Flame-retardant aromatic polycarbonate resin composition and molded articles formed therefrom

Abstract

This invention provides a flame-retardant aromatic polycarbonate resin composition that complies with PFBS and PFAS regulations while simultaneously achieving excellent transparency, flame retardancy, and high temperature and humidity resistance. [Solution] A flame-retardant aromatic polycarbonate resin composition containing (A) 100 parts by mass of a branched aromatic polycarbonate resin (component A) having a branching rate of 0.1 to 2.5 mol%, and (B) 0.01 parts by mass or more and less than 0.3 parts by mass of an organometallic salt compound represented by the following formula (1) (component B). [Formula 1] JPEG2026137199000014.jpg2756 (M represents alkali metals, R 1 (This indicates a hydrocarbon group.)

Description

[Technical Field]

[0001] The present invention relates to a flame-retardant aromatic polycarbonate resin composition and molded articles formed therefrom, and more specifically, to a flame-retardant aromatic polycarbonate resin composition and molded articles formed therefrom that comply with PFBS regulations and PFAS regulations, and that have excellent transparency, flame retardancy, and high temperature and humidity resistance. [Background technology]

[0002] Aromatic polycarbonate resins are widely used in various industrial fields as materials for molded products through simple and highly productive processing methods such as injection molding. In particular, aromatic polycarbonate resins are widely used in applications requiring high transparency, such as various lighting covers and protective covers for transparent displays, taking advantage of their excellent transparency, exemplified by their high light transmittance and extremely low haze. Furthermore, in these applications, flame retardancy in the event of a fire is also a concern, and there is a demand for resin compositions that possess advanced flame retardancy in addition to the above-mentioned properties.

[0003] Conventionally, halogen-based flame retardants have been used to impart flame retardancy to polycarbonate resins. In recent years, phosphorus-based flame retardants, organic sulfonic acid metal salt flame retardants, and silicone compounds have been used. Among the various flame retardants, alkali (earth) metal salts of perfluoroalkyl sulfonates have been extensively studied due to their high flame retardancy. (Patent Documents 1 and 2)

[0004] However, in recent years, fluorine compounds have become subject to international regulations, primarily in Japan, Europe, and the United States, and there are moves to further strengthen these regulations. It is even predicted that regulations will be tightened and their use will be banned in a few years, so there is a strong demand for polycarbonate resin compositions that exhibit excellent flame retardancy without relying on fluorine compounds. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Special Publication No. 47-40445 [Patent Document 2] Japanese Patent Publication No. 2011-84670 [Overview of the project] [Problems that the invention aims to solve]

[0006] Potassium 3-(phenylsulfonyl)benzenesulfonate and 3,3'-sulfonylbis(potassium benzenesulfonate), which have been extensively studied as organic sulfonic acid metal salt-based flame retardants that do not contain fluorine atoms, can achieve V0 flame retardancy in UL-94 tests by increasing the amount added. However, it has been found that they have issues with heat resistance to moisture at high temperatures.

[0007] The object of the present invention is to provide a flame-retardant aromatic polycarbonate resin composition that complies with PFBS and PFAS regulations and achieves excellent transparency, flame retardancy, and high temperature and humidity resistance. [Means for solving the problem]

[0008] The inventors of this invention conducted extensive research to achieve this objective and, as a result, discovered that the above problem can be solved by combining a branched aromatic polycarbonate resin with a non-fluorine-based organic alkali metal salt having a specific structure, thus completing the present invention. That is, the present invention is as follows.

[0009] 1. A flame-retardant aromatic polycarbonate resin composition containing (A) 0.01 parts by mass or more and less than 0.3 parts by mass of an organometallic salt compound represented by the following formula (1) per 100 parts by mass of a branched aromatic polycarbonate resin (component A) having a branching rate of 0.1 to 2.5 mol%, and (B) an organometallic salt compound represented by the following formula (1) (component B). [ka] (M represents alkali metals, R 1 (This indicates a hydrocarbon group.) 2. The flame-retardant aromatic polycarbonate resin composition according to item 1 above, wherein the branched aromatic polycarbonate resin of component A contains a branched structure derived from a compound represented by the following formula (2).

Chemical formula

Chemical formula

Advantages of the Invention

[0010] The flame-retardant aromatic polycarbonate resin composition of the present invention is a resin composition in which a non-fluorine-based organic alkali metal salt having a specific structure is blended with a branched aromatic polycarbonate resin. By limiting the structure and blending amount of the organic alkali metal salt within a specific range, it has excellent flame retardancy while maintaining transparency and high-temperature moisture and heat resistance. These technologies are not available in conventional flame-retardant technologies. The flame-retardant aromatic polycarbonate resin composition of the present invention can impart high transparency, flame retardancy, and high-temperature moisture and heat resistance without using fluorine compounds, which are expected to be more strictly regulated in the future. It is extremely useful for various industrial applications such as the OA equipment field and the electric and electronic equipment field, and the industrial effect it exhibits is extremely large.

Modes for Carrying Out the Invention

[0011] The present invention will be described in more detail.

[0012] <Component A: Branched Aromatic Polycarbonate Resin> In the branched aromatic polycarbonate resin having a branched structure in the present invention, the branching ratio (X) is 0.1 to 2.5 mol%. Preferably it is 0.2 to 1.5 mol%, more preferably 0.5 to 1.3 mol%, and even more preferably 0.7 to 1.2 mol%. The branching ratio (X) means the number of moles of the structural unit derived from the branching agent with respect to the total number of moles of the structural units derived from the divalent phenol used in the production contained in the whole resin (represented by {the number of moles of the structural unit derived from the branching agent / the total number of moles of the structural units derived from the divalent phenol} × 100 mol%). When the branching ratio is less than the above lower limit, satisfactory branching characteristics cannot be obtained and the melt tension is too low, making it difficult to exhibit the flame retardancy, particularly the drip prevention property, of the resulting resin composition. Further, extrusion molding and blow molding become difficult, which is not preferable. Also, when the branching ratio is higher than the above upper limit, the polymer crosslinks, gels are generated, and the impact resistance of the polymer decreases. Incidentally, such a ratio 1 can be calculated by 1H-NMR measurement.

[0013] In the branched aromatic polycarbonate resin having a branched structure in the present invention, the total amount of N (nitrogen) in the branched aromatic polycarbonate resin is preferably 0 to 20 ppm, more preferably 0 to 10 ppm. Also, the total amount of Cl (chlorine) is preferably 0 to 200 ppm, more preferably 0 to 150 ppm. When the total amount of N in the branched aromatic polycarbonate resin having a branched structure exceeds the above upper limit or the total amount of Cl exceeds the above upper limit, the thermal stability may decrease.

[0014] The viscosity average molecular weight of the branched aromatic polycarbonate resin having a branched structure of the present invention preferably ranges from 16,000 to 32,000, more preferably from 17,000 to 30,000, and even more preferably from 19,000 to 26,000. When the viscosity average molecular weight exceeds the above upper limit, the melt tension may be high and the moldability may be inferior. When the viscosity average molecular weight is less than the above lower limit, the drip prevention effect when the molded piece is burned becomes insufficient, that is, it becomes difficult to exhibit the excellent flame retardancy of the present invention, and the melt tension may be low, making extrusion molding and blow molding difficult.

[0015] The viscosity-average molecular weight referred to in the present invention is first determined by using an Ostwald viscometer from the specific viscosity calculated by the following formula from a solution prepared by dissolving 0.7 g of a polycarbonate resin in 100 mL of methylene chloride at 20°C. Specific viscosity (η SP ) = (t - t0) / t0 [t0 is the dropping seconds of methylene chloride, t is the dropping seconds of the sample solution] The obtained specific viscosity is inserted into the following formula to determine the viscosity-average molecular weight Mv. 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

[0016] The branched aromatic polycarbonate resin having a branched structure of the present invention is obtained by the reaction of a dihydric phenol, a branching agent, monohydric phenols and phosgene.

[0017] Typical examples of divalent phenols used to obtain the branched aromatic polycarbonate resin having the branched structure of the present invention include 2,2-bis(4-hydroxyphenyl)propane (commonly known as bisphenol A), hydroquinone, resorcinol, 4,4'-biphenol, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, and 1,1-bis(4-hydroxyphenyl) Examples include nyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 2,2-bis(4-hydroxyphenyl)pentane, 4,4'-(p-phenylenediisopropylidene)diphenol, 4,4'-(m-phenylenediisopropylidene)diphenol, 1,1-bis(4-hydroxyphenyl)-4-isopropylcyclohexane, bis(4-hydroxyphenyl)oxide, bis(4-hydroxyphenyl)sulfide, and bis(4-hydroxyphenyl)sulfoxide. These may be used individually or in combination of two or more. Among these, 2,2-bis(4-hydroxyphenyl)propane, i.e., bisphenol A, is preferred.

[0018] Typical examples of trivalent or higher phenols (branching agents) used in the present invention include 1,1,1-tris(4-hydroxyphenyl)ethane, 4,6-dimethyl-2,4,6-tri(4-hydroxyphenyl)heptene-2, 4,6-dimethyl-2,4,6-tri(4-hydroxyphenyl)heptane, 1,3,5-tri(4-hydroxyphenyl)benzene, 2,6-bis(2-hydroxy-5-methylbenzyl)-4-methylphenol, tetra(4-hydroxyphenyl)methane, trisphenol, bis(2,4-dihydroxyphenyl)ketone, phloroglucin, phloroglucid, isanthin bisphenol, 1,4-bis(4,4-dihydroxytriphenylmethyl)benzene, trimellitic acid, pyromellitic acid, etc. These may be used alone or in combination of two or more.

[0019] Among these, the compound represented by the following formula (2) is preferred, and 1,1,1-tris(4-hydroxyphenyl)ethane is particularly preferred.

[0020] [ka] (R in the formula 2 (where represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.)

[0021] The monovalent phenol (end-stopper) used in the production of the branched aromatic polycarbonate resin having the branched structure of the present invention can have any structure and is not particularly limited. Examples include p-tert-butylphenol, p-tert-octylphenol, p-cumylphenol, 4-hydroxybenzophenone, and phenol. These may be used alone or in combination of two or more. Among these, p-tert-butylphenol is preferred.

[0022] In other words, the branched aromatic polycarbonate resin having a branched structure according to the present invention preferably has a branched structure portion derived from 1,1,1-tris(4-hydroxyphenyl)ethane, a linear structure portion excluding the branched structure portion derived from bisphenol A, and a terminal structure derived from p-tert-butylphenol.

[0023] The branched aromatic polycarbonate resin having the branched structure of the present invention is preferably manufactured by the first or second method described below.

[0024] The first manufacturing method involves reacting divalent phenols with phosgene in the presence of a solvent to obtain a polycarbonate oligomer. This oligomer is then reacted with monovalent phenols. Next, the obtained polycarbonate oligomer is reacted with a branching agent, the polycarbonate oligomer is emulsified, and polymerization is carried out under unstirred conditions. The reaction temperature from phosgenation to before emulsification is preferably 10 to 40°C, more preferably 15 to 30°C. The reaction temperature after emulsification is preferably 20 to 50°C, more preferably 30 to 40°C. The polymerization time is preferably 1 to 6 hours, more preferably 2 to 4 hours. The obtained reaction mixture is treated by conventional means such as washing and separation to obtain a branched aromatic polycarbonate resin having the desired branched structure of the present invention.

[0025] The second manufacturing method involves first reacting a divalent phenol with a branching agent and phosgene in the presence of a solvent to obtain a polycarbonate oligomer. This is then reacted with a monovalent phenol. After emulsifying the obtained polycarbonate oligomer, an amount of divalent phenol equal to 1 / 30 to 1 / 200 of the amount of divalent phenol initially reacted, preferably 1 / 40 to 1 / 100, is added, and polymerization is carried out under stirring conditions.

[0026] The reaction temperature from phosgenation to before emulsification is preferably 10 to 40°C, more preferably 15 to 30°C. The reaction temperature after emulsification is preferably 20 to 50°C, more preferably 30 to 40°C. When the polymerization reaction is carried out continuously, the stirring speed in each polymerization tank should be 100 rpm or less, preferably 50 rpm or less, and the high-viscosity emulsion fluid in the polymerization tank should be mixed to the extent that there is little difference in residence time in the direction perpendicular to the direction of fluid flow in a roughly piston flow manner. The polymerization time is preferably 1 to 6 hours, more preferably 2 to 4 hours. The obtained reaction mixture is processed by conventional means such as washing and separation to obtain a branched aromatic polycarbonate resin having the branched structure of the present invention as desired.

[0027] While tertiary amines such as triethylamine, tetra-n-butylammonium bromide, and tetra-n-butylphosphonium bromide can be used as reaction catalysts, these catalysts can react with chloroformate groups to form thermally unstable urethane bonds, or residual catalyst can increase the total nitrogen content in the branched polycarbonate resin. Therefore, the amount of tertiary amine used is preferably 0.2 mol% or less, more preferably 0.1 mol% or less, and even more preferably 0.05 mol% or less, relative to the divalent phenol used. It is particularly preferable to carry out the above reaction without a catalyst.

[0028] Furthermore, in such polymerization reactions, in order to reduce the number of phenolic terminal groups, compounds such as bis(chlorophenyl) carbonate, bis(bromophenyl) carbonate, bis(nitrophenyl) carbonate, bis(phenylphenyl) carbonate, chlorophenylphenyl carbonate, bromophenylphenyl carbonate, nitrophenylphenyl carbonate, phenylphenyl carbonate, methoxycarbonylphenylphenyl carbonate, and ethoxycarbonylphenylphenyl carbonate can be added in the later stages or after the completion of the polycondensation reaction. Among these, 2-chlorophenylphenyl carbonate, 2-methoxycarbonylphenylphenyl carbonate, and 2-ethoxycarbonylphenylphenyl carbonate are preferred, and 2-methoxycarbonylphenylphenyl carbonate is particularly preferred.

[0029] Furthermore, it is preferable to use an inactivator to neutralize the activity of the catalyst in such polymerization reactions. Specific examples of such inactivators include sulfonic acid esters such as benzenesulfonic acid, p-toluenesulfonic acid, methyl benzenesulfonate, ethyl benzenesulfonate, butyl benzenesulfonate, octyl benzenesulfonate, phenyl benzenesulfonate, methyl p-toluenesulfonate, ethyl p-toluenesulfonate, butyl p-toluenesulfonate, octyl p-toluenesulfonate, and phenyl p-toluenesulfonate; as well as trifluoromethanesulfonic acid, naphthalenesulfonic acid, sulfonated polystyrene, methyl acrylate-sulfonated styrene copolymer, dodecylbenzenesulfonate-2-phenyl-2-propyl, dodecylbenzenesulfonate-2-phenyl-2-butyl, tetrabutylphosphonium octylsulfonate, tetrabutylphosphonium decylsulfonate, tetrabutylphosphonium benzenesulfonate, and tetraethyl dodecylbenzenesulfonate. Examples of compounds that can be used include, but are not limited to, phosphonium salts, tetrabutylphosphonium dodecylbenzenesulfonate, tetrahexylphosphonium dodecylbenzenesulfonate, tetraoctylphosphonium dodecylbenzenesulfonate, decylammonium butyl sulfate, decylammonium decyl sulfate, dodecylammonium methyl sulfate, dodecylammonium ethyl sulfate, dodecylmethylammonium methyl sulfate, dodecyldimethylammonium tetradecyl sulfate, tetradecyldimethylammonium methyl sulfate, tetramethylammonium hexyl sulfate, decyltrimethylammonium hexadecyl sulfate, tetrabutylammonium dodecylbenzyl sulfate, tetraethylammonium dodecylbenzyl sulfate, and tetramethylammonium dodecylbenzyl sulfate. Two or more of these compounds can also be used in combination.

[0030] Among the deactivators, phosphonium salt or ammonium salt type deactivators are preferred. The amount of such a deactivator is preferably used at a ratio of 0.5 to 50 mol per 1 mol of the remaining catalyst, and also at a ratio of 0.01 to 500 ppm, more preferably 0.01 to 300 ppm, particularly preferably 0.01 to 100 ppm, based on the branched aromatic polycarbonate resin after polymerization.

[0031] In addition, in order to reduce the total Cl content in the branched aromatic polycarbonate resin having a branched structure, it is necessary to remove chlorinated hydrocarbon solvents such as dichloromethane (methylene chloride), dichloroethane, trichloroethane, tetrachloroethane, pentachloroethane, hexachloroethane, dichloroethylene, chlorobenzene, and dichlorobenzene, which are used as solvents during the reaction. For example, sufficient drying treatment of the branched aromatic polycarbonate resin powder or pellets having a branched structure can be mentioned.

[0032] Also, the branched aromatic polycarbonate resin having a branched structure of the present invention may be mixed with one or more kinds of branched aromatic polycarbonate resins having a branched structure so that the molecular weight satisfies the above-mentioned preferred molecular weight range. In this case, it is of course possible to mix a branched aromatic polycarbonate resin having a branched structure whose viscosity average molecular weight is outside the above-mentioned preferred molecular weight range.

[0033] The branched aromatic polycarbonate resin having a branched structure of the present invention preferably contains substantially no halogen atom. Containing substantially no halogen atom means that it does not contain halogen-substituted dihydric phenols or the like in the molecule, and does not target trace amounts of solvents remaining in the production method of the above-mentioned branched aromatic polycarbonate resin or even carbonate precursors.

[0034] <Component B: Organometallic Salt Compound> The organometallic salt compound used as Component B of the present invention is represented by the following formula (1). [Chemical formula] (M represents alkali metals, R 1 (This indicates a hydrocarbon group.)

[0035] Examples of alkali metals include lithium, sodium, potassium, rubidium, and cesium, preferably lithium, sodium, and potassium, more preferably sodium and potassium, and even more preferably sodium.

[0036] Preferred hydrocarbon groups include alkyl groups, aralkyl groups, alkenyl groups, or aryl groups.

[0037] Examples of alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, and tetradecyl groups. Alkyl groups having 1 to 18 carbon atoms are preferred, alkyl groups having 1 to 12 carbon atoms are more preferred, alkyl groups having 1 to 8 carbon atoms are even more preferred, alkyl groups having 1 to 6 carbon atoms are particularly preferred, and alkyl groups having 1 to 4 carbon atoms are most preferred.

[0038] Examples of aralkyl groups include benzyl groups and phenylethyl groups. Aralkyl groups with 7 to 20 carbon atoms are preferred, aralkyl groups with 7 to 15 carbon atoms are more preferred, and aralkyl groups with 7 to 10 carbon atoms are even more preferred.

[0039] Examples of alkenyl groups include methenyl, ethenyl, propenyl, butenyl, and pentenyl groups. Alkenyl groups with 2 to 10 carbon atoms are preferred, and alkenyl groups with 2 to 6 carbon atoms are more preferred.

[0040] Examples of aryl groups include phenyl groups and naphthyl groups. Aryl groups having 6 to 14 carbon atoms are preferred, and aryl groups having 6 to 10 carbon atoms are more preferred. The aryl group may have substituents in place of the hydrogen atoms. Preferred substituents are alkyl groups having 1 to 8 carbon atoms, more preferably alkyl groups having 1 to 6 carbon atoms, and even more preferably alkyl groups having 1 to 4 carbon atoms.

[0041] Examples of alkoxy groups include methoxy, ethoxy, propoxy, butoxy, and pentoxy groups. Alkoxy groups with 1 to 10 carbon atoms are preferred, and alkoxy groups with 1 to 6 carbon atoms are more preferred.

[0042] In particular, R in equation (1) 1 It is preferable that the following formula (3) is used. [ka] (* in the formula represents a bonding site.)

[0043] Specifically, examples include diphenylphosphinobenzene-3-sulfonate sodium salt, diphenylphosphinobenzene-3-sulfonate potassium salt, diphenylphosphinobenzene-4-sulfonate sodium salt, and diphenylphosphinobenzene-4-sulfonate potassium salt. Among these, diphenylphosphinobenzene-3-sulfonate sodium salt is particularly preferred.

[0044] The amount of component B contained in the resin composition of the present invention is 0.01 parts by mass or more and less than 0.3 parts by mass per 100 parts by mass of branched aromatic polycarbonate resin (component A), preferably 0.02 parts by mass or more and 0.25 parts by mass or less, more preferably 0.03 parts by mass or more and 0.22 parts by mass or less, even more preferably 0.04 parts by mass or more and 0.2 parts by mass or less, particularly preferably 0.05 parts by mass or more and 0.15 parts by mass or less, and most preferably 0.05 parts by mass or more and 0.1 parts by mass or less.

[0045] If the amount of component B is too high, the resin will decompose during molding, which will actually decrease its flame retardancy. If the amount added is too low, the flame retardancy will be insufficient, and the flame retardancy that is the objective of this invention will not be achieved.

[0046] <Other ingredients> The flame-retardant aromatic polycarbonate resin composition of the present invention may be blended with other resins to impart various functions or improve the properties of the molded article; however, the type and amount of other resins should be carefully considered so as not to impair the objectives of the present invention.

[0047] The flame-retardant aromatic polycarbonate resin composition of the present invention may contain additives such as heat stabilizers, plasticizers, light stabilizers, polymerization metal deactivators, flame retardant aids, lubricants, antistatic agents, surfactants, antibacterial agents, antioxidants, ultraviolet absorbers, and mold release agents, as needed, to impart various functions to molded articles and improve their properties.

[0048] (Flame retardant additive: Silicone compound) In the present invention, for example, a silicone compound can be used as a flame retardant aid. The silicone compound is a silicone compound that contains aromatic groups and Si-H groups, and does not contain vinyl groups bonded to silicon atoms.

[0049] In the present invention, when the viscosity of the silicone compound suitably used as a flame retardant additive increases, the dispersion state of the silicone compound deteriorates, and the transparency of the molded article decreases. Therefore, the lower the viscosity, the more advantageous it is in terms of the transparency of the molded article.

[0050] In the present invention, the silicone compound suitably used as a flame retardant is a silicone compound that does not contain vinyl groups bonded to silicon atoms. Silicone compounds containing vinyl groups bonded to silicon atoms tend to result in lower transparency of molded articles when used in combination with organic salts, and also have disadvantages in terms of cost, safety, and quality stability in the manufacture of the silicone compound itself.

[0051] Furthermore, the flame retardancy of the silicone compound is influenced by its dispersion state during the combustion process, and viscosity is one of the factors that determine the dispersion state. This is because if the silicone compound is too volatile during the combustion process, i.e., if the viscosity is too low, the amount of silicone remaining in the system during combustion becomes dilute, making it difficult to form a uniform silicone structure during combustion. Moreover, if the viscosity is low and the volatility is high, it becomes difficult to stably manufacture the silicone compound itself. From this viewpoint, the viscosity at 25°C is preferably 10 to 300 cSt, more preferably 15 to 200 cSt, and even more preferably 20 to 170 cSt.

[0052] The aromatic groups in this silicone compound are bonded to the silicone atoms, enhancing compatibility with polycarbonate resin and contributing to maintaining transparency. This is also advantageous for the formation of a carbonized film during combustion, thus contributing to the flame-retardant effect. Without aromatic groups, it tends to be difficult to achieve transparency in molded products and to obtain high levels of flame retardancy.

[0053] The silicone compound in question is a silicone compound containing Si-H groups. The presence of Si-H groups allows for the formation of a network structure through reactions between silicone compounds or between the resin and the silicone, making it possible to obtain a high degree of flame retardancy.

[0054] Furthermore, it is desirable that the silicone compound having the aromatic group has a refractive index in the range of 1.40 to 1.60 at 25°C. A refractive index in the range of 1.42 to 1.59 is more preferable, and a range of 1.44 to 1.59 is even more preferable. When the refractive index is within the above range, the silicone compound is finely dispersed in the aromatic polycarbonate resin, providing a resin composition with less cloudiness.

[0055] More specifically, a silicone compound containing aromatic groups and Si-H groups, and not containing vinyl groups bonded to silicon atoms (KR-2710, manufactured by Shin-Etsu Chemical Co., Ltd.) is preferred.

[0056] The content of the silicone compound is preferably 0.1 to 7 parts by weight, more preferably 0.1 to 4 parts by weight, even more preferably 0.1 to 2 parts by weight, and particularly preferably 0.1 to 1 part by weight, per 100 parts by weight of the branched aromatic polycarbonate resin (component A). Within this range, the heat resistance of the resin does not decrease, gas generation during processing is reduced, and flame retardancy is excellent.

[0057] <Regarding the manufacture of flame-retardant aromatic polycarbonate resin compositions> Any method can be used to produce the flame-retardant aromatic polycarbonate resin composition of the present invention. For example, one method is to thoroughly mix component A, component B, and other components as needed using pre-mixing means such as a V-type blender, Henschel mixer, mechanochemical device, or extruder, then granulate using an extruder or briquetting machine as needed, and then melt-knead in a melt-kneader such as a vented twin-screw extruder, and then pelletize using equipment such as a pelletizer. Alternatively, one method is to supply component A, component B, and other components as needed independently to a melt-kneader such as a vented twin-screw extruder, to pre-mix component A and a portion of the other components and then supply them to the melt-kneader independently with the remaining components, to dilute and mix other components with water or an organic solvent as needed and then supply to the melt-kneader, or to pre-mix such diluted mixture with other components and then supply to the melt-kneader. If there are liquid components to be blended, a so-called liquid injection device or liquid additive device can be used to supply them to the melt-kneader.

[0058] <Manufacturing of molded products> The flame-retardant aromatic polycarbonate resin composition of the present invention can be used to manufacture various products by injection molding of the pellets to obtain molded articles. In such injection molding, it is possible to manufacture not only using the conventional cold runner molding method but also using a hot runner that enables runnerless molding. Furthermore, in injection molding, in addition to conventional molding methods, gas-assisted injection molding, injection compression molding, ultra-high-speed injection molding, injection press molding, two-color molding, sandwich molding, in-mold coating molding, insert molding, foam molding (including those using supercritical fluids), rapid heating and cooling mold molding, in-mold remelting molding, and molding methods consisting of combinations thereof can be used. Furthermore, the flame-retardant aromatic polycarbonate resin composition of the present invention can also be molded into a product by rotational molding without melt mixing.

[0059] Furthermore, molded articles formed from flame-retardant aromatic polycarbonate resin compositions can undergo various surface treatments. These surface treatments include decorative coating, hard coating, water-repellent / oil-repellent coating, hydrophilic coating, UV-absorbing coating, infrared-absorbing coating, electromagnetic wave-absorbing coating, heat-generating coating, antistatic coating, antistatic coating, conductive coating, and metallizing (plating, chemical vapor deposition (CVD), physical vapor deposition (PVD), thermal spraying, etc.). Articles coated with a transparent conductive layer on a transparent sheet are particularly preferred.

[0060] <Transparency> In the flame-retardant aromatic polycarbonate resin composition of the present invention, it is preferable that the haze (turbidity) of a 2 mm thick molded article formed from the resin composition be less than 5% in order to achieve excellent transparency.

[0061] Furthermore, in the flame-retardant aromatic polycarbonate resin composition of the present invention, it is preferable that the difference in haze (turbidity) before and after steam treatment (a so-called pressure cooker test) of a 2 mm thick molded article formed from the resin composition under conditions of 120°C and 2 atmospheres for 24 hours is less than 15% because this indicates excellent transparency.

[0062] <Flame-retardant> In the flame-retardant aromatic polycarbonate resin composition of the present invention, a molded article with a thickness of 1.6 mm formed from the resin composition can achieve at least V-1 in the UL-94 flame retardancy level. Particularly preferably, V-0 can be achieved. [Examples]

[0063] The present invention will be further described in detail by the following examples, but the present invention is not limited thereto. The evaluation was performed according to the following method. Evaluation Method (1) Transparency of molded products Haze was measured using molded parts (2mm thick) for haze evaluation, employing a color and turbidity simultaneous measuring instrument (COH400, manufactured by Nippon Denshoku Industries Co., Ltd.). A haze value of less than 5% was evaluated as "○", and a value of 5% or more was evaluated as "×".

[0064] (2) High temperature and humidity resistance (transparency after PCT) A molded product (2 mm thick) for haze evaluation was subjected to steam treatment for 24 hours at 120°C and 2 atmospheres using a Yamato Scientific SN-510 steam sterilizer (a so-called pressure cooker test; hereinafter referred to as "PCT"). Subsequently, haze (turbidity) was measured using a color and turbidity simultaneous meter (COH400, manufactured by Nippon Denshoku Industries Co., Ltd.). The change in transparency before and after PCT was calculated according to the following formula. A smaller ΔHaze indicates better high-temperature and humid heat resistance. ΔHaze = (Haze of molded product after PCT treatment measured in (2)) - (Haze of molded product before PCT treatment measured in (1)) For the evaluation of high-temperature and humid heat resistance, a value of "○" was used if ΔHaze was less than 15%, and "×" if it was 15% or more.

[0065] (3) Measurement of branching rate JEOL's JNM-AL400 1 Each repeating unit was measured using 1H-NMR, and the branching rate was calculated.

[0066] (4) Viscosity average molecular weight The specific viscosity (η) is calculated using the following formula. SP The viscosity of the sample was determined using an Ostwald viscometer from a solution prepared by dissolving 0.7 g of the sample in 100 ml of methylene chloride at 20°C. Specific viscosity (η SP ) = (t-t0) / t0 [t0 is the number of seconds for the methylene chloride to fall, and t is the number of seconds for the sample solution to fall.] The viscosity-average molecular weight Mv is calculated by substituting the obtained specific viscosity 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

[0067] (5) Flame retardant A vertical combustion test according to UL standard 94 was conducted on a 1.6 mm thick sample, and its grade was evaluated. If the result did not meet any of the criteria for V-0, V-1, or V-2, it will be indicated as "not V" here.

[0068] [Examples 1-3, Comparative Examples 1-10] A resin composition having the blending ratios described in Table 1 was prepared as follows. The explanations will be made according to the symbols in the following table. Each component in the ratios described in Table 1 and Table 2 was weighed and uniformly mixed, and such a mixture was put into an extruder. As the extruder, a twin-screw extruder with a diameter of 15 mm φ (Technovel KZW15-25MG Co., Ltd.) was used. Strands were extruded under the conditions that the cylinder temperature and the die temperature were 280 °C and the vent suction degree was 3000 Pa, cooled in a water bath, and then strand cut with a pelletizer to be pelletized. The pellets of the obtained resin composition were dried in a hot air circulation dryer at 120 °C for 6 hours, and then a test piece for vertical flame retardancy evaluation and a molded product with a thickness of 2 mm for Haze evaluation were molded by an injection molding machine (JSW J75E3, manufactured by Nippon Steel Works) at a cylinder temperature of 300 °C and a mold temperature of 100 °C.

[0069] In addition, the raw materials and the like used in Table 1 and Table 2 are as follows. (Component A) (PC1 (linear): Linear aromatic polycarbonate resin) Charge 12,544 parts of ion-exchanged water, 5,340 parts of 25% aqueous sodium hydroxide solution, and 0.84 parts of hydrosulfite into a reactor equipped with a thermometer, a stirrer, and a reflux condenser. After dissolving 4,005 parts of bisphenol A (manufactured by Nippon Steel Chemical & Material Co., Ltd.) under stirring, add 12,976 parts of methylene chloride, and blow in 2,000 parts of phosgene over about 60 minutes at 15 - 25°C to carry out a reaction to obtain a polycarbonate oligomer. Add a solution prepared by dissolving 87.0 parts of p-tert-butylphenol in 870 parts of methylene chloride to this reaction mixture, then add 1,405 parts of 25% aqueous sodium hydroxide solution, stir vigorously to achieve high emulsification, and then let it stand at 26 - 35°C for 3 hours to complete the reaction. After the reaction is completed, separate the organic phase, dilute it with methylene chloride, repeat washing with ion-exchanged water, and add hydrochloric acid when the washing liquid becomes neutral. Then, repeat washing with ion-exchanged water until the conductivity of the aqueous phase is almost the same as that of ion-exchanged water to obtain a methylene chloride solution of polycarbonate. Next, drop the obtained methylene chloride solution into warm water maintained at 50 - 80°C to evaporate and remove the solvent, and obtain a powdery solid. Dry the obtained solid at 120°C for 24 hours to obtain a white powdery linear aromatic polycarbonate resin PC1 (linear). The viscosity average molecular weight was 22,500.

[0070] <PC2 (branched): Branched aromatic polycarbonate resin having a branched structure> In a reactor equipped with a thermometer, stirrer, and reflux condenser, 12,381 parts of deionized water, 5,475 parts of 25% sodium hydroxide aqueous solution, and 2,873 parts of hydrosulfite were charged. Under stirring, 4,104 parts of bisphenol A (manufactured by Nippon Steel Chemical & Material Co., Ltd.) were dissolved, and then 13,289 parts of methylene chloride and 1,257 parts of 25% sodium hydroxide aqueous solution were added. Furthermore, a solution prepared by dissolving 0.11 parts of hydrosulfite and 60.6 parts of 1,1,1-tris(4-hydroxyphenyl)ethane (manufactured by Honshu Chemical Co., Ltd.) in a mixture of 182 parts of deionized water and 230.4 parts of 25% sodium hydroxide aqueous solution was added, and then 2,140 parts of phosgene were blown in at 15-25°C over approximately 60 minutes to obtain polycarbonate oligomers. To this reaction mixture, a solution of 140.4 parts p-tert-butylphenol dissolved in 1404 parts methylene chloride was added, followed by 2394 parts methylene chloride and 1104 parts 25% aqueous sodium hydroxide solution. The mixture was vigorously stirred to achieve high emulsification, and then allowed to stand at 26-35°C for 3 hours to complete the reaction. After the reaction was complete, the organic phase was separated, diluted with methylene chloride, and repeatedly washed with deionized water. When the washing solution became neutral, hydrochloric acid was added. Subsequently, the mixture was repeatedly washed with deionized water until the conductivity of the aqueous phase was approximately the same as that of the deionized water, thereby obtaining a polycarbonate methylene chloride solution. Next, the obtained methylene chloride solution was added dropwise to warm water maintained at 50-80°C, and the solvent was evaporated to obtain a powdery solid. The obtained solid was dried at 120°C for 24 hours to obtain a white powdery branched aromatic polycarbonate resin PC2 (branched). The viscosity-average molecular weight was 22,500, and the branching rate was 0.9 mol%.

[0071] (B component) B-1: Diphenylphosphinobenzene-3-sulfonate sodium salt (manufactured by Tokyo Chemical Industry Co., Ltd.) was used. This is indicated as SDS in the table. B-2: A mixture of potassium 3-(phenylsulfonyl)benzenesulfonate and 3,3'-sulfonylbis(potassium benzenesulfonate) (KSS-FR: manufactured by Kinsei Matec Co., Ltd.) was used. In the table, it is abbreviated as KSS.

[0072] Furthermore, B-1 and B-2 have the following chemical structures. [ka] [ka]

[0073] [Table 1]

[0074] [Table 2]

[0075] From the comparison of the examples and comparative examples in Tables 1 and 2, it can be seen that the branched aromatic polycarbonate resin composition of the present invention exhibits excellent high temperature and humidity resistance while maintaining high transparency and flame retardancy. [Industrial applicability]

[0076] The flame-retardant aromatic polycarbonate resin composition of the present invention achieves excellent transparency, flame retardancy, and high-temperature and humid heat resistance simultaneously by using an organometallic salt compound having a specific structure as a flame retardant. These properties are not found in conventional flame-retardant aromatic polycarbonate resins that do not use fluorine compounds. Therefore, the flame-retardant aromatic polycarbonate resin composition of the present invention is extremely useful not only for lighting covers and protective covers for transmissive displays, but also for various industrial applications in fields such as office automation equipment and electrical and electronic equipment, and the industrial effects it provides are extremely significant.

Claims

1. A flame-retardant aromatic polycarbonate resin composition containing (A) 0.01 parts by mass or more and less than 0.3 parts by mass of an organometallic salt compound represented by the following formula (1) per 100 parts by mass of a branched aromatic polycarbonate resin (component A) having a branching rate of 0.1 to 2.5 mol%, and (B) an organometallic salt compound represented by the following formula (1) (component B). 【Chemistry 1】 (M represents alkali metals, R １ (This indicates a hydrocarbon group.)

2. The flame-retardant aromatic polycarbonate resin composition according to claim 1, wherein the branched aromatic polycarbonate resin of component A includes a branched structure derived from a compound represented by the following formula (2). 【Chemistry 2】 (In the formula R ２ (This represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.)

3. R in formula (1) １ The flame-retardant aromatic polycarbonate resin composition according to claim 1, wherein is the following formula (3). 【Transformation 3】 (* in the formula represents a bonding site.)

4. The flame-retardant aromatic polycarbonate resin composition according to claim 1, wherein M in formula (1) is sodium.

5. A molded article formed from the flame-retardant aromatic polycarbonate resin composition described in any one of claims 1 to 4.

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