JP5460078B2 - Aromatic polycarbonate resin composition and molded article - Google Patents

Description

  The present invention provides an aromatic polycarbonate resin composition excellent in thermal stability comprising a combination of an aromatic sulfonic acid metal salt compound and a titanium oxide having a specific composition, and further flame retardant by blending with polytetrafluoroethylene. The present invention relates to an excellent aromatic polycarbonate resin composition and a resin molded body obtained by molding the composition, specifically, a light reflecting member. More specifically, the present invention relates to an aromatic polycarbonate resin composition having excellent light reflectivity, light shielding properties, light resistance, hue, and other thermal properties, and a resin molding while maintaining the original properties of the polycarbonate resin.

  Polycarbonate resin is a general-purpose engineering plastic that has excellent transparency, mechanical strength, electrical properties, heat resistance, dimensional stability, etc., so electrical / electronic equipment parts, OA equipment, machine parts, vehicle parts, building parts, It is used in a wide range of fields such as various containers, leisure goods and miscellaneous goods.

  Among these fields of use, thin film transistors (TFT) and other information display devices such as computers and televisions, backlight reflectors for liquid crystal display devices, illuminated push switches and reflectors for photoelectric switches, etc. Display devices incorporating reflectors that require a high degree of light reflectance are becoming common.

  These light reflecting members that require a high degree of light reflectivity are resin molded bodies formed by molding a polycarbonate resin composition with a high content of fine particles such as titanium oxide in terms of light reflectivity, moldability, and impact strength. Is used.

  A light reflecting member made of a polycarbonate resin composition has a strong demand for flame retardant resin materials. In order to meet these demands, an aromatic polycarbonate resin, a halogen compound, a phosphorus compound, a siloxane compound, a polyfluoro A number of techniques for making flame retardant by blending ethylene and the like have been proposed. Recently, in consideration of the environment, a flame retardant resin composition using another flame retardant without using a brominated flame retardant or a phosphorus flame retardant has been desired.

Patent Documents 1 to 3 can be cited as examples of flame retardant polycarbonate using an organic metal salt and titanium oxide in combination, but it is difficult to say that all have sufficient performance.

For example, Patent Document 1 describes a resin composition comprising polycarbonate resin and aromatic sulfonic acid sodium salt and polytetrafluoroethylene. However, since there is no addition of titanium oxide, the reflection characteristics and the flame retardance at a thin wall are inferior, so that it cannot be said that the performance is sufficient as a flame retardant light reflecting material.

Patent Document 2 describes a resin composition obtained by adding (B) titanium oxide and (C) 1 to 8 parts by weight (parts by mass) of an alkylbenzenesulfonic acid-based antistatic agent to (A) polycarbonate resin. However, since the amount of the alkali metal salt added is large, the molecular weight of the polycarbonate is greatly reduced at the time of molding, and the moldability and flame retardancy are lowered.

Patent Document 3 describes a resin composition in which polytetrafluoroethylene, an organic metal salt, and a silicone compound are further added with specific titanium oxide to a polycarbonate resin. However, the appearance like silver streak depends greatly on the state of secondary aggregation of titanium oxide, and satisfactory results cannot be obtained. In addition, poor appearance occurs due to the addition of the silicone compound.

JP 2000-239509 A JP-A-11-181267 JP 2006-241262 A

  The object of the present invention is to maintain the original characteristics of a polycarbonate resin and to obtain a product having a good appearance with excellent light reflectivity, flame retardancy, impact and thermal stability even in a thin molded product. The object is to provide a composition and a resin molded body obtained by molding the composition, specifically, a light reflecting member.

  In order to solve the above problems, the present inventors have intensively studied an aromatic polycarbonate resin composition. By paying attention to the combination of an aromatic sulfonic acid metal salt compound and a specific titanium oxide, an aromatic polycarbonate resin composition having excellent light reflectance, flame retardancy, impact and thermal stability, and a good appearance And it discovered that a light reflection member was obtained, and completed this invention.

That is, the gist of the present invention is that, with respect to 100 parts by mass of the aromatic polycarbonate resin (A), 3 to 30 parts by mass of the titanium oxide additive (B) surface-treated with alumina and organosiloxane, an aromatic sulfonic acid metal salt ( C) 0.01 to 1 part by mass, 0.01 to 1.5 parts by mass of polyfluoroethylene (D), and obtained by X-ray fluorescence analysis of the titanium oxide-based additive (B) Aluminum content a (mass%) in titanium oxide-based additive, carbon content c (mass%) in titanium oxide-based additive obtained by analyzing titanium oxide-based additive using high-frequency combustion type carbon analyzer ) And the average particle diameter (μm) of titanium oxide is d,
(Formula 1) 11.4 ≦ (a / d ² ) ≦ 15 and (Formula 2) 5 ≦ (c / d ² ) ≦ 25
In the light reflecting member comprising the aromatic polycarbonate resin composition and the resin molded body thereof.

  The aromatic polycarbonate resin composition of the present invention not only has light resistance, light shielding properties, light reflectivity, hue, flame retardancy molding stability, but also impact resistance, heat resistance, dimensional stability inherent to polycarbonate resins. At the same time, the appearance characteristics are maintained. Therefore, taking advantage of these features, light reflectors for backlights of liquid crystal display devices, light reflecting frames or sheets, lighting devices such as electric / electronic devices and advertising lights, automotive equipment such as automotive meter panels, etc. It can be used widely as a light reflecting member.

(A) Aromatic polycarbonate resin The (A) aromatic polycarbonate resin used in the present invention is a branched product obtained by reacting an aromatic dihydroxy compound or a small amount thereof with phosgene or a carbonic acid diester. It may be a thermoplastic polymer or copolymer. The production method of the aromatic polycarbonate resin is not particularly limited, and those produced by a conventionally known phosgene method (interfacial polymerization method) or melting method (transesterification method) can be used. Further, when the melting method is used, a polycarbonate resin in which the amount of OH groups of terminal groups is adjusted can be used.

  As the raw material aromatic dihydroxy compound, 2,2-bis (4-hydroxyphenyl) propane (= bisphenol A), tetramethylbisphenol A, bis (4-hydroxyphenyl) -p-diisopropylbenzene, hydroquinone, resorcinol, 4 , 4-dihydroxydiphenyl and the like, preferably bisphenol A. In addition, a compound in which one or more tetraalkylphosphonium sulfonates are bonded to the above aromatic dihydroxy compound can also be used.

In order to obtain a branched aromatic polycarbonate resin, a part of the above-mentioned aromatic dihydroxy compound is mixed with the following branching agents, that is, phloroglucin, 4,6-dimethyl-2,4,6-tri (4-hydroxyphenyl). Heptene-2,4,6-dimethyl-2,4,6-tri (4-hydroxyphenyl) heptane, 2,6-dimethyl-2,4,6-tri (4-hydroxyphenylheptene-3,1, Polyhydroxy compounds such as 3,5-tri (4-hydroxyphenyl) benzene and 1,1,1-tri (4-hydroxyphenyl) ethane, and 3,3-bis (4-hydroxyaryl) oxindole (= isa) Tin bisphenol), 5-chloruisatin, 5,7-dichloroisatin, 5-bromoisatin, etc. Dose, the aromatic dihydroxy compound is 0.01 to 10 mol%, preferably 0.1 to 2 mol%.

(A) As aromatic polycarbonate resin, among the above-mentioned, polycarbonate resin derived from 2,2-bis (4-hydroxyphenyl) propane, or 2,2-bis (4-hydroxyphenyl) propane and other Polycarbonate copolymers derived from aromatic dihydroxy compounds are preferred. Further, it may be a copolymer mainly composed of a polycarbonate resin, such as a copolymer with a polymer or oligomer having a siloxane structure. Furthermore, you may mix and use 2 or more types of the aromatic polycarbonate resin mentioned above.

In order to adjust the molecular weight of the aromatic polycarbonate resin, a monovalent aromatic hydroxy compound may be used. For example, m- and p-methylphenol, m- and p-propylphenol, p-tert-butylphenol, p- Long chain alkyl substituted phenols and the like.

The molecular weight of the (A) aromatic polycarbonate resin used in the present invention is arbitrary depending on the use and may be appropriately selected and determined. From the viewpoint of moldability, strength, etc., the molecular weight of the (A) aromatic polycarbonate resin is a solvent. The viscosity average molecular weight [Mv] converted from the solution viscosity measured at a temperature of 25 ° C. using methylene chloride is preferably 10,000 to 40,000, more preferably 10,000 to 30,000. As described above, when the viscosity average molecular weight is 10,000 or more, the mechanical strength tends to be further improved, and the viscosity average molecular weight is more preferable when used for an application requiring high mechanical strength. On the other hand, by setting it as 40000 or less, it exists in the tendency to suppress and improve a fluid fall more, and is more preferable from a viewpoint of easy moldability.

  Among them, the viscosity average molecular weight is preferably 10,000 to 22,000, more preferably 12,000 to 22,000, and particularly preferably 14,000 to 20,000. Two or more types of aromatic polycarbonate resins having different viscosity average molecular weights may be mixed. In this case, an aromatic polycarbonate resin having a viscosity average molecular weight outside the above preferred range may be mixed. In this case, the viscosity average molecular weight of the mixture is preferably within the above range.

(B) Titanium oxide-based additive The titanium oxide-based additive (B) in the present invention functions so as to improve the light-shielding property, whiteness, light reflection property and the like of a molded product obtained from the polycarbonate resin composition. The titanium oxide used for the titanium oxide-based additive (B) is not particularly limited in terms of production method, crystal form, average particle diameter, and the like. There are (1) the sulfuric acid method and (2) the chlorine method in the production method of titanium oxide. However, since titanium oxide produced by the sulfuric acid method tends to be inferior in whiteness of the composition to which this is added, the present invention In order to effectively achieve the above objective, those produced by the chlorine method are preferred.

  The crystal form of titanium oxide includes a rutile type and an anatase type, but a rutile type crystal form is preferred from the viewpoint of light resistance. The average particle size of the titanium oxide-based additive is usually 0.1 to 0.7 μm, preferably 0.1 to 0.4 μm. When the average particle diameter is less than 0.1 μm, the light shielding property of the molded product is poor, and when it exceeds 0.7 μm, the surface of the molded product is roughened or the mechanical strength of the molded product is lowered. In the present invention, two or more types of titanium oxides having different average particle diameters may be mixed and used.

  The titanium oxide-based additive (B) is preferably pretreated with an alumina-based surface treatment agent before being surface-treated with an organosiloxane-based surface treatment agent described later. Alumina hydrate is preferably used as the alumina-based surface treatment agent. Furthermore, it may be pretreated with silicic acid hydrate together with alumina hydrate. The pretreatment method is not particularly limited, and any method can be used. The pretreatment with alumina hydrate and, if necessary, silicic acid hydrate is preferably carried out in the range of 1 to 15% by weight with respect to titanium oxide.

  Titanium oxide pretreated with alumina hydrate and, if necessary, silicic acid hydrate can further improve the thermal stability by surface treatment with an organosiloxane-based surface treatment agent. In addition, it improves the uniform dispersibility and the stability of the dispersed state in the polycarbonate resin composition. As the organosiloxane-based surface treatment agent, a polyorganohydrogensiloxane compound is preferable.

  There are (1) a wet method and (2) a dry method as surface treatment methods using an organosiloxane-based surface treatment agent of titanium oxide. In the wet method, a mixture of an organosiloxane-based surface treatment agent and a solvent is added with alumina hydrate, and if necessary, titanium oxide pretreated with silicic acid hydrate. Furthermore, it is a method of heat-processing at 100-300 degreeC after that. In the dry method, pretreated titanium oxide and polyorganohydrogensiloxane are mixed with a Henschel mixer in the same manner as described above, and an organic solution of polyorganohydrogensiloxane is sprayed on the pretreated titanium oxide. And a method of heat-treating at 100 to 300 ° C. The amount of the siloxane-based surface treatment agent is not particularly limited, but in consideration of the reflectivity of titanium oxide, the moldability of the resin composition, etc., usually in the range of 1 to 5% by weight with respect to titanium oxide. is there.

Among these, the titanium oxide-based additive (B) used in the present invention is characterized by exhibiting good thermal stability in a polycarbonate composition in the presence of an aromatic sulfonic acid metal salt compound. Specifically, the following two expressions are satisfied.

The aluminum content a (mass%) in the titanium oxide-based additive obtained by fluorescent X-ray analysis of the titanium oxide-based additive (B) and the titanium oxide-based additive using a high-frequency combustion carbon analyzer. The amount of carbon c (mass%) in the titanium oxide-based additive obtained by analysis and the average particle size (μm) of titanium oxide is d,
(Formula 1) 6.5 ≦ (a / d ² ) ≦ 15 and (Formula 2) 5 ≦ (c / d ² ) ≦ 25
When satisfying the above, it exhibits excellent effects in thermal stability, flame retardancy, and light reflectivity.

In order to obtain better thermal stability, the value of (a / d ² ) in (Formula 1) is preferably 8 or more, and the value of (c / d ² ) in (Formula 2) is preferably It is less than 20, more preferably less than 15.

The average particle size and surface area of titanium oxide have a correlation, and the surface area per unit mass increases as the average particle size decreases. In the present invention, an excellent light reflectivity can be obtained by using a titanium oxide having a relatively small average particle diameter, that is, a fine particle diameter, and dispersing an appropriate amount of aluminum or the like on the surface of the titanium oxide having a small particle diameter. . (A / d ² ) represents the amount of aluminum added to the unit surface area of titanium oxide, and (c / d ² ) represents the amount of organic carbon contained in the organosiloxane surface treatment agent relative to the unit surface area of titanium oxide. .
By satisfying the ranges of (Formula 1) and (Formula 2), the surface treatment for titanium oxide becomes appropriate, and a polycarbonate resin excellent in thermal stability, flame retardancy, and light reflectivity can be obtained.

When the value of (a / d ² ) is less than 6.5, the dispersion of titanium oxide in the composition becomes insufficient, and secondary agglomeration is likely to occur, and a molded product with good appearance and reflectance cannot be obtained. On the other hand, when it exceeds 15, the basicity of the titanium oxide particles is further increased by the alumina treatment, so that the thermal stability of the polycarbonate resin composition is lowered, and the impact property and molding stability may be inferior. If the value of (c / d ² ) is less than 5, the surface activity by titanium oxide and the activity of titanium oxide particles that do not require basicity by alumina cannot be sufficiently covered, so the thermal stability and adhesion of the polycarbonate resin composition May decrease and impact properties and molding stability may be inferior. On the other hand, if it exceeds 25, the organosiloxane surface treatment agent that is not chemically bonded to titanium oxide tends to volatilize during molding, causing mold contamination.

The compounding quantity of a titanium oxide type additive (B) is the range of 3-30 mass parts with respect to 100 mass parts of aromatic polycarbonate resin (A). When the compounding amount of the titanium oxide-based additive (B) is less than 3 parts by mass, the light-shielding properties and the reflection characteristics of the molded product obtained from the resin composition are insufficient, and when it exceeds 30 parts by mass, the resin composition Impact resistance is insufficient. The preferable compounding quantity of a titanium oxide type additive (B) is 3-25 mass parts with respect to 100 mass parts of aromatic polycarbonate resin, More preferably, it is 5-20 mass parts. In addition, the mass of the titanium oxide-based additive (B) means the mass including these treatment agents when surface treatment is performed with an alumina hydrate, silicic acid hydrate, or an organosiloxane-based surface treatment agent. To do.

(C) Aromatic sulfonic acid metal salt The aromatic sulfonic acid metal salt used in the present invention is a metal salt that can be added to polycarbonate to improve flame retardancy. Of these, aromatic alkylsulfonic acid metal salts and derivatives thereof are preferably used.

  The metal of the aromatic sulfonic acid metal salt is preferably an alkali metal or an alkaline earth metal. Examples of the alkali metal and alkaline earth metal include sodium, lithium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, and barium. Of these, sodium and potassium are preferable as the alkali metal, and magnesium, calcium and cesium are preferable as the alkaline earth metal from the viewpoint of compatibility with the polycarbonate resin and flame retardancy, and the aromatic sulfonic acid metal salt is 2 It may be a mixture of seeds or more.

  Examples of aromatic sulfonic acid metal salts include sodium diphenylsulfone-3-sulfonate, potassium diphenylsulfone-3-sulfonate, sodium 4 / 4'-dibromodiphenyl-sulfone-3-sulfone, 4 / 4'-dibromodiphenyl. -Sulfone-3-sulfone potassium, 4-chloro-4'-nitrodiphenyl sulfone-3-sulfonic acid calcium, diphenyl sulfone-3.3'-disulfonic acid disodium, diphenyl sulfone-3.3'-disulfonic acid dipotassium It is done. Among them, examples of non-halogen aromatic sulfonic acid metal salts include sodium dodecylbenzene sulfonate and sodium styrene sulfonate. Among them, sodium paratoluene sulfonate or para Potassium toluenesulfonate is preferably used.

(C) The compounding quantity of an aromatic sulfonic acid metal salt is 0.01-1 mass part normally with respect to 100 mass parts of (A) aromatic polycarbonate. If it is less than 0.01 part by mass, the effect of improving flame retardancy is insufficient, and if it exceeds 1 part by mass, the thermal stability during molding of the polycarbonate resin composition and the physical properties in the wet heat test may be deteriorated. Especially, it is preferable to use in 0.03-0.8 mass part with respect to 100 mass parts of polycarbonate resin (A), especially 0.05-0.6 mass part.

(D) Polyfluoroethylene In the present invention, (D) polyfluoroethylene is preferably polytetrafluoroethylene having fibril-forming ability. Polytetrafluoroethylene having fibril-forming ability is classified as type 3 according to the ASTM standard. Examples of polytetrafluoroethylene having fibril-forming ability include Teflon (registered trademark) 6J manufactured by Mitsui DuPont Fluorochemical Co., Ltd., and Polyflon F201L, FA500B, and FA500C manufactured by Daikin Chemical Industries, Ltd. Examples of the aqueous dispersion of polytetrafluoroethylene include Fluon D-1 manufactured by Daikin Chemical Industries, Ltd. and polyfluoroethylene compounds having a multilayer structure formed by polymerizing vinyl monomers. Any type can be used for the resin composition of the present invention.

In order to further improve the appearance of a molded article obtained by injection molding a flame retardant resin composition containing polyfluoroethylene, a specific coated polyfluoroethylene (hereinafter referred to as coated polyfluoroethylene) coated with an organic polymer is used. May be abbreviated). The specific coated polyfluoroethylene is one in which the content ratio of polyfluoroethylene in the coated polyfluoroethylene falls within the range of 40 to 95% by mass, of which 43 to 80% by mass, and more preferably 45 to 70% by mass. %, Particularly 47 to 60% by mass is preferable. As the specific coated polyfluoroethylene of the present invention, for example, Metablene A-3800, A-3700, KA-5503 manufactured by Mitsubishi Rayon Co., Ltd., Poly TS AD001 manufactured by PIC, or the like can be used.

The compounding quantity of the polyfluoroethylene (D) of this invention is 0.01-1.5 mass parts with respect to 100 mass parts of aromatic polycarbonate resin (A), and 0.05-0.9 mass part is preferable. 0.1 to 0.7 parts by mass is particularly preferable. In the case of coated polyfluoroethylene, the amount added corresponds to the amount of pure polyfluoroethylene. (C) When the blending amount of polyfluoroethylene is less than 0.01 parts by mass, the flame retardancy may be reduced. On the other hand, when it exceeds 1.5 parts by mass, the appearance of the molded product may be deteriorated. .

In the polycarbonate resin composition of the present invention, if necessary, other resins, various resin additives, and the like may be used in addition to the components described above as long as the effects of the present invention are not impaired. Specific examples of the other resins include polyolefin resins such as polyethylene resins and polypropylene resins, polyamide resins, polyimide resins, polyetherimide resins, polyurethane resins, polyphenylene ether resins, polyphenylene sulfide resins, polysulfone resins, and polymethacrylates. Examples thereof include resins, polyester resins, acrylonitrile-styrene-butadiene copolymer resins (ABS), and the like.

  Resin additives include impact modifiers, mold release agents, dyes and pigments, flame retardants, antistatic agents, antifogging agents, lubricants / antiblocking agents, fluidity improving agents, plasticizers, dispersants, antibacterial agents Agents, fluorescent brighteners, UV absorbers, inorganic resin additives include glass fiber, glass milled fiber, glass flake, glass bead, carbon fiber, silica, alumina, calcium sulfate powder, gypsum, gypsum Examples include inorganic fillers such as whiskers, barium sulfate, talc, mica, calcium silicate, carbon black, and graphite. These may be used alone or in combination of two or more in any ratio.

Heat stabilizer and antioxidant The polycarbonate resin composition of the present invention is further used for the purpose of suppressing yellowing that occurs during melt processing or when used for a long period of time at a high temperature, and further for suppressing the decrease in mechanical strength. It is preferable to contain a stabilizer and an antioxidant.

  As the heat stabilizer and the antioxidant, any conventionally known one can be used. Among them, a phosphorus compound is preferable as the heat stabilizer, and a phenol compound is preferable as the antioxidant, and these may be used in combination. Phosphorus compounds are generally effective in improving the residence stability at high temperatures and heat stability when using resin moldings when melt-kneading polycarbonate resins, and phenol compounds are generally effective in heat aging resistance, etc. The heat resistance stability when using the polycarbonate resin molded body is high. Further, by using a phosphorus compound and a phenol compound in combination, the effect of improving the colorability is further improved.

  Examples of the phosphorus compound used in the present invention include phosphorous acid, phosphoric acid, phosphite ester, phosphate ester, etc. Among them, phosphite contains trivalent phosphorus and easily exhibits a discoloration suppressing effect. Phosphites such as phosphonite are preferred.

  Specific examples of the phosphite include triphenyl phosphite, tris (nonylphenyl) phosphite, dilauryl hydrogen phosphite, triethyl phosphite, tridecyl phosphite, tris (2-ethylhexyl) phosphite, and tris. (Tridecyl) phosphite, tristearyl phosphite, diphenyl monodecyl phosphite, monophenyl didecyl phosphite, diphenyl mono (tridecyl) phosphite, tetraphenyl dipropylene glycol diphosphite, tetraphenyl tetra (tridecyl) pentaerythritol tetra Phosphite, hydrogenated bisphenol A phenol phosphite polymer, diphenyl hydrogen phosphite, 4,4′-butylidene-bis (3-methyl-6-te rt-butylphenyldi (tridecyl) phosphite) tetra (tridecyl) 4,4'-isopropylidenediphenyldiphosphite, bis (tridecyl) pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, dilauryl Pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tris (4-tert-butylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, hydrogenated bisphenol A pentaerythritol phosphite Polymer, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphat And 2,2′-methylenebis (4,6-di-tert-butylphenyl) octyl phosphite, bis (2,4-dicumylphenyl) pentaerythritol diphosphite, and the like.

  Examples of phosphonites include tetrakis (2,4-di-iso-propylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2,4-di-n-butylphenyl) -4,4′-biphenyl. Range phosphonite, tetrakis (2,4-di-tert-butylphenyl) -4,4'-biphenylene diphosphonite, tetrakis (2,4-di-tert-butylphenyl) -4,3'-biphenylene diphospho Knight, tetrakis (2,4-di-tert-butylphenyl) -3,3'-biphenylenediphosphonite, tetrakis (2,6-di-iso-propylphenyl) -4,4'-biphenylenediphosphonite, Tetrakis (2,6-di-n-butylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2,6-di-ter t-butylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2,6-di-tert-butylphenyl) -4,3′-biphenylenediphosphonite, and tetrakis (2,6-di-tert) -Butylphenyl) -3,3'-biphenylenediphosphonite and the like.

  Examples of the acid phosphate include methyl acid phosphate, ethyl acid phosphate, propyl acid phosphate, isopropyl acid phosphate, butyl acid phosphate, butoxyethyl acid phosphate, octyl acid phosphate, 2-ethylhexyl acid phosphate, decyl acid phosphate, and lauryl phosphate. Phosphate, stearyl acid phosphate, oleyl acid phosphate, behenyl acid phosphate, phenyl acid phosphate, nonyl phenyl acid phosphate, cyclohexyl acid phosphate, phenoxyethyl acid phosphate, alkoxy polyethylene glycol acid phosphate, bisphenol A acid Sulfate, dimethyl acid phosphate, diethyl acid phosphate, dipropyl acid phosphate, diisopropyl acid phosphate, dibutyl acid phosphate, dioctyl acid phosphate, di-2-ethylhexyl acid phosphate, dioctyl acid phosphate, dilauryl acid phosphate, distearyl acid phenyl Acid phosphate, bisnonylphenyl acid phosphate, etc. are mentioned.

  Among the phosphites, distearyl pentaerythritol diphosphite, tris (2,4-di-tert-butylphenyl) phosphite, bis (2,6-di-tert-butyl-4-methylphenyl) penta Erythritol diphosphite, 2,2′-methylenebis (4,6-di-tert-butylphenyl) octyl phosphite, bis (2,4-dicumylphenyl) pentaerythritol diphosphite are preferable, and heat resistance is good. Tris (2,4-di-tert-butylphenyl) phosphite is particularly preferred in that it is difficult to hydrolyze.

  As the antioxidant, a phenol compound having a specific structure in the molecule is preferable. Specifically, for example, 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 4,4′-butylidenebis (6-tert -Butyl-3-methylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 3,9-bis [2- {3- (3-tert- Butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5.5] undecane, triethylene glycol bis [β- (3 -Tert-butyl-4-hydroxy-5-methylphenyl) propionate], 1,6-hexanediol bis [β- (3-tert-butyl 4-hydroxy-5-methylphenyl) propionate], pentaerythritol-tetrakis [β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate], octadecyl [β- (3-tert-butyl-4) -Hydroxy-5-methylphenyl) propionate] and the like.

  Among these, 4,4′-butylidenebis (6-tert-butyl-3-methylphenol), 1,1,3-tris (2-methyl-) is necessary because it is necessary to suppress yellowing when kneaded with a polycarbonate resin. 4-hydroxy-5-tert-butylphenyl) butane, 3,9-bis [2- {3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl ] -2,4,8,10-tetraoxaspiro [5.5] undecane is preferred, especially 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 3 , 9-bis [2- {3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] -2,4,8,10 -Tetraoxaspiro [5.5] undecane is preferred.

  The content of the heat stabilizer and the antioxidant used in the present invention may be appropriately selected and determined, but is usually 0.0001 to 0.5 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A). Yes, 0.0003 to 0.3 parts by mass is preferable, and 0.001 to 0.1 parts by mass is particularly preferable. If the content of the heat stabilizer or the antioxidant is too small, the effect is insufficient. On the other hand, if the content is too large, the molecular weight of the polycarbonate resin may be lowered or the hue may be lowered.

As the release agent that may be used in the present invention, at least one selected from aliphatic carboxylic acids, aliphatic carboxylic acid esters, and polysiloxane silicone oils is used. Among these, at least one selected from aliphatic carboxylic acids and aliphatic carboxylic acid esters is preferably used.

  Examples of the aliphatic carboxylic acid include saturated or unsaturated aliphatic monocarboxylic acid, dicarboxylic acid, and tricarboxylic acid. Here, the aliphatic carboxylic acid also includes an alicyclic carboxylic acid. Of these, preferred aliphatic carboxylic acids are mono- or dicarboxylic acids having 6 to 36 carbon atoms, and aliphatic saturated monocarboxylic acids having 6 to 36 carbon atoms are more preferred. Specific examples of such aliphatic carboxylic acids include palmitic acid, stearic acid, valeric acid, caproic acid, capric acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, melicic acid, tetratriacontanoic acid. , Montanic acid, glutaric acid, adipic acid, azelaic acid and the like.

  As the aliphatic carboxylic acid component constituting the aliphatic carboxylic acid ester, the same aliphatic carboxylic acid as that described above can be used. On the other hand, examples of the alcohol component constituting the aliphatic carboxylic acid ester include saturated or unsaturated monohydric alcohols and saturated or unsaturated polyhydric alcohols. These alcohols may have a substituent such as a fluorine atom or an aryl group. Of these alcohols, monovalent or polyvalent saturated alcohols having 30 or less carbon atoms are preferable, and aliphatic saturated monohydric alcohols or polyhydric alcohols having 30 or less carbon atoms are more preferable. Here, the aliphatic alcohol also includes an alicyclic alcohol.

  Specific examples of these alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, dipentaerythritol. Etc. These aliphatic carboxylic acid esters may contain an aliphatic carboxylic acid and / or alcohol as impurities, and may be a mixture of a plurality of compounds.

  Specific examples of the aliphatic carboxylic acid ester include beeswax (mixture based on myricyl palmitate), stearyl stearate, behenyl behenate, octyldodecyl behenate, glycerin monopalmitate, glycerin monostearate, glycerin Examples thereof include distearate, glycerin tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, and pentaerythritol tetrastearate.

  The compounding quantity of a mold release agent is 2 mass parts or less with respect to 100 mass parts of aromatic polycarbonate resin (A), Preferably it is 1 mass part or less. When the amount exceeds 2 parts by mass, there are problems such as degradation of hydrolysis resistance and mold contamination during injection molding. The release agent can be used alone or in combination.

As a method for mixing and melt-kneading each component of the composition of the present invention, a method applied to a conventionally known thermoplastic resin composition can be applied. Examples thereof include a method using a ribbon blender, a Henschel mixer, a Banbury mixer, a drum tumbler, a single-screw or twin-screw extruder, a kneader, and the like. The temperature for melt kneading is not particularly limited, but is usually in the range of 240 to 320 ° C.

The polycarbonate resin composition according to the present invention can be used as a molding material for various molded products. As the applicable molding method, a method applicable to the molding of a thermoplastic resin can be applied as it is, an injection molding method, an extrusion molding method, a hollow molding method, a rotational molding method, a compression molding method, a differential pressure molding method, a transfer molding. Law.

Since the molded article according to the present invention is excellent in flame retardancy, light reflectivity, and impact resistance, it is useful for light reflectors for liquid crystal backlights and reflector frame parts.

The present invention will be described more specifically with reference to the following examples and comparative examples. However, the present invention is not limited to the following examples unless it exceeds the gist. In the following Examples and Comparative Examples, “part” and “%” mean “part by mass” and “% by mass” unless otherwise specified.

[raw materials]
(A) Aromatic polycarbonate resin poly-4,4-isopropylidene diphenyl carbonate: "Iupilon (registered trademark) H-3000" manufactured by Mitsubishi Engineering Plastics Co., Ltd., viscosity average molecular weight 18,000 (flow value Q value: 17, hereinafter abbreviated as PC)

(B) Titanium oxide additive (B-1) “Kronos (trade name) 2233” manufactured by Kronos
(B-2) “Tipure (trade name) PCX-01” manufactured by Du Pont
(B-3) “PC-5” manufactured by Regino Color
(B-4) “Kronos (trade name) 2230” manufactured by Kronos
(B-5) "Ishihara Sangyo Co., Ltd."
(B-6) Ishihara Sangyo Co., Ltd., “Taipeku (trade name) PF-740”
(B-7) “TiONA (trade name) 188” manufactured by Millennium Chemical
(B-8) “RCL-69” manufactured by Millennium Chemical
Table 1 shows the component analysis results of titanium oxide used in Examples and Comparative Examples.

(C) Aromatic sulfonic acid metal salt (C-1) Toluenesulfonic acid sodium salt Chembridge International,
“Chemguard (trade name) NATS”
(C-2) Toluenesulfonic acid potassium salt Chembridge International,
“Chemguard (trade name) PABS”

(D) Polyfluoroethylene (PTFE)
"Polyflon (trade name) F-201L" manufactured by Daikin Industries, Ltd.

(E) Thermal stabilizer (E-1) Tris (2,4-di-tert-butylphenyl) phosphite “AS2112” manufactured by ADEKA
(E-2) Bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, “PEP36” manufactured by ADEKA

(F) Release agent Pentaerythritol stearate, “NOYSTAR (trade name) H476D” manufactured by NOF Corporation

[Examples 1-6 and Comparative Examples 1-12]
(A) aromatic polycarbonate resin, titanium oxide-based additive, (C) aromatic sulfonic acid metal salt, (D) polyfluoroethylene, thermal stability so that the ratio (mass ratio) shown in Tables 2 to 4 is obtained. After mixing an agent and a release agent and mixing with a tumbler, the mixture was put into a hopper of a twin screw extruder (12 blocks, TEX30XCT). Each resin component was melt-kneaded under the conditions of a cylinder temperature of 270 ° C., 200 rpm, and an extrusion rate of 25 kg / hour to obtain pellets of resin compositions described in Tables 2 to 4. The obtained resin composition was subjected to various evaluations by the following methods. The results are shown in Tables 2-4.

[Measurement of surface treatment components of titanium oxide]
As for the surface treatment amount of Al of the titanium oxide-based additive, a wavelength dispersive X-ray fluorescence spectrometer ZSXminiII manufactured by Rigaku Corporation was used, a palladium tube for the X-ray tube, a voltage of 40 kV / tube current of 1.2 mA, a measurement area diameter of 30 mm, It calculated using the intensity ratio of the spectrum of Ti and Al under vacuum atmosphere conditions. The amount of C was calculated by applying a high frequency current of anode power: 2.3 kW, frequency: 18 MHz, 175 mA using a high frequency induction heating furnace type EMIA-921V carbon analyzer manufactured by Horiba, Ltd. The results are shown in Table 1.

[Method for measuring average particle diameter of titanium oxide]
The measurement of the primary particle diameter of the titanium oxide-based additive used in Examples and Comparative Examples was performed by preparing a sample by the following method.

In (A) aromatic polycarbonate resin, 5 parts by mass of (B) titanium oxide-based additive used in Examples and Comparative Examples was added, and pellets were produced by the same kneading method as in Comparative Examples. An ultra-thin section of about 200 nm thickness for STEM observation was cut out from this pellet with an ultramicrotome, and was oxidized by STEM observation (magnification: 50,000 times) using a scanning electron microscope S-4800 manufactured by Hitachi High-Technologies Corporation. A primary particle image of titanium was obtained. The average value of the major axis and minor axis of the primary particles was taken as the primary particle size, and the average value of 30 primary particles (value in increments of 0.05 μm) was used for the measurement of the primary particle size. The results are shown in Table 1.

[Method for evaluating physical properties of molded products]
(1) For each resin composition obtained in the flammability examples and comparative examples, injection molding is performed under the conditions of a set temperature of 280 ° C. and a mold temperature of 80 ° C. using an injection molding machine J50 manufactured by Nippon Steel Works, A molded article having a length of 127 mm, a width of 12.7 mm, and a thickness of 1.0 mm was obtained as a test piece. About the obtained test piece, the vertical combustion test based on UL94 was done, the flammability result was set to V-0, V-1, V-2 from the favorable order, and the thing outside a specification was classified into NG.

(2) Flow Value As an evaluation of the fluidity and thermal stability of the resin composition, the pellet flow value (Q value) was evaluated by the method described in Appendix C of JIS K7210. Measurement was performed using a flow tester CFD500D manufactured by Shimadzu Corporation, using a die with a hole diameter of 1.0 mmφ and a length of 10 mm, under conditions of a test temperature of 280 ° C., 300 ° C. and 320 ° C., a test force of 160 kg / cm ² , and a preheating time of 420 sec. The amount of molten resin discharged (× 0.01 cc / sec) was measured.

(3) Impact As an evaluation of impact properties, Charpy impact strength was used and measured using a test piece with a thickness of 3 mm and a notch in accordance with ISO 179-2. The test piece was molded using an injection molding machine SG75 manufactured by Sumitomo Heavy Industries, Ltd. under the conditions of set temperatures of 280 ° C. and 300 ° C., and a mold temperature of 80 ° C.

(4) Appearance For each resin composition obtained in the examples and comparative examples, two stages having a thickness of 1 mm and 3 mm at a cylinder temperature of 280 ° C. and a mold temperature of 80 ° C. using an injection molding machine J50 manufactured by Nippon Steel Works The plate was molded and visually observed to evaluate the appearance of the molded product. Silver and resin burns were not recognized, and those with good appearance were evaluated as “◯”, and those with large appearance defects were determined as “x”.

(5) The reflectance of the 3 mm thick part of the plate used in the reflectance appearance evaluation was measured. The measurement was performed using a spectrocolorimeter CM3600d manufactured by Konica Minolta, in a D65 / 10 degree field of view and SCI normal measurement mode, and a reflectance value at a wavelength of 440 nm was used.

From the results in Table 2, the following can be understood. The resin compositions of Examples 1 to 5 described in claims have excellent thermal stability, flammability, appearance, strength, and reflection characteristics. In Example 3, the metal of the sulfonic acid metal salt was made different, but the same effect as in Examples 1 and 2 was exhibited. Example 4 changes the kind of titanium oxide type additive used for Examples 1-3, and exhibits an effect equivalent to the composition of Examples 1-3. However, Example 4 is slightly inferior in impact property at high temperature. In Example 5 , the amount of the titanium oxide-based additive was changed, and while having the same thermal stability as that of Example 1, it has more excellent reflection characteristics.

On the other hand, looking at Tables 3 and 4, Comparative Examples 1 and 2 are inferior in reflectance because the amount of titanium oxide-based additive is insufficient, and Comparative Example 3 is insufficient in the amount of aromatic sulfonic acid metal salt. Therefore, sufficient combustibility cannot be obtained, and in Comparative Example 4, the amount of the aromatic sulfonic acid metal salt is excessive and combustibility is obtained, but the appearance is deteriorated. In Comparative Example 5, the amount of polyfluoroethylene added is small, and the combustibility is insufficient. On the other hand, in Comparative Example 6, the amount of polyfluoroethylene added is poor and the appearance and impact characteristics are poor. In Comparative Example 7, sufficient flammability is obtained, but impact resistance at high temperature (300 ° C.) molding is inferior. Comparative Examples 8 and 10-12 are inferior in thermal stability, impact characteristics, appearance, and flammability because the surface treatment amount of the titanium oxide-based additive under the use of the aromatic sulfonic acid metal salt is not appropriate. In Comparative Example 9, in the absence of an aromatic sulfonic acid metal salt, even if a titanium oxide-based additive other than the present invention is used, it has good thermal stability but is inferior in flame retardancy.

  As described above, the flame retardant polycarbonate resin composition of the present invention is superior in heat stability, flame retardancy, appearance, impact properties, and light reflectance as compared with conventional flame retardant polycarbonate compositions. It can be said that this is a material suitable for a reflecting member such as a liquid crystal display member. Therefore, the industrial value of the present invention is remarkable.

Claims (3)

3 to 30 parts by mass of titanium oxide-based additive (B) surface-treated with alumina and organosiloxane, sodium paratoluenesulfonate and / or potassium paratoluenesulfonate (100 parts by mass of aromatic polycarbonate resin (A)) C) 0.01 to 1 part by mass, 0.01 to 1.5 parts by mass of polyfluoroethylene (D), and obtained by X-ray fluorescence analysis of the titanium oxide-based additive (B) Aluminum content a (mass%) in titanium oxide-based additive, carbon content c (mass%) in titanium oxide-based additive obtained by analyzing titanium oxide-based additive using high-frequency combustion type carbon analyzer ) And the average particle diameter (μm) of titanium oxide is d,
(Formula 1) 11.4 ≦ (a / d ² ) ≦ 15 and (Formula 2) 5 ≦ (c / d ² ) ≦ 25
An aromatic polycarbonate resin composition characterized by satisfying The molded object obtained from the aromatic polycarbonate resin composition of Claim 1 . The molded article according to claim 2 , wherein the molded article is a light reflecting member.