Polycarbonate resin composition and molded article comprising the same

Abstract

To provide a polycarbonate resin composition that excels in flame retardancy, low heat build-up, and low smoke emission; and a molded article comprising the same.SOLUTION: A polycarbonate resin composition comprising (A) a carbonate structural unit derived from a dihydric phenol compound and (B) at least one structural unit selected from structural units comprising a fluorene derivative, wherein the content of the structural unit (B) is in the range of 5 to 70 pts. mass per 100 pts. mass of the total structural units. As the structural unit (B), 9,9-bis(4-hydroxy-3,5-dialkylphenyl) fluorene is preferred.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polycarbonate resin composition having excellent flame retardancy, heat generation and smoke generation properties, and to a molded article made from the same. [Background technology]

[0002] Polycarbonate resin has excellent transparency, impact resistance, heat resistance and dimensional stability, making it an engineering plastic that is used in a wide range of fields, including housings for electrical and electronic devices, interior and exterior parts for automobiles, building materials, furniture, musical instruments and miscellaneous goods.

[0003] In recent years, there has been a strong demand for flame-retardant resin materials, particularly in applications such as office automation equipment and home appliances. To meet this demand, numerous flame-retardant studies have been conducted. Traditionally, such polymer alloys typically used a combination of a halogen-based flame retardant containing a bromine atom or the like and a flame-retardant coagent such as antimony trioxide. However, due to concerns about the release of harmful substances during combustion, flame-retardant materials that do not contain halogen-based compounds have been actively investigated. For example, a method of blending triphenyl phosphate and fibril-forming polytetrafluoroethylene with a polymer alloy containing polycarbonate resin (Patent Document 1) and a method of blending a phosphate-based oligomer, which is a condensed phosphate ester (Patent Document 2), have been proposed. Meanwhile, in addition to these basic flame-retardant properties, there has also been an increasing demand for low heat generation and low smoke generation during combustion. Interior materials for aircraft and railway vehicles are required to satisfy all of these properties at a high level.

[0004] To solve these problems, for example, a method has been proposed in which a polyarylate resin, a silicone compound, and a phosphate ester are blended with a polycarbonate resin (Patent Document 3). However, the heat generation properties obtained with this method are not sufficient, and there is no mention of smoke generation properties. Another method has been proposed in which a polycarbonate having a bisphenol C skeleton, a phosphorus-based flame retardant, and a silicone flame retardant are blended with a polycarbonate resin (Patent Document 4). However, the heat generation properties and smoke generation properties obtained with this method are not sufficient, and there is no mention of flame retardancy. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2-32154 [Patent Document 2] Japanese Patent Application Publication No. 2-115262 [Patent Document 3] Patent Publication No. 2021-38298 [Patent Document 4] Patent No. 6285085 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention provides a polycarbonate resin composition that is excellent in flame retardancy, heat generation, and smoke generation, and a molded article made from the same. [Means for solving the problem]

[0007] According to the present invention, the above-mentioned object of the present invention is achieved by the following polycarbonate resin composition and molded article thereof.

[0008] (Configuration 1) A polycarbonate resin composition comprising (A) a carbonate structural unit (A) derived from a dihydric phenol compound and (B) at least one structural unit (B) selected from the structural units represented by the following formulas (1) to (3), wherein the structural unit (B) is contained in an amount of 5 to 70 mass% relative to 100 mass% of all structural units:

[0009] [ka] (In formulas (1) to (3), R 1 ~R 12 represents an alkyl group, W represents the following formula (4), and R 13 ~R 22 represents a hydrogen atom or a methyl group. [ka]

[0010] (Configuration 2) 2. The polycarbonate resin composition according to claim 1, wherein W is a fluorene derivative. (Configuration 3) 3. The polycarbonate resin composition according to claim 1 or 2, further comprising (C) a siloxane structural unit (C), wherein the amount of Si element derived from the siloxane structural unit is 0.3 to 10.0% by mass relative to 100% by mass of all structural units. (Configuration 4) The polycarbonate resin composition according to any one of Configurations 1 to 3, further comprising (D) 5 to 30 mass% of at least one inorganic filler selected from the group consisting of talc, wollastonite, mica, and kaolin, relative to 100 mass% of all structural units. (Configuration 5) A molded article formed from the polycarbonate resin composition according to any one of the first to fourth aspects. [Effects of the Invention]

[0011] The polycarbonate resin composition of the present invention is significantly superior in flame retardancy, heat generation, and smoke generation properties to conventional polycarbonate resin compositions, and is therefore useful in a wide range of applications, including housing equipment, building materials, daily necessities, infrastructure equipment, automobiles, office equipment and cleaners, aviation, and railways, and the industrial effects of the present invention are extremely significant. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be further described in detail below.

[0013] <(A) Carbonate structural unit (A) derived from a dihydric phenol compound> The polycarbonate resin having carbonate structural units derived from the dihydric phenol compound (A) used in the present invention can be obtained by reacting the dihydric phenol compound with a carbonate precursor. Examples of reaction methods include interfacial polycondensation, melt transesterification, solid-phase transesterification of carbonate prepolymers, and ring-opening polymerization of cyclic carbonate compounds. The dihydric phenol compound (A) does not include the structural unit (B), which will be described later.

[0014] Representative examples of the dihydric phenol compound (A) used herein include hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl, bis(4-hydroxyphenyl)methane, bis{(4-hydroxy-3,5-dimethyl)phenyl}methane, 1,1-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 2,2-bis(4-hydroxyphenyl)propane (commonly known as bisphenol A), 2,2-bis{(4-hydroxy-3-methyl)phenyl}propane, 2,2-bis{(3-isopropyl-4-hydroxy)phenyl}propane, 2,2-bis{(4-hydroxy-3-phenyl)phenyl}propane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)-3-methylbutane, 2,2-bis(4-hydroxyphenyl)-3-methylbutane, 2,2-bis(4-hydroxyphenyl)prop ... 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ester, and the like. Examples of the 4,4'-dihydroxydiphenyl ether include 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ester, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ether, and the like. Examples of the 4,4'-dihydroxydiphenyl ether include 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ester, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ether, and the like.

[0015] Among these, polycarbonate homopolymers or polycarbonate copolymers having carbonate structural units derived from at least one dihydric phenol compound selected from the group consisting of bisphenol A, 2,2-bis{(4-hydroxy-3-methyl)phenyl}propane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)-3-methylbutane, 2,2-bis(4-hydroxyphenyl)-3,3-dimethylbutane, 2,2-bis(4-hydroxyphenyl)-4-methylpentane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, and α,α'-bis(4-hydroxyphenyl)-m-diisopropylbenzene are preferred, and those containing carbonate structural units derived from bisphenol A are even more preferred. In particular, polycarbonate homopolymers having carbonate structural units derived from bisphenol A, and polycarbonate copolymers having carbonate structural units derived from bisphenol A, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, and bisphenol A, 2,2-bis{(4-hydroxy-3-methyl)phenyl}propane, or α,α'-bis(4-hydroxyphenyl)-m-diisopropylbenzene are preferably used.

[0016] Carbonyl halides, carbonate esters, haloformates, etc. are used as carbonate precursors, and specific examples include phosgene, diphenyl carbonate, and dihaloformates of dihydric phenols.

[0017] When producing a polycarbonate resin by reacting the dihydric phenol with a carbonate precursor by the interfacial polycondensation method or the melt transesterification method, a catalyst, a terminal terminator, an antioxidant for the dihydric phenol, etc. may be used as necessary. The polycarbonate resin may be a branched polycarbonate resin copolymerized with a trifunctional or higher polyfunctional aromatic compound, or a polyester carbonate resin copolymerized with an aromatic or aliphatic bifunctional carboxylic acid, or a mixture of two or more of the obtained polycarbonate resins.

[0018] The reaction modes of the methods for producing the polycarbonate resin of the present invention, such as interfacial polymerization, melt transesterification, solid-phase transesterification of carbonate prepolymers, and ring-opening polymerization of cyclic carbonate compounds, are well known in various literatures and patent publications.

[0019] If the viscosity average molecular weight of the polycarbonate resin is less than 15,000, cracks may occur during molding, and if it exceeds 25,500, fluidity may deteriorate and molding processability may decrease. Therefore, the viscosity average molecular weight is preferably 15,000 to 25,500, more preferably 15,300 to 25,000, and even more preferably 15,500 to 24,500.

[0020] Two or more polycarbonate resins may be mixed together, and in this case, it is of course possible to mix a polycarbonate resin having a viscosity average molecular weight outside the above range.

[0021] The viscosity average molecular weight referred to in the present invention is the specific viscosity (η) determined from a solution prepared by dissolving 0.7 g of polycarbonate resin in 100 ml of methylene chloride at 20°C. SP ) into the following equation: η SP / c=[η]+0.45×[η] 2 c (where [η] is the intrinsic viscosity) [η]=1.23×10 -4 M 0.83 c=0.7

[0022] <Constituent Unit (B)> The structural unit (B) used in the present invention has at least one structural unit (B) represented by the following formulas (1) to (3).

[0023] [ka] (In formulas (1) to (3), R 1 ~R 12represents an alkyl group, W represents the following formula (4), and R 13 ~R 22 represents a hydrogen atom or a methyl group.

[0024] [ka]

[0025] In the above formulas (1) to (3), R 1 ~R 12 is preferably an alkyl group having 1 to 8 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, further preferably a methyl group or an ethyl group, and particularly preferably a methyl group.

[0026] Preferred specific examples of the structural units represented by the above formulas (1) to (3) include 2,2-bis(4-hydroxy-3,5-dialkylphenyl)propane, 1,1-bis(4-hydroxy-3,5-dialkylphenyl)cyclohexane, and 9,9-bis(4-hydroxy-3,5-dialkylphenyl)fluorene, with 9,9-bis(4-hydroxy-3,5-dialkylphenyl)fluorene being preferred.

[0027] In addition, from the viewpoint of compatibility with polycarbonate resins, it is preferable that the copolymer is a polycarbonate copolymer derived from a dihydric phenol compound and a compound that constitutes the structural unit represented by the above formula (2).

[0028] Examples of the dihydric phenol compound include the same dihydric phenol compounds as those explained in the section <(A) Carbonate structural unit (A) derived from a dihydric phenol compound>, with bisphenol A being particularly preferred.

[0029] In the polycarbonate copolymer obtained from the dihydric phenol compound and the compound constituting the structural unit represented by the formula (2) as raw materials, the proportion of the structural unit represented by the formula (2) is not particularly limited, but is preferably 25 to 90 mol %, more preferably 30 to 85 mol %, and even more preferably 35 to 80 mol %. When the polycarbonate copolymer is used in this range, it has excellent flame retardancy, heat buildup, and smoke generation properties.

[0030] The content of the structural units represented by formulas (1) to (3) used in the present invention is 5 to 70% by mass, preferably 6 to 60% by mass, and more preferably 7 to 50% by mass, relative to 100% by mass of all structural units (carbonate structural units derived from (A) dihydric phenol compounds, structural unit (B) component, and other necessary components).Within the above ranges, sufficient flame retardancy, heat generation, and smoke generation properties are obtained.

[0031] (<(C) Siloxane structural unit>) The siloxane constituent unit (C) used as component (C) of the present invention as needed is not particularly limited as long as it contains an Si component, but from the viewpoint of flame retardancy, it preferably contains a siloxane constituent unit derived from a polyorganosiloxane represented by the following formula (5): Among these, those having an aromatic ring such as a phenyl group in the molecule are preferred, and from the viewpoint of compatibility with polycarbonate resins in particular, polycarbonate copolymers obtained from raw materials of a bisphenol compound and a polyorganosiloxane are preferred.

[0032] [ka]

[0033] In the above formula (5), R 3 , R 4 , R 5 , R 6 , R 7 and R 8 are each independently 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.

[0034] Examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a dodecyl group, etc. Preferred are alkyl groups having 1 to 6 carbon atoms.

[0035] Examples of the substituted or unsubstituted aryl group having 6 to 12 carbon atoms include a phenyl group, a naphthyl group, etc. Examples of the substituent include an alkyl group having 1 to 12 carbon atoms, such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group.

[0036] R 3 , R 4 , R 5 , R 6 , R 7 and R 8 is preferably a phenyl group, a propyl group, an ethyl group, or a methyl group, and more preferably a methyl group.

[0037] R 9 and R 10 are each independently 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.

[0038] Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.

[0039] Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a dodecyl group, etc. Preferred are alkyl groups having 1 to 6 carbon atoms.

[0040] Examples of the alkoxy group having 1 to 10 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentoxy group, a hexoxy group, a heptoxy group, an octoxy group, etc. An alkoxy group having 1 to 6 carbon atoms is preferred.

[0041] R 9 and R 10 is preferably a hydrogen atom, a methoxy group, or an ethoxy group, more preferably a hydrogen atom or a methoxy group, and even more preferably a hydrogen atom.

[0042] p is a natural number, preferably 20 to 100, more preferably 30 to 90, and even more preferably 35 to 70.

[0043] q is 0 or a natural number, preferably 0 to 80, and more preferably 0 to 50.

[0044] The average chain length p+q is preferably a natural number from 20 to 100, more preferably a natural number from 30 to 90, and even more preferably a natural number from 35 to 70. Within the above range, sufficient impact resistance is obtained, and furthermore, the appearance (color unevenness, peeling failure) is improved.

[0045] X is a divalent aliphatic group having 2 to 8 carbon atoms. Examples of the divalent aliphatic group include alkylene groups having 2 to 8 carbon atoms. Examples of the alkylene group include an ethylene group, a trimethylene group, and a tetramethylene group, with a trimethylene group being preferred.

[0046] The polydiorganosiloxane block represented by the above formula (5) is preferably a block derived from an alkenylphenol-terminated polydiorganosiloxane, more preferably a block derived from an allylphenol-terminated polydiorganosiloxane, and even more preferably a block derived from a (2-allylphenol)-terminated polydiorganosiloxane or a (2-methoxy-4-allylphenol)-terminated polydiorganosiloxane. That is, in formula [1], X is a trimethylene group and R 9 and R 10 is a hydrogen atom, or X is a trimethylene group and R 9 and R 10 is preferably a methoxy group.

[0047] The content of Si atoms derived from the siloxane structural units used as needed in the present invention is preferably 0.3 to 10.0 mass%, more preferably 0.7 to 8.0 mass%, and even more preferably 1.0 to 6.0 mass%, based on 100 mass% of all structural units ((A) carbonate structural units derived from a dihydric phenol compound, (B) structural units represented by the above formulas (1) to (3), (C) the total of siloxane structural units and other necessary components). If the content is within the above range, sufficient flame retardancy and moldability may be obtained. When the siloxane structural units are siloxane structural units derived from a polyorganosiloxane represented by the above formula (5), the content is expressed as the mass% of the Si element in the polyorganosiloxane block.

[0048] <Method for producing polycarbonate-polydiorganosiloxane copolymer> <Raw material for polycarbonate-polydiorganosiloxane copolymer> (bisphenol compound component of polycarbonate block) The bisphenol compound used as a raw material for the polycarbonate block is preferably bisphenol (I) represented by the following formula (6).

[0049] [ka]

[0050] (In the above formula (6), R 1 and R 2each independently represents 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 represents a single bond or at least one group selected from the group consisting of groups represented by the following formula (7):

[0051] [ka]

[0052] [In the above formula (7), R 11 ,R 12 ,R 13 ,R 14 ,R 15 ,R 16 ,R 17 and R 18 each independently represents 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 represents 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 multiple groups, they may be the same or different; g is an integer of 1 to 10, and h is an integer of 4 to 7.

[0053] Examples of the bisphenol compound (I) 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 (commonly known as bisphenol A), 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-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'-dihydroxy-3,3'-diphenyldiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-diphenyldiphenyl sulfide, 1,3-bis{2-(4-hydroxyphenyl)propyl}benzene, 1,4-bis{2-(4-hydroxyphenyl)propyl}benzene, 1,Examples include 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.

[0054] Among these, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 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, with 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 1,1-bis(4-hydroxyphenyl)cyclohexane (BPZ), 4,4'-sulfonyldiphenol, and 9,9-bis(4-hydroxy-3-methylphenyl)fluorene being particularly preferred. Among these, 2,2-bis(4-hydroxyphenyl)propane (bisphenol A) is the most suitable due to its excellent strength and durability. These may be used alone or in combination.

[0055] (Dihydroxy compound component of polydiorganosiloxane block) The dihydroxy compound used as the raw material for the polydiorganosiloxane block (A-1) is preferably a polydiorganosiloxane having a specific average chain length, and more preferably a polydiorganosiloxane represented by the hydroxyaryl-terminated polydiorganosiloxane (II) represented by the following formula (8):

[0056] [ka] (In the above formula (8), R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , p, q and X are the same as in formula (5) above.

[0057] In the above formula (8), the average chain length p+q is preferably a natural number between 20 and 100, more preferably between 30 and 90, and even more preferably between 35 and 70. When the average chain length p+q is within the above range, sufficient impact resistance is obtained, and further, the appearance (color unevenness, peeling failure) is improved. Furthermore, to satisfy this specific chain length range, two or more different hydroxyaryl-terminated polydiorganosiloxane (II) raw materials having average chain lengths p+q may be mixed to prepare the polydiorganosiloxane. In this case, it is preferable to use as raw materials a polydiorganosiloxane (B-1) having an average chain length p+q of 1 or more but less than 60 and a polydiorganosiloxane (B-2) having an average chain length p+q of 60 or more but less than 200. The polydiorganosiloxane raw material can be prepared by mixing appropriate hydroxyaryl-terminated polydiorganosiloxane raw materials together, or by premixing polydiorganosiloxane precursors having an appropriate average chain length before the end is hydroxyaryl-modified, followed by hydroxyaryl-terminated modification. The polycarbonate-polydiorganosiloxane copolymer (PC-POS copolymer) obtained by reacting the polydiorganosiloxane raw material with a bisphenol and a polycarbonate precursor has an average chain length p+q of the polydiorganosiloxane blocks, as described above, of preferably 20 to 100, more preferably 30 to 90, and even more preferably 35 to 70. The average chain length p+q is calculated by nuclear magnetic resonance (NMR) measurement.

[0058] The polycarbonate-polydiorganosiloxane copolymer of the present invention can be produced by the following steps. The step is a step of reacting the bisphenol compound (I) represented by the above formula (6) with phosgene in a mixed solution of a water-insoluble organic solvent and an alkaline aqueous solution to prepare a solution containing a carbonate oligomer having a terminal chloroformate group.

[0059] As described above, the method for producing the PC-POS copolymer used in the present invention uses a polydiorganosiloxane having a specific average chain length as a raw material, and the hydroxyaryl-terminated polydiorganosiloxane (II) may be one type or two or more types. Specifically, a raw material is used that is represented by the hydroxyaryl-terminated polydiorganosiloxane (II) represented by the above formula (8) and has an average chain length p+q of 20 to 100. In addition, two or more different types of hydroxyaryl-terminated polydiorganosiloxane (II) raw materials having average chain lengths p+q may be mixed and used to satisfy this specific chain length range. In this case, the polydiorganosiloxane (B-1) having an average chain length p+q of 1 or more but less than 60 and the polydiorganosiloxane (B-2) having an average chain length p+q of 60 or more but less than 200 may be used as raw materials for preparation, or a raw material obtained by pre-mixing polydiorganosiloxane precursors having an appropriate average chain length before the terminals are hydroxyaryl-modified and then modifying the terminals with hydroxyaryl groups may be used. Furthermore, before reacting with the carbonate precursor and bisphenol, the polydiorganosiloxane (B-1) and the polydiorganosiloxane (B-2) may be pre-blended, or may be added to the reaction solution in parallel without pre-blending, or (B-1) and (B-2) may be added to the reaction solution in portions and sequentially reacted with the carbonate precursor and bisphenol. More preferably, the polydiorganosiloxane (B-1) is added to the reaction solution, and then the polydiorganosiloxane (B-2) is added to the reaction solution to react with the carbonate precursor and dihydric phenol. This is desirable from the viewpoint of efficiency and cost effectiveness due to simplification of the production process equipment. The mass ratio of the polydiorganosiloxanes (B-1) and (B-2) used as raw materials is as described above.

[0060] In the interfacial polycondensation method for obtaining the PC-POS copolymer used in the present invention, the amount of the water-insoluble organic solvent per mole of the total amount of the dihydroxy compounds represented by the above formula (6) and the above formula (8) is preferably 8 moles or more and less than 16 moles.

[0061] Here, the total amount of dihydroxy compounds means the total amount of bisphenol and polydiorganosiloxane monomer, which are raw materials for polycarbonate.

[0062] The amount of the insoluble organic solvent is the total amount used up to the point at which the catalyst is added and the polycondensation reaction is initiated, and is the total amount of the amount used in producing the polycarbonate oligomer, the amount used to dissolve the polydiorganosiloxane monomer and the terminal terminator, and the amount added to adjust the emulsified state during the interfacial polycondensation reaction.

[0063] In the interfacial polycondensation method for obtaining the PC-POS copolymer used in the present invention, if the amount of water-insoluble organic solvent per mole of the total amount of dihydroxy compounds represented by formulas (6) and (8) is less than the lower limit, the polymer quality will deteriorate due to poor emulsion during polymerization, and productivity will decrease due to excessively high solution viscosity. If the amount exceeds the upper limit, the poor emulsion state makes it difficult to incorporate polydiorganosiloxane blocks into the copolymer, resulting in poor appearance. Furthermore, the water-insoluble organic solvent may be added immediately after the reaction of the carbonate precursor, bisphenol compound, and polydiorganosiloxane proceeds. Specifically, it is desirable to add at least 2 moles of water-insoluble organic solvent per mole of the total amount of dihydroxy compounds represented by formulas (6) and (8) when the proportion of unreacted polydiorganosiloxane in the reaction solution reaches 10% or less. This ensures sufficient reaction progress while also reducing the risk of precipitation of polymer components due to high concentration.

[0064] Furthermore, other comonomers than the bisphenol compound (I) and the hydroxyaryl-terminated polydiorganosiloxane (II) can be used in combination in an amount of up to 10% by mass based on the total mass of the copolymer, provided that the comonomer does not interfere with the production method of the present invention.

[0065] In the production method of the present invention, a mixed solution containing an oligomer having a terminal chloroformate group is prepared in advance by reacting bisphenol (I) with a carbonate ester-forming compound in a mixed solution of a water-insoluble organic solvent and an alkaline aqueous solution.

[0066] In producing an oligomer of the bisphenol compound (I), the entire amount of the bisphenol compound (I) used in the method of the present invention may be converted into an oligomer at once, or a part of the oligomer may be added as a post-added monomer as a reaction raw material to the interfacial polycondensation reaction in the subsequent stage. The post-added monomer is added to rapidly proceed with the polycondensation reaction in the subsequent stage, 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 out the reaction in a solvent in the presence of an acid binder.

[0067] The proportion of the carbonate ester-forming compound used may be adjusted appropriately in consideration of the stoichiometric ratio (equivalents) of the reaction. When a gaseous carbonate ester-forming compound such as phosgene is used, it is preferable to blow it into the reaction system.

[0068] 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 of these.

[0069] The proportion of the acid binder used may be determined appropriately in consideration of the stoichiometric ratio (equivalents) of the reaction, as described above. Specifically, it is preferable to use 2 equivalents or a slight excess of the acid binder relative to the number of moles of the bisphenol compound (I) used to form the oligomer (usually 1 mole corresponds to 2 equivalents).

[0070] The solvent may be any of various inert solvents used in the production of known polycarbonates, either singly 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.

[0071] The reaction pressure for oligomer formation is not particularly limited and may be normal, elevated, or reduced pressure, but it is usually advantageous to carry out the reaction under normal 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 0.2 to 10 hours. The pH range of the oligomer formation reaction is the same as that of known interfacial reactions, and the pH is always adjusted to 10 or higher.

[0072] In the present invention, after obtaining a mixed solution containing an oligomer of bisphenol compound (I) having terminal chloroformate groups in this manner, the hydroxyaryl-terminated polydiorganosiloxane (II) is added to the bisphenol compound (I) while stirring the mixed solution, and the hydroxyaryl-terminated polydiorganosiloxane (II) and the oligomer are subjected to interfacial polycondensation to obtain a polycarbonate-polydiorganosiloxane copolymer.

[0073] When carrying out the interfacial polycondensation reaction, an acid binder may be added as appropriate, taking into account the stoichiometric ratio (equivalents) of the reaction. Examples of acid binders that can be used 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 bisphenol compound (I) used as described above is added as a post-added monomer to this reaction stage, it is preferable to use 2 equivalents or more of alkali relative to the total number of moles of the post-added bisphenol compound (I) and the hydroxyaryl-terminated polydiorganosiloxane (II) (usually 1 mole corresponds to 2 equivalents).

[0074] The polycondensation by interfacial polycondensation reaction between the oligomer of the bisphenol compound (I) and the hydroxyaryl-terminated polydiorganosiloxane (II) is carried out by vigorously stirring the mixture.

[0075] In such polymerization reactions, a terminal terminator or a molecular weight modifier is usually used. Examples of terminal terminators include compounds having a monovalent phenolic hydroxyl group, such as ordinary phenol, p-tert-butylphenol, p-cumylphenol, tribromophenol, etc., 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 the total dihydric phenol compounds used, and it is of course possible to use two or more compounds in combination.

[0076] To accelerate the polycondensation reaction, a catalyst such as a tertiary amine such as triethylamine or a quaternary ammonium salt may be added.

[0077] The reaction time for this polymerization reaction must be relatively long to reduce unreacted polydiorganosiloxane blocks, preferably 30 minutes or more, more preferably 50 minutes or more. On the other hand, since stirring the reaction solution for a long period of time can cause polymer precipitation, the reaction time is preferably 180 minutes or less, more preferably 90 minutes or less.

[0078] If desired, a small amount of an antioxidant such as sodium sulfite or hydrosulfide may be added.

[0079] The PC-POS copolymer used in the present invention can be converted into a branched polycarbonate by using a branching agent in combination with the above-mentioned dihydroxy compound. 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.

[0080] The reaction pressure can be reduced, normal, or increased, but is usually preferably normal pressure or the inherent pressure of the reaction system. The reaction temperature is selected from the range of -20 to 50°C, and in many cases, water or ice cooling is desirable because heat is generated during polymerization. The reaction time cannot be generally determined because it varies depending on other conditions such as the reaction temperature, but is usually 0.5 to 10 hours.

[0081] In some cases, the obtained polycarbonate copolymer may be subjected to a suitable physical treatment (mixing, fractionation, etc.) and / or chemical treatment (polymer reaction, crosslinking treatment, partial decomposition treatment, etc.) to obtain a desired reduced viscosity [η SP It can also be obtained as a polycarbonate copolymer of [(2-hydroxybenzoyl)-2-propanol / c].

[0082] 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 of the desired purity (degree of purification).

[0083] (Component D: inorganic filler) In the present invention, the inorganic filler preferably used as component D is at least one inorganic filler selected from the group consisting of talc, wollastonite, mica, and kaolin. Inorganic fillers other than these may have poor flame retardancy.

[0084] The content of component D is preferably 5 to 30% by mass, more preferably 10 to 25% by mass, and even more preferably 15 to 20% by mass, relative to 100% by mass of all structural units ((A) carbonate structural units derived from dihydric phenol compounds, (B) structural units represented by the above formulae (1) to (3), and other necessary components). A content of 5% by mass or more provides excellent flame retardancy, while a content of 30% by mass or less provides excellent molding processability.

[0085] (Other additives) The polycarbonate resin composition of the present invention may contain flame retardants, various stabilizers and mold release agents for preventing a decrease in molecular weight during molding and for stabilizing color tone.

[0086] (i) Flame retardants The polycarbonate resin composition of the present invention can be blended with various compounds known as flame retardants. The blending of compounds used as flame retardants not only improves flame retardancy, but also brings about improvements in antistatic properties, fluidity, rigidity, thermal stability, etc., depending on the properties of each compound.

[0087] Examples of such flame retardants include organic metal salt-based flame retardants (e.g., organic alkali (earth) metal sulfonates, metal borate-based flame retardants, and metal stannate-based flame retardants), organic phosphorus-based flame retardants (e.g., monophosphate compounds, phosphate oligomer compounds, phosphonate oligomer compounds, phosphonitrile oligomer compounds, and phosphonic acid amide compounds), silicone-based flame retardants made of silicone compounds, and halogen-based flame retardants (e.g., brominated epoxy resins, brominated polystyrene, brominated polycarbonates (including oligomers), brominated polyacrylates, and chlorinated polyethylene).

[0088] (ii) Stabilizers The polycarbonate resin composition of the present invention may contain various known stabilizers, such as phosphorus-based stabilizers, hindered phenol-based antioxidants, ultraviolet absorbers, and light stabilizers.

[0089] (iii) Mold release agent The polycarbonate resin composition of the present invention can further contain known release agents such as fatty acid esters, polyolefin waxes, silicone compounds, fluorine compounds (such as fluorinated oils typified by polyfluoroalkyl ethers), paraffin wax, and beeswax, in order to improve productivity during molding and the dimensional accuracy of molded articles. The polycarbonate resin composition of the present invention has good fluidity, resulting in good pressure transmission and the production of molded articles with uniform strain. However, in the case of molded articles with complex shapes that have high mold release resistance, there is a risk of deformation of the molded article during mold release. The incorporation of the above-mentioned specific components solves this problem without impairing the properties of the polycarbonate resin composition.

[0090] [Method for producing polycarbonate resin composition] The method for producing the polycarbonate resin composition of the present invention is not particularly limited, and any known method can be used. For example, the components constituting the structural units (A) and (B) above and any other additives are thoroughly mixed using a premixing means such as a V-type blender, a Henschel mixer, a mechanochemical device, or an extrusion mixer, and then the premix is granulated as needed using an extrusion granulator or a briquetting machine, and then the mixture is melt-kneaded in a melt kneader such as a vented twin-screw extruder, and then pelletized using a pelletizer.

[0091] Other examples include a method of independently feeding each component into a melt kneader, such as a vented twin-screw extruder; a method of feeding into a melt kneader using a supercritical fluid; and a method of premixing a portion of each component and then feeding the remaining components into a melt kneader independently. Examples of a method of premixing a portion of each component include a method of premixing components other than component (A) in advance and then mixing them with component (A) or feeding them directly into an extruder. Examples of premixing methods include, when component (A) is in powder form, blending a portion of the powder with the additives to be added to produce a masterbatch of the additives diluted with the powder, and then using this masterbatch. Another example is a method of independently feeding one component into the middle of a melt extruder. If the components to be added are liquid, a so-called liquid injection device or liquid addition device can be used to feed the components into the melt extruder.

[0092] The extruder preferably has a vent that can remove moisture from the raw materials and volatile gases generated from the melt-kneaded resin. A vacuum pump is preferably installed in the vent to efficiently discharge the generated moisture and volatile gases to the outside of the extruder. A screen for removing foreign matter mixed into the extrusion raw materials can also be installed in a zone before the extruder die to remove foreign matter from the resin composition. Examples of such a screen include wire mesh, a screen changer, and a sintered metal plate (such as a disc filter). In addition to twin-screw extruders, examples of melt-kneaders include Banbury mixers, kneading rolls, single-screw extruders, and multi-screw extruders with three or more screws.

[0093] The extruded resin as described above is either directly cut and pelletized, or formed into strands, which are then cut and pelletized using a pelletizer. If it is necessary to reduce the influence of external dust during pelletization, it is preferable to purify the atmosphere around the extruder. Furthermore, in the production of such pellets, various methods already proposed for polycarbonate resins for optical disks can be used to narrow the pellet shape distribution, reduce miscuts, reduce fine powder generated during shipping and handling, and reduce bubbles (vacuum bubbles) generated inside the strands or pellets. These methods can achieve high molding cycle times and reduce the incidence of defects such as silver spots. The pellets can be shaped in a variety of common shapes, including cylindrical, prismatic, and spherical, with cylindrical shapes being preferred. The diameter of the cylinder is preferably 1 to 5 mm, more preferably 1.5 to 4 mm, and even more preferably 2 to 3.3 mm. The length of the cylinder is preferably 1 to 30 mm, more preferably 2 to 5 mm, and even more preferably 2.5 to 3.5 mm.

[0094] The polycarbonate resin composition of the present invention can be used to produce various products by injection molding the pellets produced as described above to obtain molded articles. Such injection molding can be performed not only by conventional molding methods, but also by injection compression molding, injection press molding, gas-assisted injection molding, foam molding (including methods involving the injection of supercritical fluids), insert molding, in-mold coating molding, heat-insulating mold molding, rapid heating and cooling mold molding, two-color molding, sandwich molding, and ultra-high-speed injection molding. Molding can be performed using either a cold runner system or a hot runner system.

[0095] The polycarbonate resin composition of the present invention can also be used in the form of various profile extrusion molded products, sheets, films, etc. by extrusion molding. Sheets and films can also be molded by inflation, calendaring, casting, etc. Furthermore, by subjecting the composition to a specific stretching operation, it can also be molded into heat-shrinkable tubing. The polycarbonate resin composition of the present invention can also be molded into molded articles by rotational molding, blow molding, etc.

[0096] <Characteristic values of resin molded products> (Flame retardant) Flammability tests were conducted using 1.5 mm thick UL test specimens obtained using the method described below in accordance with the UL94 vertical flame test established by the U.S. Underwriters Laboratories, Inc. The results were evaluated and categorized into V-0, V-1, V-2, and not V. The polycarbonate resin composition of the present invention preferably has a rating of V-1 or higher, more preferably V-0 or higher, in the UL94 vertical flame test.

[0097] (pyregenic) The polycarbonate resin composition of the present invention was measured by subjecting the obtained test piece to a cone calorimeter at 50 kW / m 2 When tested under conditions of heater irradiance of 1000 W / m² and ignition on, the maximum average rate of heat emission (MARHE) is preferably 90 kW / m². 2 The smaller the MARHE value, the better, and more preferably 85 kW / m 2 It is more preferable that it is 80 kW / m or less. 2 The following is particularly preferred: 75 kW / m 2 The following is indicated, and most preferably 70 kW / m 2 The following is shown: MARHE is 90kW / m 2 In the following cases, for example, in the European railway standard EN45545-2, it can be applied to components that require a higher level of flame retardancy at the hazard level (HL) set based on escape time and vehicle structure.

[0098] (Smoke-producing) In accordance with ISO5659-2, the above test specimen was cut into a length of 75 mm, width of 75 mm, and thickness of 3 mm, and subjected to 50 kW / m 2 The test was conducted using a flameless method with a heater irradiance of 1000 kJ / s, and the specific optical density Ds(4) was determined 4 minutes after the start of the test, which is an index of smoke generation.

[0099] The smaller the value of Ds(4), the better. In the polycarbonate resin composition of the present invention, it is preferably 200 or less, 180 or less, 170 or less, 160 or less, 150 or less, 140 or less, or 130 or less.

[0100] <Applications of resin molded products> The resin molded article of the present invention can be used as parts for, for example, automobile-related parts, railway-related parts, aircraft-related parts, household electrical appliance parts, electric / electronic appliance parts, housing equipment parts, office automation equipment parts, play equipment parts, eyeglass parts, etc.

[0101] Examples of railway-related parts include interior walls, heat insulating materials, interior equipment housings, luggage areas, operating surfaces, windows, curtains, tables, seating components, air ducts, and interior displays. Of these, interior walls, tables, and seating are preferred.

[0102] Examples of aircraft-related parts include ceiling interior walls, partitions, galley components, luggage racks, windows, soundproofing materials, air ducts, in-flight displays, and switches, with partitions, luggage racks, windows, and switches being preferred. [Example]

[0103] The present invention will be described in more detail below with reference to examples, but these examples are not intended to limit the scope of the present invention. Unless otherwise specified, parts in the examples are parts by mass and % is mass %. Evaluations were made according to the following methods.

[0104] (Component A) A: Aromatic polycarbonate resin (polycarbonate resin powder with a viscosity-average molecular weight of 23,900, made by a conventional method from bisphenol A and phosgene, Teijin Ltd., product name: Panlite L-1250WP)

[0105] (B component) B-1: Polycarbonate copolymer obtained from bisphenol A and 9,9-bis(4-hydroxy-3,5-methylphenyl)fluorene (referred to as BXF) (bisphenol A:BXF = 30:70 (molar ratio)) (Production method of B-1) A reactor equipped with a thermometer, stirrer, and reflux condenser was charged with 4,554 parts of 48% aqueous sodium hydroxide solution and 22,730 parts of ion-exchanged water, to which 4,345 parts of 9,9-bis(4-hydroxy-3,5-methylphenyl)fluorene (Osaka Gas Chemicals), 1,125 parts of bisphenol A (Nippon Steel Chemical), and 7.94 parts of hydrosulfite (Wako Pure Chemical Industries) were dissolved. 13,415 parts of methylene chloride was added, and 2,000 parts of phosgene was blown in over approximately 70 minutes at 15 to 25°C with stirring. After completion of the phosgene blowing, 650 parts of 48% aqueous sodium hydroxide solution and 92.3 parts of p-tert-butylphenol were added, stirring was resumed, and after emulsification, 5.6 parts of triethylamine was added. The mixture was further stirred at 28 to 35°C for 1 hour to complete the reaction.

[0106] After the reaction was complete, the product was diluted with methylene chloride and washed with water, then hydrochloric acid was added to acidify it and washed with water. Further washing with water was repeated until the conductivity of the aqueous phase was nearly 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 0.3 μm openings and added dropwise to warm water in a kneader 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, and the liquid-containing flakes were subsequently crushed and dried to obtain powder (B-1).

[0107] B-2: Polycarbonate copolymer obtained from bisphenol A and 9,9-bis(4-hydroxy-3,5-ethylphenyl)fluorene (referred to as BZF) (bisphenol A:BZF = 50:50 (molar ratio)) (Production method of B-2) Powder B-2 was obtained in the same manner as in the manufacturing example of B-1, except that 9,9-bis(4-hydroxy-3,5-methylphenyl)fluorene was not used and 2,386 parts of 9,9-bis(4-hydroxy-3,5-ethylphenyl)fluorene and 1,439 parts of bisphenol A were used. B-3: BXF (Osaka Gas Chemicals, 9,9-bis(4-hydroxy-3,5-methylphenyl)fluorene) B-4 (Comparative Example): BCF (Osaka Gas Chemicals, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene) B-5 (Comparative Example): BPF (Osaka Gas Chemicals, 9,9-bis(4-hydroxyphenyl)fluorene)

[0108] (C component) C-1: Polycarbonate copolymer of bisphenol A and polydiorganosiloxane (C-1 manufacturing method) A reactor equipped with a thermometer, a stirrer, and a reflux condenser was charged with 17,890 parts of ion-exchanged water and 7,003 parts of a 25% aqueous sodium hydroxide solution, and 3,812 parts of 2,2-bis(4-hydroxyphenyl)propane (bisphenol A) as the dihydric phenol (I) represented by the general formula (5) and 7.5 parts of hydrosulfite were dissolved therein. Then, 14,310 parts of methylene chloride was added, and 1,900 parts of phosgene was blown in over 70 minutes at 22 to 30°C with stirring. 7150 parts of methylene chloride was added, and a solution of 1347 parts of 25% aqueous sodium hydroxide and 149 parts of p-tert-butylphenol dissolved in 850 parts of methylene chloride was added. While stirring, a solution of 428 parts of KF-2201 (0.55 molar equivalents relative to the total amount of dihydric phenol) dissolved in 800 parts of methylene chloride as dihydric phenol (II) represented by general formula (5) was added at a rate of 0.0008 molar equivalents / min relative to dihydric phenol (I) to emulsify, and then vigorously stirred again. Under such stirring, 4.3 parts of triethylamine was added when the reaction solution was at 26 ° C., and the reaction was continued by stirring at a temperature of 26 to 31 ° C. for 1 hour to complete the reaction. After the reaction was complete, the organic phase was separated, diluted with methylene chloride, washed with water, and then acidified with hydrochloric acid and washed again. When the conductivity of the aqueous phase reached nearly the same level as that of ion-exchanged water, the mixture was placed in a kneader filled with warm water and the methylene chloride was evaporated while stirring to obtain a polycarbonate-polydiorganosiloxane copolymer powder. After dehydration, the mixture was dried at 100°C for 12 hours in a hot air circulating dryer. The resulting polycarbonate-polydiorganosiloxane copolymer had a viscosity-average molecular weight of 16,000 and a Si content of 8.4% by mass in the polydiorganosiloxane blocks. (C-2 manufacturing method) This was prepared in the same manner as in the production method for B-2, except that the amount of 2,2-bis(4-hydroxyphenyl)propane (bisphenol A) was changed to 3,996 parts, the amount of p-tert-butylphenol to 149 parts, and the amount of KF-2201 to 648 parts. The viscosity average molecular weight of the resulting polycarbonate-polydiorganosiloxane copolymer was 20,500, and the Si content of the polydiorganosiloxane blocks was 14.5 mass%.

[0109] (D component) D-1: Victorlite TK-RC, talc (manufactured by Shokozan Mining Co., Ltd.)

[0110] (E component) E-1: Diakarna 30M, modifier (Mitsubishi Chemical Corporation) E-2: KBM3130, modifier (Shin-Etsu Chemical Co., Ltd.)

[0111] [Examples 1 to 11, Comparative Examples 1 to 6] The ingredients shown in Table 1 were mixed in the ratios shown in Table 1, melt-kneaded at 280°C using a twin-screw extruder [TEX30α-3, manufactured by The Japan Steel Works, Ltd.], and pellets were made while degassing through a vacuum vent. Some of the resulting pellets were dried in a hot air circulation dryer at 120°C for 6 hours, and then molded into flat plates and UL test pieces using an injection molding machine at a cylinder temperature of 280°C and a mold temperature of 80°C.

[0112] [Table 1]

[0113] It is clear from Table 1 that the formulation of the present invention makes it possible to provide a polycarbonate resin composition excellent in flame retardancy, heat buildup and smoke generation, and a molded article made from the same. [Industrial Applicability]

[0114] The flame-retardant polycarbonate resin composition of the present invention satisfies the requirements for flame retardancy, heat generation, and smoke generation at a high level, and is therefore useful in a wide range of fields, including housing equipment applications, building materials, daily necessities, infrastructure equipment applications, automobiles, office equipment and cleaning applications, and is particularly useful in outdoor applications where durability is required.

Claims

1. A polycarbonate resin composition comprising (A) a carbonate structural unit (A) derived from a dihydric phenol compound and (B) at least one structural unit (B) selected from the structural units represented by the following formulas (1) to (3), wherein the structural unit (B) is contained in an amount of 5 to 70% by mass relative to 100% by mass of all structural units: 【Chemical 1】 (In formulas (1) to (3), R １ ~R １２ represents an alkyl group, W represents the following formula (4), and R １３ ~R ２２ represents a hydrogen atom or a methyl group.) 【Chemistry 2】

2. 2. The polycarbonate resin composition according to claim 1, wherein W is a fluorene derivative.

3. The polycarbonate resin composition according to claim 1, further comprising (C) a siloxane structural unit (C), wherein the amount of Si element derived from the siloxane structural unit is 0.3 to 10.0 mass% relative to 100 mass% of all structural units.

4. The polycarbonate resin composition according to claim 1, further comprising (D) 5 to 30% by mass of at least one inorganic filler selected from the group consisting of talc, wollastonite, mica, and kaolin, relative to 100% by mass of all structural units.

5. A molded article formed from the polycarbonate resin composition according to any one of claims 1 to 4.

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