TWI839324B - Light-shielding sliding film, light-shielding sliding member, and resin composition for light-shielding sliding film - Google Patents

Abstract

Provided are a light-shielding sliding film that has excellent coating strength and abrasion resistance, a light-shielding sliding member, and the like. On at least one surfaces (11a, 11b) of a substrate (11), a light-shielding sliding film (21) comprising urethane-based binder resin, carbon black and particulate wax is disposed. The urethane-based binder resin is a cured product of polyol and poisocyanate curing agent, and the blending ratio of the polyol and the poisocyanate curing agent in terms of the isocyanate group of the isocyanate to the hydroxyl group of the polyol is 1 : 1.21 to 1 : 1.40. Preferably, the light-shielding sliding film (21) is substantially free of inorganic fillers having an average particle size D50 of 3.0 μm or more and/ or resin beads having an average particle size D50 of 3.0 μm or more.

Description

Light-shielding sliding film, light-shielding sliding member, and resin composition for light-shielding sliding film

The present invention relates to a light-shielding sliding film, a light-shielding sliding member and a resin composition for the light-shielding sliding film.

In the shutter and aperture components of various optical devices such as SLR cameras, compact cameras, and video cameras, components with light-shielding properties are used from the viewpoint of preventing halo or ghosting caused by external light. Furthermore, in these light-shielding components, good slip properties and low gloss are also required in terms of their usage.

In addition, in the past, as shutters and aperture components of various optical devices, metal films coated with black paint were used. However, in recent years, there has been a study on replacing them with lightweight plastic materials.

As such a non-metallic light-shielding member, the present applicant has proposed a light-shielding member for optical devices in which a light-shielding film containing a particulate lubricant such as a binder resin, carbon black, polyethylene wax, and fine particles with an oil absorption of 250 (g/100g) or more is formed on a substrate composed of a synthetic resin film (see Patent Document 1). In addition, the present applicant has proposed a light-shielding member for optical devices in which a light-shielding film containing a specific amount of a binder resin, carbon black, a particulate lubricant, and fine particles is formed on a film substrate (see Patent Document 2).

On the other hand, as a light-shielding component with high blackness and coating strength, the applicant has proposed a light-shielding component for optical devices, in which a light-shielding layer containing a binder resin and black particles is provided on the roughened surface of a removable substrate (see Patent Document 3). [Prior Art Document] [Patent Document]

[Patent Document 1] International Publication No. 2006/016555 [Patent Document 2] Japanese Patent Publication No. 2011-123255 [Patent Document 3] Japanese Patent Publication No. 2012-088499

In recent years, light-shielding sliding films are required to have not only sliding properties but also excellent wear resistance (durability). However, the light-shielding components for optical devices described in Patent Documents 1 and 2 still have room for improvement in wear resistance. In addition, since these contain huge and hard microparticles such as silicon dioxide, there is a problem that the microparticles are easy to fall off during sliding. Furthermore, when the adhesive resin falls off or is damaged during sliding, the huge and hard microparticles will be exposed on the surface of the light-shielding film. Therefore, in shutter or aperture components, a structure is usually adopted in which two or more light-shielding sliding films (light-shielding films) are arranged opposite to each other and slide with their surfaces in contact with each other. At this time, the huge and hard particles exposed on the surface of one or both light-shielding films will damage the light-shielding sliding film (light-shielding film) on the opposite surface, which may also cause the durability of the light-shielding sliding film on the opposite surface to deteriorate rapidly.

On the other hand, Patent Document 3 requires the use of a roughened substrate film, which has poor versatility. In addition, Patent Document 3 is directed to light-shielding components with high blackness and coating strength, and does not take into account the high sliding properties and wear resistance required in sliding components such as shutters or aperture components of various optical devices.

The present invention is made in view of the above-mentioned subject. That is, the purpose of the present invention is to provide a light-shielding sliding film with improved coating strength and wear resistance, a light-shielding sliding component using the same, and a resin composition for the light-shielding sliding film that can be used therefor.

The inventors of the present invention have made great efforts to study and research to solve the above problems. As a result, they found that the above problems can be solved by combining a specific urethane adhesive resin, carbon black and granular wax, thus completing the present invention.

That is, the present invention provides the specific aspects shown in the following (1) to (11).

(1) A light-shielding sliding film characterized by comprising at least a polyol and a polyisocyanate curing agent, a urethane adhesive resin, carbon black and a granular wax, wherein the polyol and the polyisocyanate curing agent are mixed in a ratio of 1.21 to 1.40, based on the ratio of the NCO group of the polyisocyanate curing agent to the OH group of the polyol (NCO/OH ratio).

(2) The light-shielding sliding film of (1) above does not substantially contain inorganic fillers having an average particle size _D50 of 3.0 μm or more and/or resin beads having an average particle size _D50 of 3.0 μm or more.

(3) The light-shielding sliding film as described in (1) or (2) above, wherein the film contains 60 to 85% by mass of the aforementioned urethane adhesive resin, calculated as solid content.

(4) A light-shielding sliding film as described in any one of (1) to (3) above, which contains 7.5 to 18.0% by mass of the aforementioned carbon black in terms of solid content.

(5) The light-shielding sliding film according to any one of (1) to (4) above, wherein the carbon black has an average particle size D ₅₀ of 0.01 to 1.0 μm.

(6) A light-shielding sliding film as described in any one of (1) to (5) above, wherein the film contains 7.5 to 18.0% by mass of the aforementioned particulate wax in terms of solid content.

(7) The light-shielding sliding film according to any one of (1) to (6) above, wherein the particulate wax has an average particle size D ₅₀ of 2 to 18 μm.

(8) A light-shielding sliding film as described in any one of (1) to (7) above, having an optical density (OD) of 5.4 to 6.0.

(9) A light-shielding sliding film as described in any one of (1) to (8) above, having a thickness of not less than 0.5 μm and not more than 30 μm.

(10) A light-shielding sliding member, which comprises at least a substrate and a light-shielding sliding film as described in any one of (1) to (9) above, disposed on at least one surface of the substrate.

(11) A resin composition for a light-shielding sliding film, characterized by containing at least a prepolymer of a polyol and a polyisocyanate curing agent, carbon black, a granular wax, and a solvent, wherein the prepolymer is a mixture of the polyol and the polyisocyanate curing agent, and the ratio of the NCO group of the polyisocyanate curing agent to the OH group of the polyol (NCO/OH ratio) is 1.21 to 1.40.

According to the present invention, a light-shielding sliding film and a light-shielding sliding member with excellent coating strength and wear resistance can be provided. In the light-shielding sliding film, etc., huge and hard particles such as silicon dioxide are not essential components, so the content ratio of resin components, carbon black and/or granular wax can be relatively increased. That is, according to the present invention, the degree of design freedom can be increased, and the dispersibility, film-forming properties, operability, etc. during manufacturing can also be improved.

The following is a detailed description of the implementation of the present invention with reference to the drawings. Furthermore, the positional relationship of up, down, left, right, etc., unless otherwise specified, is based on the positional relationship shown in the drawings. Furthermore, the dimensional ratio of the drawings is not limited to the ratio shown in the drawings. However, the following implementation forms are examples for illustrating the present invention, and the present invention is not limited to them and can be implemented with any changes within the scope of the gist. Furthermore, in this specification, the expression of a numerical range such as "1~100" refers to the one that includes both the upper limit "1" and the lower limit "100". Moreover, the expression of other numerical ranges is the same.

FIG1 is a cross-sectional view schematically showing the important parts of the light-shielding sliding member 100 and the light-shielding sliding film 21 of the first embodiment of the present invention. The light-shielding sliding member 100 has a sheet-like substrate 11 and a light-shielding sliding film 21 disposed on at least one surface of the substrate 11. In this embodiment, the light-shielding sliding film 21 is disposed on two locations of the main surface 11a of the substrate 11 and the other main surface 11b.

Here, in this specification, "arranged on the surface of the substrate" means not only a state where the light-shielding sliding film 21 is directly placed on the surface of the substrate 11 (e.g., the main surface 11a or the main surface 11b) as in the present embodiment, but also includes a state where any layer (e.g., a primer layer, a bonding layer, etc.) exists between the surface of the substrate 11 and the light-shielding sliding film 21. In addition, in the present embodiment, the light-shielding sliding film 21 is arranged on both surfaces (the main surface 11a and the main surface 11b) of the substrate 11, but of course, the light-shielding sliding film 21 may be arranged on only one surface (the main surface 11a or the main surface 11b) of the sheet-like substrate 11. By providing the light-shielding sliding films 21 on both sides of the substrate 11, the operability of the light-shielding sliding member 100 tends to be improved.

The type of the substrate 11 is not particularly limited as long as it can support the light-shielding sliding film 21. Specific examples include paper, synthetic paper, metal sheets, alloy sheets, metal foils, synthetic resin films, and laminates thereof, but are not particularly limited thereto. Furthermore, the substrate 11 may or may not be adhesive to the light-shielding sliding film 21. The substrate 11 that is not adhesive to the light-shielding sliding film 21 can function as a release film. From the perspective of dimensional stability, mechanical strength, and light weight, it is preferred to use a synthetic resin film.

Specific examples of synthetic resin films include polyester films, ABS (acrylonitrile-butadiene-styrene) films, polyimide films, polystyrene films, polycarbonate films, etc. In addition, acrylic, polyolefin, cellulose, polysulfone, polyphenylene sulfide, polyethersulfone, and polyetheretherketone films can also be used. Among these, polyester films are particularly suitable for use as the substrate 11. In particular, uniaxial or biaxially stretched films, especially biaxially stretched polyester films, are particularly preferred due to their excellent mechanical strength and dimensional stability. In addition, for heat-resistant applications, uniaxially or biaxially stretched polyimide films are particularly preferred.

The appearance of the substrate 11 can be any of transparent, translucent, and opaque, without any particular limitation. For example, a foamed synthetic resin film such as a foamed polyester film, or a synthetic resin film containing a black pigment such as carbon black or other pigments can also be used. When a thinner and higher light-shielding property is required, the optical density of the entire light-shielding sliding member 100 can be enhanced by using a substrate 11 with a high optical density such as a black polyester film.

The thickness of the substrate 11 can be appropriately set according to the required performance and purpose, and there is no special limitation. Generally speaking, it is 1μm or more and less than 250μm. From the perspective of the strength or rigidity of the light-shielding sliding member 100, the thickness of the substrate 11 is preferably 36μm or more and less than 250μm. On the other hand, from the perspective of lightweight and thin film, the thickness of the substrate 11 is preferably 1μm or more and 50μm or less; more preferably 1μm or more and 25μm or less, and even more preferably 4μm or more and 10μm or less; particularly preferably 5μm or more and 7μm or less. Furthermore, from the perspective of improving the adhesion with the light-shielding sliding film 21, the surface of the substrate 11 can also be subjected to various known surface treatments such as anchoring treatment or corona treatment as needed.

The light-shielding sliding film 21 contains at least a urethane adhesive resin, carbon black and granular wax. The urethane adhesive resin used here is a cured product of a polyol and a polyisocyanate curing agent, and is a urethane resin in which the ratio of the NCO group of the polyisocyanate curing agent to the OH group of the polyol (NCO/OH ratio) is 1.21 to 1.40. The components are described in detail below.

Polyols constituting the urethane adhesive resin may be various well-known polyols such as acrylic polyols, polyester polyols, epoxy polyols, and polyether polyols, and the types thereof are not particularly limited. Among these, acrylic polyols, polyester polyols, and polyether polyols are preferred from the viewpoints of film strength, slip, and wear resistance; acrylic polyols and polyester polyols are more preferred. These polyols preferably have two or more OH groups at the molecular ends, more preferably three or more, and even more preferably four or more. The OH groups crosslink with the polyisocyanate hardener to form a three-dimensional network structure, so it is preferred that the molecule contain more OH groups. In particular, when the OH group is located at the molecular end, the reactivity with the hardener is high, so it is preferred. In addition, from the perspective of obtaining high dispersibility and high durability, the polyol may also have polar groups such as carboxylic acid groups, sulfonic acid groups, phosphoric acid groups, etc. as needed. These can be used alone or in combination of two or more.

Examples of the polyisocyanate curing agent constituting the urethane adhesive resin include isocyanates such as toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, xylene diisocyanate, naphthalene-1,5-diisocyanate, o-toluidine diisocyanate, isophorone diisocyanate, and triphenylmethane triisocyanate; products of these isocyanates and polyols; and polyisocyanates formed by condensation of isocyanates, but are not particularly limited to these. Commercially available polyisocyanate curing agents include Burnock D-750, Burnock DN-950, Burnock DN-980 (all trade names, manufactured by Tosoh Co., Ltd.); Coronate L, Coronate HL, Coronate 2030, Coronate 2031, Millionate MR, Millionate MTL (all trade names, manufactured by Tosoh Co., Ltd.); Takenate D-102, Takenate D-110N, Takenate D-200, Takenate D-202 (all trade names, manufactured by Mitsui Chemicals Co., Ltd.); Desmodur L, Desmodur IL, Desmodur N, Desmodur HL (all trade names, manufactured by Sumitomo Bayer Urethane Co., Ltd.), etc., which are easily available in the market. These polyols can be used alone or in combination of two or more. These can be used alone or in combination of two or more.

The above-mentioned blending ratio of polyol and polyisocyanate hardener, the ratio of NCO group of polyisocyanate hardener to OH group of polyol (NCO/OH ratio), must be 1.21~1.40. From the perspective of film strength, slip, wear resistance, film formation, operability, etc., the preferred NCO/OH ratio is 1.23~1.39, and the more preferred NCO/OH ratio is 1.25~1.38. The urethane adhesive resin formed by such a blending ratio not only has excellent operability, but also has an excellent balance of film strength, slip, and wear resistance.

The content of the urethane adhesive resin in the light-shielding sliding film 21 is not particularly limited. It is preferably 60-85% by mass, more preferably 67-83% by mass, and even more preferably 70-80% by mass, relative to the total amount of the light-shielding sliding film 21, in terms of solid content. By making the content of the urethane adhesive resin within the above-mentioned preferred range, it is easy to obtain a light-shielding sliding film 21 with highly balanced physical properties such as film strength, sliding properties, and wear resistance. In particular, by making the content of the urethane adhesive resin higher, it is easy to improve the dispersibility of carbon black or particulate wax, the film-forming properties of the light-shielding sliding film 21, film strength, operability, adhesion, sliding properties, wear resistance, etc.

Furthermore, the light-shielding sliding film 21 may further contain a resin component other than the above-mentioned urethane adhesive resin. Such arbitrary resin components include poly(meth)acrylic resins, polyester resins, polyvinyl acetate resins, polyvinyl chloride resins, polyvinyl butyral resins, cellulose resins, polystyrene/polybutadiene resins, polyurethane resins, alkyd resins, acrylic resins, unsaturated polyester resins, epoxy resins, etc. Thermoplastic resins or thermosetting resins such as ester resins, epoxy resins, acrylic epoxy resins, urethane acrylate resins, polyester acrylate resins, polyether acrylate resins, phenol resins, melamine resins, urea resins, diallyl phthalate resins, etc. may be used, but are not particularly limited thereto. In addition, thermoplastic elastomers, thermosetting elastomers, ultraviolet curing resins, electron beam curing resins, etc. may also be used. These may be used alone or in combination of two or more.

The carbon black contained in the light-shielding sliding film 21 is used to color the light-shielding sliding film 21 black to impart light-shielding properties. Carbon black produced by various known production methods such as oil furnace black, lamp black, channel black, natural gas furnace black, acetylene black, thermal black, and Ketjen black can be used without particular limitation. In the present embodiment, as the carbon black contained in the light-shielding sliding film 21, conductive carbon black is preferred from the viewpoint of imparting conductivity to the light-shielding sliding film 21 to prevent static charging. Carbon black has a long history, and various grades of carbon black single substances and carbon black dispersions are commercially available, for example, from Mitsubishi Chemical Co., Ltd., Asahi Carbon Co., Ltd., Tokai Carbon Co., Ltd., Mikoku Color Co., Ltd., Restino Color Co., Ltd., Cabot Corporation, and Degussa Corporation. You can select an appropriate one from them according to the required performance or purpose. These may be used alone or in combination of two or more.

The particle size of the carbon black used here can be appropriately set according to the required performance, etc., and is not particularly limited. From the viewpoint of making the surface gloss of the light-shielding sliding film 21 low and improving the sliding property, the average particle size _D50 of the carbon black is preferably 0.01~1.0μm, more preferably 0.05~0.9μm, and even more preferably 0.08~0.8μm. In addition, the average particle size in this specification means the median diameter ( _D50 ) measured by a laser diffraction particle size distribution measuring device (for example, SALD-7000 of Shimadzu Corporation). In addition, the 50% volume particle size ( _D50 ) means the particle size when the amount of particles in the particle distribution is calculated cumulatively from the small particle size side to become 50%.

The content of carbon black in the light-shielding sliding film 21 is not particularly limited, but is preferably 7.5 to 18.0% by mass, more preferably 8.5 to 16.5% by mass, and even more preferably 10.0 to 15.0% by mass, relative to the total amount of the light-shielding sliding film 21, in terms of solid content. By making the content of carbon black within the above preferred range, it is easy to obtain a light-shielding sliding film 21 with excellent light-shielding properties. In addition, by keeping the content of urethane adhesive resin or granular wax relatively high, it is easy to improve the dispersibility of carbon black or granular wax, the film-forming property, film strength, workability, adhesion, sliding property, wear resistance, etc. of the light-shielding sliding film 21.

Furthermore, the light-shielding sliding film 21 may further contain a black pigment or dye other than the above-mentioned carbon black. Examples of such black pigments as an arbitrary component include black resin particles, titanium black, magnetite-based black, copper/iron/manganese-based black, titanium black, etc., but are not particularly limited to these. These may be used alone or in combination of two or more. Furthermore, examples of the dyes as an arbitrary component include known dyes of black, blue, green, yellow, red, etc. Specifically, the compounds include diarylmethane series, triarylmethane series, thiazole series, methine series such as merocyanidin and pyrazolone methine series, azomethine series such as indoaniline, acetophenone methine, pyrazolyl methine, imidazole methine, imidazolyl methine, xanthene series, oxazine series, cyanomethylene series such as dicyanostyrene and tricyanostyrene, thiazine series, azine series, acridine series, phenylazo series, azo series such as pyridone azo, thiophene azo, isothiazole azo, pyrrole azo, imidazole azo, thiadiazole azo, triazole azo, bis azo, spiropyran series, indoline spiropyran series, fluorescent yellow matrix series, naphthoquinone series, anthraquinone series, quinoline yellow series, etc., but the compounds are not particularly limited to these. These may be used alone or in combination of two or more. Furthermore, dyes may be used to control the color tone of the light-shielding sliding film 21.

When the light-shielding sliding film 21 further contains black pigments other than the above-mentioned carbon black, the content of all black pigments (including carbon black) in the light-shielding sliding film 21 is not particularly limited. From the viewpoints of dispersibility, film-forming properties of the light-shielding sliding film 21, operability, adhesion, slippage, matteness, abrasion resistance, etc., it is preferably 7.5 mass% to 25 mass% in terms of solid content (phr) relative to all resin components (excluding particulate wax) contained in the light-shielding sliding film 21; more preferably 8.5 mass% to 23 mass%; and even more preferably 10 mass% to 20 mass%.

The particulate wax contained in the light-shielding sliding film 21 is a room temperature solid compound with a molecular weight of 200 to 10,000 and a melting point of 40 to 160°C, and is used to improve the slipperiness (slipperiness) of the surface of the light-shielding sliding film 21 and impart matte properties. The light-shielding sliding film 21 contains particulate wax, so that the frictional resistance during sliding is reduced and the scratch resistance of the surface is improved. As the particulate wax, various well-known waxes can be used. Specific examples of waxes include mineral waxes such as brown carbon wax and ground wax; petroleum waxes such as stone wax and microcrystalline wax; and synthetic waxes, but are not particularly limited to these. Among these, petroleum waxes and synthetic waxes are particularly preferred; more preferred is synthetic wax. These waxes may be used alone or in combination of two or more.

Synthetic waxes include polyolefin waxes such as polyethylene wax and polypropylene wax; metallocene waxes such as metallocene polyethylene and metallocene polypropylene; fatty acid waxes such as stearic acid and 12-hydroxystearic acid; amide waxes such as stearamide, oleamide, erucamide; ester waxes such as butyl stearate and monoglyceride stearate; Fischer-Tropsch wax; castor wax; saponified products thereof; oxidized products thereof; fluorinated modified products thereof, but are not particularly limited to these. Among these, polyolefin waxes and metallocene waxes are particularly preferred. Furthermore, the acid value (mgKOH/g) of the synthetic wax is preferably 0-15, and the saponification value (mgKOH/g) is preferably 0-15. These may be used alone or in combination of two or more.

The particle size of the granular wax can be appropriately set according to the required performance, etc., and is not particularly limited. From the viewpoint of maintaining the surface gloss of the light-shielding sliding film 21 at a low level and improving the sliding property, the average particle size D ₅₀ of the granular wax is preferably larger than that of carbon black, and specifically, preferably 2 to 18 μm, more preferably 3 to 17 μm, and even more preferably 4 to 16 μm.

Commercially available granular waxes having such an average particle size D ₅₀ include Ceridust 3620 (average particle size D ₅₀ : 7.5-9.5 μm), Ceridust 3610 (average particle size D 50 : 4.5-5.5 μm), Ceridust 3715 (average particle size D ₅₀ : 7.5-9.5 μm), Ceridust 6050M (average particle size D ₅₀ : 6.5-12.5 μm), Ceridust 9610F (average particle size D ₅₀ : 7.5-9.5 μm), Ceridust 9630F (average particle size D 50 : 7.0-9.5 μm), Ceridust 3920F ...3920F (average particle size D 50 : 7.5-9.5 μm), Ceridust 3920F (average particle size D ₅₀ : 7.5-9.5 μm), Ceridust 3920M (average particle size D ₅₀ : 7.5-9.5 μm), Ceridust 3920M (average particle size D ₅₀ : 7.5-9.5 μm), Ceridust 3920M (average ：5.0~7.0μm）、Ceridust 3940F(average particle size D ₅₀ ：12~15μm）、Ceridust 9615A(average particle size D ₅₀ ：5.5~7.5μm）、Ceridust 3910(average particle size D ₅₀ ：5.5~7.5μm）、Ceridust 5551(average particle size D ₅₀ ：7.5~9.5μm）、Ceridust 2051(average particle size D ₅₀ ：5.5~7.5μm）、Ceridust 8020(average particle size D ₅₀ ：7.0~9.5μm）、Ceridust 8330TP(average particle size D ₅₀ ：4.5~6.5μm）、Ceridust 8091TP(average particle size D ₅₀ : 8μm), Ceridust 9202F (average particle size D ₅₀ : 2.0-6.0μm), Ceridust 9205F (average particle size D ₅₀ : 5.5-10.5μm), etc. (all of the above are trade names, manufactured by Clariant Chemicals Co., Ltd.) and are easily available in the market.

The content ratio of the particulate wax in the light-shielding sliding film 21 is not particularly limited, but is preferably 7.5 to 18.0% by mass, more preferably 8.5 to 16.5% by mass, and even more preferably 10.0 to 15.0% by mass, relative to the total amount of the light-shielding sliding film 21, in terms of solid content. By making the content of the particulate wax within the above preferred range, it is easy to obtain a light-shielding sliding film 21 with excellent sliding properties. In addition, by keeping the content of the urethane adhesive resin or carbon black relatively high, it is easy to improve the dispersibility of carbon black, the film-forming property of the light-shielding sliding film 21, the film strength, light-shielding property, workability, adhesion, sliding property, wear resistance, etc.

Furthermore, the light-shielding sliding film 21 may also contain a matting agent (matting agent). By containing a matting agent, the glossiness (mirror glossiness) of the surface of the light-shielding sliding film 21 can be reduced, and the sliding property or light-shielding property can be improved. The matting agent can be a well-known one. Specifically, organic microparticles such as cross-linked acrylic beads; inorganic microparticles such as silica, talc, magnesium aluminum metasilicate, titanium oxide, etc. can be listed, but it is not particularly limited to these. Among these, silica or talc is particularly preferred from the perspective of dispersibility or cost. These can be used alone or in combination of two or more.

On the other hand, the light-shielding sliding film 21 preferably contains substantially no large and hard microparticles other than the above-mentioned urethane adhesive resin, carbon black and granular wax. Such large and hard microparticles include inorganic fillers with an average particle size _D50 of 3.0 μm or more, preferably 4.0 μm or more, and more preferably 5.0 μm or more; and resin beads with an average particle size _D50 of 3.0 μm or more, preferably 4.0 μm or more, and more preferably 5.0 μm or more. Such large and hard microparticles can be mixed into the light-shielding film as a matting agent, lubricant, and a material for improving sliding properties in the field of the present invention. More specifically, solid lubricants in the form of particles such as silica particles, talc particles, magnesium aluminum metasilicate, and titanium oxide; acrylic resin beads such as cross-linked polymethyl methacrylate particles; styrene resin beads such as cross-linked polystyrene particles; fluorine resin beads such as fluorine resin particles such as polyvinylidene fluoride, etc. are equivalent to this. For example, by making the light-shielding sliding film 21 substantially free of large and hard particles such as amorphous silica particles or acrylic resin beads commonly used as matting agents or lubricants in the art, there is a tendency to suppress the shedding of particles during sliding or the deterioration of the durability of the light-shielding sliding film on the opposite surface. In addition, the relative content of urethane adhesive resin, carbon black, and particulate wax in the light-shielding sliding film 21 can be high, so that the above-mentioned dispersibility, film-forming property, film strength, operability, adhesion, sliding property, wear resistance, etc. tend to be improved. Furthermore, in this specification, "substantially free" means that the content of huge and hard microparticles is 0-3% by mass relative to the total amount of the light-shielding sliding film 21, calculated as solid content, more preferably 0-1% by mass, still more preferably 0-0.5% by mass, and particularly preferably 0-0.1% by mass.

Furthermore, the light-shielding sliding film 21 may further contain other components. The other components may include conductive agents, flame retardants, antibacterial agents, mildew-proof agents, antioxidants, plasticizers, leveling agents, flow regulators, defoaming agents, dispersants, etc., but are not particularly limited to these. The content ratio of these is not particularly limited, and is generally preferably 0.01 to 5 mass % relative to the total resin components contained in the light-shielding sliding film 21, calculated as solid content.

The thickness of the light-shielding sliding film 21 can be appropriately set according to the required performance and purpose, and is not particularly limited. It is preferably greater than 0.5 μm and less than 30 μm; more preferably greater than 1 μm and less than 20 μm; and even more preferably greater than 3 μm and less than 10 μm.

Furthermore, the surface gloss of the light-shielding sliding film 21 is preferably less than 15%. When the surface gloss is low, the reflection of the incident light decreases and the light absorption tends to increase. The surface gloss of the light-shielding sliding film 21 is more preferably less than 10%. Furthermore, in this specification, the surface gloss refers to the 60-degree surface gloss (G60 surface gloss) measured according to JIS-Z8741:1997.

Furthermore, from the viewpoint of having sufficient antistatic performance, the surface resistivity of the light-shielding sliding film 21 is preferably less than 1.0×10 ¹⁰ Ω, more preferably less than 1.0×10 ⁹ Ω, and even more preferably less than 1.0×10 ⁸ Ω. In this specification, the surface resistivity is a value measured according to JIS-K6911:1995.

Furthermore, the light-shielding sliding film 21 preferably has an optical density (OD) of 5.4 to 6.0, more preferably 5.5 to 6.0, from the viewpoint of having sufficient light-shielding properties. Similarly, the light-shielding sliding member 100 preferably has an optical density (OD) of 5.4 to 6.0, more preferably 5.5 to 6.0, from the viewpoint of having sufficient light-shielding properties. In this specification, the optical density (OD) is a value measured according to JIS-K7651:1988.

The manufacturing method of the light-shielding sliding member 100 and the light-shielding sliding film 21 of the present embodiment is not particularly limited as long as the above-mentioned structure and composition can be obtained. From the viewpoint of good reproducibility, easy and low-cost manufacturing of the desired light-shielding sliding film 21, it is suitable to use a conventionally known coating method such as doctor coating, dip coating, roll coating, rod coating, die coating, blade coating, air knife coating, kiss coating, spray coating, and spin coating.

For example, a coating liquid containing a prepolymer, carbon black, and granular wax as a pre-driving agent for the urethane adhesive resin, and any other optional components as needed in a solvent can be applied to one or both sides of the substrate 11, dried, and then subjected to heat treatment or pressure treatment as needed to form a light-shielding sliding film 21 on the substrate 11. The solvent of the coating liquid used here can be water; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester solvents such as methyl acetate, ethyl acetate, and butyl acetate; ether solvents such as methyl cellulose and ethyl cellulose; alcohol solvents such as methanol, ethanol, and isopropyl alcohol; and mixed solvents thereof. In addition, a coating liquid containing only one of the above-mentioned polyol and polyisocyanate curing agent may be prepared in advance to replace the prepolymer as a precursor, and the other of these may be mixed during film formation. Furthermore, in order to improve the adhesion between the substrate 11 and the light-shielding sliding film 21, anchoring treatment or corona treatment may be performed as needed. Furthermore, an intermediate layer such as a bonding layer may be provided between the substrate 11 and the light-shielding sliding film 21 as needed.

Furthermore, in this embodiment, the light-shielding sliding member 100 is a laminated structure in which the light-shielding sliding film 21 is provided on the substrate 11, but the present invention can also be implemented in an aspect in which the substrate 11 is omitted. For example, by peeling off the substrate 11 from the light-shielding sliding member 100, a light-shielding sliding film 21 of a single-layer structure can be easily obtained.

Furthermore, the coating liquid can be effectively implemented as a resin composition that can easily and reproducibly obtain the light-shielding sliding member 100 and the light-shielding sliding film 21, as one aspect of the present invention. By using the resin composition, it can be formed into a desired shape by various known forming methods such as thermoforming, compression molding, injection molding, blow molding, transfer molding, extrusion molding, etc., and a light-shielding sliding member having a desired shape can be easily obtained. Moreover, once formed into a sheet, vacuum forming or pressure forming can also be performed.

In the light-shielding sliding member and light-shielding sliding film of the present invention, by combining a urethane adhesive resin and a granular wax with a specific NCO/OH ratio, the film strength and wear resistance are improved, even if huge and hard particles such as silica are not contained as essential components. Therefore, the problems caused by the falling off or exposure of huge and hard particles during sliding that have occurred in the past are prevented. At the same time, the defects or falling off of essential components such as urethane adhesive resins, carbon black and granular wax are also suppressed. In addition, along with the omission or reduction of the admixture of huge and hard particles such as silica, the content ratio of urethane adhesive resins, carbon black and/or granular wax can be relatively increased. It is estimated that as a result of these combined forces, a light-shielding sliding film and a light-shielding sliding member having both high sliding properties and high wear resistance can be obtained. However, the effects of the present invention are not limited to these.

As described above, the light-shielding sliding member and light-shielding sliding film of the present invention can be widely and effectively used in applications requiring sliding properties and wear resistance. In particular, the light-shielding sliding member and light-shielding sliding film of the present invention have high utilization value as high-performance light-shielding sliding materials in the fields of precision machinery, semiconductors, and optical machines, and can be particularly suitable for use as sliding members, such as shutter and aperture members, of various optical machines such as high-performance SLR cameras, compact cameras, video cameras, mobile phones, and projectors. [Examples]

The following examples and comparative examples are given to illustrate the present invention in detail, but the present invention is not limited to these examples. The present invention can adopt various conditions as long as they do not deviate from the gist of the present invention and can achieve the purpose of the present invention. In addition, unless otherwise specified, "part" means "part by mass".

[Preparation of resin composition (coating liquid)] (Preparation Example 1) A resin composition having the following blending composition was prepared (solid content concentration: 29.8% by mass). ･Urethane adhesive resin (NCO/OH ratio: 1.23) 73.6 parts by mass Acrylic polyol component (Acrydic A804: manufactured by DIC, OH value: 40, solid content: 50% by mass) Polyisocyanate hardener component (Takenate D110N: manufactured by Mitsui Chemicals, NCO value: 11.5, solid content: 75% by mass) ･Carbon black 13.2 parts by mass (Vulcan XC-72R: manufactured by Cabot Corporation, average primary particle size 30nm, aggregate particle size 0.4μm) ･Particulate wax 13.2 parts by mass (Ceridust 3620: manufactured by Clariant Chemicals, average particle size _D50 : 7.5~9.5μm) ･0.2 parts by weight of leveling agent (M-ADDITIVE, a silicone additive manufactured by Dow Corning Toray Co., Ltd.) ･Dilution solvent (a mixed solvent of MEK: toluene: butyl acetate = 4:3:3)

(Preparation Example 2) A resin composition having the following blending composition was prepared (solid content: 29.8% by mass). ･Urethane adhesive resin (NCO/OH ratio: 1.30) 73.6 parts by mass Acrylic polyol component (Acrydic A804: manufactured by DIC, OH value: 40, solid content: 50% by mass) Polyisocyanate hardener component (Takenate D110N: manufactured by Mitsui Chemicals, NCO value: 11.5, solid content: 75% by mass) ･Carbon black 13.2 parts by mass (Vulcan XC-72R: manufactured by Cabot Corporation, average primary particle size 30nm, aggregate particle size 0.4μm) ･Particulate wax 13.2 parts by mass (Ceridust 3620: manufactured by Clariant Chemicals, average particle size _D50 : 7.5~9.5μm) ･0.2 parts by weight of leveling agent (M-ADDITIVE, a silicone additive manufactured by Dow Corning Toray Co., Ltd.) ･Dilution solvent (a mixed solvent of MEK: toluene: butyl acetate = 4:3:3)

(Preparation Example 3) A resin composition having the following blending composition was prepared (solid content: 29.4 mass %). ･Urethane adhesive resin (NCO/OH ratio: 1.37) 73.6 parts by mass Acrylic polyol component (Acrydic A804: manufactured by DIC, OH value: 40, solid content: 50% by mass) Polyisocyanate hardener component (Takenate D110N: manufactured by Mitsui Chemicals, NCO value: 11.5, solid content: 75% by mass) ･Carbon black 13.2 parts by mass (Vulcan XC-72R: manufactured by Cabot Corporation, average primary particle size 30nm, aggregate particle size 0.4μm) ･Particulate wax 13.2 parts by mass (Ceridust 3620: manufactured by Clariant Chemicals, average particle size _D50 : 7.5~9.5μm) ･0.2 parts by weight of leveling agent (M-ADDITIVE, a silicone additive manufactured by Dow Corning Toray Co., Ltd.) ･Dilution solvent (a mixed solvent of MEK: toluene: butyl acetate = 4:3:3)

(Preparation Example 4) A resin composition having the following blending composition was prepared (solid content: 29.5 mass %). ･Urethane adhesive resin (NCO/OH ratio: 1.40) 73.6 parts by mass Acrylic polyol component (Acrydic A804: manufactured by DIC, OH value: 40, solid content: 50% by mass) Polyisocyanate hardener component (Takenate D110N: manufactured by Mitsui Chemicals, NCO value: 11.5, solid content: 75% by mass) ･Carbon black 13.2 parts by mass (Vulcan XC-72R: manufactured by Cabot Corporation, average primary particle size 30nm, aggregate particle size 0.4μm) ･Particulate wax 13.2 parts by mass (Ceridust 3620: manufactured by Clariant Chemicals, average particle size _D50 : 7.5~9.5μm) ･0.2 parts by weight of leveling agent (M-ADDITIVE, a silicone additive manufactured by Dow Corning Toray Co., Ltd.) ･Dilution solvent (a mixed solvent of MEK: toluene: butyl acetate = 4:3:3)

(Preparation Example 5) A resin composition having the following blending composition was prepared (solid content: 28.3 mass %). ･Urethane adhesive resin (NCO/OH ratio: 1.37) 82.0 parts by mass Acrylic polyol component (Acrydic A804: manufactured by DIC, OH value: 40, solid content: 50% by mass) Polyisocyanate hardener component (Takenate D110N: manufactured by Mitsui Chemicals, NCO value: 11.5, solid content: 75% by mass) ･Carbon black 9.0 parts by mass (Vulcan XC-72R: manufactured by Cabot Corporation, average primary particle size 30nm, aggregate particle size 0.4μm) ･Particulate wax 9.0 parts by mass (Ceridust 3620: manufactured by Clariant Chemicals, average particle size _D50 : 7.5~9.5μm) ･0.2 parts by weight of leveling agent (M-ADDITIVE, a silicone additive manufactured by Dow Corning Toray Co., Ltd.) ･Dilution solvent (a mixed solvent of MEK: toluene: butyl acetate = 4:3:3)

(Preparation Example 6) A resin composition having the following blending composition was prepared (solid content: 28.5 mass %). ･Urethane adhesive resin (NCO/OH ratio: 1.37) 65.0 parts by mass Acrylic polyol component (Acrydic A804: manufactured by DIC, OH value: 40, solid content: 50% by mass) Polyisocyanate hardener component (Takenate D110N: manufactured by Mitsui Chemicals, NCO value: 11.5, solid content: 75% by mass) ･Carbon black 17.5 parts by mass (Vulcan XC-72R: manufactured by Cabot Corporation, average primary particle size 30nm, aggregate particle size 0.4μm) ･Particulate wax 17.5 parts by mass (Ceridust 3620: manufactured by Clariant Chemicals, average particle size _D50 : 7.5~9.5μm) ･0.2 parts by weight of leveling agent (M-ADDITIVE, a silicone additive manufactured by Dow Corning Toray Co., Ltd.) ･Dilution solvent (a mixed solvent of MEK: toluene: butyl acetate = 4:3:3)

(Preparation Example 7) A resin composition having the following blending composition was prepared (solid content: 28.2 mass %). ･Urethane adhesive resin (NCO/OH ratio: 1.37) 77.7 parts by mass Acrylic polyol component (Acrydic A804: manufactured by DIC, OH value: 40, solid content: 50% by mass) Polyisocyanate hardener component (Takenate D110N: manufactured by Mitsui Chemicals, NCO value: 11.5, solid content: 75% by mass) ･Carbon black 8.3 parts by mass (Vulcan XC-72R: manufactured by Cabot Corporation, average primary particle size 30nm, aggregate particle size 0.4μm) ･Particulate wax 14.0 parts by mass (Ceridust 3620: manufactured by Clariant Chemicals, average particle size _D50 : 7.5~9.5μm) ･0.2 parts by weight of leveling agent (M-ADDITIVE, a silicone additive manufactured by Dow Corning Toray Co., Ltd.) ･Dilution solvent (a mixed solvent of MEK: toluene: butyl acetate = 4:3:3)

(Preparation Example 8) A resin composition having the following blending composition was prepared (solid content: 28.4 mass %). ･Urethane adhesive resin (NCO/OH ratio: 1.37) 83.2 parts by mass Acrylic polyol component (Acrydic A804: manufactured by DIC, OH value: 40, solid content: 50% by mass) Polyisocyanate hardener component (Takenate D110N: manufactured by Mitsui Chemicals, NCO value: 11.5, solid content: 75% by mass) ･Carbon black 8.4 parts by mass (Vulcan XC-72R: manufactured by Cabot Corporation, average primary particle size 30nm, aggregate particle size 0.4μm) ･Particulate wax 8.4 parts by mass (Ceridust 3620: manufactured by Clariant Chemicals, average particle size _D50 : 7.5~9.5μm) ･0.2 parts by weight of leveling agent (M-ADDITIVE, a silicone additive manufactured by Dow Corning Toray Co., Ltd.) ･Dilution solvent (a mixed solvent of MEK: toluene: butyl acetate = 4:3:3)

(Comparative Preparation Example 1) A resin composition having the following blending composition was prepared (solid content: 29.7 mass %). ･Urethane adhesive resin (NCO/OH ratio: 1.20) 72.0 parts by mass Acrylic polyol component (Acrydic A804: manufactured by DIC, OH value: 40, solid content: 50% by mass) Polyisocyanate hardener component (Takenate D110N: manufactured by Mitsui Chemicals, NCO value: 11.5, solid content: 75% by mass) ･Carbon black 12.9 parts by mass (Vulcan XC-72R: manufactured by Cabot Corporation, average primary particle size 30nm, aggregate particle size 0.4μm) ･Partial wax 12.9 parts by mass (Ceridust 3620: manufactured by Clariant Chemicals, average particle size _D50 : 7.5~9.5μm) ･Silica 2.2 parts by mass (ACEMATT TS100, Evonik Degussa Japan, average particle size 4μm) ･Leveling agent 0.2 parts by mass (polysilicone additive M-ADDITIVE: Toray Dow Corning Co., Ltd.) ･Dilution solvent (MEK: toluene: butyl acetate = 4:3:3 mixed solvent)

(Comparative Preparation Example 2) A resin composition having the following blending composition was prepared (solid content: 30.0 mass %). ･Urethane adhesive resin (NCO/OH ratio: 1.42) 72.0 parts by mass Acrylic polyol component (Acrydic A804: DIC, OH value: 40, solid content: 50% by mass) Polyisocyanate hardener component (Takenate D110N: Mitsui Chemicals, NCO value: 11.5, solid content: 75% by mass) ･Carbon black 12.9 parts by mass (Vulcan XC-72R: Cabot, average primary particle size 30nm, aggregate particle size 0.4μm) ･Partial wax 12.9 parts by mass (Ceridust 3620: Clariant Chemicals, average particle size _D50 : 7.5~9.5μm) ･Silica 2.2 parts by mass (ACEMATT TS100, Evonik Degussa Japan, average particle size 4μm) ･Leveling agent 0.2 parts by mass (polysilicone additive M-ADDITIVE: Toray Dow Corning Co., Ltd.) ･Dilution solvent (MEK: toluene: butyl acetate = 4:3:3 mixed solvent)

(Comparative Preparation Example 3) A resin composition having the following blending composition was prepared (solid content: 29.7% by mass). ･Urethane adhesive resin (NCO/OH ratio: 1.20) 73.6 parts by mass Acrylic polyol component (Acrydic A804: manufactured by DIC, OH value: 40, solid content: 50% by mass) Polyisocyanate hardener component (Takenate D110N: manufactured by Mitsui Chemicals, NCO value: 11.5, solid content: 75% by mass) ･Carbon black 13.2 parts by mass (Vulcan XC-72R: manufactured by Cabot Corporation, average primary particle size 30nm, aggregate particle size 0.4μm) ･Particulate wax 13.2 parts by mass (Ceridust 3620: manufactured by Clariant Chemicals, average particle size _D50 : 7.5~9.5μm) ･0.2 parts by weight of leveling agent (M-ADDITIVE, a silicone additive manufactured by Dow Corning Toray Co., Ltd.) ･Dilution solvent (a mixed solvent of MEK: toluene: butyl acetate = 4:3:3)

(Comparative Preparation Example 4) A resin composition having the following blending composition was prepared (solid content: 29.5 mass %). ･Urethane adhesive resin (NCO/OH ratio: 1.00) 73.6 parts by mass Acrylic polyol component (Acrydic A804: manufactured by DIC, OH value: 40, solid content: 50% by mass) Polyisocyanate hardener component (Takenate D110N: manufactured by Mitsui Chemicals, NCO value: 11.5, solid content: 75% by mass) ･Carbon black 13.2 parts by mass (Vulcan XC-72R: manufactured by Cabot Corporation, average primary particle size 30nm, aggregate particle size 0.4μm) ･Particulate wax 13.2 parts by mass (Ceridust 3620: manufactured by Clariant Chemicals, average particle size _D50 : 7.5~9.5μm) ･0.2 parts by weight of leveling agent (M-ADDITIVE, a silicone additive manufactured by Dow Corning Toray Co., Ltd.) ･Dilution solvent (a mixed solvent of MEK: toluene: butyl acetate = 4:3:3)

(Comparative Preparation Example 5) A resin composition having the following blending composition was prepared (solid content: 40.4 mass %). ･Urethane adhesive resin (NCO/OH ratio: 1.01) 72.6 parts by mass Acrylic polyol component (Acrydic A804: manufactured by DIC, OH value: 40, solid content: 50% by mass) Polyisocyanate hardener component (Takenate DN980: manufactured by Mitsui Chemicals, NCO value: 15.5, solid content: 75% by mass) ･Carbon black 13.4 parts by mass (Vulcan XC-72R: manufactured by Cabot Corporation, average primary particle size 30nm, aggregate particle size 0.4μm) ･Partial wax 9.5 parts by mass (Ceridust 3620: manufactured by Clariant Chemicals, average particle size _D50 : 7.5~9.5μm) ･Matting agent 4.5 parts by mass (ACEMATT TS100, Evonik Degussa Japan, average particle size 4μm) ･Leveling agent 0.2 parts by mass (polysilicone additive M-ADDITIVE: Toray Dow Corning Co., Ltd.) ･Dilution solvent (MEK: toluene: butyl acetate = 4:3:3 mixed solvent)

(Examples 1 to 8, and Comparative Examples 1 to 5) The resin compositions of the above-mentioned Preparation Examples 1 to 8 and Comparative Examples 1 to 5 are used to prepare light-shielding sliding components of Examples 1 to 8 and Comparative Examples 1 to 5, respectively. Here, the above-mentioned resin compositions are applied to both sides of a 6μm thick polyester film (K200: Mitsubishi Chemical Polyester Co., Ltd.) as a substrate by a rod coating method in such a manner that the thickness after drying becomes 3μm, and then dried to form a light-shielding sliding film with a thickness of 3μm on both sides of the substrate, thereby preparing light-shielding sliding components. The respective blending compositions are shown in Table 1.

[Evaluation method and evaluation criteria] For the obtained light-shielding sliding member, various physical properties were measured and evaluated. Table 1 shows the evaluation results. In addition, the evaluation method and evaluation criteria of each physical property are as described below.

＜G60 Surface Gloss＞ 　　Using a digital angular gloss meter (UGV-5K: manufactured by Suga Testing Instruments Co., Ltd.), the surface gloss (mirror gloss) (%) of the light-shielding sliding film surface at an incident angle of 60° was measured according to JIS-Z8741:1997 and judged according to the following criteria. 　　Less than 10% ◎ 　　Less than 15% ○

<Surface resistivity> The surface resistivity (Ω) of the light-shielding sliding film was measured in accordance with JIS K6911:1995 and judged according to the following criteria: Less than 1.0×10 ⁸ Ω ◎ Less than 1.0×10 ⁹ Ω ○ Less than 1.0×10 ¹⁰ Ω △

＜Optical density OD＞ 　　According to JIS-K7651:1988, the optical density of the light-shielding part of the optical device is measured using an optical densitometer (TD-904: GretagMacbeth). In addition, the measurement is performed using a UV filter. 　　6.0 or more ○

＜Adhesion＞ 　　Evaluated based on the checkerboard tape method of JIS-K5400:1990. 　　100 pieces out of 100 remain ◎ 　　99 pieces out of 100 remain ○

＜Coating Strength＞ 　　According to the pencil scratch test of JIS-K5400, a surface measuring machine (HEIDON-14: manufactured by Shinto Science Co., Ltd.) is used to move a pencil of a specific hardness at a speed of 0.5mm/sec under a load of 1000g, and the limit of pencil hardness that does not cause cracks in the light-shielding sliding film (scratches are also OK) is measured. 　　H or above ◎ 　　6B or above and less than H ○ 　　Less than 6B ×

＜Sliding property＞ 　　According to JIS-K7125:1999, the static friction coefficient (μs) and dynamic friction coefficient (μk) of the light-shielding sliding film were measured under the conditions of load 200 (g) and speed 100 (mm/min), and evaluated according to the following standards. 　　Static friction coefficient (μs) 　　Less than 0.25 ◎ 　　0.25 or more and less than 0.30 ○ 　　0.30 or more and less than 0.35 △ 　　0.35 or more × 　　Dynamic friction coefficient (μk) 　　Less than 0.25 ◎ 　　0.25 or more and less than 0.30 ○ 　　0.30 or more and less than 0.35 △ 　　0.35 or more × 　　Difference between static friction coefficient and dynamic friction coefficient (μk) 　　Less than 0.02 ◎ 　　0.02 or more and less than 0.04 ○ 　　0.04 or more ×

<Abrasion resistance> 　　In the movable part and fixed part of the abrasion tester (NUS-ISO-1), set the sample pieces of light-shielding components for optical instruments, respectively, and slide them back and forth with a load of 300g to perform the abrasion test. While visually observing the scratches on the surface of the sample piece set in the fixed part (the surface of the light-shielding sliding film), calculate the number of back and forth movements until it becomes unusable. 　　More than 200 times ◎ 　　More than 150 times and less than 200 times ○

[Industrial Availability]

The present invention can be widely and effectively used as a high-performance light-shielding sliding member in applications requiring sliding properties and wear resistance, such as in the fields of precision machinery, semiconductors, and optical machines. In particular, it can be particularly effectively used as a sliding member, such as a shutter or aperture member, of various optical machines such as high-performance SLR cameras, compact cameras, video cameras, mobile phones, smart phones, PDA information terminals, and projectors.

100‧‧‧Light-shielding sliding member 11‧‧‧Base material 11a‧‧‧Surface (main surface) 11b‧‧‧Surface (main surface) 21‧‧‧Light-shielding sliding film

[Fig. 1] A cross-sectional view schematically showing a light-shielding sliding member and a light-shielding sliding film in one embodiment.

100‧‧‧Light-shielding sliding member

11‧‧‧Base material

11a‧‧‧Surface (main surface)

11b‧‧‧Surface (main surface)

21‧‧‧Light-shielding sliding film

Claims (10)

A light-shielding sliding film, characterized by at least a polyol and a polyisocyanate curing agent, a urethane adhesive resin, carbon black, and a granular wax, and containing 10.0% to 18.0% by mass of the granular wax in terms of solid content. The polyol and the polyisocyanate curing agent are mixed in a ratio of 1.21 to 1.40 in terms of the ratio of the NCO group of the polyisocyanate curing agent to the OH group of the polyol (NCO/OH ratio). The light-shielding sliding film of claim 1 substantially does not contain inorganic fillers having an average particle size _D50 of 3.0 μm or more and/or resin beads having an average particle size _D50 of 3.0 μm or more. The light-shielding sliding film of claim 1 contains 60-85% by mass of the aforementioned urethane adhesive resin in terms of solid content. The light-shielding sliding film of claim 1 contains 7.5-18.0 mass % of the aforementioned carbon black in terms of solid content. The light-shielding sliding film of claim 1, wherein the carbon black has an average particle size D ₅₀ of 0.01-1.0 μm. The light-shielding sliding film of claim 1, wherein the granular wax has an average particle size D ₅₀ of 2-18 μm. The light-shielding sliding film of claim 1 has an optical density (OD) of 5.4~6.0. The light-shielding sliding film of claim 1 has a thickness of more than 0.5 μm and less than 30 μm. A light-shielding sliding member, which comprises at least a substrate and a light-shielding sliding film as described in any one of claims 1 to 8 disposed on at least one surface of the substrate. A resin composition for a light-shielding sliding film, characterized by containing at least a prepolymer of a polyol and a polyisocyanate curing agent, carbon black, a granular wax, and a solvent, wherein the granular wax is contained in an amount of 10.0% to 18.0% by mass in terms of solid content, and the prepolymer is a mixture of the polyol and the polyisocyanate curing agent, and the ratio of the NCO group of the polyisocyanate curing agent to the OH group of the polyol (NCO/OH ratio) is 1.21 to 1.40.

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