ELECTROPLATABLE HIGH-DENSITY PLASTIC

Abstract

An electroplatable high-density plastic comprises cerium oxide and at least one of polyphenylene sulfide (PPS) and high-rigidity nylon (MXD6). The polyphenylene sulfide and high-rigidity nylon make the article made of the electroplatable high-density plastic electroplatable, such that a metal layer can be electroplated thereon to give a metallic luster. Simultaneously, the polyphenylene sulfide causes the article to have a metal-like crisp sound when colliding. In addition, the cerium oxide can increase the density of the electroplatable high-density plastic, and confer the articles made of the electroplatable high-density plastic the properties of hard texture, thereby resulting in the advantages of folding and scratch resistance and low hygroscopicity, which not only expands the application range of the articles made of the electroplatable high-density plastic, but also enhances the value thereof.

Claims

1. An electroplatable high-density plastic, comprising cerium oxide and at least one of polyphenylene sulfide (PPS) and high-rigidity nylon (MXD6), wherein the cerium oxide accounts for 20% to 80% by weight of the electroplatable high-density plastic.

2. The electroplatable high-density plastic of claim 1, wherein the electroplatable high-density plastic has a tensile strength of 652 to 1,100 kg/cm.sup.2, as measured according to ASTM D638.

3. The electroplatable high-density plastic of claim 1, wherein the electroplatable high-density plastic has an elongation rate of 0.2 to 5%, as measured according to ASTM D640.

4. The electroplatable high-density plastic of claim 1, wherein the electroplatable high-density plastic has a flexural strength of 772 to 1,600 kg/cm.sup.2, as measured according to ASTM D790.

5. The electroplatable high-density plastic of claim 1, wherein the electroplatable high-density plastic has a flexural modulus of 40,500 to 169,000 kg/cm.sup.2, as measured according to ASTM D790.

6. The electroplatable high-density plastic of claim 1, wherein the electroplatable high-density plastic has a density of 1.28 to 3.73 g/cm.sup.3, as measured according to ASTM D792.

7. The electroplatable high-density plastic of claim 1, wherein the electroplatable high-density plastic has a shrinkage ratio of 0.3 to 0.69 cm/cm, as measured according to ASTM D955.

8. The electroplatable high-density plastic of claim 1, wherein the electroplatable high-density plastic has a pencil hardness of HB to 3H, as measured according to ASTM D2240.

9. The electroplatable high-density plastic of claim 1, wherein the at least one of polyphenylene sulfide and high-rigidity nylon accounts for 20% to 80% by weight of the electroplatable high-density plastic.

10. The electroplatable high-density plastic of claim 1, wherein the cerium oxide accounts for 40% to 80% by weight of the electroplatable high-density plastic.

11. The electroplatable high-density plastic of claim 10, wherein the electroplatable high-density plastic has a tensile strength of 700 to 857 kg/cm.sup.2, as measured according to ASTM D638.

12. The electroplatable high-density plastic of claim 10, wherein the electroplatable high-density plastic has an elongation rate of 0.8 to 3%, as measured according to ASTM D640.

13. The electroplatable high-density plastic of claim 10, wherein the electroplatable high-density plastic has a flexural modulus of 51,000 to 169,000 kg/cm.sup.2, as measured according to ASTM D790.

14. The electroplatable high-density plastic of claim 10, wherein the electroplatable high-density plastic has a density of 1.65 to 3.73 g/cm.sup.3, as measured according to ASTM D792.

15. The electroplatable high-density plastic of claim 3, wherein the at least one of polyphenylene sulfide and high-rigidity nylon (MXD6) accounts for 20% to 60% by weight of the electroplatable high-density plastic.

16. The electroplatable high-density plastic of claim 1, further comprising at least one of zinc oxide and barium sulfate.

17. The electroplatable high-density plastic of claim 1, wherein the cerium oxide has an average particle diameter of 0.2 to 40 m.

18. The electroplatable high-density plastic of claim 1, comprising a metal plating layer constituting a surface of the electroplatable high-density plastic.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0009] An electroplatable high-density plastic according to a preferred embodiment of the present invention comprises cerium oxide (CeO.sub.2), and at least one of polyphenylene sulfide (PPS) and high-rigidity nylon (MXD6). In this embodiment, the average particle diameter of the cerium oxide is 0.2 to 40 m, but is not limited thereto. The cerium oxide and the at least one of polyphenylene sulfide and high-rigidity nylon (MXD6) are stirred and mixed by a mixer, and then placed in an injection molding machine to inject the electroplatable high-density plastic into a mold to form a specific shape. In addition, since the polyphenylene sulfide is white, the coloring material can be stirred together with the polyphenylene sulfide and the cerium oxide before the injection molding to form articles of different colors.

[0010] When an article made of polyphenylene sulfide (or the high-rigidity nylon) and cerium oxide that are served as the plastic raw materials, is collided, the article will generate a crisp sound like a metal collision due to the material properties of polyphenylene sulfide (or the high-rigidity nylon). Cerium oxide is a material with higher hardness, so it can resonate with polyphenylene sulfide (or the high-rigidity nylon) to enhance the crisp sound.

[0011] In addition, due to the material properties of polyphenylene sulfide and the high-rigidity nylon, the article produced therefrom has electroplatability. The article can be further electroplated to have a surface metal layer (such as an aluminum layer), so that the article has a metallic luster, and its appearance is almost the same as that of a metal product, thereby enhancing the product value in the consumer's mind.

[0012] Cerium oxide has a large molecular weight and can increase the density of plastics. Therefore, compared with the conventional plastics, the high-density plastics are relatively heavy and have a relative hard texture, which provides better support and scratch resistance, and relatively extensive scope of application. Taking the support frame as an example, but not limited thereto, most of the support frame made of conventional plastics can only be used for supporting light articles, such as mobile phones, stationery, etc. However, for large and heavy articles, such as the TV set, if placed on a support frame made of conventional plastic, not only will there be doubts of insufficient support force, but the overall center of gravity of the support frame and the TV set is too high due to the light weight of the plastic support frame, thereby affecting the stability and causing the TV set to slightly shake and collapse. The support frame made of the high-density plastic described above not only has better supporting force, but also can be used for supporting articles such as the TV set and the like because of its relatively heavy weight (compared with the support frame made of conventional plastics having the same volume). The overall center of gravity of the article, e.g. the TV set, and the support frame moves toward the support frame and close to the ground, thereby improving the overall stability.

[0013] All the articles that can be produced by injection molding can be made of the electroplatable high-density plastic. In addition, the articles made of the electroplatable high-density plastic can not only replace the conventional plastic products, but also have the characteristics of hard texture, high deformation resistance and high density, so that the electroplatable high-density plastic can be used in the fields that never use the conventional plastic products. For example, the electroplatable high-density plastic can be used to make a bearing, or even a musical instrument, such as: Ocarina, clarinet, etc.

[0014] Another example is the bathroom accessory (such as the showerhead). In order to have both good texture and impact resistance, the conventional bathroom accessory is mostly made of metal. However, the parts of the bathroom accessory are complicated in structure and large in number. When the parts of the bathroom accessory are made of metal, complicated processing steps, including: cutting, grinding, polishing, etc. will be required. Moreover, with the increase of the complexity of the structures of the parts, the processing difficulty will also increase, which will not only greatly increase the production cost, but also lengthen the processing time.

[0015] In contrast, if the bathroom accessory is made of high-density plastics, once the mold is completed, the parts of the bathroom accessory can be produced quickly in large quantities by injection molding without additional processing steps. Even if the parts are complicated in structure, the technical difficulties to be overcome with respect to injection molding are relatively simple, as compared to metal processing.

[0016] Polyphenylene sulfide and the high-rigidity nylon have the characteristics of non-hygroscopicity and low hygroscopicity, respectively, so the high-density plastic can be made into the rotor of the rear-mirror, and the rotor will not expand due to water absorption, and can have longer service life. In addition, the high-rigidity nylon has the advantage of low coefficient of thermal expansion, so the articles made of the plastic with high density containing the high-rigidity nylon, such as hot-water bottles, the tee tubes of a water heater, etc. are suitable to be used in a high temperature environment and will not be easily deformed, and thus has dimensional stability.

[0017] The electroplatable high-density plastic can be used to manufacture articles that have high density, heavy weight, hard texture, and the metallic appearance. Besides, the articles produce a crisp sound like metal collision when colliding, and thus can replace almost the metal products. In addition, using the electroplatable high-density plastic to manufacture articles has the advantage of rapid and mass production and is therefore superior to the metal processing.

[0018] The electroplatable high-density plastic is increased in density by cerium oxide. In other words, the higher the weight percentage of cerium oxide in the plastic, the higher the density of the plastic. The manufacturer can adjust the density of the plastic by adjusting the ratio of polyphenylene sulfide (or the high-rigidity nylon) to cerium oxide during manufacturing.

[0019] Please refer to Tables 1 and 2 below, which show the influence of polyphenylene sulfide and cerium oxide at different weight ratios on the physical properties of corresponding high-density plastics.

TABLE-US-00001 TABLE 1 Weight percentages of polyphenylene sulfide and cerium oxide in each product. Raw Product materials P1 P2 P3 P4 P5 P6 P7 Cerium oxide (%) 20 30 40 50 60 70 80 Polyphenylene 80 70 60 50 40 30 20 sulfide (%)

TABLE-US-00002 TABLE 2 Comparison of physical properties of each product in Table 1. Physical properties Unit ASTM P1 P2 P3 P4 P5 P6 P7 Tensile kg/cm.sup.2 D638 652 834 857 810 800 850 700 strength Elongation % D640 2.4 3.5 3 1.99 1.8 0.2 0.8 rate Flexural kg/cm.sup.2 D790 1260 1330 1330 1385 1370 1100 772 strength Flexural kg/cm.sup.2 D790 40500 44000 51000 58000 77000 111000 169000 modulus Impact kg/cm/ D256 5 6 6 6.68 7.3 4.6 4 strength cm (23 C.) Pencil D2240 HB HB HB HB F 2H 3H hardness Heat C. D648 122 122 120 166 160 150 120 distortion temp. Density g/cm.sup.3 D792 1.6 1.763 1.97 2.254 2.604 3.1 3.73 Thermal 10.sup.5/ C. D696 4.5 4.1 3.8 3.5 3.2 2.8 2.5 expansion coefficient

[0020] Please refer to Tables 3 and 4 below, which show the influence of the high-rigidity nylon and cerium oxide at different weight ratios on the physical properties of corresponding high-density plastics.

TABLE-US-00003 TABLE 3 Weight percentages of the high-rigidity nylon and cerium oxide in each product. Raw Product materials P1 P2 P3 P4 P5 P6 P7 Cerium oxide (%) 20 30 40 50 60 70 80 High-rigidity nylon 80 70 60 50 40 30 20 (%)

TABLE-US-00004 TABLE 4 Comparison of physical properties of each product in Table 3. Physical properties Unit ASTM P1 P2 P3 P4 P5 P6 P7 Tensile kg/cm.sup.2 D638 900 1000 1100 1050 1000 950 900 strength Elongation % D640 5 3 1 1 0.8 0.8 0.7 rate Flexural kg/cm.sup.2 D790 1500 1600 1600 1400 1360 1350 1360 strength Flexural kg/cm.sup.2 D790 45000 55000 66000 80000 92000 105000 125000 modulus Impact kg/cm/ D256 5 5 5 4 4 5 4 strength cm (23 C.) Pencil D2240 HB HB HB F F F F hardness Heat C. D648 110 130 135 150 155 140 135 distortion temp. Density g/cm.sup.3 D792 1.28 1.4 1.65 1.95 2.3 2.65 3.1 Thermal 10.sup.5/ C. D696 5.5 5 4.5 4 3.6 3.2 2.8 expansion coefficient

[0021] Since cerium oxide is expensive, it is optional to add 5-10% zinc oxide (ZnO), 5-10% barium sulfate (BaSO4), or a combination thereof to reduce the cost and retain the property of high density.

[0022] It must be pointed out that the embodiments described above are only some embodiments of the present invention. All equivalent products which employ the concepts disclosed in this specification and the appended claims should fall within the scope of the present invention.