JPS60257605A - Reflecting plate for circularly polarized wave antenna - Google Patents

Abstract

PURPOSE:To obtain a reflecting plate for a circularly polarized wave antenna with excellent durability by laminating sequentially a layer comprising an oxymethylenic polymer layer contg. an inorganic filler having 500mu-15mm. and a thermoplastic resin layer having a thickness of 5mu-5mm.. CONSTITUTION:The antenna consists of a reflecting plate A for a circularly polarized wave antenna, a converter B, a converter supporting rod C, a reflecting plate supporting rod D and wiring E. The cross section of the reflecting plate for the circularly polarized wave antenna is formed with a laminated substance I comprising a thermoplastic resin layer excellent in the weather resistance, a primer layer and the primer layer and the metallic forming layer, and with an oxymethylenic polymer II contg. an inorganic filler. In expanding the cross section of the reflecting plate, it consists of the oxymethylenic polymer layer I contg. the inorganic filler, the metallic forming 2, the thermoplastic resin layer 3 excellent in the weather resistance and primer layers 2a, 2b.

Description

DETAILED DESCRIPTION OF THE INVENTION [I] Object of the Invention The present invention relates to a reflector for a circularly polarized antenna, which is made of a laminate having as an intermediate layer at least one type of shape selected from the group consisting of loss and net. More specifically, at least (A) a thermoplastic resin layer with good weather resistance, (B) at least one shaped material selected from the group consisting of metallic mats, cloths and nets, and (C) an oxymethylene-based material containing an inorganic filler. It is a laminate consisting of sequentially laminated polymer layers, the thickness of the thermoplastic resin layer is 5 microns to 5 ml11, and the metallic mats, cloths and nets are finer than two meshes and are inorganic filled. The thickness of the agent-containing oxymethylene polymer layer is from 500 microns to 151 microns,
The present invention relates to a reflector for a circularly polarized antenna, characterized in that the content of the inorganic filler in this layer is 10 to 80%, and provides a reflector for a circularly polarized antenna with good weather resistance. The purpose is to

[TI] Background of the Invention Satellite broadcasting such as high-definition television broadcasting, still image broadcasting, audio broadcasting, and facsimile 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. There is. However, since geostationary satellites have 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 radio waves, it is very difficult to make the radio waves horizontally or vertically linearly polarized and use cross-polarization discrimination to match the polarization plane of the receiving antenna to the polarization plane of the broadcast radio waves. However, when receiving radio waves from a broadcasting satellite, the polarization plane as described in 11. It is difficult to match.

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, regardless of the deviation of the polarization plane as mentioned above, it is easy to identify the direction of rotation of the circularly polarized waves, so that general listeners cannot receive them easily. Not only can the pointing direction of the receiving antenna be adjusted to direct it to the desired broadcasting satellite, but it 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. , it is possible to obtain 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 Goupoles at right angles, and parabolic antennas that use these antennas as the primary radiator. Both have complex structures, are large, and require manufacturing costs, so they are not suitable for general audience receiving antennas for receiving satellite broadcast radio waves using microwaves in the 12 gigahertz band. is not suitable.

On the other hand, the structure is extremely simple, and as a small and lightweight microwave antenna, a rectangular waveguide is extended in the axial direction from the center of a parabolic reflector, and its tip is curved so that the opening end surface becomes a parabolic shape. There is a so-called heat-type parabolic antenna 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 Heehat-type parabolic antennas use the aforementioned rectangular waveguide to transmit and receive linearly polarized waves. Therefore, it cannot be used for circularly polarized waves.

Generally, metal plates or metal nets have been used as parabolic antennas. However, metals need to be corroded. If anti-corrosion alloys are used, they are expensive; on the other hand, anti-corrosion coatings require repeated application several times to achieve complete corrosion protection, which not only makes them expensive, but also increases the cost of use over many years. There is a problem that the painted object deteriorates. 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 reflective layer at a constant thickness and without unevenness.

[m] Constitution of the Invention In light of H, the present inventors have developed a reflector for a circularly polarized antenna that has a simple manufacturing process, has radio wave reflecting ability, and can maintain its performance for a long period of time. As a result of various searches for obtaining at least (A) a thermoplastic resin layer with good weather resistance, (B) "at least one type of shaped object selected from the group consisting of metallic mats, cloths, and nets"
(Hereinafter referred to as "metallic shape") (C) An oxymethylene polymer layer containing an inorganic filler! I
It is a laminate formed by laminating IQ layers, the thickness of the thermoplastic resin layer is 5 microns to 5 mm, the metal shape is finer than 2 meshes, and the oxymethylene polymer layer containing an inorganic filler is Thickness is 500 microns to 15m
m, and the content of the inorganic filler in this layer is 10 to 80% by weight.The reflector plate for circularly polarized antennas has not only good durability but also excellent radio wave reflection characteristics. The present invention was achieved by discovering that

[17] 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 inorganic filler-containing oxymethylene polymer layer is extremely low, no peeling occurs between the layers even if the layer 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) It is possible to form a metallic object uniformly, and there is no uneven reflection of radio waves.

(5) Inorganic filler-containing oxymethylene polymers 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 is generally between 10,000 and 100,000. Typical thermoplastic resins are homopolymers of monomers 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 (HMA resin) butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber (NBR), styrene-butadiene copolymer rubber (SBR), acrylic rubber, ethylene-propylene copolymer comb (EPR), ethylene-
Graft copolymer resins obtained by graft copolymerizing styrene alone or styrene and other vinyl compounds (e.g., acrylonitrile, methyl methacrylate) to rubbers such as propylene-diene copolymer rubber (EPDM) and chlorinated polyethylene. , polyamide resin, polyester resin, polyphenylene oxide resin and polycarbonate resin. 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 still have excellent pressurizing properties. 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. In addition, even resins based on vinyl chloride, ethylene and/or propylene can be used in these formulations because their weather resistance can be improved by adding UV absorbers. can also be used as desired. Furthermore, polyamide resins, polyester resins and polycarbonate resins can also be used. Among these thermoplastic resins, olefin resins (
Organic compounds having at least one double bond (in particular,
It is advantageous to use part or all of a modified resin obtained by graft polymerizing an unsaturated carboxylic acid and its anhydride (preferably an unsaturated carboxylic acid and its anhydride) because it has excellent adhesion to the metal layer described below.

(B) Metal Furthermore, typical examples of metals that are raw materials for the metallic shapes in the present invention include simple metals such as aluminum, iron, nickel, copper, and zinc, and alloys containing these metals as main components (for example, stainless steel, brass). These metals do not need to be surface-treated, and may be previously subjected to surface treatment such as chemical treatment or plating treatment. Furthermore, those that have been painted or printed can also be preferably used.

(C) Oxymethylene polymer The oxymethylene polymer used to produce the inorganic filler-containing oxymethylene polymer layer in the present invention is a thermoplastic resin containing formaldehyde or trioxane as a component. Typical oxymethylene polymers include formaldehyde homopolymers, trioxane homopolymers, and formaldehyde and/or trioxane in an amount of 0.1 to 15% by weight (preferably,
Copolymers with cyclic ethers, cyclic acetals, and/or linear polyacetals (0.1 to 10i% by weight) can be mentioned.

Typical examples of cyclic ethers or cyclic acetals are:
Examples include compounds represented by the following formula [Formula (1)].

In formula (I), R1 to R may be the same or different and represent a phenyl group, an alkyl group, or a halogen-substituted alkyl group, and R5 is a methylene group, an oxymethylene group, an alkyl or a halogen-substituted methylene group. or when it is an oxymethylene group, n is O or an integer from 1 to 3, and the group -(OCH2CR2)
m For OCR2 text, n is l and m is an integer from 1 to 3.

Among the cyclic ethers or cyclic acetals represented by formula (I), those in which R1 to R4 have an alkyl group of 1 to 5 carbon atoms are preferred, and those in which R1 to R4 have an alkyl group of 1 to 3 carbon atoms are preferred. suitable. Further, it may be substituted with 1 to 3 halogen atoms (preferably chlorine atoms). Furthermore, cyclic ethers having 3 to 5 rings or 5
Preference is given to using cyclic acetals having ~9 rings.

Comonomers include epoxide compounds such as ethylene oxide, propylene oxide, 1,2-butylene oxide, styrene oxide, epichlorohydrin and oxetane or derivatives thereof (for example, 3,3-bistallomethyloxetane, tetrahydrofuran), and cyclic Formals (e.g. 1,3-dioxacyclohebutane, 1,3,6t-trioxacyclohebutane) and methyl, ethyl, chloromethyl groups,
Mention may be made of Ft conversion products of the above-mentioned compounds substituted with trichloromethyl or phenyl groups (for example, 4-phenyl-1,3-dioxolane, 4-methyl-1,3-dioxane). Furthermore, the secondary
Derivatives substituted at positions with methyl, ethyl, phenyl, chloromethyl or vinyl groups can also be used.

It is also possible to use linear polyacetals which decompose during polymerization and act as comonomers. Such linear polyacetals can be prepared by polymerizing or copolymerizing the above-mentioned cyclic acetals and further adding dihydric alcohols (e.g., ethylene glycol, diethylene glycol,
1,3-butylene gellicol and propylene glycol, transquinilla], p-xylylene diol) and aldehydes (particularly formaldehyde).

A large number of polymerization catalysts are used in producing oxymethylene polymers, but preferred polymerization catalysts include those containing boron fluoride, thionyl chloride, fluorosulfonic acid, metadisulfonic acid, and phosphorus trichloride. , titanium tetrachloride, ferric chloride.

Examples include zirconium tetrachloride, aluminum trichloride, stannous chloride, and stannic chloride. Particularly suitable polymerization catalysts include boron fluoride and boron fluoride-containing substances (
Examples include boron fluoride hydrate, boron fluoride dihydrate, boron fluoride trihydrate).

The oxymethylene polymer is generally prepared by adding formaldehyde and/or trioxane or the above-mentioned comonomers thereof in the presence of the above-mentioned polymerization catalyst in an organic inert solvent described below at a temperature of 20 to 115°C (preferably 60 to 100°C).
It is obtained by homopolymerization or copolymerization at a temperature of (°C).

Inert organic solvents include cyclohexane, benzene,
Examples include pentane, )-lichloroethylene, ligroin, carbon tetrachloride, octane, di-n-butyl ether, and petroleum ether. The amount of said solvent present in the feed polymerization mixture (of the polymerizable substances present therein, trioxane, formaldehyde, comonomers) is usually at most 20% by weight (preferably from 0.25 to 10% by weight).

Generally, the reduced viscosity of oxymethylene polymers (0.5 g
(measured at 140°C with a solution of γ-butyrolactone 1001 containing 2% diphenylamine)
is 0.2 to 3.0, particularly preferably 0.5 to 3.0. In addition, the melting index (according to JIS -7210,
Measured under condition 4, hereinafter referred to as rMFl j ) from 0.1 to
50 g/10 min is preferable, especially 0.5~
40g and 710 minutes is 90% better.

Oxymethylene polymers are produced in a T-guide manner and are used in a wide variety of fields, and various manufacturing methods, mechanical techniques, etc. are also widely known.

(D) Inorganic filler Further, the inorganic filler used to produce the inorganic filler-containing oxymethylene polymer layer is generally one widely used in the fields of synthetic resins and rubber. These inorganic fillers are preferably inorganic compounds that do not react with oxygen and water and do not decompose during kneading and molding. The inorganic fillers include metals such as aluminum, copper, iron, lead and nickel, as well as magnesium, calcium,
barium, zinc, zirconium, molybdenum, silicon,
Oxides of metals such as antimony and titanium, and their hydrates (
Hydroxide), sulfates, carbonates, silicates, their double salts, and mixtures thereof.

Typical examples of the inorganic filler include the above-mentioned metals, aluminum oxide (alumina), its hydrates, and hydroxide
1. Lead oxides such as magnesium oxide (magnesia), magnesium hydroxide, zinc oxide (zinc oxide), red lead and white lead, magnesium carbonate, calcium carbonate, basic magnesium carbonate, white carbon, asbestos, mica, Talc, glass peas, crow powder, glass peas, clay, diatom 11 Silica, wollastonite, iron oxide, antimony oxide, titanium oxide (titania), lithopone, pumice powder, aluminum sulfate (gypsum nato), silicic acid Examples include zirconium, zirconium oxide, barium carbonate, dolomite), molybdenum disulfide, and iron sand. Among these inorganic fillers, those in powder form preferably have a diameter of 1 square or less (preferably j±0.5 mm or more). 111 again! Fibrous ones have a diameter of 1 to 500 microns (preferably 1 to 300 microns) and a length of O, i.
~ emm (suitably 0.1-5 mm) is desirable. Furthermore, it is preferable that the diameter of the flat plate is 2 mm 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 between 5 microns and 51 Il111, preferably between 10 microns and 5 mm, particularly between 10 microns and 1
mm is preferred. If the thickness of this thermoplastic resin layer is less than 5 microns, not only will the metal layer corrode, but also the metal layer will wear out and become exposed due to contact and friction with other articles during use. occurs and there is a problem.

On the other hand, if it exceeds 5 mm, it is not preferable because it not only lowers the reflectance of radio waves but also increases the cost and weight of the laminate.

(2) Metallic shaped article The metallic shaped article of the present invention can be produced by machining the metal fibrous article by methods such as plain weaving, twill weaving, tatami hem, grass weaving, twisted cotton weaving, triple weaving, and clamp weaving. It is woven or braided in the shape of a cross, a cross or a net. As a fibrous material, its diameter is usually 0.0020-1 mm, and
．． 0050 to 0.5 mm is desirable, especially 0
．． 01 to 0.3 mm is suitable. Among these, those made of knitted steel wires are preferred because they have elasticity in the vertical and horizontal directions. If the i5 diameter of the fibrous material is less than 0.0020 mm, it is difficult to process it into a mat, cloth, or net shape. On the other hand, if the diameter exceeds II, not only will the weight increase, but the cost will also increase, and problems arise when the laminate is curved, bent, etc.

The size of the mesh of this metallic shape is important in determining the radio wave reflection performance. The size of the mesh is smaller than 2 meshes, preferably smaller than 4 meshes, and particularly preferably smaller than 8 meshes. If a metallic object with a rougher shape than 2 meshes is used, the reflectance of circularly polarized waves will be significantly reduced.

(3) Inorganic filler-containing oxymethylene polymer layer The composition ratio of the inorganic filler in the inorganic filler-containing oxymethylene polymer layer of the present invention is 10 to 80% by weight (i.e., oxymethylene polymer layer). The composition ratio of the combination is 90
~20% by weight), preferably 10 to 70% by weight, #1
0 to 60% by weight is preferred. The composition ratio of the inorganic filler in the inorganic filler-containing oxymethylene polymer layer is 1
If it is less than 0% by weight, the linear expansion coefficient of the inorganic filler-containing oxymethylene polymer layer will be too different from that of the metal layer, and the metal layer and the inorganic filler-containing oxymethylene polymer layer will peel off due to heat cycles. There is a problem that not only this may occur, 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 through the production of C.I. and injection molding, etc. described below. During manufacturing, it is not possible to obtain a good product (laminate).

The thickness of this inorganic filler-containing oxymethylene polymer layer is 500 microns to 15 mm, and 1 to 10 mm.
is desirable, especially 1~? mm is preferred.

The thickness of the inorganic filler-containing oxymethylene polymer layer is approximately 50
If the thickness is less than 0 micron, the rigidity is insufficient and deformation/damage occurs due to external force, which is not desirable. On the other hand, if the length exceeds 15 m+n, cooling during molding requires more space between surfaces, and not only does sinking easily occur on the surface, but the weight increases, causing problems during use.

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

When blending the above additives into the thermoplastic resin of the present invention and when producing an oxymethylene polymer containing an inorganic filler (including the case where the above additives are blended), these are commonly used in the respective industries. It may be tri-blended using a mixer such as a Henschel mixer, or may be obtained by melt R-kneading using a mixer such as a Banbury mixer, kneader, roll mill, or screw extruder. can. At this time, a homogeneous composition can be obtained by triblending in advance and melting and kneading the resulting composition (mixture).

In particular, it is preferable to use the oxymethylene polymer in the form of powder, since this allows for more uniform mixing.

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

When melt-kneading is performed to produce the compound described in 4- below, it must be carried out at a temperature higher than the melting point or softening point of the thermoplastic resin or oxymethylene polymer used. However, if carried out at a high temperature, the thermoplastic Resin and oxymethylene polymer deteriorate. For these reasons, the temperature is generally 20°C higher (preferably higher than 50°C) than the melting point or softening point of the respective thermoplastic resin or oxymethylene polymer, but it does not cause deterioration. It is carried out in a temperature range that is not

(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. In Fig. 2, ■ is a laminate consisting of a thermoplastic resin layer with excellent weather resistance, one layer of primer, a layer of metallic shapes, and one layer of primer (any primer layer may or may not be present). and II is an oxymethylene polymer containing an inorganic filler.

Furthermore, in FIG. 3, 1 is an oxymethylene polymer layer containing an inorganic filler, and 2 is a metallic shape. Moreover, 3 is a thermoplastic resin layer with excellent weather resistance. Further, 2a and 2b are single layers of primer. As is clear from these drawings, the feature of the reflector for a circularly polarized antenna of the present invention is that it has a structure consisting of at least three layers. In addition, the reflective plate for a circularly polarized antenna of the present invention has adhesion between each layer between the highly weather-resistant thermoplastic resin layer and the metallic object, and between the metallic object and the inorganic filler-containing oxymethylene polymer layer. A primer can also be used to strengthen the strength. Further, in order to attach the reflecting plate for a circularly polarized antenna of the present invention to a support, ribs may be provided for attachment to the oxymethylene polymer layer containing an inorganic filler. You can also add reinforcing ribs to strengthen the board. Furthermore, it is also possible to drill holes and pressurize the support for a circularly polarized antenna obtained by the present invention, and 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 manufacturing a reflector for a circularly polarized antenna The reflector for a circularly polarized antenna of the present invention is produced by manufacturing a metal shape that is laminated in advance, and then using the laminated metal shape by a vacuum forming method. , a stamping molding method, an injection molding method, or the like. Manufacturing methods using these molding methods will be explained in more detail.

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

The dry lamination method is generally used to laminate (adhere) the thermoplastic resin layer with excellent weather resistance and the metal shaped object. For olefinic polymers that can be extruded at high temperatures, the thermoplastic resin layer and the metallic shape can be laminated (adhered) by an extrusion lamination method. Manufacturing laminated metal shapes using extrusion lamination method 1. Extrude the resin to the above thickness using a T-gui film molding machine at a resin temperature in the range of 240 to 370°C. At the same time, a cooling pressure roll may be used to bond the metal shape.

When using a thermoplastic resin that has excellent adhesion to a metallic shape, a laminated metallic shape can be produced as described above. However, when using a thermoplastic resin whose adhesion to metallic objects is not fully satisfactory, a primer (anchor coating agent) commonly used in the field of thermoplastic resins is applied in advance to the metallic object. It is applied to one side of the object by gravure coating method or perspective coating method and dried at 50-100°C. Next, a thermoplastic resin film or sheet is pressed onto the surface of the primer of the metallic shape using a pressure roll heated to 50 to 100°C. The primer 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) Manufacture by vacuum forming or pressure forming When extruding the agent-containing oxymethylene polymer into a sheet shape using the 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 metallic shape, and an oxymethylene polymer layer containing an inorganic filler are sequentially laminated. 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 is attached to ceramic heaters or sheathed wires arranged below. Pull it into a device that can heat it with a heater and heat it. When the sheet is heated, it begins to melt, but once the sheet sag, as the heating continues, it becomes taut in the cotton that holds 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 cotton is pulled out and placed in the second part 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 -L part of the mold, a chamber (box) for compressed air is covered from one 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 punching the mold.

In addition, in any molding method, the surface temperature is 180 to 200℃.
°C is the preferred temperature.

(3) Manufacturing by stamping molding method To manufacture the circularly polarized antenna reflector of the present invention by this method, the weather-resistant A laminate sheet in which a superior thermoplastic resin layer, a metallic shape, and an inorganic filler-containing oxy-dimethylene polymer layer are sequentially laminated is introduced into a drawing die attached to a vertical press, and
50 kg/c rn” (preferably 1.0 to 20 kg
The desired molded product is obtained by heating and pressing at a pressure of /cm').Then, the product is obtained by cooling with wind or wood spray and releasing the mold. The pressurizing time is usually 15 seconds or longer, and 15 to 40 seconds is common.In addition, in order to improve the surface properties, it is preferable to perform the molding under two-stage pressure conditions.In this case, the first stage 10~20kg/c
After pressurizing for 15 to 40 seconds under a pressure of m', the second stage
A molded product with excellent surface smoothness can be obtained by pressing and stirring for 5 seconds or more under a pressure of 0 to 50 kg/cm'. This two-step molding method is particularly desirable when using an inorganic filler-containing ogymethylene polymer layer that has poor squirtability. Note that a suitable molding temperature in the stamping molding method is a surface temperature of 140 to 200°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. Insert injection molding is performed on the metal shape coated with the coating when forming a reflector for a circularly polarized antenna. To perform insert injection molding, the metal shape 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. ) and close the mold. Thereafter, the oxymethylene 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 oxymethylene polymer of the inorganic filler-containing olefin polymer, but lower than the thermal decomposition temperature of the oxymethylene polymer.

Insert injection molding is carried out at a temperature range of 190-230°C. In addition, if the injection pressure is 40 kg/crn' or more at the gauge pressure at the nozzle part of the cylinder of the injection molding machine, it is possible to form the inorganic filler-containing oxymethylene polymer into a shape almost similar to that of the mold. Not only is it possible to produce a product, but also a product with good appearance can be obtained. The injection pressure is generally 40 to 140 kg/Crrf, especially 7
0-120 kg/crn' is desirable.

[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,
Harmful changes such as blistering, peeling of metallic shapes, and cracks) were evaluated. Furthermore, a heat cycle test was performed in which the sample was exposed to 80°C for 2 hours, then 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 repeat this cycle for 10
After conducting the test 0 times, the appearance of the surface of the sample was evaluated in the same manner as in the weather resistance test. Peel strength was measured by cutting a test piece with a width of 15 mm from a manufactured reflector for a circularly polarized antenna, and peeling a metallic object at a splinter speed of 50 mm/min in accordance with AST)l 11-903. The strength was evaluated when peeled at 180 degrees.

Additionally, bending stiffness was measured according to ASTM D-790, and coefficient of thermal expansion was measured according to ASTM D-69f3.

The types and physical properties of the thermoplastic resin, oxymethylene polymer, inorganic filler, and metallic shape of the thermoplastic resin layer used in Examples and Comparative Examples are shown below.

[(A) Heat! T plastic resin] As a thermoplastic resin, Melt Flowray-1-(AST
M D-1238+: Therefore, polyvinylidene fluoride (hereinafter referred to as rPVdFJ) with a temperature of 250°C and a load of 10 kg) is e, Ig/10 min.
, a propylene homopolymer containing 0.4% by weight of a benzotriazole-based ultraviolet absorber and 0.5% by weight of carbon black [Melt Flow Index (JI)]
Measured according to S K-8758 at a temperature of 230°C and a load of 2.16 kg, hereinafter referred to as rMFIJ) for 0.5 g 710 minutes, hereinafter referred to as rPP(A) J], benzotriazole-based ultraviolet rays 0.4 absorbent
High-density polyethylene containing % demolding and 0.5% by weight carbon blank [Harm level 0.958 g/c
m', melt index (according to JIS K-8760, measured at a temperature of 80°C and a load of 2.16 kg, hereinafter referred to as rM, 1.J) is 0.8E/
10 minutes, hereinafter referred to as "rH[]PE(1)"] chlorinated polyethylene (chlorine content 3.15% by weight, amorphous , raw material polyethylene molecular weight approximately 200,000) and 80 parts by weight of acrylonitrile-styrene copolymer resin (acrylonitrile content 23% by weight) and 2 parts by weight of dibutyltin malate stabilizer [Sankyoki Manufactured by Gosei Co., Ltd., product name: Stann BM
] was cross-wired for 10 minutes using a roll (surface temperature 180°C), and the resulting composition (hereinafter referred to as AC5J), 20 parts by weight of dioctyl phthalate] (as a plasticizer), and 5.0 Parts by weight of dibutyltin malate (as a dehydrochlorination inhibitor) were mixed with 100 parts by weight of vinyl chloride homopolymer (degree of polymerization 1100, hereinafter referred to as rPVcJ).
A mixture of the following was used.

[(B) Oxymethylene polymer cooxymethylene polymer with MFI of 1.0 g/1
Oxymethylene homopolymer [hereinafter referred to as rPOM]
(1) J ], contains ethylene oxide, M
An oxymethylene copolymer with an FI of 9.0 g/10 min [hereinafter referred to as rPOM(2)J] and an oxymethylene copolymer containing ethylene oxide and an MFI of 20 g/10 min [hereinafter referred to as rPOM(3) ) I used J.

[(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 ffl Calcium carbonate (hereinafter referred to as rCaC0aJ) having a fiber diameter of 11 microns, a cut length of 3 mm, hereinafter referred to as rGFJ), and an average particle size of 0.8 microns was used.

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

Examples 1 to 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 Vinyroll 92T) was applied to one side of each metal shape to a thickness of 20 microns, and a urethane primer (Toyo Morton Co., Ltd.) was applied to the other side. Co., Ltd., trade name Atocoat 335) was applied to a thickness of 20 microns each and dried (in addition,
In Examples 7 and 10, the urethane-based primer was applied to both surfaces). In addition, inorganic fillers and oxymeth1
Table 1 shows the content of the inorganic filler in the composition for each type of inorganic filler and oxymethylene polymer. (not blended) were tri-blended for 5 minutes each using a Henschel mixer, and each of the 4 blends was blended at a resin temperature of 200℃.
The composition was prepared using a vented extruder under conditions of 'C. A sheet having a thickness of 2 mm was produced from each of the obtained compositions (pellets) using a T-Guy molding machine.

The thermoplastic resin film produced in this way (not used in Comparative Example 1), a metallic shape coated with primer on both sides, and an oxymethylene polymer sheet containing an inorganic filler were used. The laminate was manufactured by adhering by dry lamination method. The obtained laminate was vacuum-formed at 180°C (the surface temperature of the laminate) using a bowl-shaped female mold (outer diameter 750 mm, height 80 mm) to form a circularly polarized antenna. A reflector was manufactured (Example 1.2).

Manufactured in the same manner as Examples 1 and 2.1. (Table 1 shows the types of inorganic fillers and oxymethylene copolymers and the content of the inorganic fillers in the composition, as well as the types of metallic shapes in Table 1). 170°
Stamping was carried out in two stages by holding the first stage under a pressure of 11 or 20 kg/cm' for 30 seconds and the second stage 1' under a pressure of 50 kg/cm' for 20 seconds under the conditions of C. (the shape is the same as in Example 1), and a reflector for a circularly polarized antenna was manufactured (Example 3.4).

After applying the above acrylic primer to one side of each metal shape whose type is shown in Table 1 to a dry thickness of 20 microns, apply each thermoplastic resin whose type is shown in Table 1. A film (20 microns thick) was laminated. A urethane primer was applied to the other surface of the obtained laminate in the same manner as in Example 1. Each coated laminate thus obtained was inserted into an injection molding machine (clamping force: 1500 tons) so that the thermoplastic resin film was in contact with the male mold surface of the mold. After closing the mold, the injection pressure was 80 kg/crn' and the resin temperature was 210°C. Table 1 shows the types of oxymethylene polymer and inorganic filler and the content of the inorganic filler in the composition. is the first
The compositions shown in the table were subjected to insert injection molding to produce reflectors for circularly polarized antennas having the same shape as in Example 1 (Examples 5 to 12, Comparative Examples 1 and 2).

The elastic modulus and linear expansion coefficient of the inorganic filler-containing oxymethylene polymer layer of each circularly polarized antenna reflector obtained as follows, and the metal The peel strength of the shaped objects was measured. The results are shown in Table 1.

(The following is a blank space) When the radio wave reflectance of each reflector for a circularly polarized antenna obtained as described below was measured, it was 98%. In addition, weather resistance tests and heat cycle tests [・
However, except for Comparative Example 1, Table m1 shows discoloration, fading,
No harmful changes such as changes in gloss, crazing, blistering, peeling or cracking of metallic shapes could be observed.

However, in Comparative Example 1, the aluminum cloth on the surface corroded.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial perspective view of an antenna with a typical reflector for a circularly polarized antenna manufactured according to the present invention. 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 sectional view of FIG. A...Reflector for circularly polarized antenna, B...Converter, C...Converter support, D...Reflector support rod, E...Wiring, ■...Excellent weather resistance A laminate consisting of a thermoplastic resin layer, one layer of primer, a metallic shaped object layer and one layer of primer, II... oxymethylene polymer layer containing an inorganic filler,
■...Inorganic filler-containing oxymethylene polymer layer, 2
...Metallic shaped object, 3...Thermoplastic resin layer with excellent weather resistance, 2a...
Primer layer 1, 2b... Primer layer patent applicant Showa Denko Co., Ltd. Representative Patent attorney Sei Kikuchi - Figure 3

Claims (1)

[Claims] At least (A) a thermoplastic resin layer with good weather resistance (B)
) A laminate formed by sequentially laminating at least one shaped object selected from the group consisting of metallic mats, cloths, and nets, and (C) an oxymethylene polymer layer containing an inorganic filler; The thickness of the plastic resin layer is 5 microns to 51 mm, the metallic mat, cloth, and net are finer than 2 meshes, and the thickness of the oxymethylene polymer layer containing an inorganic filler is 500 microns to 15 mm. A reflector plate for a circularly polarized antenna, characterized in that the content of the inorganic filler in this layer is 10 to 80% by weight.