JPS60127354A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To provide a three-component thermoplastic resin composition having remarkably improved low-temperature impact resistance and the thickness dependency of impact strength, and composed of an aromatic polycarbonate resin, an aromatic saturated polyester resin and a specific acrylic ester copolymer. CONSTITUTION:The objective composition is produced by mixing, melting and kneading (A) 60-90(wt)% aromatic polycarbonate resin (preferably using bisphenol A as a raw material) with (B) 8-30% aromatic saturated polyester resin (e.g. polytetramethylene terephthalate) and (C) 1-20% acrylic ester copolymer composed of a copolymer of an acrylate or methacrylate having 1-5C (un)saturated straight or branched chain aliphatic hydrocarbon group [preferably methyl (meth)acrylate, ethyl (meth)acrylate, etc.] wherein the acrylate accounts for about 50-85% of the copolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermoplastic resin composition that exhibits various mechanical properties, particularly excellent impact resistance at low temperatures, chemical resistance and appearance, as well as good moldability. In detail, A, aromatic polycarbonate resin 60-90 wt% B, aromatic saturated polyester resin 8-30-1% and C
, containing 1 to 20 wt% of an acrylic ester copolymer,
The acrylic ester copolymer comprises (1) an acrylic ester having a saturated or unsaturated straight chain or branched aliphatic hydrocarbon group having 1 to 5 carbon atoms, and (2) a carbon number 1.
This is a thermoplastic resin composition characterized in that it is a copolymer with a methacrylic acid ester having ~5 saturated or unsaturated linear or branched aliphatic hydrocarbon groups.

As is well known, aromatic polycarbonate resins are tough, have excellent impact resistance, electrical properties, and good dimensional stability, and are therefore widely used as useful engineering plastics. On the other hand, it has disadvantages such as high melt viscosity and poor moldability, thickness dependence of impact resistance, and problems with chemical resistance such as cranking when it comes into contact with aromatic solvents or gasoline. As a result, the scope of its application is actually limited.

In order to improve these drawbacks, proposals have been made to blend various resins into aromatic polycarbonate resins. For example, Japanese Patent Publication No. 40-1'7663 discloses polyolefin, Japanese Patent Publication No. 40-24191 discloses ethylene-propylene copolymer, Japanese Patent Publication No. 38-15225 discloses A
BS resin, Special Publication No. 39-71 Niha MBS 414
mj, Japanese Patent Publication No. 48-29308: It is taught to mix MAS resin, and although these improve molding processability and impact resistance, they are caused by lower heat distortion temperature and poor compatibility. There are various defects such as surface peeling phenomenon and weakness of the weld portion, and improvements cannot necessarily be said to be sufficient for practical use. Also, special public service 36-1403
Publication No. 5 proposes blending an aromatic polyester resin with an aromatic polycarbonate resin to improve solvent resistance, but these resins have poor compatibility and the resulting composition has low impact resistance. However, neither the thickness dependence of impact strength nor the improvement has been achieved. Furthermore, JP-A No. 49-41442 proposes a ternary composition of an aromatic polycarbonate resin, a saturated polyester resin, and an ABS resin.
Although moldability and solvent resistance have been improved, this composition has the disadvantages of poor heat resistance and weather resistance, and poor low-temperature impact resistance. Furthermore, JP-A-53-129246
The publication proposes a ternary composition using MAS resin in place of the above ABS resin. Although this composition has good weather resistance, poor dispersibility caused by the MAS resin causes problems in molded products. Pearl luster appears and causes poor appearance.
It also has the disadvantage of poor low-temperature impact resistance.

The present inventors have developed a resin composition that has well-balanced molding processability of aromatic polycarbonate resin as well as various mechanical properties, thermal properties, chemical properties, etc. In particular, the thickness dependence of low-temperature impact resistance and impact strength The present inventors have discovered a ternary thermoplastic resin composition that shows significant improvement in the properties of the ternary thermoplastic resin composition, and have completed the present invention.

The present invention will be explained in detail below.

The aromatic polycarbonate resin of the present invention is an optionally branched thermoplastic polycarbonate polymer made by reacting aromatic dihydroxy or a small amount of a polyhydroxy compound with phosgene or a diester of carbonic acid. An example of an aromatic dihydroxy compound is
2.2-bis(4-hydroxyphenyl)propane (bisphenol A), tetramethylbisphenol A2 tetrabromobisphenol A1 bis(4-hydroxyphenyl>-p-diisopropylbenzene, hydroquinone, resorcinol, 4.4'-dihydroxydiphenyl etc., and bisphenol A is particularly preferred.In addition, to obtain a branched aromatic polycarbonate resin,
Phloroglucin, 4,6-cymethyl-2.4.6-)
(4-hydroxyphenyl)hebutene-2,4,6
-Simethyl-2.4.6-)li(4-hydroxyphenyl)hebutane, 2.6-cymethyl-2.4.6-1
-li(4-hydroxyphenyl)hebutene-3,4,
6-dimethyl-2.4.6-tri(4-hydroxyphenyl)hebutane, 1゜3.5-)li(4-hydroxyphenyl)benzene, Ll,1-)li(4-hydroxyphenyl)ethane, etc. Exemplified polyhydroxy compounds and 3゜3-bis(4-hydroxyaryl)
Oxindole (-isatin bisphenol), 5-
Chlorisatin, 5.7-dichloroisatin, 5-bromiisatin, etc. are used as a part of the dihydroxy compound, for example 0.2 to 2 mol%, as a polyhydroxy compound.

Replace with Furthermore, m-aromatic hydroxy compounds suitable for opening the molecular weight include m- and p-methylphenol, tri- and p-propylphenol, p-bromophenol, p-tertbutylphenol, and p long-chain alkyl-substituted phenol. is preferred. Typical aromatic polycarbonate resins include polycarbonates whose main raw material is bis(4-hydroxyphenyl)alkane dihydroxy compounds, particularly bisphenol A, which can be obtained by using two or more aromatic dihydroxy compounds in combination. Branched polycarbonate obtained by using a small amount of a polycarbonate copolymer and a trivalent phenol compound can also be mentioned. Aromatic polycarbonate resins may be used as a mixture of two or more types.

The aromatic saturated polyester resin used in the present invention is
It is a polymer obtained by reacting aromatic dicarboxylic acid or its diester with glycol or alkylene oxide by a known method. Specifically, the aromatic dicarboxylic acid has terephthalic acid or dimethyl terephthalate as the main component, Examples include polyethylene terephthalate and polytetramethylene terephthalate obtained by reacting this with ethylene glycol, butanediol, ethylene oxide, or the like. The aromatic saturated polyester resin may be a copolymer or may be used in the form of a mixture of two or more types. The aromatic saturated polyester resin used in the present invention has an intrinsic viscosity (intrinsic viscosity) of 0.8 or more, usually 1.0 or more, as measured at 30°C in a mixed solvent of phenol and tetrachloroethylene in a weight ratio of 6:4. 0
It is preferable to have a molecular weight of 1.5 to 1.5, and if it is less than 0.8, impact strength and chemical resistance will not be sufficiently improved.

In the present invention, in the above resin composition of A, aromatic polycarbonate resin and B, aromatic saturated polyester resin, as C, acrylic ester copolymer, A copolymer of an acrylic ester having a straight or branched aliphatic hydrocarbon group and a methacrylic ester having a saturated or unsaturated straight or branched aliphatic hydrocarbon group having 1 to 5 carbon atoms. Add and mix.

Here, (ii) the acrylic ester having a saturated or unsaturated straight chain or branched aliphatic hydrocarbon group having 1 to 5 carbon atoms is preferably methyl acrylate, ethyl acrylate, isobutyl acrylate, diacrylic acid 1 , 4-butanediol, n-butyl acrylate, diacrylic acid 1.3
-Butylene is exemplified. In addition, (1) methacrylic acid esters having a saturated or unsaturated straight chain or branched aliphatic hydrocarbon group having 1 to 5 carbon atoms are preferably methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, methacrylic acid 1. Examples include 3-butylene and n-butyl methacrylate.

In the present invention, the acrylic ester moiety in the acrylic ester copolymer preferably ranges from about 50 to 85 wt%, such as a 3:2 weight ratio of n-butyl acrylate to methyl methacrylate. It is. As such an acrylic ester copolymer, one commercially available from Rohm & Haas under the trade name [Paraloid KM330J] is preferably used.

To the above in the thermoplastic resin composition of the present invention.

Aromatic polycarbonate resin is 60-90 wt%, B
The aromatic saturated polyester resin is in the range of 8 to 30 wt% and the C, acrylic acid ester copolymer is in the range of ~2 (ht%).If the aromatic polycarbonate resin is less than 60 wt%, heat resistance is required for engineering plastics. The dimensional stability was poor, and the 90w
If it exceeds t%, the improvement in moldability will be insufficient and the chemical resistance will also be insufficient. If the aromatic saturated polyester resin is less than 8 wt%, the improvement in chemical resistance will be insufficient, and if it exceeds 30 wt%, it will cause poor dimensional stability. Furthermore, if the acrylic ester copolymer content is less than 1 wt%, impact resistance will not be improved, and if it exceeds 20 wt%, it will cause poor heat resistance.

The thermoplastic resin assembly of the present invention as described above may contain various additives such as stabilizers, pigments, dyes, flame retardants, and lubricants, reinforcing materials such as inorganic or organic fiber substances, glass beads, etc., as desired. Various fillers may be blended, and other resin components may also be blended within a range that does not impair the characteristics of the present invention. For example, polycarbonate oligomers from bisphenol A or tetrabromobisphenol A can be used to improve moldability, lf flammability, and surface properties, and heat-resistant polyesters such as polyester carbonates and polyarylates (e.g., trade names: U Polymer, Unitika LI@) For improving heat resistance, the following may be added.

In preparing the thermoplastic resin composition of the present invention,
Any conventionally known method may be used, and methods of kneading using an extruder, Banbury mixer, rolls, etc. may be selected as appropriate.

Hereinafter, it will be explained by examples and comparative examples, but "%"
and "molecular weight" are based on weight unless otherwise specified.

Examples 1 to 4 and Comparative Examples 1 to 5 Aromatic polycarbonate resin made from bisphenol A (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name Newpiron S-1000, molecular weight 2
8,000), polyethylene terephthalate (manufactured by Toyobo ■, trade name: Univet RT-580, intrinsic viscosity 1.2 at 30°C, in a mixed solvent of phenol/tetrachloroethylene-6/4 wt ratio) and acrylic ester copolymer (manufactured by Rohm & Haas, trade name: Valaloid KM330) was placed in a blender at the ratio shown in Table 1, and mixed for 30 minutes.

The resulting mixture was fed into a 4Qmm vented extruder,
The mixture was melted and kneaded at a cylinder temperature of 260°C to form pellets. After drying the pellets in a hot air dryer at 120° C. for 5 hours or more, test pieces for measuring physical properties were molded by injection molding. The test results are shown in Table 1.

For comparison, instead of the acrylic ester copolymer of the present invention, MAS resin (manufactured by Mitsubishi Rayon ■, trade name: Metablen H529) and MBS resin (manufactured by Japan Synthetic Rubber ■, trade name: JSRMBS 67) were used. Things (comparative example-1~
3) and for reference, the physical properties of a composition of aromatic polycarbonate resin and polyethylene terephthalate (Comparative Example-4) and aromatic polycarbonate resin alone (Comparative Example-5) were measured in the same manner as in the examples. Test results
It is shown in Table 1.

Examples 5 to 7 and Comparative Examples 6 to 7 In Examples 1 to 4, polytetramethylene terephthalate (manufactured by Toyobo ■, trade name: Toughpet N-1200, intrinsic viscosity 1,
2 at 30°C, a mixed solvent with a phenol/tetrachlorethylene-6/dwt ratio) was used, and the same resin components were used, mixed in the proportions shown in Table 1, and the cylinder temperature of the vented extruder was set at 250°C. A test piece for measuring physical properties was molded in the same manner except that. The measurement results are shown in Table 1.

For comparison, a resin composition (Comparative Example-6) using MAS resin (same as that used in Comparative Example-2) instead of the acrylic ester copolymer used in the present invention and an aromatic polycarbonate resin were prepared. The results were also shown in Table 1 for a resin composition of polytetramethylene terephthalate and polytetramethylene terephthalate (Comparative Example-7) in the same manner as above.

Examples 8 to 10 The resin components used in Examples 1 to 7 were mixed in the proportions shown in Table 1, and test pieces for measuring physical properties were formed in the same manner as in Examples 1 to 7. Physical properties were measured. The results are shown in Table 1.

Proceedings (Spontaneous) January 22, 1985 1, Indication of the case 1988 Patent Application No. 234593 2, Name of the invention Thermoplastic resin composition 3, Relationship with the amended person case (Patent (Applicant) 4. The following amendments are made to the [Detailed Description of the Invention] column 5 of the specification to be amended and the "Detailed Description of the Invention" column of the description of contents of the amendment.

■Correct "thickness dependence also" on page 3, line 19 to "thickness dependence".

■ Bolicarbo ° in column Ratio-6 of Table 1 on pages 14-15
Correct "80" in the row for nate resin to "70".

that's all

Claims (1)

[Claims] ^, aromatic polycarbonate resin 60-90wt%B
, 8 to 30 wt% of aromatic saturated polyester resin and 1 to 20 wt% of C, acrylic ester copolymer, wherein the acrylic ester copolymer is or a copolymer of an acrylic ester having a branched aliphatic hydrocarbon group and a methacrylic ester having a saturated or unsaturated linear or branched aliphatic hydrocarbon group having 1 to 5 carbon atoms. Characteristic thermoplastic resin composition.