JPS617705A - Manufacture of passive reflector for circularly polarized wave antenna - Google Patents

Abstract

PURPOSE:To improve the weather resisting property of a passive reflector, by mixing methyl methacrylic polymerizing syrup, inorganic filler, and catalyst for syrup polymerization with each other and pouring the mixture onto the surface of the casting, and then, hardening the mixture when the passive reflector is manufactured. CONSTITUTION:The thickness of a thermoplastic resin layer which is excellent in weather resisting property is set to 5mu-5mm. and a metallic mat and net is made finer than two mesh, and then, the thickness of a methyl methacrylic polymer containing an inorganic filler is set to 500mu-15mm.. The inorganic filler content of the polymer layer is set to 10-80wt% and the resin layer, selected a kind of shaping layer composed of the mat and net, and polymer layer are successively piled up and the laminated material is used for manufacturing the passive reflector of a circularly polarized wave antenna. Moreover, a mixture of methyl methacrylic polymerizing syrup, inorganic filler, and catalyst for syrup polymerization is poured on the surface of metallic molds (a) and (b) for lower and upper castings and the mixture is hardened so as to improve the weather resisting property of the reflector at the time of manufacture.

Description

Detailed Description of the Invention [I] Purpose of the Invention The present invention provides a radio wave reflecting layer consisting of a laminate having at least one shape selected from the group consisting of metallic mats, cloths and nets as an intermediate layer. The present invention relates to a method of manufacturing a reflector for a circularly polarized antenna.

More specifically, at least (A) a thermoplastic resin layer with good weatherability; (B) at least one shaped article selected from the group consisting of metallic mats, cloths, and nets;
) A laminate in which methyl methacrylate polymer layers containing an inorganic filler are laminated in sequence, the thickness of the thermoplastic resin layer is 5 microns to 5 mm, and the metallic mat, cloth, and net are 2 meshes. A reflector plate for a circularly polarized antenna, wherein the methyl methacrylate polymer 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. Manufacturing a reflector plate for a circularly polarized antenna, which comprises mixing a methyl methacrylate polymerizable syrup, an inorganic filler, and a syrup polymerization catalyst, pouring the mixture onto a casting surface, and curing the mixture. The present invention relates to a method and aims to provide a reflector for a circularly polarized antenna with good weather resistance.

[II] Background of the Invention Satellite broadcasting such as high-definition television broadcasting using geostationary satellites, static 1F: picture broadcasting, teletext broadcasting, PCM (pulse contention code φ modulation) audio broadcasting, and facsimile broadcasting is widely used in Europe, America, Japan, and other countries. Many countries are planning to put it into practical use in the near future. However, since a geostationary satellite has only one orbit, there is a risk of interference between multiple broadcast radio waves. In order to avoid such mutual interference of broadcast waves, it is necessary to utilize cross-polarization identification of satellite broadcast receiving antennas. In this way, when receiving terrestrial broadcast waves, the radio waves are linearly polarized horizontally or vertically, and the polarization plane of the receiving antenna is matched to the polarization plane of the broadcast waves, using cross-polarization discrimination. Although it is not difficult to do so, when receiving radio waves from broadcasting satellites, there is a shift in the plane of polarization due to disturbances caused by the ionosphere in the radio wave propagation path and the angle of incidence of the radio waves at the receiving point. It is difficult to match the planes of polarization as described above.

Frequency allocation to multiple broadcasting satellites is considered to be done taking into consideration polarization plane discrimination from the point of view of effective use of satellite broadcasting frequency bands, but for satellite broadcasting radio waves with such frequency allocation, Since the quality of the polarization plane adjustment of the receiving antenna directly determines the level of interference between broadcast channels, it cannot be expected to obtain a high degree of cross-polarization discrimination when broadcast satellite radio waves are linearly polarized waves. However, when broadcasting satellite radio waves are circularly polarized waves, it is easy for ordinary listeners to identify them by the direction of the circularly polarized wave, regardless of the deviation of the polarization plane as described above. The receiving antenna not only adjusts its pointing direction to point to the desired broadcasting satellite, but also does not require adjustment of the plane of polarization, making it much easier to adjust the receiving antenna than when linearly polarized waves are used. Therefore, it is possible to obtain the degree of polarization discrimination as designed for the receiving antenna. 'For these reasons, plans are being made to use circularly polarized waves for broadcasting satellite radio waves in future satellite broadcasting systems.

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 the Nogura Polar antenna that uses these antennas as the primary radiator. Both have complex structures, are large, and require manufacturing costs, so they are not suitable for receiving antennas for general viewers to receive satellite broadcast radio waves using microwaves in the 12 gigahertz (GH) band. Not suitable.

On the other hand, the structure is extremely simple, and as a small and lightweight microwave antenna, a rectangular waveguide is extended in the axial direction from the center of a parabolic reflector, and its tip is curved so that the opening end surface becomes a parabolic shape. There is a so-called heat-type parabolic antenna that faces a parabolic reflector at its focal point and uses this as a -order radiator. This antenna is widely used in microwave antennas for mobile relays, etc., but all conventional Heehat-type parabolic antennas use the aforementioned rectangular waveguide to transmit and receive linearly polarized waves. Therefore, it cannot be used for circularly polarized waves.

Generally, metal plates or metal nets have been used as parabolic antennas. However, since metals corrode, it is necessary to use anti-corrosion alloys or apply anti-corrosion coatings. If anti-corrosion alloys are used, they are expensive. On the other hand, with anti-corrosion coatings, it is necessary to repeat the coating several times to achieve complete corrosion protection, which is not only expensive but also
There is a problem in that the painted material deteriorates after being used for many years. Furthermore, attempts have been made to manufacture a radio wave reflecting plate made of m layers of glass whose surface is metalized as a radio wave reflecting layer on a thermosetting resin such as unsaturated polyester resin, but the manufacturing method is complicated. At the same time, it is extremely difficult to maintain the radio wave reflecting layer at a constant thickness and without unevenness.

[I [1] Structure of the Invention From the above, the present inventors have developed a reflector for a circularly polarized antenna that has a simple manufacturing process, has radio wave reflecting ability, and can maintain its performance for a long period of time. As a result of various searches to obtain at least (A) a thermoplastic resin layer with good weather resistance, and (B) "at least one type of shape selected from the group consisting of metallic mats, cloths, and nets"
(hereinafter referred to as a "metallic shaped object") and (C) a laminate formed by sequentially laminating layers of a methyl methacrylate polymer containing an inorganic filler, and the thickness of the thermoplastic resin layer is 5 microns to 5III11. The metallic mats, cloths and nets are finer than 2 meshes, and the thickness of the inorganic filler-containing methyl methacrylate polymer layer is 500 microns to 15 mm, and the inorganic filler content of this layer is In manufacturing a reflector for a circularly polarized antenna having a concentration of 10 to 80% by weight, a methyl methacrylate polymerizable syrup, an inorganic filler, and a syrup polymerization catalyst are mixed and cast on the casting surface, and the mixture is cured. A method for manufacturing a reflector for a circularly polarized antenna is provided.

The inventors have discovered that it is possible to manufacture a reflector plate for circularly polarized antennas that not only has good durability but also has excellent radio wave reflection characteristics, and that the manufacturing process is relatively simple, and the present invention has been achieved.

[IV] Effects of the invention The circularly polarized antenna reflector obtained by the manufacturing method of the invention has the following effects (characteristics) including its manufacturing process.
demonstrate.

(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 inorganic filler-containing methyl methacrylate polymer layer is extremely low, peeling does not occur in the living room even when subjected to heat cycles (repetitive cycles of cold and heat) for a long period of time.

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

(4) It is possible to form a metallic object uniformly, and there is no uneven reflection of radio waves.

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

(6) The mechanical strength (especially rigidity) of the circularly polarized antenna reflector is excellent.

[V] 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. Typical thermoplastic resins include homopolymers of monomers having double bonds such as ethylene, propylene, vinylidene fluoride, vinyl chloride, and styrene, and copolymers containing these as the main component (50% by weight or more). Polymer, copolymer of styrene and acrylonitrile (
AS resin) Resin whose main component is methyl phthalate (HM
A resin) Butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber (NBR), styrene-butadiene copolymer rubber (SBR), acrylic rubber, ethylene-propylene copolymer comb (EPR), ethylene-propylene-diene ternary copolymer Graft copolymer resins, polyamide resins, polyester resins obtained by graft copolymerizing styrene alone or styrene and other vinyl compounds (e.g., acrylonitrile, methyl methacrylate) to rubbers such as rubber (EPDM) and chlorinated polyethylene; Examples include polyphenylene 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 because of their excellent weather resistance.

Furthermore, even if it is a resin whose main component is vinyl chloride, a resin whose main component is ethylene and/or propylene,
These formulations can also be used with preference since the weather resistance can be improved by adding UV absorbers. Furthermore, polyamide resins, polyester resins and polycarbonate resins can also be used. Among these thermoplastic resins, methyl methacrylate resins (ethylene homopolymer, propylene homopolymer,
A modified resin obtained by graft polymerizing an organic compound having at least one double bond (especially preferably an unsaturated carboxylic acid and its anhydride) to a copolymer mainly composed of ethylene and/or propylene. It is advantageous to use a part or all of it because it has excellent adhesion to the metal shape described later.

(B) Metal Furthermore, typical examples of metals that are raw materials for the metallic shapes 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, 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) Methyl methacrylate-based polymerizable syrup Furthermore, the methyl methacrylate-based polymerizable syrup used for producing the inorganic filler-containing methyl methacrylate-based polymer layer in the present invention is described in, for example, "Plastic Handbook" (1981, Asakura As described on page 388 (published by Shotensha), 0.0% of methyl methacrylate (methyl methacrylate-1) alone or methyl methacrylate and other polymerizable monomers (at most 35 mol %) as described below.
Adding 1 to 5.0% by weight of the syrup polymerization catalyst described below,
It can be manufactured by heating to an appropriate pressure and temperature. Generally, 50 to 15
Reflux prepolymerization at a temperature of 0°C (polymerization rate is usually 10
%), then adding a cold monomer (methyl methacrylate alone or methyl methacrylate and other monomers) and quenching. Other monomers include methacrylates with alkyl groups or cycloalkyl groups having at most 12 carbon atoms (e.g., ethyl methacrylate, butyl methacrylate, cyclohexane methacrylate); Acrylates with alkyl groups (e.g. ethyl acrylate,
butyl acrylate, cyclohexane acrylate),
Vinyl compounds with one double bond, such as styrene and vinyl acetate, and polyvinyl compounds with two or more double bonds, such as ethylene dimethacrylate, propylene dimethacrylate, polyethylene glycol dimethacrylate, divinylbenzene, triallyl cyanurate, and diallyl cyanurate. Examples include functional organic compounds. Regarding the other monomers in the methyl methacrylate polymerizable syrup of the present invention, the copolymerization ratio of the vinyl compound is usually at most 20 mol%, preferably 15 mol% or less. The copolymerization ratio of the vinyl compound is 20 mol%
If it exceeds this amount, the properties of the methyl methacrylate polymer cannot be fully exhibited. Further, the copolymerization ratio of the polyfunctional organic compound is generally at most 10 mol%, and particularly preferably 8 mol% or less. If the copolymerization ratio of the polyfunctional organic compound exceeds 10 mol %, the processability of the resulting methyl methacrylate polymer is poor. Furthermore, additives such as ultraviolet absorbers, binders, and mold release agents can be added as necessary.

(D) Catalyst for Syrup Polymerization Furthermore, examples of the catalyst for syrup polymerization include a peroxide as a polymerization initiator, a basic metal compound as a polymerization catalyst, and a chain transfer agent, which will be described later.

Representative examples of peroxides include organic peroxides commonly used in homopolymerization or copolymerization by radical polymerization of methyl methacrylate, and those represented by the general formula (1) below. Organic peroxides include dicumyl peroxide, azobisinbutylnitrile and benzoyl peroxide.

In formula (I), Me is a Group 1A metal or a divalent metal (e.g., zinc, lead, conoheld, nickel, manganese, copper), and X is an integer of 1 or more (the valence of the metal). and R is a saturated alkyl group.

Further, examples of basic metal compounds include metal oxides and hydroxides such as calcium and magnesium, and carbonates, benzoates, phosphates and sulfides such as sodium, potassium and zinc.

Furthermore, as chain transfer agents, thiophenol and
Examples include lauryl mercaptan or aryl mercaptan.

(E) Inorganic filler Further, the inorganic filler used to produce the inorganic filler-containing methyl methacrylate polymer layer is generally one widely used in the fields of synthetic resins and rubber. These inorganic fillers are preferably inorganic compounds that do not react with oxygen and water, and that do not decompose during crosstalk or molding. The inorganic fillers include metals such as aluminum, copper, iron, lead and nickel, oxides of these metals and metals such as magnesium, calcium, barium, zinc, zirconium, molybdenum, silicon, antimony and titanium, and their water. It is broadly classified into compounds such as hydrates (hydroxides), sulfates, carbonates, silicates, their double salts, and mixtures thereof. Typical examples of the inorganic fillers include the metals mentioned above, aluminum oxide (alumina), its hydrates, calcium hydroxide, magnesium hydroxide (magnesia), magnesium hydroxide, zinc oxide (zinc white), red lead, and lead. Lead oxide such as mortar, magnesium carbonate, calcium carbonate, basic magnesium carbonate, white carbon, asbestos, mica, talc, glass fiber, glass powder, glass peas, clay, silica, silica, wollastonite, Iron oxide, antimony oxide, titanium oxide (titania), lithopone.

Pumice grains, aluminum sulfate (gypsum, etc.), zirconium silicate, zirconium oxide, barium carbonate, dolomite,
Examples include molybdenum disulfide and iron sand. Among these inorganic fillers, those in powder form have a diameter of 1 mm or less (
0.5 mm or less) is preferred. In addition, in the case of fibrous materials, the diameter is 1 to 500 microns (preferably 1 to 500 microns).
~300 microns) and length 0.1~E1mm
(preferably 0.1 to 5 mm) is desirable. Furthermore, the diameter of the flat plate is 2+am or less (preferably 11I
1111 or less) are preferred.

(F) Structure of Each Layer (1) Thermoplastic Resin Layer The thermoplastic resin layer of the present invention serves to prevent the occurrence of corrosion of metal shaped objects, which will be described later.

From this, the thickness is 5 microns to 5 mm,
10 microns to 5 mm are preferred, particularly 10 microns to 1 mm. If the thickness of this thermoplastic resin layer is less than 5 microns, not only will the metal shape be corroded, but also the metal shape will be exposed due to wear due to contact and friction with other objects during use. This is a problem because it sometimes stops. On the other hand, if it exceeds 5 mm, it is not preferable because it not only lowers the reflectance of radio waves but also increases the cost and weight of the laminate.

(2) Metal shaped article The metallic shaped article of the present invention can be made into a mat shape by using the above-mentioned metal fibrous article by methods such as plain weaving, twill weaving, tatami hem, black weaving, twisted Is weaving, triple weaving, and clamp weaving. It is woven or braided in the form of a cross or net. #iI! The diameter of the fibrous material is usually 0.0020 to 1 mm, preferably 0.0050 to 0.5 mm, and particularly preferably 0.01 to 0.3 mm. Among these, those made of knitted steel wires are preferred because they have elasticity in the vertical and horizontal directions. The diameter of the fibrous material is 0.002
If it is less than 0 mm, it is difficult to process it into matte, cross or net shapes. On the other hand, if the diameter exceeds 1+nm, not only will the weight increase, but the cost will also increase, and furthermore, it will cause problems when bending, bending, etc. The size of the mesh of this metallic shape is important in determining the radio wave reflection performance. The size of the mesh is smaller than 2 meshes, preferably smaller than 4 meshes, and particularly preferably smaller than 8 meshes. If a metal shape that is rougher than 2 meshes is used, the reflectance of circularly polarized waves will be significantly reduced.

(3) Inorganic filler-containing methyl methacrylate polymer layer The composition ratio of the inorganic filler in the inorganic filler-containing methyl methacrylate polymer layer of the present invention is 10 to 80% by weight.
(That is, the composition ratio of the methyl methacrylate polymer is 80 to 20% by weight), preferably 10 to 70% by weight, and particularly preferably 10 to 60% by weight. If the composition ratio of the inorganic filler in the inorganic filler-containing methyl methacrylate polymer layer is less than 10% by weight, the linear expansion coefficient of the inorganic filler-containing methyl methacrylate polymer layer is too different from that of the metal layer. There is a problem that not only may peeling occur between the metal layer and the inorganic filler-containing methyl methacrylate polymer layer due to heat cycling, but also that the resulting laminate lacks rigidity. on the other hand,
If it exceeds 80% by weight, it will be difficult to produce a uniform composition, and even if a uniform composition is obtained, it will be difficult to produce a laminate by sheet production or injection molding as described below. , it is not possible to obtain a good product (laminate).

The thickness of this inorganic filler-containing methyl methacrylate polymer layer is 500 microns to 15 mm, and 1 to 10 mm thick.
mm is desirable, and 1 to 7 m+s is especially suitable.

If the thickness of the inorganic filler-containing methyl methacrylate polymer layer is less than 500 microns, it is undesirable because it lacks rigidity and may be deformed or damaged by external force. On the other hand, 1! +m
If it exceeds m, it will not only take time to cool down during molding, but also cause sink marks and distortion to occur on the surface.
There are problems in use due to the increased weight.

In producing the thermoplastic resin layer and the inorganic filler-containing methyl methacrylate polymer layer, stabilizers against oxygen, heat and ultraviolet rays, metal deterioration inhibitors, flame retardants, and colorants commonly used in the respective fields are used. The thermoplastic resin layer and the inorganic filler-containing methyl methacrylate polymer layer composition of the present invention contain additives such as additives, electrical property modifiers, antistatic agents, lubricants, processability modifiers, and tack modifiers. It may be added within a range that does not impair the properties it has.

When blending the above-mentioned additives into the thermoplastic resin of the present invention and when producing an inorganic filler-containing methyl methacrylate polymer (including cases where the above-mentioned additives are blended), the methods commonly used in the respective industries are used. Tri-blending may also be performed using a mixer such as a Henschel mixer.
It can be obtained by melt-kneading using a mixer such as a Banbury mixer, Nigu, roll mill, or screw extruder. At this time, a homogeneous composition can be obtained by triblending in advance and melt-kneading the resulting composition (mixture).

In producing the inorganic filler-containing methyl methacrylate polymer of the present invention, all the ingredients may be mixed at the same time, or some of the ingredients may be mixed in advance to produce a so-called masterbatch, and the resulting master The batch and remaining formulation ingredients may be mixed.

(G) Reflector for Circularly Polarized Antenna The reflector for circularly polarized antenna of the present invention will be explained below with reference to FIGS. 1 to 3. FIG. 1 is a partial perspective view of an antenna to which a reflector for a circularly polarized antenna is attached. FIG. 2 is a sectional view of the reflector for the circularly polarized antenna. Also, the third
The figure is a partially enlarged view of the sectional view. In FIG. 1, A is a reflector for a circularly polarized antenna of the present invention, B is a converter, C is a converter support rod, and D is a reflector support rod. Further, E is a wiring. In addition, in Fig. 2, ■ is a laminate consisting of a thermoplastic resin layer with excellent weather resistance, one layer of primer, a metal shape, and one layer of primer (either primer layer may or may not be present). II is a methyl methacrylate polymer layer containing an inorganic filler. Furthermore, in FIGS. 2 and 3, 1 is a methyl methacrylate polymer layer containing an inorganic filler, and 2 is a metallic shape. Moreover, 3 is a thermoplastic resin layer with excellent weather resistance. Further, 2a and 2b are single layers of primer. As is clear from these drawings, the feature of the reflector for a circularly polarized antenna of the present invention is that it has a structure consisting of at least three layers. In addition, the reflection plate for a circularly polarized antenna of the present invention has adhesion between each layer between a thermoplastic resin layer with excellent weather resistance and a metallic object, and between a metallic object and an inorganic filler-containing methyl methacrylate polymer layer. A primer can also be used to strengthen the strength. Furthermore, in order to attach the reflector for a circularly polarized antenna of the present invention to a support, ribs may be provided to the methyl methacrylate polymer layer containing an inorganic filler so that the reflector can be attached to the support. It is also possible to add reinforcing ribs for reinforcement. 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. In addition, the diameter of the reflector for the circularly polarized antenna is usually 60c+w to 1200m.
It is.

(H) Method for manufacturing a reflector for a circularly polarized antenna The reflector for a circularly polarized antenna of the present invention is produced by manufacturing a laminated metal shape in advance, and then casting the laminated metal shape. It can be manufactured by molding using a molding method such as a molding method. Manufacturing methods using these molding methods will be explained in more detail.

(1) Method for manufacturing a laminated metallic object In the present invention, laminating a thermoplastic resin onto the metallic object can be achieved by applying a commonly practiced method. below,
The method will be explained in detail.

The method of laminating (adhering) the thermoplastic resin layer with excellent weather resistance and the metallic shape can generally be carried out by dry lamination, but extrusion in a thermoplastic resin at high temperature is generally possible. For olefinic polymers that can be used, the thermoplastic resin layer and the metallic shape can be laminated (adhered) by extrusion lamination. To manufacture laminated metal shapes using the extrusion lamination method, use a T-gui film molding machine at a resin temperature of 240 to 370°C.
It is sufficient to extrude it to the above-mentioned thickness at a temperature range of 200 to 3000, and at the same time bond it to a metal shape using a cooling pressure roll.

When using a thermoplastic resin that has excellent adhesion to a metallic shape, a laminated metallic shape can be produced in the following manner. However, when using a thermoplastic resin whose adhesion to metallic objects is not fully satisfactory, a primer (anchor coating agent) commonly used in the field of thermoplastic resins is applied in advance to the metallic object. It is applied to one side of the object by gravure coating method or perspective coating method and dried at 50 to 100°C. Next, a thermoplastic resin film or sheet is pressed onto the surface of the primer of the metallic shape using a pressure roll heated to 50 to 100°C. The primer may vary depending on the type of thermoplastic resin used to form the thermoplastic resin layer.

It is commonly used in various fields, and there are aqueous and solvent types. In addition, the types include vinyl,
There are acrylic-based, polyamide-based, epoxy-based, rubber-based, urethane-based and titanium-based.

(2) Production by cast molding method Figures 4 and 5 show cross-sectional structural diagrams of a typical cast mold device used to manufacture the circularly polarized antenna reflector of the present invention by this method. . In these figures, a indicates a lower casting mold, and b indicates an upper casting mold. The laminated metal shape is placed on the convex lower casting mold a. Then, the methyl methacrylate polymerizable syrup is injected. At this time, the methyl methacrylate-1 polymerizable syrup is a mixture obtained by mixing peroxide, a syrup polymerization catalyst, and other additives. Next, filtration and defoaming are performed under reduced pressure, and after casting into a mold, the upper casting mold is sealed. The sealed mold of syrup is heated to 4o using an air bath or water bath.
Polymerization is carried out at a temperature range of 1 to 100 °C (preferably 40 to 70 °C) for 1 to 10 hours (preferably 4 to 10 hours).
00~200'C (preferably 100~120'C)
Heat for 0.5 to 5 hours (preferably 2 to 5 hours). Thereafter, the mold is allowed to cool and the product is peeled off from the mold.

Furthermore, by annealing at about 120° C. for several hours, a molded product (reflector for circularly polarized antenna) with a smooth surface can be obtained. The temperature and time of polymerization and the temperature and time of heating are determined by the respective relationships, the type and amount of the syrup polymerization catalyst used, and other conditions.

[VT] 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 using a rectangular waveguide as a microwave reflection coefficient based on the voltage standing wave ratio when the tip of the waveguide was short-circuited. In addition, weather resistance tests were conducted using a Sunshine Carbon Weather Meter, with a black panel temperature of 83°C and a due cycle of 12 minutes/60 minutes of irradiation. Gloss change, crazing,
Harmful changes such as blistering, peeling of metallic shapes, and cracks) were evaluated. Furthermore, the heat cycle test was performed by exposing the sample to 80'Q for 2 hours, then gradually cooling it to -45℃ over 4 hours, exposing it to this temperature for 2 hours, and then gradually heating it to 80℃ over 4 hours. and repeat this cycle for 10
After conducting the test 0 times, the appearance of the surface of the sample was evaluated in the same manner as in the weather resistance test. Peel strength was measured by cutting a test piece with a width of 15,111 m from a manufactured reflector for a circularly polarized antenna, and peeling a metallic object at 180 degrees at a peel rate of 50 mm/min in accordance with ASTM D-903. Evaluation was made based on the strength when peeled off.

Additionally, bending stiffness was measured according to ASTM D-7110, and coefficient of thermal expansion was measured according to ASTM' D-8B6.

In addition, the thermoplastic resin of the thermoplastic resin layer used in the examples and comparative examples, the methyl methacrylate polymerizable syrup (containing a catalyst for syrup polymerization, etc.), the inorganic filler, the type and physical properties of the metallic shape, etc. Shown below.

[(A) Thermoplastic resin] As a thermoplastic resin, melt flow rate (ASTM
D-1238, 0.4 weight of polyvinylidene fluoride (hereinafter referred to as PVdFJ), a benzotriazole-based ultraviolet absorber, with a weight of 6.1g (measured at a temperature of 250°C and a load of 10kg) for 710 minutes. % and 0.5% by weight of carbon black [melt flow index (JIS K
-8758 at a temperature of 230°C and a load of 2
．． Measured under the condition of 18 kg, hereinafter referred to as r MFIJ) is 0.5 g 710 minutes, hereinafter referred to as rpp(A) J],
High-density polyethylene containing 0.4% by weight of benzotriazole-based ultraviolet absorber and 0.5% by weight of carbon black [density 0.958 g/cm', melt index (according to JIS K-6780,
Measured at a temperature of 190'O and a load of 2.18 kg;
20 weight of chlorinated polyethylene (chlorine content 3.15% by weight, non-grade, molecular weight of raw material polyethylene approximately 200,000) having a Mooney viscosity (ML1+4) of 108 as a mixture (hereinafter referred to as "IDPE (1)") and 80 parts by weight of a 7-acrylochotolyl-styrene copolymer resin (acrylochotolyl content: 23% by weight) and 2 parts by weight of a dibutyl tin malate stabilizer [manufactured by Sankyoki Gosei Co., Ltd.] Stann BM] was kneaded for 10 minutes using a roll (surface temperature 180°C), and the resulting composition (hereinafter referred to as rAC5J) and 2
0 parts by weight of dioctyl phthalate (as a plasticizer) and 5.0 parts by weight of dibutyltin maleate (as a dehydrochlorination inhibitor) were combined with 100 parts by weight of vinyl chloride homopolymer (
A mixture having a polymerization degree of 1100 (hereinafter referred to as PvCJ) was used.

[(B) Methyl methacrylate-based polymerizable syrup Co-methyl methacrylate-based polymerizable syrup 2: 100 parts by weight of methyl methacrylate, 0.65 parts by weight of calcium hydroxide, 0.2 parts by weight of water, 0.2 parts by weight of glycol dimethyl captoacetate and 2.0 parts by weight of tertiary-butylperoxymaleic acid were added in a kneader.
Syrup produced by stirring for 1 minute [hereinafter referred to as "syrup (1
)'', 100 parts by weight of methyl methacrylate, 0.5 parts by weight of lauryl mercaptan, and 1.0 parts by weight of benzoyl peroxide [hereinafter the syrup produced by stirring in the same manner as in the production of syrup (1)] ``Syrup (2)J]) was used.

[(C) Inorganic filler] As the inorganic filler, talc with an average particle size of 3 microns (aspect ratio of about 7), mica with an average particle size of 3 microns (aspect ratio of about 8), glass fiber (single fiber) Diameter: 11 microns, cut length: 3mm, hereinafter referred to as rG
FJ) and calcium carbonate (hereinafter referred to as rcacO3J) having an average particle size of 0.8 microns were used.

[(D) Metallic shaped object] As a metallic shaped object, each fiber diameter is about 0.3 mm.
A 40-mesh plain weave wire cloth made of aluminum (hereinafter referred to as rAJIJ), copper, brass, and silver was used.

Examples 1 to 12, Comparative Examples 1 and 2 The thermoplastic resins were molded to produce films each having a thickness of 20 microns. In addition, an acrylic primer (manufactured by Chowa Kobunshi Co., Ltd., trade name Vinylol 92T) was applied to one side of each metal shape to a thickness of 20 microns, and a urethane primer (Toyo Morton Co., Ltd.) was applied to the other side. Atcoat 335 (trade name, manufactured by Co., Ltd.) was coated to a thickness of 20 microns on each coat and dried (in Examples 7 and 10, the urethane primer was coated on both sides). Furthermore, inorganic fillers and methyl methacrylate-based polymeric syrup (the types of each inorganic filler and methyl methacrylate-based polymeric syrup and the content of the inorganic filler in the mixture are shown in Table 1. and (without inorganic filler) were mixed using a kneader for 5 minutes to produce an inorganic filler-containing methyl methacrylate polymerizable syrup.

Tri-blending was performed using a Henschel mixer, and each mixture was used to produce a composition using a vented extruder at a resin temperature of 230°C.

After applying the above acrylic primer to one side of each metal shape whose type is shown in Table 81 to a dry thickness of 20 microns, apply each thermoplastic resin whose type is shown in Table 1. A film (20 microns thick) was laminated. A urethane primer was applied to the other surface of the obtained laminate in the same manner as in Example 1. Each coated laminate obtained was placed on the lower convex mold of the casting mold shown in FIG. 4, and then the mold was assembled. Then, methyl methacrylate-based polymeric syrup was injected. Polymerization was then carried out in a water bath at a temperature of 70°C for 6 hours. Furthermore, at 110°C in an air bath.
Polymerization was completed by heating under these conditions for 4 hours.

The elastic modulus and linear expansion coefficient of the inorganic filler-containing methyl methacrylate polymer layer and the inorganic filler-containing methyl methacrylate-1 polymer layer of each circularly polarized antenna reflector obtained as above. The peel strength of the metallic shapes was measured. The results are shown in Table 1.

(The following is a blank space) When the radio wave reflectance of each circularly polarized antenna reflector obtained as described above was measured, it was 98%. Furthermore, weather resistance tests and heat cycle tests were conducted, but no harmful changes such as discoloration, fading, change in gloss, crazing, blistering, peeling of metallic shapes, cracks, etc. were observed on the surface of all samples except Comparative Example 1. could not. However, in Comparative Example 1, the aluminum cloth on one surface corroded.

[Brief explanation of the drawing]

FIG. 1 is a partial perspective view of an antenna to which a typical reflector for a circularly polarized antenna manufactured according to the present invention is attached. Moreover, FIG. 2 is a sectional view of the reflector for the circularly polarized antenna. Furthermore, FIG. 3 is a partially enlarged view of the cross-sectional view. Furthermore, FIGS. 4 and 5 are cross-sectional structural views of a typical cast-type device used to manufacture the reflector for a circularly polarized antenna of the present invention. A... Reflector for circularly polarized antenna, B... Converter, C... Converter support rod,
D...Reflector support rod, E...Wiring, l...Methyl methacrylate polymer layer containing inorganic filler, 2...Metallic shape, 3...Thermoplastic with excellent weather resistance Resin layer, 2a...
Primer layer, 2b... Primer layer heavy... A laminate consisting of a thermoplastic resin layer with excellent weather resistance, a primer layer, a metal shaped object, and a primer layer (any primer layer may or may not be present) ), II... Methyl methacrylate polymer layer containing inorganic filler,

Claims (1)

[Claims] At least (A) a thermoplastic resin layer with good weather resistance (B)
A laminate formed by sequentially laminating at least one shaped object selected from the group consisting of metallic mats, cloths and nets and (C) an inorganic filler-containing methyl methacrylate polymer layer, the thermoplastic resin layer The thickness of the metal mat, cloth, and net is finer than 2 mesh, and the thickness of the inorganic filler-containing methyl methacrylate polymer layer is 500 microns to 15 mm. The content of the inorganic filler in the layer is 10 to 80% by weight.In manufacturing a reflector for a circularly polarized antenna, a methyl methacrylate polymerizable syrup, an inorganic filler, and a syrup polymerization catalyst are mixed to form a cast surface. A method for manufacturing a reflector for a circularly polarized antenna, comprising pouring the mixture onto the top and curing the mixture.