JPH05170992A - Polycarbonate resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition for automobile, household appliances, industrial components, etc., consisting of a polycarbonate resin, an acrylonitrile-styrene copolymer and an acrylic resin and excellent in stiffness, fluidity, scratch resistance and strand stability. CONSTITUTION:The objective polycarbonate resin composition excellent in stiffness, fluidity, scratch resistance and strand stability and capable of using for automobile field, household appliance field, industrial component, etc., is obtained by blending (A) 40-95 pts.wt. polycarbonate resin with (B) 5-60 pts.wt. acrylonitrile-styrene based copolymer and (C) 1-25 pts.wt. (based on 100 pts.wt. total amount of the components A and B) acrylate based resin such as methyl methacrylate, heating and melt-mixing the blend by a twin-screw extruder whose cylinder temperature is set to 230-250 deg.C, drawing a strand from the tip and cutting the strand by a pelletizer to give pellet-like molding material composition.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a polycarbonate resin composition having excellent rigidity, fluidity, scratch resistance and strand stability.

[0002]

2. Description of the Related Art Conventionally, polycarbonate resins have been widely used because of their excellent mechanical properties such as impact resistance and electrical properties such as electrical insulation. But this resin
Moldability is poor due to poor fluidity. Further, in a specific application, the rigidity of the polycarbonate resin is not satisfied, and higher rigidity, that is, excellent bending elastic modulus and bending strength are required.

In order to impart high rigidity and good fluidity while maintaining the mechanical properties of the polycarbonate resin, various attempts have been made so far to blend the polycarbonate resin with another thermoplastic resin. A resin composition obtained by blending a polycarbonate resin with an acrylonitrile-styrene copolymer can obtain a sufficiently satisfactory rigidity, but in the production process of this resin composition, the polycarbonate resin and the acrylonitrile-styrene copolymer are extruded. When melt-kneading with a machine, a large die swell occurs at the die strand outlet at the tip of the extruder and the strand diameter is not stable, so strand breakage occurs and it is impossible to use the conventional manufacturing method.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polycarbonate resin composition having excellent rigidity, fluidity, scratch resistance and strand stability.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a polycarbonate resin and an acrylonitrile-styrene copolymer have a high rigidity thermoplastic resin composition having a specific amount ratio. By further adding a specific amount of an acrylate resin, a thermoplastic resin composition having high rigidity and excellent fluidity, scratch resistance and strand stability was found, and the present invention was reached.

That is, the present invention comprises (A) 40 to 95 parts by weight of a polycarbonate resin, (B) 5 to 60 parts by weight of an acrylonitrile-styrene copolymer, (C), (A) and (B).
1 to 25 parts by weight of acrylate resin for 100 parts by weight
It is a polycarbonate resin composition consisting of parts by weight.

The polycarbonate resin used as a constituent component of the polycarbonate resin composition of the present invention is usually a reaction of a dihydric phenol and phosgene in the presence of an acid acceptor and a molecular weight modifier, or a dihydric phenol and diphenyl carbonate. It is produced by a transesterification reaction. As the dihydric phenol that can be used, bisphenols are preferable, and 2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as bisphenol A) is preferable. Further, a part or all of bisphenol A may be replaced with another dihydric phenol. Bisphenol A
Examples of dihydric phenols other than, for example, compounds such as hydroquinone, 4,4′-dihydroxyphenyl, bis (4-hydroxyphenyl) alkane, bis (4-hydroxyphenyl) cycloalkane, or 2,2-
Mention may be made of halogenated bisphenols such as bis (3,5-dibromo-4-hydroxyphenyl) propane. Further, the polycarbonate resin may be a homopolymer of these dihydric phenols, a copolymer of two or more kinds, or a polyblend thereof.

The acrylonitrile-styrene type copolymer used in the present invention is obtained by copolymerizing a monovinyl aromatic monomer and an unsaturated nitrile monomer. Monovinyl aromatic monomers include styrene, α-methylstyrene,
Examples thereof include α-halogenated styrenes such as vinyltoluene, chlorostyrene, bromostyrene, and vinylnaphthalene, α-alkylated styrenes, nuclear halogenated styrenes, and nuclear alkylated styrenes, with preference given to styrene. In addition, the copolymerizable monovinyl aromatic monomer may be replaced with a part of styrene as long as the physical properties are not affected. Examples of the unsaturated nitrile monomer include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-alkylacrylonitrile, α-halogenated acrylonitrile and the like, and acrylonitrile is preferable. Further, the copolymerizable unsaturated nitrile monomer may be replaced with a part of acrylonitrile as long as the physical properties are not affected. The acrylonitrile-styrene type copolymer used in the present invention is used regardless of the copolymer ratio.

The acrylate monomer constituting the acrylate resin of the present invention includes methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, octyl acrylate, dodecyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl. Methacrylate, hexyl methacrylate, octyl methacrylate, dodecyl methacrylate and the like can be mentioned, with preference given to methyl methacrylate. In addition, the copolymerizable acrylate monomer may be replaced with a part of methyl methacrylate as long as the physical properties are not affected.

The polycarbonate resin composition of the present invention is
40 to 95 parts by weight of these (A) polycarbonate resins,
50 to 80 parts by weight, (B) acrylonitrile-styrene copolymer 5 to 60 parts by weight, preferably 20
The amount of the acrylate resin (C) is 1 to 25 parts by weight based on 100 parts by weight of the sum of (A) and (B).
It should be in the range of 5 parts by weight, preferably 5 to 20 parts by weight. If the content is out of this range, the resin composition cannot have good fluidity, scratch resistance, strand stability or rigidity, and other mechanical properties.

When the polycarbonate resin is less than 40 parts by weight, good fluidity and high flexural modulus can be obtained, but sufficient flexural strength cannot be obtained, and when 95 parts by weight or more of the polycarbonate resin is used, sufficient flexural elasticity is obtained. Rate and scratch resistance cannot be obtained. If the amount of the acrylate resin is less than 1 part by weight, the stability of the strand cannot be obtained. If the amount of the acrylate resin is 25 parts by weight or more, a high flexural modulus can be obtained, but the bending strength is low, which is not preferable.

The polycarbonate resin composition of the present invention having good rigidity, fluidity and strand stability includes various elastomers, plasticizers, pigments, stabilizers, in addition to the above (A), (B) and (C). Fillers, metal powders, etc. are appropriately used depending on the application.

The composition of the present invention is obtained by dry blending the above (A), (B) and (C), then heating and melting and mixing with an extruder to draw a strand from the tip and cutting with a pelletizer to obtain ordinary pellets. It is obtained by the method of obtaining a molding material composition. Further, the molding material composition produced according to the present invention can be used for producing an arbitrary molded article by injection molding, blow molding or the like.

The composition of the present invention has strand stability which is difficult to obtain with a resin composition which is a conventionally known mixture of a polycarbonate resin and an acrylonitrile-styrene copolymer.

[0015]

EXAMPLES The present invention will now be described in detail with reference to examples, but the present invention is not limited thereto. In addition,
The physical property evaluations described in Examples and Comparative Examples were carried out according to the following methods. (1) Evaluation of Strand Stability "○" indicates that the strand could be drawn from the die strand outlet at the tip of the extruder, and "○" indicates that the die swell was too large to draw the strand. X ". (2) Evaluation of scratch resistance Steel wool test The surface of the molded article was rubbed with steel wool 10 times, and the surface was visually observed. Those with 10 or less scratches were marked with "O", and those with 10 or more scratches were marked with "X". (3) Evaluation of fluidity Melt flow index Based on JIS-K7210. It was measured at a load of 2.16 kg and a temperature of 280 ° C. (4) Evaluation of rigidity Bending test (bending strength, bending elastic modulus) Based on JIS-K7113. Example 1 50 parts by weight of a pre-dried polycarbonate resin (Taflon A2200 manufactured by Idemitsu Petrochemical Co., Ltd.) and an acrylonitrile-styrene copolymer (Mitsui Toatsu Chemicals, Inc.)
50 parts by weight of Lightac 100PCF, and methyl methacrylate resin (Kuraray Co., Ltd., Parapet H)
R-1000) 10 parts by weight are mixed, and the cylinder temperature is adjusted to 2
A twin-screw extruder set at 30 to 250 ° C. was used for heating, melting and mixing, drawing a strand from the tip, and cutting with a pelletizer to obtain a pelletized molding material composition. During this extrusion, die swell does not occur,
The strands were always stable and did not cause any trouble in the method for obtaining a usual pellet-shaped molding material composition.

The composition obtained by the above method was added to 260 to 2
Test pieces were molded with an injection molding machine set at 80 ° C., and the physical properties of each were measured. Example 2 Example 1 except that the polycarbonate resin was 60 parts by weight and the acrylonitrile-styrene copolymer was 40 parts by weight.
Same as. Also in this case, as in Example 1, die swell did not occur at the time of extrusion, the strand was always stable, and no trouble occurred in the method for obtaining a usual pellet-shaped molding material composition. It was Example 3 Example 1 except that the polycarbonate resin was 80 parts by weight and the acrylonitrile-styrene copolymer was 20 parts by weight.
Same as. Also in this case, as in Example 1, die swell did not occur at the time of extrusion, the strand was always stable, and no trouble occurred in the method for obtaining a usual pellet-shaped molding material composition. It was Example 4 Same as Example 1 except that 5 parts by weight of methyl methacrylate resin was used. Also in this case, as in Example 1, die swell did not occur at the time of extrusion, the strand was always stable, and no trouble occurred in the method for obtaining a usual pellet-shaped molding material composition. It was Example 5 Except that 15 parts by weight of methyl methacrylate resin was used,
Same as Example 1. Also in this case, as in Example 1, die swell did not occur at the time of extrusion, the strand was always stable, and no trouble occurred in the method for obtaining a usual pellet-shaped molding material composition. It was Comparative Example 1 60 parts by weight of a pre-dried polycarbonate resin,
And 40 parts by weight of acrylonitrile-styrene copolymer are mixed, heated by a twin-screw extruder having a cylinder temperature of 230 to 250 ° C., melt-mixed, and a strand is drawn from the tip to obtain a pelletized molding material composition. However, since the strand diameter was not stable due to the large die swell and the strand could not be drawn, a pelletized composition could not be obtained by this method. Therefore, in this case, the composition kneaded with a twin-screw extruder is extruded to form a lump without cutting the strands, and the lump composition is crushed by a crusher to obtain a molding material composition. This comparative composition was molded into a test piece by injection molding in the same manner as in the example, and the physical properties were measured. Further, in this case, the scratch resistance of the molded product is poor, which is not preferable. Comparative Example 2 35 parts by weight of a pre-dried polycarbonate resin,
An attempt was made to produce a composition in the same manner as in Example except that 65 parts by weight of acrylonitrile-styrene copolymer and 10 parts by weight of methylmethacrylate resin were used, but the strand was not stable because the die swell was large. No pelletized composition was obtained. Therefore, in this case, the composition kneaded by the twin-screw extruder is extruded to form a lump without cutting the strand, and the lump composition is crushed by a crusher to obtain a molding material composition. Similarly to Example 1, this comparative composition was molded into a test piece by injection molding, and its physical properties were measured. Comparative Example 3 98 parts by weight of a pre-dried polycarbonate resin,
Same as Example 1 except that 2 parts by weight of acrylonitrile-styrene copolymer and 10 parts by weight of methyl methacrylate resin were used. In this case, sufficient flexural strength and flexural modulus cannot be obtained, and the scratch resistance of the molded product is poor, which is not preferable. Comparative Example 4 80 parts by weight of a pre-dried polycarbonate resin,
Same as Example 1 except 20 parts by weight of acrylonitrile-styrene copolymer and 30 parts by weight of methyl methacrylate resin. In this case, sufficient bending strength cannot be obtained, which is not preferable.

[0017]

[Table 1]

[0018]

[Table 2]

[0019]

Since the polycarbonate resin composition of the present invention has excellent rigidity, fluidity, scratch resistance and strand stability, it can be used in the fields of automobiles, home appliances, industrial parts and the like, and its utility value is great.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical indication location C08L 33:06) (72) Inventor Susumu Kishi 1190, Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Incorporated (72) Inventor Tomoyuki Nakata 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemicals, Inc.

Claims (1)

[Claims] 1. (A) Polycarbonate resin 40 to 95
Polycarbonate resin composition consisting of 1 to 25 parts by weight of (A) acrylonitrile-styrene copolymer (5 to 60 parts by weight) and (C) (A) and (B) to 100 parts by weight. object.