JPS60203005A - Production of reflector plate for circular polarized wave antenna - Google Patents

Abstract

PURPOSE:To improve greatly the adhesion properties between a metallic foil and an olefinic polymer layer containing an inorganic filler, by injection molding said olefinic polymer to a metallic foil containing an olefinic polymer layer. CONSTITUTION:A thermoplastic resin layer A having excellent weather resistance is laminated on a single side of a metallic foil B with an olefinic polymer layer C laminated on the other side of the foil B respectively. Such a foil B is attached to the suface of a metallic mold at the shift side of a metallic mold for injection molding. Then a metallic mold is closed and an olefinic polymer containing an inorganic filler is injection molded to obtain a reflector plate for circular polarized wave antenna. In this case, the molding with insertion is carried out so that the layer C of the foil B is turned toward the metallic mold at the fixed side. Thus the adhesion properties can be greatly improved between the foil B and an olefinic polymer layer D containing an inorganic filler.

Description

[Detailed Description of the Invention] [I] Purpose of the Invention The present invention consists of a coating layer with excellent weather resistance, a metal foil that reflects radio waves, and an olefinic polymer layer containing an inorganic filler that functions as a structure. The present invention relates to a method of manufacturing a reflector for a circularly polarized antenna made of a laminate. More specifically,
Using a metal foil laminated with a coating layer with excellent weather resistance on one side and an olefin polymer layer on the other side, the laminated metal foil is attached to the moving side mold surface of an injection mold. This is a method of manufacturing a reflector for a circularly polarized antenna by injection molding an olefin polymer containing an inorganic filler after closing the mold, and the olefin polymer layer of the laminated metal foil is on the fixed side. This relates to a method for manufacturing a reflector plate for a circularly polarized antenna, which is characterized by insert molding in a way that the plate faces the mold, and includes an olefin polymer containing an inorganic filler that functions as a metal foil and a structure. The object of the present invention is to provide a reflector for a circularly polarized antenna, which has significantly improved adhesion to the layers.

[II] Background of the Invention Satellite broadcasting using geostationary satellites is planned to be put into practical use in Europe, America, Japan, and other countries around the world 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 the cross-polarization identification of the satellite broadcasting antenna. In this way, when receiving terrestrial broadcast waves, the radio waves are made horizontally or i-vertically linearly polarized, and the polarization plane of the receiving antenna is adjusted to the polarization plane of the broadcast waves to achieve cross-polarization discrimination. It's not that difficult to use, but
When receiving radio waves from a broadcasting satellite, the plane of polarization may shift due to disturbances such as the ionosphere in the radio wave propagation path and the angle of incidence of the radio wave at the receiving point, so it is not possible to align the planes of polarization as described above. Have difficulty.

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 for ordinary listeners to identify them by the direction of the circularly polarized wave, regardless of the deviation of the polarization plane as described above. The receiving antenna not only adjusts its pointing direction to point to the desired broadcasting satellite, but also does not require adjustment of the plane of polarization, making it much easier to adjust the receiving antenna than when linearly polarized waves are used. 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. In contrast, conventional circularly polarized antennas include those that use a conical horn, those that combine two dipoles at right angles, and parabolic antennas that use these antennas as primary radiators. The structure is complex and large, and manufacturing costs are high, so it is not suitable for general audience receiving antennas for receiving satellite broadcast radio waves using microwaves in the 12 gigahertz (G&) 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 a parabolic shape. There is a so-called Hehat-type parabolic ann which is opposed to a parabolic reflector at the focal position and is used 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.

[m1 From the structure of the invention, the present inventors have obtained a reflector for a circularly polarized antenna that has a simple manufacturing process, has radio wave reflecting ability, and can maintain its performance for a long period of time. As a result of various investigations, we found that we used a metal foil laminated with a coating layer with excellent weather resistance on one side and an olefin polymer layer on the other side, and placed the laminated metal foil in an injection mold. This is a method of manufacturing a reflector plate for a circularly polarized antenna by attaching it to the moving side mold surface and closing the mold, and then injection molding an olefin polymer containing an inorganic filler. The manufacturing method for circularly polarized antenna reflectors, which is characterized by insert molding with the polymer layer facing the stationary mold, not only has good durability but also has excellent radio wave reflection properties. The inventors have discovered that it is possible to manufacture a reflector for a circularly polarized antenna, and have arrived at the present invention.

[■ Effects of the Invention The reflector for circularly polarized antenna manufactured by the present invention exhibits the following effects (features) including its manufacturing process.

(1) Since it has excellent IFFL 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 foil and the inorganic filler-containing olefin polymer layer is extremely small, no peeling occurs between the layers 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) It is possible to form the metal foil 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.

(8) Since the olefin polymer layer is interposed between the inorganic filler-containing olefin polymer layer and the metal foil, which functions as a structure, the inorganic filler-containing olefin polymer layer and the metal foil are Adhesion has been greatly improved, and even if you try to separate the inorganic filler-containing olefin polymer layer from the metal foil, by selecting a primer for the metal foil and the olefin polymer layer, the metal foil will not peel off. It should be able to exhibit enough adhesive strength to cut.

(7) Contains an inorganic filler that functions as a structure because the olefin polymer layer on which the metal foil is laminated and the olefin polymer layer containing an inorganic filler are partially mixed during injection molding. It does not adversely affect the mechanical strength such as rigidity of the olefin polymer layer.

(8) The laminated metal foil is easy to handle;
For example, it is possible to store it in a roll.

(8) When setting the laminated metal foil in the mold at the time of 14-molding, the laminated metal foil can be used in a roll, so it can be continuously supplied, reducing production. Sex is large 1111. Improve to i.

[V] Detailed description of the entire invention (A) Material The paint used to produce the metal layer having a coating layer with good weather resistance of the present invention is widely produced industrially and is widely used as a paint for metals. It is used in many areas. 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, polyurethane resin paints obtained by reacting polyester polyols, polyether polyols, or polyurethane polyols with diisocyanates, aminoalkyd resin paints, Acrylic resin paint, melamine resin paint, cyanoacrylate resin paint, epoxy resin paint, silicone resin paint, organic titanate paint, vinyl chloride resin paint, acrylic urethane resin paint, amide resin paint, and fluoride resin paint Examples include fluorine-containing resin paints such as vinylidene resin. Furthermore, these paints contain matting agents such as silicic acid, coloring agents such as pigments and dyes,
Additives such as antioxidants and ultraviolet absorbers can be mixed and used. 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, typical 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). Examples include steel, painting style). 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 on which the metal foil is laminated in the present invention is an ethylene homopolymer. a homopolymer of propylene, a copolymer of ethylene and propylene, ethylene and/or propylene and another α having at most 12 carbon atoms;
- Copolymers with olefins (copolymerization ratio of α-olefins is at most 20% by weight). The melt index (JISK-87
Measured at a temperature of 190°C and a load of 2°18kg according to EiO (hereinafter referred to as "ni, 2.16kg
Measured under the conditions of 0. O1～
100g/10 minutes is preferable, especially 0.02~
80 g/10 minutes is preferred. M, 1. t
If an olefin polymer having an MFI of less than 0.01 g/10 minutes is used, the resulting mixture will not have good moldability. - If an olefin polymer with a force exceeding 100 g/10 minutes is used, the mechanical properties of the resulting molded product will be poor. Furthermore, low density (0,900 g/cm') to high density (0,880 g/cm') ethylene homopolymer, copolymer of ethylene and a small amount of the above α-olefin, propylene homopolymer, or Random or block copolymers of propylene and ethylene and/or other alpha-olefins 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 a compound having at least one double bond (for example, an unsaturated carboxylic acid, a base carboxylic acid, a vinyl silane compound) 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 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 do not decompose during kneading and molding. The inorganic fillers include metals such as aluminium, copper, iron, lead and nitrogen, these metals and magnesium, calcium, 15
Compounds such as oxides of metals such as lithium, zinc, zirconium, molybdenum, silicon, antimony, and titanium, their hydrates (hydroxides), sulfates, carbonates, and silicates,
It is broadly classified into these 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, zinc oxide (zinc oxide), lead oxides such as 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, zirconium oxide, carbonate These include barium, dolomite, molybdenum disulfide and iron sand. Among these inorganic fillers, those in powder form preferably have a diameter of lam or less (preferably 0.5 mm or less). In addition, in the case of an am-shaped one, the diameter is 1 to 500 microns (preferably 1 to 3 microns).
00 microns) and the length is 0.1 to f3m+o
(preferably 0.1 to 5+im) (7) is desirable. Furthermore, the diameter of the flat plate is 2 mm or less (preferably lam or less). (E) Structure of each layer (1) Coating layer The coating layer of the present invention prevents corrosion of the metal layer. It is something that does the work of From this, the thickness is between 5 microns and 1 mm, preferably between 10 microns and 0.5 am, particularly preferably between 10 microns and 0.3 mm. If the thickness of this coating layer is less than 5 microns, not only will the metal layer corrode, but it will also wear out and become exposed due to contact and friction with other items during use. There is a problem that occurs. On the other hand, if it exceeds 5 mm, 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 (metal foil) Furthermore, the metal layer (metal foil) of the present invention serves to reflect radio waves. The thickness of this metal layer is between 5 microns and 1III1, preferably between 5 and 500 microns, especially between 10 and 500 microns. If the thickness of the metal layer is less than 5 microns, 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, III
If it exceeds this, not only will the weight increase, but also the cost will increase, and furthermore, it will cause problems when bending or bending the laminate.

(3) Olefin polymer layer The olefin polymer layer constituting the laminated metal foil in the present invention is an adhesive between the metal foil serving as a radio wave reflecting layer and the inorganic filler-containing olefin polymer layer functioning as a structure. This function not only improves the properties of the laminated metal foil but also facilitates storage and handling of the laminated metal foil. The thickness of this olefinic polymer layer is usually 5 to 5 microns.
00 microns, preferably 5 to 300 microns,
Particularly preferred is 5 to 200 microns. If the thickness of the olefin polymer layer is less than 5 microns, the olefin polymer tends to wrinkle when producing laminated metal foil, which affects the surface of the metal foil, resulting in poor appearance and performance. There is a problem above. On the other hand, 500
If it exceeds microns, it becomes a problem because the mechanical properties such as strength and rigidity of the inorganic filler-containing olefin polymer layer deteriorate.

(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 80-20% 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, the linear expansion coefficient of the inorganic filler-containing olefin polymer layer will be too different from that of the metal foil, resulting in heat cycle failure. Therefore, there is a problem that not only peeling may occur between the metal foil and the inorganic filler-containing olefin polymer layer, but also 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 is difficult to produce a laminate by sheet production or injection molding as described below. In this case, it is not possible to obtain a good product (laminate).

The thickness of this inorganic filler-containing olefin polymer layer is 50
0 micron to 15m11. With tea, 1-10ml1
1 is desirable, and 1 to 7 mm is particularly preferred. If the thickness of the inorganic filler-containing olefin polymer layer is less than 500 microns, it is undesirable because it lacks rigidity and is easily deformed and damaged by external forces. On the other hand, if it exceeds 15 mm, it will take time to cool down during molding, and not only will sink marks be more likely to occur on the surface, but the weight will increase, causing problems in use.

In producing the olefin polymer layer and the inorganic filler-containing olefin polymer layer, stabilizers against oxygen, heat and ultraviolet rays, metal deterioration Vj Ih agents, and flame retardants commonly used in the field of olefin polymers are used. Additives such as coloring agents, colorants, electrical property improvers, antistatic agents, lubricants, processability improvers, and tack improvers are added to the olefin polymer layer of the present invention and the inorganic filler-containing olefin polymer layer. They may be added as long as they do not impair the properties of the composition.

When blending the above-mentioned additives into the olefin-based polymer of the present invention and when producing an olefin-based polymer containing inorganic fillers (including cases where the above-mentioned additives are blended), The mixture may be triblended using a mixer such as a Henschel mixer, which is commonly used, or may be obtained by melt-kneading using a mixer such as a Banbury mixer, Nigu, roll mill, or screw extruder. At this time, the composition (mixture) obtained by tri-blending in advance
A homogeneous composition can be obtained by melt-kneading.

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 of 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 master patch, which is then obtained. 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, it is generally 20% lower than the melting point or softening point of the olefin polymer.
It is carried out at temperatures higher than 50°C (preferably above 50°C), but in a temperature range that does not cause deterioration.

(F) Method for manufacturing laminated metal foil The laminated metal foil used to manufacture the reflector for a circularly polarized antenna of the present invention can be manufactured by a so-called dry lamination method. Ir and its manufacturing method will be explained in detail.

In producing this laminated metal foil, one side of the metal foil is coated with a film of an olefinic polymer, such as a modified polyolefin grafted with an unsaturated carboxylic acid or its anhydride, which has adhesion to the metal. If you use a film with excellent properties, you can laminate it directly as described below, but if you are using an olefin polymer film that has poor adhesion to metal foil, it is necessary to apply a primer and dry it in advance as described below. After this, a film of the olefin polymer may be laminated on the primer-coated surface. On the other hand, for the other side of the metal foil, an inorganic filler-containing olefin polymer is injection molded onto the laminated metal foil as described below, and then a coating is applied to the molded metal foil as described below. It's okay. Alternatively, a laminated metal foil may be manufactured by applying a roughening paint to this surface. In this case, if the paint used has good adhesion to the metal foil, it may be applied directly to the metal foil, but if the paint has poor adhesion, it may be necessary to apply a primer to the metal foil in advance as described below. The paint may be applied to this coated surface using a gravure coating method.

The method of applying the primer is by gravure coating or eight-coating method, and then
It may be dried at 100'0. Also.

The olefin polymer film may be laminated using a pressure roll heated to 50 to 100°C.

There are water-based and solvent-based primers, including vinyl, acrylic, polyamide, epoxy, rubber, and urethane primers. ) will be explained using Figure @1. This 1st M is a partially enlarged sectional view of the laminated metal foil. In this drawing, A is a coating layer with excellent weather resistance, and B is a metal layer (metal foil).

Further, C is an olefin polymer layer. Furthermore, a and b are primers, and -c. , A does not exist).

(G) Manufacture of reflector for circularly polarized antenna A coating layer of laminated metal foil obtained as described above (metal foil when using one without coating)
is attached to the moving mold surface of the injection molding machine so that the olefin polymer layer becomes the fixed mold surface, and the mold is closed. Next, the reflection plate for a circularly polarized antenna of the present invention can be manufactured by injection molding the inorganic filler-containing olefin polymer. 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, but lower than the thermal decomposition temperature of the olefin polymer. When using a propylene polymer as the olefin polymer, insert injection molding is performed at 170 to 280°C.
It is desirable to carry out the test in a temperature range of On the other hand, when using an ethylene polymer as the olefin polymer,
Insert injection molding is carried out at a temperature range of 120-250°C. In addition, if the injection pressure is 40 kg/cm' or more at the gauge pressure 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 that, but also a product with good appearance can be obtained.

The injection pressure is generally 40 to 140 kg/crn', preferably TO to 120 kg/c In'.

There is no special method for applying paint to the metal foil of a molded product that has not been coated with paint or paint and primer. There are methods using a roll coater, etc., but industrially, a method using a spray gun is more efficient.
In particular, a method of applying using a robot is preferred.

(H) Reflector for Circularly Polarized Antenna The reflector for circularly polarized antenna of the present invention obtained as described above will be explained below with reference to FIGS. 2 and 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. Moreover, FIG. 3 is a partially enlarged view of the cross-sectional view. In FIG. 1, I is a reflector for a circularly polarized antenna of the present invention, 11 (i converter), ■ is a converter support rod, ■ is a reflector support rod, and ■ is a reflector support rod. In addition, in Figures 3 and 4, A is a thermoplastic resin layer with excellent weather resistance, B is a metal foil, C is an olefin polymer layer, and D is a It is an olefinic polymer layer containing an inorganic filler.Furthermore, a and b are single layers of primer, but one or both may be absent.Furthermore, the reflector for a circularly polarized antenna obtained in this way is Ribs may be attached to the inorganic filler-containing olefin polymer layer so that it can be attached to the support, and reinforcing ribs may also be attached to reinforce the reflector. Further, 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 80 cm to 120 cm+.

[VI] Examples and Comparative Examples The present invention will be explained in more detail with reference to Examples below.

In the Examples and Comparative Examples, the radio wave reflectance was measured as a microwave reflection coefficient based on the voltage standing wave ratio when a rectangular waveguide was used and the tip of the waveguide was short-circuited. Weather resistance tests were conducted using a Sunshine Carbon Weather Meter under the conditions of a black panel temperature of 83°C and a due cycle of 12 minutes/(60 minutes of irradiation).
The appearance of the surface after a period of time (adverse changes such as discoloration, fading, gloss, crazing, blistering, peeling of metal foil, cracking, etc.) was evaluated. Furthermore, the heat cycle test tested the sample at 80%
°C for 2 hours, then gradually cooled to -45°C over 4 hours, exposed to this temperature for 2 hours, then gradually heated to 80°C over 4 hours, repeating this cycle for 10
After conducting the test 0 times, the appearance of the surface of the sample was evaluated in the same manner as in the weather resistance test. Peel strength was measured by cutting a test piece with a width of 15 mm from a manufactured reflector for a circularly polarized antenna, and laminating a metal foil with a laminated metal foil at a peeling speed of 50 a+m/min in accordance with ASTM D-903.
The strength was evaluated when peeled at 0 degrees. In this column of Table 1, "cohesive failure" refers to the fact that the adhesive strength between the laminated metal foil and the inorganic filler-containing olefin polymer layer is too strong, causing the metal foil to break. Additionally, bending stiffness was measured according to ASTM D-7flO, and coefficient of thermal expansion was measured according to ASTM D-8138.

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

[(A) Paint] Two-component fluororesin (manufactured by Dainippon Toyo Co., Ltd., product name: V-Flon, hereinafter referred to as "F paint") and two-component polyurethane resin (manufactured by Nippon Oil Co., Ltd., product name: Hi-Flyon) were used as paints. Urethane (hereinafter referred to as "U paint") was used.

[(B) Olefin polymer As a coolefin polymer, MFI is 2.0 g/10
Propylene homopolymer [hereinafter referred to as rPP(B) J
1. Propylene-ethylene block copolymer with MFI of 15 g/10 minutes [ethylene content 15% by weight, hereinafter referred to as rPP(C)J], 11
．． High-density ethylene homopolymer with a density of 0.8 g/10 min [density 0.950 g/crn', hereinafter rHDP
E(2) J] and M, I.

Highly enriched ethylene homopolymer [density 0.961 g/cm'', hereinafter r)l[]PE(3
) I used J.

[(C) Inorganic filler] As the inorganic filler, talc with an average particle size of 3 microns (aspect ratio of about 7), mica with an average particle size of 3 microns (aspect ratio of about 8), glass fiber (single fiber) Diameter: 11 microns, cut length: 3mm, hereinafter referred to as rG
F'') and calcium carbonate (hereinafter referred to as rCaCO5J) having an average particle size of 0.8 microns were used.

[(D) Metal foil] Aluminum foil each having a thickness of about 20 microns (
(hereinafter referred to as "A pattern"), copper, brass, and silver foil were used.

Example 1-11, Comparative Examples 1-3 An epoxy resin primer (manufactured by Dainippon Toyo Co., Ltd., trade name: V-Fron Primer) was applied to one side of the metal foil whose type is shown in Table 3. It was coated to a thickness of 20 microns and dried.

Paints whose types are shown in Table 1 (U paint for Example 6, F paint for the others) were applied to the primer-coated surface of the obtained metal foil so that the dry thickness was 30 microns.
-Leave it alone day and night.

The PP (B) and HDPE (2) were molded to produce films each having a thickness of 50 microns. In addition, a urethane primer (manufactured by Toyo Morton Co., Ltd., trade name Atcoat 335) was applied to the other side of each metal foil to a thickness of 2.
It was coated to a thickness of 0 microns and dried (in Examples and , the urethane primer was coated on both sides). The metal foil and olefin polymer film (not used in the comparative example), on which the paint thus produced was applied on one side and the primer was applied on the other side, were adhered by dry lamination. A laminated metal foil was produced by this process.

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 230°C.

The thus produced laminated metal foil was inserted into a mold of an injection molding machine (clamping force: 1500 tons) so that the moving side mold surface (the olefin polymer layer was the fixed mold surface). After closing the mold, the injection pressure is 130kg/cm
' and a resin temperature of 240°C, insert the composition in which the type of olefin polymer and inorganic filler and the content of the inorganic filler in the composition are shown in Table 1. Injection molding was performed to produce a reflector for a circularly polarized antenna having the same shape as in Example 1.

The elastic modulus and linear expansion coefficient of the inorganic filler-containing olefin polymer layer of each circularly polarized antenna reflector obtained as described above, and the peel strength of the metal foil from the inorganic filler-containing olefin polymer layer. Measurements were made. The results are shown in Table 1.

(The following is a blank space) When the radio wave reflectance of each circularly polarized antenna reflector obtained as described above was measured, it was 98% in all cases. Furthermore, we conducted a weather resistance test and a heat cycle test, but no harmful changes such as discoloration, fading, change in gloss, crazing, blistering, peeling of metal foil, or cracks were observed on the surface of all cases except for Comparative Example 1. Ta. However, in Comparative Example 1, the aluminum foil on the surface corroded.

[Brief explanation of the drawing]

FIG. 1 is a partially enlarged sectional view of a laminated metal foil. Furthermore, FIG. 2 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. 3 is a sectional view of the reflector for the circularly polarized antenna. Furthermore, FIG. 4 is a partially enlarged view of the sectional view. A... Thermoplastic resin layer with excellent weather resistance, B... Metal layer (metal foil), C... Olefin polymer layer, a.
... One layer of primer, b... One layer of primer, D... Inorganic filler-containing olefin polymer layer, D... Reflector for circularly polarized antenna, II... Converter, ■... Converter support Rod, ■...Reflector support rod, ■...Wiring, Patent applicant Showa Denko Co., Ltd. Representative Patent attorney Sei Kikuchi

Claims (1)

[Claims] Using a metal foil laminated with a coating layer with excellent weather resistance on one side and an olefin polymer layer on the other side, the laminated metal foil is attached to the moving side mold surface of an injection mold. This is a method of manufacturing a reflector for a circularly polarized antenna by injection molding an olefin polymer containing an inorganic filler after closing the mold, and the olefin polymer layer of the laminated metal foil is on the fixed side. A method for manufacturing a reflector for a circularly polarized antenna, which is characterized by insert-molding the reflector by attaching it so as to face a mold.