JPH093310A - Light-diffusing aromatic polycarbonate resin composition and light-diffusing and transmitting molded article - Google Patents

Abstract

(57) [Summary] [Purpose] A light-diffusing aromatic polycarbonate resin composition having high light-transmittance and good light-diffusivity, little coloration during molding, and suppressed discoloration under high-temperature dry heat. And a molded article for light diffusion and transmission therefrom. [Structure] (A) Aromatic polycarbonate resin, (B)
A light-diffusing aromatic polycarbonate in which a specific amount of (D) a phosphite compound and / or a phosphate compound and (E) a phenolic antioxidant are added to a mixture of calcium carbonate and (C) a short glass fiber in a specific ratio. Resin composition and molded article for light diffusion and transmission therefrom.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light diffusing aromatic polycarbonate resin composition and a light diffusing and transmitting molded article comprising the same. More specifically, a light-diffusing aromatic polycarbonate resin composition having a high light-transmitting property and a good light-diffusing property, less coloring during molding and less discoloration under high temperature dry heat, and a light-diffusing aromatic polycarbonate resin composition comprising the same Regarding molded products.

[0002]

2. Description of the Related Art Aromatic polycarbonate resins have excellent mechanical properties, heat resistance and weather resistance, and are widely used as resins having high light transmittance. In applications such as various lighting equipment covers, liquid crystal displays, and various nameplates, materials that transmit and diffuse light rays emitted from a light source are required. As a material suitable for this type of application, a method of dispersing and blending particles having light diffusibility in a transparent resin is known. For example, JP-A-61-36354
The publication discloses a composition in which glass beads and an organic phosphorus compound are mixed with an aromatic polycarbonate resin. However, although the light diffusion property is insufficient and the coloring at the time of molding can be suppressed, the discoloration under high temperature dry heat cannot be sufficiently suppressed. Similarly, Japanese Patent Publication No. 3-62187
Japanese Patent Laid-Open Publication No. 9-242242 discloses a composition in which glass particles and an organic phosphorus compound are blended with an aromatic polycarbonate resin, but the coloring during molding can be suppressed but the discoloration under high temperature dry heat can be sufficiently suppressed. is not. In addition, Japanese Patent Laid-Open No. 3-1
Japanese Patent No. 26766 discloses a composition in which polymer particles and a blue dye are mixed with a transparent resin, but there is a problem that the light transmittance is reduced although the coloring during molding is suppressed.

On the other hand, Japanese Patent Publication No. 57-24816 discloses a composition in which an aromatic polycarbonate resin is mixed with calcium carbonate and titanium oxide. And the decrease in the molecular weight of the aromatic polycarbonate resin is remarkable, and further the discoloration is large due to the heat from the light source such as an incandescent lamp, which is not practically usable. Also, JP-A-63-2170
Japanese Unexamined Patent Publication (Kokai) No. 4 and Japanese Unexamined Patent Publication (Kokai) No. 1-209402 disclose a composition obtained by mixing calcium carbonate and short glass fibers in a polycarbonate resin, but suppressing coloring during molding and discoloration under high temperature dry heat. Not something you can do. Therefore, there is a demand for a light-diffusing aromatic polycarbonate resin composition which has excellent light transmittance and light diffusivity, and is less likely to be colored during molding and discolored by heat from a light source.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a light-diffusing aromatic compound which has a high light-transmitting property and a good light-diffusing property, is less colored during molding, and is suppressed from being discolored under high temperature dry heat. An object of the present invention is to provide a polycarbonate resin composition and a molded article for light diffusion / transmission from the same. The present inventor has conducted extensive studies to achieve the above object, and as a result, a mixture of a specific proportion of an aromatic polycarbonate resin, calcium carbonate and a short glass fiber is mixed with a specific phosphorus compound and a phenolic antioxidant. The aromatic polycarbonate resin composition was found to have little coloring during molding and to suppress discoloration under high-temperature dry heat, and arrived at the present invention.

[0005]

That is, according to the present invention, (A) an aromatic polycarbonate resin 60-99.8.
%, (B) 0.1 to 20% by weight of calcium carbonate and (C) 0.1 to 20% by weight of glass short fibers, and (D) phosphite compound based on 100 parts by weight of the mixture. And / or a light diffusing aromatic polycarbonate resin composition containing 0.001 to 1 part by weight of a phosphate compound and 0.001 to 1 part by weight of (E) a phenolic antioxidant, and a molded article for light diffusing and transmitting the same. Provided.

The aromatic polycarbonate resin used in the present invention is a resin generally used as an engineering resin, and is an aromatic polycarbonate resin obtained by reacting a dihydric phenol and a carbonate precursor. Typical examples of the dihydric phenol used here include 2,2-bis (4-hydroxyphenyl) propane (commonly called bisphenol A), bis (4-hydroxyphenyl) methane, and 1,1-bis (4 -Hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis (4-hydroxy-)
3,5-Dimethylphenyl) propane, 2,2-bis (4
-Hydroxy-3,5-dibromophenyl) propane,
2,2-bis (4-hydroxy-3-methylphenyl)
Propane, bis (4-hydroxyphenyl) ether,
4,4'-dihydroxydiphenyl, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone and the like can be mentioned. Preferred dihydric phenols are bis (4-hydroxyphenyl) alkanes, of which bisphenol A is particularly preferred.

As the carbonate precursor, carbonyl halide, carbonate ester, haloformate or the like is used, and specific examples thereof include phosgene, diphenyl carbonate or dihaloformate of dihydric phenol.

In producing the aromatic polycarbonate resin by reacting the above dihydric phenol with the carbonate precursor, the dihydric phenol may be used alone or in combination of two or more kinds, and the aromatic polycarbonate resin may be trifunctional or more. It may be a branched polycarbonate resin obtained by copolymerizing a polyfunctional aromatic compound or a mixture of two or more aromatic polycarbonate resins. Further, if necessary, a catalyst, a molecular weight modifier, an antioxidant, etc. may be used.

Any molecular weight of the aromatic polycarbonate resin can be used. For example, when an aromatic polycarbonate resin is obtained by using bisphenol A as a dihydric phenol and phosgene as a carbonate precursor, the concentration is 0.7 g / It is preferable that the specific viscosity (η _sp ) measured with a dl methylene chloride solution at a temperature of 20 ° C. is 0.15 to 1.5.

The calcium carbonate used in the present invention is not particularly limited and is generally used as a reinforcing material for synthetic resins. Such calcium carbonate is obtained by a method which is generally used industrially, carbon dioxide gas compounding method, lime milk soda compounding method,
There are those produced by chemical synthesis such as the calcium chloride soda method or those obtained by finely crushing natural limestone,
It does not matter which method is used.

The weight average particle diameter of calcium carbonate is 0.1.
Those having a thickness of -20 μm are preferable, and those having a thickness of 1-15 μm are particularly preferable. If the weight average particle diameter is less than 0.1 μm, the total light transmittance is lowered, and if it exceeds 20 μm, in order to obtain a sufficient light diffusivity, the addition amount becomes large and the workability and the appearance of the molded product deteriorate. Therefore, it is not preferable. The particle shape of the calcium carbonate is not particularly limited, and any shape such as a cubic shape, a spindle shape, a needle shape, and a rod shape may be used. The difference in the refractive index from the refractive index of the aromatic polycarbonate resin used is preferably 0.01 to 0.15. When the difference in refractive index is less than 0.01, the diffusion of light becomes insufficient, and when it exceeds 0.15, the effect of dispersing light is high, but the total light transmittance decreases, which is not suitable.

The blending ratio of calcium carbonate is 0.1 to 20% by weight, preferably 0.5 to 15% by weight, based on 100% by weight of the mixture of aromatic polycarbonate resin, calcium carbonate and short glass fibers. If the blending ratio is less than 0.1% by weight, sufficient light diffusion cannot be obtained, and 2
When it is more than 0% by weight, the workability and the appearance of the molded article are deteriorated, which is not preferable. Such calcium carbonate is preferably surface-treated with a coupling agent such as a silane coupling agent or a titanate coupling agent, an organic fatty acid and / or a metal salt of an organic fatty acid, a surfactant, a phosphoric acid compound, and the like. Those surface-treated with a metal salt of a fatty acid and / or an organic fatty acid are preferable.

The short glass fiber used in the present invention is obtained by cutting or crushing glass fiber, and is generally used as a reinforcing material for synthetic resin. The short glass fiber is a glass fiber satisfying L / D ≦ 10, where L is the average length of the short glass fiber, and D is the average diameter. If the L / D value is larger than 10, the appearance of the molded product is deteriorated and the uniform light diffusivity is lost due to the orientation of the glass fibers in the molded product, which is not preferable. The diameter of the glass short fibers is not particularly limited, but is preferably in the range of 3 to 20 μm.

As the glass short fibers, alkali-free glass is preferable, and aluminum-borosilicate glass (E glass) is particularly preferable. The difference between the refractive index and the refractive index of the aromatic polycarbonate resin used is preferably 0.01 to 0.04. When the difference in refractive index is less than 0.01, the diffusion of light becomes insufficient, and when it exceeds 0.04, the effect of dispersing light is high but the total light transmittance is lowered, which is not suitable.

The mixing ratio of the glass short fibers is 0.1 to 20% by weight based on 100% by weight of the mixture of aromatic polycarbonate resin, calcium carbonate and glass short fibers.
And 1 to 15% by weight is preferable. When the blending ratio of the glass short fibers is less than 0.1% by weight, sufficient light diffusibility cannot be obtained, and when it exceeds 20% by weight, the workability and the appearance of the molded article are deteriorated, which is not preferable. Such glass short fibers are preferably surface-treated with a coupling agent such as a silane coupling agent or a titanate coupling agent. Such short glass fibers can be easily obtained from the market as milled fibers or glass powder.

The blending ratio of calcium carbonate and short glass fibers used in the present invention is not particularly limited, and the blending ratio can be arbitrarily selected so as to satisfy the required total light transmittance and light diffusivity. it can.

In the present invention, a phosphite compound and / or a phosphate compound is added to the mixture.
By blending a phosphite compound and / or a phosphate compound, coloring during molding can be suppressed.

Examples of the phosphite compound include triphenyl phosphite, trimethyl phosphite,
Tricresyl phosphite, diphenyl nonyl phenyl phosphite, tris (nonyl phenyl) phosphite, trioctyl phosphite, diphenyl isodecyl phosphite, triisodecyl phosphite, trioleyl phosphite, trilauryl trithiophosphite, diisodecyl phosphite Fight, dilauryl phosphite, dioleyl phosphite, tris (2,4-di-t
-Butylphenyl) phosphite, distearyl pentaerythritol diphosphite and bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, and the like, and examples of the phosphate compound include trimethyl. Phosphate, tributyl phosphate, tricresyl phosphate, triphenyl phosphate, trichlorophenyl phosphate, triethyl phosphate, diphenyl cresyl phosphate, diphenyl monoorthoxenyl phosphate, tributoxyethyl phosphate, phenylphosphonic acid dimethyl ester, 3,5-di- t-butyl-4-
Examples thereof include hydroxybenzylphosphonic acid dimethyl ester, dibutyl phosphate, dioctyl phosphate and diisopropyl phosphate. Among these, tris (nonylphenyl) phosphate, distearyl pentaerythritol diphosphite and trimethyl phosphate are particularly preferably used. These may be used alone or as a mixture of two or more.

The amount of the phosphite compound and / or phosphate compound is 0.001 to 1 part by weight based on 100 parts by weight of the mixture of the aromatic polycarbonate resin, calcium carbonate and short glass fibers, and 005 to 0.8 part by weight is preferable, and 0.01 to
More preferably 0.5 part by weight. When the content is less than 0.001 part by weight, the improvement of the coloring property during molding is insufficient, and when it exceeds 1 part by weight, the aromatic polycarbonate resin deteriorates, which is not preferable.

In the present invention, a phenolic antioxidant is added to the mixture. By blending a phenolic antioxidant, coloring under high temperature dry heat can be suppressed.

Examples of the phenolic antioxidant include n-octadecyl-3- (4-hydroxy-3,5)
-Di-t-butylphenyl) propionate, tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane, 1,1,3
-Tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, distearyl (4-hydroxy-
5-t-butylphenyl) butane, distearyl (4-
Hydroxy-3-methyl-5-t-butyl) benzyl malonate and 4-hydroxymethyl-2,6-di-t
-Butylphenol and the like. Among them, n-octadecyl-3- (4-hydroxy-3,5-di-t-butylphenyl) propionate is particularly preferable. These may be used alone or as a mixture of two or more.

The amount of the phenolic antioxidant blended is 0.001 to 1 part by weight based on 100 parts by weight of the mixture of the aromatic polycarbonate resin, calcium carbonate and short glass fibers, and 0.005 0.8 parts by weight is preferable, and 0.01 to 0.5 parts by weight is more preferable. When the content is less than 0.001 part by weight, coloring during molding and discoloration under high temperature dry heat occur, and when it exceeds 1 part by weight, the aromatic polycarbonate resin deteriorates, which is not preferable.

By using the above-mentioned phosphite compound and / or phosphate compound in combination with a phenolic antioxidant, a light-diffusing aromatic polycarbonate resin which is less colored during molding and is suppressed from discoloration under high temperature dry heat It is possible to obtain compositions and moldings therefrom, and the effects are each unexpected compared to their use alone.

The molded article for light diffusion and transmission, which comprises the aromatic polycarbonate resin composition of the present invention, has high light transmission, has excellent light diffusivity, and is colored during molding and under high temperature dry heat. Since it is less discolored, it is suitable for use as an incandescent bulb lighting glove, for example.

In particular, this molded product for light diffusion transmission has a total light transmittance of 35% or more for a sheet having a thickness of 3 mm, a dispersity of 20 ° or more, and an initial hue (b value) of a sheet having a thickness of 2 mm. ) Is 2 or less, and the thermochromic value (ΔE) is 1
It is preferably 0 or less. The total light transmittance as referred to herein is measured according to ASTM D1003, and the dispersity is as shown in FIG. 1 when the amount of transmitted light when γ = 0 degree when the light rays are vertically applied to the sheet from above is 100. It is the angle of γ when the amount of transmitted light is 50, and the initial hue is the b value of the Hunter color system measured by the reflection method according to JIS Z8722 by melting and kneading the aromatic polycarbonate resin composition and measuring the sheet formed therefrom. The thermal discoloration value (ΔE) is the color difference (ΔE) in the Hunter color system between the hue after treatment and the hue before treatment measured according to JIS Z8722 after treating the sheet at 150 ° C. for 240 hours.
It is.

Any method or apparatus can be used for producing the aromatic polycarbonate resin composition of the present invention. For example, a method of kneading with an extruder, a Banbury mixer, a roll or the like is appropriately selected. The aromatic polycarbonate resin composition of the present invention is a conventionally known method, for example, injection molding, extrusion molding, blow molding, injection blow molding,
It can be molded by compression molding or powder molding. In particular, blow molding the aromatic polycarbonate resin composition of the present invention,
A molded product obtained by injection blow molding has a high whiteness and a high-grade light diffusion / transmission molded product in which the adhesion between the glass short fibers and calcium carbonate and the polycarbonate resin is changed by the stretching process.

The aromatic polycarbonate resin composition of the present invention contains a flame retardant, a flame retardant aid, an ultraviolet absorber, an optical brightening agent, a release agent, a flow modifier, and the like, within a range that does not impair the object of the present invention. A coloring agent, a lubricant, a foaming agent and the like may be added in an expression amount thereof as needed. Further, other fillers such as glass beads, glass flakes, barium sulfate, silica, clay, talc, mica, titanium oxide and zinc sulfide can be used together. Examples of the above-mentioned flame retardant include brominated bisphenol A, brominated polycarbonate, brominated polystyrene, red phosphorus, and the like, examples of flame retardant aids include antimony trioxide, sodium antimonate, and the like, and ultraviolet absorbers. Examples include benzotriazole-based UV absorbers, benzophenone-based UV absorbers, acrylonitrile-based UV absorbers, and the like.

[0028]

The present invention will be further described with reference to the following examples. The evaluation was performed by the following methods (1) to (4). (1) Total light transmittance: Using a test piece having a side length of 150 mm and a thickness of 3 mm, a haze meter HR-100 manufactured by Murakami Color Research Laboratory Co., Ltd. was used to measure the transmittance in the thickness direction according to ASTM D1003. did. (2) Dispersity: A test piece having a side length of 150 mm and a thickness of 3 mm was used and measured using a dispersity meter manufactured by Nippon Denshoku Industries Co., Ltd. The measuring method is shown in FIG. Incidentally, the degree of dispersion means the angle of γ when the amount of transmitted light becomes 50 when the amount of transmitted light when γ = 0 degree when the light beam is vertically applied to the surface of the test piece in FIG. 1 is 100. . (3) Initial hue: A color analyzer T manufactured by Tokyo Denshoku Industries Co., Ltd. using a test piece having a side of 150 mm and a thickness of 2 mm.
Using R-1800MK-II, JIS Z872
According to 2, the Hunter color system b value measured by the reflection method was evaluated. (4) Dry heat discoloration value: A test piece having a side length of 150 mm and a thickness of 2 mm was treated at 150 ° C. for 240 hours, and then Tokyo Denshoku Industries Co., Ltd.
The color difference (ΔE) in the Hunter color system between the hue after the treatment and the initial hue measured according to JIS Z8722 using a color analyzer TR-1800MK-II manufactured by K.K.

Examples 1 to 6 and Comparative Examples 1 to 9 After dry blending the aromatic polycarbonate resin, calcium carbonate, short glass fiber, phosphorus compound and phenolic antioxidant shown in Table 1 in the proportions shown in Table 1. Cylinder temperature 2 using a uniaxial extruder with a screw diameter of 30 mm and a vent [VSK-30 manufactured by Nakatani Machinery Co., Ltd.]
The mixture was melt-kneaded at 90 ° C., extruded, and strand-cut to obtain pellets, which were dried at 120 ° C. for 5 hours with a hot air circulation dryer. After that, an injection molding machine [manufactured by Toshiba Machine Co., Ltd .: IS-150EN] was used for molding at a cylinder temperature of 310 ° C. and a mold temperature of 100 ° C. to obtain a test piece for evaluation. Table 1 shows the evaluation results.

The symbols of aromatic polycarbonate resin, calcium carbonate, short glass fibers, phosphorus compounds and phenolic antioxidants in Table 1 are shown below.
In addition, the parts by weight showing the added amounts of the phosphorus compound and the phenolic antioxidant are the ratios with respect to 100 parts by weight of the mixture of the aromatic polycarbonate resin, calcium carbonate and glass fiber. PC: Aromatic polycarbonate resin [Tanjin Kasei Co., Ltd. Panlite L-1225 η _sp = 0.41] CA-1: Calcium carbonate [Cypro Kasei Co., Ltd. Cypron A weight average particle size 10 μm] G-1: Glass Short fiber [PFE-30 manufactured by Nitto Boseki Co., Ltd.
1 average diameter 9 μm, average length 40 μm] P-1: trimethyl phosphate P-2: tris (nonylphenyl) phosphite P-3: distearyl pentaerythritol diphosphite F-1: n-octadecyl-3- (4 -Hydroxy-
3,5-di-t-butylphenyl) propionate F-2: tetrakis [methylene-3- (3,5-di-t
-Butyl-4-hydroxyphenyl) propionate]
methane

[0031]

[Table 1]

[0032]

EFFECT OF THE INVENTION The aromatic polycarbonate resin composition of the present invention and the molded article for light diffusion / transmission from the same have high light transparency and excellent light diffusion, little coloring during molding, and high temperature drying. Since the discoloration under heat is suppressed, it is suitable for a field requiring light diffusion under a high temperature environment, for example, as an incandescent bulb lighting glove, and its industrial effect is exceptional.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a method for measuring the degree of dispersion according to the present invention.

[Explanation of symbols]

 A Test piece (sheet) B Light source

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C08K 7/14 KKN C08K 7/14 KKN G02B 1/04 G02B 1/04 5/02 5/02 A

Claims (3)

[Claims] 1. (A) Aromatic polycarbonate resin 60
To 99.8% by weight, (B) calcium carbonate 0.1 to 20% by weight and (C) glass short fiber 0.1 to 20% by weight, based on 100 parts by weight of the mixture.
(D) Phosphite compound and / or phosphate compound 0.001 to 1 part by weight and (E) 0.001 to 1 part by weight of phenolic antioxidant are blended, a light diffusing aromatic polycarbonate resin composition characterized by the above-mentioned. Stuff. 2. A molded article for light diffusion and transmission, which is formed from the resin composition according to claim 1. 3. A sheet having a thickness of 3 mm has a total light transmittance of 3
5% or more, dispersity is 20 ° or more, thickness 2 m
The light diffusion and transmission molded article according to claim 2, wherein the m sheet has an initial hue (b value) of 2 or less and a thermochromic value (ΔE) of 10 or less.