JP2000056108A - Plastic reflector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively provide a reflector having high dimensional accuracy due to decrement of shrinkage factor after molded without requiring the applying an undercoat in vacuum depositing on a surface of a molding from a single grade plastic base material, and which is used for electro-plating and electroless- plating, and improved in heat resistance. SOLUTION: The surface of a reflector 3 is subject to mirror finishing treatment and this reflector is produced from a granular plastic base material obtd, by adding inorg. base additives to one kind of plastic selected from an olefin base resin, an ABS resin and a styrene resin. The additives are selected from an oxide, a hydroxide, a carbonate, a sulfate, a silicate, a nitride, carbons, and potassium titanate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflector made of plastic which is mounted on a headlight of an automobile at night to reflect road center lines or guardrails for traffic safety.

[0002]

2. Description of the Related Art Conventionally, a reflector which has been installed with its surface exposed to the center line of a road is formed by heating and melting a plastic material and subjecting the surface of the plastic obtained by injection molding to mirror treatment, that is, metal plating. It has been given,
By applying this plating, physical properties such as heat resistance and wear resistance of the reflector can be improved. As this plating method, a vacuum evaporation plating method belonging to a dry method is known,
In this evaporation plating, aluminum is most often used as an evaporation film. In this aluminum vapor deposition method, aluminum is heated in a vacuum, evaporated, and the evaporated molecules adhere to the surface of a plastic molded product having a low vapor temperature, where the vapor condenses to form a thin film. This thin film is extremely thin, usually about 0.05 to 0.1 μm. Since the gloss of the surface of the deposited reflector differs depending on the roughness of the plastic and the atmosphere at the time of deposition, an undercoat agent is applied in advance to smooth the surface, and the gas emitted from the plastic is suppressed to suppress the gas emitted during the deposition. It is necessary to keep the pressure low. Further, since the deposited film lacks abrasion resistance, a top coat agent is applied to form a protective film.

[0003] Also, electroplating on plastic molded articles,
When performing electroless plating (chemical plating), before injection molding this plastic molded body, each time, select a material of a special grade for electroplating or electroless plating from plastic materials, and select this material. After injection molding the obtained material, it was necessary to perform electric or electroless plating.

[0004] In addition, a technique capable of performing not only vacuum deposition such as aluminum deposition, but also electroplating and electroless plating (chemical plating) on a molded product formed of a single-grade plastic material has not yet been completed. .

[0005]

By the way, even in the case of a reflector made of an olefin resin, for example, polyethylene or polypropylene, it is difficult to deposit aluminum and sputter by vapor deposition. This is necessary, and accordingly, the production cost of the reflector is increased, and the molded product of the olefin resin has problems such as a decrease in heat resistance and a high shrinkage rate upon cooling after molding.

Also, in the case of molded articles made of ABS resin, aluminum vapor deposition and sputtering vapor deposition are difficult as in the case of olefin-based resins. Therefore, pretreatment for applying an undercoat agent is required as described above, and reflection is difficult. The production cost of the body increases, and the molded article of the ABS resin has problems such as a decrease in heat resistance and a high shrinkage rate upon cooling after molding.

Further, a styrene resin (polystyrene)
Also in the case of the molded article, aluminum vapor deposition and sputtering vapor deposition are difficult as in the case of the resin, and therefore, a pretreatment of applying an undercoat agent is required as described above, and the manufacturing cost of the reflector increases, Further, a molded article of a styrene resin has problems such as reduced heat resistance and a high shrinkage rate upon cooling after molding.

[0008] As a method of mirror surface treatment, in order to apply secondary processing means of electroplating and electroless plating to a plastic molded body, electroplating and electroless plating are performed before injection molding of the plastic molded body. It is necessary to select a dedicated grade for plating, and therefore requires experience knowledge to select. further,
In the process of kneading and injection molding the selected special-grade plastic material, many years of experience and skill were required.

Accordingly, an object of the present invention is to eliminate the need for a pre-treatment of applying an undercoat agent when vacuum-depositing aluminum or sputtering by mirror-finish treatment on the surface of a plastic molded article. In other words, a plastic reflector that improves plating characteristics, improves heat resistance of molded products, reduces shrinkage after molding, has high dimensional accuracy, and can be manufactured at low cost. To get.

Another object of the present invention is to provide a mirror-finished electroplating or electroless plating on the surface of a plastic molded article without the need to select a special grade plastic material, and to mold from a single grade material. Electroplating, electroless plating,
Furthermore, vacuum deposition such as aluminum deposition is possible, so that plating work is easy even without skill,
Improve plating characteristics, improve heat resistance of molded products, reduce shrinkage after molding, high dimensional accuracy,
An object of the present invention is to provide a plastic reflector which can be manufactured at low cost.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a plastic reflector according to the present invention is characterized by using a granular plastic obtained by adding an inorganic additive to a plastic. The surface of this reflector is mirror-finished. The plastic is one selected from an olefin resin, an ABS resin, and a styrene resin, and the additives are oxides, hydroxides, carbonates, sulfates, silicates, nitrides, carbons, titanates. It is selected from potassium.

Another feature of the present invention is that the mirror surface treatment is a treatment selected from aluminum deposition, sputtering deposition, electroplating, and electroless plating.

Still another feature of the present invention is that the oxide is selected from silica, diatomaceous earth, alumina, magnesium oxide, titanium oxide, zinc oxide and antimony oxide, and the hydroxide is magnesium hydroxide. , Aluminum hydroxide, those selected from basic magnesium carbonate, wherein the carbonate is selected from calcium carbonate, magnesium carbonate, barium carbonate, and the sulfate is from calcium sulfate, calcium sulfite, barium sulfate. Selected, wherein the silicate is calcium silicate, talc, kaolin clay, mica, zeolite,
Attapulgite, bentonite, sericite, aluminum silicate, feldspar powder, magnesium silicate, apatite, the nitride is silicon nitride, and the carbons are selected from carbon black, graphite. There is a place.

Still another feature of the present invention relates to the amount of the additive, wherein the amount of the above-mentioned oxide silica, diatomaceous earth, alumina and magnesium oxide is 20 to 60% by weight.
Wherein the addition amount of the oxides of titanium oxide, zinc oxide and antimony oxide is 25 to 70% by weight, the addition amount of the hydroxide is 20 to 60% by weight, and the carbonate is calcium carbonate; The addition amount of magnesium carbonate is 20-60
%, And the amount of barium carbonate in the above carbonate is 2%.
5 to 70% by weight, wherein the sulfate is calcium sulfate,
The addition amount of calcium sulfite is 20 to 60% by weight,
The addition amount of barium sulfate of the above sulfate is 25 to 70% by weight.
Wherein the amount of the silicate is 20 to 60% by weight, the amount of the nitride is 20 to 60% by weight, the amount of the carbons is 10 to 50% by weight, The amount of potassium titanate is 20 to 60% by weight.

The reason for limiting the range of the above addition amount is as follows.
Below the lower limit, the adhesion of the vacuum-deposited plating is insufficient, and the peeling strength in electroplating is reduced. If the upper limit is exceeded, the film thickness increases, but the physical properties of the plastic product itself, such as tensile yielding Strength, tensile strength at break, elongation at break, flexural strength, flexural elasticity decrease.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of a reflector according to an embodiment of the present invention, which is mounted on a guardrail of a road. A corrugated guard plate 2 is connected between the poles, and a reflector 3 according to the present invention is mounted on the support pole. The reflector 3 includes a cylindrical mounting portion 31 and a protruding portion 32 protruding from the side of the road of the mounting portion, and the surface of the reflector is mirror-finished. Therefore, the light of the headlight of the automobile C is reflected by the reflector 3.

The reflector 3 is formed by molding a granular plastic material obtained by adding an inorganic additive to a plastic.
BS resin, one selected from styrene resin,
The olefin resin is, for example, polyethylene or polypropylene. The additive is selected from oxides, hydroxides, carbonates, sulfates, silicates, nitrides, carbons, and potassium titanate.

Specifically, the above-mentioned additive is selected from one or more of the above-mentioned oxides from silica, diatomaceous earth, alumina, magnesium oxide, titanium oxide, zinc oxide and antimony oxide. The hydroxide is selected from one or more of magnesium hydroxide, aluminum hydroxide, and basic magnesium carbonate. The carbonate is at least one selected from calcium carbonate, magnesium carbonate, and barium carbonate.

The sulfate is one or more selected from calcium sulfate, calcium sulfite, and barium sulfate, and the silicate is calcium silicate, talc, kaolin clay, mica, zeolite, attapulgite,
It is one or more selected from bentonite, sericite, aluminum silicate, feldspar powder, magnesium silicate, and apatite. The nitride is silicon nitride,
The carbons are selected from carbon black and graphite.

Next, the amount of the above additive will be described.

The above-mentioned oxide silica, diatomaceous earth, alumina,
The addition amount of magnesium oxide is 20 to 60% by weight,
The amount of addition of titanium oxide, zinc oxide, and antimony oxide of the oxide is 25 to 70% by weight, the amount of addition of the hydroxide is 20 to 60% by weight, The addition amount is 20 to 60% by weight, and the addition amount of barium carbonate of the above carbonate is 25 to 70%.
%, The amount of the sulfate is 20 to 60% by weight of calcium sulfate and calcium sulfite, and the amount of the barium sulfate is 25 to 70% by weight of the sulfate.
The addition amount of the silicate is 20-60% by weight, the addition amount of the nitride is 20-60% by weight, the addition amount of the carbons is 10-50% by weight, and the potassium titanate is Is 20 to 60% by weight.

The range of the addition amount is limited by securing the adhesive strength of the plating of vacuum evaporation and the peel strength of electroplating, electroless plating and sputtering deposition and the physical properties of the plastic product itself, for example, tensile yield strength, tensile breaking strength. This is to prevent the elongation at break, the bending strength and the bending elasticity from decreasing.

[0023]

EXAMPLE A case was injection molded by adding 30% by weight of silicate talc to polypropylene. The values in parentheses at the end are the values of the physical properties of the samples without additives. Product shrinkage rate: 1.1 to 1.5% (1.5 to 2.5
%) Tensile yield strength (test method: D638); 270 kgf / cm2
(250 kgf / cm2) Tensile breaking strength (test method: D638); 210 kgf / cm2
(170kgf / cm2) Elongation at break (Test method: D638); 15%
(680%) Flexural strength (Test method: D790); 470 kgf / cm2
(340kgf / cm2) Flexural elasticity (Test method: D790); 34,200kgf / cm
2 (12,000kg f / cm2)

[0024]

According to the present invention, it is possible to eliminate the necessity of applying an undercoat agent which is a pre-treatment in performing vacuum deposition of a mirror surface treatment on the surface of the reflector according to the present invention, thereby improving heat resistance of the reflector,
Furthermore, since the shrinkage of the reflector can be reduced, the reflector has high dimensional accuracy and can be manufactured at low cost. In addition, in order to mirror-treat the surface of a molded article of a single-grade plastic material, secondary processing such as electroplating and electroless plating can be performed in addition to vacuum deposition.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a state where a reflector is attached to a guardrail.

[Explanation of symbols]

 3 Reflector 31 Mounting part 32 Projecting part

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08K 3/34 C08K 3/34 C08L 23/00 C08L 23/00 25/04 25/04 55/02 55 / 02 C23C 14/14 C23C 14/14 B 18/31 18/31 A C25D 5/26 C25D 5/26 B E01F 9/00 E01F 9/00

Claims (4)

[Claims] 1. A plastic molded from a granular plastic material obtained by adding an inorganic additive to a plastic, and the surface thereof is mirror-finished. The plastic is an olefin resin, an ABS resin, a styrene resin. Wherein the additive is selected from the group consisting of oxides, hydroxides, carbonates, sulfates, silicates, nitrides, carbons and potassium titanate. body. 2. The plastic reflector according to claim 1, wherein the mirror surface treatment is a treatment selected from aluminum deposition, sputtering deposition, electroplating, and electroless plating. 3. The method according to claim 1, wherein the oxide is selected from silica, diatomaceous earth, alumina, magnesium oxide, titanium oxide, zinc oxide, and antimony oxide. Aluminum, selected from basic magnesium carbonate, the carbonate is selected from calcium carbonate, magnesium carbonate, barium carbonate, and the sulfate is selected from calcium sulfate, calcium sulfite, barium sulfate Wherein the silicate is selected from calcium silicate, talc, kaolin clay, mica, zeolite, attapulgite, bentonite, sericite, aluminum silicate, feldspar powder, magnesium silicate, and apatite. The nitride is silicon nitride, and the carbons are carbon A plastic reflector characterized by being selected from black and graphite. 4. The method according to claim 3, wherein the oxide, silica, diatomaceous earth, alumina and magnesium oxide are added in an amount of 2
0 to 60% by weight, the addition amount of the oxides of titanium oxide, zinc oxide and antimony oxide is 25 to 70% by weight, the addition amount of the hydroxide is 20 to 60% by weight, As for the salt, the addition amount of calcium carbonate and magnesium carbonate is 20 to 60% by weight, and the addition amount of barium carbonate of the above carbonate is 25 to 70% by weight.
The addition amount of calcium sulfate and calcium sulfite is 20 to 60% by weight, and the addition amount of barium sulfate of the sulfate is 25 to 70% by weight.
Wherein the addition amount of the silicate is 20 to 60% by weight, the addition amount of the nitride is 20 to 60% by weight, the addition amount of the carbons is 10 to 50% by weight, A plastic reflector characterized in that the addition amount of potassium titanate is 20 to 60% by weight.