KR0129093B1 - Thermoplastic resin composition - Google Patents

Abstract

The thermoplastic resin composition having a good strength, a tensile strength, an elasticity and size stability was prepared. 70-90 Wt.% of glass fiber and 5-25 wt.% of mica, flame retardants were mixed in the composition of 60 wt.% of polycarbonate resin, 20 wt.% of styrene-acrylonitrile resin, followed by extrusion of the mixed composition to give a pellet type thermoplastic resin.

Description

Thermoplastic resin composition and its manufacturing method which improved the dimensional stability of moldings

Field of invention

The present invention relates to a composite drop thermoplastic resin composition.

More specifically, the present invention relates to a thermoplastic resin composition and a method of manufacturing the same, which are used as materials of moldings of electrical and electronic products in the industrial field, including electronic products in the OA field,

In particular, the present invention relates to a thermoplastic resin composition having improved dimensional stability of the molding.

Background of the Invention

Resin raw materials for manufacturing parts of OA office equipment such as facsimile machines and copiers, parts of electrical and electronic products such as cameras, or parts of precision industrial machines such as hunger should have high rigidity, high impact resistance, and good heat resistance and dimensional stability. do. Resin compositions for meeting the required physical properties of the molded products of electrical and electronic products of all these industrial fields have been developed through a long research.

The most representative resin composition for use for this purpose is polycarbonate (PC). Polycarbonate is a resin composition with high toughness and a flexural modulus is 25,000 kgf / cm 2 or more. Since polycarbonate is amorphous, its heat resistance does not differ by load deflection temperature. In addition, PC has excellent electrical insulation in the dominant frequency range, so it can be used as a solid insulator from commercial frequency to high frequency (Hosaka Norio, the point of precision molding seen in high-performance resins; polycarbonate (PC), Plastic Science (1993.9)). ).

As the resin composition used in the molding of electrical and electronic products in the industrial field, as well as the development of the polycarbonate itself as described above, glass fiber or carbon fiber reinforced polycarbonate has been developed. Glass fiber or carbon fiber-reinforced polycarbonates have not only improved rigidity but also improved molding shrinkage and thermal expansion coefficient. Particularly in the molding shrinkage rate, since both glass fibers and carbon fibers are inorganic fibers, there is no shrinkage of the fiber itself, and there are differences in the number-of-tuft ratios in the direction of flow of the molding and at right angles depending on the orientation of the reinforcing fibers.

Particularly important physical properties for moldings of electrical and electronic products are the dimensional stability of the moldings. Reinforcement resin compositions that improve the dimensional stability, including the stiffness, heat resistance, and modulus of the moldings, are mainly styrene acrylonitrile / glass fibers (SAN / GF), which are reinforced with glass fibers, Acrylonitrile butadiene styrene / glass fiber (ABS / GF), polycarbonate / glass fiber (PC / GF), modified polyphenylene oxide / glass fiber oxide (MPPO) / glass fiber; Noryl / GF).

In the present invention, a part of the ABS resin which is excellent in moldability rather than the polycarbonate resin without using all the polycarbonate resin is used to produce a thermoplastic resin having excellent moldability and good dimensional stability of the molding.

An object of the present invention is to provide a thermoplastic resin composition having good dimensional stability of a molding as well as physical properties such as rigidity, tensile strength, elastic modulus of the resin composition.

Another object of the present invention is to provide a thermoplastic resin composition having excellent molding processability and good dimensional stability of a molded article by partially using ABS resin in the polycarbonate resin.

Another object of the present invention is to provide a thermoplastic resin composition having good dimensional stability of a molded article by using glass fibers and mica as reinforcing materials in the resin composition.

It is still another object of the present invention to provide a thermoplastic resin composition having good dimensional stability of a molded product containing polycarbonate resin, ABS resin, glass fiber, and mica as a main component, molded from the resin composition, and a method for producing the resin composition. By

Summary of the Invention

The present invention relates to a thermoplastic resin composition, comprising a polycarbonate resin, an ABS resin, a glass fiber, and a mica, and a resin composition for imparting good dimensional stability to a molded article.

The thermoplastic resin composition of the present invention is adapted to each need in a resin composition of about 60% by weight polycarbonate resin, about 20% by weight styrene acrylonitrile resin, and about 20% by weight graft-acrylonitrile butadiene styrene resin. The additives (flame retardant, flame retardant aid, etc.) according to the present invention are mixed and 5 to 25 parts by weight of glass fibers and 5 to 25 parts by weight of mica are mixed with 90 to 70 parts by weight of the resin mixture.

The present invention also mixes the predetermined amount of polycarbonate resin, ABS resin, mica, and the necessary additives in a blender, and then extrudes by injecting into the hopper of the extruder, and extruded by injecting glass fibers from the side hopper of the middle of the extruder It also includes a method for producing a thermoplastic resin of the present invention characterized in that the pellet (pellet).

Detailed Description of the Invention

The thermoplastic resin composition of the present invention is characterized by being composed of polycarbonate resin, ABS resin, glass fiber, and mica.

Polycarbonate resin is a resin composition with high toughness, and its flexural modulus is 25,000 kgf / cm 2 or more. Since this resin is amorphous, its heat resistance does not differ from the load deflection temperature. Since the electrical insulation is excellent in the high frequency range, it is used as a solid insulating material from the commercial frequency to the high frequency. In the present invention, a commercially available polycarbonate resin was used.

ABS resin used in the present invention is composed of styrene acrylonitrile (SAN) and graft-acrylonitrile butadiene styrene (g-ABS) having a molecular weight of about 180,000.

That is, the resins used in the present invention are polycarbonate resins, styrene acrylonitrile resins, and graft-acrylonitrile butadiene styrene resins, and additives for imparting their physical properties to these resin compositions are required in an amount required. Is added. Additives used herein include flame retardants and flame retardant aids to impart flame retardancy of the resin.

The thermoplastic resin composition of the present invention is mixed with about 60% by weight of polycarbonate resin, about 20% by weight of styrene acrylonitrile resin, and about 20% by weight of graft-acrylonitrile butadiene resin as a reinforcing material as glass fiber and mica. To extrude the resin composition.

Glass fiber as a reinforcing material used in the present invention is commonly used in this field, and the length thereof is 1/4 inch, 1/8 inch, etc., the diameter is about 3㎛. Since the aspect ratio by the length and diameter of the glass fiber is very large, the vertical and horizontal shrinkage in the flow direction of the molding is different, resulting in large anisotropic shrinkage. Such characteristics resulted in deformation of the molded article, which was not suitable for the molded article of the resin composition requiring precision.

In the present invention, by using a mica having a glass fiber and an aspect ratio less than the glass fiber as a reinforcing material, it is possible to minimize the anisotropic shrinkage of the molded product and to develop a thermoplastic resin composition having good dimensional stability. Reinforcing material consisting of glass fibers and mica used in the present invention, the glass fiber relative to about 90 to 70 parts by weight of the resin mixture of polycarbonate resin, styrene acrylonitrile resin, graft-acrylonitrile butadiene resin, and additives It is about 5-25 weight part, and a mica is about 5-25 weight part.

The mica used in the present invention is Suzorite (trade name) mica manufactured and sold by Kuraray Co., Ltd. (Japan), and specific data thereof is shown in Table 1. As shown in Table 1, the mica used in the present invention has an aspect ratio in the range of 30 to 90. Example results show that mica having such aspect ratio improves anisotropic shrinkage of the molding, that is, dimensional stability.

TABLE 1

In the method of preparing the resin composition of the present invention, a predetermined amount of polycarbonate resin, ABS resin, mica, and the necessary additives are mixed in a mixer, and then injected into an extruder's hopper to extrude, and the glass fiber is formed at the side hopper of the middle of the extruder. It is characterized in that the extrusion to put. The reason why the glass fiber is added using a separate hopper is to prevent the glass fiber from being cut in the mixing process. The resin composition extruded by the extruder is manufactured in pellet form, and used as a raw material of each desired molding. Techniques relating to molds and injection machines for producing moldings are readily available to those of ordinary skill in the art.

The following examples are not intended to limit or reduce the protection scope of the present invention, but are merely examples of the present invention.

Example

Examples 1-3

Examples 1 to 3 show 20 parts by weight of glass fiber and 10 parts by weight of organic mineral per 70 parts by weight of a resin mixture consisting of 60 parts by weight of polycarbonate resin, 20 parts by weight of SAN, and 20 parts by weight of g-ABS, as shown in Table 2. Reinforcing materials, that is, mica is shown in Table 1, each component content used. As described above, the mica was mixed together in the resin mixture and the glass fibers were added separately at the sides.

TABLE 2

Comparative Examples 1 and 2

The compositions of Comparative Examples 1 and 2 for comparison with the resin composition of the present invention were carried out as in Table 3 below. In Comparative Example 1, 10 parts by weight of CaCo ₃ was used instead of the mica of Examples 1 to 3 above. In Comparative Example 2, only 30 parts by weight of glass fibers and no organic mineral reinforcement were used in the resin composition of Example 1 above.

TABLE 3

Dimensional stability test and evaluation

1) Sample Manufacturing

Mold sample: discs requiring insulation

Injection Machine: 8OZ Billion Injection Machine

Injection condition:

Temperature ; 270 ° C, 260 ° C, 250 ° C and 230 ° C

Injection stroke; First order; 20%, secondary; 30%, tertiary; 40%, 4th order; 80%

Injection speed; First order; 10%, secondary; 15%, tertiary; 15%, 4th order; 80%

Weighing: 69cm3

Weighing Speed: 90T / min

Back pressure: 5bar

Cooling time: 15 seconds

2) How to measure

A 2 kg load was applied to one side of the disc and measured according to ASTM D229.

3) Evaluation

The measured values of the above samples according to the above measurement method are shown in Table 4 and Table 5,

By evaluation, it can be seen that the samples of Examples 1 to 3 of the present invention are good, and among them, Example 2 is the best.

HM-3020 compared in Tables 4 and 5 is a sample using Noryl resin, in which glass fiber is added as a reinforcing material to MPPO of General Electric (USA), which is known to have good dimensional stability. Table 4 is the data measured at room temperature, Table 5 is the data measured after 2 hours at 100 ℃.

TABLE 4

TABLE 5

From the above table, the resin composition of the present invention has excellent dimensional stability as compared to Comparative Example 2 containing only glass fibers as a reinforcing material, and Comparative Example 1 containing calcium carbonate instead of glass fibers and mica. You can see that.

Compare other physical properties

In comparing physical properties, the sample of Example 2 with the best dimensional stability among the Example of this invention, and the other conventional sample were made into the object.

1) general physical properties

TABLE 6

In Table 6, Lexan 3413 is a resin composition in which glass fiber is added as a reinforcing material to General Electric's polycarbonate, and HM-3020 is a resin composition in which glass fiber is added as a reinforcing material to modified polyphenylene oxide of General Electric.

2) strength

FDI (load 2.0 kg)

TABLE 7

Impact strength (unnotched) (kgcm / cm)

TABLE 8

3) Warpage (mm)

TABLE 9

From the above physical property comparison results, it can be seen that the resin composition of the present invention is not inferior in strength and other physical properties as compared with various resin compositions containing only glass fibers as reinforcing materials.

Claims (7)

A thermoplastic resin composition having improved dimensional stability, characterized in that it consists of polycarbonate resin, ABS resin, glass fiber, and mica having an aspect ratio in the range of 30 to 90. The thermoplastic resin composition according to claim 1, wherein the ABS resin is composed of styrene acrylonitrile resin and graft-acrylonitrile butadiene styrene resin. 90-70 parts by weight of a resin composition according to claim 2, comprising 60% by weight of polycarbonate resin, 20% by weight of styrene acrylonitrile resin, and about 20% by weight of graft-acrylonitrile butadiene styrene resin, A thermoplastic resin composition comprising 5 to 25 parts by weight of glass fiber and 5 to 25 parts by weight of mica. Polycarbonate resin, ABS resin and mica are mixed in a blender, and then extruded by mixing into an hopper of an extruder, and extruded by inserting glass fibers from a side hopper of an intermediate part of the extruder. How to manufacture The method of claim 4, wherein the ABS resin is composed of styrene acrylonitrile resin and graft-acrylonitrile butadiene styrene resin. The composition ratio of the material to be charged is 60% by weight of polycarbonate resin, 20% by weight 90 to 70 parts by weight of the resin composition containing 5% by weight of styrene acrylonitrile resin and 20% by weight of graft-acrylonitrile butadiene styrene resin, 5 to 25 parts by weight of glass fiber and 5 to 25 parts by weight of mica How to. The method according to any one of claims 4, 5 or 6, characterized in that the mica has an aspect ratio of 30 to 90.