JP4958950B2 - Light shielding member for optical equipment - Google Patents

Description

  The present invention relates to a light shielding member suitably used as a shutter and a diaphragm member of an optical apparatus such as a high-performance single-lens reflex camera, a compact camera, a video camera, a mobile phone, and a projector.

  In recent years, due to demands for miniaturization and weight reduction of high-performance single-lens reflex cameras, compact cameras, video cameras, and the like, shutters and diaphragm members of optical devices made of metal materials are being replaced by plastic materials.

  As such a diaphragm for a plastic material, a light-shielding film in which a base film is provided with a light-shielding film containing carbon black, a lubricant, and fine particles is known (Patent Document 1).

JP-A-9-274218

  However, in the light-shielding film as described above, a large amount of fine particles must be contained in order to impart matting properties to the light-shielding film, resulting in a decrease in the content of carbon black and lubricant in the light-shielding film. Further, there has been a problem that the light shielding property, the sliding property and the like are not sufficiently exhibited.

  In order to solve the above-described problems, a light-shielding member that has a matte property and retains the properties of the light-shielding film such as a light-shielding property and a sliding property has been desired.

  As a result of diligent research to solve the above-mentioned problems, the present inventor uses a lubricant having an average particle size larger than the average particle size of the fine particles, so that the matte property can be improved despite a small amount of fine particles. It was found that it can be given.

  That is, although the reason is not clear, by using a lubricant having an average particle size larger than the average particle size of the fine particles, the matte property can be obtained with a small amount of fine particles, resulting in carbon black in the light shielding film, The present inventors have found that the content of the lubricant can be increased and that the physical properties of the light-shielding film such as light-shielding property and slidability can be maintained, and the present invention has been achieved. In addition, even if the amount of the fine particles is small, a sufficient matting effect can be obtained because fine unevenness is formed by the fine particles on the surface unevenness formed by the lubricant, and as a result, reflection of incident light can be reduced. by.

  The light shielding member for optical equipment of the present invention comprises a base material made of a synthetic resin film and a light shielding film formed on at least one surface of the base material, and the light shielding film comprises a binder resin, carbon black, and a particulate lubricant. And the content of carbon black and lubricant in the light-shielding film is 5 to 20% by weight, and the average particle size of the lubricant is larger than the average particle size of the fine particles. To do.

  In the above invention, the difference between the average particle size of the lubricant and the average particle size of the fine particles is preferably 0.5 μm or more. The average particle size of the lubricant is preferably in the range of 3 to 20 μm, and the average particle size of the fine particles is preferably in the range of 1 to 10 μm. The content of fine particles in the light shielding film is preferably 3% by weight or less in the light shielding film.

  In the said invention, it is preferable that the content rate of the microparticles | fine-particles in a light shielding film is the range of 1-10 weight%. More preferably, the content ratios of carbon black, lubricant and fine particles in the light shielding film are in the range of 10 to 20% by weight, 10 to 20% by weight and 1 to 5% by weight, respectively. The fine particles are silica, and preferably contain silica having an oil absorption of 250 (g / 100 g) or more.

  According to the present invention, by adopting a lubricant whose average particle size is larger than the average particle size of the fine particles as the lubricant contained in the light-shielding film, the unevenness of the surface shape of the light-shielding film is complicated in a state where the function of the lubricant can be exhibited. Even if the content of the fine particles is small, a more excellent matte property can be realized. As a result, the content of carbon black and lubricant in the light-shielding film can be increased (both 5% by weight or more), so that the physical properties of the light-shielding film such as light-shielding property and slidability can be achieved while having matte properties. The held light-shielding member for optical equipment is obtained. Therefore, such a light-shielding member for an optical device can be suitably used for a high-performance single-lens reflex camera, a compact camera, a video camera, a mobile phone, a projector, and the like.

The figure which shows one Embodiment of the light-shielding member for optical devices of this invention

Hereinafter, embodiments of the light shielding member for optical equipment according to the present invention will be described.
As shown in FIG. 1, the light shielding member 1 for an optical device of the present invention comprises a base material 2 made of a synthetic resin film and a light shielding film 3 formed on at least one surface. The light shielding film 3 comprises a binder resin and carbon black. 31, the particulate lubricant 32 and the fine particles 33, the carbon black and the lubricant content in the light-shielding film 3 are both 5 to 20% by weight, and the average particle size of the lubricant 32 is the average particle size of the fine particles 33. Is bigger than that.

  Examples of the base material used as the light-shielding member for optical equipment of the present invention include synthetic resin films such as a polyester film, a polyimide film, a polystyrene film, and a polycarbonate film. Among them, a polyester film is preferably used, and stretch processing, In particular, a biaxially stretched polyester film is particularly preferable in that it has excellent mechanical strength and dimensional stability. The base material may be a transparent polyester film, a synthetic resin film containing a black pigment such as carbon black, or other pigments. In this case, the above-mentioned base material can be selected appropriately for each application. For example, when used as a light-shielding member, the light collected by the lens etc. on the synthetic resin film portion of the member cross section is reflected and adversely affected, so if high light-shielding properties are required, a black pigment such as carbon black The contained synthetic resin film can be used, and in other cases, a transparent or foamed synthetic resin film can be used.

  In the present invention, since the light-shielding film itself provides sufficient light-shielding properties as a light-shielding member, when the synthetic resin film contains a black pigment, the synthetic resin film appears to be visually black, that is, the optical density. May be contained so as to be about 3. Therefore, since the black pigment is not contained in the synthetic resin film until the limit that the physical properties as the base material are impaired as in the prior art, it can be obtained at low cost without changing the physical properties of the synthetic resin film.

  Although the thickness of a base material changes with uses to be used, it is generally preferable to set it as 25 micrometers-250 micrometers from viewpoints, such as lightness and the intensity | strength and rigidity as a light-shielding member.

  Moreover, an anchor process or a corona process can also be performed to a base material as needed from a viewpoint of improving adhesiveness with a light shielding film.

  Next, the light-shielding film formed on at least one surface of the substrate used as the light-shielding member for optical equipment of the present invention contains a binder resin, carbon black, particulate lubricant, fine particles, and carbon black in the light-shielding film. The lubricant content is 5 to 20% by weight, and the average particle size of the lubricant is larger than the average particle size of the fine particles.

  The binder resin contained in the light shielding film includes poly (meth) acrylic resin, polyester resin, polyvinyl acetate resin, polyvinyl chloride, polyvinyl butyral resin, cellulose resin, polystyrene / polybutadiene resin, polyurethane resin, alkyd resin. , Acrylic resin, unsaturated polyester resin, epoxy ester resin, epoxy resin, epoxy acrylate resin, urethane acrylate resin, polyester acrylate resin, polyether acrylate resin, phenol resin, melamine resin, urea resin, diallyl A thermoplastic resin such as a phthalate resin or a thermosetting resin may be used, and one or more of these may be used in combination.

  The content of the binder resin is preferably 50% by weight to 80% by weight in the light shielding film, and more preferably 55% by weight to 75% by weight. By making it 50% by weight or more in the light-shielding film, it is possible to prevent the adhesion between the substrate and the light-shielding film from being lowered. By making it 80% by weight or less, the light-shielding property, slidability, and matte It is possible to prevent the physical properties of the light-shielding film such as the property from deteriorating.

  Next, the carbon black contained in the light-shielding film is for coloring the binder resin black to impart light-shielding properties and to impart electrical conductivity to prevent electrostatic charging.

  The average particle size of carbon black is preferably 1 μm or less, and more preferably 0.5 μm or less, in order to obtain sufficient light shielding properties.

  The content of carbon black is 5 wt% to 20 wt% in the light shielding film, preferably 10 wt% to 20 wt%. By making it 5% by weight or more in the light-shielding film, it is possible to prevent the light-shielding property and conductivity from being lowered, and by making it 20% by weight or less, the adhesiveness and scratch resistance are improved. It is possible to prevent a decrease in strength and an increase in cost.

  Next, the particulate lubricant contained in the light-shielding film improves the slidability of the surface of the light-shielding member, reduces the frictional resistance during operation when processed into a diaphragm member, etc., and provides scratch resistance on the surface. It is for improving. As such materials, any organic or inorganic materials can be used as long as they are solid, for example, hydrocarbon lubricants such as polyethylene wax and paraffin wax, stearic acid, 12-hydroxystearic acid. Fatty acid lubricants such as oleic acid amide, amide amides such as erucic acid amide, ester lubricants such as stearic acid monoglyceride, alcohol lubricants, metal soap, talc, solid lubricants such as molybdenum disulfide, silicone resin particles, Fluorine resin particles such as polytetrafluoroethylene wax, cross-linked polymethyl methacrylate particles, cross-linked polystyrene particles, and the like can be mentioned, but organic ones are particularly preferably used. Moreover, these 1 type (s) or 2 or more types can also be mixed and used.

  The average particle size of the lubricant is preferably 3 μm to 20 μm, and more preferably 5 μm to 10 μm. By setting it as such a range, an appropriate unevenness | corrugation is formed in the surface and slidability is acquired.

  Further, as shown in FIG. 1, the average particle size of the lubricant 32 is preferably larger than the average particle size of the fine particles 33, and more preferably the difference between the two is 0.5 μm or more. By making the average particle diameter of the lubricant 32 larger than the average particle diameter of the fine particles 33, fine unevenness is formed by fine particles on the unevenness of the surface formed by the lubricant, so that the reflection of incident light is reduced. This is because sufficient matting properties can be obtained and sliding properties can also be obtained.

  The content of the lubricant is 5% by weight to 20% by weight in the light shielding film, preferably 10% by weight to 20% by weight. By setting the content to 5% by weight or more in the light-shielding film, appropriate irregularities can be formed on the surface and slidability can be obtained. By setting the content to 20% by weight or less, the relative content of carbon black can be increased. It is possible to prevent the light shielding property and the conductivity from being lowered.

  Next, the fine particles contained in the light-shielding film reduce the reflection of incident light by forming fine irregularities on the surface and reduce the glossiness of the surface (specular glossiness). It is for improving the property.

  The fine particles are indispensable for imparting a matte surface property when used as a light shielding member, but the ratio of the fine particles that can be contained in the light shielding film is limited as follows. First, if the content of fine particles is increased without changing the proportion of the resin and other components, the content of carbon black, lubricant, etc. will decrease accordingly, so that the light shielding properties, slidability, etc. as a light shielding member This leads to a decrease in physical properties. Further, in order to maintain physical properties such as light shielding properties, the content of carbon black and lubricant in the light shielding film is maintained, while the content of fine particles is increased by reducing the content of binder resin, The adhesion between the light shielding film and the light-shielding film is poor, and the scratch resistance is deteriorated. In other words, if the light-shielding film contains a sufficient amount of fine particles that give matting properties, physical properties such as light-shielding properties and slidability cannot be maintained, or the scratch resistance is poor.

In the present invention, different from the fine particles used as a matting agent in the conventional light shielding member, specific fine particles, that is, fine particles having an oil absorption of 250 (g / 100 g) or more, preferably an oil absorption of 300 (g / 100 g) or more. Fine particles can be used. When such specific fine particles are used, the matte property of the surface can be obtained with a small amount, and the content of carbon black, lubricant, etc. in the light shielding film can be increased. As a result, the light-shielding film can sufficiently exhibit physical properties such as light-shielding property and slidability while having the matte property.
In this specification, the oil absorption amount is based on ISO787 / V-1968, and is the amount (g) of oil necessary for wet mixing linseed oil with 100 g of fine particles to form a hard paste.

  As such specific fine particles, any organic type such as crosslinked acrylic beads, inorganic type such as silica, magnesium aluminate metasilicate, and titanium oxide can be used, but inorganic type is preferable. Silica is preferably used from the viewpoints of fine particle dispersibility and low cost. Moreover, these 1 type (s) or 2 or more types can also be mixed and used.

  The average particle diameter of the fine particles is preferably 1 μm to 10 μm, and more preferably 1 μm to 6 μm. By setting it as such a range, a fine unevenness | corrugation is formed in the surface of a light shielding member, and matte property is acquired.

  The content of the fine particles is preferably 1% by weight to 10% by weight in the light shielding film, and more preferably 1% by weight to 5% by weight. By setting the content to 1% by weight or more in the light-shielding film, it is possible to prevent the surface glossiness (mirror glossiness) from increasing and the matting property from being lowered. By setting the content to 10% by weight or less, the light-shielding member It is possible to prevent the fine particles from falling off due to the sliding, and to reduce the sliding property.

  In particular, when high light-shielding properties and slidability are required, the content of fine particles is preferably 3% by weight or less in the light-shielding film from the above range. As described above, the fine particles used in the present invention can obtain a high matte property even in a small amount, so that by setting it to 3% by weight or less, a sufficient matte property can be obtained, and relatively, carbon black, lubricant It is possible to increase the content of the light and improve physical properties such as light shielding properties and slidability.

  If the light-shielding film of the present invention does not impair the functions of the present invention, flame retardants, antibacterial agents, fungicides, antioxidants, plasticizers, leveling agents, flow regulators, antifoaming agents, dispersants, etc. Various additives can be contained.

  The thickness of the light shielding film is preferably 5 μm to 30 μm, and more preferably 5 μm to 20 μm. By setting the thickness to 5 μm or more, pinholes and the like can be prevented from being generated in the light shielding film, and sufficient light shielding properties can be obtained. Moreover, it can prevent that a crack arises in a light shielding film by setting it as 30 micrometers or less.

  The light-shielding member for an optical device of the present invention is for a light-shielding film containing the binder resin, carbon black, particulate lubricant, and specific fine particles as described above on one or both sides of a base material made of a synthetic resin film as described above. It can be obtained by applying the coating solution by a conventionally known coating method such as dip coating, roll coating, bar coating, die coating, blade coating, air knife coating, etc., drying, and then heating / pressing as necessary. it can. As the solvent of the coating solution, water, an organic solvent, a mixture of water and an organic solvent, or the like can be used.

  As described above, the light-shielding member for optical equipment of the present invention has a matte property because it has the light-shielding film configured as described above on at least one surface of the base material made of the synthetic resin film as described above. However, it retains the properties of the light-shielding film, such as light-shielding properties and sliding properties, so it is suitable as a shutter and diaphragm member for optical devices such as high-performance single-lens reflex cameras, compact cameras, video cameras, mobile phones, and projectors. Can be used.

  The following examples further illustrate the present invention. “Parts” and “%” are based on weight unless otherwise specified.

1. Production of light shielding member for optical device [Experimental Examples 1 to 8]
A black polyethylene terephthalate film (Lumirror X30: Toray Industries, Inc.) having a thickness of 50 μm is used as a base material, and the coating thicknesses (a) to (h) for the light-shielding film of the following formulation are applied to both surfaces by the bar coating method. Each was applied so as to have a thickness of 10 μm, and dried to form light shielding films A to H, thereby producing light shielding members for optical devices of Experimental Examples 1 to 8. In addition, Table 1 shows the contents (parts) of acrylic polyol and the like in the coating solutions (a) to (h) for the light-shielding film having the following formulation. In addition, Table 2 shows the content (%) of acrylic polyol and the like in the formed light shielding films A to H.

<Prescription of coating solutions (a) to (h) for light shielding film>
Acrylic polyol (solid content 50%) (Parts listed in Table 1)
(Acridic A804: Dainippon Ink & Chemicals, Inc.)
・ Isocyanate (solid content 75%) (part shown in Table 1)
(Bernock DN980: Dainippon Ink & Chemicals, Inc.)
・ Carbon black (parts listed in Table 1)
(Vulcan XC-72: Cabot Corporation)
・ Lubricant (Parts listed in Table 1)
(Average particle size 8.5μm) (Ceridust 3620: Hoechst)
・ Fine particles (silica) (Fine particles and parts listed in Table 1)
・ Methyl ethyl ketone 60 parts ・ Toluene 40 parts

微粒子Ｐ：ＴＳ１００：デグサ社、吸油量３９０(g/100g)、平均粒径４μｍ
微粒子Ｑ：ＡＺ−２００：東ソー・シリカ社、吸油量３３０(g/100g)、平均粒径２．４μｍ
微粒子Ｒ：ＴＫ９００：デグサ社、吸油量９０(g/100g)、平均粒径８μｍ
微粒子Ｓ：サイリシア７３０：富士シリシア化学社、吸油量９５(g/100g)、平均粒径４μｍ

Fine particles P: TS100: Degussa, oil absorption 390 (g / 100 g), average particle size 4 μm
Fine particles Q: AZ-200: Tosoh Silica Co., Ltd., oil absorption 330 (g / 100 g), average particle size 2.4 μm
Fine particles R: TK900: Degussa, oil absorption 90 (g / 100 g), average particle size 8 μm
Fine particles S: Silicia 730: Fuji Silysia Chemical Ltd., oil absorption 95 (g / 100 g), average particle size 4 μm

2. Evaluation About the light-shielding member for optical devices obtained in Experimental Examples 1-8 as mentioned above, the physical property was evaluated by the following method. Each result is shown in Table 3. However, for the following (1) evaluation of light-shielding properties, light-shielding films A to H of the formulations of Experimental Examples 1 to 8 are formed to a thickness of 10 μm on one side of a transparent polyethylene terephthalate film (Lumirror T60: Toray Industries, Inc.) having a thickness of 50 μm. This was done using the prepared samples.

(1) Evaluation of light-shielding properties The samples of Experimental Examples 1 to 8 were measured for optical density using an optical densitometer (TD-904: Gretag Macbeth) based on JIS K7651: 1988, exceeding 4.0, The density in the non-measurable area was indicated by “◯”, and the density of 4.0 or less was designated by “X”. Note that a UV filter was used for the measurement.

(2) Evaluation of slidability The light-shielding member for optical equipment obtained in Experimental Examples 1 to 8 was subjected to a static friction coefficient (μs) under the conditions of a load of 200 (g) and a speed of 100 (mm / min) based on JIS K7125: 1999. ) And the dynamic friction coefficient (μk) were measured. Those with a static friction coefficient (μs) of 0.35 or less were marked with “◯”, and those with 0.35 or more were marked with “x”. In addition, those having a dynamic friction coefficient (μk) of 0.30 or less were designated as “◯”, and those having a coefficient of 0.30 or more as “x”. In addition, “−” indicates that the light shielding film was shaved and measurement was impossible.

(3) Evaluation of matte property The glossiness (mirror glossiness) (%) of the surface of the light shielding member for optical equipment obtained in Experimental Examples 1 to 8 was measured based on JIS Z8741: 1997.

(4) Conductivity Evaluation The surface resistivity (Ω) of the light shielding member for optical equipment obtained in Experimental Examples 1 to 8 was measured based on JIS K6911: 1995. A surface resistivity of less than 1.0 × 10 ⁵ Ω is “◯”, a surface resistivity of 1.0 × 10 ⁵ Ω or more and less than 1.0 × 10 ⁸ Ω is “Δ”, and 1.0 × 10 ⁸ Ω or more. The thing was made into "x".

(5) Evaluation of adhesiveness The light-shielding member for optical equipment obtained in Experimental Examples 1 to 8 was measured based on the cross-cut tape method in JIS K5400: 1990. When the surface texture of the cross section was peeled off by 5% or more, “×” was given, and “○” was given when it was less than 5%.

(6) Evaluation of scratch resistance Using the light-shielding member for optical equipment obtained in Experimental Examples 1 to 8 as a diaphragm member of a camera, it was operated 1 million times to examine the presence or absence of scratches on the coating film surface, peeling, Those with no peeling were marked with “◯”, and those with scratches and peeling were marked with “x”.

  As is clear from the results in Table 3, the light shielding members for optical devices obtained in Experimental Examples 1 and 2 are binder resin, carbon black, particulate lubricant and fine particles on both surfaces of the base material, that is, the average particle size of the fine particles. Forms a light-shielding film containing a lubricant having an average particle size larger than the diameter, and has an appropriate content of carbon black and lubricant in the light-shielding film, so that matte properties can be obtained with a small amount of fine particles. As a result, the properties of the light-shielding film, such as light-shielding properties and sliding properties, were maintained while having matte properties, and the properties as light-shielding members for optical devices were excellent.

  The light-shielding member for an optical device obtained in Experimental Examples 3 and 4 is obtained by containing fine particles in the light-shielding film at the same content as that used in Experimental Examples 1 and 2. Compared to the light shielding member for optical equipment, the matte property was inferior.

Further, since the light shielding member for optical equipment obtained in Experimental Examples 5 and 6 contains a large amount of fine particles in order to impart matting properties to the light shielding film, carbon black and lubricant in the light shielding film As a result, the light shielding property, slidability, and conductivity were inferior to those of the light shielding members for optical devices of Experimental Examples 1 and 2. Furthermore, since the content of the lubricant is low, appropriate irregularities are not formed on the surface, and since the content of carbon black is also low, as a result, the inclusion of fine particles for the purpose of imparting matte properties Although the amount was increased, the matte properties were inferior to those of Experimental Examples 1 and 2.

  In addition, the light shielding members for optical devices obtained in Experimental Examples 7 and 8 have a binder resin content while maintaining the carbon black and lubricant content in the light shielding film in order to maintain physical properties such as light shielding properties. It was confirmed that the material contained a large amount of fine particles and had excellent matting properties and excellent light shielding properties.

DESCRIPTION OF SYMBOLS 1 .... Light-shielding member for optical equipment 2 ..... Base material 3 .... Light-shielding film 31 ...... Binder resin and carbon black 32 ... ..Lubricant 33 ... Fine particles

Claims (7)

The substrate comprises a synthetic resin film, and a light shielding film formed on at least one surface of the substrate. The light shielding film contains a binder resin, carbon black, a particulate lubricant, and fine particles, and the light shielding film carbon black click in the middle, slip agent and fine particles content is 5-20 wt%, respectively, and at 5 to 20 wt% and 3 wt% or less, an average particle diameter of the lubricant is, than the average particle size of the fine particles A light-shielding member for optical equipment, characterized by being large. The light blocking content of fine particles in the film, 1 to 10% by weight of the light-shielding member for optical devices according to claim 1, wherein the ranges. 3. The optical apparatus according to claim 2, wherein the content of carbon black, lubricant and fine particles in the light shielding film is in the range of 10 to 20% by weight, 10 to 20% by weight and 1 to 5% by weight, respectively. Shading member for use. The fine particles, the light-shielding member for optical device according to any one of claims 1 to 3, characterized in that the silica.   The substrate comprises a synthetic resin film, and a light shielding film formed on at least one surface of the substrate. The light shielding film contains a binder resin, carbon black, a particulate lubricant, and fine particles, and the light shielding film A light-shielding member for an optical instrument, wherein the content of the fine particles in the inside is 3% by weight or less, and the average particle size of the lubricant is larger than the average particle size of the fine particles.   The substrate comprises a synthetic resin film, and a light shielding film formed on at least one surface of the substrate. The light shielding film contains a binder resin, carbon black, a particulate lubricant, and fine particles, and the light shielding film A light-shielding member for an optical device, wherein the content of the fine particles is 1 to 10% by weight, and the average particle size of the lubricant is larger than the average particle size of the fine particles. Shielding member for optical apparatus according to any one of claims 1 to be used for the shutter or diaphragm member 6.

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