JPS61244103A - Manufacture of reflector for circular polarized wave antenna - Google Patents

Abstract

PURPOSE:To not only obtain superior strength to external pressure, but also eliminate the cutting of a metallic layer after molding by forming a reflector for a circular polarized wave antenna so that the thickness is smaller at the peripheral part than at the center part. CONSTITUTION:The thickness of the inorganic filler incorporated thermoplastic resin layer of the reflecting plate for the circular polarized wave antenna is normally 3-10mm at the center part and preferably 3-8mm. The thickness, however, is 2-8mm at the peripheral part and preferably 2-6mm. The thickness of the peripheral part is 1/6-5/6 and preferably 1/4-5/6 time as large as that of the center part. When the thickness of the peripheral part is <=1/6 time as large as that of the center part, the thickness of the peripheral part becomes extremely small and not only the strength to external pressure, but also moldability decrease. When the thickness becomes >=5/6 time, the weight increases and the metallic layer (metallic foil) is easily cut; and harmful deformation such as a twist occurs to a molding.

Description

[Detailed Description of the Invention] CI) Purpose of the Invention (Industrial Field of Application) The present invention is directed to the manufacture of 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 method. More specifically,
Using a metal foil laminated with a thermoplastic resin layer with excellent weather resistance on one side and a thermoplastic resin layer on the other side,
The thermoplastic resin layer with excellent weather resistance of the laminated metal foil is attached in advance to the moving side of the injection mold, and after the mold is closed, the inorganic filler-containing thermoplastic resin is injection molded. , the thickness of the circumferential part is 178 to 5/6 of the thickness of the center part of this circularly polarized antenna reflector.
The present invention relates to a method for manufacturing a reflector for a circularly polarized antenna, which is characterized by forming the reflector plate so that it becomes gradually thinner so that the reflector plate becomes thinner and thinner. The object of the present invention is to provide a reflector for a circularly polarized antenna.

(II) Background of the invention (prior art and problems to be solved by the invention) High-definition television broadcasting using geostationary satellites, still image broadcasting, text multiplex broadcasting, PCM (pulse code modulation) audio broadcasting, facsimile broadcasting, etc. Satellite broadcasting is planned to be put into practical use in the near future in Europe, the United States, Japan, and other countries around the world, 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 using a conical horn, two Goupoles combined 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, making it impossible to achieve the surface precision that is most important for a parabolic antenna.
Attempts have been made to manufacture radio wave reflectors in which glass fibers or carbon fibers with metalized surfaces are laminated to thermosetting resins such as unsaturated polyester resins, 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.

In addition, a parabolic antenna has been proposed in which an aluminum plate is used as the radio wave reflection layer and an olefin resin containing glass mat is formed and laminated as the base material layer by compression molding. It is difficult to insert mold bosses 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. , at least (A) a thermoplastic resin layer with good weatherability, (B) a metal layer, and (C) an inorganic filler-containing thermoplastic resin layer are laminated in sequence, and the thermoplastic resin layer has The thickness is 5 microns to 5 cm, and the thickness of the metal layer is 5 microns to 5 cm.
A circle characterized in that the thickness of the inorganic filler-containing thermoplastic resin layer is 500 microns to 15 mm, and the content of the inorganic filler in this layer is 10 to 80% by weight. We discovered that a reflector for polarized antennas not only has excellent durability, but also has good radio wave reflection characteristics, and also exhibits various effects, and we have previously proposed it (for example, in Japanese Patent Application No. 59-8535). No. 59-13465, No. 59-948θ, No. 58-1
No. 4478, No. 59-28945, No. 59-6111
G52).

However, the adhesion between the inorganic filler-containing thermoplastic resin layer of the reflector for a circularly polarized antenna obtained in this way and the metal foil cannot necessarily be said to be satisfactory. Using a metal foil laminated with a thermoplastic resin layer with excellent weather resistance and an olefin polymer layer on the other side, the thermoplastic resin layer of the laminated metal foil is placed in the moving side mold of the injection mold. The olefin polymer layer containing an inorganic filler is attached to the surface so that the olefin polymer layer is on the fixed mold side, and after the mold is closed, the olefin polymer containing an inorganic filler is injection molded. It was discovered that the adhesion between the metal layer and the metal layer was extremely excellent, and was previously proposed (Japanese Patent Application No. 1985-2185Ei).

However, in all of the obtained reflecting plates for circularly polarized antennas, wrinkles occur around the circumference of the radio wave reflecting surface, and unevenness due to sink marks occurs around the circumference. 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 that one side of the metal foil was coated with a ``thermoplastic resin with excellent weather resistance'' [hereinafter referred to as ``thermoplastic resin'']. a layer called “resin (1)”;
``Thermoplastic resin'' on the other side [hereinafter [thermoplastic resin (■
)" using a metal foil with a calendar laminated thereon, the thermoplastic resin (I) layer of the laminated metal foil is attached in advance so as to be on the moving side of the injection mold,
After closing the mold, the inorganic filler-containing "thermoplastic resin"
Hereinafter referred to as "thermoplastic resin (■)"] is injection molded,
A reflector for a circularly polarized antenna, characterized in that the reflective plate for a circularly polarized antenna is formed so that the thickness of the circumferential part becomes gradually thinner from 1/6 to 5/6 of the center part. The method of manufacturing the board.

The inventors have discovered that it is possible to obtain a reflector plate for a circularly polarized antenna that not only has excellent strength against external pressure, but also does not have the metal layer cut after molding, and has thus arrived at the present invention.

(IV) Detailed description of the invention (A) Thermoplastic resin (I) The thermoplastic resin (I) used for manufacturing 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 1
It is from 10,000 to 1,000,000. Typical thermoplastic resins (I) include heptad homopolymers having double bonds such as ethylene, propylene, vinylidene fluoride, vinyl chloride, and styrene, and these as main components (50% by weight). % or more), a copolymer of styrene and 7-crylonitrile (AS resin), a resin whose main component is methyl methacrylate (MMA resin), butadiene copolymer rubber,
Acrylonitrile-butadiene copolymer rubber (NBR)
, styrene-butadiene copolymer rubber (SBR), acrylic rubber, ethylene-propylene copolymer rubber (EPR)
, ethylene-propylene-diene ternary copolymer rubber (E
Graft copolymer resins, polyamide resins, polyester resins, polyphenylene obtained by graft copolymerizing styrene alone or styrene with other vinyl compounds (e.g., acrylonitrile, methyl methacrylate) on rubbers such as PD) and chlorinated polyethylene. Examples include oxide resins and polycarbonate resins. Furthermore, even if these thermoplastic resins are modified by grafting an organic compound having at least one double bond (for example, an unsaturated carboxylic acid or its anhydride), they have excellent processability. You can use it if you like. Furthermore, in addition to the graft copolymer resins described above, compositions obtained by blending the above-mentioned rubbers with these thermoplastic resins (the blending ratio of rubber is generally at most 40% by weight) can also be used. 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 resin,
Polyester resins and polycarbonate resins can also be used. Among these thermoplastic resins, organic compounds (especially, It is advantageous to use part or all of a modified resin obtained by graft polymerization of an unsaturated carboxylic acid and its anhydride (preferably an unsaturated carboxylic acid and its anhydride) because it has excellent adhesion to metals described below.

(B) Metal 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, alloys containing these metals as main components (for example, Stainless steel and yellow (G4) may be mentioned.These metals do not need to be surface-treated, and may be surface-treated in advance by chemical treatment or plating. Furthermore, those that have been painted or printed can also be preferably used.

(C) Thermoplastic resin (II) Furthermore, the thermoplastic resin (II) used to produce the inorganic filler-containing thermoplastic resin layer of the present invention is the same type as the above-mentioned thermoplastic resin (I). can do.

Among these thermoplastic resins (II), acrylonitrile and styrene are graft copolymerized to propylene resin (pp), resin 01MA resin whose main component is methyl methacrylate), butadiene rubber, acrylonitrile-butadiene rubber, or styrene-butadiene rubber. Acrylonitrile-butadiene terpolymer resin (ABS resin) obtained by ), polyphenylene oxide resin (PPO resin), polyethylene terephthalate (PE
T), polybutylene terephthalate (PBT) and polycarbonate resin (PC resin), these thermoplastic resins (II) are industrially produced like thermoplastic resin (I) and are used in a wide range of fields. It is something that exists. Regarding their manufacturing method and various physical properties, please refer to Japanese Patent Application No. 59-8535. d-448
No. 5, No. 59-941118, No. 59-948? issue,
No. 59-13517, No. 5111-14478, No. 59-28!345, No. 59-88852, No. 59
-! 301El? No. 59-90170 and the specifications of Encyclopedia of Polymer Science and Technology (Encyclopedia of Polymer Science and Technology).
edia of Polymer 5ciance a
nd Technology” (Interscience Publishers (A division of John)
Wiley & 5ons, Inc., published from 1864 to 1971].

(D) Inorganic filler Further, the inorganic filler used to produce the inorganic filler-containing thermoplastic resin layer is generally one widely used in the fields of synthetic resins and rubber. These inorganic fillers are preferably inorganic compounds that do not react with oxygen and water, and that do not decompose during crosstalk or molding. The inorganic fillers include metals such as aluminum, copper, iron, lead and nickel, and these metals as well as magnesium, calcium, barium,
Fermentations of metals such as zinc, zirconium, molybdenum, silicon, antimony, titanium, etc., and their hydrates (hydroxides)
, sulfates, charcoal! ! i! compounds such as salts, silicates,
It is broadly classified into these double salts and mixtures thereof. Typical examples of the inorganic filler include the metals mentioned above, aluminum oxide (alumina), its hydrate, calcium hydroxide,
Magnesium oxide (magnesia), magnesium hydroxide, zinc oxide (zinc oxide), oxides of lead such as red lead and white lead, magnesium carbonate, calcium carbonate, basic magnesium carbonate, white carbon, asbestos, mica, talc, iron. Glass fiber, glass powder, glass beads,
Clay, silica, silica, wollastonite, iron oxide, antimony oxide, titanium oxide (titania), lithopone, pumice powder, aluminum sulfate (gypsum, etc.), zirconium silicate, zirconium oxide, barium carbonate, dolomite, disulfide Examples include molybdenum and iron sand. Among these inorganic fillers, those in powder form preferably have a diameter of 1 µm or less (preferably 0.5 µm or less), and those in fibrous form have a diameter of 1 to 500 microns (preferably 0.5 µm or less). is 1-300
A fist with a length of 0.1 to 8 mm (preferably 0.1 to 5 microns) and a length of 0.1 to 8 mm (preferably 0.1 to 5 vs. , ) (E) Thermoplastic resin (m) Furthermore, the thermoplastic resin (m) used in the present invention is the same as the thermoplastic resin (II) used for producing the inorganic filler-containing thermoplastic resin layer at room temperature. Or does it have excellent adhesion at injection molding temperatures? It is preferred to use However, if a thermoplastic resin (m) that has poor adhesion to the thermoplastic resin (II) of the inorganic filler-containing thermoplastic resin layer is used, the inorganic filler-containing thermoplastic resin layer and the thermoplastic resin layer This is undesirable because it causes delamination, and therefore, those in which the thermoplastic resin (II) and the thermoplastic resin (m) are the same are suitable.

In addition, even if the thermoplastic resin (IU) and the thermoplastic resin (IU) are not the same type, it is preferable that they have the same 7/ma units (for example, ABS resin and ACS
resin or MBS resin). Thermoplastic resins that are the same or do not have the same heptad unit can be preferably used as long as they have the same structure. (
(e.g., PBT and PET), but also thermoplastics optionally mixed with each other (e.g., PvC and ABS), as described by O. Olabisi, L. M. Robson. and M.T.-9 Show (0,0laisi, L,
M, Robesonand M, T, Shaw
), “Polymer-Polymer Miscellaneousness”
17mer-Polymer Miscibility
)” [Academic Printing Co., Ltd., New York (Ac
academic Press, New York),
Published in 1879], D.E.R. Paul and Niss Newman (D.

``Polymer Blends'' by Paul R. and Newman S.
” (Academic Printing Co., Ltd., New York (Ac
academic Press, New York),
Published in 1978], written by K. Solda (K, 5olc),
゛°Polymer Compatibility and Incocompatibility 4
property andImco+npatibility)
++ C no＼Ryutsudo Akademi Tsuku Publisher, -
Knee York (Harwood Academic Pr.
ess, New York), published in 1982] and Elle.

M Robeson (L, M, Robeson), ``Polymer Engineering Science''
r Engineering 5science)” 2nd
4, No. 8, p. 587, (1884).

(F) Structure of each layer (1) Thermoplastic resin (I) layer The thermoplastic resin (I) 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 m+a, preferably 10 microns to 5 mm, particularly 10
Microns to 1 mm are preferred. If the thickness of this thermoplastic resin (I) layer is less than 5 microns, not only will the metal layer be corroded, but it will also wear out and be exposed due to contact and friction with other articles during use. There are problems caused by things like this happening. On the other hand, if it exceeds 5II1 m, it is not preferable because it not only lowers the reflectance of radio waves but also increases the cost and weight of the laminate.

(2) Metal M (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 inch, preferably between 5 and 500 microns, and 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 1mm,
This not only increases the weight, but also increases the cost, and also poses a problem when curving or bending the laminate.

(3) Thermoplastic resin (m) layer The thermoplastic resin (m) layer constituting the laminated metal foil in the present invention is an inorganic filler-containing thermoplastic resin layer that functions as a radio wave reflecting layer and a metal foil. This function not only improves the adhesion with the laminated metal foil, but also facilitates storage and handling of the laminated metal foil. The thickness of this thermoplastic resin (m) layer is usually 5 to 500 microns, preferably 5 to 300 microns,
Particularly preferred is 5 to 200 microns. If the thickness of the thermoplastic resin (III) is less than 5 microns, wrinkles will easily occur in the thermoplastic resin (III) layer during the production of laminated metal foil, and the surface of the metal foil will not be affected by this. , there are problems in terms of appearance and performance. On the other hand, if it exceeds 500 microns, a problem arises because the mechanical properties such as strength and rigidity of the inorganic filler-containing thermoplastic resin layer deteriorate.

(4) Inorganic filler-containing thermoplastic resin layer The composition ratio of the inorganic filler in the inorganic filler-containing thermoplastic resin layer of the present invention is 10 to 80% by weight (i.e., the composition of the thermoplastic resin (II) The ratio is 90-20ji
%], preferably 10 to 70% by weight, particularly 10 to 60% by weight
% by weight is preferred. If the composition ratio of the inorganic filler in the inorganic filler-containing thermoplastic resin layer is less than 10% by weight,
The linear expansion coefficient of the inorganic filler-containing thermoplastic resin layer is too different from that of the metal layer, and there is a possibility that peeling may occur between the metal layer and the inorganic filler-containing thermoplastic resin layer due to heat cycling. In addition, there is a problem that the rigidity of the obtained laminate is insufficient. 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. However, it is not possible to obtain a good product (laminate).

The thickness of this inorganic filler-containing thermoplastic resin layer will be explained in detail later.

The thermoplastic resin (I) layer and thermoplastic resin (m) 1
and stabilizers against oxygen, heat and ultraviolet rays, metal deterioration inhibitors, flame retardants, colorants, and electrical property improvers commonly used in the respective fields for producing thermoplastic resin layers containing inorganic fillers. Additives such as antistatic agents, lubricants, processability improvers and tack improvers are added to the thermoplastic resin (I) 7! of the present invention. and thermoplastic resins (
It may be added to the extent that the properties of the compositions of the layer III) and the inorganic filler-containing thermoplastic resin layer are not impaired.

Thermoplastic resin (E) and thermoplastic resin (m) of the present invention
When blending the above-mentioned additives and manufacturing the inorganic filler-containing thermoplastic resin layer (including the case where the above-mentioned additives are blended), a mixer such as a Henschel mixer, which is commonly used in each industry, is used. It can be obtained by melt-kneading using a mixer such as a Banbury mixer, Nigoo, roll mill, or single screw extruder. At this time, the composition obtained by triblending in advance (
Mixture) A homogeneous composition can be obtained by melt-kneading.

In particular, thermoplastic resin (I) or thermoplastic resin (m
) It is preferable to use both of them in powder form because they can be mixed more uniformly.

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 thermoplastic resin (II) of the present invention, all the ingredients may be mixed at the same time, or some of the ingredients may be mixed in advance to produce a so-called masterbatch. The masterbatch and the remaining ingredients may be mixed.

When melt-kneading is carried out in the production of the above blends, it must be carried out at a temperature equal to or higher than the melting point or softening point of the thermoplastic resin (I), thermoplastic resin (II) or thermoplastic resin (III) used. , thermoplastic resin (1), thermoplastic resin (TI) and thermoplastic resin (m) deteriorate when carried out at high temperatures. For these reasons, generally the respective thermoplastic resins (I) and thermoplastic resins (II
') or at a temperature 20°C higher than the melting point or softening point of the thermoplastic resin (III) (preferably a temperature higher than 50°C), but within a temperature range that does not cause deterioration.

(G) Manufacturing method of laminated metal foil In the present invention, the method of laminating the metal foil with the thermoplastic resin CI) layer and the thermoplastic resin (III) layer is a commonly practiced dry lamination method (extrusion lamination). This can be achieved by applying the law).

This method can be achieved in the same manner as the method described in the section ``Method for manufacturing laminated metal foil'' of Japanese Patent Application No. 59-218513.

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 (I) layer with excellent weather resistance, B is a metal layer (metal foil), and D is a thermoplastic resin (m) Jl. Furthermore, C1 and C2 are primer calendars (in addition, if one or both of the primers is not used, Ct
and/or C2 is not present).

()l) Manufacture of reflector for circularly polarized antenna Attach the thermoplastic resin layer of the laminated metal foil obtained as described above so that it becomes the moving side mold surface of the mold of an injection molding machine, Close the mold.

Next, the reflective plate for a circularly polarized antenna of the present invention can be manufactured by injection molding the thermo-Machida resin containing an inorganic filler. At this time, the injection molding temperature is the resin temperature, which is a thermoplastic resin (II
), but the temperature is higher than the melting point of the thermoplastic resin (II
) is lower than the thermal decomposition temperature of Therefore, the molding temperature varies depending on the type of thermoplastic resin (11) used. The typical molding temperature range of thermoplastic resin (II) is shown below.

Type Molding temperature range (“0”) P P
170~290ABS resin
200~290AC3 resin ieo~2
40Pro resin 220~300P E T
250-300P BT
230-280P C250-30
0 In addition, if the injection pressure is 40 kg/crn” or higher at the nozzle of the cylinder of the injection molding machine, the thermoplastic resin containing an inorganic filler can be shaped into a shape almost similar to that of the mold. Injection pressure is generally 40 to 14 mm.
0 Kg/crn', especially 70-12
0 Kg/ 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 the male mold and 2 is the female mold. Further, 3 is a laminated metal foil, and 4 is a female gate. moreover,
5 is a thermoplastic resin layer containing an inorganic filler. First, the fifth
The thermoplastic resin layer of the metal foil laminated on the male die 1 of the die shown in the figure is attached to the male die of the die so that it is on the moving side of the die. Then, after closing the mold, a thermoplastic resin containing an inorganic filler is injection molded through the gate 4 under the conditions of the resin temperature and injection pressure (the state at this time is shown in FIG. 6). The injection molding machine used is not unique to the present invention, but may be any one used in the field of general thermoplastic resins, and the operating conditions are also the same as in normal cases.

('') Reflector for Circularly Polarized Antenna The reflector for a 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 Figures 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. Also, D
is a thermoplastic resin (III) F#, and E is an inorganic filler-containing thermoplastic resin (II) 1 consisting of an inorganic filler and a thermoplastic resin (II). Furthermore, C1 and C2
is a single layer of braima, but one or both may be absent. Furthermore, in order to attach the circularly polarized antenna reflector obtained in this way to a support, ribs may be provided to enable attachment to the inorganic filler-containing thermoplastic resin layer. You can also add reinforcing ribs to strengthen the board. Furthermore, it is also possible to drill holes in the circularly polarized antenna support obtained by the present invention and attach various support attachment parts using bolts, nuts, etc. Further, the diameter of the reflector for the circularly polarized antenna is usually 80 cm to 120 cm.

The thickness of the inorganic filler-containing thermoplastic resin layer of this reflector for a circularly polarized antenna is usually 3 to 10 m5 at the center, preferably 3 to 8 m5, and 2 to 811 m at the periphery. However, the thickness of the peripheral part is preferably I/8 to 5/8 with respect to the thickness of the center part.
6, preferably 1/4 to 5/6. If the thickness of the peripheral part is less than 1/8 of the thickness of the central part, the thickness of the peripheral part becomes very thin and the strength against external pressure is reduced. Not only does this decrease, but also the moldability decreases. On the other hand, if it exceeds 5/6, the peripheral part becomes thicker than the center part, which not only makes the circularly polarized antenna reflector heavier, but also makes the metal layer (metal foil) easier to cut, and the molded product Harmful deformations such as twisting occur. The thickness of this inorganic filler-containing thermoplastic resin 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 thermoplastic resin layer is extremely small, no peeling occurs between the layers even if subjected to heat cycles (repetition of cold and heat) for a long period of time.

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

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

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

(8) 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.

(10) Thermoplastic resin (III) between the inorganic filler-containing thermoplastic resin layer that functions as a structure and the metal foil
Because of the presence of the layer, the adhesion between the inorganic filler-containing thermoplastic resin layer and the metal foil is greatly improved, and even if an attempt is made to separate the inorganic filler-containing thermoplastic resin layer and the metal foil, the metal By selecting a primer for the foil and the thermoplastic resin (m)l, it is possible to exhibit adhesive strength to the extent that the metal foil can be cut.

(11) Inorganic filler that functions as a structure because the thermoplastic resin (III) layer on which the metal foil is laminated and the inorganic filler-containing thermoplastic resin layer are partially mixed during injection molding. It does not adversely affect the mechanical strength such as rigidity that the thermoplastic resin layer contains.

(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/(80 minutes irradiation) (discoloration, fading, gloss change, crazing, blistering,
Detrimental changes such as peeling and cracking of the metal foil were evaluated. Furthermore, in the heat cycle test, the sample was exposed to 80℃ for 2 hours and then gradually cooled to -45℃ over 4 hours.
Exposure to this temperature for 2 hours, then gradually increase over 4 hours to 8
After heating to 0° C. and repeating this cycle 100 times, the surface appearance of the sample was evaluated in the same manner as in the INFt weathering test. In addition, the peel strength was determined by cutting a test piece with a width of 15I from the manufactured circularly polarized antenna reflector.
Peeling speed is 50+sm according to ASTM D-803
The strength was evaluated when the metal foil laminated at a speed of 180 degrees was peeled off at a speed of 180 degrees.

Additionally, bending stiffness was measured according to ASTM D-790, and coefficient of thermal expansion was measured according to ASTM D-898.

The types and physical properties of the thermoplastic resin (1), thermo-Machida resin (II), thermoplastic resin (■), inorganic filler and metal foil used in the thermoplastic resin layer used in Examples and Comparative Examples are as follows. Shown below.

[(A) Thermoplastic resin (■)]

A thermoplastic resin (I) with excellent weather resistance has a melt flow rate (measured according to ASTM D-1238 at a temperature of 250°C and a load of 10 kg) of 8.
Polyvinylidene fluoride (PV
dF), 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 (temperature according to JIS K-6758)]. Measured at 230℃ and a load of 2.1eKg, hereinafter referred to as rMFI J) for 0.5g/10 minutes, hereinafter rP
P (A)
8g/c, melt index (JIS K-13
According to 760, the temperature is 180℃ and the load is 2.1
Measured under the condition of 8Kg, hereinafter rM, 1. J) is 0.
8g/10 minutes, hereinafter referred to as rHDPE(1) J]
As a mixture, chlorinated polyethylene with a Mooney viscosity (ML1+4) of 108 (chlorine content 3.15% by weight,
Non-quality, molecular weight of raw material polyethylene (approximately 200,000) 20 parts by weight and 80 parts by weight of 7-acrylonitrile-styrene copolymer resin (acrylonitrile content 23% by weight) and 2 parts by weight of dibutyltin malate stabilizer as a stabilizer. Agent [manufactured by Sankyoki Gosei Co., Ltd., trade name: Stann BM]
] was kneaded for 10 minutes using a roll (surface temperature 180°C) to obtain a composition (hereinafter referred to as rAcs J).
and 20 parts by weight of dioctyl phthalate (as a plasticizer) and 5.0 parts by weight of dibutyltin maleate (as a dehydrochlorination inhibitor) and 100 parts by weight of vinyl chloride homopolymer (degree of polymerization 1100, hereinafter referred to as r rPVCJ). ) was used.

[(B) Thermoplastic resin (TI) and thermoplastic resin (■)]

Thermoplastics (IT) and thermoplastics (III) used to produce inorganic filler-bearing thermoplastics
The following thermoplastic resin was used as the thermoplastic resin (m) used to manufacture the layer.

(1) Olefin polymers The olefin polymers include a propylene homopolymer (hereinafter referred to as rPP(B)J) with an MFI of 2.0 g/10 min, and a propylene-ethylene block copolymer with an MFI of 15 g/10 min. A composite [ethylene content 15% by weight, hereinafter referred to as rPP(C)J] was used.

(2) Polycarbonate resin As the polycarbonate resin, a medium-density polycarbonate resin (density 1.2/cm', IIIFI 4.5 g/10 min, hereinafter referred to as "rPc") manufactured using bisphenol A as the main raw material was used.

(3) Acrylonitrile-butadiene-styrene ternary copolymer resin (ABS resin) As the acrylonitrile-butadiene-styrene ternary copolymer resin, ABS resin (hereinafter rABsJ
) was used.

(4) 7ri! Jtff Nitrile Chlorinated Polyethylene
- Styrene ternary copolymer resin (^C7 resin) ACS (1> and Similarly, a graft product (hereinafter referred to as rACSJ) was manufactured, and this ACS
A dibutyl malate stabilizer was mixed therein and used in the same manner as in JP-A-58-191751.

In addition, chlorinated polyethylene, acrylonitrile-styrene copolymer resin, and a stabilizer were mixed in the same manner as the mixture (2) used in the example of No. 5Lll11751,
The resulting mixture was used.

(5) Aromatic polyester Aromatic polyester (I) Polyethylene terephthalate (hereinafter referred to as rPETJ) having an intrinsic viscosity of 0.65 and polybutylene terephthalate (hereinafter referred to as rPBTJ) having an intrinsic viscosity of 0.85 are used as the ester. Ta.

(e) Modified PPO (grafted product) Modified PPO produced as described below was used.

First, 2,6-xylenol is polycondensed by an oxidative coupling method, and poly2. B-dimethylphenylene-1,
4-! - Chill [Intrinsic viscosity (30'Q, ri' 1m?
+ Measured in Jtt A, unit 1/g) 0.53, hereinafter referred to as rPPo J) was produced. 100 parts by weight of P
Po, 25 parts by weight of styrene monomer, 10 parts by weight of styrene polymer [melt flow index (JIS
71
0 minutes] and 2.1 parts of di-tertiary-butyl peroxide using a Henschel mixer for 10 minutes, and then mixed using a twin screw extruder (diameter 30 Il 11, resin temperature 27
A styrene-grafted PPO mixture (hereinafter referred to as modified PPOJ) was produced using a styrene-grafted PPO mixture (hereinafter referred to as modified PPOJ).

[(C) 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 am, rcg below
) and calcium carbonate (hereinafter referred to as rcacOsJ) having an average particle size of 0.11 microns.

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

Examples 1-6. Comparative Examples 1 to 9 The above-mentioned PVdF C thermoplastic resin (I)] and PP(^) [as thermoplastic resin 1)] were molded to form films each having a thickness of 100 microns. In addition, acrylic primer (manufactured by Showa Kobunshi Co., Ltd., trade name: Vinyroll 82) was applied to one side of the cross-chains, each with a thickness of 2
Apply to 0 micron, and apply urethane primer (manufactured by Toyo Morton Co., Ltd., product name: Atcoat 3) to other surfaces.
35) was applied to a thickness of 20 microns each and dried.

In this way, a laminated metal foil was produced by adhering the film, the metal foil coated with a primer on the same surface, and the PP(A) film to PVdF by a dry lamination method.

Furthermore, 30 parts by weight of CF (as an inorganic filler) and 70 parts by weight of PP (as a c-B thermoplastic resin (as a filler)) were each tri-blended for 5 minutes using a Henschel mixer. 230°C
pellets (composition) using a vented extruder under conditions of
was manufactured.

The laminated metal foil produced as described above was applied to the male side of the mold of an injection molding machine (clamping force: 1500 m). ). 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, the cutting of the ^ text was evaluated by observing the appearance with the naked eye. In this section, rOJ is A
This means that there was no missed cut, and "x" means that there was A missed cut. The deformation of the reflector plate was determined by the deviation of the entire circumferential surface from the horizontal plane after the obtained molded product (reflector plate) was placed face down on a horizontal plane. In this section, "O" means that there was no deviation from the horizontal plane, "Δ" means that there was a slight deviation from the horizontal plane, and "X" means that there was a considerable deviation from the horizontal plane. . Moreover, "moldability" was determined by the wrapping of the inorganic filler-containing thermoplastic resin around the circumference of the obtained molded product. In this section, "0" means that the entire surface of the mold was covered, "Δ" means that the mold did not go all the way around the circumference, and "x" means that the entire surface of the circumference was covered. It means that there was no going around. Moreover ° “sink mark”
was determined based on the presence or absence of unevenness in the center and circumference. In this section, "O" means that no unevenness occurred in the center or circumference, and "x" means that unevenness occurred. Obtained molded product (reflector)
The determination results are shown in Table 1.

(Left below blank) Examples 7 to 28, Comparative Examples 10.11 Thermoplastic resin (I) and thermoplastic resin (m) whose types are shown in Table 2
to produce films each having a thickness of 100 microns. In addition, an acrylic primer was applied to one side and a urethane primer was applied to the other side in the same manner as in Example 2 to one side of each metal foil whose type is shown in Table 2, and then dried (Examples 25 to 28 Then apply urethane primer to both sides.)

Furthermore, the inorganic filler and thermoplastic resin (II) (the types of each inorganic filler and thermoplastic resin (II) and the content of the inorganic filler in the composition are shown in Table 2, Comparative Example 1O In this case, tri-blending was carried out in the same manner as in Example 2 (without adding an inorganic filler).The obtained mixtures were kneaded under the resin temperature conditions shown in Table 3 using a vented extruder. A composition was produced.

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, the thermoplastic resin (II) containing an inorganic filler was injected at a pressure of 80K as in Example 2.
Insert injection molding was performed under the conditions shown in g/Crtf and resin temperature shown in Table 83, to produce a reflector for a circularly polarized antenna having the same shape as in Example 2.

Measurement of the peel strength of the metal foil from the inorganic filler-containing thermoplastic resin layer of each reflective plate obtained as described above, and measurement of the flexural modulus and linear expansion coefficient of each inorganic filler-containing thermoplastic resin composition. I did this. Those results in the third
Shown in the table.

(Leaving space below) Table 3 (Part 1) Table 3 (Part 2) Note that in all of the reflectors for circularly polarized antennas obtained in Examples F to 28, no cutting of the An foil was observed. There wasn't. Furthermore, regarding the deformation of the reflector 1, there was no deviation from the horizontal plane, and regarding moldability, the inorganic filler-containing thermoplastic resin 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. . In addition, an attempt was made to measure the peel strength, but in all cases the adhesive strength was high, so the metal foil was cut before the inorganic filler-containing thermoplastic resin (II) and the metal foil were peeled off. 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. Furthermore, FIG. 4 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 foils C1 and C2 ... Primer layer D ...
・Thermoplastic resin (III) layer E... Inorganic filler-containing thermoplastic resin (If) layer a... Laminated metal foil b... Inorganic filler-containing heat Plastic resin layer 1...male die 2...female die 3...laminated metal foil 4...
female gate

Claims (1)

[Claims] Using a metal foil laminated with a thermoplastic resin layer with excellent weather resistance on one side and a thermoplastic resin layer on the other side,
The thermoplastic resin layer with excellent weather resistance of the laminated metal foil is attached in advance to the moving side of the injection mold, and after the mold is closed, the inorganic filler-containing thermoplastic resin is injection molded. , the thickness of the circumferential part is 1/6 to 5/6 of the thickness of the center part of this circularly polarized antenna reflector.
1. A method for manufacturing a reflector for a circularly polarized antenna, characterized by forming the reflector plate so that it becomes thinner and thinner.