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), 0.01-0.5 pts.mass of an acid phosphate compound (C), and 0.0001-0.5 pts.mass of a phosphorus-based antioxidant (D), wherein the crosslinked acrylic polymer particles (B) have a 10% weight reduction temperature measured by a calorimetry apparatus of 330°C or higher.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 are highly heat-resistant, excellent in retention stability, and satisfy the total light transmittance and diffusibility in a well-balanced manner.

Background Art

[0002] Polycarbonate resin is a highly 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 come to be 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 illumination light by imparting light diffusibility, and in these, it is required to maintain high light diffusibility and light transmittance 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. In addition, 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 come in various shapes, and there has been a trend towards larger sizes and longer lengths. For example, optical members for long articles exceeding 1 m have also appeared. When injection molding a molded article of such a long article, since the resin composition stays at a high temperature for a long time, the retention deterioration is severe, and in some cases, it becomes impossible to mold due to a decrease in the viscosity of the raw material resin, so it is essential to be excellent in heat resistance.

[0006] Patent Document 1 describes an invention in which a phosphite antioxidant is contained in an acrylic resin diffusing agent and then blended with 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 by blending a crosslinked acrylic polymer particle (B) having a 10% weight loss temperature of a specific temperature or higher, an acidic phosphate ester compound (C), and a phosphorus antioxidant (D) in specific amounts with a polycarbonate resin, the above problems can be solved, and the present invention has been completed. The present invention relates to the following polycarbonate resin compositions and molded articles.

[0010] 1. A polycarbonate resin composition, comprising 100 parts by mass of a polycarbonate resin (A), 0.2 to 1.0 part by mass of crosslinked acrylic polymer particles (B), 0.01 to 0.5 part by mass of an acidic phosphate compound (C), and 0.0001 to 0.5 part by mass of a phosphorus-based antioxidant (D), wherein the 10% weight loss temperature measured by a calorimeter of the crosslinked acrylic polymer particles (B) is 330 °C or higher. 2. The polycarbonate resin composition according to 1 above, further comprising 0.0001 to 0.5 part by mass of a phenolic antioxidant (E) based on 100 parts by mass of the polycarbonate resin (A). 3. The polycarbonate resin composition according to 1 or 2 above, wherein the acidic phosphate compound (C) is one or more phosphates selected from alkyl acid phosphates, alkenyl acid phosphates, and metal salts thereof. 4. A molded article comprising the polycarbonate resin composition according to any one of 1 to 3 above. 5. The molded article according to 4 above, which is a lighting component or an optical member.

Advantages 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 with reference to 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 contains 0.2 to 1.0 parts by mass of crosslinked acrylic polymer particles (B), 0.01 to 0.5 parts by mass of an acidic phosphate ester compound (C), and 0.0001 to 0.5 parts by mass of a phosphorus-based antioxidant (D) with respect to 100 parts by mass of the polycarbonate resin (A), and is characterized in that the 10% weight loss temperature measured by a calorimeter for the crosslinked acrylic polymer particles (B) is 330°C or higher. Hereinafter, each component constituting the polycarbonate resin composition of the present invention, molded articles, etc. 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), an aromatic polycarbonate resin is preferable 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), 1,4-dihydroxybenzene; Dihydroxybiphenyls such as 2,5-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, 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, 2,7-dihydroxynaphthalene;

[0017] Dihydroxydiaryl ethers such as 2,2'-dihydroxydiphenyl ether, 3,3'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, 1,4-bis(3-hydroxyphenoxy)benzene, 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, bis(Hydroxyaryl)alkanes such as the above;

[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, bis(hydroxyaryl)cycloalkanes such as;

[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. may be 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) and 2,2-bis(3-methyl-4-hydroxyphenyl)propane (i.e., bisphenol C) are preferred. In addition, as the aromatic dihydroxy compound, one kind may be used, or two or more kinds may be used in combination at an arbitrary combination and ratio.

[0023] Among the monomers that are raw materials for polycarbonate resins, examples of carbonate precursors include carbonyl halides, carbonate esters, etc. Note that one type of carbonate precursor may be used, or two or more types may be used in combination at any combination and ratio.

[0024] Specific examples of carbonyl halides include, for example, phosgene; haloformates such as bis(chloroformate) derivatives of dihydroxy compounds and mono(chloroformate) derivatives of dihydroxy compounds.

[0025] Specific examples of carbonate esters include, for example, diaryl carbonates such as diphenyl carbonate and ditolyl carbonate; dialkyl carbonates such as dimethyl carbonate and diethyl carbonate; carbonate derivatives of dihydroxy compounds such as bis(carbonate) derivatives of dihydroxy compounds, mono(carbonate) derivatives 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 the interfacial polymerization method, the melt transesterification method, the pyridine method, the ring-opening polymerization method of cyclic carbonate compounds, and the solid-phase transesterification method of prepolymers. Among these, the one by the interfacial polymerization method is particularly preferred.

[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 the solvent, preferably 10,000 to 50,000, more preferably 10,000 to 40,000, particularly 10,000 to 30,000, 10,000 to 26,000, still more preferably 10,500 or more, 11,000 or more, especially 11,500 or more, most preferably 12,000 or more, and further preferably 24,000 or less, particularly preferably 20,000 or less. By setting the viscosity average molecular weight to be not less 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 not more 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, the molding processability can be enhanced, and thin-wall molding can be easily performed. In addition, two or more types of 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 preferred range may be mixed.

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

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 is 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, and more preferably 50% by mass or less, of the polycarbonate resin (A). This is because 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), and those having a 10% weight loss temperature measured by a calorimeter of 330 °C or higher are used.

[0032] As the crosslinked acrylic polymer particles (B), preferably, crosslinked acrylic resin-based 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, etc., and methacrylic esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, etc. 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, vinyl acetate, etc.

[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 increase 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. However, it has been found that when those with 330°C or higher are blended, even if the residence time during molding becomes long, the change in the total light transmittance and the 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, and especially 365°C or higher. The upper limit is usually up to about 400°C for crosslinked acrylic polymers.

[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, and it is also possible by selecting and using from commercially available products.

[0038] The crosslinked acrylic polymer particles (B) preferably have an average particle diameter of 1 to 10 μm. When the average particle diameter is within this range, the light diffusion rate and the degree of dispersion are higher. The average particle diameter is preferably 1.5 to 7 μm, more preferably 2 to 4 μm. The measurement of the particle diameter is D50 carried out by the Coulter counter method based on the number standard.

[0039] 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). Within such a range, by combining with specific amounts of the acidic phosphate ester compound (C) and the phosphorus-based antioxidant (D), a polycarbonate resin composition can be obtained that has high heat resistance, excellent retention stability, and satisfies the total light transmittance and diffusibility in a well-balanced manner. 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.

[0040] [Acidic phosphate ester compound (C)] The polycarbonate resin composition of the present invention contains an acidic phosphate ester compound (C). As the acidic phosphate ester compound (C), one or more phosphates selected from alkyl acid phosphates, alkenyl acid phosphates, and metal salts thereof are preferred.

[0041] The alkyl acid phosphate or alkenyl acid phosphate is preferably represented by the following formula (I). The alkyl acid phosphate or alkenyl acid phosphate is represented by the following general formula (I), and the alkyl acid phosphate metal salt or alkenyl acid phosphate metal salt is preferably a metal salt such as a zinc salt or an aluminum salt of the alkyl acid phosphate or alkenyl acid phosphate represented by the following formula (I). O=P(OH) n (OR) 3-n …(I) (In the formula, R represents an alkyl group or an alkenyl group having 9 to 30 carbon atoms, and n represents an integer of 1 or 2. When n is 1, the two Rs may be the same or different.)

[0042] The alkyl group represented by R in the above formula (I) may be a linear alkyl group or may have a branch. Specific examples of the alkyl group of R include nonyl, isononyl, decyl, isodecyl, dodecyl, tridecyl, isotridecyl, tetradecyl, hexadecyl, octadecyl (stearyl), eicosyl, tetracosyl groups and the like. Also, the alkenyl group represented by R may be a linear alkenyl group or may have a branch. Specific examples of the alkenyl group of R include an oleyl group and the like. n is 1 or 2, and a mixture thereof may also be acceptable.)

[0043] The number of carbon atoms of the alkyl group or alkenyl group represented by R in the above formula (I) is more preferably any one of 13, 18, and 24. As the alkyl acid phosphate, particularly, it is represented by the following formula (II), and a mixture of distearyl acid phosphate with n = 1 and monostearyl acid phosphate with n = 2 in formula (II) is preferred.) O=P(OH) n (OC 18 H 37 ) 3-n …(II)

[0044] Also, as the metal salt of the alkyl acid phosphate, a mixture of the zinc salt of distearyl acid phosphate represented by the following formula (IIIa) and the zinc salt of monostearyl acid phosphate represented by the following formula (IIIb) is preferred.)

Chemical formula

[0045] The content of the acidic phosphate ester compound (C) is 0.01 to 0.5 parts by mass with respect to 100 parts by mass of the polycarbonate resin. Within such a range, by combining with specific amounts of the crosslinked acrylic polymer particles (B) and the phosphorus-based antioxidant (D), a polycarbonate resin composition can be obtained which has high heat resistance, excellent retention stability, and satisfies the total light transmittance and diffusibility in a well-balanced manner. The content of the acidic phosphate ester compound (C) is preferably 0.015 parts by mass or more, more preferably 0.02 parts by mass or more, preferably 0.4 parts by mass or less, more preferably 0.3 parts by mass or less, particularly preferably 0.2 parts by mass or less, 0.1 parts by mass or less, 0.08 parts by mass or less, and 0.05 parts by mass or less.

[0046] [Phosphorus-based antioxidant (D)] The polycarbonate resin composition of the present invention further contains a phosphorus-based antioxidant (D). The content of the phosphorus-based antioxidant (D) 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 specific amounts of the crosslinked acrylic polymer particles (B) and the acidic phosphate ester compound (C), a polycarbonate resin composition can be obtained which has high heat resistance, excellent retention stability, and satisfies the total light transmittance and diffusibility in a well-balanced manner. The preferred content of the phosphorus-based antioxidant (D) 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, particularly preferably 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.

[0047] Examples of the phosphorus-based antioxidant (D) include phosphorous acid, phosphoric acid, phosphite esters, phosphate esters (excluding the above-mentioned acidic phosphate ester compound (C)), etc. Among them, phosphite esters such as phosphites and phosphonites are preferred in terms of containing trivalent phosphorus and being likely to exhibit a discoloration suppression effect.

[0048] Examples of the phosphite 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.

[0049] In addition, examples of the phosphonite include tetrakis(2,4-di-iso-propylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,4-di-n-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,3'-biphenylene diphosphonite, tetrakis(2,4-di-tert-butylphenyl)-3,3'-biphenylene diphosphonite, tetrakis(2,6-di-iso-propylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,6-di-n-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,3'-biphenylene diphosphonite, tetrakis(2,6-di-tert-butylphenyl)-3,3'-biphenylene diphosphonite, and the like.

[0050] 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 preferable. Tris(2,4-di-tert-butylphenyl) phosphite is particularly preferable in terms of good heat resistance and low hydrolyzability.

[0051] The phosphorus-based antioxidant (D) may be used alone or in combination of two or more.

[0052] [Phenolic antioxidant (E)] The polycarbonate resin composition of the present invention preferably contains a phenolic antioxidant (E). By containing a phenolic antioxidant, it is possible to suppress hue deterioration and a decrease in mechanical properties during heat retention.

[0053] Examples of the phenolic antioxidant (E) 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.

[0054] 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. 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.

[0055] The phenolic antioxidant (E) may be used alone or in combination of two or more.

[0056] When the phenolic antioxidant (E) 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, among which 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, based on 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), the acidic phosphate ester compound (C), and the phosphorus-based antioxidant (D), a polycarbonate resin composition with high heat resistance, excellent retention stability, and well-balanced total light transmittance and diffusibility can be obtained.

[0057] [Ultraviolet absorber (F)] The polycarbonate resin composition of the present invention preferably contains an ultraviolet absorber (F). Examples of the ultraviolet absorber (F) 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 preferred, and benzotriazole compounds are more preferred. By selecting an organic ultraviolet absorber, the transparency and mechanical properties of the resin composition of the present invention become good.

[0058] 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.

[0059] 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, and the like.

[0060] Specific examples of the salicylate compound include, for example, phenyl salicylate, 4-tert-butylphenyl salicylate, and the like. 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 ogisanilide compound include, for example, 2-ethoxy-2'-ethyloxalinic 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.

[0061] When the ultraviolet absorber (F) 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. The ultraviolet absorber may be contained singly or in any combination and ratio of two or more.

[0062] [Release agent (G)] The resin composition of the present invention preferably contains a release agent (G). Examples of the release agent (G) include aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds having a number average molecular weight of 200 to 15,000, polysiloxane-based silicone oils, and the like.

[0063] 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 preferably 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.

[0064] As the aliphatic carboxylic acid in the ester of an aliphatic carboxylic acid and an alcohol, for example, the same ones as the above 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, aliphatic is used as a term including alicyclic compounds.

[0065] 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.

[0066] In addition, the above esters may contain aliphatic carboxylic acids and / or alcohols as impurities. Also, the above esters may be pure substances, or may be mixtures of a plurality of compounds. Furthermore, for the aliphatic carboxylic acid and alcohol that combine to form one ester, one type may be used respectively, or two or more types may be used in combination at an arbitrary combination and ratio.

[0067] 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, etc.

[0068] 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, etc. Here, the aliphatic hydrocarbons include alicyclic hydrocarbons. Also, these hydrocarbons may be partially oxidized. Among these, paraffin wax, polyethylene wax or partially oxidized polyethylene wax is preferable, and paraffin wax and polyethylene wax are more preferable. Also, the number average molecular weight of the above aliphatic hydrocarbon is preferably 5000 or less. Note that the aliphatic hydrocarbon may be a single substance, or even a mixture of various components and molecular weights, as long as the main component is within the above range, it can be used.

[0069] Examples of the polysiloxane-based silicone oil include dimethyl silicone oil, methylphenyl silicone oil, diphenyl silicone oil, fluorinated alkyl silicone, and the like.

[0070] In addition, the above-mentioned release agent may contain one kind, or may contain two or more kinds in any combination and ratio.

[0071] The content of the release agent (G) is usually 0.001 part by mass or more, preferably 0.01 part by mass or more, more preferably 0.05 part by mass or more, and usually 2 parts by mass or less, preferably 1 part by mass or less, more preferably 0.7 part by mass or less, and even more preferably 0.5 part by mass or less, based on 100 parts by mass of the polycarbonate resin (A). 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, there may be a decrease in hydrolysis resistance and mold contamination during injection molding.

[0072] [Additives, etc.] The polycarbonate resin composition of the present invention can contain other additives other than those described above, such as fluorescent whitening agents, pigments, dyes, polymers other than polycarbonate resins, flame retardants, impact resistance improvers, antistatic agents, plasticizers, compatibilizers, and the like. 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).

[0073] [Method for producing polycarbonate resin composition] There is no restriction 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 compounded as necessary are premixed using various mixers such as a tumbler or a Henschel mixer, and then melt-kneaded using a mixer such as a Banbury mixer, a roll, a Brabender, a single-screw kneading extruder, a twin-screw kneading extruder, or a kneader. The temperature for melt-kneading is not particularly limited, but is usually in the range of 240 to 320°C.

[0074] [Molded article] The polycarbonate resin composition of the present invention can be used to produce a molded article by molding pellets obtained by pelletizing the above-described polycarbonate resin composition by various molding methods. Alternatively, the resin melt-kneaded by an extruder can be directly molded into a molded article without passing through pellets.

[0075] Since the polycarbonate resin composition of the present invention has high heat resistance and excellent retention stability, it is particularly suitable for use in injection molding, especially for molding molded articles with a long residence time, such as 10 minutes or more, more preferably 15 minutes or more, and particularly preferably 20 minutes or more, such as molded articles with a length exceeding 1 m, particularly those with a length of 1 m 50 cm or more. During injection molding, the resin temperature can be set higher than the general range of 260 to 300°C for polycarbonate resins, and a resin temperature above 300°C to 400°C is also possible.

[0076] Since the resin composition of the present invention has excellent retention stability, it is possible to preferably control the total light transmittance change (3 mm thickness, Δ transmittance), haze value change (3 mm thickness, ΔHaze), and flow value change per unit time (ΔQ) of the resin composition after a residence time of 20 minutes as follows. Δ transmittance (%) = |[Initial total light transmittance] - [Total light transmittance after a residence time of 20 minutes]| Preferably 3.0% or less, more preferably 2.5% or less, and even more preferably 2.0% or less ΔHaze (%) = |[Initial haze] - [Haze after a residence time of 20 minutes]| Preferably 1.2% or less, more preferably 1% or less, still more preferably 0.8% or less, particularly preferably 0.6% or less, 0.5% or less, and especially 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, particularly preferably 2.5 or less, 2 or less, and especially preferably 1.5 or less. In addition, for the resin composition of the present invention, the total light transmittance (%) is preferably 60% or more, more preferably 70% or more, still more preferably 75% or more, and particularly preferably 80% or more as its initial value. The haze is preferably 90% or more, more preferably 95% or more, and still more preferably 96% or more as its initial value. Q value (×10 -2 cm 3 / sec) is preferably 11 or more, more preferably 13 or more, and still more preferably 14 or more as its initial value.

[0077] 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.

[0078] As the molded product, it is particularly suitable for lighting parts or optical members, and examples include parts of devices and instruments 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, more than 30 cm, 50 cm or more, 80 cm or more, particularly preferably more than 100 cm, 120 cm or more, and especially more than 150 cm. Typical examples include light guides that efficiently guide light incident from a light source on one side to the other using internal reflection, such as lighting light guides and lighting diffusion covers installed in vehicles (automobiles and trains) or aircraft. In addition, light guides in vehicle headlamps; lighting light guides and diffusion covers for various lighting purposes; electric signs; various display devices; light guide plates used in various portable devices such as liquid crystal TVs, mobile phones, and portable terminals, and personal computers; scanner light source units, various lenses, etc. can also be suitably used.

[0079] In addition, the shape of the molded product may be long, flat, rod-shaped, cylindrical, spiral, lens-shaped, or even film-shaped or sheet-shaped.

Examples

[0080] 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.

[0081]

Table 1

[0082] The 10% weight loss temperature of the crosslinked acrylic polymer particles and the like described above was measured using a calorimetry device "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 became 10% when the weight at room temperature was taken as 100% was measured.

[0083] (Examples 2~3, Reference Example 1, 4 ~12, Comparative Examples 1~13) [Manufacture of Resin Composition Pellets] The above-described respective components were blended at the ratios (parts by mass) shown in Table 2 below, and after mixing for 20 minutes in a tumbler, they were supplied to a twin-screw extruder (“TEM26SX” manufactured by Shibaura Machine Co., Ltd.), and kneaded under the conditions of a screw rotation speed of 200 rpm, a discharge rate of 25 kg / hour, 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, using an injection molding machine (“J55-60H” manufactured by Japan Steel Works, Ltd.), 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] was molded 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. Furthermore, the total light transmittance (initial total light transmittance) and 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 were measured in the same manner as above, and Δ transmittance and Δ Haze were determined by the following equations. Δ transmittance (%) = |[Initial total light transmittance] - [Total light transmittance after 20 minutes of residence time]| Δ Haze (%) = |[Initial haze] - [Haze after 20 minutes of residence time]|

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

[0089] In Comparative Example 5 of Table 3 above, a large amount of silver was generated in the molded product, making it difficult to accurately evaluate the optical properties.

Industrial Applicability

[0090] The polycarbonate resin composition of the present invention is a polycarbonate resin composition that has high heat resistance, excellent residence stability, and satisfies the total light transmittance and diffusibility in a well-balanced manner, and thus can be suitably used for various molded products.

Claims

1. Based on 100 parts by mass of the polycarbonate resin (A), it contains 0.2 to 1.0 parts by mass of crosslinked acrylic polymer particles (B), 0.01 to 0.5 parts by mass of an acidic phosphate ester compound (C), and 0.0001 to 0.5 parts by mass of a phosphorus-based antioxidant (D). The 10% weight loss temperature measured by a calorimeter for the crosslinked acrylic polymer particles (B) is 330 °C or higher, The initial value of the total light transmittance at a thickness of 3 mm is 80% or higher, and the initial value of the haze at a thickness of 3 mm is 96% or higher. A polycarbonate resin composition characterized by this.

2. Furthermore, a polycarbonate resin composition according to Claim 1, which contains 0.0001 to 0.5 parts by mass of a phenolic antioxidant (E) based on 100 parts by mass of the polycarbonate resin (A).

3. The polycarbonate resin composition according to Claim 1 or 2, wherein the acidic phosphate ester compound (C) is one or more phosphates selected from alkyl acid phosphates, alkenyl acid phosphates, and metal salts thereof.

4. A molded article made of the polycarbonate resin composition according to any one of Claims 1 to 3.

5. The molded article according to Claim 4, which is a lighting part or an optical member.

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