JPS60235505A - Reflecting plate for circularly polarized wave antenna - Google Patents

Abstract

PURPOSE:To keep the radio wave reflecting characteristic for a long period and to eliminate exfoliation among layers by constituting the reflecting plate with the lamination of a metallic layer having a high weather resistant coating film layer, an olefinic polymer layer contg. an inorganic filler, and a denatured olefinic polymer layer and specifying the thickness of each layer and the content of the inorganic filler. CONSTITUTION:The reflecting late is constitued with the lamination of the metallic layer 2 having the excellent weather resistant coating film layer 3, the olefinic polymer layer 1 contg. the inorganic filler and a denatured olefinic polymer layer 5 obtained by denaturing the olefinic polymer with an unsaturated carboxylic acid and/or its anhydride between the layers 1 and 2, the thickness of the layers 3, 2, 1, 5 is respectively 5mu-5mm., 5mu-1mm., 0.5-15mm. and 10-500mu. The content of the inorganic filler is 10-80wt%. Further, primer layers are used. As the olefinic polymer, an ethylene or propylene homopolymer is used. The inorganic filler is a conventional filler used in the field of synthetic resin. As a typical example of the unsaturated carboxylic acid or its anhydride, a monobasic carboxylic acid having at most a carbon number of 10 and at least a double bond.

Description

Detailed Description of the Invention [NObjective of the Invention The present invention provides an intermediate layer having a metal layer serving as a radio wave reflecting layer, and between the metal layer having a coating layer and an olefinic polymer layer containing a mechanical filler. The present invention relates to a reflector for a circularly polarized antenna comprising a modified olefin polymer layer interposed therebetween. More specifically, an olefinic polymer is interposed between (A) a metal layer having a coating layer with excellent weatherability and (B) an inorganic filler-containing olefinic polymer layer. It is composed of a laminate obtained by interposing a modified olefin polymer layer obtained by modification with an anhydride, and the thickness of the coating layer with excellent weather resistance is 5 microns to 5 IIlfl. , the thickness of the metal layer is 5 microns to 1 mm, and the thickness of the inorganic filler-containing olefinic polymer layer is 0.5 m.
This invention relates to a reflector for a circularly polarized antenna, characterized in that the thickness of the modified olefin polymer layer is 10 to 500 microns. It is an object of the present invention to provide a simple reflector for a circularly polarized antenna, which has excellent adhesion between a metal layer serving as a reflective layer and the two types of olefin polymer layers described above.

[II] Background of the Invention Satellite broadcasting such as high-definition television broadcasting, still image broadcasting, text multiplex broadcasting, PCM (pulse code modulation) audio broadcasting, and facsimile broadcasting using geostationary satellites is widely used in countries around the world such as Europe, America, and Japan. Its practical application is planned 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 waves, the radio waves are linearly polarized horizontally or vertically, and the polarization plane of the receiving antenna is matched to the polarization plane of the broadcast waves, using cross-polarization discrimination. However, when receiving radio waves from broadcasting satellites, deviations in the plane of polarization occur 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 the planes of polarization as described above.

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 blindly combine two Goupoles, and parabolic antennas that use these antennas as the primary radiator. Since the structure is complex and large, and manufacturing costs are high, it is not suitable for general listening and beach reception 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 Heehat-type parabolic antenna that faces a parabolic reflector at its focal point 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 a radio wave reflecting plate in which a thermosetting resin such as an unsaturated polyester resin is laminated with glass mm whose surface is metalized as a radio wave reflecting layer, 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, the present inventors have conducted various searches to obtain a reflector for circularly polarized antennas that has a simple manufacturing process, has radio wave reflecting ability, and can maintain its performance for a long period of time. , at least (A) a coating layer with good weather resistance, (B) a metal layer, and (G) an inorganic filler-containing olefinic polymer layer are laminated in sequence, and the circularly polarized antenna reflector is durable. We discovered that not only is it good, but also has excellent radio wave reflection characteristics, and we proposed it previously (
(See Japanese Patent Application No. 59-8538). However, the adhesion between the thermoplastic resin layer and the metal layer and between the inorganic filler-containing olefin polymer layer and the metal layer is not always sufficient. For this reason, the adhesion is solved by interposing a primer between the thermoplastic resin layer and the metal layer, and between the metal layer and the inorganic filler-containing olefin polymer layer. However, interposing a primer not only requires time to apply and dry the primer, but also involves applying and drying the primer to the metal foil, and adhering a pre-prepared thermoplastic resin film or sheet to the coated surface. However, it is necessary to go through several steps in the manufacturing process, such as applying a primer to other surfaces and drying, which makes the manufacturing process complicated.

[II[] Background of the Invention Based on the above, the present inventors have discovered that not only the above-mentioned excellent effects are exhibited, but also the adhesion between the metal layer and the olefin polymer layer is good; As a result of various searches for obtaining a reflector for a circularly polarized antenna using a simple manufacturing process, we found that at least (A) a metal layer having a coating layer with good weatherability and (B) an olefin-based reflector containing an inorganic filler. It is composed of a laminate obtained by interposing a modified olefin polymer layer obtained by modifying an olefin polymer with an unsaturated carboxylic acid and/or its anhydride between the polymer layer, and The thickness of the coating layer with excellent weather resistance is 5 to 5 microns.
mn+, and the thickness of the metal layer is 5 microns to 1 mm.
and the thickness of the inorganic filler-containing olefin polymer layer is 0.5 mm to 15 mm, and the thickness of the modified olefin polymer layer is 10 to 500 microns. The reflector for use in commercial use not only has good durability, but also has excellent radio wave reflection properties, and also has good adhesion between the metal layer and the olefin polymer.
The present invention was achieved by discovering that it can be easily obtained.

['lV] Effects of the Invention The reflector for a circularly polarized antenna of the present invention exhibits the following effects (features) including its manufacturing process.

(1) Since it has 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.

The adhesion between the metal layer and the inorganic filler-containing olefin polymer layer is excellent, and since no primer is required, complicated steps such as primer application and drying can be omitted.

[V] Detailed Description of the Invention (A) Paint The paint used to manufacture the metal layer that supports the coating 1IiJ 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 ways. 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 of these paints are:
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 paints, melamine resin paints, cyano Acrylate resin paint, epoxy resin paint, silicone resin paint, organic titanate paint,
Vinyl chloride resin paint, acrylic urethane resin paint,
Examples include amide resin-based paints and fluorine-containing resin-based paints such as 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 Furthermore, typical examples of metals that are raw materials for the metal layer in the present invention include metal carriers 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 to produce the inorganic filler-containing olefin polymer layer and the modified olefin polymer in the present invention is an ethylene homopolymer or a propylene homopolymer! copolymers of ethylene and propylene; copolymers of ethylene and/or propylene with other α-olefins having at most 12 carbon atoms (
The copolymerization ratio of α-olefin is 20% by weight at most. The melt index of these olefin polymers (according to JIS K-8780, the temperature is 1
Measured at 90℃ and a load of 2.1Bkg, hereinafter "
x.

1, J ) or melt flow index (J
Measured according to Is K-6758 at a temperature of 230°C and a load of 2.18 kg, hereinafter referred to as r MFIJ) is preferably 0.01 to 100 g/10 minutes, particularly 0.02 to 80 g/10 minutes. Preferably. If an olefin polymer having M, T, or Mjl of less than 0.01 g/10 min 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. Additionally, it has a low density (0,900g/c
rn') or high density (0,!380 g/cm
An ethylene homopolymer or a copolymer of ethylene with a small amount of the above α-olefin, a propylene homopolymer, or a random or block copolymer of propylene and ethylene and/or other α-olefins are desirable.

These olefinic polymers are based on a catalyst system (so-called ≠-
catalyst systems (so-called Phillips catalysts) or radical initiators (e.g. organic peroxides) obtained by supporting a chromium-containing compound (e.g. chromium oxide) on a carrier (e.g. silica).
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.

These olefin polymers and modified polyolefins may be used alone or in combination of two or more. Furthermore, among these olefin polymers and modified polyolefins, two kinds of uh may be used as a resin blend in an arbitrary ratio.

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 that do not decompose during crosstalk or molding. The inorganic fillers include metals such as aluminum, copper, iron, lead and nickel;
Compounds such as oxides, hydrates (hydroxides), sulfates, carbonates, and silicates of these metals and metals such as magnesium, calcium, barium, zinc, zirconium, molybdenum, silicon, antimony, and titanium. , these double salts, and mixtures thereof. Typical examples of the inorganic fillers include the above-mentioned metals, aluminum oxide (alumina), its hydrates, calcium hydroxide, magnesium oxide (magnesia), magnesium hydroxide, zinc oxide (zinc white), red lead, and lead. White lead oxide, magnesium carbonate, calcium carbonate, basic magnesium carbonate, white carbon, asbestos, mica, talc, glass Ii & m, crow powder, glass peas, clay, diatomaceous earth, silica, wollastonite, oxidation Examples include iron, antimony oxide, titanium oxide (titania), lithopone, pumice powder, aluminum sulfate (gypsum, etc.), zirconium silicate, 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 microns (preferably 1 to 3 microns).
00 microns) and has a length of 0.1 to 8 mm (preferably 0.1 to 5 mm) (7). Furthermore, the diameter of the flat plate is 2 mm or less (preferably 1 mm).
The following) are preferred.

(E) Unsaturated carboxylic acid and its anhydride Further, as a typical example of the unsaturated carboxylic acid or its anhydride used for producing the modified olefin polymer layer of the present invention, the number of carbon atoms is at most 10. monobasic carboxylic acids having at least one double bond (e.g. acrylic acid, methacrylic acid) and dibasic carboxylic acids having at most 15 carbon atoms and having at least one double bond (e.g. (maleic acid) and anhydrides of the dibasic carboxylic acids (for example, maleic anhydride, hymic anhydride). Among these unsaturated carboxylic acids or derivatives thereof, maleic acid and maleic anhydride are particularly preferred.

Hereinafter, the coating layer, metal layer, inorganic filler-containing olefin polymer layer, and modified olefin polymer layer with excellent weather resistance that constitute the reflector for a circularly polarized antenna of the present invention will be described in detail.

(F) Coating layer The coating layer of the present invention serves to prevent corrosion of the metal layer. From this, the thickness is between 5 microns and 1 mm, preferably between 10 microns and 0.5 mm, particularly preferably between 10 microns and 0.3 am. If the thickness of this coating layer is less than 5 microns, not only will the metal layer corrode, but also the metal layer will wear out 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.

(G) Metal layer Furthermore, the metal layer of the present invention serves to reflect radio waves. The thickness of this metal layer is between 5 microns and 1 mm.
and preferably 5 to 500 microns, especially 1
0-500 microns is preferred. The thickness of the metal layer is 5
When the thickness is less than microns, wrinkles and folds tend to occur in the metal layer during the production of a laminate, resulting in problems in terms of appearance and performance.

On the other hand, if it exceeds 1 mm, not only will the weight increase, but also the cost will increase, and furthermore, it will cause problems when bending or bending the laminate.

()I) 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 ratio of the olefin polymer is 80 to 20% by weight),
10 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 layer, resulting in heat cycle failure. Therefore, there is a problem that not only peeling may occur between the metal layer and the inorganic filler-containing olefin polymer layer, but also that the resulting laminate lacks rigidity. On the other hand, 80% by weight
If it exceeds this, it will be difficult to produce a uniform composition, and even if a uniform composition is obtained, it will be difficult to produce a good product when producing sheets or laminates by injection molding as described below. (laminate) cannot be obtained.

The thickness of this inorganic filler-containing olefin polymer layer is 50
0 micron to 15mm, 1” 10mm
is desirable, and 1 to 7fflI11 is particularly preferred. The thickness of the inorganic filler-containing olefin polymer layer is 500 mm.
If it is less than a micron, it is not desirable because it lacks rigidity and can be deformed or damaged by external force. 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 this inorganic filler-containing olefinic polymer layer, we use stabilizers against oxygen, heat and ultraviolet rays, metal deterioration inhibitors, flame retardants, colorants, electrical Additives such as physical property improvers, antistatic agents, lubricants, pressure improvers, and adhesion improvers are added to the extent that they do not impair the properties of the inorganic filler-containing olefin polymer layer composition of the present invention. You may.

In addition, a blowing agent commonly used in the field of olefin polymers (
A reflector for a circularly polarized antenna is prepared by the vacuum forming method, stamping molding method or injection molding method (injection molding method is particularly preferred) as described below. An inorganic filler-containing olefinic polymer layer consisting of an essentially unfoamed skin layer and a foamed core layer (average expansion ratio of 1.50 or less, core layer thickness is 85% or less of the inorganic filler olefinic polymer layer).

When producing the inorganic filler-containing olefin polymer of the present invention (including cases in which the above additives are blended), trials were carried out using a mixer such as a Henschel mixer, which is commonly used in the olefin polymer industry. They may be blended and may be obtained by melt kneading using mixers such as Banbury mixers, kneaders, roll mills and single screw extruders. At this time, the composition (mixture) obtained by tri-blending in advance
A uniform 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, then molded into pellets, and 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 some of the ingredients may be mixed in advance to produce a so-called masterbatch, and the resulting master/ The hetsuchi and the remaining ingredients may be mixed.

When melt-kneading the following formulations, it must be carried out at the melting point or softening point of the olefinic polymer used; however, if carried out at high temperatures, the olefinic polymer will deteriorate. do. For these reasons, it is generally 2 times lower than the melting point or softening point of the olefin polymer.
0°C higher temperature (preferably higher than 50°C)
However, it is carried out within a temperature range that does not cause deterioration.

(J) Modified olefin polymer layer The modified olefin polymer layer of the present invention is composed of the above-mentioned coating layer with excellent weather resistance, a metal layer (metal foil), and a metal layer and an inorganic filler-containing olefin polymer layer. It is interposed between these to improve their adhesion.

Modified olefinic polymers are generally obtained by treating olefinic polymers with unsaturated carboxylic acids and/or derivatives thereof in the presence of organic peroxides.

In order to produce the modified olefin polymer of the present invention, any of various known production methods (eg, solution method, suspension method, melt method) can be employed.

Among these production methods, when modifying an olefin polymer with an unsaturated carboxylic acid or its derivative by a solution method, the olefin polymer and the unsaturated carboxylic acid and/or its derivative are placed in a nonpolar organic solvent. A modified olefin polymer can be obtained by further adding a radical initiator and heating at a high temperature. Inorganic organic solvents used in this case include hexane, heptane, benzene, toluene, xylene, chlorobenzene and tetrachloroethane. In addition, as a radical initiator, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 2,5-dimethyl-
Organic peroxides such as 5,5-di(tert-butylperoxy)hexyne-3 and benzoyl peroxide may be mentioned. - Furthermore, the processing temperature used is 110~
IBO°C, particularly preferably 130-150°C.

In addition, when modifying an olefinic polymer with an unsaturated carboxylic acid or its derivative by the suspension method, the olefinic polymer and the unsaturated carboxylic acid and/or its derivative are placed in a polar solvent (generally water). , by further adding the above-mentioned radical initiator and treating under high pressure at a temperature of 100° C. or higher.

Furthermore, when modifying an olefinic polymer with an unsaturated carboxylic acid or its derivative by a melting method, the olefinic polymer is , an unsaturated carboxylic acid and/or its derivative, and the above-mentioned radical generator while melt-kneading. The crosstalk temperature at this time varies depending on the type of olefin polymer and radical generator used, but is in the temperature range from above the melting point of the olefin polymer used to below 300°C. In the case of ethylene polymers, the temperature is generally 120 to 270°C, and in the case of propylene polymers, it is generally 180 to 270°C.

The total content of unsaturated carboxylic acids and their derivatives grafted into the modified olefin polymer obtained as described above is 0.01 to 10% by weight, and 0.0% by weight.
5 to 5.0% by weight is desirable, especially 0.1 to 5.0% by weight.
% by weight is preferred. If the content of these grafted in the modified olefin polymer is less than 0.01% by weight, almost no crosslinking reaction occurs, so the olefin polymer layer and metal layer and the metal layer and inorganic filling have excellent weather resistance. Adhesion to the agent-containing olefin polymer layer is poor. Also,
If it exceeds 10% by weight, the moldability of the crosslinked product (modified olefin polymer layer) will be significantly impaired.

The thickness of this modified olefin polymer layer is 10 to 500 mm.
micron, preferably 10 to 400 micron,
Particularly suitable is 10 to 300 microns. If the thickness of the modified olefin polymer layer is less than 10 microns, it will not be possible to exhibit uniform adhesion.

On the other hand, if the thickness exceeds 500 microns, not only will it be difficult to perform the lamination method described later when manufacturing the circularly polarized antenna reflector of the present invention, but the cost will increase.

(K) 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 FIG. 2, ■ is a laminate consisting of a coating layer with excellent weather resistance, a primer layer, a metal layer and a modified olefin polymer, and II is an olefin polymer layer containing an inorganic filler. Furthermore, in FIG. 3, 1 is an inorganic filler-containing olefin polymer layer, and 2 is a metal layer (metal foil). Moreover, 3 is an olefin polymer layer with excellent weather resistance. Further, 4 is a single layer of primer, and 5 is a modified olefin polymer 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. If the adhesion between the metal layer and the paint layer is good, it may be used as is, but if the adhesion is poor, use an adhesive such as a primer to maintain sufficient adhesion (adhesion) between the metal layer and the paint layer. A sex-imparting agent may be present. Further, the reflector for a circularly polarized antenna of the present invention uses a modified olefin polymer to strengthen the adhesive force between the metal layer and the inorganic filler-containing olefin polymer layer. . Furthermore, in order to attach the reflector for a circularly polarized antenna of the present invention to a support, ribs may be added to the inorganic filler-containing olefin polymer layer, and the reflector may be reinforced. It is also possible to add reinforcing ribs. 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 80 cm to 120 cm.

(L) Method for manufacturing a reflector for a circularly polarized antenna As is clear from FIG. ), a metal layer (metal foil), a modified olefin polymer, and an olefin polymer layer containing an inorganic filler.

In the reflector for a circularly polarized antenna of the present invention, as long as the adhesiveness (adhesion) between the paint used and the metal foil (metal layer) is good, the paint layer and metal layer can be directly laminated. However, if the adhesion is not fully satisfactory, an adhesion imparting agent such as a primer may be interposed to maintain sufficient adhesion between them.

There are various methods for manufacturing the circularly polarized antenna reflector of the present invention. A typical example of this method is to interpose a modified olefin polymer between a metal layer and an inorganic filler-containing olefin polymer layer, without applying a primer to the surface of the metal layer of the resulting laminate in advance. Alternatively, it may be applied, dried, and then coated with paint. In addition, a laminate consisting of a metal layer, a single layer of primer, and a paint layer, or a metal layer and a paint film can be created by applying a primer to one side of the metal layer, or by drying it and then applying paint to this side. A laminate consisting of layers may be manufactured, a modified olefin polymer may be laminated on the metal layer of the resulting laminate, and an inorganic filler olefin polymer may be laminated on this modified olefin polymer layer, and this laminate A modified olefin polymer layer prepared in advance and an inorganic filler olefin polymer layer may be laminated on the metal layer.

There are various molding methods for manufacturing the circularly polarized antenna reflector of the present invention using the method described below. Typical examples of such methods include vacuum forming, pressure forming, stamping molding, and injection molding.These forming methods are not unique to the present invention, and if commonly used methods are applied. good. The manufacturing method using these molding methods will be explained in more detail. In addition.

The manufacturing method using the molding method shown below is only some of the manufacturing methods of the reflector for a circularly polarized antenna of the present invention, and it can be manufactured by other methods as well.

(1) Manufacture by vacuum forming method or pressure forming method To manufacture by these methods, a modified olefin polymer must be laminated in advance on one side of a metal layer on which a coating layer with excellent weather resistance has been laminated, or simultaneously. When an inorganic filler-containing olefin polymer is extruded into a sheet by T-die molding, one side is laminated to provide a coating layer, a metal layer, a modified olefin polymer layer, and a layer with excellent weather resistance. A laminate in which inorganic filler-containing olefin polymer layers are sequentially laminated is obtained. The laminate (sheet) obtained in this way is fixed with iron cotton or claw-like objects, mounted on a jig that is easy to handle, and then heated with ceramic heaters or sheathed wire heaters arranged below. Pull it into a device that can heat it and heat it. When the sheet is heated, it begins to melt, and at that time, the droop of the sheet changes its shape, and then, as the heating continues, it becomes stretched in the cotton that holds the sheet down. When this stretching phenomenon occurs, the best timing for forming the sheet is when the molded product is in a good heating state without wrinkles or uneven thickness. At this time, the sheet work is pulled out, placed on the H portion of the mold, and vacuum formed from the mold side under a reduced pressure of one atmosphere to obtain the desired molded product. Then, the product is cooled by wind or water spray and released from the mold.

On the other hand, in compressed air forming, the sheet that is easier to mold is pulled out to the L part of the mold, a chamber (box) for compressed air is covered from the H side of the sheet, and the sheet is placed on the mold side with a pressure of 3 to 5 atmospheres. A molded article can be obtained by pressing the sheet and punching the mold.

In addition, in any molding method, the surface temperature of the propylene polymer whose main component is propylene is If (5 to 175
℃ is the optimum temperature, and for an ethylene polymer containing ethylene as a main component, a suitable surface temperature is 125 to 145°C.

(2) Manufacturing by stamping molding method In order to manufacture an uninvented reflector for a circularly polarized antenna by this method, it is necessary to have the same weather resistance as in the above-mentioned vacuum forming method for manufacturing a reflector for a circularly polarized antenna. A laminate (sheet) in which a superior coating layer, a metal layer, and an inorganic filler-containing olefin polymer layer are laminated in sequence is introduced into a drawing die attached to a vertical press machine, and the laminate is drawn into a drawing die of 5 to 50 kg/cm.
The desired molded product can be obtained by heating and pressing under a pressure of m' (preferably 10 to 20 kg/cm'). The product is then obtained by cooling with air or water spray and releasing from the mold. Pressure time during molding is usually 15 seconds or more, and 15 to 4
0 seconds is common. Further, in order to improve surface properties, it is preferable to perform molding under two-step pressure conditions.

In this case, after pressurizing for 15-40 seconds under a pressure of 10-20 kg/cm' in the first stage, 40-50 kg in the second stage.
/ cm' for 5 seconds or more, a molded product with excellent surface smoothness can be obtained. This two-stage molding method is particularly desirable when using an inorganic filler-containing olefin polymer layer with poor fluidity. In addition, the molding temperature in the stamping molding method is as follows when a propylene polymer containing propylene as a main component is used as the olefin polymer of the S machine filler-containing olefin polymer layer.
The optimum surface temperature is 125 to 135°C. Also,
When using an ethylene polymer containing ethylene as a main component, a suitable surface temperature is 85 to 110°C.

Note that the vacuum forming method, pressure forming method, and stamping molding method described below are all cases in which a single layer of primer is not interposed between the paint film layer and the metal layer, but as described above, the paint and metal foil used are If the adhesion between the two is not satisfactory, a layer of primer (adhesive agent) may be interposed between them. This primer may be applied by any commonly used method, and is usually applied to one side of a metal foil by gravure coating or perspective coating, and dried at 50 to 100°C.

The primer differs depending on the type of paint used to form the coating layer, but it is generally used in various fields and is broadly classified into water-based and solvent-based. The types include vinyl, acrylic, polyamide, epoxy, rubber, urethane, and titanium.

(3) Manufacturing by injection molding method To manufacture the circularly polarized antenna reflector of the present invention by injection molding method, a coating layer with excellent weather resistance is laminated on one side in advance, and a primer layer is applied on the other side. Insert injection molding is performed when forming a reflector plate for a circularly polarized antenna with a metal layer that is not coated or has been coated. To carry out insert injection molding, the laminate is inserted between the male and female molds of the injection molding machine, and the olefin polymer layer with excellent weatherability is placed on the male mold side. ) and close the mold. Thereafter, the inorganic filler-containing olefin polymer is filled into the mold through the gate of the mold, and after cooling, the mold is opened to obtain a desired reflector for a circularly polarized antenna. For insert injection molding, 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 a propylene polymer is used as the olefin polymer, insert injection molding is performed at a rate of 170 to 290.
It is desirable to carry out in the temperature range of °C. On the other hand, when an ethylene polymer is used as the olefin polymer, insert injection molding is carried out at a temperature in the range of 120 to 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, it is possible to form the inorganic filler-containing olefin polymer into a shape that is almost similar to the shape of the mold. Not only is it possible to produce a product, but also a product with good appearance can be obtained. The injection pressure is generally 40-140 kg/cm',
Especially desirable is 70 to 120 kg/cm'.

Note that the method of applying paint to the metal foil of a molded product manufactured by vacuum forming, pressure forming, stamping molding, or injection molding, which has not been coated with paint, as described above, is not a special method, but a primer. A method of using a spray gun to apply said paint without prior application or application.

There are methods using a brush and a roll coater, but from an industrial perspective, a method using a spray can is more efficient, and a method using a robot is particularly preferred.

[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. In addition, the weather resistance test was 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). (discoloration, fading, gloss change, crazing,
(Detrimental changes such as blistering, peeling of metal foil, and cracks) were evaluated. Furthermore, a heat cycle test tested the sample at 80°C.
After being exposed for 2 hours, it was gradually cooled to -45°C over 4 hours, exposed to this temperature for 2 hours, and then gradually heated to 80°C over 4 hours, after 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 peel strength was measured by cutting a test piece with a width of 15 mm from the manufactured reflector for a circularly polarized antenna, and measuring the peel strength at a peel speed of 50 m in accordance with ASTM' D-903.
The strength was evaluated when the metal layer was peeled off at 180 degrees at a speed of m/min. Furthermore, the bending rigidity is ASTM D-79.
0, the coefficient of thermal expansion is ASTM D-6
88.

The types and physical properties of the paints, olefin polymers, modified olefin polymers, inorganic fillers, and metal foils used in the coating layers with excellent weather resistance are shown below.

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

[(B) Olefin polymer As a coolefin polymer, a propylene-ethylene block copolymer (ethylene content - $ 10.5 wt%, hereinafter referred to as r PP(B)J) having a Fl of 0.7 g 710 min. ), M, 1. High-density ethylene fluorescent polymer with a density of 20 g/10 min (density 0.98 Ig/c
m', hereinafter referred to as r)IDPE(2)'') was used.

[(C) Modified olefin polymer] The modified olefin polymer has an MFI of 0.5 g/1
Propylene homopolymer (density 0.900g
/am') 100 parts by weight, 0.01 parts by weight of 2,5-dimethyl-2,5-di(butylperoxy)hexane (as an organic peroxide) and maleic anhydride were mixed in advance in a Henschel mixer for 5 minutes. Triblending is performed, and the resulting mixture is heated to a resin temperature of 23°C using an extruder.
Modified propylene polymer produced by melt-kneading at 0°C (maleic anhydride content: 0.32
% by weight (hereinafter referred to as "modified PPJ") and an ethyl/7-based polymer (M, 1. A modified ethylene polymer (maleic anhydride content: 0.24% by weight, hereinafter [modified P
EJ) was used.

[(D) 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 S Fiber diameter: 11 microns, cut length: 3 mm, hereinafter referred to as rG
FJ) and calcium carbonate (hereinafter referred to as rcacO3J) having an average particle size of 0.8 microns were used.

[(E) Metal foil] Aluminum (each having a thickness of about 20 microns)
(hereinafter referred to as rAIJ) and copper foil were used.

Examples 1 to 9, Comparative Examples 1 to 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 1. It was applied to a thickness of 20 microns and dried.

Paints whose types are shown in Table 1 (U paints for Examples 5 to 8, F paints for others) are applied to the primer-coated surface of the obtained metal foil so that the dry thickness is 30 microns. -Leave it for day and night. On the other side of the metal layer of the laminate thus obtained, a film (
The metal layer and the modified olefin polymer layer were adhered while forming a thickness of 50 microns. 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. (without any agent) were tri-blended for 5 minutes using a Henschel mixer, and each mixture was produced into a composition using a vented extruder at a resin temperature of 230"O. Each of the resulting compositions A sheet having a thickness of 2 mm was produced using a T-die molding machine.

The laminate consisting of the coating layer, the primer layer, the metal layer and the modified olefin polymer layer produced as described above was processed into a sheet of an olefin polymer containing an inorganic filler.
The 5-layer laminate thus obtained was laminated by the dry lamination method at
Bowl-shaped (outer diameter 7
Using a female mold with a diameter of 50 mm and a height of 80 mm, vacuum forming was performed to produce a reflector for a circularly polarized antenna (Example 1.2).

A laminate consisting of five layers produced in the same manner as in Examples 1 and 2 (the types of inorganic filler and olefin polymer, the content of the inorganic filler in the composition, and the type of metal foil are shown in Table 1). ) under a surface temperature of 135°C, the first stage under a pressure of 20 kg/cm' for 30 seconds, and the second stage under a pressure of 50 kg/cm' for 20 seconds.
By holding it, stamping molding was performed in three stages (the shape of the mold was the same as in Example 1), and a reflector for a circularly polarized antenna was manufactured (Example 3.4).

The laminate produced as described above was inserted into an injection molding machine (clamping force: 1500 mm) so that the coating layer having excellent weather resistance was in contact with the male mold surface of the mold. After closing the mold, the types of olefinic resin and inorganic filler and the content of inorganic filler in the composition are shown in Table 1 under the conditions of injection pressure of 80 kg/crn' and resin temperature of 240°C. The compositions shown in the table were subjected to insert injection molding to produce reflectors for circularly polarized antennas having the same shape as in Example 1 (Examples 5 to 9, Comparative Examples 2 and 3).

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. In the column of peel strength in Table 1, "cohesive failure" means that the metal layer (metal foil) breaks due to strong adhesive force.

(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 88% 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 samples except for Comparative Example 1. . However, in Comparative Example 2, the aluminum foil on the surface corroded.

[Brief explanation of the drawing]

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, ■...Laminated product consisting of a coating layer with excellent weather resistance, one layer of primer, a metal layer (metal foil) and a modified olefin polymer layer, II...Olefin type containing inorganic filler Polymer layer, ■・
...Olefin polymer layer containing inorganic filler, 2...Metal layer (metal foil), 3...Coating layer with excellent weather resistance, 4...Single layer of primer, 5...Modified olefin system Polymer layer patent applicant Showa Denko Co., Ltd. Representative Patent attorney Sei Kikuchi - Figure 3

Claims (1)

[Claims] At least (A) a metal layer having a coating layer with excellent k# weatherability and (B) an inorganic filler-containing olefin polymer layer, an olefin polymer is interposed between an unsaturated carboxylic acid and/or its anhydride. The thickness of the coating layer with excellent weather resistance is 5 microns to 5 mII+, and the thickness of the coating layer is 5 microns to 5 mII+. The thickness is 5 microns to 1 mm, and the thickness of the inorganic filler-containing olefinic polymer layer is 0.5 mm to 15 mm, and the content of the S filler in this layer is 1 mm.
A reflector for a circularly polarized antenna, characterized in that the modified olefin polymer layer has a thickness of 10 to 500 microns.