JPH03237804A - Reflection plate for circularly polarized wave antenna - Google Patents

Abstract

PURPOSE:To keep radio wave reflection performance over a long period by interposing a layer using an olefin group polymer of the same kind as a component of a core member as the major component between a metallic layer and an inorganic filler containing olefin group polymer layer. CONSTITUTION:A metallic layer 2 is provided between a coating film layer 3 being a surface layer and an inorganic filler containing olefin group polymer layer 1 being a rear side structure and a layer 2a having an olefin group polymer as the major component is interposed between the metallic layer 2 and the inorganic filler containing olefin group polymer layer 1. Then the thickness of the coating film layer 3 is selected to be 5mum-1mm, the thickness of the metallic layer is selected to be 5mum-1mm, the thickness of the layer 2a having the olefin group polymer as the major component is selected to be 10mum-3mm, the thickness of the inorganic filler containing olefin group polymer layer 1 is selected to be 0.5-15mm, and the content of the inorganic filler in the inorganic filler containing olefin group polymer layer is selected to be 10-80wt.%. Thus, excellent corrosion resistance is obtained and no change is caused in the radio wave reflecting characteristic over a long period.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a reflector for a circularly polarized antenna having an inorganic filler-containing olefinic polymer layer as a core material.

More specifically, an olefin polymer of the same type as the olefin polymer that is a component of the core material is interposed between the metal layer necessary for receiving from a broadcasting satellite and the inorganic-filled olefin polymer layer that is the core material. The present invention relates to a reflector for a circularly polarized antenna in which a layer as a main component is interposed.

[Conventional technology]

Satellite broadcasting using geostationary satellites is being carried out in some countries around the world, including Europe, the United States, and Japan, and some of them are planned for practical use in the near future. However, since a geostationary satellite has only one orbit, there is a risk of interference between multiple broadcast radio waves. In order to avoid such mutual interference of broadcast waves, it is necessary to utilize cross-polarization identification of satellite broadcast receiving antennas. In this way,
When receiving terrestrial broadcast radio waves, it is very difficult to make the radio waves horizontally or vertically linearly polarized and use cross-polarization discrimination to match the polarization plane of the receiving antenna to the polarization plane of the broadcast radio waves. However, when receiving radio waves from a broadcasting satellite, there is a shift in the plane of polarization due to disturbances such as the ionosphere in the radio wave propagation path and the angle of incidence of the radio waves at the receiving point. It is difficult to match.

Frequency allocation to multiple broadcasting satellites is considered to be done taking into consideration polarization plane discrimination from the point of view of effective use of satellite broadcasting frequency bands, but for satellite broadcasting radio waves with such frequency allocation, Since the quality of the polarization plane adjustment of the receiving antenna directly determines the level of interference between broadcast channels, it cannot be expected to obtain a high degree of cross-polarization discrimination when broadcast satellite radio waves are linearly polarized waves. However, when broadcasting satellite radio waves are circularly polarized waves, it is easy to identify them by the direction of the circularly polarized waves, regardless of the shift in the plane of polarization as described above, so it is difficult for ordinary listeners to receive the waves. Not only can the pointing direction of the receiving antenna be adjusted to direct it to the desired broadcasting satellite, but it is also extremely easy to adjust the receiving antenna compared to the case of linearly polarized waves because it does not require g adjustment of the plane of polarization. Therefore, it is possible to obtain the degree of polarization discrimination as designed for the receiving antenna.

For these reasons, plans are being made to use circularly polarized waves for broadcast satellite radio waves in future satellite broadcasting systems. On the other hand, conventional circularly polarized antennas include those using a conical horn, two dipoles set at right angles, and parabolic antennas that use these antennas as the primary radiator. Because the structure is complex, large, and expensive to manufacture, it is not suitable for general audience receiving antennas for receiving satellite broadcast radio waves using microwaves in the 12 gigahertz (GHz) band. do not have.

On the other hand, the structure is extremely simple, and as a small and lightweight microwave antenna, a rectangular waveguide is extended in the axial direction from the center of a parabolic reflector, and its tip is curved so that the opening end surface becomes the focus of the parabola. There is a so-called Hehat-type parabolic antenna that is positioned opposite to a parabolic reflector and uses this as a -order radiator. This antenna is widely used in microwave antennas for mobile relays, etc., but all conventional Heehat-type parabolic antennas use the aforementioned rectangular waveguide to transmit and receive linearly polarized waves. Therefore, it cannot be used for circularly polarized waves.

Generally, metal plates or metal nets have been used as parabolic antennas. However, since metals corrode, it is necessary to use anti-corrosion alloys or apply anti-corrosion coatings. If anti-corrosion alloys are used, they are expensive. On the other hand, with anti-corrosion coatings, it is necessary to repeat the coating several times to achieve complete corrosion protection, which is not only expensive but also
There is a problem in that the painted material deteriorates after being used for many years. Furthermore, attempts have been made to manufacture radio wave reflecting plates in which glass fibers with metallized surfaces are laminated to thermosetting resins such as unsaturated polyester resins as radio wave reflecting layers, but the manufacturing method is complicated and It has been extremely difficult to maintain the radio wave reflective layer at a constant thickness and without unevenness.

Based on these facts, (A) is used to obtain a circularly polarized antenna reflector that has a simple manufacturing process, has radio wave reflecting ability, and can be maintained for a long period of time.
A reflector for a circularly polarized antenna has been proposed, which is composed of a metal layer having a coating layer with good weather resistance and (B) an olefinic polymer layer containing an inorganic filler.
No. 53203).

[Object to be Solved by the Invention 38] However, the circularly polarized antenna reflector described in the present invention exhibits the above-mentioned effects. However, a problem arises in the adhesion method when laminating a metal layer having a coating layer with good weather resistance and an inorganic filler-containing olefin polymer layer. That is, it is clear that if the bonding method is inappropriate, the desired bond strength cannot be obtained. Therefore, it is essential to develop optimal bonding techniques.

From the above, the present invention has the above-mentioned effects, that is, the manufacturing process is simple, it has radio wave reflecting ability, and its performance can be maintained for a long period of time. The object of the present invention is to obtain a reflector for a circularly polarized antenna that has excellent interlayer peel strength with a polymer layer.

[Means and effects for solving the problems] According to the present invention, these problems are solved by at least the surface layer, which is a coating layer with excellent weather resistance, and the back structure, which is an olefinic polymer containing an inorganic filler. a metal layer between the metal layer and the inorganic filler-containing olefin polymer layer, the main component being an olefin polymer of the same type as the inorganic filler-containing olefin polymer. layer (hereinafter referred to as "olefin polymer layer"), the thickness of the coating layer is 5-
The thickness of the metal layer is from 5 to 12 mm.
(3), the thickness of the olefin polymer layer is 1 Oura to 3 days 1, the thickness of the inorganic filler-containing olefin polymer layer is 0.5 to 15 mm, and the inorganic filler-containing olefin polymer layer is This problem can be solved by a reflector for a circularly polarized antenna, characterized in that the content of the inorganic filler in the polymer layer is 10 to 80% by weight. The present invention will be explained in detail below.

(^) Paint The paint used to produce the coating layer with good weather resistance of the present invention is widely produced industrially and is used in a wide range of applications as a paint for metals. The manufacturing method and various physical properties of these paints are well known.

These paints are classified into solvent type using organic solvents such as toluene and xylene, aqueous emulsion type, and solvent-free type, but any type of paint can be selected depending on the coating method.

Typical examples of these paints include unsaturated or saturated polyester resin paints, polyester polyols,
Polyurethane resin paints obtained by reacting polyether polyols or polyurethane polyols with diisocyanates, aminoalkyd resin paints, acrylic resin paints, melamine resin paints, cyanoacrylate resin paints, epoxy resin paints, silicone resins. Examples include fluorine-containing resin-based paints such as organic titanate-based paints, vinyl chloride resin-based paints, acrylic urethane resin-based paints, amide resin-based paints, and vinylidene fluoride resins. Furthermore, additives such as matting agents such as silicic acid, coloring agents such as pigments and dyes, antioxidants, and ultraviolet absorbers can be added to these paints. Among the above paints, polyurethane resin paints, acrylic resin paints, epoxy resin paints, aminoalkyd resin paints, and vinylidene fluoride resin paints are preferred because of their excellent weather resistance. Particularly, by incorporating an antioxidant and an ultraviolet absorber into the paint of the present invention, a paint with good weather resistance can be obtained, which is suitable.

(B) Metal layer Furthermore, representative examples of metals that are raw materials for the metal layer in the present invention include simple metals such as aluminum, iron, nickel, copper, and zinc, and alloys containing these metals as main components (for example, stainless steel, brass). These metals do not need to be surface-treated, and may be previously subjected to surface treatment such as chemical treatment or plating treatment. Furthermore, those that have been painted or printed can also be preferably used.

(C) Olefin polymer The olefin polymer used for producing the olefin polymer layer and the inorganic filler-containing olefin polymer layer in the present invention may be an ethylene homopolymer or a propylene homopolymer. Polymers, copolymers of ethylene and propylene, copolymers of ethylene and/or propylene with other α-olefins having at most 12 carbon atoms (copolymerization ratio of α-olefins is at most 20% by weight)
) can be given. The melt index of these olefin polymers (according to JIS K-7210,
Measured under conditions 4 in the table, hereinafter referred to as rMFR(1)J] or melt flow index (JIS K-72
10, measured under conditions 14 in Table 1, hereinafter referred to as "M
FR(2)J] is 0, Oi ~ 100g/10
min. is preferable, and 0.02 to 80 g/10 min. is particularly preferable. MFR(L) or MFR
If an olefin polymer having (2) less than o, oig/10 minutes is used, the resulting mixture will not have good moldability. On the other hand, if an olefin polymer exceeding 100 g/10 minutes is used, the mechanical properties of the resulting molded product will be poor. Sarani, low density Wt (0,900g/cei) Nai L
High density (0,980 g/ca) ethylene homopolymer or copolymer of ethylene with a small amount of the above α-olefins or propylene homopolymer or random or block of propylene with ethylene and/or other α-olefins Copolymers are preferred.

These olefinic polymers are obtained by using a catalyst system (so-called Ziegler catalyst) obtained from a transition metal compound and an organoaluminium compound, and by supporting a chromium-containing compound (e.g., chromium oxide) on a carrier (e.g., silica). catalyst systems (so-called Phillips catalysts) or radical initiators (e.g. organic peroxides)
It can also be obtained by homopolymerizing or copolymerizing olefins using.

Furthermore, in the present invention, modified polyolefins obtained by graft polymerizing compounds having at least one double bond (for example, unsaturated carboxylic acids, -base carboxylic acids, vinyl silane compounds) to these olefin polymers are also used. included.

The production methods for these olefin resins and modified polyolefins are well known.

These olefin polymers and modified polyolefins may be used alone or in combination of two or more. Furthermore, two or more of these olefin polymers and modified polyolefins may be used as a resin blend in any proportion.

The production methods for these olefin polymers and modified polyolefins are well known.

(D) Inorganic filler Furthermore, the inorganic filler used to produce the inorganic filler-containing olefin polymer layer is generally one widely used in the fields of synthetic resins and rubber. These inorganic fillers are preferably inorganic compounds that do not react with oxygen and water, and that do not decompose during crosstalk or molding. As the inorganic filler,
Metals such as aluminium, copper, iron, lead and nickel, oxides of these metals and metals such as magnesium, calcium, barium, zinc, zirconium, molybdenum, silicon, antimony, titanium, and their hydrates (hydroxides) It is broadly classified into compounds such as sulfates, carbonates, silicates, their double salts, and mixtures thereof. Typical examples of the inorganic filler include the metals mentioned above, aluminum oxide (alumina), its hydrate, calcium hydroxide, magnesium oxide (magnesia), magnesium hydroxide,
Lead oxides such as zinc oxide (zinc white), red lead and white lead, magnesium carbonate, calcium carbonate, basic magnesium carbonate, white carbon, asbestos, mica,
Talc, glass fiber, glass powder, glass peas, clay, diatomaceous earth, silica, wollastonite, iron oxide, antimony oxide, titanium oxide (titania), lithopone, pumice powder, aluminum sulfate (gypsum, etc.), zirconium silicate,
Examples include zirconium oxide, barium carbonate, dolomite, molybdenum disulfide and iron sand. Among these inorganic fillers, those in powder form preferably have a diameter of 1 mm or less (preferably 0.5 mm or less).

In the case of fibrous materials, the diameter is 1 to 500 m (preferably 1 to 300 tns) and the length is 0.1 to 611 m.
(Preferably one is 0.1 to 51). Furthermore, the diameter of the flat plate is 2mm or less (preferably 1m1m or less). (E) Structure of each layer (1) Coating layer The coating layer of the present invention prevents corrosion of the metal layer. It works to prevent From this, the thickness is 1m to 1m.
m, preferably from 10 m to 0.51 m, especially I
O- to 0.31 mm is preferred. If the thickness of this coating layer is less than 5 mm, not only will corrosion of the metal layer occur, but
There is a problem in that the metal layer may become exposed due to wear due to contact and friction with other articles during use. On the other hand, if it exceeds 5 angles, it is not preferable because it not only lowers the reflectance of radio waves but also increases the cost and weight of the laminate.

(2> Metal layer The metal layer of the present invention functions to reflect radio waves. The thickness of this metal layer is 5 μm to 1 mm, and 5 μm to 1 mm.
500- is desirable, and 10 to 500- is especially suitable. If the thickness of the metal layer is less than 5 Lffi, the metal layer is likely to wrinkle or fold during the production of a laminate, resulting in problems in terms of appearance and performance. On the other hand, 1m
If it exceeds m, not only will the weight increase, but also the cost will increase, and furthermore, it will cause problems when curving or bending the laminate.

(3) Olefin polymer layer The thickness of the olefin polymer layer of the present invention is 10 μm to 3 mm, preferably 15 μm to 3 μl, and particularly preferably 20 μm to 2.5 μl. If the thickness of the olefin polymer layer is less than 1O-, breakage will occur during the production of a laminate, making it impossible to obtain sufficient adhesion.

On the other hand, if the length exceeds 5m1m, not only the weight will increase, but also the cost will increase.

The olefin polymer layer mainly contains a polymer of the same type as the olefin polymer used in the inorganic filler-containing olefin polymer layer described below (usually at most 50% by weight).
That is.

It is usually obtained by forming the olefin polymer layer into a film or sheet. At this time, appropriate amounts of additives such as suitable antioxidants, pigments, etc. may be added.

(4) Inorganic filler-containing olefin polymer layer The composition ratio of the inorganic filler in the inorganic filler-containing olefin polymer layer of the present invention is 10 to 80% by weight (i.e., the composition of the olefin polymer The proportion is 90-20% by weight), 1
0 to 70% by weight is preferred, particularly 10 to 60% by weight. If the composition ratio of the inorganic filler in the inorganic filler-containing olefin polymer layer is less than 10% by weight, there is a problem that the resulting laminate lacks rigidity. on the other hand,
If it exceeds 80% by weight, it is difficult to produce a uniform composition, and even if a uniform composition is obtained, it will be difficult to produce a laminate by sheet production or injection molding as described below. It is not possible to obtain a good product (laminate).

The thickness of this inorganic filler-containing olefin polymer layer is 0.
5mm (500m) to 15n+, 1 to 10I
IIl is preferred, and 1 to 7 mm is particularly preferred.

If the thickness of the inorganic filler-containing olefin polymer layer is less than 0.5 mm, it is undesirable because it lacks rigidity and may be deformed or damaged by external force. On the other hand, if it exceeds 15mm,
It takes time to cool down during molding, and not only does it tend to generate whiskers on the surface, but it also increases the weight, which poses problems in use.

In producing the inorganic filler-containing olefinic polymer layer, stabilizers against oxygen, heat and ultraviolet rays, metal deterioration inhibitors, flame retardants, colorants, electrical Additives such as property improvers, antistatic agents, lubricants, processability improvers, and tackiness improvers may be added to the extent that they do not impair the properties of the inorganic filler-containing olefin polymer layer composition of the present invention. It's okay.

When producing the inorganic filler-containing olefin polymer of the present invention (including the case where the above additives are blended), triblending is performed using a mixer such as a Henschel mixer that is commonly used in each industry. It can also be obtained by melt-kneading using a mixer such as a Banbury mixer-kneader, a roll mill, or a screw extruder. At this time, a homogeneous composition can be obtained by tri-blending in advance and melt-kneading the resulting composition (mixture).

In particular, it is preferable to use the olefin polymer in the form of powder because it allows for more uniform mixing.

In this case, the mixture is generally melt-kneaded and then molded into a pellet-like material, which is then subjected to the molding described later.

In producing the inorganic filler-containing olefin polymer of the present invention, all the ingredients may be mixed at the same time, or a part of the ingredients may be mixed in advance to produce a so-called masterbatch. and the remaining ingredients may be mixed.

When melt-kneading is performed to produce the above-mentioned blend, it must be carried out at a temperature higher than the melting point or softening point of the olefinic polymer used; however, if carried out at high temperatures, the olefinic polymer will deteriorate. For these reasons, the temperature is generally 20°C higher than the melting point or softening point of each olefin polymer (preferably higher than 50°C), but it is carried out within a temperature range that does not cause deterioration. .

(F) Reflector for Circularly Polarized Antenna The reflector for circularly polarized antenna of the present invention will be explained below with reference to FIGS. 1 to 3. FIG. 1 is a partial perspective view of an antenna to which a reflector for a circularly polarized antenna is attached. FIG. 2 is a sectional view of the reflector for the circularly polarized antenna. Also, the third
The figure is a partially enlarged view of the sectional view. In FIG. 1, A is a reflector for a circularly polarized antenna of the present invention, B is a converter, C is a converter support rod, and D is a reflector support rod. Further, E is a wiring. Further, in FIGS. 2 and 3, 1 is an inorganic filler-containing olefin polymer layer, and 2 is a metal layer (metal foil). Moreover, 3 is a coating layer with good weather resistance. Additionally, 2a and 2b are primer layers (one or both may be absent). Furthermore, ■ is a laminate whose surface layer is a coating layer and the back side is a metal foil (metal layer), ■ is an olefin polymer layer containing an inorganic filler, and ■ is an olefin polymer layer. It is a combined layer.

As is clear from these drawings, the feature of the reflector for a circularly polarized antenna of the present invention is that it has a structure consisting of at least four layers. The reflector for a circularly polarized antenna of the present invention is composed of a metal layer having a coating layer and an inorganic filler-containing olefin polymer layer. Brimers can be used to strengthen the adhesion between each layer. Furthermore, in order to attach the reflector for a circularly polarized antenna of the present invention to a support, ribs may be provided to the inorganic filler-containing olefin polymer layer to enable attachment. You can also add a reinforcing lip to strengthen it. Furthermore, it is also possible to drill holes in the circularly polarized antenna support obtained by the present invention and attach various support attachment parts using bolts, nuts, etc. Further, the diameter of the reflector for the circularly polarized antenna is usually 20 aa to 120 cm.

(G) Method for manufacturing a reflector for a circularly polarized antenna There are various methods for manufacturing the reflector for a circularly polarized antenna of the present invention. A typical method is to apply paint to one side of the metal foil (metal layer) as described below, and apply paint to the other side (laminated metal foil) of the metal foil (laminated metal foil) that has the resulting paint layer. There is also a method in which an olefin polymer layer is interposed on the non-containing surface) and an inorganic filler-containing olefin polymer is injection molded as described below. When manufacturing laminated metal foil, the adhesion between the paint used and the metal foil (
If the adhesion is not sufficiently satisfactory, a primer (adhesive agent) may be applied and dried on one side of the metal foil in advance, and a paint may be applied to this primer layer. Furthermore, a film or sheet-like olefinic polymer layer is laminated on metal foil or metal foil coated with a primer, and then an inorganic filler-containing olefinic polymer is injection molded as described below, and the resulting molded metal is The paint may be applied to the foil surface without applying and drying the brusher, or after these treatments.

(1) Method of applying paint When using a paint that has excellent adhesion to the metal layer, it is sufficient to apply the paint directly to the metal foil. However, when using a paint whose adhesion to metal foil is not fully satisfactory, apply a brusher commonly used in the field of paint to one side of the metal foil in advance by gravure coating or perspective coating. and dry at 50-100°C. Then,
Apply paint to the primer side of the metal foil and let dry.

(2) Method for laminating olefin polymer layers The same type of olefin polymer used for the inorganic filler-containing olefin polymer used in injection molding described later is prepared by general film molding or sheet molding, and then It can be laminated by laminating a metal foil having a coating layer of . At this time, if the adhesion to the metal foil is not fully satisfactory, a brimer is applied and dried in the same manner as above. In addition, the application of the brimer and the application of the paint are not special methods, and may be performed by methods generally used in industry. Further, the type of brimer used varies depending on the type of paint and olefin polymer used, but it is commonly used in various fields, and there are aqueous type and solvent type. The types include vinyl, acrylic, polyamide, epoxy, rubber, urethane, and titanium.

(3) Manufacture by injection molding method The reflector plate for a circularly polarized antenna of the present invention is manufactured by an injection molding method. The manufacturing method is as follows: First, a highly weather-resistant paint layer is coated on one side of the foil as described above, and an olefin polymer layer is laminated on a metal layer that is not coated with a brimer as described above. Insert injection molding is performed during molding. At this time, an inorganic filler-containing olefinic polymer layer is obtained by injection molding. To carry out insert injection molding, the metal layer is inserted between the male molds of the injection molding machine so that the paint layer with excellent weather resistance is on the male mold side), Close the mold. After filling the mold with an inorganic filler-containing olefin polymer through the gate of the mold and cooling it,
By opening the mold, a desired reflector for a circularly polarized antenna can be manufactured. At this time, the injection molding temperature is such that the resin temperature is higher than the melting point of the inorganic filler-containing olefin polymer used, and lower than the thermal decomposition temperature of the olefin polymer. When a propylene polymer is used as the olefin polymer, insert injection molding is performed at 170 to 29
It is desirable to carry out in the temperature range of 0°C. On the other hand, when an ethylene polymer is used as the olefin polymer, insert injection molding is carried out at a temperature range of 120 to 250°C. Furthermore, if the injection pressure is 40 kg/cd or higher at the nozzle part of the cylinder of the injection molding machine, the inorganic filler-containing olefin polymer can be shaped into a shape almost similar to that of the mold. Not only
A product with good appearance can also be obtained. The injection pressure is generally 40 to 140 kg/cj, especially 70 kg/cj.
~120) cg/cd is desirable.

As mentioned above, the method of applying paint to the metal foil of the molded product manufactured by the injection molding method, which has not been coated with paint, does not require a special method, but the method of applying the paint using a spray gun, or the method of applying the paint with a brush. Although there are methods using a roll coater and the like, a method using a spray gun is industrially effective, and a method using a robot is particularly preferred.

[Examples and comparative examples]

Hereinafter, the present invention will be explained in more detail with reference to Examples.

In the Examples and Comparative Examples, the radio wave reflectance was measured as a micro reflection coefficient using a rectangular waveguide and a voltage standing wave ratio when the tip of the waveguide was short-circuited. In addition, the weather resistance test was conducted using a Sunshine Carbon Weather Meter, and the surface appearance after 2,000 hours (discoloration, fading, Adverse changes such as changes in gloss, crazing, blistering, peeling of metal foil, and cracks) were evaluated.

In addition, heat cycle tests test samples at 60°C for 2
After exposing for 4 hours, gradually cool to -40℃.
After exposing the sample to this temperature for 2 hours and then gradually heating it to 80° C. over 4 hours and repeating this cycle 100 times, the appearance of the surface of the sample was evaluated in the same manner as in the weather resistance test. In addition, the bending rigidity is ASTM D-790.
Measured according to.

The types and physical properties of the paints, olefin polymers, inorganic fillers, and metal foils constituting the coating layers used in Examples and Comparative Examples are shown below.

[(A) Paint] As the paint, a two-component fluororesin [manufactured by Dainippon Toyo Co., Ltd., trade name: V-Flon, hereinafter referred to as "F paint"] and a two-component polyurethane resin [manufactured by NOF Co., Ltd., trade name] High urethane (hereinafter referred to as "U paint") was used.

[(B> Olefin polymer) As an olefin polymer, MFR (2) is 0.7 t/
Propylene-ethylene block copolymer [
High-density ethylene homopolymer (density 0.981 g/-1 or less r
HDPEJ] was used.

[(C) Inorganic filler - Inorganic fillers include talc with an average particle size of 3- [aspect ratio about 7], mica with an average particle size of 3- [aspect ratio about 8], glass fiber [single fiber] Diameter 11
-, cut length 3 mm, hereinafter referred to as rGFJ], and an average particle size of 0.8-
C03J] was used.

[(D) Metallic foil] Aluminum foil each having a thickness of about 20 mm [hereinafter referred to as r
AII J], copper, brass and silver foil were used.

Examples 1 to 11, Comparative Examples 1 to 3 An epoxy resin primer (manufactured by Dainippon Toyo Co., Ltd., trade name: V Freon Primer) was applied to one side of the metal foil whose type is shown in Table 1. It was coated in such a manner that the coating was 20- and dried. Paints whose types are shown in Table 1 (U paint in Example 6, Film materials in others) were applied to the primer-coated surface of the obtained metal foil so that the dry thickness was 30. -Leave it alone day and night. A urethane primer (manufactured by Toyo Morton Co., Ltd., trade name: Atocoat 335) was applied to the other side of the metal foil having the coating layer thus obtained, so that the dry thickness was 15#.
Dry.

Also,'! Table J1 lists each type or its composition (
A composition consisting of 80 parts by weight of PP and 40 parts by weight of mica (hereinafter referred to as "composition (^)") and a composition consisting of 80 parts by weight of PP and 40 parts by weight of talc (hereinafter referred to as "composition (B)") A film with a thickness of 150 mm was produced using a film forming machine.

Said painting! ! Urethane primer (manufactured by Toyo Morton Co., Ltd., product name Atcoat 900) on the back side of the metal foil
was applied at a rate of 15 g/rrf (dry), and the produced films were laminated to obtain a multilayer foil by a dry lamination method.

The laminated metal foil produced as described above was inserted into an injection molding machine (mold clamping pressure: 850 tons) so that the coating layer side was the movable surface of the mold. After closing the mold,
Products were manufactured using the compositions shown in Table 1 under conditions of an injection pressure of 80 kg/cd and a resin temperature of 270°C. The shape of the obtained product was a bowl-like object (outer diameter: 500 mm, height: 50 nm) as shown in FIG.

Furthermore, an inorganic filler and an olefin polymer (the types of each inorganic filler and olefin polymer and the content of the inorganic filler in the composition are shown in Table 1. In Comparative Example 2, the inorganic filler 5 each (without any agent)
Tri-blending was performed using a Henschel mixer for a minute, and each mixture was used to produce a composition using a vented extruder at a resin temperature of 280°C.

The flexural modulus of the inorganic filler-containing olefin polymer layer and the peel strength between the olefin polymer layer and the metal foil of each circularly polarized antenna reflector obtained as described above were measured. The results are shown in Table 2.

In addition, for the tensile test, the reflector was cut into 15n width pieces, and the interface between the inorganic filler-containing olefin polymer layer and the metal layer having a coating layer with excellent weather resistance was measured using a 90 degree peeling method. The results are shown in Table 2.

When the radio wave reflectance of each of the circularly polarized antenna reflectors obtained as described above was measured, it was 98%. Furthermore, weather resistance tests and heat cycle tests were conducted, but with the exception of Comparative Examples 1 and 3, no harmful changes such as discoloration, fading, changes in gloss, crazing, blistering, peeling of metal foil, or cracks were observed on the surface. could not. However, in Comparative Example 1, the aluminum foil on the surface corroded.

Furthermore, in Comparative Example 2, the radio wave reflectance decreased significantly.

Moreover, in Comparative Example 3, blistering occurred on the surface and the aluminum foil peeled off.

〔Effect of the invention〕

The circularly polarized antenna reflector of the present invention exhibits the following effects (features) including its manufacturing process.

(1) Due to its excellent corrosion resistance, there is no change in radio wave reflection characteristics over a long period of time.

(2) Since the coefficient of linear expansion of the metal layer and the inorganic filler-containing olefin polymer layer is extremely small, peeling between the layers will not occur even if subjected to heat cycles (repetition of cold and heat) for a long period of time.

(3) The reflector for a circularly polarized antenna is lightweight and the manufacturing process is simple.

(4) The metal layer can be formed uniformly,
There is no uneven reflection of radio waves.

(5) Olefinic polymers containing inorganic fillers can be easily formed into various complex shapes, and therefore have good appearance and functionality.

(6) The mechanical strength (especially rigidity) of the circularly polarized antenna reflector is excellent.

(7) It is lightweight.

(8) Since a layer of an olefin polymer of the same type as the inorganic filler-containing olefin polymer or a composition thereof is interposed at the interface between the metal layer and the inorganic filler-containing olefin polymer layer, the peel strength between the layers is increased. improves.

[Brief explanation of drawings]

FIG. 1 is a partial perspective view of an antenna to which a typical reflector for a circularly polarized antenna manufactured according to the present invention is attached. Moreover, FIG. 2 is a sectional view of the reflector for the circularly polarized antenna. Furthermore, FIG. 3 is a partially enlarged view of the cross-sectional view. A...Reflector for circularly polarized antenna B...Converter C...Converter support rod D...Reflector support rod E
... Wiring 1 ... Inorganic filler-containing olefin polymer layer 2 ...
Metal layer (metal foil) 3... Coating layer with excellent weather resistance 2a... Brimer layer 2b... Brimer layer ■... Metal foil coated with paint ■... Inorganic filler-containing olefin System polymer layer...
Thick cylindrical part

Claims (1)

[Claims] At least a metal layer is provided between the surface layer, which is a coating layer with excellent weather resistance, and the back structure, which is an olefin polymer layer containing an inorganic filler, and the metal layer and the inorganic filler-containing olefin polymer layer are A layer mainly composed of an olefin polymer of the same type as the inorganic filler-containing olefin polymer is interposed between the combined layer and the coating layer has a thickness of 5 μm to 1 m.
m, the thickness of the metal layer is 5 μm to 1 mm,
The thickness of the layer mainly composed of olefin polymer is 10 μm
and 3 mm, and the thickness of the inorganic filler-containing olefin polymer layer is 0.5 to 15 mm, and the content of the inorganic filler in the inorganic filler-containing olefin polymer layer is 10 to 80 mm by weight. %.A reflector for a circularly polarized antenna.