Polycarbonate resin composition

Abstract

To provide a polycarbonate resin composition which has high heat resistance and is excellent in retention stability, and satisfies total light transmittance and diffusibility in a balanced manner.SOLUTION: A polycarbonate resin composition contains, with respect to 100 pts.mass of a polycarbonate resin (A), 0.2-1.0 pts.mass of crosslinked acrylic polymer particles (B), wherein the crosslinked acrylic polymer particles (B) have a 10% weight reduction temperature measured by a calorimetry apparatus of 330°C or higher, and the total amount of Na, K and Ca contained in the crosslinked acrylic polymer particles (B) is 100 ppm or less.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a polycarbonate resin composition, and to a polycarbonate resin composition and a molded article thereof that have high heat resistance, excellent retention stability, and satisfy the total light transmittance and diffusibility in a well-balanced manner.

Background Art

[0002] Polycarbonate resin is a high-functional resin having excellent physical properties such as impact resistance, heat resistance, weather resistance, and flame retardancy, and having a high light transmittance. In particular, taking advantage of its excellent optical properties and flame retardancy, in recent years, it has been used as parts for lighting equipment and optical members.

[0003] Among these, in members such as lighting covers using LEDs or the like as light sources, various displays, and vehicle light guides, there are those that spread the illumination light by imparting light diffusibility, and in these, high light diffusibility and light transmittance are required to be maintained so as not to reduce the illumination efficiency.

[0004] As polycarbonate resins imparted with light diffusibility, various polycarbonate resin compositions blended with acrylic resin particles such as polymethyl methacrylate have been proposed. Further, it has also been proposed to add silicone-based particles instead of acrylic resin particles. However, although silicone-based particles are excellent in heat resistance, their optical properties that require both light transmittance and light diffusibility are not sufficient compared to acrylic resin particles, and acrylic resin particles are useful.

[0005] In recent years, lighting parts and optical members have various shapes, and are becoming larger and longer. For example, optical members for long articles exceeding 1 m have also appeared. When injection molding such long article molded products, the resin composition stays at a high temperature for a long time, so the retention deterioration is severe, and it may become impossible to mold due to a decrease in the viscosity of the raw material resin. Therefore, it is essential to have excellent heat resistance.

[0006] Patent Document 1 describes an invention in which a phosphite antioxidant is contained in an acrylic resin diffusing agent and then compounded into a polycarbonate resin to prevent discoloration of the polycarbonate resin. However, it is not easy to produce a diffusing agent containing a phosphite antioxidant, and the effect of the phosphite antioxidant is not always sufficient.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a polycarbonate resin composition that is highly heat-resistant, has excellent retention stability, and satisfies the total light transmittance and diffusibility in a well-balanced manner in a system containing acrylic resin particles.

Means for Solving the Problems

[0009] As a result of intensive studies to achieve the above problems, the present inventors have found that the above problems can be solved by blending a crosslinked acrylic polymer particle (B) having a 10% weight loss temperature of a specific temperature or higher and a total amount of Na, K, and Ca of 100 ppm or less in a specific amount into a polycarbonate resin, and have completed the present invention. The present invention relates to the following polycarbonate resin compositions and molded articles.

[0010] 1. A polycarbonate resin composition, comprising 0.2 to 1.0 parts by mass of crosslinked acrylic polymer particles (B) with respect to 100 parts by mass of a polycarbonate resin (A), wherein the 10% weight loss temperature measured by a calorimeter of the crosslinked acrylic polymer particles (B) is 330°C or higher, and the total amount of Na, K, and Ca contained in the crosslinked acrylic polymer particles (B) is 100 ppm or less. 2. The polycarbonate resin composition according to 1 above, further comprising 0.0001 to 0.5 parts by mass of a phosphorus-based antioxidant (C) and / or 0.0001 to 0.5 parts by mass of a phenolic antioxidant (D) with respect to 100 parts by mass of the polycarbonate resin (A). 3. A molded article comprising the polycarbonate resin composition according to 1 or 2 above. 4. The molded article according to 3 above, which is a lighting component or an optical member.

Effects of the Invention

[0011] The polycarbonate resin composition of the present invention has high heat resistance, excellent retention stability, satisfies the total light transmittance and diffusibility in a well-balanced manner, and also has excellent moldability.

Modes for Carrying Out the Invention

[0012] Hereinafter, the present invention will be described in detail by showing embodiments, examples, and the like. In this specification, "~" is used to mean including the numerical values described before and after as the lower limit value and the upper limit value, unless otherwise specified.

[0013] The polycarbonate resin composition of the present invention is characterized in that it contains 0.2 to 1.0 parts by mass of crosslinked acrylic polymer particles (B) with respect to 100 parts by mass of a polycarbonate resin (A), the 10% weight loss temperature measured by a calorimeter of the crosslinked acrylic polymer particles (B) is 330°C or higher, and the total amount of Na, K, and Ca contained in the crosslinked acrylic polymer particles (B) is 100 ppm or less. Hereinafter, each component constituting the polycarbonate resin composition of the present invention, the molded article, and the like will be described in detail.

[0014] [Polycarbonate resin (A)] The polycarbonate resin (A) used in the present invention is not particularly limited, and various types can be used. Polycarbonate resins can be classified into aromatic polycarbonate resins in which the carbon directly bonded to the carbonate bond is aromatic carbon, and aliphatic polycarbonate resins in which the carbon is aliphatic carbon, and either can be used. Among them, as the polycarbonate resin (A), aromatic polycarbonate resins are preferred from the viewpoints of heat resistance, mechanical properties, electrical properties, etc.

[0015] Among the monomers that are raw materials for aromatic polycarbonate resins, examples of aromatic dihydroxy compounds include Dihydroxybenzenes such as 1,2-dihydroxybenzene, 1,3-dihydroxybenzene (i.e., resorcinol), and 1,4-dihydroxybenzene; Dihydroxybiphenyls such as 2,5-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, and 4,4'-dihydroxybiphenyl;

[0016] Dihydroxynaphthalenes such as 2,2'-dihydroxy-1,1'-binaphthyl, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, and 2,7-dihydroxynaphthalene;

[0017] Dihydroxy diaryl ethers such as 2,2'-dihydroxy diphenyl ether, 3,3'-dihydroxy diphenyl ether, 4,4'-dihydroxy diphenyl ether, 4,4'-dihydroxy-3,3'-dimethyl diphenyl ether, 1,4-bis(3-hydroxyphenoxy)benzene, and 1,3-bis(4-hydroxyphenoxy)benzene;

[0018] 2,2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A), 1,1-Bis(4-hydroxyphenyl)propane, 2,2-Bis(3-methyl-4-hydroxyphenyl)propane (i.e., bisphenol C), 2,2-Bis(3-methoxy-4-hydroxyphenyl)propane, 2-(4-Hydroxyphenyl)-2-(3-methoxy-4-hydroxyphenyl)propane, 1,1-Bis(3-tert-butyl-4-hydroxyphenyl)propane, 2,2-Bis(3,5-dimethyl-4-hydroxyphenyl)propane, 2,2-Bis(3-cyclohexyl-4-hydroxyphenyl)propane, 2-(4-Hydroxyphenyl)-2-(3-cyclohexyl-4-hydroxyphenyl)propane, α,α'-Bis(4-hydroxyphenyl)-1,4-diisopropylbenzene, 1,3-Bis[2-(4-hydroxyphenyl)-2-propyl]benzene, Bis(4-hydroxyphenyl)methane, Bis(4-hydroxyphenyl)cyclohexylmethane, Bis(4-hydroxyphenyl)phenylmethane, Bis(4-hydroxyphenyl)(4-propenylphenyl)methane, Bis(4-hydroxyphenyl)diphenylmethane, Bis(4-hydroxyphenyl)naphthylmethane, 1,1-Bis(4-hydroxyphenyl)ethane, 1,1-Bis(4-hydroxyphenyl)-1-phenylethane, 1,1-Bis(4-hydroxyphenyl)-1-naphthylethane, 1,1-Bis(4-hydroxyphenyl)butane, 2,2-Bis(4-hydroxyphenyl)butane, 2,2-Bis(4-hydroxyphenyl)pentane, 1,1-Bis(4-hydroxyphenyl)hexane, 2,2-Bis(4-hydroxyphenyl)hexane, 1,1-Bis(4-hydroxyphenyl)octane, 2,2-Bis(4-hydroxyphenyl)octane, 4,4-Bis(4-hydroxyphenyl)heptane, 2,2-Bis(4-hydroxyphenyl)nonane, 1,1-Bis(4-hydroxyphenyl)decane, 1,1-Bis(4-hydroxyphenyl)dodecane, and other bis(hydroxyaryl)alkanes;

[0019] 1,1-Bis(4-hydroxyphenyl)cyclopentane, 1,1-Bis(4-hydroxyphenyl)cyclohexane, 1,1-Bis(4-hydroxyphenyl)-3,3-dimethylcyclohexane, 1,1-Bis(4-hydroxyphenyl)-3,4-dimethylcyclohexane, 1,1-Bis(4-hydroxyphenyl)-3,5-dimethylcyclohexane, 1,1-Bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 1,1-Bis(4-hydroxy-3,5-dimethylphenyl)-3,3,5-trimethylcyclohexane, 1,1-Bis(4-hydroxyphenyl)-3-propyl-5-methylcyclohexane, 1,1-bis(4-hydroxyphenyl)-3-tert-butyl-cyclohexane, 1,1-Bis(4-hydroxyphenyl)-4-tert-butyl-cyclohexane, 1,1-Bis(4-hydroxyphenyl)-3-phenylcyclohexane, 1,1-Bis(4-hydroxyphenyl)-4-phenylcyclohexane, and other bis(hydroxyaryl)cycloalkanes;

[0020] 9,9-Bis(4-hydroxyphenyl)fluorene, Bisphenols containing a cardo structure such as 9,9-bis(4-hydroxy-3-methylphenyl)fluorene;

[0021] 4,4'-Dihydroxydiphenyl sulfide, Dihydroxydiaryl sulfides such as 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide; Dihydroxydiaryl sulfoxides such as 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide; 4,4'-Dihydroxydiphenyl sulfone, Dihydroxydiaryl sulfones such as 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone; etc. are mentioned.

[0022] Among these, bis(hydroxyaryl)alkanes are preferred, and among them, bis(4-hydroxyphenyl)alkanes are preferred. Particularly from the viewpoints of impact resistance and heat resistance, 2,2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A), 2,2-bis(3-methyl-4-hydroxyphenyl)propane (i.e., bisphenol C) are preferred. Note that as the aromatic dihydroxy compound, one kind may be used, or two or more kinds may be used in any combination and ratio.

[0023] Among the monomers that are raw materials for the polycarbonate resin, examples of the carbonate precursor include carbonyl halide, carbonate ester, etc. Note that as the carbonate precursor, one kind may be used, or two or more kinds may be used in any combination and ratio.

[0024] Specific examples of the carbonyl halide include, for example, phosgene; halocarbonates such as the bischloroformate form of the dihydroxy compound, the monochloroformate form of the dihydroxy compound, etc.

[0025] Examples of the carbonate ester include, specifically, diaryl carbonates such as diphenyl carbonate and ditolyl carbonate; dialkyl carbonates such as dimethyl carbonate and diethyl carbonate; carbonate bodies of dihydroxy compounds such as biscarbonate bodies of dihydroxy compounds, monocarbonate bodies of dihydroxy compounds, and cyclic carbonates.

[0026] The method for producing the polycarbonate resin (A) is not particularly limited, and any method can be adopted. Examples thereof include an interfacial polymerization method, a melt transesterification method, a pyridine method, a ring-opening polymerization method of a cyclic carbonate compound, and a solid-phase transesterification method of a prepolymer. Among these, the one by the interfacial polymerization method is particularly preferable.

[0027] The molecular weight of the polycarbonate resin (A) is the viscosity-average molecular weight (Mv) converted from the solution viscosity measured at a temperature of 25 °C using methylene chloride as a solvent, preferably 10,000 to 50,000, more preferably 10,000 to 40,000, especially 10,000 to 30,000, 10,000 to 26,000, further 10,500 or more, 11,000 or more, particularly 11,500 or more, most preferably 12,000 or more, and further 24,000 or less, particularly preferably 20,000 or less. By setting the viscosity-average molecular weight to be equal to or higher than the lower limit value of the above range, the mechanical strength of the polycarbonate resin composition of the present invention can be further improved. By setting the viscosity-average molecular weight to be equal to or lower than the upper limit value of the above range, the decrease in fluidity of the polycarbonate resin composition of the present invention can be suppressed and improved, and the molding processability can be enhanced to easily perform thin-wall molding. In addition, two or more polycarbonate resins having different viscosity-average molecular weights may be mixed and used. In this case, a polycarbonate resin having a viscosity-average molecular weight outside the above preferable range may be mixed.

[0028] The viscosity-average molecular weight [Mv] means the value calculated from the intrinsic viscosity [η] (unit: dl / g) at 25 °C using an Ubbelohde viscometer with methylene chloride as the solvent, according to Schnell's viscosity formula, i.e., η = 1.23×10 -4 Mv 0.83 . The intrinsic viscosity [η] is the value calculated by measuring the specific viscosity [η sp at each solution concentration [C] (g / dl) using the following formula. [Equation]

[0029] In addition, in order to improve the appearance and fluidity of the molded product, the polycarbonate resin (A) may contain a polycarbonate oligomer. The viscosity-average molecular weight [Mv] of this polycarbonate oligomer is usually 1500 or more, preferably 2000 or more, and usually 9500 or less, preferably 9000 or less. Furthermore, the content of the polycarbonate oligomer is preferably 30% by mass or less of the polycarbonate resin (including the polycarbonate oligomer).

[0030] Furthermore, the polycarbonate resin (A) may be not only virgin raw materials but also polycarbonate resins recycled from used products (so-called material-recycled polycarbonate resins). However, the recycled polycarbonate resin is preferably 80% by mass or less, more preferably 50% by mass or less, of the polycarbonate resin (A). Since the recycled polycarbonate resin is likely to have undergone deterioration such as thermal degradation and aging degradation, if such a polycarbonate resin is used in an amount exceeding the above range, the hue and mechanical properties may be deteriorated.

[0031] [Crosslinked acrylic polymer particles (B)] The polycarbonate resin composition of the present invention contains crosslinked acrylic polymer particles (B), has a 10% weight loss temperature measured by a calorimeter of 330 °C or higher, and uses those in which the total amount of Na, K, and Ca contained in the crosslinked acrylic polymer particles (B) is 100 ppm or less.

[0032] As the crosslinked acrylic polymer particles (B), preferably, crosslinked acrylic resin particles produced from a non-crosslinkable acrylic monomer and a crosslinkable monomer, preferably by suspension polymerization, are used. As the non-crosslinkable acrylic monomer, an acrylic monomer alone or a combination of a plurality of acrylic monomers is used. As the acrylic monomer, acrylic esters such as methyl acrylate, n-butyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and methacrylic esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate are preferably mentioned, and these can be used alone or in combination of two or more. Among them, methyl methacrylate is preferably used. In addition, a monomer copolymerizable with the (meth)acrylic acid ester monomer may be added to the monomer. Examples of such a monomer include monomers having a vinyl group such as styrene, α-methylstyrene, and vinyl acetate.

[0033] As the crosslinkable monomer, a compound having two or more unsaturated bonds in the molecule is preferably used. For example, trimethylolpropane tri(meth)acrylate, allyl methacrylate, triallyl cyanurate, triallyl isocyanate, ethylene glycol dimethacrylate, propylene glycol diallyl ether, divinylbenzene, diethylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, etc. are mentioned. Among them, trimethylolpropane tri(meth)acrylate is preferable.

[0034] The crosslinked acrylic polymer particles (B) can be produced by suspension polymerization of a non-crosslinkable acrylic monomer and a crosslinkable monomer. For example, both monomers are suspended using polyvinyl alcohol as a dispersant and polymerized, and then obtained by filtration, washing, sieving, and drying. The usage ratio of both monomers is preferably 90 to 99% by mass of the non-crosslinkable acrylic monomer and 10 to 1% by mass of the crosslinkable monomer. If the amount of the crosslinkable monomer is too small, the dispersibility of the obtained bead-shaped crosslinked acrylic polymer particles in the polycarbonate resin tends to be poor. Increasing the amount of the crosslinkable monomer can raise the 10% weight loss temperature, but if it is too much, the crosslinked acrylic polymer particles become too hard and the impact strength tends to decrease, which is not preferable.

[0035] The 10% weight loss temperature of the crosslinked acrylic polymer particles (B) is 330°C or higher. It has been found that when those with 330°C or higher are blended, even if the residence time during molding is long, the total light transmittance and haze change of the resin composition are small. The 10% weight loss temperature is preferably 335°C or higher, particularly preferably 340°C or higher, 345°C or higher, 350°C or higher, 355°C or higher, 360°C or higher, especially 365°C or higher. The upper limit is usually up to about 400°C for a crosslinked acrylic polymer.

[0036] The measurement of the 10% weight loss temperature is carried out by a calorimetry device (TGA) under a nitrogen atmosphere by measuring the temperature at which 10% of the resin weight decreases during the process of raising the temperature from 40°C to 520°C at a rate of 10°C / min. The specific method is as described in the examples.

[0037] To obtain crosslinked acrylic polymer particles (B) with a 10% weight loss temperature of 330°C or higher, it is possible by conventional methods such as increasing the amount of the crosslinkable monomer or increasing the molecular weight of the polymer, or by selecting and using from commercially available products.

[0038] In the present invention, as the crosslinked acrylic polymer particles (B), those having a 10% weight loss temperature of 330°C or higher and a total amount of Na, K, and Ca in the crosslinked acrylic polymer particles (B) of 100 ppm or less are used, whereby the decomposition and deterioration of the polycarbonate resin during heat retention can be significantly reduced. When the total amount of Na, K, and Ca exceeds 100 ppm, even if the 10% weight loss temperature is 330°C or higher, the retention stability of the polycarbonate resin composition becomes extremely poor. The total amount of Na, K, and Ca is preferably 50 ppm or less, more preferably 40 ppm or less, particularly preferably 30 ppm or less, 20 ppm or less, and especially 15 ppm or less. The lower limit is preferably 1 ppm or more, particularly preferably 3 ppm or more, and especially 5 ppm or more.

[0039] The amount of Na is preferably 20 ppm or less, more preferably 15 ppm or less, particularly preferably 14 ppm or less, and especially preferably 13 ppm or less. The amount of K is preferably 20 ppm or less, more preferably 15 ppm or less, particularly preferably 10 ppm or less, 5 ppm or less, 3 ppm or less, 2 ppm or less, and especially 1 ppm or less. The amount of Ca is preferably 20 ppm or less, more preferably 15 ppm or less, particularly preferably 10 ppm or less, 5 ppm or less, 3 ppm or less, 2 ppm or less, and especially preferably 1 ppm or less.

[0040] The measurement of the amounts of Na, K, and Ca in the crosslinked acrylic polymer particles (B) is the amount of metal detected by ICP emission spectrometry. The details are as described in the examples.

[0041] Na, K, and Ca in the crosslinked acrylic polymer particles (B) are considered to be derived from those contained in the dispersant, catalyst, etc. used in the polymerization step during their production. However, in order to achieve the above ppm amounts, it can be adjusted by strengthening washing and purification after polymerization, or it is also possible to select and use from commercially available products.

[0042] The crosslinked acrylic polymer particles (B) preferably have an average particle size of 1 to 10 μm. When the average particle size is within this range, the light diffusion rate and dispersibility are higher. The average particle size is preferably 1.5 to 7 μm, more preferably 2 to 4 μm. The particle size measurement is D50 carried out by the Coulter counter method on a number basis.

[0043] The content of the crosslinked acrylic polymer particles (B) is 0.2 to 1.0 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A). By containing it within such a range, a polycarbonate resin composition with high heat resistance, excellent retention stability, and a well-balanced total light transmittance and diffusibility can be obtained. The preferred amount of the crosslinked acrylic polymer particles (B) is 0.2 to 0.9 parts by mass, more preferably 0.2 to 0.8 parts by mass.

[0044] [Phosphorus-based antioxidant (C)] The polycarbonate resin composition of the present invention preferably contains a phosphorus-based antioxidant (C). The content of the phosphorus-based antioxidant (C) is 0.0001 to 0.5 parts by mass with respect to 100 parts by mass of the polycarbonate resin. Within such a range, by combining with a specific amount of the crosslinked acrylic polymer particles (B), it becomes easy to obtain a polycarbonate resin composition with high heat resistance, excellent retention stability, and a well-balanced total light transmittance and diffusibility. The preferred content of the phosphorus-based antioxidant (C) is 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, preferably 0.4 parts by mass or less, more preferably 0.3 parts by mass or less, especially preferably 0.3 parts by mass or less, 0.2 parts by mass or less, 0.1 parts by mass or less, 0.08 parts by mass or less, and particularly preferably 0.05 parts by mass or less.

[0045] Examples of the phosphorus-based antioxidant (C) include phosphorous acid, phosphoric acid, phosphite esters, phosphate esters, etc. Among them, phosphite esters such as phosphite and phosphonite are preferred because they contain trivalent phosphorus and are likely to exhibit a discoloration suppression effect.

[0046] Examples of phosphites include triphenyl phosphite, tris(nonylphenyl) phosphite, dilauryl hydrogen phosphite, triethyl phosphite, tridecyl phosphite, tris(2-ethylhexyl) phosphite, tris(tridecyl) phosphite, tristearyl phosphite, diphenyl monodecyl phosphite, monophenyl didecyl phosphite, diphenyl mono(tridecyl) phosphite, tetraphenyl dipropylene glycol diphosphite, tetraphenyl tetra(tridecyl) pentaerythritol tetraphosphite, hydrogenated bisphenol A phenol phosphite polymer, diphenyl hydrogen phosphite, 4,4'-butylidene-bis(3-methyl-6-tert-butylphenyldi(tridecyl) phosphite), tetra(tridecyl) 4,4'-isopropylidenediphenyl diphosphite, 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 diphosphite, 2,2'-methylenebis(4,6-di-tert-butylphenyl) octyl phosphite, bis(2,4-dicumylphenyl) pentaerythritol diphosphite, and the like.

[0047] Examples of phosphonites include tetrakis(2,4-di-isopropylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,4-di-n-butylphenyl Examples include (R)-4,4'-biphenylenediphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,3'-biphenylenediphosphonite, tetrakis(2,4-di-tert-butylphenyl)-3,3'-biphenylenediphosphonite, tetrakis(2,6-di-isopropylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,6-di-n-butylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,3'-biphenylenediphosphonite, tetrakis(2,6-di-tert-butylphenyl)-3,3'-biphenylenediphosphonite, and the like.

[0048] Among the phosphites, distearyl pentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phosphite, bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, 2,2'-methylenebis(4,6-di-tert-butylphenyl) octyl phosphite, and bis(2,4-dicumylphenyl) pentaerythritol diphosphite are preferred. Tris(2,4-di-tert-butylphenyl) phosphite is particularly preferred in terms of good heat resistance and low hydrolyzability.

[0049] The phosphorus-based antioxidant (C) may be used alone or in combination of two or more.

[0050] [Phenolic antioxidant (D)] The polycarbonate resin composition of the present invention preferably contains a phenolic antioxidant (D). By containing a phenolic antioxidant, it is possible to suppress hue deterioration and a decrease in mechanical properties during heat retention.

[0051] Examples of the phenolic antioxidant (D) include hindered phenolic antioxidants. Specific examples thereof include pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, thiodiethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide)], 2,4-dimethyl-6-(1-methylpentadecyl)phenol, diethyl [[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]phosphate, 3,3',3'',5,5',5''-hexa-tert-butyl-a,a',a''-(mesitylene-2,4,6-triyl)tri-p-cresol, 4,6-bis(octylthiomethyl)-o-cresol, ethylene bis(oxyethylene) bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], hexamethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazin-2-ylamino)phenol, and the like.

[0052] Among them, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are preferred. Examples of commercially available products of such phenolic antioxidants include, for example, "Irganox 1010" and "Irganox 1076" manufactured by BASF, "Adekastab AO-60" and "Adekastab AO-50" manufactured by ADEKA, and the like.

[0053] The phenolic antioxidant (D) may be used alone or in combination of two or more thereof.

[0054] When the phenolic antioxidant (D) is contained, its content is preferably 0.0001 part by mass or more, more preferably 0.001 part by mass or more, still more preferably 0.01 part by mass or more, preferably 0.5 part by mass or less, more preferably 0.4 part by mass or less, still more preferably 0.3 part by mass or less, particularly preferably 0.2 part by mass or less, 0.1 part by mass or less, 0.08 part by mass or less, and particularly preferably 0.05 part by mass or less with respect to 100 parts by mass of the polycarbonate resin (A). Within such a range, by combining with the specific amounts of the crosslinked acrylic polymer particles (B) and the phosphorus-based antioxidant (C), a polycarbonate resin composition having high heat resistance, excellent retention stability, and satisfying the total light transmittance and diffusibility in a well-balanced manner can be obtained.

[0055] In the polycarbonate resin composition of the present invention, it is preferable to contain both the phosphorus-based antioxidant (C) and the phenolic antioxidant (D). In this case, it is preferable that the phosphorus-based antioxidant and the phenolic antioxidant are contained in a total amount of 0.0002 to 1 part by mass in 100 parts by mass of the polycarbonate resin (A) at a mass ratio of phosphorus-based antioxidant:phenolic antioxidant = 1:0.5 to 20.

[0056] [Ultraviolet absorber (E)] The polycarbonate resin composition of the present invention preferably contains an ultraviolet absorber (E). Examples of the ultraviolet absorber (E) include inorganic ultraviolet absorbers such as cerium oxide and zinc oxide; organic ultraviolet absorbers such as benzotriazole compounds, benzophenone compounds, salicylate compounds, cyanoacrylate compounds, triazine compounds, ogisanilide compounds, malonic ester compounds, and hindered amine compounds. Among these, organic ultraviolet absorbers are preferable, and benzotriazole compounds are more preferable. By selecting an organic ultraviolet absorber, the transparency and mechanical properties of the resin composition of the present invention become good.

[0057] Specific examples of the benzotriazole compound include, for example, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-[2'-hydroxy-3',5'-bis(α,α-dimethylbenzyl)phenyl]-benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butyl-phenyl)-benzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butyl-phenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-tert-amyl)-benzotriazole, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol], etc. Among them, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole and 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol] are preferred, and particularly 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole is preferred.

[0058] Specific examples of the benzophenone compound include, for example, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-n-dodecyloxybenzophenone, bis(5-benzoyl-4-hydroxy-2-methoxyphenyl)methane, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, etc.

[0059] Specific examples of the salicylate compound include, for example, phenyl salicylate, 4-tert-butylphenyl salicylate, etc. Specific examples of the cyanoacrylate compound include, for example, ethyl-2-cyano-3,3-diphenylacrylate, 2-ethylhexyl-2-cyano-3,3-diphenylacrylate, and the like. Specific examples of the oxanilide compound include, for example, 2-ethoxy-2'-ethyloxalyni c acid bisanilide, and the like. As the malonic ester compound, 2-(alkylidene) malonic esters are preferred, and 2-(1-arylalkylidene) malonic esters are more preferred.

[0060] When the ultraviolet absorber (E) is contained, the content is usually 0.05 parts by mass or more, preferably 0.1 parts by mass or more, and usually 1 part by mass or less, preferably 0.5 parts by mass or less, based on 100 parts by mass of the polycarbonate resin (A). When the content of the ultraviolet absorber is less than the lower limit of the above range, the effect of improving weather resistance may be insufficient. When the content of the ultraviolet absorber exceeds the upper limit of the above range, mold deposits and the like may occur, which may cause mold contamination. One kind of ultraviolet absorber may be contained, or two or more kinds may be contained in any combination and ratio.

[0061] [Release agent (F)] The resin composition of the present invention preferably contains a release agent (F). Examples of the release agent (F) include aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds having a number average molecular weight of 200 to 15000, polysiloxane-based silicone oils, and the like.

[0062] Examples of the aliphatic carboxylic acid include saturated or unsaturated aliphatic monovalent, divalent or trivalent carboxylic acids. Here, the aliphatic carboxylic acid includes alicyclic carboxylic acids. Among these, preferred aliphatic carboxylic acids are monovalent or divalent carboxylic acids having 6 to 36 carbon atoms, and more preferred are aliphatic saturated monovalent carboxylic acids having 6 to 36 carbon atoms. Specific examples of such aliphatic carboxylic acids include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, melissic acid, tetratriacontanoic acid, montanic acid, adipic acid, azelaic acid and the like.

[0063] As the aliphatic carboxylic acid in the ester of the aliphatic carboxylic acid and the alcohol, for example, the same ones as the above-mentioned aliphatic carboxylic acids can be used. On the other hand, examples of the alcohol include saturated or unsaturated monohydric or polyhydric alcohols. These alcohols may have substituents such as fluorine atoms and aryl groups. Among these, monohydric or polyhydric saturated alcohols having 30 or less carbon atoms are preferred, and aliphatic saturated monohydric alcohols or aliphatic saturated polyhydric alcohols having 30 or less carbon atoms are more preferred. Here, the term "aliphatic" is used as a term including alicyclic compounds.

[0064] Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, dipentaerythritol and the like.

[0065] In addition, the above ester may contain an aliphatic carboxylic acid and / or an alcohol as impurities. Further, the above ester may be a pure substance or a mixture of a plurality of compounds. Furthermore, as the aliphatic carboxylic acid and the alcohol constituting one ester by bonding, each may be used alone or two or more kinds may be used in combination at an arbitrary combination and ratio.

[0066] Specific examples of esters of aliphatic carboxylic acids and alcohols include beeswax (a mixture mainly composed of myricyl palmitate), stearyl stearate, behenyl behenate, stearyl behenate, glycerin monopalmitate, glycerin monostearate, glycerin distearate, glycerin tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, pentaerythritol tetrastearate, and the like.

[0067] Examples of aliphatic hydrocarbons having a number average molecular weight of 200 to 15,000 include, for example, liquid paraffin, paraffin wax, micro wax, polyethylene wax, Fischer-Tropsch wax, α-olefin oligomers having 3 to 12 carbon atoms, and the like. Here, the aliphatic hydrocarbons include alicyclic hydrocarbons. Further, these hydrocarbons may be partially oxidized. Among these, paraffin wax, polyethylene wax or a partially oxidized product of polyethylene wax is preferable, and paraffin wax and polyethylene wax are more preferable. Further, the number average molecular weight of the above-mentioned aliphatic hydrocarbon is preferably 5000 or less. Note that the aliphatic hydrocarbon may be a single substance, or a mixture of various components and molecular weights, as long as the main component is within the above range, it can be used.

[0068] Examples of polysiloxane-based silicone oils include dimethyl silicone oil, methylphenyl silicone oil, diphenyl silicone oil, fluorinated alkyl silicone, and the like.

[0069] Note that the above-mentioned release agent may contain one kind, or may contain two or more kinds in any combination and ratio.

[0070] The content of the release agent (F) is usually 0.001 parts by mass or more, preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, based on 100 parts by mass of the polycarbonate resin (A). Also, it is usually 2 parts by mass or less, preferably 1 part by mass or less, more preferably 0.7 parts by mass or less, and even more preferably 0.5 parts by mass or less. When the content of the release agent is less than the lower limit of the above range, the effect of mold release may not be sufficient. When the content of the release agent exceeds the upper limit of the above range, a decrease in hydrolysis resistance, mold contamination during injection molding, etc. may occur.

[0071] [Additives, etc.] The polycarbonate resin composition of the present invention can contain other additives other than those described above, for example, additives such as fluorescent whitening agents, pigments, dyes, polymers other than polycarbonate resins, flame retardants, impact resistance improvers, antistatic agents, plasticizers, compatibilizers, etc. These additives may be blended singly or in combination of two or more. However, when containing a polymer other than the polycarbonate resin (A), its content is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, still more preferably 5 parts by mass or less, and particularly preferably 3 parts by mass or less, based on 100 parts by mass of the polycarbonate resin (A).

[0072] [Method for producing polycarbonate resin composition] There is no limitation on the method for producing the polycarbonate resin composition of the present invention, and known methods for producing polycarbonate resin compositions can be widely adopted. The above-described essential components and other components blended as necessary are, for example, premixed using various mixers such as tumblers and Henschel mixers, and then melt-kneaded using mixers such as Banbury mixers, rolls, Brabenders, single-screw kneading extruders, twin-screw kneading extruders, and kneaders. The temperature of the melt-kneading is not particularly limited, but is usually in the range of 240 to 320°C.

[0073] [Molded article] The polycarbonate resin composition of the present invention can produce molded articles by molding pellets obtained by pelletizing the above-described polycarbonate resin composition by various molding methods. Also, without passing through pellets, the resin melt-kneaded by an extruder can be directly molded into a molded article.

[0074] Since the polycarbonate resin composition of the present invention has high heat resistance and excellent retention stability, it is particularly suitable for molding molded articles, such as those with a long residence time, for example, 10 minutes or more, further 15 minutes or more, especially 20 minutes or more, by an injection molding method. For example, it is particularly preferably used for molding long molded articles with a length exceeding 1 m, especially 1 m 50 cm or more. During injection molding, it is also possible to perform molding at a resin temperature higher than the general 260 to 300 °C for polycarbonate resins, and a resin temperature of over 300 °C to 400 °C is also possible.

[0075] Since the resin composition of the present invention has excellent retention stability, it is possible to preferably make the haze value change (3 mm thickness, ΔHaze) and the flow value change per unit time (ΔQ) for the resin composition after a residence time of 20 minutes as follows. ΔHaze (%) = |[Initial haze] - [Haze after 20 minutes of residence time]| Preferably 1.2% or less, more preferably 1% or less, still more preferably 0.8% or less, especially 0.6% or less, 0.5% or less, and particularly preferably 0.3% or less. ΔQ (×10 -2 cm 3 / sec) = |[Q value after 20 minutes of residence time] - [Initial Q value]| Preferably 4 or less, more preferably 3.5 or less, still more preferably 3 or less, especially 2.5 or less, 2 or less, and particularly preferably 1.5 or less. Also, for the total light transmittance (%) of the resin composition of the present invention, the initial value is preferably 60% or more, more preferably 70% or more, still more preferably 75% or more, and particularly preferably 80% or more. The haze is preferably 90% or more, more preferably 95% or more, still more preferably 96% or more as the initial value. Q value (×10 -2 cm 3 / sec) is preferably 11 or more, more preferably 13 or more, and even more preferably 14 or more as its initial value.

[0076] Details of the measurement methods of the total light transmittance, haze, and Q value and the method for obtaining the Δ value thereof are as described in the examples.

[0077] As a molded product, it is particularly suitable for lighting parts or optical members, and examples include parts of devices and appliances that directly or indirectly utilize light sources such as LEDs, organic ELs, incandescent bulbs, fluorescent lamps, and cathode tubes. It is particularly suitable for long optical members with a long optical path length, for example, exceeding 30 cm, 50 cm or more, 80 cm or more, especially 100 cm or more, 120 cm or more, and particularly 150 cm or more. Typical examples include a light guide that efficiently guides light incident from a light source on one side to the other using internal reflection, such as a lighting light guide or a lighting diffusion cover installed in a vehicle (automobile or train) or an aircraft. In addition, a light guide in a vehicle headlamp; a lighting light guide and a diffusion cover for various lighting purposes; a decorative signboard; various display devices; a light guide plate used in various portable devices such as a liquid crystal TV, a mobile phone, and a portable terminal, and a personal computer; a scanner light source unit, various lenses, etc. can also be suitably used.

[0078] In addition, the shape of the molded product may be a long shape, a flat plate shape, a rod shape, a cylindrical shape, a helical shape, a lens shape, or a film or sheet.

Examples

[0079] Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not construed as being limited to the following examples. The raw materials used in the following examples and comparative examples are as shown in Table 1.

[0080]

Table 1

[0081] The 10% weight loss temperature of the crosslinked acrylic polymer particles and the like described above was measured using a calorimeter "TG / DTA7200" manufactured by Hitachi High-Technologies Corporation in a nitrogen atmosphere. When 10 mg of the sample was heated from 40°C at a heating rate of 10°C / min, the temperature at which the weight loss reached 10% when the weight at room temperature was set to 100% was measured.

[0082] Also, the amounts of Na, K, and Ca were quantified by inductively coupled plasma atomic emission spectrometry (ICP-AES method) using an iCAP7600 Duo manufactured by Thermo Fisher Scientific. For the above-mentioned crosslinked acrylic polymer particles and the like, after performing an open-system wet decomposition treatment using sulfuric acid, nitric acid, and hydrogen peroxide, quantification was carried out.

[0083] (Examples 1 to 4、 10, Reference Examples 5 to 9 Comparative Examples 1 to 7) [Manufacture of resin composition pellets] The above-described respective components were blended at the ratios (parts by mass) shown in Table 2 below, mixed in a tumbler for 20 minutes, and then supplied to a twin-screw extruder ("TEM26SX" manufactured by Shibaura Machine Co., Ltd.). Kneading was performed under the conditions of a screw rotation speed of 200 rpm, a discharge rate of 25 kg / h, and a barrel temperature of 280°C, and pellets were obtained by strand cutting.

[0084] [Total light transmittance (unit: %), haze (unit: %)] The pellets obtained by the above method were dried in a hot air circulation dryer at 120°C for 5 hours, and then molded into a three-stage plate (90 mm × 50 mm × thickness: 3 mm (length 20 mm), 2 mm (length 45 mm), 1 mm (length 25 mm) from the gate side) using an injection molding machine ("J55-60H" manufactured by Japan Steel Works, Ltd.) under the conditions of a cylinder temperature of 330°C, a mold temperature of 80°C, a screw rotation speed of 100 rpm, and an injection speed of 40 mm / s. At this time, after molding in the normal cycle, the molding machine was temporarily stopped, and the molten resin was held in the injection cylinder for 20 minutes, and then the above three-stage plate was molded. The 3 mm thick portion of the three-stage plate obtained in the above normal cycle was measured for the total light transmittance (initial total light transmittance) and haze (initial haze) based on JIS K7136 and JIS K7361 using a haze meter "SH7000" manufactured by Nippon Denshoku Industries Co., Ltd. Further, the haze (initial haze) of the 3 mm thick portion of the three-stage plate molded after holding the molten resin in the injection cylinder for 20 minutes was measured in the same manner as above, and ΔHaze was determined by the following formula. ΔHaze (%) = |[Initial haze] - [Haze after 20 minutes of residence time]|

[0085] [Flow rate per unit time (Q value, unit: ×10 -2 cm 3 / sec)] After drying the three-stage plate of the normal cycle obtained by the above-described method at 120 °C for 5 hours, the flow rate per unit time (initial Q value, unit: ×10 -2 cm 3 / sec) of the composition was measured using an elevated flow tester under the conditions of a temperature of 280 °C and a load of 160 kgf. Furthermore, the Q value (Q value after 20 minutes of residence time) of the three-stage plate molded after holding the molten resin in the injection cylinder for 20 minutes obtained by the above-described method was measured in the same manner as above, and ΔQ value was determined by the following formula. ΔQ = |[Q value after 20 minutes of residence time] - [Initial Q value]| The larger the ΔQ value, the more the decomposition of the polycarbonate resin progresses, indicating poor residence stability.

[0086] The above evaluation results are shown in Table 2 below.

[0087]

Table 2

[0088]

Table 3

Industrial Applicability

[0089] Since the polycarbonate resin composition of the present invention has high heat resistance and excellent retention stability, and satisfies the total light transmittance and diffusibility in a well-balanced manner, it can be suitably used for various molded articles.

Claims

1. Based on 100 parts by mass of the polycarbonate resin (A), 0.2 to 1.0 parts by mass of crosslinked acrylic polymer particles (B), 0.0001 to 0.5 parts by mass of bis(2,4-dicumylphenyl)pentaerythritol diphosphite as the phosphorus-based antioxidant (C), 0.0001 to 0.5 parts by mass of the phenolic antioxidant (D), and does not contain an ultraviolet absorber, or when it contains, it contains 0.05 to 0.5 parts by mass of 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol], the 10% weight loss temperature measured by a calorimeter of the crosslinked acrylic polymer particles (B) is 350°C or higher, and the total amount of Na, K, and Ca contained in the crosslinked acrylic polymer particles (B) is 15 ppm or less. A polycarbonate resin composition characterized by the above.

2. A molded article comprising the polycarbonate resin composition according to Claim 1.

3. The molded article according to Claim 2, which is a lighting part or an optical member.

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