JP7680943B2 - Polycarbonate resin composition - Google Patents

Description

The present invention relates to a polycarbonate resin composition and a molded article, and more specifically, to a polycarbonate resin composition and a molded article that have extremely high light blocking properties and excellent impact resistance.

Polycarbonate resin is often used in electrical and electronic components, automotive parts, camera lenses and their parts, etc., taking advantage of its advantages such as transparency, heat resistance, and mechanical strength.

In recent years, cameras with image sensors are widely used in mobile phones, game consoles, personal computers, car-mounted cameras, etc. Camera devices equipped with these lenses are made of resin to reduce weight and cost, and the lens, barrel, holder, etc. are modularized. In particular, camera modules have recently been rapidly becoming smaller, lighter, and more powerful.

The miniaturized camera module is made up of multiple lenses made of polycarbonate resin, and a barrel and holder that support the lenses. The barrel must be highly impact resistant so that it will not break even if dropped, and must also have a very high degree of light blocking properties to improve the image quality of the captured images.

To impart light-blocking properties to resin materials, various blackening dyes or carbon black can be blended into the resin. Patent Document 1 describes that a resin composition containing a transparent or translucent thermoplastic resin (specifically, polyethylene or polypropylene), carbon black, and a light diffusing agent with a specific refractive index difference from the resin and an average particle size of less than 0.3 μm, has excellent bluish and high blackness, that is, jet blackness. However, it is not easy to achieve the high level of light-blocking properties described above with this material, and it is difficult to say that the impact resistance is sufficient.

JP 2020-125376 A

The present invention was made in consideration of the above circumstances, and its objective (objective) is to provide a polycarbonate resin composition that has extremely high light-blocking properties and excellent impact resistance.

The present inventors discovered that by combining specific amounts of a light diffusing agent having an average particle size within a specific range with carbon black, and further by specifying the content ratio of the two, it is possible to achieve high levels of both impact resistance and heat resistance, and thus completed the present invention.
The present invention relates to the following polycarbonate resin composition and molded article.

1. A polycarbonate resin composition comprising, per 100 parts by mass of polycarbonate resin (A), more than 0.5 parts by mass and not more than 10 parts by mass of a light diffusing agent (B) and more than 0.5 parts by mass and not more than 3 parts by mass of carbon black (C), wherein the average particle size of the light diffusing agent (B) is 1.1 to 3.9 μm, and the content ratio (B)/(C) of the light diffusing agent (B) to the carbon black (C) is 1 or more.
2. The polycarbonate resin composition according to the above 1, wherein the absolute value of the difference between the refractive index n1 of the polycarbonate resin (A) and the refractive index n2 of the light diffusing agent (B) (|n1-n2|) is 0.12 or more.
3. The polycarbonate resin composition according to the above 1 or 2, wherein the light diffusing agent (B) is a silicone-based light diffusing agent.
4. The polycarbonate resin composition according to any one of the above 1 to 3, wherein the light diffusing agent (B) is polymethylsilsesquioxane.

5. The polycarbonate resin composition according to any one of 1 to 4 above, which has a spectral transmittance in the thickness direction measured on a 35 μm-thick film molded from the resin composition of less than 1%.
6. The polycarbonate resin composition according to any one of 1 to 5 above, which has a notched Charpy impact strength measured in accordance with ISO 178 of 30 kJ/ ^m2 or more.
7. A molded article made of the polycarbonate resin composition according to any one of 1 to 6 above.
8. An optical module comprising the molded article according to 7 above.

The polycarbonate resin composition of the present invention has extremely high light-shielding properties, and is also excellent in impact resistance and heat resistance.
Furthermore, when the molded article of the present invention is used as a part of an optical module (for example, a camera module or the like), it has the effect of enabling high impact resistance capable of withstanding a fall and improvement in the quality of captured images.

Each component used in the polycarbonate resin composition of the present invention will be described in detail below.
In this specification, when a range is expressed using "~" with numerical values or physical property values on either side, the range includes the values before and after the range.

[Polycarbonate resin (A)]
Polycarbonate resin is a polymer having a basic structure with a carbonate bond represented by the formula: -[-O-X-O-C(=O)-]-. In the formula, X is generally a hydrocarbon, but X having a heteroatom or heterobond may be used to impart various properties.
Polycarbonate resins can be classified into aromatic polycarbonate resins in which the carbons directly bonded to the carbonate bonds are aromatic carbons, and aliphatic polycarbonate resins in which the carbons directly bonded to the carbonate bonds are aliphatic carbons, and either of these can be used. Among these, aromatic polycarbonate resins are preferred from the viewpoints of heat resistance, mechanical properties, electrical properties, etc.

There is no restriction on the specific type of polycarbonate resin, but examples include polycarbonate polymers obtained by reacting a dihydroxy compound with a carbonate precursor. In this case, in addition to the dihydroxy compound and the carbonate precursor, a polyhydroxy compound or the like may be reacted. Also, a method of reacting carbon dioxide as a carbonate precursor with a cyclic ether may be used. Also, the polycarbonate polymer may be linear or branched. Furthermore, the polycarbonate polymer may be a homopolymer consisting of one type of repeating unit, or may be a copolymer having two or more types of repeating units. In this case, various copolymerization forms such as a random copolymer and a block copolymer can be selected. Note that such a polycarbonate polymer is usually a thermoplastic resin.

Among the monomers that are raw materials for aromatic polycarbonate resins, examples of aromatic dihydroxy compounds include:
Dihydroxybenzenes such as 1,2-dihydroxybenzene, 1,3-dihydroxybenzene (i.e., resorcinol), and 1,4-dihydroxybenzene;
Dihydroxybiphenyls such as 2,5-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, and 4,4'-dihydroxybiphenyl;

Dihydroxynaphthalenes such as 2,2'-dihydroxy-1,1'-binaphthyl, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, and 2,7-dihydroxynaphthalene;

Dihydroxydiaryl ethers such as 2,2'-dihydroxydiphenyl ether, 3,3'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, 1,4-bis(3-hydroxyphenoxy)benzene, and 1,3-bis(4-hydroxyphenoxy)benzene;

2,2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A),
1,1-bis(4-hydroxyphenyl)propane,
2,2-bis(3-methyl-4-hydroxyphenyl)propane (i.e., bisphenol C),
2,2-bis(3-methoxy-4-hydroxyphenyl)propane,
2-(4-hydroxyphenyl)-2-(3-methoxy-4-hydroxyphenyl)propane,
1,1-bis(3-tert-butyl-4-hydroxyphenyl)propane,
2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane,
2,2-bis(3-cyclohexyl-4-hydroxyphenyl)propane,
2-(4-hydroxyphenyl)-2-(3-cyclohexyl-4-hydroxyphenyl)propane,
α,α'-bis(4-hydroxyphenyl)-1,4-diisopropylbenzene,
1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene,
bis(4-hydroxyphenyl)methane,
bis(4-hydroxyphenyl)cyclohexylmethane,
bis(4-hydroxyphenyl)phenylmethane,
bis(4-hydroxyphenyl)(4-propenylphenyl)methane,
bis(4-hydroxyphenyl)diphenylmethane,
bis(4-hydroxyphenyl)naphthylmethane,
1,1-bis(4-hydroxyphenyl)ethane,
1,1-bis(4-hydroxyphenyl)-1-phenylethane,
1,1-bis(4-hydroxyphenyl)-1-naphthylethan,
1,1-bis(4-hydroxyphenyl)butane,
2,2-bis(4-hydroxyphenyl)butane,
2,2-bis(4-hydroxyphenyl)pentane,
1,1-bis(4-hydroxyphenyl)hexane,
2,2-bis(4-hydroxyphenyl)hexane,
1,1-bis(4-hydroxyphenyl)octane,
2,2-bis(4-hydroxyphenyl)octane,
4,4-bis(4-hydroxyphenyl)heptane,
2,2-bis(4-hydroxyphenyl)nonane,
1,1-bis(4-hydroxyphenyl)decane,
1,1-bis(4-hydroxyphenyl)dodecane,
Bis(hydroxyaryl)alkanes such as:

1,1-bis(4-hydroxyphenyl)cyclopentane,
1,1-bis(4-hydroxyphenyl)cyclohexane,
1,1-bis(4-hydroxyphenyl)-3,3-dimethylcyclohexane,
1,1-bis(4-hydroxyphenyl)-3,4-dimethylcyclohexane,
1,1-bis(4-hydroxyphenyl)-3,5-dimethylcyclohexane,
1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane,
1,1-bis(4-hydroxy-3,5-dimethylphenyl)-3,3,5-trimethylcyclohexane,
1,1-bis(4-hydroxyphenyl)-3-propyl-5-methylcyclohexane, 1,1-bis(4-hydroxyphenyl)-3-tert-butyl-cyclohexane,
1,1-bis(4-hydroxyphenyl)-4-tert-butyl-cyclohexane,
1,1-bis(4-hydroxyphenyl)-3-phenylcyclohexane,
1,1-bis(4-hydroxyphenyl)-4-phenylcyclohexane,
Bis(hydroxyaryl)cycloalkanes such as:

9,9-bis(4-hydroxyphenyl)fluorene,
Cardo structure-containing bisphenols such as 9,9-bis(4-hydroxy-3-methylphenyl)fluorene;

4,4'-dihydroxydiphenyl sulfide,
Dihydroxydiaryl sulfides such as 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide;

Dihydroxydiaryl sulfoxides such as 4,4'-dihydroxydiphenyl sulfoxide and 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide;

4,4'-dihydroxydiphenyl sulfone,
Dihydroxydiarylsulfones such as 4,4'-dihydroxy-3,3'-dimethyldiphenylsulfone;
etc.

Of these, bis(hydroxyaryl)alkanes are preferred, and bis(4-hydroxyphenyl)alkanes are particularly preferred. In particular, from the standpoints of impact resistance and heat resistance, 2,2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A) and 2,2-bis(3-methyl-4-hydroxyphenyl)propane (i.e., bisphenol C) are preferred.
The aromatic dihydroxy compound may be used alone or in any combination of two or more kinds in any ratio.

Among the monomers that are the raw materials for polycarbonate resin, examples of carbonate precursors include carbonyl halides and carbonate esters. Note that one type of carbonate precursor may be used, or two or more types may be used in any combination and ratio.

Specific examples of carbonyl halides include phosgene; haloformates such as bischloroformates of dihydroxy compounds and monochloroformates of dihydroxy compounds; and the like.

Specific examples of carbonate esters include diaryl carbonates such as diphenyl carbonate and ditolyl carbonate; dialkyl carbonates such as dimethyl carbonate and diethyl carbonate; biscarbonates of dihydroxy compounds, monocarbonates of dihydroxy compounds, and carbonates of dihydroxy compounds such as cyclic carbonates.

The method for producing polycarbonate resin is not particularly limited, and any method can be used. Examples include interfacial polymerization, melt transesterification, pyridine method, ring-opening polymerization of cyclic carbonate compounds, and solid-phase transesterification of prepolymers.

Preferred examples of polycarbonate resins include polycarbonate resins using bisphenol A as the dihydroxy compound or a combination of bisphenol A and other aromatic dihydroxy compounds, polycarbonate resins using bisphenol C or a combination of bisphenol C and other aromatic dihydroxy compounds (particularly bisphenol A), and further blends of these resins.

The molecular weight of the polycarbonate resin (A), in terms of viscosity average molecular weight (Mv), is preferably in the range of 16,000 to 50,000, more preferably 18,000 or more, even more preferably 20,000 or more, more preferably 45,000 or less, even more preferably 40,000 or less, and particularly preferably 38,000 or less. If the viscosity average molecular weight is less than 16,000, the impact resistance of the molded product is likely to decrease and cracks may occur, which is undesirable, and if it is more than 50,000, the fluidity is poor and moldability problems are likely to occur, which is undesirable.
The polycarbonate resin (A) may be a mixture of two or more polycarbonate resins having different viscosity average molecular weights. In this case, a polycarbonate resin having a viscosity average molecular weight outside the above-mentioned preferred range may be mixed.

In the present invention, the viscosity average molecular weight [Mv] of the polycarbonate resin is determined by measuring the intrinsic viscosity [η] (unit: dl/g) at a temperature of 25° C. using methylene chloride as a solvent and an Ubbelohde viscometer, and calculating the viscosity average molecular weight [Mv] according to Schnell's viscosity formula, i.e.,
η means a value calculated from η = 1.23 × 10 ^-4 Mv ^0.83 . The intrinsic viscosity [η] is a value calculated from the following formula by measuring the specific viscosity [η _sp ] at each solution concentration [C] (g/dl).

In addition, in the present invention, the polycarbonate resin may be formed as a copolymer mainly composed of polycarbonate resin, such as a copolymer with an oligomer or polymer having a siloxane structure for the purpose of further improving flame retardancy and impact resistance; a copolymer with a monomer, oligomer, or polymer having a phosphorus atom for the purpose of further improving thermal oxidation stability and flame retardancy; a copolymer with a monomer, oligomer, or polymer having a dihydroxyanthraquinone structure for the purpose of improving thermal oxidation stability; a copolymer with an oligomer or polymer having an olefin structure such as polystyrene for improving optical properties; or a copolymer with a polyester resin oligomer or polymer for the purpose of improving chemical resistance.

In order to improve the appearance and flowability of the molded product, the polycarbonate resin may contain a polycarbonate oligomer. The viscosity average molecular weight (Mv) of this polycarbonate oligomer is usually 1500 or more, preferably 2000 or more, and usually 9500 or less, preferably 9000 or less. When polycarbonate oligomer is contained, the content is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and particularly preferably 10 parts by mass or less, per 100 parts by mass of polycarbonate resin (A). The lower limit when contained is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and particularly preferably 3 parts by mass or more.

Furthermore, the polycarbonate resin may be not only a virgin raw material, but also a polycarbonate resin regenerated from a used product (so-called material recycled polycarbonate resin).
However, the recycled polycarbonate resin is preferably 80% by mass or less, more preferably 50% by mass or less, of the polycarbonate resin (A) because the recycled polycarbonate resin is highly likely to have been deteriorated by heat, aging, etc., and if such a polycarbonate resin is used in an amount greater than the above range, the hue and mechanical properties may be deteriorated.

[Light Diffuser (B)]
The polycarbonate resin composition of the present invention contains a light diffusing agent (B) having an average particle size of 1.1 to 3.9 μm.
More preferred examples of the light diffusing agent include acrylic resin fine particles and/or silicone fine particles.

As the acrylic resin fine particles, crosslinked acrylic polymer fine particles are preferred.
Preferred examples of the crosslinked acrylic polymer include an acrylic monomer alone, and a copolymer of an acrylic monomer and a styrene monomer.

Specific examples of acrylic monomers include methacrylate monomers such as methyl methacrylate and ethyl methacrylate; acrylate monomers such as methyl acrylate and ethyl acrylate; and acrylamide. Specific examples of styrene monomers include styrene, α-methylstyrene, and vinyltoluene.

When polymerizing or copolymerizing these monomers, these may be used as the main components, and other monomers may be copolymerized as crosslinking agents, etc., as necessary. Examples of such crosslinking agents include various polyfunctional monomers such as ethylene glycol dimethacrylate, divinylbenzene, 1,6-hexanediol, trimethylpropane trimethacrylate, trimethylpropane trimethacrylate, and trimethylpropane triacrylate.

As the silicone-based fine particles, crosslinked siloxane-based polymer particles are preferred, and examples of the polyorganosiloxanes constituting these include polyorganosiloxanes having a phenyl group, a diphenyl group, a vinyl group, or an alkoxy group (e.g., a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group, etc.), polyorganosiloxanes having a phenyl group and a diphenyl group, polyorganosiloxanes having a vinyl group and an alkoxy group, polyorganosiloxanes having a phenyl group, an alkoxy group, and a vinyl group, etc.

The polyorganosilsesquioxane is preferably a polyorganosiloxane. Polyorganosilsesquioxane refers to a polyorganosiloxane having a trifunctional siloxane unit (hereinafter sometimes referred to as "T unit") represented by R-SiO _1.5 (R is a monovalent organic group), and refers to a polyorganosiloxane that accounts for 50 mol% or more of the total siloxane units of 100 mol%. The proportion of T units is more preferably 80 mol% or more, even more preferably 90 mol% or more, and particularly 95 mol% or more.

Preferred examples of the organic group R bonded to the polyorganosilsesquioxane include alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, propyl, butyl, hexyl, decyl, dodecyl, and octadecyl groups, cyclic alkyl groups, such as cyclohexyl groups, aryl groups, such as phenyl, tolyl, and xylyl groups, and aralkyl groups, such as phenylethyl and phenylpropyl groups. As the polyorganosilsesquioxane, polyalkylsilsesquioxanes, and particularly polymethylsilsesquioxane siloxane, are preferred.

The light diffusing agent (B) is preferably a silicone-based light diffusing agent, and polymethylsilsesquioxane siloxane is particularly preferred because it has a high light diffusing effect and a high thermal decomposition temperature, which improves the heat resistance of the resin composition.

The light diffusing agent (B) used has an average particle diameter of 1.1 to 3.9 μm. By combining a light diffusing agent with such an average particle diameter with carbon black (C), a high level of light blocking can be achieved. If the particle diameter is less than 1.1 μm, the effect of improving the light diffusibility of the resulting polycarbonate resin composition is small, and light transmission due to light diffraction may occur. In addition, dispersion during the production of the resin composition is difficult, and light leakage due to poor dispersion is likely to occur. If the particle diameter exceeds 3.9 μm, light leakage due to poor dispersion during the production of the resin composition is likely to occur, and the light blocking effect is small and the light blocking property is likely to deteriorate. The average particle diameter is preferably 1.3 μm or more, more preferably 1.5 μm or more, among which 1.7 μm or more, 1.9 μm or more, and especially 2 μm or more are preferred, and also preferably 3.7 μm or less, more preferably 3.5 μm or less, among which 3.3 μm or less, 3.2 μm or less, and especially 3 μm or less are preferred, and especially 2 to 3 μm are preferred.

The average particle size can be determined as the _D50 average value from a particle size distribution diagram using a laser diffraction/scattering type particle size distribution measuring device or the like.

The refractive index of the light diffusing agent (B) is preferably 1.3 to 1.6, and more preferably 1.4 to 1.5. The absolute value of the difference between the refractive index n2 of the light diffusing agent (B) and the refractive index n1 of the polycarbonate resin (A) (|n1-n2|) is preferably 0.12 or more, and such a refractive index difference can block light by impeding its path, thereby further improving the light blocking properties. |n1-n2| is more preferably 0.13 or more, even more preferably 0.14 or more, particularly preferably 0.15 or more, and more preferably 0.21 or less, even more preferably 0.20 or less, particularly preferably 0.19 or less, and is particularly preferably in the range of 0.15 to 0.19.

The content of the light diffusing agent (B) is more than 0.5 parts by mass and not more than 10 parts by mass per 100 parts by mass of the polycarbonate resin (A). By including it in such an amount, it is possible to achieve high light blocking properties and impact resistance. If it exceeds 10 parts by mass, the impact resistance and heat resistance of the resin composition decrease, and if it is 0.5 parts by mass or less, the light blocking properties become insufficient. The content is preferably 0.7 parts by mass or more, more preferably 0.8 parts by mass or more, 0.9 parts by mass or more, and especially 1 part by mass or more, and is preferably 8 parts by mass or less, more preferably 7 parts by mass or less, 6 parts by mass or less, and especially 5 parts by mass or less, and 1 to 5 parts by mass is especially preferred.

[Carbon black (C)]
The polycarbonate resin composition of the present invention contains carbon black (C).
The carbon black is not limited in its production method, raw material type, etc., and any conventionally known carbon black can be used, such as oil furnace black, channel black, acetylene black, ketjen black, etc. Among these, oil furnace black is preferred from the standpoint of colorability and cost.

The average particle size of the carbon black (C) may be appropriately selected and determined, but is preferably 5 to 60 nm, more preferably 7 to 55 nm, and even more preferably 10 to 50 nm. By making the average particle size 5 nm or more, the flowability tends to improve, and by making it 60 nm or less, the light blocking properties of the molded body are improved.

The nitrogen adsorption specific surface area of carbon black (C) is preferably less than 1000 m ² /g, and more preferably 50 to 400 m ² /g. By making the nitrogen adsorption specific surface area less than 1000 ^{m 2} /g, the flowability of the polycarbonate resin composition of the present invention and the appearance of the molded article tend to be improved, which is preferable. The nitrogen adsorption specific surface area can be measured in accordance with JIS K6217.
The DBP absorption of carbon black (C) is preferably less than 300 ^cm3 /100g, and more preferably 30 to 200 ^cm3 /100g. By making the DBP absorption less than 300 ^cm3 /100g, the flowability of the polycarbonate resin composition and the appearance of the molded article tend to be improved, which is preferable. The DBP absorption can be measured in accordance with JIS K6217.

Carbon black (C) can be used alone or in combination of two or more kinds. Carbon black can also be granulated using a binder, and it is also preferable to use it as a masterbatch in which it is melt-kneaded at a high concentration in a resin such as a polystyrene-based resin.

The content of carbon black (C) is more than 0.5 parts by mass and not more than 3 parts by mass per 100 parts by mass of polycarbonate resin (A). By including it in such an amount, it is possible to achieve high light blocking properties and impact resistance. If it exceeds 3 parts by mass, the impact resistance of the resin composition will be significantly reduced and the heat resistance will also be deteriorated, and if it is 0.5 parts by mass or less, the light blocking properties will be insufficient. The content is preferably 0.6 parts by mass or more, more preferably 0.7 parts by mass or more, 0.8 parts by mass or more, and particularly 1 part by mass or more, and is preferably 2.5 parts by mass or less, more preferably 2 parts by mass or less, and particularly preferably 1 to 2 parts by mass.

In the present invention, the ratio (B)/(C) of the content of the light diffusing agent (B) to the content of the carbon black (C) is set to 1 or more. By setting it to 1 or more, it is possible to improve the impact resistance and provide excellent light blocking properties. If the carbon black (C) is relatively high, that is, if it is less than 1, the impact resistance decreases. (B)/(C) is preferably 1.2 or more, more preferably 1.3 or more, of which 1.4 or more, particularly preferably 1.5 or more, and more preferably 5 or less, of which 4.5 or less, 4 or less, particularly preferably 3.5 or less.

[Filling material]
The polycarbonate resin composition of the present invention preferably contains a filler.
As the filler, it is preferable to use a filler having an average particle size of 0.1 to 10 μm, more preferably 9 μm or less, among which 8 μm or less, 7 μm or less, 6 μm or less, 5 μm or less, 4 μm or less, further 3 μm or less, and particularly 2.5 μm or less is preferable.
Also, it is preferably 0.12 μm or more, more preferably 0.15 μm or more, 0.18 μm or more, of which 0.2 μm or more is particularly preferred, and 0.25 μm or more is particularly preferred.

The average particle size of the filler can be determined as the _D50 average value by a laser diffraction method.

The filler is preferably an inorganic filler, more preferably a plate-like filler, specifically talc, mica, glass flake, montmorillonite, hydrotalcite, sericite, kaolin, alumina, clay, graphite, etc., and one type may be used alone or two or more types may be mixed and used.

Among these, talc and mica are preferred, with talc being particularly preferred.
By including talc together with the various components described below, the resin composition can have lower anisotropy and lower linear expansion, and can also have improved rigidity.

Talc with an average particle size of 0.1 to 10 μm is used. The average particle size is preferably 0.3 to 8 μm, and more preferably 0.7 to 5 μm. By making the average particle size 0.1 μm or more, the thermal stability of the resin composition tends to be improved, and by making the average particle size 10 μm or less, the appearance and rigidity of the molded product of the resin composition are improved.

It is also preferable that the talc is surface-treated to enhance its affinity with the polycarbonate resin (A). Specific examples of the surface treatment agent include at least one selected from alcohols such as trimethylolethane, trimethylolpropane, and pentaerythritol, alkanolamines such as triethylamine, organic silicone compounds such as organopolysiloxanes, higher fatty acids such as stearic acid, fatty acid metal salts such as calcium stearate and magnesium stearate, hydrocarbon lubricants such as polyethylene wax and liquid paraffin, basic amino acids such as lysine and arginine, polyglycerin and derivatives thereof, and coupling agents such as silane coupling agents, titanate coupling agents, and aluminum coupling agents.

From the viewpoint of surface appearance and thermal stability when contained in a resin composition, it is also preferable that the talc is in a granular form granulated using a binder. In the case of granular talc, the bulk density is preferably 0.4 to 1.5 g/ml.

The preferred filler content is 1 to 50 parts by mass per 100 parts by mass of polycarbonate resin (A). This range provides low linear expansion and sufficient mechanical properties. If the filler content is less than 1 part by mass, it becomes difficult to achieve low linear expansion and rigidity is likely to be insufficient, while if it exceeds 50 parts by mass, production stability and toughness are likely to decrease. The filler content is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, and is preferably 45 parts by mass or less, more preferably 40 parts by mass or less, even more preferably 35 parts by mass or less, and particularly preferably 30 parts by mass or less.

[ABS resin]
The resin composition of the present invention also preferably contains an ABS resin.
The ABS resin preferably comprises an aromatic vinyl monomer component (c1), a vinyl cyanide monomer component (c2), a diene rubber polymer component (c3) and other monomer components (c4), and preferably comprises 40 to 80 mass% of the aromatic vinyl monomer component (c1), 10 to 30 mass% of the vinyl cyanide monomer component (c2), 10 to 30 mass% of the diene rubber polymer component (c3) and 0 to 30 mass% of the other monomer components (c4) relative to 100 mass% in total of the components (c1) to (c4).

Examples of the aromatic vinyl monomer component (c1) in the ABS resin include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, vinylxylene, ethylstyrene, dimethylstyrene, p-tert-butylstyrene, vinylnaphthalene, methoxystyrene, monobromostyrene, dibromostyrene, fluorostyrene, and tribromostyrene, with styrene being particularly preferred.
The proportion of the aromatic vinyl monomer component (c1) in the ABS resin is preferably in the range of 40 to 80 mass%, more preferably 45 mass% or more, even more preferably 50 mass% or more, particularly preferably 55 mass% or more, and more preferably 77 mass% or less, even more preferably 74 mass% or less, particularly preferably 70 mass% or less, based on 100 mass% of the ABS resin.

Examples of the vinyl cyanide monomer component (c2) in the ABS resin include acrylonitrile and methacrylonitrile, with acrylonitrile being particularly preferred.
The proportion of the vinyl cyanide monomer component (c2) is, as described above, preferably in the range of 10 to 30% by mass, based on 100% by mass of the ABS resin, but is more preferably 12% by mass or more, even more preferably 14% by mass or more, particularly preferably 15% by mass or more, and is more preferably 28% by mass or less, even more preferably 26% by mass or less, particularly preferably 25% by mass or less.

As the diene rubber polymer component (c3) of the ABS resin, for example, rubber components such as polybutadiene, polyisoprene, and styrene-butadiene copolymer are used, and the proportion of the diene rubber polymer component (c3) in the ABS resin is preferably in the range of 10 to 30 mass% of 100 mass% of the ABS resin, more preferably 11 mass% or more, even more preferably 12 mass% or more, particularly preferably 13 mass% or more, more preferably 25 mass% or less, and even more preferably 20 mass% or less.

Furthermore, they may be copolymerized with other monomer components (c4) copolymerizable therewith. In this case, examples of the other copolymerizable monomers include maleimide-based monomers such as maleimide, N-methylmaleimide, N-cyclohexylmaleimide, and N-phenylmaleimide, acrylamide-based monomers such as acrylamide and N-methylacrylamide, unsaturated acid anhydrides such as maleic anhydride and itaconic anhydride, unsaturated acids such as acrylic acid and methacrylic acid, glycidyl acrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and methoxypolyethylene glycol methacrylate.
As described above, the ratio of the other monomer component (c4) in the ABS resin is preferably in the range of 0 to 30% by mass, more preferably 20% by mass or less, and even more preferably 10% by mass or less, based on 100% by mass of the ABS resin.

Specific examples of ABS resins include acrylonitrile-butadiene-styrene copolymers, acrylonitrile-butadiene-styrene-α-methylstyrene copolymers, and acrylonitrile-butadiene-styrene-N-phenylmaleimide copolymers.

When ABS resin is contained, the content is 1 to 20 parts by mass, preferably 3 parts by mass or more, more preferably 5 parts by mass or more, and preferably 18 parts by mass or less, more preferably 15 parts by mass or less, even more preferably 12 parts by mass or less, and particularly preferably 10 parts by mass or less, per 100 parts by mass of polycarbonate resin (A). If it is less than 1 part by mass, it is not preferred because impact resistance at low temperatures decreases. On the other hand, if the content of ABS resin exceeds 20 parts by mass, it is not preferred because heat resistance and surface hardness decrease.

[Olefin-maleic anhydride copolymer]
By containing the olefin-maleic anhydride copolymer together with the components described above and below, direct contact between the polycarbonate resin and the filler is inhibited, and the thermal stability and mechanical properties of the resin composition can be improved, thereby further improving the impact resistance.

As the olefin-maleic anhydride copolymer, an olefin-maleic anhydride copolymer and/or a maleic anhydride-modified olefin polymer are preferred.

Examples of olefin-maleic anhydride copolymers include copolymers of maleic anhydride and α-olefins, copolymers with conjugated diene monomers, and copolymers with conjugated dienes and aromatic vinyl monomers.

Preferred examples of α-olefins include α-olefins having 2 to 10 carbon atoms, such as ethylene, propylene, butene-1, pentene-1, hexene-1, 4-methylpentene-1, octene-1, and 1-decene, and these may be used alone or in combination. Among these, ethylene, propylene, butene-1, hexene-1, and octene-1 are more preferable, and a combination of ethylene with propylene, butene-1, hexene-1, or octene-1 is particularly preferable.

As the conjugated diene monomer, 1,3-butadiene, isoprene (i.e., 2-methyl-1,3-butadiene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, etc., can be used alone or in combination. These polymers in which a part or all of the unsaturated bonds present therein have been reduced by hydrogenation can also be preferably used.
Examples of aromatic vinyl monomers include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, 1,3-dimethylstyrene, and vinylnaphthalene, and among these, styrene is preferably used.

As the α-olefin-maleic anhydride copolymer, maleic anhydride-ethylene-propylene copolymer and maleic anhydride-ethylene-butene-1 copolymer are particularly preferred.

Examples of olefin polymers in maleic anhydride modified olefin polymers include homopolymers or ethylene copolymers of α-olefins such as ethylene, propylene, butene-1, pentene-1, hexene-1, 4-methylpentene-1, and octene-1, conjugated diene polymers (homopolymers or copolymers of diolefin monomers), conjugated diene/aromatic vinyl hydrocarbon copolymers, and non-conjugated dienes, and these can be used in combination of two or more.

The homopolymers referred to here include polyethylene, polypropylene, polybutene, etc. As the polyethylene, LDPE, LLDPE, HDPE, etc., any one of the molecular structures can be preferably used.
Furthermore, the ethylene-based copolymer refers to a copolymer or multicomponent copolymer of ethylene and another monomer. In the ethylene-based copolymer, the copolymerization amount of ethylene is preferably 50 to 99 mol %. The other monomer to be copolymerized with ethylene can be selected from α-olefins having 3 or more carbon atoms, non-conjugated dienes, vinyl acetate, etc.
Examples of the α-olefin having 3 or more carbon atoms include propylene, butene-1, pentene-1, 3-methylpentene-1, and octene-1, with propylene and butene-1 being preferred.

Among these ethylene-based copolymers, copolymers of ethylene and α-olefins having 3 or more carbon atoms are preferred, and specifically, ethylene-propylene copolymers and ethylene-butene-1 copolymers are particularly preferred.

Non-conjugated dienes include 5-methylidene-2-norbornene, 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, 5-propenyl-2-norbornene, 5-isopropenyl-2-norbornene, 5-crotyl-2-norbornene, 5-(2-methyl-2-butenyl)-2-norbornene, 5-(2-ethyl-2-butenyl)-2-norbornene, and 5-methyl-5-vinylnorbornene. Norbornene compounds, dicyclopentadiene, methyltetrahydroindene, 4,7,8,9-tetrahydroindene, 1,5-cyclooctadiene, 1,4-hexadiene, isoprene, 6-methyl-1,5-heptadiene, 11-tridecadiene, etc., and preferred examples include 5-methylidene-2-norbornene, 5-ethylidene-2-norbornene, dicyclopentadiene, 1,4-hexadiene, etc.

Examples of conjugated diene polymers include homopolymers or copolymers of conjugated diene monomers such as 1,3-butadiene, isoprene (2-methyl-1,3-butadiene), 2,3-dimethyl-1,3-butadiene, and 1,3-pentadiene. Polymers in which some or all of the unsaturated bonds present in these polymers have been reduced by hydrogenation are also preferably used.

Furthermore, copolymers of conjugated dienes and aromatic vinyl hydrocarbons can also be used. For example, there are block copolymers or random copolymers with various ratios of conjugated dienes and aromatic vinyl hydrocarbons. Examples of conjugated dienes that constitute these include the above-mentioned monomers, and 1,3-butadiene and isoprene are particularly preferred. Examples of aromatic vinyl hydrocarbons include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, 1,3-dimethylstyrene, and vinylnaphthalene, and among these, styrene is preferably used. Also, conjugated diene-aromatic vinyl hydrocarbon copolymers in which some or all of the unsaturated bonds other than the aromatic rings have been reduced by hydrogenation can also be preferably used. Preferred examples include styrene-butadiene-styrene block copolymers and copolymers obtained by partially hydrogenating styrene-butadiene-styrene block copolymers.

Preferable examples of the olefin polymers described above include ethylene-propylene copolymers, ethylene-butene-1 copolymers, and copolymers obtained by partially hydrogenating styrene-butadiene-styrene block copolymers, with ethylene-propylene copolymers being particularly preferred.

The maleic anhydride-modified olefin polymer is obtained by graft-modifying the olefin polymer with maleic anhydride. A known method can be used for the graft-modification. For example, a predetermined amount of unsaturated carboxylic acid can be mixed and reacted with a molten olefin polymer using an extruder.
The amount of maleic anhydride to be grafted is usually in the range of 0.005 to 25% by mass, preferably 0.01 to 20% by mass, based on 100% by mass of the maleic anhydride-modified olefin polymer.

The preferred content of the olefin-maleic anhydride copolymer is 0.1 to 5 parts by mass per 100 parts by mass of the polycarbonate resin (A). This range can suppress resin deterioration of the polycarbonate resin, improve impact resistance, and reduce mold contamination due to generated gas. If the content of the copolymer is less than 0.1 parts by mass, the impact resistance of the molded product is likely to decrease, and if it exceeds 5 parts by mass, the rigidity of the molded product is likely to decrease and mold contamination due to generated gas during molding is likely to increase. The more preferred content of the copolymer is 0.3 parts by mass or more, even more preferably 0.5 parts by mass or more, more preferably 4.5 parts by mass or less, even more preferably 4 parts by mass or less, among which 3.5 parts by mass or less, 3 parts by mass or less, 2.5 parts by mass or less, and particularly 2 parts by mass or less are preferred.

[Elastomer]
The polycarbonate resin composition of the present invention preferably contains an elastomer, which can improve the impact resistance of the resin composition.

The elastomer used in the present invention is preferably a graft copolymer obtained by graft-copolymerizing a rubber component with a monomer component that is copolymerizable therewith. The method for producing the graft copolymer may be any method such as bulk polymerization, solution polymerization, suspension polymerization, or emulsion polymerization, and the copolymerization method may be either one-stage grafting or multi-stage grafting.

The rubber component usually has a glass transition temperature of 0° C. or less, preferably −20° C. or less, and more preferably −30° C. or less. Specific examples of the rubber component include polybutadiene rubber, polyisoprene rubber, polyalkyl acrylate rubber such as polybutyl acrylate, poly(2-ethylhexyl acrylate), and butyl acrylate-2-ethylhexyl acrylate copolymer, silicone rubber such as polyorganosiloxane rubber, butadiene-acrylic composite rubber, IPN (Interpenetrating Polymer Network) type composite rubber consisting of polyorganosiloxane rubber and polyalkyl acrylate rubber, styrene-butadiene rubber, ethylene-α-olefin rubber such as ethylene-propylene rubber, ethylene-butene rubber, and ethylene-octene rubber, ethylene-acrylic rubber, and fluororubber. These may be used alone or in a mixture of two or more.
Among these, polybutadiene rubber, polyalkyl acrylate rubber, polyorganosiloxane rubber, IPN type composite rubber consisting of polyorganosiloxane rubber and polyalkyl acrylate rubber, and styrene-butadiene rubber are preferred from the standpoint of mechanical properties and surface appearance.

Specific examples of monomer components that can be graft-copolymerized with the rubber component include aromatic vinyl compounds, vinyl cyanide compounds, (meth)acrylic acid ester compounds, (meth)acrylic acid compounds, epoxy group-containing (meth)acrylic acid ester compounds such as glycidyl (meth)acrylate; maleimide compounds such as maleimide, N-methylmaleimide, and N-phenylmaleimide; α,β-unsaturated carboxylic acid compounds such as maleic acid, phthalic acid, and itaconic acid, and their anhydrides (e.g., maleic anhydride, etc.). These monomer components may be used alone or in combination of two or more. Among these, from the standpoint of mechanical properties and surface appearance, aromatic vinyl compounds, vinyl cyanide compounds, (meth)acrylic acid ester compounds, and (meth)acrylic acid compounds are preferred, and (meth)acrylic acid ester compounds are more preferred. Specific examples of (meth)acrylic acid ester compounds include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, cyclohexyl (meth)acrylate, and octyl (meth)acrylate.

From the viewpoints of impact resistance and surface appearance, the graft copolymer in which the rubber component is copolymerized is preferably a core/shell type graft copolymer. Among them, a core/shell type graft copolymer is particularly preferred, which is composed of a core layer made of at least one rubber component selected from polybutadiene-containing rubber, polybutyl acrylate-containing rubber, polyorganosiloxane rubber, and an IPN type composite rubber made of polyorganosiloxane rubber and polyalkyl acrylate rubber, and a shell layer formed by copolymerizing (meth)acrylic acid ester around the core layer. The above-mentioned core/shell type graft copolymer preferably contains 40% or more by mass of the rubber component, and more preferably contains 60% or more by mass. In addition, it is preferable that the (meth)acrylic acid content is 10% or more by mass.

Of the above elastomers, the core/shell type elastomer is preferably one having a silicone/acrylic composite, acrylic rubber, or butadiene rubber core, and more preferably one having a butadiene rubber core.

In addition, the core/shell type in the present invention does not necessarily mean that the core layer and the shell layer are clearly distinguishable, but is intended to broadly include compounds obtained by graft polymerizing a rubber component around the core portion.

Specific examples of preferred core/shell type graft copolymers include methyl methacrylate-butadiene-styrene copolymer (MBS), methyl methacrylate-acrylonitrile-butadiene-styrene copolymer (MABS), methyl methacrylate-butadiene copolymer (MB), methyl methacrylate-acrylic rubber copolymer (MA), methyl methacrylate-acrylic rubber-styrene copolymer (MAS), methyl methacrylate-acrylic-butadiene rubber copolymer, methyl methacrylate-(acrylic-silicone IPN rubber) copolymer, silicone-acrylic composite rubber containing polyorganosiloxane and polyalkyl(meth)acrylate, etc., and silicone-acrylic composite rubber containing polyorganosiloxane and polyalkyl(meth)acrylate and methyl methacrylate-butadiene copolymer are particularly preferred. Such rubbery polymers may be used alone or in combination of two or more.

The content of the elastomer is preferably 1 to 25 parts by mass, more preferably 2 parts by mass or more, even more preferably 2.5 parts by mass or more, particularly preferably 3 parts by mass or more, and more preferably 20 parts by mass or less, even more preferably 18 parts by mass or less, particularly preferably 15 parts by mass or less, based on 100 parts by mass of the polycarbonate resin (A).
The elastomer may be one kind or two or more kinds. When two or more kinds are contained, the total amount is within the above range.

[Fluorine-containing resin]
By containing the fluorine-containing resin together with each of the above-mentioned components, the fluorine-containing resin acts like a surfactant to improve impact resistance, further improving the mechanical properties of the resin composition, and further improving the flame retardancy by improving the ability to prevent dripping during combustion. By setting the content ratio of the elastomer to the fluorine-containing resin (elastomer/fluorine-containing resin) to preferably more than 1 to 250, the impact strength is dramatically improved, and high rigidity and high impact resistance can be achieved.

The fluorine-containing resin is preferably a fluoroolefin resin. The fluoroolefin resin is usually a polymer or copolymer containing a fluoroethylene structure, and specific examples thereof include a difluoroethylene resin, a tetrafluoroethylene resin, and a tetrafluoroethylene/hexafluoropropylene copolymer resin, with the tetrafluoroethylene resin being preferred.
The fluororesin is preferably one having fibril-forming ability, specifically, a fluoroolefin resin having fibril-forming ability. The fibril-forming ability significantly improves impact resistance and flexural modulus, and also tends to improve drip prevention during combustion.

In addition, an organic polymer-coated fluoroolefin resin can also be suitably used as the fluorine-containing resin. By using an organic polymer-coated fluoroolefin resin, dispersibility is improved, the surface appearance of the molded article is improved, and surface foreign matter can be suppressed.
As a monomer for producing an organic polymer that coats the fluoroolefin resin, from the viewpoint of dispersibility when blended with a polycarbonate resin, one having high affinity with the polycarbonate resin is preferred, and an aromatic vinyl monomer, a (meth)acrylic acid ester monomer, or a vinyl cyanide monomer is more preferred.

One type of fluorine-containing resin may be used, or two or more types may be used in any combination and in any ratio.

The content of the fluorine-containing resin is preferably 0.05 to 10 parts by mass relative to 100 parts by mass of the polycarbonate resin (A), and the upper limit is preferably 8 parts by mass or less, more preferably 5 parts by mass or less, even more preferably 3 parts by mass or less, and particularly preferably 2 parts by mass or less.
By setting the content of the fluororesin to 0.05 parts by mass or more, a sufficient effect of improving mechanical properties can be easily obtained, and by setting it to 10 parts by mass or less, appearance defects due to poor dispersion of the fluororesin in a molded article obtained by molding the resin composition are made less likely to occur, and high mechanical strength can be easily maintained.

[Flame retardant]
The polycarbonate resin composition preferably contains a flame retardant in an amount of 0.01 to 30 parts by mass, more preferably 0.03 to 20 parts by mass, based on 100 parts by mass of the polycarbonate resin (A).
Examples of the flame retardant include organic metal salt-based flame retardants, siloxane-based flame retardants, phosphorus-based flame retardants, boron-based flame retardants, nitrogen-based flame retardants, and halogen-based flame retardants. In the present invention, the organic metal salt-based flame retardants are particularly preferred.

As the organometallic salt compound, an organosulfonic acid metal salt is particularly preferred.
The metal of the metal salt compound is preferably an alkali metal or an alkaline earth metal, and examples of such metals include alkali metals such as lithium (Li), sodium (Na), potassium (K), rubidium (Rb), and cesium (Cs); and alkaline earth metals such as magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba). Among these, sodium, potassium, and cesium are particularly preferred.

Examples of metal organic sulfonates include lithium organic sulfonates, sodium organic sulfonates, potassium organic sulfonates, rubidium organic sulfonates, cesium organic sulfonates, magnesium organic sulfonates, calcium organic sulfonates, strontium organic sulfonates, and barium organic sulfonates. Among these, alkali metal organic sulfonates such as sodium organic sulfonates, potassium organic sulfonates, and cesium organic sulfonates are particularly preferred.

Among the organic sulfonic acid metal salt compounds, preferred examples include metal salts of fluorine-containing aliphatic sulfonic acids or aromatic sulfonic acids. Specific examples of preferred compounds include alkali metal salts of fluorine-containing aliphatic sulfonic acids having at least one C-F bond in the molecule, such as potassium perfluorobutanesulfonate, lithium perfluorobutanesulfonate, sodium perfluorobutanesulfonate, and cesium perfluorobutanesulfonate; alkaline earth metal salts of fluorine-containing aliphatic sulfonic acids having at least one C-F bond in the molecule, such as magnesium perfluorobutanesulfonate, calcium perfluorobutanesulfonate, barium perfluorobutanesulfonate, magnesium trifluoromethanesulfonate, calcium trifluoromethanesulfonate, and barium trifluoromethanesulfonate; and other fluorine-containing aliphatic sulfonic acid metal salts.

Dipotassium diphenylsulfone-3,3'-disulfonate, potassium diphenylsulfone-3-sulfonate, sodium benzenesulfonate, sodium (poly)styrenesulfonate, sodium paratoluenesulfonate, sodium (branched)dodecylbenzenesulfonate, sodium trichlorobenzenesulfonate, potassium benzenesulfonate, potassium styrenesulfonate, potassium (poly)styrenesulfonate, potassium paratoluenesulfonate, potassium (branched)dodecylbenzenesulfonate, potassium trichlorobenzenesulfonate, cesium benzenesulfonate, cesium (poly)styrenesulfonate Examples of aromatic sulfonic acid metal salts include alkali metal salts of aromatic sulfonic acids having at least one aromatic group in the molecule, such as cesium paratoluenesulfonate, cesium (branched) dodecylbenzenesulfonate, and cesium trichlorobenzenesulfonate; and alkaline earth metal salts of aromatic sulfonic acids having at least one aromatic group in the molecule, such as magnesium paratoluenesulfonate, calcium paratoluenesulfonate, strontium paratoluenesulfonate, barium paratoluenesulfonate, magnesium (branched) dodecylbenzenesulfonate, and calcium (branched) dodecylbenzenesulfonate.

Among the above-mentioned examples, alkali metal salts of fluorinated aliphatic sulfonic acids and alkali metal salts of aromatic sulfonic acids are more preferred, alkali metal salts of fluorinated aliphatic sulfonic acids are particularly preferred, and alkali metal salts of perfluoroalkanesulfonic acids are further preferred, specifically potassium perfluorobutanesulfonate and the like are preferred.
The metal salt compounds may be used alone or in any combination of two or more in any ratio.

When an organic metal salt flame retardant is contained, the content is preferably 0.01 to 1.5 parts by mass, more preferably 0.02 parts by mass or more, even more preferably 0.03 parts by mass or more, more preferably 1 part by mass or less, even more preferably 0.5 parts by mass or less, of which 0.3 parts by mass or less, and particularly preferably 0.15 parts by mass or less, per 100 parts by mass of polycarbonate resin (A).

[Additives, etc.]
The polycarbonate resin composition may contain additives other than those described above, such as stabilizers, release agents, colorants, fluorescent brighteners, antistatic agents, plasticizers, compatibilizers, etc. These additives or other resins may be blended in one or more types.

The polycarbonate resin composition may also contain other resins other than the polycarbonate resin (A), olefin-maleic anhydride copolymer, ABS resin, and elastomer. Examples of other resins include thermoplastic polyester resins such as polyethylene terephthalate resin, polytrimethylene terephthalate resin, and polybutylene terephthalate resin; polyolefin resins such as polyethylene resin and polypropylene resin; polyamide resin; polyimide resin; polyetherimide resin; polyphenylene ether resin; polyphenylene sulfide resin; polysulfone resin, etc. One type of other resin may be contained, or two or more types may be contained in any combination and ratio.
However, when a resin other than the polycarbonate resin (A) is contained, the content thereof is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 5 parts by mass or less, and particularly preferably 3 parts by mass or less, per 100 parts by mass of the polycarbonate resin (A).

[Production of polycarbonate resin composition]
There is no limitation on the method for producing the polycarbonate resin composition, and a wide variety of known methods for producing polycarbonate resin compositions can be used, including a method in which the above-mentioned essential components and other components to be blended as necessary are mixed in advance using various mixers such as a tumbler or a Henschel mixer, and then melt-kneaded using a mixer such as a Banbury mixer, a roll, a Brabender, a single-screw kneading extruder, a twin-screw kneading extruder, a kneader, etc. The temperature for melt-kneading is not particularly limited, but is usually in the range of 260 to 320°C.

The polycarbonate resin composition of the present invention can be pelletized to produce various molded products by molding the pellets using various molding methods. It is also possible to directly mold the resin melt-kneaded in an extruder into a molded product without going through the pellet process.

The polycarbonate resin composition of the present invention has extremely excellent light-shielding properties, and when molded into a molded article, it exhibits excellent light-shielding properties even in its extremely thin parts. That is, the spectral transmittance in the thickness direction measured on a 35 μm-thick film molded from the resin composition is preferably less than 1%, more preferably 0.8% or less, even 0.7% or less, among which 0.6% or less, 0.5% or less, 0.4% or less, and particularly 0.3% or less.

The polycarbonate resin composition of the present invention has excellent impact resistance, and the notched Charpy impact strength (4 mmt) measured in accordance with ISO179 is preferably 35 kJ/ ^m2 or more.

The polycarbonate resin composition has excellent heat resistance, and the deflection temperature under load DTUL measured according to ISO 75 A method is preferably 120°C or higher, more preferably 121°C or higher, even more preferably 122°C or higher, and particularly preferably 123°C or higher.

The molded article obtained from the polycarbonate resin composition of the present invention is excellent in impact resistance and flexural modulus, and further exhibits low anisotropy.
Therefore, its applications include, for example, housing parts and lens barrels for cameras, telescopes, microscopes, projection exposure devices, optical measuring devices, etc.; housing parts and mechanism parts for mobile phone cameras, smartphone cameras, tablet cameras, car-mounted cameras, action cameras, laptop PC cameras, drive recorders, surveillance cameras, small cameras mounted on drones, etc.; housings and mechanism parts for sensors such as car collision prevention sensors, rear monitor sensors, vehicle speed sensors, temperature sensors, security sensors, and motion sensors for game consoles; and frame members and exterior panel members for automobiles, motorcycles, bicycles, wheelchairs, etc. Preferred examples of the material include panel components and mechanical parts of home televisions, personal computer displays, in-vehicle monitors, smartphones, and head-mounted displays; housings and mechanical parts of reading devices such as barcode readers and scanners; housings and mechanical parts of air conditioners, air purifiers, compressors, etc.; housings and mechanical parts of information devices such as wired and wireless LAN routers, WIFI receivers, WIFI storage, USB memories, memory cards, card readers, and data server storage devices; manufacturing and processing facility parts such as optical devices, semiconductor package substrates, and semiconductor manufacturing equipment; and measuring instrument parts.

In particular, the molded article obtained from the polycarbonate resin composition of the present invention can be suitably used for optical equipment parts, and is suitable for optical modules, particularly optical modules having a lens holder, and is particularly suitable for camera modules containing the molded article, such as lens barrels that constitute lens units, lens holders, spacers, stoppers, etc., and sleeves, pedestals, housings, etc. that constitute actuator units.

The present invention will be explained in more detail below with reference to examples. However, the present invention should not be interpreted as being limited to the following examples.

The raw materials used in the following Examples and Comparative Examples are as shown in Table 1 below.

(Examples 2 to 4, Reference Example 1, Comparative Examples 1 to 7)
[Production of resin composition pellets]
The above-mentioned components were blended in the ratios shown in Table 2 (all parts by mass) and mixed uniformly in a tumbler mixer, and then fed from a hopper to an extruder for melt-kneading.
The extruder used was a twin-screw extruder manufactured by Japan Steel Works, Ltd. ("TEX25αIII", L/D = 52.5), and melt extrusion was performed under the conditions of a screw rotation speed of 200 rpm, a cylinder temperature of 280° C., and a discharge rate of 25 kg/hr. The extruded strand was quenched in a water tank and pelletized using a pelletizer.

The pellets obtained by the above manufacturing method were dried at 120°C for 5 hours, and then molded into 4 mm thick ISO dumbbell test specimens using a Nissei Plastic Industrial Co., Ltd. NEX80 injection molding machine under the following conditions: cylinder temperature 280°C, mold temperature 100°C, injection speed 30 mm/s, and holding pressure 90 MPa.

[Measurement of Charpy impact strength (notched)]
Using the ISO dumbbell specimens (thickness 4 mm) obtained above, the notched Charpy strength (unit: kJ/m ² ) was measured in accordance with ISO179.

[Measurement of heat resistance (deflection temperature under load, DTUL)]
The ISO dumbbell specimen (thickness 4 mm) obtained above was used to measure the deflection temperature under load (DTUL, unit: ° C.) under a load of 1.80 MPa according to ISO 75 A method.

[Measurement of transmittance (%)]
The pellets obtained by the above manufacturing method were dried at 120° C. for 4 hours, and then molded into a film having a thickness of 35 μm at a temperature of 240° C. and a press pressure of 25 MPa using a press molding machine "Mini Test Press" manufactured by Toyo Seiki Seisakusho.
The film was subjected to measurement of the spectral transmittance (unit: %) in the thickness direction at a wavelength of 700 nm using a Shimadzu UV-2700 ultraviolet-visible spectrophotometer with a C light source and a 2° visual field.

The above evaluation results are shown in Table 2 below. Note that the amount of carbon black (C1) in Table 2 is shown as the amount of carbon black, not as the amount of master batch.

The polycarbonate resin composition of the present invention has extremely high light-shielding properties and excellent impact resistance, making it suitable for use in a variety of applications, including optical equipment parts.

Claims (6)

the composition contains, relative to 100 parts by mass of polycarbonate resin (A), more than 0.5 parts by mass and not more than 10 parts by mass of light diffusing agent (B) and more than 0.5 parts by mass and not more than 3 parts by mass of carbon black (C), the average particle size of the light diffusing agent (B) is 1.1 to 3.9 μm, and the content ratio (B)/(C) of the light diffusing agent (B) to the carbon black (C) is 1.5 or more ,
a spectral transmittance in the thickness direction measured on a 35 μm-thick film molded from the resin composition is 0.5% or less;
A polycarbonate resin composition having a notched Charpy impact strength measured in accordance with ISO 178 of 40 kJ/m2 or more ^. The polycarbonate resin composition according to claim 1, in which the absolute value of the difference between the refractive index n1 of the polycarbonate resin (A) and the refractive index n2 of the light diffusing agent (B) (|n1-n2|) is 0.12 or more. The polycarbonate resin composition according to claim 1 or 2, wherein the light diffusing agent (B) is a silicone-based light diffusing agent. The polycarbonate resin composition according to any one of claims 1 to 3, wherein the light diffusing agent (B) is polymethylsilsesquioxane. A molded article made of the polycarbonate resin composition according to any one of claims 1 to 4 . An optical module comprising the molded article according to claim 5 .