JP2023094097A - Fiber-reinforced resin laminate, shutter device and optical device - Google Patents

Abstract

To provide a fiber-reinforced laminate which satisfies light-shielding property and has high rigidity.SOLUTION: A fiber-reinforced resin laminate includes a resin substrate 42, and fiber-reinforced layers 41 provided on each of both surfaces of the resin substrate 42, wherein the resin substrate 42 is a layer having highest optical density among the layers constituting the fiber-reinforced resin laminate. The resin substrate is a polyester resin, and may have the optical density of 3 or more. A shutter device has a fiber-reinforced resin laminate as a shutter blade, and has a driving part for driving the shutter blade.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a fiber-reinforced laminate, shutter blades and shutter devices, and optical instruments such as cameras.

As a fiber reinforced laminate, it is known that the fiber direction of carbon fiber reinforced plastics (hereinafter referred to as CFRP) is changed by 90° between adjacent layers and laminated alternately to improve the strength. Such fiber-reinforced laminates are lightweight and highly rigid, and are therefore favorably used for shutter blades such as focal plane shutters used in single-lens reflex cameras, which move and stop across the optical path in an extremely short period of time. be.

A fiber-reinforced laminate in which CFRPs are alternately laminated is lightweight, has high strength, and has excellent properties. . Then, the light shielding property of the open eyes may be lowered.

In Patent Document 1, in order to improve the light-shielding property, a reinforcing member in which a plastic film is used as a base material, a light-shielding coating film having a light-shielding property is formed on both sides thereof, and carbon fibers are aligned on the light-shielding coating film. are laminated and a lubricating black coating film is formed on each reinforcing member.

In the configuration of Patent Document 1, by interposing a light-shielding coating film between the carbon fiber reinforced resin layer in the laminate constituting the blade material, the necessary light-shielding properties of the shutter blade can be obtained.

Japanese Patent No. 3215815

Lightweight, high-strength shutter blades contribute to increased durability of the shutter and increase the shutter speed. is required.

The present invention has been made in view of such problems, and provides a light-shielding fiber-reinforced laminate capable of further improving durability characteristics.

In order to solve the above problems, the fiber-reinforced laminate of the present invention is a fiber-reinforced resin laminate including a resin substrate and fiber-reinforced layers provided on both sides of the resin substrate, wherein the resin substrate is , the layer having the highest optical density among the layers constituting the fiber-reinforced resin laminate.

According to the fiber-reinforced laminate of the present invention, a fiber-reinforced laminate having high bending strength can be realized. The shutter blade having the fiber-reinforced laminate of the present invention has improved durability, and a camera using this shutter blade can achieve high durability and improved shutter speed.

The figure showing the fiber reinforced resin layered product concerning one embodiment. The figure showing the shutter apparatus which concerns on one Embodiment. FIG. 3 is a cross-sectional view taken along line II-II' of FIG. 2;

The present invention will be described in embodiments described later, but as shown in FIG. As a laminate, the resin substrate 42 is a fiber-reinforced laminate having the highest optical density among the layers constituting the fiber-reinforced resin laminate. Such a fiber-reinforced laminate has high bending strength and sufficient light-shielding properties, and can be suitably used as a material for shutter blades and the like. Moreover, the structure of the fiber-reinforced laminate described above also leads to weight reduction of the shutter blade.

In particular, the resin substrate is preferably made of polyester resin, and if the optical density is 3 or more, the number of other layers of the shutter blade that need to have a high optical density can be reduced. It is easy to take a structure with higher rigidity. The resin substrate further preferably has an optical density of 4 or more, more preferably an optical density of 6 or more, and preferably an optical density of 10 or less in consideration of the thickness and the like. Optical density OD is calculated by OD=-logT (T is transmittance). The higher the optical density, the more difficult it is for light to pass through. The optical density of this example can be measured with EXACT BASIC (X-rite).

In addition to that shown in FIG. 1A, as shown in FIG. can be improved, and a fiber-reinforced laminate that is more difficult to peel off can be obtained. Also, as shown in FIG. 1C, the adhesiveness can be improved by forming an uneven structure 46 on the surface layer of the resin substrate 42 . When the concave-convex structure 46 is formed on the surface layer of the resin substrate 42, the volume fraction of carbon fibers in the vicinity of the surface layer of the carbon fiber reinforced resin layer 41 located in the opposite direction to the resin substrate 42 is similar to that of the resin substrate 42. It is relatively higher than the volume fraction of carbon fibers in the vicinity of the interface with layer 41 . A relative increase in the proportion of carbon fibers in the vicinity of the surface layer of the carbon fiber reinforced resin layer 41 makes it possible to increase the bending resistance strength and rigidity of the fiber reinforced laminate.

An example of the fiber-reinforced laminate of the present invention will be described below with reference to the drawings.

In order to facilitate understanding of the present invention, an embodiment in which the fiber-reinforced laminate of the present invention is used as shutter blades of a shutter device will be described. Needless to say, it is also applied to blinds and various structural materials that require

FIG. 2 shows the front shape of the shutter device according to one embodiment. The shutter device 10 shown in FIG. 2 is a focal plane shutter unit. 3 is a cross-sectional view taken along line II-II' of FIG. The focal plane shutter unit 10 according to this embodiment is of a so-called vertical type. That is, the focal plane shutter unit 10 has a front curtain 11 and a rear curtain 12 that move vertically, and the opening of the shutter base plate 24 is opened and closed using these front curtain 11 and rear curtain 12 . The front curtain 11 and the rear curtain 12 are composed of one or more shutter blades. Specifically, the front curtain 11 is composed of five mutually overlapping shutter blades 13, 14, 15, 16 and 17, and the rear curtain 12 is composed of four mutually overlapping shutter blades 18, 19, 20 and 21. Configured. The longitudinal direction of each of the shutter blades 13-21 is substantially orthogonal to the moving direction.

A frame-shaped cover plate 23 is attached in parallel to the frame-shaped shutter base plate 24 via a plurality of spacers 22, and the shutter blades 13 to 17 of the front curtain 11 spread in a direction orthogonal to the blade traveling direction. to prevent Between the cover plate 23 and the shutter base plate 24 , a frame-like partition plate 25 is attached at an angle to the shutter base plate 24 to separate the running space of the front curtain 11 and the running space of the rear curtain 12 . ing. The front curtain 11 is arranged between the cover plate 23 and the partition plate 25 , and the rear curtain 12 is arranged between the partition plate 25 and the shutter base plate 24 .

One end in the longitudinal direction (left side in FIG. 2) of the shutter blades 13 to 17 constituting the front curtain 11 is attached to the front curtain support arm 26 and the front curtain drive arm 27 via caulking dowels. 17 are configured to run continuously in the vertical direction. The front curtain support arm 26 and the front curtain drive arm 27 are rotatably attached to the shutter base plate 24 at their base ends.

Similarly, one end in the longitudinal direction of the shutter blades 18 to 21 constituting the rear curtain 12 is attached to a rear curtain support arm 28 and a rear curtain drive arm 29 via caulking dowels, respectively. It is configured to run in a row in the direction. The rear curtain support arm 28 and the rear curtain drive arm 29 are rotatably attached to the shutter base plate 24 at their base ends.

The front curtain drive arm 27 and the rear curtain drive arm 29 are slidably engaged with arc-shaped guide grooves 30 and 31 formed in the cover plate 23 and the shutter base plate 24, respectively. Further, when the front-curtain drive arm 27 and the rear-curtain drive arm 29 receive a driving force from a drive section (not shown) and rotate, the front-curtain support arm 26 and the rear-curtain support arm 28 also move in conjunction with each other, causing the shutter blade 13 to move. ~17 and 18~21 overlap and unfold.

That is, in the photographing standby state, the shutter blades 13 to 17 of the front curtain 11 are in the unfolded state, and the shutter blades 18 to 21 of the rear curtain 12 are in the overlapping state. When photographing is performed, the shutter blades 13 to 17 of the front curtain 11 are started to overlap each other, and after a predetermined time has passed since the start of this operation, the shutter blades 18 to 21 of the rear curtain 12 are expanded. Action is started. When the photographing is completed, the shutter blades 13 to 17 of the front curtain 11 and the shutter blades 18 to 21 of the rear curtain 12 are ready for photographing.

As the shutter blades 13 to 17 of the front curtain 11 and the shutter blades 18 to 21 of the rear curtain 12 run, a frame-shaped frame through which the photographing light beam passes is formed at the center of the partition plate 25, the shutter base plate 24 and the cover plate 23. A light passage opening is formed, and a photographing light beam incident from a lens (not shown) passes through the light passage opening to expose an imaging element such as a CCD or a film.

The configuration of the focal plane shutter unit 10 as described above is merely an example, and the known configurations described in Japanese Patent Application Laid-Open Nos. 10-186448, 2002-229097, and 2003-280065 are used. can be used.

Also, the shutter device of the present embodiment can be used by being installed in a camera, which is an example of an optical device, for example. That is, in a camera that includes a housing, an optical system such as a lens, and an imaging unit such as an imaging device, it is possible to arrange a shutter device so as to block an optical path that passes through the optical system and enters the imaging device. can.

Next, the configuration of the shutter blades 13-21 will be described. At least one of the shutter blades 13-21 can be a shutter blade made of the fiber-reinforced laminate of the present invention.

A shutter blade made of this fiber-reinforced laminate is hereinafter referred to as a shutter blade according to the present embodiment. It is preferable that all of the shutter blades 13 to 21 are shutter blades according to the present embodiment in terms of durability and light shielding properties. However, in order to reduce costs, the shutter blade according to this embodiment may be used in combination with other shutter blades. Since the shutter blade according to this embodiment has high strength, it is preferable to use it as a shutter blade that is more susceptible to impact. Specifically, the shutter blade according to the present embodiment can be used as a shutter blade having a larger amount of movement when opening and closing the shutter. In the example of FIG. 1, the shutter blades according to the present embodiment can be used as the shutter blades 13, 14, 20, and 21 that move more and are more susceptible to impact. Shutter blades that can be used in combination are not particularly limited, but include, for example, shutter blades made of an aluminum alloy plate material.

FIG. 1 represents a cross-sectional view of an example of a fiber-reinforced laminate according to one embodiment. The fiber reinforced laminate has a carbon fiber reinforced resin layer 41 and a black resin substrate 42 . The optical density of the resin substrate 42 is 6 or more, and the optical density of the carbon fiber reinforced resin layer 41 varies depending on whether the fibers are aligned in the fiber direction and is about 0.2 to 2.0. Preferably, the optical density of the carbon fiber reinforced resin layer 41 is less than 3. The resin substrate 42 is preferably made of PET, which is lightweight and highly rigid, as a polyester film, and contains black particles. The carbon fiber reinforced resin layer 41 contains a matrix resin 45 that is a resin composition that holds the carbon fibers 44 .

In one embodiment, the black particles include carbon black. The average particle diameter of carbon black is preferably less than 1 μm, more preferably 0.5 μm or less, in order to obtain sufficient light shielding properties. The average particle size of the black particles is measured by a dynamic light scattering type particle size distribution analyzer or the like as a 50% cumulative value of the volume-based particle size distribution.

The content of black particles is 30% by mass or less in one embodiment, 20% by mass or less in another embodiment, and 20% by mass or less in another embodiment, in order to improve the adhesion between the substrate and the carbon fiber reinforced resin layer and the coating strength. In form, it can be 18% by mass or less.

In order to obtain a structure having high bending elasticity, when a plastic material having a thickness of 10 μm or more and 35 μm or less is used as the rigid resin substrate, the thickness of the plastic material should not exceed the thickness of the carbon fiber reinforced resin layer. preferably.

Furthermore, the interface between the resin substrate and the carbon fiber reinforced resin layer may have an uneven structure. Adhesiveness can be improved by suitably contacting the uneven surface of the black resin substrate with an increased area. In addition, since the surface reflection is scattered and easily absorbed by the carbon fiber reinforced resin, the light shielding property of the fiber reinforced laminate can be improved.

The average height difference of the unevenness is obtained by setting a reference line parallel to the substrate surface across the unevenness in a cross section of a field of view of 10 μm × 10 μm including the interface in the thickness direction of the fiber reinforced laminate, and for each unevenness, from the reference line It is obtained from the sum of the average of the distances on the convex side and the average of the distances on the concave side from the reference line. A cross section of the fiber-reinforced laminate is observed with an electron microscope.

(Carbon fiber reinforced resin layer)
The carbon fiber reinforced resin layer 41 can be a carbon fiber reinforced resin prepreg sheet (hereinafter referred to as a CFRP prepreg sheet) formed by impregnating carbon reinforced fibers with a thermoplastic resin or the like. The thickness of the CFRP prepreg sheet may be 10 μm or more in one embodiment, 15 μm or more in another embodiment, and 20 μm or more in still another embodiment in order to distribute the CFRP prepreg sheet uniformly in the matrix resin and improve the strength. can. The thickness of the CFRP prepreg sheet is 80 μm or less in one embodiment, 60 μm or less in another embodiment, in order to increase the speed of the shutter drive and achieve a thin shutter unit when used as a shutter blade. In yet another embodiment, it can be 40 μm or less.

In addition, when forming a fiber reinforced laminate with materials having different bending strengths in each layer, the bending strength of the outer layer contributes greatly to the bending strength of the fiber reinforced laminate. should be Therefore, if a CFRP prepreg sheet having a thickness greater than that of the substrate is used, a fiber-reinforced laminate having high bending strength can be obtained.

(Resin substrate)
The resin substrate 42 is an organic compound on which a carbon fiber reinforced resin layer can be provided, and is a plate-like member containing inorganic compound particles or metal particles. In one embodiment, the substrate may consist of a plastic material. Usable plastic materials include synthetic resin films such as polyester films, polyimide films, polystyrene films, and polycarbonate films. In one embodiment, a polyester film is used, and in order to improve mechanical strength and dimensional stability, a biaxially stretched polyester film (such as a biaxially stretched PET film) that has been stretched, particularly biaxially stretched is used. . By using a plastic material for the substrate, it is possible to form a fiber-reinforced resin laminate that is lighter than a metal material.

In one embodiment, the thickness of the plastic material is 5 μm or more, and in another embodiment, 10 μm or more, in order to improve the strength of the plastic material itself and to increase the speed of shutter driving when the fiber-reinforced laminate is used as a shutter blade. , and in yet another embodiment 20 μm or greater. In one embodiment, the thickness of the plastic material can be 30 μm or less, more preferably 40 μm or less, in order to achieve a thin shutter unit when the fiber-reinforced laminate is used as the shutter blade.

When the fiber reinforced resin layer is formed on the surface of the plastic material, from the viewpoint of improving the adhesiveness between the plastic material and the fiber reinforced resin layer, the plastic material may be subjected to UV ozone treatment or corona treatment as necessary. processing can also be performed. Synthetic resin films containing carbon black pigments and other pigments contain fine colored particles inside. have a relatively large impact on Therefore, it is preferable to use a plastic material having a thickness of 20 μm or more and 30 μm or less for the black resin substrate.

The thickness of the entire shutter blade may be 60 μm or greater in one embodiment, 80 μm or greater in another embodiment, and 90 μm or greater in yet another embodiment for improved strength and faster shutter actuation. . The thickness of the entire shutter blade can be 140 μm or less in one embodiment, 120 μm or less in another embodiment, and 100 μm or less in still another embodiment to achieve a thin shutter unit.

(Method for Curing and Molding Fiber Reinforced Laminate)
Next, a curing molding method for suitably forming the fiber-reinforced laminate of the present embodiment will be described. The curing and molding method of the present embodiment is particularly a curing and molding method for a fiber reinforced laminate having a structure in which a substrate is sandwiched between two sheets of carbon fiber reinforced resin from both sides and laminated as shown in FIG. 1 as an intermediate layer. A hot press method or an autoclave method, for example, can be applied as the curing molding method. In this embodiment, a case in which the hot press method is applied will be described.

First, two CFRP prepreg sheets are used as a precursor of the carbon fiber reinforced resin layer. Next, carbon black is contained as black particles in a plastic material (plastic sheet) that is an intermediate layer that serves as a substrate.

The plastic sheets are sandwiched between prepared CFRP prepreg sheets and overlapped to form a laminated sheet. After that, a releasing film made of polytetrafluoroethylene (PTFE) sheet or the like is superimposed on the surface of the CFRP prepreg sheet in order to make this laminate sheet into a fiber-reinforced laminate.

The laminated sheet on which the release film is superimposed is placed between the pressure plates of a hot press, and is heated to 0.1 MPa to 0.5 MPa at a temperature of 120° C. or higher and 140° C. or lower for 1 hour or longer and 2 hours or shorter. Heat curing molding is performed by setting the conditions so that the following pressures are obtained. This heat-curing molding reduces the viscosity of the uncured matrix resin in the CFRP prepreg sheet, allowing the matrix resin to flow into the recesses formed on the surface of the black resin substrate. As a result, the curing reaction of the matrix resin proceeds, and a fiber-reinforced laminate composed of a laminate in which each layer is adhered by lamination may be formed.

After that, the heating of the hot press is stopped and the material is slowly cooled. The temperature at which the laminated sheet is taken out from the pressure plate of the hot press can be 50° C. or less in one embodiment. The release sheets placed on both sides of the taken-out fiber reinforced laminate are removed to obtain a fiber reinforced laminate for forming shutter blades.

After curing and molding, the fiber-reinforced laminate is stamped into a desired contour shape and finished into a shutter blade. As a punching method, there are methods such as wire cutting and press punching, but in one embodiment, the punching method is press punching in consideration of low cost.

As described above, the black resin substrate according to the present embodiment has the highest optical density among the layers constituting the fiber-reinforced resin laminate. When this fiber-reinforced laminate is used as a shutter blade, it becomes possible to realize the rigidity and light shielding properties required for the shutter blade. In addition, since a black coating with low rigidity is not included between the black resin substrate and the carbon fiber resin layer, when the thickness of the fiber reinforced laminate is constant, the rigidity is higher than that of the conventional shutter blade, and A lightweight shutter blade can be provided. As a result, it is possible to provide a fiber-reinforced laminate for shutter blades that improves driving durability characteristics when used as an ultra-high-speed shutter.

EXAMPLES The embodiments of the present invention will be further described below with reference to examples, but the present invention is not limited to these as long as the gist thereof is not exceeded.

(Example 1)
FIG. 1A shows a cross-sectional view of the basic configuration of the fiber-reinforced laminate according to this embodiment.

First, as a carbon fiber reinforced resin layer constituting a shutter blade material, carbon fibers are continuously aligned in one direction, and a CFRP prepreg sheet (manufactured by Mitsubishi Rayon, trade name Pyrofil prepreg CFRP, manufactured by Mitsubishi Rayon, A thickness of 32 μm and a recommended curing temperature of 130° C.) are used. The carbon fiber monofilament diameter (diameter in the transverse direction) used in this CFRP prepreg sheet is 7 μm.

Next, a biaxially stretched black PET sheet (thickness 25 μm, optical density 6 or more, polyester film #25-X36 manufactured by Toray Industries, Inc.) is used as the plastic material constituting the substrate.

Next, the PET sheet and the CFRP prepreg sheet (CFRP) were laminated to form a laminated sheet having a CFRP/PET/CFRP layer structure. Also, the CFRP prepreg sheets are arranged plane-symmetrically so that their fiber directions are parallel to each other. Furthermore, a PTFE sheet having a thickness of 50 μm is overlaid on both sides of the laminated sheet as a release sheet.

The laminated sheet overlaid with the release sheet was set in a hot press, and the pressure was adjusted to 0.3 MPa. Thereafter, under the pressure molding conditions described above, the temperature was raised from room temperature to 130° C. at a rate of 1.5° C./min, and held at 130° C. for 2 hours. After that, the heating of the hot press machine is stopped, and the laminated sheet is gradually cooled, and after confirming that the temperature of the laminated sheet as a laminated body is 50° C. or less, the laminated sheet is taken out.

After that, when the release sheet placed on the surface layer of the laminate sheet is removed, a fiber-reinforced laminate for obtaining camera shutter blades is obtained. In order to obtain a predetermined number of camera shutter blades, a fiber reinforced laminate is produced in a similar manner. The fiber-reinforced laminate is punched out by a press to form shutter blades of a predetermined shape in a predetermined number, thereby obtaining camera shutter blades.

Further, a plurality of shutter blades manufactured in this embodiment are prepared as front curtain shutter blades and rear curtain shutter blades, respectively, and incorporated into a shutter device (focal plane shutter) as shown in FIG. When this shutter device was installed in a camera and a drive endurance test was conducted at shutter speeds of 1/6500 second and 1/8000 second, it did not come into contact with the image sensor during operation, and had sufficient bending rigidity with little deflection. It is confirmed that

(Example 2)
FIG. 1(B) shows a cross-sectional view of a configuration in which the adhesive strength between the resin base material of the fiber-reinforced laminate and the matrix resin contained in the carbon fiber-reinforced resin layer according to the present embodiment is improved.

A biaxially stretched black PET sheet (thickness: 25 μm, optical density: 6 or more, polyester film #25-X36 manufactured by Toray Industries, Inc.) is used as a plastic material for the substrate. For the purpose of improving the adhesive strength between the base material and the matrix resin contained in the carbon fiber reinforced resin layer, the PET sheet surface is subjected to UV ozone treatment, and the surface is cleaned and modified. Then, the surface modified layer 43 was formed. Thereafter, as in Example 1, a fiber-reinforced laminate can be cured and formed.

(Example 3)
FIG. 1(C) shows a cross-sectional view of a configuration in which the adhesive strength between the resin base material of the fiber-reinforced laminate according to the present embodiment and the matrix resin contained in the carbon fiber-reinforced resin layer is further improved.

A biaxially stretched black PET sheet (thickness: 25 μm, optical density: 6 or more, polyester film #25-X36 manufactured by Toray Industries, Inc.) is used as a plastic material for the substrate. For the purpose of improving the adhesive strength between the base material and the matrix resin contained in the carbon fiber reinforced resin layer, the PET sheet is subjected to heat and pressure using a mold having a shape opposite to the fine uneven structure to be formed. was added to transfer the fine concave-convex structure 46 to the surface of the PET sheet. In this embodiment, from the viewpoint of inexpensive and stable production of large-area processing, a method of pressing a stamper having a fine uneven structure to transfer fine unevenness to a PET sheet was used. The shape of fine unevenness is not particularly limited, but can be appropriately selected according to the purpose. For example, in this embodiment, the shape is cylindrical, the outer diameter is 10 μm, the distance between the protrusions is 10 μm, and the height of the protrusions is 5 μm. The size range of the fine irregularities is preferably an outer diameter of 5 to 20 μm, particularly preferably an outer diameter of 10 to 15 μm. Also, the interval between adjacent protrusions is preferably 5 to 20 μm, particularly preferably 10 to 15 μm. Moreover, the height of the protrusions is preferably 5 μm to 15 μm, particularly preferably 5 μm to 10 μm. In addition, if the surface of the substrate is to be roughened more simply, it may be made into a random shape by sandblasting.

Thereafter, as in Example 1, a fiber-reinforced laminate can be cured and formed. At this time, the uneven structure scatters the incident light, so that the light shielding property can also be improved.

Although each embodiment has been specifically described as an example of the present invention, the present invention is not limited to the embodiments described above.

10: Shutter device (focal plane shutter unit)
11: front curtain 12: rear curtain 13-21: shutter blade 22: spacer 23: cover plate 24: shutter base plate 25: partition plate 26: front curtain support arm 27: front curtain drive arm 28: rear curtain support arm 29: rear Curtain drive arms 30, 31: guide groove 41: carbon fiber reinforced resin layer 42: substrate (plastic layer)

Claims (5)

a resin substrate;
A fiber reinforced resin laminate comprising fiber reinforced layers provided on both sides of the resin substrate,
A fiber-reinforced resin laminate, wherein the resin substrate is a layer having the highest optical density among the layers constituting the fiber-reinforced resin laminate. 2. The fiber-reinforced resin laminate according to claim 1, wherein the resin substrate is made of polyester resin and has an optical density of 3 or more. 3. The fiber-reinforced resin laminate according to claim 1, wherein a surface modified layer is formed on the surface layer of the resin substrate. A shutter device comprising the fiber-reinforced resin laminate according to any one of claims 1 to 3 as shutter blades, and a drive unit for driving the shutter blades. 5. An optical apparatus comprising: the shutter device according to claim 4; and an imaging device that captures an image of light that has passed through the shutter device.

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