JPH10204277A - Thermoplastic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermoplastic resin composition excellent in mechanical strength, heat resistance and scratch resistance by formulating specific portions of an aromatic polycarbonate resin, a polyester elastomer and an agent for imparting sliding properties. SOLUTION: The objective composition is obtained by formulating (A) 94.9-65wt.% aromatic polycarbonate resin, (B) 5-30wt.%, preferably 10-20wt.% polyester elastomer and (C) 0.1-5wt.%, preferably 0.5-3wt.% agent for imparting sliding properties such as a polyolefin, an olefinic wax, polytetrafluoroethylene, a silicone powder, a silicone oil, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition having good mechanical strength and heat resistance, and more particularly to a thermoplastic resin composition having excellent scratch resistance.

[0002]

2. Description of the Related Art Aromatic polycarbonate resins are engineering plastics having excellent mechanical strength and heat resistance, and are widely used in various fields such as electric and electronic equipment. Particularly, molded articles such as containers are often used because of their excellent properties. However, there is a problem that the molded article put in a container, particularly the molded article made of a polycarbonate resin, may damage the molded article. One of the methods for improving this is Japanese Patent Publication No. 36-76.
41, as described in JP-A-48-40849, etc., it is effective to improve the sliding properties by adding silicone oil, polytetrafluoroethylene and an olefin wax, etc. Still not enough.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermoplastic resin composition having good mechanical strength, heat resistance and the like and further having excellent scratch resistance.

The inventor of the present invention has conducted intensive studies to achieve the above object. As a result, the hardness of the molded article surface is reduced by blending a polyester elastomer with an aromatic polycarbonate resin, and further, a slidability imparting agent is blended. The present inventors have found that by reducing the frictional resistance, it is possible to obtain a thermoplastic resin composition which is excellent in prevention of intended scratching and has good mechanical strength, heat resistance and the like, and has reached the present invention.

[0005]

According to the present invention, (A) 94.9 to 65% by weight of an aromatic polycarbonate resin, (B) 5 to 30% by weight of a polyester elastomer, and (C) a slidability imparting agent. A thermoplastic resin composition comprising 0.1 to 5% by weight is provided.

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

The basic means for producing the aromatic polycarbonate resin as the component (A) in the present invention will be briefly described.

In the case of the solution method using, for example, phosgene as the carbonate precursor, the reaction is usually carried out in the presence of an acid binder and a solvent. Examples of the acid binder include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide and amine compounds such as pyridine. As the solvent, for example, halogenated hydrocarbons such as methylene chloride and chlorobenzene are used. For promoting the reaction, a catalyst such as a tertiary amine or a quaternary ammonium salt may be used. At that time, the reaction temperature is usually 0 to 40 ° C.
And the reaction time is a few minutes to 5 hours. As a carbonate precursor other than phosgene in this solution method, a carbonate ester or a haloformate can be used, and specific examples include diphenyl carbonate or a dihaloformate of a dihydric phenol.

In a transesterification reaction (melting method) using a carbonic acid diester as a carbonate precursor, a predetermined ratio of a dihydric phenol component is stirred with a carbonic acid diester under heating in an inert gas atmosphere to produce alcohol or phenols. It is carried out by a method of distilling. The reaction temperature varies depending on the boiling point of the produced alcohol or phenol, and is usually in the range of 120 to 300 ° C. The reaction is completed under reduced pressure from the beginning while distilling off alcohol or phenols produced. Further, a catalyst usually used in a transesterification reaction to promote the reaction can be used. Examples of the carbonic acid diester used in the transesterification reaction include diphenyl carbonate, dinaphthyl carbonate, bis (diphenyl) carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate and the like. Of these, diphenyl carbonate is particularly preferred.

In producing the aromatic polycarbonate resin by reacting the above-mentioned dihydric phenol with a carbonate precursor, the dihydric phenol may be used alone or in combination of two 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 regulator and an antioxidant may be used.

Any molecular weight can be used for the aromatic polycarbonate resin. For example, when an aromatic polycarbonate resin is obtained using bisphenol A as a dihydric phenol and phosgene as a carbonate precursor, a concentration of 0.7 g / The specific viscosity (ηsp) measured at a temperature of 20 ° C. with a dl methylene chloride solution is 0.15 to 1.
Five are preferred.

The polyester elastomer used as the component (B) in the present invention comprises a dicarboxylic acid containing at least 70 mol% of terephthalic acid, a glycol component containing at least 70 mol% of tetramethylene glycol, and an average molecular weight of 500 to 5,000. Is a copolymer obtained by copolymerizing three components of poly (oxyalkylene) glycol.

The poly (oxyalkylene) glycol preferably has an average molecular weight of 500 to 5,000 and a ratio of the number of carbon atoms to oxygen atoms contained in the glycol of 2.0 to 4.3. Examples thereof include poly (tetramethylene oxide) glycol, poly (ethylene oxide) glycol, poly (propylene oxide) glycol, and copolymers thereof.
Particularly, poly (tetramethylene oxide) glycol is preferable. The amount of poly (oxyalkylene) glycol in the polyester elastomer is from 20 to 80% by weight, preferably from 30 to 80% by weight, particularly preferably from 50 to 80% by weight.
~ 80% by weight. The degree of polymerization of the polyester elastomer is 1.2 g / 10
Those having a reduced viscosity of 0.5 to 5.0 measured at a concentration of 0 ml are preferred, and those having a reduced viscosity of 0.7 to 4.0 are particularly preferred.

The amount of the polyester elastomer is 5 to 30% by weight, preferably 10 to 20% by weight. If it is less than 5% by weight, the decrease in surface hardness is small, so that the anti-scratch property is inferior.

The slidability imparting agent used as the component (C) in the present invention is an additive which imparts slidability to the resin component. This additive is not particularly limited as long as it imparts slidability. Examples of additives that impart slidability include polyolefin, olefin-based wax, polytetrafluoroethylene, silicone powder, and silicone oil. Of these, olefin waxes and polytetrafluoroethylene, which have an excellent balance between sliding characteristics and mechanical strength, are preferably used alone or in combination.

The compounding amount of the slidability imparting agent is 0.1 to 5
%, Preferably in the range of 0.5 to 3% by weight.
If the amount is less than 0.1% by weight, sufficient sliding properties cannot be obtained, so that the anti-scratch property is poor. If the amount exceeds 5% by weight, peeling, reduction in mechanical strength, and the like occur, which is not preferable.

The proportion of each of the above components of the thermoplastic resin composition of the present invention is adjusted so that the total of the components (A), (B) and (C) becomes 100% by weight. A flame retardant, a flame retardant auxiliary, a coloring agent, an antistatic agent and the like may be blended as long as the purpose and the effect are not impaired, and other thermoplastic resins may be blended.

Further, according to the present invention, there is provided a molded product obtained by melt-kneading and molding the thermoplastic resin composition. This molded product is charged into a mixer, for example, a V-blender, a ribbon mixer or a tumbler, and uniformly mixed, and then melt-kneaded with a single-screw or twin-screw extruder, followed by injection molding, compression molding or rotational molding. And the like. Alternatively, after some of the components are previously mixed and kneaded, the remaining components may be further added, kneaded, and melt-extruded.

[0019]

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples. The evaluation was performed according to the following methods (1) to (4).

(1) Impact resistance: Notched Izod impact strength of a 1/4 ″ test piece was measured according to ASTM D256.

(2) Heat resistance: The deflection temperature under a load of 18.6 kgf / cm ² was measured in accordance with ASTM D648.

(3) Surface hardness: Pencil hardness at a weight of 1 kg and a pencil moving speed of 0.5 mm / sec was measured in accordance with JIS K5400. In addition, the hardness of the pencil when the surface of the test piece was not damaged was determined as the surface hardness.

(4) Coefficient of dynamic friction: outer diameter 25 mm, inner diameter 2
A 0 mm cylindrical test piece was prepared, and a friction tester (Frictron friction and wear tester manufactured by Orientec Co., Ltd.) was subjected to a thrust friction and wear test. The sliding speed was 20 cm / sec, and the partner material was carbon steel for machine structural use (S-45C), and the dynamic friction coefficient in an unlubricated state was measured.

[Examples 1 to 5 and Comparative Examples 1 to 7] A polycarbonate resin, a polyester elastomer, a slidability-imparting agent and a stabilizer were mixed in the proportions shown in Table 1 in a V-type blender to form a vent having a diameter of 30 mm. A twin-screw extruder (TEX30XSST manufactured by Japan Steel Works, Ltd.) pelletized at a cylinder temperature of 270 ° C.
After drying at 0 ° C. for 5 hours, the cylinder temperature was 270 using an injection molding machine (T-150D, manufactured by FANUC CORPORATION).
Test pieces were prepared at a temperature of 70 ° C. and a mold temperature of 70 ° C. The evaluation results are shown in Table 1. In addition, the symbol which shows each component of Table 1 is as follows.

PC: Polycarbonate resin [Panlite L-1225, ηsp = 0.41, manufactured by Teijin Chemicals Ltd.] PTEE: Polyester elastomer [Nuvellan TR-ER1, manufactured by Teijin Limited] Sliding agent 1: Polytetra Fluoroethylene resin [Lubron L-5 manufactured by Daikin Industries, Ltd.] Sliding property imparting agent 2: olefin-based wax [High wax 310MP manufactured by Mitsui Petrochemical Co., Ltd.]

[0026]

[Table 1]

[0027]

The thermoplastic resin of the present invention is useful for molded articles such as containers because it has excellent scratch resistance, mechanical strength and heat resistance.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI (C08L 69/00 67:00 83:04) (C08L 67/00 69:00 23:00)

Claims (2)

[Claims] (A) Aromatic polycarbonate resin 9
4.9-65% by weight, (B) 5-30% by weight of a polyester elastomer, (C) 0.1-5% by weight of a slidability imparting agent
A thermoplastic resin composition comprising: (C) The slidability imparting agent is a polyolefin,
Olefin wax, polytetrafluoroethylene,
1 selected from silicone powder and silicone oil
The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin composition is a kind or two or more kinds.