JP2011084662A - Method for producing polycarbonate resin composition, and molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a polycarbonate resin composition excellent in flame retardance and drip-prevention on burning, and also improved in the formation of clusters, and a molded article of the same. <P>SOLUTION: This method for producing the polycarbonate resin composition includes mixing (A-1) a granular polycarbonate resin with an aqueous dispersion of a fluorine-based resin in the presence of (A-2) a pellet-formed polycarbonate resin, and blending (A-3) a polycarbonate resin with the obtained mixture and melting/kneading, and the molded article obtained from the same is also provided. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing a polycarbonate resin composition and a molded product obtained thereby, and more specifically, a polycarbonate resin composition having excellent flame retardancy, anti-dripping property at the time of combustion, and improved generation of blisters The present invention relates to a method for producing a molded article and a molded article obtained thereby.

  Polycarbonate resin is a resin that excels in heat resistance, mechanical properties, and electrical properties. For example, it is widely used in automotive materials, electrical and electronic equipment materials, housing materials, lighting equipment materials, and other parts manufacturing materials in industrial fields. Has been. In particular, the flame-retardant polycarbonate resin composition is suitably used as a member of computers, notebook computers, mobile phones, printers, copiers and other office automation / information equipment, and lighting equipment.

As means for imparting flame retardancy to a polycarbonate resin, conventionally, a halogen-based flame retardant or a phosphorus-based flame retardant has been added to the polycarbonate resin. However, a polycarbonate resin composition containing a halogen-based flame retardant containing chlorine or bromine may lead to a decrease in thermal stability or corrosion of a molding machine screw or molding die during molding processing. In addition, a polycarbonate resin composition containing a phosphorus-based flame retardant impairs high transparency, which is a characteristic of polycarbonate resin, and causes a decrease in impact resistance and heat resistance, so its use is limited. There was.
In addition, halogen-based flame retardants and phosphorus-based flame retardants may cause environmental pollution at the time of product disposal and recovery, and in recent years, it has been desired to make them flame retardant without using these flame retardants. ing.

  On the other hand, metal salt compounds represented by organic alkali metal salt compounds and organic alkaline earth metal salt compounds such as alkali metal perfluoroalkane sulfonates and sodium aromatic sulfonates are used as flame retardants. The flame retardant effect is obtained to some extent. However, the flame retardant effect obtained by such a metal salt compound is not yet satisfactory, and is particularly insufficient in terms of fire extinguishing properties and preventing dripping during combustion.

Therefore, fluorine resins such as tetrafluoroethylene have been used to improve fire extinguishing properties and dripping prevention properties, and the effect is thought to be due to the fibril structure formation of the fluorine resin. It has been.
However, it is never easy to sufficiently form such a fluorinated resin in a polycarbonate resin to form fibrils, and it is difficult to obtain uniform dispersion by ordinary mixing and melt-kneading. In other words, so-called irregularities occur and the appearance of the product is impaired.
In particular, in the case of extrusion molding, the extrusion pressure is relatively low, and thus it is easy for cracks to occur. Furthermore, in the case of profile extrusion, the extrusion time is long and the extrusion pressure does not take much, so the problem of the occurrence of bumps is a serious problem. .

For the purpose of improving dripping prevention and product appearance, Patent Document 1 and Patent Document 2 disclose an aqueous solution in which a polycarbonate resin and a flame retardant are melt-kneaded, and a fluorine-based resin is dispersed in the melt-kneaded material with an aqueous dispersion medium. Proposals have been made to add it as a dispersion.
However, even in this method, the dispersion of the fluorine-based resin is never sufficient, and it is easy to leave stagnation, and it is strongly desired to improve this point.

JP 10-338814 A JP 11-92678 A

  An object of the present invention is to provide a method for producing a fluororesin-containing polycarbonate resin composition that is excellent in flame retardancy, anti-dripping property at the time of combustion, and improved in occurrence of blisters, in view of the above-mentioned problems of the prior art, and It is to provide a molded article obtained thereby.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors mixed granular polycarbonate resin and fluororesin aqueous dispersion in the presence of pellet-shaped polycarbonate resin, and obtained mixture It is found that a polycarbonate resin composition excellent in flame retardancy and anti-dripping property at the time of combustion and improved in occurrence of fluff can be obtained by blending and kneading a polycarbonate resin in the present invention, thereby completing the present invention. It came to.

  That is, according to the first invention of the present invention, there is provided a method for producing a resin composition comprising a polycarbonate resin (A) and a fluororesin (B) having a fibril-forming ability, which comprises a granular polycarbonate resin ( A-1) and an aqueous dispersion of the fluororesin are mixed in the presence of a pellet-shaped polycarbonate resin (A-2), and the resulting mixture is blended with a polycarbonate resin (A-3) and melt-kneaded. A method for producing a polycarbonate resin composition is provided.

  Moreover, according to 2nd invention of this invention, in 1st invention, the quantity of the said pellet-form polycarbonate resin (A-2) is 1-20 mass% in 100 mass% of polycarbonate resin compositions. A method for producing a polycarbonate resin composition is provided.

  According to the third invention of the present invention, in the first or second invention, the amount of the fluororesin (B) is 0.01 to 1% by mass in 100% by mass of the polycarbonate resin composition. A method for producing a polycarbonate resin composition is provided.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the granular polycarbonate resin (A-1), the pellet-shaped polycarbonate resin (A-2), and the fluororesin (B ) And the mass ratio of the polycarbonate resin (A-3) to be blended in the mixture is 10 to 40:90 to 60, and a method for producing a polycarbonate resin composition is provided.

  Moreover, according to the 5th invention of this invention, the molded article formed by shape | molding the polycarbonate resin composition obtained by the manufacturing method to the 1st-5th invention is provided.

  Furthermore, according to the sixth invention of the present invention, in the fifth invention, a molded product is provided in which the molded product is a profile extrusion molded product.

  The mechanism expressed by the method of the present invention is not clear, but the polycarbonate resin pellets are pulverized during mixing of the lumps formed by partially wetting the granular polycarbonate resin with the water of the fluororesin aqueous dispersion. It is presumed that the aggregation of the fluororesin is suppressed and the formation of bumps is suppressed even when the resulting composition is molded.

  According to the method for producing a polycarbonate resin composition of the present invention, it is possible to produce a polycarbonate resin composition which is excellent in flame retardancy and anti-dripping property at the time of combustion, and improved in the generation of blisters. The molded product from the composition has no defects and is excellent in the appearance of the product, and solves the problem of poor appearance particularly in a deformed extruded product that easily generates defects.

  Hereinafter, the present invention will be described in detail with reference to embodiments and examples, but the present invention is not limited to the following embodiments and examples and the like, and is within the scope of the present invention. Any change can be made.

[1. Overview]
In the method for producing a polycarbonate resin composition of the present invention, an aqueous dispersion of a granular polycarbonate resin (A-1) and a fluororesin having a fibril-forming ability is present in the presence of a pellet-like polycarbonate resin (A-2). It mixes and mixes and kneads | mixes a polycarbonate resin (A-3) with the obtained mixture, It is characterized by the above-mentioned.

[2. Polycarbonate resins (A-1) to (A-3)]
Examples of the polycarbonate resins (A-1), (A-2) and (A-3) used in the present invention include aromatic polycarbonate resins, aliphatic polycarbonate resins, and aromatic-aliphatic polycarbonates. Resin, preferably an aromatic polycarbonate resin. Specifically, a thermoplastic aromatic polycarbonate polymer or copolymer obtained by reacting an aromatic dihydroxy compound with phosgene or a diester of carbonic acid is used. It is done.

  Aromatic dihydroxy compounds include 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), tetramethylbisphenol A, α, α'-bis (4-hydroxyphenyl) -p-diisopropylbenzene, hydroquinone, resorcinol 4,4′-dihydroxydiphenyl and the like. Further, as a part of the dihydroxy compound, when the above-mentioned aromatic dihydroxy compound is combined with one or more tetraalkylphosphonium sulfonates, or a polymer or oligomer containing both terminal phenolic OH groups having a siloxane structure, A highly flame-retardant polycarbonate resin can be obtained.

  Preferred examples of the polycarbonate resin used in the present invention include 2,2-bis (4-hydroxyphenyl) propane as a dihydroxy compound, or 2,2-bis (4-hydroxyphenyl) propane and another aromatic dihydroxy compound. The polycarbonate resin used together is mentioned.

  The molecular weight of the polycarbonate resin used in the present invention is a viscosity average molecular weight converted from the solution viscosity measured at a temperature of 25 ° C. using methylene chloride as a solvent, and is usually 14,000 to 30,000, preferably 18,000 to 29. , 000. When the viscosity average molecular weight is within this range, a resin composition can be obtained that gives a molded article having good moldability and high mechanical strength. The most preferred molecular weight range of the polycarbonate resin is 22,000-28,000.

The method for producing the polycarbonate resin is not limited, but it is usually produced by any of an interfacial polymerization method (phosgene method) and a melting method (transesterification method).
In the interfacial polymerization method, the polymerization reaction is usually carried out in the presence of an organic solvent inert to the reaction and an aqueous alkaline solution, and the pH is usually kept at 9 or higher. An aromatic dihydroxy compound and, if necessary, a molecular weight modifier (end stopper) And an antioxidant for preventing oxidation of the aromatic dihydroxy compound, and after reacting with phosgene, a polymerization catalyst such as a tertiary amine or a quaternary ammonium salt is added, and interfacial polymerization is carried out to obtain a polymer. A sulfonate resin is obtained. The addition of the molecular weight regulator is not particularly limited as long as it is from the time of phosgenation to the start of the polymerization reaction. In addition, reaction temperature is 0-40 degreeC, for example, and reaction time is several minutes (for example, 10 minutes)-several hours (for example, 6 hours), for example.

  Here, examples of the organic solvent inert to the reaction include chlorinated hydrocarbons such as dichloromethane, 1,2-dichloroethane, chloroform, monochlorobenzene and dichlorobenzene, and aromatic hydrocarbons such as benzene, toluene and xylene. . Examples of the alkali compound used in the alkaline aqueous solution include hydroxides of alkali metals such as sodium hydroxide and potassium hydroxide.

  Examples of the molecular weight regulator include compounds having a monovalent phenolic hydroxyl group. Examples of the compound having a monovalent phenolic hydroxyl group include m-methylphenol, p-methylphenol, m-propylphenol, p-propylphenol, p-tert-butylphenol and p-. Long chain alkyl substituted phenols and the like. The amount of the molecular weight regulator used is preferably 50 to 0.5 mol, more preferably 30 to 1 mol, per 100 mol of the aromatic dihydroxy compound.

  As a polymerization catalyst, tertiary amines such as trimethylamine, triethylamine, tributylamine, tripropylamine, trihexylamine and pyridine: quaternary ammonium salts such as trimethylbenzylammonium chloride, tetramethylammonium chloride, triethylbenzylammonium chloride Etc.

  Next, the melting method will be described. The polymerization reaction in this production method is, for example, a transesterification reaction between a carbonic acid diester and an aromatic dihydroxy compound. Examples of the carbonic acid diester include dialkyl carbonate compounds such as dimethyl carbonate, diethyl carbonate and di-tert-butyl carbonate, and substituted diphenyl carbonates such as diphenyl carbonate and ditolyl carbonate. An example is a bonate. The carbonic acid diester is preferably diphenyl carbonate or substituted diphenyl carbonate, more preferably diphenyl carbonate.

  In the aromatic polycarbonate resin, the amount of terminal hydroxyl groups greatly affects the thermal stability, hydrolysis stability, color tone and the like of the product polycarbonate resin, and may be appropriately adjusted by any conventionally known method. In the melt transesterification reaction, usually, the mixing ratio of the carbonic acid diester and the aromatic dihydroxy compound and the degree of pressure reduction during the transesterification reaction are adjusted to obtain an aromatic polycarbonate resin having the desired molecular weight and terminal hydroxyl group content adjusted. be able to.

  Usually, in the melt transesterification reaction, an equimolar amount or more of carbonic acid diester is used with respect to 1 mol of the aromatic dihydroxy compound, among which 1.001 to 1.3 mol, particularly 1.01 to 1.2 mol is used. preferable. Further, as a more aggressive adjustment method, there is a method of adding a terminal terminator separately at the time of reaction, and examples of the terminal terminator in this case include monohydric phenols, monovalent carboxylic acids, and carbonic acid diesters. It is done.

  By increasing the number of moles of carbonic acid diester per mole of aromatic dihydroxy compound to more than 1.001, the increase in terminal OH groups of the fused aromatic polycarbonate resin is suppressed, and the thermal stability and hydrolysis resistance are improved. Although the terminal OH group of the melt-processed aromatic polycarbonate resin is reduced by being within 1.3, the aromatic polycarbonate resin has a desired molecular weight while maintaining the transesterification rate under the same conditions. This is preferable because it tends to be easy to produce.

In the present invention, a granular polycarbonate resin (A-1) and an aqueous dispersion of a fluorinated resin having a fibril-forming ability are mixed in the presence of a pellet-shaped polycarbonate resin (A-2), and the resulting mixture is mixed. The polycarbonate resin (A-3) is blended and melt-kneaded. The components (A-1), (A-2), and (A-3) may be produced by an interfacial polymerization method or a melt method. Moreover, what mixed both may be used.
However, since the polycarbonate resin obtained by the interfacial polymerization method is usually taken out from the polymerization apparatus in a granular form, it can be preferably used as the granular polycarbonate resin (A-1) component in the present invention.

The granular form in the granular polycarbonate resin (A-1) component refers to an aggregate of polycarbonate resin powder, and the shape is not limited and includes what is called a flake form. The bulk density of the granular polycarbonate resin is usually 0.2 to 0.9 g / ml, more preferably 0.3 to 0.8 g / ml, and particularly preferably 0.4 to 0.7 g / ml. It is.
In addition, what is commonly referred to as “powder” in the industry in contrast to pellets is also included in this granular polycarbonate resin unless it has such a bulk density.

Here, the bulk density is a value obtained by the following method.
(1) Place the polycarbonate resin on a sieve having an opening of 1.4 mm, and pass the sieve while sweeping lightly with a brush.
(2) The polycarbonate tree passed through the sieve is put into a receiver attached to the bulk density measuring device specified in JIS K5101 until it reaches a heap.
(3) The top of the polycarbonate tree from the inlet of the receiver is scraped off with a spatula, the weight of the polycarbonate tree in the receiver is measured, and the bulk density is calculated by the following equation.
Bulk density (g / ml) = weight of granular silicate compound in the receiver (g) / capacity of receiver (ml)

  The average particle size of the granular polycarbonate resin (A-1) is preferably 0.3 to 2 mm, and particularly preferably 0.5 to 1.5 mm.

By adopting such a granular polycarbonate resin as the component (A-1) and mixing in the presence of the pellet-shaped polycarbonate resin (A-2), the aqueous dispersion of the fluororesin (B) Dispersibility can be further improved.
As described above, the pellet-like polycarbonate resin (A-2) component may be one obtained by an interfacial polymerization method, one obtained by a melting method, or a mixture of both. Since it is manufactured as pellets and other additives can be blended with good dispersibility, it is preferable to use a melt polycarbonate resin.

  In addition, the polycarbonate resin (A-3) component to be blended in the mixture of the components (A-1) and (A-2) and the fluororesin aqueous dispersion can be obtained by the interfacial polymerization method or the melt method. Although it may be a thing, the thing which mixed both, a granular thing, or a pellet, the pellet of the polycarbonate resin by a melting method is preferable for the same reason as said (A-2). The component (A-3) is preferably the same as the component (A-2).

  Furthermore, the polycarbonate resins of the components (A-1), (A-2) and (A-3) each or at least one component contains the polycarbonate resin having a structural viscosity index N in a predetermined range in a total amount or a certain proportion or more. It is preferable to do. That is, in the polycarbonate resin (A), it is usually 20% by mass or more, preferably 50% by mass or more, and more preferably 60% by mass or more. There is no restriction | limiting in the upper limit of content of the predetermined N polycarbonate resin in polycarbonate resin, Usually, it is 100 mass% or less, Preferably it is 90 mass% or less, More preferably, it is 85 mass% or less.

The structural viscosity index N is an index for evaluating the flow characteristics of a melt as described in detail in the document “Rheology for chemists” (Chemical Doujin, 1982, pp. 15-16). . Usually, the melting characteristics of polycarbonate resin can be expressed by the formula: γ = a · σ ^N. In the above formula, γ: shear rate, a: constant, σ: stress, N: structural viscosity index.

  In the above formula, when N = 1, Newtonian fluidity is shown, and as the value of N increases, non-Newtonian fluidity increases. That is, the flow characteristics of the melt are evaluated by the magnitude of the structural viscosity index N. In general, a polycarbonate resin having a large structural viscosity index N tends to have a high melt viscosity in a low shear region. For this reason, when a polycarbonate resin having a large structural viscosity index N is mixed with another polycarbonate resin, dripping at the time of combustion of the obtained polycarbonate resin composition can be suppressed, and flame retardancy can be improved. However, in order to maintain the moldability of the obtained polycarbonate resin composition in a favorable range, the structural viscosity index N of the polycarbonate resin is preferably not excessively large.

Therefore, the polycarbonate resin in the polycarbonate resin composition of the present invention has a structural viscosity index N of usually 1.2 or more, preferably 1.25 or more, more preferably 1.28 or more, and usually 1.8 or less. The polycarbonate resin is preferably 1.7 or less, and preferably contains a certain proportion or more of an aromatic polycarbonate resin.
A high structural viscosity index N means that the polycarbonate resin has a branched chain. By containing a polycarbonate resin having a high structural viscosity index N in this way, dripping of the polycarbonate resin composition during combustion is suppressed. , Flame retardancy can be improved.

The “structural viscosity index N” is expressed by Log η _a = [(1-N) / N] × Log γ + C derived from the above formula, as described in, for example, Japanese Patent Laid-Open No. 2005-232442. It is also possible. In the above formula, N: structural viscosity index, γ: shear rate, C: constant, η _a : apparent viscosity.
As can be seen from this equation, the N value can also be evaluated from γ and ηa in _a low shear region in which the viscosity behavior is greatly different. For example, the N value can be determined from η _a at γ = 12.16 sec ⁻¹ and γ = 24.32 sec ⁻¹ .

  An aromatic polycarbonate resin having a structural viscosity index N of 1.2 or more is obtained by a melting method (transesterification method) as described in JP-A-8-259687 and JP-A-8-245782, for example. When reacting an aromatic dihydroxy compound and a carbonic acid diester, an aromatic polycarbonate resin having a high structural viscosity index and excellent hydrolytic stability can be obtained without adding a branching agent by selecting catalyst conditions or production conditions. be able to.

  An aromatic polycarbonate resin having a structural viscosity index N of 1.2 or more can also be produced by a method using a branching agent when produced by the above-described interfacial polymerization method or melting method. Specific examples of the branching agent include phloroglucin, 4,6-dimethyl-2,4,6-tris (4-hydroxyphenyl) heptene-2, 4,6-dimethyl-2,4,6-tris (4-hydroxy). Phenyl) heptane, 2,6-dimethyl-2,4,6-tris (4-hydroxyphenylheptene-3,1,3,5-tris (4-hydroxyphenyl) ethane and the like, and Examples include 3,3-bis (4-hydroxyaryl) oxindole (= isatin bisphenol), 5-chlorouisatin bisphenol, 5,7-dichloroisatin bisphenol, 5-bromoisatin bisphenol, etc. Is in the range of 0.01 to 10 mol%, particularly preferably 0.1 to 3 mol, based on the aromatic dihydroxy compound. It is in the range of.

  The molecular weight of the aromatic polycarbonate resin having a structural viscosity index N of 1.2 or more is a viscosity average molecular weight in the range of 16,000 to 30,000 converted from the solution viscosity measured at a temperature of 25 ° C. using methylene chloride as a solvent. Is preferred.

  The polycarbonate resin may contain a polycarbonate resin having a structural viscosity index N outside the above range, in addition to the above-described polycarbonate resin having a structural viscosity index N of 1.2 or more. Although there is no restriction | limiting in the kind, A linear polycarbonate resin is preferable especially. By combining these, there is an advantage that it is easy to balance the flame retardancy (anti-dripping property) and moldability (fluidity) of the obtained polycarbonate resin composition. From this viewpoint, it is particularly preferable that the polycarbonate resin (A) is composed of a polycarbonate resin having a structural viscosity index N of 1.2 or more and a linear polycarbonate resin. In addition, the structural viscosity index N of this linear polycarbonate resin is usually about 1-1.15.

  When the polycarbonate resin contains a linear polycarbonate resin, the proportion of the linear polycarbonate resin in the polycarbonate resin is usually 80% by mass or less, preferably 50% by mass or less, more preferably 40% by mass or less, Usually, it is more than 0% by mass, preferably 10% by mass or more, more preferably 15% by mass or more. By setting the content of the linear polycarbonate resin in the polycarbonate resin within the above range, good dispersibility of other metal salt flame retardants and other additives can be easily obtained, and the flame retardancy and moldability are excellent. The advantage that a polycarbonate resin is easily obtained is obtained.

  Further, the polycarbonate resin (A) used in the present invention may be not only a polycarbonate resin as a virgin raw material, but also a polycarbonate resin regenerated from a used product, that is, a so-called material recycled polycarbonate resin.

[3. Fluorine Resin (B) Having Ability to Form Fibrils]
The fluororesin used as the component B of the present invention is an anti-drip agent that easily disperses in a resin composition and shows a tendency to form a fibrous structure by bonding polymers to each other. Is a fluorine-based resin. The molecular weight of the fluororesin tree having the ability to form fibrils has a very high molecular weight of 1,000,000 to 10,000,000, and shows a tendency to join together the fluororesins by an external action such as shearing force to form a fiber. is there. Examples of the fluororesin include tetrafluoroethylene (TFE) resin, perfluoroalkoxy (PFA) resin, and fluorinated ethylene propylene (FEP) resin, and polytetrafluoroethylene is particularly preferable.

Examples of the polytetrafluoroethylene having fibril forming ability include Teflon (registered trademark) 6J manufactured by Mitsui DuPont Fluorochemical Co., Ltd. and polyflon manufactured by Daikin Chemical Industries, Ltd. The fluororesin (B) is in the form of its aqueous dispersion, and in the presence of water, in the presence of granular polycarbonate resin (A-1) and pellet-like polycarbonate resin (A-2). Mix with.
By mixing in the presence of water, the aggregation of the fluororesin is suppressed, the dispersion of the fluororesin in the resin composition becomes good, no lumps occur, and no flaws occur on the surface of the molded body.

This dispersion is an aqueous dispersion produced by adding a surfactant to a fluororesin latex usually obtained by emulsion polymerization, and concentrating and stabilizing the dispersion. The content of the fluororesin in the aqueous dispersion is preferably 20 to 80% by mass, particularly preferably 30 to 70% by mass. The fluororesin having a fibril forming ability preferably has a primary particle size in the range of 0.05 to 1.0 μm, more preferably 0.1 to 0.5 μm.
In the resin composition, the fluororesin (B) is mainly in the form of a fibril having a thickness of 0.5 microns or less, and the fibril is present in a network structure and / or in a branched form. Is preferred.

As an aqueous dispersion of polytetrafluoroethylene, Teflon (registered trademark) 30J manufactured by Mitsui DuPont Fluorochemical Co., Ltd., Fullon D-1 manufactured by Daikin Chemical Industries, Ltd., and a vinyl monomer are polymerized. A polytetrafluoroethylene polymer having a multilayer structure, for example, Metabrene A-3800 manufactured by Mitsubishi Rayon Co., Ltd. may be mentioned.
The blending amount of the fluorine-based resin (B) is preferably 0.01 to 1% by mass in 100% by mass of the polycarbonate resin composition. Without exceeding 1% by mass, the mechanical strength and processing fluidity of the resin composition are likely to be lowered, and the appearance of the molded product is likely to be deteriorated, more preferably 0.03 to 0.8% by mass. Preferably it is 0.05-0.6 mass%.

[4. Method for producing resin composition]
In the present invention, first, the above-described granular polycarbonate resin (A-1) and an aqueous dispersion of a fluorine-based resin are mixed in the presence of the pellet-shaped polycarbonate resin (A-2).
For mixing, use a known mixing device such as a Henschel mixer, super mixer, tumbler, banbury mixer, turn bull mixer, ribbon blender, etc., but use a high-speed stirring type mixer such as a super mixer. The stirring rotation speed is preferably about 300 to 1500 rpm, and the time is preferably about 30 seconds to 5 minutes.
The temperature of the polycarbonate resin at the time of mixing is preferably 20 to 80 ° C., more preferably 20 to 60 ° C. for uniform dispersion. Aggregation tends to occur if the temperature rises too much. It is also preferable to carry out in an inert gas atmosphere such as nitrogen.

As described above, the amount of the pellet-like polycarbonate resin (A-2) is preferably 1 to 20% by mass, more preferably 2 to 15% by mass, particularly 3 to 10% by mass in 100% by mass of the polycarbonate resin composition. The amount of the fluororesin (B) is preferably 0.01 to 1% by mass in 100% by mass of the polycarbonate resin composition.
The mixing ratio of the component (A-1), the component (A-2) and the fluororesin dispersion in this mixing step is preferably 5 to 24: 1 to 15: 0.2 to 1.2, more preferably 6 -22: 2-12: 0.3-1.0. Because of the presence of water, too much granular polycarbonate resin is likely to cause lumps, and even if there is too much pellet-like polycarbonate resin, it becomes sticky and feedability deteriorates, and the quantitativeness of feed deteriorates. .

An additional polycarbonate resin (A-3) is further added to the mixture thus obtained, and the mixture is melt-kneaded together.
The method of melt-kneading is not particularly limited, but it is preferable to melt-knead using a twin-screw extruder in order to further achieve good dispersion of the fluororesin having a fibril forming ability and the polycarbonate resin. The screw shape of the extruder may be a normal one or a kneading strengthened type. Moreover, in order to finally deaerate the vapor | steam generated from the water | moisture content of an aqueous dispersion, what has a vent is preferable.
The resin extruded from the extruder is directly cut into pellets, or after forming a strand, the resin is cut with a pelletizer and pelletized. Moreover, it is also possible to make the resin melt-kneaded by an extruder into a molded product without going through the pellets.

[5. Other flame retardants]
The polycarbonate resin composition of this invention can mix | blend flame retardants other than the said (B) component. Examples of such flame retardants include halogen flame retardants, phosphorus flame retardants, metal salt flame retardants, and inorganic filler flame retardants. Among these, metal salt flame retardants are preferable, organic metal salt compounds are more preferable, and organic sulfonic acid metal salt compounds are particularly preferable. By selecting the organic sulfonic acid metal salt compound, the polycarbonate resin composition of the present invention has good transparency, mechanical properties, and thermal properties.

  Among such organic sulfonic acid metal salt compounds, fluorine-containing aliphatic sulfonic acid alkali metal salts such as potassium trifluoromethanesulfonate and potassium perfluorobutanesulfonate, potassium diphenylsulfone-3-sulfonate, benzenesulfone, and the like. Acid sodium, sodium (poly) styrenesulfonate, potassium (poly) styrenesulfonate, sodium paratoluenesulfonate, potassium paratoluenesulfonate, cesium paratoluenesulfonate, (sodium (branched) dodecylbenzenesulfonate, trichlorobenzenesulfone An aromatic sulfonic acid alkali metal salt such as sodium acid can be preferably used.

The content of the flame retardant is usually 0.01 parts by mass or more, preferably 0.03 parts by mass or more, and usually 20 parts by mass or less, preferably 10 parts by mass or less with respect to 100 parts by mass of the polycarbonate resin. is there. If the flame retardant content is less than or equal to the lower limit of the range, the flame retardancy improving effect may be insufficient, and if the flame retardant content exceeds the upper limit of the range, the transparency In addition, mechanical properties and thermal properties may be degraded.
Furthermore, when a metal salt compound is selected as the flame retardant, it is particularly preferably 0.05 parts by mass or more and 1 part by mass or less. By setting it as such a range, the heat stability and wet heat stability of the polycarbonate resin composition of this invention will become favorable.

[6. Other ingredients]
In the polycarbonate resin composition of the present invention, other components other than those described above may be blended as necessary as long as the desired physical properties are not significantly impaired. Examples of other components include resins other than polycarbonate resins and various resin additives. In addition, 1 type may contain other components and 2 or more types may contain them by arbitrary combinations and ratios.

Other resins Examples of other resins include thermoplastic polyester resins such as polyethylene terephthalate resin (PET resin), polytrimethylene terephthalate (PTT resin), and polybutylene terephthalate resin (PBT resin);
Polystyrene resin (PS resin), high impact polystyrene resin (HIPS), acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-styrene-acrylic rubber copolymer (ASA) Resin), styrene resin such as acrylonitrile-ethylene propylene rubber-styrene copolymer (AES resin);

  Core / shell of styrene-butadiene rubber, isobutylene-isoprene rubber, ethylene-propylene rubber, acrylic elastomer, methyl methacrylate-butadiene-styrene copolymer (MBS), methyl methacrylate-acrylic rubber-styrene copolymer (MAS), etc. Type elastomers, elastomers such as polyester elastomers;

Polyolefin resins such as polyethylene resin (PE resin), polypropylene resin (PP resin), cyclic cycloolefin resin (COP resin), cyclic cycloolefin copolymer (COP) resin;
Polyamide resin (PA resin); Polyimide resin (PI resin); Polyetherimide resin (PEI resin); Polyurethane resin (PU resin); Polyphenylene ether resin (PPE resin); Polyphenylene sulfide resin (PPS resin); Polysulfone resin (PSU) Resin); polymethacrylate resin (PMMA resin); and the like.

-Resin additives Examples of resin additives include light diffusing agents, mold release agents, heat stabilizers, antioxidants, UV absorbers, dyes and pigments, antistatic agents, antifogging agents, lubricants, antiblocking agents, and fluids. Examples include property improvers, plasticizers, dispersants, antibacterial agents, and fillers. In addition, 1 type may contain resin additive and 2 or more types may contain it by arbitrary combinations and a ratio.
Hereinafter, the example of an additive suitable for the polycarbonate resin composition of this invention is demonstrated concretely.

.. Light diffusing agent The light diffusing agent is fine particle inorganic or organic particles, and examples thereof include organic fine particles such as glass fine particles, polystyrene resin, (meth) acrylic resin, silicone resin, among which organic fine particles are preferable, From the viewpoint of the light diffusion effect, the fine particles are preferably spherical.
The preferable average particle diameter of the particulate light diffusing agent is 0.1 to 50 μm, more preferably 0.5 to 30 μm, and particularly 1 to 20 μm.

  As such organic fine particles, crosslinked organic fine particles that do not melt in the polycarbonate resin even when heated to the molding temperature of the polycarbonate resin are preferable. Specifically, organic fine particles of a crosslinked (meth) acrylic resin or silicone resin are preferable. It is. Specific examples include partially cross-linked polymethyl methacrylate polymer fine particles, cross-linked silicone resin particles, silicone rubber powder obtained by coating silicone rubber with a silicone resin, and the like.

  The preferable content of the light diffusing agent is 0.1 to 10 parts by mass, and more preferably 0.2 to 6 parts by mass with respect to 100 parts by mass of the polycarbonate resin. When the blending ratio of the light diffusing agent is less than 0.1 parts by mass, the effect of reducing glare is insufficient in the case of lighting fixture parts, and when the blending amount of the light diffusing agent is too large, the necessary illumination brightness is obtained. Disappear.

.. Release agent Examples of the release agent include aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds having a number average molecular weight of 200 to 15,000, polysiloxane silicone oil, and the like. Can be mentioned.
Examples of the aliphatic carboxylic acid include saturated or unsaturated aliphatic monovalent, divalent or trivalent carboxylic acid. Here, the aliphatic carboxylic acid includes alicyclic carboxylic acid. Among these, preferable aliphatic carboxylic acids are monovalent or divalent carboxylic acids having 6 to 36 carbon atoms, and aliphatic saturated monovalent carboxylic acids having 6 to 36 carbon atoms are more preferable. Specific examples of such aliphatic carboxylic acids include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, mellicic acid, tetrariacontanoic acid, montanic acid, adipine Examples include acids and azelaic acid.

  As aliphatic carboxylic acid in ester of aliphatic carboxylic acid and alcohol, the same thing as the said aliphatic carboxylic acid can be used, for example. On the other hand, examples of the alcohol include saturated or unsaturated monohydric or polyhydric alcohols. These alcohols may have a substituent such as a fluorine atom or an aryl group. Among these, a monovalent or polyvalent saturated alcohol having 30 or less carbon atoms is preferable, and an aliphatic or alicyclic saturated monohydric alcohol or aliphatic saturated polyhydric alcohol having 30 or less carbon atoms is more preferable.

Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, dipentaerythritol, and the like. Is mentioned.
Specific examples of esters of aliphatic carboxylic acids and alcohols include beeswax (a mixture based on myricyl palmitate), stearyl stearate, behenyl behenate, stearyl behenate, glycerin monopalmitate, glycerin monostearate Examples thereof include rate, glycerol distearate, glycerol tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, pentaerythritol tetrastearate and the like.

Examples of the aliphatic hydrocarbon having a number average molecular weight of 200 to 15,000 include liquid paraffin, paraffin wax, microwax, polyethylene wax, Fischer-Tropsch wax, and α-olefin oligomer having 3 to 12 carbon atoms. Here, the aliphatic hydrocarbon includes alicyclic hydrocarbons.
Among these, paraffin wax, polyethylene wax, or a partial oxide of polyethylene wax is preferable, and paraffin wax and polyethylene wax are more preferable.
The number average molecular weight of the aliphatic hydrocarbon is preferably 5,000 or less.

  The content of the release agent is usually 0.001 part by mass or more, preferably 0.01 part by mass or more, and usually 2 parts by mass or less, preferably 1 part by mass or less with respect to 100 parts by mass of the polycarbonate resin. It is. When the content of the release agent is not more than the lower limit of the above range, the effect of releasability may not be sufficient, and when the content of the release agent exceeds the upper limit of the above range, hydrolysis resistance And mold contamination during injection molding may occur.

.. Heat stabilizer Examples of the heat stabilizer include phosphorus compounds. Any known phosphorous compound can be used. Specific examples include phosphorus oxo acids such as phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid, and polyphosphoric acid; acidic pyrophosphate metal salts such as acidic sodium pyrophosphate, acidic potassium pyrophosphate, and acidic calcium pyrophosphate; phosphoric acid Examples thereof include phosphates of Group 1 or Group 10 metals such as potassium, sodium phosphate, cesium phosphate, and zinc phosphate; organic phosphate compounds, organic phosphite compounds, and organic phosphonite compounds.

  Among them, triphenyl phosphite, tris (monononylphenyl) phosphite, tris (monononyl / dinonyl phenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, monooctyl diphenyl phosphite, Dioctyl monophenyl phosphite, monodecyl diphenyl phosphite, didecyl monophenyl phosphite, tridecyl phosphite, trilauryl phosphite, tristearyl phosphite, 2,2-methylenebis (4,6-di-tert-butylphenyl) ) Organic phosphites such as octyl phosphite are preferred.

As such an organic phosphite compound, specifically, for example, “Adeka Stub 1178”, “Adeka Stub 2112”, “Adeka Stub HP-10”, manufactured by Adeka Co., Ltd., manufactured by Johoku Chemical Industry Co., Ltd. Examples thereof include “JP-351”, “JP-360”, “JP-3CP”, “Irgaphos 168” manufactured by Ciba Specialty Chemicals.
In addition, 1 type may contain the heat stabilizer and 2 or more types may contain it by arbitrary combinations and a ratio.

  The content of the heat stabilizer is usually 0.001 part by mass or more, preferably 0.01 part by mass or more, more preferably 0.03 part by mass or more, based on 100 parts by mass of the polycarbonate resin. It is not more than part by mass, preferably not more than 0.7 part by mass, more preferably not more than 0.5 part by mass. If the amount of the heat stabilizer is too small, the heat stabilization effect may be insufficient. If the amount of the heat stabilizer is too large, the effect may reach a peak and may not be economical.

.. Antioxidants Examples of antioxidants include hindered phenol antioxidants. Specific examples thereof include pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl). ) Propionate, thiodiethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], N, N′-hexane-1,6-diylbis [3- (3,5-di-) tert-butyl-4-hydroxyphenylpropionamide), 2,4-dimethyl-6- (1-methylpentadecyl) phenol, diethyl [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl ] Methyl] phosphoate, 3,3 ′, 3 ″, 5,5 ′, 5 ″ -hexa-tert-butyl-a, a ′, a ″-(mesi Tylene-2,4,6-triyl) tri-p-cresol, 4,6-bis (octylthiomethyl) -o-cresol, ethylenebis (oxyethylene) bis [3- (5-tert-butyl-4- Hydroxy-m-tolyl) propionate], hexamethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,3,5-tris (3,5-di-tert- Butyl-4-hydroxybenzyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, 2,6-di-tert-butyl-4- (4,6-bis ( Octylthio) -1,3,5-triazin-2-ylamino) phenol and the like.

Among them, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate preferable. Specific examples of such phenolic antioxidants include “Irganox 1010” (registered trademark, the same shall apply hereinafter) manufactured by Ciba Specialty Chemicals, “Irganox 1076”, and “Adeka Stub” manufactured by Adeka. AO-50 "," ADK STAB AO-60 "and the like.
In addition, 1 type may contain antioxidant and 2 or more types may contain it by arbitrary combinations and a ratio.

  The content of the antioxidant is usually 0.001 part by mass or more, preferably 0.01 part by mass or more, and usually 1 part by mass or less, preferably 0.5 part by mass with respect to 100 parts by mass of the polycarbonate resin. Or less. When the content of the antioxidant is less than or equal to the lower limit of the range, the effect as an antioxidant may be insufficient, and when the content of the antioxidant exceeds the upper limit of the range, There is a possibility that the effect reaches its peak and is not economical.

..Ultraviolet absorbers Examples of ultraviolet absorbers include inorganic ultraviolet absorbers such as cerium oxide and zinc oxide; benzotriazole compounds, benzophenone compounds, salicylate compounds, cyanoacrylate compounds, triazine compounds, oxanilide compounds, malonic acid ester compounds, Examples include organic ultraviolet absorbers such as hindered amine compounds. In these, an organic ultraviolet absorber is preferable and a benzotriazole compound is more preferable. By selecting the organic ultraviolet absorber, the polycarbonate resin composition of the present invention has good transparency and mechanical properties.

  Specific examples of the benzotriazole compound include, for example, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- [2′-hydroxy-3 ′, 5′-bis (α, α-dimethylbenzyl). ) Phenyl] -benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-tert-butyl-phenyl) -benzotriazole, 2- (2′-hydroxy-3′-tert-butyl-5 ′) -Methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butyl-phenyl) -5-chlorobenzotriazole), 2- (2'-hydroxy-3 ', 5'-di-tert-amyl) -benzotriazole, 2- (2'-hydroxy-5'-tert-octylphenyl) benzotriazole, 2,2′-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2N-benzotriazol-2-yl) phenol] and the like, among others, 2- (2′- Hydroxy-5'-tert-octylphenyl) benzotriazole, 2,2'-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2N-benzotriazol-2-yl) phenol] And 2- (2′-hydroxy-5′-tert-octylphenyl) benzotriazole is particularly preferable.

  Specific examples of such benzotriazole compounds include “Seesorb 701”, “Seesorb 702”, “Seesorb 703”, “Seesorb 704”, and “Seesorb 705” manufactured by Sipro Kasei Co., Ltd. (trade names, the same applies hereinafter). , “Seasorb 709”, “Biosorb 520”, “Biosorb 580”, “Biosorb 582”, “Biosorb 583” manufactured by Kyodo Yakuhin Co., Ltd. “Chemisorb 71”, “Chemisorb 72” manufactured by Chemipro Kasei Co., Ltd. “UV5411”, “LA-32”, “LA-38”, “LA-36”, “LA-34”, “LA-31”, manufactured by Adeka Corporation, “Tinuvin P”, “Cinuvin 234” manufactured by Ciba Specialty Chemicals , “Tinubin 326”, “Tinubin 327”, “Tinubin 328 Etc. The.

  The content of the ultraviolet absorber is usually 0.01 parts by mass or more, preferably 0.1 parts by mass or more, and usually 3 parts by mass or less, preferably 1 part by mass or less with respect to 100 parts by mass of the polycarbonate resin. It is. If the content of the UV absorber is below the lower limit of the above range, the effect of improving the weather resistance may be insufficient, and if the content of the UV absorber exceeds the upper limit of the above range, the mold Debogit etc. may occur and cause mold contamination. In addition, 1 type may contain the ultraviolet absorber and 2 or more types may contain it by arbitrary combinations and a ratio.

-Dye / pigment Examples of the dye / pigment include inorganic pigments, organic pigments, and organic dyes.
Examples of inorganic pigments include sulfide pigments such as carbon black, cadmium red, and cadmium yellow; silicate pigments such as ultramarine blue; titanium oxide, zinc white, petal, chromium oxide, iron black, titanium yellow, zinc- Oxide pigments such as iron brown, titanium cobalt green, cobalt green, cobalt blue, copper-chromium black and copper-iron black; chromic pigments such as chrome lead and molybdate orange; Examples include Russian pigments.

Examples of organic pigments and organic dyes include phthalocyanine dyes such as copper phthalocyanine blue and copper phthalocyanine green; azo dyes such as nickel azo yellow; thioindigo, perinone, perylene, quinacridone, dioxazine, iso Examples thereof include condensed polycyclic dyes such as indolinone and quinophthalone; quinoline, anthraquinone, heterocyclic and methyl dyes.
Among these, titanium oxide, carbon black, cyanine-based, quinoline-based, anthraquinone-based, phthalocyanine-based dyes and the like are preferable from the viewpoint of thermal stability.
In addition, 1 type may contain the dye / pigment, and 2 or more types may contain it by arbitrary combinations and a ratio. In addition, dyes and pigments may be used as masterbatches with polystyrene resins, polycarbonate resins, and acrylic resins for the purpose of improving handling during extrusion and improving dispersibility in the resin composition. Good.

  The content of the dye / pigment is usually 5 parts by mass or less, preferably 3 parts by mass or less, more preferably 2 parts by mass or less with respect to 100 parts by mass of the polycarbonate resin. If the content of the dye / pigment is too large, the impact resistance may not be sufficient.

[7. Molding]
The polycarbonate resin composition of the present invention thus obtained can be produced by molding the produced pellets by various molding methods. Further, the resin melt-kneaded by an extruder can be directly made into a sheet, a film, a profile extrusion-molded product, a blow-molded product, an injection-molded product or the like without going through pellets.

  The manufacturing method of a molded article is not particularly limited, and a molding method generally adopted for a polycarbonate resin composition can be arbitrarily adopted. For example, injection molding method, ultra-high speed injection molding method, injection compression molding method, two-color molding method, hollow molding method such as gas assist, molding method using heat insulating mold, rapid heating mold were used. Molding method, foam molding (including supercritical fluid), insert molding, IMC (in-mold coating molding) molding method, extrusion molding method, profile extrusion molding method, sheet molding method, thermoforming method, rotational molding method, laminate molding method , Press molding method, direct blow molding method, injection blow molding method and the like.

  In particular, it solves the problem of poor appearance in molding where the resin pressure is not so high, such as extrusion molding, profile extrusion molding, and sheet molding. In particular, so-called profile extrusion molding, in which the molten resin discharged from the extruder is molded with a sizing die that gives the desired cross-sectional shape, the resin pressure is relatively low and the extrusion time is slow, so there are bumps. Although it is easy, by using the composition obtained by this invention, generation | occurrence | production of a chip is suppressed and the molded article with a favorable external appearance can be manufactured in a short time, Therefore The productivity on an industrial scale can be improved.

  Examples of molded products include parts such as lighting equipment, electrical and electronic equipment, OA equipment, information terminal equipment, machine parts, home appliances, vehicle parts, building members, various containers, leisure goods and miscellaneous goods, and the like. Among these, it is particularly suitable for use in parts such as electrical and electronic equipment, OA equipment, information terminal equipment, home appliances, etc., and particularly suitable for use in parts of electrical and electronic equipment.

  There are no particular restrictions on the shape or application of the lighting device, but it can be used as a cover for various types of lighting lamps and lighting fixtures. For example, fluorescent lamp covers and cover tubes, vending machine lamp covers, lamps, etc. It can be suitably used for a cover for a shade, a stand, a bracket, a ceiling light, an electric signboard, a sign lamp, and a vehicle lamp such as an automobile or a motorcycle. Moreover, it can use suitably also for the cover of the lighting fixture which uses light sources with little heat dissipation, such as LED and organic EL.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples, and can be arbitrarily modified and implemented without departing from the gist of the present invention.

1. Measurement / Evaluation Method [Flame Retardancy Evaluation]
The flame retardancy of each polycarbonate resin composition was evaluated as follows.
-Molding of the combustion test piece After drying the pellet of the resin composition obtained by the method described later at 120 ° C for 5 hours, it was injection-molded using a J50-EP type injection molding machine manufactured by Nippon Steel Works, and length A test piece for UL test of 125 mm, width 13 mm, and thickness 1.2 mm was molded.

-UL test The obtained test specimen for UL test was conditioned for 48 hours in a temperature-controlled room with a temperature of 23 ° C and a humidity of 50%, and the UL94 test (equipment of the instrument) defined by US Underwriters Laboratories (UL) (Combustion test of plastic material for parts) UL94V is a method for evaluating flame retardancy from the after-flame time and drip properties after indirect flame of a burner for 10 seconds on a test piece of a predetermined size held vertically, V-0, V- In order to have flame retardancy of 1 and V-2, it is necessary to satisfy the criteria shown in Table 1 below.

  Here, the after-flame time is the length of time for which the flammable combustion of the test piece is continued after the ignition source is moved away. Further, the cotton ignition by drip is determined by whether or not the marking cotton, which is about 300 mm below the lower end of the test piece, is ignited by a drip from the test piece. Further, when any one of the five samples did not satisfy the above criteria, it was evaluated as NR (not rated) because V-2 was not satisfied. In Table 3, “flame retardant” is indicated.

[Evaluation]
The resin composition pellets obtained by the method described below were dried at 120 ° C. for 5 hours and then injection-molded using a J50-EP type injection molding machine manufactured by Nippon Steel, length 90 mm, width 50 mm, thickness Three-stage test pieces of 3 mm, 2 mm and 1 mm were formed.
A 1 mm thick portion was visually observed with a stereomicroscope using transmitted light, and surface irregularities were evaluated.
A: No irregularities were found.
○: Some irregularities were observed.
(Triangle | delta): Buzz was clearly recognized and it was inadequate as a product.
X: Buzz was observed on the entire surface and was insufficient as a product.
In Table 3, it is expressed as “But”.

[Total light transmittance]
Evaluation of total light transmittance was based on JIS K-7361-1, and measured with the NDH-2000 type | mold haze meter by Nippon Denshoku Industries Co., Ltd. about the 1 mm thickness test piece manufactured above. The total light transmittance is used as a scale indicating the transparency of the resin, and the larger the value, the higher the transparency. In Table 3, it is expressed as “transmittance”.

(Examples 1-5, Comparative Examples 1-4)
The granular polycarbonate resin (A-1) described in Table 2 below, the fluororesin dispersion (B) described in Table 3 below, the polycarbonate resin (A-2) described in Table 2, and further Table 3 The other additives described in 1 above were added to the supermixer in the amounts described in Table 4 below (expressed in terms of mass% of the final composition) and mixed at a rotational speed of 500 rpm for 2 minutes to obtain a mixture.
This mixture was fed from the first feeder of a twin-screw extruder (TEX-30XCT, fully meshed, rotating in the same direction, two-thread screw) manufactured by Nippon Steel Works, equipped with one vent, and the polycarbonate resin described in Table 2 ( A-3) is fed from the second feeder in the amounts shown in Table 4, melt-kneaded under the conditions of a screw rotation speed of 150 rpm, a discharge rate of 20 kg / hour, and a barrel temperature of 280 ° C., extruded into a strand, and in a water bath Quenched and pelletized using a pelletizer to obtain pellets of polycarbonate resin composition.
Using the obtained pellets, various test pieces were molded by the method described above. Table 4 shows the evaluation results.

  From the results shown in Table 4, the granular polycarbonate resin (A-1) and the fluororesin aqueous dispersion are premixed in the presence of the pellet-like polycarbonate resin (A-2), thereby forming the future molding. It can be seen that the product has no flaws, has a high degree of flame retardancy, and has excellent transmittance.

  According to the method for producing a polycarbonate resin composition of the present invention, a polycarbonate resin composition having excellent flame retardancy, anti-dripping property at the time of combustion, and improved generation of blisters can be obtained. Lighting equipment parts such as fluorescent lamp cover tubes, LED lighting covers, lamp covers of vending machines, electrical and electronic equipment and parts, OA equipment, information terminal equipment, battery packs, machine parts, home appliances, vehicle parts, building components, It can be used in a wide range of fields, such as various containers, leisure goods, and miscellaneous goods. Especially, when producing an extrusion-molded product, it is difficult for occurrence of blisters, and industrial applicability is very high.

Claims (6)

A method for producing a resin composition comprising a polycarbonate resin (A) and a fluororesin (B) having a fibril-forming ability, comprising a granular polycarbonate resin (A-1) and an aqueous dispersion of the fluororesin Is mixed in the presence of a pellet-like polycarbonate resin (A-2), and the polycarbonate resin (A-3) is blended into the obtained mixture and melt-kneaded.   2. The method for producing a polycarbonate resin composition according to claim 1, wherein the amount of the pellet-like polycarbonate resin (A-2) is 1 to 20% by mass in 100% by mass of the polycarbonate resin composition.   The method for producing a polycarbonate resin composition according to claim 1 or 2, wherein the amount of the fluororesin (B) is 0.01 to 1% by mass in 100% by mass of the polycarbonate resin composition.   The mass ratio of the total amount of the granular polycarbonate resin (A-1), the pellet-shaped polycarbonate resin (A-2) and the fluororesin (B) and the polycarbonate resin (A-3) to be blended in the mixture is as follows: It is 10-40: 90-60, The manufacturing method of the polycarbonate resin composition in any one of Claims 1-3 characterized by the above-mentioned.   A polycarbonate resin composition molded article obtained by the production method according to claim 1.   The molded product according to claim 5, wherein the molded product is a profile extrusion molded product.