JPH0326362B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a reflecting mirror particularly useful as a solar light concentrator.

Solar reflecting mirrors used for solar thermal power generation, etc., require extremely high-precision reflecting surface shapes and sufficient strength to maintain a predetermined reflecting surface shape in order to increase light collection efficiency.
At the same time, it is desirable to be lightweight since it performs solar tracking drive.

As a product that almost satisfies these requirements,
A thin glass mirror with a thickness of 2 mm or less is attached with adhesive to a reinforcing panel made by joining two thin sheets of glass fiber reinforced resin (FRP) with a paper honeycomb layer interposed between them and bending as necessary. Curved mirrors or single-sided mirrors are attracting attention.

Although the reflecting mirror of the above structure has the advantage of having very high reflection efficiency since there is almost no light absorption loss when passing through the glass, and is high in strength and lightweight, it also has the following problems.

In other words, since the reflecting mirrors used in solar heat collectors are usually large, measuring several meters on a side, it is difficult to apply adhesive with a uniform thickness over the entire area of the mirror when bonding the thin glass mirror to the reinforcing panel. This is very difficult and tends to cause localized unbonded areas between the reinforcing panel and the thin mirror.

If there are such unbonded areas, even if the thin mirrors are assembled on a surface plate with a predetermined surface shape in the bonding process and the reinforcing panel is pressed onto this while laminating and bonding, there will be voids in the adhesive. In some areas, no pressing force acts on the thin glass mirror, and the mirror's elastic restoring force causes local deformation away from the surface plate.

If there is local unevenness on the reflecting surface in this way, the reflected light from this area will not enter the heat collector, causing a reduction in the reflection efficiency of the entire reflecting mirror.

In addition, since a thin glass mirror with a thickness of 1 mm or less is used, if the surface is subjected to an impact, the unbonded parts of the glass are likely to break.On the other hand, reflective mirrors are used outdoors and are susceptible to impact from dust, etc. Easy to accept.

An object of the present invention is to provide a novel method for manufacturing a reflecting mirror that solves the above-mentioned conventional problems. is placed with its reflective surface facing down, then inorganic fibers are laminated over the entire surface of the mirror on the backing protective layer, and resin liquid is poured over this to the extent that it protrudes outside the side of the mirror. The above resin layer is sequentially pressed from one end to the other with a roller to remove air bubbles, and an uncured inorganic fiber-reinforced resin plate is integrally bonded to the back surface of the mirror, and then a honeycomb core material is laminated on top of this. Then, by layering inorganic fibers on this honeycomb core material, pouring a resin liquid, and pulling it with a roller, an uncured back side inorganic fiber reinforced resin plate is formed, and in this process both inorganic fiber reinforced resin plates are The constituent resin liquid penetrates into the core of the honeycomb core material to form a fillet, and then a molded and pressed sheet is placed on the back side inorganic fiber reinforced resin plate, and a weight is placed on top of this so that the load is evenly distributed throughout. The gist of this method is to forcibly press the entire thin glass mirror onto the surface of the surface plate by placing a weight on it, and while maintaining this state, heat the resin of both inorganic fiber-reinforced resin plates to harden it.

According to the present invention, an adhesive application process for bonding the reinforcing material and the glass mirror is not necessary, and an inorganic fiber-reinforced resin plate (hereinafter referred to as
The thin glass mirror can be attached at the same time as the FRP plate (hereinafter referred to as FRP plate), which simplifies the manufacturing process and enables mass production at low cost.

In addition, instead of providing an adhesive layer between the surface of the pre-formed reinforcing material and the back of the mirror as in the past, uncured resin and inorganic fibers are alternately laminated on the back of the mirror, and they are joined together as is. In order to use it as a reinforcing material,
The overall thickness can be reduced, and at the same time, there is no space left unfilled with adhesive in contact with the back surface of the mirror, unlike in the conventional mirror.

In addition, only the reflective mirror that requires highly accurate curved surface formation is matched to the mold of the surface plate, and a resin that also serves as an adhesive and inorganic fibers is stacked on top of it, semi-cured and semi-fixed, and the front side is made of FRP.
A board is formed, and a honeycomb core material that can be bent freely is stacked on top of the honeycomb core material, and a resin that also serves as an adhesive and inorganic fibers is stacked and bonded on top of the honeycomb core material in the same way as before.

At this time, since the core material is free from distortion on the top surface, the stress is absorbed on the top surface without applying stress to the reflective surface side, and inorganic fibers and resin are stacked in a semi-hardened and fixed state to form the back FRP board.

According to this manufacturing method, all expansion and contraction distortion during curing is absorbed by the upper side (on the back side when finished), and therefore no stress is generated on the reflective surface, which requires a highly accurate curved surface, and the curvature accuracy is improved. A highly reflective surface can be created. In addition, in this process, the matrix resin liquid constituting both FRP plates permeates into the core of the honeycomb core material due to surface tension, forming a so-called fillet. Such fillets ensure a sufficient bonding area between the honeycomb core material and both FRP plates, making it possible to create a highly rigid reflecting mirror.

Therefore, according to the present invention, it is possible to obtain a highly accurate reflecting surface that is extremely faithful to the surface shape of the surface plate that supports the mirror, and also to obtain a lightweight reflecting mirror with high joint strength.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments shown in the drawings.

FIG. 1 is a side view of a reflecting mirror according to the present invention, and FIG. 2 is an enlarged cross-sectional view of the same essential part, showing a transparent glass substrate 1A having a thickness of 2 m/m or less, preferably 1.0 m/m to 0.3 m/m. It is constructed by integrally bonding a reinforcing panel 2 to the back of a thin plate mirror 1 whose surface is provided with a protective backing layer 1C made of a silver film 1B, a copper film, and a synthetic resin film. The reinforcing panel 2 is made of paper honeycomb 4 made of FRP board 3 impregnated with phenolic resin, and other materials.
FRP plates 5 are sequentially laminated and bonded to form an integrated structure.

To give a specific numerical example, the thickness of the glass fiber reinforced resin plates 3 and 5 is 2 to 5 mm, the thickness of the paper honeycomb 4 is 50 to 100 m/m, and the core diameter of the honeycomb is 5 to 20 m/m.

And, without providing a different adhesive layer between the FRP plate 3 on the front side and the glass thin plate mirror 1, the FRP
The thin plate mirror is integrally joined by the adhesive force of the matrix resin (generally unsaturated polyester resin) that constitutes the plate 3.

In addition, the front FRP board 3 and the paper honeycomb 4 and the back FRP board 5 are bonded using the adhesive strength of the matrix resin that makes up the FRP boards 3 and 5, without using different adhesives. ing.

Next, a preferred method for manufacturing a reflecting mirror having the above structure will be explained with reference to FIGS. 3A to 3D.

First, a surface plate 6 whose upper surface is precisely finished in a predetermined reflective surface shape is prepared, a release material layer such as fluororesin film or wax is provided on this surface plate 6, and a flat glass thin plate mirror is placed on top of this. 1 with its reflective surface facing down.

Next, glass fibers 7 such as roving cloth or filament mats are layered uniformly and thinly over the entire surface of the mirror 1 on the protective backing layer of the mirror 1, and additives such as curing catalysts, curing accelerators, hardness modifiers, etc. are added on top of this. The mixed unsaturated polyester resin liquid 8 is poured to the extent that it slightly protrudes outside the side periphery of the mirror 1.

Next, the resin layer 8 is sequentially pressed from one end to the other with a roller 9 to remove air bubbles, and glass fibers are laminated again and the resin liquid is allowed to flow.

In this way, by repeating glass fiber lamination, pouring resin liquid, and roller pulling several times, the uncured FRP board 3 with a thickness of about 2 to 5 m/m is finally integrally joined on the back surface of the mirror 1. Form.
Next, a flat plate-shaped or curve-molded paper honeycomb 4 impregnated with phenol resin is laminated thereon, and glass fibers are laminated on this paper honeycomb 4 in the same manner as described above, resin liquid is poured, and roller pulling is repeated. , finally the thickness is 2
A back side FRP board 5 in an uncured state with a thickness of about 5 m/m is formed.

At this level, the matrix resin liquid constituting both FRP plates 3 and 5 penetrates into the core of the paper honeycomb 4 due to surface tension, forming a so-called fillet (fillet) 10 as shown in FIG. With such a fillet 10, the paper honeycomb 4 and both
A sufficient bonding area is ensured between the FRP plates 3 and 5.

Next, a fluororesin film is placed on the back side FRP board 5,
A molding press sheet 11 is placed through a mold release material such as polyethylene film or wax, and a weight 12 is placed on top of the sheet 11 so as to distribute the load uniformly over the entire sheet to forcibly press the entire thin glass mirror onto the surface of the surface plate.

While maintaining this state, the matrix resin of the FRP plates 3 and 5 is heated, for example, at 40 to 60° C. for about 2 hours to harden it.

After the curing process was completed, the irregular part on the side of the combined mirror and reinforcement panel 2 was cut out, and the FRP board 3,
The paper honeycomb 4 is airtightly protected by applying an edge seal 12 over the entire circumference using the matrix resin putty used in step 5. Also, if necessary, paint all surfaces other than mirrors with weather-resistant paint.

In the manner described above, a reflecting mirror in which the thin glass mirror 1 and the reinforcing panel 2 are firmly and integrally joined can be manufactured.

Although the illustrated example shows the manufacture of a curved mirror, a flat reflecting mirror can be manufactured in exactly the same manner as described above by using a flat surface plate as the surface plate.

FIG. 5 shows another embodiment of the invention.

This example is a reflective mirror panel in which only a glass fiber reinforced resin plate 3 with a thickness of about 2 to 5 m/m is integrally bonded to the back side of a thin plate mirror 1 with a glass thickness of 1 m/m or less using the matrix resin itself that constitutes this resin plate 3. It is.

Since the structure of this example is highly flexible, it is possible to form any reflecting surface with a wide range of degrees of freedom in accordance with the shape of the rigid support installed at the site, making it extremely versatile.

Further, it is also possible to construct a rigid reflective mirror panel with a flat or curved reflective surface by integrally bonding it with a plate-shaped reinforcing body for each reflective mirror panel of this example.

For example, a honeycomb core material 4 made of paper, thin metal plate, etc., as shown in FIG. Accordingly, a rigid reflective mirror panel can be manufactured by bonding these laminates to each other while bending them.

Although the above description has been made using glass fiber reinforced resin as an example, any inorganic fiber such as carbon fiber can be used in addition to glass fiber as the resin reinforcing fiber.

[Brief explanation of drawings]

Figure 1 is a side view showing one embodiment of the present invention, Figure 2 is a side view showing one embodiment of the present invention.
The figure is an enlarged sectional view of the main part, Figures 3 A to D are side sectional views showing step by step an example of the manufacturing method of the reflecting mirror of the present invention, and Figure 4 is a side sectional view showing the finished state of the side circumference of the reflecting mirror. The cross-sectional view, FIG. 5, is a side cross-sectional view showing another embodiment of the present invention. 1... Glass thin plate mirror, 2... Reinforcement panel, 3,
5...Glass fiber reinforced resin board, 4...Paper honeycomb.

Claims (1)

[Claims] 1. A thin glass mirror is placed with its reflective surface facing down on a surface plate whose upper surface has been finished in a predetermined reflective surface shape, and then inorganic fibers are placed on the protective backing layer of the mirror over the entire surface of the mirror. Laminate the layers, pour resin liquid over the mirror until it protrudes outside the side periphery of the mirror, and then press the resin layer sequentially from one end to the other with a roller to remove air bubbles and form an uncured inorganic fiber reinforced layer. A resin plate is integrally bonded onto the back surface of the mirror, then a honeycomb core material is laminated on top of this, inorganic fibers are laminated on top of this honeycomb core material, resin liquid is poured in, and the uncured material is rolled by a roller. The back side inorganic fiber reinforced resin plate is molded, and during this process, the resin liquid that makes up both inorganic fiber reinforced resin plates penetrates into the core of the honeycomb core material to form a fillet, and then the back side inorganic fiber reinforced resin plate is formed. A forming press sheet is placed on top of the sheet, and a weight is placed on top of this to ensure an even load distribution over the entire thin glass mirror to forcibly press the entire thin glass mirror onto the surface plate surface.While maintaining this state, both inorganic fiber reinforcements are placed. A method for manufacturing a reflecting mirror, characterized by heating and curing the resin of the resin plate.