JPH0516683B2 - - Google Patents

Description

[Detailed description of the invention]

[] Purpose of the invention The present invention provides a thermosetting coating layer with excellent weather resistance,
The present invention relates to a method for producing a reflector for a circularly polarized antenna, which is made of a laminate comprising a metal foil that reflects radio waves and an inorganic filler-containing olefinic polymer layer that functions as a structure. More specifically, a metal foil is used in which a thermosetting coating layer with excellent weather resistance is laminated on one side and an olefin polymer layer is laminated on the other side, and the laminated metal foil is placed in an injection molding mold. After attaching it to the moving side mold surface and closing the mold,
This is a method of manufacturing a reflector plate for a circularly polarized antenna by injection molding an olefin polymer containing an inorganic filler, and the laminated metal foil is attached so that the olefin polymer layer faces the stationary mold. This relates to a method for manufacturing a reflector for a circularly polarized antenna, which is characterized by insert molding, and the adhesion between the metal foil and the inorganic filler-containing olefinic polymer layer that functions as a structure is greatly improved. It is an object of the present invention to provide a reflector for a circularly polarized antenna. [] 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 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 a broadcasting satellite, the polarization plane shifts 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, so the above-mentioned method is not possible. It is difficult to match such planes of polarization. Frequency allocation to multiple broadcasting satellites is likely to be done taking into account the degree of polarization plane discrimination from the point of view of effective use of satellite broadcasting frequency bands.
For satellite broadcast radio waves with such frequency allocation, the quality of the polarization plane adjustment of the receiving antenna directly determines the level of interference between broadcast channels, so if the broadcast satellite radio waves are linearly polarized, there will be large cross-polarization. One cannot expect to obtain any degree of discrimination. However, when broadcasting satellite radio waves are circularly polarized waves, it is easy for ordinary listeners 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. 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. In contrast, conventional circularly polarized antennas include those that use a conical horn, those that combine two dipoles at right angles, and parabolic antennas that use these antennas as primary radiators. Because the structure is complex and large, and the above-mentioned costs are high, it is not suitable as a reception antenna for general viewers to receive satellite broadcast radio waves using microwaves in the 12 gigahertz (GHz) band. do not have. On the other hand, the structure is extremely simple, and as a small-sized microwave antenna, a rectangular waveguide extends in the axial direction from the center of a parabolic reflector, and its tip is curved so that the opening end surface becomes parabolic. facing the parabolic reflector at the focal position of
There is a so-called Hihat-type parabolic antenna that uses this as a primary radiator. This antenna is widely used in microwave antennas for mobile relays, etc., but all conventional Hihatt-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 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, regarding anti-corrosion coating,
In order to achieve complete corrosion protection, it is necessary to repeat the coating several times, which is not only expensive, but also causes the problem that the coated product deteriorates over many years of use. Furthermore, attempts have been made to manufacture radio wave reflecting plates in which glass fibers with metallized surfaces are laminated to thermosetting resins such as unsaturated polyester resins as radio wave reflecting layers, but the manufacturing method is complicated and It has been extremely difficult to maintain the radio wave reflecting layer at a constant thickness and without unevenness. [] Constitution of the Invention Based on the above, the present inventors have aimed to obtain 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 for
A metal foil with an olefin polymer layer laminated on the other side is used, and after the laminated metal foil is attached to the moving side mold surface of an injection mold and the mold is closed, the inorganic filler-containing This is a method of manufacturing a reflector for a circularly polarized antenna by injection molding an olefin polymer, and insert molding is performed by attaching the laminated metal foil so that the olefin polymer layer faces the stationary mold. We discovered that a method for manufacturing a reflector for circularly polarized antennas, which is characterized by the following, not only has good durability, but also enables the production of reflectors for circularly polarized antennas that have excellent radio wave reflection characteristics. invention has been achieved. [] Effects of the Invention The circularly polarized antenna reflector manufactured by the present invention exhibits the following effects (features) including its manufacturing process. (1) Due to its 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 between the metal foil and the inorganic filler-containing olefinic polymer layer is extremely small, no delamination will occur between the layers even if the metal foil is subjected to heat cycles (repetition of cold and heat) for a long period of time. (3) The reflector for a circularly polarized antenna is lightweight and the manufacturing process is simple. (4) The metal foil can be molded uniformly, and there is no uneven reflection of radio waves. (5) Olefinic polymers containing inorganic fillers can be easily formed into various complex shapes, and therefore have good appearance and functionality. (6) Since the olefinic polymer layer is interposed between the inorganic filler-containing olefinic polymer layer and the metal foil, which functions as a structure, the interaction between the inorganic filler-containing olefinic polymer layer and the metal foil is Adhesion has been greatly improved, and even if an attempt is made to separate the inorganic filler-containing olefin polymer layer from the metal foil, by selecting a primer for the metal foil and the olefin polymer layer, the metal foil will remain intact. It can exhibit adhesive strength to the extent that it can be cut. (7) An inorganic filler-containing olefin that functions as a structure because the olefin polymer layer on which the metal foil is laminated and the inorganic filler-containing olefin polymer layer are partially mixed during injection molding. It does not adversely affect the mechanical strength such as rigidity inherent in the polymer layer. (8) The laminated metal foil is easy to handle and can be stored, for example, in a roll. (9) When setting the laminated metal foil in the mold during injection molding, the laminated metal foil can be used in a rolled state, so it can be continuously supplied, increasing productivity. will be significantly improved. [] Detailed Description of the Invention (A) Paint The paint used for manufacturing the metal layer having a thermosetting coating layer with good weather resistance of the present invention is widely produced industrially and is widely used for metals. It is used in a variety of ways as a paint. The manufacturing method and various physical properties of these paints are well known. These paints are classified into solvent type using organic solvents such as toluene and xylene, aqueous emulsion type, and solvent-free type, but any type of paint can be selected depending on the coating method. Typical examples of these paints include water-saturated polyester resin paints, polyurethane resin paints obtained by reacting polyester polyols, polyether polyols, or polyurethane polyols with diisocyanates, aminoalkyd resin paints, and thermal Examples include curable acrylic resin paints, melamine resin paints, cyanoacrylate resin paints, epoxy resin paints, silicone resin paints, organic titanate paints, and acrylic urethane resin paints. Furthermore, additives such as matting agents such as silicic acid, coloring agents such as pigments and dyes, antioxidants, and ultraviolet absorbers can be added to these paints. Among the above paints, polyurethane resin paints, thermosetting acrylic resin paints, epoxy resin paints, and aminoalkyd resin paints are preferred because of their excellent weather resistance. Particularly, by incorporating an antioxidant and an ultraviolet absorber into the paint of the present invention, a paint with good weather resistance can be obtained, which is suitable. (B) Metal layer Furthermore, typical examples of metals that are raw materials for the metal layer in the present invention include simple metals such as aluminum, iron, nickel, copper, and zinc, and alloys containing these metals as main components (for example, stainless steel). steel, brass). These metals do not require surface treatment; they have been subjected to chemical treatment,
It may be surface-treated such as plating. Furthermore, those that have been painted or printed can also be preferably used. (C) Olefin polymer In addition, the olefin polymer used for producing the olefin polymer layer and the inorganic filler-containing olefin polymer layer on which the metal foil is laminated in the present invention is an ethylene homopolymer. homopolymers of propylene, copolymers of ethylene and propylene, copolymers of ethylene and/or propylene with other α-olefins having at most 12 carbon atoms (the proportion of copolymerization of α-olefins is high) 20% by weight). Melt index (JIS K) of these olefin polymers
−6760, the temperature is 190℃ and the load is
2.16Kg (hereinafter referred to as "MI") or melt flow index (according to JIS K-6758, measured at a temperature of 230℃ and a load of 2.16Kg, hereinafter referred to as "MFI") is 0.01 ~100g/
A ratio of 10 minutes is preferred, and a ratio of 0.02 to 80%/10 minutes is particularly preferred. MI or MFI is 0.01g/10
If you use an olefinic polymer of less than
The moldability of the resulting mixture is poor. On the other hand, 100
If an olefinic polymer having a molecular weight exceeding 100 g/10 min is used, the mechanical properties of the resulting molded product will be poor. In addition, low density (0.900g/cm ³ ) to high density (0.980
g/cm ³ ) of an ethylene homopolymer or a copolymer of ethylene with a small amount of the above α-olefin, or a propylene homopolymer or a random or block copolymer of propylene with ethylene and/or other α-olefins. desirable. These olefinic polymers are produced by using a catalyst system (so-called Ziegler catalyst) obtained from a transition metal compound and an organoaluminum compound, and a chromium-containing compound (e.g., chromium oxide) supported on a carrier (e.g., silica). It can also be obtained by homopolymerizing or copolymerizing olefins using a catalyst system (so-called Phillips catalyst) or a radical initiator (eg, an organic peroxide). Furthermore, in the present invention, modified materials obtained by graft polymerizing these olefinic polymers with a compound having at least one double bond (for example, an unsaturated carboxylic acid, a monobasic carboxylic acid, a vinyl silane compound) Also included are polyolefins. The production methods for these olefin resins and modified polyolefins are well known. These olefin polymers and modified polyolefins may be used alone or in combination of two or more. Furthermore, among these olefin polymers and modified polyolefins,
Two or more types may be used as a resin blend in any ratio. The production methods for these olefin polymers and modified polyolefins are well known. (D) Inorganic filler The inorganic filler used to produce the inorganic filler-containing olefinic polymer layer is generally one widely used in the fields of synthetic resins and rubber. These inorganic fillers include:
An inorganic compound that does not react with oxygen or water and does not decompose during kneading and molding is preferably used. The inorganic fillers include metals such as aluminum, copper, iron, lead and nickel;
These metals and magnesium, calcium,
Metal oxides such as barium, zinc, zirconium, molybdenum, silicon, antimony, titanium, etc.
It is broadly classified into compounds such as its hydrate (hydroxide), sulfate, carbonate, and silicate, their double salts, and mixtures thereof. Typical examples of the inorganic filler include the metals mentioned above, aluminum oxide (alumina), its hydrate, calcium hydroxide, magnesium oxide (magnesia), magnesium hydroxide,
Zinc oxide (zinc oxide), lead oxides such as red lead and lead mortar, magnesium carbonate, calcium carbonate,
Basic magnesium carbonate, white carbon, asbestos, mica, talc, glass fiber, glass powder, glass beads, clay, diatomaceous earth, silica,
Examples include wollastonite, iron oxide, antimony oxide, titanium oxide (titania), lithopone, pumice powder, aluminum sulfate (gypsum, etc.), zirconium silicate, zirconium oxide, barium carbonate, dolomite, molybdenum disulfide and iron sand. Among these inorganic fillers, those in powder form have a diameter of 1
It is preferably 0.5 mm or less (preferably 0.5 mm or less).
In addition, fibrous materials have a diameter of 1 to 500 microns (preferably 1 to 300 microns) and a length of 0.1 microns.
-6 mm (preferably 0.1-5 mm) is desirable.
Furthermore, the diameter of the flat plate is 2 mm or less (preferably 1 mm or less) (E) Structure of each layer (1) Coating layer The coating layer of the present invention prevents corrosion of the metal layer. It is something that works. From this, the thickness is 5
Micron to 1mm, 10 micron to 1mm
0.5 mm is preferred, particularly 10 microns to 0.3 mm. If the thickness of this coating layer is less than 5 microns, not only will the metal layer corrode, but it will also suffer from contact and friction with other products during use.
There is a problem in that the metal layer is exposed due to wear. On the other hand, if it exceeds 5 mm, not only will the reflectance of radio waves decrease, but the cost will increase.
This is undesirable because it increases the weight of the laminate. (2) Metal layer (metal foil) Furthermore, the metal layer (metal foil) of the present invention functions to reflect radio waves. The thickness of this metal layer is between 5 microns and 1 mm, preferably between 5 and 500 microns, especially between 10 and 500 microns. If the thickness of the metal layer is less than 5 microns, the metal layer is likely to wrinkle or fold during the production of a laminate, resulting in problems in terms of appearance and performance. On the other hand, if it exceeds 1 mm, not only will the weight increase, but the cost will also increase, and furthermore, it will cause problems when bending or bending the laminate. (3) Olefin polymer layer The olefin polymer layer constituting the laminated metal foil in the present invention is an adhesive between the metal foil serving as a radio wave reflecting layer and the inorganic filler-containing olefin polymer layer functioning as a structure. This function not only improves the properties of the laminated metal foil but also facilitates storage and handling of the laminated metal foil. The thickness of this olefinic polymer layer is usually 5 to 500 microns, preferably 5 to 300 microns, and particularly preferably 5 to 200 microns. If the thickness of the olefin polymer layer is less than 5 microns, the olefin polymer will tend to wrinkle when manufacturing the laminated metal foil, which will affect the surface of the metal foil, resulting in poor appearance and performance. There is a problem with this. On the other hand, if it exceeds 500 microns, a problem arises because the mechanical properties such as strength and rigidity of the inorganic filler-containing olefinic polymer layer decrease. (4) Inorganic filler-containing olefin polymer layer The composition ratio of the inorganic filler in the inorganic filler-containing olefin polymer layer of the present invention is 10 to 80% by weight.
(that is, the composition ratio of the olefin polymer is 90 to 20% by weight), preferably 10 to 70 parts by weight,
Particularly suitable is 10 to 60% by weight. If the composition ratio of the inorganic filler in the inorganic filler-containing olefin polymer layer is less than 10% by weight, the linear expansion coefficient of the inorganic filler-containing olefin polymer layer will be too different from that of the metal foil, resulting in heat cycle failure. As a result, there is a problem that not only peeling may occur between the metal foil and the inorganic filler-containing olefinic polymer layer, but also that the resulting laminate lacks rigidity. On the other hand, if it exceeds 80% by weight, it is difficult to produce a uniform composition, and even if a uniform composition is obtained, it will be difficult to produce a laminate by sheet production or injection molding as described below. In this case, it is not possible to obtain a good product (laminate). The thickness of this inorganic filler-containing olefinic polymer layer is 500 microns to 15 mm, preferably 1 to 10 mm, particularly preferably 1 to 7 mm. If the thickness of the inorganic filler-containing olefinic 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, if it exceeds 15 mm, it will not only take time to cool down during molding, but also cause sink marks to occur on the surface.
There are problems in use due to the increased weight. In producing the olefinic polymer layer and the inorganic filler-containing olefinic polymer layer, stabilizers against oxygen, heat and ultraviolet rays, metal deterioration inhibitors, and flame retardants commonly used in the field of olefinic polymers are used. Additives such as additives, colorants, electrical property improvers, antistatic agents, lubricants, processability improvers, and tack improvers are added to the olefinic polymer layer and the inorganic filler-containing olefinic polymer layer of the present invention. It may be added as long as it does not impair the properties of the laminate. When blending the above additives into the olefin polymer of the present invention and when producing an inorganic filler-containing olefin polymer (including the case where the above additives are blended), It may be dry blended using a mixer such as a Henschel mixer, which is commonly used, or may be obtained by melt kneading using a mixer such as a Banbury mixer, kneader, roll mill, or screw extruder. . At this time, a homogeneous composition can be obtained by dry blending in advance and melt-kneading the resulting composition (mixture). In particular, it is preferable to use the olefinic polymer in the form of powder because it allows for more uniform mixing. In this case, the mixture is generally melt-kneaded and then molded into pellets, which are then subjected to the molding described later. In producing the inorganic filler-containing olefin 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 masterbatch and the remaining may be mixed with other ingredients. When melt-kneading is performed to produce the above-mentioned blend, it must be carried out at a temperature higher than the melting point or softening point of the olefinic polymer used, but if carried out at a high temperature, the olefinic polymer will deteriorate. For these reasons, the temperature is generally 20°C higher than the melting point or softening point of the olefin polymer (preferably higher than 50°C), but it is carried out within a temperature range that does not cause deterioration. (F) Method for manufacturing laminated metal foil The laminated metal foil used to manufacture the circularly polarized antenna reflector of the present invention can be manufactured by a so-called dry lamination method. The manufacturing method will be described in detail below. In producing this laminated metal foil, a film of an olefin polymer is coated on one side of the metal foil, such as a modified polyolefin grafted with an unsaturated carboxylic acid or its anhydride, which adheres closely to the metal. If you use a film with excellent properties, you can laminate it directly as described below, but if you are using an olefin polymer film that has poor adhesion to metal foil, it may be necessary to apply a primer and laminate it in advance as described below. After drying, an olefin polymer film may be laminated on the primer-coated surface. On the other hand, for the other side of the metal foil, an inorganic filler-containing olefin polymer is injection molded onto the laminated metal foil as described below, and a coating is applied to the molded metal foil as described later. It's okay. Alternatively, a laminated metal foil may be manufactured by applying paint to this surface in advance. In this case, if the paint used has good adhesion to the metal foil, it may be applied directly to the metal foil, but if the paint has poor adhesion, it may be necessary to apply a primer to the metal foil in advance as described below. The paint may be applied to this coated surface using a gravure coating method. The primer may be applied by gravure coating or bar coating, and then dried at 50 to 100°C. Also,
The olefin polymer film can be laminated using a pressure roll heated to 50 to 100°C. Note that there are water-based and solvent-based primers, including vinyl-based, acrylic-based, polyamide-based, epoxy-based, rubber-based, and urethane-based primers. The laminated metal foil (metal layer) produced in this manner will be explained with reference to FIG. FIG. 1 is a partially enlarged sectional view of the laminated metal foil. In this drawing, A is a thermosetting coating layer with excellent weather resistance, and B is a metal layer (metal foil). Further, C is an olefin polymer layer. Furthermore, a and b are primer layers (if one or both of the primers is not used, a and/or b will not exist.Furthermore, if no paint is applied,
A does not exist. ). (G) Manufacture of reflector for circularly polarized antenna The laminated metal foil coating layer obtained as described above (metal foil when using one without coating) is placed in the mold of an injection molding machine. The olefin polymer layer is attached to the movable side of the mold so that it becomes the fixed side of the mold, and the mold is closed. Next, the reflector plate for a circularly polarized antenna of the present invention can be manufactured by injection molding the inorganic filler-containing olefin polymer. At this time, the resin temperature during injection molding is higher than the melting point of the olefinic polymer containing an inorganic filler.
This temperature is lower than the thermal decomposition temperature of the olefin polymer. When a propylene polymer is used as the olefin polymer, insert injection molding is preferably carried out at a temperature in the range of 170 to 290°C. On the other hand, when an ethylene polymer is used as the olefin polymer, insert injection molding is carried out at a temperature in the range of 120 to 250°C. In addition, if the injection pressure is 40 kg/cm ² or more at the gauge pressure at the nozzle of the cylinder of the injection molding machine, the inorganic filler-containing olefin polymer can be shaped into a shape almost similar to that of the mold. Not only that, but also a product with good appearance can be obtained. The injection pressure is generally 40-140Kg/ ^cm2 , especially 70-120Kg/cm2.
^cm2 is preferred. There is no special method for applying paint to the metal foil of a molded product that has not been coated with paint or paint and primer. Although there are methods using a roll coater and the like, a method using a spray gun is industrially efficient, and a method using a robot is particularly preferred. (H) Reflector for Circularly Polarized Antenna The reflector for circularly polarized antenna of the present invention obtained as described above will be explained below with reference to FIGS. 2 and 3. FIG. 1 is a partial perspective view of an antenna to which a reflector for a circularly polarized antenna is attached. FIG. 2 is a sectional view of the reflector for the circularly polarized antenna. Moreover, FIG. 3 is a partially enlarged view of the cross-sectional view. 1st
In the figure, I is a reflector for a circularly polarized antenna according to the present invention, I is a converter, I is a converter support rod, and I is a reflector support rod. Further, V is a wiring. Further, in FIGS. 3 and 4, A is a thermosetting coating layer with excellent weather resistance, and B is a metal foil. Moreover, C is an olefin polymer layer, and D is an olefin polymer layer containing an inorganic filler. Further, although a and b are primer layers, one or both may be absent. Furthermore, in order to attach the thus obtained reflector for a circularly polarized antenna to a support, a mounting rib may be provided so that it can be attached to the inorganic filler-containing olefin polymer layer, and the reflector may be reinforced. It is also possible to add reinforcing ribs for this purpose. 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. Also,
The diameter of the reflector for the circularly polarized antenna is usually 60cm or more.
It is 120cm. [] 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, the weather resistance test was conducted using a Sunshine Carbon Weather Meter, with a black panel temperature of 83°C and a due cycle of 12 minutes/12 minutes.
The surface appearance (adverse changes such as discoloration, fading, gloss change, crazing, blistering, peeling of metal foil, and cracks) after 2000 hours under the conditions of (60 minutes of irradiation) was evaluated.
In addition, heat cycle tests test samples at 80°C.
After 2 hours of exposure to temperature, the temperature was gradually cooled to -45℃ over 4 hours, exposed to this temperature for 24 hours, and then gradually heated to 80℃ over 4 hours, and the cycle continued.
After carrying out the test 100 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 mm from a manufactured reflector for a circularly polarized antenna, and laminating the laminated metal foil at 180 degrees at a peeling speed of 50 mm/min in accordance with ASTM D-903. The strength was evaluated when it was peeled off. In this column of Table 1, "cohesive failure" refers to the fact that the adhesive strength between the laminated metal foil and the inorganic filler-containing olefinic polymer layer is too strong, causing the metal foil to break. Furthermore, the bending stiffness was measured according to ASTM D-790, and the coefficient of thermal expansion was measured according to ASTM D-696. The types and physical properties of the paint, olefin polymer, inorganic filler, and metal foil used in the coating layer in Examples and Comparative Examples are shown below. [(A) Paint] Two-component polyurethane resin (manufactured by Nihon Yushi Co., Ltd., trade name: Hi-urethane, hereinafter "U paint") was used as the paint.
) was used. [(B) Olefin polymer] As an olefin polymer, MFI is 2.0g/10
Propylene homopolymer [hereinafter referred to as “PP(B)”]
] was used. [(C) Inorganic filler] As the inorganic filler, talc (aspect ratio of about 7) having an average particle size of 3 microns and mica (aspect ratio of about 8) having an average particle size of 3 microns were used. [(D) Metal Foil] Aluminum (hereinafter referred to as "Al"), brass, and silver foils each having a thickness of about 20 microns were used. Examples 1 to 4, Comparative Example 1 An epoxy resin primer (manufactured by Dainippon Toyo Co., Ltd., trade name: V-Fron Primer) was applied to one side of the metal foils whose types are shown in Table 1.
It was applied to a thickness of 20 microns and dried. Apply the paint (U paint) whose type is shown in Table 1 to the primer-coated surface of the obtained metal foil to a dry thickness of 30 mm.
It was applied to a micron thickness and left overnight. The PP (B) was molded to produce films each having a thickness of 50 microns. Also, apply a urethane primer (manufactured by Toyo Morton Co., Ltd.) to the other side of each metal foil.
Adcoat 335 (trade name) was applied to each layer to a thickness of 20 microns and dried. (In addition,
In Examples and Examples, the urethane primer was applied to both sides). Metal foils and olefinic polymer films coated with the paint thus produced on one side and a primer coated on the other side are laminated by dry lamination. produced foil. Furthermore, each inorganic filler-containing olefin polymer (the types of each inorganic filler and olefin polymer and the content of the inorganic filler in the composition are shown in Table 1) was added for 5 minutes using a Henschel mixer. Each mixture was dry-blended using a vented extruder at a resin temperature of 230°C to produce a composition. The laminated metal foil thus produced was inserted into a mold of an injection molding machine (clamping force: 1500 tons) so that the moving side mold surface (the olefin polymer layer was the fixed mold surface). After closing the mold, the injection pressure
Under the conditions of 80Kg/cm ² and resin temperature of 240℃, the first
Insert injection molding was performed on the composition whose types of olefin polymer and inorganic filler and the content of the inorganic filler in the composition are shown in Table 1, and it had the same shape as Example 1. A reflector for circularly polarized antennas was manufactured. The elastic modulus and linear expansion coefficient of the inorganic filler-containing olefin polymer layer of each circularly polarized antenna reflector obtained as described above, and the peel strength of the metal foil from the inorganic filler-containing olefin polymer layer. measurements were carried out. The results are shown in Table 1.

[Table] When we measured the radio wave reflectance of each circularly polarized antenna reflector obtained as above, all of them were
It was 38%. Furthermore, a weather resistance test and a heat cycle test were conducted, and all of them except Comparative Example 1 showed discoloration, fading, change in gloss, crazing, etc.
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 partially enlarged sectional view of a laminated metal foil. Furthermore, FIG. 2 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. 3 is a sectional view of the reflector for the circularly polarized antenna. Furthermore, FIG. 4 is a partially enlarged view of the sectional view. A...Thermosetting coating layer with excellent weather resistance, B
...Metal layer (metal foil), C...Olefin polymer layer, a...Primer layer, b...Primer layer, D...Olefin polymer layer containing inorganic filler,...For circularly polarized antenna Reflector, converter, converter support rod, reflector support rod, wiring.

Claims (1)

[Claims] 1 Using a metal foil laminated with a thermosetting coating layer with excellent weather resistance on one side and an olefin polymer on the other side, the laminated metal foil is placed on the moving side of an injection mold. This is a method of manufacturing a reflector for a circularly polarized antenna by attaching it to a mold surface and closing the mold, and then injection molding an olefin polymer containing an inorganic filler, in which the olefin polymer of the laminated metal foil is A method for manufacturing a reflector for a circularly polarized antenna, characterized in that the layer is attached and insert-molded so as to face a stationary mold.