JP7540957B2 - Polycarbonate resin composition and resin-metal composite molded body made from the same - Google Patents

Description

The present invention relates to a polycarbonate resin composition suitable for molding a resin-metal composite molded body, and a resin-metal composite molded body made from the same. More specifically, the present invention relates to a polycarbonate resin composition that has excellent adhesion to metals and shows little decrease in bonding strength even in various environments, and a resin-metal composite molded body made from the same.

Polycarbonate resin is excellent in transparency, impact resistance, heat resistance, and dimensional stability, and is therefore used as an engineering plastic in a wide range of fields, such as housings and parts for electrical, electronic, and office equipment, interior and exterior parts for automobiles, furniture, musical instruments, and miscellaneous goods. In addition, molded bodies obtained from reinforced polycarbonate resins containing at least one selected from the group consisting of fibers such as glass fibers, plate-like fillers such as talc, and granular fillers such as calcium carbonate, are significantly stronger and more rigid than molded bodies obtained from polycarbonate resins that do not contain fibers or fillers, and are being used more widely as metal substitutes from the viewpoint of moldability and weight reduction of parts. In particular, with the development of the communications field in recent years, the application of resin parts to parts that require insulation, such as antenna covers, has been increasing. However, it is often difficult to replace all metal parts with resin. In such cases, it is possible to manufacture new composite parts by bonding and integrating metal and resin molded bodies. Technology for bonding and integrating metal and resin molded bodies is required in a wide range of fields, such as the manufacture of parts for automobiles, home appliances, industrial equipment, etc., and many adhesives have been developed for this purpose. On the other hand, many methods that do not use adhesives have been developed as more rational joining methods. Patent documents 1 to 4 report metal-resin composites consisting of a surface-treated metal shape and a crystalline resin such as polyalkylene terephthalate or polyphenylene sulfide. These are intended to improve the adhesive strength between the metal and the resin by a physical anchor effect, with the molten resin penetrating into the unevenness of the metal surface formed by the surface treatment. For this reason, crystalline resins that have excellent melt flow properties at temperatures above their melting points are used. On the other hand, Patent document 5 reports a resin composition consisting of an aromatic polycarbonate resin and an aromatic carboxylic acid diester of bisphenol for adhesion between polycarbonate resin and metal. Patent document 6 reports a resin composition consisting of a polycarbonate resin and polycaprolactone. However, although all of these have excellent aluminum vapor deposition properties on resin molded bodies, they are still insufficient for adhesion between metal shapes and resins. Patent document 7 reports a resin composition for metal bonding consisting of a polycarbonate resin and a specific phosphorus-based plasticizer. This document reports that the resin composition has excellent adhesive strength with the shaped metal object, but the adhesive strength may be insufficient under environments such as moist heat conditions. Patent Documents 8 and 9 report a metal-resin composite structure of a metal member and an amorphous thermoplastic resin member, in which the surface roughness of the shaped metal object is controlled by a specific surface treatment, and a method for producing the same. However, although these are amorphous thermoplastic resins that have excellent adhesive strength with the shaped metal object, the adhesive strength may be insufficient under environments such as moist heat conditions and chemical treatment conditions, and are not satisfactory.

JP 2003-103563 A JP 2003-200453 A JP 2003-251654 A JP 2006-001216 A Japanese Patent Application Publication No. 01-065166 Japanese Patent Application Publication No. 07-102166 JP 2019-099621 A JP 2016-027189 A JP 2016-074116 A

The object of the present invention is to provide a polycarbonate resin composition that has excellent adhesion to metals and exhibits little decrease in bonding strength even in various environments, and a resin-metal composite molded product made from the same.

As a result of intensive research aimed at achieving the above object, the inventors discovered that a polycarbonate resin composition consisting of a modified polycarbonate resin containing a specific carbonate structural unit and a reinforcing filler containing a specific glass satisfies the above object, and thus arrived at the present invention.

That is, according to the present invention, there is provided a polycarbonate resin composition for producing a resin molded body in a composite molded body in which a metal molded body and a resin molded body are joined, the polycarbonate resin composition comprising 100 parts by weight of a resin component consisting of (A) 50 to 100% by weight of a modified polycarbonate resin (component A) containing a structural unit (A) represented by the following formula [1] and a structural unit (B) represented by the following formula [2] and (B) 0 to 50% by weight of a polycarbonate resin other than component A (component B), and (C) 52.0 to 57.0% by weight of SiO ₂ , 13.0 to 17.0% by weight of Al ₂ O ₃ , 15.0 to 21.5% by weight of B ₂ O ₃ , 2.0 to 6.0% by weight of MgO, 2.0 to 6.0% by weight of CaO, 1.0 to 4.0% by weight of TiO ₂ and less than 1.5% by weight of F ₂ based on the total amount of _glass , and The polycarbonate resin composition is characterized by containing 10 to 100 parts by weight of a reinforcing filler (component C) containing glass in which the total amount of O, Na ₂ O and K ₂ O is less than 0.6% by weight.

(In the formula, W represents a single bond, an alkylene group having 1 to 6 carbon atoms, an arylene group having 6 to 10 carbon atoms, or a cyclic alkylene group having 3 to 8 carbon atoms.)

One of the more preferred aspects of the present invention is the polycarbonate resin composition described in (1) above, characterized in that (2) component C is a reinforcing filler containing at least one type of glass selected from the group consisting of flat cross-section glass fibers (component C-1) having an average major axis of 10 to 50 μm and an average major axis to minor axis ratio (major axis/minor axis) of 1.5 to 8, and circular cross-section glass fibers (component C-2) having a fiber diameter of 1 to 30 μm.

One of the more preferred aspects of the present invention is the polycarbonate resin composition described in the above configuration (1) or (2), which is characterized in that it contains 1 to 100 parts by weight of (D) polyolefin resin (component D) and 1 to 50 parts by weight of (E) styrene-based thermoplastic elastomer (component E) per 100 parts by weight of (3) resin component.

One of the more preferred aspects of the present invention is (4) a composite molded body in which a metal molded body having an uneven surface is bonded to a resin molded body made of a polycarbonate resin composition described in any one of the above configurations (1) to (3), and the metal molded body and the resin molded body are bonded together as one body by the resin molded body entering the uneven surface of the metal molded body.

The following provides further details about the present invention.

<Component A Modified Polycarbonate Resin>
The polycarbonate resin used as component A in the present invention is a modified polycarbonate resin containing a structural unit (A) represented by the following formula [1] and a structural unit (B) represented by the following formula [2].

(In the formula, W represents a single bond, an alkylene group having 1 to 6 carbon atoms, an arylene group having 6 to 10 carbon atoms, or a cyclic alkylene group having 3 to 8 carbon atoms.)

The structural unit represented by the general formula [1] is preferably a structural unit derived from at least one selected from the group consisting of 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, and 2,2'-methyl-4,4'-biphenyldiol, and more preferably a structural unit derived from 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane or 2,2-bis(4-hydroxy-3-methylphenyl)propane.

The modified polycarbonate resin is obtained by reacting a dihydric phenol which derives the repeating units represented by the general formulas [1] and [2], and, if necessary, an aliphatic and/or alicyclic difunctional alcohol, with a carbonate precursor. Examples of the reaction method include an interfacial polycondensation method, a melt transesterification method, a solid-phase transesterification method of a carbonate prepolymer, and a ring-opening polymerization method of a cyclic carbonate compound. In the case of interfacial polycondensation, a monohydric phenol-based end terminator is usually used. In addition, it may be a branched polycarbonate obtained by polymerizing a trifunctional component, or a copolymerized polycarbonate obtained by copolymerizing an aliphatic dicarboxylic acid, an aromatic dicarboxylic acid, and a vinyl monomer.

In the reaction using, for example, phosgene as a carbonate precursor, the reaction is usually carried out in the presence of an acid binder and a solvent. As the acid binder, for example, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide or an amine compound such as pyridine is used. As the solvent, for example, a halogenated hydrocarbon such as methylene chloride or chlorobenzene is used. In addition, a catalyst such as a tertiary amine or a quaternary ammonium salt can be used to promote the reaction. In this case, the reaction temperature is usually 0 to 40°C, and the reaction time is several minutes to 5 hours.

The transesterification reaction using, for example, a carbonic acid diester as a carbonate precursor is carried out by heating and stirring a predetermined proportion of aromatic dihydroxy components with a carbonic acid diester under an inert gas atmosphere, and distilling off the resulting alcohol or phenol. The reaction temperature varies depending on the boiling point of the resulting alcohol or phenol, but is usually in the range of 120 to 300°C. The reaction is completed by reducing the pressure from the beginning and distilling off the resulting alcohol or phenol. In order to promote the reaction, a catalyst usually used in transesterification reactions can also be used. Examples of carbonic acid diesters used in the transesterification reaction include diphenyl carbonate, dinaphthyl carbonate, bis(diphenyl)carbonate, dimethyl carbonate, diethyl carbonate, and dibutyl carbonate. Of these, diphenyl carbonate is particularly preferred.

Monofunctional phenols that are commonly used as end terminators can be used. In particular, in the case of reactions using phosgene as a carbonate precursor, monofunctional phenols are commonly used as end terminators to adjust molecular weight, and the resulting polycarbonate resin has excellent thermal stability compared to those that are not, since the ends are blocked with groups based on monofunctional phenols. Specific examples of the monofunctional phenols include, for example, phenol, m-methylphenol, p-methylphenol, m-propylphenol, p-propylphenol, 1-phenylphenol, 2-phenylphenol, p-tert-butylphenol, p-cumylphenol, isooctylphenol, and p-long-chain alkylphenol.

The viscosity average molecular weight of the modified polycarbonate resin used as component A of the present invention is preferably in the range of 12,500 to 50,000, more preferably 16,000 to 30,000, even more preferably 18,000 to 28,000, and most preferably 19,000 to 26,000. If the molecular weight exceeds 50,000, the melt viscosity may become too high and moldability may be poor, and if the molecular weight is less than 12,500, problems may occur with mechanical strength. The viscosity average molecular weight referred to in the present invention is first calculated by using an Ostwald viscometer to determine the specific viscosity calculated by the following formula from a solution in which 0.7 g of polycarbonate resin is dissolved in 100 ml of methylene chloride at 20°C, and then inserting the calculated specific viscosity into the following formula to determine the viscosity average molecular weight M.

Specific viscosity (η _SP )=(t−t ₀ )/t ₀
[ _t0 is the number of seconds that methylene chloride falls, and t is the number of seconds that the sample solution falls]
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 proportion of the structural unit represented by general formula [1] in all structural units of component A is preferably 50 to 100 mol%, more preferably 60 to 100 mol%, and even more preferably 80 to 100 mol%. If the proportion of structural unit (A) represented by general formula [1] is less than 50 mol%, the adhesive strength to the metal may decrease.

The content of the modified polycarbonate resin used as component A in the present invention is 50 to 100% by weight, preferably 60 to 100% by weight, and more preferably 70 to 100% by weight, out of 100% by weight of the total of components A and B. If the content of component A is less than 50% by weight, the adhesive strength with the metal decreases.

<Component B: Polycarbonate resin other than component A>
The polycarbonate resin used as component B of the present invention is a polycarbonate resin other than component A, and is preferably a polycarbonate resin consisting only of the repeating structural unit (B) represented by the above general formula [2], and is produced by a reaction means known per se for producing ordinary aromatic polycarbonate resins, for example, a method of reacting an aromatic dihydroxy component with a carbonate precursor such as phosgene or a carbonate diester. The basic means for this production method will be briefly explained.

In a reaction using, for example, phosgene as a carbonate precursor, the reaction is usually carried out in the presence of an acid binder and a solvent. As the acid binder, for example, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide or an amine compound such as pyridine is used. As the solvent, for example, a halogenated hydrocarbon such as methylene chloride or chlorobenzene is used. In addition, a catalyst such as a tertiary amine or a quaternary ammonium salt can be used to promote the reaction. In this case, the reaction temperature is usually 0 to 40°C, and the reaction time is several minutes to 5 hours. In an ester exchange reaction using a carbonic acid diester as a carbonate precursor, a predetermined ratio of aromatic dihydroxy components is stirred with the carbonic acid diester while heating in an inert gas atmosphere, and the resulting alcohol or phenol is distilled off. The reaction temperature varies depending on the boiling point of the resulting alcohol or phenol, but is usually in the range of 120 to 300°C. The reaction is completed by reducing the pressure from the beginning and distilling off the resulting alcohol or phenol. In addition, a catalyst usually used in ester exchange reactions can be used to promote the reaction.

In the present invention, a terminal terminator is used in the polymerization reaction. The terminal terminator is used to adjust the molecular weight, and the resulting polycarbonate resin has excellent thermal stability compared to those that are not terminated, since the ends are blocked. Examples of such terminal terminators include monofunctional phenols represented by the following general formulas [3] to [5].

[In formula [3], A is a hydrogen atom, an alkyl group having 1 to 9 carbon atoms, an alkylphenyl group (the alkyl portion has 1 to 9 carbon atoms), a phenyl group, or a phenylalkyl group (the alkyl portion has 1 to 9 carbon atoms), and r is an integer of 1 to 5, preferably 1 to 3].

[In formulas [4] and [5], Y is -R-O-, -R-CO-O-, or -R-O-CO-. Here, R represents a single bond or a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms, and n represents an integer of 10 to 50.]

Specific examples of monofunctional phenols represented by the above general formula [3] include, for example, phenol, isopropylphenol, p-tert-butylphenol, p-cresol, p-cumylphenol, 2-phenylphenol, 4-phenylphenol, and isooctylphenol. In addition, the monofunctional phenols represented by the above general formulas [4] and [5] are phenols having a long-chain alkyl group or an aliphatic ester group as a substituent, and when these are used to block the ends of polycarbonate resin, they not only function as end terminators or molecular weight regulators, but also improve the melt flowability of the resin, making molding easier, and have the effect of lowering the water absorption rate of the resin, and are preferably used. As the substituted phenols of the above general formula [4], those in which n is 10 to 30, particularly 10 to 26, are preferred, and specific examples thereof include, for example, decylphenol, dodecylphenol, tetradecylphenol, hexadecylphenol, octadecylphenol, eicosylphenol, docosylphenol, and triacontylphenol. As the substituted phenols of the above general formula [5], compounds in which Y is -R-CO-O- and R is a single bond are suitable, and those in which n is 10 to 30, particularly 10 to 26, are preferred, and specific examples thereof include decyl hydroxybenzoate, dodecyl hydroxybenzoate, tetradecyl hydroxybenzoate, hexadecyl hydroxybenzoate, eicosyl hydroxybenzoate, docosyl hydroxybenzoate, and triacontyl hydroxybenzoate. Among these monofunctional phenols, the monofunctional phenols represented by the above general formula [3] are preferred, more preferably alkyl- or phenylalkyl-substituted phenols, and particularly preferably p-tert-butylphenol, p-cumylphenol, or 2-phenylphenol. It is desirable that the terminal terminator of these monofunctional phenols is introduced into the terminals of at least 5 mol %, preferably at least 10 mol %, of the total terminals of the obtained polycarbonate resin, and the terminal terminator may be used alone or in combination of two or more.

The viscosity average molecular weight of the polycarbonate resin used as component B of the present invention is preferably in the range of 12,500 to 50,000, more preferably 16,000 to 30,000, even more preferably 18,000 to 28,000, and most preferably 19,000 to 26,000. If the molecular weight exceeds 50,000, the melt viscosity may become too high, resulting in poor moldability, and if the molecular weight is less than 12,500, problems with mechanical strength may occur.

<Component C: Glass-containing reinforcing filler>
The glass-containing reinforcing filler used as component C of the present invention is a reinforcing filler containing 52.0-57.0% by weight of SiO ₂ , 13.0-17.0% by weight of Al ₂ O ₃ , 15.0-21.5% by weight of B ₂ O ₃ , 2.0-6.0% by weight of MgO, 2.0-6.0% by weight of CaO, 1.0-4.0% by weight of TiO ₂ and less than 1.5% by weight of F ₂ based on the total amount of glass, and the total amount of Li ₂ O, Na ₂ O and K ₂ O is less than 0.6% by weight, and is preferably a glass fiber having this composition. If a filler other than the glass-containing reinforcing filler having this composition is used, the adhesive strength under moist heat conditions decreases.

Further, the glass-containing reinforcing filler may contain impurities other than the above-mentioned components in a range of less than _0.4 % by weight based on the total amount of glass. Examples of impurities that may be contained include _Fe2O3 , _{Cr2O3 , ZrO2} , _MoO3 , _SO3 , _Cl2 , etc. Among these, the content of _Fe2O3 in the total amount of glass is preferably in the range of 0.05 to 0.15% by weight because it affects the absorption of radiant heat in the molten glass and the coloring of the glass-containing _reinforcing filler.

In addition, in the case of reinforced fillers containing glass, the content of each of the above-mentioned components can be measured using an ICP optical emission spectrometer for the light element Li, and a wavelength dispersive X-ray fluorescence analyzer for the other elements.

As a measurement method, first, the polycarbonate resin composition is heated, for example, in a muffle furnace at 300 to 650°C for about 0.5 to 24 hours to decompose the organic matter. Next, the remaining glass-containing reinforced filler is placed in a platinum crucible and melted while stirring in an electric furnace at a temperature of 1550°C for 6 hours to obtain a homogeneous molten glass. Next, the obtained molten glass is poured onto a carbon plate to produce glass cullet, which is then crushed and powdered. For the light element Li, the glass powder is decomposed by alkali and acid melting, and then quantitatively analyzed using an ICP emission spectrometer. For the other elements, the glass powder is molded into a disk shape using a press machine, and then quantitatively analyzed using a wavelength dispersive X-ray fluorescence analyzer. The results of these quantitative analyses are converted into oxides to calculate the content and total amount of each component, and the content of each of the above-mentioned components can be obtained from these values.

In the present invention, the glass fibers contained in the polycarbonate resin composition preferably have a number average fiber length of 30 to 5000 μm. If the number average fiber length of the glass fibers is less than 30 μm, the glass fiber reinforced resin molded product may not be able to obtain sufficient tensile strength and impact strength. In addition, since breakage of the glass fibers occurs during the manufacturing process of the polycarbonate resin composition, it is difficult to make the number average fiber length of the glass fibers exceed 5000 μm. In addition, the method for measuring the number average fiber length of the glass fibers in the polycarbonate resin composition of the present invention is to first decompose the organic matter by heating the polycarbonate resin composition, for example, in a muffle at 300 to 650 ° C for about 0.5 to 24 hours. Next, the remaining glass fibers are transferred to a glass petri dish and dispersed on the surface of the petri dish using acetone. Next, the fiber length of 500 or more glass fibers dispersed on the surface is measured using a stereomicroscope, and the number average fiber length is calculated.

Component C is preferably a reinforcing filler containing at least one type of glass selected from the group consisting of flat cross-section glass fibers (component C-1) with an average major axis of the fiber cross-section of 10 to 50 μm and an average major axis to minor axis ratio (major axis/minor axis) of 1.5 to 8, and circular cross-section glass fibers (component C-2) with a fiber cross-section diameter of 1 to 30 μm.

The average ratio of the major axis to the minor axis (major axis/minor axis) of the C-1 component is preferably 2.2 to 6.0, and more preferably 3.2 to 4.5. When the glass fiber has such a cross section, the improvement rate of the tensile strength and notched Charpy impact strength based on the tensile strength and notched Charpy impact strength of a polycarbonate resin composition using the glass fiber under the same conditions except for the composition may be extremely high, compared to when the glass fiber has a circular cross section.

In addition, the C-1 component preferably has a noncircular cross section in which the fiber diameter when the cross-sectional area is converted to a perfect circle (hereinafter sometimes referred to as the converted fiber diameter) is in the range of 3.0 to 35.0 μm, more preferably in the range of 6.0 to 20.0 μm, and even more preferably in the range of 6.5 to 16.0 μm.

As for the non-circular shape of component C-1, a cocoon shape, an ellipse, or an oval shape (a rectangle with semicircular shapes on both ends, or a shape similar thereto) is preferred, as this provides excellent flowability when producing a polycarbonate resin composition, with an oval shape being more preferred.

The polycarbonate resin composition of the present invention can contain both the glass fibers having a noncircular cross section and the glass fibers having a circular cross section. When the polycarbonate resin composition of the present invention contains both the glass fibers having a noncircular cross section and the glass fibers having a circular cross section, for example, the ratio of the content (wt%) of the glass fibers having a circular cross section to the content (wt%) of the glass fibers having a noncircular cross section (glass fibers having a circular cross section (wt%)/glass fibers having a noncircular cross section (wt%)) can be in the range of 0.1 to 1.0.

In the present invention, the glass fiber (component C-2) with a circular cross section contained in the polycarbonate resin composition has a circular cross section with a fiber diameter preferably in the range of 1.0 to 30 μm, more preferably 7.0 to 13.0 μm. If the fiber diameter is less than 1.0 μm, the strength may be insufficient, and if it exceeds 30 μm, the processability of the glass fiber may be poor.

The content of component C is 10 to 100 parts by weight, preferably 10 to 80 parts by weight, and more preferably 15 to 60 parts by weight, per 100 parts by weight of the resin component. If the content of component C is less than 10 parts by weight, the adhesion strength decreases, and furthermore, the adhesive strength under moist heat conditions also decreases. If it exceeds 100 parts by weight, the moldability decreases.

<Component D: Polyolefin resin>
The resin composition of the present invention may contain a polyolefin resin as component D. The polyolefin resin is preferably a polymer of propylene, and may also be a copolymer with other monomers. Examples of the polypropylene resin of the present invention include homopolypropylene resin, a block copolymer of propylene with ethylene and an α-olefin having 4 to 10 carbon atoms (also referred to as "block polypropylene"), and a random copolymer of propylene with ethylene and an α-olefin having 4 to 10 carbon atoms (also referred to as "random polypropylene"). The "block polypropylene" and "random polypropylene" are collectively referred to as "polypropylene copolymer".

In the present invention, one or more of the above-mentioned homopolypropylene resins, block polypropylenes, and random polypropylenes may be used as the polypropylene resin, with homopolypropylene and block polypropylene being preferred.

Examples of α-olefins having 4 to 10 carbon atoms used in polypropylene copolymers include 1-butene, 1-pentene, isobutylene, 3-methyl-1-butene, 1-hexene, 3,4-dimethyl-1-butene, 1-heptene, and 3-methyl-1-hexene.

The content of ethylene in the polypropylene copolymer is preferably 5% by weight or less of the total monomers. The content of α-olefins having 4 to 10 carbon atoms in the polypropylene copolymer is preferably 20% by weight or less of the total monomers.

The polypropylene copolymer is preferably a copolymer of propylene and ethylene or a copolymer of propylene and 1-butene, and is particularly preferably a copolymer of propylene and ethylene.

The melt flow rate (230°C, 2.16 kg) of the polypropylene resin in the present invention is preferably 0.1 to 40 g/10 min, more preferably 0.2 to 20 g/10 min, and even more preferably 0.5 to 10 g/10 min. If the melt flow rate of the polypropylene resin is less than 0.1 g/10 min, the moldability may be poor due to high viscosity, and if it exceeds 40 g/10 min, the tensile breaking strength may not improve and the extrusion processability may be poor. The melt flow rate is also called "MFR". MFR was measured in accordance with ISO 1133.

In the present invention, modified polyolefin resins modified with maleic anhydride can be used alone or in combination. Examples of modified polyolefin resins include polyethylene resins and polypropylene resins, with polypropylene resins being preferred. Modified polypropylene resins include propylene homopolymers, propylene random copolymers, and propylene block copolymers. The crystallization temperature (Tc) of the modified olefin resin is usually 90 to 125°C, preferably 110 to 120°C. The intrinsic viscosity is usually 0.1 to 2.4 dl/g, preferably 0.2 to 1.6 dl/g. The crystallization temperature (Tc) of the modified polyolefin resin can be measured by a differential scanning calorimeter (DSC). The intrinsic viscosity of the modified polyolefin resin can be measured in tetralin at 135°C.

The modified polyolefin resin is preferably a modified polypropylene resin such as a random propylene copolymer grafted with maleic anhydride.

The amount of groups derived from maleic anhydride in the modified polyolefin resin is preferably 1.5 to 2.2% by weight, more preferably 1.6 to 2.2% by weight, even more preferably 1.6 to 2.0% by weight, and particularly preferably 1.7 to 1.9% by weight, based on the total weight of the modified polyolefin resin. If the amount of modification is less than 1.5% by weight, extrusion processability may deteriorate, and if it exceeds 2.2% by weight, the appearance may be impaired.

The melt flow rate (MFR) (190°C; 2.16 kg) of modified polyolefin resins measured in accordance with the general definition of ISO 1133 is preferably 80 to 300 g/10 min, more preferably 90 to 200 g/10 min, and even more preferably 100 to 150 g/10 min. If the MFR is less than 80 g/10 min, problems may arise with the tensile breaking strength, and if it exceeds 300 g/10 min, extrusion processability may deteriorate.

In addition, the melting temperature Tm of the modified polypropylene resin is preferably in the range of 120 to 150°C, more preferably in the range of 125 to 145°C, and most preferably in the range of 130 to 140°C.

The modified polypropylene resin is preferably obtained from a solid-phase grafting process consisting of a polymer, a monomer, and a reaction initiator, and such process steps are well known in the art.

The content of component D is preferably 1 to 100 parts by weight, more preferably 10 to 95 parts by weight, even more preferably 10 to 60 parts by weight, and particularly preferably 20 to 60 parts by weight, per 100 parts by weight of the resin component. If the content of component D is less than 1 part by weight, chemical resistance may be insufficient, and if it exceeds 100 parts by weight, heat resistance, tensile strength at break, dimensional stability, surface appearance, and extrusion processability may be insufficient.

<Component E: Styrene-based thermoplastic elastomer>
The resin composition of the present invention may contain a styrene-based thermoplastic elastomer as component E. Examples of the styrene-based thermoplastic elastomer include styrene-ethylene/butylene-styrene block copolymer, styrene-hydrogenated butadiene-styrene triblock copolymer, styrene-isoprene-styrene triblock copolymer, styrene-hydrogenated isoprene-styrene triblock copolymer, styrene-hydrogenated butadiene diblock copolymer, styrene-hydrogenated isoprene diblock copolymer, and styrene-isoprene diblock copolymer, among which styrene-ethylene/butylene-styrene block copolymer is most suitable.

Also preferably used are block copolymers represented by the following formula (I) or (II):
X-(Y-X) _n ...(I)
(X-Y) _n ...(II)
In general formulas (I) and (II), X is a styrene polymer block, and in formula (I), the degrees of polymerization at both ends of the molecular chain may be the same or different. Y is at least one selected from an isoprene polymer block, a hydrogenated butadiene polymer block, and a hydrogenated isoprene polymer block. Also, n is an integer of 1 or more.

The content of the X component in the block copolymer is desirably in the range of 20 to 80% by weight, preferably 25 to 70% by weight. If this amount is less than 20% by weight, the rigidity of the resin composition tends to decrease, and if it exceeds 80% by weight, the moldability and impact strength tend to decrease, both of which are undesirable. Specific examples of such block copolymers include styrene-hydrogenated butadiene-styrene triblock copolymer, styrene-isoprene-styrene triblock copolymer, styrene-hydrogenated isoprene-styrene triblock copolymer, styrene-hydrogenated butadiene diblock copolymer, styrene-hydrogenated isoprene diblock copolymer, and styrene-isoprene diblock copolymer.

The weight average molecular weight of the styrene-based thermoplastic elastomer is preferably 250,000 or less, more preferably 220,000 or less, and even more preferably 200,000 or less. If the weight average molecular weight exceeds 250,000, the moldability may decrease and the dispersibility in the thermoplastic resin may also deteriorate. There is no particular limit to the lower limit of the weight average molecular weight, but it is preferably 40,000 or more, and more preferably 50,000 or more. The weight average molecular weight was measured by the following method. That is, the molecular weight was measured in terms of polystyrene using a gel permeation chromatograph, and the weight average molecular weight was calculated.

The content of component E is preferably 1 to 50 parts by weight, more preferably 3 to 30 parts by weight, even more preferably 5 to 20 parts by weight, and particularly preferably 5 to 15 parts by weight, per 100 parts by weight of the resin component. If the content of component D is less than 1 part by weight, the strength may not improve, and if it exceeds 50 parts by weight, it is not economical.

<Other ingredients>
In the polycarbonate resin composition of the present invention, additives used for improving the thermal stability, mold releasability, design and functionality can be advantageously used. These additives will be specifically described below.

(I) Heat Stabilizer Various known stabilizers can be blended into the polycarbonate resin composition of the present invention. Examples of the stabilizer include phosphorus-based stabilizers and hindered phenol-based antioxidants.

(i) Phosphorus-based stabilizer The polycarbonate resin composition of the present invention is preferably blended with a phosphorus-based stabilizer to the extent that it does not promote hydrolysis. Such phosphorus-based stabilizers improve the thermal stability during production or molding processing, and improve mechanical properties, color, and molding stability. Examples of phosphorus-based stabilizers include phosphorous acid, phosphoric acid, phosphonous acid, phosphonic acid, and esters thereof, as well as tertiary phosphines. Specific examples of the phosphite compound include triphenyl phosphite, tris(nonylphenyl)phosphite, tridecyl phosphite, trioctyl phosphite, trioctadecyl phosphite, didecyl monophenyl phosphite, dioctyl monophenyl phosphite, diisopropyl monophenyl phosphite, monobutyl diphenyl phosphite, monodecyl diphenyl phosphite, monooctyl diphenyl phosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite, tris(diethylphenyl)phosphite, tris(di-iso-propylphenyl)phosphite, and tris(di-n-butylphenyl)phosphite. bis(2,4-di-tert-butylphenyl) phosphite, tris(2,6-di-tert-butylphenyl) phosphite, distearyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-ethylphenyl) pentaerythritol diphosphite, phenyl bisphenol A pentaerythritol diphosphite, bis(nonylphenyl) pentaerythritol diphosphite, dicyclohexyl pentaerythritol diphosphite, etc. Furthermore, as other phosphite compounds, those which react with dihydric phenols to have a cyclic structure can also be used. For example, 2,2'-methylenebis(4,6-di-tert-butylphenyl)(2,4-di-tert-butylphenyl)phosphite, 2,2'-methylenebis(4,6-di-tert-butylphenyl)(2-tert-butyl-4-methylphenyl)phosphite, 2,2'-methylenebis(4-methyl-6-tert-butylphenyl)(2-tert-butyl-4-methylphenyl)phosphite, 2,2'-ethylidenebis(4-methyl-6-tert-butylphenyl)(2-tert-butyl-4-methylphenyl)phosphite, and the like can be mentioned. Examples of the phosphate compound include tributyl phosphate, trimethyl phosphate, tricresyl phosphate, triphenyl phosphate, trichlorophenyl phosphate, triethyl phosphate, diphenyl cresyl phosphate, diphenyl monoorthoxenyl phosphate, tributoxyethyl phosphate, dibutyl phosphate, dioctyl phosphate, diisopropyl phosphate, and the like, and preferably triphenyl phosphate and trimethyl phosphate.

Phosphonite compounds include tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,3'-biphenylene diphosphonite, tetrakis(2,4-di-tert-butylphenyl)-3,3'-biphenylene diphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,3'-biphenylene diphosphonite, tetrakis(2,6-di-tert-butylphenyl)-3,3'-biphenylene diphosphonite, bis(2,4-di-tert-butylphenyl)-4-phenyl-phenylphosphonite, bis Examples of the phosphonite include (2,4-di-tert-butylphenyl)-3-phenyl-phenyl phosphonite, bis(2,6-di-n-butylphenyl)-3-phenyl-phenyl phosphonite, bis(2,6-di-tert-butylphenyl)-4-phenyl-phenyl phosphonite, and bis(2,6-di-tert-butylphenyl)-3-phenyl-phenyl phosphonite. Tetrakis(di-tert-butylphenyl)-biphenylene diphosphonite and bis(di-tert-butylphenyl)-phenyl-phenyl phosphonite are preferred, and tetrakis(2,4-di-tert-butylphenyl)-biphenylene diphosphonite and bis(2,4-di-tert-butylphenyl)-phenyl-phenyl phosphonite are more preferred. Such phosphonite compounds can be used in combination with a phosphite compound having an aryl group substituted with two or more alkyl groups, and are therefore preferred. Examples of the phosphonate compound include dimethyl benzene phosphonate, diethyl benzene phosphonate, and dipropyl benzene phosphonate. Examples of tertiary phosphines include triethylphosphine, tripropylphosphine, tributylphosphine, trioctylphosphine, triamylphosphine, dimethylphenylphosphine, dibutylphenylphosphine, diphenylmethylphosphine, diphenyloctylphosphine, triphenylphosphine, tri-p-tolylphosphine, trinaphthylphosphine, and diphenylbenzylphosphine. A particularly preferred tertiary phosphine is triphenylphosphine. The phosphorus-based stabilizer can be used alone or in combination of two or more. Among the phosphorus-based stabilizers, it is preferable to use an alkyl phosphate compound, such as trimethyl phosphate. It is also preferable to use such an alkyl phosphate compound in combination with a phosphite compound and/or a phosphonite compound.

(ii) Hindered phenol-based stabilizer The polycarbonate resin composition of the present invention may further contain a hindered phenol-based stabilizer. Such incorporation exerts the effect of suppressing deterioration of hue during molding processing and deterioration of hue over long-term use. Examples of hindered phenol-based stabilizers include α-tocopherol, butyl hydroxytoluene, sinapyl alcohol, vitamin E, n-octadecyl-β-(4'-hydroxy-3',5'-di-tert-butylphenyl)propionate, 2-tert-butyl-6-(3'-tert-butyl-5'-methyl-2'-hydroxybenzyl)-4-methylphenyl acrylate, 2,6-di-tert-butyl-4-(N,N- dimethylaminomethyl)phenol, 3,5-di-tert-butyl-4-hydroxybenzylphosphonate diethyl ester, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 4,4'-methylenebis(2,6-di-tert-butylphenol), 2,2'-methylenebis(4-methyl-6-cyclohexylphenol), 2, 2'-Dimethylen-bis(6-α-methyl-benzyl-p-cresol) 2,2'-ethylidene-bis(4,6-di-tert-butylphenol), 2,2'-butylidene-bis(4-methyl-6-tert-butylphenol), 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), triethylene glycol-N-bis-3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate , 1,6-hexanediol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], bis[2-tert-butyl-4-methyl 6-(3-tert-butyl-5-methyl-2-hydroxybenzyl)phenyl]terephthalate, 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1,-dimethylethyl}-2,4,8,10-tetrahydrofuran Laoxaspiro[5,5]undecane, 4,4'-thiobis(6-tert-butyl-m-cresol), 4,4'-thiobis(3-methyl-6-tert-butylphenol), 2,2'-thiobis(4-methyl-6-tert-butylphenol), bis(3,5-di-tert-butyl-4-hydroxybenzyl)sulfide, 4,4'-di-thiobis(2,6-di-tert-butylphenol), 4,4'-tri-thiobis(2 ,6-di-tert-butylphenol), 2,2-thiodiethylene bis-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,4-bis(n-octylthio)-6-(4-hydroxy-3',5'-di-tert-butylanilino)-1,3,5-triazine, N,N'-hexamethylene bis-(3,5-di-tert-butyl-4-hydroxyhydrocinnamide), N,N'-bis[3-(3, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tris(3,5-di-tert-butyl-4-hydroxyphenyl)isocyanurate, tris(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine, Examples of such stabilizers include 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate, 1,3,5-tris2[3(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy]ethyl isocyanurate, and tetrakis[methylene-3-(3',5'-di-tert-butyl-4-hydroxyphenyl)propionate]methane. All of these are easily available. The above hindered phenol stabilizers can be used alone or in combination of two or more. The amount of the phosphorus stabilizer and the hindered phenol stabilizer to be blended is preferably 0.0001 to 1 part by weight, more preferably 0.001 to 0.5 parts by weight, and even more preferably 0.005 to 0.3 parts by weight, based on 100 parts by weight of the resin component.

(iii) Heat Stabilizers Other Than the Phosphorus-Based Stabilizer and the Hindered Phenol-Based Stabilizer The polycarbonate resin composition of the present invention may also contain heat stabilizers other than the phosphorus-based stabilizer and the hindered phenol-based stabilizer. Suitable examples of such heat stabilizers include lactone-based stabilizers, such as the reaction product of 3-hydroxy-5,7-di-tert-butyl-furan-2-one and o-xylene. Details of such stabilizers are described in JP-A-7-233160. Such a compound is commercially available as Irganox HP-136 (trademark, manufactured by CIBA SPECIALTY CHEMICALS), and this compound can be used. Furthermore, stabilizers in which this compound is mixed with various phosphite compounds and hindered phenol compounds are commercially available. Suitable examples include Irganox HP-2921 manufactured by the same company. The amount of the lactone-based stabilizer to be added is preferably 0.0005 to 0.05 part by weight, and more preferably 0.001 to 0.03 part by weight, based on 100 parts by weight of the resin component.

Other examples of stabilizers include sulfur-containing stabilizers such as pentaerythritol tetrakis (3-mercaptopropionate), pentaerythritol tetrakis (3-laurylthiopropionate), and glycerol-3-stearylthiopropionate. The amount of such sulfur-containing stabilizers is preferably 0.001 to 0.1 parts by weight, more preferably 0.01 to 0.08 parts by weight, per 100 parts by weight of the total of components A and B.

The polycarbonate resin composition of the present invention can contain an epoxy compound. Such an epoxy compound is added for the purpose of suppressing mold corrosion, and basically all epoxy functional groups can be used. Specific examples of preferred epoxy compounds include 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexylcarboxylate, 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol, copolymers of methyl methacrylate and glycidyl methacrylate, and copolymers of styrene and glycidyl methacrylate. The amount of such an epoxy compound to be added is preferably 0.003 to 0.2 parts by weight, more preferably 0.004 to 0.15 parts by weight, and even more preferably 0.005 to 0.1 parts by weight, per 100 parts by weight of the resin component.

(II) Ultraviolet Absorber The polycarbonate resin composition of the present invention can be blended with an ultraviolet absorber as a stabilizer against ultraviolet light. Specific examples of the ultraviolet absorber include benzophenone-based ultraviolet absorbers such as 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, 2-hydroxy-4-methoxy-5-sulfoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxy-5-sodiumsulfoxybenzophenone, bis(5-benzoyl-4-hydroxy-2-methoxyphenyl)methane, 2-hydroxy-4-n-dodecyloxybenzophenone, and 2-hydroxy-4-methoxy-2'-carboxybenzophenone. Specific examples of the ultraviolet absorbent include benzotriazole-based compounds such as 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole, 2-(2-hydroxy-3,5-dicumylphenyl)phenylbenzotriazole, 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-5-chlorobenzotriazole, and 2,2′-methylenebis[ 4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol], 2-(2-hydroxy-3,5-di-tert-butylphenyl)benzotriazole, 2-(2-hydroxy-3,5-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2-hydroxy-3,5-di-tert-amylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl) Examples of the copolymer include 2-hydroxyphenyl-2H-benzotriazole skeleton-containing polymers such as 2-(2-hydroxy-5-acryloxyethylphenyl)-2H-benzotriazole, 2-(2-hydroxy-5-tert-butylphenyl)-benzotriazole, 2-(2-hydroxy-4-octoxyphenyl)-benzotriazole, 2,2'-methylenebis(4-cumyl-6-benzotriazolephenyl), 2,2'-p-phenylenebis(1,3-benzoxazin-4-one), and 2-[2-hydroxy-3-(3,4,5,6-tetrahydrophthalimidomethyl)-5-methylphenyl]benzotriazole, as well as copolymers of 2-(2'-hydroxy-5-methacryloxyethylphenyl)-2H-benzotriazole and vinyl monomers copolymerizable with the monomer, and copolymers of 2-(2'-hydroxy-5-acryloxyethylphenyl)-2H-benzotriazole and vinyl monomers copolymerizable with the monomer. Specific examples of the ultraviolet absorber include hydroxyphenyltriazine-based compounds such as 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxyphenol, 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-methyloxyphenol, 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-ethyloxyphenol, 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-propyloxyphenol, and 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-butyloxyphenol. Further examples include compounds in which the phenyl group of the above-mentioned compounds is replaced with a 2,4-dimethylphenyl group, such as 2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl)-5-hexyloxyphenol. Specific examples of the ultraviolet absorber include cyclic iminoesters such as 2,2'-p-phenylenebis(3,1-benzoxazine-4-one), 2,2'-m-phenylenebis(3,1-benzoxazine-4-one), and 2,2'-p,p'-diphenylenebis(3,1-benzoxazine-4-one). Specific examples of the ultraviolet absorber include cyanoacrylates such as 1,3-bis-[(2'-cyano-3',3'-diphenylacryloyl)oxy]-2,2-bis[(2-cyano-3,3-diphenylacryloyl)oxy]methyl)propane, and 1,3-bis-[(2-cyano-3,3-diphenylacryloyl)oxy]benzene. Furthermore, the ultraviolet absorber may be a polymer type ultraviolet absorber obtained by copolymerizing such an ultraviolet absorbing monomer and/or a light stable monomer with a monomer such as an alkyl (meth)acrylate by adopting a structure of a monomer compound capable of radical polymerization. Suitable examples of the ultraviolet absorbing monomer include compounds containing a benzotriazole skeleton, a benzophenone skeleton, a triazine skeleton, a cyclic imino ester skeleton, and a cyanoacrylate skeleton in the ester substituent of a (meth)acrylic acid ester. Among the above, benzotriazole and hydroxyphenyl triazine are preferred in terms of ultraviolet absorbing ability, and cyclic imino ester and cyanoacrylate are preferred in terms of heat resistance and color. Specific examples include "Chemisorb 79" from Chemipro Chemical Co., Ltd. and "Tinuvin 234" from BASF Japan Co., Ltd. The ultraviolet absorber may be used alone or in a mixture of two or more kinds.

The content of the UV absorber is preferably 0.01 to 3 parts by weight, more preferably 0.01 to 1 part by weight, even more preferably 0.05 to 1 part by weight, and particularly preferably 0.05 to 0.5 parts by weight, per 100 parts by weight of the resin component.

(III) Dyes and Pigments Various dyes and pigments can be blended into the polycarbonate resin composition of the present invention to improve various design properties. Examples of dyes and pigments include perylene dyes, coumarin dyes, thioindigo dyes, anthraquinone dyes, thioxanthone dyes, ferrocyanides such as Prussian blue, perinone dyes, quinoline dyes, quinacridone dyes, dioxazine dyes, isoindolinone dyes, and phthalocyanine dyes. Furthermore, the polycarbonate resin composition of the present invention can be blended with a metallic pigment to obtain a better metallic color. Aluminum powder is suitable as the metallic pigment. In addition, by blending a fluorescent brightener or other fluorescent dye that emits light, a better design effect can be imparted by making use of the luminous color.

(IV) Fluorescent Brightening Agent In the polycarbonate resin composition of the present invention, the fluorescent brightening agent is not particularly limited as long as it is used to improve the color tone of the resin or the like to white or bluish white, and examples thereof include stilbene-based, benzimidazole-based, benzoxazole-based, naphthalimide-based, rhodamine-based, coumarin-based, and oxazine-based compounds. Specific examples thereof include CI Fluorescent Brightener 219:1, Eastman Chemical Company's EASTOBRITE OB-1, and Showa Chemical Company's "HAKCOL PSR." Here, the fluorescent brightening agent has the effect of absorbing the ultraviolet energy of light and radiating this energy in the visible region. The content of the fluorescent brightening agent is preferably 0.001 to 0.1 parts by weight, more preferably 0.001 to 0.05 parts by weight, based on 100 parts by weight of the resin component. If the amount exceeds 0.1 part by weight, the effect of improving the color tone of the composition is small.

(V) Compounds with Heat Absorption Ability The polycarbonate resin composition of the present invention may contain a compound with heat absorption ability. Suitable examples of such compounds include phthalocyanine-based near infrared absorbing agents, metal oxide-based near infrared absorbing agents such as ATO, ITO, iridium oxide, ruthenium oxide, immonium oxide, and titanium oxide, various metal compounds with excellent near infrared absorbing ability such as metal boride-based and tungsten oxide-based near infrared absorbing agents such as lanthanum boride, cerium boride, and tungsten boride, and carbon fillers. As such phthalocyanine-based near infrared absorbing agents, for example, MIR-362 manufactured by Mitsui Chemicals, Inc. is commercially available and easily available. Examples of carbon fillers include carbon black, graphite (both natural and artificial), and fullerene, and preferably carbon black and graphite. These can be used alone or in combination of two or more. The content of the phthalocyanine-based near infrared absorber is preferably 0.0005 to 0.2 parts by weight, more preferably 0.0008 to 0.1 parts by weight, and even more preferably 0.001 to 0.07 parts by weight, relative to 100 parts by weight of the total of Components A and B. The contents of the metal oxide-based near infrared absorber, metal boride-based near infrared absorber, and carbon filler are preferably in the range of 0.1 to 200 ppm (weight ratio), and more preferably in the range of 0.5 to 100 ppm, in the polycarbonate resin composition.

(VI) Light Diffuser The polycarbonate resin composition of the present invention can be blended with a light diffuser to impart a light diffusion effect. Examples of such light diffusers include polymer fine particles, inorganic fine particles with a low refractive index such as calcium carbonate, and composites thereof. Such polymer fine particles are fine particles already known as light diffusers for polycarbonate resins. More preferred examples include acrylic crosslinked particles with a particle size of several μm and silicone crosslinked particles represented by polyorganosilsesquioxane. Examples of the shape of the light diffuser include spherical, discoid, columnar, and indefinite shapes. Such a sphere does not need to be a perfect sphere and includes deformed ones, and such a columnar shape includes a cube. A preferred light diffuser is a sphere, and the more uniform the particle size, the more preferred it is. The content of the light diffuser is preferably 0.005 to 20 parts by weight, more preferably 0.01 to 10 parts by weight, and even more preferably 0.01 to 3 parts by weight, based on 100 parts by weight of the resin component. Two or more types of light diffusers can be used in combination.

(VII) Highly light-reflective white pigment A highly light-reflective white pigment can be blended into the polycarbonate resin composition of the present invention to impart a light-reflecting effect. Titanium dioxide pigment (particularly titanium dioxide treated with an organic surface treatment agent such as silicone) is particularly preferred as such a white pigment. The content of such highly light-reflective white pigment is preferably 3 to 30 parts by weight, more preferably 8 to 25 parts by weight, per 100 parts by weight of the resin component. Two or more types of highly light-reflective white pigments can be used in combination.

(VIII) Mold release agent The polycarbonate resin composition of the present invention can be blended with a mold release agent as necessary. As such a mold release agent, a known one can be used. For example, saturated fatty acid esters, unsaturated fatty acid esters, polyolefin waxes (such as polyethylene wax or 1-alkene polymers. These may also be modified with a functional group-containing compound such as an acid-modified one), silicone compounds (such as linear or cyclic polydimethylsiloxane oils and polymethylphenyl silicone oils). These may also be modified with a functional group-containing compound such as an acid-modified one), fluorine compounds (such as fluorine oils represented by polyfluoroalkyl ethers), paraffin wax, beeswax, etc. can be mentioned. Among these, saturated fatty acid esters, linear or cyclic polydimethylsiloxane oils, polymethylphenyl silicone oils, etc., and fluorine oils can be mentioned. Preferred release agents include saturated fatty acid esters, for example, monoglycerides such as stearate monoglyceride, polyglycerol fatty acid esters such as decaglycerol deca stearate and decaglycerol tetrastearate, lower fatty acid esters such as stearic acid stearate, higher fatty acid esters such as sebacate behenate, and erythritol esters such as pentaerythritol tetrastearate. The content of such release agents is preferably 0.01 to 1 part by weight, more preferably 0.01 to 0.5 parts by weight, per 100 parts by weight of the resin component. Two or more types of release agents can be used in combination.

(IX) Polytetrafluoroethylene having fibril-forming ability The polycarbonate resin composition of the present invention can be blended with polytetrafluoroethylene having fibril-forming ability as necessary. The polytetrafluoroethylene having fibril-forming ability (fibrillated PTFE) may be fibrillated PTFE alone or a mixture of fibrillated PTFE particles, i.e., a polytetrafluoroethylene mixture consisting of fibrillated PTFE particles and an organic polymer. Fibrillated PTFE has an extremely high molecular weight and shows a tendency to bond PTFE particles together to become fibrous due to external action such as shear force. Its number average molecular weight is in the range of 1.5 million to tens of millions. The lower limit is more preferably 3 million. The number average molecular weight is calculated based on the melt viscosity of polytetrafluoroethylene at 380°C, as disclosed in JP-A-6-145520. That is, the fibrillated PTFE has a melt viscosity at 380°C measured by the method described in this publication in the range of ¹⁰⁷ to ¹⁰¹³ poise, preferably ¹⁰⁸ to ¹⁰¹² poise. Such PTFE can be used in the form of a solid or an aqueous dispersion. In addition, such fibrillated PTFE can be used as a PTFE mixture mixed with other resins to improve dispersibility in resins and obtain better flame retardancy and mechanical properties. In addition, as disclosed in JP-A-6-145520, a structure in which such fibrillated PTFE is the core and low molecular weight polytetrafluoroethylene is the shell is also preferably used. Examples of commercially available products of such fibrillated PTFE include Teflon (registered trademark) 6J from Mitsui DuPont Fluorochemical Co., Ltd., and Polyflon MPA FA500 and F-201L from Daikin Chemical Industries, Ltd. Examples of mixed fibrillated PTFE include (1) a method of mixing an aqueous dispersion of fibrillated PTFE with an aqueous dispersion or solution of an organic polymer and co-precipitating to obtain a coagulated mixture (methods described in JP-A-60-258263, JP-A-63-154744, etc.), (2) a method of mixing an aqueous dispersion of fibrillated PTFE with dried organic polymer particles (method described in JP-A-4-272957), and (3) a method of uniformly mixing an aqueous dispersion of fibrillated PTFE with a solution of organic polymer particles and extracting the coagulated mixture from the mixture. (4) a method of simultaneously removing the mediums (methods described in JP-A-06-220210, JP-A-08-188653, etc.), (5) a method of polymerizing a monomer that forms an organic polymer in an aqueous dispersion of fibrillated PTFE (method described in JP-A-09-95583), and (6) a method of uniformly mixing an aqueous dispersion of PTFE and an organic polymer dispersion, and then polymerizing a vinyl monomer in the mixed dispersion to obtain a mixture (method described in JP-A-11-29679, etc.). The ratio of fibrillated PTFE in the mixed form is preferably 1% by weight to 95% by weight, more preferably 10% by weight to 90% by weight, and most preferably 20% by weight to 80% by weight, of the 100% by weight of the mixture. When the ratio of fibrillated PTFE in the mixed form is within this range, good dispersibility of fibrillated PTFE can be achieved. As commercially available products of these mixed forms of fibrillated PTFE, the Metablen A series represented by "Metablen A3000" (trade name), "Metablen A3700" (trade name), and "Metablen A3800" (trade name) of Mitsubishi Rayon Co., Ltd., SN3705 (trade name) of Shine Polymer Co., Ltd., and "BLENDEX B449" (trade name) of GE Specialty Chemicals Co., Ltd. are exemplified.

The fibrillated PTFE is preferably branched polytetrafluoroethylene. When the polytetrafluoroethylene contained is branched polytetrafluoroethylene, sufficient drip prevention effect can be obtained even if the amount of polytetrafluoroethylene added is reduced. Examples of commercially available polytetrafluoroethylene with fibril forming ability using branched polytetrafluoroethylene include "SN3306" (product name) and "SN3300B7" (product name) from Shine Polymer.

The content of fibrillated PTFE is preferably 0.01 to 1 part by weight, more preferably 0.1 to 0.8 parts by weight, even more preferably 0.1 to 0.4 parts by weight, and most preferably 0.1 to 0.18 parts by weight, per 100 parts by weight of the resin component. Note that the content of fibrillated PTFE indicates the amount of net PTFE, and indicates the amount of net PTFE even in the case of mixed PTFE.

(X) Flame retardant The polycarbonate resin composition of the present invention may contain various compounds known as flame retardants for polycarbonate resins. The incorporation of such compounds improves flame retardancy, but also improves antistatic properties, fluidity, rigidity, and thermal stability, etc., based on the properties of each compound. Examples of such flame retardants include (i) organometallic salt-based flame retardants (e.g., organic sulfonic acid alkali (earth) metal salts, organic boric acid metal salt-based flame retardants, and organostannic acid metal salt-based flame retardants), (ii) organophosphorus-based flame retardants (e.g., organic group-containing monophosphate compounds, phosphate oligomer compounds, phosphonate oligomer compounds, phosphonitrile oligomer compounds, and phosphonic acid amide compounds), (iii) silicone-based flame retardants made of silicone compounds, and (iv) halogen-based flame retardants, among which organometallic salt-based flame retardants and organophosphorus-based flame retardants are preferred.

(X-i) Organic Metal Salt Flame Retardant The organic metal salt flame retardant is preferably an alkali (earth) metal salt of an organic acid having 1 to 50, preferably 1 to 40 carbon atoms, preferably an alkali (earth) metal salt of an organic sulfonate. The alkali (earth) metal salt of an organic sulfonate includes a metal salt of a fluorine-substituted alkylsulfonic acid such as a metal salt of a perfluoroalkylsulfonic acid having 1 to 10, preferably 2 to 8, carbon atoms and an alkali metal or alkaline earth metal, and a metal salt of an aromatic sulfonic acid having 7 to 50, preferably 7 to 40, carbon atoms and an alkali metal or alkaline earth metal. Examples of the alkali metal constituting the metal salt include lithium, sodium, potassium, rubidium, and cesium, and examples of the alkaline earth metal include beryllium, magnesium, calcium, strontium, and barium. More preferably, it is an alkali metal. Among these alkali metals, rubidium and cesium, which have a larger ionic radius, are suitable when transparency is required, but they are not widely used and are difficult to purify, which may result in a disadvantage in terms of cost. On the other hand, metals with a smaller ionic radius, such as lithium and sodium, may be disadvantageous in terms of flame retardancy. Taking these factors into consideration, the alkali metals in the alkali metal sulfonates may be used differently, but in all respects, potassium sulfonates, which have an excellent balance of properties, are most suitable. Such potassium salts may also be used in combination with alkali metal sulfonates made of other alkali metals.

Specific examples of the alkali metal salt of perfluoroalkyl sulfonate include potassium trifluoromethanesulfonate, potassium perfluorobutanesulfonate, potassium perfluorohexanesulfonate, potassium perfluorooctane sulfonate, sodium pentafluoroethanesulfonate, sodium perfluorobutanesulfonate, sodium perfluorooctane sulfonate, lithium trifluoromethanesulfonate, lithium perfluorobutanesulfonate, lithium perfluoroheptanesulfonate, cesium trifluoromethanesulfonate, cesium perfluorobutanesulfonate, cesium perfluorooctane sulfonate, cesium perfluorohexanesulfonate, rubidium perfluorobutanesulfonate, and rubidium perfluorohexanesulfonate, and these can be used alone or in combination of two or more. Here, the carbon number of the perfluoroalkyl group is preferably in the range of 1 to 18, more preferably in the range of 1 to 10, and even more preferably in the range of 1 to 8. Among these, potassium perfluorobutanesulfonate is particularly preferred. In the alkali (earth) metal salt of perfluoroalkylsulfonic acid made of an alkali metal, fluoride ions (F ⁻ ) are usually mixed in no small amount. The presence of such fluoride ions can be a factor in reducing flame retardancy, so it is preferable to reduce them as much as possible. The proportion of such fluoride ions can be measured by ion chromatography. The content of fluoride ions is preferably 100 ppm or less, more preferably 40 ppm or less, and particularly preferably 10 ppm or less. It is also preferable that the content is 0.2 ppm or more for production efficiency. The alkali (earth) metal salt of perfluoroalkylsulfonic acid having a reduced amount of fluoride ions can be produced by using a known production method, and by a method of reducing the amount of fluoride ions contained in the raw material when producing a fluorine-containing organic metal salt, a method of removing hydrogen fluoride obtained by the reaction by gas generated during the reaction or by heating, and a method of reducing the amount of fluoride ions by using a purification method such as recrystallization and reprecipitation when producing a fluorine-containing organic metal salt. In particular, since organic metal salt flame retardants are relatively soluble in water, it is preferable to produce them by using ion-exchanged water, particularly water having an electrical resistance of 18 MΩ cm or more, i.e., an electrical conductivity of approximately 0.55 μS/cm or less, and dissolving and washing the material at a temperature higher than room temperature, followed by cooling and recrystallization. Specific examples of the aromatic sulfonic acid alkali (earth) metal salt include disodium diphenyl sulfide-4,4'-disulfonate, dipotassium diphenyl sulfide-4,4'-disulfonate, potassium 5-sulfoisophthalate, sodium 5-sulfoisophthalate, polysodium polyethylene terephthalate polysulfonate, calcium 1-methoxynaphthalene-4-sulfonate, disodium 4-dodecylphenyl ether disulfonate, polysodium poly(2,6-dimethylphenylene oxide) polysulfonate, polysodium poly(1,3-phenylene oxide) polysulfonate, polysodium poly(1,4-phenylene oxide) polysulfonate, polypotassium poly(2,6-diphenylphenylene oxide) polysulfonate, lithium poly(2-fluoro-6-butylphenylene oxide) polysulfonate, potassium sulfonate of benzenesulfonate, sodium benzenesulfonate, and benzenesulfonic acid. Examples of the sulfonate include strontium, magnesium benzenesulfonate, dipotassium p-benzenedisulfonate, dipotassium naphthalene-2,6-disulfonate, calcium biphenyl-3,3'-disulfonate, sodium diphenylsulfone-3-sulfonate, potassium diphenylsulfone-3-sulfonate, dipotassium diphenylsulfone-3,3'-disulfonate, dipotassium diphenylsulfone-3,4'-disulfonate, sodium α,α,α-trifluoroacetophenone-4-sulfonate, dipotassium benzophenone-3,3'-disulfonate, disodium thiophene-2,5-disulfonate, dipotassium thiophene-2,5-disulfonate, calcium thiophene-2,5-disulfonate, sodium benzothiophenesulfonate, potassium diphenylsulfoxide-4-sulfonate, a formalin condensate of sodium naphthalenesulfonate, and a formalin condensate of sodium anthracenesulfonate. Of these alkali (earth) metal salts of aromatic sulfonates, potassium salts are particularly preferred. Among these alkali (earth) metal salts of aromatic sulfonates, potassium diphenylsulfone-3-sulfonate and dipotassium diphenylsulfone-3,3'-disulfonate are particularly preferred, and mixtures thereof (wherein the weight ratio of the former to the latter is 15/85 to 30/70) are particularly preferred.

Suitable examples of organic metal salts other than alkali (earth) metal sulfonates include alkali (earth) metal salts of sulfates and alkali (earth) metal salts of aromatic sulfonamides. Examples of alkali (earth) metal salts of sulfates include alkali (earth) metal salts of sulfates of monohydric and/or polyhydric alcohols, and examples of sulfates of monohydric and/or polyhydric alcohols include methyl sulfate, ethyl sulfate, lauryl sulfate, hexadecyl sulfate, sulfate of polyoxyethylene alkylphenyl ether, mono-, di-, tri-, and tetrasulfate of pentaerythritol, sulfate of lauric acid monoglyceride, sulfate of palmitic acid monoglyceride, and sulfate of stearic acid monoglyceride. Examples of the alkali (earth) metal salts of these sulfates include alkali (earth) metal salts of lauryl sulfate. Examples of alkali (earth) metal salts of aromatic sulfonamides include saccharin, N-(p-tolylsulfonyl)-p-toluenesulfonimide, N-(N'-benzylaminocarbonyl)sulfanilimide, and alkali (earth) metal salts of N-(phenylcarboxyl)sulfanilimide.

The content of the organometallic salt flame retardant is preferably 0.01 to 1.0 parts by weight, more preferably 0.01 to 0.5 parts by weight, even more preferably 0.01 to 0.3 parts by weight, and particularly preferably 0.03 to 0.15 parts by weight, per 100 parts by weight of the resin component.

(X-ii) Phosphorus-based flame retardant As the phosphorus-based flame retardant, at least one phosphorus-based flame retardant selected from the group consisting of compounds represented by the following general formula [6] and compounds represented by the following general formula [7] is suitably used.

In the above formula [6], M represents a divalent organic group derived from a dihydric phenol. Examples of dihydric phenols include 1,2-dihydroxybenzene (catechol), 1,3-dihydroxybenzene (resorcinol), 1,4-dihydroxybenzene (hydroquinone), 4,4'-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxyphenyl)decane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 2,2-bis(4-hydroxy-3,3'-biphenyl)propane, 2,2-bis(4-hydroxyphenyl)-1,2-bis(4-hydroxyphenyl)- ...1,2-bis(4-hydroxyphenyl)-1,2-bis(4-hydroxyphenyl)-1,2-bis(4-hydroxyphenyl)-1,2-bis(4-hydroxyphenyl)-1,2-bis(4-hydroxyphenyl)-1,2-bis(4-hydroxyphenyl)-1,2-bis(4-hydroxyphenyl)-1, (4-hydroxy-3-isopropylphenyl)propane, 2,2-bis(3-t-butyl-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)octane, 2,2-bis(3-bromo-4-hydroxyphenyl)propane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, 2,2-bis(3-cyclohexyl-4-hydroxyphenyl)propane, 1,1-bis(3-cyclohexyl-4-hydroxyphenyl)cyclohexane, bis(4-hydroxyphenyl)diphenylmethane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)cyclopentane, 4,4'-dihydroxydiphenyl ether, 4, 4'-dihydroxy-3,3'-dimethyldiphenyl ether, 4,4'-sulfonyldiphenol, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxydiphenyl sulfide, 2,2'-dimethyl-4,4'-sulfonyldiphenol, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide, 2,2'-diphenyl-4,4'-sulfonyldiphenol, 4,4'-dihydroxy-3,3'-diphenyldiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-diphenyldiphenyl sulfide, 1,3-bis{2-(4-hydroxyphenyl)propyl}benzene, 1,4-bis{2-(4-hydroxyphenyl)propyl}benzene , 1,4-bis(4-hydroxyphenyl)cyclohexane, 1,3-bis(4-hydroxyphenyl)cyclohexane, 4,8-bis(4-hydroxyphenyl)tricyclo[5.2.1.02,6]decane, 4,4'-(1,3-adamantanediyl)diphenol, 1,3-bis(4-hydroxyphenyl)-5,7-dimethyladamantane, etc., among which 1,2-dihydroxybenzene (catechol), 1,3-dihydroxybenzene (resorcinol), 1,4-dihydroxybenzene (hydroquinone), 4,4'-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, and 2,2-bis(4-hydroxyphenyl)propane are preferred.

R ¹ , R ² , R ³ , and R ⁴ are each independently a group selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms, of which an aryl group having 6 to 10 carbon atoms is preferred. Specific examples of suitable monohydric phenols from which R ¹ , R ² , R ³ , and R ⁴ are derived include phenol, cresol, xylenol, isopropylphenol, butylphenol, and p-cumylphenol, of which phenol and 2,6-dimethylphenol are preferred. Furthermore, g, h, i, and j are each independently 0 or 1, m is an integer of 0 to 5, and in the case of a mixture of phosphate esters having different degrees of polymerization m, m represents the average value thereof and is a value of 0 to 5.

In the above formula [7], R ⁵ and R ⁶ are each independently a group selected from the group consisting of an alkoxy group having 1 to 10 carbon atoms, a cycloalkoxy group having 6 to 20 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, and an aralkyloxy group having 7 to 20 carbon atoms, of which an aryloxy group having 6 to 10 carbon atoms is preferred. Furthermore, k is an integer of 3 to 10, preferably 4 to 8, and more preferably 5 to 7.

The content of the organic phosphorus flame retardant is preferably 1 to 20 parts by weight, more preferably 2 to 15 parts by weight, and even more preferably 2 to 10 parts by weight, per 100 parts by weight of the resin component.

(X-iii) Silicone-based flame retardant consisting of a silicone compound Silicone compounds used as silicone-based flame retardants improve flame retardancy by chemical reactions during combustion. As such compounds, various compounds proposed as flame retardants for aromatic polycarbonate resins can be used. It is believed that silicone compounds impart flame retardant effects to polycarbonate resins by forming structures by themselves or by combining with components derived from the resin during combustion, or by a reduction reaction during the formation of the structures. Therefore, it is preferable that the silicone compound contains a group that is highly active in such reactions, and more specifically, it is preferable that the silicone compound contains a predetermined amount of at least one group selected from alkoxy groups and hydrogens (i.e., Si-H groups). The content ratio of such groups (alkoxy groups, Si-H groups) is preferably in the range of 0.1 to 1.2 mol/100g, more preferably in the range of 0.12 to 1 mol/100g, and even more preferably in the range of 0.15 to 0.6 mol/100g. Such ratios can be determined by measuring the amount of hydrogen or alcohol generated per unit weight of the silicone compound by alkaline decomposition. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, and particularly preferably a methoxy group. In general, the structure of a silicone compound is formed by arbitrarily combining the following four types of siloxane units. That is, M units are monofunctional siloxane units such as ( _CH3 ) _{3SiO1 /2} , H( _CH3 )2SiO1 _{/ 2} , _H2 ( _CH3 )SiO1 _/ 2, ( _CH3 ) ₂ ( _CH2 =CH)SiO1/2, ( _CH3 ) ₂ ( _C6H5 )SiO1 _{/ 2} , ( _CH3 )( _{C6H5 )} (CH2=CH)SiO1 _{/2 ,} D units are bifunctional siloxane units such as ( _CH3 ) _2SiO , H( _CH3 )SiO, _H2SiO , H(C6H5)SiO, (CH3)( _CH2 =CH)SiO, ( _C6H5 ) _2SiO , T units are monofunctional siloxane units such as (CH3)2SiO, H( _CH3 )SiO, _H2SiO , H( _C6H5 )SiO, ( _CH3 )(CH2=CH)SiO, ( _C6H5 ) _2SiO , etc. )SiO _3/2 , (C ₃ H ₇ )SiO _3/2 , HSiO _3/2 , (CH ₂ ═CH)SiO _3/2 , (C ₆ H ₅ )SiO _3/2 , etc., and tetrafunctional siloxane units represented by Q units:SiO _2. Specific examples of the structure of the silicone compound used in the silicone-based flame retardant include rational formulas Dn, Tp, MmDn, MmTp, MmQq, MmDnTp, MmDnQq, MmTpQq, MmDnTpQq, DnTp, DnQq, and DnTpQq. Among these, preferred structures of the silicone compound are MmDn, MmTp, MmDnTp, and MmDnQq, and more preferred structures are MmDn or MmDnTp.

Here, the coefficients m, n, p, and q in the rational formula are integers of 1 or more that represent the degree of polymerization of each siloxane unit, and the sum of the coefficients in each rational formula is the average degree of polymerization of the silicone compound. This average degree of polymerization is preferably in the range of 3 to 150, more preferably in the range of 3 to 80, even more preferably in the range of 3 to 60, and particularly preferably in the range of 4 to 40. The more preferable the range, the better the flame retardancy. Furthermore, as described later, in silicone compounds containing a predetermined amount of aromatic groups, the transparency and hue are also excellent. As a result, good reflected light can be obtained. In addition, when any of m, n, p, and q is a value of 2 or more, the siloxane unit with the coefficient can be two or more kinds of siloxane units with different hydrogen atoms or organic residues bonded thereto.

The silicone compound may be linear or branched. The organic residue bonded to the silicon atom is preferably an organic residue having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms. Specific examples of such organic residues include alkyl groups such as methyl, ethyl, propyl, butyl, hexyl, and decyl, cycloalkyl groups such as cyclohexyl, aryl groups such as phenyl, and aralkyl groups such as tolyl. More preferred are alkyl groups, alkenyl groups, or aryl groups having 1 to 8 carbon atoms. As the alkyl group, alkyl groups having 1 to 4 carbon atoms, such as methyl, ethyl, and propyl, are particularly preferred. Furthermore, the silicone compound used as the silicone flame retardant preferably contains an aryl group. On the other hand, the silane and siloxane compounds used as the organic surface treatment agents for titanium dioxide pigments are clearly distinguished from silicone flame retardants in their preferred aspects in that they are more effective when they do not contain an aryl group. The silicone compound used as the silicone-based flame retardant may contain reactive groups other than the Si-H group and alkoxy group. Examples of such reactive groups include amino groups, carboxyl groups, epoxy groups, vinyl groups, mercapto groups, and methacryloxy groups.

The amount of silicone flame retardant to be added is preferably 0.01 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, and even more preferably 1 to 5 parts by weight, per 100 parts by weight of the resin component.

(X-iv) Halogen-Based Flame Retardant As the halogen-based flame retardant, brominated polycarbonate (including oligomer) is particularly suitable. Brominated polycarbonate has excellent heat resistance and can significantly improve flame retardancy. As the brominated polycarbonate, the constitutional unit represented by the following general formula [8] is preferably at least 60 mol %, more preferably at least 80 mol %, of all constitutional units, and particularly preferably a brominated polycarbonate compound substantially composed of the constitutional unit represented by the following general formula [8].

In formula [8], Z is an alkylene group having 1 to 4 carbon atoms, an alkylidene group having 1 to 4 carbon atoms, or -SO ₂ -. In formula [8], Z is preferably a methylene group, an ethylene group, an isopropylidene group, or -SO ₂ -, and particularly preferably an isopropylidene group. The brominated polycarbonate has a small amount of remaining chloroformate terminals, and the amount of terminal chlorine is preferably 0.3 ppm or less, more preferably 0.2 ppm or less. The amount of terminal chlorine can be determined by dissolving a sample in methylene chloride, adding 4-(p-nitrobenzyl)pyridine to react with terminal chlorine (terminal chloroformate), and measuring the result with an ultraviolet-visible spectrophotometer (U-3200 manufactured by Hitachi, Ltd.). When the amount of terminal chlorine is 0.3 ppm or less, the thermal stability of the polycarbonate resin composition is improved, and molding at higher temperatures is possible, resulting in a resin composition with better molding processability. Moreover, the brominated polycarbonate preferably has a small amount of residual terminal hydroxyl groups. More specifically, the amount of terminal hydroxyl groups is preferably 0.0005 mol or less, more preferably 0.0003 mol or less, per mol of the constituent unit of the brominated polycarbonate. The amount of terminal hydroxyl groups can be determined by dissolving a sample in deuterated chloroform and measuring by ¹ H-NMR. Such an amount of terminal hydroxyl groups is preferable because the thermal stability of the polycarbonate resin composition is further improved. The specific viscosity of the brominated polycarbonate is preferably in the range of 0.015 to 0.1, more preferably in the range of 0.015 to 0.08. The specific viscosity of the brominated polycarbonate is calculated according to the above-mentioned specific viscosity calculation formula used when calculating the viscosity average molecular weight of the polycarbonate resin, which is the component A of the present invention. The content of the halogen-based flame retardant is preferably 1 to 30 parts by weight, more preferably 2 to 27 parts by weight, and even more preferably 3 to 25 parts by weight, per 100 parts by weight of the total of the A and B components.

Furthermore, the halogen-based flame retardant can further increase the flame retardancy of the resin composition by using it in combination with an antimony oxide compound. As the antimony oxide compound, antimony trioxide, antimony tetraoxide, antimony pentoxide represented by (NaO)p.(Sb ₂ O ₅ ).qH ₂ O (p=0-1, q=0-4) and sodium antimonate can be used. The antimony oxide compound is preferably used as particles having a particle size of 0.02-5 μm. The amount of the antimony oxide compound to be blended is preferably 0.5-10 parts by weight, more preferably 1-5 parts by weight, per 100 parts by weight of the resin component.

(XI) Other resins and elastomers The polycarbonate resin composition of the present invention can also contain other resins and elastomers in small proportions within the range in which the effects of the present invention are exhibited. The amount of other resins and elastomers is preferably 20% by weight or less, more preferably 10% by weight or less, and even more preferably 5% by weight or less, based on 100% by weight of the polycarbonate resin composition. Examples of such other resins include polyamide resins, polyimide resins, polyetherimide resins, polyurethane resins, silicone resins, polyphenylene ether resins, polyphenylene sulfide resins, polysulfone resins, polymethacrylate resins, phenolic resins, and epoxy resins. Examples of the elastomer include isobutylene/isoprene rubber, styrene/butadiene rubber, ethylene/propylene rubber, acrylic elastomers, polyester elastomers, polyamide elastomers, and core-shell elastomers such as MBS (methyl methacrylate/styrene/butadiene) rubber, MB (methyl methacrylate/butadiene) rubber, and MAS (methyl methacrylate/acrylonitrile/styrene) rubber.

(XII) Other Additives The polycarbonate resin composition of the present invention may further contain other flow modifiers, antibacterial agents, dispersants such as liquid paraffin, photocatalytic antifouling agents, photochromic agents, and the like.

<Production of Resin Composition>
Any method can be used to prepare the resin composition of the present invention. For example, the A component, B component, C component, and optionally other components are premixed, then melt-kneaded, and pelletized. Examples of premixing means include a Nauta mixer, a V-type blender, a Henschel mixer, a mechanochemical device, and an extrusion mixer. In premixing, granulation can be performed using an extrusion granulator or a briquetting machine, if necessary. As another method, for example, when a powder form is included, a master batch of additives is produced by blending a part of the powder with the additive to be mixed and diluting the additive with the powder, and the master batch is used. After premixing, the additives are melt-kneaded with a melt kneader, typically a vented twin-screw extruder, and pelletized with a device such as a pelletizer. Other examples of the melt kneader include a Banbury mixer, a kneading roll, and a thermostatic stirring vessel, but a vented twin-screw extruder is preferred.

Alternatively, each component may be fed independently to a melt kneader, typically a twin-screw extruder, without premixing. Another method is to premix some of the components and then feed them to the melt kneader independently of the remaining components. In particular, when an inorganic filler is mixed, it is preferable to feed the inorganic filler into the molten resin from a feed port midway through the extruder using a feed device such as a side feeder. The premixing method and granulation are the same as described above. If the components to be mixed are liquid, a so-called liquid injection device or liquid addition device can be used to feed the components to the melt kneader.

The extruder preferably has a vent that can remove moisture in the raw materials and volatile gases generated from the molten and kneaded resin. A vacuum pump is preferably installed from the vent to efficiently exhaust the generated moisture and volatile gases to the outside of the extruder. It is also possible to install a screen in the zone before the extruder die section to remove foreign matter mixed into the extrusion raw materials, and to remove foreign matter from the resin composition. Examples of such screens include wire mesh, screen changers, and sintered metal plates (disc filters, etc.).

In addition to twin-screw extruders, examples of melt kneading machines include Banbury mixers, kneading rolls, single-screw extruders, and multi-screw extruders with three or more screws.

The resin extruded as described above is either directly cut and pelletized, or formed into strands, which are then cut by a pelletizer and pelletized. If it is necessary to reduce the influence of external dust during pelletization, it is preferable to purify the atmosphere around the extruder. Furthermore, in the manufacture of such pellets, various methods already proposed for polycarbonate resins for optical disks can be used to narrow the shape distribution of the pellets, reduce miscuts, reduce fine powder generated during transportation or shipping, and reduce bubbles (vacuum bubbles) generated inside the strands or pellets. These prescriptions can be used to increase the cycle of molding and reduce the rate of defects such as silver. The shape of the pellets can be any of the general shapes such as cylinders, prisms, and spheres, but is more preferably a cylinder. The diameter of such a cylinder is preferably 1 to 5 mm, more preferably 1.5 to 4 mm, and even more preferably 2 to 3.3 mm. On the other hand, the length of the cylinder is preferably 1 to 30 mm, more preferably 2 to 5 mm, and even more preferably 2.5 to 3.5 mm.

<Metal Molded Body>
The metal material forming the resin-metal composite molded body of the present invention is preferably a metal material having an uneven surface, and a metal material having a joint having a groove. The metal constituting the metal material is not particularly limited, and can be appropriately selected from known metals depending on the application. For example, it can be selected from iron, various stainless steels, aluminum or its alloys, copper, magnesium, and alloys containing them. Among these, aluminum (aluminum alone) and aluminum alloys are preferred from the viewpoint of light weight and high strength, and aluminum alloys are more preferred. The metal molded body is processed into, for example, a flat plate, a curved plate, a rod, a tube, a block, etc. by cutting the metal material, plastic processing by pressing, etc., punching, cutting, polishing, electric discharge machining, etc. The surface of the metal molded body is preferably one having a large surface area in order to improve adhesion with the resin, and specifically, one having a roughened surface is preferably one. The roughening treatment method for the surface of the metal member is preferably a chemical etching method using a known etching agent or a laser treatment method using a laser.

<Preparation of resin-metal composite molding>
The resin-metal composite molded body of the present invention is a composite molded body characterized in that the metal material and the resin molded body are joined and integrated by the resin molded body entering the groove portion of the metal material. The method for producing the composite molded body is not particularly limited, and includes resin molding methods such as injection molding, extrusion molding, hot press molding, compression molding, transfer molding, laser welding molding, reaction injection molding (RIM molding), rim molding (LIM molding), and spray molding. In addition, when manufacturing a composite made of an aluminum resin composition film in which an aluminum surface is coated with a resin composition film, a coating method in which a resin composition is dissolved or dispersed in a solvent and applied, and other various painting methods can be mentioned. Other painting methods include baking painting, electrodeposition painting, electrostatic painting, powder painting, ultraviolet curing painting, and the like. Among them, injection molding and transfer molding are preferred from the viewpoint of the degree of freedom of the shape of the resin composition part and productivity. The molding conditions of the molding methods listed above can be known conditions depending on the resin composition.

The polycarbonate resin composition of the present invention contains a modified polycarbonate resin having specific structural units, and as a result, the resin composition has improved adhesion to metals and suffers little loss of bonding strength even in a variety of environments. These technologies are not available in conventional resin-to-metal adhesion technologies, and are extremely useful in various industrial applications such as in the office automation equipment and electrical and electronic equipment fields, and the industrial effects they provide are extremely significant.

The present inventors currently consider the best form of the present invention to be one that combines the preferred ranges of each of the above-mentioned requirements, and representative examples are described in the following examples. Of course, the present invention is not limited to these forms.

The present invention will be further explained below with reference to examples, but is not limited thereto.
The evaluation was carried out on the following items.

(i) Adhesion strength Pellets obtained from each composition of the examples were dried in a hot air dryer at 100°C for 5 hours, and a test piece for resin-metal adhesion test conforming to ISO19095-2 was molded using an injection molding machine [Sumitomo Heavy Industries, Ltd. SG150U-S-M IV] at a cylinder temperature of 280°C and a mold temperature of 90°C. (length 170 mm x width 10 mm, thickness 4 mm: butt type) As the metal molded body, an aluminum plate material (thickness: 4 mm) of alloy number 5052 specified in JIS H4000 was cut to a dimension of 85 mm x 10 mm, and then a metal molded body in which a joint having a groove on the metal surface was formed by a laser was used. The diameter of the groove was 40 to 80 μm, the depth was 75 to 125 μm, and the distance between the grooves was 90 to 120 μm. The obtained test piece was conditioned for 24 hours under conditions of 23° C. and 50% RH, and then the resin-metal adhesion strength was measured in accordance with ISO 19095-3. (Tensile strength by butt joint test piece)
(ii) Metal Adhesion Strength After Wet Heat Test The composite molding used in "(i) Adhesion strength" was treated at 80°C and 85% RH for 200 hours, and the resin-metal adhesion strength after treatment was measured.

[Examples 1 to 6, Comparative Examples 1 to 6]
A resin composition having the blending ratio shown in Table 2 was prepared as follows. The explanation will be given according to the symbols in the table. Each component in the ratio shown in the table was weighed and mixed uniformly using a tumbler, and the mixture was fed into an extruder to prepare a resin composition. The extruder used was a vented twin-screw extruder (TEX-30XSST) (fully intermeshed, rotating in the same direction, two-thread screw) manufactured by Japan Steel Works, Ltd. The extrusion conditions were a discharge rate of 20 kg/h, a screw rotation speed of 150 rpm, a vent vacuum of 3 kPa, and an extrusion temperature of 260 to 290°C. The reinforcing filler was supplied from the second supply port using a side feeder of the extruder, and the remaining polycarbonate resin and additives were supplied to the extruder from the first supply port. The first supply port here is the supply port farthest from the die, and the second supply port is the supply port located between the die and the first supply port of the extruder. Using the obtained pellets, a test piece for evaluation was molded using an injection molding machine as described above. The results of the evaluations are shown in Table 2. In addition, in Comparative Example 4, pelletization was not possible.

The components represented by symbols in Table 2 are as follows:
(Component A: Modified polycarbonate resin)
A-1: Modified polycarbonate resin powder having a viscosity average molecular weight of 22,300 obtained by the following manufacturing method A reactor equipped with a thermometer, a stirrer and a reflux condenser was charged with 4229 parts of 48% aqueous sodium hydroxide solution and 20,000 parts of ion-exchanged water, and 2191 parts of 1,1-bis(4-hydroxy-3-methylphenyl)propane (hereinafter abbreviated as Bis-1), 1951 parts of bisphenol A and 8.3 parts of hydrosulfite were dissolved therein, and 11,620 parts of methylene chloride was added, and 2,200 parts of phosgene were blown in over about 60 minutes at 15 to 25 ° C. under stirring. After the blowing of phosgene was completed, 704 parts of 48% aqueous sodium hydroxide solution and 102 parts of p-tert-butylphenol were added, stirring was resumed, and 4.32 parts of triethylamine were added after emulsification, and the reaction was terminated by further stirring at 28 to 33 ° C. for 1 hour. After the reaction was completed, the product was diluted with methylene chloride and washed with water, then acidified with hydrochloric acid and washed with water, and further washed with water repeatedly until the conductivity of the aqueous phase was almost the same as that of ion-exchanged water, to obtain a methylene chloride solution of polycarbonate resin. Next, this solution was passed through a filter with an opening of 0.3 μm, and further dropped into warm water in a kneader with an isolation chamber having a foreign matter outlet in the bearing part, and the polycarbonate resin was flaked while distilling off the methylene chloride, and the liquid-containing flakes were subsequently pulverized and dried to obtain a powder. (Content of structural unit (A): 50 mol%)
A-2: Modified polycarbonate resin powder having a viscosity average molecular weight of 22,100. A powder was obtained in the same manner as A-1, except that Bis-1 was changed to 4,382 parts and bisphenol A was changed to 0 parts. (Content of structural unit (A): 100 mol%)

(Component B: polycarbonate resin)
B-1: Aromatic polycarbonate resin (polycarbonate resin powder having a viscosity average molecular weight of 19,800, produced by a conventional method from bisphenol A and phosgene, manufactured by Teijin Limited, Panlite L-1225WX (product name))

(Component C: reinforcing filler)
Ci: Circular cross-section glass fiber having composition 1 shown in Table 1 (fiber diameter 11 μm, cut length 3 mm, long axis/short axis ratio = 1.0)
C-ii: Noncircular cross section glass fiber having composition 1 shown in Table 1 (fiber diameter 15 μm, cut length 3 mm, major axis 28 μm, minor axis 7 μm)
(Other than component C: reinforcing filler)
C-iii: Circular cross section glass fiber having composition 2 shown in Table 1 (fiber diameter 11 μm, cut length 3 mm, long diameter/short diameter ratio = 1.0)
C-iv: Noncircular cross section glass fiber having composition 2 shown in Table 1 (fiber diameter 15 μm, cut length 3 mm, major axis 28 μm, minor axis 7 μm)
The fiber diameter of a glass fiber having a non-circular cross-sectional shape means the fiber diameter when the cross-sectional area is converted into that of a perfect circle (converted fiber diameter).

(Component D: Polyolefin resin)
D-1: Homopolypropylene resin (SunAllomer PL400A (product name) manufactured by SunAllomer Co., Ltd., MFR = 2.0 g/10 min)
(Component E: styrene-based thermoplastic elastomer)
E-1: Styrene-ethylene propylene-styrene block copolymer [styrene content: 65 wt%, MFR: 0.4 g/10 min, Septon 2104 (product name) manufactured by Kuraray Co., Ltd.]

Claims (4)

A polycarbonate resin composition for producing a resin molded body in a composite molded body in which a metal molded body and a resin molded body are joined, the polycarbonate resin composition comprising 100 parts by weight of a resin component consisting of (A) 50 to 100% by weight of a modified polycarbonate resin (component A) containing a structural unit (A) represented by the following formula [1] and a structural unit (B) represented by the following formula [2] and (B) 0 to 50% by weight of a polycarbonate resin other than component A (component B), and (C) 52.0 to 57.0% by weight of SiO ₂ , 13.0 to 17.0% by weight of Al ₂ O ₃ , 15.0 to 21.5% by weight of B ₂ O ₃ , 2.0 to 6.0% by weight of MgO, 2.0 to 6.0% by weight of CaO, 1.0 to 4.0% by weight of TiO ₂ and less than 1.5% by weight of F ₂ based on the total amount of glass, and further comprising Li ₂ O, Na ₂ O and K 2. A polycarbonate resin composition comprising 10 to 100 parts by weight of a reinforcing filler (component C) containing glass having a total content of _O of less than 0.6% by weight.
(In the formula, W represents a single bond, an alkylene group having 1 to 6 carbon atoms, an arylene group having 6 to 10 carbon atoms, or a cyclic alkylene group having 3 to 8 carbon atoms.)
The polycarbonate resin composition according to claim 1, characterized in that component C is a reinforcing filler containing at least one type of glass selected from the group consisting of flat cross-section glass fibers (component C-1) having an average major axis of 10 to 50 μm and an average major axis to minor axis ratio (major axis/minor axis) of 1.5 to 8, and circular cross-section glass fibers (component C-2) having a fiber diameter of 1 to 30 μm. The polycarbonate resin composition according to claim 1 or 2, characterized in that it contains 1 to 100 parts by weight of (D) polyolefin resin (component D) and 1 to 50 parts by weight of (E) styrene-based thermoplastic elastomer (component E) per 100 parts by weight of the resin component. A composite molded body in which a metal molded body having an uneven surface is bonded to a resin molded body made of the polycarbonate resin composition according to any one of claims 1 to 3, the composite molded body being characterized in that the metal molded body and the resin molded body are bonded together as one body by the resin molded body entering the uneven surface of the metal molded body.