JPS62174701A - Production of carbon fiber reinforced plastic mirror - Google Patents

Abstract

PURPOSE:To obtain a mirror having good shape accuracy, small surface roughness of a specular surface and high reflectivity by depositing an inorg. material by evaporation on a mold having a polished surface and adhering a vapor- deposited surface and CFRP laminate by an adhesive agent of a non-solvent type then stripping the polished surface and the vapor-deposited surface and depositing a metal by evaporation on the smoothed surface thereby forming the specular surface. CONSTITUTION:The inorg. material such as silicon oxide is deposited by evaporation on a projecting mold 4 which is precisely polished to provide the smooth vapor-deposited inorg. material surface 3. A release agent is preferably and preliminarily coated on the projecting mold 4. The adhesive agent 5 of the non-solvent type such as epoxy resin comspn. is coated on the surface of the surface 3 and the CFRP (carbon fiber reinforced plastic) laminate 2 having a recessed surface is placed thereon and the adhesive agent 5 is cured. The surface 3 is transferred to the laminate and the CFRP laminate 7 having the smoothed surface is obtd. when the CFRP laminate 2 is stripped from the mold 4. A CFRP mirror 1 is obtd. when a metal 6 is deposited by evaporation on the laminate 7.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides a collimator mirror for a large space chamber/bar;
Suitable for artificial hygiene condensing mirrors, etc. The present invention relates to a method of manufacturing a carbon fiber reinforced plastic (hereinafter also referred to as CFRP) mirror.

(Prior technology) Parabolic mirrors that collect parallel light and collimator mirrors that convert focused light into parallel light are used in the space environment or in a laboratory (space chamber) that simulates the space environment on the ground. To widen the field of view,
Flat mirrors and convex mirrors are used. In the space environment, there is a large temperature difference between day and night, and the mirror has a temperature of 100% during illumination (daytime).
℃, and during darkness (night) the temperature drops to nearly -60℃.

The material of the mirror is generally light metal (e.g. aluminum alloy) or fiber reinforced plastic (FRP, e.g. CPRP), and in both cases the mirror surface is metal (e.g. aluminum).
Formed by vapor deposition. It is preferable that the material of the mirror is light and has high rigidity. Generally, the ratio of the elastic modulus to the specific gravity is called the specific elastic modulus, and the larger the ratio, the thinner it is, the less it bends, and the lower the launch cost for artificial sanitary mirrors, and the lighter the hanging hardware for space chamber mirrors. I can do it.

This specific modulus is the same for metals such as aluminum alloys and high-strength steels.

While titanium alloys etc. have a ratio of about 9/- to 3000,
Approximately 5000kg/I for CFRP! It's 11m,
CF 几P is more advantageous. Furthermore, if the mirror undergoes thermal expansion or contraction in response to temperature changes, the radius of curvature or focal length of the mirror will change, making it impossible to fully perform the two functions. In general, the coefficient of thermal expansion of metals is.

1,2 X 10-'m/mo"c (high tensile strength steel)
~l 5 × 10-'m/mm°C (aluminum alloy), it cannot fully function as a mirror in the temperature range of the space environment. On the other hand, the coefficient of thermal expansion of CFRP is very small, about 0.03 x 10-5 m+n/mm°C, so the influence of temperature changes #1 is negligible.

For the above reasons, the materials for mirrors for space equipment are:
CFRP is more suitable than metal.

However, creating a mirror surface requires some ingenuity.

CF 几P concave mirror consists of a CFRP laminate and a mirror surface. The mirror surface is generally a metal with high light reflectance (e.g. aluminum)
Formed by vapor deposition.

Furthermore, CFRP laminates are generally obtained by impregnating carbon cloth with a thermosetting resin composition (for example, an epoxy resin composition) and hot press molding the impregnated carbon cloth.

To make a CF-P laminate with at least one side concave,
By passing a flat plate and machining it to create a concave surface.

A mold with a convex surface matched with a concave surface in advance may be used. Even in the latter case, it is difficult to achieve the final mirror-like precision by molding because of the thermal expansion of the mold during high-temperature curing of the wrinkles, where the shape precision of the mold was insufficient. A glass convex type made of glass with a small coefficient of thermal expansion polished into a convex surface with high accuracy may be used, but it is expensive and easily damaged. In particular, a surface pressure of about 10 kg/c♂ is applied during hot pressing.

If the coating is uneven, the glass mold may break. Therefore, a convex mold is used, but even in that case, machining is required to obtain the final jit shape for the reasons mentioned above. Generally, the carbon fiber of carbon cloth is the base material of CFRP.

The diameter is approximately 7 μm. When machining CFRP, the carbon fibers and resin are removed from the two surfaces, and even the polished surface has irregularities of several micrometers in size. Even if metal is deposited on this surface, a shiny mirror surface with high reflectance cannot be obtained.

Then we coated the polished CFRP surface with resin.

I tried to erase the unevenness equivalent to the diameter of carbon fiber, but
The part where the fibers are exposed has a property of repelling the coating resin, and with a resin coat up to a thickness of about 100 μm, the surface unevenness increases, and this cannot be reduced. In addition, when the coating was applied as thick as about 1 circle, the thickness was uneven in the center and periphery of the concave mirror, and the overall shape accuracy was rejected. So I used abrasive paper to precisely polish it.

Frictional heat momentarily generates high heat locally.

A deep wound occurred.

In addition, bonding the polished surface and the CI+1P laminate with a solvent-free adhesive and then releasing the mold, and then vapor depositing metal on the smoothed surface of the CFRP laminate, is a good way to release the metal from the polished surface. It is necessary to apply a molding agent.

Since the mold release agent adhered and remained on the smoothed round surface of the CPRP laminate, even if metal was deposited on the smoothed surface, a clean mirror surface could not be obtained.

t7'? , a CFRP mirror in which the metal surface deposited on the polished surface and the CFRP laminate are bonded with a solvent-free adhesive, and then the polished surface and the metal-deposited surface are released from the mold to transfer the mirror surface to the CFRP laminate. Manufacturing method (Patent application 1984-148284)
According to this manufacturing method, 0FFLP with good shape accuracy, small mirror surface roughness, and high reflectance.
Mirrors can be easily obtained.

However, since this manufacturing method integrally forms a mirror surface with metal vapor deposited on it, it is necessary to prevent contamination from the atmosphere until it is actually used.

(Problems to be Solved by the Invention) The object of the present invention is to produce a C'F'lLP that has extremely good shape accuracy, small mirror surface roughness, and high reflectance.
The object of the present invention is to easily obtain mirrors in a less polluted environment.

(Means for Solving the Problems) The present invention is a method for manufacturing a CFRP mirror in which a mirror surface is formed by depositing metal on the smoothed surface of a CFR or PfJi layered product. After bonding the resulting inorganic-deposited surface and the CFR, P laminate with a solvent-free adhesive, the polished surface and the inorganic-deposited surface are released from the mold, and the inorganic-deposited surface is bonded to the CF RP laminate. After transferring to CFRP, metal is deposited on this smoothed surface to form a mirror surface.
Concerning the manufacturing method of mirrors.

The manufacturing method of the present invention is applicable to any of mirrors in which the M-plane is flat, concave, or convex.

As the material for the polished surface of the present invention, glass or polished metal such as chromium or titanium is used.

When transferring the inorganic vapor-deposited surface to the CF-P laminate, glass was used as the material for the polished surface, and the distribution of the adhesive was observed through the glass with the glass facing upward.

It is preferable to perform the transfer while controlling the distribution of the adhesive, since it is possible to prevent the generation of voids due to non-uniform distribution of the adhesive.

There are no particular restrictions on the polishing method, but it is preferable that the polishing be as precise as possible.

An inorganic substance is vapor-deposited on the polished surface, and the vapor-deposition is performed using nine known methods and conditions, and there are no particular limitations on the two vapor-deposition conditions. The inorganic material is preferably one that has good adhesion to adhesives and metals, such as silicon oxide.

In the present invention, a solvent-free adhesive is used to prevent the generation of bubbles, examples of which include epoxy resin adhesives and unsaturated polyester adhesives.

CFRP laminates are made by laminating carbon fiber base materials such as carbon cloth, pressing them in a mold, impregnating them with a thermosetting resin composition such as an epoxy resin composition under reduced pressure, and curing them by heating, or by pre-heating and impregnating them with a thermosetting resin composition such as an epoxy resin composition. A semi-cured prepreg sheet is laminated onto a carbon fiber base material such as cloth, impregnated with a thermosetting resin composition such as an epoxy resin composition.

Those that are hot press molded in a mold are used.

FIG. 1 is a longitudinal sectional front view showing an example of the manufacturing method of the present invention. In the figure, an inorganic material was deposited on a precisely polished convex mold 4 to provide a smooth inorganic material deposition surface 3. In the present invention, the vapor deposition surface in contact with the convex mold 4 is in contact with the mirror surface of the CFR, P mirror. Since the shape accuracy and surface roughness of the mirror surface mirror those of the concave surface of the convex mold 4, it is desirable to make this convex mold by polishing the glass.

It may be metal. In order to make it easier for the inorganic material-deposited surface to peel off from the convex mold 4, it is desirable to apply a thin layer of a release agent (for example, silicone-based, fluorine thread) to the convex mold before vapor-depositing the metal.

Next, an adhesive 5 is applied to the surface of the surface 3 on which the inorganic substance has been vapor-deposited, a concave CFRP laminate 2 is placed thereon, and the adhesive 5 is cured. After that, the KCFRP laminate product 2 was molded into a convex shape 4.
When pulled apart, the inorganically deposited surface 3 is transferred to the CPRP laminate 2, resulting in a CPRP laminate 7 with a smoothed surface (see FIG. 2). When the metal 6 is deposited on the CF laminate 7 having the smoothed surface, the CFR
P mirror 1 is obtained. If bubbles form inside the adhesive, they will leave traces on the mirror surface, so a solvent-free adhesive is used. The concave surface of Maku CF 几P is rough, and the adhesive will get stuck in the dents.

It may be left in the processed state, but in order to improve adhesion with the adhesive 5, it is better to sand it with sand vapor (for example, Su 600). Furthermore, regarding the shape accuracy of the KCFRP concave surface, some errors are allowed because irregularities in shape compared to the precision convex surface can be covered by the thickness of the adhesive.

The metal deposited on the smoothed surface of the CF'RP laminate is preferably aluminum, which has the highest reflectance, but may also be chromium, nickel, silver, or the like. In both cases, the vapor-deposited surface is dense and has extremely small surface roughness, and the surface of the reverse KCF'P laminate is preferably porous and uneven to improve adhesion with inorganic materials. Such a evaporation surface can be obtained by depositing aluminum, for example, thickly (about 1 to 3 μm) at a fairly high speed (about 20 to 100×/sec).

In the present invention, it is desirable that the solvent-free adhesive applied to the metal-deposited surface be cured at around room temperature.

In addition, adhesives include inorganic powder with small particle size (for example).

It is preferable to fill the cured product with titanium oxide, iron oxide 9 quartz, alumina) to reduce the coefficient of thermal expansion of the cured product. The inorganic powder preferably has an average diameter of 0.5 μm or less from the viewpoint of mirror reflectance.

In the manufacturing method of the present invention, if the shape accuracy of the CFRP surface is poor with respect to the polished surface, the adhesive becomes thick in 9 parts.

In this case, instead of using an adhesive alone, a woven or non-woven fabric made of inorganic fibers (e.g. glass fiber) or organic fibers (e.g. polyester) or a laminated mica sheet made of fine mica particles is impregnated and inserted. Good too.

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

Example 1 The smoothed surface was transferred from a glass convex lens to a CF in the following manner.
The CFRP mirror of the present invention was obtained by transferring to RP and then metal vapor deposition.

A glass convex lens with a diameter of 30 an, focal length of 7 m, and thickness of approximately 1.5 cm was used. The convex surface was coated with silicone mold release agent (QZ-133 manufactured by Chipa Corporation) and wiped with a cloth until almost no traces of wiping were visible. Ta.

2. Apply silicon monoxide to this side. OX 10-' Tor
It was deposited to a thickness of 1.0 μm at room temperature in a vacuum of r. The deposition rate was approximately 20X/sec.

CF'RP laminated products are plain weave carbon cloth (east side).

Toraykana 6343) is laminated at a density of 4.5 sheets/fence.

An alicyclic epoxy resin composition (blended with 100 parts of alicyclic epoxy resin ERL4221 manufactured by UCC, 90 parts of hexahydrophthalic anhydride, and 1 part of benzyldimethylamine) was heated at 70°C for 0. After vacuum impregnation at OI Torr, 120℃ under atmospheric pressure for 3 hours, and then 160℃
, which was obtained by curing for 5 hours.

Apply a convex mold to one side and a flat plate mold to the other side and apply a surface pressure of approximately 10 kg/am.
The sheets were stacked. The maximum shape tolerance between the convex mold and the glass convex lens was 0.10 m.

Sand the concave surface of CFRP with 600 grit sandpaper.

The molded surface was lightly polished to the extent that the gloss was no longer visible.

This CFRP concave surface was heated to 130°C, and an adhesive epoxy resin composition (bisphenol type epoxy resin CY2O manufactured by Ciba Corporation) was applied to the center of the concave surface in an amount of about 20 cm in diameter.
5100 parts of the acid anhydride curing agent HY-904 and 100 parts of the amine curing accelerator DY-0632) were poured onto the glass convex lens preheated to 130°C.
The lens was placed with the mirror surface facing down, and 5 to 9 weights were applied on top of the lens, the epoxy resin in the center was spread and extruded, and the lens was left to harden at 130° C. for 12 hours. After curing, the mold was released at room temperature, and the vapor-deposited surface was transferred to CFRP, resulting in a smoothed surface. 2. Pure aluminum on this side. O
It was deposited to a thickness of 1.0 μm at room temperature in a vacuum of X 10 −' Torr. The deposition rate was approximately 80 A/sec for a thickness of 0.5 μm, and approximately 2 oX/sec for a thickness of 0.5 μm.

Although it was confirmed that the reflection of the mirror surface thus obtained was extremely good and the surface roughness of 9 was sufficiently small, thick ridges corresponding to the texture of the carbon cloth were visually observed. Therefore, we used a stylus-type surface roughness measuring device (SURFC manufactured by Tokyo Seimitsu Co., Ltd.).
OM), the waviness was measured. Figure 3 shows the correspondence between the texture of the carbon cloth on the CFRP surface and the measurement results of the waviness of the mirror surface.

9. Carbon cloth uses 3000 carbon fiber threads. The thread density of plain weave is 10 for both warp and weft.
There are five fences. In Figure 3, carbon cloth 8 is
It consists of warp yarns 9 and weft yarns 10. The undulations appear in the vertical and horizontal directions as well, but here, the undulation measurement M1
Measured along 1.

AI in FIG. 3 shows the measurement results of waviness at room temperature. The pitch of the undulations is the same as the pitch of the warp yarns 9, with the center of the yarn being the most convex and the space between the yarns being the most concave. Its height is approximately 1.5 μIn. Next, it was discovered that when this material was heated to a high temperature, the visually observed waviness gradually became smaller, and at 130° C., which is the curing temperature of the adhesive, there was no waviness at all.

CFRP mirrors placed in the space environment have temperatures of approximately 100℃ to -6
It is used in a temperature range of 0°C, with the intermediate temperature being 20°C, or approximately room temperature. Therefore, if the adhesive is cured at around room temperature, it will be at the operating temperature.

Since the ridge becomes almost 0 and the temperature change thereafter is relatively narrow, it is thought that undulation is unlikely to occur.

Example 2 In Example 1, only the adhesive was added to a room temperature curable epoxy resin composition (100 parts of bisphenol epoxy resin BP-807 manufactured by Shell Co., Ltd. was mixed with 150 parts of modified diaminodiphenylmethane EH-55 manufactured by Asahi Denka Co., Ltd.). The procedure was carried out in the same manner with the following changes. The glass convex lens and CFRP were preheated to 50°C, a 7 kg weight was placed on them, the adhesive was spread and extruded, and then cured at 30°C for 12 hours. The ridges on the mirror surface of the CFRP mirror formed in this way were measured in the same manner as in Example 1.
B2. It is B3. B1 was measured at 30° C. and has 0 ridges. B2 was measured at -60°C, and B3 was measured at 100°C, and the height of the unevenness is approximately 0.7 μm in both cases, which is smaller than the value at room temperature in the case of curing at 130°C mentioned above. . The positions of the concave and convex portions of B2 and B3 are reversed.

Example 3 A glass convex lens with a diameter of 30 cm, a focal length of 3 m, and a thickness of approximately 1.5 cm was used, and the convex surface was coated with a silicone mold release agent (
QZ-13) manufactured by Ciba Corporation was applied and wiped off with a cloth until almost no scratches were visible.

2. Apply silicon monoxide to this side. OX 10” Torr
The film was deposited to a thickness of 1.0 μm in a vacuum at room temperature. The deposition rate was about 20 A/sec.

The concave surface of CFRP molded in the same manner as in Example 1 was lightly polished with 600-grade sandpaper to the extent that the gloss of the molded surface was no longer visible. There is a diameter of 2 in the center of this CF RP concave surface.
Adhesive epoxy resin (epoxy resin CY225 manufactured by Ciba Co., Ltd. 100 parts, modified acid anhydride curing agent HY
225 (mixed with 80 parts) and placed a glass convex lens on top of this with the silicon monoxide deposited side facing down, spread the adhesive in the center and pass it through the glass convex lens to the adhesive interface while visually observing the adhesive interface. Care was taken not to entrap air. Next, it was cured at 130° C. for 12 hours. After curing, the mold was released at room temperature, and the vapor-deposited surface was transferred to the CFRP, resulting in a smooth surface with no air bubbles. 2. Pure aluminum on this side. OX 10-' Tor
It was deposited to a thickness of 1.0 μm at room temperature in a vacuum of r. The deposition rate was approximately 80^/sec up to a thickness of 0.5 μm, and thereafter was approximately 20^/sec.

Although it was confirmed that the reflection of the mirror surface thus obtained was extremely good and the surface roughness was sufficiently small, the state of the undulations corresponding to the texture of the carbon cloth was the same as in Example 1.

Comparative Example 1 The same procedure as in Example 1 was carried out except that silicon monoxide was not deposited.

After the adhesive has cured, it is allowed to cool to room temperature and released from the mold.

The vapor-deposited surface was not transferred to the CFRP neatly, and clouds of the mold release agent were observed unevenly. Pure aluminum was vapor-deposited on this surface, but the vapor-deposited surface was not clean and the cloudy pattern of the mold release agent stood out, making it impossible to obtain a glossy mirror surface with high reflectance.

(Effects of the Invention) According to the present invention, a CFRP mirror with good shape accuracy, small mirror surface roughness, and high reflectance can be manufactured in an environment that is unlikely to be contaminated.

[Brief explanation of drawings]

Figure 1 is a schematic cross-sectional view showing the smoothing treatment of the CPR,P laminate used in the present invention, and Figure 2 is the CFF of the present invention.
FIG. 3 is a schematic cross-sectional view showing the LP mirror. It is a schematic diagram showing the measurement results of the texture of carbon cloth on the surface of CFRP and the corresponding waviness of the mirror surface. Explanation of symbols 1... CFRP concave mirror 2... CF'RP laminate product 3... Inorganic material deposited surface 4... Convex type 5...
Adhesive surface 6...Metal-deposited mirror surface 7...
・CFR, P laminate product with smoothed surface 8...Carbon cloth 9...Warp thread 10...Weft thread
11... Ridge measuring device ++＼ Agent: Kunihiko Wakabayashi, patent attorney ・1/θ search cut, ffJB figure

Claims (1)

[Claims] 1. In the manufacturing method of a carbon fiber reinforced plastic mirror, in which a mirror surface is formed by vapor depositing metal on the smoothed surface of a carbon fiber reinforced plastic laminate, an inorganic substance is vapor deposited on a mold having a polished surface, and the obtained inorganic substance vapor deposited surface and a carbon fiber-reinforced plastic laminate with a solvent-free adhesive, the polished surface and the inorganic-deposited surface are released from the mold, and the inorganic-deposited surface is transferred to the carbon-fiber-reinforced plastic laminate. A method for producing a carbon fiber-reinforced plastic mirror, which is characterized by forming a mirror surface by vapor-depositing metal on the treated surface.