JPS60212005A - Reflecting plate for circularly polarized wave antenna - Google Patents

Abstract

PURPOSE:To obtain a reflecting plate for a circularly polarized wave antenna having simple manufacture process, a radio reflecting capability and keeping its performance for a long period by forming a laminated layer where a thermoplastic resin layer with excellent weather resistance, a metallic layer and an aromatic group polyester layer including an inorganic packing agent are laminated sequentially. CONSTITUTION:The thickness of the thermoplastic resin layer 3 is 5mu-5mm., the thickness of the metallic layer 2 is 5mu-1mm., the thickness of the aromatic polyester layer 1 including the inorganic packing agent is 0.5mm.-15mm. and the content of the inorganic packing agent of the layer is 10-80wt%. The molecular weight of the thermoplastic resin layer 3 is 10,000-1,000,000. As a representative of the thermoplastic resin, a single polymer of a monomer having a double bond such as ethylene or propylene. As a typical example of the metallic layer 2, a simple substance of a metal such as aluminum, copper, iron, nickel or zinc or an alloy using the metal as major component is used. The aromatic group polyester 1 including the inorganic packing agent is a polyester having an aromatic group ring as the unit of chains of a polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION [I] Object of the Invention The present invention relates to a reflector for a circularly polarized antenna made of a laminate having a metal layer serving as a radio wave reflecting layer as an intermediate layer. More specifically, a thermoplastic resin layer with excellent weather resistance, a metal layer that reflects radio waves, and an aromatic polyester layer containing an inorganic filler are sequentially laminated, and the thickness of the thermoplastic resin layer is 5 microns to 5+u+. Regarding a reflector for a circularly polarized antenna, the metal layer has a thickness of 5 microns to 1 cm, and the inorganic filler-containing aromatic polyester layer has a thickness of 0.5 mm to 15+u+. The object of the present invention is to provide a reflector for a circularly polarized antenna with good weather resistance.

[II] Background of the Invention Satellite broadcasting using geostationary satellites is planned to be put into practical use in Europe, America, Japan, and other countries around the world 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 the cross-polarization identification of the satellite broadcasting antenna. In this way, when receiving broadcast radio waves from the ground or E, the radio waves are made horizontally or vertically linearly polarized, and the polarization plane of the reception antenna is aligned with the polarization plane of the broadcast radio waves to generate cross-polarized waves. Although it is not very difficult to use the degree of discrimination, when receiving radio waves from broadcasting satellites, deviations in the plane of polarization occur 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. For,
It is difficult to match the planes of polarization as described above.

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

For these reasons, plans are being made to use circularly polarized waves for broadcast satellite radio waves in future satellite broadcasting systems. 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. Because the structure is complex and large, and manufacturing costs are high, it is difficult to use a receiving antenna for general listeners to receive satellite broadcast radio waves using microwaves in the 12 gigahertz (GHz) 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. It faces a parabolic reflector at the focal point, and is widely used in microwave antennas, etc., but all conventional Heehat-type parabolic antennas use a short waveguide as described above to achieve linear polarization. It is designed to transmit and receive waves, and cannot be used for circularly polarized waves.

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

[m] Structure of the invention - Based on the above, the present inventors have created 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. As a result of various searches on how to obtain it, we found that it is a laminate in which at least (A) a thermoplastic resin layer with good weatherability, (B) a metal layer, and (C) an aromatic polyester layer containing an inorganic filler are sequentially laminated, The thickness of the thermoplastic resin layer is 5 microns to 5 mm, and the thickness of the metal layer is 5 microns to 1 mm.

and the thickness of the inorganic filler-containing aromatic polyester layer is 50
0 micron to 15o+e, and the content of inorganic filler in this layer is 10 to 80% by weight.A reflector plate for a circularly polarized antenna not only has good durability but also has a high resistance to radio waves. It was discovered that the reflective properties were excellent, and the present invention was achieved.

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

(1) Since it has excellent corrosion resistance, there is no change in radio wave reflection characteristics over a long period of time.

(2) Metal layer and aromatic polyester layer containing inorganic filler! ! 111 has an extremely low elongation, so even if it is subjected to heat cycles (repetitive cold and heat) for a long period of time, no delamination will occur between the layers.

(3) The reflector laminate 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) Aromatic polyesters 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 are heptad homopolymers having double bonds such as ethylene, propylene, vinylidene fluoride, vinyl chloride, and styrene, and these are the main components (50% by weight or more). copolymer of styrene and acrylonitrile (
AS resin) Resin whose main component is methyl phthalate (HM
A resin) Butadiene copolymer rubber 5 Acrylonitrile-butadiene copolymer rubber (NBR), styrene-butadiene copolymer rubber (SBR), acrylic rubber, ethylene-propylene copolymer rubber (EPR), ethylene-propylene-diene terpolymerization 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 with vinyl chloride-based resins, ethylene and/or propylene-based resins, the weather resistance of these formulations can be improved by adding UV absorbers. You can use it as you like. Furthermore, polyamide resins, polyester resins and polycarbonate resins can also be used.

Among these thermoplastic resins, organic compounds ( 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 layer described below.

(B) Metal 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 , 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) Aromatic polyester Further, the aromatic polyester used to produce the inorganic filler-containing aromatic polyester layer in the present invention is a polyester having an aromatic ring in the chain unit of the polymer. It is a polymer or copolymer obtained by a condensation reaction containing an aromatic dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof as main components.

Examples of the aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid,
, 7-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, bis(p-carboxyphenyl)methane,
anthracene dicarboxylic acid, 3,3'-diphenyl dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 4,4'-bis(carboxyphenoxy)ethane,
4,4°-diphenylsulfonedicarboxylic acid and 4,
Mention may be made of 4°-tertiary-phenylenedicarboxylic acid and ester-forming derivatives thereof.

In addition, in order to produce the aromatic polyester of the present invention, if the acid component is at most 40 mol%, adipic acid,
Aliphatic dicarboxylic acids such as sebacic acid, azelaic acid and dodecanedioic acid and aromatic dicarboxylic acids such as cycloaliphatic dicarboxylic acids such as 1,3-cyclohexanedicarboxylic acid and 1,4-cyclohexanecarboxylic acid and ester-forming derivatives thereof. You may substitute with other dicarboxylic acids.

Furthermore, the diols include aliphatic diols having 2 to 20 carbon atoms, ie, ethylene glycol, 1.2-
7'lopanediol, propylene glycol, 1.4-
Butanediol, neopentyl glycol, 1,5-bentanediol, 1,8-hexanediol, decamethylene glycol, cyclohexanediol and 1,4
- Cyclohexane dimetatool.

Incidentally, some of the diols listed above (at most 50 mol%) include long chain glycols with a molecular weight of 400 to 400 to 100, ie, polyethylene glycol, poly-1,3-propylene glycol, and polytetramethylene glycol. .

The following aromatic dicarboxylic acids, dicarboxylic acids other than the aromatic dicarboxylic acids used after tetraconversion, diols, and long chain glycols used as substitutes for the diols may be used alone or in combination with two or more. May be used in combination.

Among the aromatic polyesters used in the present invention,
Representative examples of preferred ones include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate,
Polycyclohexylene dimethylene terephthalate, polyethylene-2,8-naphthalate, polyethylene-1,
2-diphenoxyethane-4,4'-dicarboxylate is mentioned. Among these aromatic polyesters,
Polyethylene terephthalate and polybutylene terephthalate are preferred.

The manufacturing methods and mechanical properties of these aromatic polyesters are well known.

Further, the aromatic polyester was prepared by using a mixed solvent of phenol and tetrachloroethane at a ratio of 1:1 (weight ratio) to 30% by weight.
The intrinsic viscosity measured at °C is usually in the range of 0.4 to 1.5, preferably 0.4 to 1.3, especially 0.5
~1.3 is preferred. If an aromatic polyester having an intrinsic viscosity of less than 0.4 is used, a reflector for a circularly polarized antenna with sufficient mechanical strength cannot be obtained. on the other hand,
If it exceeds 1.5, the surface quality of the molded product will deteriorate.

(D) Inorganic filler The inorganic filler used to produce the inorganic filler-containing aromatic polyester layer is generally one widely used in the fields of synthetic resins and rubber. These inorganic fillers are preferably inorganic compounds that do not react with oxygen and water and do not decompose during kneading and molding. The inorganic fillers include metals such as aluminum, copper, iron, lead and nickel;
Compounds such as oxides of these metals and metals such as magnesium, calcium, barium, zinc, zirconium, molybdenum, silicon, antimony, and titanium, their hydroxides, sulfates, carbonates, and silicates, It is broadly classified into these double salts and mixtures thereof. Typical examples of the inorganic filler include the above-mentioned metals, aluminum oxide (alumina), its hydrate, calcium hydroxide, magnesium oxide (magnesia), magnesium hydroxide, lead oxide (zinc white), and red lead. and lead oxides such as lead H, magnesium carbonate, calcium carbonate, basic magnesium carbonate, white carbon, asbestos, mica,
Talc, glass fiber, glass powder, glass peas, clay, diatomaceous earth, silica, wollastonite, iron oxide, antimony oxide, titanium oxide (titania), lithopone, pumice powder, 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). In the case of fibrous materials, the diameter is 1 to 500 microns (preferably 1 to 3 microns).
00 microns) and a length of 0.1 to 8 mm (preferably 0.1 to 5+ am). Furthermore, the diameter of the flat plate is 2 mm or less (preferably 1 m
The following) are preferred.

(E) 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. From this, the thickness is 5 microns to 5 mm, and the thickness is 10 microns to 5 mm.
+u+ is preferred, particularly 10 microns to 1.5 microns. 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, 5
If it exceeds mm, it is not preferable because not only the radio wave reflectance decreases but also the cost increases and the weight of the laminate increases.

(2) Metal layer The metal layer of the present invention functions to reflect radio waves. The thickness of this metal layer is between 5 microns and 1 mm.
and preferably 5 to 500 microns, especially l
O to 500 microns is preferred. The thickness of the metal layer is 5
When the thickness is less than microns, wrinkles and folds are likely to occur in the metal layer during the production of a laminate, resulting in problems in terms of appearance and performance.

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

(3) Inorganic filler-containing aromatic polyester layer The composition ratio of the inorganic filler in the inorganic filler-containing aromatic polyester layer of the present invention is 10 to 80% by weight (that is, the composition ratio of the aromatic polyester is 80% by weight). ~20% by weight), 1
It is preferably 0 to 70% by weight, particularly preferably 10 to 80% by weight. If the composition ratio of the inorganic filler in the inorganic filler-containing aromatic polyester layer is less than 10% by weight, the linear expansion coefficient of the inorganic filler-containing aromatic polyester layer will be too different from that of the metal layer, and the metal will There is a problem that not only may peeling occur between the layer and the inorganic filler-containing aromatic polyester 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. However, it is not possible to obtain a good product (laminate).

The thickness of this inorganic filler-containing aromatic polyester layer is 50
0 micron to 15 mm, preferably 1 to 10 mm, especially 1 to 7 mm. If the thickness of the inorganic filler-containing aromatic polyester 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, if it exceeds 15 mm, it not only takes time to cool down during molding and sink marks are likely to occur on one surface, but also causes problems in use because N m increases.

In producing the thermoplastic resin layer and the inorganic filler-containing aromatic polyester layer, stabilizers against oxygen, heat and ultraviolet rays, metal deterioration inhibitors, flame retardants, colorants, commonly used in the respective fields, Additives such as electrical property modifiers, antistatic agents, lubricants, processability modifiers, and tack modifiers are added to the thermoplastic resin layer and inorganic filler-containing aromatic polyester layer compositions of the present invention. It may be added within the range.

When blending the above-mentioned additives into the thermoplastic resin of the present invention and when producing an aromatic polyester containing an inorganic filler (including the case where L additives are blended), the Henschel Tri-blending may be performed using a mixer such as a mixer, or it may 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 particular, it is preferable to use the aromatic polyester in the form of powder because it can be mixed more uniformly.

In this case, the mixture is generally melt-kneaded and then molded into a pellet-like material, which is then subjected to the molding described later.

In producing the inorganic filler-containing aromatic polyester 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 masterbatch and It may be mixed with the remaining ingredients.

When melt-kneading the above formulations, it must be carried out at a temperature above the melting point or softening point of the thermoplastic resin or aromatic polyester used; however, if carried out at high temperatures, the thermoplastic resin and aromatic Group polyesters deteriorate. For these reasons, the temperature is generally 20°C higher than the melting point or softening point of the respective thermoplastic resin or aromatic polyester (preferably higher than 50°C), but the temperature range does not cause deterioration. It will be carried out in

(F) Reflector for Circularly Polarized Antenna The reflector for circularly polarized antenna of the present invention will be explained below with reference to FIGS. 1 to 3. FIG. 1 is a partial perspective view of an antenna to which a reflector for a circularly polarized antenna is attached. FIG. 2 is a sectional view of the reflector for the circularly polarized antenna. Also, the third
The figure is a partially enlarged view of the sectional view. In FIG. 1, A is a reflector for a circularly polarized antenna of the present invention, B is a converter, C is a converter support rod, and D is a reflector support rod. Further, E is a wiring. Further, in FIGS. 2 and 3, l is an aromatic polyester layer containing an inorganic filler, and 2 is a metal layer (metal foil). 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 reflector for a circularly polarized antenna of the present invention is designed to strengthen the adhesion between the thermoplastic resin layer, which has excellent weather resistance, and the metal layer, and between the metal layer and the aromatic polyester layer containing an inorganic filler. Primers can also be used. Furthermore, as in the case of the circularly polarized wave according to the present invention, ribs may be attached to the reflector, or reinforcing ribs may be attached 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 80 cm to 120 cm.

(G) 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 foil in advance, and then using the laminated metal foil by a vacuum forming method or a stamping method. It can be manufactured by molding by a molding method such as injection molding.

Manufacturing methods using these molding methods will be explained in more detail.

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

The method of laminating (adhering) the thermoplastic resin layer with excellent weather resistance and the metal foil, which is the metal layer, can generally be carried out by a dry lamination method, but it is possible to perform the method by pressing the thermoplastic resin layer at high temperature. For olefinic polymers that can be released, the thermoplastic resin layer and the metal foil can be laminated (adhered) by an extrusion lamination method. To produce laminated metal foil using the extrusion lamination method, the resin is extruded using a T-gui film molding machine at a temperature range of 240 to 370°C to the above thickness, and simultaneously cooled and heated. It may be bonded to the metal foil (metal layer) using a pressure roll.

When using thermoplastic resins that have excellent adhesion to metal foils, laminated metal foils can be produced as described below.

However, when using thermoplastic resin whose adhesion to metal foil is not fully satisfactory, apply a primer (anchor coating agent) commonly used in the field of thermoplastic resin to one side of the metal foil in advance. It is applied 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 metal foil primer using a pressure roll heated to 50 to 100°C. The primer varies depending on the type of thermoplastic resin used to form the thermoplastic resin layer, but it is commonly used in various fields,
Available in water-based and solvent-based forms.

Examples of types include vinyl, acrylic, polyamide, epoxy, rubber, urethane, and chikun.

(2) Manufacture by vacuum forming method To manufacture by this method, a primer is applied to one side of the metal layer on which the thermoplastic resin layer obtained as described above is laminated. When extruding into a sheet form by T-Guy molding method,
By laminating on one side, a laminate can be obtained in which a thermoplastic resin layer with excellent weather resistance, a metal layer, and an aromatic polyester layer containing an inorganic filler are sequentially laminated. The laminate (sheet) obtained in this way is fixed with iron workpieces or claw-like objects, placed in a jig that is easy to knuckle, and is attached to ceramic heaters or sheathed wires arranged under E. Pull it into a device that can be heated with a heater and heat it. When the sheet is heated, it begins to melt.

Once the sheet sag, if you continue heating it, it will stretch inside the creases that hold it down. When this stretching phenomenon is observed, the best timing for sheet molding is when the molded product is in a good heating state without wrinkles or uneven thickness. At this time, the desired molded product is obtained by pulling out the sheet work, placing it on the upper part of the mold, and performing vacuum forming from the mold side under a reduced pressure of one atmosphere. Then, the product is cooled by wind or water spray and released from the mold.

On the other hand, in compressed air forming, the sheet that is easier to mold is pulled out to the top of the mold, a chamber (box) for compressed air is placed over the sheet, and the sheet is pressed against the mold side with a pressure of 3 to 5 atm. A molded product can be obtained by pushing up the mold together with the mold.

In addition, in any molding method, for polyethylene terephthalate, the optimum surface temperature is 130 to 200°C, and for polybutylene terephthalate, the surface temperature is 130 to 200°C.
A suitable temperature is 00 to 180°C.

(3) Manufacturing by stamping molding method In order to manufacture the reflector plate for a circularly polarized antenna of the present invention by this method, the weatherproofing method used in the above-mentioned vacuum forming method is used in the order of manufacturing the reflector plate for a circularly polarized antenna. A laminate sheet in which a thermoplastic resin layer with excellent properties, a metal layer, and an inorganic filler-containing aromatic polyester layer are laminated in sequence is introduced into a drawing die attached to a vertical press machine, and a laminate sheet with a weight of 5 to 50 kg/
cr' (preferably 10 to 20 kg/cr
By heating and pressing under the pressure n'), the desired molded product can be obtained. The product is then obtained by cooling with air or water spray and releasing from the mold. During molding, the pressurizing time is usually 15 seconds or more, typically 15 to 40 seconds. In addition, in order to improve the surface properties, it is preferable to perform molding under two-stage pressure conditions. In this case, the pressure in the first stage is 10 to 20 kg/c rn'.
After applying pressure for 15 to 40 seconds, the second stage
A molded product with excellent surface smoothness can be obtained by applying pressure for 5 seconds or more under a pressure of 50 kg/cm'. This two-stage molding method is particularly desirable when using an aromatic polyester layer containing an inorganic filler with poor fluidity. Note that the optimum molding temperature in the stamping molding method is a surface temperature of 80 to 180° C. when polyethylene terephthalate is used as the aromatic polyester of the inorganic filler-containing aromatic polyester layer. In addition, when using polybutylene terephthalate, the surface temperature is 7.
A suitable temperature is 0 to 180°C.

(4) Manufacture by injection molding method In order to manufacture the reflector plate for a circularly polarized antenna of the present invention by injection molding method, a thermoplastic resin layer with excellent weather resistance is laminated on one side in advance, and a primer layer is placed on the other side. The metal layer coated with is subjected to insert injection molding when molding a reflector for a circularly polarized antenna. To carry out insert injection molding, the metal layer is inserted between the male and female molds of the injection molding machine, and the thermoplastic resin layer with excellent weather resistance is placed on the male mold side.) , close the mold.

After that, the inorganic filler-containing aromatic polyester was filled into the mold through the gate of the mold and cooled.

By opening the mold, a desired reflector for a circularly polarized antenna can be obtained. For insert injection molding, the resin temperature must be higher than the melting point of the aromatic polyester of the inorganic filler-containing olefinic polymer, but lower than the thermal decomposition temperature of the aromatic polyester. When using polyethylene terephthalate as the aromatic polyester, insert injection molding
It is desirable to carry out in the temperature range of °C. On the other hand, when using polybutylene terephthalate as the aromatic polyester, insert injection molding
It is carried out in the temperature range of °C. In addition, the injection pressure is 40 kg/cr gauge pressure at the nozzle part of the cylinder of the injection molding machine.
If n' or more, not only can the inorganic filler-containing aromatic polyester be shaped into a shape almost similar to the shape of the mold, but also a product with good appearance can be obtained.

Injection pressure is generally 407140 kg/cm'
Especially desirable is 70 to 120 kg/crn'.

[VI] Examples and Comparative Examples The present invention will be explained in more detail with reference to Examples below.

In the Examples and Comparative Examples, the radio wave reflectance was measured as a microwave reflection coefficient based on the voltage standing wave ratio when a rectangular waveguide was used and the tip of the waveguide was short-circuited. In addition, 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,
(Detrimental changes such as blistering, peeling of metal foil, and cracks) were evaluated. Furthermore, a heat cycle test tested the sample at 80°C.
After 2 hours of exposure to temperature, the sample was gradually cooled to -45°C over 4 hours, exposed to this temperature for 2 hours, and then gradually heated to 80°C over 4 hours, and after repeating this cycle 100 times. The appearance of the surface 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+sm from the manufactured reflector for a circularly polarized antenna, and in accordance with ASTM DJO3, and a peeling rate of 50 mm/cm.
The strength was evaluated when the metal layer was peeled off at 180 degrees at a speed of 10 minutes. Furthermore, the bending rigidity is ASTM D-7130.
The coefficient of thermal expansion was measured according to ASTM D-He
Measured according to.

The types and physical properties of the thermoplastic resin, aromatic polyester, 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, melt flow rate (ASTM
D-1238, polyvinylidene fluoride (hereinafter referred to as rPVdFJ) with a benzotriazole-based ultraviolet absorber having a fl. propylene homopolymer containing 0.5 wt.% and 0.5 wt.% carbon black [melt flow index (JIS
Measured according to K-8758 at a temperature of 230°C and a load of 2.18 kg, hereinafter referred to as "liver ■") is 0.
．． 5 g/10 min, hereinafter referred to as rPPCA) J], high-density polyethylene containing 0.4% by weight of a benzotriazole-based UV absorber and 0.5% by weight of carbon black [density 0.1158 g/c Go , Melt index (measured according to JIS K-13760 at a temperature of 180°C and a load of 2.18 kg.

Below rM, 1. J) is 0.8g/10min, hereinafter r
chlorinated polyethylene (HDPE(1)) with a Mooney viscosity (ML1+4) of 108.
Chlorine content 3.15% by weight, amorphous, raw material polyethylene molecular weight approximately 200,000 parts) and 80 parts by weight of 7 acrylonitrile-styrene copolymer resin (acrylonitrile content 23% by weight) and 2 as a stabilizer. Parts by weight of a dibutyl tin malate stabilizer (manufactured by Sankyoki Gosei Co., Ltd., trade name: Stann ON) was mixed for 10 minutes using a roll (surface temperature: 180°C), and the resulting composition (hereinafter referred to as r AC5J) and 20 parts by weight of dioctyl phthalate (as a plasticizer) and 5.0 parts by weight of dibutyltin malate (as a dehydrochlorination inhibitor).
100 parts by weight of vinyl chloride homopolymer (degree of polymerization: 11
00, hereinafter referred to as rPVGJ) was used.

[(B) Aromatic Polyester] As the aromatic polyester, polyethylene terephthalate (hereinafter referred to as rPETJ) having an intrinsic viscosity of 0.65 and polyethylene terephthalate (hereinafter referred to as rPBTJ) having an intrinsic viscosity of 0.85 were used. Ta.

[(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: 3+am, hereinafter r
GFJ) and calcium carbonate (hereinafter referred to as rlEacO3J) having an average particle size of 0.8 microns were used.

[(D) Metal foil] Aluminum foil each having a thickness of about 20 microns (
(hereinafter referred to as rAiJ), copper, brass and silver foils were used.

Examples 1-12, Comparative Example 1.2 The thermoplastic resin was molded to produce films each having a thickness of 20 microns. In addition, an acrylic primer (manufactured by Showa Kobunshi Co., Ltd., trade name Vinylol 82) was applied to one side of each metal foil to a thickness of 20 microns, and a urethane primer (manufactured by Toyo Morton Co., Ltd.) was applied to the other side. , product name Atcoat 335) with a thickness of 2
It was coated to a thickness of 0 microns and dried (in Examples 7 and 10, the urethane primer was coated on both sides). Furthermore, inorganic fillers and aromatic polyesters (the types of each inorganic filler and aromatic polyester and the content of the inorganic fillers in the composition are shown in Table 1). (not blended) were tri-blended for 5 minutes using a Henschel mixer, and each mixture was used to produce a composition using a vented extruder at a resin temperature of 280°C. Each of the obtained compositions (pellets) was used to produce a sheet with a thickness of 2 layers using a T-Guy molding machine.

The thermoplastic resin film produced in this manner (not used in Comparative Example 1), metal foil coated with primer on both sides, and aromatic polyester sheet containing an inorganic filler were dried by dry lamination. A laminate was produced by gluing. The obtained laminate was heated to a bowl shape (outer diameter
A reflector for a circularly polarized antenna was manufactured by vacuum forming using a female mold having a shape of 750 fil1m and a height of 80 fil1m (Example 1.2).

Laminates produced in the same manner as in Examples 1 and 2 (the types of inorganic fillers and aromatic polyesters, the content of S filler in the composition, and the type of metal foil are shown in Table 1) Stamping was carried out in two stages at a surface temperature of 130°C by holding the first stage under a pressure of 20 kg/cm' for 30 seconds and the second stage under a pressure of 50 kg/cm' for 20 seconds. (The shape of the mold was the same as in Example 1), and a reflector for a circularly polarized antenna was manufactured (Examples 3 and 4).

After applying the above acrylic primer to one side of each metal foil whose type is shown in Table 1 to a dry thickness of 20 microns, a film of each thermoplastic resin whose type is shown in Table 1 is applied. (thickness 20 microns) was laminated. A urethane primer was applied to the other surface of the metal foil of the obtained laminate in the same manner as in Example 1. Each coated laminate obtained was placed in an injection molding machine (clamping force: 1500
The thermoplastic resin film was inserted into the mold so that it was in contact with the male surface of the mold. When the mold is closed, the injection pressure is 80k.
g/cm'' and a resin temperature of 270°C, the compositions whose types of aromatic polyester and inorganic filler and the content of the inorganic filler in the composition are shown in Table 1 are shown in Table 1. Insert injection molding was performed to produce circularly polarized antenna reflectors having the same shape as in Example 1 (Examples 5 to 12, Comparative Examples 1 and 2).

Measurement of the elastic modulus and linear expansion coefficient of the inorganic filler-containing aromatic polyester layer of each circularly polarized antenna reflector obtained as above, and the peel strength of metal foil from the inorganic filler-containing aromatic polyester layer. I did this. 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 88% in all cases. Furthermore, a weather resistance test and a heat cycle test were conducted, but all except Comparative Example 1 showed discoloration, fading, change in gloss, and craze on the surface.

No harmful changes such as blistering, peeling of the metal foil, or cracks were observed. However, in Comparative Example 1, the aluminum foil on the surface corroded.

[Brief explanation of the drawing]

FIG. 1 is a partial perspective view of an antenna to which a typical reflector for a circularly polarized antenna manufactured according to the present invention is attached. Moreover, FIG. 2 is a sectional view of the reflector for the circularly polarized antenna. Furthermore, FIG. 3 is a partially enlarged view of the cross-sectional view. A: Reflector for circularly polarized antenna, B: Converter, C: Converter support rod, D: Reflector support rod, E: Wiring, 1: Inorganic filler-containing fragrance Group polyester layer, 2...
・Metal layer (metal foil), 3... Thermoplastic resin layer with excellent weather resistance, 2a...
Primer 1st layer, 2b... Primer 1st layer patent applicant Showa Denko Co., Ltd. Agent Patent attorney Sei Kikuchi

Claims (1)

[Claims] A thermoplastic resin layer with excellent weather resistance, a metal layer that reflects radio waves, and an aromatic polyester layer containing an inorganic filler are sequentially laminated, and the thickness of the thermoplastic resin layer is 5 microns to 5 mm. The thickness is 5 microns to 1+
nm, and the thickness of the inorganic filler-containing aromatic polyester layer is 0.5 mm to 1511!11, and the content of the inorganic filler in this layer is 10 to 80% by weight. Reflector for polarized antenna.