JP2001284959A - Reflecting plate for paraboloidal and producing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reflecting plate for a paraboloidal antenna, improved in strength, rigidity, further, appearance and productivity per unit mass and an efficient producing method therefor. SOLUTION: The reflector for a paraboloidal antenna is constituted by laminating a resin protecting layer, a metal layer and a fiber-containing thermoplastic resin layer having void in this order. Concerning the fiber-containing thermoplastic resin layer having void, a quantity (A) of contained resins is 5 to 70 wt.%, an average fiber length (B) is 1 to 20 mm and an average dummy density (C) is 200 to 1000 kg/m3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflector for a polarographic antenna which has a metal layer having a resin protective layer and a fiber-containing thermoplastic resin layer, is lightweight, and has excellent strength per weight and rigidity, and its reflection plate. It relates to a manufacturing method.

[0002]

2. Description of the Related Art With the spread of satellite broadcasting, high-quality images,
Audio has become easier to enjoy at home.
Accordingly, a parabolic antenna is necessary to efficiently receive radio waves from satellites. In this parabolic antenna, a bowl-shaped reflector for receiving radio waves over a large area and collecting it at one point plays an important role.

[0003] Standards such as radio wave reflection characteristics of this parabolic antenna are defined, and it is necessary to satisfy these standards. Furthermore, since this parabolic antenna is generally installed outdoors on roofs, verandas, etc., it is exposed to the wind and rain, so it has excellent weather resistance to ultraviolet rays, rain, etc., and has properties such as strength and rigidity to withstand wind pressure etc. Is required. In addition, it is lightweight for installation, handling, etc.,
Moreover, it is required to be inexpensive.

As these reflectors for parabolic antennas, those obtained by applying a paint to a metal reflector obtained by pressing a zinc-plated iron plate or an aluminum plate are most commonly used. However, in addition to the heavy weight, the metal reflection plate has a problem in that even if the surface is protected by painting, the durability is poor and rust easily occurs when used for a long period of time. Here, although the aluminum reflector is lighter than iron, it still needs a certain thickness in order to satisfy strength, rigidity and the like, and improvement is desired in terms of weight and price.

The use of metal in a reflector for a parabolic antenna is a means for efficiently receiving radio waves, that is, a means for reflecting received radio waves and collecting them at one point, and it is not always necessary to make the entire reflector made of metal. Absent. Therefore, many proposals have been made to use a metal material as a radio wave reflection layer and to form a multilayer composite structure with a thermoplastic resin which is responsible for strength, rigidity, durability and the like.

For example, a method of laminating a glass fiber reinforced thermoplastic resin on the resin layer side of a laminate composed of a metal foil and an adhesive resin layer, followed by thermocompression bonding. A method of press-forming a conductive nonwoven fabric and a fiber-reinforced unsaturated polyester sheet. A method in which a multilayer material including a weather-resistant resin protective layer, a metal layer, and an adhesive layer is pre-shaped, and a thermoplastic resin is injection-molded and integrated. A method in which an inorganic filler such as talc is blended with a thermoplastic resin to be injection molded. A method of blending a fiber having a relatively long fiber length with a thermoplastic resin is known.

[0007] The reflector obtained by these methods is complicated in manufacture, and may cause distortion of the reflection surface after the manufacture, and it may be difficult to integrally form a mounting member on the back surface of the reflector.
In addition, when the attachment member is integrated, there remains a problem that distortion is easily generated on the reflection surface. Further, those using a thermoplastic resin mixed with talc or glass fiber are improved in strength, rigidity and the like, but may not be sufficient in terms of weight reduction.

For this reason, for example, Japanese Patent Publication No. 5-1668
No. 4, Japanese Patent Publication No. 5-62482, Japanese Unexamined Patent Publication No.
JP-A-235503 discloses a metal layer having a weather-resistant thermoplastic resin layer or a thermosetting coating layer and an inorganic filler.
The polyolefin layer containing 0 to 80% by mass has a specific thickness, and the polyolefin layer has an average expansion ratio of 1.0.
For example, a reflector for a circularly polarized antenna in which the thickness is 5 to 45% of the layer thickness is a non-foamed skin layer has been proposed.

However, the average expansion ratio of the inorganic filler-containing thermoplastic resin layer is only specified in the range of 1.15 to 1.23. The effect is substantially less. In addition, the total thickness of the reflection plate is as large as about 8 mm, and there is a limit to the weight reduction as a whole. Therefore, in order to ensure the rigidity of the reflector, a certain thickness or more is required, and it may be difficult to reduce the weight. Therefore, although a number of reflectors for parabolic antennas with a composite structure with these thermoplastic resins have been proposed, it is actually the case that metallic reflectors such as aluminum are used based on comprehensive evaluations such as weight reduction, performance and cost. It is.

[0010]

In a conventional reflector for a parabolic antenna comprising a metal layer for radio wave reflection and a thermoplastic resin layer, corrosion of the metal layer is prevented by blending talc or glass fiber, and the reflector is made of a metal. Stiffness etc. are secured. Further, by forming the talc or glass fiber blend layer into a foamed structure having a skin, the ribs and the thick portions provided on the back surface of the reflector correspond to the ribs and the thick portion on the back surface of the metal layer on the front surface of the reflector. The problem that sinks occur in portions, the appearance becomes poor, and the performance of the radio wave reflecting plate is reduced is solved. However, weight reduction and cost while securing strength and rigidity are not yet sufficient. Therefore, the present invention provides a reflector for a parabolic antenna which is excellent in strength, rigidity, appearance, and productivity per unit weight, and an efficient manufacturing method thereof.

[0011]

Under the circumstances described above, the present inventor has conducted intensive studies on the weight reduction of a reflector for a parabolic antenna, its radio wave reflection performance, mechanical performance such as strength and rigidity, and appearance. As a result, it has been found that a multilayer structure reflector having a specific structure satisfies excellent appearance and physical properties as well as weight reduction, and can be substituted for a metal reflector or a composite reflector with a resin. It is completed.

That is, the present invention provides: (1) a resin protective layer, a metal layer and a fiber-containing thermoplastic resin layer having voids are laminated in this order, and the fiber-containing thermoplastic resin layer having voids comprises (A) Fiber content is 5
~ 70% by mass, (B) average fiber length is 1 ~ 20mm,
(C) The average apparent density is 200 to 1,000 kg / m ³
A reflector for a parabolic antenna. (2) The parabolic antenna reflector according to (1), further comprising an adhesive layer between the metal layer and the fiber-containing thermoplastic resin layer. (3) The metal layer is selected from the group consisting of foil, plate, mat, cloth, and net, and has a thickness of 5 to 5.
The parabolic antenna reflector according to (1) or (2), which is 1,000 μm. (4) The fiber is at least one of glass fiber and carbon fiber, and the thermoplastic resin is at least one selected from a polyethylene resin, a polypropylene resin, a polystyrene resin, a polyamide resin, a polyester resin, and a polycarbonate resin. The reflector for a parabolic antenna according to any one of (1) to (3), which is a kind of resin. (5) A preform formed of a multilayer material having a resin protective layer and a metal layer is arranged so that the resin protective layer side is on the convex side of the molding die, the mold is closed, and then the fibers are melt-expanded. After injection or injection compression filling of a thermoplastic resin having
The method for producing a parabolic antenna reflector according to any one of (1) to (4), wherein a fiber-containing thermoplastic resin layer having voids is formed. (6) A thermoplastic resin having melt-expandability is obtained by melt-kneading a molding material containing at least a fiber-reinforced thermoplastic resin pellet, and the pellet has a total length of 3 to 100 mm.
The method according to (5), wherein the reflector has a length equal to the total length and contains 20 to 90% by mass of fibers arranged in parallel with each other. It is about.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The reflector for a parabolic antenna according to the present invention comprises a resin protective layer, a metal layer, and a fiber-containing thermoplastic resin layer having voids laminated in this order, and the fiber-containing thermoplastic resin layer having voids comprises (A) a fiber-containing thermoplastic resin layer. The amount is 5-70% by weight,
(B) An average fiber length is 1 to 20 mm, and (C) an average apparent density is 200 to 1,000 kg / m ³ .

The reflector for a parabolic antenna according to the present invention is, for example, as shown in FIG.
Is a reflector plate 1 for a parabolic antenna used in the present invention. The parabolic antenna reflector 1 (hereinafter may be simply abbreviated as a reflector) is attached to the parabolic antenna reflector mounting column 23. A converter 21 is provided at the tip of a converter support arm 22 attached to the back surface of the reflector 1, and radio waves from satellites
Reflected at the converter 21 and collected by the converter 21 and the cable 2
4 to be sent to the receiver.

As shown in FIG. 1, the parabolic antenna reflector 1 of the present invention comprises a laminate in which a resin protective layer 2, a metal layer 3, and a fiber-containing thermoplastic resin layer 4 having voids are laminated in this order. Have been. In this laminate, the fiber-containing thermoplastic resin layer having voids has (A) a fiber content of 5 to 70% by mass and (B) an average fiber length of 1 to 20 m.
m, (C) the average apparent density is 200 to 1,000 kg /
m ³ is a feature of the present invention.

On the back surface of the reflector 1, mounting bosses 5 such as a reflector mounting column 23 and a converter support arm 22 are provided. Further, an adhesive layer 6 (not shown) may be provided between the metal layer 3 and the fiber-containing thermoplastic resin layer 4 having voids.

Here, the metal layer has a function of reflecting radio waves, and various metals are used. For example, a simple substance of aluminum, iron, copper, nickel, zinc, or the like, or stainless steel or brass, which are alloys containing these metals as main components, may be used. These metal materials may be plated or painted. Examples of the form of the metal layer include a foil, a plate, a mat, a cloth, and a net, and a foil or a plate is preferably used.

Here, the thickness of the metal layer is 5 to 5.
It is in the range of 1,000 μm, preferably 10-500 μm. If the thickness of the metal layer is less than 5 μm, the radio wave reflection performance may be inferior due to workability, partial deformation during processing, and the like. If it exceeds 1,000 μm, the weight of the reflector increases, resulting in a reduction in weight and cost. Is difficult to achieve. Further, in a parabolic shape (hereinafter, sometimes referred to as a bowl shape).
In some cases, the preformability may deteriorate the moldability.

Next, the resin protective layer protects the metal layer, which is used for preforming the metal layer into a bowl shape, for protecting the metal layer at the time of final molding, and for using the parabolic antenna. It is provided for the purpose of protection from ultraviolet rays, wind and rain. Here, as the resin used for the protective layer, any of a thermoplastic resin and a thermosetting resin can be used.

Here, the thermoplastic resin includes polyethylene, polypropylene, ethylene-α-olefin copolymer, propylene-ethylene copolymer, styrene-acrylonitrile copolymer, polymethyl (meth) acrylate, polyamide, polyester, polyphenylene oxide. , Polyphenylene sulfide, polycarbonate, polyvinylidene fluoride and the like. Further, a resin containing a resin modified by graft polymerization of an unsaturated carboxylic acid or its anhydride, derivative, or the like is also preferably used because of its excellent adhesiveness to metal.

Examples of the thermosetting resin include polyurethane obtained by reacting unsaturated polyester, polyester polyol or polyurethane polyol with diisocyanate, amino alkyd resin, thermosetting acrylic resin, melamine resin, cyanoacrylate resin, epoxy resin. And acrylic urethane resin. In these thermosetting resins, a resin protective layer is usually formed as a solvent-type, aqueous emulsion-type, or solvent-free coating using an organic solvent such as toluene or xylene.

These resin protective layers may optionally contain a matting agent such as silicic acid, a pigment such as titanium oxide, a coloring agent such as various dyes, various ultraviolet absorbers, a light stabilizer and an antioxidant. You. The main purpose of this resin protective layer is to prevent corrosion of the metal layer as described above. From this, the thickness of the resin protective layer is 5 to 1,000 μm,
Preferably it is 10 to 500 μm. Prior to forming the resin protective layer on the metal layer, various primer layers may be provided on one side or both sides of the metal layer. By forming the primer layer, the adhesive strength between the layers can be improved. This primer layer includes acrylic, epoxy, phenol, polyester,
Examples include a polyurethane-based and polyamide-based primer. The thickness of the primer layer is 0.1 to 300
It is about μm.

Next, it is preferable to form an adhesive layer on the back surface of the multilayer board composed of the resin protective layer and the metal layer, if necessary. This is effective for enhancing the adhesion to the metal layer when forming a fiber-containing thermoplastic resin layer having voids, which is a feature of the reflector of the present invention, on the back surface of the multilayer board, as described later. Because there is. However, if the fiber-containing thermoplastic resin is a resin containing a modified resin grafted with an unsaturated carboxylic acid such as maleic anhydride or a derivative thereof, the thermoplastic resin layer itself has adhesiveness to the metal plate. It may not be necessary.

Therefore, considering the type of thermoplastic resin of the fiber-containing thermoplastic resin layer and the adhesiveness to metal, etc., the adhesive layer is made of the above-mentioned maleic anhydride-grafted modified polyolefin resin or various types of thermoplastic resin. A resin containing a plastic elastomer or the like is used. This adhesive layer, extrusion lamination of the adhesive resin to a metal plate,
It can be obtained by a method of laminating after previously forming an adhesive resin film. Here, the thickness of the adhesive layer is 5 to 500 μm, preferably 10 to 300 μm.

The reflector for a parabolic antenna according to the present invention comprises a multilayer laminate in which a fiber-containing thermoplastic resin layer having voids is formed on the back surface of the multilayer plate formed in a bowl shape as an antenna. I have. In this laminate,
The fiber-containing thermoplastic resin layer having voids has (A) a fiber content of 5 to 70% by mass, and (B) an average fiber length of 1 to 20 m.
m, (C) the average apparent density is 200 to 1,000 kg /
m is ^3. Here, the average fiber length is a mass average fiber length.

Hereinafter, the details and the forming method of the fiber-containing thermoplastic resin layer having the voids will be described based on the injection molding method (injection compression molding method) which is the most common method for manufacturing a reflector for a parabolic antenna. .

First, the above-mentioned resin protective layer and metal layer, or
There is a method in which a multilayer board composed of a metal layer and an adhesive resin layer is further mounted on a bowl-shaped convex surface of an injection molding die and insert-molded. Further, there is a method in which a multi-layer board is pre-formed into a parabolic shape (bowl shape) including a peripheral flange shape, for example, pre-press-formed, and similarly insert-molded. From the appearance of the outer peripheral portion, it is preferable to adopt the latter preforming. Note that this preforming step can be omitted depending on the type, thickness, shape, and the like of the metal of the metal layer. The size of the reflector for a parabolic antenna is 500 to 1000 mm, preferably 600 to 80 mm.
It is in the range of 0 mm.

The multilayer body prepress-molded into a bowl shape with its outer peripheral part folded is inserted into a mold, the mold is closed, and a fiber-containing thermoplastic resin having melt-expandability is injected and filled. The molding method for expanding the fiber-containing thermoplastic resin by opening a predetermined amount will be described.

The thermoplastic resin used in the fiber-containing thermoplastic resin layer of the present invention is not particularly limited. Examples thereof include polypropylene, propylene / ethylene block copolymer, propylene / ethylene random copolymer, and low crystallinity. Polyolefin resin such as polypropylene resin, high-density polyethylene, ethylene-α-olefin copolymer, polystyrene, rubber-modified impact-resistant polystyrene, polystyrene containing syndiotactic structure, ABS resin, AS resin, and other polystyrene resin , Polyvinyl chloride resin, polyamide resin, polyester resin, polyacetal resin, polycarbonate resin, polyphenylene sulfide, polyaromatic ether or thioether resin, polyaromatic ester resin, polysulfone resin, acryle DOO-based resin, thermoplastic elastomer or the like can be employed. Here, the thermoplastic resin may be used alone, or two or more kinds may be used in combination.

Among them, for example, at least one selected from polyethylene resins, polypropylene resins, polystyrene resins, polyamide resins, polyester resins, and polycarbonate resins is preferable.

Here, the thermoplastic resin preferably contains unsaturated carboxylic acids such as maleic anhydride, fumaric acid, and acrylic acid, or resins modified with derivatives thereof. Here, the modified resins include the above-mentioned thermoplastic resins and various elastomers, and the modification method is usually graft modification, but may be a copolymer. Examples of the modified resins include polyolefin resins such as polypropylene resins and polyethylene resins, polyolefin elastomers, and polystyrene resins. The content of the unsaturated carboxylic acid or its derivative in the modified resin of the unsaturated carboxylic acid or its derivative is usually 0.1.
01 to 10% by mass. In addition, the content of the modified resin,
Usually, it is 0.5 to 20% by mass.

Next, the fiber used in the present invention is not particularly limited, and is selected from various fibers having expandability during melt-kneading and extrusion. For example, glass fiber, inorganic fiber such as carbon fiber, copper fiber, brass fiber, steel fiber, stainless fiber, aluminum fiber, metal fiber such as aluminum alloy fiber, boron fiber, silicon carbide fiber, alumina fiber, silicon nitride fiber And organic fibers such as ceramic fibers such as zirconia fibers, aromatic polyester fibers, polyamide fibers, aramid fibers, polyarylate fibers, polyphenylene sulfide fibers, polysulfone fibers, and ultrahigh molecular weight polyethylene fibers. These fibers may be used in combination of two or more, such as inorganic fibers and organic fibers.

As these fibers, the layer constitution of the reflection plate,
It can be appropriately selected in consideration of the ratio of the metal layer and the like to satisfy the required characteristics. Among them, glass fiber, carbon fiber, and the like are preferable because they have excellent strength, rigidity, and heat resistance, are long fibers, and can be easily impregnated with a molten resin. In particular, glass fibers are preferably used.

Here, as the glass fibers, glass fibers such as E-glass and S-glass having an average fiber diameter of 25 μm or less, preferably in the range of 3 to 20 μm can be preferably employed. Glass fiber diameter 3
If it is less than μm, the glass fiber does not fit into the resin during the production of pellets by melt resin impregnation drawing, and it becomes difficult to impregnate the resin, while if it exceeds 20 μm, the appearance is reduced and the fiber is difficult to flow. Become
Cutting and chipping tend to occur during melt kneading. Using these thermoplastic resins and glass fibers, when producing pellets by a pultrusion method or the like, the glass fibers are subjected to a surface treatment with a coupling agent, and then a 100-
It is desirable to bundle them in 10,000, preferably in the range of 150 to 5,000.

The coupling agent can be appropriately selected from so-called silane coupling agents and titanium coupling agents which have been conventionally used. For example, γ-aminopropyltriethoxysilane, N-β-
(Aminoethyl) -γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane,
Aminosilane and epoxysilane such as β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane can be employed. In particular, it is preferable to employ the amino silane compound.

As the sizing agent, for example, urethane type, olefin type, acrylic type, butadiene type, epoxy type and the like can be used, and among these, urethane type and olefinic type can be preferably used. Among these, the urethane-based sizing agent is usually an oil-modified type or a moisture-curable type as long as it contains a polyisocyanate obtained by a polyaddition reaction between a diisocyanate compound and a polyhydric alcohol at a ratio of 50% by weight or more. And one-pack type such as block type,
Also, any of two-pack types such as a catalyst-curable type and a polyol-curable type can be adopted. On the other hand, a modified polyolefin resin modified with an unsaturated carboxylic acid or a derivative thereof can be used as the olefin sizing agent.

The fiber-containing molding material used in the present invention is not particularly limited as long as it has melt expansion properties. However, fiber reinforced resin pellets reinforced with glass fibers by adhering and impregnating a thermoplastic resin to the glass fibers converged by the sizing agent as described above are preferably used. As a method of attaching and impregnating a thermoplastic resin to glass fibers, for example, a method of passing a fiber bundle through a molten resin and impregnating the resin with the fiber, a method of impregnating the fiber bundle through a coating die, or a method using a die A method in which the molten resin adhering around the fibers is spread and impregnated into the fiber bundle can be adopted.

Here, in order to make the fiber bundle and the resin well-fitted, that is, to improve the wettability, the fiber bundle is pulled out through a tensioned fiber bundle into a die having an uneven portion on the inner periphery. After the fiber bundle is impregnated with the molten resin, if necessary, a pultrusion method in which a step of pressing the fiber bundle with a pressure roller can be adopted. If the glass fiber and the molten resin are compatible with each other and have good wettability, the molten resin can be easily impregnated into the glass fiber, and the pellet can be easily manufactured. May be omitted. Here, as a method of making the resins compatible with each other, a method of imparting polarity to the resin or grafting a functional group that reacts with the coupling agent on the surface of the glass fiber is effective.

When a long fiber bundle (strand or the like) impregnated with a resin is cut along the longitudinal direction of the fiber by the above-described method, a long fiber bundle having the same length as the entire length of the pellet is contained. A fiber-reinforced resin pellet can be obtained. At this time, as the resin pellets, the fiber bundle is formed into a strand, and the cross-sectional shape is not limited to a cut resin-containing long fiber bundle having a substantially circular shape. The resin-containing long fiber bundle in the shape of a band or a band may be cut into a predetermined length.

Further, as the fiber-containing thermoplastic resin molding material preferably used in the method of manufacturing a reflector for a parabolic antenna according to the present invention, as described above, a total length of 3 to 100 mm manufactured by melt resin impregnation drawing is used. And a fiber-reinforced thermoplastic resin pellet having a length equal to the total length and containing 20 to 90% by mass of fibers arranged in parallel with each other or a mixture of the pellet and another pellet. Is 10 to 70% by mass of the whole
It is preferable that the molding material be used.

If pellets are used in which the fibers are arranged in parallel with each other and contain 20 to 90% by mass of the whole, the glass fibers are impregnated and coated with the molten resin. Even if plasticization, melting, and kneading are performed with a screw, fiber breakage is unlikely to occur, and the dispersibility is also improved. As a result, the spring-back phenomenon of the fiber-containing molten thermoplastic resin having melt-expandability after being injected into the molding die cavity is improved, and the fiber length remaining in the final molded product is increased, thereby improving the physical properties. ,
Surface appearance is improved. Here, if a mixture with other pellets is used, the amount of high-concentration glass fiber reinforced thermoplastic resin pellets used is small and economical, and at the same time, the adjustment of the fiber content in the molded product and the adjustment of the melt viscosity are performed. There is a merit that can be.

In the method for manufacturing a reflector for a parabolic antenna according to the present invention, the expandability of the molten resin is due to a restoring force due to a springback phenomenon caused by entanglement of fibers such as glass fibers contained therein. However, a small amount, for example, about 0.01 to 3% by mass of a foaming agent can be contained to supplement the expandability. Here, the foaming agent is not particularly limited as long as it generates gas by heat, and includes a chemical foaming agent and a physical foaming agent. For example, azodicarbonamide (ADCA), benzenesulfohydrazide, N, N-dinitropentamethylenetetramine, terephthalazide and the like can be mentioned.

In most cases, the reflector for a parabolic antenna according to the present invention is installed and used on a roof, a roof, a veranda or the like, and is required to have weather resistance. Therefore, it is desirable to add additives such as an ultraviolet absorber and a light stabilizer in addition to the antioxidant and the heat stabilizer used for general thermoplastic resins. These additives may be used alone or in combination of two or more. The antioxidant is not particularly limited, and conventionally known ones, for example,
Phenol, phosphorus, sulfur and the like can be used.

Examples of the phenolic antioxidant include 2,6-di-t-butyl-4-methylphenol,
n-octadecyl-3- (3,5-di-t-butyl-4
-Hydroxyphenyl) propionate, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-
4-hydroxyphenyl) propionate], 2-t-
Butyl-6- (3-tert-butyl-2-hydroxy-5-
Methylbenzyl) -4-methylphenyl acrylate,
2- [1- (2-hydroxy-3,5-di-t-pentylphenyl) ethyl] -4,6-di-t-pentylphenyl acrylate, triethylene glycol-bis-
[3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis- [3- (3,5-di-t-butyl-4-hydroxyphenyl) Propionate], 3,9-bis [1,1-di-methyl-2- [β- (3-t-butyl-
4-hydroxy-5-methylphenyl) propionyloxy] ethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, 1,3,5-trimethyl-
2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tris (3,5-di-t
-Butyl-4-hydroxybenzyl) isocyanurate, tris (4-t-butyl-2,6-di-methyl-3)
-Hydroxybenzyl) isocyanurate and the like.

Examples of the phosphorus antioxidant include tris (nonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite,
Bis (2,4-di-t-butylphenyl) pentaerythritol-diphosphite, bis (2,6-di-t-t
-Butyl-4-methylphenyl) pentaerythritol-diphosphite, bis (2,4,6-tri-t-
Butylphenyl) pentaerythritol-di-phosphite, methylenebis (2,4-di-t-butylphenyl) octylphosphite, tetrakis (2,4-di-t-butylphenyl) -4,4'-biphenylene-di -Phosphonite, tetrakis (2,4-di-t-butyl-5-methylphenyl) -4,4'-biphenylene-di-phosphonite and the like.

Further, as the sulfur-based antioxidant, for example, dilauryl thiodipropionate, dimyristyl thiodipropionate, distearyl thiodipropionate, glycerin tributyl thiopropionate, glycerin trioctyl thiopropionate Glycerin trilauryl thiopropionate, glycerin tristearyl thiopropionate, trimethylol ethane tributyl thiopropionate, trimethylol ethane trioctyl thiopropionate, trimethylol ethane trilauryl thiopropionate, trimethylol ethane Stearyl thiopropionate, pentaerythritol tetrabutyl thiopropionate, pentaerythritol tetraoctyl thiopropionate, pentaerythritol tetralau Lucio propionate, pentaerythritol tetra distearyl propionate, and the like.

These antioxidants may be used alone or in combination of two or more. Further, the content of the antioxidant is usually 0.1 to the thermoplastic resin.
The range is from 02 to 2.0% by mass, and preferably from 0.05 to 1.5% by mass.

Next, examples of the ultraviolet absorber include salicylic acid derivatives, benzophenones, benzotriazoles and benzoates, and among these, benzotriazoles and benzoates are preferred. As the benzotriazole-based light absorber, 2- (3-t-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-t-butyl-2-) (Hydroxyphenyl) -5-chlorobenzotriazole, 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) benzotriazole,
-(2-hydroxy-5-t-octylphenyl) benzotriazole, 2- (2-hydroxy-3,5-di-t
-Amylphenyl) benzotriazole and the like. As the benzoate-based light absorber, for example, 2,4-di-t-butylphenyl-3,5-
Examples thereof include di-t-butyl-4-hydroxybenzoate and hexadecyl-3,5-di-t-butyl-4-hydroxybenzoate.

The light stabilizer includes a hindered amine light stabilizer and a phenylbenzoate light stabilizer. Specific examples of the hindered amine or phenylbenzoate light stabilizer include bis (2,2,6,6
-Tetramethyl-4-piperidyl) separate, succinic acid and N- (2-hydroxypropyl) -2,2,6,6
Condensate with tetramethyl-4-hydroxypiperidine, tetrakis (2,2,6,6-tetramethyl-4-
Piperidyl), 1,2,3,4-butanetetracarboxylate, N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine and 1,
A polycondensate with 2-dibromoethane, bis (2,2,6,
6-tetramethylpiperidyl) adipate, bis (2
2,6,6-tetramethylpiperidyl) fumarate, poly [[6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl]
[(2,2,6,6-tetramethyl-4-piperidyl)
Imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]], 4-hydroxy-
Dimethyl succinate polymer containing 2,2,6,6-tetramethyl-1-piperidineethanol, 2,4-di-t-butylphenyl-3,5-di-t-butyl-4-
Hydroxybenzoate, 4-octylphenyl-3,
5-di-t-butyl-4-hydroxybenzoate, n
-Hexadecyl-3,5-di-t-butyl 4-hydroxybenzoate and the like.

The content of these additives is 0.05 to 1.0% by mass, preferably 0.1 to 0.6% by mass, and 0.05 to 1.0% by mass of an ultraviolet absorber and 0.05 to 1.0% by mass of a thermoplastic resin. 1.0
% By mass, preferably about 0.2 to 0.6% by mass.
In addition, the above-mentioned respective types of additives may be used in combination of a plurality of additives.

Further, the thermoplastic resin includes metal powder, carbon black, graphite, talc, titanium oxide, zinc oxide, dispersant, antistatic agent, flame retardant, flame retardant auxiliary, plasticizer, epoxy compound, metal inert. Agents, pigments, dyes and the like can also be added.

Hereinafter, a method for manufacturing a reflector for a parabolic antenna according to the present invention will be described in detail together with a molding material. The reflection plate of the present invention comprises a surface layer formed of a multilayer material having a resin protective layer and a metal layer, and injects or injects a thermoplastic resin containing a thermoplastic resin and a fiber such as glass fiber and having a melt-expanding property. After filling, the molten resin layer is expanded to laminate and integrate a low-density fiber-containing thermoplastic resin layer having voids.

Here, the thermoplastic resin containing fibers and having a melt-expanding property is a molten resin that can be expanded by itself when the mold cavity is expanded after being filled into a molding die by injection or injection compression. is there. The molding material is not particularly limited as long as it enables this. However, the fiber-reinforced thermoplastic resin pellets having a total length of 3 to 100 mm, preferably 4 to 50 mm, having a length equal to the total length and containing 20 to 90% by mass of fibers arranged in parallel with each other. It is preferable to use a molding material in which the fibers are used alone or in a mixture of these pellets and other pellets, and the fiber accounts for 10 to 70% by mass. Here, the other pellets are usually thermoplastic resins of the same type, or those containing various additives therein. By selecting the preferable molding material pellets, it is possible to easily obtain a melt-kneaded resin having excellent melt expandability in the cavity of the injection mold.

Here, if the fiber content in the fiber-containing thermoplastic resin is less than 10% by mass, the melt-expandability becomes insufficient and the effect of improving the physical properties such as strength and rigidity by the fiber cannot be expected. . On the other hand, if it exceeds 70% by mass, the melt-kneading properties and the dispersibility of the fibers are reduced, and the injection moldability and
In some cases, the stability of the quality such as the expandability, the appearance of the molded product, and the homogeneity is reduced.

Here, when the fiber-containing thermoplastic resin is a polypropylene resin, there is no particular limitation on the MI (melt index) of the polypropylene resin, and the MI as a whole [based on JIS K7210, temperature: 230
° C, load: measured at 21.18 N], but 5 to 1,000 g
/ 10 minutes, preferably 10 to 600 g / 10 minutes.
Usually, a molding material composed of a mixture of glass fiber reinforced polypropylene resin pellets and polypropylene resin pellets is used. Therefore, as the polypropylene resin and the polypropylene resin pellet for diluting the glass fiber in the glass fiber-containing polypropylene resin master pellet, it is free to use a pellet having a different MI, and the size of the reflection plate, the metal layer and the resin Layer thickness,
In consideration of the density of the resin layer and the like, it can be appropriately determined in consideration of characteristics such as bending strength, bending stiffness, impact strength, heat resistance, heat resistance dimensional stability, and moldability required for the reflection plate.

However, the reflector of the present invention has a relatively small mold cavity thickness at the time of molding and contains glass fibers having a relatively long fiber length, and has good moldability, that is, good melt fluidity. Is required. Therefore, the MI of the polypropylene resin for dilution is 30 to
1,000 g / 10 min, preferably 40 to 800 g / 1
It is also possible to appropriately select a polypropylene resin having a relatively large MI of 0 minutes. In ordinary injection molding, such a large MI is generally taken into consideration in consideration of the fluidity of the molten resin.
When the polypropylene-based resin is used, the impact strength is remarkably reduced and is not practical. Therefore, the upper limit of MI is naturally limited.

In the reflector of the present invention, the MI of the polypropylene-based resin is relatively larger than that of the conventional general injection molding method, that is, the molecular weight is significantly lower to improve the moldability. be able to. Even with such a low MI, in the present invention, while containing glass fibers, entanglement of glass fibers, random distribution of glass fibers, formation of a dense surface layer, formation of voids by fibers and resin, etc. In addition, it is possible to obtain characteristics such as strength and rigidity that sufficiently satisfy the characteristics as the reflector of the present invention.

The polypropylene resin used in the present invention may be a homopolypropylene resin or a block copolymer of propylene with another olefin, or a random copolymer of propylene with another olefin of several mass% or less for impact resistance. Copolymers are preferred. In order to further improve the impact resistance, a thermoplastic resin elastomer or an amorphous or low-crystalline polypropylene resin can be appropriately contained.

Examples of the thermoplastic elastomer include, for example, ethylene / propylene copolymer elastomer (EPR), ethylene / butene-1 copolymer elastomer, ethylene / octene-1 copolymer elastomer, ethylene / propylene / butene elastomer There are olefin-based elastomers such as 1 copolymer elastomer, ethylene-propylene-diene copolymer elastomer (EPDM), ethylene-propylene-ethylidene norbornene copolymer elastomer, soft polypropylene, and soft polypropylene-based copolymer. Of these, the ethylene content of the ethylene-based elastomer is usually about 40 to 90% by mass. These elastomers have a Mooney viscosity (ML _{1 + 4} 100) of usually 5 to 100, preferably 10 to 100.
60 is used.

As the styrene-based elastomer,
For example, styrene-butadiene copolymer elastomer, styrene-isoprene copolymer elastomer, styrene-butadiene-isoprene copolymer elastomer,
Alternatively, styrene / ethylene / butylene / styrene copolymer elastomers (SEBS) and styrene / ethylene / propylene / styrene copolymers (SEPS) obtained by completely or partially hydrogenating these copolymers can be exemplified. As these elastomers, a melt index (MI) [based on JIS K7210, temperature: 20
0 ° C., load: measured at 49.03 N], but 0.1 to 120
g / 10 min, preferably 8 to 100 g / 10 min.

Next, glass fibers having various fiber lengths are used, and the average glass fiber length in the fiber-containing resin layer in the molded article as the reflection plate of the present invention is 1 to 20 mm.
In particular, it is in the range of about 2 to 15 mm. Therefore, the molding material is not particularly limited as long as the average fiber length of the glass fibers in the reflector is within the above range. However, in order to keep the glass fiber length in the molded article at a certain level, the total length is generally 3 to 100 mm, preferably 4 to 50 mm, and glass fibers having a length equal to this total length are parallel to each other. It is preferable to use glass fiber reinforced thermoplastic resin pellets which are arranged and have a glass fiber content of 20 to 90% by mass. Here, the glass fiber reinforced thermoplastic resin pellets are obtained by the above-mentioned known method of drawing a plurality of glass fiber bundles in a molten resin, impregnating the resin into strands, and cutting the strands into 3 to 100 mm.

Next, a method of manufacturing a reflector for a parabolic antenna according to the present invention will be described with reference to the drawings. FIG. 3 is a conceptual sectional view of a molding die of an injection molding apparatus used in the method of manufacturing a reflector for a parabolic antenna according to the present invention. FIG. 3 also shows the reflector 1 after molding. In FIG. 3, reference numeral 11 denotes a fixed mold, 12 denotes a movable mold, 13 denotes a movable core, 14 denotes a cavity, 15 denotes a convex mold surface, 16 denotes a gas injection pipe, and 17 denotes a gas exhaust pipe.

In the method of manufacturing the reflector of the present invention, an injection molding method is usually employed, but an injection compression molding method is employed if necessary. As shown in FIG. 3, the molding die needs to be able to change the volume (thickness) of the molding die cavity 14 (when the die is closed: not shown).
That is, an injection mold apparatus having a function of moving the movable core 13 forward and backward is used.

As the injection molding machine, a molding machine generally capable of injection compression molding, or an injection molding machine equipped with a unit for moving a movable core to and from a general injection molding machine is used. Here, the device for moving the movable core 13 forward and backward can be provided on the movable mold mounting plate side (FIG. 3) or on the fixed mold mounting plate side.

The method of manufacturing the reflector of the present invention is shown in FIG. 3 [showing the reflector 1 as a molded product when the product is taken out when the mold is opened. First, the movable core 13 is held in the movable mold 12 at the position (a) indicated by the dashed line in the molding mold in the illustrated state, and the movable core 13 is previously set on the convex mold surface of the movable core 13. The multilayer board 10 having the formed resin protective layer 2 and metal layer 3 is mounted. Next, the movable mold 12 is moved forward together with the movable core 13 to perform mold clamping,
A cavity 14 (not shown) into which the multilayer board 10 is inserted is formed.

On the other hand, melt kneading of the fiber-containing thermoplastic resin
Plasticization metering is started and the cavity is injection-filled. After the surface on the fixed mold side is cooled to some extent, the movable core 13 is retracted from the position (a) to the position (b). Thereby, the fiber-containing expandable thermoplastic resin is
It expands as the cavity volume (thickness) increases. That is, the injection-filled resin expands by an amount corresponding to the thickness D. This does not substantially change the absolute mass of the reflector, but increases its thickness.

If necessary, particularly when the melt fluidity is low, the injection amount of the molten resin at the time of injection of the fiber-containing molten resin is set to be usually 2/3 or less of the substantial volume of the molding die cavity. And then move the movable core 13 forward.
It can be compressed to fill the entire cavity and then expanded similarly. When this injection compression filling method is adopted,
This is a preferable embodiment because the resin pressure is low and the orientation of the resin and the fiber is small or does not substantially occur.

Thus, the multilayer board (1) constituting the surface portion
0) and the fiber-containing thermoplastic resin layer 4 having voids are laminated and integrated to form the reflecting plate 1.
Is retracted, and the reflecting plate 1 is taken out by moving the movable core 13 forward. In the compression step, as shown in the figure, in addition to controlling the position of the molding die cavity clearance, it can be controlled by a compression force.

The method of manufacturing a reflector according to the present invention is basically the above-described method. However, after the movable core 13 starts to retract, nitrogen gas or the like can be injected from the gas injection pipe 16. The injection of the gas assists the expansion by the glass fiber and, after expansion, presses the reflecting plate against the surface of the mold, thereby contributing to improvement in mold transferability and appearance. Further, while controlling the pressure of the injected gas to a certain level as required, the gas is exhausted from the gas exhaust pipe 17 and the gas is circulated through the reflector, whereby cooling of the reflector can be promoted. This allows the cooling from the inside of the reflector to be changed to the inconvenience of having to cool the reflector that has been insulated by the formation of the air gap by using a mold.
This greatly contributes to the improvement of the molding cycle. The injection gas is not particularly limited, but an inert gas such as a nitrogen gas or an argon gas is preferably used. The gas pressure is in the range of 0.01 to 20 MPa,
Preferably, it is selected in the range of 0.1 to 5 MPa.

The gas is usually a gas at room temperature, but a cooling gas having a temperature of 15 ° C. or lower, preferably 0 ° C. or lower can also be used. At this time, if a liquid such as volatile water is entrained, the cooling efficiency is further improved. Further, the gas is opened to one of a gas injection nozzle provided inside a nozzle of an injection device for plasticizing and injecting the molten resin, or a sprue, a runner and a cavity provided inside the mold. Can be injected into the interior of the fiber-containing molten resin from a gas injection nozzle or a gas injection pin. Among these, it is preferable to inject from a gas injection pin provided in the mold, particularly from a gas injection pin opened in the cavity.

It is preferable that a convex portion such as a boss 5 for mounting to a mounting column or the like, a rib, or the like be integrally formed on the back surface of the reflecting plate 1. As described above, even when the convex portion is provided on the back surface of the reflection plate 1, since the fiber-containing resin layer has the void structure, sink occurs even when the metal layer is, for example, aluminum foil. There is no adverse effect on the reflection characteristics of radio waves.

The expansion of the mold cavity for expansion of the fiber-containing resin is performed by using a method using a device for moving a movable core provided on a fixed mold separately from the case where the cavity is provided on the movable mold side shown in the figure. Is sometimes preferred. In this case, as the movable core advance / retreat device provided in the fixed mold, a device having a structure in which a hole is formed at the center and from which the injection nozzle can advance / retreat can be used. An example of a device for moving the molding die having this structure is the device described in JP-A-10-244542.

The fiber-containing thermoplastic resin layer 4 of the reflection plate of the present invention has a structure in which fibers such as glass fibers having a relatively long fiber length are randomly distributed in the thermoplastic resin, and the resin expands inside the molded body. And a structure having substantially continuous voids. In addition, the direction of the contained fibers becomes random and uniform as the molten resin expands. In addition, the fiber-containing thermoplastic resin layer is excellent in light weight due to the lightening due to the generation of voids due to the expansion of the inside, the molding integrated multilayer structure with the dense surface layer on the surface part, and the reinforcing effect of fibers such as glass fibers. It exhibits physical properties.

The thickness of each layer in the reflector of the present invention is as follows:
It depends on the size of the reflector, the type of resin, the average apparent density, and the like. Here, the fiber-containing thermoplastic resin layer 4 is appropriately determined from required properties such as the thickness of the metal layer, the degree of weight reduction, strength, rigidity, and impact resistance. Usually 0.5 to 50 mm, preferably about 0.7 to 20 mm, particularly preferably 1 to 8 m
m.

The average apparent density (fiber-containing resin layer:
The total of the skin layer and the void-containing layer) is 200 to 1,000.
kg / m ^3, preferably 300~800kg / m ^3. This broad control of the apparent density is made possible by self-expansion with fiber-containing melt-expandability. In addition, when the expansion ratio is high, it can be easily achieved by using the gas injection method in combination. Therefore, the expansion ratio varies depending on the type and content of the fibers in the fiber-containing thermoplastic resin, but is usually 1.2 to 9 times, preferably 1.3 to 8 times, particularly preferably 1.5 to 7 times. It is said.

Such expansion at a high magnification cannot be achieved at all by the foaming of the resin containing an inorganic filler with a foaming agent as described in the prior art. In the reflector for a parabolic antenna according to the present invention, even when the apparent density is remarkably reduced due to such high expansion, the reinforcing effect by the long fibers in the high-density layer of the surface portion, particularly by the fiber in the layer having voids, is obtained. In combination with this, it has excellent strength and rigidity while being lightweight as a whole. Furthermore, the amount of the fiber-containing thermoplastic resin used can be significantly reduced, and the cost can be reduced. In addition, transportation and handling are facilitated by weight reduction.

That is, the reflector for a parabolic antenna according to the present invention comprises a resin protective layer, a metal layer, and a fiber-containing thermoplastic resin layer having voids laminated in this order. A) fiber content of 5 to 70% by mass, preferably 10 to 60% by mass; (B) average material fiber length of 1 to 20 mm, preferably 2 to 15 mm;
The average apparent density of 200~1,000kg / m ^3, preferably 300~800kg / m ^3.

[0078]

EXAMPLES Next, the effects of the present invention will be described based on specific examples, but the present invention is not limited to these examples.

Example 1 Molding resin material (molding material for thermoplastic resin containing fibers and having melt-expandability) Glass fibers (diameter: 13 μm) are arranged in parallel, the content is 60% by mass, and the length is Glass fiber reinforced polypropylene resin pellets of 12 mm (containing 3% by weight of maleic anhydride-modified polypropylene) at 50% by mass and melt index (MI) [Temperature: 230 ° C, load: 21.18
N] is 60 g / 10 min of polypropylene resin pellet 5
Mixed pellets consisting of 0% by mass.

The two resin materials were used in an amount of 100 parts by mass of the molding material with respect to an antioxidant [Irganox 1076].
(Chipa Specialty Chemicals) = 0.2 parts by mass, and an ultraviolet absorber [Tinuvin 327 (Chipa Specialty Chemicals) = 0.2 parts by mass] were added.

The injection molding machine used a clamping force of 1500 t and a screw having a compression ratio of 1.8 in order to minimize breakage of the glass fiber. IPM unit (made by Idemitsu Petrochemical Co., Ltd.) for moving the movable mold so that the volume (thickness) of the mold cavity can be changed.
Is an injection molding apparatus having a mold structure equipped with. The mold was provided with a facility for injecting and exhausting nitrogen gas into the cavity. The molding die (see FIG. 3) has a diameter of 450
A parabolic antenna reflector test die having a thickness variable in mm was used.

First, an aluminum plate (paint film: 10 μm, aluminum: 0.3 mm) preliminarily curved and coated with a thermosetting resin was mounted on the convex surface of the movable core. Then, the cavity thickness of the molding die is 1.5 m.
The movable core was adjusted so as to obtain m, and the movable mold was moved forward to clamp the mold.

Then, the glass fiber-containing expandable polypropylene resin melt-kneaded and plasticized and measured (resin temperature = 23)
(0 ° C.) was injected in an amount corresponding to a cavity thickness of 0.75 mm at the time of pressurized filling, and the movable core was advanced and compressed and filled at the same time as the completion of the injection. Three seconds after the completion of the filling, the movable core was retracted to expand the resin portion twice. Two seconds after the start of the retraction of the movable core, a nitrogen gas of 3 MPa was injected into the resin from a gas injection pin. Thereafter, after cooling and solidification and gas exhaustion, the mold was opened to obtain a reflection plate.

The resulting reflector had no deformation and had a good appearance. Table 1 shows the evaluation results of the obtained reflection plates. The thickness of the resin layer of this reflector was determined by the apparent average bending stiffness (E) of the aluminum reflector of Comparative Example 2 described later.
^{· I) = E · bh 3} /12 in [MPa · mm ^4], when the b = 1, · E · I is 3,000 MPa m
On the basis of the time when m ⁴ is set, b is set to 1 and set so as to have the same apparent average bending stiffness (EI).
The thickness of the glass fiber-containing thermoplastic resin layer was determined in the same manner in the following Examples and Comparative Examples. Table 1 shows the evaluation results of the glass fiber-containing thermoplastic resin layer having voids in the reflector and the reflector.

Example 2 In Example 1, the resin amount corresponding to the cavity thickness of 0.6 mm was injected, and the expansion ratio due to the retraction of the movable core was set to 3
Molding was performed in the same manner except that the size was doubled to obtain a reflection plate. Table 1 shows the evaluation results.

Example 3 A laminate of a 50 μm soft aluminum foil and a 30 μm polyvinyl fluoride film on one side and a 30 μm ethylene-vinyl acetate copolymer film on the other side was formed by dry lamination using a polyurethane adhesive. Obtained. This laminate was mounted on a mold, and then a reflector was formed according to Example 2.

The obtained reflector had no deformation and good appearance. Table 1 shows the evaluation results. Comparative Example 1 As a molding resin material, 30% by mass of glass fiber (diameter: 13 μm, length: 3 mm) and melt index (MI)
[Temperature: 230 ° C, Load: 21.18N] is 60g / 1
Dry blending of 70% by weight of 0 minute polypropylene resin (containing 3% by weight of maleic anhydride-modified polypropylene), melt kneading and extrusion, using pellets obtained by blending azodicarboxylic acid amide as a blowing agent. A resin molding material was used. The laminate of Example 3 was mounted on a mold, and a reflection plate having a low foaming resin layer was obtained by ordinary injection foaming molding. Table 1 shows the evaluation results.

Comparative Example 2 Table 1 shows the evaluation results of commercially available aluminum reflectors.

[0089]

[Table 1] From Table 1, it is clear that the reflector of Example of the present invention can be significantly reduced in weight when the apparent average bending stiffness is made substantially constant as compared with the current aluminum reflector of Comparative Example 2. In addition, in Example 3 and Comparative Example 1, in comparison with the low-foaming resin layer of Comparative Example 1, which is an appearance-improving invention, it is much more lightweight to have the glass fiber-containing layer which is reduced in weight by the high expansion ratio of the present invention. It is clear that this can be done.

[0090]

The reflector for a parabolic antenna according to the present invention comprises:
When compared at the same bending stiffness level, the total mass of the reflector is lower than that of a reflector obtained by low foam molding using an aluminum reflector or a conventional inorganic filler reinforced thermoplastic resin. Significant weight savings, ease of transport and installation, and lower costs. Further, the glass fiber length in the fiber-containing thermoplastic resin layer is long, and the impact resistance is excellent. Also, the amount of raw materials used can be reduced, which contributes to cost reduction and resource saving. Moreover, despite its light weight, even if the boss or rib is integrally formed on the back surface, there is no occurrence of sink marks and the like, the appearance is good, and the radio wave reflection characteristics are not adversely affected. In addition, the expansion ratio (apparent density) can be set arbitrarily, so that the degree of freedom in design is high and the diameter can be increased.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a reflector for a parabolic antenna according to the present invention.

FIG. 2 is a schematic perspective view of a parabolic antenna to which a parabolic antenna reflector of the present invention is attached.

FIG. 3 is a schematic cross section of a molding die of an injection molding apparatus used in the method of manufacturing a reflector for a parabolic antenna according to the present invention.

[Explanation of symbols]

 1: Reflector for parabolic antenna 2: Resin protective layer 3: Metal layer 4: Fiber-containing thermoplastic resin layer having voids 5: Mounting boss 6: Adhesive layer 10: Laminated plate 11: Fixed mold 12: Moving mold 13: movable core 14: cavity 15: convex mold surface 16: gas injection pipe 17: gas exhaust pipe 20: parabolic antenna 21: converter 22: converter support arm 23: reflector mounting column 24: cable

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (Reference) B29K 69:00 B29K 69:00 77:00 77:00 B29L 9:00 B29L 9:00 31:00 31:00 C08L 101 : 00 C08L 101: 00 F term (reference) 4F072 AA02 AB09 AB10 AD04 AD05 AD37 AD41 AD44 AH04 AK15 AL12 4F206 AA04 AA11 AA13 AA24 AA28 AA29 AB25 AD16 AG03 AH41 JA07 JN25 JN33 JQ81 5J020 AA03 BA09 BA19 BC02

Claims (6)

[Claims] 1. A resin protective layer, a metal layer and a fiber-containing thermoplastic resin layer having voids are laminated in this order, and the fiber-containing thermoplastic resin layer having voids has (A) a fiber content of 5 to 70%. Mass%, (B) average fiber length is 1 to 20 m
m, (C) the average apparent density is 200 to 1,000 kg /
reflector dish, which is a m ^3. 2. The method according to claim 1, wherein the metal layer and the fiber-containing thermoplastic resin layer are
The reflector for a parabolic antenna according to claim 1, further comprising an adhesive layer. 3. The reflection for a parabolic antenna according to claim 1, wherein the metal layer is selected from the group consisting of a foil, a plate, a mat, a cloth, and a net, and has a thickness of 5 to 1,000 μm. Board. 4. The fiber is at least one of glass fiber and carbon fiber, and the thermoplastic resin is selected from a polyethylene resin, a polypropylene resin, a polystyrene resin, a polyamide resin, a polyester resin, and a polycarbonate resin. 4. At least one kind of resin.
The reflector for a parabolic antenna according to any one of the above. 5. A preform formed of a multilayer material having a resin protective layer and a metal layer is disposed so that the resin protective layer side is on the convex side of the molding die, the mold is closed, and the fiber is melted. 5. A fiber-containing thermoplastic resin layer having voids is formed by injecting or injecting and compressing an expandable thermoplastic resin and then expanding the cavity of a molding die by expanding the cavity. A method for manufacturing the parabolic antenna reflector according to any one of the above. 6. A thermoplastic resin having a melt-expanding property is obtained by melt-kneading a molding material containing at least a fiber-reinforced thermoplastic resin pellet, and the pellet has a total length of 3 to 10.
6. The method for manufacturing a parabolic antenna reflector according to claim 5, wherein the length is equal to 0 mm, and the fiber contains 20 to 90% by mass of fibers arranged in parallel with each other.