JPWO2012005148A1 - Light shielding member for optical equipment - Google Patents

Abstract

An object of the present invention is to provide a light-shielding member for an optical device that is stiff even if it is thinned and hardly breaks the film. The light shielding member for optical equipment of the present invention has 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 has a hydroxyl value of 100 (mgKOH). / G) Binder resin, carbon black, inorganic particles, and resin particles having an average particle diameter of 1 to 10 μm are contained. The resin particles are cross-linked polymethyl methacrylate particles.

Description

  The present invention relates to a light-shielding member for optical equipment that can be used for shutters and diaphragm members of various optical equipment.

  In recent years, due to demands for reducing the size and weight of various optical devices such as high-performance single-lens reflex cameras, compact cameras, and video cameras, the shutters and diaphragm members of optical devices that have been 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 light-shielding film containing carbon black, a lubricant, fine particles, and a binder resin is formed on a film substrate is known (Patent Documents 1 and 2).

JP-A-9-274218 WO2006 / 016555

  The above-described light-shielding film is extremely weak compared to a light-shielding member made of a metal material. Therefore, if the light-shielding film is used as a shutter or a diaphragm member of an optical device, it cannot be used and is in contact with other members. There has been a problem that distortion occurs from the part, and deformation or damage occurs. Such a problem can be said to be a big problem in the recent situation where thinning is required.

  In order to solve this, a design in which highly elastic particles are contained in the light shielding film is conceivable, but in such a case, the relative content of other materials constituting the light shielding film is reduced, so that the light shielding member As a result, the balance of performance such as shading and slipperiness will be hindered.

  On the other hand, a method of reducing the thickness of a light shielding member made of a metal material can be considered. However, when the light shielding member is used as a shutter or a diaphragm member, deformation easily occurs due to contact with other members. Such deformation does not return to the original due to the nature of the metal material, and such a light shielding member is not convenient. Metal materials are more expensive than plastic materials in the first place.

  Thus, there is a need for a light-shielding member for an optical device that is stiff even if it is thinned without using a metal material, and is less likely to cause damage to the film.

  In contrast, the inventors of the present invention provide a light shielding member including a binder resin having a hydroxyl value of 100 (mgKOH / g) or more as a binder resin in the light shielding film and resin particles having an average particle diameter of 1 to 10 μm. As a result, the present inventors have found that there is stiffness even when the thickness is reduced, and that the film can be hardly damaged even if it comes into contact with other members.

  That is, the light shielding member for optical equipment of the present invention includes 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 has a hydroxyl value of 100. The binder resin, carbon black, inorganic particles, and resin particles having an average particle diameter of 1 to 10 μm are contained in an amount of (mg KOH / g) or more.

  In the light shielding member for optical equipment of the present invention, the resin particles are preferably crosslinked polymethyl methacrylate particles.

  Moreover, the light-shielding member for optical equipment of the present invention preferably contains 20 to 150 parts by weight of resin particles with respect to 100 parts by weight of the binder resin.

  According to the above-described invention, the inclusion of the binder resin having a hydroxyl value of 100 (mgKOH / g) or more and the resin particles having an average particle diameter of 1 to 10 μm in the light-shielding film may cause a reduction in thickness. Moreover, it can be set as the light-shielding member which is hard to produce a damage etc. of a film.

The figure explaining the measuring apparatus for measuring the stiffness of the light-shielding member for optical instruments

Hereinafter, an embodiment of a light shielding member for an optical device according to the present invention (hereinafter sometimes referred to as “light shielding member”) will be described.
The light shielding member of the present invention includes a base material made of a synthetic resin film and a light shielding film formed on at least one surface of the base material. The light-shielding film contains a binder resin having a hydroxyl value of 100 (mgKOH / g) or more, carbon black, inorganic particles, and resin particles having an average particle diameter of 1 to 10 μm.

  In addition, the average particle diameter as used in the field of this invention refers to the median diameter (D50) measured with a laser diffraction type particle size distribution measuring apparatus (for example, Shimadzu Corporation SALD-7000).

  The substrate made of synthetic resin film is made of polyester, ABS (acrylonitrile-butadiene-styrene), polyimide, polystyrene, polycarbonate, acrylic, polyolefin, cellulose resin, polysulfone, polyphenylene sulfide, polyethersulfone, polyetheretherketone, etc. Things. Among them, a polyester film is preferably used, and a stretched polyester film, particularly a biaxially stretched polyester film, is particularly preferable in terms of excellent mechanical strength and dimensional stability.

  Moreover, as a base material, a synthetic resin film containing not only a transparent material but also a foamed polyester film, a black pigment such as carbon black, and other pigments can be used. 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 embodiment, the light shielding film itself provides sufficient light shielding properties as a light shielding member. Therefore, when the synthetic resin film contains a black pigment, the synthetic resin film looks visually black, that is, optical. It may be contained so that the concentration is 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.

  As a thickness of a base material, 4-50 micrometers is preferable and 4-38 micrometers is more preferable from a viewpoint of thickness reduction especially. 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.

  The light-shielding film formed on at least one side of the substrate contains a binder resin having a hydroxyl value of 100 (mgKOH / g) or more, carbon black, inorganic particles, and resin particles having an average particle diameter of 1 to 10 μm.

  When the binder resin having a hydroxyl value of 100 (mgKOH / g) or more contains resin particles having an average particle diameter of 1 to 10 μm, the resin particles are locally aggregated in the binder resin. It is thought that it is uniformly dispersed. As a result, the dispersion balance of the resin particles becomes suitable for the entire light shielding film, and even when used as a light shielding member, local deflection and distortion hardly occur and the stiffness can be strong.

  In this regard, a method of containing a dispersing agent in order to uniformly disperse particles in the light shielding film is also conceivable. However, in this method, the amount of the dispersing agent added to the light shielding film is sufficient to configure the light shielding film. The relative content of the material will be reduced. As a result, the performance required as a light shielding member such as matteness and slipperiness may be deteriorated.

  On the other hand, according to the light shielding member of the present invention, the dispersing agent is obtained by containing a binder resin having a hydroxyl value of 100 (mgKOH / g) or more and resin particles having an average particle diameter of 1 to 10 μm in the light shielding film. Since the resin particles can be uniformly dispersed in the light shielding film without using excessively, it is not necessary to reduce the relative content of other materials constituting the light shielding film. Therefore, according to the light shielding member of the present invention, the thickness of the light shielding film can be reduced without reducing various performances as the light shielding member, and the film can be hardly damaged.

  Examples of the binder resin having a hydroxyl value of 100 (mgKOH / g) or more include poly (meth) acrylic acid resins, polyester resins, polyvinyl acetate resins, polyvinyl chloride, polyvinyl butyral resins, cellulose resins, polystyrene / polybutadiene resins. , 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 And thermoplastic resins such as urea-based resins and diallyl phthalate-based resins, and thermosetting resins. These can be used alone or in combination.

  The hydroxyl value of binder resin shall be 100 (mgKOH / g) or more. By setting the hydroxyl value of the binder resin to 100 (mgKOH / g) or more, as described above, the resin particles having an average particle diameter of 1 to 10 μm are uniformly dispersed in the light shielding film, thereby reducing the thickness of the light shielding film. However, the entire light shielding member is stiff, and the film can be hardly damaged. The hydroxyl value of the binder resin is preferably 125 (mgKOH / g) or more, and more preferably 200 (mgKOH / g) or more, from the viewpoint of further exerting stiffness. On the other hand, as an upper limit, it is preferable to set it as 250 (mgKOH / g) or less from a viewpoint of preventing that a bending stress falls and a coating film becomes weak.

  The content of the binder resin having a hydroxyl value of 100 (mgKOH / g) or more is preferably 15% by weight or more, more preferably 20% by weight or more in the light shielding film. By making the content rate of the binder resin 15% by weight or more in the light shielding film, it is possible to prevent the adhesiveness between the base material and the light shielding film from being lowered. On the other hand, the content of the binder resin in the light shielding film is preferably 50% by weight or less, more preferably 45% by weight or less, and still more preferably 40% by weight or less. By setting the content of the binder resin to 50% by weight or less in the light-shielding film, it is possible to prevent physical properties of the light-shielding film such as light shielding properties, slidability, and matte properties from being deteriorated.

  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 diameter 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 preferably 10% by weight to 50% by weight and more preferably 15% by weight to 45% by weight in the light shielding film. When the content of the light shielding film is 10% by weight or more, it is possible to prevent the light shielding property and conductivity from being deteriorated, and when the content is 50% by weight or less, the adhesiveness and scratch resistance are improved. It is possible to prevent a decrease in film strength and an increase in cost.

  The inorganic 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.

  Examples of inorganic particles include silica, magnesium aluminate metasilicate, and titanium oxide. Among these, silica is preferably used from the viewpoint of particle dispersibility, low cost, and the like. These 1 type (s) or 2 or more types can also be mixed and used.

  The average particle diameter of the inorganic 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 inorganic particles is preferably 0.5% by weight to 10% by weight in the light shielding film, and more preferably 0.5% by weight to 5% by weight. By setting the content to 0.5% by weight or more in the light shielding film, it is possible to prevent the glossiness of the surface (mirror glossiness) from increasing and the matting property from being lowered. On the other hand, by setting the content to 10% by weight or less, it is possible to prevent the inorganic particles from falling off due to the sliding of the light shielding member, or to prevent the light shielding member itself from being damaged, and to prevent a decrease in dynamic sliding property. Can do.

  In particular, when high light-shielding properties and slidability are required, the content of inorganic particles is preferably 5% by weight or less in the light-shielding film from the above range. As described above, the inorganic particles used in the present embodiment can obtain a high matte property even in a small amount. Therefore, by setting the amount to 5% by weight or less, a sufficient matte property can be obtained, and relatively, carbon black can be obtained. Thus, it becomes possible to increase the content of the resin particles described later, and it is possible to improve physical properties such as light shielding properties and slidability without reducing stiffness.

  The resin particles having an average particle diameter of 1 to 10 μm contained in the light shielding film improve the slidability of the surface of the light shielding member, reduce the frictional resistance during operation when processed into a diaphragm member, and the like. This is for improving the scratch resistance. Moreover, as described above, by using the resin particles together with a binder resin having a hydroxyl value of 100 (mgKOH / g) or more, the dispersion balance of the resin particles becomes suitable as the entire light shielding film, and it is used as a light shielding member. However, it is difficult for local deflection and distortion to occur, and it can be strong. Furthermore, since it is difficult for local deflection and distortion to occur, thermal deformation can hardly occur. The average particle diameter of the resin particles is particularly preferably 2 to 8 μm.

  Examples of such lubricants include hydrocarbon lubricants such as polyethylene wax and paraffin wax, fatty acid lubricants such as stearic acid and 12-hydroxystearic acid, amide lubricants such as oleic acid amide and erucic acid amide, and stearic acid. Examples thereof include ester lubricants such as monoglycerides, alcohol lubricants, silicone resin particles, fluorine resin particles such as polytetrafluoroethylene wax, crosslinked polymethyl methacrylate particles, and crosslinked polystyrene particles. Among these, it is more preferable to use crosslinked polymethylmethacrylate particles because the stiffness of the light shielding member is particularly strong. These particles can be used alone or in combination.

  The average particle size of the resin particles is preferably larger than the average particle size of the inorganic particles, and more preferably the difference between the two is 0.5 μm or more. By making the average particle diameter of the resin particles larger than the average particle diameter of the inorganic particles, fine irregularities are formed by the inorganic particles on the irregularities of the surface formed by the resin particles. This is because if the amount is less, sufficient matteness can be obtained, and slidability can also be obtained.

  The content of the resin particles is preferably 3% by weight to 40% by weight in the light shielding film, and more preferably 5% by weight to 35% by weight. By setting the content to 3% 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 40% by weight or less, the relative content of carbon black can be increased. It is possible to prevent the light shielding property and conductivity from being lowered while obtaining stiffness.

  The content ratio of the resin particles to the binder resin is more preferably 20 to 150 parts by weight, and more preferably 30 to 90 parts by weight, with respect to 100 parts by weight of the binder resin. . With such a content ratio, the dispersion balance of the resin particles in the light shielding film is further improved while maintaining various performances as a light shielding member such as light shielding property and conductivity, and the light shielding member having better stiffness. It can be.

  If the light-shielding film formed on at least one side of the substrate does not impair the function of the present invention, a flame retardant, an antibacterial agent, a fungicide, an antioxidant, a plasticizer, a leveling agent, a flow regulator, Various additives such as an antifoaming agent and a dispersing agent can be contained.

  The thickness of the light shielding film is preferably 3 μm to 30 μm, and more preferably 5 μm to 25 μm. By setting the thickness to 3 μm or more, it is possible to prevent pinholes and the like from being generated in the light shielding film and to obtain sufficient light shielding properties. 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 embodiment has a binder resin, carbon black, inorganic particles, and an average particle diameter of 1 to 1 on one side or both sides of the base material having a hydroxyl value as described above of 100 (mgKOH / g) or more. A light shielding film coating solution containing 10 μm resin particles is applied by a conventionally known coating method such as dip coating, roll coating, bar coating, die coating, blade coating, air knife coating, etc., dried, and then heated as necessary. -It can be obtained by pressurization. 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 an optical device according to the present embodiment includes a specific light-shielding film on at least one surface of the base material. Since it retains its physical properties, it can be suitably used as a shutter and aperture member for optical devices such as high-performance single-lens reflex cameras, compact cameras, video cameras, mobile phones, projectors, and the like.

  In particular, the light-shielding film of the present embodiment contains a binder resin having a hydroxyl value of (mgKOH / g) or more and resin particles having an average particle diameter of 1 to 10 μm, and therefore contains an excessive amount of a dispersant. It is possible to uniformly disperse the resin particles without causing damage, so that the performance as a light shielding member is not hindered, and even if the thickness is reduced, the light shielding member is less likely to be damaged. it can. As a result, it is particularly preferably used for shutters, diaphragm members, and the like of camera-equipped mobile phones that have recently been required to be thin. Furthermore, since it is difficult for local deflection and distortion to occur, thermal deformation can hardly occur.

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

1. Production of light shielding member [Example 1]
A black polyethylene terephthalate film (Lumirror X30: Toray Industries, Inc.) having a thickness of 25 μm is used as a base material, and a coating solution for a light-shielding film having the following formulation is applied to both surfaces of the base material by a bar coating method, respectively, and the thickness when dried is 10 μm, respectively. Thus, the light shielding film was formed by coating and drying, and the light shielding member for optical equipment of Example 1 was produced.

<Coating solution for light shielding film of Example 1>
Polyester polyol 9.68 parts (Bernock 11-408: DIC Corporation, hydroxyl value 200 (mgKOH / g), solid content 70%)
・ Isocyanate 9.37 parts (Bernock DN980: DIC, solid content 75%)
・ 4.57 parts of carbon black (Vulcan XC-72: Cabot)
Inorganic particles (silica) 0.89 parts (TS100: Evonik Degussa Japan, average particle size 4 μm)
-Resin particles (cross-linked polymethyl methacrylate particles) 5.30 parts (Chemisnow MX-500: Soken Chemicals, average particle size 5 μm)
・ Methyl ethyl ketone 36.93 parts ・ Toluene 15.83 parts

[Example 2]
Of the coating solution for light-shielding film used in Example 1, the polyester polyol was changed to polyester polyol (Bernock J-517: DIC, hydroxyl value 140 (mgKOH / g), solid content 70%), and the amount of isocyanate added A light-shielding member for optical equipment of Example 2 was produced in the same manner as Example 1 except that was changed to 6.56 parts by weight.

[Example 3]
Of the coating solution for light shielding film used in Example 1, the polyester polyol was changed to polyester polyol (Bernock D-144-65BA: DIC, hydroxyl value 100 (mgKOH / g), solid content 65%) and added. Was made in the same manner as in Example 1 except that the amount of isocyanate added was 5.04 parts by weight, and a light-shielding member for optical equipment of Example 3 was produced.

[Example 4]
Example 1 of the coating solution for light shielding film used in Example 1 except that the resin particles were changed to resin particles (crosslinked polymethyl methacrylate particles, Chemisnow MX-150: Soken Chemical Co., Ltd., average particle size 1.5 μm). In the same manner as described above, a light shielding member for optical equipment of Example 4 was produced.

[Example 5]
Of the coating solution for the light-shielding film used in Example 1, the resin particles were changed to resin particles (cross-linked polymethyl methacrylate particles, Chemisnow MX-1000: Soken Chemical Co., Ltd., average particle diameter: 10 μm). Thus, a light shielding member for optical equipment of Example 5 was produced.

[Example 6]
Of the coating solution for light shielding film used in Example 1, the amount of acrylic polyol added was 100 parts by weight, and the amount of resin particles added was 13 parts by weight. A light shielding member for optical equipment was produced.

[Comparative Example 1]
Of the coating solution for the light-shielding film used in Example 1, the polyester polyol was changed to an acrylic polyol (Acridic A-801P: DIC, hydroxyl value 50 (mgKOH / g), solid content 50%), and the addition amount was changed. A light shielding member for optical equipment of Comparative Example 1 was produced in the same manner as in Example 1 except that the amount was 13.55 parts by weight and the amount of isocyanate added was 3.28 parts by weight.

[Comparative Example 2]
Of the coating solution for the light-shielding film used in Example 1, resin particles were changed to resin particles (crosslinked polymethyl methacrylate particles, Chemisnow MX-1500H: Soken Chemical Co., Ltd., average particle size: 15 μm). Thus, a light shielding member for optical equipment of Comparative Example 2 was produced.

[Comparative Example 3]
Of the coating solution for the light-shielding film used in Example 1, the resin particles were changed to inorganic particles (barium sulfate, BMH: Sakai Chemical Industry Co., Ltd., average particle size 2.5 μm) in the same manner as in Example 1, The light shielding member for optical equipment of Comparative Example 3 was produced.

2. Evaluation About the light-shielding member for optical apparatuses obtained in Examples 1-6 and Comparative Examples 1-3 as mentioned above, the physical property was evaluated by the following method. The results are shown in Table 1.

(1) Light shielding properties The light shielding members for optical devices obtained in Examples 1 to 6 and Comparative Examples 1 to 3 were optically measured using an optical densitometer (TD-904: Gretag Macbeth) based on JIS K7651: 1988. Concentration was measured. The case where the optical density exceeded 4.0 and became the density of the non-measurable region was indicated as “◯”, and the case where it was 4.0 or less was indicated as “X”. Note that a UV filter was used for the measurement. The measurement results are shown in Table 1.

(2) Matting property The glossiness (mirror glossiness) (%) of the surface of the light shielding member for optical equipment obtained in Examples 1 to 6 and Comparative Examples 1 to 3 was measured based on JIS Z8741: 1997. . The case where the glossiness was less than 10 (%) was “◯”, and the case where the glossiness was 10 (%) or more was assigned “X”. The measurement results are shown in Table 1.

(3) Sliding property The light-shielding member for optical equipment obtained in Examples 1 to 6 and Comparative Examples 1 to 3 was subjected to a load of 200 (g) and a speed of 100 (mm / min) based on JIS K7125: 1999. The static friction coefficient (μs) and the dynamic friction coefficient (μk) were measured. The thing with a static friction coefficient (microsecond) of less than 0.35 was set to "(circle)", and 0.35 or more was set to "x". In addition, a coefficient of dynamic friction (μk) of less than 0.30 was “◯”, and a coefficient of 0.30 or more was “x”. The measurement results are shown in Table 1.

(4) Strength of Koshi Samples of Examples 1 to 6 and Comparative Examples 1 to 3 having a width of 1.5 cm and a length of 20 cm from the light shielding members for optical devices obtained in Examples 1 to 6 and Comparative Examples 1 to 3 The sample is rounded twice in the length direction to form a cylinder, and the sample is present on the outermost surface of the cylindrical sample with polyester tape (Nichiban Co., Ltd.) so that the sample does not overlap three times. At the position where the end side is the center, the width 1.5 cm and the length 1.8 cm are bonded, the width (height) 1.5 cm, and the cylindrical examples 1 to 6 and the comparative examples 1 to 3 having a diameter of about 3.2 cm. A sample was made.

  Next, as shown in FIG. 1, the measuring unit 3 is a commercially available electronic balance (BX3200D: Shimadzu Corporation) and the upper fixing unit 2 and the gap between the measuring unit 3 and the upper fixing unit is 2 cm. A measuring device 10 was prepared. In the gap between the measuring unit 3 and the upper fixing unit 2 of the measuring apparatus 10, the cylindrical samples 1 to 6 having a diameter of about 3.2 cm and the samples 1 of the comparative examples 1 to 3 are placed on the cylindrical side surface. Was placed in contact with the measuring unit 3 and the upper fixing unit 2 of the measuring device 10, and the weighing amount of the electronic balance of the measuring unit 3 after 10 seconds due to the elastic force of the sample 1 was measured. As a result of measurement, a case where the weighing amount was 1 g or more was designated as “◎”, a case where the weight was 0.7 g or more but less than 1 g was designated as “◯”, and a case where the weight was less than 0.7 g was designated as “X”. . The measurement results are shown in Table 1.

(5) Durability Using the light-shielding member for optical equipment obtained in Examples 1 to 6 and Comparative Examples 1 to 3 as a diaphragm member of the camera, the optical-shading member for optical equipment is deformed or damaged by operating 5000 times. The presence or absence was confirmed visually. The case where there was no deformation or breakage was designated as “Δ”, and the case where there was deformation or breakage was designated as “X”. In addition, for those that were not deformed or damaged, operate again 20,000 times, and when confirmed visually later, “○” indicates that there was no deformation or breakage, and further operated 25,000 times. Even when visually confirmed, there was no deformation or breakage, and “◎” was given. The measurement results are shown in Table 1.

(6) Thermal deformation A light-shielding member for an optical device was prepared in which the light-shielding films of Examples 1 to 6 and Comparative Examples 1 to 3 were provided on one surface of the substrate. It was cut into 10 cm × 10 cm in length and width and allowed to stand in an environment at 80 ° C. for 5 minutes, and the curl amount at the end was measured. The case where the total of the four corners of the curl amount was 0 mm or more and less than 30 mm was “◯”, and the case where it was 30 mm or more was “x”. The measurement results are shown in Table 1.

(7) Adhesiveness The adhesiveness between the light-shielding film and the base material of the light-shielding member for optical equipment obtained in Experimental Examples 1 to 6 and Comparative Examples 1 to 3 is changed to the cross-cut tape method in JIS 5600-5-6. Based on measurement and evaluation. The case where the surface texture of the cross section was peeled off by 10% or more was indicated as “X”, the case where it was 5% or more and less than 10% was indicated as “Δ”, and the case where it was less than 5% was indicated as “◯”.

  As can be seen from the results in Table 1, the light shielding member for optical equipment obtained in Examples 1 to 6 includes a base material made of a synthetic resin film and a light shielding film formed on at least one side of the base material. Since the light-shielding film contains a binder resin having a hydroxyl value of 100 (mgKOH / g) or more, carbon black, inorganic particles, and resin particles having an average particle diameter of 1 to 10 μm, While exhibiting performance as a light-shielding member such as light-shielding and matte properties, it can be strong even if it is thinned, and because it has excellent durability, it is difficult to cause damage to films etc. We were able to.

  In particular, since the light shielding members for optical devices of Examples 1, 2, 4, and 5 had a hydroxyl value of the binder resin of 125 (mgKOH / g) or more, the strength of the stiffness was particularly high. Since the light shielding members for optical devices of Examples 1, 4, and 5 have a hydroxyl value of the binder resin of 200 (mgKOH / g) or more, the stiffness is particularly high and the durability is particularly high. It was.

  On the other hand, since the light shielding member for optical equipment of Comparative Example 1 used a binder resin having a hydroxyl value of less than 100 (mgKOH / g), the fine particles were not uniformly dispersed in the light shielding film, and the stiffness was weak. Moreover, this also made the durability poor.

  Moreover, since the light shielding member for optical equipment of Comparative Example 2 used resin particles having an average particle diameter exceeding 10 μm, the fine particles were not uniformly dispersed in the light shielding film, and the stiffness was weak. Moreover, this also made the durability poor.

  Moreover, since the light shielding member for optical equipment of Comparative Example 3 used inorganic particles instead of resin particles, the fine particles were not uniformly dispersed in the light shielding film, and the stiffness was weak. Moreover, this also made the durability poor.

  In the light-shielding member for optical equipment obtained in Examples 1 to 6, the light-shielding film has a binder resin, carbon black, inorganic particles, and an average particle diameter of 1 to 10 μm whose hydroxyl value is 100 (mgKOH / g) or more. The resin particles can be uniformly dispersed in the light-shielding film, and even if the light-shielding film is provided on one side of the substrate as a light-shielding member, the resin particles can be uniformly dispersed in the light-shielding film. Therefore, it was possible to prevent the occurrence of deflection and strain and thermal deformation.

  Since the light shielding member for optical equipment obtained in Comparative Example 1 has a high pigment ratio in the light shielding film, it is difficult to cause thermal deformation due to the binder resin. However, since the pigment ratio is high and the resin particles are not uniformly dispersed, the adhesion to the substrate is poor.

  The light shielding member for optical equipment obtained in Comparative Examples 2 and 3 has the same pigment ratio in the light shielding film as the light shielding member for optical equipment obtained in Example 1, but has an average particle diameter of 1 to 10 μm. In other words, the resin particles were not uniformly dispersed in the coating film, resulting in local deflection / strain and thermal deformation. Further, the adhesion with the substrate was inferior to that of Example 1.

DESCRIPTION OF SYMBOLS 1 ... Optical apparatus light-shielding member 2 ... Upper fixed part 3 ... Measuring part 10 ... Measuring apparatus

Claims (3)

A light-shielding member for an optical device comprising a base material made of a synthetic resin film and a light-shielding film formed on at least one surface of the base material,
The light-shielding film contains a binder resin having a hydroxyl value of 100 (mgKOH / g) or more, carbon black, inorganic particles, and resin particles having an average particle diameter of 1 to 10 μm. Element. The light-shielding member for optical equipment according to claim 1,
The light shielding member for optical equipment, wherein the resin particles are crosslinked polymethyl methacrylate particles. The light-shielding member for an optical device according to claim 1 or 2,
A light-shielding member for optical equipment, wherein 20 to 150 parts by weight of the resin particles are contained with respect to 100 parts by weight of the binder resin.

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