JPH086018B2 - Thermoplastic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Field of Application> The present invention relates to a thermoplastic resin composition, more specifically, a specific gravity of 1.
The present invention relates to an aromatic polycarbonate composition having a bending elastic modulus of 70 × 10 ³ kg · f / cm ² or more and excellent mechanical strength and moldability.

<Prior Art> Aromatic polycarbonates are widely used in various fields because of their excellent mechanical strength. Conventionally, because of its light weight and high strength, it has been used in large quantities for aluminum die casting and metal component replacement. Further, in recent years, materials having a large specific gravity and a high flexural modulus have begun to be demanded for special applications. Examples thereof include the resonance part of audio equipment and the vibration parts of office equipment. As specific requirements, it is desired that the material has a specific gravity of 1.5 or more and a flexural modulus of 70 × 10 ³ kg · f / cm ² or more.

In order to increase the specific gravity, a method of mixing various inorganic fillers can be considered, but when a large amount of the filler is added, the physical properties of the polycarbonate resin composition are largely deteriorated, and a practical one cannot be obtained.

As a result of repeated intensive studies to solve the above requirements, the present inventors have found that the aromatic polycarbonate resin has a Na ₂ O content of 0.
By mixing 1% by weight or less of aluminum oxide and fibrous reinforcing material, the specific gravity is 1.5 or more, and the bending elastic modulus is 70 × 1.
The present invention has been achieved by finding that a practical material having a mechanical strength of 0 ³ kg · f / cm ² or more and excellent mechanical properties and moldability can be obtained.

<Object of the Invention> The present invention has a specific gravity of 1.5 or more and a flexural modulus of 70 × 10 ³ kg.
It is an object to provide an aromatic polycarbonate composition having f / cm ² or more and excellent mechanical strength and moldability.

<Structure of the Invention> The present invention includes (A) 20 to 80% by weight of an aromatic polycarbonate, (B) 10 to 70% by weight of aluminum oxide having a Na ₂ O content of 0.1% by weight or less, and (C) a fibrous reinforcing material. The present invention relates to a thermoplastic resin composition comprising 10 to 70% by weight and having a specific gravity of 1.5 or more and a flexural modulus of 70 × 10 ³ kg · f / cm ² or more.

The aromatic polycarbonate used in the present invention is produced by a solution method or a melting method of a dihydric phenol and a carbonate precursor. Typical examples of the dihydric phenol include 2,2-bis (4-hydroxyphenyl) propane [bisphenol A], bis (4-hydroxyphenyl) methane, 2,2-bis (4-hydroxy-3, 5-Dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4-
Hydroxy-3-methylphenyl) propane, bis (4
-Hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone and the like can be mentioned. Preferred 2
The hydric phenol is based on bis (4-hydroxyphenyl) alkane, especially bisphenol A.
Further, examples of the carbonate precursor include carbonyl halide, carbonyl ester, haloformate and the like, and specific examples thereof include phosgene, diphenyl carbonate, dihydric phenol dihaloformate and a mixture thereof. In producing the aromatic polycarbonate, the above 2
The polyphenols may be used alone or in combination of two or more. Further, two or more kinds of aromatic polycarbonates thus obtained may be mixed and used.

The molecular weight of aromatic polycarbonate is generally 10,000 to 10
10,000, preferably 15,000 to 60,000. In producing an aromatic polycarbonate having these molecular weights, addition of an appropriate molecular weight modifier, a branching agent for improving processability, a catalyst for accelerating the reaction, etc. may be added.

The aluminum oxide used in the present invention is generally produced by a so-called Bayer method using bauxite and caustic soda as raw materials, and has a specific gravity in the range of 3 to 4 and an average particle size in the range of 0.1 to 100 μ. Is preferred. Aluminum oxide is usually Na
₂ O is mixed. In the present invention, a Na ₂ O content of 0.1% by weight or less is used. When it is 0.1% by weight or less, when it is added to an aromatic polycarbonate resin, a resin composition excellent in moldability can be obtained without substantially decomposing the resin.

Further, the stability of the aromatic polycarbonate composition can be further improved by subjecting the aluminum oxide used to the following treatment.

(1) Treatment with silane coupling agent As the silane coupling agent used, a commercially available one is usually used. For example, Shin-Etsu Silicone KBM-40
3, KBM-573 etc. can be given. In the treatment, the silane coupling agent is dissolved in a volatile solvent such as alcohol, and aluminum oxide is uniformly dispersed therein, and then the solvent is removed. At this time, the amount of the silane coupling agent is preferably 0.01 to 10% by weight of aluminum oxide. Furthermore, the stability of the composition can be further improved by adding these silane coupling agents in an amount of 0.01 to 10% by weight of aluminum oxide when producing the composition of the present invention.

(2) Washing Stirring and washing with water are preferable, and it is desirable to wash at a water temperature of 30 ° C or higher until the pH of the supernatant of the stirrer becomes 8.5 or less.

Examples of the fibrous reinforcing material used in the present invention include glass fibers, carbon fibers, metal fibers, organic fibers such as aromatic polyamide fibers and wholly aromatic polyester fibers. As the fibrous reinforcing material, chopped strands having a fiber diameter of 2 to 30 μm and a fiber length of 0.5 to 6 mm are preferably used. It is also possible to use the rovings coated with a composition of aromatic polycarbonate and aluminum oxide and then cut into chips, in which case the length will be approximately equal to the length of the chips, usually 2-4 mm. Further, it is more preferable that the surface of the fibrous reinforcing material is subjected to surface treatment for increasing the affinity with the resin, for example, epoxy treatment, silane treatment, aminosilane treatment, oxidation treatment and the like.

In the resin composition of the present invention, 20 to 80% by weight of the component (A), 10 to 70% by weight of the component (B) and 10 to 70% by weight of the component (C) are mixed in terms of specific gravity, mechanical properties and moldability. When any one of the components deviates from the above mixing ratio, the performance balance of these components is lost, and therefore it is not appropriate.
If the aromatic polycarbonate component of (A) is less than 20% by weight, the fluidity is poor and molding is difficult.
If it exceeds, the requirements for specific gravity and flexural modulus cannot be satisfied.
Similarly, if the aluminum oxide component (B) exceeds 70% by weight, the fluidity is poor and molding is difficult. If it is less than 10% by weight, the specific gravity requirement cannot be satisfied. When the content of the fibrous reinforcing material (C) exceeds 70% by weight, the fluidity is poor and molding becomes difficult, and when it is less than 10% by weight, the requirement of the flexural modulus cannot be satisfied. The preferred mixing ratio is 35 to 70% by weight of component (A), 15 to 50% by weight of component (B), and 15 to 50% by weight of component (C).
Range.

Any method may be used for producing the resin composition of the present invention. For example, a method of kneading and extruding a mixture of aromatic polycarbonate, aluminum oxide and a fibrous reinforcing material with a single-screw or twin-screw extruder, a method of kneading with a Banbury mixer, a heating roll, etc., a method of injection molding with an injection molding machine, etc. can give.

Furthermore, various combinations such as a method of previously kneading an aromatic polycarbonate with aluminum oxide or a fibrous reinforcing material, and then kneading the rest, and the like can be mentioned, and any method can sufficiently exert the effect.

ABS, MBS, within the range of not impairing the properties of the resin composition of the present invention,
Other resins such as saturated polyester, PS, AS, polysulfone and polyacrylate may be mixed.

In addition, the resin composition of the present invention may contain various additives, such as stabilizers, release agents, and the like, if necessary, in such an amount that the effects are exhibited.
It does not matter if flame retardants, UV absorbers, fillers, dyes and pigments are included.

<Effect of the Invention> The thermoplastic resin composition of the present invention has a large specific gravity of 1.5 or more, a bending elastic modulus of 70 × 10 ³ kg · f / cm ² or more, good mechanical properties, and excellent moldability. Therefore, it is a useful resin composition that can be widely used in many fields where these properties are required.

<Example> The present invention is described in detail below with reference to Examples and Comparative Examples, but the invention is not limited thereto.

Examples 1 to 10 and Comparative Examples 1 to 9 Aromatic polycarbonate (manufactured by Teijin Chemicals Ltd .: Panlite L-1250), aluminum oxide and fibrous reinforcing agent shown in Table 1 were heated at 120 ° C. for 6 hours, respectively. After drying with a circulation dryer and premixing with a tumbler at the compounding ratio shown in Table 2, immediately using a single-screw vent extruder (NSK Katani Co., Ltd. VSK-30) set to a cylinder temperature of 300 ° C. Extruded and pelletized.

After drying the obtained pellets at 120 ° C for 6 hours, a test piece for measuring physical properties was molded using an injection molding machine (Sumitomo Saicap S480 / 150) at a cylinder temperature of 310 ° C and a mold temperature of 110 ° C.

The specific gravity and flexural modulus of the obtained test piece were measured by a conventional method, and the results are shown in Table 2.

In the table (1) Polycarbonate resin L- manufactured by Teijin Chemicals Ltd.
1250 (2) Chopped Strand 3J-941 manufactured by Nitto Boseki Co., Ltd. (3) Wash with warm water at 80 ° C until the pH of the supernatant reaches 7.2
(4) Chopped Strand made by Toyo Rayon Co., Ltd.
HTA-C6-S (5) Shin-Etsu Chemical previously containing 1.0% by weight of aluminum oxide
Treated with KBM 403, a silane coupling agent manufactured by K.K.
Gaku Co., Ltd. treated with silane coupling agent KBM 573 (7) When mixing the three components, 1.
0% by weight Shin-Etsu Chemical Co., Ltd. silane coupling agent KBM
 (8) Teijin Ltd. aromatic polyamide fiber Technora
As is clear from Table 2 of T-320, the aluminum oxide used
Na contains Na₂O content is stable for aromatic polycarbonate
And the moldability are significantly affected,
Aluminum oxide is Na₂O content is 0.1% by weight or less
Must be regulated by.

Further, it is clear from Comparative Examples 5 to 7 that the elastic modulus is insufficient only with the aromatic polycarbonate and aluminum oxide, and the specific gravity is insufficient with only the aromatic polycarbonate and the fibrous reinforcing material.

Furthermore, Comparative Example 8 is an example in which the fibrous reinforcing material is insufficient, and Comparative Example 9 is an example in which aluminum oxide is insufficient. None of them have achieved the effects of the present invention.

Claims (1)

[Claims] (A) 20-80% by weight of aromatic polycarbonate (B) 10-70% by weight of aluminum oxide having a Na ₂ O content of 0.1% by weight or less (C) 10-70% by weight of fibrous reinforcing material A thermoplastic resin composition having a specific gravity of 1.5 or more and a flexural modulus of 70 × 10 ³ kg · f / cm ² or more.