JP4984113B2 - Polycarbonate resin composition - Google Patents

Description

  Since the present invention is excellent in fluidity and heat stability during molding and excellent in transparency and the like, it can be used for various electrical and electronic parts, machine parts, safety products, medical supplies, daily goods, packaging supplies, etc. The present invention relates to a polycarbonate resin composition that can be used in various fields.

  Polycarbonate resins have excellent properties such as transparency, heat resistance, dimensional stability, impact resistance, and electrical properties. For example, cellular phones, personal computer parts, automobile parts, magnetic cards, and compact disk bases. Etc. are used. In particular, as electric parts such as mobile phones and automobile parts such as rear spoilers, parts with more complex shapes and large parts are used in response to the recent demand from industry for high functionality. Is increasing.

  However, the polycarbonate resin generally has a very high heat melt viscosity and low fluidity during molding. For this reason, when a polycarbonate resin alone is used when manufacturing a product having a complicated shape such as a thin wall shape or a large product having a long resin flow distance, generally, a weld line, a flow mark, a meat sink, a warp deformation, a short There was a problem that a defective phenomenon called shot, color unevenness, burn, and the like occurred, resulting in poor molding processability.

  Therefore, as a method for improving the molding processability and fluidity of the polycarbonate resin, the conventional polycarbonate resin, acrylonitrile-butadiene-styrene resin (ABS resin), polyethylene terephthalate resin (PET resin), polybutylene terephthalate resin (PBT resin), And a method of using a polycarbonate resin composition obtained by mixing and alloying a polyolefin resin or the like is known.

  As the alloyed polycarbonate resin composition, for example, one containing a polycarbonate resin and a low molecular weight polyester compound as a melt viscosity reducing agent is known (for example, see Patent Document 1).

However, the polycarbonate resin composition may cause an excessive transesterification reaction between the polycarbonate resin and the melt viscosity reducing agent due to the influence of the melt viscosity reducing agent and heat to be used. The polycarbonate resin composition has a problem that the obtained molded product is discolored to yellow and transparency and mechanical properties are impaired.
JP 2002-121373 A

  The problem to be solved by the present invention is to provide a polycarbonate resin composition excellent in moldability and fluidity without impairing the excellent transparency of the polycarbonate resin.

  The inventors of the present invention, while proceeding with the study to solve the above problems, can be used in combination with a polycarbonate resin or a polyester compound, by using a plurality of specific compounds, molding processability without impairing the characteristics of the polycarbonate resin, We found that fluidity can be improved.

That is, the present invention contains a polycarbonate resin (a), a polyester compound (b) whose molecular ends are sealed with a monovalent alcohol, and a phosphite compound (c) or a phosphonite compound (d). such Lupo a polycarbonate resin composition, the polyester compound (b) is an aromatic dicarboxylic acid having 8 to 18 aliphatic diol and carbon atoms 2 to 25 carbon atoms, aliphatic 4 to 18 carbon atoms carbide It is obtained by reacting with a monohydric alcohol having a hydrogen group or an alicyclic hydrocarbon group. The melting point is 140 to 220 ° C., the hydroxyl value is 15 or less, and the temperature is increased at a rate of 10 ° C. per minute in air. And a ratio of the mass after heating to 300 ° C. to the mass of the polyester compound before heating is 95% by mass or more. It relates Boneto resin composition.

  If the polycarbonate resin composition of the present invention is used, it is possible to obtain a product having excellent transparency and a complicated shape such as a thin shape or a large product.

  The present invention comprises a polycarbonate resin (a), a polyester compound (b) having a molecular end sealed with a monohydric alcohol, and a phosphite compound (c) or a phosphonite compound (d). In addition, it is a polycarbonate resin composition containing various additives as required.

First, the polycarbonate resin (a) used in the present invention will be described.
The polycarbonate resin (a) used in the present invention is, for example, a method of interfacial polycondensation of divalent phenol and carbonyl halide, or a method of melt polymerization (transesterification method) of divalent phenol and carbonic acid diester. What was manufactured by etc. can be used.

  Examples of the divalent phenol include hydroquinone, resorcin, catechol, 4,4′-dihydroxydiphenyl, 1,1-bis (4-hydroxyphenyl) ethane, and 2,2-bis (4-hydroxyphenyl) propane [bisphenol. A], 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4′-hydroxyphenyl) butane, bis (4-hydroxyphenyl) cycloalkane, bis (4- Hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) ketone, 4,4′-dihydroxydiphenyl ether and the like can be used alone or in combination of two or more. Among these, as the divalent phenol, bis (hydroxyphenyl) alkanes such as bisphenol A that are commercially available are preferably used as main raw materials, and obtained by molding a polycarbonate resin composition using these. The molded product has excellent impact resistance.

  As the carbonyl halide, for example, carbonyl chloride generally referred to as phosgene, carbonyl bromide, and a mixture thereof can be used.

  Examples of the carbonic acid diester include diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, diethyl carbonate, dimethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, and mixtures thereof. be able to.

  The method of interfacial polycondensation of the divalent phenol and the carbonyl halide is generally referred to as, for example, the phosgene method. Specifically, the sodium hydroxide aqueous solution in which the divalent phenol is dispersed, In this method, the dissolved methylene chloride solution is mixed, stirred and subjected to interfacial polycondensation.

  The divalent phenol and carbonic acid diester are melt-polymerized (transesterification method) by, for example, heating and melting the divalent phenol and carbonic acid diester and proceeding the transesterification reaction by dephenol reaction to polycondensation. It is a method to make it.

  As the method for producing the polycarbonate resin (a), among the various production methods described above, the method of interfacial polycondensation of the divalent phenol and carbonyl halide is the content of low molecular weight by-products such as phenols. Is preferable because of less. In addition, the polycarbonate resin (a) obtained by such a method can exhibit high impact resistance after molding.

  As the polycarbonate resin (a), one having a weight average molecular weight (the weight average molecular weight described below is a value in terms of styrene measured by GPC) in the range of 15000 to 60000 is used. Is preferable from the viewpoint of excellent balance of mechanical strength, impact resistance, and composition fluidity of the obtained molded product, and if a material having a weight average molecular weight in the range of 25000 to 45000 is used, further excellent mechanical properties are obtained. It is more preferable because a balance between physical properties and composition fluidity can be obtained.

Next, the polyester compound (b) used in the present invention will be described.
The polyester compound (b) used in the present invention is a polyester compound having a structure in which the terminal is sealed with a monohydric alcohol, and has excellent flowability in the polycarbonate resin (a) having high heat melt viscosity and low fluidity. Sex can be imparted.

  The polyester compound (b) is produced, for example, by reacting a polyester having a carboxyl group at a terminal obtained by esterifying a polyvalent carboxylic acid and a polyhydric alcohol with a known method and a monohydric alcohol. can do.

  The esterification reaction can be promoted by an acid catalyst such as paratoluenesulfonic acid or phosphoric acid, or a metal catalyst such as tetraisopropyl titanate, tetrabutyl titanate, dibutyltin oxide, or zinc chloride. In particular, it is preferable to use the metal catalyst in the esterification reaction. Moreover, it is preferable to perform the said esterification reaction under a 130-270 degreeC heating.

  As the polyvalent carboxylic acid, an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid, or an aromatic tricarboxylic acid can be preferably used. Especially, it is preferable to use C8-C18 aromatic dicarboxylic acid from a viewpoint of improving the compatibility with the said polycarbonate resin (a) and the heat resistance of the polycarbonate resin composition obtained.

  The aromatic dicarboxylic acid is preferably terephthalic acid, isophthalic acid, phthalic acid, naphthalene 2,6 dicarboxylic acid, α, β- (4-carboxyphenoxy) ethane, 4,4′-dicarboxydiphenyl, 5- Sodium sulfoisophthalic acid or ester derivatives thereof can be used.

  As the polyhydric alcohol, an aliphatic diol, an aliphatic triol, or a dihydric phenol can be preferably used. Especially, it is preferable to use diol from a viewpoint of reducing the melt viscosity of the said polycarbonate resin (a), and it is more preferable to use C2-C25 aliphatic diol.

  The diol is preferably ethylene glycol, propylene glycol, 1,4-butanediol, 3-methyl-1,3-propanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, Decamethylene glycol, cyclohexanediol, cyclohexanedimethanol and the like can be used.

  As the monohydric alcohol, those having an aliphatic hydrocarbon group or alicyclic hydrocarbon group having 4 to 18 carbon atoms are preferable. Specifically, butanol, hexanol, isohexanol, heptanol, octanol, isooctanol, 2 -Ethylhexanol, nonanol, isononanol, 2-methyloctanol, decanol, isodecanol, undecanol, dodecanol, tridecanol, tetradecanol, hexadecanol, cyclohexanol and the like. These can be used as one kind or a mixture of two or more kinds. In particular, it is more preferable to use 2-ethylhexanol from the balance of mechanical strength and fluidity.

  As the polyester compound (b), its volatilization loss, that is, the mass after heating the polyester compound (b) at a rate of 10 ° C. per minute in the air until it reaches 300 ° C., before heating. The ratio of the polyester compound (b) to the mass is preferably 95% by mass or more from the viewpoint of maintaining the stability when the polycarbonate resin composition of the present invention is heat-processed such as injection molding, and is 98% by mass. More preferably.

  As said polyester compound (b), it is preferable to use what has the weight average molecular weight of the range of 1000-8000, and it is more preferable to use what has the weight average molecular weight of the range of 2000-6000 especially. It is more preferable to use the polyester compound (b) having a weight average molecular weight within the above range since the fluidity of the polycarbonate resin (a) can be improved and the volatilization of the polyester compound (b) can be suppressed. .

  Further, the polyester compound (b) preferably has a melting point in the range of 140 to 220 ° C, and more preferably has a melting point in the range of 150 to 180 ° C. If it is the said range, when compounding this polycarbonate resin composition, since it can prevent blocking under the hopper of an extruder, it is easy to handle and can improve the fluidity | liquidity of the polycarbonate resin (a) to be used easily.

  The acid value of the polyester compound (b) is preferably 2 or less, and the hydroxyl value of the polyester compound (b) is preferably 15 or less. When the polyester compound (b) having an acid value or hydroxyl value within the above range is used, the mechanical strength of the molded product obtained without reducing the molecular weight of the polycarbonate resin (a) when melt-mixed with the polycarbonate resin (a). Keeps impact resistance and does not cause coloring. More preferably, the acid value is 1 or less and the hydroxyl value is 5 or less.

  The compounding amount of the polyester compound (b) can greatly improve the fluidity of the polycarbonate resin (a) and can form a molded article having excellent transparency, mechanical strength, impact resistance and the like. When obtaining a resin composition, the range of 1-15 mass% is preferable with respect to the total mass of the polycarbonate resin composition of this invention, and the range of 3-10 mass% is more preferable.

Next, the phosphite compound (c) and the phosphonite compound (d) used in the present invention will be described.
The phosphite compound (c) and the phosphonite compound (d) used in the present invention suppress the reactivation of the metal catalyst used when the polyester compound (b) is produced, and the polycarbonate resin composition is colored. And the molecular weight reduction of the polycarbonate resin (a) can be effectively suppressed.

  The phosphite compound (c) is preferably bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bisoctadecylpentaerythritol diphosphite, bis (4-methyl-2,6 -Di-tert-butylphenyl) pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, and the like can be used. Particularly preferred is bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite.

  As the phosphonite compound (d), tetrakis (2,4-di-tert-butylphenyl) [1,1-biphenyl] -4,4′-diylbisphosphonite can be preferably used. .

  The phosphite compound (c) and the phosphonite compound (d) may be used alone or in combination of two or more.

  The phosphite compound (c) and the phosphonite compound (d) preferably have a weight average molecular weight in the range of 500 to 2000, particularly those having a weight average molecular weight in the range of 600 to 1500. More preferred. By using a phosphite compound (c) or a phosphonite compound (d) having a weight average molecular weight in the above range, sublimation when heating and kneading the polycarbonate resin composition of the present invention, foaming of the resin, Contamination of the mold used for heating and melting and molding can be suppressed.

  Content of the said phosphite type compound (c) and a phosphonite type compound (d) changes according to residual amounts and kinds, such as a metal catalyst used when manufacturing the said polyester compound (b). In general, when the residual amount of the metal catalyst is large, it is preferable to increase the contents of the phosphite compound (c) and the phosphonite compound (d). However, from the viewpoint of suppressing an excessive transesterification reaction of the polyester compound (b) and suppressing a defect in the surface and appearance of a molded article made of the polycarbonate resin composition of the present invention, the total amount of the polycarbonate resin composition , Preferably in the range of 0.01 to 0.5 mass%, more preferably in the range of 0.02 to 0.1 mass%.

  In the polycarbonate resin composition of the present invention, in addition to the phosphite compound (c) and the phosphonite compound (d), it is possible to use a hindered phenol compound (e) as an antioxidant. It is preferable from the viewpoint of further improving the thermal stability of the product.

  Examples of the hindered phenol compound (e) include 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, triethylene glycol-bis [3-(-tert-butyl). -5-methyl-4-hydroxyphenyl) propionate], pentaerythrityl tetrakis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate), octadecyl 3- (3,5-di-tert) -Butyl-4-hydroxyphenyl) propionate, N, N′-hexamethylenebis (3,5-di-tert-butyl-4-hydrocinnamamide), 1,3,5-trimethyl-2,4,6 -Tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 1,6-hexanediol-bis (3- (3 -Di-tert-butyl-4-hydroxyphenyl) propionate), 2,2-thio-diethylenebis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate), 3,9-bis [2- [3- (3-tert-Butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro (5,5) Undecane, particularly preferably pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate can be used.

  As the hindered phenol compound (e), those having a weight average molecular weight in the range of 500 to 2000 are preferably used, and those having a weight average molecular weight in the range of 600 to 1500 are more preferably used. preferable. By using the hindered phenolic compound (e) having a weight average molecular weight within the above range, when the polycarbonate resin composition of the present invention is heated and melt-kneaded, the resin is foamed, or when the resin is heated and melted and molded. It is possible to suppress the contamination of the mold used in the process.

  The hindered phenol-based compound (e) is the total mass of the polycarbonate resin composition of the present invention from the viewpoint of improving the thermal stability of the obtained polycarbonate resin composition and preventing the appearance of the molded product from being defective. Is preferably used in the range of 0.01 to 0.5% by mass, and more preferably in the range of 0.02 to 0.1% by mass.

  In the polycarbonate resin composition of the present invention, other stabilizers, antistatic agents, lubricants, mold release agents, compatibilizing agents, hydrolysis inhibitors, and the like can be used as long as the object of the present invention is not impaired. .

  The polycarbonate resin (a), the polyester compound (b), the phosphite compound (c) or the phosphonite compound (d), and the hindered phenol compound (e), if necessary, are mixed. As a method for producing the polycarbonate resin composition of the present invention, for example, using a mixer such as a Banbury or a kneader, a roll, a single screw kneading extruder, a twin screw extrusion kneader, or the like, heating and kneading them, During the polymerization reaction of the polycarbonate resin (a), the polyester compound (b), the phosphite compound (c) or the phosphonite compound (d), and the hindered phenol compound (e) as necessary. In the organic solvent solution of the polycarbonate resin (a) and the polyester compound (b), And the hindered phenolic compound (e), if necessary, after being dispersed, and then a solvent by a method such as a coagulation method, a casting method or a direct drying method. The method etc. which remove | eliminate are mentioned.

  As a method for producing the carbonate resin composition of the present invention, the polycarbonate resin (a), the polyester compound (b), and the phosphite compound are used from the viewpoint of productivity using a twin-screw extrusion kneader. A method in which (c) or the phosphonite compound (d) and, if necessary, the hindered phenol compound (e) and the like are heated, melted and kneaded to form a compound is preferable.

  When producing the carbonate resin composition of the present invention, the polycarbonate resin (a), the polyester compound (b), the phosphite compound (c) or the phosphonite compound (d), and as necessary. The above-mentioned various kinds of kneaders such as those obtained by homogenizing the hindered phenol compound (e) etc. in advance using, for example, a Henschel mixer or a ribbon blender, or those obtained by master batching a plurality of raw materials Or may be supplied separately. The polycarbonate resin (a), the polyester compound (b), the phosphite compound (c) or the phosphonite compound (d), and the hindered phenol compound (e) as necessary It is preferable that the material is sufficiently dried in advance.

  The above-mentioned heat melting and kneading of various raw materials should be performed with a sufficient share at a resin temperature in the range of “Tg + 20 ° C. to Tg + 150 ° C.”, where Tg is the glass transition temperature of the polycarbonate resin (a). It is preferable for improving the ease of kneading and preventing the deterioration of various raw materials due to heat.

  Moreover, the polycarbonate resin composition of the present invention that has been heat-melt-kneaded and compounded by the above-described method may be pelletized as necessary, for example.

  The polycarbonate resin composition of the present invention can be molded by various methods. For example, a molding method such as an injection molding method, a hollow molding method, an extrusion molding method, or a compression molding method can be applied, and among them, it is preferably applied to an injection molding method in which high fluidity is required for the resin composition.

  When the polycarbonate resin composition of the present invention is molded by an injection molding method, the mold temperature and the cylinder temperature are generally set lower than when injection molding because the resin composition is excellent in fluidity when heated and melted. It is possible to mold by reducing the injection pressure and mold clamping pressure.

  As described above, by using the polycarbonate resin composition of the present invention, it is possible to manufacture a molded product having a complicated shape, which has been difficult in the past, to manufacture a molded product having a shape having a thin-walled portion, or to a resin composition. Large moldings requiring a high level of fluidity can be produced. And since the molded product obtained by molding the polycarbonate resin composition of the present invention is excellent in transparency, heat resistance, etc., for example, mobile phones, personal computers, car navigation systems and buttons, keys, display function parts, etc. It can be used for automobile parts such as electric and electronic parts and rear spoilers with brake lamps.

  Hereinafter, the present invention will be described in detail based on examples.

<Production Example 1>
A 1-liter four-necked flask is charged with 543 parts by mass of dimethyl terephthalate, 227 parts by mass of 1,4-butanediol, and 255 parts by mass of 2-ethylhexanol. 0.031 parts by mass of isopropyl titanate was added, and after 1 hour, the temperature was raised to 230 ° C., and the reaction was further carried out for 5 hours. Furthermore, the excess alcohol was removed under reduced pressure of 5 mmHg for 5 hours, and the catalyst was deactivated by adding 0.021 parts by mass of 85% by mass phosphoric acid, whereby the end of the molecule was sealed with a monovalent alcohol ( b-1) 651 parts by mass (acid value 0.4, hydroxyl value 1.1) was prepared.

<Production Example 2>
A 1-liter four-necked flask is charged with 542 parts by weight of phthalic anhydride, 253 parts by weight of propylene glycol, and 192 parts by weight of isononyl alcohol. 031 parts by mass was added, and the reaction was further performed for 5 hours. Furthermore, the excess alcohol was removed under reduced pressure of 5 mmHg for 5 hours, and the catalyst was deactivated by adding 0.021 parts by mass of 85% by mass phosphoric acid, whereby the end of the molecule was sealed with a monovalent alcohol ( b-2) 687 parts by mass (acid value 0.5, hydroxyl value 4.2) were prepared.

<Example 1>
Next, 5 parts by mass of the polyester compound (b-1) with respect to 95 parts by mass of the polycarbonate resin (a-1) having an average weight molecular weight of 37000, which is polycondensed by phosgene method and sufficiently dried using bisphenol A as a raw material, Bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite (IRGAFOS 126 manufactured by Ciba Specialty Chemicals, hereinafter abbreviated as I-126) as a phosphite compound, 0.05 parts by mass, hindered Pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate (IRGANOX 1010 manufactured by Ciba Specialty Chemicals: hereinafter abbreviated as I-1010) 0.05 mass as a phenol compound Part premixed with a Henschel mixer After, and compounded by extruding at a temperature of 280-260 ° C. using a small twin-screw extruder (Brabender), and then to obtain a polycarbonate resin composition pellet shape by cutting the strand.

<Example 2>
Except for changing the blending amount of the polyester compound (b-1) from 5 parts by weight to 10 parts by weight and changing the blending amount of the polycarbonate resin (a-1) from 95 parts by weight to 90 parts by weight, A pellet-shaped polycarbonate resin composition was obtained in the same manner as in Example 1.

<Example 3>
Tetrakis (2,4-di-tert-butylphenyl) [1,1-biphenyl] -4,4′-diylbisphosphonite (IRGAFOS manufactured by Ciba Specialty Chemicals) instead of I-126 A pellet-shaped polycarbonate resin composition was obtained in the same manner as in Example 1 except that 0.05 part by mass of P-EPQ (hereinafter abbreviated as P-EPQ) was used.

<Example 4>
A pellet-shaped polycarbonate resin composition was obtained in the same manner as in Example 1 except that 5 parts by mass of the polyester compound (b-2) was used instead of the polyester compound (b-1).

<Comparative Example 1>
Except not using the said polyester compound (b-1) and having changed the usage-amount of polycarbonate resin (a-1) from 95 mass parts to 100 mass parts, it is pellet-shaped by the method similar to Example 1. A polycarbonate resin composition was obtained.

<Comparative example 2>
A pellet-shaped polycarbonate resin composition was obtained in the same manner as in Example 1 except that I-126 was not used.

<Comparative Example 3>
A pellet-shaped polycarbonate resin composition was obtained in the same manner as in Example 1 except that a polybutylene terephthalate resin was used instead of the polyester compound (b-1).

[Evaluation method]

(Liquidity)
Each pellet-shaped polycarbonate resin composition was dried at 120 ° C. for 5 hours, and then fluidity was measured by melt index (MI). The measurement conditions were 280 ° C. and load 2.16 kgf. In addition, it is practically preferable that the value of the outflow amount of the heat-melted polycarbonate resin composition is 20 g / 10 min or more.

<Molding processability>
(Evaluation of appearance defects and molding defects)
After drying each pellet-shaped polycarbonate resin composition at 120 ° C. for 5 hours, using a 30 ton vertical injection molding machine, 1/4 inch under molding conditions of cylinder temperature 280 ° C., injection pressure 96 MPa, mold temperature 80 ° C. Using a mold capable of simultaneously molding a thickness bar test piece and a 1/16 inch thickness bar test piece (both width 12.7 mm × length 127 mm, one side gate), 100 sheets were each continuously formed.
Polycarbonate resin (a-1), polyester compound (b-1), bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, tetrakis ( 2,4-di-tert-butylphenyl) [1,1-biphenyl] -4,4′-diylbisphosphonite and other degradation products such as mold contamination and molding appearance defects evaluated. When the contamination of the mold or the appearance defect of the molded product occurred, the evaluation was x, and when it did not occur at all, the evaluation was ○.
Moreover, it was evaluated as x when a partial defect or the like of the obtained molded product, which is generally referred to as a short shot, occurred, and when it did not occur at all.

(transparency)
After drying each pellet-shaped polycarbonate resin composition at 120 ° C. for 5 hours, using a 30 ton vertical injection molding machine, 1/4 inch under molding conditions of cylinder temperature 280 ° C., injection pressure 96 MPa, mold temperature 80 ° C. A thickness bar specimen was molded. The obtained test piece was yellowishly colored or its transparency was visually evaluated.
X: Coloring was confirmed.
Δ: Some coloring was confirmed.
○: Uncolored.

Claims (4)

  Polycarbonate resin composition comprising a polycarbonate resin (a), a polyester compound (b) whose molecular ends are sealed with monohydric alcohol, and a phosphite compound (c) or a phosphonite compound (d) And the polyester compound (b) is an aliphatic diol having 2 to 25 carbon atoms, an aromatic dicarboxylic acid having 8 to 18 carbon atoms, and an aliphatic hydrocarbon group or alicyclic hydrocarbon having 4 to 18 carbon atoms. It was obtained by reacting with a monohydric alcohol having a group. The melting point was 140 to 220 ° C., the hydroxyl value was 15 or less, the temperature was increased in air at a rate of 10 ° C. per minute and heated to 300 ° C. The ratio of the latter mass to the mass of the polyester compound before heating is 95% by mass or more, and the compounding amount of the polyester resin (b) is polycarbonate. The content of the phosphite compound (c) and the phosphonite compound (d) is 0.01 to the total mass of the polycarbonate resin composition. Polycarbonate resin composition characterized by being -0.5% by mass.   The polycarbonate resin composition according to claim 1, wherein the phosphite compound (c) and the phosphonite compound (d) have a molecular weight of 500 to 2,000.   The polycarbonate resin composition according to claim 1, further comprising a hindered phenol compound (e). The polycarbonate resin composition according to claim 3 , wherein the hindered phenol compound (e) has a molecular weight of 500 to 2,000.