JP7744446B2 - Aromatic polycarbonate resin composition and molded article thereof - Google Patents

Description

The present invention relates to an aromatic polycarbonate resin composition that has excellent thermal stability and moist heat resistance, and in which molded articles made from the composition have wavelength-selective absorption properties, and further has excellent thermal and light stability of the absorption properties.

Autonomous driving technology has rapidly developed in recent years. Infrared sensing systems play an important role in autonomous driving technology. Examples of infrared sensing systems include driver monitoring systems that monitor the driver and LiDAR that detect other vehicles and buildings. Near-infrared light in the 800 to 1000 nm range is generally used for sensing. However, when performing infrared sensing, visible light to near-infrared light becomes noise, so a cover material is required that transmits the wavelength range used for sensing and blocks transmission of wavelengths below that range. Glass and resin are used as cover materials, and transparent resins such as acrylic resin and polycarbonate resin are commonly used, but there is a great demand for polycarbonate resin, which has good transparency and excellent impact resistance and heat resistance.
Studies on wavelength-selectively controlled polycarbonate resins have been conducted in the past. These involve the combined use of multiple colorants with different absorption wavelength bands to block light from the visible light range to a portion of the near-infrared range (see Patent Documents 1 to 4). However, these documents do not disclose the stability of absorption characteristics. Furthermore, because the cover materials for infrared sensors used in autonomous driving technology are molded to thin thicknesses of approximately 1 to 3 mm, polycarbonate resins with a viscosity-average molecular weight of 24,000 or less and relatively high fluidity are preferred, and molding temperatures are also high, at 300 to 340°C. Therefore, the thermal stability of wavelength characteristics during high-temperature molding is extremely important. Furthermore, resins are constantly exposed to light inside automobiles, and it is important that their wavelength characteristics remain stable even when exposed to light for long periods of time. In other words, to realize a safe autonomous driving society, infrared sensor cover materials must have thermal and light stability in their absorption characteristics.

Patent No. 5040827 Patent No. 6354888 WO2019/022169 publication Patent No. 6658942

The object of the present invention is to provide an aromatic polycarbonate resin composition and molded articles thereof that have excellent thermal stability and moist heat resistance, and in which molded articles made from the composition have wavelength-selective absorption properties, and further have excellent thermal and light stability of the absorption properties.

As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by an aromatic polycarbonate resin composition containing a specific colorant and a heat stabilizer. That is, the present inventors have found that the above-mentioned problems can be solved by the following aromatic polycarbonate resin composition and molded article thereof.
1. A resin composition containing 100 parts by weight of (A) an aromatic polycarbonate resin (Component A), 0.055 to 1.3 parts by weight of (B) a colorant (Component B) containing (B1) a colorant (Component B1) having an absorption maximum at less than 650 nm and (B2) a colorant (Component B2) having an absorption maximum at 650 to 880 nm, and 0.003 to 0.5 parts by weight of (C) a phosphorus-based heat stabilizer and/or a phenol-based heat stabilizer (Component C), wherein the resin composition has an average light transmittance in the thickness direction of a 3 mm-thick molded article at 400 to 700 nm of 1.5% or less.
2. The resin composition according to item 1 above, wherein the weight ratio of component B1 to component B2 (component B1/component B2) is 2/1 to 40/1.
3. The resin composition according to item 1 or 2, wherein the maximum light transmittance in the thickness direction of a molded article having a thickness of 3 mm is 5.0% or less at wavelengths from 400 nm to the wavelength at which the absorption of component B2 is maximum.
4. The resin composition according to any one of items 1 to 3 above, wherein Component B2 is at least one colorant selected from the group consisting of anthraquinone-based colorants, phthalocyanine-based colorants, perylene-based colorants, and heterocyclic colorants.
5. The resin composition according to any one of items 1 to 4 above, further comprising 0.01 to 1 part by weight of (D) a benzotriazole-based ultraviolet absorber (Component D) per 100 parts by weight of Component A.
6. The resin composition according to any one of items 1 to 5 above, wherein component A has a viscosity average molecular weight of 24,000 or less.
7. A molded article obtained by molding the resin composition according to any one of items 1 to 6 above.
8. The molded article according to the preceding paragraph 7, which is a cover material for covering an infrared sensor.
9. The molded article according to the preceding paragraph 8, which is a cover material for covering an infrared sensor used in a driver monitoring system that monitors the driver and a LiDAR that detects other vehicles and buildings.

The resin composition of the present invention has excellent thermal stability and moist heat resistance, and molded articles made therefrom have wavelength-selective absorption characteristics. Infrared light sources used in infrared sensors for autonomous driving systems come in multiple specifications, including 805 nm, 850 nm, 905 nm, and 940 nm. Since wavelength characteristics requirements vary depending on the vehicle manufacturer, the resin composition of the present invention can meet the needs of different vehicle manufacturers. Furthermore, molded articles made from the resin composition of the present invention have excellent thermal and light stability of absorption characteristics, making them stable under all molding conditions and even under conditions of long-term exposure to light. Therefore, the resin composition of the present invention is particularly useful as a cover material for infrared sensors, particularly those used in driver monitoring systems that monitor drivers and LiDAR systems that detect other vehicles and buildings, and can contribute to the safety of future autonomous driving systems.

(Component A: aromatic polycarbonate resin)
The aromatic polycarbonate resin used as component A in the present invention is obtained by reacting a dihydric phenol with a carbonate precursor, and examples of the reaction method include interfacial polymerization, melt transesterification, solid-phase transesterification of carbonate prepolymers, and ring-opening polymerization of cyclic carbonate compounds.

Representative examples of dihydric phenols used herein include hydroquinone, resorcinol, 4,4'-biphenol, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)propane (commonly known as bisphenol A), 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 2,2-bis(4-hydroxyphenyl)pentane, 4,4'-(p-phenylene) Examples of suitable dihydric phenols include 4,4'-(m-phenylenediisopropylidene)diphenol, 4,4'-(m-phenylenediisopropylidene)diphenol, 1,1-bis(4-hydroxyphenyl)-4-isopropylcyclohexane, bis(4-hydroxyphenyl)oxide, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)sulfoxide, bis(4-hydroxyphenyl)sulfone, bis(4-hydroxyphenyl)ketone, bis(4-hydroxyphenyl)ester, bis(4-hydroxy-3-methylphenyl)sulfide, 9,9-bis(4-hydroxyphenyl)fluorene, and 9,9-bis(4-hydroxy-3-methylphenyl)fluorene. Preferred dihydric phenols are bis(4-hydroxyphenyl)alkanes, and among these, bisphenol A is particularly preferred and widely used in terms of impact resistance.

In the present invention, in addition to bisphenol A polycarbonate, which is a general-purpose polycarbonate, it is also possible to use special polycarbonates produced using other dihydric phenols as component A.

For example, polycarbonates (homopolymers or copolymers) using 4,4'-(m-phenylenediisopropylidene)diphenol (hereinafter sometimes abbreviated as "BPM"), 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (hereinafter sometimes abbreviated as "Bis-TMC"), 9,9-bis(4-hydroxyphenyl)fluorene, and 9,9-bis(4-hydroxy-3-methylphenyl)fluorene (hereinafter sometimes abbreviated as "BCF") as part or all of the dihydric phenol component are suitable for applications where strict requirements for dimensional change due to water absorption and dimensional stability are required. These dihydric phenols other than BPA are preferably used in an amount of 5 mol% or more, and particularly 10 mol% or more, of the total dihydric phenol components constituting the polycarbonate.

In particular, when high rigidity and better hydrolysis resistance are required, it is particularly preferable that the component A constituting the resin composition is a copolymer polycarbonate of the following (1) to (3).
(1) A copolymeric polycarbonate in which, based on 100 mol% of the dihydric phenol component constituting the polycarbonate, BPM accounts for 20 to 80 mol% (more preferably 40 to 75 mol%, and even more preferably 45 to 65 mol%) and BCF accounts for 20 to 80 mol% (more preferably 25 to 60 mol%, and even more preferably 35 to 55 mol%).
(2) A copolymer polycarbonate in which, based on 100 mol% of the dihydric phenol component constituting the polycarbonate, BPA accounts for 10 to 95 mol% (more preferably 50 to 90 mol%, even more preferably 60 to 85 mol%) and BCF accounts for 5 to 90 mol% (more preferably 10 to 50 mol%, even more preferably 15 to 40 mol%).
(3) A copolymer polycarbonate in which, based on 100 mol% of the dihydric phenol component constituting the polycarbonate, BPM accounts for 20 to 80 mol% (more preferably 40 to 75 mol%, even more preferably 45 to 65 mol%) and Bis-TMC accounts for 20 to 80 mol% (more preferably 25 to 60 mol%, even more preferably 35 to 55 mol%).

These special polycarbonates may be used alone or in a suitable mixture of two or more. They may also be mixed with the commonly used bisphenol A polycarbonate.

The manufacturing methods and properties of these special polycarbonates are described in detail, for example, in Japanese Patent Application Laid-Open Nos. 6-172508, 8-27370, 2001-55435, and 2002-117580.

Among the various polycarbonates described above, those in which the copolymer composition and the like are adjusted to bring the water absorption and Tg (glass transition temperature) within the ranges (i) or (ii) below have good hydrolysis resistance of the polymer itself and are remarkably excellent in terms of low warpage after molding, and are therefore particularly suitable in fields where dimensional stability is required.
(i) Polycarbonate having a water absorption of 0.05 to 0.15%, preferably 0.06 to 0.13%, and a Tg of 120 to 180°C.
(ii) Polycarbonate having a Tg of 160 to 250°C, preferably 170 to 230°C, and a water absorption of 0.10 to 0.30%, preferably 0.13 to 0.30%, more preferably 0.14 to 0.27%.

The water absorption rate of polycarbonate is measured using a circular test piece with a diameter of 45 mm and a thickness of 3.0 mm, after immersing it in water at 23°C for 24 hours in accordance with ISO 62-1980. Furthermore, Tg (glass transition temperature) is a value determined by differential scanning calorimetry (DSC) in accordance with JIS K7121.

Carbonate precursors include carbonyl halides, carbonic acid diesters, or haloformates, such as phosgene, diphenyl carbonate, or dihaloformates of dihydric phenols.

When producing polycarbonate resins by interfacial polymerization of the dihydric phenol and carbonate precursor, catalysts, end-capping agents, antioxidants to prevent oxidation of the dihydric phenol, and the like may be used as needed. The polycarbonate resins of the present invention also include branched polycarbonate resins copolymerized with trifunctional or higher polyfunctional aromatic compounds, polyester carbonate resins copolymerized with aromatic or aliphatic (including alicyclic) bifunctional carboxylic acids, copolymeric polycarbonate resins copolymerized with bifunctional alcohols (including alicyclic), and polyester carbonate resins copolymerized with such bifunctional carboxylic acids and bifunctional alcohols. Mixtures of two or more of the resulting polycarbonate resins may also be used.

The branched polycarbonate resin can impart anti-drip properties to the resin composition of the present invention. Examples of trifunctional or higher polyfunctional aromatic compounds used in such branched polycarbonate resins include phloroglucin, phloroglucside, 4,6-dimethyl-2,4,6-tris(4-hydroxyphenyl)heptene-2,2,4,6-trimethyl-2,4,6-tris(4-hydroxyphenyl)heptane, 1,3,5-tris(4-hydroxyphenyl)benzene, 1,1,1-tris(4-hydroxyphenyl)ethane, 1,1,1-tris(3,5-dimethyl-4-hydroxyphenyl)ethane, 2,6-bis(2-hydroxy-5-methylbenzyl)-4-methylphenol, 4-{4-[1,1-bis(4- Examples of the 4-hydroxyphenyl ether include trisphenols such as {4-hydroxyphenyl)ethyl]benzene}-α,α-dimethylbenzylphenol, tetra(4-hydroxyphenyl)methane, bis(2,4-dihydroxyphenyl)ketone, 1,4-bis(4,4-dihydroxytriphenylmethyl)benzene, trimellitic acid, pyromellitic acid, benzophenonetetracarboxylic acid, and acid chlorides thereof. Among these, 1,1,1-tris(4-hydroxyphenyl)ethane and 1,1,1-tris(3,5-dimethyl-4-hydroxyphenyl)ethane are preferred, and 1,1,1-tris(4-hydroxyphenyl)ethane is particularly preferred.

In the branched polycarbonate, the structural units derived from polyfunctional aromatic compounds preferably account for 0.01 to 1 mol %, more preferably 0.05 to 0.9 mol %, and even more preferably 0.05 to 0.8 mol %, of the total 100 mol % of structural units derived from dihydric phenols and structural units derived from such polyfunctional aromatic compounds.

In particular, in the case of the melt transesterification method, branched structural units may be generated as a side reaction, and the amount of such branched structural units is preferably 0.001 to 1 mol %, more preferably 0.005 to 0.9 mol %, and even more preferably 0.01 to 0.8 mol %, based on a total of 100 mol % including the structural units derived from the dihydric phenol. The proportion of such branched structures can be calculated by ¹ H-NMR measurement.

Preferred aliphatic difunctional carboxylic acids are α,ω-dicarboxylic acids. Preferred examples of aliphatic difunctional carboxylic acids include linear saturated aliphatic dicarboxylic acids such as sebacic acid (decanedioic acid), dodecanedioic acid, tetradecanedioic acid, octadecanedioic acid, and icosane dioic acid, as well as alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid. Alicyclic diols are more preferred as difunctional alcohols, such as cyclohexanedimethanol, cyclohexanediol, and tricyclodecanedimethanol.

The reaction methods used to produce the aromatic polycarbonate resin of the present invention, such as interfacial polymerization, melt transesterification, carbonate prepolymer solid-phase transesterification, and ring-opening polymerization of cyclic carbonate compounds, are well known in various literature and patent publications.

The melt volume rate (300°C, 1.2 kg load) of the aromatic polycarbonate resin in the present invention is not particularly limited, but is preferably 1 to 60 cm ³ /10 min, more preferably 3 to 30 cm ³ /10 min, and even more preferably 5 to 20 cm ³ /10 min. Resin compositions obtained from aromatic polycarbonate resins with a melt volume rate of less than 1 cm ³ /10 min may be less versatile due to poor fluidity during injection molding. On the other hand, aromatic polycarbonate resins with a melt volume rate of more than 60 cm ³ /10 min may not be able to achieve good mechanical properties. The melt volume rate is also called "MVR" and is measured in accordance with ISO 1133.

The viscosity-average molecular weight (M) of the aromatic polycarbonate resin in the present invention is preferably 24,000 or less, more preferably 22,500 or less, and even more preferably 20,000 or less. If the viscosity-average molecular weight exceeds 24,000, poor fluidity is required to obtain thin-walled molded products with a thickness of 1 to 3 mm for use as sensor cover materials, which may lead to thermal decomposition of the resin or coloring agent. The lower limit of the viscosity-average molecular weight is not particularly limited, but is preferably 14,000 or more from the perspective of impact resistance. The viscosity-average molecular weight (M) in the present invention is determined by first determining the specific viscosity (η _SP ) calculated by the following formula using an Ostwald viscometer from a solution of 0.7 g of polycarbonate resin dissolved in 100 ml of methylene chloride at 20°C.
Specific viscosity (η _SP )=(t−t ₀ )/t ₀
[ _t0 is the number of seconds for methylene chloride to fall, and t is the number of seconds for the sample solution to fall]
The viscosity average molecular weight M is calculated from the determined specific viscosity (η _SP ) using the following formula.

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 aromatic polycarbonate resin (component A) of the present invention may be a polycarbonate-polydiorganosiloxane copolymer resin, preferably a copolymer resin prepared by copolymerizing a dihydric phenol represented by the following general formula (1) with a hydroxyaryl-terminated polydiorganosiloxane represented by the following general formula (3):

[In the above general formula (1), ^R1 and ^R2 each independently represent a group selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, a cycloalkoxy group having 6 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms, an aryloxy group having 6 to 14 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an aralkyloxy group having 7 to 20 carbon atoms, a nitro group, an aldehyde group, a cyano group, and a carboxy group; when there are multiple of each, they may be the same or different; e and f each represent an integer of 1 to 4; and W is a single bond or at least one group selected from the group consisting of groups represented by the following general formula (2)]

[In the above general formula (2), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ each independently represent a group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 14 carbon atoms and an aralkyl group having 7 to 20 carbon atoms; R ¹⁹ and R ²⁰ each independently represent a group selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, a cycloalkoxy group having 6 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an aralkyloxy group having 7 to 20 carbon atoms, a nitro group, an aldehyde group, a cyano group, and a carboxy group; when there are a plurality of 20, they may be the same or different; g is an integer from 1 to 10, and h is an integer from 4 to 7.]

[In the above general formula (3), R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ₈ each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms; R ⁹ and R ¹⁰ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms; p is a natural number; q is 0 or a natural number; and p+q is a natural number from 10 to 300. X is a divalent aliphatic group having 2 to 8 carbon atoms.]
Examples of the dihydric phenol (I) represented by the general formula (1) include 4,4'-dihydroxybiphenyl, bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 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-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, 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 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'-di Examples of such hydroxy-3,3'-diphenyldiphenyl sulfoxide include 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, and 1,3-bis(4-hydroxyphenyl)-5,7-dimethyladamantane.

Among these, 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)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4'-sulfonyldiphenol, 2,2'-dimethyl-4,4'-sulfonyldiphenol, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 1,3-bis{2-(4-hydroxyphenyl)propyl}benzene, and 1,4-bis{2-(4-hydroxyphenyl)propyl}benzene are preferred, and 2,2-bis(4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane (BPZ), 4,4'-sulfonyldiphenol, and 9,9-bis(4-hydroxy-3-methylphenyl)fluorene are particularly preferred. Among these, 2,2-bis(4-hydroxyphenyl)propane is the most suitable due to its excellent strength and durability. These may be used alone or in combination of two or more.

As the hydroxyaryl-terminated polydiorganosiloxane represented by the above general formula (3), for example, the compounds shown below are preferably used.

Hydroxyaryl-terminated polydiorganosiloxane (II) is easily produced by subjecting a phenol having an olefinically unsaturated carbon-carbon bond, preferably vinylphenol, 2-allylphenol, isopropenylphenol, or 2-methoxy-4-allylphenol, to a hydrosilylation reaction at the end of a polysiloxane chain having a predetermined degree of polymerization. Among these, (2-allylphenol)-terminated polydiorganosiloxane and (2-methoxy-4-allylphenol)-terminated polydiorganosiloxane are preferred, with (2-allylphenol)-terminated polydimethylsiloxane and (2-methoxy-4-allylphenol)-terminated polydimethylsiloxane being especially preferred. Hydroxyaryl-terminated polydiorganosiloxane (II) preferably has a molecular weight distribution (Mw/Mn) of 3 or less. To achieve even better low outgassing properties during high-temperature molding and low-temperature impact resistance, the molecular weight distribution (Mw/Mn) is more preferably 2.5 or less, and even more preferably 2 or less. If the upper limit of this preferred range is exceeded, the amount of outgassing during high-temperature molding may be large, and low-temperature impact resistance may be poor.

In addition, to achieve high impact resistance, the diorganosiloxane degree of polymerization (p + q) of the hydroxyaryl-terminated polydiorganosiloxane (II) is preferably 10 to 300. Such diorganosiloxane degree of polymerization (p + q) is preferably 10 to 200, more preferably 12 to 150, and even more preferably 14 to 100. Below the lower limit of this preferred range, the impact resistance that is characteristic of polycarbonate-polydiorganosiloxane copolymers is not effectively exhibited, while above the upper limit of this preferred range, poor appearance appears.

The polydiorganosiloxane content of the polycarbonate-polydiorganosiloxane copolymer resin is preferably 0.1 to 50 wt % based on the total weight. The polydiorganosiloxane component content is more preferably 0.5 to 30 wt %, and even more preferably 1 to 20 wt %. At or above the lower limit of this preferred range, excellent impact resistance and flame retardancy are achieved, while at or below the upper limit of this preferred range, a stable appearance that is less susceptible to the effects of molding conditions is likely to be achieved. The polydiorganosiloxane polymerization degree and polydiorganosiloxane content can be calculated by ^1H -NMR measurement.

In the present invention, only one type of hydroxyaryl-terminated polydiorganosiloxane (II) may be used, or two or more types may be used.

In addition, other comonomers other than the above dihydric phenol (I) and hydroxyaryl-terminated polydiorganosiloxane (II) can also be used in combination in an amount of up to 10% by weight based on the total weight of the copolymer, provided that this does not interfere with the performance of the present invention.

In the present invention, a mixed solution containing an oligomer having a terminal chloroformate group is prepared in advance by reacting a dihydric phenol (I) with a carbonate ester-forming compound in a mixed solution of a water-insoluble organic solvent and an alkaline aqueous solution.

When producing oligomers of dihydric phenol (I), the entire amount of dihydric phenol (I) used in the method of the present invention may be converted into an oligomer at once, or a portion of the oligomer may be added as a post-added monomer as a reaction raw material in the subsequent interfacial polycondensation reaction. A post-added monomer is added to speed up the subsequent polycondensation reaction, and there is no need to add it if it is not necessary.

The method for this oligomer formation reaction is not particularly limited, but it is usually preferable to carry it out in a solvent in the presence of an acid binder.

The proportion of the carbonate ester-forming compound used can be adjusted appropriately, taking into account the stoichiometric ratio (equivalents) of the reaction. Furthermore, when using a gaseous carbonate ester-forming compound such as phosgene, it is preferable to blow it into the reaction system.

Examples of the acid binder include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal carbonates such as sodium carbonate and potassium carbonate, organic bases such as pyridine, and mixtures thereof. Similarly, the proportion of the acid binder used can be determined appropriately taking into account the stoichiometric ratio (equivalents) of the reaction. Specifically, it is preferable to use 2 equivalents or a slight excess of the acid binder relative to the number of moles of dihydric phenol (I) used to form the oligomer (typically 1 mole corresponds to 2 equivalents).

The solvent may be any of a variety of inert solvents, such as those used in the production of known polycarbonates, and may be used alone or in combination. Typical examples include hydrocarbon solvents such as xylene, and halogenated hydrocarbon solvents such as methylene chloride and chlorobenzene. Halogenated hydrocarbon solvents such as methylene chloride are particularly preferred.

There are no particular restrictions on the reaction pressure for oligomer formation, and it can be atmospheric, elevated, or reduced pressure, but it is usually advantageous to carry out the reaction at atmospheric pressure. The reaction temperature is selected from the range of -20 to 50°C, and since heat is often generated during polymerization, water or ice cooling is desirable. The reaction time depends on other conditions and cannot be specified in general, but is usually carried out for 0.2 to 10 hours. The pH range for the oligomer formation reaction is the same as known interfacial reaction conditions, and the pH is always adjusted to 10 or higher.

In this way, the present invention obtains a mixed solution containing an oligomer of dihydric phenol (I) having terminal chloroformate groups, and then, while stirring the mixed solution, adds a hydroxyaryl-terminated polydiorganosiloxane (II) represented by general formula (3) that has been highly purified to a molecular weight distribution (Mw/Mn) of 3 or less to the dihydric phenol (I), and then performs interfacial polycondensation between the hydroxyaryl-terminated polydiorganosiloxane (II) and the oligomer to obtain a polycarbonate-polydiorganosiloxane copolymer.

When conducting the interfacial polycondensation reaction, an acid binder may be added as needed, taking into account the stoichiometric ratio (equivalents) of the reaction. Examples of acid binders include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal carbonates such as sodium carbonate and potassium carbonate, organic bases such as pyridine, and mixtures thereof. Specifically, when the hydroxyaryl-terminated polydiorganosiloxane (II) or a portion of the dihydric phenol (I) used is added to this reaction stage as a post-added monomer, it is preferable to use 2 equivalents or more of alkali per total mole of the post-added dihydric phenol (I) and hydroxyaryl-terminated polydiorganosiloxane (II) (typically 1 mole corresponds to 2 equivalents).

Polycondensation by interfacial polycondensation reaction between the oligomer of dihydric phenol (I) and the hydroxyaryl-terminated polydiorganosiloxane (II) is carried out by vigorously stirring the above mixture.

In such polymerization reactions, a terminal terminator or molecular weight regulator is typically used. Examples of terminal terminators include compounds with a monovalent phenolic hydroxyl group, such as ordinary phenol, p-tert-butylphenol, p-cumylphenol, and tribromophenol, as well as long-chain alkylphenols, aliphatic carboxylic acid chlorides, aliphatic carboxylic acids, hydroxybenzoic acid alkyl esters, hydroxyphenyl alkyl acid esters, and alkyl ether phenols. The amount used is in the range of 100 to 0.5 mol, preferably 50 to 2 mol, per 100 mol of all dihydric phenol compounds used; it is of course also possible to use two or more compounds in combination.

A catalyst such as a tertiary amine such as triethylamine or a quaternary ammonium salt may be added to promote the polycondensation reaction.

The reaction time for such a polymerization reaction is preferably 30 minutes or more, and more preferably 50 minutes or more. If desired, a small amount of an antioxidant such as sodium sulfite or hydrosulfide may be added.

A branching agent can be used in combination with the above-mentioned dihydric phenol compound to produce a branched polycarbonate-polydiorganosiloxane. Examples of trifunctional or higher polyfunctional aromatic compounds used in such branched polycarbonate-polydiorganosiloxane copolymer resins include phloroglucin, phloroglucside, 4,6-dimethyl-2,4,6-tris(4-hydroxyphenyl)heptene-2,2,4,6-trimethyl-2,4,6-tris(4-hydroxyphenyl)heptane, 1,3,5-tris(4-hydroxyphenyl)benzene, 1,1,1-tris(4-hydroxyphenyl)ethane, 1,1,1-tris(3,5-dimethyl-4-hydroxyphenyl)ethane, 2,6-bis(2-hydroxy-5-methylbenzyl)-4-methylphenol, 4-[4-[1 ,1-bis(4-hydroxyphenyl)ethyl]benzene}-α,α-dimethylbenzylphenol, trisphenols such as tetra(4-hydroxyphenyl)methane, bis(2,4-dihydroxyphenyl)ketone, 1,4-bis(4,4-dihydroxytriphenylmethyl)benzene, trimellitic acid, pyromellitic acid, benzophenonetetracarboxylic acid, and acid chlorides thereof. Among these, 1,1,1-tris(4-hydroxyphenyl)ethane and 1,1,1-tris(3,5-dimethyl-4-hydroxyphenyl)ethane are preferred, and 1,1,1-tris(4-hydroxyphenyl)ethane is particularly preferred. The proportion of the polyfunctional compound in the branched polycarbonate-polydiorganosiloxane copolymer resin is preferably 0.001 to 1 mol %, more preferably 0.005 to 0.9 mol %, even more preferably 0.01 to 0.8 mol %, and particularly preferably 0.05 to 0.4 mol %, based on the total amount of the polycarbonate-polydiorganosiloxane copolymer resin. The amount of branched structure can be calculated by ¹ H-NMR measurement.

The reaction pressure can be reduced, normal, or increased, but is usually best carried out at normal pressure or the inherent pressure of the reaction system. The reaction temperature is selected from the range of -20 to 50°C, and since heat is often generated during polymerization, water or ice cooling is desirable. The reaction time cannot be generally determined as it varies depending on other conditions such as the reaction temperature, but is usually carried out for 0.5 to 10 hours.

In some cases, the obtained polycarbonate-polydiorganosiloxane copolymer resin can be subjected to an appropriate physical treatment (mixing, fractionation, etc.) and/or chemical treatment (polymer reaction, crosslinking treatment, partial decomposition treatment, etc.) to obtain a polycarbonate-polydiorganosiloxane copolymer resin with a desired reduced viscosity [η _SP /c].

The resulting reaction product (crude product) can be subjected to various post-treatments, such as known separation and purification methods, to recover a polycarbonate-polydiorganosiloxane copolymer resin of the desired purity (degree of purification).

The average size of the polydiorganosiloxane domains in polycarbonate-polydiorganosiloxane copolymer resin molded articles is preferably in the range of 1 to 40 nm. Such an average size is more preferably 1 to 30 nm, and even more preferably 5 to 25 nm. Below the lower limit of this preferred range, impact resistance and flame retardancy may not be fully exhibited, while above the upper limit of this preferred range, impact resistance may not be stably exhibited. This provides a resin composition with excellent impact resistance and appearance.

The average domain size of the polydiorganosiloxane domains in the polycarbonate-polydiorganosiloxane copolymer resin molded articles of the present invention was evaluated by small angle X-ray scattering (SAXS). Small angle X-ray scattering is a method for measuring diffuse scattering and diffraction that occur in the small angle region of scattering angles (2θ) less than 10°. In this small angle X-ray scattering method, if there are regions with different electron densities of approximately 1 to 100 nm in a substance, the diffuse scattering of X-rays is measured based on the electron density difference. The particle size of the object to be measured is determined based on the scattering angle and scattering intensity. In the case of polycarbonate-polydiorganosiloxane copolymer resins, which form an aggregate structure in which polydiorganosiloxane domains are dispersed within a polycarbonate polymer matrix, the difference in electron density between the polycarbonate matrix and the polydiorganosiloxane domains causes diffuse scattering of X-rays. The scattering intensity I at each scattering angle (2θ) within a range of scattering angles (2θ) less than 10° is measured to obtain a small-angle X-ray scattering profile. Assuming that the polydiorganosiloxane domains are spherical and that there is variation in particle size distribution, a simulation is performed using commercially available analytical software based on a hypothetical particle size and a hypothetical particle size distribution model to determine the average size of the polydiorganosiloxane domains. Small-angle X-ray scattering allows for accurate, simple, and reproducible measurement of the average size of polydiorganosiloxane domains dispersed within a polycarbonate polymer matrix, which cannot be accurately measured by observation with a transmission electron microscope. The average domain size refers to the number average of the individual domain sizes. The term "average domain size" used in connection with the present invention refers to a measurement obtained by measuring a 1.0 mm thick portion of a three-tiered plate prepared by the method described in the Examples using the small-angle X-ray scattering method. Analysis is performed using an isolated particle model that does not take into account interparticle interactions (interparticle interference).
(Component B: coloring agent)
The coloring agent used as component B in the present invention is a coloring agent containing a coloring agent (component B1) having an absorption maximum at less than 650 nm and a coloring agent (component B2) having an absorption maximum at 650 to 880 nm. The weight ratio of component B1 to component B2 in component B (component B1/component B2) is preferably 2/1 to 40/1, more preferably 2.5/1 to 30/1, and even more preferably 3/1 to 25/1. If the ratio is less than 2/1, sufficient cutoff characteristics may not be obtained at wavelengths of 700 nm or less. If the ratio exceeds 40/1, absorption characteristics may be insufficient at wavelengths of 650 to 880 nm, resulting in an increase in the amount of sunlight entering the sensor as noise, which may adversely affect sensing accuracy.

The colorant can be selected from dyes (organic or inorganic), pigments (organic or inorganic), etc., and is not particularly limited as long as the aromatic polycarbonate resin composition of the present invention can be obtained. Dyes are preferred as they do not cause diffused reflection of light on the particle surface. Examples of dye-based colorants include anthraquinone-based colorants, perinone-based colorants, perylene-based colorants, methine-based colorants, azo-based colorants, quinoline-based colorants, phthalocyanine-based colorants, squarylium-based colorants, and heterocyclic-based colorants. Among these, anthraquinone-based colorants, phthalocyanine-based colorants, perylene-based colorants, and heterocyclic-based colorants, which have high heat resistance, are more preferred.

The content of Component B is 0.055 to 1.3 parts by weight, preferably 0.08 to 1.0 parts by weight, and more preferably 0.1 to 0.5 parts by weight, per 100 parts by weight of Component A. If the content of Component B is less than 0.055 parts by weight, sufficient cutting properties in the 400 to 700 nm range cannot be obtained. On the other hand, if the content exceeds 1.3 parts by weight, the thermal stability of the resin composition deteriorates.
(Component C: Heat stabilizer)
The aromatic polycarbonate resin composition of the present invention contains a phosphorus-based heat stabilizer and/or a phenol-based heat stabilizer. The phosphorus-based heat stabilizer improves thermal stability during production or molding processing, and improves mechanical properties, color, and molding stability. Examples of phosphorus-based heat 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(2,6-di-tert-butylphenyl) phosphite, tris(2,4-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, and diisopropyl phosphate, and preferred are 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 suitable phosphonite compounds 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. Preferred are tetrakis(di-tert-butylphenyl)-biphenylene diphosphonite and bis(di-tert-butylphenyl)-phenyl-phenyl phosphonite. 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 the above-mentioned phosphite compounds having an aryl group substituted with two or more alkyl groups, which is preferred. Examples of suitable phosphonate compounds include dimethyl benzenephosphonate, diethyl benzenephosphonate, and dipropyl benzenephosphonate. 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 above phosphorus-based heat stabilizers can be used alone or in combination of two or more. Among the above phosphorus-based heat stabilizers, it is preferable to incorporate an alkyl phosphate compound, such as trimethyl phosphate. It is also a preferred embodiment to use such an alkyl phosphate compound in combination with a phosphite compound and/or a phosphonite compound.

Phenol-based heat stabilizers are not particularly limited as long as they have antioxidant properties, but examples include n-octadecyl-3-(4'-hydroxy-3',5'-di-t-butylphenyl)propionate, tetrakis{methylene-3-(3',5'-di-t-butyl-4-hydroxyphenyl)propionate}methane, distearyl(4-hydroxy-3-methyl-5-t-butylbenzyl)malonate, triethyleneglycol-bis{3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate}, 1,6-hexanediol-bis{3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate}, pentaerythrityl-tetrakis{3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate}, 2,2-thiodiethyl olefinbis{3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate}, 2,2-thiobis(4-methyl-6-t-butylphenol), 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, 2,4-bis{(octylthio) methyl}-o-cresol, isooctyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,5,7,8-tetramethyl-2(4',8',12'-trimethyltridecyl)chroman-6-ol, 3,3',3",5,5',5"-hexa-t-butyl-a,a',a"-(mesitylene-2,4,6-triyl)tri-p-cresol, and the like.

Among these, n-octadecyl-3-(4'-hydroxy-3',5'-di-t-butylphenyl)propionate, pentaerythrityl-tetrakis{3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate}, 3,3',3",5,5',5"-hexa-t-butyl-a,a',a'-(mesitylene-2,4,6-triyl)tri-p-cresol, 2,2-thiodiethylenebis{3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate}, etc. are preferred.

The content of Component C is 0.003 to 0.5 parts by weight, preferably 0.005 to 0.3 parts by weight, and more preferably 0.01 to 0.2 parts by weight, per 100 parts by weight of Component A. If the content of Component C is less than 0.003 parts by weight, the thermal stability of the resin composition and the thermal stability of the absorption characteristics will also deteriorate. On the other hand, if the content exceeds 0.5 parts by weight, the moist heat resistance of the resin composition will deteriorate.
(Component D: Benzotriazole-based ultraviolet absorber)
The aromatic polycarbonate resin composition of the present invention preferably contains a benzotriazole-based ultraviolet absorber. Examples of the benzotriazole-based ultraviolet absorber include 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-5-chlorobenzotriazole, and 2,2'-methylenebiphenyl. bis[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-octyl Examples of such a polymer include 2-hydroxyphenyl-2H-benzotriazole skeletons, such as 2-(2-hydroxy-5-acryloxyethylphenyl)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, and 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. Furthermore, the ultraviolet absorber may be a polymeric ultraviolet absorber obtained by copolymerizing such an ultraviolet-absorbing monomer and/or a photostable monomer with a monomer such as an alkyl (meth)acrylate by adopting a structure of a radically polymerizable monomer compound. Suitable examples of the ultraviolet-absorbing monomer include compounds containing a benzotriazole skeleton in the ester substituent of a (meth)acrylic acid ester. Among these, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, as typified by TINUVIN 234 (BASF Japan Ltd.), and 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-5-chlorobenzotriazole, as typified by TINUVIN 326 (BASF Japan Ltd.), are more preferred.

The content of Component D is preferably 0.01 to 1 part by weight, more preferably 0.05 to 0.8 parts by weight, and even more preferably 0.1 to 0.5 parts by weight, relative to 100 parts by weight of Component A. If the content of Component D is less than 0.01 part by weight, the light stability of the absorption characteristics may deteriorate, while if it exceeds 1 part by weight, the thermal stability of the resin composition may decrease.
(Other additives)
In order to improve the thermal stability and designability of the aromatic polycarbonate resin composition of the present invention, additives used to improve these properties can be advantageously used. These additives will be specifically described below.
(I) Heat Stabilizers Other Than Component C The aromatic polycarbonate resin composition of the present invention can also contain heat stabilizers other than the phosphorus-based heat stabilizer and phenol-based heat 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 Japanese Patent Application Laid-Open No. 7-233160. This compound is commercially available as Irganox HP-136 (trademark, manufactured by CIBA SPECIALTY CHEMICALS), and this compound can be used. Furthermore, stabilizers containing this compound in combination with various phosphite compounds and hindered phenol compounds are commercially available. A suitable example is Irganox HP-2921 manufactured by the same company. The content of the lactone-based stabilizer is preferably 0.0005 to 0.05 parts by weight, more preferably 0.001 to 0.03 parts by weight, per 100 parts by weight of Component A. Other stabilizers include sulfur-containing stabilizers such as pentaerythritol tetrakis(3-mercaptopropionate), pentaerythritol tetrakis(3-laurylthiopropionate), and glycerol-3-stearylthiopropionate. The content 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 Component A. An epoxy compound can be blended into the polycarbonate resin composition of the present invention as needed. Such epoxy compounds are blended for the purpose of inhibiting mold corrosion, and essentially any compound having an epoxy functional group 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, a copolymer of methyl methacrylate and glycidyl methacrylate, a copolymer of styrene and glycidyl methacrylate, etc. The content of such epoxy compounds 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 Component A.
(II) Mold Release Agent In order to further improve the releasability from a mold during melt molding, the aromatic polycarbonate resin composition of the present invention may contain a mold release agent within a range that does not impair the object of the present invention.

Such release agents include higher fatty acid esters of monohydric or polyhydric alcohols, higher fatty acids, paraffin wax, beeswax, olefin waxes, olefin waxes containing carboxy groups and/or carboxylic anhydride groups, silicone oils, organopolysiloxanes, etc. Preferred higher fatty acid esters are partial or complete esters of monohydric or polyhydric alcohols having 1 to 20 carbon atoms with saturated fatty acids having 10 to 30 carbon atoms. Examples of such partial or complete esters of monohydric or polyhydric alcohols with saturated fatty acids include stearic acid monoglyceride, stearic acid diglyceride, stearic acid triglyceride, stearate monosorbitate, stearyl stearate, behenic acid monoglyceride, behenyl behenate, pentaerythritol monostearate, pentaerythritol tetrastearate, pentaerythritol tetrapelargonate, propylene glycol monostearate, stearyl stearate, palmityl palmitate, butyl stearate, methyl laurate, isopropyl palmitate, biphenyl biphenate, sorbitan monostearate, and 2-ethylhexyl stearate. Among these, stearic acid monoglyceride, stearic acid triglyceride, pentaerythritol tetrastearate, and behenyl behenate are preferred. As the higher fatty acid, saturated fatty acids having 10 to 30 carbon atoms are preferred. Such fatty acids include myristic acid, lauric acid, palmitic acid, stearic acid, and behenic acid.

These release agents may be used alone or in combination of two or more. The content of such release agents is preferably 0.01 to 5 parts by weight per 100 parts by weight of component A.
<Method of producing resin composition>
Any method can be used to produce the polycarbonate resin composition of the present invention. For example, the components and optionally other components can be premixed, followed by melt-kneading and pelletizing. Examples of premixing methods include a Nauta mixer, a V-blender, a Henschel mixer, a mechanochemical device, and an extrusion mixer. Premixing can also be performed using an extrusion granulator or briquetting machine. After premixing, the components are melt-kneaded in a melt mixer, typically a vented twin-screw extruder, and pelletized using a pelletizer or other device. Other examples of melt mixers include a Banbury mixer, a kneading roll, and a thermostatically stirred vessel. A vented twin-screw extruder is preferred. Alternatively, the components and optionally other components can be independently fed to a melt mixer, typically a twin-screw extruder, without premixing.
<About molded products>
The polycarbonate resin composition of the present invention obtained as described above can be injection-molded into various products. Furthermore, it is also possible to directly form sheets, films, profile extrusions, and injection-molded articles from the melt-kneaded resin in an extruder without first passing through pelletization. In such injection molding, molded articles can be obtained using not only conventional molding methods but also injection compression molding, injection press molding, gas-assisted injection molding, foam molding (including supercritical fluid injection), insert molding, in-mold coating molding, adiabatic mold molding, rapid heating and cooling mold molding, two-color molding, sandwich molding, and ultra-high-speed injection molding, depending on the purpose. The advantages of these various molding methods are already widely known. Molding can be performed using either a cold runner system or a hot runner system. The resin composition of the present invention can also be extruded to form various profile extrusions and sheets.

Molded articles made from the resin composition of the present invention must have an average light transmittance in the thickness direction of a 3 mm-thick molded article at 400 to 700 nm of light of 1.5% or less. The average light transmittance is more preferably 1.0% or less, and even more preferably 0.5% or less. If the average light transmittance exceeds 1.5%, the amount of sunlight that becomes noise increases, adversely affecting sensing. There is no particular lower limit for the average light transmittance, but it is preferably 0% or more.

Moreover, for a molded article made from the resin composition of the present invention, the maximum light transmittance in the thickness direction of a molded article molded to a thickness of 3 mm at wavelengths from 400 nm to the wavelength at which the absorption of component B2 is maximum is preferably 5.0% or less, more preferably 3.0% or less, and even more preferably 2.0% or less. If the maximum light transmittance exceeds 5.0%, light near the maximum transmittance may become noise, adversely affecting sensing. There is no particular lower limit for the maximum light transmittance, but it is preferably 0% or more.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" are parts by weight. Evaluations were carried out by the following methods.
[Evaluation of Resin Composition]
1. Average value of light transmittance in the range of 400 to 700 nm For a continuously molded product produced by the method described below, the spectral light transmittance was measured in the range of 300 to 2500 nm using an ultraviolet-visible-near-infrared spectrophotometer (V-770 manufactured by JASCO Corporation). From the obtained spectral spectrum, the average value of the light transmittance in the range of 400 to 700 nm was calculated.
2. Maximum light transmittance at wavelengths from 400 nm to the maximum absorption wavelength of component B2 The spectral light transmittance was measured in the same manner as in "1. Average light transmittance at wavelengths from 400 nm to 700 nm." From the obtained spectrum, the maximum light transmittance at wavelengths from 400 nm to the maximum absorption wavelength of component B2 was read.
3. Thermal stability of absorption characteristics The spectral light transmittance of continuous molded products was measured using the same method as in "1. Average light transmittance in the 400-700 nm range." The obtained spectrum was scanned from a wavelength of 1100 nm toward lower wavelengths, and the wavelength at which transmittance first reached 80% or less (transmission wavelength λt) was read. The transmission wavelength λtr of retention molded products was also read using the same method. λtr-λt = 0-5 was evaluated as ◎, 6-10 as ○, 11-20 as △, and 21 or more as ×.
4. Light stability of absorption characteristics The transmission wavelength λtx was measured for the light-exposed product using the same method as in "1. Average light transmittance in the 400 to 700 nm range." When |λtx - λt| was 0 to 5, it was evaluated as ◎, when it was 6 to 10, it was evaluated as ○, when it was 11 to 20, it was evaluated as △, and when it was 21 or more, it was evaluated as ×.
5. Thermal stability of resin composition (viscosity average molecular weight)
The viscosity average molecular weight (M ₀ ) of the continuous molded product and the viscosity average molecular weight (M ₁ ) of the retention molded product were measured by the following method. Cases where M ₀ -M ₁ <1,000 was satisfied were marked with ◯, and cases where this was not satisfied were marked with ×.

The viscosity average molecular weight (M) was determined by first determining the specific viscosity (η _SP ) calculated by the following formula using an Ostwald viscometer from a solution prepared by dissolving 0.7 g of a molded product obtained by the following method in 100 ml of methylene chloride at 20°C.
Specific viscosity (η _SP )=(t−t ₀ )/t ₀
[ _t0 is the number of seconds for methylene chloride to fall, and t is the number of seconds for the sample solution to fall]
The specific viscosity (η _SP ) was calculated from the obtained specific viscosity (η SP ) using the following formula.

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
6. Moisture and heat resistance of resin composition (viscosity average molecular weight)
The viscosity average molecular weight (M ₀ ) of the continuous molded product and the viscosity average molecular weight (M ₂ ) of the moist heat treated product were measured in the same manner as in "5. Thermal stability of resin composition." Cases where M ₀ - M ₂ < 1,000 was satisfied were marked with ○, and cases where this was not satisfied were marked with ×.
[Examples 1 to 41, Comparative Examples 1 to 4]
[Preparation of resin pellets]
Based on the components and amounts shown in Tables 1 to 4, various components were mixed using a tumbler and melt-kneaded at a cylinder temperature of 280°C using a twin-screw extruder (TEX30α, manufactured by The Japan Steel Works, Ltd.) to obtain various pellets. The components used are as follows:
[Production of molded products by injection molding]
The pellets obtained by the above method were dried in a hot air circulation dryer at 120°C for 5 hours, and then molded into 3 mm thick plate-shaped test pieces using an injection molding machine (ROBOSHOT α-S100iA, manufactured by FANUC Corporation) under conditions of a cylinder temperature of 340°C and a mold temperature of 80°C. Molding was performed continuously, and injection was stopped for 10 minutes while resin was present in the cylinder, and then molding was performed again. Products molded continuously without stopping injection midway were designated continuous molded products, and products molded after injection was stopped for 10 minutes while resin was present in the cylinder were designated retention molded products.
[Light exposure treatment of molded products]
The continuous molded product obtained by the above method was subjected to light exposure treatment for 1000 hours using a xenon weather meter (NX75Z, Suga Test Instruments Co., Ltd.) under conditions of a black panel temperature of 63°C, a tank temperature of 50°C, a relative humidity of 50%, and an irradiation intensity of 0.35 W/ ^m2 (@340 nm). The molded product was designated as a light-exposed product.
[Moist heat treatment of molded products]
The continuous molded product obtained by the above method was subjected to a moist heat treatment for 1000 hours under conditions of a temperature of 80°C and a humidity of 85% using a thermo-hygrostat (PR-3J, manufactured by Espec Corporation). The resulting molded product was designated as a moist heat-treated product.
(Component A)
A-1: Panlite L-1225WX (viscosity average molecular weight: 19,700) manufactured by Teijin Limited
A-2: Panlite L-1225WP (viscosity average molecular weight: 22,400) manufactured by Teijin Limited
A-3: Polycarbonate resin produced by the following method: A reactor equipped with a thermometer, a stirrer, and a reflux condenser was charged with 3,844 parts of a 48% aqueous sodium hydroxide solution and 22,380 parts of ion-exchanged water, and 1,992 parts of 2,2-bis(4-hydroxy-3-methylphenyl)propane (Bis-C, manufactured by Honshu Chemical Industry Co., Ltd.), 1,773 parts of 2,2-bis(4-hydroxyphenyl)propane (Bis-A, manufactured by Nippon Steel Chemical Co., Ltd.), and 7.53 parts of hydrosulfite (manufactured by Wako Pure Chemical Industries, Ltd.) were dissolved therein. Then, 13,210 parts of methylene chloride was added, and 2,000 parts of phosgene was blown in over approximately 60 minutes at 15 to 25°C with stirring. After the phosgene injection was completed, 640 parts of a 48% aqueous solution of sodium hydroxide and 93.2 parts of p-tert-butylphenol were added, and stirring was resumed. After emulsification, 3.24 parts of triethylamine was added, and the mixture was stirred at 28 to 33°C for an additional 1 hour to terminate the reaction. 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. Further washing with water was repeated until the conductivity of the aqueous phase was approximately the same as that of ion-exchanged water, yielding a methylene chloride solution of polycarbonate resin. This solution was then passed through a filter with a 0.3 μm mesh and added dropwise to warm water in a kneader equipped with an isolation chamber and a foreign matter outlet in the bearing section. The polycarbonate resin was flaked while the methylene chloride was distilled off. The liquid-impregnated flakes were subsequently pulverized and dried to obtain a powder. The viscosity-average molecular weight was 20,000.
(B1 component)
B1-1: NUBIAN BLACK PC-5857 (Orient Chemical Industries Co., Ltd., maximum absorption wavelength 599 nm)
(B2 component)
B2-1: Phthalocyanine colorant FDR-004 (Yamada Chemical Co., Ltd., maximum absorption wavelength 720 nm)
B2-2: Anthraquinone colorant SDO-7 (Arimoto Chemical Industry Co., Ltd., maximum absorption wavelength 676 nm)
B2-3: Anthraquinone colorant SDO-11 (Arimoto Chemical Industry Co., Ltd., maximum absorption wavelength 761 nm)
B2-4: Heterocyclic colorant SDO-C33 (Arimoto Chemical Industry Co., Ltd., maximum absorption wavelength 847 nm)
B2-5: Perylene-based colorant Lumogen IR-765 (BASF Japan Ltd., maximum absorption wavelength 769 nm)
(C component)
C-1: Phosphorus-based heat stabilizer Adekastab 2112 (ADEKA Corporation)
C-2: Phenolic heat stabilizer AO-50 (ADEKA Corporation)
(D component)
D-1: Benzotriazole-based ultraviolet absorber Tinuvin 234 (BASF Japan Ltd.)
D-2: Benzotriazole-based ultraviolet absorber Tinuvin 326 (BASF Japan Ltd.)
D-3: Benzotriazole-based ultraviolet absorber Seesorb 709 (Shipro Chemical Co., Ltd.)
(Other ingredients)
E-1: Unistar H476S (NOF Corporation)
E-2: Rikestar EW-400 (Riken Vitamin Co., Ltd.)
G-1: Phthalocyanine colorant FDN-004 (Yamada Chemical Co., Ltd., maximum absorption wavelength 887 nm)

All of the examples listed in Tables 1 to 4 have excellent thermal stability and humidity and heat resistance, and have wavelength-selective absorption properties, making them compatible with the various infrared light sources used in infrared sensors in autonomous driving systems. Furthermore, the results showed excellent thermal and light stability of the absorption properties.

For component B, when the content was less than the lower limit, the average light transmittance at 400 nm to 700 nm exceeded 1.5%, and the maximum light transmittance at 400 nm to the absorption maximum wavelength of component B2 exceeded 5.0%. When the content exceeded the upper limit, the thermal stability of the resin composition deteriorated. For component C, when the content was less than the lower limit, the thermal stability of the absorption characteristics was poor, and when the content exceeded the upper limit, the moist heat resistance of the resin composition was poor.

Claims (7)

(A) A resin composition comprising 100 parts by weight of aromatic polycarbonate resin (Component A), (B) 0.055 to 1.3 parts by weight of a colorant (Component B) containing (B1) a colorant (Component B1) having an absorption maximum at less than 650 nm and (B2) a colorant (Component B2) having an absorption maximum at 650 to 880 nm, wherein the weight ratio of Component B1 to Component B2 (Component B1/Component B2) is 2.5/1 to 40/1, (C) 0.003 to 0.5 parts by weight of a phosphorus-based heat stabilizer and/or a phenol-based heat stabilizer (Component C), and (D) 0.01 to 1 part by weight of a benzotriazole-based ultraviolet absorber (Component D), and wherein the resin composition has an average light transmittance in the thickness direction of a 3 mm-thick molded article at 400 to 700 nm of 1.5% or less. The resin composition according to claim 1, characterized in that the maximum light transmittance in the thickness direction of a molded article having a thickness of 3 mm is 5.0% or less at wavelengths from 400 nm to the wavelength at which the absorption of component B2 is maximum. The resin composition according to claim 1 or 2, wherein component B2 is at least one colorant selected from the group consisting of anthraquinone-based colorants, phthalocyanine-based colorants, perylene-based colorants, and heterocyclic colorants. 3. The resin composition according to claim 1 , wherein the viscosity average molecular weight of component A is 24,000 or less. A molded article obtained by molding the resin composition according to claim 1 or 2 . The molded article according to claim 5, which is a cover material for covering an infrared sensor. The molded article according to claim 6 is a cover material for covering an infrared sensor used in a driver monitoring system that monitors the driver and in LiDAR for detecting other vehicles and buildings.