JP2010106171A - Aromatic polycarbonate resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an excellent aromatic polycarbonate resin composition, excellent in hydrolysis resistance, capable of maintaining transparency and molecular weight even under a highly moist and high temperature environment wherein, conventional aromatic polycarbonate resin compositions can not be used by the reduction of the transparency and reduction of physical properties caused by the decrease of its molecular weight. <P>SOLUTION: The aromatic polycarbonate is characterized by blending (B) 0.01 to 5 pts.wt. carbodiimide compound based on (A) 100 pts.wt. of an aromatic polycarbonate produced from an aromatic dihydroxy compound with a carbonic diester by a transesterification method. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an aromatic polycarbonate resin composition excellent in various properties. More specifically, the present invention relates to an aromatic polycarbonate resin composition which is particularly excellent in hydrolysis resistance and exhibits excellent characteristics even in a high-temperature and high-humidity environment, which has been difficult to use with conventional aromatic polycarbonates.

  Aromatic polycarbonate resin is an engineering plastic with excellent mechanical properties such as impact resistance, heat resistance, and transparency. Electronic parts such as optical lenses and OA parts, sheets, automobile parts, and construction materials. It is widely used for etc. In particular, it is widely used for applications such as building materials, sheets, and automotive interior and exterior parts, taking advantage of its impact resistance and transparency. In such applications, the appearance of an aromatic polycarbonate resin excellent in hydrolysis resistance is particularly desired.

  As a method for producing an aromatic polycarbonate resin, a so-called interface method in which an aromatic dihydroxy compound such as bisphenol and phosgene are reacted in an interface polycondensation method has been industrialized. However, the interfacial method requires the use of phosgene, which is harmful to the human body, and requires a solvent such as dichloromethane, which has a high environmental load, and the incorporation of a large amount of by-product sodium chloride into the polymer. Problems such as corrosion when used in electronic parts have been pointed out.

  On the other hand, as another method for producing an aromatic polycarbonate resin, transesterification of a carbonic acid diester and an aromatic dihydroxy compound in a molten state to obtain an aromatic polycarbonate while removing low molecular weight substances such as phenol as a by-product from the system, A so-called melt polymerization method (hereinafter referred to as transesterification method) is also known.

  The transesterification method has no problems with the interface method as described above, but the polymerization rate and the performance of the aromatic polycarbonate resin to be produced, especially the hydrolysis resistance, are aromatic polycarbonates produced by the interface method (hereinafter referred to as interface). There is a problem that it is insufficient as compared with legal PC).

  As a method for improving the hydrolysis resistance of an aromatic polycarbonate produced by the transesterification method (hereinafter sometimes referred to as transesterification method PC), for example, while the transesterification polycarbonate is in a molten state, a phosphorus compound and A method for adding a sulfur-containing acidic compound has been proposed (see, for example, Patent Document 1).

  Moreover, the composition (for example, refer patent document 2) which mix | blended the sulfonic acid compound, the phenolic antioxidant, and the dihydro oxaphosphaphenanthrene type phosphorus compound with the transesterification method polycarbonate, or the transesterification method polycarbonate is a molten state. In the meantime, a method has been proposed in which a sulfonic acid compound, a phosphorus compound, or a partial ester of an aliphatic carboxylic acid and a polyhydric alcohol is added to a portion in a pressurized state of a twin-screw extruder (see, for example, Patent Document 3). .)

  However, the aromatic polycarbonate resin composition obtained by the methods described in Patent Documents 1 to 3 has insufficient improvement in hydrolysis resistance, and further improvement has been desired.

  On the other hand, as a method for improving hydrolysis resistance in a thermoplastic resin other than an aromatic polycarbonate resin, specifically, for example, a method using a polycarbodiimide compound in thermoplastic polyester has been proposed (see, for example, Patent Document 4). ).

  In Patent Document 4, for example, polycarbonate, ABS resin, polyphenylene ether, polyamide, ethylene, (meth) acrylic acid ester, vinyl acetate, styrene and the like are mixed with 100 parts by weight of the thermoplastic polyester resin. Although it is described that 0.01 to 50 parts by weight of the coal may be blended, there is no description or suggestion about improvement of hydrolysis resistance regarding a specific aromatic polycarbonate resin.

  Patent Document 5 discloses a thermoplastic resin composition having excellent hydrolysis stability by blending an aliphatic carbodiimide compound and a phosphorus-based antioxidant into a resin having an ester group (having an ester bond in the main chain). Is known (see, for example, Patent Document 5).

  However, the resin whose characteristics are to be improved in Patent Document 5 is different from the aromatic polycarbonate resin having a carbonate bond in the main chain, and moreover, it is resistant to hydrolysis in a specific aromatic polycarbonate resin, that is, transesterification method PC. There is no mention or suggestion of sex issues or improvement methods.

JP-A-5-009286 Japanese Patent Laid-Open No. 11-209597 JP 2001-19838 A JP-A-8-73719 JP 2005-82642 A

  The present invention has been made in view of such circumstances, and its purpose is excellent in hydrolysis resistance, and the conventional aromatic polycarbonate resin composition is difficult to use due to a decrease in physical strength due to a decrease in transparency and molecular weight. An object of the present invention is to provide an excellent aromatic polycarbonate resin composition capable of maintaining transparency and molecular weight even in a high-humidity heat environment.

  As a result of intensive studies, the inventors of the present invention significantly improved the hydrolysis resistance, which was not effective in the interfacial polycarbonate resin when the carbodiimide compound was blended with the aromatic polycarbonate resin, especially the transesterification polycarbonate resin. I found an unexpected effect.

  This transesterification polycarbonate resin composition maintains its transparency and molecular weight even in a high humidity environment where conventional aromatic polycarbonate resins are difficult to use due to the decrease in physical strength due to the decrease in transparency and molecular weight. As a result, the present inventors have found that the range of application of the resin molded body is widened and becomes more excellent, thereby completing the present invention.

  That is, the gist of the present invention is characterized by containing 0.01 to 5 parts by weight of a carbodiimide compound with respect to 100 parts by weight of an aromatic polycarbonate resin produced by an ester exchange method from an aromatic dihydroxy compound and a carbonic acid diester. The present invention relates to an aromatic polycarbonate resin composition and a resin molded body formed by molding the same.

  The aromatic polycarbonate resin composition of the present invention is excellent in hydrolysis resistance and suppresses a decrease in physical strength and transparency even in a high-humidity heat environment, so that a wide range of OA parts, automobile parts, building materials, sheets and the like are particularly wide. A suitable use for the application can be expected.

  Hereinafter, the present invention will be described in detail. The aromatic polycarbonate resin used in the present invention can be obtained by transesterification using an aromatic dihydroxy compound and a carbonic acid diester as raw materials in the presence of a transesterification catalyst. The carbonic acid diester compound used in the present invention is a compound represented by the following general formula (1).

（式中、Ｒ及びＲ’は、炭素数１〜１８の、置換されていてもよい、脂肪族基又は芳香族基であり、ＲとＲ’とは、同一でも異なってもよい。）

(In the formula, R and R ′ are an aliphatic group or an aromatic group having 1 to 18 carbon atoms, which may be substituted, and R and R ′ may be the same or different.)

  Specific examples of the carbonic acid diester compound represented by the formula (1) include substituted diphenyl carbonates such as dimethyl carbonate, diethyl carbonate, di-t-butyl carbonate, diphenyl carbonate, and ditolyl carbonate. Diphenyl carbonate and substituted diphenyl carbonate, particularly diphenyl carbonate are preferred. These carbonic acid diester compounds may be used alone or in admixture of two or more.

  Along with the carbonic acid diester compound, dicarboxylic acid or dicarboxylic acid ester may be used preferably in an amount of 50 mol% or less, more preferably 30 mol% or less. Examples of such dicarboxylic acid or dicarboxylic acid ester include terephthalic acid, isophthalic acid, diphenyl terephthalate, and diphenyl isophthalate. When such carboxylic acid or carboxylic acid ester is used in combination with a carbonic acid diester compound, polyester carbonate is obtained.

The aromatic dihydroxy compound used in the present invention is a compound represented by the following formula (2).

（式中、Ｂは、１〜１５の炭素数を有する２価の炭化水素基、ハロゲン置換の２価の炭化水素基、−Ｓ−基、−ＳＯ２−基、−ＳＯ−基、−Ｏ−基又は−ＣＯ−基を示し、Ｘは、ハロゲン原子、炭素数１〜１４のアルキル基、炭素数６〜１８のアリール基、炭素数１〜８のオキシアルキル基又は炭素数６〜１８のオキシアリール基を示す。ｍは、０又は１であり、ｙは、０〜４の整数である。）

(In the formula, B is a divalent hydrocarbon group having 1 to 15 carbon atoms, a halogen-substituted divalent hydrocarbon group, -S- group, -SO2- group, -SO- group, -O- X represents a halogen atom, an alkyl group having 1 to 14 carbon atoms, an aryl group having 6 to 18 carbon atoms, an oxyalkyl group having 1 to 8 carbon atoms, or an oxy group having 6 to 18 carbon atoms. Represents an aryl group, m is 0 or 1, and y is an integer of 0-4.)

  Examples of the aromatic dihydroxy compound represented by the formula (2) include 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, , 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′-dihydroxydiphenylsulfone, bis (4-hydroxyphenyl) sulfide, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3 Examples include '-dichlorodiphenyl ether, 4,4'-dihydroxy-2,5-diethoxydiphenyl ether, and the like. Among these, 2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as “bisphenol A”) is preferable. Moreover, these aromatic dihydroxy compounds can be used individually or in mixture of 2 or more types.

  The use ratio of the carbonic acid diester compound and the aromatic dihydroxy compound may be determined by appropriately selecting the desired molecular weight of the aromatic polycarbonate and the amount of terminal hydroxy groups. In an aromatic polycarbonate resin, if the amount of terminal hydroxy groups is too large, the thermal stability and hydrolysis resistance of the aromatic polycarbonate resin are reduced, and conversely, if the amount is too small, an aromatic polycarbonate resin having a desired molecular weight can be produced. It can be difficult.

  Therefore, the amount of terminal hydroxy groups of the aromatic polycarbonate resin used in the present invention is usually 100 to 2000 ppm, preferably 100 to 1500 ppm, more preferably 200 to 1000 ppm, and particularly preferably 300 to 800 ppm.

  In order to produce such an aromatic polycarbonate resin having a terminal hydroxy group amount of 100 to 2000 ppm by transesterification, a carbonate diester compound is usually used in an equimolar amount or more with respect to 1 mol of the aromatic dihydroxy compound. Among them, it is preferable to use 1.001 to 1.300 mol, more preferably 1.010 to 1.200 mol, and particularly preferably 1.020 to 1.150 mol.

  The viscosity average molecular weight of the aromatic polycarbonate resin used in the present invention is arbitrary and may be appropriately selected and determined. However, if the viscosity average molecular weight is too low, the mechanical strength becomes insufficient. Workability is reduced. Therefore, the viscosity average molecular weight of the aromatic polycarbonate resin to be used is usually 10,000 to 50,000, preferably 13,000 to 40,000, more preferably 13,000 to 30,000, and particularly preferably 15,000 to 27,000.

  In the transesterification reaction between an aromatic dihydroxy compound and a carbonic acid diester compound, a transesterification catalyst is usually used. In the present invention, an alkali metal compound and an alkaline earth metal compound are used, and a basic boron compound and a base are supplementarily used. It is also possible to use a basic compound such as a basic phosphorus compound, a basic ammonium compound or an amine compound in combination. These catalysts may be used alone or in combination of two or more.

  Examples of the alkali 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, carbonate Cesium, 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 phenyl borohydride, potassium potassium phenide, lithium phenyl phenide, cesium phenyl phenide, sodium benzoate, potassium benzoate, lithium benzoate, cesium benzoate, 2 hydrogen phosphates Lithium, 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, and disodium salt, dipotassium salt, dilithium salt, and dicesium salt of bisphenol A.

  Specific examples of the alkaline earth metal compound include calcium hydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide, calcium bicarbonate, barium bicarbonate, magnesium bicarbonate, strontium bicarbonate, calcium carbonate, carbonate Barium, magnesium carbonate, strontium carbonate, calcium acetate, barium acetate, magnesium acetate, strontium acetate, calcium stearate, barium stearate, magnesium stearate, strontium stearate, and the like.

  Specific examples of the basic boron compound include tetramethylboron, tetraethylboron, tetrapropylboron, tetrabutylboron, trimethylethylboron, trimethylbenzylboron, trimethylphenylboron, triethylmethylboron, triethylbenzylboron, triethylphenylboron. , Hydroxides such as tributylbenzylboron, tributylphenylboron, tetraphenylboron, benzyltriphenylboron, methyltriphenylboron, and butyltriphenylboron.

  Specific 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, butyl triphenyl ammonium hydroxide, and the like.

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

The transesterification reaction is generally performed in a multistage process of two or more stages. Specifically, the reaction in the first stage is usually performed at a temperature of 120 to 260 ° C., preferably 180 to 240 ° C. under a reduced pressure of 9.3 × 10 ^{4 to} 1.33 × 10 ³ Pa. The reaction is carried out for 1 to 5 hours, preferably 0.1 to 3 hours. Next, the reaction temperature is raised while raising the degree of vacuum of the reaction system, and finally a polycondensation reaction is performed at a temperature of 240 to 320 ° C. under a reduced pressure of 133 Pa or less. The type of reaction may be any of batch type, continuous type, or a combination of batch type and continuous type, and the apparatus used may be any type of tank type, tube type or column type.

  In the transesterification aromatic polycarbonate produced by the above method, low molecular weight compounds such as raw material monomers, catalysts, aromatic hydroxy compounds by-produced by transesterification, and aromatic polycarbonate oligomers usually remain. Among these, the carbonic acid diester compound and the aromatic hydroxy compound, which are raw material monomers, have a large residual amount and adversely affect physical properties such as heat aging resistance and hydrolysis resistance, and therefore must be removed upon commercialization.

  The method for removing them is not particularly limited, and may be continuously devolatilized by, for example, a vent type extruder. At that time, the basic transesterification catalyst remaining in the resin is preliminarily added with an acidic compound or a precursor thereof to deactivate, thereby suppressing side reactions during devolatilization, and efficiently starting monomer and Aromatic hydroxy compounds can be removed.

  There is no restriction | limiting in particular in the acidic compound to add, or its precursor, As long as it has an effect which neutralizes the basic transesterification catalyst used for a polycondensation reaction, all can be used. Specifically, hydrochloric acid, nitric acid, boric acid, sulfuric acid, sulfurous acid, phosphoric acid, phosphorous acid, hypophosphorous acid, polyphosphoric acid, adipic acid, ascorbic acid, aspartic acid, azelaic acid, adenosine phosphoric acid, benzoic acid, Formic acid, valeric acid, citric acid, glycolic acid, glutamic acid, glutaric acid, cinnamic acid, succinic acid, acetic acid, tartaric acid, oxalic acid, p-toluenesulfinic acid, p-toluenesulfonic acid, naphthalenesulfonic acid, nicotinic acid, picrine Examples thereof include Bronsted acids such as acid, picolinic acid, phthalic acid, terephthalic acid, propionic acid, benzenesulfinic acid, benzenesulfonic acid, malonic acid, maleic acid, and esters thereof.

  These may be used alone or in combination of two or more. Of these acidic compounds or precursors thereof, sulfonic acid compounds or ester compounds thereof, such as p-toluenesulfonic acid, methyl p-toluenesulfonate, and butyl p-toluenesulfonate are particularly preferable.

  The addition amount of these acidic compounds or precursors thereof is 0.1 to 50 times mol, preferably 0.5 to 30 times mol, of the neutralization amount of the basic transesterification catalyst used in the polycondensation reaction. Add in range. The timing of adding the acidic compound or its precursor may be any time after the polycondensation reaction, and there is no particular limitation on the addition method, depending on the properties of the acidic compound or its precursor and the desired conditions, Any method such as a method of adding directly, a method of adding by dissolving in an appropriate solvent, a method of using a pellet or a flaky master batch may be used.

  The extruder used for devolatilization may be uniaxial or biaxial. The twin screw extruder is a meshing type twin screw extruder, and the rotation direction may be the same direction or different direction. For the purpose of devolatilization, those having a vent part after the acidic compound addition part are preferred. The number of vents is not limited, but usually a multistage vent of 2 to 10 stages is used. In the extruder, (B) the carbodiimide compound used in the present invention, and various other additives as required can be added and melt-kneaded.

  The carbodiimide compound used in the present invention is a compound having at least one carbodiimide group in the molecule. These carbodiimide compounds may be any of aliphatic, alicyclic, and aromatic. Among them, 4,4′-dicyclohexylmethanecarbodiimide (degree of polymerization = 2 to 20) described in JP-A-2005-82642 and the like is particularly preferable. An aliphatic carbodiimide compound having one or more carbodiimide groups in the molecule is preferred.

  The number average molecular weight of the carbodiimide compound is preferably 500 to 5,000 in terms of styrene as measured by GPC. If the number average molecular weight is too small, the heat resistance of the polycarbonate resin composition may be insufficient. Conversely, if the number average molecular weight is too large, the hydrolysis resistance and thermal stability may be lowered.

  The carbodiimide compound is preferably a carbodiimide-modified isocyanate having an isocyanate terminal at the end of the aliphatic carbodiimide compound in order to enhance the hydrolysis resistance improving effect and obtain a good initial hue.

  The content of the carbodiimide compound is 0.01 to 5 parts by weight with respect to 100 parts by weight of the transesterification aromatic polycarbonate. If the content of the carbodiimide compound is less than 0.01 parts by weight, the effect of improving hydrolysis resistance and transparency is small. On the contrary, if it exceeds 5 parts by weight, the transparency is lowered and the thermal stability is also lowered. is there.

  The method for adding the carbodiimide compound is not particularly defined, and any method that is usually used in the method for producing a resin composition may be adopted. For example, a method of adding a carbodiimide compound and melt-kneading them when the aromatic polycarbonate resin is in a molten state using a short-axis or biaxial extruder is mentioned.

  In the aromatic polycarbonate resin composition of the present invention, various additives are blended depending on the purpose of improvement such as mechanical strength, electrical characteristics, environmental characteristics, dimensional stability, etc. within the range not impairing the effects of the present invention. be able to.

  Specifically, for example, glass fibers, asbestos fibers, silica fibers, silica / alumina fibers, alumina fibers, zirconia fibers, boron nitride fibers, silicon nitride fibers, carbon fibers, boron fibers, potassium titanate fibers, stainless steel and other metal fibers , Fibrous reinforcing fillers such as aramid fiber; carbon black, graphite, silica, quartz powder, glass beads, milled fiber, glass balloon, glass powder, calcium silicate, aluminum silicate, kaolin, clay, diatomaceous earth, wollastonite Silicates such as iron oxide, titanium oxide, zinc oxide, antimony trioxide and alumina, metal carbonates such as calcium carbonate, sulfates such as barium sulfate, ferrite, silicon carbide, silicon nitride, nitriding Powdered inorganic fillers such as boron and various metal powders; mica, talc, Platy fillers such as Las flakes and the like.

  Furthermore, examples of other additives include slidability imparting agents, lubricants, antioxidants, heat stabilizers, ultraviolet absorbers, colorants, mold release agents, antistatic agents, surfactants, dyes and the like. However, it is not limited to these.

Further, the thermoplastic resin composition of the present invention can be blended with other resins within a range where the object of the present invention is not impaired, that is, in a small proportion. Examples of such other resins include polyamide resins, polyimide resins, polyetherimide resins, polyurethane resins, polyphenylene ether resins, polyphenylene sulfide resins, polysulfone resins, polyolefin resins such as polyethylene and polypropylene, polyethylene terephthalate, and polybutylene terephthalate. Examples of the resin include polyester resin, polymethacrylate resin, phenol resin, and epoxy resin.

  Hereinafter, the present invention will be described by way of examples. In addition, unless otherwise indicated, the display of% and a part in an Example shows weight% and a weight part, respectively. In the following examples and comparative examples, the physical properties of the obtained aromatic polycarbonate resin compositions were measured and evaluated by the following methods.

[Measurement and evaluation methods]
(1) Viscosity average molecular weight (Mv): The intrinsic viscosity of a 6 g / liter methylene chloride solution was measured using an Ubbelohde viscometer, and the viscosity average molecular weight was determined by the following formula.
[Η] = 1.23 × 10 ⁻⁴ (Mv) ^0.83

  (2) Amount of terminal OH: Colorimetric determination was performed by the titanium tetrachloride / acetic acid method (Makromol Chem. 88 215 (1965)). The measured value was expressed in ppm units of the terminal OH group weight relative to the aromatic polycarbonate weight.

  (3) Haze (cloudiness): A two-stage plate of 90 mm × 50 mm, thickness 2 mm and 3 mm was injection-molded at 280 ° C., and haze (cloudiness) at a thickness of 3 mm using a Nippon Denshoku Industries Co., Ltd. haze meter NDH-2000 Was measured.

  (4) Hydrolysis resistance: The test piece injection-molded in the above (3) was subjected to hydrolysis treatment at a temperature of 120 ° C. and a humidity of 100% for a predetermined time in an autoclave PC-304RIII manufactured by Hirayama Seisakusho. Before and after the hydrolysis treatment, viscosity average molecular weight (Mv) and haze (haze) were measured to evaluate hydrolysis resistance.

  (5) Yellowness (YI): The yellowness (YI) at a thickness of 3 mm was measured with a spectroscopic color meter SE-2000 manufactured by Nippon Denshoku Industries Co., Ltd. by injection molding in the above (3).

  (6) Q value (flow value): The plate molded by the above method and the plate subjected to hydrolysis treatment were flow-tested by Shimadzu Test Machine, flow tester CFT-500D, LOAD: 160, preheating time: 420 seconds, The Q value was measured under conditions of a die hole diameter: 1.0 mm, a die hole length: 10 mm, and a temperature of 280 ° C.

(Production Example 1 of Transesterification Aromatic Polycarbonate)
The transesterification method aromatic polycarbonate used in the present invention will be described in accordance with the flow sheet of one embodiment shown in FIG.

  In FIG. 1, 1 is a DPC (diphenyl carbonate) storage tank, 2 is a stirring blade, 3 is a BPA (bisphenol A) hopper, 4a and b are raw material mixing tanks, 5 is a DPC flow control valve, 6 is a BPA flow control valve, and 7 is Pump, 8 is a catalyst flow rate control valve, 9 is a program control device, 10 is a pump, 11 is a catalyst storage tank, 12 is a by-product discharge pipe, 13a, b, and c are vertical polymerization tanks, 14 is a Max Blend blade, and 15 is A horizontal polymerization tank 16 indicates a lattice blade.

  A diphenyl carbonate melt prepared at 120 ° C. under a nitrogen gas atmosphere and a bisphenol A powder weighed under a nitrogen gas atmosphere from a DPC storage tank (1) of 205.0 mol / h and a BPA hopper (3), respectively. To 197.1 mol / h (raw material molar ratio: 1.040), measured with a micro motion type flow meter and a loss-in-weight type weight feeder, and adjusted to 140 ° C. in a nitrogen atmosphere. It supplied continuously to the mixing tank (4a).

  Subsequently, the raw material mixture was continuously supplied to the raw material mixing tank (4b) and further to the first vertical stirring polymerization tank (13a) having a capacity of 100 L via the pump (7). On the other hand, simultaneously with the start of the supply of the above mixture, a 2% by weight cesium carbonate aqueous solution as a catalyst was supplied through a catalyst introduction tube at 1.6 mL / h (set catalyst amount: 0.51 μmol with respect to 1 mol of bisphenol A). Continuous supply was started at a flow rate.

  At this time, in the actual catalyst flow rate control, the program control device (9) calculates the set catalyst flow rate from the BPA flow rate and the set catalyst amount detected by the BPA flow rate control valve (6), and this value and the catalyst flow rate control are calculated. This was accomplished by controlling the opening of the catalyst flow rate control valve (8) so that the catalyst flow rate actually measured by the measuring device provided in the valve (8) coincided.

  The first vertical stirring polymerization tank (13a) equipped with the Max blend blade (14) is controlled at 220 ° C. under atmospheric pressure and nitrogen atmosphere, and further the polymer at the bottom of the tank so that the average residence time is 60 minutes. The liquid level was kept constant while controlling the valve opening degree provided in the discharge line.

  The polymerization liquid discharged from the bottom of the tank was subsequently provided with a vertical stirring polymerization tank (13b, 13c) having a capacity of 100 L equipped with second and third Max Blend blades, and a fourth lattice blade (16). The continuous polymerization tank (15) having a capacity of 150 L was continuously supplied. As shown in the table below, the reaction conditions in the second to fourth polymerization tanks were set so that the temperature, the high vacuum, and the low stirring speed became as the reaction progressed.

  During the reaction, the liquid level is controlled so that the average residence time in the second to fourth polymerization tanks is 60 minutes. In each polymerization tank, by-product phenol is removed as a by-product discharge pipe ( It was removed from 12). The system was continuously operated for 1500 hours under the above conditions. In addition, the aromatic polycarbonate extracted from the polymer outlet at the bottom of the fourth polymerization tank is introduced into a twin-screw extruder equipped with a three-stage vent port in a molten state, and butyl p-toluenesulfonate is aromatic. 4.0 ppm (4.4 times mol of the neutralization amount of the catalyst) was added to the weight of the polycarbonate, hydrogenated, devolatilized, and pelletized.

  The obtained aromatic polycarbonate had a viscosity average molecular weight (Mv) and a terminal OH group content of 21500 and 500 ppm, respectively. This is represented as transesterification polycarbonate.

Comparative production example 1 of interfacial aromatic polycarbonate
Bisphenol A was polycondensed by an interfacial method and end-capped with t-butyl-phenol. The obtained aromatic polycarbonate had a viscosity average molecular weight (Mv) and a terminal OH group content of 21500 and 30 ppm, respectively. This is referred to as interfacial polycarbonate.

[Additives] The following were used as additives.
(1) Carbodiimide: Nisshinbo Polycarbodiimide LA-1 (LA-1)

(2) Phosphorus stabilizer: Tris (2.4-di-t-butylphenyl) phosphite manufactured by Adeka Company, Grade / Adeka Stub 2112 (AS2112)

(3) Hindered phenol-based stabilizer: Okudadecyl-3- (3.5-di-t-butyl-4-hydroxyphenyl) propionate (Irganox 1076 (Irg. 1076)) manufactured by Ciba Specialty Chemicals

(4) Mold release agent: Pentaerythritol tetrastearate H476 (H476) manufactured by NOF Corporation

(5) PBT resin: PBT resin manufactured by Mitsubishi Engineering Plastics, Novaduran 5020C (IV = 1.20).

[Examples 1 to 3, Comparative Examples 1 to 7]
An aromatic polycarbonate resin and various additives were blended in the blending amounts (parts by weight) shown in Table 2, and kneaded and pelletized at a barrel temperature of 270 ° C. with a single screw extruder (manufactured by Tanabe Plastics). After drying the obtained pellets at 120 ° C. for 5 hours, a test piece was prepared by injection molding under the conditions of cylinder temperature 280 ° C. and mold temperature 80 ° C. using SE50D (clamping force 50 t) manufactured by Sumitomo Heavy Industries, Ltd. Created. This test piece was evaluated by conducting a hydrolysis test under the conditions of a temperature of 120 ° C. and a humidity of 100%. The results are shown in Table 3.

  As is clear from Table 3, the transesterification polycarbonate resin compositions of Examples 1 and 2 of the present invention have little increase in haze (deterioration of transparency) and decrease in molecular weight (deterioration of physical properties) due to hydrolysis treatment, Excellent hydrolyzability.

  On the other hand, the resin compositions of Comparative Examples 1 to 4 have a large increase in haze and a decrease in molecular weight due to hydrolysis treatment, and are inferior in hydrolysis resistance. Further, from Comparative Examples 5 and 6, it was confirmed that even when a carbodiimide compound was blended with the interfacial polycarbonate, there was no effect of improving hydrolysis resistance, and the yellowing degree (YI) was deteriorated by blending carbodiimide. It was.

  Moreover, since it is difficult to measure the molecular weight of PC / PBT alloy in Example 3 and Comparative Example 7, the degree of hydrolysis was determined by Q value measurement, and the results are shown in Table 4. Q value evaluated the measured value in the hydrolysis test in temperature 105 degreeC and humidity 100%.

  As is apparent from Table 4, in Example 3, the increase in the Q value was suppressed as compared with Comparative Example 7, and it was found that hydrolysis was clearly suppressed. Carbodiimide is commonly used as a hydrolyzation improver for polyesters such as PBT. However, in alloying with PC, carbodiimide has no effect on interfacial PC, so in melting alloy of PC and PBT. , You can see that it is more effective.

  The action mechanism of carbodiimide is to improve the hydrolysis resistance by reacting with the end of the polymer and sealing the end to improve the hydrolysis resistance, and also by deactivating the remaining catalyst in the polymer. Therefore, the amount of carbodiimide may be appropriately adjusted depending on the amount of residual catalyst of PBT to be used.

One aspect of polycarbonate resin production equipment scheme

Explanation of symbols

1: DPC (diphenyl carbonate) storage tank 2: Stirring blade 3: BPA (bisphenol A) hopper 4a, 4b: Raw material mixing tank 5: DPC flow control valve 6: BPA flow control valve 7, 10: Pump 8: Catalyst flow control valve 9: Program control device 11: Catalyst storage tank 12: By-product discharge pipe 13a, 13b, 13c: Vertical polymerization tank 14: Max blend blade 15: Horizontal polymerization tank 16: Lattice blade

Claims (6)

  An aromatic polycarbonate resin composition containing 0.01 to 5 parts by weight of a carbodiimide compound with respect to 100 parts by weight of an aromatic polycarbonate resin produced by transesterification from an aromatic dihydroxy compound and a carbonic acid diester .   The aromatic polycarbonate resin composition according to claim 1, wherein the aromatic polycarbonate resin has a viscosity average molecular weight of 13,000 to 30,000.   The aromatic polycarbonate resin composition according to claim 1, wherein the terminal hydroxyl group concentration of the aromatic polycarbonate resin is 100 to 1500 ppm.   4. The aromatic polycarbonate resin composition according to any one of claims 1 to 3, wherein the carbodiimide compound is a polycarbodiimide compound having a number average molecular weight of 500 to 5000.   The aromatic polycarbonate resin composition according to claim 1, wherein the carbodiimide compound is a carbodiimide-modified isocyanate.   The resin molding formed by shape | molding the aromatic polycarbonate resin composition in any one of Claims 1 thru | or 5.

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