Flame-retardant polycarbonate resin composition and molded article made thereof

Abstract

The present invention provides a flame-retardant polycarbonate resin composition and molded articles made therefrom that offer excellent alkali-oil resistance, thin-wall flame retardancy, and impact resistance. [Solution] A flame-retardant polycarbonate resin composition characterized by containing, in 100 parts by weight of a component consisting of (A) 20 to 50 parts by weight of polycarbonate resin (component A) and (B) 80 to 50 parts by weight of polybutylene terephthalate resin (component B), (C) 10 to 25 parts by weight of brominated polycarbonate-based flame retardant (component C), (D) 1 to 5 parts by weight of antimony pentoxide (component D), (E) impact modifier (component E) 1 to 4.5 parts by weight, (F) talc (component F) more than 2 parts by weight and not more than 5 parts by weight, (G) drip inhibitor (component G) 0.1 to 1 part by weight, (H) transesterification reaction inhibitor (component H) 0.01 to 0.5 parts by weight, and (I) glycidyl group-containing compound (component I), satisfying the following formula (1). 0.00001

Description

[Technical Field]

[0001] The present invention relates to a flame-retardant polycarbonate resin composition and molded articles made therefrom, which have excellent alkali-oil resistance, thin-walled flame retardancy, and impact resistance. [Background technology]

[0002] Polycarbonate resin is used in many applications such as machine parts, automotive parts, electrical and electronic components, and office equipment parts due to its excellent mechanical properties, thermal properties, and self-extinguishing properties. However, polycarbonate resin has the disadvantage of being prone to residual stress during molding due to its high melt viscosity and low fluidity during injection molding, and is also prone to cracking when in contact with alkaline chemicals, making it difficult to apply to exterior materials for FA (factory automation) equipment that frequently uses highly corrosive alkaline oils. To solve the above problems, a method of melt-mixing polybutylene terephthalate resin with polycarbonate resin has been disclosed.

[0003] Furthermore, FA equipment exterior materials require not only alkali-oil resistance but also high impact resistance and flame retardancy. However, as with other electrical and electronic components, equipment is becoming thinner and smaller, and achieving flame retardancy becomes more difficult as molded products become thinner. For example, in recent years, the UL94-5VA standard has required flame retardancy at thinner walls. As methods for achieving thin-walled 5VA, resin compositions consisting of polycarbonate resin, polyester resin, phosphorus-based flame retardant, epoxy-modified block copolymer, silicone, silicate compound, fluororesin, and olefin resin have been disclosed (Patent Document 1), and resin compositions consisting of polybutylene terephthalate resin, polycarbonate resin, brominated polycarbonate-based flame retardant, antimony compound, and polyolefin-based mold release agent have been disclosed (Patent Document 2). However, Patent Document 1 has a low polyester resin content, resulting in insufficient alkali-oil resistance, and Patent Document 2 has a 5VA test passing thickness of 3.0 mm, which is insufficient for thin-walled flame retardancy. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2000-53851 [Patent Document 2] Japanese Patent Publication No. 2019-70162 [Overview of the project] [Problems that the invention aims to solve]

[0005] In view of the above, the object of the present invention is to provide a flame-retardant polycarbonate resin composition and a molded article made therefrom that has excellent alkali-oil resistance, thin-wall flame retardancy, and impact resistance. [Means for solving the problem]

[0006] The inventors of the present invention conducted diligent research to solve the above problems and found that by adding polybutylene terephthalate resin, brominated polycarbonate-based flame retardant, antimony pentoxide, impact modifier, talc, drip inhibitor, transesterification reaction inhibitor, and glycidyl group-containing compound to polycarbonate resin, a flame-retardant polycarbonate resin composition with excellent alkali oil resistance, thin-wall flame retardancy, and impact resistance can be obtained, thus completing the present invention.

[0007] According to the present invention, the above problems are solved by the following items 1 to 6. 1. A flame-retardant polycarbonate resin composition characterized by containing, per 100 parts by weight of a component consisting of (A) 20 to 50 parts by weight of polycarbonate resin (component A) and (B) 80 to 50 parts by weight of polybutylene terephthalate resin (component B), (C) 10 to 25 parts by weight of brominated polycarbonate-based flame retardant (component C), (D) 1 to 5 parts by weight of antimony pentoxide (component D), (E) impact modifier (component E) 1 to 4.5 parts by weight of (F) talc (component F) exceeding 2 parts by weight and not exceeding 5 parts by weight, (G) drip inhibitor (component G) 0.1 to 1 part by weight of (H) transesterification reaction inhibitor (component H) 0.01 to 0.5 parts by weight of (I) glycidyl group-containing compound (component I), and satisfying the following formula (1). 0.00001 < Content of Component I (parts by weight) per 100 parts by weight of Component 1 composed of Component A and Component B / Epoxy equivalent of Component I (g / eq) < 0.001 ··· (1) 2. The flame - retardant polycarbonate resin composition according to item 1 above, wherein Component I is at least one compound selected from the group consisting of glycidyl methacrylate copolymers and bisphenol A - type epoxy resins. 3. The flame - retardant polycarbonate resin composition according to item 1 or 2 above, wherein Component E is a graft copolymer obtained by using as a core component one kind of rubber selected from the group consisting of acrylic rubber and silicone - acrylic composite rubber, and graft - polymerizing a (meth) acrylate compound as a shell component. 4. The flame - retardant polycarbonate resin composition according to any one of items 1 to 3 above, wherein Component H is at least one compound selected from the group consisting of phosphite compounds and phosphate compounds. 5. A molded article made of the flame - retardant polycarbonate resin composition according to any one of items 1 to 4 above. 6. The molded article according to item 5 above, which is an outer material for FA equipment.

[0008] Hereinafter, the details of the present invention will be described. (Component A: Polycarbonate resin) The polycarbonate resin used in the present invention is obtained by reacting a divalent phenol with a carbonate precursor. Examples of the reaction method include interfacial polymerization method, melt transesterification method, solid - phase transesterification method of carbonate prepolymer, and ring - opening polymerization method of cyclic carbonate compound, etc.

[0009] Typical examples of divalent phenols used here include hydroquinone, resorcinol, 4,4'-biphenol, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)propane (commonly known as bisphenol A), 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 2,2-bis(4-hydroxyphenyl)pentane, and 4,4'-(p-phenyl Examples include bis(4-hydroxyphenyl)diphenol, 4,4'-(m-phenylenediisopropylidene)diphenol, 1,1-bis(4-hydroxyphenyl)-4-isopropylcyclohexane, bis(4-hydroxyphenyl)oxide, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)sulfoxide, bis(4-hydroxyphenyl)sulfone, bis(4-hydroxyphenyl)ketone, bis(4-hydroxyphenyl)ester, bis(4-hydroxy-3-methylphenyl)sulfide, 9,9-bis(4-hydroxyphenyl)fluorene, and 9,9-bis(4-hydroxy-3-methylphenyl)fluorene. Preferred divalent phenols are bis(4-hydroxyphenyl)alkanes, among which bisphenol A is particularly preferred and widely used in terms of impact resistance.

[0010] In this invention, in addition to bisphenol A-based polycarbonate resins, which are general-purpose polycarbonate resins, it is also possible to use special polycarbonate resins manufactured using other divalent phenols as component A.

[0011] For example, polycarbonate resins (homopolymers or copolymers) using 4,4'-(m-phenylenediisopropylidene)diphenol (sometimes abbreviated as "BPM"), 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (sometimes abbreviated as "Bis-TMC"), 9,9-bis(4-hydroxyphenyl)fluorene, and 9,9-bis(4-hydroxy-3-methylphenyl)fluorene (sometimes abbreviated as "BCF") as some or all of the divalent phenol components are suitable for applications where dimensional changes due to water absorption and morphological stability are particularly demanding. It is preferable to use these divalent phenols other than BPA in an amount of 5 mol% or more, particularly 10 mol% or more, of the total divalent phenol components constituting the polycarbonate resin.

[0012] In particular, when high rigidity and better hydrolysis resistance are required, it is especially preferable that component A constituting the resin composition is one of the copolymer polycarbonate resins (1) to (3) below. (1) A copolymer polycarbonate resin in which, of 100 mol% of the divalent phenol component constituting the polycarbonate resin, BPM is 20 to 80 mol% (more preferably 40 to 75 mol%, even more preferably 45 to 65 mol%) and BCF is 20 to 80 mol% (more preferably 25 to 60 mol%, even more preferably 35 to 55 mol%). (2) A copolymer polycarbonate resin in which, of 100 mol% of the divalent phenol component constituting the polycarbonate resin, BPA is 10 to 95 mol% (more preferably 50 to 90 mol%, even more preferably 60 to 85 mol%) and BCF is 5 to 90 mol% (more preferably 10 to 50 mol%, even more preferably 15 to 40 mol%). (3) A copolymer polycarbonate resin in which, of 100 mol% of the divalent phenol component constituting the polycarbonate resin, BPM is 20 to 80 mol% (more preferably 40 to 75 mol%, even more preferably 45 to 65 mol%) and Bis-TMC is 20 to 80 mol% (more preferably 25 to 60 mol%, even more preferably 35 to 55 mol%).

[0013] These special polycarbonate resins may be used alone or may be appropriately mixed and used in two or more kinds. They can also be used in mixture with the commonly used bisphenol A type polycarbonate resin.

[0014] The manufacturing methods and properties of these special polycarbonate resins are described in detail, for example, in Japanese Patent Application Laid-Open No. 6-172508, Japanese Patent Application Laid-Open No. 8-27370, Japanese Patent Application Laid-Open No. 2001-55435, Japanese Patent Application Laid-Open No. 2002-117580, and the like.

[0015] Among the various polycarbonate resins described above, those in which the copolymer composition and the like are adjusted so that the water absorption rate and Tg (glass transition temperature) are within the following ranges have good hydrolysis resistance of the polymer itself and are also remarkably excellent in the low warpage property after molding, and thus are particularly suitable in the fields where morphological stability is required. (i) A polycarbonate resin having a water absorption rate of 0.05 to 0.15%, preferably 0.06 to 0.13%, and a Tg of 120 to 180°C, or (ii) A polycarbonate resin having a Tg of 160 to 250°C, preferably 170 to 230°C, and a water absorption rate of 0.10 to 0.30%, preferably 0.13 to 0.30%, more preferably 0.14 to 0.27%.

[0016] Here, the water absorption rate of the polycarbonate resin is a value obtained by measuring the moisture content after immersing a disk-shaped test piece having a diameter of 45 mm and a thickness of 3.0 mm in water at 23°C for 24 hours in accordance with ISO62-1980. The Tg (glass transition temperature) is a value obtained by differential scanning calorimeter (DSC) measurement in accordance with JIS K7121.

[0017] As the carbonate precursor, carbonyl halide, carbonic acid diester, haloformate or the like is used, and specifically, phosgene, diphenyl carbonate, dihaloformate of dihydric phenol or the like can be mentioned.

[0018] When producing a polycarbonate resin by the interfacial polymerization method using the above-mentioned dihydric phenol and carbonate precursor, a catalyst, a terminal stopper, an antioxidant for preventing oxidation of the dihydric phenol, etc. may be used as necessary. Further, the polycarbonate resin of the present invention includes a branched polycarbonate resin copolymerized with a polyfunctional aromatic compound having three or more functional groups, a polyester carbonate resin copolymerized with an aromatic or aliphatic (including alicyclic) difunctional carboxylic acid, a copolymerized polycarbonate resin copolymerized with a difunctional alcohol (including alicyclic), and a polyester carbonate resin copolymerized with such a difunctional carboxylic acid and a difunctional alcohol. Further, a mixture obtained by mixing two or more of the obtained polycarbonate resins may also be used.

[0019] Reaction forms such as the interfacial polymerization method, melt transesterification method, carbonate prepolymer solid-phase transesterification method, and ring-opening polymerization method of cyclic carbonate compounds, which are the production methods of the polycarbonate resin of the present invention, are methods well known in various literatures and patent gazettes.

[0020] The viscosity average molecular weight (M) of the polycarbonate resin is not particularly limited, but is preferably 1.8×10 4 ~4.0×10 4 and more preferably 1.9×10 4 ~3.5×10 4 and even more preferably 2.0×10 4 ~3.0×10 4 . In the case of a polycarbonate resin having a viscosity average molecular weight of less than 1.8×10 4 , good mechanical properties may not be obtained. On the other hand, a resin composition obtained from a polycarbonate resin having a viscosity average molecular weight exceeding 4.0×10 4 may be inferior in versatility in terms of inferior fluidity during injection molding.

[0021] The viscosity average molecular weight referred to in the present invention is first determined using an Ostwald viscometer from a solution obtained by dissolving 0.7 g of a polycarbonate resin in 100 ml of methylene chloride at 20°C to obtain the specific viscosity (η SP ), 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 specific viscosity (η) SP The viscosity-average molecular weight M is calculated from the following formula. η SP / c=[η]+0.45×[η] 2 c (where [η] is the intrinsic viscosity) [η] = 1.23 × 10 -4 M 0.83 c = 0.7 Furthermore, the viscosity-average molecular weight of the polycarbonate resin in the flame-retardant polycarbonate resin composition of the present invention is calculated in the following manner. Specifically, the composition is mixed with methylene chloride in an amount 20 to 30 times its weight to dissolve the soluble components in the composition. These soluble components are collected by Celite filtration. The solvent is then removed from the resulting solution. The solid after solvent removal is thoroughly dried to obtain a solid of the components that dissolve in methylene chloride. The specific viscosity at 20°C is determined from a solution obtained by dissolving 0.7 g of this solid in 100 ml of methylene chloride in the same manner as above, and the viscosity-average molecular weight M is calculated from this specific viscosity in the same manner as above.

[0022] A polycarbonate-polydiorganosiloxane copolymer resin can also be used as the polycarbonate resin in this invention. Furthermore, recycled polycarbonate resin, which is made from used products, can also be used as the polycarbonate resin. Preferred used products include various glazing materials such as soundproof walls, automobile windows, translucent roofing materials and automobile sunroofs, transparent components such as windshields and automobile headlamp lenses, containers such as water bottles, light guide plates, eyeglass lenses, and optical recording media. In addition, crushed materials obtained from unsuitable products, sprues, runners, etc., or pellets obtained by melting them can also be used.

[0023] (Component B: Polybutylene terephthalate resin) The resin composition of the present invention contains polybutylene terephthalate resin as component B. Polybutylene terephthalate resin is obtained by polycondensation of terephthalic acid or its ester-forming derivative with a C4 alkylene glycol or its ester-forming derivative. Alternatively, the polybutylene terephthalate resin may be a copolymer containing 70% or more by weight of itself.

[0024] Other dibasic acid components besides terephthalic acid and its lower alcohol esters include aliphatic and aromatic polybasic acids such as isophthalic acid, naphthalenedicarboxylic acid, adipic acid, sebacic acid, trimellitic acid, and succinic acid, or their ester-forming derivatives. Other glycol components besides 1,4-butanediol include ordinary alkylene glycols such as ethylene glycol, diethylene glycol, propylene glycol, trimethylene glycol, hexamethylene glycol, neopentyl glycol, cyclohexanedimethanol, etc., lower alkylene glycols such as 1,3-octanediol, aromatic alcohols such as bisphenol A and 4,4'-dihydroxybiphenyl, alkylene oxide adduct alcohols such as the 2-mol ethylene oxide adduct of bisphenol A and the 3-mol propylene oxide adduct of bisphenol A, polyhydroxy compounds such as glycerin and pentaerythritol, or their ester-forming derivatives.

[0025] In the present invention, any polybutylene terephthalate resin produced by polycondensation using the above-mentioned compounds as monomer components can be used as component B of the present invention, either alone or in a mixture of two or more types.

[0026] The intrinsic viscosity of the polybutylene terephthalate resin used in this invention is not particularly limited, but is preferably 0.6 to 1.4 dl / g, more preferably 0.7 to 1.35 dl / g, and even more preferably 0.8 to 1.3 dl / g. If the intrinsic viscosity is less than 0.6 dl / g, good mechanical properties may not be obtained. On the other hand, resin compositions obtained from polybutylene terephthalate resins with an intrinsic viscosity exceeding 1.4 dl / g may be less versatile due to poor fluidity during injection molding. The intrinsic viscosity of the polybutylene terephthalate resin is the value measured at 35°C with o-chlorophenol as the solvent.

[0027] The content of component B is 50 to 80 parts by weight, preferably 52 to 78 parts by weight, and more preferably 54 to 76 parts by weight, in 100 parts by weight of the component consisting of components A and B. If the content of component B is less than 50 parts by weight, alkali oil resistance deteriorates, and if it exceeds 80 parts by weight, thin-wall flame retardancy and impact resistance deteriorate.

[0028] (Component C: Brominated polycarbonate flame retardant) The resin composition of the present invention contains a brominated polycarbonate-based flame retardant as component C. Brominated polycarbonate-based flame retardants have excellent heat resistance and can significantly improve flame retardancy. The brominated polycarbonate-based flame retardant used in the present invention is preferably a brominated polycarbonate compound consisting substantially of the constituent units represented by the following formula (1), preferably at least 60 mol%, more preferably at least 80 mol%, of the total constituent units.

[0029] [ka]

[0030] In formula (1), X is a bromine atom, and R is an alkylene group having 1 to 4 carbon atoms, an alkylidene group having 1 to 4 carbon atoms, or -SO2-. In addition, in formula (1), R preferably represents a methylene group, an ethylene group, an isopropylidene group, -SO2-, and particularly preferably an isopropylidene group.

[0031] The brominated polycarbonate flame retardant preferably has a small amount of residual chloroformate groups at the ends, with a terminal chlorine content of 0.3 ppm or less, and more preferably 0.2 ppm or less. This terminal chlorine content can be determined by dissolving the sample in methylene chloride, adding 4-(p-nitrobenzyl)pyridine to react with the terminal chlorine (terminal chloroform), and measuring the result using a UV-Vis spectrophotometer (Hitachi U-3200). When the terminal chlorine content is 0.3 ppm or less, the thermal stability of the flame-retardant polycarbonate resin composition is improved, allowing for molding at higher temperatures, and as a result, a resin composition with superior moldability may be provided.

[0032] Furthermore, it is preferable that the brominated polycarbonate flame retardant has a small number of remaining hydroxyl group terminals. More specifically, it is preferable that the amount of terminal hydroxyl groups is 0.0005 moles or less, and more preferably 0.0003 moles or less, per mole of constituent units of the brominated polycarbonate flame retardant. The amount of terminal hydroxyl groups is determined by dissolving the sample in deuterated chloroform. 1 This can be determined by measurement using 1H-NMR. Such a terminal hydroxyl group content may further improve the thermal stability of the flame-retardant polycarbonate resin composition.

[0033] The specific viscosity of the brominated polycarbonate flame retardant is preferably 0.015 to 0.1, more preferably 0.015 to 0.08. The specific viscosity of the brominated polycarbonate flame retardant was calculated according to the specific viscosity calculation formula used when calculating the viscosity-average molecular weight of the polycarbonate resin, which is component A of the present invention, as described above.

[0034] The content of component C is 10 to 25 parts by weight, preferably 12 to 23 parts by weight, and more preferably 13 to 21 parts by weight, per 100 parts by weight of the component consisting of components A and B. If the content of component C is less than 10 parts by weight, sufficient thin-walled flame retardancy cannot be obtained, and if it exceeds 25 parts by weight, alkali oil resistance and impact resistance deteriorate.

[0035] (Component D: Antimony pentoxide) The flame-retardant polycarbonate resin composition of the present invention contains antimony pentoxide as component D. Antimony pentoxide enhances the flame-retardant effect as a flame-retardant additive, working synergistically with component C to increase flame retardancy.

[0036] While antimony trioxide is commonly used as a flame retardant additive, using antimony trioxide as a flame retardant additive in resin compositions containing polycarbonate resin and polybutylene terephthalate resin easily leads to transesterification reactions between the polycarbonate resin and the polybutylene terephthalate resin, significantly degrading the alkali-oil resistance and impact resistance of the resin composition. On the other hand, using antimony pentoxide as a flame retardant additive suppresses transesterification reactions, thereby preventing deterioration of the alkali-oil resistance and impact resistance of the resin composition.

[0037] As antimony pentoxide, for example, a compound represented by xNa2O·Sb2O5·yH2O (x = a rational number from 0 to 1, y = a rational number from 0 to 4) can be used. The particle size of the antimony pentoxide is not particularly limited, but 0.5 to 50 μm is preferred. Furthermore, the antimony pentoxide may be surface-treated with epoxy compounds, silane compounds, isocyanate compounds, titanate compounds, etc., as needed.

[0038] Furthermore, the antimony pentoxide used in this invention is preferably one whose slurry has a pH of 5 to 9 when dispersed in water, and more preferably one with a pH of 6 to 8. If the slurry has a pH of less than 5 or more than 9, it promotes the decomposition of the polycarbonate resin and polybutylene terephthalate resin during melting, which can increase the amount of gas generated from the resin and worsen alkali oil resistance, thin-wall flame retardancy, impact resistance, and surface appearance.

[0039] The content of component D is 1 to 5 parts by weight, preferably 1.3 to 4.5 parts by weight, and more preferably 1.6 to 4 parts by weight, per 100 parts by weight of the component consisting of components A and B. If the content of component D is less than 1 part by weight, sufficient thin-walled flame retardancy cannot be obtained, and if it exceeds 5 parts by weight, the impact resistance deteriorates.

[0040] (Component E: Impact modifier) The flame-retardant polycarbonate resin composition of the present invention contains an impact modifier as component E. A core-shell type graft copolymer is preferred as the impact modifier. A core-shell type graft polymer is a graft copolymer obtained by copolymerizing rubber with a glass transition temperature of 10°C or lower as the core component, with one or more monomers selected from vinyl compounds, including (meth)acrylic acid ester compounds and aromatic vinyl compounds, as the shell component. The inclusion of component E enables the achievement of good impact resistance. Note that (meth)acrylic is a collective term for acrylic and methacrylic.

[0041] Examples of rubbers that are the core component of component E include butadiene rubber, butadiene-acrylic composite rubber, acrylic rubber, silicone-acrylic composite rubber, isobutylene-silicone composite rubber, isoprene rubber, styrene-butadiene rubber, chloroprene rubber, ethylene-propylene rubber, nitrile rubber, ethylene-acrylic rubber, silicone rubber, epichlorohydrin rubber, fluororubber, and those to which hydrogen has been added to the unsaturated bond portion, with acrylic rubber and silicone-acrylic composite rubber being particularly preferred. A composite rubber refers to a rubber obtained by copolymerizing two types of rubber components or a rubber polymerized to take on an IPN structure in which the components are intertwined in an inseparable manner.

[0042] Examples of aromatic vinyl copolymerized as the shell component of component E include styrene, α-methylstyrene, p-methylstyrene, alkoxystyrene, and halogenated styrene. Examples of (meth)acrylic acid ester compounds include methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, octyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, and octyl methacrylate. Among these, it is particularly preferable to include a (meth)acrylic acid ester compound as an essential component.

[0043] Component E is preferably a graft copolymer obtained by graft polymerization of a (meth)acrylic acid ester compound as a shell component, with one type of rubber selected from the group consisting of acrylic rubber and silicone-acrylic composite rubber as the core component.

[0044] The content of component E is 1 to 4.5 parts by weight, preferably 1.5 to 4.2 parts by weight, and more preferably 2 to 4 parts by weight, per 100 parts by weight of the component consisting of components A and B. If the content of component E is less than 1 part by weight, sufficient impact resistance cannot be obtained, and if it exceeds 4.5 parts by weight, the thin-walled flame retardancy deteriorates.

[0045] (Component F: Talc) The flame-retardant polycarbonate resin composition of the present invention contains talc as component F. In this invention, talc is chemically composed of hydrated magnesium silicate, generally represented by the chemical formula 4SiO2·3MgO·2H2O, and is typically a flaky particle with a layered structure. Its composition consists of approximately 56-65% by weight of SiO2, 8-35% by weight of MgO, and about 5% by weight of H2O. Other minor components include 0.03-1.2% by weight of Fe2O, 0.05-1.5% by weight of Al2O, 0.05-1.2% by weight of CaO, 0.2% by weight or less of K2O, and 0.2% by weight or less of Na2O. A more preferable composition of talc is SiO2: 62-63.5% by weight, MgO: 31-32.5% by weight, Fe2O3: 0.03-0.15% by weight, Al2O3: 0.05-0.25% by weight, and CaO: 0.05-0.25% by weight. Furthermore, it is preferable that the ignition loss is 2 to 5.5% by weight. In such a preferred composition, a resin composition with good thermal stability and hue can be obtained, and good molded products may be produced even with further increases in molding temperature. This makes it possible to further increase the fluidity of the composition of the present invention, which may allow for the production of larger or more complex-shaped thin-walled molded products.

[0046] The particle size of component F is not particularly limited, but from the viewpoint of surface appearance, an average particle size of 0.1 to 10 μm is preferred, more preferably 0.3 to 7 μm, and particularly preferably 0.5 to 4 μm. Note that talc with an average particle size of less than 0.1 μm is difficult to produce industrially. On the other hand, if the average particle size exceeds 10 μm, the surface appearance may deteriorate. The average particle size of talc is the D50 (median diameter of the particle size distribution) measured by X-ray transmission, one of the liquid-phase sedimentation methods. A specific example of an instrument for performing such a measurement is the Sedigraph 5100 manufactured by Micromeristics.

[0047] Furthermore, there are no particular restrictions on the manufacturing method for crushing talc from its raw material, and methods such as axial flow milling, annular milling, roll milling, ball milling, jet milling, and container-rotating compression shear milling can be used. In addition, the crushed talc is preferably classified using various classifiers to ensure a uniform particle size distribution. There are no particular restrictions on the classifiers used, and examples include impactor-type inertial force classifiers (such as variable impactors), Coanda effect-based inertial force classifiers (such as elbow jets), and centrifugal field classifiers (such as multi-stage cyclones, microplexes, dispersion separators, AccuCut, turboclassifiers, turboplexes, micron separators, and superseparators).

[0048] Furthermore, talc is preferably in an aggregated state for ease of handling, and such a method includes degassing and compression, and compression using a sizing agent. The degassing and compression method is particularly preferred because it is simple and does not introduce unnecessary sizing agent resin components into the resin composition of the present invention.

[0049] The content of component F is more than 2 parts by weight and 5 parts by weight or less, preferably 2.2 to 4.5 parts by weight, and more preferably 2.4 to 4 parts by weight, based on 100 parts by weight of the component consisting of components A and B. If the content of component E is 2 parts by weight or less, sufficient thin-walled flame retardancy cannot be obtained, and if it exceeds 5 parts by weight, the impact resistance deteriorates.

[0050] (Component G: Drip prevention agent) The flame-retardant polycarbonate resin composition of the present invention contains a drip inhibitor as component G. The inclusion of this drip inhibitor makes it possible to achieve good flame retardancy without impairing the physical properties of the molded product.

[0051] Examples of drip inhibitors include fluorine-containing polymers having fibril-forming ability, such as polytetrafluoroethylene, tetrafluoroethylene copolymers (e.g., tetrafluoroethylene / hexafluoropropylene copolymer, etc.), partially fluorinated polymers as described in U.S. Patent No. 4,379,910, and polycarbonate resins produced from fluorinated diphenols. Among these, polytetrafluoroethylene (hereinafter sometimes referred to as PTFE) is preferred.

[0052] Furthermore, in the present invention, coated branched PTFE can be used as a drip-preventing agent. Coated branched PTFE is a polytetrafluoroethylene mixture consisting of branched polytetrafluoroethylene particles and an organic polymer, and has a coating layer on the outside of the branched polytetrafluoroethylene consisting of an organic polymer, preferably a polymer containing styrene monomer-derived units and / or acrylic monomer-derived units. The coating layer is formed on the surface of the branched polytetrafluoroethylene. It is also preferable that the coating layer contains a copolymer of styrene monomers and acrylic monomers.

[0053] The content of component G is 0.1 to 1 part by weight, preferably 0.2 to 0.8 parts by weight, and more preferably 0.3 to 0.6 parts by weight, per 100 parts by weight of the component consisting of components A and B. If the content of component G is less than 0.1 parts by weight, sufficient thin-wall flame retardancy cannot be obtained, and if it exceeds 1 part by weight, the impact resistance and thin-wall flame retardancy deteriorate.

[0054] (Component H: Transesterification inhibitor) The flame-retardant polycarbonate resin composition of the present invention contains a transesterification inhibitor as component H. Any compound that deactivates the transesterification catalyst can be used as the transesterification inhibitor without particular limitations, but phosphite compounds, phosphate compounds, phosphonius compounds, phosphonic acid compounds and their esters, and tertiary phosphines are preferred. Among these, phosphate compounds and phosphite compounds are more preferred because they deactivate the transesterification catalyst quickly, and phosphate compounds are particularly preferred.

[0055] Examples of phosphate compounds include tributyl phosphate, trimethyl phosphate, tricresyl phosphate, triphenyl phosphate, trichlorophenyl phosphate, triethyl phosphate, diphenyl cresyl phosphate, diphenyl monoorthoxenyl phosphate, tributoxyethyl phosphate, dibutyl phosphate, dioctyl phosphate, diisopropyl phosphate, stearyl acid phosphate, octadecyl phosphate, and stearyl acid phosphate metal salts.

[0056] Examples of phosphite compounds include trialkyl phosphites such as tridecyl phosphite, dialkyl monoaryl phosphites such as didecyl monophenyl phosphite, monoalkyldiaryl phosphites such as monobutyldiphenyl phosphite, triaryl phosphites such as triphenyl phosphite and tris(2,4-di-tert-butylphenyl) phosphite, distearyl pentaerythritol diphosphite, and bis(2,4-di-tert-butylphenyl) pentaerythritol. Examples include pentaerythritol phosphites such as tol diphosphite, bis(2,4-dicumylphenyl)pentaerythritol diphosphite and bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, as well as cyclic phosphites such as 2,2-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite and 2,2'-methylenebis(4,6-di-tert-butylphenyl)(2,4-di-tert-butylphenyl) phosphite.

[0057] The above transesterification inhibitors can be used alone or in combination of two or more.

[0058] The content of component H is 0.01 to 0.5 parts by weight, preferably 0.02 to 0.4 parts by weight, and more preferably 0.03 to 0.3 parts by weight, per 100 parts by weight of the component consisting of components A and B. If the content is less than 0.01 parts by weight, the transesterification reaction is promoted, resulting in deterioration of alkali oil resistance, thin-wall flame retardancy, and impact resistance. On the other hand, if the content exceeds 0.5 parts by weight, thin-wall flame retardancy and impact resistance also deteriorate.

[0059] (Component I: Glycidyl group-containing compound) The flame-retardant polycarbonate resin composition of the present invention contains a glycidyl group-containing compound as component I. Component I is not particularly limited as long as it contains a glycidyl group, and examples include resins having glycidyl groups, homopolymers of monomers having glycidyl groups, or copolymers of monomers having glycidyl groups and monomers not having glycidyl groups. These can be used individually or in combination of two or more types.

[0060] Examples of resins containing glycidyl groups include bisphenol A type epoxy resins.

[0061] Examples of monomers having a glycidyl group include glycidyl acrylate and glycidyl methacrylate, which can be used individually or in combination of two or more.

[0062] Examples of monomers without a glycidyl group that can be copolymerized with monomers having a glycidyl group include alkyl acrylates such as methyl acrylate and butyl acrylate, olefin monomers such as ethylene and propylene, and aromatic vinyl monomers such as styrene and styrene-acrylonitrile. These can be used individually or in combination of two or more types.

[0063] Glycidyl methacrylate copolymers are widely used as copolymers of monomers having a glycidyl group and monomers not having a glycidyl group. Specific examples of glycidyl methacrylate copolymers include styrene-glycidyl methacrylate copolymers, ethylene-glycidyl methacrylate copolymers, ethylene-glycidyl methacrylate-methacrylate copolymers, glycidyl methacrylate-styrene-acrylonitrile copolymers, glycidyl methacrylate-styrene-methyl methacrylate copolymers, and copolymers obtained by graft polymerization of glycidyl methacrylate-styrene-acrylonitrile copolymers onto polycarbonate.

[0064] From the perspective of compatibility with Component A and Component B, at least one compound selected from the group consisting of glycidyl methacrylate copolymers and bisphenol A type epoxy resins is particularly preferred for Component I. These glycidyl group-containing compounds can be easily obtained as commercial products.

[0065] The content of Component I is defined by the epoxy equivalent of Component I. That is, the content of Component I and the epoxy equivalent are defined by the following formula (1). When outside the defined range, the thin-film flame retardancy decreases. The epoxy equivalent can be measured according to JIS K7236. 0.00001 < Content of Component I (parts by weight) per 100 parts by weight of the component composed of Component A and Component B / Epoxy equivalent of Component I (g / eq) < 0.001 ··· (1)

[0066] (Other additives) (i) Phenolic stabilizer The resin composition of the present invention can contain a phenolic stabilizer. Examples of phenolic stabilizers generally include hindered phenols, semi-hindered phenols, and res-hindered phenol compounds. However, hindered phenol compounds are more preferably used from the perspective of applying a heat stabilization formulation to the polycarbonate resin.

[0067] (ii) Ultraviolet absorber The flame-retardant polycarbonate resin composition of the present invention may contain an ultraviolet absorber. Examples of ultraviolet absorbers include compounds such as benzophenone-based, benzotriazole-based, hydroxyphenyltriazine-based, and cyclic iminoester-based compounds. Furthermore, the ultraviolet absorber may be a polymer-type ultraviolet absorber obtained by copolymerizing such an ultraviolet-absorbing monomer and / or a photostable monomer with a monomer such as an alkyl (meth)acrylate, by adopting the structure of a monomer compound that can be radically polymerized. Examples of the ultraviolet-absorbing monomers include compounds containing a benzotriazole skeleton, benzophenone skeleton, triazine skeleton, cyclic iminoester skeleton, and cyanoacrylate skeleton in the ester substituent of a (meth)acrylic acid ester. The ultraviolet absorbers can be used alone or in combination of two or more.

[0068] (iii) Hindered amine light stabilizers The flame-retardant polycarbonate resin composition of the present invention may contain a hindered amine light stabilizer. Hindered amine light stabilizers are generally called HALS (Hindered Amine Light Stabilizer) and are compounds having a 2,2,6,6-tetramethylpiperidine skeleton in their structure. Hindered amine light stabilizers are broadly classified into three types depending on the bonding partner of the nitrogen atom in the piperidine skeleton: NH type (hydrogen bonded to the nitrogen atom), NR type (alkyl group (R) bonded to the nitrogen atom), and N-OR type (alkoxy group (OR) bonded to the nitrogen atom). However, when applied to polycarbonate resins, from the viewpoint of the basicity of the hindered amine light stabilizer, it is more preferable to use the low-basic NR type or N-OR type. Hindered amine light stabilizers can be used alone or in combination of two or more types.

[0069] (iv) Release agent The flame-retardant polycarbonate resin composition of the present invention preferably contains a release agent to improve productivity during molding and reduce distortion of molded products. Known release agents can be used. Examples include saturated fatty acid esters, unsaturated fatty acid esters, polyolefin waxes (polyethylene wax, 1-alkene polymers, etc., including those modified with functional group-containing compounds such as acid modification), silicone compounds, fluorine compounds (fluorine oils such as polyfluoroalkyl ethers), paraffin wax, and beeswax. Among these, fatty acid esters and polyolefin waxes are preferred release agents.

[0070] (v) dyes and pigments The flame-retardant polycarbonate resin composition of the present invention can further contain various dyes and pigments to provide molded articles exhibiting diverse design properties. By incorporating fluorescent whitening agents or other fluorescent dyes that emit light, even better design effects can be imparted by utilizing the luminescent color. Furthermore, a flame-retardant polycarbonate resin composition that can be colored with minute amounts of dyes and pigments and exhibits vivid color development can also be provided.

[0071] (vi) Filling material The flame-retardant polycarbonate resin composition of the present invention may contain various fillers as reinforcing fillers, to the extent that the effects of the present invention are exhibited. Examples include silicate minerals other than talc, calcium carbonate, glass fibers, glass beads, glass balloons, glass milled fibers, glass flakes, carbon fibers, carbon flakes, carbon beads, carbon milled fibers, graphite, vapor-deposited ultrafine carbon fibers (fiber diameter less than 0.1 μm), carbon nanotubes (fiber diameter less than 0.1 μm and hollow), fullerenes, metal flakes, metal fibers, metal-coated glass fibers, metal-coated carbon fibers, metal-coated glass flakes, silica, metal oxide particles, metal oxide fibers, metal oxide balloons, and various whiskers (potassium titanate whiskers, aluminum borate whiskers, and basic magnesium sulfate, etc.). These reinforcing fillers may be included individually or in combination of two or more.

[0072] (vii) Other additives In addition, the flame-retardant polycarbonate resin composition of the present invention may contain small amounts of well-known additives to impart various functions to molded articles or improve their properties. These additives are added in normal amounts as long as they do not impair the objectives of the present invention. Examples of such additives include lubricants (e.g., PTFE particles), light diffusing agents (e.g., acrylic crosslinked particles, silicone crosslinked particles, ultrathin glass flakes, calcium carbonate particles), antistatic agents, nucleating agents, inorganic and organic antimicrobial agents, photocatalytic antifouling agents (e.g., fine titanium dioxide particles, fine zinc oxide particles), radical generators, infrared absorbers (heat absorbers), and photochromic agents.

[0073] (Manufacturing of resin compositions) Any method can be used to produce the resin composition of the present invention. For example, components A to I and optionally other additives can be thoroughly mixed using pre-mixing means such as a V-type blender, Henschel mixer, mechanochemical device, or extruder mixer, and then the pre-mixed mixture can be granulated as needed using an extruder granulator or briquetting machine, followed by melt-kneading in a melt-kneader such as a vented twin-screw extruder, and then pelletized in a pelletizer. Other methods include supplying each component independently to a melt-kneader such as a vented twin-screw extruder, or pre-mixing some of the components and then supplying them independently to the melt-kneader along with the remaining components. Preferably, an extruder 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. Furthermore, a screen can be installed in the zone in front of the extruder die to remove foreign matter mixed into the extrusion raw material, thereby removing foreign matter from the resin composition. Examples of such screens include wire mesh, screen changers, and sintered metal plates (such as disc filters). Examples of melting and mixing machines include twin-screw extruders, Banbury mixers, mixing rolls, single-screw extruders, and multi-screw extruders with three or more shafts.

[0074] As described above, the extruded resin is either directly cut and pelletized, or strands are formed and then cut in a pelletizer to form pellets. If it is necessary to reduce the influence of external dust and other contaminants during pelletization, it is preferable to clean the atmosphere around the extruder. Furthermore, in the production of such pellets, various methods already proposed for polycarbonate resins for optical discs can be used to appropriately narrow the shape distribution of the pellets, reduce miscuts, reduce fine powder generated during transportation or transport, and reduce air bubbles (vacuum bubbles) generated inside the strands and pellets. These formulations can enable high-cycle molding and reduce the rate of defects such as silver. The shape of the pellets can be general shapes such as cylinders, prismatics, and spheres, but cylinders are more preferable. The diameter of such cylinders is preferably 1 to 5 mm, more preferably 1.5 to 4 mm, and even more preferably 2 to 3.3 mm. On the other hand, the length of the cylinders is preferably 1 to 30 mm, more preferably 2 to 5 mm, and even more preferably 2.5 to 3.5 mm.

[0075] (Molded article made from the resin composition of the present invention) The resin composition of the present invention can be used to manufacture various products by injection molding pellets obtained by the method described above. In such injection molding, molded products can be obtained using injection molding methods such as injection compression molding, injection press molding, gas-assisted injection molding, foam molding (including injection molding with supercritical fluid), 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, depending on the purpose. The advantages of these various molding methods are already widely known. Furthermore, molding can be performed using either a cold runner or a hot runner method. The resin composition of the present invention can also be used in the form of various irregularly shaped extruded products, sheets, films, etc., by extrusion molding. For molding sheets and films, methods such as inflation molding, calendering, and casting can also be used. Furthermore, it is possible to mold it as a heat-shrinkable tube by applying a specific stretching operation. The resin composition of the present invention can also be molded into products by rotational molding or blow molding. [Effects of the Invention]

[0076] The flame-retardant polycarbonate resin composition of the present invention is excellent in alkali-oil resistance, thin-wall flame retardancy, and impact resistance, and is therefore widely useful not only in FA equipment exterior materials but also in medical equipment, housing equipment, building materials, daily necessities, infrastructure equipment, automobiles, OA / EE applications, outdoor equipment, and various other fields. Therefore, the industrial effects of the present invention are extremely significant. [Modes for carrying out the invention]

[0077] The embodiments for carrying out the present invention are a combination of preferred ranges of the above requirements, and representative examples are described in the following examples. Of course, the present invention is not limited to these embodiments. The evaluation was carried out by the following method. [Examples]

[0078] (i) alkali oil resistance Using ISO tensile test specimens obtained by the method described below, a 1% strain was applied using the three-point bending test method. A cloth impregnated with pH=9 alkaline oil (Super Tech DOT3 Brake Fluid, manufactured by Technical Chemical Co.) was then placed over the specimens and left at 23°C for 200 hours before measuring the tensile strength. The tensile strength before the above treatment was also measured, and the tensile strength retention rate after the alkali oil resistance test was calculated according to the formula below. Tensile strength retention rate (%) = 100 × (Tensile strength of the specimen after alkali oil resistance test) / (Tensile strength of the specimen before alkali oil resistance test) In this context, tensile strength refers to the higher of the tensile breaking strength and the tensile yield strength.

[0079] (ii) Thin-walled flame retardant 5VA test specimens (thicknesses of 2.0 mm, 2.2 mm, 2.4 mm, and 2.6 mm) obtained by the method described below were used to conduct 5VA tests in accordance with UL94. The thinner the specimen, the better its flame retardancy. Specifically, the order of thin-walled flame retardancy from best to worst was: 2.0 mm thickness for 5VA pass > 2.2 mm thickness for 5VA pass > 2.4 mm thickness for 5VA pass > 2.6 mm thickness for 5VA pass. It is preferable for a specimen with a thickness of 2.4 mm to pass the 5VA test.

[0080] (iii) Impact resistance Using ISO bending test specimens with a thickness of 4 mm obtained by the method described below, the notched Charpy impact strength was measured in accordance with ISO 179 under an atmosphere of 23°C.

[0081] [Examples 1-21, Comparative Examples 1-16] The mixture was supplied from the first feed port of the extruder with the compositions shown in Tables 1 to 3. The amount of mixture supplied was precisely measured using a measuring instrument [Kubota Corporation CWF]. Extrusion was performed using a 30 mmφ vented twin-screw extruder (Japan Steel Works Ltd. TEX30α-38.5BW-3V), with a screw rotation speed of 230 rpm, a discharge rate of 25 kg / h, and a vent vacuum of 3 kPa, by melt-kneading to obtain pellets. The extrusion temperature was 260°C from the first feed port to the die section. A portion of the obtained pellets was dried in a hot air circulating dryer at 100-110°C for 6 hours. Then, using an injection molding machine, ISO tensile test specimens (compliant with ISO 527-1 and ISO 527-2), ISO bending test specimens (compliant with ISO 178, ISO 179, ISO 75-1 and ISO 75-2), and 5VA test specimens (150 mm long × 150 mm wide × 2.0, 2.2 mm, 2.4 mm, and 2.6 mm thick) were prepared at a cylinder temperature of 260°C and a mold temperature of 80°C.

[0082] The components represented by the symbols in Tables 1 to 3 are as follows: (Component A) A-1: Aromatic polycarbonate resin (polycarbonate resin powder with a viscosity-average molecular weight of 23,900, produced by conventional methods from bisphenol A and phosgene; manufactured by Teijin Limited, product name: Panlite L-1250WP) (B component) B-1: Polybutylene terephthalate resin (Intrinsic viscosity: 0.965 dl / g, manufactured by Changchun Artificial Resin Co., Ltd., product name 1100-211MD) (C component) C-1: Brominated polycarbonate flame retardant (brominated carbonate oligomer with a bisphenol A skeleton, bromine content: 58.0%, manufactured by Teijin Limited, product name FG-8500) (D component) D-1: Antimony pentoxide (BurnEx6220 (product name) manufactured by Nyacol Nano Technologies, Ink.) (E component) E-1: Impact modifier (A core-shell type graft copolymer in which the core is mainly composed of silicone-acrylic composite rubber and methyl methacrylate is graft copolymerized as the shell component; manufactured by Mitsubishi Chemical Corporation, product name: Metabren S-2030) E-2: Impact modifier (A core-shell type graft copolymer in which methyl methacrylate is graft copolymerized as the shell component, with the core mainly composed of butyl acrylate and 2-ethylhexyl acrylate (DOW Chemical Co., Ltd., Paraloid EXL-2390 (product name))) (F component) F-1: Talc (average particle size 2 μm, manufactured by Katsumitsuyama Mining Co., Ltd., product name: Victorilite TK-RC) (G component) G-1: Drip prevention agent (polytetrafluoroethylene, manufactured by Daikin Industries, Ltd., Polyflon MPA FA500H (product name)) (H component) H-1: Transesterification inhibitor (octadecyl phosphate, manufactured by ADEKA Corporation, product name: ADEKA Stab AX-71) H-2: Transesterification inhibitor (Bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, manufactured by Songwon Industrial, Co. Ltd., SONGNIOX 6260 PW (product name)) (Component I) I-1: Styrene-glycidyl methacrylate copolymer (epoxy equivalent: 310 g / eq, manufactured by NOF Corporation, Marproof G-0250SP (product name)) I-2: Ethylene-glycidyl methacrylate copolymer (epoxy equivalent: 350 g / eq, manufactured by Sumitomo Chemical Co., Ltd., BondFirst E (product name)) I-3: Bisphenol A type epoxy resin (epoxy equivalent: 8,000 g / eq, manufactured by Mitsubishi Chemical Corporation, product name jER1256)

[0083] [Table 1]

[0084] Table 2

[0085] Table 3

Claims

1. A flame-retardant polycarbonate resin composition characterized by containing, per 100 parts by weight of a component consisting of (A) 20 to 50 parts by weight of polycarbonate resin (component A) and (B) 80 to 50 parts by weight of polybutylene terephthalate resin (component B), (C) 10 to 25 parts by weight of brominated polycarbonate-based flame retardant (component C), (D) 1 to 5 parts by weight of antimony pentoxide (component D), (E) impact modifier (component E) 1 to 4.5 parts by weight of (F) talc (component F) more than 2 parts by weight and not more than 5 parts by weight of (G) drip inhibitor (component G) 0.1 to 1 part by weight of (H) transesterification reaction inhibitor (component H) 0.01 to 0.5 parts by weight of (I) glycidyl group-containing compound (component I), and satisfying the following formula (1). 0.00001 < Content of component I per 100 parts by weight of component A and component B (parts by weight) / Epoxy equivalent of component I (g / eq) < 0.001 ... (1)

2. The flame-retardant polycarbonate resin composition according to claim 1, characterized in that component I is at least one compound selected from the group consisting of glycidyl methacrylate copolymers and bisphenol A type epoxy resins.

3. The flame-retardant polycarbonate resin composition according to claim 1 or 2, characterized in that component E is a graft copolymer obtained by graft polymerization of a (meth)acrylic acid ester compound as a shell component, with one rubber selected from the group consisting of acrylic rubber and silicone-acrylic composite rubber as the core component.

4. The flame-retardant polycarbonate resin composition according to claim 1 or 2, characterized in that component H is at least one compound selected from the group consisting of phosphite compounds and phosphate compounds.

5. A molded article made from the flame-retardant polycarbonate resin composition according to claim 1 or 2.

6. A molded article according to claim 5, which is an exterior material for FA equipment.

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