JPS60102002A - Reflector for reflector antenna - Google Patents

Abstract

PURPOSE:To improve the separation resistance of metallic foil against heat cycles of day and night and seasonal changes by adhering a fabric base material to the reverse surface of the metallic foil with a flexible adhesive, and adhering a thermosetting resin layer to the base material by heating and pressure application. CONSTITUTION:An anticorrosive layer 2 formed of a film of a thermosetting type acrylic resin with an about 20 and several mum thickness is provided over the surface of the metallic foil 11 having, for example, a 0.1-0.5mm. thickness, and the flexible adhesive 3 is provided over the reverse surface. The flexible adhesive 3 uses a polymer of vinyl chloride and acryl, linear polyester, compatible compound of linear polyester and amino resin, ethylene vinyl acetate copolymer, or hot melt adhesive of polyamide. The fiber fabric base material 4 is adhered to the flexible adhesive layer 3 to form and set a compound layer 5 by heating and pressure application, and the metallic foil 1 is adhered. Consequently, a reflector for a reflector antenna which has superior resistance to a heat cycle is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a beam mirror for a beam flap antenna.

A reflector antenna consists of a primary radiator and a reflecting mirror. Reflector antennas include parabolic antennas, horn reflector antennas, Cassegrain antennas,
There are shaped beam reflector antennas, etc., but the shape of the reflecting mirror is either a paraboloid of revolution, a parabolic cylinder, or a sphere.

Conventionally, as the above-mentioned reflecting mirror, it is known that a curved plate is formed from a thermosetting resin composition, for example, SMC, and aluminum foil is bonded to the concave curved surface of the curved plate.

However, this reflecting mirror is disadvantageous in that it requires a large number of manufacturing steps. Therefore, the present inventor thought of omitting the step of adhering the aluminum foil, and when molding a curved plate from a premix, which is a thermosetting resin compound, by setting the aluminum foil in the mold and starting the molding process. At the same time, we attempted to integrate aluminum foil into the molded plate. However, it has been found that in the case of a mirror that can be warped in this way, if the reflecting mirror is subjected to a cycling under the plate, the aluminum foil will peel off, making it difficult to put it to practical use.

This result is caused by the fact that the shape of the reflecting mirror is a curved surface, and the causes of this are considered as follows.

FIG. 1 shows a cross section of the above reflecting mirror, where 1' is the aluminum foil and 2' is the tree IJ layer.

In FIG. 1, the coefficient of thermal expansion of each layer (the one for the aluminum foil 1' is marked 1, and the one for the resin layer 2' is marked 2) is α1. α2. Let Young's modulus be El, E
2. Calculate the moment of inertia of area by ■11 ■2 + thickness.
h2. If the temperature change is t, and it is assumed to be a flat surface without considering the influence of dimensions or curved surfaces, the compressive or tensile force acting on each layer (unit: IJ) l)++P21 Moment acting on each layer (however, 4 'r position I+] hit) MI
The following relationship exists between +M2+bending radius r and strain 5It82 of each layer.

PI=P2°P -One P(111+h,)- 2M 1+ M 2-■ M, = Hibiki ■ M2-Ennie C s, = α ro 1 E,, h1-廿-0 82-0・t+-6possible+Tyar ■ S, = S2 = S □■ The above P corresponds to the shear force acting on the interface between the aluminum 2゜ convexity and the resin layer, and this shear force P is calculated from 0゜ and the formula 0. It is.

However, if we consider the influence of the curved shape of the reflecting mirror, if an axial force (tensile force or compressive force) is applied to a curved surface, a moment will be generated, so in equations Q) and @, Ml1M2 is As a result, the shear force P shown in equation 0 increases dramatically due to this increase in -.

As is clear from the above explanation, the interface peeling of the aluminum foil caused by the heat cycle in the above-mentioned mirror V is the result of excessive shearing force acting on the interface.

Therefore, in order to make the reflector produced by the above-mentioned simple manufacturing method (method of simultaneously forming a curved plate and adhering aluminum foil) to a daily heat cycle and a seasonal heat cycle, it can be used for antennas. It is necessary to improve the peeling resistance of aluminum foil, and the present invention aims at such an improvement.

That is, the reflector for a reflector antenna according to the present invention is obtained by bonding a fiber cloth base material to the back surface of a metal foil via a flexible adhesive, and molding a thermosetting resin layer onto the base material under heat and pressure. That! 1! It is assumed to have a J sign.

Examples of binary reflector antennas include parabolic antennas (offset parabolic antennas, center-feed parabolic antennas), horn reflector antennas, Cassegrain antennas, shaped beam reflector antennas, and the like.

FIG. 2 shows a sectional view of a reflecting mirror according to the present invention.

In Figure 2, l is a metal foil, usually aluminum foil is used, but other metal foils such as copper foil can also be used.
iru. 2 is an anti-corrosion layer provided on the surface of the metal foil 1. 3 is a flexible adhesive layer provided on the back surface of the metal foil 1, 4 is an adhesive N
3 is a fiber cloth base material (1 and 5 is a cured layer (hereinafter referred to as a molding layer) of a thermosetting resin composition, and the composition layer 5 is molded and cured by heating. At the same time, the metal foil 1 is made m;'+.

The curved shape of the reflector differs depending on the type of antenna, but in the case of a parabolic antenna, it is determined by・, set the aperture efficiency to η (usually 50~
60%), it is determined by GC-7) η.

1. The flexibility of the flexible adhesive layer 3 means that the Young's modulus is sufficiently smaller than that of the molding layer 5 in the temperature range of -30 to 120°C.

In FIG. 2, even if a shearing force acts between the -C1 aluminum foil 1 and the molded Jg 115, the shearing force can be well alleviated due to the low stress deformation of the flexible adhesive layer 3. Still, the adhesive layer 3 and the molding layer 5 are inserted between the fibers of the textile base material 4, and the imager is bonded via the textile base material 4 by the so-called anchor effect.

Due to such shear force relaxation effect and anchor effect, the peeling resistance of aluminum foil can be significantly improved.

”1, the aluminum foil usually has a thickness of 0.1 to 0.5 mm.
Use a thick one. As flexible adhesives, we use vinyl chloride and acrylic copolymers, linear polyesters, linear polyester and amine resin combinations, ethylene-vinyl acetate copolymers, or polyamide-based hot melt adhesives. The thickness of the adhesive layer is usually 0.05~
It is 0.10 tomo. Both nonwoven fabric and woven fabric can be used for the fiber cloth base material, and the thickness is usually 0.03 to 0, the tensile density is 0.4 to 0.6 seconds, and the tensile strength is 0.8 to 3. .0K
g/15 mm width, elongation is 12-25%. Premix, SMC, etc. can be used as the thermosetting resin composition, and unsaturated polyester or epoxy resin is usually used as the thermosetting resin. As fillers in the thermosetting A61 fat composition, quartz, calcium carbonate, mica, talc, etc.
9 can be used for inorganic and organic fibers, and the blending ratio (weight ratio) is, for example, in the case of IJ mix (20% fat, 70% filler, and other (hardening agent, reinforcing agent)). material, mold release agent) 10%.

The anti-Q=I mirror manufactured in this example is for a parabolic antenna, and has a focal length of 300 mm and a diameter of 850 mm.

Aluminum foil with a thickness of 0.3 mm (material is JISH4001-1)
A coating film of thermosetting acrylic resin with a thickness of approximately 23 μm is provided as an anti-corrosion layer on the surface of an aluminum material 5052) corresponding to 982, and an adhesive layer is provided on the back side of the aluminum foil.
7. Z0. lO carp vinyl chloride/acrylic 4fn 1
A 117J1j1 combined layer was provided, and heat treatment was performed at 150°C for 30 seconds.

Next, the press mold was filled with aluminum foil, thickness: O,
O6, non-oriented polyester nonwoven fabric (apparent density (y/
cni): 0.51, tensile load (Kg/15t
nrn width): Vertical, 0.811, Horizontal, 2.51, Elongation (F): Vertical, 13.0, Horizontal, 24.3) and polyester premix (unsaturated polyester resin = 20
% by weight, calcium carbonate 270% by weight, others (hardening agent, short glass fiber, release agent): 10% by weight),
A reflector with a thickness of 3 mm was processed under the conditions of 140° C., l OK9/cni, and 5 minutes. .

Comparative Example 1 In contrast to the example, the adhesive layer and the polyester nonwoven fabric were omitted.

Comparative example 2 In contrast to the examples, only the polyester nonwoven fabric was omitted.

When the peeling resistance (180° heel back test) of the aluminum foil was tested for the example product and the comparative example product thus obtained, the comparative example product 1 had a resistance of 3Kf/25 ram.
The width was 5 Ky/25 11] or less in Comparative Example Product 2, but 10 K9/25 in the Example Product.
mm 111 or more (15 Kg725 m
y II], the aluminum foil broke).

The reflector for a reflector antenna according to the present invention has a double configuration, and although it is capable of bonding the resin curved plate and the metal foil at the same time,
? It is possible to ensure extremely high peeling resistance of l'l,
With a simple manufacturing process, we can provide an anti-qXJ mirror with excellent weather resistance, especially heat cycle resistance.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing a conventional reflector reflector for a reflector antenna, and Fig. 2 is an explanatory diagram showing a reflector for a reflector antenna according to the present invention.
, is an explanatory diagram showing an I mirror. In the figure, 1 is a metal foil, 3 is a flexible adhesive layer, 4 is a textile base, and 5 is a thermosetting resin layer.

Claims (2)

[Claims] (1) A reflector for a reflector antenna, characterized in that a fiber cloth base material is adhered to the back surface of a metal foil via a flexible adhesive, and a thermosetting resin layer is molded on the base material under heat and pressure. . (2) Flexible adhesives include vinyl chloride and acrylic copolymers, linear polyesters, linear polyester and amine resin combinations, ethylene vinyl acetate copolymer hot melt adhesives, and polyamide hot melt adhesives. 2. A projecting mirror for a flap antenna according to claim 1, characterized in that it is made of any one of adhesives.