JPH06271755A - Polycarbonate resin composition - Google Patents

Abstract

PURPOSE:To improve not only the light scattering and transmission properties but also the moldability and resistances to steam, heat, light discolorion, and impact of a polycarbonate resin compsn. CONSTITUTION:This resin compsn. comprises 86-99.8 pts.wt. polycarbonate resin (A), 0-2 pts.wt. impact modifier (B), 0-2 pts.wt. ethylene copolymer (C) having 1-20wt.% glycidyl (meth)acrylate units and 0-50wt.% vinyl acetate and/or methyl (meth)acrylate units, and calcium carbonate (D) having a mean particle size of 0.1-30mum provided that the sum of all the components is 100 pts.wt. and that the amt. of either component B or component C is 0.1 pt.wt. or higher.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel polycarbonate resin composition. More specifically, the present invention relates to a polycarbonate resin composition having excellent steam resistance, heat resistance, light discoloration resistance, impact resistance, and moldability as well as light diffusion and light transmission properties.

[0002]

2. Description of the Related Art Polycarbonate, which is excellent in transparency, heat resistance and impact resistance, is used in various fields such as vehicles, light electric appliances and household products, but when it is used as a lighting cover material, it is excellent. Not only transparency (light transmittance) but also light diffusion, that is, prevention of see-through of the internal light source is required. In a hot and humid environment such as a bathroom or a sauna room, its use is limited due to deterioration due to hydrolysis of polycarbonate and discoloration or fading due to fluorescent or incandescent light bulbs.

A polycarbonate composition using calcium carbonate and titanium oxide in combination has already been proposed as an illumination lamp cover material which is semi-milky and excellent in semi-transparency (Japanese Patent Publication No. Sho 5).
However, since it is inferior in steam resistance, heat resistance, light discoloration resistance, and impact resistance, it was insufficient as a bathroom light cover material.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides not only light diffusivity and light transmissivity but also steam resistance, heat resistance, light discoloration resistance and impact resistance without sacrificing the original excellent properties of polycarbonate. The present invention relates to a polycarbonate resin composition having excellent moldability.

[0005]

As a result of intensive studies on the above problems, the present inventors have solved the above problems by blending a specific polymer and a specific amount of calcium carbonate with polycarbonate. The inventors have found out what can be done and have reached the present invention.

That is, the present invention relates to polycarbonate (A), impact strength improver (B), glycidyl (meth).
An ethylene-based copolymer (C) containing 1 to 20% by weight of acrylate and 0 to 50% by weight of vinyl acetate and / or methyl (meth) acrylate and an average particle size of 0.
1 to 30 μm of calcium carbonate (D) with a composition ratio of (A), (B), (C) and (D) totaling 100
86.0 to 99.8 parts by weight of (A) per part by weight,
(B) 0 to 2 parts by weight, (C) 0 to 2 parts by weight, (D) 0.
1 to 10 parts by weight and at least 0.1 part by weight of (B) or (C), light diffusivity, light transmittance, steam resistance, heat resistance, light discoloration resistance, A polycarbonate resin composition having excellent impact resistance and moldability is provided. By using the resin composition of the present invention, an excellent bathroom light cover can be provided.

The present invention will be described in detail below. The polycarbonate (A) used in the present invention is a polymer obtained by a phosgene method in which various dihydroxydiaryl compounds are reacted with phosgene, or a transesterification method in which a dihydroxydiaryl compound is reacted with a carbonic acid ester such as diphenyl carbonate. And a typical example is a polycarbonate produced from 2,2-bis (4-hydroxyphenyl) propane (bisphenol A).

Examples of the dihydroxydiaryl compound include bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, and 2,2-bis (4-hydroxyphenyl), in addition to bisphenol A.
Butane, 2,2-bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, 2,2-bis (4-hydroxyphenyl-3-methylphenyl) propane, 1,1-bis (4 -Hydroxy-3-tert-butylphenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) propane,
2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4-hydroxy-3,
Bis (hydroxyaryl) alkanes such as 5-dichlorophenyl) propane, bis (hydroxyaryl) such as 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclohexane Cycloalkanes, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-
Dihydroxy diaryl ethers such as 3,3′-dimethyldiphenyl ether, 4,4′-dihydroxydiphenyl sulfide, 4,4′-dihydroxy-3,
Dihydroxydiaryl sulfides such as 3'-dimethyldiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-
Examples thereof include dihydroxydiaryl sulfoxides such as 3,3′-dimethyldiphenyl sulfoxide, 4,4′-dihydroxydiphenyl sulfone, and dihydroxydiaryl sulfones such as 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfone. To be

These may be used alone or in admixture of two or more, but in addition to these, piperazine, dipiperidyl hydroquinone, resorcin, 4,4'-dihydroxydiphenyl and the like may be mixed and used.

Further, the above-mentioned dihydroxyaryl compound may be mixed with a phenol compound having a valence of 3 or more as shown below. As trihydric or higher phenol, phloroglucin, 4,6-dimethyl-2,4,6-tri-
(4-Hydroxyphenyl) -heptene-2,4,6-
Dimethyl-2,4,6-tri- (4-hydroxyphenyl) -heptane, 1,3,5-tri- (4-hydroxyphenyl) -benzol, 1,1,1-tri- (4-hydroxyphenyl) -Ethane and 2,2-bis-
[4,4- (4,4′-dihydroxydiphenyl) -cyclohexyl] -propane and the like can be mentioned.

The viscosity average molecular weight of the polycarbonate (A) is not particularly limited, but is usually 10,000 to 100,000, preferably 15,000 to 3 from the viewpoint of moldability and strength.
It is 5000. In producing such a polycarbonate, a molecular weight modifier, a catalyst and the like can be used if necessary.

Examples of the impact strength improver (B) used in the present invention include already known impact strength improvers for polycarbonate. For example, polybutadiene, polyisoprene, polybutyl acrylate, hydrogenated polybutadiene, hydrogenated polyisoprene, or those obtained by graft-polymerizing a vinyl compound such as methyl methacrylate or styrene to these are exemplified. Particularly preferred is a polymer obtained by grafting methyl methacrylate and styrene onto polybutyl acrylate. In the present invention, the impact strength improver (B) simultaneously provides the polycarbonate composition with an impact strength improving effect and a transmittance adjusting effect.

Glycidyl (meth) used in the present invention
Examples of the ethylene-based copolymer (C) containing 1 to 20% by weight of acrylate and 0 to 50% by weight of vinyl acetate and / or methyl (meth) acrylate include glycidyl (meth) acrylate-ethylene copolymer and glycidyl. (Meth) acrylate-vinyl acetate-ethylene copolymer, glycidyl (meth) acrylate-methyl (meth) acrylate-ethylene copolymer, glycidyl (meth) acrylate-vinyl acetate-methyl (meth) acrylate-
An ethylene copolymer may be used. Glycidyl (meth) acrylate, or vinyl acetate and / or (meth)
If the methyl acrylate is out of the range, the intended composition cannot be obtained. Particularly preferably, glycidyl (meth)
It is an ethylene-based copolymer composed of 4 to 15% by weight of acrylate, 4 to 40% by weight of vinyl acetate and / or methyl (meth) acrylate and 92 to 45% by weight of ethylene.

The calcium carbonate (D) used in the present invention has an average particle size of 0.1 to 30 μm, preferably 1 to 10 μm. With an average particle size of 0.1 or less, even if the amount used is increased, the light diffusivity is inferior, and when used for an illumination lamp cover, the outline of the light source is seen through. On the other hand, when the average particle size exceeds 30 μm, not only the surface irregularities increase, but also the mechanical strength of the composition decreases.

The composition of the present invention comprises 1 to 20% by weight of the above-mentioned polycarbonate (A), impact strength improver (B), glycidyl (meth) acrylate and vinyl acetate and / or methyl (meth) acrylate. It is composed of an ethylene-based copolymer (C) containing 0 to 50% by weight and calcium carbonate (D) having an average particle diameter of 0.1 to 30 μm, the composition ratios of which are (A), (B) and (C). ) And (D) per 100 parts by weight in total, (A) 86.0-9
9.8 parts by weight, (B) 0 to 2 parts by weight, (C) 0 to 2 parts by weight, and (D) 0.1 to 10 parts by weight. When the amount of the component (B) or the component (C) exceeds 2 parts by weight, the light transmittance is poor. Further, if the amount of the component (D) is less than 0.1 parts by weight, the light diffusion property is poor, and if it exceeds 10 parts by weight, the impact resistance is poor. Particularly preferably, (A) 99. per 100 parts by weight of the total of A to D.
5 to 93.5 parts by weight, (B) 0.1 to 0.5 parts by weight,
(C) 0.2 to 1.0 parts by weight, (D) 0.2 to 5 parts by weight.

Further, in the composition of the present invention,
It is essential to contain at least 0.1 part by weight of either component (B) or (C). If the content of either component (B) or (C) is not more than 0.1 parts by weight, the impact resistance is poor. Particularly preferably, the sum of (B) and (C) is 0.2 to
2 parts by weight.

There is no particular limitation on the mixing method and mixing order of the above components (A), (B), (C) and (D), and known mixers such as tumblers, ribbon blenders,
It can be performed by mixing with a high-speed mixer or the like and then melt-kneading. It is also possible to mix the above four components at once, or to mix only the specific components and then add and mix the remaining components.

Further, at the time of mixing, known additives such as antistatic agents, release agents, antioxidants, ultraviolet absorbers, flame retardants, dyes and pigments may be added, if desired.

The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[Example] Containing polycarbonate (A), impact resistance improver (B), glycidyl (meth) acrylate in an amount of 3% by weight or more and vinyl acetate and / or methyl (meth) acrylate in an amount of 0 to 30% by weight. Ethylene copolymer (C) and average particle size 0.1 to 30 μm
The calcium carbonate (D) was mixed in a tumbler based on the blending ratio shown in Table 1, and then melt-kneaded in an extruder to obtain pellets. Using a 4 ounce injection molding machine from the obtained pellets, various test pieces were prepared at a cylinder set temperature of 280 ° C. and used for the test. The test results are shown in Table-2.
~ 3. The materials obtained in this example are as follows.

P C: An aromatic polycarbonate composed of bisphenol A and phosgene and having a viscosity average molecular weight of 20,000.

B-1: Polybutyl acrylate graft-polymerized with methyl methacrylate and styrene (METATABLEN W-529 manufactured by Mitsubishi Rayon Co., Ltd.) B-2: Polybutyl acrylate graft-polymerized with methyl methacrylate and styrene. (Metablene W-800 manufactured by Mitsubishi Rayon Co., Ltd.) B-3: Methyl methacrylate and styrene graft-polymerized on polybutyl acrylate (Paraloid EXL-2314 manufactured by Kureha Chemical Co., Ltd.) B-4: Hydrogenated polyisoprene and further grafted with styrene (Septon 21 manufactured by Kuraray Co., Ltd.)
04)

C-1: 6 glycidyl methacrylate
%, Ethylene-glycidyl methacrylate-methyl acrylate copolymer obtained by copolymerizing 30% by weight of methyl acrylate (Sumitomo Chemical Co., Ltd. Bondfast 20M) C-2: 12% by weight of glycidyl methacrylate, vinyl acetate 5% by weight of ethylene-glycidyl methacrylate-vinyl acetate copolymer (Sumitomo Chemical Co., Ltd. Bondfast 2B)

D: Average particle size 4.5 to 5.0 μm
Calcium carbonate (Lumipearl DSN-30 manufactured by Nemoto Special Chemical Co., Ltd.) X: Titanium oxide having an average particle diameter of 0.2 to 0.3 μm (R-TC-30 manufactured by Taioxide)

Various test methods are as follows. o Light diffusivity: An automatic goniophotometer was used. As the sample, an injection molded plate (a three-stage plate having a thickness of 1 mm, 2 mm, and 3 mm) was used. A straight ray from the light source is applied from the normal direction of the sample, the intensity of the transmitted light is measured with a movable light receiver, the transmittance is plotted against the angle from the normal direction, and the straight light transmittance is 10%. The angle at which the transmissivity was obtained was calculated. The unit is "degree", and the larger the numerical value, the better.

O Light transmittance: Measurement was carried out using a transmittance measuring device. Samples are injection molded plates (1mm, 2mm and 3m
m three-stage plate) was used. With respect to the incident light from the normal direction, the intensity of the light transmitted in the normal direction was measured, and the transmitted light intensity with respect to the incident light was used. The unit is "%", and the larger the numerical value, the better.

Steam resistance: The injection-molded test pieces were exposed to steam using a pressure cooker at 140 ° C. and 100% relative humidity for 48 hours. The test piece before and after exposure was dissolved in dichloromethane and centrifuged to remove precipitates and suspended matter. The dried product was dissolved in dichloromethane, the viscosity of the solution was measured using a Canon-Fenske viscometer, the molecular weight of the polycarbonate was measured, and the reduced molecular weight was calculated. The smaller the value, the better.

O Heat resistance: The injection-molded plate (thickness: 3 mm) was aged for 100, 200 and 400 hours using a hot air circulating oven at 140 ° C., and its yellowing degree was measured using a high speed color analyzer. Shown as ΔYI. The smaller the value, the better.

O Light resistance to discoloration: An injection-molded plate (thickness: 3 mm) was used for 5 and 10 in a normal room exposed to a fluorescent lamp and natural light.
After being left for 20 days, the degree of yellowing was measured using a high-speed color analyzer. Shown as ΔYI. 0 as a numerical value
Is preferred.

O Impact strength: ASTM D-256 1 /
8 inches, Izod with notch, 23 ° C. The unit is “Kg · cm / cm 2”, and the larger value is preferable.

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

[Table 3]

[0034]

EFFECTS OF THE INVENTION The polycarbonate resin composition of the present invention is excellent not only in light diffusivity and light transmittance but also in steam resistance, heat resistance, light discoloration resistance, impact resistance and moldability. It is useful as an illumination lamp cover material used in bathrooms, saunas, etc.

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Claims (1)

[Claims] 1. Polycarbonate (A), impact strength improver (B) and glycidyl (meth) acrylate are contained in an amount of 1 to 2.
A composition comprising an ethylene-based copolymer (C) containing 0% by weight and 0 to 50% by weight of vinyl acetate and / or methyl (meth) acrylate and calcium carbonate (D) having an average particle size of 0.1 to 30 μm. The ratio is (A), (B),
(A) per 100 parts by weight of the total of (C) and (D)
86.0-99.8 parts by weight, (B) 0-2 parts by weight,
(C) 0 to 2 parts by weight, (D) 0.1 to 10 parts by weight and one or more of (B) and (C) in an amount of 0.1 parts by weight or more. Composition.