JP4588408B2 - Method for producing polycarbonate resin pellets and method for producing molded products - Google Patents

Description

  The present invention relates to a polycarbonate resin molded article and a polycarbonate resin pellet used therein. More specifically, the present invention relates to a polycarbonate resin molded article having excellent thermal stability and transparency and excellent hue, and a polycarbonate resin pellet used in the molded article.

  Polycarbonate resins are used in a wide range of fields because they have many excellent physical properties such as transparency, heat resistance and mechanical strength. Among them, the demand for optical molded products is remarkable, and it is widely used as a material for lenses, prisms, substrates for information recording media, etc. Especially for optical molded products such as eyeglass lenses, it has good transparency and high temperature environment during use. It is preferably used because of its excellent heat resistance under the surface and impact resistance during handling. In addition, it is important that the optically molded product is excellent in appearance and hue in addition to transparency, and therefore a heat stabilizer is usually used in the polycarbonate resin.

  Conventionally, phosphorus heat stabilizers, sulfur heat stabilizers, hindered phenol heat stabilizers, and the like are known as heat stabilizers for polycarbonate resins (see Patent Document 1 and Patent Document 2). In particular, as a heat stabilizer for optical polycarbonate resin, a phosphorus-based heat stabilizer for the purpose of decomposing peroxide generated in the resin during melt extrusion molding is used. Decreasing the thermal stability for some reason may cause a decrease in molecular weight or coloring, and this improvement has been demanded.

JP 57-158254 A JP 2000-351892 A

  An object of the present invention is to provide a polycarbonate resin molded product having excellent thermal stability and transparency and excellent hue in a molded product obtained by melt-molding polycarbonate resin pellets.

  As a result of intensive studies in order to solve the above problems, the present inventor used a phosphorus-based heat stabilizer as a heat stabilizer for polycarbonate resin under high shear stress and high temperature. The self-decomposition of the phosphorus-based heat stabilizer and the exchange reaction with the polycarbonate resin occur to produce a compound of the following formula [1], which not only loses the activity as the original heat stabilizer, but also a compound of the following formula [1] Was found to cause a decrease in molecular weight and coloration of the polycarbonate resin. In addition, content of the compound of following formula [1] is calculated | required by measuring phosphorus content after processing polycarbonate resin with n-hexane and extracting a phosphorus stabilizer.

（Ｒ：末端停止剤基）

(R: terminal terminator group)

  And this inventor is the phosphorus compound after said n-hexane treatment of the molded article obtained by carrying out melt residence molding of the total phosphorus content and polycarbonate resin pellet which are contained in a polycarbonate resin pellet (said Formula [ 1) The content of the compound in the range of the specific amount makes it possible to obtain a polycarbonate resin molded article having good thermal stability and transparency and excellent hue, and a polycarbonate having the phosphorus content. The present inventors have found a melt extrusion method for producing resin pellets and arrived at the present invention.

Thus, according to the present invention,
1. When a polycarbonate resin powder having a viscosity average molecular weight (X) of 10,000 to 50,000 and a total phosphorus content of 20 to 120 ppm is melt-extruded by an extruder, the resin temperature Y (° C.) is 185 × ln X−1605 ≦ Y ≦ 256 × 10 ⁻⁵ X + 266 (where X is the viscosity average molecular weight of the polycarbonate resin powder to be used) is a method of producing a polycarbonate resin pellet by melting and extruding the polycarbonate resin pellet. The OH number of the phenolic OH group of the terminal group is in the range of 5 to 50 eq / ton per polycarbonate resin, (i) the total phosphorus content in the polycarbonate resin pellet is 35 to 100 ppm, and (ii) Resin molding of polycarbonate resin pellets at 340 ° C for 10 minutes Was a resin molded article is treated with n- hexane, the total phosphorus content in the resin molded article after n- hexane process satisfies that the 1～30Ppm, method for producing a polycarbonate resin pellets.

2. The polycarbonate resin pellet is (ii) a resin molded product obtained by dwelling a polycarbonate resin pellet at 340 ° C. for 10 minutes, treated with n-hexane, and containing all phosphorus in the resin molded product after n-hexane treatment. 2. The method for producing a polycarbonate resin pellet as described in 1 above, wherein the amount is 5 to 25 ppm.

3 . 2. The method for producing polycarbonate resin pellets according to item 1 above, wherein the polycarbonate resin pellets contain a trivalent phosphorus compound.

4. The trivalent phosphorus compound of the preceding paragraph 3 is tris (2,4-di -tert- butylphenyl) phosphite or 4,4'-biphenylene phosphinic acid tetrakis (2,4-di -tert- butylphenyl) The manufacturing method of the polycarbonate resin pellet of description.

5 . When a polycarbonate resin powder having a viscosity average molecular weight (X) of 10,000 to 50,000 and a total phosphorus content of 20 to 120 ppm is melt-extruded by an extruder, the resin temperature Y (° C.) is 185 × ln X−1605 ≦ Y ≦ 256 × 10 ⁻⁵ X + 266 (where X is the viscosity average molecular weight of the polycarbonate resin powder to be used) is melt-extruded to obtain polycarbonate resin pellets, and the obtained pellets are melt-molded to obtain polycarbonate resin A method for producing a molded article, wherein the polycarbonate resin pellet has an OH value of a phenolic OH group as a terminal group in the range of 5 to 50 eq / ton per polycarbonate resin, (i) in the polycarbonate resin pellet The total phosphorus content is 35-100 ppm, and (ii A resin molded product obtained by residence molding of polycarbonate resin pellets at 340 ° C. for 10 minutes is treated with n-hexane, and the total phosphorus content in the resin molded product after n-hexane treatment is 1 to 30 ppm. A satisfactory method for producing a polycarbonate resin molded product .

Hereinafter, the present invention will be described in detail.
The polycarbonate resin targeted in the present invention is a polycarbonate resin obtained by reacting a dihydric phenol compound and a carbonate precursor. There is no restriction | limiting in particular as a dihydric phenol compound used here, A various well-known thing can be used.

  Representative examples of dihydric phenol compounds include hydroquinone, resorcinol, 4,4′-dihydroxydiphenyl, bis (4-hydroxyphenyl) methane, bis {(4-hydroxy-3,5-dimethyl) phenyl} methane, 1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 2,2-bis (4-hydroxyphenyl) propane (commonly called bisphenol A), 2, 2-bis {(4-hydroxy-3-methyl) phenyl} propane, 2,2-bis {(4-hydroxy-3,5-dimethyl) phenyl} propane, 2,2-bis {(3,5-dibromo -4-hydroxy) phenyl} propane, 2,2-bis {(3-isopropyl-4-hydroxy) phenyl} propane, 2,2- Su {(4-hydroxy-3-phenyl) phenyl} propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) -3-methylbutane, 2,2-bis ( 4-hydroxyphenyl) -3,3-dimethylbutane, 2,4-bis (4-hydroxyphenyl) -2-methylbutane, 2,2-bis (4-hydroxyphenyl) pentane, 2,2-bis (4- Hydroxyphenyl) -4-methylpentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -4-isopropylcyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis {(4- Droxy-3-methyl) phenyl} fluorene, α, α′-bis (4-hydroxyphenyl) -o-diisopropylbenzene, α, α′-bis (4-hydroxyphenyl) -m-diisopropylbenzene, α, α ′ -Bis (4-hydroxyphenyl) -p-diisopropylbenzene, 1,3-bis (4-hydroxyphenyl) -5,7-dimethyladamantane, 4,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenylsulfoxide 4,4′-dihydroxydiphenyl sulfide, 4,4′-dihydroxydiphenyl ketone, 4,4′-dihydroxydiphenyl ether, and 4,4′-dihydroxydiphenyl ester. These may be used alone or in combination of two or more. Can be used.

  Among them, bisphenol A, a copolymer of 9,9-bis {(4-hydroxy-3-methyl) phenyl} fluorene and bisphenol A, 1,1-bis (4-hydroxyphenyl) -3,3,5 -A copolymer of trimethylcyclohexane and bisphenol A, 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane or α, α'-bis (4-hydroxyphenyl) -m-diisopropylbenzene is preferred. In particular, bisphenol A is preferred.

  Examples of the carbonate precursor include carbonyl halide, diaryl carbonate, haloformate, and the like. Specific examples include phosgene, diphenyl carbonate, dihaloformate of dihydric phenol, and the like.

  As an example of the method for producing the polycarbonate resin in the present invention, a method in which an alkaline aqueous solution of a dihydric phenol compound and a carbonate precursor are reacted by a solution polymerization method (interfacial condensation polymerization method) is used. In producing the polycarbonate resin, if necessary, a catalyst, a terminal terminator, a dihydric phenol antioxidant, and the like may be used. The polycarbonate resin may be a branched polycarbonate resin copolymerized with a trifunctional or higher polyfunctional aromatic compound, or may be a polyester carbonate resin copolymerized with an aromatic or aliphatic difunctional carboxylic acid, Moreover, the mixture which mixed 2 or more types of the obtained polycarbonate resin may be sufficient.

  The reaction by the interfacial condensation polymerization method is usually a reaction between an alkaline aqueous solution of a dihydric phenol compound and phosgene, and is reacted in the presence of an organic solvent. As the alkali used in the alkaline aqueous solution, for example, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide are preferably used. As the organic solvent, for example, halogenated hydrocarbons such as methylene chloride and chlorobenzene are used, and methylene chloride is particularly preferably used. In order to accelerate the reaction, a catalyst such as a tertiary amine such as triethylamine, tetra-n-butylammonium bromide or tetra-n-butylphosphonium bromide, a quaternary ammonium compound or a quaternary phosphonium compound may be used. it can. At that time, the reaction temperature is usually 0 to 40 ° C., the reaction time is preferably about 10 minutes to 5 hours, and the pH during the reaction is preferably maintained at 9 or more.

  In such a polymerization reaction, a terminal stopper is usually used. Monofunctional phenols can be used as such end terminators. Monofunctional phenols are commonly used as end terminators for molecular weight control, and the resulting polycarbonate resins are compared to those that do not because the ends are blocked by groups based on monofunctional phenols. Excellent thermal stability. Such monofunctional phenols are generally phenols or lower alkyl-substituted phenols, and can be monofunctional phenols represented by the following formula [2].

［式中、Ａは水素原子、炭素数１〜９の直鎖または分岐のアルキル基あるいはアリールアルキル基であり、ｒは１〜５、好ましくは１〜３の整数である。］

[Wherein, A is a hydrogen atom, a linear or branched alkyl group having 1 to 9 carbon atoms or an arylalkyl group, and r is an integer of 1 to 5, preferably 1 to 3. ]

  Specific examples of the monofunctional phenols include phenol, p-tert-butylphenol, p-cumylphenol and isooctylphenol.

  These end terminators are desirably introduced at least at 5 mol%, preferably at least 10 mol%, based on the total end of the resulting polycarbonate resin. You may mix and use seeds or more.

  The organic solvent solution of the polycarbonate resin obtained by the interfacial polycondensation method is usually ion-exchanged water until the electric conductivity of washing water becomes 10 μS / cm or less, preferably 5 μS / cm or less, more preferably 1 μS / cm or less. The organic solvent solution of the polycarbonate resin that has been washed with distilled water or the like and further washed is powdered by removing the organic solvent, and this powder is dried, melt-extruded, and pelletized to provide a molding material.

In the present invention, as a method for pelletizing the polycarbonate resin powder, a known single-screw or multi-screw extruder can be used, and a single-screw extruder is preferably used. As conditions for melt extrusion, the resin temperature Y (° C.) of the polycarbonate resin is in the range of 185 × ln X−1605 ≦ Y ≦ 256 × 10 ⁻⁵ X + 266 (where X is the viscosity average molecular weight of the polycarbonate resin powder used). A method of melt extrusion so as to satisfy the above is preferably employed. The resin temperature Y (° C.) during melt extrusion is preferably 150 ° C. to 340 ° C., particularly preferably 200 ° C. to 320 ° C. The polycarbonate resin pellet obtained by melt extrusion under such conditions is excellent in thermal stability when the polycarbonate resin pellet is subjected to stay molding at 340 ° C. for 10 minutes, and the resulting resin molded product is a compound of the formula [1] Therefore, the molded product has a good hue.

The molecular weight of the polycarbonate resin is preferably 10,000 to 50,000, more preferably 13,000 to 40,000, and particularly preferably 15,000 to 30,000 in terms of viscosity average molecular weight (M). A polycarbonate resin having such a viscosity average molecular weight is preferable because sufficient strength can be obtained, the melt fluidity during molding is good, and molding distortion does not occur. The viscosity average molecular weight is obtained by inserting the specific viscosity (η _sp ) obtained from a solution obtained by dissolving 0.7 g of a polycarbonate resin in 100 ml of methylene chloride at 20 ° C. into the following equation.
η _sp /c=[η]+0.45×[η] ² c (where [η] is the intrinsic viscosity)
[Η] = 1.23 × 10 ⁻⁴ M ^0.83
c = 0.7

The OH value of the phenolic OH group at the end group of the obtained polycarbonate resin pellet is preferably 5 to 50 eq / ton, particularly preferably 10 to 30 eq / ton, per the polycarbonate resin. An amount of the phenolic OH group within this range is preferable as a polycarbonate resin for which the effects of the present invention are exhibited. The OH value of the phenolic OH group can be determined by measuring ¹ H-NMR of the polycarbonate resin.

  In the present invention, the polycarbonate resin contains a phosphorus-based heat stabilizer. Examples of phosphorus-based heat stabilizers include phosphorous acid, phosphoric acid, phosphonous acid, phosphonic acid, and esters thereof. Specifically, triphenyl phosphite, tris (nonylphenyl) phosphite, Tris (2,4-di-tert-butylphenyl) phosphite, tris (2,6-di-tert-butylphenyl) phosphite, tridecyl phosphite, trioctyl phosphite, trioctadecyl phosphite, didecyl mono Phenyl phosphite, dioctyl monophenyl phosphite, diisopropyl monophenyl phosphite, monobutyl diphenyl phosphite, monodecyl diphenyl phosphite, monooctyl diphenyl phosphite, bis (2,6-di-tert-butyl-4-methylphenyl) Pentaeri Ritol diphosphite, 2,2-methylenebis (4,6-di-tert-butylphenyl) octyl phosphite, bis (nonylphenyl) pentaerythritol diphosphite, bis (2,4-di-tert-butylphenyl) ) Pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tributyl phosphate, triethyl phosphate, trimethyl phosphate, triphenyl phosphate, diphenyl monoorthoxenyl phosphate, dibutyl phosphate, dioctyl phosphate, diisopropyl phosphate, 4,4'-biphenylene Tetrakis diphosphinate (2,4-di-tert-butylphenyl), dimethyl benzenephosphonate, diethyl benzenephosphonate, benzenephospho Acid dipropyl, and the like.

  Of these, phosphites or phosphonites (trivalent phosphorus compounds) are preferred, and specifically, tris (2,4-di-tert-butylphenyl) phosphite, tris (2,6-di). -Tert-butylphenyl) phosphite and 4,4'-biphenylenediphosphinic acid tetrakis (2,4-di-tert-butylphenyl) are preferably used, especially tris (2,4-di-tert-butylphenyl) phos Phyto and 4,4′-biphenylenediphosphinic acid tetrakis (2,4-di-tert-butylphenyl) are preferably used. These can be used individually or in mixture of 2 or more types. The blending amount of these heat stabilizers is preferably 0.001 to 0.1 parts by weight, preferably 0.002 to 0.05 parts by weight, based on 100 parts by weight of the polycarbonate resin. The phosphorus content is preferably 20 to 120 ppm, more preferably 30 to 120 ppm, still more preferably 40 to 110 ppm, and particularly preferably 50 to 100 ppm.

  The heat stabilizer may be added to the polycarbonate resin by any method of adding to the polycarbonate resin solution after the polymerization reaction and adding to the polycarbonate resin powder. In particular, the method of adding to the polycarbonate resin solution after the polymerization reaction preferably improves the hue and thermal stability of the polycarbonate resin, and the method of adding to the polycarbonate resin solution after completion of purification or warm water when granulating with warm water The method of adding in is preferable. The heat stabilizer may be added after being dissolved in a solvent, or may be added as it is.

  The polycarbonate resin pellet obtained in the present invention has a total phosphorus content of 35 to 100 ppm, preferably 35 to 80 ppm, more preferably 35 to 60 ppm. Moreover, when the polycarbonate resin pellet obtained in the present invention is retained and molded at 340 ° C. for 10 minutes, the production of the phosphorus compound of the formula [1] is small, and the obtained molded product is treated with n-hexane, The total phosphorus content in the resin molded product after n-hexane treatment is 1 to 30 ppm, preferably 3 to 28 ppm, more preferably 5 to 25 ppm.

  Moreover, when the polycarbonate resin pellet obtained in the present invention is treated with n-hexane, the total phosphorus content in the polycarbonate resin pellet after the n-hexane treatment is preferably 1 to 25 ppm, more preferably 1 to 20 ppm, Preferably it is 1-15 ppm.

  Furthermore, the molded product obtained when the polycarbonate resin pellets obtained in the present invention were stay-molded at 340 ° C. for 10 minutes and the molded product obtained when not stay-molded were each treated with n-hexane, and n- When the total phosphorus content in the resin molded product after hexane treatment is compared, the difference in the total phosphorus content is preferably 0 to 15 ppm, more preferably 0 to 10 ppm.

  Polycarbonate resin pellets obtained by the method of the present invention include antioxidants, mold release agents (fatty acid esters, etc.), lubricants, plasticizers, antistatic agents, whitening agents, ultraviolet absorbers, weathering agents, antibacterial agents, pigments , Dyes, fillers, reinforcing agents, other resins, polymers such as rubber, and modifiers such as flame retardants can be contained.

  The polycarbonate resin pellets obtained by the method of the present invention are excellent in hue and thermal stability. For example, spectacle lenses, magneto-optical disks, various write-once disks, digital audio disks (so-called compact disks), optical video disks ( As a material for an optical disk substrate such as a so-called laser disk or a digital versatile disk (DVD), it can be suitably used as a material for a precision equipment container such as a silicon wafer.

  The polycarbonate resin pellets obtained in the present invention are excellent in thermal stability, and the molded product obtained from the polycarbonate resin pellets has a good hue and can be preferably used for applications such as eyeglass lenses. Is.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely according to an Example, this invention is not limited to these Examples. The evaluation was performed by the following method.

(1) Viscosity average molecular weight of polycarbonate resin (M)
The viscosity average molecular weight was obtained from the specific viscosity measured at 20 ° C. by dissolving 0.7 g of polycarbonate resin in 100 ml of methylene chloride.
η _sp /c=[η]+0.45×[η] ² c (where [η] is the intrinsic viscosity)
[Η] = 1.23 × 10 ⁻⁴ M ^0.83
c = 0.7

(2) Hue (b value)
The obtained polycarbonate resin pellets are plasticized at a cylinder temperature of 340 ° C. using an injection molding machine (manufactured by Nippon Steel Co., Ltd .: Nikko Anchor V-17-65 type), and then a 2 mm thick 50 mm square plate is molded. did. The molded plate was measured for b value using a color difference meter (manufactured by Nippon Denshoku Co., Ltd.).

(3) Thermal stability (△ E)
A test piece (thickness) of the polycarbonate resin pellets obtained and not retained for 10 minutes at a cylinder temperature of 340 ° C. using an injection molding machine (manufactured by Nippon Steel Works, Ltd .: Nikko Anchor V-17-65 type). A 2 mm thick 50 mm square plate) was prepared, and the change in hue (ΔE) and the change in viscosity average molecular weight (ΔM) were measured. The change in hue was calculated by measuring the L, a and b values with a color difference meter (manufactured by Nippon Denshoku Co., Ltd.) and using the following equation.
ΔE = [(L′−L) ² + (a′−a) ² + (b′−b) ² ] ^1/2
(L, a, b are not retained, L ′, a ′, b ′ are retained for 10 minutes)

(4) n-Hexane Treatment About 3 g of the obtained polycarbonate resin pellet and a test piece (a 50 mm square plate having a thickness of 2 mm) of which the polycarbonate resin pellet was retained for 10 minutes at a cylinder temperature of 340 ° C. in methylene chloride. It melt | dissolved, n-hexane was dripped at this solution, and it concentrated. The precipitated resin was filtered off and dried to obtain a powdery resin.

(5) Total phosphorus content (X-ray fluorescence)
About 10 g of the polycarbonate resin was compression-molded, and the total disk content of the obtained disk was measured using a fluorescent X-ray measuring apparatus (manufactured by Rigaku Denki Kogyo Co., Ltd .: RIX-2000).

(6) OH value 0.02 g of polycarbonate resin pellets were dissolved in 0.4 ml of deuterated chloroform, and OH value of phenolic OH group (eq) using ¹ H-NMR (AL-400 manufactured by JEOL Ltd.) at 20 ° C. / Ton).

[Example 1]
A polycarbonate resin powder having a viscosity average molecular weight of 19,800 to which tris (2,4-di-tert-butylphenyl) phosphite is added so that the total phosphorus content is 60 ppm is a single screw extruder (manufactured by Nippon Steel Works Co., Ltd .: P115-28-0-V type), extruded at a resin temperature of 280 ° C. and a vent pressure of 12 torr, a total phosphorus content of 55 ppm, a viscosity average molecular weight of 19700, and a phenolic OH group having an OH number of 15 eq / ton. Got. When the obtained pellet was evaluated by the above-described method, the b value = 2.65, ΔE = 0.31, and ΔM = 300. Moreover, the total phosphorus content in the molded product after n-hexane treatment of the resin molded product obtained by staying for 10 minutes was 20 ppm.

[Example 2]
A polycarbonate resin powder having a viscosity average molecular weight of 21,200 to which tris (2,4-di-tert-butylphenyl) phosphite is added so that the total phosphorus content is 60 ppm is a twin-screw extruder (manufactured by Nippon Steel Works, Ltd .: TEX140α-28BW-V) was extruded at a resin temperature of 300 ° C. and a vent pressure of 12 torr to obtain a polycarbonate resin pellet having a total phosphorus content of 53 ppm, a viscosity average molecular weight of 21,200, and an OH number of phenolic OH groups of 13 eq / ton. It was. When the obtained pellet was evaluated by the above-mentioned method, b value = 2.71, ΔE = 0.23, ΔM = 400. Moreover, the total phosphorus content in the molded product after n-hexane treatment of the resin molded product obtained by staying for 10 minutes was 18 ppm.

[Example 3]
A polycarbonate resin powder having a viscosity average molecular weight of 25200 to which tris (2,4-di-tert-butylphenyl) phosphite is added so that the total phosphorus content is 60 ppm is a twin screw extruder (manufactured by Nippon Steel Works, Ltd .: TEX140α-28BW-V type) is extruded at a resin temperature of 325 ° C. and a vent pressure of 12 torr to obtain a polycarbonate resin pellet having a total phosphorus content of 53 ppm, a viscosity average molecular weight of 25100, and an OH number of phenolic OH groups of 10 eq / ton. It was. When the obtained pellet was evaluated by the above-described method, the b value was 3.66, ΔE = 0.35, and ΔM = 600. Further, the total phosphorus content in the molded product after n-hexane treatment of the resin molded product obtained by staying for 10 minutes was 25 ppm.

[Comparative Example 1]
A polycarbonate resin powder having a viscosity average molecular weight of 21,200 to which tris (2,4-di-tert-butylphenyl) phosphite is added so that the total phosphorus content is 60 ppm is a twin-screw extruder (manufactured by Nippon Steel Works, Ltd .: TEX140α-28BW-V type) was extruded at a resin temperature of 325 ° C. and a vent pressure of 12 torr to obtain a polycarbonate resin pellet with a total phosphorus content of 53 ppm, a viscosity average molecular weight of 21100, and an OH number of phenolic OH groups of 16 eq / ton. It was. When the obtained pellet was evaluated by the above-described method, the b value was 3.22, ΔE = 1.23, and ΔM = 600. Further, the total phosphorus content in the molded product after n-hexane treatment of the resin molded product obtained by staying for 10 minutes was 38 ppm.

Claims (5)

When a polycarbonate resin powder having a viscosity average molecular weight (X) of 10,000 to 50,000 and a total phosphorus content of 20 to 120 ppm is melt-extruded by an extruder, the resin temperature Y (° C.) is 185 × ln X−1605 ≦ Y ≦ 256 × 10 ⁻⁵ X + 266 (where X is the viscosity average molecular weight of the polycarbonate resin powder to be used) is a method of producing a polycarbonate resin pellet by melting and extruding the polycarbonate resin pellet. The OH number of the phenolic OH group of the terminal group is in the range of 5 to 50 eq / ton per polycarbonate resin, (i) the total phosphorus content in the polycarbonate resin pellet is 35 to 100 ppm, and (ii) Resin molding of polycarbonate resin pellets at 340 ° C for 10 minutes Was a resin molded article is treated with n- hexane, the total phosphorus content in the resin molded article after n- hexane process satisfies that the 1～30Ppm, method for producing a polycarbonate resin pellets. The polycarbonate resin pellet is (ii) a resin molded product obtained by dwelling a polycarbonate resin pellet at 340 ° C. for 10 minutes, treated with n-hexane, and containing all phosphorus in the resin molded product after n-hexane treatment. The method for producing a polycarbonate resin pellet according to claim 1, wherein the amount is 5 to 25 ppm. The said polycarbonate resin pellet is a manufacturing method of the polycarbonate resin pellet of Claim 1 containing a trivalent phosphorus type compound. The trivalent phosphorus compound is tris (2,4-di-tert-butylphenyl) phosphite or 4,4'-biphenylenediphosphinic acid tetrakis (2,4-di-tert-butylphenyl). 3. A method for producing polycarbonate resin pellets according to 3 . When a polycarbonate resin powder having a viscosity average molecular weight (X) of 10,000 to 50,000 and a total phosphorus content of 20 to 120 ppm is melt-extruded by an extruder, the resin temperature Y (° C.) is 185 × ln X−1605 ≦ Y ≦ 256 × 10 ⁻⁵ X + 266 (where X is the viscosity average molecular weight of the polycarbonate resin powder to be used) is melt-extruded to obtain polycarbonate resin pellets, and the obtained pellets are melt-molded to obtain polycarbonate resin A method for producing a molded article, wherein the polycarbonate resin pellet has an OH value of a phenolic OH group as a terminal group in the range of 5 to 50 eq / ton per polycarbonate resin, (i) in the polycarbonate resin pellet The total phosphorus content is 35-100 ppm, and (ii A resin molded product obtained by residence molding of polycarbonate resin pellets at 340 ° C. for 10 minutes is treated with n-hexane, and the total phosphorus content in the resin molded product after n-hexane treatment is 1 to 30 ppm. A satisfactory method for producing a polycarbonate resin molded product .