JPH05140435A - Polycarbonate resin composition with improved flowability - Google Patents

Abstract

PURPOSE:To improve the melt flowability of a polycarbonate resin without detriment to the good mechanical properties and heat resistance inherent in the resin by compounding it with a low-mol. acrylic copolymer. CONSTITUTION:A resin compsn. comprising 70-99wt.% polycarbonate resin and 30-1wt.% low-mol. acrylic copolymer, which is generally prepd. by reacting a dihydric phenol with a carbonate precursor such as phosgene, a halogenoformate, or a carbonate ester, and one prepd. from bisphenol A is esp. suitable. The copolymer contains at least 5wt.% pref. 20-40wt.%, 1-5C alcohol ester of (meth)acrylic acid and has a wt.-average mo1.wt. of 50,000 or lower, pref. 25,000 or lower.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polycarbonate resin composition, and more particularly, a polycarbonate resin composition having improved melt flowability without impairing good mechanical properties and heat resistance, and further improved melt flowability. And a filler-reinforced polycarbonate resin composition.

[0002]

2. Description of the Related Art Generally, a polycarbonate resin is a resin having excellent mechanical properties and heat resistance and is widely used as an engineering plastic. Also, blending with various resins is known utilizing such properties. Further, in order to make full use of these characteristics, attempts have been made to improve the mechanical strength, heat resistance, hardness, dimensional stability, etc. of the resin composition by adding a filler such as glass fiber. However, since the polycarbonate resin has a high viscosity when melted, it is inferior in moldability. further,
When the filler is added, the viscosity is remarkably increased.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a polycarbonate resin composition and a filler-reinforced polycarbonate resin composition having improved melt fluidity without impairing good mechanical properties and heat resistance. To do.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a resin composition of a polycarbonate resin and a specific low molecular weight acrylic copolymer can achieve the above object. They have found the present invention and reached the present invention. That is, the present invention is a polycarbonate resin
A polycarbonate resin composition comprising 70 to 99% by weight and a low molecular weight acrylic copolymer of 30 to 1% by weight, and a filler-reinforced polycarbonate resin composition obtained by adding a filler to the polycarbonate resin composition. ..

The polycarbonate resin used in the present invention is a compound known per se. Generally, they are prepared by reacting dihydric phenols with carbonate precursors, such as phosgene, halogen formates, or carbonate esters. Homopolymers derived from bisphenol A are preferably used in the present invention.

The low molecular weight acrylic copolymer used in the present invention is acrylic acid or methacrylic acid having 1 to 5 carbon atoms.
At least 5% by weight of ester with alcohol,
Preferably 10 to 50 wt%, more preferably a copolymer containing 20 to 40 wt%, the weight average molecular weight is 50,000 or less,
It is preferably 25,000 or less. Examples of such acrylic acid ester include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, and 1,3-butylene-diacrylate. Examples of the methacrylic acid ester include methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, 1,3-butylene-dimethacrylate and the like, and butyl methacrylate is preferable. Further, examples of the component copolymerized with these esters include vinyl monomers such as styrene, acrylonitrile, ethylene, propylene, butadiene, butene-1, and isobutylene. Preferred components include styrene and acrylonitrile.

The filler used in the present invention includes glass fiber, carbon fiber, glass, carbon black, silicon carbide fiber, carbon whiskers, asbestos, graphite, magnesium carbonate, calcium carbonate, clay, mica, talc, silica and sulfuric acid. In addition to materials such as barium, alumina, inorganic pigments, wood powder, pulp, polyester fiber, iron, aluminum, copper, lead, zinc,
Examples of the metal material include metals such as tin and nickel, oxides of these metals, and alloys containing these as a main component (eg, stainless copper, brass). These fillers can be added alone or in combination of two or more. In particular, glass fibers and carbon fibers are preferable because they have an excellent balance of mechanical properties and melt fluidity.

In the polycarbonate resin composition of the present invention, the blending amount of (a) the polycarbonate resin and (b) the low molecular weight acrylic copolymer is 30% in (b) with respect to 70 to 99% by weight in (a). ~ 1% by weight, preferably 15-3% by weight
The range is. If the blending amount of (b) exceeds 30% by weight, the original properties of the resin of component (a) are lost, and the mechanical strength and heat resistance are unfavorably reduced. When (b) is less than 1% by weight, the effect of improving the fluidity is insufficient, which is not preferable.

The filler can be added within a range in which the mechanical strength of the polycarbonate resin composition is not significantly lowered, but preferably (a) the polycarbonate resin and (b).
The amount is in the range of 3 to 100 parts by weight with respect to 100 parts by weight of the low molecular weight acrylic copolymer composition.

The method for producing the polycarbonate resin composition of the present invention is not particularly limited, and a commonly known method can be adopted. That is, (a) a polycarbonate resin and (b) a low molecular weight acrylic copolymer are uniformly mixed with a high-speed stirrer, etc., and then melt-kneaded with a uniaxial or multiaxial extruder having sufficient kneading ability. To be done.

Further, various elastomers, antioxidants, ultraviolet absorbers, lubricants, flame retardants, antistatic agents and the like can be added depending on the purpose.

[0012]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. The characteristic evaluations described in Examples and Comparative Examples were carried out according to the following methods.

(1) IZOD impact strength It conforms to JIS-K7110.

(2) Deflection temperature under load (heat resistance) It was measured according to JIS-K7207.

Bending stress 18.56 kg / cm ² (3) Melt flow index (fluidity) According to JIS-K7210.

Load 2.16 kg, temperature 280 ° C. Example 1 90% by weight of Panlite L-1225 [manufactured by Teijin Kasei Co., Ltd.] as a polycarbonate resin, a low molecular weight acrylic copolymer having a weight average molecular weight of After mixing 10% by weight of 20000 styrene-butylmethacrylate copolymer (butylmethacrylate 30% by weight: St-BA) with a Henschel mixer, using a twin screw extruder with a screw diameter of 30 mm and L / D = 30,
It was extruded at a melting temperature of 280 ° C. and a screw rotation speed of 100 rpm to obtain pellets. The pellets were injection-molded into test pieces, and the physical properties of the test pieces were tested by the above-mentioned methods. The results are shown in Table 1. All have high fluidity and have sufficient mechanical properties to withstand practical use. Examples 2 to 3 Same as Example 1 except that the compounding ratio of the polycarbonate resin and the low molecular weight acrylic copolymer was changed as shown in Table 1. The results are shown in Table 1. All have high fluidity and have sufficient mechanical properties to withstand practical use. Example 4 The same as Example 1 except that a styrene-acrylonitrile-butyl methacrylate copolymer having a weight average molecular weight of 25000 (butyl methacrylate 30% by weight: AS-BA) was used as the low molecular weight acrylic copolymer. .. The results are shown in Table 1. It has high fluidity and sufficient mechanical properties for practical use. Comparative Example 1 In Example 1, Table 2 shows the results of the physical property test of the case where the low molecular weight acrylic copolymer was not used, that is, the polycarbonate resin alone. Low melt flow index and poor fluidity. Comparative Example 2 Same as Example 1 except that the addition amount of the low molecular weight acrylic copolymer was changed. Table 2 shows the compounding ratio and the result of the physical property test. Although the melt flow index is improved, mechanical strength and heat resistance are greatly reduced, which is not preferable. Comparative Example 3 The same procedure as in Example 1 was carried out except that a styrene-butyl methacrylate copolymer having a weight average molecular weight of 70,000 (30% by weight of butyl methacrylate) was used in place of the low molecular weight acrylic copolymer. Table 2 shows the compounding ratio and the physical property test results.
Shown in. The melt flow index is low, which is not preferable. Example 5 (a) As a polycarbonate resin, Panlite L-1225
[Manufactured by Teijin Kasei Co., Ltd.], 90 parts by weight, (b) 10 parts by weight of a styrene-butyl methacrylate copolymer (butyl methacrylate 30% by weight) having a weight average molecular weight of 20000 as a low molecular weight acrylic copolymer, Furthermore, glass chopped strands (a) + (b) 100 with a length of 3 mm as filler
After mixing 30 parts by weight to parts by weight with a tumbler, melt temperature 2 with a twin screw extruder with a screw diameter of 30 mm and L / D = 30.
Pellets were obtained by extrusion at 80 ° C and a screw rotation speed of 100 rpm. The pellets were injection-molded into test pieces, and the physical properties of the test pieces were tested by the above-mentioned methods. The results are shown in Table 1. It has sufficient mechanical properties for practical use. Comparative Example 4 The same procedure as in Example 5 was carried out except that the low molecular weight acrylic copolymer was not used. Table 2 shows the compounding ratio and the physical property test results.
Shown in. The melt flow index is low, which is not preferable.

[0017]

[Table 1]

[0018]

[Table 2]

[0019]

The polycarbonate resin composition of the present invention is excellent in melt fluidity, mechanical properties and heat resistance, and can be used for molding home electric appliance parts, automobile parts, industrial parts and the like, and its practical value is great.

 ─────────────────────────────────────────────────── (72) Inventor Tomoyuki Nakata 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd. (72) Kaoru Yoda 1190 Kasama-cho, Sakae-ku, Yokohama, Kanagawa Mitsui Toatsu Chem. Within the corporation

Claims (4)

[Claims] 1. A polycarbonate resin composition comprising (a) 70 to 99% by weight of a polycarbonate resin and (b) 30 to 1% by weight of a low molecular weight acrylic copolymer. 2. A filler-reinforced polycarbonate resin composition containing 3 to 100 parts by weight of a filler with respect to 100 parts by weight of the polycarbonate resin composition according to claim 1. 3. The polycarbonate resin composition according to claim 1, wherein the low molecular weight acrylic copolymer is a copolymer of a styrene monomer and an acrylate monomer. 4. The low molecular weight acrylic copolymer is a copolymer of styrene monomer and butyl methacrylate monomer or a copolymer of styrene monomer, acrylonitrile monomer and butyl methacrylate monomer. The polycarbonate resin composition according to claim 1.