JPS6194002A - Production of fiber reinforced plastic mirror - Google Patents

Abstract

PURPOSE:To decrease the waving of a specular face by depositing preliminarily aluminum by evaporation on a polished surface, plating preliminarily nickel to the surface of an FRP laminate and adhering the aluminum layer deposited by evaporation and the nickel plating layer then releasing the polished surface from the aluminum layer deposited by evaporation and transferring the aluminum specular face. CONSTITUTION:A silica layer 5 deposited by evaporation and the aluminum layer 4 deposited by evaporation are preliminarily formed on the surface of a glass mold 6 in (b). On the other hand, the nickel plating layer 2 is preliminarily formed by an electroplating or chemical plating method on an FRP substrate 1. Both layers are adhered by an adhesive agent 3 and are then stripped, by which the layer 5 is released from the mold 6 and the aluminum layer specular face which is deposited by evaporation and is protected by the transparent layer 5 on the surface is transferred to the FRP and the FRP mirror (a) is manufactured. The effect of decreasing the waving is low when the thickness of the nickel plating layer is <20mum, and when the thickness exceeds 80mum, there is the possibility of stripping according to a heat cycle and therefore the thickness is kept within a 20-80mum range.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for manufacturing a mirror made of fiber reinforced plastic (FRP), which is particularly suitable for use in environments with severe temperature changes.

(Prior Art) Conventionally, mirrors have generally been made of glass, stainless steel, aluminum, etc. A mirror made of glass plated with silver or metal vapor-deposited has a mirror surface with extremely small surface roughness and high light reflectance. On the other hand, mirror surfaces made of polished metals such as stainless steel or aluminum do not have the same level of smoothness as glass mirrors, and their light reflectance is somewhat low.

By the way, recently, parabolic mirrors that collect parallel light, collimator mirrors (concave mirrors) that convert focused light into parallel light, and cameras that are placed in the space environment or in laboratories (space chambers) that simulate the space environment on the ground are being used. A flat or convex mirror is required to expand the field of view.

These mirrors undergo a heat cycle many times a day, in which the temperature reaches nearly 100° C. when illuminated (daytime) and drops to nearly -180° C. during darkness (night).

Glass mirrors may break due to such heat cycles. Furthermore, it is desirable that mirrors mounted on space satellites and mirrors suspended from the ceiling of space chambers be lightweight. The specific gravity of FRP is generally about 1/2 that of glass or aluminum, which is much lower than that of stainless steel, so there is little risk of it breaking under heat.

It is extremely preferable as a mirror substrate. However, when forming a mirror surface, even if aluminum is deposited directly on the FRP surface,
Alternatively, it has been found that even if PRP is coated with resin or metal plated and then aluminum is vapor deposited, a mirror surface with small surface roughness and high reflectivity cannot be obtained. This is because the reinforcing fibers that make up FRP have a diameter of 6 to 9 μm, and if some of these are exposed, even with resin coating or metal plating, the unevenness cannot be covered, leaving a surface roughness on the order of several μm. ,
The entire image becomes whitish and reflects on a mirror surface with low reflectivity.

In response, one inventor developed a "transfer method" and succeeded in creating a cylindrical mirror surface with a reflectance of 9 on an FRP substrate. First, aluminum is vapor-deposited onto the surface of a glass mold or polished metal mold to create a mirror surface. Next, prepare an FRP board whose one surface is molded or machined approximately in accordance with the shapes of these molds (flat, concave, convex). F.R.
A solvent-free adhesive (such as an epoxy resin composition or an unsaturated polyester resin composition) is applied to the P plate surface or the aluminum vapor-deposited surface, and it is adhered to the glass-type (or metal-type) aluminum vapor-deposited layer. Next, let them both be released from the mold.

The aluminum vapor deposited layer is transferred to the PR, P plate and becomes a mirror surface. This method allows the surface shape of the mold to be determined with sufficient precision.
Even if the accuracy of Fll and P surfaces is not very good,
Since the gap is filled with adhesive, the mirror surface has the advantage of being sufficiently accurate.

This mirror surface is due to the aluminum vapor deposited surface formed in contact with the glass mold (or metal mold) appearing on the surface.

The result is a mirror surface that is extremely dense and highly reflective. When transferring the aluminum evaporated layer, in order to facilitate release from the glass mold (or metal mold), first apply a silicone mold release agent to the surface of the glass mold (or metal mold) or apply silica (usually -oxidized) to the surface of the glass mold (or metal mold). It is advisable to vapor-deposit silicon (5 inches) before vapor-depositing aluminum.

A solvent-free adhesive is used because if voids remain in the adhesive layer, the mirror-like aluminum vapor deposited layer will become dull or dented in those areas.

Further, since it is necessary to be sufficiently stable even at the upper limit of the operating temperature (approximately 100° C.), a heat-curable epoxy resin composition is generally preferred. In this case, the mirror surface is flat at the curing temperature of the adhesive (usually 80°C to 150°C), that is, at the transfer temperature, but when the temperature is at room temperature or low temperature, the texture of the FRP base material in one skin part changes. It has been found that surface irregularities (referred to as "undulations") corresponding to the eyes occur.

(Purpose of the invention) The present invention further comprises plating Niracle to a thickness of 20 μm to 80 μm on the surface of an FRP layered product with reduced mirror waviness, and then bonding the aluminum vapor deposited layer and the nickel plating layer with a solvent-free adhesive. After bonding, the polished surface and the aluminum evaporated layer are released from the mold to transfer the aluminum mirror surface to the FRP laminate.
This invention relates to a method for manufacturing mirrors.

The mirror surface may be flat, concave, or convex.

The material for the polished surface is glass or chrome.

Polished metal such as titanium is used.

There are no particular restrictions on the polishing method.

FRP is glass fiber reinforced plastic (GFR).
P), carbon fiber reinforced plastic (CFRP),
Aramid fiber-reinforced plastic (KFRP) or hybrid FRP (a composite of these) is used.

Generally, FRP laminates are made of reinforced fiber base material (cross).

mats, etc.) are laminated and impregnated with a thermosetting resin composition to form a plate (laminate). The warp and weft yarns of this reinforced fiber cloth may be of the same type or different types. Further, the resin is not particularly limited as long as it is an epoxy resin, unsaturated polyester resin, phenol resin, polyimide resin, or any other resin used in ordinary PR and P.

In other words, the present invention is an FRP mirror made by forming a mirror surface with good light reflectivity on the surface of various ordinary FRP laminates, and there are no particular restrictions on the structure of the FRP laminate that serves as the substrate.

FIG. 1 is a longitudinal sectional view showing an example of a mirror made of FRP6 obtained by the manufacturing method of the present invention. Although a plane mirror is shown here, a concave or convex mirror has exactly the same configuration. In Figure 1, 1 is an FRP board that serves as a substrate.
2 is a nickel plating layer, 3 is an adhesive layer, and 4 is an aluminum vapor deposited layer with a mirror surface.

5 is a silica vapor deposited layer, which is glass type (or metal type)
It has the effect of making it easier to release the aluminum vapor deposited layer from the mold and increasing the scratch resistance of the mirror surface.

FIG. 2 is a longitudinal cross-sectional view showing an example of a method for manufacturing an FRP mirror according to the present invention. 6 is a glass type.

A silica vapor deposition layer 5 and an aluminum vapor deposition layer 4 are formed on this surface. These vapor-deposited layers are usually deposited on a glass mold by vaporizing silicon oxide and pure aluminum, respectively, by a resistance heating method in a high vacuum of 10 to 10 Torr. On the other hand, FR
A nickel plating layer 2 is formed on the P substrate l by electroplating or chemical plating. Next, after bonding the two with adhesive 3, when peeled off, the mold is released between the silica vapor deposited layer 5 and the glass mold 6, leaving one surface transparent (mirror surface) of the aluminum vapor deposited layer protected by the silica vapor deposited layer 5. is transferred to FRP, creating the p RP mirror shown in FIG.

Thickness of the nickel plating layer I''i 20μmi Less than 208m The effect of reducing bending is small, and if it exceeds 80μm, there is a risk of fading due to heat cycles, so 20μm
The range is 80 μm.

(Example) The present invention will be described in detail. Parts are by weight.

First, on one side of a glass plate 30 cm square and 3 cm thick, 2 silicon oxides (made by Osaka Titanium, 200 mesh) were applied.
Approximately 20 oX in a room temperature atmosphere of 10-5 Torr
/second to a thickness of approximately 2μm, and then pure aluminum (made of vacuum material, 99.99%) was deposited in the same atmosphere to a thickness of approximately 2μm.
It was deposited to a thickness of about 1 μm at a rate of 00×/sec.

P　R, P plates are plain woven carbon cloth (east side).

Trading cards φ634:N are laminated at a density of 4.5 sheets/mm.

A cycloaliphatic epoxy resin composition (100 parts of cycloaliphatic epoxy resin ERL4221 manufactured by IJ-CC), 90 parts of hexahydrophthalic anhydride, and benzyldimethylamine were impregnated under reduced pressure at 120° C. for 3 hours under atmospheric pressure.

Further, a CFRP plate having a size of approximately 250 mm and a thickness of 10 W at the corners, which was obtained by curing at 160° C. for 5 hours, was used.

One side of this CFRP board was roughened with ≠150 sandpaper 71, and chemically nickel plated to a thickness of IQ μm.
20μm, 40μm, 60μm, 80μm.

Six types of 100 μm nickel plating layers were formed. In addition, as a comparative example, a CFRP board without a nickel plating layer was used.

The same alicyclic epoxy resin composition as mentioned above was applied to these CF)'LP plates and combined with the glass plates.

After adhering at 120° C. for 24 hours, the mold was released, and the aluminum vapor deposited layer and silica vapor deposited layer were transferred to a CFRP board. Next, these CFRP mirrors were heated to +100°C and -196°.
When a heat cycle of C (immersion in liquid nitrogen) was applied, the thickness of the nickel plating layer exceeded 80 μm.
Within 10 times, the CFR, P and nickel plating layer were removed. However, when the thickness of the nickel plating layer was 80 μIn or less, it did not fade even after 50 times of application. Considering that the device is used in an environment with severe temperature changes, the thickness of the nickel plating layer is set to be 80 μm or less.

Next, when we measured the unevenness on the surface of the CFRP mirror using a stylus-type surface roughness measuring device (SIJRFCOM manufactured by Tokyo Seimitsu), we found that there were no unevenness with a small pitch (so-called surface roughness), which was similar to the texture of the carbon cloth. A corresponding undulation was observed. This waviness was measured at room temperature.

FIG. 3 is a diagram showing the correspondence between the texture of the carbon cloth in the skin layer of CFRP and the measurement results of the waviness of the mirror surface. Third
In the figure, 8 is the warp thread and 9 is the weft thread of the carbon cloth 7 forming the skin layer of C F I'L P.

The waviness of the mirror surface was measured along the measurement line 10. Result A is the case where there is no nickel plating layer. The area where the warp and weft intersect is convex, and the other areas are concave, creating regular undulations. Its height was about 0.7 μm. Result B is when there is a 20 μm thick nickel plating layer.
The height of the undulations is approximately 0.2 μm. If the swell is below this level.

It has almost no effect on the reflectance as a mirror surface.

Further, when the thickness is 10 μm, the height of the waviness is about 0.5 μm, which is unsatisfactory as a mirror surface. Note that when the thickness of the nickel plating layer is 40 μm or more, the waviness becomes 0.1 μm or less in height. From the above results, the thickness of the nickel plating layer is 2
It should be in the range of 0 μm or more and 80 μm or less.

(Effects of the Invention) The present invention provides an FRP mirror with reduced mirror surface waviness.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view showing an example of a FrLP mirror obtained by the manufacturing method of the present invention, Fig. 2 is a longitudinal cross-sectional view showing an example of the manufacturing method, and Fig. 3 is a weave of reinforcing fiber cloth on the PRP surface. FIG. 6 is a diagram showing the correspondence between the eye and the measurement results of the waviness of the mirror surface. Explanation of symbols 1... PRP board 2... Nickel plating layer 3... Adhesive 4... Aluminum vapor deposited layer (mirror surface) 5... Silica vapor deposited layer 6... Glass mold 7...
・Carbon cloth 8...Warp thread 901. weft
1o... Swell measurement line rod 1 mouth $2! 3rd mouth 1071ηt

Claims (1)

[Claims] 1. Deposit aluminum on the polished surface, plate the surface of the fiber-reinforced plastic laminate with nickel to a thickness of 20 μm to 80 μm, and bond the aluminum deposited layer and nickel plating layer with a solvent-free adhesive. A method for manufacturing a fiber-reinforced plastic mirror, characterized by releasing the polished surface and the aluminum vapor-deposited layer to transfer an aluminum mirror surface onto the fiber-reinforced plastic laminate.