light transmittance at a wavelength of 350 nm of a molded body (thickness 3 mm) molded from the resin of 60% or more. The polycarbonate resin as described.
[11] Wavelength 320 of a molded body (thickness 3 mm) molded from the polycarbonate resin
The polycarbonate resin according to any one of [1] to [10], wherein the light transmittance at nm is 30% or more.
[12] 63 ° C. of a molded body (thickness 3 mm) molded from the polycarbonate resin,
Yellow in accordance with ASTM D1925-70 measured with transmitted light after irradiation for 100 hours at an irradiance of 1.5 kW / m ² with a wavelength of 300 nm to 400 nm using a metal halide lamp in an environment with a relative humidity of 50%. The polycarbonate resin according to any one of [1] to [11], wherein an index (YI) value is 12 or less.
[13] The polycarbonate resin according to any one of [1] to [12], wherein an initial yellow index value of a molded body (thickness 3 mm) molded from the polycarbonate resin is 7 or less.
[14] An initial yellow index value of a molded body (thickness 3 mm) molded from the polycarbonate resin and an irradiance of 1 to 300 nm to 400 nm using a metal halide lamp in an environment of 63 ° C. and 50% relative humidity. The absolute value of the difference from the yellow index (YI) value based on ASTM D 1925-70 measured with transmitted light after irradiation treatment at 0.5 kW / m ² for 100 hours is 6 or less [1 ] To [13].
[15] The polycarbonate resin according to any one of [1] to [14], wherein an L * value of a molded body (thickness 3 mm) molded from the polycarbonate resin is 96.3 or more.
[16] A polycarbonate resin molded product obtained by molding the polycarbonate resin according to any one of [1] to [15].
[17] The polycarbonate resin molded product according to [16], wherein the polycarbonate resin molded product is molded by an injection molding method.

  According to the present invention, not only has excellent light resistance, but also excellent transparency, hue, heat resistance, thermal stability, and mechanical strength, and the field of injection molding of electrical / electronic parts, automotive parts, etc. , Film, sheet field, bottle, container field, camera lens, finder lens, lens application such as CCD and CMOS lens, retardation film used for liquid crystal and plasma display, diffusion sheet, polarizing film, etc. Polycarbonate resin applicable to a wide range of fields such as film, sheet, optical disc, optical material, optical component, binder application for immobilizing dyes and charge transfer agents, etc. can be provided, especially including ultraviolet rays such as outdoors and lighting components It becomes possible to provide a polycarbonate resin suitable for an application exposed to light.

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 The polycarbonate resin of the present invention comprises a dihydroxy compound containing a dihydroxy compound having a site represented by the following general formula (1) in a part of the structure, and a carbonic acid diester represented by the following general formula (2). , A polycarbonate resin obtained by polycondensation in the presence of a catalyst that is a compound of at least one metal selected from the group consisting of lithium and two groups in the long-period periodic table, wherein the amount of the compound of the metal is a metal The amount of the polycarbonate resin is 20 μmol or less per mol of the dihydroxy compound and 700 ppm by weight or less of the aromatic monohydroxy compound.

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

(In General Formula (2), A ¹ and A ² are each independently a substituted or unsubstituted aliphatic group having 1 to 18 carbon atoms, or a substituted or unsubstituted aromatic group.)
The polycarbonate resin of the present invention is obtained by polycondensing a dihydroxy compound containing the above specific dihydroxy compound and a carbonic acid diester in the presence of a specific amount of a specific catalyst, and specifying the content of the aromatic monohydroxy compound. By making it below the amount, a polycarbonate resin excellent in light resistance, transparency, hue, heat resistance, thermal stability, and mechanical strength is obtained. In particular, with regard to light resistance, absorption in the visible light region has conventionally been watched, but the present inventor has not been able to absorb visible light and coloring is not recognized by the human eye. When exposed to illumination, etc., it was found that there are resins that are colored and resins that are not colored, and unexpectedly, the present invention has been achieved based on the knowledge that the light transmittance of a specific wavelength can be solved above a certain level. It is a thing.

That is, the polycarbonate resin of the present invention preferably has a light transmittance at a wavelength of 350 nm of a molded product (thickness 3 mm) molded from the polycarbonate resin of 60% or more, more preferably 65% or more, particularly preferably. 70% or more. When the light transmittance at the wavelength is less than 60%, the absorption increases and the light resistance may deteriorate.
Furthermore, in the polycarbonate resin of the present invention, the light transmittance at a wavelength of 320 nm of a molded product (thickness 3 mm) molded from the polycarbonate resin is preferably 30% or more, more preferably 40% or more, and 50%. The above is particularly preferable. When the light transmittance at the wavelength is less than 30%, the light resistance tends to deteriorate.

The polycarbonate resin of the present invention is obtained by subjecting a molded body (thickness: 3 mm) molded from the polycarbonate resin to an irradiance of 1.30 nm to 400 nm using a metal halide lamp in an environment of 63 ° C. and a relative humidity of 50%. It is preferable that the yellow index (YI) value based on ASTM D 1925-70 measured by transmitted light after irradiation treatment at 5 kW / m ² for 100 hours is 12 or less, more preferably 10 or less, particularly preferably 8 It is as follows.
In addition, although the irradiation process using the metal halide lamp in the present invention will be described later, a specific device is used and a specific filter or the like is used to mainly emit light with a wavelength of 300 nm to 400 nm (light with a wavelength outside this wavelength range is as much as possible). Removed), which means irradiating the sample for 100 hours with an irradiance of 1.5 kW / m ² .

In addition, the polycarbonate resin of the present invention has a yellow index value (measured with transmitted light) of a molded body (thickness 3 mm) molded from the polycarbonate resin without performing irradiation treatment with the metal halide lamp as described above. The initial yellow index value (referred to as the initial YI value) is usually 10 or less, preferably 7 or less, particularly preferably 5 or less, and the absolute value of the difference between the yellow index values before and after the metal halide lamp irradiation is 6 or less. Is preferable, more preferably 4 or less, and particularly preferably 3 or less.
When the initial yellow index (YI) value exceeds 10, light resistance tends to deteriorate.

Furthermore, the polycarbonate resin of the present invention usually has an L * value of 96.3 or more as defined by the International Commission on Illumination (CIE) in which a molded article (thickness 3 mm) molded from the polycarbonate resin is measured with transmitted light. , Preferably 96.6 or more, and preferably 96.8 or more. L * value is 9
If it falls below 6.3, the light resistance tends to deteriorate.
The polycarbonate resin as described above produces the effects of the present invention. Such a polycarbonate resin, for example, appropriately selects the type and amount of the catalyst, appropriately selects the temperature and time during polymerization, Of compounds having ultraviolet absorption ability, such as reducing residual phenol and residual diphenyl carbonate, reducing the amount of substances having absorption in the ultraviolet region as raw material monomers, and substances having absorption in the ultraviolet region contained as impurities in the raw materials. It can be manufactured by reducing the amount used. In particular, the type and amount of the catalyst, the temperature and time during the polymerization are important.
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 includes a dihydroxy compound containing a dihydroxy compound having a site represented by the following general formula (1) in a part of the structure (hereinafter sometimes referred to as “the dihydroxy compound of the present invention”) and carbonic acid. It can be obtained by polycondensation by a transesterification reaction using a diester as a raw material. That is, the polycarbonate resin of the present invention includes at least a structural unit derived from a dihydroxy compound having a site represented by the following general formula (1).

(However, the case where the site represented by the general formula (1) is a part of —CH ₂ —O—H is excluded.) That is, the dihydroxy compound of the present invention has two hydroxyl groups and the following general formula. The thing containing at least the structural unit of Formula (1) is said.
The dihydroxy compound of the present invention is not particularly limited as long as it has a site represented by the above general formula (1) in a part of its structure. Specifically, diethylene glycol, triethylene glycol, Oxyalkylene glycols such as tetraethylene glycol, 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-methylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-isopropylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-isobutylphenyl) fluorene, 9,9-bis ( 4- (2-hydroxyethoxy) -3-tert-butylphenyl) fluorene, 9,9-bis (4- (2 Hydroxyethoxy) -3-cyclohexylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-phenylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3, 5-Dimethylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-tert-butyl-6-methylphenyl) fluorene 9,9-bis (4- (3-hydroxy-2,2 -Dimethylpropoxy) phenyl) fluorene and the like, a compound having an aromatic group in the side chain and an ether group bonded to the aromatic group in the main chain, represented by the dihydroxy compound represented by the following general formula (3) Examples include anhydrous sugar alcohols and compounds having a cyclic ether structure such as spiroglycol represented by the following general formula (5). From the viewpoints of ease, handling, reactivity during polymerization, and hue of the obtained polycarbonate resin, diethylene glycol and triethylene glycol are preferable, and from the viewpoint of heat resistance, they are represented by dihydroxy compounds represented by the following general formula (3). An anhydrous sugar alcohol, a compound having a cyclic ether structure represented by the following general formula (5) is preferred.

  These may be used alone or in combination of two or more depending on the required performance of the polycarbonate resin to be obtained.

Examples of the dihydroxy compound represented by the general formula (4) include isosorbide, isomannide and isoidet which are related to stereoisomers, and these may be used alone or in combination of two or more. It may be used.
Of these dihydroxy compounds, it is preferable to use a dihydroxy compound having no aromatic ring structure from the viewpoint of the light resistance of the polycarbonate resin, and among them, it is abundant as a plant-derived resource and is produced from various easily available starches. Isosorbide obtained by dehydrating and condensing sorbitol is most preferable from the viewpoints of availability and production, light resistance, optical properties, moldability, heat resistance, and carbon neutral.

  The polycarbonate resin of the present invention may contain a structural unit derived from a dihydroxy compound other than the above-mentioned dihydroxy compound of the present invention (hereinafter may be referred to as “other dihydroxy compound”). , Ethylene glycol, 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 1,5-heptanediol, 1,6- Aliphatic dihydroxy compounds such as hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, tricyclodecane dimethanol, pentacyclopentadecane dimethanol, 2,6- Decalin dimethanol, 1,5-decalin Alicyclic dihydroxy compounds such as methanol, 2,3-decalin dimethanol, 2,3-norbornane dimethanol, 2,5-norbornane dimethanol, 1,3-adamantane dimethanol, 2,2-bis (4- Hydroxyphenyl) propane [= bisphenol A], 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5-diethylphenyl) propane, 2, 2-bis (4-hydroxy- (3,5-diphenyl) phenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4-hydroxyphenyl) pentane 2,4′-dihydroxy-diphenylmethane, bis (4-hydroxyphenyl) methane, bis (4-hydroxy- -Nitrophenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 3,3-bis (4-hydroxyphenyl) pentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, bis (4-hydroxy) Phenyl) sulfone, 2,4′-dihydroxydiphenylsulfone, bis (4-hydroxyphenyl) sulfide, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3′-dichlorodiphenyl ether, 9,9-bis Aromatics such as (4- (2-hydroxyethoxy-2-methyl) phenyl) fluorene, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-2-methylphenyl) fluorene Bisphenols are mentioned.

  Among these, from the viewpoint of the light resistance of the polycarbonate resin, a dihydroxy compound having no aromatic ring structure in the molecular structure, that is, an aliphatic dihydroxy compound and / or an alicyclic dihydroxy compound is preferable. 1,3-propanediol, 1,4-butanediol, and 1,6-hexanediol are preferable, and as the alicyclic dihydroxy compound, 1,4-cyclohexanedimethanol and tricyclodecanedimethanol are particularly preferable.

  By using these other dihydroxy compounds, it is possible to obtain effects such as improvement in flexibility of polycarbonate resin, improvement in heat resistance, improvement in moldability, but structural units derived from other dihydroxy compounds. When the content ratio is too large, mechanical properties and heat resistance may be lowered. Therefore, the ratio of the structural unit derived from the dihydroxy compound of the present invention to the structural unit derived from all dihydroxy compounds is 20 mol. % Or more, preferably 30 mol% or more, and particularly preferably 50 mol% or more.

The dihydroxy compound of the present invention may contain a stabilizer such as a reducing agent, antioxidant, oxygen scavenger, light stabilizer, antacid, pH stabilizer, heat stabilizer, etc. Since the dihydroxy compound is easily altered, it is preferable to include a basic stabilizer. Basic stabilizers include Group 1 or Group 2 metal hydroxides, carbonates, phosphates, phosphites, hypophosphites in the Long Periodic Periodic Table (Nomenclature of Inorganic Chemistry IUPAC Recommendations 2005). Salts, borates, fatty acid salts, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylethylammonium hydroxide, trimethylbenzylammonium hydroxide, trimethylphenylammonium hydroxide, Triethylmethylammonium hydroxide, triethylbenzylammonium hydroxide, triethylphenylammonium hydroxide, tributylbenzylammonium hydroxide, tributylphenylan Basic ammonium compounds such as nium hydroxide, tetraphenylammonium hydroxide, benzyltriphenylammonium hydroxide, methyltriphenylammonium hydroxide, butyltriphenylammonium hydroxide, 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 And amine compounds such as aminoquinoline. Of these, Na or K phosphates and phosphites are preferred, and hydrogen phosphate 2Na and hydrogen phosphite 2Na are particularly preferred, because of their effects and ease of distillation removal described below.

  The content of these basic stabilizers in the dihydroxy compound of the present invention is not particularly limited, but if it is too small, there is a possibility that the effect of preventing alteration of the dihydroxy compound of the present invention may not be obtained, and if it is too large, the present invention. Therefore, it is usually 0.0001% by weight to 1% by weight, preferably 0.001% by weight to 0.1% by weight, based on the dihydroxy compound of the present invention.

  Further, when the dihydroxy compound of the present invention containing these basic stabilizers is used as a raw material for the production of polycarbonate resin, the basic stabilizer itself becomes a polymerization catalyst, which makes it difficult to control the polymerization rate and quality, as well as the initial stage. It is preferable to remove the basic stabilizer by ion exchange resin, distillation or the like before using it as a raw material for producing polycarbonate resin in order to cause deterioration of hue and consequently deteriorate light resistance of the molded product.

  When the dihydroxy compound of the present invention has a cyclic ether structure such as isosorbide, it is likely to be gradually oxidized by oxygen. It is important to use an oxygen agent or the like or handle it under a nitrogen atmosphere. When isosorbide is oxidized, decomposition products such as formic acid may be generated. For example, when isosorbide containing these decomposition products is used as a polycarbonate resin production raw material, the resulting polycarbonate resin may be colored, and not only the physical properties may be significantly degraded, but also the polymerization reaction may be affected. In some cases, a high molecular weight polymer cannot be obtained.

  In order to obtain the dihydroxy compound of the present invention which does not contain the above oxidative decomposition product, and in order to remove the above basic stabilizer, it is preferable to carry out distillation purification. The distillation in this case may be simple distillation or continuous distillation, and is not particularly limited. As distillation conditions, it is preferable to carry out distillation under reduced pressure in an inert gas atmosphere such as argon or nitrogen. In order to suppress thermal denaturation, it is 250 ° C. or lower, preferably 200 ° C. or lower, particularly 180 °. It is preferable to carry out under the conditions of ℃ or less.

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

(Carbonated diester)
The polycarbonate resin of the present invention can be obtained by polycondensation by a transesterification reaction using the above-mentioned dihydroxy compound containing the dihydroxy compound of the present invention and a carbonic acid diester as raw materials.
As a carbonic acid diester used, what is normally represented by following General formula (2) is mentioned. These carbonic acid diesters may be used alone or in combination of two or more.

(In General Formula (2), A ¹ and A ² are each independently a substituted or unsubstituted aliphatic group having 1 to 18 carbon atoms, or a substituted or unsubstituted aromatic group.) Examples of the carbonic acid diester represented by the general formula (2) include substituted diphenyl carbonates such as diphenyl carbonate and ditolyl carbonate, dimethyl carbonate, diethyl carbonate, and di-t-butyl carbonate. Diphenyl carbonate and substituted diphenyl carbonate are preferable, and diphenyl carbonate is particularly preferable. Carbonic acid diesters may contain impurities such as chloride ions, which may hinder the polymerization reaction or worsen the hue of the resulting polycarbonate resin. It is preferable to use what was done.

<Transesterification reaction catalyst>
The polycarbonate resin of the present invention is produced by transesterifying the dihydroxy compound containing the dihydroxy compound of the present invention and the carbonic acid diester represented by the above general formula (2) as described above. More specifically, it can be obtained by transesterification and removing by-product monohydroxy compounds and the like out of the system. In this case, polycondensation is usually carried out by transesterification in the presence of a transesterification catalyst.

The transesterification reaction catalyst (hereinafter sometimes 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 can particularly affect the light transmittance at a wavelength of 350 nm and the yellow index value.
The catalyst used is not limited as long as it can satisfy the light resistance among the light resistance, transparency, hue, heat resistance, thermal stability, and mechanical strength of the produced polycarbonate resin. , Metal compounds, basic boron compounds, basic phosphorus compounds, basic ammonium compounds, amines of Group 1 or Group 2 (hereinafter simply referred to as “Group 1” or “Group 2”) in the periodic table And basic compounds such as compounds. Preferably, Group 1 metal compounds and / or Group 2 metal compounds are used.

It is possible to use a basic compound such as a basic boron compound, a basic phosphorus compound, a basic ammonium compound, and an amine compound in combination with the Group 1 metal compound and / or the Group 2 metal compound. It is particularly preferred to use only Group 1 metal compounds and / or Group 2 metal compounds.
In addition, the group 1 metal compound and / or the group 2 metal compound are usually used in the form of a hydroxide or a salt such as a carbonate, a carboxylate, or a phenol salt. From the viewpoint of easiness, a hydroxide, carbonate, and acetate are preferable, and acetate is preferable from the viewpoint of hue and polymerization activity.

  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, lithium carbonate, Cesium carbonate, sodium acetate, potassium acetate, lithium acetate, cesium acetate, sodium stearate, potassium stearate, lithium stearate, cesium stearate, sodium borohydride, potassium borohydride, lithium borohydride, cesium borohydride , Sodium borohydride, potassium borohydride, lithium phenide boron, cesium phenide boron, sodium benzoate, potassium benzoate, lithium benzoate, cesium benzoate, 2 sodium hydrogen phosphate 2 potassium potassium 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, 2 potassium salt, 2 lithium salt, 2 cesium salt, etc. Among them, lithium compounds are preferable.

  Examples of the Group 2 metal compound include calcium hydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide, calcium hydrogen carbonate, barium hydrogen carbonate, magnesium hydrogen carbonate, strontium hydrogen carbonate, calcium carbonate, barium carbonate, magnesium carbonate, Examples include strontium carbonate, calcium acetate, barium acetate, magnesium acetate, strontium acetate, calcium stearate, barium stearate, magnesium stearate, strontium stearate, etc. From the viewpoint of the hue of the polycarbonate resin obtained, a magnesium compound and / or a calcium compound is more preferable, and a calcium compound is most preferable.

  Examples of the basic boron compound include tetramethyl boron, tetraethyl boron, tetrapropyl boron, tetrabutyl boron, trimethylethyl boron, trimethylbenzyl boron, trimethylphenyl boron, triethylmethyl boron, triethylbenzyl boron, triethylphenyl boron, tributylbenzyl. Examples include sodium, potassium, lithium, calcium, barium, magnesium, or strontium salts such as boron, tributylphenylboron, tetraphenylboron, benzyltriphenylboron, methyltriphenylboron, butyltriphenylboron, etc. It is done.

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 hydroxide Sid, butyl triphenyl ammonium hydroxide, and the like.

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

  The amount of the polymerization catalyst used is usually 0.1 μmol to 300 μmol, preferably 0.5 μmol to 100 μmol per 1 mol of all dihydroxy compounds used in the polymerization. Among them, from the group consisting of lithium and two groups in the long-period type periodic table When a compound containing at least one selected metal is used, particularly when a magnesium compound and / or a calcium compound is used, the amount of metal is usually 0.1 μmol or more, preferably 0, per 1 mol of the total dihydroxy compound. .5 μmol or more, particularly preferably 0.7 μmol or more. Further, the upper limit is usually 20 μmol, preferably 10 μmol, more preferably 3 μmol, particularly preferably 1.5 μmol, and most preferably 1.0 μmol.

  If the amount of the catalyst is too small, the polymerization rate is slowed down. As a result, when trying to obtain a polycarbonate resin having a desired molecular weight, the polymerization temperature has to be increased, and the hue and light resistance of the obtained polycarbonate resin are deteriorated. Or the unreacted raw material volatilizes during the polymerization, and the molar ratio of the dihydroxy compound containing the dihydroxy compound of the present invention to the carbonic acid diester represented by the general formula (2) may collapse, and the desired molecular weight may not be reached. There is. On the other hand, when there is too much usage-amount of a polymerization catalyst, the hue of the polycarbonate resin obtained will be deteriorated and the light resistance of a polycarbonate resin may deteriorate.

  Furthermore, when the polycarbonate resin of the present invention is produced using a substituted diphenyl carbonate such as diphenyl carbonate or ditolyl carbonate as the carbonic acid diester represented by the general formula (2), phenol and substituted phenol are by-produced to produce polycarbonate. Although it is unavoidable that it remains in the resin, phenol and substituted phenols also have an aromatic ring, which absorbs ultraviolet rays and may cause deterioration of light resistance, as well as causing odor during molding. There is a case. The polycarbonate resin contains an aromatic monohydroxy compound having an aromatic ring such as by-product phenol of 1000 ppm by weight or more after a normal batch reaction, but from the viewpoint of light resistance and odor reduction, it is removed. It is preferably 700 ppm by weight or less, more preferably 500 ppm by weight or less, and particularly preferably 300 ppm by weight or less using a horizontal reactor having excellent volatility or an extruder with a vacuum vent. However, it is difficult to remove completely industrially, and the lower limit of the content of the aromatic monohydroxy compound is usually 1 ppm by weight.

These aromatic monohydroxy compounds may naturally have a substituent depending on the raw material used, and may have, for example, an alkyl group having 5 or less carbon atoms.
In addition, Group 1 metals, especially sodium, potassium, and cesium, especially lithium, sodium, potassium, and cesium, may have an adverse effect on the hue when they are contained in a large amount in the polycarbonate resin. The total amount of these in the polycarbonate resin is usually 1 ppm by weight or less, preferably 0.8 ppm by weight or less, more preferably 0.8 ppm or less as the amount of metal. 7 ppm by weight or less.
The amount of metal in the polycarbonate resin can be measured using a method such as atomic emission, atomic absorption, or inductively coupled plasma (ICP) after recovering the metal in the polycarbonate resin by a method such as wet ashing.

<Manufacturing method>
The polycarbonate resin of the present invention can be obtained by polycondensation of the dihydroxy compound containing the dihydroxy compound of the present invention and the carbonic acid diester of the above general formula (2) by a transesterification reaction. The raw material dihydroxy compound and carbonic acid diester are: It is preferable to mix 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 resulting in problems such as solidification. If the mixing temperature is too high, the dihydroxy compound may be thermally deteriorated, resulting in a deterioration of the hue of the polycarbonate resin thus obtained, which may adversely affect light resistance.

  The operation of mixing the dihydroxy compound containing the dihydroxy compound of the present invention, which is a raw material of the polycarbonate resin of the present invention, and the carbonic acid diester represented by the general formula (2) is an oxygen concentration of 10 vol% or less, and further 0.0001 vol%. From the viewpoint of preventing hue deterioration, it is preferably performed in an atmosphere of from 10 to 10% by volume, especially from 0.0001% to 5% by volume, particularly from 0.0001% to 1% by volume.

In order to obtain the resin of the present invention, the carbonic acid diester represented by the general formula (2) is in a molar ratio of 0.90 to 1.20 with respect to the dihydroxy compound including the dihydroxy compound of the present invention used in the reaction. The molar ratio is preferably 0.95 to 1.10.
When this molar ratio is decreased, the terminal hydroxyl group of the produced polycarbonate resin is increased, the thermal stability of the polymer is deteriorated, coloring occurs at the time of molding, the rate of transesterification reaction is decreased, and the desired high molecular weight. The body may not be obtained.

Moreover, when this molar ratio becomes large, the rate of transesterification may decrease, or it may be difficult to produce a polycarbonate 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 light resistance of the resulting polycarbonate resin.
Furthermore, when the molar ratio of the carbonic acid diester represented by the general formula (2) is increased with respect to the dihydroxy compound containing the dihydroxy compound of the present invention, the amount of residual carbonic acid diester in the obtained polycarbonate resin increases. May absorb ultraviolet rays and deteriorate the light resistance of the polycarbonate resin, which is not preferable. The concentration of the carbonic acid diester remaining in the polycarbonate resin of the present invention is preferably 200 ppm by weight or less, more preferably 100 ppm by weight or less, particularly preferably 60 ppm by weight or less, and particularly preferably 30 ppm by weight or less. Actually, the polycarbonate resin may contain unreacted carbonic acid diester, and the lower limit of the concentration is usually 1 ppm by weight.

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 type of reaction may be any of batch type, continuous type, or a combination of batch type and continuous type.
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 viewpoints of hue and light resistance. For example, if either the temperature or the pressure is changed too quickly before the polymerization reaction reaches a predetermined value, the unreacted monomer will be distilled, causing the molar ratio of the dihydroxy compound and the carbonic acid diester to change, resulting in a decrease in the polymerization rate. Or a polymer having a predetermined molecular weight or terminal group cannot be obtained, and as a result, the object of the present invention may not be achieved.

Furthermore, it is effective to use a reflux condenser for the polymerization reactor in order to suppress the amount of the monomer to be distilled off, and the effect is particularly great in a reactor at the initial stage of polymerization where there are many unreacted monomer components.
The temperature of the refrigerant introduced into the reflux cooler can be appropriately selected according to the monomer used. Usually, the temperature of the refrigerant introduced into the reflux cooler is 45 ° C. to 180 ° C. at the inlet of the reflux cooler. Preferably, it is 80 degreeC-150 degreeC, Most preferably, it is 100 degreeC-130 degreeC. If the temperature of the refrigerant introduced into the reflux condenser is too high, the reflux amount is reduced and the effect is reduced. If it is too low, the distillation efficiency of the monohydroxy compound to be originally distilled tends to be reduced. 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, but not to impair the hue, thermal stability, light resistance, etc. of the final polycarbonate resin, Selection is important.
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 method of the present invention may be at least two or more. However, from the viewpoint of production efficiency and the like, three or more, preferably 3 to 5, particularly preferably 4 are used. One.
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, the reaction in the first stage is performed at 140 to 270 ° C., preferably 180 to 240 ° C., more preferably 200 to 230 ° C. as the maximum internal temperature of the polymerization reactor. The monohydroxy compound generated is removed from the reaction system at a pressure of 1 kPa, preferably 70 kPa to 5 kPa, more preferably 30 kPa to 10 kPa (absolute pressure) for 0.1 hours to 10 hours, preferably 0.5 hours to 3 hours. Carried out while distilling.

  In the second and subsequent stages, the pressure in the reaction system is gradually reduced from the pressure in the first stage, and the monohydroxy compound that is subsequently generated is removed from the reaction system. 200 Pa or less, maximum internal temperature of 210 ° C. to 270 ° C., preferably 220 ° C. to 250 ° C., usually 0.1 hour to 10 hours, preferably 1 hour to 6 hours, particularly preferably 0.5 hour. Perform for ~ 3 hours.

In particular, in order to suppress the coloring and thermal deterioration of the polycarbonate resin and obtain a polycarbonate resin having a good hue and light resistance, the maximum internal temperature in all reaction stages is less than 250 ° C., particularly 225 ° C. to 245 ° C. preferable. In addition, the lowering of the polymerization rate in the latter half of the polymerization reaction is suppressed,
In order to minimize deterioration due to thermal history, it is preferable to use a horizontal reactor excellent in plug flow property and interface renewability at the final stage of polymerization.

In order to obtain a polycarbonate resin having a predetermined molecular weight, if the polymerization temperature is increased and the polymerization time is too long, the ultraviolet transmittance decreases and the YI value tends to increase.
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.

At that time, in the extruder, the residual monomer under reduced pressure devolatilization, and generally known heat stabilizers, neutralizers, UV absorbers, mold release agents, colorants, antistatic agents, lubricants, lubricants, A plasticizer, a compatibilizer, a flame retardant, etc. 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 150 ° C to 300 ° C, preferably 200 ° C to 270 ° C, more preferably 230 ° C to 260 ° C. When the melt-kneading temperature is lower than 150 ° 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 thermal deterioration of the polycarbonate becomes severe, resulting in a decrease in mechanical strength due to a decrease in molecular weight, coloring, and gas generation.

  When producing the polycarbonate resin of the present invention, it is desirable to install a filter in order to prevent foreign matter from entering. The filter installation position is preferably on the downstream side of the extruder, and the foreign matter removal size (opening) of the filter is preferably 100 μm or less as the filtration accuracy for 99% removal. In particular, in the case of disagreeing with the entry of minute foreign matters for film use etc., it is preferably 40 μm or less, more preferably 10 μm or less.

Extrusion of the polycarbonate resin of the present invention is preferably carried out in a clean room having a higher degree of cleanliness than class 6, more preferably class 6 as defined in JIS B 9920 (2002), in order to prevent foreign matter from being mixed after extrusion. It is desirable.
Moreover, when cooling the extruded polycarbonate resin into chips, it is preferable to use a cooling method such as air cooling or water cooling. As the air used for air cooling, it is desirable to use air from which foreign substances in the air have been removed in advance with a hepa filter or the like to prevent reattachment of foreign substances in the air. When water cooling is used, it is desirable to use water from which metal in water has been removed with an ion exchange resin or the like, and foreign matter in water has been removed with a filter. The opening of the filter to be used is preferably 10 μm to 0.45 μm as 99% removal filtration accuracy.

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 is measured using a Ubbelohde viscometer at a temperature of 20.0 ° C. ± 0.1 ° C., precisely prepared at a polycarbonate concentration of 0.6 g / dL using methylene chloride as a solvent.
Furthermore, the lower limit of the concentration of the terminal group represented by the following general formula (6) in the polycarbonate resin of the present invention is usually 20 μeq / g, preferably 40 μeq / g, particularly preferably 50 μeq / g, and the upper limit is usually 160 μeq / g, preferably 140 μeq / g, particularly preferably 100 μeq / g.

If the concentration of the end group represented by the following general formula (6) is too high, even if the hue at the time of polymerization or at the time of molding is good, the hue after UV exposure may be deteriorated. Thermal stability may be reduced.
In order to control the concentration of the terminal group represented by the following general formula (6), the molar ratio of the dihydroxy compound containing the dihydroxy compound of the present invention as a raw material and the carbonic acid diester represented by the general formula (2) is controlled. In addition, the method and the like of controlling the type and amount of the catalyst during the transesterification reaction, the polymerization pressure and the polymerization temperature can be mentioned.

Further, when the mole number of H bonded to the aromatic ring in the polycarbonate resin of the present invention is (A) and the mole number of H bonded to other than the aromatic ring is (B), the number of moles of H bonded to the aromatic ring. The ratio of the total H to the number of moles is represented by A / (A + B). However, since the aromatic ring having an ultraviolet absorbing ability may affect the light resistance as described above, A / (A + B) is preferably 0.1 or less, more preferably 0.05 or less, particularly preferably 0.02 or less, and preferably 0.01 or less. A / (A + B) can be quantified by ¹ H-NMR.

The polycarbonate resin of the present invention can be formed into a molded product by a generally known method such as an injection molding method, an extrusion molding method, or a compression molding method.
In addition, the polycarbonate resin of the present invention is, as necessary, before performing various moldings, heat stabilizer, neutralizer, ultraviolet absorber, mold release agent, colorant, antistatic agent, lubricant, lubricant, Additives such as plasticizers, compatibilizers, and flame retardants can also be mixed with a tumbler, super mixer, floater, V-type blender, nauter mixer, Banbury mixer, extruder or the like.

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

  ADVANTAGE OF THE INVENTION According to this invention, the polycarbonate resin excellent in light resistance, transparency, a hue, heat resistance, thermal stability, and mechanical strength can be provided.

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

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

(2) Measurement of reduced viscosity A polycarbonate resin sample was dissolved using methylene chloride as a solvent to prepare a polycarbonate solution having a concentration of 0.6 g / dL. Using Moritomo Rika Co. Ubbelohde viscometer tube was measured at a temperature of 20.0 ° C. ± 0.1 ° C., determine the relative viscosity ηrel using the following equation from the transit time t of the solvent passage time t ₀ and a solution,
ηrel = t / t ₀
From the relative viscosity, the specific viscosity ηsp was determined from the following formula.
ηsp = (η−η ₀ ) / η ₀ = ηrel-1 The specific viscosity was divided by the concentration c (g / dL) to obtain the reduced viscosity ηsp / c. The higher this value, the higher the molecular weight.

(3) Measurement of the structural unit ratio derived from each dihydroxy compound in the polycarbonate resin and the terminal phenyl group concentration The structural unit ratio derived from each dihydroxy compound in the polycarbonate resin was obtained by weighing 30 mg of the polycarbonate resin and measuring about 0 deuterochloroform. This was dissolved in 7 mL to obtain a solution, which was put in an NMR tube having an inner diameter of 5 mm, and ¹ H NMR spectrum was measured at room temperature using JNM-AL400 (resonance frequency 400 MHz) manufactured by JEOL. The structural unit ratio derived from each dihydroxy compound was determined from the signal intensity ratio based on the structural unit derived from each dihydroxy compound. The terminal phenyl group concentration was determined from the signal intensity ratio based on the internal standard and the terminal phenyl group by measuring ¹ H-NMR in the same manner as described above using 1,1,2,2-tetrabromoethane as the internal standard.

(4) Measurement of metal concentration in polycarbonate resin:
About 0.5 g of a polycarbonate resin pellet was precisely weighed in a microwave decomposition container manufactured by PerkinElmer, and 2 mL of 97% sulfuric acid was added, and the mixture was sealed and heated at 230 ° C. for 10 minutes. After cooling to room temperature, 1.5 mL of 68% nitric acid is added, sealed and microwave heated at 150 ° C. for 10 minutes, cooled again to room temperature, added with 2.5 mL of 68% nitric acid, and sealed again. And microwaved at 230 ° C. for 10 minutes to completely decompose the contents. After cooling to room temperature, the liquid obtained above was diluted with pure water, and the metal concentration was measured by ICP-MS manufactured by ThermoQuest.

(5) Measurement of phenol concentration and DPC concentration in polycarbonate resin Dissolve 1.25 g of polycarbonate resin sample in 7 ml of methylene chloride to make a solution, and then add acetone to make the total amount 25 ml and perform reprecipitation treatment. It was. Next, the treatment liquid was filtered through a 0.2 μm disk filter and quantified by liquid chromatography.

(6) Method for evaluating initial hue of polycarbonate resin The pellets of the polycarbonate resin were dried at 110 ° C. for 10 hours in a nitrogen atmosphere. Next, the dried polycarbonate resin pellets were supplied to an injection molding machine (J75EII type, manufactured by Nippon Steel Co., Ltd.), and injection molded pieces (width 60 mm × length 60 mm × under conditions of a resin temperature of 220 ° C. and a molding cycle of 23 seconds) Repeat the operation to form a 3mm thickness), and measure the yellow index (initial YI) value and L * value in the transmitted light in the thickness direction of the injection molded pieces obtained in the 10th to 20th shots. The average value was calculated using CM-3700d) manufactured by Minolta. The smaller the YI value, the better the quality without yellowness, and the larger the L * value, the higher the brightness.

(7) Method for evaluating hue of polycarbonate resin staying in heated state In the above-described evaluation of the initial hue of polycarbonate resin, the molding cycle of the injection molded piece by the injection molding machine is changed from 20th shot to 60 seconds, up to the 30th shot. Repeat the molding operation. And the YI value in the transmitted light in the thickness direction of the injection molded product obtained at the 30th shot was measured using the color tester, and the average value was calculated.

(8) Measurement of light transmittance at wavelengths of 350 nm and 320 nm Light in the thickness direction of the injection-molded piece (width 60 mm × length 60 mm × thickness 3 mm, 10th shot to 20th shot) obtained in (6) above The transmittance was measured using an ultraviolet-visible spectrophotometer (U2900 manufactured by Hitachi High-Technologies Corporation), and the average value was calculated and evaluated.

(9) Ratio of moles of H bonded to the aromatic ring (A) to moles of total H (A + B) (where (B) is the number of moles of H not bonded to the aromatic ring)
The spectrum of only deuterated chloroform to which tetramethylsilane (TMS) was previously added and mixed as an internal standard substance was measured, and the signal ratio of residual H contained in TMS and deuterated chloroform was determined. Next, 30 mg of polycarbonate resin was weighed and dissolved in about 0.7 mL of the deuterated chloroform. This was put into an NMR tube having an inner diameter of 5 mm, and a ¹ H NMR spectrum was measured at room temperature using JNM-AL400 (resonance frequency 400 MHz) manufactured by JEOL. From the integrated value of the signal appearing at 6.5 ppm to 8.0 ppm in the obtained NMR chart, the integrated value of the residual H signal contained in deuterated chloroform (the integrated value of the TMS signal and the previously calculated TMS and The value obtained by subtracting (determined from the ratio to the residual H contained in chloroform) is a. On the other hand, when the integral value of the signal appearing at 0.5 ppm to 6.5 ppm is b, a / (a + b) = A / (A + B) is obtained.

(10) Metal halide lamp irradiation test Using a metal ring weather meter M6T manufactured by Suga Test Instruments Co., Ltd., a horizontal metal ring lamp as a light source, quartz as an inner filter, and quartz Attach a # 500 filter as an outer filter around, set the irradiance at a wavelength of 300 nm to 400 nm to 1.5 kw / m ² , and obtain the 20th shot flat plate (width 60 mm × length) obtained in (6) above. A square surface having a thickness of 60 mm × thickness of 3 mm was subjected to irradiation treatment for 100 hours. The YI value after irradiation was measured in the same manner as (6) above.

The abbreviations of the compounds used in the description of the following examples are as follows.
ISB: Isosorbide (Rocket Fleure, trade name POLYSORB)
CHDM: 1,4-cyclohexanedimethanol (Eastman)
DEG: Diethylene glycol (Mitsubishi Chemical Corporation)
BPA: Bisphenol A (Mitsubishi Chemical Corporation)
DPC: Diphenyl carbonate (Mitsubishi Chemical Corporation)

[Example 1]
In a polymerization reactor equipped with a stirring blade and a reflux condenser controlled at 100 ° C., ISB and CHDM, DPC and calcium acetate monohydrate having a chloride ion concentration of 10 ppb or less by purification by distillation, in a molar ratio. ISB / CHDM / DPC / calcium acetate monohydrate = 0.70 / 0.30 / 1.00 / 1.3 × 10 ⁻⁶ , and sufficiently purged with nitrogen (oxygen concentration 0.0005 vol% ~ 0.001 vol%). Subsequently, heating was performed with a heating medium, and stirring was started when the internal temperature reached 100 ° C., and the contents were melted and made uniform while controlling the internal temperature to be 100 ° C. After that, temperature increase was started, the internal temperature was adjusted to 210 ° C in 40 minutes, and control was performed to maintain this temperature when the internal temperature reached 215 ° C. At the same time, pressure reduction was started, and 215 ° C was reached. After 90 minutes, the pressure was changed to 13.3 kPa (absolute pressure, the same applies hereinafter), and the pressure was maintained for another 60 minutes. The phenol vapor produced as a by-product with the polymerization reaction is led to a reflux condenser using a steam controlled at 100 ° C. as the inlet temperature to the reflux condenser, and a monomer component contained in the phenol vapor in a slight amount is introduced into the polymerization reactor. Then, the phenol vapor that did not condense was recovered by guiding it to a condenser using 45 ° C. warm water as a refrigerant.

  The content thus oligomerized is once restored to atmospheric pressure, and then transferred to another polymerization reaction apparatus equipped with a stirring blade and a reflux condenser controlled in the same manner as described above. The internal temperature was set to 220 ° C. and the pressure was set to 200 Pa in 60 minutes. Thereafter, the internal temperature was set to 230 ° C. and the pressure was 133 Pa or less over 20 minutes, and when the predetermined stirring power was reached, the pressure was restored. The contents were extracted in the form of strands and pelletized with a rotary cutter.

The obtained pellets were extruded in a strand shape using a twin screw extruder (LABOTEX30HSS-32) manufactured by Nippon Steel Works with two vents so that the resin temperature at the outlet was 250 ° C, and cooled and solidified with water. Then, it was pelletized with a rotary cutter. At this time, the vent port was connected to a vacuum pump, and the pressure at the vent port was controlled to be 500 Pa. Table 1 shows the analysis results of the obtained polycarbonate resin and the results evaluated in the above method. A polycarbonate resin having a small yellowness, excellent lightness and good color tone was obtained, and light resistance was also good.

[Example 2]
The same procedure as in Example 1 was performed except that the molar ratio of ISB to CHDM was changed. As in Example 1, the obtained polycarbonate resin had a small yellowness, an excellent lightness, a good color tone, and a good light resistance.

[Example 3]
ISB / CHDM, DPC and calcium acetate monohydrate in a molar ratio of ISB / CHDM / DPC / calcium acetate monohydrate = 0.70 / 0.30 / 1.00 / 2.5 × 10 ⁻⁶ The same procedure as in Example 1 was performed, except that charging was performed. As in Example 1, a polycarbonate resin having a small yellowness, excellent lightness, good color tone, and good light resistance was obtained.

[Example 4]
ISB / CHDM / DPC / calcium acetate monohydrate in a molar ratio of ISB / CHDM / DPC / calcium acetate monohydrate = 0.70 / 0.30 / 1.00 / 0.9 × 10 ⁻⁶ The same procedure as in Example 1 was performed, except that charging was performed. A polycarbonate resin having a smaller yellowness than that of Example 1, excellent lightness, good color tone, and good light resistance was obtained.

[Example 5]
The same procedure as in Example 3 was performed except that magnesium acetate tetrahydrate was used instead of calcium acetate monohydrate. As in Example 3, a polycarbonate resin having a small yellowness, excellent lightness, good color tone, and good light resistance was obtained.

[Example 6]
The same procedure as in Example 3 was performed except that barium acetate was used instead of calcium acetate monohydrate. As in Example 3, a polycarbonate resin having a small yellowness, excellent lightness, good color tone, and good light resistance was obtained.

[Example 7]
The same procedure as in Example 3 was performed except that lithium acetate was used instead of calcium acetate monohydrate. As in Example 3, a polycarbonate resin having a small yellowness, excellent lightness, good color tone, and good light resistance was obtained.

[Example 8]
The same procedure as in Example 3 was performed except that DEG was used instead of CHDM. As in Example 3, a polycarbonate resin having a small yellowness, excellent lightness, good color tone, and good light resistance was obtained.

[Comparative Example 1]
The same procedure as in Example 1 was performed except that cesium carbonate was used in place of calcium acetate monohydrate. Compared with Example 1, the ultraviolet transmittance decreased and the initial YI value tended to increase. Moreover, the brightness and light resistance were also inferior.

[Comparative Example 2]
The same procedure as in Comparative Example 1 was performed except that the vent port was not depressurized with an extruder. Compared with Comparative Example 1, the ultraviolet transmittance decreased, the initial YI value was high, and the brightness and light resistance were also inferior.

[Comparative Example 3]
The same procedure as in Example 1 was conducted except that calcium acetate monohydrate was increased as shown in Table 1. The ultraviolet transmittance decreased, the initial YI value was high, and the brightness and light resistance were also inferior.

[Comparative Example 4]
The same procedure as in Example 3 was performed except that the temperature at the final stage of the polymerization was 260 ° C. and the vent port was not decompressed with an extruder. Compared with Example 3, the ultraviolet transmittance decreased, the YI value was high, and the brightness and light resistance were also inferior.

[Example 9]
In Example 1, the setting of the final stirring power of polymerization was lowered to obtain polycarbonate resin pellets having a reduced viscosity of 0.40 dL / g and a phenol content of 3500 ppm by weight. This polycarbonate resin pellet is melted in a nitrogen atmosphere by a single-screw extruder set at a barrel temperature of 230 ° C., and has two stirring shafts in the horizontal direction and a plurality of stirring blades installed discontinuously on the shaft. It was introduced into a horizontal reactor (manufactured by Hitachi Plant Technology Co., Ltd., glasses blade, effective internal volume 6 L). The pressure in the horizontal reactor was 133 Pa, the internal temperature was 230 ° C., the polycondensation reaction was continuously performed for 60 minutes, the molten polycarbonate resin was extracted in the form of strands, and pelletized with a rotary cutter. The reduced viscosity of the obtained polycarbonate resin was 0.50 dL / g, and the phenol concentration was 204 ppm by weight.

  The polycarbonate of the present invention can stably produce a polycarbonate having excellent transparency, hue, heat resistance, moldability, mechanical strength and excellent optical properties, and injection of electrical / electronic parts, automotive parts, etc. Retardation film used in molding field, film and sheet field, bottle and container field that requires heat resistance, and lens applications such as camera lens, finder lens, CCD and CMOS lens, liquid crystal and plasma display It is possible to provide materials for a wide range of fields such as binders for fixing films such as diffusion sheets and polarizing films, sheets, optical disks, optical materials, optical components, dyes, charge transfer agents, and the like.

Claims (17)

A dihydroxy compound containing a dihydroxy compound having a site represented by the following general formula (1) as part of its structure and a carbonic acid diester represented by the following general formula (2) are obtained by polycondensation in the presence of a catalyst. A polycarbonate resin, wherein the catalyst is a compound containing lithium and at least one metal selected from the group consisting of Group 2 in the long-period periodic table, and the amount of the compound containing the metal is the amount of the dihydroxy A polycarbonate resin characterized by being 20 μmol or less per 1 mol of the compound and containing 700 ppm by weight or less of an aromatic monohydroxy compound.

(However, the case where the site represented by the general formula (1) is —CH ₂ —O—H is excluded.)

(In General Formula (2), A ¹ and A ² are each independently a substituted or unsubstituted aliphatic group having 1 to 18 carbon atoms, or a substituted or unsubstituted aromatic group.)   2. The polycarbonate resin according to claim 1, wherein the compound containing at least one metal selected from the group consisting of lithium and two groups in the long-period periodic table is a magnesium compound and / or a calcium compound.   The polycarbonate resin according to claim 1 or 2, wherein a total amount of sodium, potassium, and cesium in the polycarbonate resin is 1 ppm by weight or less as a metal amount.   The polycarbonate resin according to any one of claims 1 to 3, wherein a total amount of lithium, sodium, potassium, and cesium in the polycarbonate resin is 1 ppm by weight or less as a metal amount.   The polycarbonate resin according to any one of claims 1 to 4, wherein the polycarbonate resin contains 60 ppm by weight or less of a carbonic acid diester represented by the general formula (2). 6. The dihydroxy compound having a site represented by the general formula (1) in a part of the structure is a compound represented by the following general formula (3). The polycarbonate resin described in 1.

  The polycarbonate resin is at least selected from the group consisting of a structural unit derived from a dihydroxy compound having a site represented by the general formula (1) in a part of the structure, and an aliphatic dihydroxy compound and an alicyclic dihydroxy compound. The polycarbonate resin according to claim 1, comprising a structural unit derived from one kind of compound. 8. The polycarbonate according to claim 1, wherein the concentration of the terminal group represented by the following general formula (4) in the polycarbonate resin is 20 μeq / g or more and 160 μeq / g or less. resin.

  When the mole number of H bonded to the aromatic ring in the polycarbonate resin is (A) and the mole number of H bonded to other than the aromatic ring is (B), A / (A + B) ≦ 0.05 The polycarbonate resin according to any one of claims 1 to 8.   10. The light transmission rate at a wavelength of 350 nm of a molded body (thickness 3 mm) molded from the polycarbonate resin is 60% or more, wherein the polycarbonate resin is any one of claims 1 to 9. Polycarbonate resin.   11. The polycarbonate resin according to claim 1, wherein a light transmittance at a wavelength of 320 nm of a molded body (thickness: 3 mm) molded from the polycarbonate is 30% or more. A molded body (thickness: 3 mm) molded from the above polycarbonate at a temperature of 63 ° C. and a relative humidity of 50% using a metal halide lamp at an irradiance of 1.5 kW / m ² at a wavelength of 300 nm to 400 nm for 100 hours. The polycarbonate resin according to any one of claims 1 to 11, wherein a yellow index (YI) value based on ASTM D 1925-70 measured by transmitted light after irradiation treatment is 12 or less.   13. The polycarbonate resin according to claim 1, wherein an initial yellow index value of a molded body (thickness 3 mm) molded from the polycarbonate is 7 or less. An initial yellow index value of a molded body (thickness: 3 mm) molded from the polycarbonate resin and an irradiance of 1.5 kW at a wavelength of 300 nm to 400 nm using a metal halide lamp in an environment of 63 ° C. and a relative humidity of 50%. The absolute value of the difference from the yellow index (YI) value according to ASTM D 1925-70 measured with transmitted light after 100 hours of irradiation treatment at / m ² is 6 or less. 14. The polycarbonate resin according to any one of 13. The polycarbonate resin according to any one of claims 1 to 14, wherein an L * value of a molded body (thickness 3 mm) molded from the polycarbonate resin is 96.3 or more.   A polycarbonate resin molded article obtained by molding the polycarbonate resin according to any one of claims 1 to 15.   The polycarbonate resin molded product according to claim 16, wherein the polycarbonate resin molded product is molded by an injection molding method.