Flame-retardant aromatic polycarbonate resin composition and molded article formed from same
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- TEIJIN LTD
- Filing Date
- 2026-01-22
- Publication Date
- 2026-08-06
Smart Images
Figure JP2026002028_06082026_PF_FP_ABST
Abstract
Description
Flame-retardant aromatic polycarbonate resin composition and molded articles formed therefrom
[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 have excellent transparency, flame retardancy, and high temperature and moisture resistance.
[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.
[0005] Japanese Patent Publication No. 47-40445, Japanese Patent Publication No. 2011-84670
[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 in UL-94 testing by increasing their additive amount, but it has been found that they have issues with moisture resistance 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 moisture resistance.
[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 having a specific branching ratio with a non-fluorinated organic alkali metal salt having a specific structure in a specific blending ratio, thus completing the present invention. That is, the present invention is as follows.
[0009] 1. 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). (M represents alkali metals, R １ (wherein indicates a hydrocarbon group.) 2. The flame-retardant aromatic polycarbonate resin composition according to item 1, wherein the branched aromatic polycarbonate resin of component A includes a branched structure derived from a compound represented by the following formula (2). (In the formula R ２ (wherein R represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.) 3. Furthermore, the flame-retardant aromatic polycarbonate resin composition according to item 1 or 2 above, comprising 0.1 to 7 parts by mass of (C) a silicone compound containing aromatic groups and Si-H groups and not containing vinyl groups bonded to silicon atoms, per 100 parts by mass of (A) a branched aromatic polycarbonate resin (component A). 4. R in formula (1) above １A flame-retardant aromatic polycarbonate resin composition according to any one of items 1 to 3 above, wherein the formula is (3) below. (* in the formula represents a bonding site.) 5. A flame-retardant polycarbonate aromatic resin composition according to any one of items 1 to 4 above, wherein M in formula (1) is potassium. 6. A flame-retardant aromatic polycarbonate resin composition according to any one of items 1 to 5 above, wherein the resin other than component A is contained in an amount of less than 10.0 parts by mass per 100 parts by mass of component A. 7. A molded article formed from the flame-retardant aromatic polycarbonate resin composition according to any one of items 1 to 6 above.
[0010] The flame-retardant aromatic polycarbonate resin composition of the present invention is a resin composition obtained by blending a branched aromatic polycarbonate resin having a specific branching ratio with a non-fluorinated organic alkali metal salt having a specific structure. By limiting the structure and amount of the organic alkali metal salt to a specific range, it is possible to achieve excellent flame retardancy while maintaining transparency and high temperature and humidity resistance. These technologies are not found in conventional flame retardancy technologies. The flame-retardant aromatic polycarbonate resin composition of the present invention can also be given high flame retardancy and high temperature and humidity resistance without using fluorine compounds, which are expected to be subject to stricter regulations in the future. It is extremely useful for various industrial applications such as office automation equipment and electrical and electronic equipment, and the industrial effects it has are extremely large.
[0011] The present invention will be described in more detail.
[0012] <Component A: Branched Aromatic Polycarbonate Resin> The branched aromatic polycarbonate resin having a branched structure in the present invention has a branching rate (X) of 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 rate (X) means the number of moles of structural units derived from the branching agent relative to the total number of moles of structural units derived from divalent phenol used in the production of the entire resin (expressed as moles of structural units derived from the branching agent / total number of moles of structural units derived from divalent phenol × 100 mol%). If the branching rate is below the above lower limit, satisfactory branching characteristics cannot be obtained, the melt tension is too low, and the flame retardancy, especially the drip prevention properties, of the resulting resin composition will not be easily exhibited, and furthermore, extrusion molding and blow molding will become difficult, which is undesirable. Also, if the branching rate is higher than the above upper limit, the polymer will crosslink, gel will be generated, and the impact resistance of the polymer will decrease. １ It can be calculated by H-NMR measurement.
[0013] The branched aromatic polycarbonate resin having a branched structure in the present invention preferably has a total nitrogen (N) content of 0 to 20 ppm, more preferably 0 to 10 ppm. Furthermore, the total chlorine (Cl) content is preferably 0 to 200 ppm, more preferably 0 to 150 ppm. If the total nitrogen (N) content or the total chlorine (Cl) content in the branched aromatic polycarbonate resin having a branched structure exceeds the above upper limits, the thermal stability may decrease.
[0014] The viscosity-average molecular weight of the branched aromatic polycarbonate resin having the branched structure of the present invention is preferably in the range of 16,000 to 32,000, more preferably in the range of 17,000 to 30,000, and particularly preferably in the range of 19,000 to 26,000. If the molecular weight exceeds the above upper limit, the melt tension may be high and the moldability may be poor, and if the molecular weight is below the above lower limit, the drip prevention effect when the molded piece is burned will be insufficient, that is, the excellent flame retardancy of the present invention may not be exhibited, and the melt tension will be low, which may make 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 - t ０ ) / t ０ [t ０ is the dropping seconds of methylene chloride, t is the dropping seconds of the sample solution] The determined 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 Mv 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. Typical examples of the dihydric phenol used to obtain the branched aromatic polycarbonate resin having a 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, 1,1-bis(4-hydroxyphenyl)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, bis(4-hydroxyphenyl)sulfoxide, and the like. These may be used alone or in combination of two or more. Among them, 2,2-bis(4-hydroxyphenyl)propane, that is, bisphenol A is preferred.
[0017] 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, isanthine 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. Among these, the compound represented by the following formula (2) is preferred, and 1,1,1-tris(4-hydroxyphenyl)ethane is particularly preferred.
[0018] (In the formula R ２ (This represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.)
[0019] 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.
[0020] 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.
[0021] The branched aromatic polycarbonate resin having the branched structure of the present invention is preferably manufactured by the first or second method described below.
[0022] 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.
[0023] 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.
[0024] 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 in a manner that is roughly piston-flow, with little difference in residence time in the direction perpendicular to the direction of fluid flow. The polymerization time is preferably 1 to 6 hours, more preferably 2 to 4 hours. The obtained reaction mixture can be processed by conventional means such as washing and separation to obtain a branched polycarbonate having the branched structure of the present invention as desired.
[0025] 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.
[0026] 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.
[0027] 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, dodecylbenzenesulfonic acid-2-phenyl-2-propyl, dodecylbenzenesulfonic acid-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.
[0028] Among the deactivators, phosphonium salt or ammonium salt type ones are preferable. The amount of such a deactivator is preferably used at a ratio of 0.5 to 50 mol with respect to 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, with respect to the polycarbonate resin after polymerization.
[0029] 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 used as a solvent during the reaction. For example, it is possible to sufficiently perform the drying treatment of the branched aromatic polycarbonate resin powder or pellets having a branched structure.
[0030] In addition, the branched aromatic polycarbonate resin having a branched structure of the present invention may be mixed with one or more branched aromatic polycarbonate resins having a branched structure so that the molecular weight satisfies the above-mentioned preferable 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 preferable molecular weight range.
[0031] The branched aromatic polycarbonate having a branched structure of the present invention preferably substantially does not contain a halogen atom. Substantially not containing a halogen atom means that it does not contain a halogen-substituted dihydric phenol 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 or even carbonate precursors.
[0032] <B component: Organometallic salt compound> The organometallic salt compound used as the B component of the present invention is a compound represented by the following formula (1), that is, a sulfonylimide compound.
[0033] (M represents an alkali metal, and R １ represents a hydrocarbon group.)
[0034] As the alkali metal, lithium, sodium, potassium, rubidium, and cesium can be mentioned. Lithium, sodium, and potassium are preferable, sodium and potassium are more preferable, and potassium is even more preferable.
[0035] As the hydrocarbon group, an alkyl group, an aralkyl group, an alkenyl group, or an aryl group is preferable.
[0036] Examples of the alkyl group 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, a tetradecyl group, etc. An alkyl group having 1 to 18 carbon atoms is preferable, an alkyl group having 1 to 12 carbon atoms is more preferable, an alkyl group having 1 to 8 carbon atoms is even more preferable, an alkyl group having 1 to 6 carbon atoms is particularly preferable, and an alkyl group having 1 to 4 carbon atoms is most preferable.
[0037] Examples of the aralkyl group include a benzyl group, a phenylethyl group, etc. An aralkyl group having 7 to 20 carbon atoms is preferable, an aralkyl group having 7 to 15 carbon atoms is more preferable, and an aralkyl group having 7 to 10 carbon atoms is even more preferable.
[0038] Examples of the alkenyl group include a methenyl group, an ethenyl group, a propenyl group, a butenyl group, a pentenyl group, etc. An alkenyl group having 2 to 10 carbon atoms is preferable, and an alkenyl group having 2 to 6 carbon atoms is more preferable. <(
[0039] Examples of the aryl group include a phenyl group, a naphthyl group, etc. An aryl group having 6 to 14 carbon atoms is preferable, and an aryl group having 6 to 10 carbon atoms is more preferable. The hydrogen atom of the aryl group can be replaced with a substituent, and as the substituent, an alkyl group having 1 to 8 carbon atoms is preferable, an alkyl group having 1 to 6 carbon atoms is more preferable, and an alkyl group having 1 to 4 carbon atoms is even more preferable.
[0040] Examples of alkoxy groups include methoxy, ethoxy, propoxy, butoxy, and pentoxy groups. Alkoxy groups having 1 to 10 carbon atoms are preferred, and alkoxy groups having 1 to 6 carbon atoms are more preferred. In particular, R in formula (1) １ It is preferable that it is the following formula (3). (* in the formula represents a bonding site.)
[0041] In the resin composition of the present invention, component B has the structure of formula (1), which provides high thermal stability due to the aromatic sulfonamide skeleton, and achieves the effect of preventing decomposition and volatilization even at the processing temperature of the polycarbonate resin. Furthermore, the combination of the sulfonate structure and alkali metal ions promotes the carbonization reaction when the resin is heated, contributing to improved flame retardancy. In addition, the hydrophobicity derived from the hydrocarbon group suppresses hydrolysis and additive migration in a humid and hot environment, improving the heat and humidity resistance of the resin. In particular, when the hydrocarbon group is an aryl group, it has multiple aromatic rings, resulting in good dispersibility in the resin and less likelihood of deterioration of physical properties. Due to the synergistic effect of these properties, this compound effectively imparts both flame retardancy and heat and humidity resistance to polycarbonate resin.
[0042] 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, 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 to 0.15 parts by mass, and most preferably 0.05 parts by mass or more and 0.1 parts by mass or less.
[0043] If the content of component B is too high, the resin will decompose during molding, which will actually decrease its flame retardancy, and in some cases, its transparency in high-temperature and high-humidity environments may be impaired. If the content of component B is too low, the flame retardancy will be insufficient, and the flame retardancy that is the objective of this invention will not be achieved.
[0044] <Component C: Silicone Compound> The silicone compound used as component C of the present invention as needed is a silicone compound that contains aromatic groups and aromatic Si-H groups, and does not contain vinyl groups bonded to silicon atoms.
[0045] When the viscosity of the silicone compound used as component C increases, the dispersion state of the silicone compound deteriorates, reducing the transparency of the molded product. Therefore, the lower the viscosity, the more advantageous it is in terms of the transparency of the molded product.
[0046] The silicone compound used as component C 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 products when used in combination with organic salts, and also have disadvantages in terms of cost, safety, and quality stability during the manufacturing of the silicone compound itself.
[0047] 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.
[0048] The aromatic groups in component C are bonded to 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.
[0049] The silicone compound of component C 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.
[0050] Furthermore, it is desirable that the silicone compound containing the aromatic group of component C has a refractive index in the range of 1.40 to 1.60 at 25°C. More preferably, the refractive index is in the range of 1.42 to 1.59, and most preferably, it is a silicone compound in the range of 1.44 to 1.59. When the refractive index is within the above range, the silicone compound is finely dispersed in the aromatic polycarbonate, providing a resin composition with less cloudiness.
[0051] The content of the silicone compound, which is component C of the present invention, is preferably 0.1 to 7 parts by mass, more preferably 0.1 to 4 parts by mass, even more preferably 0.15 to 2 parts by mass, and particularly preferably 0.2 to 1 part by mass, per 100 parts by mass of the branched aromatic polycarbonate resin (component A). If the content is too high, the heat resistance of the resin may decrease or gas may be easily generated during processing, and if it is too low, flame retardancy may not be exhibited.
[0052] <Other Components> The flame-retardant aromatic polycarbonate resin composition of the present invention may contain other resins besides component A, such as linear polycarbonate resins, in order to impart various functions to the molded article or improve its properties. However, the type and amount of these resins should be carefully considered so as not to impair the objectives of the present invention. The resins other than component A may be present in amounts of less than 10.0 parts by mass, 8.0 parts by mass or less, 6.0 parts by mass or less, 4.0 parts by mass or less, 2.0 parts by mass or less, or 1.0 part by mass or less, per 100 parts by mass of component A.
[0053] 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 retardants, 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.
[0054] <Regarding the production of the resin composition> Any method can be used to produce the flame-retardant aromatic polycarbonate resin composition of the present invention. For example, components A, B, and optionally component C and optionally other components may be thoroughly mixed using pre-mixing means such as a V-type blender, Henschel mixer, mechanochemical device, or extruder, and then granulation may be performed using an extruder or briquetting machine as needed, followed by melt-kneading in a melt-kneader represented by a vented twin-screw extruder, and then pelletization using equipment such as a pelletizer. Alternatively, components A, B, and optionally component C and optionally other components may be supplied independently to a melt-kneader represented by a vented twin-screw extruder, a part of component A and other components may be pre-mixed and then supplied to a melt-kneader with the remaining components, and component C may be diluted and mixed with water or an organic solvent and then supplied to a melt-kneader, or such diluted mixture may be pre-mixed with other components and then supplied to a melt-kneader. Furthermore, if any of the ingredients to be blended are in liquid form, a so-called liquid injection device or liquid additive device can be used to supply them to the melting and mixing machine.
[0055] <Manufacturing of Molded Articles> 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.
[0056] 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. In addition, various surface treatments can be applied to molded products formed from the flame-retardant aromatic polycarbonate resin composition. These surface treatments include decorative coating, hard coating, water-repellent / oil-repellent coating, hydrophilic coating, ultraviolet-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.). Products coated with a transparent conductive layer on a transparent sheet are particularly preferred.
[0057] <Transparency> In the flame-retardant aromatic polycarbonate resin composition of the present invention, it is preferable that no clouding occurs when a molded product with a thickness of 2.0 mm formed from the resin composition is visually inspected. Furthermore, a haze (turbidity) of 15 or less is preferable because it indicates excellent transparency.
[0058] <Flame Retardancy> 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 flame retardancy level of the UL-94 standard. Particularly preferably, V-0 can be achieved.
[0059] 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.
[0060] (Evaluation Method) (i) Transparency of Molded Plates: Molded plates with a thickness of 2.0 mm were formed from each resin composition, and their transparency was visually confirmed. Transparency was evaluated as "A" if transparent, and "B" if cloudiness occurred. (ii) Transparency after PCT Treatment (High Temperature and Humidity Resistance): Molded plates with a thickness of 2.0 mm were formed from each resin composition, and steam treatment was performed for 24 hours under conditions of 120°C and 2 atmospheres using a Yamato Scientific SN-510 steam sterilizer (so-called Pressure Cooker Test: hereinafter referred to as "PCT treatment"). After that, transparency was visually confirmed. Transparency was evaluated as "A" if transparent, and "B" if cloudiness occurred. (iii) Measurement of Branching Rate: JEOL Ltd. JNM-AL400 １ Each repeating unit was measured by H-NMR and the branching rate was calculated. (iv) Viscosity-average molecular weight The specific viscosity (η) is calculated by the following formula. ＳＰ The specific viscosity (η) 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. ＳＰ ) = (t - t ０ ) / t ０ [t ０ [where 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. ＳＰ / c = [η] + 0.45 × [η] ２ c (where [η] is the intrinsic viscosity) [η] = 1.23 × 10 －４ Mv ０．８３ c = 0.7 (v) Flame retardancy A vertical combustion test according to UL standard 94 was performed on a 1.6 mm thick sample to evaluate its rating. If the rating did not meet any of the criteria for V-0, V-1, or V-2, it will be indicated as "not V" here.
[0061] [Examples 1-6, Comparative Examples 1-15] Resin compositions with the blending ratios listed in Table 1 were prepared in the following manner. The explanation will be given according to the symbols in the table below. Each component in the ratios listed in Table 1 was weighed and mixed uniformly, and the mixture was put into an extruder. A twin-screw extruder with a diameter of 15 mmφ (Technovel Co., Ltd. KZW15-25MG) was used as the extruder. The strands were extruded under conditions of cylinder temperature and die temperature of 280°C and vent suction of 3000 Pa, cooled in a water bath, and then the strands were cut with a pelletizer to form pellets. The obtained resin composition pellets were dried in a hot air circulation dryer at 120°C for 6 hours, and then test pieces for vertical flame retardancy evaluation and 2 mm thick molded products for transparency evaluation were molded using an injection molding machine (Japan Steel Works JSW J75E3) at a cylinder temperature of 300°C and a mold temperature of 100°C.
[0062] The raw materials used, as listed in Table 1, are as follows: (Component A) <PC1 (linear): Linear aromatic polycarbonate resin> 12,544 parts of deionized water, 5,340 parts of 25% sodium hydroxide aqueous solution, and 0.84 parts of hydrosulfite were charged into a reactor equipped with a thermometer, stirrer, and reflux condenser. 4,005 parts of bisphenol A (manufactured by Nippon Steel Chemical & Material Co., Ltd.) were dissolved under stirring, and then 12,976 parts of methylene chloride were added. 2,000 parts of phosgene were blown in over approximately 60 minutes at 15-25°C to obtain a polycarbonate oligomer. A solution of 87.0 parts of p-tert-butylphenol dissolved in 870 parts of methylene chloride was added to this reaction mixture, followed by 1,405 parts of 25% sodium hydroxide aqueous solution. The mixture was vigorously stirred to achieve high emulsification, and then allowed to stand for 3 hours at a temperature of 26-35°C 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 solution 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 methylene chloride solution of polycarbonate. Next, the obtained methylene chloride solution was added dropwise to warm water maintained at 50-80°C to evaporate and remove the solvent, obtaining a powdery solid. The obtained solid was dried at 120°C for 24 hours to obtain a white powdery linear polycarbonate resin PC1 (linear). The viscosity-average molecular weight was 22,500.
[0063] <PC2 (branched): Branched aromatic polycarbonate resin with 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 a polycarbonate oligomer. 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% sodium hydroxide aqueous 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%.
[0064] (Component B) B-1: N-(p-tolylsulfonyl)-p-toluenesulfonamide potassium salt (indicated as SAK in Table 1) B-2 (Comparative Example): 3-(phenylsulfonyl)benzenesulfonate potassium and 3,3'-sulfonylbis(benzenesulfonate potassium) (indicated as KSS in Table 1) Note that B-1 and B-2 have the following chemical structures.
[0065]
[0066]
[0067] (Component C) C-1: 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.)
[0068]
[0069]
[0070]
[0071] From the comparison of the examples and comparative examples in Tables 1 to 3, it can be seen that the flame-retardant aromatic polycarbonate resin composition of the present invention exhibits excellent high-temperature and moisture resistance while maintaining high transparency and flame retardancy.
[0072] The flame-retardant aromatic polycarbonate resin composition of the present invention achieves both transparency, flame retardancy, and high-temperature and moisture resistance 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, it is extremely useful not only for lighting covers and protective covers for transparent 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) 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). (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). (In the formula R ２ (This represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.) 3. The flame-retardant aromatic polycarbonate resin composition according to claim 1 or 2, further comprising 0.1 to 7 parts by mass of (C) a silicone compound containing aromatic groups and Si-H groups and not containing vinyl groups bonded to silicon atoms, per 100 parts by mass of (A) a branched aromatic polycarbonate resin (component A).
4. R in formula (1) above １ A flame-retardant aromatic polycarbonate resin composition according to any one of claims 1 to 3, wherein is the following formula (3). (* in the formula represents a bonding site.) 5. The flame-retardant aromatic polycarbonate resin composition according to any one of claims 1 to 4, wherein M in formula (1) is potassium.
6. The flame-retardant aromatic polycarbonate resin composition according to any one of claims 1 to 5, wherein the resin other than component A is contained in an amount of less than 10.0 parts by mass per 100 parts by mass of component A.
7. A molded article formed from the flame-retardant aromatic polycarbonate resin composition described in any one of claims 1 to 6.