JP3136602B2 - Plate material for shading blades - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is used for light-shielding blades that are required to move at high speed, such as a focal plane shutter of a camera, a shutter blade or an aperture blade of a lens shutter. Plate material.

[Conventional technology]

It is desirable that the light-shielding blade be operated at high speed while reducing the amount of operating force and maintaining sufficient bending rigidity. For that purpose, a light-weight, high-strength, high-rigidity light-shielding blade is required.

JP-A-59-61827 discloses a plate material for this type of light-shielding blade.
As disclosed in JP-A-62-199439 and JP-A-63-17435, (1) a reinforcement comprising a continuous fiber of carbon fibers aligned in one direction and a matrix resin containing the same. (2) A plate member having a laminated structure including a reinforced resin surface layer made of a continuous fiber of carbon fibers aligned in one direction and a matrix resin containing the same, and The surface material layer is laminated so that the longitudinal directions of the carbon fibers are orthogonal or almost orthogonal to each other, and the plate thickness is 60
Plates of ~ 120μ have been proposed.

The plate members are, of course, stacked symmetrically in the thickness direction. Further, the intermediate layer and the surface material layer may not be a single layer but may be a laminate of a plurality of thin reinforced resin sheets. This plate material is punched or cut into a predetermined shape of the light shielding blade (punched or cut so that the longitudinal direction of the carbon fiber of the intermediate layer is orthogonal to the longitudinal direction of the light shielding blade).
About 50 light-weight, high-strength, high-rigidity light-shielding blades can be obtained.
These light-shielding blades have been put to practical use in cameras having a shutter speed of 1/8000 second.

[Problems to be solved by the invention]

However, this type of light-shielding blade has a thickness of 60-120.
Due to its thinness of μ, there is a first problem that plate thickness unevenness is large and a second problem that flatness is poor (there is warpage) at the stage of the plate material. There is a third problem that the flatness is poor after punching or cutting into the light shielding blades.

 The present invention is to solve these problems.

[Means for solving the problem]

The present inventor has conducted intensive studies on the causes of these problems. As a result, the conventional plate material has a low resin content of 30 to 40% by weight in both the surface layer and the intermediate layer. It was found that the content was low.

As a result of further research, the present inventors found that the resin content of the intermediate layer was 50-60% by weight for continuous fibers, and 60- 75% by weight
By increasing the above, the above-mentioned problems are solved, and the carbon fibers of the intermediate layer are not continuous fibers but also short fibers, as long as they are aligned in one direction, they find that there is no problem and constitute the present invention. Reached.

Accordingly, the present invention provides a `` continuous fiber of carbon fibers aligned in one direction or a reinforced resin intermediate layer comprising short fibers and a matrix resin containing the same, and a continuous fiber of carbon fibers aligned in one direction. This is a plate material having a laminated structure composed of a reinforced resin surface material layer composed of a matrix resin including the same, and the intermediate layer and the surface material layer are laminated such that the longitudinal directions of the carbon fibers are orthogonal or substantially orthogonal to each other. In a light-shielding blade plate material having a plate thickness of 60 to 120 μm, the resin content of the surface layer is 30 to 45% by weight, and the resin content of the intermediate layer is 50% in the case of continuous fiber.板 60% by weight, and in the case of short fibers, 60-75% by weight.

[Action]

As described above, the reinforced resin constituting the intermediate layer and the surface material layer is composed of continuous fibers of carbon fibers aligned in one direction (short fibers may be used in the case of the intermediate layer) and a matrix resin containing the same. However, as a material, a prepreg sheet (pr
It is preferred to use epreg sheets).

The prepreg sheet is obtained by impregnating a reinforcing fiber with a thermosetting resin liquid (e.g., an uncured liquid of an epoxy resin or an unsaturated polyester) which is a precursor of a matrix resin,
The resin liquid is in the B-stage state (solidified and has no apparent fluidity, but can be finally cured by heating)
It was made.

In order to obtain the plate material used in the present invention, at least one prepreg sheet having a thickness of about 10 to 60 μm is provided for at least one intermediate layer, and at least two sheets are provided for the surface layer sandwiching the prepreg sheet. Laminated so that the longitudinal directions of the directional carbon fibers are orthogonal or almost orthogonal to each other, and are plane-symmetric with respect to the central axis in the thickness direction of the plate material, and then hot-pressed, the resin liquid is applied. What is necessary is just to harden.

Both the intermediate layer and the surface material layer may be used as a single prepreg sheet instead of a single prepreg sheet (for example, 2 to 5 sheets). In this case, the fiber direction may be alternately perpendicular to the intermediate layer or the surface material layer itself, or may be parallel (all in the same direction).
For example, one prepreg sheet is used for the surface layer, and two prepreg sheets are used for the intermediate layer so that the fiber direction is perpendicular to the prepreg sheet (the two sheets have fiber directions parallel to each other).
May be used.

The carbon fiber used for the intermediate layer may be a short fiber because of the intermediate layer, and its fiber length is suitably about 1 to 30 mm, especially about 5 to 15 mm.

As the carbon fibers, those having a diameter of about 3 to 10 μm for both continuous fibers and short fibers are suitable.

When the light-shielding property and the surface lubricity are insufficient, about 5 to 15% by weight of carbon black may be added to the prepreg sheet in advance with respect to the resin liquid (solid content of 100 parts by weight). The average particle size of the carbon black is preferably 0.07 μm or less. Carbon black may be added only to the surface layer or may be added only to the intermediate layer. Each has its own unique characteristics.

If the laminated prepreg sheet is heated and pressed, a plate material is obtained. At this stage, the surface may be subjected to black coating (dry loop coating). This coating is performed for the purpose of improving light-shielding properties, lowering surface reflectivity, improving appearance and appearance, and improving surface lubricity. The thickness of the paint is 0.1-10
Although μ is appropriate, when the thickness is reduced to about 0.1 to 3 μ, the danger of the sheet material being warped is reduced.

By punching or cutting the plate material thus obtained into a predetermined shape of the light shielding blade (punching or cutting such that the longitudinal direction of the carbon fiber of the intermediate layer is orthogonal to the longitudinal direction of the light shielding blade), about 20 to 50 sheets are obtained. Light-shielding blades are obtained. The blades may be painted black.

Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited thereto.

[Example 1] (1) First, carbon fibers (average diameter 6 to 7μ) are continuous fibers and are arranged on one side, the matrix resin is an epoxy resin, and the resin content is 35 to 45% by weight. 20 thickness
A prepreg sheet A of 4040 μ was prepared.

(2) Next, the carbon fiber (average diameter 6 to 7μ) has a length of 1 to
A prepreg sheet B having a short fiber of 30 mm, which is arranged on one side, the matrix resin is an epoxy resin, the resin content is 60 to 75% by weight, and the thickness is 10 to 50μ is prepared. This sheet is manufactured by a centrifugal pulling method applying papermaking technology.

(3) Prepare two sheets A and one sheet B, and set the fiber direction to 0 繊 維 (surface layer) / 90 ゜ (intermediate layer) / 0 ゜ (surface layer) and the type of sheet. A (surface material layer) / B (intermediate layer) / A (surface material layer) are laminated in a plane-symmetric manner so that the three sheets are stacked, and a pressure of 5 to 15 kg / cm ² is applied at a temperature of 130 ° C. In this state, the epoxy resin was cured by leaving it to stand for 1 to 2 hours, and then slowly cooled to room temperature to obtain a plate material having a plate thickness of 60 to 120 μm.

Similarly, a large number of plate members were manufactured, and the obtained plate members were measured for thickness unevenness and the presence or absence of warpage, and the yield (hereinafter, referred to as a first yield) was obtained as to how many plate members having good flatness were present. .

(4) Twenty to fifty light-shielding blades for focal plane were manufactured from one sheet material having good flatness by press punching. However, punching was performed such that the direction of the carbon fibers in the intermediate layer was perpendicular to the longitudinal direction of the light-shielding blade.

At this time, for the obtained light-shielding blades, the thickness unevenness and the presence or absence of warpage were measured to determine the number of light-shielding blades having good flatness, and the yield (hereinafter, referred to as second yield).

(5) Dry lube coating was applied to both front and back surfaces of each of the many light-shielding blades having good flatness with a thickness of 4 μm on each side.

Due to the painting, internal distortion of the light-shielding blades becomes apparent, and warpage may occur. Therefore, with respect to the obtained “painted light-shielding blade”, the presence or absence of warpage was measured to determine the number of light-shielding blades having good flatness and the yield (hereinafter, referred to as third yield).

 Table 1 shows the results of the above yields.

[Comparative Example 1] Three prepreg sheets A used in Example 1 were prepared, and these sheets were laminated so that the fiber direction was 0 ° / 90 ° / 0 °, and thereafter, the same as in Example 1 To sequentially produce a plate material, light-shielding blades, and "light-shielding blades with paint",
Asked for yield.

 Table 1 shows the results of the yield.

[Example 2] A prepreg sheet A 'which is the same as the prepreg sheet A used in Example 1 except that carbon black having an average particle diameter of 0.01 µ or less is added at 10% by weight per 100 parts by weight of the resin. Got ready.

Hereinafter, a plate material, light-shielding blades, and "painted light-shielding blades" were sequentially manufactured in the same manner as in Example 1 except that sheet A 'was used instead of sheet A.

[Example 3] A prepreg sheet B 'which is the same as the prepreg sheet B used in Example 1, except that carbon black having an average particle diameter of 0.01 µ or less is added at 10% by weight per 100 parts by weight of the resin. Got ready.

Hereinafter, a plate material, light-shielding blades, and “painted light-shielding blades” were sequentially manufactured in the same manner as in Example 1 except that sheet B ′ was used instead of sheet B.

Example 4 Two prepreg sheets A and B2 used in Example 1
Prepare these sheets and place these sheets in the direction of fiber 0 ゜ / 90 ゜ / 90.
The above four sheets are laminated in a plane-symmetric manner so as to be {/ 0} and the type of sheet is A / B / B / A.
A plate was manufactured in the same manner as described above. This plate material has an intermediate layer of 2
It is composed of two sheets B.

Thereafter, in the same manner as in Example 1, light-shielding blades and “painted light-shielding blades” were sequentially manufactured.

Example 5 First, carbon fibers (average diameter 6 to 7 μm) were continuous fibers,
The matrix resin is epoxy resin, the resin content is 50-60% by weight, and the thickness is 10-50
A prepreg sheet B ″ was prepared.

Next, a plate material, light-shielding blades, and "painted light-shielding blades" were sequentially manufactured in exactly the same manner as in Example 1 except that prepreg sheet B "was used instead of prepreg sheet B.

Then, the “light-shielding vanes with paint” of Examples 1 to 5 were subjected to a high-speed shutter durability test.
Durability of more than 10,000 times was obtained, and sufficient high-speed stability and high-speed running were proved.

The prepreg sheet B as the intermediate layer may be constituted by three or more sheets having the same resin content or different resin contents, but it is necessary to determine the prepreg sheet B to be plane-symmetric. In the case where three or more sheets are used, the fiber directions may be orthogonal to each other.

〔The invention's effect〕

As described above, according to the present invention, it is possible to obtain a plate material for a light-shielding blade having a good yield in terms of planarity (first to third yields). As a result, the prepreg sheet is very expensive because it contains carbon fibers, but the manufacturing cost of the light shielding blade can be significantly reduced.

In addition, since the flatness can be ensured even when the plate thickness is made smaller, the weight can be reduced accordingly, and as a result, the present invention greatly contributes to the practical use of an ultra-high speed (1/12000 second or more) shutter blade. .

[Brief description of the drawings]

FIG. 1 is a schematic vertical sectional view of a light-shielding blade plate according to a second embodiment of the present invention. FIG. 2 is a schematic vertical sectional view of a plate material for a light-shielding blade according to a third embodiment of the present invention. (Note that the coating film is omitted in both FIGS. 1 and 2.) [Description of Signs of Main Parts] 1... Continuous carbon fiber 2... Matrix resin 3... Surface material layer 4... Carbon black 5. … Carbon fiber short fibers 6… matrix resin 7… middle layer

Claims (1)

(57) [Claims] A reinforced resin intermediate layer comprising a carbon fiber continuous fiber or short fiber aligned in one direction and a matrix resin containing the same, a unidirectional carbon fiber continuous fiber and A plate material having a laminated structure composed of a reinforced resin surface material layer composed of a matrix resin and a middle layer, wherein the intermediate layer and the surface material layer are laminated such that the longitudinal directions of the carbon fibers are orthogonal or substantially orthogonal to each other. Yes, plate thickness is 60 ~ 120
μ, the resin content of the surface layer is 30 to 45% by weight, and the resin content of the intermediate layer is 50 to 60% by weight in the case of continuous fiber.
A sheet material characterized by being 60 to 75% by weight in the case of short fibers.