JPS61186003A - Manufacture of reflecting plate for circularly polarized wave antenna - Google Patents

Abstract

PURPOSE:To improve the adhesion between a metallic layer for reflection and an olefin group copolymer contg. an inorganic packing agent by providing a denatured olefin group copolymer layer between both the layers so as to form the titled antenna plate into a prescribed form. CONSTITUTION:A thermoplastic resin layer A with excellent weather resistance is bonded to one side of a metallic layer B reflecting a radio wave via a denatured olefin group copolymer layer C1 and a denatured olefin group polymer layer C2 is bonded to the opposite face side. Then a laminated member 3 obtained in this way is set in metallic dies 1, 2 so that its thermoplastic resin layer A comes to the moving side 1 of the metallic dies. This metallic dies is so formed that the thickness of the circumference is 1/6-5/6 gradually to the thickness of the center of the reflecting plate. Then the metallic dies 1, 2 are closed and an olefin group copolymer 5 contg. an inorganic packing agent is injected for molding. Thus, the reflecting plate having excellent adhesion between the metallic layer B and the copolymer 5 and where the metallic layer after forming is not cut off is obtained.

Description

Detailed Description of the Invention (I) Purpose of the Invention (Field of Industrial Application) The present invention provides a reflector for a circularly polarized antenna, in which the thickness of the circumference is thinner than the thickness of the center of the reflector. Regarding the manufacturing method. More specifically,
In manufacturing a reflector for a circularly polarized antenna, which is made of a laminated layer of a thermoplastic resin layer with excellent weather resistance, a metal layer that reflects radio waves, and an olefinic polymer layer containing an inorganic filler,
A layer of a modified olefin polymer obtained by modifying an olefin polymer with an unsaturated carboxylic acid and/or an anhydride thereof is interposed between the metal layer and the inorganic filler-containing olefin polymer layer, A metal foil thermoplastic resin laminated with a thermoplastic resin with excellent weather resistance and a modified olefin polymer layer is attached in advance to the moving side of the injection mold, and after the mold is closed,
An inorganic filler-containing olefin polymer is injection molded, and the thickness of the circularly polarized antenna reflector is gradually thinned so that the thickness of the circumferential part is 176 to 576 mm compared to the thickness of the center part. The present invention relates to a method for manufacturing a reflector for a circularly polarized antenna, which solves the problem of cutting a metal layer after molding, and provides a reflector for a circularly polarized antenna with improved strength against external pressure. The purpose is to

CII) Background of the invention (prior art and problems to be solved by the invention) High-definition television broadcasting, still image broadcasting, text multiplex broadcasting, PCM (pulse code modulation) audio broadcasting, facsimile broadcasting, etc. using geostationary satellites. Satellite broadcasting is planned to be put into practical use in the near future in critical countries such as Europe, the United States, and Japan, and some have already been put into practical use.

In a satellite broadcasting system, plans are being made to use circularly polarized waves for broadcasting satellite radio waves when receiving radio waves from broadcasting satellites. On the other hand, conventional circularly polarized antennas include those that use a conical horn, those that combine two Gui balls at right angles, and parabolic antennas that use these antennas as the primary radiator. The structure is complex and large, and manufacturing costs are high, so it is not suitable for general audience receiving antennas for receiving satellite broadcast radio waves using microwaves in the 12 gigahertz (G&) band. do not have.

On the other hand, the structure is extremely simple, and as a small and lightweight microwave antenna, a waveguide extends in the axial direction from the center of a parabolic reflector, and its tip is curved so that the opening end face is located at the focal point of the parabolic reflector. There is a so-called Hehat-type parabolic antenna which is opposed to a parabolic reflector and which is used as a -order radiator. This antenna is widely used in microwave antennas for mobile relays, etc., but all conventional Heehat-type parabolic antennas use the waveguide described above to transmit and receive linearly polarized waves. , 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. Moreover, even if a parabolic antenna having a predetermined shape is molded, so-called springback occurs after molding, and the parabolic antenna cannot exhibit its surface viscosity, which is the most important aspect of the parabolic antenna. moreover,
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 gJm or carbon fiber whose surface is metalized as a radio wave reflecting layer, but the manufacturing method is complicated and However, it is very difficult to maintain the radio wave reflective layer with a constant thickness and no unevenness, and furthermore, the radio wave reflection properties are poor. Also,
A parabolic antenna has been proposed in which an aluminum plate is used as a radio wave reflection layer and an olefin resin containing glass mat is formed as a base layer using a compression molding method. It is difficult to insert mold the boss etc.

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 laminate formed by sequentially laminating at least (A) a thermoplastic resin layer with good weather resistance, (B) a metal layer, and (C) a thermoplastic resin layer containing an inorganic filler, and the thickness of the thermoplastic resin layer is between 5 microns and 5+am, and the thickness of the metal layer is between 5 microns and 1 mm.

A reflector for a circularly polarized antenna, characterized in that the thermoplastic resin layer containing an inorganic filler has a thickness of 500 microns to 15 mm, and the content of the inorganic filler in this layer is 10 to 80% by weight. .

We discovered that it not only has excellent durability, but also has good radio wave reflection characteristics, and also exhibits various effects, and has previously proposed (for example, Japanese Patent Application Nos. 58-8535, 59-9485, No. 59-9488, No. 5j-t4
a7e number, 59-21856, 59-2E194
No. 5, No. 513-Ei8B52).

Furthermore, when an olefin polymer is used as the thermoplastic resin for each of the thermoplastic resin layer with good weather resistance and the inorganic filler-containing thermoplastic resin layer, the olefin polymer layer with good weather resistance and the metal layer and A layer of a modified olefin polymer obtained by modifying an olefin polymer with an unsaturated carboxylic acid and/or its anhydride is interposed between the metal layer and the inorganic filler-containing olefin polymer layer. It was discovered that the adhesion between the olefin polymer layer and the metal layer, and the metal layer and the inorganic filler-containing olefin polymer layer, both of which have excellent weatherability, is extremely good and easily obtainable, and has already been proposed. (Patent Application No. 59-87458).

However, in each of the circularly polarized antenna reflectors obtained as described above, wrinkles occur around the circumferential portion of the radio wave reflecting surface, and unevenness due to sink marks occurs around the circumferential portion. Furthermore, the metal layer may be cut. Moreover, not only does the resulting molded product undergo harmful deformation such as twisting, but it is also necessary to increase the injection pressure during molding.

(m) Structure of the Invention (Means for Solving the Problems) Based on the above, the present inventors have found that the above-mentioned problems have been improved, the strength against external pressure is excellent, and the As a result of various searches to obtain a reflector for a circularly polarized antenna without cutting the metal layer (generally metal foil), we found a thermoplastic resin layer with excellent weather resistance, a metal layer that reflects radio waves, and an inorganic filler. In manufacturing a reflector for a circularly polarized antenna in which olefin-containing polymer layers are laminated, an olefin-based polymer is added between the metal layer and the inorganic filler-containing olefin-based polymer layer. A thermoplastic resin layer with excellent weather resistance is interposed with a layer of a modified olefin polymer obtained by modifying it with an anhydride thereof, and a thermoplastic resin layer of a metal foil laminated with the modified olefin polymer. Install it in advance on the moving side of the mold for the injection molding machine,
After closing the mold, the inorganic filler-containing olefin polymer is injection molded so that the thickness of the circumferential part is 178 to 5/6 of the center of the circularly polarized antenna reflector. The method for manufacturing a reflector for a circularly polarized antenna, which is characterized by forming the reflector plate so that it becomes thinner sequentially, not only has excellent strength against external pressure, but also has excellent adhesion between the metal layer and the olefinic polymer layer containing an inorganic filler. The inventors have discovered that it is possible to obtain a reflector for a circularly polarized antenna, which has improved properties (adhesiveness) and does not require cutting of the metal layer after molding, and has arrived at the present invention.

(■) Detailed description of the invention (A) Thermoplastic resin The thermoplastic resin used to manufacture the thermoplastic resin layer of the present invention is widely produced industrially and used in many fields. , their manufacturing methods and various physical properties are well known. Their molecular weight varies depending on the type, but generally ranges from 10,000 to 1,000,000. Representative thermoplastic resins (I) are described in Japanese Patent Application No. 8535/1983. Among these thermoplastic resins, fluorine-containing resins such as polyvinylidene fluoride are preferred due to their excellent weather resistance, and resins containing vinyl chloride as the main component, ethylene and/or propylene as the main component Even if the resin is used, the weather resistance can be improved by adding an ultraviolet absorber, so these formulations can also be preferably used. Furthermore, polyamide resins, polyester resins and polycarbonate resins can also be used. Among these thermoplastic resins, olefin resins (ethylene homopolymer, propylene homopolymer,
An organic compound (a copolymer mainly composed of ethylene and/or propylene) with at least one double bond (
Particularly, it is advantageous to use a modified resin obtained by graft polymerization of an unsaturated carboxylic acid and its anhydride, in part or in whole, because it has excellent adhesion to the metal described below.

(B) Minor group Furthermore, typical examples of metals that are raw materials for the metal layer in the present invention include simple metals such as aluminum, iron, nickel, copper, and zinc, and alloys containing these metals as main components (for example, stainless steel). 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 may be an ethylene homopolymer or a propylene homopolymer. Polymers, copolymers of ethylene and propylene, copolymers of ethylene and/or propylene with other α-olefins having at most 12 carbon atoms (copolymerization ratio of α-olefins is at most 20% by weight) can be given. Melt index of these olefin polymers (according to JIS K2B4O7, measured at a temperature of 180°C and a load of 2.18 kg,
(hereinafter referred to as "ni,■,") or melt flow index (according to JIS K-875fl, temperature is 2.
Measured at 30℃ and a load of 2.18kg, below r
MFIJ) is preferably 0.01 to 100 g/10 minutes, particularly preferably 0.02 to 80 g/10 minutes. M, 1. or MFI is 0.0
If less than 1 g of olefin polymer is used, the resulting mixture will not have good moldability. On the other hand, 100
g/ When using an olefin polymer exceeding 10 minutes,
The mechanical properties of the resulting molded product are poor. In addition, low density (
0,900 g/c rn'') to high density (0,9
80 g/cm”) of ethylene homopolymer or copolymer of ethylene with a small amount of the above α-olefins, or propylene homopolymer or random or block copolymer of propylene with ethylene and/or other α-olefins. is desirable.

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.

(D) Inorganic filler Further, 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. As the inorganic filler,
Metals such as aluminium, copper, iron, lead and nickel, oxides of these metals and metals such as magnesium, calcium, barium, zinc, zirconium, molybdenum, silicon, antimony, titanium, and their hydrates (hydroxides) It is broadly classified into compounds such as sulfates, carbonates, silicates, their double salts, and mixtures thereof. Typical examples of the inorganic filler include the metals mentioned above, aluminum oxide (alumina), its hydrate, calcium hydroxide, magnesium oxide (magnesia), magnesium hydroxide,
Lead oxides such as zinc oxide (zinc white), red lead and white lead, magnesium carbonate, calcium carbonate, basic magnesium carbonate, white carbon, asbestos, mica,
Talc, glass fiber, glass powder, glass peas, clay, diatomaceous earth, silica, wollastonite, iron oxide, antimony oxide, titanium oxide (titania), lithopone, pumice grains, aluminum sulfate (gypsum, etc.), zirconium silicate,
Examples include zirconium oxide, barium carbonate, dolomite, molybdenum disulfide and iron sand. Among these inorganic fillers, those in powder form preferably have a diameter of 1 mm or less (preferably 0.5 mm or less), and those in fibrous form have a diameter of 1 to 500 microns (preferably i ~30
0 microns), and the length is o, i~BIl111(
A diameter of 0.1 to 5 mm is preferable, and a plate-like diameter is preferably 2 mm or less (preferably a diameter of 1III
1 or less is preferable. ) (E>Modified olefin polymer In addition, the modified olefin polymer used in the present invention is generally prepared by treating the olefin polymer with an unsaturated carboxylic acid and/or a derivative thereof in the presence of an organic peroxide. obtained by

(1) Unsaturated carboxylic acid and its anhydride A typical example of the unsaturated carboxylic acid or its anhydride used to produce this modified olefin polymer has at most 10 carbon atoms and at least one monobasic carboxylic acids having at most 15 carbon atoms and 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 anhydrides of the dibasic carboxylic acids (for example, maleic anhydride, anhydride \ imic acid). Among these unsaturated carboxylic acids or derivatives thereof, maleic acid and maleic anhydride are particularly preferred.

(2) Manufacturing method of modified olefin polymer To manufacture the modified olefin polymer of the present invention, any of various known manufacturing methods (for example, solution method, suspension method, melt method) may be employed. can do.

Among these production methods, when modifying an olefin polymer with an unsaturated carboxylic acid or its derivative by the melt method, a melt mixer (for example, an extruder) used in the field of general synthetic resins is used. , an olefinic polymer, 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, generally 120-270℃
In the case of propylene polymers, it is generally 18
The temperature is 0 to 270°C. As a radical initiator, 2.5
- Organic peroxides such as dimethyl-2,5-di(tert-butylperoxy)hexane, 2,5-dimethyl-5,5-di(tert-butylperoxy)hexane-3 and benzoyl peroxide. can be given.

For other manufacturing methods, please refer to the patent application Sho 5i3-Ei? 4
It is described in detail in the specification of No. 58.

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.

(F) Structure of each layer (1) Thermoplastic resin layer The thermoplastic resin layer of the present invention serves to prevent corrosion of the metal layer described later. For this reason, the thickness is usually 5 microns to 5 mm, preferably 10 microns to 5 mm, particularly 10 microns to llll.
1 m is suitable. If the thickness of this thermoplastic resin layer is less than 5 microns, not only corrosion of the metal layer will occur, but also wear and exposure of the metal layer due to contact and friction with other articles 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 1M layer.

(2) Metal layer (metal foil) Furthermore, the metal layer of the present invention functions to reflect radio waves. The thickness of this metal layer is generally between 5 microns and 1 mm, preferably between 5 and 500 microns, particularly between 10 and 500 microns. If the thickness of the metal layer is less than 5 microns, the metal layer is likely to wrinkle or fold during the production of a laminate, resulting in problems in terms of appearance and performance. On the other hand, if it exceeds 1m11, not only will the weight increase, but the cost will also increase.
Furthermore, it becomes a problem when curving or bending the laminate.

(3) Modified olefin polymer layer Furthermore, the thickness of the modified olefin polymer layer is generally 1
0 to 500 microns, preferably 10 to 400 microns, particularly 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, while if it exceeds 500 microns, it will be difficult to produce the reflective plate for the circularly polarized antenna of the present invention, as described below. Not only is the lamination method difficult, but it also increases costs.

(4) It is an olefin polymer layer containing an inorganic filler [that is, the composition ratio of the olefin polymer is 90 to 20% by weight], 1O~? The amount of Ofi is preferably %, especially 10-6
0% by weight is preferred. 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. - There is a problem that not only is there a possibility that peeling occurs 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 it exceeds 80% by weight, it is difficult to produce a uniform composition, and even if a uniform composition is obtained, it is difficult to produce a laminate by sheet production or injection molding as described below. In this case, it is not possible to obtain a good product (laminate).

The thickness of this inorganic filler-containing olefin polymer layer' will be explained in detail later.

In producing the thermoplastic resin layer and the inorganic filler-containing olefin polymer layer with excellent weather resistance, additives commonly used in the respective fields are added to the thermoplastic resin layer of the present invention and the inorganic filler-containing olefin layer. It may be added as long as it does not impair the properties of the composition of the polymer layer.

Used in blending the above-mentioned additives with the thermoplastic resin with excellent weather resistance of the present invention and in producing an inorganic filler-containing olefin polymer layer (including cases in which the above-mentioned additives are blended). The compositions are manufactured by mixing according to methods practiced in the respective industries.

The above additives and mixing method are disclosed in Japanese Patent Application No. 59-F3745B.
It is described in detail in the specification of the No.

When melt-kneading is performed to produce the above blends, it must be carried out at a temperature higher than the melting point or softening point of the thermoplastic resin or olefinic polymer used. The polymer deteriorates. For these reasons, the temperature is generally 20°C higher (preferably higher than 50"C) than the melting point or softening point of the respective thermoplastic resin or olefinic polymer, but does not cause deterioration. Performed over a temperature range.

(G) Method for producing laminated metal foil In the present invention, methods for laminating the thermoplastic resin layer and modified olefin polymer layer on the metal foil include commonly used dry lamination methods, extrusion lamination methods, etc. This can be achieved by applying The method will be explained in detail below.

The thermoplastic resin layer with excellent weather resistance, the metal foil as the metal layer, and the modified olefin polymer layer are laminated (
This can be accomplished by a commonly used dry lamination method. In this method, the metal foil may be laminated with a thermoplastic resin and a modified olefin polymer at the same time, or the metal foil may be laminated with either a thermoplastic resin layer or a modified olefin polymer layer in advance. It can also be obtained by laminating other layers onto the metal foil of the laminate.

In addition, manufacturing a laminated metal foil using an extrusion lamination method can be achieved by applying an extrusion lamination method that is generally practiced using a T-Guy film forming method. In this case, the thermoplastic resin and the modified olefin polymer may be simultaneously laminated on the metal foil, or the laminate obtained by laminating either the thermoplastic resin or the modified olefin polymer on the metal foil in advance It can also be obtained by laminating other layers on the surface of the metal foil.

Furthermore, either a thermoplastic resin or a modified olefin polymer is laminated onto the metal foil by either a dry lamination method or an extrusion lamination method, and another lamination method is applied to the surface of the metal foil of the resulting laminate. It can also be manufactured by laminating other layers.

When using a thermoplastic resin that has excellent adhesion to metal foil, a laminated metal foil can be manufactured as described above. However, if the adhesiveness of the thermoplastic resin to the metal foil is not fully satisfactory, a primer (anchor coating agent) commonly used in the thermoplastic resin field may be applied to one side of the entire metal foil. Applied by gravure coating method or reverse coating method, 50-100°C
Dry with. Next, a thermoplastic resin film or sheet is pressed onto the surface of the metal foil primer using a pressure roll heated to 50 to 100°C.

The primer differs depending on the type of thermoplastic resin in the thermoplastic resin layer, but it is commonly used in various fields, and there are aqueous types and solvent types. Also,
Types include polyurethane adhesives, epoxy resins, polyester resins, acrylic resins, and cyanoacrylate resins. Among these adhesion-imparting agents, polyurethane-based adhesives are particularly preferred because they have good durability under cold and hot cycles and high-temperature environments, and have high adhesive strength. Polyurethane adhesives are basically obtained by reacting any one of polyester polyols, polyether polyols, and polyurethane polyols with diisocyanates. These adhesion imparting agents are generally widely used, and are described, for example, in the “Adhesion Handbook” edited by the Japan Adhesive Association.
(November 10, 1980, published by Nikkan Kogyo Shimbun).

The laminated metal foil (metal layer) manufactured in this manner will be explained with reference to FIG. 4. FIG. 4 is a partially enlarged sectional view of the laminated metal foil. In this drawing, A is a thermoplastic resin layer with excellent weather resistance,
B is a metal layer (metal foil), C is a modified olefin polymer layer, and D is a single layer of primer. (If not used, D does not exist).

In addition, when using an olefin polymer as a thermoplastic resin with excellent weather resistance, the above-mentioned modified olefin polymer can be used instead of this primer (in this case, the above primer can be replaced with a modified olefin polymer). layers).

(H) Manufacture of reflector for circularly polarized antenna The thermoplastic resin layer of the laminated metal foil obtained in the above manner is attached to the mold surface on the moving side of the mold of an injection molding machine. Close the mold.

Next, the reflection plate for a circularly polarized antenna of the present invention can be manufactured by injection molding the inorganic filler-containing olefin polymer. At this time, the injection molding temperature is
The resin temperature is higher than the melting point of the olefin polymer containing an inorganic filler, but lower than the thermal decomposition temperature of the olefin polymer. Therefore, the molding temperature varies depending on the type of olefin polymer used. When using a propylene polymer as the olefin polymer, the temperature is 170 to 290°C,
When using ethylene polymer, 120-250℃
It is.

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 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. Injection pressure is generally 40~
140 Kg/cm', especially 70-12
0 Kg/crn' is desirable.

The above injection molding will be explained in an easy-to-understand manner using drawings.

FIG. 5 is a sectional view before injection molding, and FIG. 6 is a sectional view after injection molding. In these drawings, 1 is a male mold, and 2 is a female mold. Further, 3 is a laminated metal foil, and 4 is a female gate. Furthermore, 5
is an olefinic polymer layer containing an inorganic filler. first,
The thermoplastic resin layer of the metal foil laminated on the male die 1 of the die shown in FIG. 5 is attached to the male die of the die so that it is on the moving side of the die. After the mold is closed, the olefin polymer containing an inorganic filler is injection molded through the gate 4 under the resin temperature and injection pressure conditions described above (the state at this time is shown in FIG. 6). Note that the injection molding machine used is not unique to the present invention, but may be one used in the field of general thermoplastic resins, and the operating conditions are also the same as in the usual case.

(J) Reflector for Circularly Polarized Antenna The reflector for circularly polarized antenna of the present invention obtained as described above will be explained below with reference to FIGS. 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. Moreover, FIG. 3 is a partially enlarged view of the cross-sectional view. In FIG. 1, I is a reflector for a circularly polarized antenna of the present invention, II is a converter, ■ is a converter support rod, and ■ is a reflector support rod. Also,■
is the wiring. In addition, in FIGS. 2 and 3, a
is a laminated metal foil, and b is a thermoplastic resin layer containing an inorganic filler. Furthermore, A is a thermoplastic resin layer with excellent weather resistance, and B is a metal foil. Moreover, E is an inorganic filler-containing olefin polymer layer consisting of an inorganic filler and an olefin polymer. Further, C is a modified olefin polymer, and D is a primer layer or a modified olefin polymer layer, but they may not exist. Furthermore, in order to attach the reflector for a circularly polarized antenna obtained in this way to a support, ribs may be attached to the inorganic filler-containing olefin polymer layer to enable attachment. It is also possible to add reinforcing ribs to reinforce the reflector. 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 flOcm to 120cm.

The thickness of the inorganic filler-containing olefin polymer layer of this reflector for a circularly polarized antenna is usually 3 to 10 mm at the center, and preferably 3 to 8 mm. Also, the periphery of 1 is 2~
8 mm, particularly preferably 2 to 8 mm. However, the thickness of the peripheral part is 1/6 to 5/6 of the thickness of the central part, and preferably 1/4 to 5/6.

If the thickness of the peripheral part is less than 1/6 of the thickness of the central part,
The thickness of the peripheral portion becomes very thin, which not only reduces the strength against external pressure but also reduces the formability. On the other hand, 5/6
Exceeding this will not only make the peripheral part thicker than the center part, but also make the circularly polarized antenna reflector heavier.

The metal layer (metal foil) becomes easy to cut, and harmful deformation such as twisting occurs in the molded product. The thickness of this inorganic filler-containing olefin polymer layer does not necessarily have to become thinner linearly from the center toward the periphery, but may be made thinner sequentially.

(V) Effects of the Invention The circularly polarized antenna reflector manufactured by 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 R does 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 laminated metal foil is easy to handle;
For example, it is possible to store it in a roll.

(7) When setting the laminated metal foil in the mold during injection molding, the laminated metal foil can be used in the form of a roll, so it can be continuously supplied, increasing productivity. is significantly improved.

(8) It can be easily molded even when the injection molding pressure is low.

(9) When attaching a boss to be inserted into the back surface, the thickness of the central portion is thick, so unevenness due to sink marks etc. does not occur on the reflective surface.

In particular, a modified olefin polymer layer is interposed between the metal layer and the inorganic filler-containing olefin polymer layer, so the thermoplastic resin has excellent adhesion between the metal layer and the inorganic filler-containing olefin polymer layer, and also has excellent weather resistance. When using an olefin polymer as a metal layer, a modified olefin polymer is interposed between the olefin polymer layer and the metal layer, eliminating the need for a primer, which eliminates the complicated steps of applying and drying the primer. can be omitted.

(Vl) Examples and Comparative Examples The present invention will now be explained in more detail with reference to Examples.

In the Examples and Comparative Examples, the radio wave reflectance was measured as a microwave reflection coefficient from the voltage standing wave ratio when a waveguide was used and the tip of the waveguide was short-circuited. Weather resistance tests were conducted using a Sunshine Carbon Weather Meter with a black panel temperature of 83°C and a due cycle of 1.
Surface appearance after 2,000 hours under conditions of 2 minutes/(60 minutes irradiation) (discoloration, fading, gloss change, crazing, blistering,
All layers were evaluated for harmful changes such as AM peeling and cracking.Furthermore, a heat cycle test was performed by heating the sample to 80℃ 2
After exposure for 4 hours, the sample was gradually cooled to -45°C, exposed to this temperature for 2 hours, and then gradually heated to 80°C over 4 hours, and after repeating this cycle 100 times. The surface appearance 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 circularly polarized antenna reflector.
Based on ASTM 0-903, peeling speed is 50mm/
The strength was evaluated by peeling the metal foil laminated at a speed of 180 degrees.

In general, bending stiffness was measured according to ASTM D-790 and coefficient of thermal expansion was measured according to ASTM D-811El.

The types and physical properties of the thermoplastic resin, olefin polymer, modified olefin polymer inorganic filler, and metal foil used in the thermoplastic resin layer in Examples and Comparative Examples are shown below.

[(A) Thermoplastic resin]

As a thermoplastic resin with excellent weather resistance, it has a melt flow rate (according to ASTM D-1238, temperature of 25
Measured at 0℃ and load 10Kg) is fl, 1g
Polyvinylidene fluoride (r PVd
FJ), a propylene homopolymer containing 0.4% by weight of a benzotriazole-based ultraviolet absorber and 0.5% by weight of Garpon black [melt flow index (according to JIS K-f3758, temperature 2
30℃ and load 2. Measured under the condition of lf3Kg.

rMFIJ) for 10 minutes, hereinafter r
PPCA) J], high-density polyethylene containing 0.4% by weight of a benzotriazole-based UV absorber and 0.5% by weight of carbon black [density 0.9
58g/c rn”, melt index (JIS
Measured according to K-8780 at a temperature of 190℃ and a load of 2.16Kg, hereinafter referred to as "Ni,■,")
is 0.8 g/10 min, hereinafter referred to as r) IDPE (1) J], and the Mooney viscosity (ML1+4) is 10
Chlorinated polyethylene (chlorine content 3.15% by weight, amorphous, molecular weight of raw material polyethylene approximately 200,000) 20
parts by weight and 80 parts by weight of a 7-acrylonitrile-styrene copolymer resin (acrylonitrile content 23% by weight) and 2 parts by weight of a dibutyl tin malate stabilizer [manufactured by Sankyoki Gosei Co., Ltd., trade name: Stan (trade name: Stan)
BM] was kneaded for 10 minutes using a roll (surface temperature 180°C), and the resulting composition (hereinafter referred to as rAGs J), 20 parts by weight of dioctyl phthalate (as a plasticizer) and 5.0 parts by weight Dibutyltin malate (
as a dehydrochlorination inhibitor) and 100 parts by weight of vinyl chloride homopolymer (degree of polymerization 1100, hereinafter r rPVCJ).
A mixture of these ingredients was used.

[(B) Olefin polymer]

As an olefin polymer, MFT is 0.7g/10
Propylene-ethylene block copolymer (ethylene content 10.5% by weight, hereinafter referred to as rPP(B)J), M, 1. High-density ethylene homopolymer with a density of 20 g/10 min (density 0.961 g/c
rn', hereinafter referred to as rH[1PE(2)'') was used.

[(C) Modified olefin polymer]

As a modified olefin polymer, MFI is 0.5g71
propylene homopolymer (density 0,110
0g/crn”) 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 using a Henschel mixer. A modified propylene polymer (maleic anhydride content: 0.32% by weight, Instead of the propylene homopolymer used to produce modified PPJ (hereinafter referred to as "modified PPJ") and modified ρρ, an ethylene L/7 polymer (M,!, 0.2. A modified ethylene polymer (maleic anhydride content: 0.24% by weight, hereinafter referred to as "modified PEJ") manufactured under the same conditions as the modified PP was used, except that 710 minutes) was used.

[(D) Inorganic filler]

As inorganic fillers, talc with an average particle size of 3 microns (aspect ratio of about 7), mica with an average particle size of 3 microns (aspect ratio of about 8), glass fiber (single fiber diameter of 11 microns, cut length of 3 mm, Below 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 approximately 20 microns thick)
rAJllJ) and copper foil were used.

Examples 1 to 6 and Comparative Examples 1 to 9 (as the above-mentioned PVdFC thermoplastic resin) were molded to form a film having a thickness of 100 microns. Also,
Apply an acrylic primer (manufactured by Showa Kobunshi Co., Ltd., trade name Vinyroll 92T) to one side of the All foil to a thickness of 2.
Apply it so that it is 0 microns. The PVdF film described above was dry-laminated on one layer of the acrylic primer of this A blank at 80° C., and extrusion lamination was performed while molding the film (thickness: 50 μm) using a T-die.

Further, 30 parts by weight of GF (as an inorganic filler) and 70 parts by weight of PP(C) (as a thermoplastic resin (II)) were each triblended for 5 minutes using a Henschel mixer. The resulting mixture was heated to a resin temperature of 230°C.
pellets (composition) using a vented extruder under conditions of
was manufactured.

The laminated AM foil produced as described above was placed on the male side of the mold of an injection molding machine (clamping force: 1500 tons) (the thermoplastic resin layer with excellent weather resistance was placed on the moving side of the mold). I inserted it so that it looks like this. Table 1 shows the thickness distribution at the center (the ratio of the thickness at the circumference to the thickness at the center).

In Table 1, "cutting of All" was evaluated by observing the appearance with the naked eye.In this section, "0"
is A9. “X” means that there was no cutting of the foil.
This means that the foil was cut. “Deformation of the reflector °°
After the obtained molded product (reflector plate) was placed face down on a horizontal surface, it was determined by the deviation of the entire circumferential portion from the horizontal surface. In this section, "o" means that there was no deviation from the horizontal plane, "ΔJ" means that a slight deviation from the horizontal plane occurred, and "x" means that a considerable deviation occurred. Moreover, "moldability" was determined by the extent to which the inorganic filler-containing thermoplastic resin surrounded the circumference of the obtained molded product. In this section.

"Oj means that it went around the entire surface of the mold,"
Δ" means that it did not go around the circumference a little, and "x" means that it did not go around the entire inner circumference. Furthermore, "sink marks" were determined by the presence or absence of unevenness at the center and circumference.In this section,
"o" means that no unevenness occurred in the center or circumference, and "x" means that unevenness occurred. Table 1 shows the evaluation results of the obtained molded product (reflection plate).

When the peel strength of each of the obtained reflective plates was measured, it was found that the adhesive strength between Bunji A (metal foil) and the inorganic filler-containing olefin polymer layer was too strong, and the Al foil was broken (
(hereinafter referred to as "cohesive failure").

(Margins below) Examples 7 to 19, Comparative Examples io, 11 Thermoplastic resins whose types are shown in Table 2 were molded, and the thickness of each was 10.
A 0 micron film was produced. In addition, an acrylic primer or a urethane primer was applied to one side of each metal foil whose type is shown in Table 2 in the same manner as in Example 2, and then dried (in Examples 16 and 17, urethane primer was applied to both sides). (In Examples 14 and 15, no acrylic primer was applied). The thermoplastic resin film was laminated on the primer surface of each metal foil thus obtained. On the metal foil surface of the laminate obtained in this way, the modified products whose types are shown in Table 2 were extruded and laminated to a thickness of 20 microns (However, in Examples 14 and 15, 1 After laminating modified olefin polymer on both sides, thermoplastic resin is laminated on one side of the metal foil.)
.

Furthermore, an inorganic filler and a thermoplastic resin (the types of each inorganic filler and thermoplastic resin and the content of the inorganic filler in the composition are shown in Table 2. In Comparative Example 1O, the inorganic filler was Tri-blending was performed in the same manner as in Example 2. A composition was manufactured using a vented extruder while kneading each of the obtained mixtures at 230 ml.

The laminated metal foil obtained as described above was inserted into the mold of an injection molding machine in the same manner as in Example 2 so as to form the male surface of the mold. After closing the mold, a thermoplastic resin containing an inorganic filler was injected at a pressure of 80 kg/c as in Example 2.
rn' and Table 2, insert injection molding was performed at a resin temperature of 240° C. to produce a reflector for a circularly polarized antenna having the same shape as in Example 2.

Olefin Polymer The flexural modulus and linear expansion coefficient of an olefin polymer composition containing an inorganic filler were measured.

The results are shown in Table 3. In addition, when the peel strength of the metal foil was measured from the olefin polymer layer containing the S filler of each of the reflectors obtained in the manner described above, all cases showed cohesive failure.

Table 3 (Part 1) Table 3 (Part 2) In all of the circularly polarized antenna reflector plates obtained in Examples 7 to 19, no cutting of the An foil could be observed. Furthermore, regarding deformation of the reflector, there was no deviation from the horizontal plane, and regarding moldability, the reflex polymer containing an inorganic filler was evenly distributed over the entire surface of the mold. Furthermore, regarding sink marks, no unevenness could be observed at the center or circumference of the reflector.

When the radio wave reflectance of each of the circularly polarized antenna reflectors obtained as described above was measured, it was 98%. Furthermore, a weather resistance test and a heat cycle test were conducted, 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 11. . However, in Comparative Example 11, the aluminum foil on the surface corroded.

[Brief explanation of drawings]

FIG. 1 is a partial perspective view of an antenna to which a reflector for a circularly polarized antenna is attached, and FIG. 2 is a sectional view of the reflector for a circularly polarized antenna. Moreover, FIG. 3 is a partially enlarged view of the cross-sectional view. Further, Figure ti44 is a partially enlarged sectional view of the laminated metal foil. Moreover, FIG. 5 is a sectional view before injection molding, and FIG. 6 is a sectional view after injection molding. ■・・・Reflector plate II for circularly polarized antenna...
・Converter ■・・・Converter support rod■・・・Reflector support rod■・・・Wiring A・・・Thermoplastic resin layer B with excellent weather resistance
...Metal foil C...Modified olefin polymer layer D...
・Primer layer E...Inorganic filler-containing olefin polymer layer a
...... Laminated metal foil b ... Inorganic filler-containing olefin polymer layer 1 ... Male mold 2 ... Female mold Type 3... Laminated metal foil 4...
female gate

Claims (1)

[Claims] In manufacturing a reflector for a circularly polarized antenna, which is made of a laminated layer of a thermoplastic resin layer with excellent weather resistance, a metal layer that reflects radio waves, and an olefinic polymer layer containing an inorganic filler,
A layer of a modified olefin polymer obtained by modifying an olefin polymer with an unsaturated carboxylic acid and/or an anhydride thereof is interposed between the metal layer and the inorganic filler-containing olefin polymer layer, A thermoplastic resin layer of metal foil laminated with a thermoplastic resin with excellent weather resistance and a modified olefin polymer layer is attached in advance to the moving side of the injection mold, and after the mold is closed, an inorganic Filler-containing olefin polymer is injection molded,
A circularly polarized antenna characterized in that the reflector for circularly polarized antenna is formed so that the thickness of the circumferential part becomes gradually thinner to 1/6 to 5/6 of the thickness of the center part. A method of manufacturing a reflector for an antenna.