TWI439797B - Light shielding components for optical machines - Google Patents

Description

Optical device shading member

The present invention relates to a light-shielding member for an optical device, which is suitable as a shutter or a diaphragm member of an optical device such as a high-performance single-lens reflex camera, a compact camera, a video camera, a portable telephone, or a projector.

In recent years, the requirements for miniaturization and weight reduction of high-performance single-lens reflex cameras, compact cameras, camcorders, and the like, the shutters and aperture members of optical devices formed of metal materials are being replaced by plastic materials.

As a light-shielding member of such a plastic material, a light-shielding film or a light-shielding member in which a light-shielding film containing carbon black, a lubricant, or fine particles is provided on a base film is known (Patent Document 1 and Patent Document 2).

[Patent Document 1] Japanese Laid-Open Patent Publication No. Hei 9-274218 (Patent Application) [Patent Document 2] WO2006/016555 (Prior Art)

However, in order to reduce the size and weight of a high-performance single-lens reflex camera, a compact camera, a video camera, etc., it is required to reduce the thickness of the light-shielding member. However, in the above-described light-shielding member, only the substrate film or When the light-shielding film is made thinner, the toughness of the light-shielding member itself becomes weak, and it is impossible to Use as a shutter, aperture member, etc.

Therefore, an object of the present invention is to provide a light shielding member for an optical device which has a high toughness although the thickness of the light shielding member is reduced.

In order to solve the above problem, the light-shielding member for an optical device of the present invention is characterized in that a laminate of a plastic film and a resin layer containing a curable resin is used as a substrate on which a light-shielding film is formed.

In the light-shielding member for an optical device according to the present invention, preferably, the substrate is made of at least two plastic films, and the resin layer is provided in an intermediate layer between the at least two plastic films.

Further, in the light shielding member for an optical device of the present invention, the thickness of the resin layer is preferably 1 to 20 μm, the thickness of the plastic film is 4 to 50 μm, and the thickness of the substrate is 60 μm or less.

Further, in the light-shielding member for an optical device of the present invention, the resin layer preferably contains 50% by weight or more of a curable resin, and has a pencil hardness of H or more.

According to the present invention, by using a laminate of a plastic film and a resin layer containing a curable resin as a base material for forming a light shielding film, since the toughness of the light shielding member can be adjusted by the intermediate layer, even if the thickness of the substrate is When the thickness is reduced, a light-shielding member for an optical device that maintains the toughness required for the light-shielding member can be obtained. In particular, by using between at least 2 plastic films The base material provided with the intermediate layer improves the punching suitability because the impact is alleviated as compared with one film of the same thickness. Such a light shielding member can be applied to a high performance single-lens reflex camera, a compact camera, a video camera, a portable telephone, a projector, and the like.

Best form for implementing the invention

Hereinafter, an embodiment of the light-shielding member for optical devices (hereinafter also referred to as "light-shielding member") of the present invention will be described.

The light-shielding member of the present invention has a basic structure composed of a base material and a light-shielding film, and the base material is composed of a laminate of a resin film made of a plastic film and a cured resin. The lamination system of the plastic film and the resin layer may have various compositions. For example, (1) a resin layer may be provided on one or both sides of one plastic film, (2) a resin layer may be provided between the two plastic films as an intermediate layer, and (3) the above (1) and/or laminated. Or the structure of the laminate of (2). Specifically, the intermediate layer is sandwiched between two plastic films, and the other plastic film is bonded by an intermediate layer or an adhesive layer. Among these, from the viewpoint of adhesion to a light-shielding film, etc., it is preferable to provide a layer made of a hardened resin between at least two plastic films as an intermediate layer.

In the first and second figures, an example in which the light shielding member 3 of the light shielding film 2 is formed on both surfaces of the substrate 1 in which the intermediate layer 12 is provided between the two plastic films 11 and 11 is shown. In Fig. 2, the 13-series adhesive layer.

Each component of the light shielding member will be described in detail below.

As the plastic film constituting the substrate, polyester, ABS (propylene) can be used. Nitrile-butadiene-styrene), polystyrene, polycarbonate, acrylic, polyolefin, cellulose resin, polyfluorene, polyphenylene sulfide, polyether oxime, polyetheretherketone, polyimine A synthetic resin film. Among them, a polyester film is preferably used, and a polyester film which is subjected to drawing processing, particularly biaxial stretching, is excellent in mechanical strength, dimensional stability, and toughness. The thickness of such a plastic film is preferably 4 to 50 μm, and more preferably 4 to 20 μm from the viewpoint of thinning.

Further, the plastic film is not only transparent, but also a foamed polyester film or a synthetic resin film containing a black pigment such as carbon black or other pigment. In this case, the plastic film may be selected according to each application. For example, when used as a light-shielding member, a synthetic resin containing a black pigment such as carbon black can be used in the synthetic resin film portion of the cross-section of the member due to the adverse effect of light reflection by a lens or the like, and high light-shielding property is required. For the film, in other cases, a transparent or foamed synthetic resin film can be used.

When two or more plastic films are used, the same type may be used, or different combinations may be used.

The layer of the hardened resin laminated on the plastic film or the intermediate layer containing the hardened resin of the two plastic films is composed of a thermosetting resin and/or an ionizing radiation curable resin. The following is not necessary to set the position of the layer containing the hardened resin, and is explained by the intermediate layer.

As the thermosetting resin and/or the ionizing radiation curing resin, a polyester resin, an acrylic resin, an urethane urethane resin, a urethane resin, an epoxy resin, or a polycarbonate system can be used. Resin, melamine resin, phenol resin, polyoxyn resin, polyester acrylate A resin which can form a cured film by heat or ionizing radiation such as an acrylate resin such as a resin, a polyurethane acrylate resin or an epoxy acrylate resin, or a room temperature curing resin can also be used. Among them, it is preferable to use an ionizing radiation curable resin excellent in hardness because the toughness as a light shielding member can be enhanced. In addition, one type or a mixture of two or more types can be used.

Such an intermediate layer has a function of adjusting the toughness of the light shielding member. In the present invention, the intermediate layer contains a curable resin. However, in order to prevent the intermediate layer from impairing the flexibility of the light-shielding member due to excessive hardening, a resin having flexibility may be mixed. As the resin for imparting flexibility as described above, a thermoplastic resin may be used, and a resin having a low glass transition temperature or a resin having a long main chain of a polymer may be used. When a resin having flexibility is contained, in order to obtain the necessary toughness, the curable resin is preferably 50% by weight or more, and more preferably 70% by weight or more, based on the entire resin component. Further, it is preferable that the pencil hardness (JIS K5600-5-4: 1999) at the time of curing is an intermediate layer of H or more, and more preferably an intermediate layer of 2H or more.

The thickness of the intermediate layer is preferably from 1 to 20 μm, more preferably from 2 to 10 μm, and particularly preferably from 4 to 8 μm. When the thickness is 1 μm or more, the toughness of the light-shielding member can be enhanced, and when the thickness is 20 μm or less, the end portion of the intermediate layer can be prevented from being damaged during the die-cutting process, and the interface between the intermediate layer and the plastic film can be prevented from being peeled off, and the light-shielding member can be made thin. Chemical.

When an intermediate layer is provided between at least two plastic films to form a substrate, as shown in FIG. 1, the adhesive layer or the like is not interposed, and only the intermediate layer 12 is bonded to the plastic film 11, as shown in FIG. Land, can also be in plastic An adhesive layer 13 is disposed between the films 11, and the intermediate layer 12 is bonded to the plastic film 11. For example, when an ionizing radiation-curable resin is used as the intermediate layer, or a thermosetting resin (for example, a thermosetting resin using blocked isocyanate as a curing agent) which can be subjected to a solvent evaporation step and a curing step individually, Before curing the hardened resin applied to one of the plastic films, after bonding to the other plastic film, a curing step such as ionizing radiation may be performed to allow the plastic film to be attached. Further, a layer of a cured resin is formed on one of the plastic films, and an adhesive layer may be provided on the other plastic film to cause the two to adhere.

Examples of the adhesive used for the adhesive layer include natural rubber, recycled rubber, chloroprene rubber, nitrile rubber, and styrene. A pressure-sensitive adhesive, a hot-melt adhesive, an ionizing radiation-curable adhesive, or the like formed of a butadiene-based, epoxy-based, urethane-based, polyester-based, acrylic-based, or acrylate-based compound.

The thickness of the adhesive layer is preferably from 1 to 10 μm, more preferably from 2 to 5 μm. When it is 1 μm or more, it is possible to prevent breakage of the end portion of the adhesive layer during die-cutting, or peeling of the interface between the adhesive layer and the plastic film, and to increase the toughness of the light-shielding member without being affected by the adhesive layer by being 10 μm or less. Moreover, the thickness of the light shielding member can be reduced.

The thickness of the entire substrate made of the plastic film and the intermediate layer is preferably from 9 to 100 μm, and particularly preferably from 9 to 60 μm, more preferably from 9 to 25 μm, from the viewpoint of thinning. Further, from the viewpoint of mechanical strength, the above range is preferably 10 μm or more. In the present invention, since the laminate of the layer of the plastic and the hardened resin is used as the substrate, it can be enhanced only by the plastic film. It is a shutter or a diaphragm member that can be used as a light-shielding member with sufficient toughness. Moreover, when the punching process is performed as a shutter or a diaphragm member by reinforcing the toughness, since the light shielding member is less likely to be bent, it is possible to reduce defects caused by the punching process.

In particular, when at least two plastic films are bonded to each other via the intermediate layer to form a base material, the toughness required as a light shielding member for an optical device can be obtained, and a hardened resin film is formed on a plastic film. The problem of substrate curl that is prone to occur does not occur.

The light-shielding film is formed on at least one surface of the substrate formed of the laminate, and contains a binder resin, carbon black, and fine particles.

Examples of the binder resin include poly(meth)acrylic resin, polyester resin, polyvinyl acetate resin, polyvinyl chloride resin, polyvinyl butyral resin, cellulose resin, and polystyrene/ Polybutadiene resin, polyurethane resin, alkyd resin, acrylic resin, unsaturated polyester resin, epoxy ester resin, epoxy resin, epoxy acrylate resin, uric acid Thermoplastic resin such as ester acrylate resin, polyester acrylate resin, polyether acrylate resin, phenol resin, melamine resin, urea resin, diallyl phthalate resin, or thermosetting type The resin may be used alone or in combination of two or more.

The content of the binder resin is preferably from 50 to 80% by weight, more preferably from 55 to 75% by weight, in the light-shielding film. When the amount of the binder resin is 50% by weight or more, the adhesion between the substrate and the light-shielding film can be prevented from being lowered, and when the content is 80% by weight or less, the physical properties of the light-shielding film such as light-shielding property, slidability, and matte property can be prevented from being lowered.

In the carbon black, the light-shielding film is colored black to impart light-shielding properties, and at the same time, it has a task of imparting conductivity and preventing electrification due to static electricity. In order to obtain sufficient light-shielding property, the average particle diameter of such carbon black is preferably 1 μm or less, more preferably 0.5 μm or less.

The content of carbon black is preferably 5 to 20% by weight, more preferably 10 to 20% by weight, in the light-shielding film. When the carbon black is 5% by weight or more, the light-shielding property and the conductivity can be imparted, and if it is 20% by weight or less, the adhesion, the scratch resistance, and the reduction in the coating film strength can be prevented, and the cost can be prevented from increasing.

The fine particles contained in the light-shielding film can reduce the reflection of light incident on the surface of the light-shielding member by forming fine irregularities on the surface, thereby reducing the glossiness of the surface (mirror gloss) and improving the extinction when used as a light-shielding member. Sex.

As such fine particles, an inorganic system such as cross-linked acrylic beads, an indulgent such as vermiculite, magnesium metasilicate aluminate, or titanium oxide can be used, and among them, an inorganic one is preferable because of high matting effect. , especially from the dispersion of microparticles. From the viewpoint of low cost and the like, it is preferred to use vermiculite. In addition, one type or a mixture of two or more types can be used.

The average particle diameter of the fine particles is preferably from 1 to 10 μm, more preferably from 1 to 6 μm. Within such a range, fine irregularities can be formed on the surface of the light shielding member to obtain matting properties.

The content of the fine particles is preferably from 1 to 10% by weight, more preferably from 1 to 5% by weight, in the light-shielding film. By making the fine particles 1% by weight or more, it is possible to prevent the decrease in the matteness due to the increase in the gloss (mirror gloss) of the surface, and it is possible to prevent the sliding of the light-shielding member by 10% by weight or less. The resulting microparticles fall off and cause a decrease in slidability.

Further, in the light-shielding film, in addition to the binder resin, carbon black, and fine particles, it is preferred to further contain a lubricant. By including a lubricant, the slidability of the surface of the light-shielding member can be improved, and when it is processed into a shutter or a diaphragm member, the frictional resistance at the time of actuation can be reduced, and the scratch resistance of the surface can be improved. In this case, the organic type or the inorganic type can be used as a solid, and examples thereof include a hydrocarbon-based slip agent such as polyethylene wax or paraffin, a fatty acid system such as stearic acid or 12-hydroxystearic acid. Solid lubricants such as slip agents, oleic acid amides, erucic acid amides such as guanamine slips, ester slips such as stearic acid monoglycerides, alcohol slips, metal soaps, talc, molybdenum disulfide, etc. The fluororesin particles such as a polysiloxane resin particle or a polytetrafluoroethylene wax, crosslinked polymethacrylate particles, and crosslinked polystyrene particles are particularly preferably used. In addition, one type or a mixture of two or more types can be used.

Such a slip agent is preferably in the form of particles, and the average particle diameter is preferably from 3 to 20 μm, more preferably from 5 to 10 μm. Since it is within such a range, appropriate irregularities can be formed on the surface to obtain slidability.

The content of the lubricant is preferably from 5 to 20% by weight, more preferably from 10 to 20% by weight, based on the light-shielding film. When the amount of the lubricant is 5% by weight or more, appropriate irregularities can be formed on the surface to obtain slidability, and when it is 20% by weight or less, the relative content of carbon black can be increased, and the light-shielding property and the conductivity can be prevented from being lowered.

The light-shielding film of the present invention may contain a flame retardant, an antibacterial agent, an antifungal agent, an antioxidant, a plasticizer, a leveling agent, a flow regulating agent, an antifoaming agent, and a dispersing agent without impairing the function of the present invention. And other additives.

The thickness of the light shielding film is preferably 5 to 30 μm, more preferably 5 to 20 μm. When it is 5 μm or more, it is possible to prevent pinholes and the like from occurring in the light-shielding film, and to reduce the light-shielding property, and to obtain sufficient light-shielding property. Moreover, when it is 30 μm or less, it is possible to prevent the light-shielding film from being damaged, thereby reducing the light-shielding property or preventing the light-shielding film from falling off from the substrate.

The intermediate layer or the light-shielding film constituting the light-shielding member is a coating liquid obtained by dissolving a resin or the like in a suitable solvent, and is applied by a well-known coating method to dry. Formed by hardening.

Further, in order to improve the adhesion of the plastic film to the intermediate layer or the light-shielding film, a primer treatment or a corona treatment may be performed as needed.

As described above, in the light-shielding member for an optical device of the present invention, since a laminate using a layer containing a plastic film and a curable resin is used as a base material for forming a light-shielding film, even if it is thin, the reduction in toughness can be suppressed, so that it can be applied. A shutter or aperture member of an optical device such as a high-performance single-lens reflex camera, a compact camera, a video camera, a portable telephone, or a projector.

[Examples]

The invention is further illustrated by the following examples. In addition, "parts" and "%" are based on weight unless otherwise indicated.

[Example 1]

On one side of a polyester film (K200: Mitsubishi Chemical Polyester Co., Ltd.) having a thickness of 6 μm, the following coating liquid for an intermediate layer was applied and dried to form An intermediate layer having a thickness of 5 μm was attached to a polyester film having a thickness of 6 μm on the intermediate layer, and ultraviolet rays were irradiated to prepare a substrate having a thickness of 17 μm. The pencil hardness of the intermediate layer (JIS K5600-5-4:1999) was 2H.

Then, the coating liquid for a light-shielding film described below was applied to both surfaces of the substrate to be formed, and dried to form a light-shielding film having a thickness of 10 μm to prepare a light-shielding member for an optical device of Example 1.

[Embodiment 2]

The following coating liquid for an intermediate layer was applied to one surface of a polyester film (K200: Mitsubishi Chemical Polyester Co., Ltd.) having a thickness of 6 μm and dried to form an intermediate layer having a thickness of 5 μm, and the following adhesion was applied to the intermediate layer. The coating liquid for the layer was dried to have a thickness of 1 μm. Next, a polyester film having a thickness of 6 μm was attached to the adhesive layer to prepare a substrate having a thickness of 18 μm. Then, a light-shielding film similar to that of Example 1 was formed on both surfaces of the produced substrate to prepare a light-shielding member for an optical device of Example 2. The pencil hardness of the intermediate layer (JIS K5600-5-4:1999) is H.

[Example 3]

The light shielding member for an optical device of Example 3 was produced in the same manner as in Example 1 except that the thickness of the intermediate layer was 10 μm.

[Comparative Example 1]

The base material was changed to a polyester film (H100: Mitsubishi Chemical Polyester Co., Ltd.) having a thickness of 12 μm, and a light-shielding film similar to that of Example 1 was formed on both surfaces of the substrate to prepare a light-shielding member for an optical device of Comparative Example 1.

[Comparative Example 2]

The following coating liquid for an intermediate layer was applied to one surface of a polyester film (K200: Mitsubishi Chemical Polyester Co., Ltd.) having a thickness of 6 μm and dried to form an intermediate layer having a thickness of 1 μm. Next, a polyester film (H100: Mitsubishi Chemical Polyester Co., Ltd.) having a thickness of 12 μm was bonded to the intermediate layer to prepare a substrate having a thickness of 19 μm. Then, a light-shielding film similar to that of Example 1 was formed on both surfaces of the produced substrate to prepare a light-shielding member for an optical device of Comparative Example 2. The pencil hardness (JIS K5600-5-4:1999) of the intermediate layer was 3B.

[Comparative Example 3]

The base material was changed to a polyester film (T100: Mitsubishi Chemical Polyester Co., Ltd.) having a thickness of 25 μm, and a light-shielding film similar to that of Example 1 was formed on both surfaces of the substrate to prepare a light-shielding member for an optical device of Comparative Example 3.

The toughness of the light-shielding members of the examples and the comparative examples was evaluated by the following method.

As shown in Fig. 3, a sample piece S having a length of 12.5 cm and a width of 2.5 cm was prepared, and a part (a portion having a length of 1 cm and a width of 2.5 cm) was fixed to the stage T, and the remaining portion was drooped. The distance D from the downward perpendicular line L of the end of the stage T to which the sample piece is fixed and the end of the sagging sample piece. When the distance D is less than 1 cm, it is regarded as ×, and when it is 1 cm or more and less than 3 cm, it is regarded as ○, and when it is 3 cm or more, it is regarded as ◎. The results are shown in Table 1.

As is clear from the results shown in the table, the light-shielding members for optical devices of Examples 1 and 2 are provided with a hardened resin layer as an intermediate layer, and compared with the light-shielding member for optical devices of Comparative Example 3, although thin. However, it has the same toughness and is excellent in workability during processing. Further, the light-shielding member for an optical device of the third embodiment is slightly thinner than the light-shielding member for an optical device of Comparative Example 3, but the toughness is superior to that of Comparative Example 3. Further, in the light-shielding members for optical devices of Examples 1 and 3, since the ionizing radiation-curable resin is used as the curable resin, the adhesive layer is not required, and sufficient toughness can be obtained in a thin form. Furthermore, since the intermediate layer is sandwiched by two plastic films, the planarity is also good. Further, the light-shielding members for optical devices of Examples 1 to 3 have moderate toughness and have no unnecessary contact portions, and are excellent in slidability as a shutter or a diaphragm member.

On the other hand, the light-shielding member for an optical device of Comparative Example 1 has no toughness, and has poor workability during processing, and has many contact portions as a shutter or a diaphragm member, and has poor slidability.

In the light-shielding member for an optical device of Comparative Example 2, the curable resin was not used as the intermediate layer, and the thickness was higher than that of the optical devices of Examples 1 and 2. The optical member is also thick, has no toughness, and has poor workability during processing, and has many contact portions as a shutter or a diaphragm member, and has poor slidability.

In the light-shielding member for an optical device of Comparative Example 3, a film having a thickness of 25 μm is used as the substrate, and the toughness is the same as that of Examples 1 and 2, but the thickness is greater than that of the optical device for the optical device of Examples 1 and 2. Thick, not suitable for thin applications.

1‧‧‧Substrate

11‧‧‧Plastic film

12‧‧‧Intermediate

13‧‧‧Adhesive layer

2‧‧‧Shade film

3‧‧‧Lighting members for optical machines

Fig. 1 is a cross-sectional view showing an embodiment of a light shielding member for an optical device of the present invention.

Fig. 2 is a cross-sectional view showing another embodiment of the light-shielding member for an optical device of the present invention.

Fig. 3 is a view for explaining a method of evaluating a light shielding member for an optical device according to an embodiment.

1‧‧‧Substrate

11‧‧‧Plastic film

12‧‧‧Intermediate

2‧‧‧Shade film

3‧‧‧Lighting members for optical machines

Claims (5)

A light shielding member for an optical device comprising a substrate and a light shielding film formed on at least one surface of the substrate, wherein the substrate is formed by a resin content containing a cured product of a curing resin. A plastic film is disposed on both sides of the intermediate layer to form a laminate having a thickness of 25 μm or less. The light-shielding member for an optical device according to claim 1, wherein the curable resin is an ionizing radiation-curable resin. The light shielding member for an optical device according to claim 1 or 2, wherein the intermediate layer has a thickness of 2 to 10 μm, and each of the plastic films has a thickness of 4 to 20 μm. The light-shielding member for optical devices according to the first or second aspect of the invention, wherein the intermediate layer contains 50% by weight or more of the cured product in the total resin content, and the pencil hardness is H or more. The light shielding member for an optical device according to claim 1 or 2, wherein the laminate system is formed by allowing an adhesive layer to exist between the intermediate layer and the plastic film on at least one side.