JPS60213102A - Reflecting plate for circularly polarized wave antenna - Google Patents

Abstract

PURPOSE:To improve corrosion resistance and to stabilize characteristics by successively laminating a thermoplastic resin layer having high weather resistance, a metallic layer and a methyl methacrylate group polymer layer containing inorganic filler. CONSTITUTION:The thermoplastic resin layer 3 having 5mu-5mm. thickness, the metallic layer 2 having 5mu-1mm. thickness and the methyl methacrylate group polymer layer 1 containing inorganic filler having 0.5mm.-15mm. thickness are laminated through primer layers 2a, 2b to obtain a reflecting plate for an antenna. Polyvinylidene fluoride or the like having high weather resistance is used as the thermoplastic resin. Aluminum, iron, nickel or the like is used as metal. Methyl methacrylate single polymer or inter polymer with another monomer containing aluminum, copper, iron or the like is used as the methyl methacrylate group polymer containing the inorganic filler. Thus, corrosion resistance is improved.

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 a methyl methacrylate polymer layer containing an inorganic filler are sequentially laminated, and the thickness of the thermoplastic resin layer is 5 microns to 5 microns. 5III11, the thickness of the metal layer is between 5 microns and 1 mm, and the metal layer is methyl metal containing an inorganic filler.

The thickness of the tafrylate polymer layer is 0.5 mm to 15 mm.
The present invention relates to a reflector for a circularly polarized antenna in which the fJ1 layer material having a thickness of 1 mm is used, and the purpose is 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, still image broadcasting, single character multiplex broadcasting, PCM (Pulse Code Modulation) audio broadcasting, and facsimile broadcasting using geostationary satellites is widely used in countries around the world such as Europe, America, and Japan. Its practical application is planned in the near future. However, [7] Since the orbit of a geostationary satellite is limited to only one, there is a risk of interference between multiple broadcast radio waves. In order to avoid such mutual interference of broadcast waves, it is necessary to utilize cross-polarization identification of satellite broadcast receiving antennas. In this way, when receiving terrestrial broadcast waves, the radio waves are linearly polarized horizontally or vertically, and the polarization plane of the receiving antenna is matched to the polarization plane of the broadcast waves, using cross-polarization discrimination. However, when receiving radio waves from broadcasting satellites, deviations in the plane of polarization occur due to disturbances caused by the radio layer 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 magnitude of interference between broadcast channels, it is not possible to expect to obtain a large degree of cross-polarization discrimination when broadcast satellite radio waves are linearly polarized. If the broadcasting satellite radio waves are circularly polarized waves, it is easy to identify them by the direction in which the circularly polarized waves are applied, regardless of the shift in the plane of polarization as described above, so that reception by general listeners is easy. The receiving antenna not only adjusts its pointing direction to direct it to the desired broadcasting satellite, but also does not require adjustment of the plane of polarization. This is simple, and it is possible to obtain polarization discrimination as designed for the receiving antenna.

For these reasons, in future satellite broadcasting systems, a 31-frame system has been established in which circularly polarized waves will be used for broadcasting satellite radio waves. 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 not suitable for general viewing antennas for receiving satellite broadcast radio waves using microwaves in the 12 gigahertz (GL) band. do not have.

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 Hihant-type parabolic antenna which faces a parabolic reflector at its focal point and uses this as a -order radiator. This antenna is widely used in microwave antennas for mobile relays, etc., but all conventional Hehat-type parabolic antennas now transmit and receive linearly polarized waves using short waveguides as described above. Therefore, it cannot be used for circularly polarized waves.

Generally, metal plates or gold B 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,
Regarding anti-corrosion coating, it is necessary to repeat the coating several times in order to achieve complete corrosion protection, which is not only expensive, but also causes the problem that the coated product deteriorates after being used for many years. Furthermore, attempts have been made to manufacture radio wave reflecting plates in which glass TA fibers with metallized surfaces are laminated to thermosetting resins such as unsaturated polyester resins as a radio wave reflecting layer, but the manufacturing method is complicated and However, it was extremely difficult to maintain the radio wave reflective layer at a constant thickness and without unevenness.

[m] Structure of the Invention From the above, the present inventors have developed a circularly polarized antenna that is moderately pure, has radio wave reflecting ability, and can maintain its performance for a long period of time. As a result of various searches to obtain a reflection grade for use in commercial use, we found that at least (^) a thermoplastic resin layer with good weather resistance, (8) a metal layer, and (C) a methyl methacrylate-based polymer layer containing a mechanical filler were sequentially formed. The thermoplastic resin layer has a thickness of 5 microns to 5 mm, the metal layer has a thickness of 5 microns to 1111!1, and a methyl methacrylate-based composite containing an inorganic filler. The layer thickness is 500
The circularly polarized antenna Kawabata Hijiboard, which is characterized by a thickness of microns to 15 Gffl and an inorganic filler content of 61% by weight of f#IO to 80 in this layer, not only has good durability but also can receive 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) Since the coefficient of linear expansion of the metal layer and the inorganic filler-containing methyl methacrylate polymer layer is extremely small, no peeling occurs between the layers even when subjected to heat cycles (repetition 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) The metal layer can be formed uniformly,
There is no 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.

(θ) The mechanical strength (especially rigidity) of the reflector for a circularly polarized antenna 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 homopolymers containing double bonds such as ethylene, propylene, vinylidene fluoride, vinyl chloride, and styrene, and these are the main components (50% by weight or more). A copolymer of styrene and 7-crylonitrile (
AS resin) Resin whose main component is methyl phthalate (HM
A resin) Butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber (NBR), styrene-butadiene copolymer rubber (5-BR), acrylic rubber, ethylene-propylene copolymer comb (EPR), ethylene-propylene-diene ternary Graft copolymer resins, polyamide resins, and polyesters obtained by graft copolymerizing styrene alone or styrene and other vinyl compounds (e.g., acrylonitrile, methyl methacrylate) to rubbers such as copolymer rubber (EPDN) and chlorinated polyethylene. Examples include resins, 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 above-mentioned graft copolymer resins, 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, methyl methacrylate resins (ethylene homopolymers, propylene homopolymers, copolymers mainly composed of ethylene and/or propylene) have at least one double bond (especially organic compounds). , unsaturated carboxylic acids and their anhydrides are preferred)
It is advantageous to use part or all of the modified resin obtained by graft polymerization because it has excellent adhesion to the metal layer described later.

(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). These metals do not need to be surface-treated; they may be pre-treated with chemical treatment or plating, or they may be painted or printed. can be used.

(C) Methyl methacrylate polymer The methyl methacrylate polymer used to produce the inorganic filler-containing methyl methacrylate polymer layer in the present invention is a thermoplastic resin containing methyl methacrylate as a main component. Typical methyl methacrylate-based polymers include methyl methacrylate homopolymers as well as copolymers of methyl methacrylate and other heptamers having at least 30 mole percent of at least one double bond. Examples of the other monomer include methacrylates having an alkyl group or cycloalkyl group having at most 12 carbon atoms (e.g., ethyl methacrylate, butyl methacrylate, cyclohexane methacrylate); Acrylates with 12 alkyl groups (e.g. ethyl acrylate, butyl acrylate, cyclohexane acrylate), vinyl compounds with one double bond such as styrene and vinyl acetate, as well as ethylene dimethacrylate, propylene dimethacrylate 1 polyethylene glycol dimethacrylate, divinyl Among the methyl methacrylate-based polymers of the present invention, copolymers include vinyl-based The copolymerization ratio of the compounds is usually at most 20 mol %, preferably 15 mol % or more. If the copolymerization ratio of the vinyl compound exceeds 20 mol %, the properties of the methyl methacrylate polymer cannot be fully exhibited. In addition, the copolymerization ratio of the polyfunctional organic compound is generally at most 10 mol%, particularly preferably 8 mol% or less. If the copolymerization ratio of the polyfunctional organic compound exceeds 10 mol%, the processability is not good.

This methyl methacrylate polymer can be produced by bulk polymerization, solution polymerization, or polymerization of methyl methacrylate alone or methyl methacrylate and a vinyl compound and/or a polyfunctional organic compound in the presence of a polymerization initiator (e.g., an organic peroxide). It can be obtained by emulsion polymerization, suspension polymerization, or a combination of these polymerization methods (for example, bulk polymerization followed by suspension polymerization). Methyl methacrylic acid of the present invention
- The average degree of polymerization of the polymer is usually 300 to 10,00
0, preferably 300 to 7,000, particularly preferably 300 to 5,000. If a methyl methacrylate polymer with an average degree of polymerization of less than 300 is used, the resulting reflector for a circularly polarized antenna will have poor mechanical strength, while if it exceeds 10,000, moldability will be poor. .

(D) Inorganic filler Furthermore, the inorganic filler used to produce the inorganic filler-containing methyl methacrylate polymer layer is one that is generally widely used in the fields of synthetic resins and rubber. These inorganic fillers are preferably inorganic compounds that do not react with lv and water, and that do not decompose during pouring or molding. The inorganic fillers include metals such as aluminum, copper, iron, lead and aluminum, these metals and magnesium.

Oxides of metals such as calcium, barium, zinc, zirconium, molybdenum, silicon, antimony, titanium, etc., their hydrates (hydroxides), compounds such as mesate, carbonic acid, silicic acid m, etc. It can be broadly divided into 1 sheet and a mixture of these. Typical examples of the filler include the above-mentioned metals, aluminum oxide (alumina), hydrates thereof,
Calcium hydroxide, magnesium oxide (magnesia),
Magnesium hydroxide, zinc oxide (zinc white), red lead and U
40E1 lead oxide, magnesium carbonate J, calcium carbonate, basic magnesium carbonate, white carbon, asbestos, mica, talc, glass fiber, glass powder, glass peas, clay, algae, silica, wollastonite, Iron oxide, antimony oxide, titanium oxide (titania), lithopone, pumice powder, aluminum sulfate (gypsum, etc.), acid dichloride.

Mention may be made of ruconium, zirconium oxide, barium carbonate, dolomite, molybdenum disulfide and iron sand. Among these inorganic fillers, powdered ones have a diameter of 1 m.
m or less (suitably 0.5 ram or less) is preferable. In addition, the la#-shaped one has a diameter of 1 to 500 microns (preferably 1 to 300 microns) and a length of 0.5 microns.
A thickness of 1 to 8 mm (preferably 0.1 to 5 mm) is desirable. Further, it is preferable that the diameter of the flat plate is 2 m+w or less (preferably 1 mm or less).

(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 S.
rm shoes are preferred, especially 10 micron to III
Ill is preferred. If the thickness of this thermoplastic resin layer is less than 5 microns, not only corrosion of the metal layer will occur, but also
There is a problem in that the metal layer is exposed due to wear due to contact and friction with other articles during use. On the other hand, if it exceeds 5 m+a, 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
If it is less than a micron, wrinkles and folds will easily occur in the metal layer during the production of laminates, so appearance ←, performance - E
There is a problem with this.

On the other hand, if it exceeds 1lIlffi, 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 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 90 to 20% by weight), preferably 10 to 70% by weight, and particularly preferably 10 to Bθ 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 peeling may occur between the metal layer and the inorganic filler base methyl methacrylate polymer layer due to heat cycling, but also that the resulting laminate lacks rigidity. On the other hand, 8
If it exceeds 0% by weight, it will be difficult to produce a homogeneous 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 mm is particularly 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, 15III
If it exceeds I11, it will take a long time to cool down during molding, and not only will sink marks be more likely to occur on the surface, but the weight will increase, causing problems in use H.

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 additives listed in (h) with the thermoplastic resin of the present invention, and when producing methyl methacrylate-1-based polymers containing inorganic fillers (including cases in which the additives listed in (g) are blended), the respective industries Tri-blending may be performed using a mixer such as a Henschel mixer commonly used in the industry, or it may be obtained by melt-kneading using a mixer such as a Banbury mixer, Nigoo, roll mill, or screw extruder. can. At this time, a homogeneous composition can be obtained by tri-blending in advance and melt-kneading the resulting composition (mixture).

In particular, it is preferable to use the methyl methacrylate polymer in the form of powder because it can be mixed more uniformly.

In this case, generally after melting and kneading, pellets 1. It is formed into a sheet and subjected to the molding described later.

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

When melt-kneading is performed to produce the compound described in 1- above, it must be carried out at a temperature below the melting point or softening point of the thermoplastic resin or methyl methacrylate polymer used, but if carried out at a high temperature, the heat Plastic resin and methyl methacrylate polymer deteriorate. For these reasons, the temperature is generally 20°C higher than the melting point or softening point of the respective thermoplastic resin or methyl methacrylate polymer (preferably, a temperature higher than 50°C), but does not cause deterioration. Performed over a temperature range.

(F) Reflector for Circularly Polarized Antenna The following is a description of the reflector for circularly polarized antenna according to the present invention with reference to FIGS. 1 to 3. FIG. 1 is a partial perspective view of an antenna to which a reflector for a circularly polarized antenna is attached. FIG. 2 is a sectional view of the reflector for the circularly polarized antenna. Also, the third
The figure is a partially enlarged view of the sectional view. In FIG. 1, A is a reflector for a circularly polarized antenna of the present invention, B is a converter, C is a converter support rod, and D is a reflector support rod. Further, E is a wiring. In Fig. 2, ■ is a laminated layer consisting of a thermoplastic resin layer with excellent weather resistance, one layer of primer, a metal layer (metal foil), 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, Figures 2 and 3
In the figure, 1 is a methyl methacrylate polymer 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 strengthens the adhesion between the thermoplastic resin layer, which has excellent weather resistance, and the metal layer, and between the metal layer and the methyl methacrylate polymer layer containing an inorganic filler. A primer can also be used for this purpose. Furthermore, in order to attach the reflective plate for a circularly polarized antenna of the present invention to a support, ribs may be provided for attachment to the methyl methacrylate polymer layer containing an inorganic filler. You can also add reinforcing ribs to strengthen the board. Further, the support for a circularly polarized antenna obtained according to the present invention was subjected to drilling.

It is also possible to attach various support attachment parts using bolts, nuts, etc. Further, the diameter of the reflector for the circularly polarized antenna is usually 60 cm to 120 cm.

(G) Method for assembling a reflector for a circularly polarized antenna The reflector for a circularly polarized antenna of the present invention is manufactured by laminating a metal foil, and using the laminated metal foil, vacuum forming and stamping are performed. It can be manufactured by molding using a molding method such as a molding method or an injection molding method.

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 the methyl methacrylate polymer that can be produced, the thermoplastic resin layer and the metal foil can be laminated (adhered) by the extrusion lamination method. is T-
Resin temperature is 240-370 using Gui film molding machine
Once extruded to the above-mentioned thickness in the temperature range of 0.degree. C., it may be bonded to the metal foil (metal layer) using a cooling pressure roll.

When using a thermoplastic resin that has excellent adhesion to metal foil, a laminated metal foil can be produced as described above.

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 differs depending on the type of thermoplastic resin used to form the thermoplastic resin layer, but it is commonly used in various fields, and there are aqueous types and solvent types.

The types include vinyl, acrylic, polyamide, epoxy, rubber, urethane, and titanium.

(2) Production by vacuum forming method To produce by this method, a primer is applied to one side of the metal layer laminated with the thermoplastic resin layer obtained as described above, and then a methyl methacrylate-based polymer containing an inorganic filler is applied. When extruding the combined material into a sheet using the T-Guy molding method, a thermoplastic resin layer with excellent weather resistance, a metal layer, and a methyl methacrylate-based heavy body layer containing an inorganic filler were sequentially laminated by laminating on one side. A laminate is obtained. The laminate (sheet) obtained in this way is fixed with iron workpieces or claw-like objects, installed in a jig that is easy to handle, and arranged vertically. Pull it into a device that can heat it with a sheathed wire heater and heat it.

When the sheet is heated, it begins to melt, but at that time, the sheet begins to sag, and then as the heating continues, it stretches inside the wafer that is holding it down. When this stretching phenomenon is observed, the best timing for sheet molding is when the molded product is in a good heating state without wrinkles or uneven thickness. At this time, the sheet work is pulled out and placed in the -L section of the mold, and vacuum forming is performed from the mold side under a reduced pressure of 1 atmosphere to obtain the desired molded product. 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 has become easier to mold is pulled out to the -F section of the mold, a chamber (box) for compressed air is covered from the back side of the sheet, and the sheet is placed on the mold side with a pressure of 3 to 5 atmospheres. A molded article can be obtained by pressing the sheet and pressing the mold.

In addition, in any molding method, the surface temperature is 140 to 210
°C is the optimum temperature.

(3) Manufacturing by stamping molding method In order to manufacture the circularly polarized antenna reflector of the present invention by this method, weather resistance is A laminate sheet in which a thermoplastic resin layer, a metal layer, and an inorganic filler-containing methyl methacrylate polymer layer having excellent properties are sequentially laminated is introduced into a drawing die attached to a vertical press machine, and then 5 to 5
0 kg/cm'' (preferably 10-20 kg/cm''
The desired molded product is obtained by heating and pressurizing the product under a pressure of 1000 ml. The molding time is usually 15 seconds or more, and 15 to 40 seconds is common.In addition, in order to improve the surface properties, it is preferable to perform molding under two-stage pressure conditions.In this case, in the first stage, 10 to 20 kg After pressurizing for 15-40 seconds under a pressure of 40-50 cm/cm', the second stage
A molded article with excellent surface smoothness can be obtained by applying pressure for 5 seconds or more under a pressure of kg/cm'. especially,
When using a sIa filler-containing methyl methacrylate polymer layer with poor fluidity, this two-stage molding method is desirable.
Note that the optimum molding temperature in the stamping molding method is a surface temperature of 120 to 1110°C.

(4) Production by injection molding method In order to produce the reflector plate for a circularly polarized antenna of the present invention by injection molding method, it is necessary to use thermoplastic sum with excellent weather resistance on one side.
The metal layer is laminated in advance and the other side is coated with a primer. Insert injection molding is performed when forming a reflector for a circularly polarized antenna. To perform insert injection molding, the metal layer is placed in an injection molding machine. A thermoplastic resin layer with excellent weatherability is inserted between the mold and the female mold.
(Insert it so that it faces the mold) 1 Close the mold.

Thereafter, a methyl methacrylate polymer containing an inorganic filler is filled into the mold through the gate of the mold, and after cooling, the mold is opened to obtain the desired reflector for a circularly polarized antenna. . For insert injection molding,
The resin temperature is higher than the melting point of the methyl methacrylate polymer of the inorganic filler base methyl methacrylate polymer, but lower than the thermal decomposition temperature of the methyl methacrylate polymer. Insert injection molding is from 220
Preferably, it is carried out in a temperature range of 270°C. In addition, the injection pressure should be 40 kg/cm' or less at the gauge pressure at the nozzle part of the cylinder of the injection molding machine.

Not only can the inorganic filler-containing methyl methacrylate polymer be shaped into a shape almost similar to the shape of the mold, but also a product with good appearance can be obtained. The injection pressure is generally 40 to 140 kg/cm', preferably 70 to 120 kg/cm'.

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

In the Examples and Comparative Examples, the radio wave reflectance was measured as a microwave reflection coefficient based on the voltage standing wave ratio when a rectangular waveguide was used and the tip of the waveguide was short-circuited. Weather resistance tests were conducted using a Sunshine Carbon Weather Meter under the conditions of a black panel temperature of 83°C and a due cycle of 12 minutes/(60 minutes of irradiation).
The appearance of the surface after 0 hours (adverse changes such as discoloration, fading, gloss, crazing, blistering, peeling of metal foil, and cracks) was evaluated. Furthermore, the heat cycle test tested the sample at 8
After 2 hours of exposure to 0°C, gradual cooling to -45°C over 4 hours, exposure to this temperature for 2 hours, and then gradual heating to 80°C over 4 hours, after repeating this cycle 100 times. The appearance of the surface of the sample was evaluated in the same manner as in the above-mentioned weatherability test. In addition, the peel strength was measured by cutting a test piece with a width of 15+e+n from the manufactured reflector for a circularly polarized antenna, and measuring the peel strength at a peel rate of 5 in accordance with ASTM D-903.
The strength was evaluated when the metal layer was peeled off at 180 degrees at a speed of 0 mm/min. Furthermore, the bending stiffness is ASTM D-
790 and the coefficient of thermal expansion is ASTM D
-696.

In addition, the thermoplastic resin of the thermoplastic resin layer used in Examples and Comparative Examples, methyl ivy acrylate polymer,
The types and physical properties of the 9# machine filler and metal foil are shown below.

[(A) Thermoplastic resin] As a thermoplastic resin, melt flow rate (ASTM
According to D-1238, polyvinylidene fluoride (hereinafter referred to as PVdF) having a value of 8.1 g/10 minutes (measured at a temperature of 250°C and a load of 100 lbs.), a benzotriazole-based ultraviolet absorber, was used at 0.1 g/10 min. Propylene homopolymer containing 4% by weight 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 rMFIJ), 0.5g710 minutes, hereinafter referred to as rPP(A)J], benzotriazole-based ultraviolet absorber, 0.4% by weight and 0.5% by weight of carbon black. High-density polyethylene containing [density 0.958 g / c nf, melt index (according to JIS K-13780,
The temperature is 190°C and the load is 2. Measured under the conditions of IElkg, hereinafter referred to as "Buy, ■,") is 0.8g 710 minutes,
20 parts by weight of chlorinated polyethylene (chlorine content 3.15% by weight, amorphous, molecular weight of raw material polyethylene approximately 200,000) having a Mooney viscosity (ML1+4) of 108 as a mixture (hereinafter referred to as "HDPE (1)") and 80 parts by weight of acrylonitrile-styrene copolymer resin (acrylonitrile content: 23% by weight) and 2 parts by weight of dibutyl tin malate stabilizer [manufactured by Sankyoki Gosei Co., Ltd., trade name: Stann BM] Roll (
The resulting composition (hereinafter referred to as "Ac1"), 20 parts by weight of dioctyl phthalate (as a plasticizer) and 5.
A mixture was used in which 0 parts by weight of dibutyltin malate (as a dehydrochlorination inhibitor) was blended with 100 parts by weight of vinyl chloride homopolymer (degree of polymerization 1100, hereinafter referred to as rPVCJ).

[(B) Methyl methacrylate polymer A methyl methacrylate polymer (hereinafter referred to as rPMMA) having an average degree of polymerization of approximately 1050 is used as a comethyl methacrylate polymer.
1) J) and methyl methacrylate (hereinafter referred to as rPMHA(2) J) having an average degree of polymerization of about 2820 were 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 "C-03") 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 rAJIJ), copper, brass and silver foils were used.

Examples 1-12. 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 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, an inorganic filler and a methyl methacrylate polymer (the types of each inorganic filler and methyl methacrylate polymer and the content of the inorganic filler in the composition are shown in Table 1. In Comparative Example 2, (without inorganic filler) were tri-blended for 5 minutes using a Henschel mixer, and each mixture was mixed at a resin temperature of 2.
The composition was manufactured using a vented extruder at 30°C.

Each of the obtained compositions (pellets) was molded using a T-gui molding machine to a thickness of 2 mm. A sheet of l intestine was prepared.

The thermoplastic resin film produced in this way (not used in the comparative example!), metal foil coated with primer on both sides, and methyl methacrylate polymer sheet containing inorganic filler were dry laminated. The laminate was produced by adhesion by a method. The obtained laminate was vacuum-formed at 150°C (the surface temperature of the laminate) using a female mold in the shape of a bowl (outer diameter ? 50 mm, height 80+e+s) to form a circularly polarized antenna. A reflecting plate was manufactured (Examples 1 and 2).

Example! and 2) (the types of inorganic fillers and methyl methacrylate polymers, the content of the inorganic fillers in the composition, and the type of metal foil are shown in Table 1) at the surface temperature. Stamping was carried out in two stages 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 at a temperature of 140°C. 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 put into an injection molding machine (clamping force +500
) The thermoplastic resin film was inserted into the mold so that it was in contact with the male surface of the mold. After closing the mold, the injection pressure is 80
kg/crn' and resin temperature of 230° C., the type of methyl methacrylate polymer and inorganic filler and the content of the inorganic filler in the composition are shown in Table 1. Insert injection molding of objects,
Reflectors for circularly polarized antennas having the same shape as in Example 1 were produced (Examples 5 to 12. Comparative Examples 1 and 2) Each of the reflectors for circularly polarized antennas obtained as described above The elastic modulus and linear expansion coefficient of the inorganic filler-containing methyl methacrylate polymer layer of the plate and the peel strength of metal foil from the inorganic filler-containing methyl methacrylate polymer layer were 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 88% in all cases. Furthermore, weather resistance tests and heat cycle tests were conducted, but no harmful changes such as discoloration, changes in gloss, crazing, blistering, peeling of metal foil, and cracks were observed on the surfaces of all cases except for Comparative Example 1. There wasn't. however,
In Comparative Example 1, the aluminum foil on the surface corroded.

[Brief explanation of drawings]

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 11. D...Reflector support rod, E...Wiring, l...Methyl methacrylate polymer layer containing inorganic filler, 2...Metal layer (metal foil). 3... Thermoplastic resin layer with excellent weather resistance, 2a...
Primer single layer, 2b...Primer single layer...Laminated product consisting of a thermoplastic resin layer with excellent weather resistance, a primer layer, a metal layer, and a primer layer (any primer layer may or may not be present) ), n...Methyl methacrylate polymer layer containing inorganic filler Patent applicant Showa Denko K.K. Representative Patent attorney Sei Kikuchi - -

Claims (1)

[Claims] A thermoplastic resin layer with excellent weather resistance, a metal layer that reflects radio waves, and a methyl methacrylate polymer layer containing an inorganic filler are sequentially laminated, and the thickness of the thermoplastic resin layer is 5 microns to 5+ am, The thickness of the metal layer is 5 microns to 1 mm, and the thickness of the inorganic filler-containing methyl methacrylate polymer layer is 0.5 m+a to 15 m+a.
III11, and the content of inorganic filler in this layer is 10
A reflector for a circularly polarized antenna, characterized in that the content is 80% by weight.