JPS60212006A - Reflecting plate for circularly polarized wave antenna - Google Patents

Abstract

PURPOSE:To obtain a reflecting plate having excellent adhesion to an olefin group polymer layer and a simple manufacture process by inserting respectively a denatured olefin group polymer layer between the olefin group polymer layer and a metallic layer and between the metallic layer and an olefin group polymer layer including an inorganic packing agent. CONSTITUTION:The olefin group polymer layer 3 with excellent weather resistance includes 0.005-2.0wt% of ultraviolet ray absorbing agent, the thickness of the layer is 5mu-5mm., the thickness of the metallic layer 2 is 5mu-1mm., the thickness of the olefin group polymer layer 1 including an inorganic packing agent is 0.5mm.-15mm. and the thickness of the denatured olefin group polymer layers 4, 5 is selected as 10-500mu. As a typical example of an unsaturated carboxylic acid or its anhydride used to manufacture the denatured olefin group polymer layer, a monobasic carboxylic acid having carbon number of 10 at most and having a double bond at least. The olefin group polymer layer acts like preventing generation of corrosion of the metallic layer.

Description

[Detailed Description of the Invention] [I] Purpose of the Invention The present invention has a metal layer serving as a radio wave reflecting layer as an intermediate layer, and an olefinic polymer layer containing an ultraviolet absorber or an inorganic filler interposed between the metal layer and the metal layer. This invention relates to a reflector for a circularly polarized antenna. More specifically, an olefinic polymer is interposed between an olefinic polymer layer having excellent weather resistance, a metal layer that reflects radio waves, and an inorganic filler-containing olefinic polymer layer. or a laminate obtained by interposing a modified olefin polymer layer obtained by modifying with or anhydride thereof, and the olefin polymer layer with excellent weather resistance is 0.005 to 2.0. % by weight of UV absorber, and the thickness of this layer is between 5 microns and 5 microns.
+++++a, and the thickness of the metal layer is 5 microns to 1
am, and the thickness of the inorganic filler-containing olefinic polymer layer is from 0.5 to 15III11, and the thickness of the modified olefinic polymer layer is from lO to 500 microns. This relates to a reflector for antennas, which not only has good weather resistance, but also has excellent adhesion between the metal layer that is the radio wave reflection layer and the two types of olefin polymer layers mentioned above, and can easily generate circularly polarized waves. The object of the present invention is to provide a reflector for an antenna.

[summer! ] Background of the Invention Satellite broadcasting such as high-definition television broadcasting, still image broadcasting, single character multiplex broadcasting, PCM (pulse and code modulation) audio broadcasting, and facsimile broadcasting using geostationary satellites will be used in Europe, America, Japan, and other countries in the near future. Its practical application is planned. 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 a broadcasting satellite, the polarization plane shifts due to disturbances caused by the ionosphere in the radio wave propagation path and the angle of incidence of the radio waves at the receiving point, so the above-mentioned method is not possible. It is difficult to match such planes of polarization.

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 is impossible to expect to obtain a high degree of cross-polarization discrimination when broadcast satellite radio waves are linearly polarized waves. However, in the case of circularly polarized waves from broadcasting satellite radio waves, it is easy to identify the circularly polarized wave by the direction of the circularly polarized wave, regardless of the deviation of the plane of polarization as described above, and therefore it is difficult for general listeners to distinguish between circularly polarized waves. 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. On the other hand, conventional circularly polarized antennas include those using a conical horn, two Goupoles combined at right angles, and parabolic antennas that use these antennas as the primary radiator. The structure is complicated 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 (GH) band. Not yet.

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 parabolic. There is a so-called Heehat-type parabolic antenna which 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 hip-hat 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 glass m#a whose surface is metalized as a radio wave reflecting layer is laminated to a thermosetting resin such as an unsaturated polyester resin, but the manufacturing method is complicated. At the same time, it is extremely difficult to maintain the radio wave reflecting 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. A reflector for a circularly polarized antenna is formed by laminating at least (A) a thermoplastic resin layer with good iTIJ weatherability, (B) a metal layer, and (C) an inorganic filler-containing olefin polymer layer in a 11V quaternary layer, It was discovered that it not only has good durability but also excellent radio wave reflection characteristics, and has previously proposed it (see Japanese Patent Application No. 8535/1983).

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.

[111] 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, and As a result of various searches to obtain a reflector for a circularly polarized antenna using a simple manufacturing process, we found an olefin polymer layer with excellent weather resistance, a metal layer that reflects radio waves, and a metal layer and an olefin 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 olefin polymer layer, The olefin polymer layer with excellent weather resistance has 0
．． Contains an ultraviolet absorber of 0.005% to 2.0% by weight of reeds,
and the thickness of this layer is 5 microns to 5 mm, the thickness of the metal layer is 5 microns to lam, and the thickness of the inorganic filler-containing olefinic polymer layer is 0.5 m+m.
A reflector for a circularly polarized antenna, characterized in that the thickness of the modified olefin polymer layer is 10 to 500 microns, has not only good durability but also excellent radio wave reflection characteristics. Furthermore, the inventors have discovered that the adhesion between the metal layer and the olefin polymer is good and that it can be easily obtained, and the present invention has been achieved.

[IV] Effects of the Invention The circularly polarized antenna reflector 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 olefinic polymer layer, which has excellent weather resistance, and the metal layer (metal foil) and between the metal layer and the olefinic polymer layer containing an inorganic filler is excellent, and since a primer is not required, it is possible to apply a primer. Also, complicated steps such as drying can be omitted.

[V] Detailed Description of the Invention (A) Olefin Polymer The olefin polymer layer used in the present invention to produce an olefin polymer layer with excellent weather resistance, an inorganic filler-containing olefin polymer layer, and a modified olefin polymer Examples of olefin polymers include ethylene homopolymers, propylene homopolymers, copolymers of ethylene and propylene, and ethylene and/or propylene copolymers having at most 1 carbon number.
Examples include copolymers with two other α-olefins (copolymerization ratio of α-olefins is at most 20% by weight).

The melt index (J
Measured according to IS K-8711i0 at a temperature of 190°C and a load of 2.18 kg, hereinafter rM, 1.
J) or melt flow index (JIS
Measured according to K-6758 at a temperature of 230°C and a load of 2.18 kg, hereinafter referred to as r MFIJ)
Preferably, the amount is 0.01 to 100 g/10 min, and particularly preferably 0.02 to 80 g/10 min. ni,■
, or if an olefinic polymer with an MFI of less than 0.01 g/10 minutes is used, the moldability of the resulting mixture is poor. 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 (0,800g/c
m) or high density (0,980 g/cm") ethylene homopolymer or ethylene and a small amount of the above α-
Copolymers with olefins or propylene homopolymers or propylene with ethylene and/or other α-
Random or block copolymers with 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.

(B) 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 aluminum, copper, iron, lead and nickel;
Compounds such as oxides, hydrates (hydroxides), sulfates, carbonates, and silicates of these metals and metals such as bugnesium, 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 brew, 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,
Examples include aluminum sulfate (such as gypsum), 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 111ff1 or less (preferably 0.5+am or less). In addition, in the case of fibrous materials, the diameter is 1 to 500 microns (preferably 1 to 500 microns).
~300 microns) and length 0.1~8mm (
0.1 to 5+am) is preferable. Furthermore, the diameter of the flat plate-like one is 2 mm or less (preferably 1+++
W or less) is preferable.

(C) Ultraviolet absorber Furthermore, the ultraviolet absorber used to produce the olefin polymer layer with excellent weather resistance of the present invention is a UV absorber that is used to modify the olefin polymer by the action of ultraviolet rays in sunlight.
It is an additive used to protect against deterioration and destructive effects such as embrittlement, and any additive that absorbs ultraviolet energy is sufficient. Typical examples of UV absorbers include phenyl salicylate, p-octylphenyl salicylate, and p-
- salicylic acid derivatives such as tertiary-butylphenyl salicylate, 2,4-dihydroxybenzophenone, 2
-Hydroxy-4-methoxybenzophenone.

2. Benzophenone compounds such as 2-dihydroxy-4-methoxybenzophenone and 4-dobutyloxy-2-hydroxybenzophenone, 2-(2'-1=droxy-3'-tert-butyl-5°-methyl-phenyl )5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butyl-phenyl)
Benzotriazole compounds such as -5-chlorobenzotriazole and 2-(2°-hydroxy-4'-n-octoxy-phenyl)benzotriazole. Examples include alinide oxalate derivatives, hindered amine type compounds, benzoic acid derivatives and nickel chelate compounds. The types, product names, and physical properties of these ultraviolet absorbers are described in detail in Rubber Digest Co., ed., "Handbook, Rubber-Plastic Compounded Chemicals" (1971, published by Rubber Digest Co., Ltd.), pages 115 to 123. There is.

(D) Metal layer Further, 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). 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.

(E) Unsaturated carboxylic acid and its water collection Further, as a typical example of the unsaturated carboxylic acid or its anhydride used to produce the modified olefin polymer layer of the present invention, the unsaturated carboxylic acid or its anhydride has at most 10 carbon atoms. 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 at least one double bond (e.g. , maleic acid) and the second 1f! Examples include anhydrides of carboxylic acid groups (eg, maleic anhydride, hymic anhydride). Among these unsaturated carboxylic acids or derivatives thereof, maleic acid and maleic anhydride are particularly preferred.

The olefin polymer 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 explained in detail below. .

(F) Olefin polymer layer with excellent weather resistance The olefin polymer layer with excellent weather resistance of the present invention functions to prevent corrosion of the metal layer described later. From this, the thickness is 5 microns to 5 mm, preferably 10 microns to 5II11, and particularly preferably 10 microns to 1111. If the thickness of this highly weather-resistant olefin polymer layer is less than 5 microns, not only will the metal layer corrode, but it will also wear out due to contact and friction with other products during use. There are problems such as exposure of On the other hand, if it exceeds 5 mm, it is not preferable because it increases the cost and the weight of the laminate. The blending ratio of the ultraviolet absorber contained in this olefin polymer layer with excellent weather resistance is 0.005 to 2.0% by weight, and 0.01 to 1.0% by weight.
5% by weight is preferred, especially 0.02-1.5% by weight
is suitable. The blending ratio of the ultraviolet absorber contained in this olefin polymer layer with excellent weather resistance is 0.0.
If it is less than 0.05% by weight, resistance to ultraviolet rays is insufficient. On the other hand, even if it is blended in excess of 2.0% by weight,
Not only is the effect not improved, but it may also bleed out onto the surface, increasing costs. Generally, if only one type of ultraviolet absorber is used, its effect will be low, so it is preferable to use two or more types in combination. Furthermore, it is desirable to add to this layer antioxidants and heat stabilizers that are commonly used in the field of olefin polymers.

(G) Metal layer Furthermore, the metal layer of the present invention functions to reflect radio waves. The thickness of this metal layer is 5 microns to 1II
I11, preferably from 5 to 500 microns, particularly preferably from lθ to 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, 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.

(H) 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%), 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 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, if the weight exceeds 80 weight, it is difficult to produce a homogeneous 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. However, 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 15m+s, 1 to 1oIllll
is desirable, and 1 to 7IIfl is particularly preferred.

If the thickness of the inorganic filler-containing olefin polymer layer is less than 50 microns, it is undesirable because it lacks rigidity and is deformed and damaged by external force. On the other hand, if it exceeds 15 +++ m, 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, processability improvers, and tackiness 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 Inorganic fillers (up to 95% of the olefinic polymer layer) may be produced.

When blending the ultraviolet absorber with the olefin polymer of the present invention and when producing an inorganic filler-containing olefin polymer (including the case where the above additives are blended), it is common practice in the olefin polymer industry to It 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, kneader, roll mill, or 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, 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 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, it is generally 20% lower than the melting point or softening point of the olefin polymer.
C. (preferably higher than 50.degree. C.), but within a temperature range that does not cause deterioration.

(J) Modified olefin polymer layer The modified olefin polymer layer of the present invention contains an olefin polymer layer containing the ultraviolet absorber and having excellent weather resistance, a metal layer (metal foil), and a metal layer and an inorganic filler. It is interposed between these layers in order to improve their adhesion to the olefin polymer layer.

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-dimethyAy-2,5-di(
tert-butylperoxy)hexane, 2,5-dimethyl-5,5-di(tert-butylperoxy)hexane-3
and organic peroxides such as benzoyl peroxide. Furthermore, the processing temperature used is 110~
160°C, particularly preferably 130 to 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 kneading 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, it is generally 120 to 270°C, and in the case of propylene polymers, it is generally 160 to 270°C.
It is.

The total content of the unsaturated carboxylic acid and its derivatives grafted into the modified olefin polymer obtained as described below is 0.01 to 10% by weight, and 0.01 to 10% by weight.
05 to 5.0% by weight is 9 years old, especially 0.1 to 5.0% by weight.
0% by weight is preferred. If the content of these grafted into the modified olefin polymer is 0. If O1 weight is less than m5,
Since almost no crosslinking reaction occurs, the adhesion between the olefinic polymer layer, which has excellent weather resistance, and the metal layer, and between the metal layer and the inorganic filler-containing olefinic polymer layer, is poor. Moreover, 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 105,707 mm, adhesiveness cannot be uniformly exhibited.

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 following is a description of the reflector for a circularly polarized antenna according to the present invention 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. In addition, in Fig. 2, ■ is a laminate consisting of an olefin polymer layer with excellent weather resistance, a modified olefin polymer layer, a metal layer, and a modified olefin polymer, and II is a laminate consisting of an olefin polymer layer containing an inorganic filler. It is a polymer layer. 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. Furthermore, 4 and 5 are modified olefin polymer layers. As is clear from these drawings, the feature of the circularly polarized antenna reflector of the present invention is that it has a structure consisting of at least five layers. In addition, the reflector for circularly polarized antennas of the present invention has strong adhesion between the modified olefin polymer layer, which has excellent weather resistance, and the metal layer, and between the metal layer and the inorganic filler-containing olefin polymer layer. This is because a modified olefin polymer is used to achieve this. 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 openings using bolts, nuts, etc. Further, the diameter of the reflector for the circularly polarized antenna is usually 80cm+i to 120cm.

(L) Method for manufacturing a reflector for a circularly polarized antenna The reflector for a circularly polarized antenna of the present invention has an olefin polymer layer (hereinafter referred to as "A layer J") which has excellent weather resistance, as shown in FIG. ), a modified olefin polymer layer (hereinafter referred to as "B layer"), a metal layer (hereinafter referred to as "0 layer"), a modified olefin polymer layer (hereinafter referred to as "D layer"), and an inorganic filler. The layer is made up of sequentially laminated layers of agent-containing olefin polymers (hereinafter referred to as "layer E"). There are various methods for manufacturing this laminate. As a method for manufacturing a laminate, one layer may be laminated one after another, or five layers may be laminated simultaneously. Alternatively, two or four of these laminates may be laminated in advance, and the remaining laminated components may be sequentially laminated on the resulting laminate, thereby creating a laminate consisting of two or three of the remaining laminated components. may be laminated. Furthermore, two types of laminates and two types of laminates may be laminated, and the remaining laminated components may be laminated on the resulting four types of laminates, or one type of laminated component may be laminated on the two types of laminates, Two types of laminates may be laminated onto the three types of laminates obtained. As described above, the reflector for a circularly polarized antenna of the present invention is a layer in which the A layer, the B layer, the 0 layer, the D layer, and the E layer are sequentially laminated. Laminates with A, 0 and E layers must not be manufactured.

(1) Method for manufacturing laminate In manufacturing the reflector for circularly polarized antenna of the present invention,
The lamination method can be achieved by applying a commonly practiced dry lamination method or extrusion lamination method.

The method will be explained in detail below.

The dry lamination method is a method in which laminated components or laminates prepared in advance are laminated under pressure using a pressure roll heated to 50 to 200°C.

In addition, in the extrusion lamination method, an olefinic polymer containing an ultraviolet absorber, a modified olefinic polymer, or an olefinic polymer containing an inorganic filler is formed into A layer at a temperature of 180 to 300°C using a T-Guy molding machine. , B
This is a method of manufacturing a laminate while molding a film or sheet that is a layer, D layer, or E layer and heat-pressing it in the same manner as described above.

The reflector plate for a circularly polarized antenna of the present invention can be manufactured by applying a commonly used vacuum forming method, stamping molding method, or injection molding method to the laminate thus obtained.

(2) Manufacture by vacuum forming method To manufacture by this method, the laminate (sheet) consisting of five layers obtained as described above is fixed with iron cotton or claw-like objects, making it easy to handle. The device is placed in a jig like this, and is heated by drawing it into a device that can heat it using ceramic heaters or sheathed wire heaters arranged vertically.

When the sheet is heated, it begins to melt, but at that time, the sheet begins to sag, and then as the heating continues, it stretches inside the wafer that is holding it down. When this stretching phenomenon is observed, the best timing for sheet molding is when the molded product is in a good heating state without wrinkles or uneven thickness. At this time, the desired molded product is obtained by pulling out the sheet work, placing it on the upper part of the mold, and performing vacuum forming from the mold side under a reduced pressure of one atmosphere. 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 top of the mold, a chamber (box) for compressed air is placed over the sheet, and the sheet is pressed against the mold side with a pressure of 3 to 5 atm. A molded product can be obtained by pushing up the mold together with the mold.

In addition, in any molding method, the surface temperature of the propylene polymer whose main component is propylene is 1135 to 175.
The optimum temperature is 125 to 145° C. for an ethylene polymer containing ethylene as a main component.

(3) Production by stamping molding method To produce the circularly polarized antenna plate of the present invention by this method, a laminate (sheet) in which the five-layer laminate described above is sequentially laminated is vertically molded. Introduced into a drawing die attached to a press machine, 5 to 50 kg/cm”
(Preferably 10-20 kg/crn') 0'
) The desired molded product can be obtained by heating and pressing under pressure. Then, the product is obtained by cooling with air or water spray and molding.

Pressure time during molding is usually 15 seconds or more, and 15 seconds or more.
~40 seconds is typical. Further, in order to improve surface properties, it is preferable to perform molding under two-step pressure conditions. In this case, after pressurizing lθ~20kg/cm' for 15~40 seconds in the first stage, 40~50kg/cm' in the first stage.
A molded product with excellent surface smoothness can be obtained by applying pressure for 5 seconds or more under a pressure of In addition, the molding temperature in the stamping molding method is such that when a propylene polymer containing propylene as a main component is used as the olefin polymer of the inorganic filler-containing olefin polymer layer, the surface temperature is 125 to 125. The optimum temperature is 135° C. In addition, when using an ethylene polymer containing ethylene as a main component, the surface temperature is preferably 85 to 110° C.

(4) Production by injection molding method In order to produce the circularly polarized antenna reflector of the present invention by injection molding method, the A layer, B layer obtained as described above,
The four-layer laminate consisting of the 0 layer and the D layer is subjected to insert injection molding when molding a reflector for a circularly polarized antenna. To carry out insert injection molding, the laminate is inserted between the male and female molds of an injection molding machine so that the olefinic polymer layer with excellent weather resistance is on the male mold side. ), close the mold. After that, the inorganic filler-containing olefin polymer is filled into the mold from the gate part of the mold,
After cooling, the mold is opened to obtain a desired reflector for a circularly polarized antenna. For insert injection molding, the resin temperature is sI! The temperature is higher than the melting point of the olefin polymer of the 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 using 1170
It is desirable to carry out at a temperature range of ~280°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 higher 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. In addition, a product with good appearance can be obtained.The injection pressure is generally 40 to 140 kg/cm', and preferably 70 to 120 kg/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 fishing season of 83°C and a due cycle of 12 minutes/(60 minutes of irradiation).
After a period of time, the external appearance of the surface (adverse changes such as discoloration, fading, gloss change, crazing, blistering, peeling of metal foil, cracking, etc.) was evaluated. Furthermore, the heat cycle test tested the sample at 80%
℃ for 2 hours, then gradually cooled to -45℃ over 4 hours, exposed to this temperature for 2 hours, then gradually heated to 80℃ over 4 hours, and 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 mm in accordance with ASTM D-803.
The strength was evaluated when the metal layer was peeled off at 180 degrees at a speed of /min. Furthermore, the bending rigidity is ASTM D-790.
The coefficient of thermal expansion is ASTM El-f
It was measured according to ill18.

In addition, the type of ultraviolet absorber-containing olefin polymer, olefin polymer, modified olefin polymer, inorganic filler, and metal foil of the olefin polymer layer with excellent weather resistance used in Examples and Comparative Examples, The physical properties are shown below.

[(A) Ultraviolet absorber-containing olefin polymer] The ultraviolet absorber-containing olefin polymer is propylene containing 0.4% by weight of a benzotriazole-based ultraviolet absorber and 0.5% by weight of carbon black. Homopolymer [melt flow index (JIS K-8758
According to the temperature force 230℃ and load 2.18kg
Measured under the following conditions, hereinafter referred to as r MFIJ) is 0.5g7
10 minutes, hereinafter referred to as rPPCA), a benzotriazole-based ultraviolet absorber at 0,4 gI% by weight and high-density polyethylene containing 0.5% by weight of carbon black (density 0.958 g/cm"). , Melt in Day/Ri x (JIS K-137,8OniL
The temperature is 180'Q and the load is 2.18kg.
Measured under the conditions of 0.8 g/1
0 minutes, hereinafter referred to as rHDPE(1) J] was used.

[(B) Olefin polymer] As the olefin polymer, a propylene-ethylene block copolymer (ethylene content 10.5% by weight, hereinafter referred to as rPP(B)J) has an MFI of 0.7 g 710 minutes. High-density ethylene homopolymer (density 0.981 g/c rn”
, hereinafter referred to as ``HDPE(2)'') was used.

[(C) Modified olefin polymer] The modified olefin polymer has an MFI of 0.5 g/1
Propylene homopolymer (density o, 900
g/cm”) 100 parts by weight, 0.01 parts by weight 2
, 5-dimethyl-2,5-di(butylperoxy)hexane (as an organic peroxide) and maleic anhydride were pre-triblended for 5 minutes using a Henschel mixer, and the resulting mixture was extruded using an extrusion method. A modified propylene polymer (containing 0.32% by weight of maleic anhydride, hereinafter referred to as "modified PPJ") produced by melt-kneading at a resin temperature of 230' and a modified PP. Instead of propylene homopolymer, which had a density of 0.950 g/cm", an ethylene L/7 polymer (M, 1.0.2 g/10 minutes) was used.
A modified ethylene polymer (maleic anhydride content: 0.24% by weight) manufactured under the same conditions as the modified PP was used, except that
, hereinafter referred to as "modified PEJ".

[(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 tafa Calcium carbonate (hereinafter referred to as "C-03") having a diameter of 11 microns and a cut length of 3 mm (hereinafter referred to as rGFJ) and an average particle size of 0.8 microns was used.

[(E) Metal foil] Aluminum (each having a thickness of about 20 microns)
rAiJ) and copper foil were used.

Examples 1 to 9, Comparative Examples 1 to 3 In order to produce an olefin polymer layer (layer A) with excellent weather resistance, the ultraviolet absorber-containing olefin polymer was molded, each having a thickness of 200 microns. produced a film. In addition, between each metal foil (layer 0) whose metal type is shown in Table 1 and the olefin polymer layer with excellent weather resistance obtained as described above, a modified olefin shown in Table 1 is added. Extrusion lamination (sandwich lamination) was performed using a T-die at 220°C using a T-die to form a film (thickness: 50 microns, B layer) while intervening the polymeric material (in Comparative Example 1, modified olefin-based without polymers). To the thus obtained laminate consisting of layer A, layer B, and layer 0, layer 0 and the modified olefin polymer layer (layer D) were adhered by extrusion lamination in the same manner as described above. 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 (without any agent) were tri-blended for 5 minutes using a Henschel mixer, and each mixture was produced into a composition using a vented extrusion method at a resin temperature of 230°C.

A sheet having a thickness of 21II11 was produced from each of the obtained compositions (pellets) using a T-die molding machine.

A layer, B layer, 0 layer and D layer manufactured as above
A laminate consisting of layers (layer E) of an olefinic polymer containing an inorganic filler was laminated at 280° C. by a dry lamination method.

The laminate consisting of five layers obtained in this way was
C (surface temperature of the laminate)
A reflector for a circularly polarized antenna was manufactured by vacuum forming using a female mold with a shape of 80 mm and 80 mm in height.
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). ) at a surface temperature of 135°C.
Stamping was performed in two stages by holding the second and second stages under a pressure of 50 kg/crn' for 20 seconds (the shape of the mold was the same as in Example 1) to produce a reflector for a circularly polarized antenna. (Examples 3 and 4).

The laminate consisting of layer A, layer B, layer 0, and layer D produced as described above was put into an injection molding machine (clamping force: 1500 mm).
A film (layer A) of an olefin polymer having excellent weather resistance was inserted into the mold so that it was in contact with the male 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/c rn' and resin temperature of 24θ°C. The compositions shown in Table 1 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 and Comparative Examples 2 and 3).

The elastic modulus and linear expansion coefficient of the inorganic filler-containing olefinic polymer layer of each circularly polarized antenna reflector obtained as above, and the sI! The peel strength of the metal foil from the filler-containing olefin polymer layer was measured. 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, ■...Excellent weather resistance A laminate consisting of an olefin polymer layer (layer A), a modified olefin polymer layer (layer B), a metal layer (metal foil, layer 0), and a modified olefin polymer layer (layer D), II... Inorganic filler-containing olefin polymer layer (E layer), l... inorganic filler-containing olefin polymer layer (E layer)
, 2... Metal layer (metal foil, 0 layer), 3... Olefin polymer layer with excellent weather resistance (A layer), 4... Modified olefin polymer layer (B layer), 5 ...
Modified olefin polymer layer (D layer), patent applicant: Showa Denko Co., Ltd., agent, patent attorney, Sei Kikuchi

Claims (1)

[Claims] An olefinic polymer layer with an unsaturated carboxylic acid and/or its anhydride is interposed between an olefinic polymer layer with excellent weather resistance and a metal layer that reflects radio waves, and between the metal layer and the olefinic polymer layer containing an inorganic filler. The olefin polymer layer with excellent weather resistance is composed of a laminate obtained by interposing modified olefin polymer layers obtained by modification, and the olefin polymer layer has a resistance of 0.005 to 2.0.
% by weight of UV absorber, and the thickness of this layer is 5% by weight.
The thickness of the metal layer is 5 microns to IIIl, and the thickness of the inorganic filler-containing olefinic polymer layer is 0.5i++a to 15 m+a.
mm, and the content of inorganic filler in this layer is 10-80
% by weight, and the thickness of the modified olefin polymer layer is 10
A reflector for a circularly polarized antenna, characterized in that the thickness is 500 microns.