Optical device and light-shielding film

Abstract

The invention relates to an optical device and a light shielding film. Provided is an optical device including a first optical element, a second optical element, a third optical element, and a light shielding film. The light-shielding film is a cured film of a photosensitive resin composition. The end surface of the first optical element and / or the end surface of the second optical element includes a chamfered portion formed by being in contact with the outer periphery of the joining surface of the first optical element and / or the second optical element. A curing reaction rate of the photosensitive resin composition on a first surface of the light shielding film in contact with an end surface of the first optical element and an end surface of the second optical element is lower than a curing reaction rate of the photosensitive resin composition on a second surface on an opposite side of the first surface. The light-shielding film contains a compound having a thiol group.

Description

Technical Field

[0001] This disclosure relates to optical devices including light-shielding films. Background Technology

[0002] In optical devices used in optical instruments, a black light-shielding film is formed in the outer region with an effective beam diameter as needed to reduce stray light.

[0003] A light-shielding film is a film formed primarily on the outer region of glass, a component of an optical device. Here, the glass can be a lens or a prism. The glass can also be other types of optical glass or optical prisms.

[0004] Japanese Patent Application Publication No. 2013-24988 discloses a black light-shielding film comprising resin, inorganic particles, and organic particles, wherein the film is harder at the air interface than at the substrate interface. Japanese Patent Application Publication No. 2011-170334 discloses a black light-shielding film for wafer-level lenses, comprising a photosensitive resin, a photopolymerization initiator, a colorant, inorganic fine particles, and a thiol.

[0005] The light-shielding film disclosed in Japanese Patent Application Publication No. 2013-24988 does not contain a curing accelerator. As a result, as the thickness of the film increases, it may become difficult to cure the film in a short time.

[0006] The lens disclosed in Japanese Patent Application Publication No. 2011-170334 is formed directly on the substrate and therefore does not include a chamfered portion. The lens disclosed in Japanese Patent Application Publication No. 2011-170334 does not include a joint. As a result, when a large thermal shock is applied to lenses with different coefficients of linear expansion when they are bonded together, strain may be induced in the lens, thereby degrading its optical performance. Summary of the Invention

[0007] This disclosure is made in view of such prior art and relates to providing optical devices with excellent manufacturability and environmental resistance, as well as light-shielding films that contribute to the optical devices.

[0008] According to one aspect of this disclosure, an optical device is provided, comprising: a first optical element; a second optical element; a third optical element configured to join the first and second optical elements together; and a light-shielding film continuously formed in contact with end faces of the first, second, and third optical elements, wherein the light-shielding film is a cured film of a photosensitive resin composition, wherein the end faces of the first and / or second optical elements include chamfered portions formed in contact with the outer periphery of the joining surfaces of the first and / or second optical elements, wherein the curing reaction rate of the photosensitive resin composition on a first surface of the light-shielding film in contact with the end faces of the first and second optical elements is lower than the curing reaction rate of the photosensitive resin composition on a second surface opposite to the first surface, and wherein the light-shielding film contains a compound having a thiol group.

[0009] According to another aspect of this disclosure, a light-shielding film for use by forming on an optical device is provided, the optical device including a first optical element, a second optical element, and a third optical element configured to bond the first optical element and the second optical element together, the end face of the first optical element and / or the end face of the second optical element including a chamfered portion formed in contact with the outer periphery of the bonding surface of the first optical element and / or the second optical element, the light-shielding film contacting the end face of the first optical element, the end face of the second optical element, and the end face of the third optical element, wherein the light-shielding film is a cured film of a photosensitive resin composition, wherein the light-shielding film has a first surface in contact with the end face of the first optical element and the end face of the second optical element, and a second surface on the opposite side of the first surface, wherein the curing reaction rate of the photosensitive resin composition on the first surface is lower than the curing reaction rate of the photosensitive resin composition on the second surface, and wherein the light-shielding film contains a compound having a thiol group.

[0010] The features of this disclosure will become apparent from the following description of the embodiments with reference to the accompanying drawings. The following description of the embodiments is illustrated by examples. Attached Figure Description

[0011] Figure 1 This is a schematic diagram illustrating an example of a light-shielding film and a lens on which the light-shielding film is formed.

[0012] Figure 2 This is a schematic diagram used to illustrate the direction of travel of light reflected from the inner surface.

[0013] Figure 3 This is a schematic cross-sectional view of the lens.

[0014] Figure 4A This is an enlarged schematic cross-sectional view of the end face of the joint lens, including the chamfered portion, when there is no protrusion of the third optical element.

[0015] Figure 4B This is an enlarged schematic cross-sectional view of the end face of the joint lens, including the chamfered portion, when a third optical element protrudes.

[0016] Figure 5 This is an enlarged schematic cross-sectional view illustrating the characteristics of the light-shielding film according to this disclosure in a joined lens including a chamfered portion.

[0017] Figure 6 It is an enlarged schematic cross-sectional view of the end face of the joint lens, including the chamfered and rounded parts.

[0018] Figure 7 This is a schematic cross-sectional view of a camera device with the lens unit (optical system) mounted on the camera unit.

[0019] Figure 8 This is a schematic diagram illustrating the method for measuring the reflectivity of an inner surface.

[0020] Figure 9 It is a schematic cross-sectional view of a test piece used to evaluate the ratio of curing reaction rate, the ratio of elastic modulus, thermal shock resistance and cleaning resistance. Detailed Implementation

[0021] First, the function of the light-shielding film used in optical devices is described with reference to the attached diagram.

[0022] Figure 1 This is a schematic diagram illustrating an example of a light-shielding film and a lens on which the light-shielding film is formed.

[0023] like Figure 1 As shown, the light-shielding film 1 is formed on any outer peripheral portion of the lens 2. Here, among the light entering the lens 2, the light that does not strike the outer peripheral portion of the lens 2 (incident light 3) passes through the lens 2 as transmitted light 4. At the same time, among the light entering the lens 2, the light that strikes the outer peripheral portion of the lens 2 (incident light 5) strikes the light-shielding film 1 formed on the outer peripheral portion of the lens 2.

[0024] If not formed Figure 1 The light-shielding film 1, when incident on the outer periphery of lens 2, is reflected by the inner surface, thus exiting lens 2 as inner surface reflected light 6, which has no effect on the image. Inner surface reflected light 6 causes flare and ghosting, which degrade image quality. Therefore, a light-shielding film 1 needs to be formed on the outer periphery of lens 2 to prevent flare and ghosting. When the light-shielding film 1 is formed, the inner surface reflected light 6 that adversely affects the image is reduced, thus preventing flare and ghosting.

[0025] The principle of internal surface reflection is described in detail with reference to the attached diagram.

[0026] Figure 2 This is a schematic diagram used to illustrate the direction of travel of light reflected from the inner surface. Figure 2 This is a diagram illustrating the pattern of the light-shielding film 1 being coated onto the outer peripheral surface of the lens 2.

[0027] like Figure 2 As shown, internal reflection mainly occurs at two interfaces: interface 7 between lens 2 and light-shielding film 1, and interface 8 between light-shielding film 1 and air. Specifically, when incident light 3 passing through lens 2 strikes interface 7, the incident light 3 splits into light reflected at interface 7 (first reflected light 9) and light passing through light-shielding film 1 (transmitted light 10). Furthermore, transmitted light 10 generates reflected light at interface 8. In this case, the reflected light serves as second reflected light 11.

[0028] Here, the first reflected light 9 can be reduced by adjusting the refractive index of the light-shielding film 1 to be closer to that of the lens 2, or by setting the refractive index of the light-shielding film 1 to be higher than that of the lens 2. As the refractive index of the glass increases, the refractive index of the light-shielding film is also required to increase.

[0029] Furthermore, the second reflected light 11 can be reduced by absorbing the transmitted light 10 in the light-shielding film 1. In order to effectively absorb the transmitted light 10 entering the light-shielding film 1, colorants, etc., are used.

[0030] Next, an example of an optical element including a chamfered portion will be described using a coupled lens.

[0031] Figure 3 This is a schematic cross-sectional view of a joining lens. A joining lens is formed by multiple lenses, for example, such as... Figure 3 The first optical element 12, the second optical element 13, and the third optical element 14 are shown. Furthermore, the light-shielding film 1 is formed in contact with the end faces of the first optical element 12, the second optical element 13, and the third optical element 14.

[0032] Figure 4A This is an enlarged schematic cross-sectional view of the end face of the joined lens, including the chamfered portion, when the protrusion of the third optical element 14 (adhesive) is absent. To prevent the lenses from colliding with each other and causing lens cracks, a chamfered portion 15 is formed on the end of each of the first optical element 12 and the second optical element 13. When the light-shielding film 1 is formed on the lens including the chamfered portion 15, a groove is formed in the chamfered portion to cause liquid to collect in the light-shielding film 1.

[0033] In recent years, optical devices have often been used under conditions of significant thermal shock, such as in cold or hot regions. Therefore, it is necessary to reduce the stress on the lens caused by the light-shielding film 1. However, in joined lenses, the light-shielding film 1 tends to accumulate in the chamfered portion 15, thus accumulating stress in the liquid collection area. Furthermore, when a large thermal shock is applied, the stress can be transmitted to the first optical element 12 or the second optical element 13 of the optical device, causing peeling of the light-shielding film 1 and defects or cracks in the optical elements.

[0034] Furthermore, in order to remove the adhesion of extremely fine contaminants to the lens during the lens manufacturing process, the lens needs to be ultrasonically cleaned in a tank filled with water or detergent after the light-shielding film 1 is formed. It is necessary to prevent the light-shielding film 1 from peeling off at the interface with the lens due to water or ultrasonic vibration during cleaning.

[0035] Furthermore, to improve lens production efficiency, it is necessary to form the light-shielding film 1 in a short time, and then immediately perform ultrasonic cleaning after the light-shielding film 1 is formed before proceeding to the next step. Therefore, the light-shielding film 1 needs to be able to cure quickly and withstand ultrasonic cleaning with water immediately after curing.

[0036] Exemplary implementations of this disclosure are described below.

[0037] First, a method for achieving an optical device in which the light-shielding film can cure in a short time, exhibits high cleanability even immediately after curing, does not cause lens cracking even under severe thermal shock, and has high internal surface reflection prevention performance is described. In addition to this method, optical systems and optical instruments, each including such an optical device, are described, and the light-shielding coatings and light-shielding films used in this disclosure are further described.

[0038] [Materials used to obtain light-shielding films with short curing time, high immediate cleaning resistance after curing, high thermal shock resistance, and high internal surface anti-reflection performance]

[0039] To suppress internal reflections, it is preferable to set the refractive index of the light-shielding film to be equal to or greater than that of the lens. To improve the refractive index, a large number of high-refractive-index inorganic nanoparticles dispersed in the resin can be added. However, inorganic particles have a high elastic modulus, so adding a large number of inorganic particles makes it difficult for the film itself to generate the large stress applied to the lens, potentially deteriorating thermal shock resistance. Furthermore, adding a large number of inorganic particles reduces adhesive strength and may worsen cleaning resistance.

[0040] To improve thermal shock resistance, the addition of a flexible resin was considered. However, while improving thermal shock resistance, this reduced the adhesion of the light-shielding film, potentially deteriorating its cleanability.

[0041] To improve cleanability, the adhesion of the light-shielding film needs to be improved, and it is envisioned that the elastic modulus of the resin be increased. However, when the elastic modulus of the resin is high, the thermal shock resistance may deteriorate.

[0042] Therefore, thermal shock resistance, cleanability, and internal surface reflection prevention are contradictory requirements, making it difficult to achieve all of them simultaneously.

[0043] (A method to achieve short-time curing, and immediate high resistance to cleaning, thermal shock, and internal surface reflection after curing)

[0044] Figure 5 This is an enlarged schematic cross-sectional view illustrating the characteristics of the light-shielding film according to this disclosure in a joined lens including a chamfered portion.

[0045] The inventors have conducted in-depth research on methods to achieve short-time curing, immediate post-curing cleanability, thermal shock resistance, and high internal surface reflection prevention performance. The results show that these requirements can be achieved through the following configuration. First, the light-shielding film 1 is a cured film of a photosensitive resin composition. The curing reaction rate of the photosensitive resin composition on the first surface 17 of the light-shielding film 1, which contacts the end faces of the first optical element 12 and the second optical element 13, is lower than the curing reaction rate of the photosensitive resin composition on the second surface 18 opposite to the first surface 17. Furthermore, the light-shielding film 1 contains a compound having a thiol group.

[0046] That is, the optical device according to this disclosure includes the following: a first optical element 12; a second optical element 13; a third optical element 14 configured to join the first optical element 12 and the second optical element 13 together; and a light-shielding film 1 continuously formed in contact with the end faces of the first optical element 12, the second optical element 13 and the third optical element 14, wherein the light-shielding film 1 is a cured film of a photosensitive resin composition, wherein the end faces of the first optical element 12 and / or the second optical element 13 include chamfered portions 15 formed in contact with the outer periphery of the joining surfaces of the first optical element 12 and / or the second optical element 13, wherein the curing reaction rate of the photosensitive resin composition on the first surface 17 of the light-shielding film 1 in contact with the end faces of the first optical element 12 and the second optical element 13 is lower than the curing reaction rate of the photosensitive resin composition on the second surface 18 on the opposite side of the first surface 17, and wherein the light-shielding film 1 contains a compound having a thiol group.

[0047] The light-shielding film 1 according to this disclosure is a cured film of a photosensitive resin composition and contains a photopolymerization initiator. The photosensitive resin composition containing the photopolymerization initiator can be cured in a short time by polymerization using a UV irradiation device or the like. The light-shielding film 1 formed in the optical device according to this disclosure is a cured film of a photosensitive resin composition, and therefore has a shorter curing time compared to cured films of thermosetting, room temperature curing, or moisture curing resin compositions.

[0048] Furthermore, the curing reaction rate of the first surface 17 of the light-shielding film 1 formed in the optical device according to the present disclosure is lower than that of the second surface 18 on the opposite side of the first surface 17. The light-shielding film according to the present disclosure has a light-shielding function. Therefore, in particular, when a portion having a large thickness, such as the chamfered portion 15, is cured mainly from the surface side using a UV irradiation device or the like, the curing reaction rate of the second surface 18 is high, and the curing reaction rate of the first surface 17, which has low light transmittance in the thick portion, is low.

[0049] Because the curing reaction rate of the first surface 17 is low, the light-shielding film 1 according to this disclosure has high thermal shock resistance. When the curing reaction rate of the first surface 17 is low, water can easily penetrate the light-shielding film 1 during cleaning, causing the film to peel off. However, it is presumed that the light-shielding film 1 according to this disclosure contains a compound with a thiol group, thus increasing its cleanability even immediately after curing. The reaction between the compound with the thiol group and water is described below.

[0050] Typically, compounds with thiol groups have the function of reacting with acryloyl, epoxy, or aryl groups to promote curing and are used as curing accelerators. Adding a compound with a thiol group can promote curing, and cleaning resistance tends to improve slightly. However, light does not reach the first surface 17, such as the portion with a large thickness in the chamfer 15. Therefore, even when a compound with a thiol group is added, the curing reaction rate of the first surface 17 is lower than that of the second surface 18, although the curing reaction rate is slightly improved.

[0051] According to this disclosure, the curing reaction rate of the first surface 17 of the light-shielding film 1 is low. Therefore, it is presumed that when the light-shielding film 1 is immersed in water, water easily penetrates the film. It is presumed that the hydroxyl groups of the water already immersed in the light-shielding film 1 react with compounds having thiol groups to convert the compounds having thiol groups into highly nucleophilic thiolate anions, and the thiolate anions react with the photosensitive resin material to further improve the curing reaction rate of the photosensitive resin material, thereby enhancing the water resistance of the film. Therefore, the light-shielding film according to this disclosure contains compounds having thiol groups, so even when the curing reaction is insufficient, a film with high water resistance immediately after curing can be obtained.

[0052] [Optical Components]

[0053] The optical device according to this disclosure is, for example, a lens barrel in an optical instrument used with imaging equipment such as a camera, video camera, or broadcasting equipment, or an optical device used in a camera body, video recorder body, surveillance camera, vehicle camera, or weather camera that can be used outdoors. The optical device according to this disclosure includes a first optical element having a chamfered portion on a mating surface side, a second optical element having a chamfered portion on a mating surface side, and a third optical element that joins the first and second optical elements together.

[0054] Optical devices of any shape can be used as lenses and other optical components. For example, optical devices with concave, convex, or combinations thereof can be used. Furthermore, the outer peripheral portion can be flat, have multiple steps, or have grooves. Additionally, the outer peripheral portion of the lens can have a straight section. Furthermore, any material can be used as a constituent component of the substrate for lenses and the like. Examples include Li₂O, Na₂O, K₂O, MgO, CaO, SrO, BaO, ZnO, Y₂O₃, La₂O₃, Nd₂O₃, Gd₂O₃, B₂O₃, Al₂O₃, TiO₂, ZrO₂, HfO₂, SiO₂, GeO, Nb₂O₅, Ta₂O₅, P₂O₅, Sb₂O₃, and WO₃. The constituent components can be used alone or in combination.

[0055] Furthermore, as mentioned above, such as Figure 3 As shown, the bonding lens includes a first optical element 12, a second optical element 13, a third optical element 14 that bonds the first optical element 12 and the second optical element 13 together, and a light-shielding film 1. The light-shielding film 1 is continuously formed in contact with the end faces of the first optical element 12, the second optical element 13, and the third optical element 14.

[0056] like Figure 4A As shown, the chamfered portion 15 is formed on the end face of the first optical element 12 and / or the end face of the second optical element 13, and contacts the end face and mating surface of the third optical element 14. As a result, a groove is formed with the end face of the third optical element 14 as the bottom surface and the chamfered portion 15 as the wall surface. Therefore, a light-shielding film 1 is formed to fill at least a portion of the groove.

[0057] Figure 4B This is an enlarged schematic cross-sectional view of the end face of the bonding lens, including the chamfered portion 15, when the third optical element 14 (adhesive) protrudes. (See diagram below.) Figure 4B As shown, the third optical element 14 can protrude into the chamfered portion 15. The maximum thickness 54 of the light-shielding film 1 in the groove is as follows: Figure 4A As shown, it becomes larger when the third optical element 14 is not protruding, and as Figure 4B As shown, it becomes smaller when the third optical element 14 protrudes.

[0058] To prevent the first optical element 12 and the second optical element 13 from colliding with each other and causing microcracks during production, chamfered portions 15 are formed. The length of each chamfered portion 15 is 0.05 mm or more and 0.5 mm or less, more preferably 0.1 mm or more and 0.4 mm or less. When the length of each chamfered portion 15 is less than 0.05 mm, microcracks may easily form when the first optical element 12 and the second optical element 13 collide with each other. When the length of each chamfered portion 15 is greater than 0.5 mm, the light-shielding film 1 tends to accumulate, thereby increasing the stress on the lens, which may result in a deterioration in thermal shock resistance.

[0059] Furthermore, there is no particular limitation on the number of lenses that can be joined in the joint lens, and two lenses can be joined, or more than two lenses can be joined for use.

[0060] The optical device according to this disclosure may have rounded corners. (See reference) Figure 6 Describe the rounded corners. Figure 6 This is an enlarged schematic cross-sectional view of the end face of the joined lens, including the chamfered and rounded corners. (See attached image.) Figure 6 As shown, the chamfer 15 on the mating surface side of the first optical element 12 may have a rounded corner 19. When the rounded corner 19 is formed, the light-shielding film 1 easily flows out during its formation due to its own weight, and the light-shielding film 1 does not easily accumulate in the groove of the chamfer. When the light-shielding film 1 is difficult to accumulate in the groove of the chamfer, stress is less likely to be generated even when thermal shock is applied, and thermal shock resistance is further improved.

[0061] The maximum diameter of the optical device according to this disclosure is preferably 5 mm or more and 1,000 mm or less, more preferably 25 mm or more and 100 mm or less. Where the maximum diameter of the optical device is less than 5 mm, the bonding lens is excessively small, and therefore it may be difficult to manufacture such a device. Furthermore, when the maximum diameter of the optical device is greater than 1,000 mm, stress is generated on the lens, and the thermal shock resistance may deteriorate.

[0062] Furthermore, examples of commercially available products used as substrates for the first optical element 12 and the second optical element 13 include: S-LAM2 (7.4ppm), S-LAM60 (5.4ppm), S-TIH53 (8.8ppm), S-BSL7 (7.2ppm), S-NBM51 (6.5ppm), L-BAL42 (7.2ppm), S-FPL55 (13.6ppm), S-FPL51 (13.1ppm), S-FPM3 (11.5ppm), S-FSL5 (9ppm), S-FPL53 (14.5ppm), S-FPM4 (12.4ppm), S-NSL36 (8ppm), and S-TIL6 (8.2ppm), all of which are manufactured by Ohara Inc.; and quartz (0.5ppm). Equivalent products are also commercially available from Schott AG, HOYA Corporation, etc., and therefore these products can be used.

[0063] The third optical element 14 is a layer obtained by curing an adhesive used to bond lenses made of glass together. Besides optical transparency, an adhesive with high adhesion and high curing speed is required, and suitable curing adhesives such as acrylic-based, epoxy-based, and polyene-polythiol-based adhesives can be used. Curing initiators can be added to these adhesives, and the adhesive can be cured by heat or UV light. However, heat curing may cause interfacial delamination or deformation of the surface shape. Therefore, UV-curable adhesives are desirable for use as the adhesive for the third optical element 14. Furthermore, from the viewpoint of reducing curing shrinkage and adjusting its optical properties, adhesives that mix and disperse inorganic fine particles are preferred. Additionally, the maximum thickness of the light-shielding film in contact with the third optical element is preferably 5 μm or more and 180 μm or less.

[0064] An antireflective film (not shown) may be formed on each of the first optical element 12 and the second optical element 13.

[0065] In addition, the joining lens is used as part of the optical system in imaging devices (including cameras or video cameras, etc.) that include imaging devices, or in optical instruments (such as telescopes, binoculars, photocopiers, or projectors). Figure 7 This is a schematic cross-sectional view of a camera device with a lens unit (optical system) mounted on a camera unit as an interchangeable lens. As an example, Figure 7A schematic cross-section of the imaging device 200 is shown with the lens unit (optical system) 20 mounted on the imaging unit 30. A bonding lens 21 (100) is disposed within a cylinder 22 serving as the housing of the lens unit 20, and the lens unit is fixed to the imaging unit 30 by a mounting member 23. The imaging unit 30 includes an imaging device 33 and a shutter 32 within a housing 31, for receiving light passing through the lens unit 20. The imaging device 33 is configured such that the optical axis 40 of the bonding lens 21 passes through its center to receive light passing through the lens unit 20. Furthermore, the imaging unit 30 includes a drive unit 34 for opening and closing the shutter 32, and a control unit 35 for controlling data readout from the drive unit 34 and the imaging device 33, etc.

[0066] [Blackout coating]

[0067] The following describes the material composition of the light-shielding coating used as a precursor for the light-shielding film used in this disclosure and the method for manufacturing the light-shielding coating used in this disclosure.

[0068] The light-blocking coating is a component corresponding to the photosensitive resin composition in this disclosure.

[0069] <Material Composition>

[0070] (Photosensitive resin material)

[0071] The photosensitive resin material in the light-shielding coating used in this disclosure is described.

[0072] Any suitable material can be used as the photosensitive resin material in the light-shielding coatings used in this disclosure, as long as the material can form a light-shielding film. It is only required that the photosensitive resin material in the light-shielding coatings used in this disclosure is reactive to UV light, and various photosensitive resin materials can be used in combination with thermosetting, moisture-curing, or room-temperature-curing resins. The photosensitive resin material can be a polymeric compound. Examples of photosensitive resin materials include acrylate resins, epoxy resins, urethane resins, acrylic urethane resins, phenolic resins, melamine resins, polyester resins, alkyd resins, aryl resins, and polyimides.

[0073] The polymerizable compound in the photosensitive resin composition preferably has an acryloyl group and a hydroxyl group.

[0074] As an acrylate resin, specifically, for example, materials selected from the following can be preferably used: M-208 (Toagosei Co., Ltd.), M-211B (Toagosei Co., Ltd.), M-215 (Toagosei Co., Ltd.), M-220 (Toagosei Co., Ltd.), M-225 (Toagosei Co., Ltd.), M-270 (Toagosei Co., Ltd.), M-309 (Toagosei Co., Ltd.), M-310 (Toagosei Co., Ltd.), M-321 (Toagosei Co., Ltd.), M-350 (Toagosei Co., Ltd.), M-360 (Toagosei Co., Ltd.), M-313 (Toagosei Co., Ltd.), M-315 (Toagosei Co., Ltd.). Co., Ltd.), M-306 (Toagosei Co., Ltd.), M-305 (Toagosei Co., Ltd.), M-450 (Toagosei Co., Ltd.), M-408 (Toagosei Co., Ltd.), DPGDA (Daicel-Allnex Ltd.), HDDA (Daicel-Allnex Ltd.), TPGDA (Daicel-Allnex Ltd.), EBECRYL 145 (Daicel-Allnex Ltd.), EBECRYL 150 (Daicel-Allnex Ltd.), PEG200DA (Daicel-Allnex Ltd.), EBECRYL 11 (Daicel-Allnex Ltd.), IRR 214-K (Daicel-Allnex Ltd.), EBECRYL 130 (Daicel-Allnex Ltd.), TMPTA (Daicel-Allnex Ltd.), EBECRYL 160S (Daicel-Allnex Ltd.), OTA 480 (Daicel-Allnex Ltd.), PETIA (Daicel-Allnex Ltd.), PETRA (Daicel-Allnex Ltd.), EBECRYL 40 (Daicel-Allnex Ltd.), EBECRYL 50 (Daicel-Allnex Ltd.), PETA (Daicel-Allnex Ltd.), EBECRYL 140 (Daicel-Allnex Ltd.)、EBECRYL 1140(Daicel-Allnex Ltd.)、EBECRYL 1142(Daicel-AllnexLtd.)、DPHA(Daicel-Allnex Ltd.)、EBECRYL 895(Daicel-Allnex Ltd.)、OGSOLEA-0200(Osaka Gas Chemicals Co.,Ltd.)、OGSOL EA-F5710(OsakaGasChemicals Co.,Ltd.)、OGSOL EA-5060P(Osaka Gas Chemicals Co.,Ltd.)、OGSOL EA-0300(Osaka Gas Chemicals Co.,Ltd.)、OGSOL GA-2800(OsakaGas Chemicals Co.,Ltd.)、Light Acrylate L-A(Kyoeisha Chemical Co.,Ltd.)、Light Acrylate S-A(Kyoeisha Chemical Co.,Ltd.)、Light Acrylate EC-A(Kyoeisha Chemical Co.,Ltd.)、Light Acrylate EHDG-AT(Kyoeisha ChemicalCo.,Ltd.)、Light Acrylate 130A(Kyoeisha Chemical Co.,Ltd.)、Light AcrylateDPM-A(Kyoeisha Chemical Co.,Ltd.)、Light Acrylate PO-A(KyoeishaChemical Co.,Ltd.)、Light Acrylate P2H-A(KyoeishaChemical Co.,Ltd.)、LightAcrylate P-200A(Kyoeisha Chemical Co.,Ltd.)、LightAcrylate THF-A(Kyoeisha Chemical Co.,Ltd.)、Light Acrylate IB-XA(KyoeishaChemical Co.,Ltd.)、Light Acrylate 9EG-A(Kyoeisha Chemical Co.,Ltd.)、LightAcrylate14EG-A(Kyoeisha Chemical Co.,Ltd.), Light Acrylate NP-A (Kyoeisha Chemical Co., Ltd.), Light Acrylate MPD-A (Kyoeisha Chemical Co., Ltd.), Light Acrylate 1.6HX-A (Kyoeisha Chemical Co., Ltd.), Light Acrylate 1.9ND-A (Kyoeisha Chemical Co., Ltd.), Light Acrylate DCP-A (Kyoeisha Chemical Co., Ltd.), LightAcrylate BP-4EAL (Kyoeisha Chemical Co., Ltd.), Light Acrylate HPP-A (Kyoeisha Chemical Co., Ltd.), Light Ester G-201P (Kyoeisha Chemical Co., Ltd.), LightAcrylate TMP-A (Kyoeisha Chemical Co., Ltd.) Co., Ltd.), Light Acrylate PE-3A (Kyoeisha Chemical Co., Ltd.), Light Acrylate PE-4A (Kyoeisha Chemical Co., Ltd.) and LightAcrylate DPE-6A (Kyoeisha Chemical Co., Ltd.). .

[0075] The content of photosensitive resin material in the light-blocking coating used in this disclosure is preferably 5% by weight or more and 87% by weight or less, more preferably 30% by weight or more and 85% by weight or less. When the content of photosensitive resin material in the light-blocking coating used in this disclosure is less than 5% by weight, the light-blocking film becomes excessively hard and may crack due to thermal shock. When the content of photosensitive resin material is greater than 87% by weight, increasing the refractive index of the film may become difficult. All weight percentage values ​​mentioned herein are based on solid content and do not include the content of volatile components.

[0076] (Coloring agent)

[0077] The light-blocking coatings used in this disclosure may contain colorants.

[0078] Any suitable material can be used as a colorant, as long as it can color the opaque coating. Examples of colorants in opaque coatings include dyes and pigments. These colorants can be used alone or as mixtures thereof.

[0079] Examples of dyes include azo dyes, quinone dyes, cyanide dyes, cationic dyes, phthalocyanine dyes, indigo dyes, and fulgide-based dyes. Furthermore, dyes with any hue can be used, including black, brown, yellow, red, blue, and green hues. These dyes can be used alone or as mixtures thereof.

[0080] Examples of pigments include carbon black, titanium black, zirconium nitride, iron oxide, copper-iron-manganese composite oxides, and iron-chromium. Pigments of any shape can be used as pigments in the light-blocking coating. Examples of pigment shapes in the light-blocking coating include spherical, amorphous, plate-like, needle-like, star-shaped, chain-like, and multilayered structures of stacked plate-like particles. Furthermore, the pigments in the light-blocking coating can be coated with other materials. The average particle size of the pigments in the light-blocking coating is preferably 1 nm or more and 200 nm or less, more preferably 5 nm or more and 50 nm or less. When the average particle size of the pigments in the light-blocking coating is less than 1 nm, the coating can be thickened. Furthermore, when the average particle size of the pigments is greater than 200 nm, the scattering of light by the film can be increased.

[0081] The colorant content in the light-blocking coating is preferably 1% by weight or more and 30% by weight or less, more preferably 2% by weight or more and 20% by weight or less. When the colorant content in the light-blocking coating is less than 1% by weight, the light entering the film cannot be completely absorbed, and the internal reflection characteristics may deteriorate. Furthermore, when the colorant content in the light-blocking coating is greater than 30% by weight, the film may become excessively stiff. All weight percentage values ​​mentioned herein are based on solid content and do not include the content of volatile components.

[0082] The light-shielding coating used in this disclosure is preferably formed to have an optical concentration (ODt) of 0.14 μm. -1 Above and 0.53μm -1 Below, more preferably 0.2μm -1 Above and 0.5μm -1 The following are examples of light-shielding films. ODt refers to the absorbance per 1 μm. ODt can be determined by using the average transmittance I at wavelengths from 400 nm to 700 nm and the incident light intensity I0. 10 (I / I0), and the absorbance is calculated by dividing the film thickness "t".

[0083] ODt = -log 10 (I / I0) / t ··· Equation (1)

[0084] When ODt is less than 0.14μm -1 When the incident light is not completely absorbed, the optical properties may deteriorate. When ODt is greater than 0.53 μm... -1When exposed to UV light, poor curing may occur.

[0085] As a colorant, specifically, for example, materials selected from the following can be preferably used: #2650 (Mitsubishi Chemical Corporation), #2600 (Mitsubishi Chemical Corporation), #2350 (Mitsubishi Chemical Corporation), #2300 (Mitsubishi Chemical Corporation), #1000 (Mitsubishi Chemical Corporation), #980 (Mitsubishi Chemical Corporation), #970 (Mitsubishi Chemical Corporation), #960 (Mitsubishi Chemical Corporation), #950 (Mitsubishi Chemical Corporation), #850 (Mitsubishi Chemical Corporation), MCF88 (Mitsubishi Chemical Corporation), MA600 (Mitsubishi Chemical Corporation), #750B (Mitsubishi Chemical Corporation), #650B (Mitsubishi Chemical Corporation), MA100 (Mitsubishi Chemical Corporation), and MA220 (Mitsubishi Chemical Corporation). Corporation).

[0086] (Inorganic particles)

[0087] Inorganic particles in the light-shielding coatings used in this disclosure are described.

[0088] The average particle size of the inorganic particles in the light-shielding coating used in this disclosure is preferably 2 nm or more and 250 nm or less, more preferably 50 nm or more and 200 nm or less, and even more preferably 100 nm or more and 180 nm or less. When the average particle size of the inorganic particles is greater than 200 nm, the scattering of light by the light-shielding film increases, and the appearance of the film may deteriorate.

[0089] The d-linear refractive index of the inorganic particles in the light-shielding coating used in this disclosure is preferably 1.6 or higher and 3.1 or lower. More preferably, it is 2.0 or higher and 3.1 or lower. When the d-linear refractive index is less than 1.6, a large amount of particles needs to be added to increase the refractive index of the light-shielding film according to this disclosure. Therefore, the elastic modulus of the light-shielding film increases, and its thermal shock resistance may deteriorate.

[0090] The inorganic particle content in the light-shielding coating used in this disclosure is preferably 2% by weight or more and 60% by weight or less, and more preferably falls within the range of 5% by weight or more and 30% by weight or less. When the inorganic particle content in the light-shielding coating used in this disclosure is less than 2% by weight, the refractive index of the light-shielding film does not increase significantly, and the internal reflection prevention performance may deteriorate. Furthermore, when the inorganic particle content in the light-shielding coating used in this disclosure is greater than 60% by weight, the elastic modulus of the light-shielding film used in this disclosure may become excessively high, and the thermal shock resistance may not be improved. All weight percentage values ​​mentioned herein are based on solid content and do not include the content of volatile components.

[0091] Any suitable metal or metal oxide can be used as the type of inorganic particles in the light-shielding coating used in this disclosure, provided that the d-line refractive index is 1.6 or higher and 3.1 or lower. Examples of inorganic particles with a d-line refractive index of 1.6 or higher in the light-shielding coating used in this disclosure include colcothart (d-line refractive index = 3.01), magnetite (d-line refractive index = 2.42), rutile titanium oxide (d-line refractive index = 2.72), anatase titanium oxide (d-line refractive index = 2.52), zirconium oxide (d-line refractive index = 2.05), cerium oxide (d-line refractive index = 2.2), zinc oxide (d-line refractive index = 2.1), tantalum pentoxide (d-line refractive index = 2.16), aluminum nitride (d-line refractive index = 1.9 to 2.2), tungsten oxide (d-line refractive index = 2.2), niobium pentoxide (d-line refractive index = 2.33), indium tin oxide (d-line refractive index = 2.33), and others. The following are listed as refractive indices: 2.06 (d-line refractive index = 2.24), 2.42 (d-line refractive index = 2.42), 1.63 (d-line refractive index = 1.63), 1.87 (d-line refractive index = 1.83), 1.74 (d-line refractive index = 1.74), 1.95 (d-line refractive index = 1.94), 1.89 (d-line refractive index = 1.89), 1.90 (d-line refractive index = 1.90), 1.90 (d-line refractive index = 1.90), 1.92 (d-line refractive index = 1.90), 3.4 (d-line refractive index = 3.4), and copper-iron-manganese composite oxides.

[0092] The inorganic particles with a d-line refractive index of 1.6 or higher used in the light-shielding coatings of this disclosure can be used alone or in combination, or in the form of a composite.

[0093] Inorganic particles of any shape can be used as the inorganic particles in the light-shielding coatings used in this disclosure. Examples of the shapes of the inorganic particles in the light-shielding coatings used in this disclosure include spherical, amorphous, plate-like, needle-like, star-shaped, chain-like, and multilayered compositions of plate-like particles. Furthermore, the inorganic particles in the light-shielding coatings used in this disclosure can be coated with other materials. Additionally, the inorganic particles in the light-shielding coatings used in this disclosure can be used alone or in combination.

[0094] As inorganic particles, specifically, for example, materials selected from the following can be preferably used: TTO-51(A) (Ishihara Sangyo Kaisha, Ltd.), TTO-51(C) (Ishihara Sangyo Kaisha, Ltd.), TTO-55(A) (Ishihara Sangyo Kaisha, Ltd.), TTO-55(B) (Ishihara Sangyo Kaisha, Ltd.), TTO-55(C) (Ishihara Sangyo Kaisha, Ltd.), TTO-55(D) (Ishihara Sangyo Kaisha, Ltd.), STR-100N (Sakai Chemical Industry Co., Ltd.), STR-100A-LP (Sakai Chemical Industry Co., Ltd.), STR-100C-LP (Sakai Chemical Industry Co., Ltd.), STR-100W-LP (Sakai Chemical Industry Co., Ltd.), STR-100C-LF (Sakai Chemical Industry Co., Ltd.). Industry Co., Ltd.), STR-100W-OTS (Sakai Chemical Industry Co., Ltd.), STR-100W(G) (Sakai Chemical Industry Co., Ltd.), STR-40-OTS (Sakai Chemical Industry Co., Ltd.), MT-01 (Tayca Corporation), MT-10EX (Tayca Corporation), MT-05 (Tayca Corporation), MT-100S (Tayca Corporation), MT-100TV (Tayca Corporation), MT-100Z (Tayca Corporation), MT-150EX (Tayca Corporation), MT-150W (Tayca Corporation), MT-100AQ (Tayca Corporation), MT-100WP (Tayca Corporation), MT-100SA (Tayca Corporation) and MT-100HD (Tayca Corporation).

[0095] (Photopolymerization initiator)

[0096] The light-blocking coating according to this disclosure contains a photopolymerization initiator in the film. When the photopolymerization initiator is added to the light-blocking coating and UV light is applied, the curing reaction rate of the first surface becomes lower than that of the second surface. Furthermore, when using the photopolymerization initiator, no heat is applied to the optical device during the curing of the light-blocking coating. Therefore, stress is reduced and thermal shock resistance is improved. The photopolymerization initiator in this disclosure can be used alone or in combination, and any material can be used. Examples include free radical photopolymerization initiators, cationic photopolymerization initiators, and anionic photopolymerization initiators. Examples of free radical photopolymerization initiators include alkyl phenyl ketone photopolymerization initiators, acylphosphine oxide photopolymerization initiators, intramolecular hydrogen abstraction photopolymerization initiators, and oxime ester photopolymerization initiators. Examples of cationic photopolymerization initiators include iodonium-based, sulfonium-based, ammonium-based, and nonionic photopolymerization initiators.

[0097] The content of the photopolymerization initiator in the light-shielding coating is preferably 0.1% by weight or more and 15% by weight or less, and more preferably falls within the range of 0.5% by weight or more and 5% by weight or less. When the content of the photopolymerization initiator is less than 0.1% by weight, the reaction does not advance when irradiated with UV light, and the cleanability may deteriorate. Furthermore, when the content of the photopolymerization initiator is greater than 15% by weight, the photopolymerization initiator may efflux from the film, thereby altering the glass composition.

[0098] As a photoinitiator, specifically, for example, materials selected from the following can be preferably used: Omnirad 651 (IGM Resins), Omnirad 184 (IGM Resins), Omnirad 1173 (IGM Resins), Omnirad 2959 (IGM Resins), Omnirad 127D (IGM Resins), Omnirad907 (IGM Resins), Omnirad 369 (IGMResins), Omnirad 369E (IGM Resins), Omnirad 379EG (IGM Resins), Omnirad TPO N (IGMResins), Omnirad819 (IGM Resins), Omnirad TPO-L (IGM Resins), Omnipol TP (IGMResins), Omnirad MBF (IGM Resins), Omnirad 754 (IGM Resins), Esacure 3644 (IGMResins), Irgacure OXE01 (BASF SE), Irgacure OXE02 (BASF SE), Irgacure OXE03 (BASFSE), Irgacure OXE04 (BASF SE), Irgacure OXE05 (BASF SE), Omnicat 270 (IGM Resins), Irgacure 290 (IGM Resins), Nikkacure YJ-04(T) (Nippon Chemical Industrial Co.,Ltd.), Nikkacure IW-15 (Nippon Chemical Industrial Co.,Ltd.), Nikkacure TG-05 (Nippon Chemical Industrial Co.,Ltd.), Nikkacure TG-10 (Nippon ChemicalIndustrial Co.,Ltd.), and Nikkacure TKG-01 (Nippon Chemical Industrial Co.,Ltd.).

[0099] (Compound having a thiol group)

[0100] In this disclosure, the light-blocking coating comprises a compound having a thiol group. The compound having a thiol group can be a monofunctional thiol having one thiol group or a polyfunctional thiol having two or more thiol groups, and various combinations of these compounds can be used. In particular, the compound having a thiol group is preferably a polyfunctional thiol because it improves the flexibility and crosslinking properties of the film.

[0101] The polyfunctional thiol can be either an ester-type thiol or an ether-type thiol. Ether-type thiols are preferred because they exhibit high water resistance and impart excellent cleaning properties to the lens. In particular, compounds containing a thiol group are preferred as they do not contain ester bonds.

[0102] Examples of compounds containing a thiol group include pentaerythritol tetra(3-thioalkylbutyrate), trimethylolpropane tri(3-mercaptobutyrate), pentaerythritol tri(3-thioalkylbutyrate), 1,3,5-tris(2-(3-thioalkylbutyryloxy)ethyl)-1,3,5-triazine-2,4,6-trione, 1,4-bis(3-mercaptobutynyloxy)butane, and 2,2-bis{[(3-thioalkylbutyryloxy)oxy]methyl}butyl 3-Thioalkylbutyrate, trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetra(3-mercaptopropionate), dipentaerythritol hexa(3-mercaptopropionate), tris[2-(3-mercaptopropoxy)ethyl]isocyanurate, pentaerythritol tripropanethiol, trimethylolpropane dipropanethiol, 2,2-bis[(3-thioalkylpropoxy)methyl]but-1-ol, pentaerythritol tetrapropanethiol, 3-{3-(3-mercapto-propoxy)-2,2- Bis-[(3-mercaptopropoxy)methyl]propoxy}-prop-1-ol, tetraethylene glycol bis(3-mercaptopropionate), tetrahydro-1,3,4,6-tetra(3-mercaptopropyl)-imidazo[4,5-d]imidazo-2,5(1H,3H)-dione, thionyl chloride, tetrahydro-1,3,4,6-tetra(2-hydroxyethyl)imidazo[4,5-d]imidazo-2,5(1H,3H)-dione, and thiourea (CAS Registry No.: 1) The reaction products of 852527-71-9) include 1,3,5-tris[3-(2-mercaptoethylthioalkyl)propyl]isocyanurate, thiocyanuric acid, 2-ethyl-2-(mercaptomethyl)-1,3-propanedithiol, 2,2-bis(mercaptomethyl)-1,3-propanedithiol, 1,3-dimercapto-2-propanol, 2,2-bis(mercaptomethyl)-1,3-propanediol and 3-mercapto-2,2-bis(mercaptomethyl)-1-propanol.

[0103] As compounds containing a thiol group, materials selected from the following are particularly preferred: TMMP (Sakai Chemical Industry Co., Ltd.), TMMP-HS (Sakai Chemical Industry Co., Ltd.), PEMP (Sakai Chemical Industry Co., Ltd.), DPMP (Sakai Chemical Industry Co., Ltd.), TEMPIC (Sakai Chemical Industry Co., Ltd.), EGMP-4 (Sakai Chemical Industry Co., Ltd.), Multhiol Y-2 (Sakai Chemical Industry Co., Ltd.), Multhiol Y-3 (Sakai Chemical Industry Co., Ltd.), Multhiol Y-4 (Sakai Chemical Industry Co., Ltd.), Karens MT BD1 (Resonac Corporation), Karens MT NR1 (Resonac Corporation), Karens MT TPMB (Resonac Corporation), ACTOCURE SS32 (Kawaguchi Chemical Industry Co., Ltd.), and ACTOCURE. ES23 (Kawaguchi Chemical Industry Co., Ltd.).

[0104] The content of the mercaptan-based compound in the light-blocking coating is preferably 0.5% by weight or more and 40% by weight or less, more preferably in the range of 1% by weight or more and 10% by weight or less. When the content of the mercaptan-based compound in the light-blocking coating is less than 0.5% by weight, the reaction does not proceed when irradiated with UV light, and the cleanability may deteriorate. Furthermore, when the content of the mercaptan-based compound is greater than 40% by weight, the film becomes excessively soft, and the water resistance may deteriorate.

[0105] (Other curing accelerators)

[0106] In this disclosure, the light-blocking coating may contain other curing accelerators in the film. When a curing accelerator is added, the film reacts further, thus improving cleanability immediately after curing. Examples of curing accelerators include photoalkalizing agents, photosensitizers, and oxygen inhibition suppressors. These curing accelerators can be used alone or in combination.

[0107] Examples of photoalkali-generating agents include 1,2-diisopropyl-3-[bis(dimethylamino)methylene]guanidine 2-(3-benzoylphenyl)propionate, 1,2-dicyclohexyl-4,4,5,5-tetramethylbiguanidine n-butyltriphenylboronic acid ester, (Z)-{[bis(dimethylamino)methylene]amino}-N-cyclohexyl(cyclohexylamino)methylimine tetra(3-fluorophenyl)boronic acid ester, 9-anthraylmethyl N,N-diethylcarbamate, (E)-1-piperidinyl-3-(2-hydroxyphenyl)-2-propen-1-one, 1-(anthraquinone-2-yl)ethylimidazolium-1-carboxylate, and 2-nitrophenylmethyl 4-methacryloyloxypiperidin-1-carboxylate.

[0108] Any photosensitizer, etc., can be used as an example of a photosensitizer, etc. Examples include coumarin-based, pyrazoline-based, thiophene-based, naphthalene-based, oxazole-based, ketone sulfone-based, and thioxanone-based photosensitizers.

[0109] Examples of oxygen inhibition inhibitors include IPEMA (Kuraray Co., Ltd.), DPNG (Kuraray Co., Ltd.), EBECRYL 80 (Daicel Corporation), EBECRYL 7100 (Daicel Corporation), and ADDITIOL LED01 (Daicel Corporation).

[0110] The content of the curing accelerator in the light-shielding coating is preferably 0.1% by weight or more and 15% by weight or less, more preferably in the range of 0.5% by weight or more and 5% by weight or less. When the content of the curing accelerator is less than 0.1% by weight, the reaction is not advanced when irradiated with UV light, and the cleanability may deteriorate. Furthermore, when the content of the curing accelerator is greater than 15% by weight, the curing accelerator may leach out from the film, thereby altering the glass composition.

[0111] (solvent)

[0112] Next, the solvents in the light-blocking coating will be described.

[0113] Any material can be used as a solvent. Furthermore, when the viscosity of the blackout coating is sufficiently low and the coating can be used as is, no solvent needs to be added. Examples of solvents include water, diluents, ethanol, isopropanol, n-butanol, ethyl acetate, propyl acetate, isobutyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, toluene, xylene, acetone, cellosolve, ethylene glycol ether, ether, hexane, cyclohexane, 1-butanol, methylcyclohexane, ethylcyclohexane, isohexane, benzyl alcohol, 2-ethyl-1-hexanol, butyl cellosolve, 1-butoxy-2-propanol, neopentane, SOLVESSO, trichloroethylene, perchloroethylene, methanol, cellosolve acetate, mineral spirit, tetrahydrofuran, dioxane, N-methyl-2-pyrrolidone, and ethyl lactate. These solvents can be used alone or in combination.

[0114] The viscosity of the light-blocking coating used in this disclosure is preferably 10 mPa·s or more and 10,000 mPa·s or less, more preferably 15 mPa·s or more and 500 mPa·s or less. When the viscosity of the light-blocking coating is less than 10 mPa·s, there may be areas of reduced thickness after coating application. Furthermore, when the viscosity is greater than 10,000 mPa·s, the coatability of the light-blocking coating may deteriorate.

[0115] (Other additives)

[0116] The light-blocking coatings used in this disclosure may contain any other additives. Examples include curing agents, dispersants, defoamers, thixotropic agents, leveling agents, matting agents, preservatives, antibacterial agents, fungicides, UV absorbers, antioxidants, coupling agents, and inorganic and organic fine particles other than those listed above for adjusting color tone. Additives are added to the extent that their properties are not degraded. Examples of curing agents include amine-based curing agents and isocyanate-based curing agents.

[0117] <Manufacturing Method of Sun-Shielding Coating>

[0118] The following describes a method for manufacturing the light-shielding coating used in this disclosure.

[0119] Any method can be used as a method for manufacturing the opaque coating used in this disclosure, as long as the inorganic particles and pigments that can be added to the opaque coating can be dispersed in the opaque coating. Examples include methods using bead mills, ball mills, spray mills, three-roll mills, planetary rotary devices, mixers, ultrasonic dispersers, and homogenizers, respectively.

[0120] When the average particle size of inorganic particles is greater than 200 nm, the film scatters light, which may degrade the appearance of the film.

[0121] [Light-shielding film]

[0122] The following describes the material composition of the light-shielding film according to the present disclosure and the method for forming the light-shielding film.

[0123] <Material Composition>

[0124] The material composition of the light-shielding film according to this disclosure is described below.

[0125] (Photosensitive resin material)

[0126] The photosensitive resin material in the light-shielding film according to this disclosure is described. The same material as described in the [Light-Shielding Coating] section above is used as the photosensitive resin material. The content of the photosensitive resin material in the light-shielding film according to this disclosure is preferably 5% by volume or more and 97% by volume or less, more preferably 30% by volume or more and 80% by volume or less. When the content of the photosensitive resin material in the light-shielding film according to this disclosure is less than 5% by volume, the light-shielding film becomes excessively hard, and film cracking may occur. When the content of the photosensitive resin material in the light-shielding film according to this disclosure is greater than 97% by volume, increasing the refractive index of the film may become difficult.

[0127] (Coloring agent)

[0128] The colorant is described. The same colorant as described in the [Opacifying Coatings] section above is used as the colorant.

[0129] The colorant content is preferably 1% by volume or more and 30% by volume or less, more preferably 2% by volume or more and 20% by volume or less. When the colorant content in the light-shielding film according to the present disclosure is less than 1% by volume, the light entering the film cannot be completely absorbed, and the optical properties may deteriorate. Furthermore, when the colorant content in the light-shielding film according to the present disclosure is greater than 30% by volume, the light-shielding film may not be able to be cured by UV light.

[0130] The optical density (ODt) of the light-shielding film according to this disclosure is preferably 0.14 μm. -1 Above and 0.53μm -1 Below, 0.2 μm is more preferred. -1 Above and 0.5μm -1 The following applies when ODt is less than 0.14 μm. -1 When the incident light is not completely absorbed, the optical properties may deteriorate. When ODt is greater than 0.53 μm... -1 When exposed to UV light, poor curing may occur.

[0131] (Inorganic particles)

[0132] Inorganic particles in a light-shielding film according to this disclosure are described. The same inorganic particles as those described in the above section [Light-shielding Coatings] are used as inorganic particles.

[0133] The inorganic particle content in the light-shielding film according to this disclosure is preferably 2% by volume or more and 70% by volume or less, more preferably in the range of 3% by volume or more and 40% by volume or less. When the inorganic particle content in the light-shielding film according to this disclosure is less than 2% by volume, the refractive index of the light-shielding film does not increase significantly, but the internal reflection prevention performance may deteriorate. Furthermore, when the inorganic particle content in the light-shielding film according to this disclosure is greater than 70% by volume, the thermal shock resistance may deteriorate.

[0134] (Photopolymerization initiator)

[0135] A photopolymerization initiator in a light-shielding film according to this disclosure is described. The same photopolymerization initiator described in the above section [Light-shielding Coatings] is used as the photopolymerization initiator.

[0136] The content of the photopolymerization initiator in the light-shielding film according to this disclosure is preferably 0.1% by volume or more and 15% by volume or less, more preferably in the range of 0.5% by volume or more and 10% by volume or less. When the content of the photopolymerization initiator in the light-shielding film according to this disclosure is less than 0.1% by volume, the reaction does not advance when irradiated with UV light, and the cleanability may deteriorate. Furthermore, when the content of the photopolymerization initiator in the light-shielding film according to this disclosure is greater than 15% by volume, the photopolymerization initiator may leach out of the film, thereby altering the glass composition.

[0137] (Compounds containing thiol groups)

[0138] Compounds having thiol groups in a light-shielding film according to this disclosure are described.

[0139] According to the present disclosure, the content of the thiol-containing compound in the light-shielding film is preferably 0.5 vol% or more and 40 vol% or less, more preferably in the range of 1 vol% or more and 10 vol% or less. When the content of the thiol-containing compound is less than 0.5 vol%, the reaction does not proceed when irradiated with UV light, and the cleanability may deteriorate. Furthermore, when the content of the thiol-containing compound is greater than 40 vol%, the film becomes excessively soft, and the water resistance may deteriorate.

[0140] (Other curing accelerators)

[0141] Other curing accelerators are described. The same curing accelerators described in the [Opacifying Coatings] section above are used as other curing accelerators.

[0142] The curing accelerator content in the light-shielding film according to this disclosure is preferably 0.1% by volume or more and 15% by volume or less, more preferably in the range of 0.5% by volume or more and 5% by volume or less. When the curing accelerator content is less than 0.1% by volume, the reaction is not advanced when irradiated with UV light, and the cleanability may deteriorate. Furthermore, when the curing accelerator content is greater than 15% by volume, the curing accelerator may leach out of the film, thereby altering the glass composition.

[0143] (Other additives)

[0144] The light-shielding film according to this disclosure may contain any other additives. Examples include curing agents, dispersants, defoamers, thixotropic agents, leveling agents, matting agents, preservatives, antibacterial agents, fungicides, UV absorbers, antioxidants, coupling agents, and inorganic and organic fine particles other than those listed above for adjusting color tone. Additives are added to the extent that their properties are not degraded. Examples of curing agents include amine-based curing agents and isocyanate-based curing agents.

[0145] (Ratio of curing reaction rate of the light-shielding film)

[0146] In recent years, the production of lenses has seen an increase in bonded lenses, in addition to unbonded lenses. With the thinning of the bonding portion and lens end face, and the increased manufacturing of soft glass, stress tends to be applied to the lens when a light-shielding film is formed on its outer periphery. Furthermore, these lenses are often used under conditions subject to significant thermal shock, such as in cold or hot regions. Therefore, it is necessary to reduce the stress on the lens caused by the light-shielding film. Assume the temperature in the cold region is approximately -30°C.

[0147] Furthermore, to remove the adhesion of extremely fine contaminants that occur during lens manufacturing, the lens needs to be ultrasonically cleaned multiple times after the light-shielding film is formed. Ultrasonic cleaning is performed at room temperature of approximately 20°C. It is crucial that the light-shielding film not peel off at the interface with the lens due to ultrasonic vibration during cleaning. Moreover, to improve lens manufacturing efficiency, cleaning needs to be performed immediately after the light-shielding film is formed and proceed to the next step. Therefore, resistance to ultrasonic cleaning is also required immediately after curing.

[0148] Based on the foregoing, in the light-shielding film according to this disclosure, the curing reaction rate of the first surface on the substrate side is lower than that of the second surface opposite to the first surface. When the curing reaction rates of the first and second surfaces are the same, it is difficult to simultaneously improve the immediate cleanliness and thermal shock resistance after curing. Furthermore, when the curing reaction rate of the first surface on the substrate side is higher than that of the second surface opposite to the first surface, both thermal shock resistance and immediate cleanliness after curing deteriorate. The first surface, measured by Fourier transform infrared spectroscopy (FT-IR), shows a curing rate of 1,407 cm⁻¹.-1 The absorbance at 700 cm⁻¹ is denoted by A1, and its absorbance at 700 cm⁻¹ is... -1 Up to 4,000cm -1 The average absorbance within the range is determined by A. avg 1 indicates. Furthermore, the second surface, measured by Fourier transform infrared spectroscopy, is at 1,407 cm⁻¹. -1 The absorbance at 700 cm⁻¹ is denoted by A², and its absorbance at 700 cm⁻¹ is... -1 Up to 4,000cm -1 The average absorbance within the range is determined by A. avg 2 indicates that, in this case, the ratio of the curing reaction rates of the first surface and the second surface can be calculated by the magnitude of the absorbance A measured by FT-IR and by the following formula (2).

[0149] R = (A² / A) avg 2) / (A1 / A avg 1) (2)

[0150] The value of R (the ratio of curing reaction rates) determined by formula (2) is preferably 0.1 or more and 0.99 or less. Furthermore, the value of R (the ratio of curing reaction rates) determined by formula (2) is more preferably 0.3 or more and 0.99 or less, even more preferably 0.5 or more and 0.99 or less, and most preferably 0.6 or more and 0.99 or less. When the ratio of curing reaction rates is less than 0.1, curing becomes insufficient, and the cleaning resistance may deteriorate. Furthermore, when the ratio of curing reaction rates is greater than 0.99, the thermal shock resistance may deteriorate.

[0151] (Ratio of elastic modulus of the light-blocking film)

[0152] For the same reason as the curing reaction rate of the light-shielding film, regarding the ratio of the elastic moduli of the light-shielding film according to this disclosure, it is preferable that the elastic modulus of the first surface on the substrate side is lower than the elastic modulus of the second surface opposite to the first surface. When the elastic moduli of the first surface and the second surface are the same, it is difficult to simultaneously improve the immediate cleaning resistance and thermal shock resistance after curing. Furthermore, when the elastic modulus of the first surface on the substrate side is higher than the elastic modulus of the second surface opposite to the first surface, both thermal shock resistance and immediate cleaning resistance after curing deteriorate. The elastic modulus can be measured using a nanoindenter, and the ratio of the elastic moduli is expressed by the following formula (3).

[0153] The ratio of elastic moduli = (elastic modulus of the first surface) / (elastic modulus of the second surface) (3) The ratio of elastic modulus of the light-shielding film according to this disclosure is preferably 0.1 or more and 0.99 or less. When the elastic moduli of the first surface and the second surface are the same, it is difficult to simultaneously improve the immediate cleaning resistance and thermal shock resistance after curing. Furthermore, when the elastic modulus of the first surface on the substrate side is higher than the elastic modulus of the second surface on the opposite side of the first surface, both the thermal shock resistance and the immediate cleaning resistance after curing deteriorate.

[0154] Furthermore, the ratio of the elastic modulus of the first surface to the second surface is preferably 0.01 or higher and 0.99 or lower, more preferably 0.1 or higher and 0.99 or lower. When the ratio of the elastic modulus is less than 0.01, curing becomes insufficient, and the cleaning resistance may deteriorate. Furthermore, when the ratio of the elastic modulus is greater than 0.99, the thermal shock resistance may deteriorate.

[0155] Furthermore, from the viewpoint of thermal shock resistance for light-shielding films intended for use in cold regions, the elastic modulus at -30°C is preferably 2,500 MPa or more and 6,000 MPa or less, more preferably 3,000 MPa or more and 4,900 MPa or less. When the elastic modulus of the light-shielding film at -30°C is less than 2,500 MPa, the elastic modulus at room temperature also decreases, thus potentially deteriorating its cleaning resistance. The elastic modulus can be set within a preferred range when the resin ratio of the light-shielding film is set to 87% by volume or more and 95% by volume or less. When the elastic modulus of the light-shielding film at -30°C is greater than 6,000 MPa, the lens may crack during thermal shock testing. Furthermore, assuming cleaning is performed at a room temperature near 20°C, the elastic modulus of the light-shielding film at 20°C is preferably 200 MPa or more and 4,000 MPa or less, more preferably 1,000 MPa or more and 2,600 MPa or less. When the elastic modulus of the light-shielding film at 20°C is less than 200 MPa, its cleaning resistance may deteriorate. Furthermore, when the elastic modulus of the light-shielding film at 20°C is greater than 4,000 MPa, its elastic modulus at -30°C also increases, thus the lens may crack during thermal shock testing.

[0156] Furthermore, from the viewpoint of improving thermal shock resistance, it is preferable that the elastic modulus of the light-shielding film is equal to or greater than the elastic modulus of the third optical element.

[0157] <Methods for forming a light-shielding film>

[0158] Regarding the thickness of the light-shielding film according to this disclosure, the average thickness of the entire coating is preferably 2 μm or more and 200 μm or less, more preferably 3 μm or more and 180 μm or less, and even more preferably 5 μm or more and 20 μm or less. The light-shielding film according to this disclosure is also formed in the chamfered portion, thus making it easy for liquid to accumulate in the light-shielding film. Therefore, the light-shielding film can have a thickness variation. Preferably, each of the end faces of the first optical element and the second optical element is formed to have an average thickness of 0.1 μm or more and 200 μm or less, preferably 1 μm or more and 150 μm or less, more preferably 2 μm or more and 30 μm or less. When the thickness of each of the end faces of the first optical element and the second optical element is less than 0.1 μm, the optical performance may deteriorate. When the thickness of each of the end faces of the first optical element and the second optical element is greater than 200 μm, the fitting accuracy with the lens barrel may deteriorate.

[0159] Preferably, the thickness of the light-shielding film formed in contact with the end face of the third optical element is at least 1 μm greater than the thickness of the light-shielding film formed in contact with the surface of the end face of the first optical element and / or the end face of the second optical element, excluding the chamfered portion.

[0160] Furthermore, the thickness of the light-shielding film in the chamfered portion is preferably 2 μm or more and 200 μm or less, more preferably 4 μm or more and 100 μm or less. When the thickness of the light-shielding film in the chamfered portion is less than 2 μm, light leakage may occur in the light-shielding film, resulting in a possible deterioration in light-shielding performance. When the thickness of the light-shielding film in the chamfered portion is greater than 200 μm, the stress on the lens increases, and the lens may crack when subjected to thermal shock.

[0161] Any coating and curing method can be used for the light-shielding coatings used in this disclosure, as long as the light-shielding coating can be applied evenly. Examples of coating methods for the light-shielding coatings used in this disclosure include brushing, spraying, dipping, spin coating, transfer printing, and inkjet printing. Furthermore, the light-shielding film can be applied by single-layer or multi-layer coating. Additionally, the glass surface can undergo dry surface treatment using UV ozone, plasma, or excimer lasers, or wet surface treatment using coupling agents, etc.

[0162] Furthermore, UV curing is preferred as the curing method for the light-shielding film according to this disclosure. UV curing does not involve heating, thus stress is less likely to accumulate on the optical device or the light-shielding film. Any device can be used for UV curing, as long as it can cure the photosensitive resin material. Examples include high-pressure mercury lamps, xenon lamps, and LEDs. Furthermore, UV irradiation can be point irradiation, surface irradiation, line irradiation, or a combination thereof. Regarding the direction of UV light application, UV light can be applied from any direction relative to the surface, and can be applied from directly above or at an angle. The distance between the light-shielding film and the end of the UV irradiator is preferably 1 mm or more and 50 cm or less, more preferably 5 mm or more and 10 cm or less. When the distance is less than 1 mm, the light-shielding film and the UV irradiator may come into contact with each other. Furthermore, when the distance is greater than 50 cm, the UV irradiation intensity may become insufficient. The UV irradiation intensity is preferably 10 mW / cm². 2 Above and 1,000 mW / cm 2 Below, 50mW / cm is preferred. 2 Above and 500mW / cm 2 The following applies when the UV irradiation intensity is less than 10 mW / cm². 2 At this time, the curing time may become excessively long. Furthermore, when the UV irradiation intensity exceeds 1000 mW / cm², the curing time may also become excessive. 2 During this process, the light-shielding film may be heated, thus accumulating stress. Furthermore, the UV irradiation time is preferably 1 second or more and 10 minutes or less, more preferably 20 seconds or more and 5 minutes or less. When the UV irradiation time is less than 1 second, curing may become insufficient. Additionally, when the UV irradiation time is greater than 10 minutes, the curing time may become too long to be considered short.

[0163] Thermal curing or moisture curing can be used in conjunction with UV curing. When thermal curing is used in conjunction with UV curing, curing can be performed using a heating oven or heater, or infrared heating. The curing temperature is preferably from 0°C to 100°C, more preferably from 23°C to 80°C. When the curing temperature is below 0°C, poor curing may occur. Furthermore, when the curing temperature is above 100°C, the stress on the optical components or light-shielding film increases, and the thermal shock resistance may deteriorate.

[0164] [Example]

[0165] Exemplary embodiments in this disclosure are described below.

[0166] The various evaluations, preparation of the light-blocking coatings, and production of the light-blocking films in each of Examples 1 to 18 were carried out by the following methods.

[0167] <Evaluation Methods>

[0168] Figure 9Schematic cross-sectional views of test specimens used to evaluate the ratio of curing reaction rate, the ratio of elastic modulus, thermal shock resistance, and cleaning resistance are shown. Figure 9 As shown, the test piece used to evaluate the curing reaction rate ratio includes: a glass component in which two circular glass pieces (i.e., a first monitoring glass 51 and a second monitoring glass 52), each including a chamfered portion 15, are bonded together by an adhesive 53; and a light-shielding film 1 formed on the outer peripheral surface of the glass component. The first and second monitoring glasses each have a thickness of 5 mm and an outer diameter of 40 mm. The outer peripheral portion of each of the first monitoring glass 51 and the second monitoring glass 52 is finished by #1200 fine grinding. Furthermore, the outer periphery of the joint of the first monitoring glass 51 and the second monitoring glass 52 is connected to each chamfered portion 15 with a length of 0.3 mm. In each of Examples 1 to 18, a light-shielding coating is applied to the outer peripheral surface of the glass component using a dispenser, such that the maximum thickness 54 of the light-shielding film 1 in the groove is 40 μm (5 μm in Example 11), and the average thickness of the light-shielding film 1 in each flat portion 55 is 5 μm, and then allowed to air dry for 1 hour. The dried test pieces are then cured under the corresponding conditions described in Examples 1 to 18. The minimum thickness of the light-shielding film 1 in each flat portion 55 is 1 μm (5 μm in Example 11).

[0169] <Method for measuring the ratio of curing reaction rate>

[0170] The curing reaction rate was measured using FT-IR. The sample produced for the reaction rate measurement was placed in an FT-IR spectrometer (Spectrum Two+, manufactured by PerkinElmer Japan GK), and measurements were taken at 700 cm⁻¹ using the attenuated total reflectance (ATR) method. -1 Up to 4,000cm -1 The absorbance A is measured within the range of [value missing]. The first surface 17 and the second surface 18 of the light-shielding film 1 are measured. The first surface 17 is measured by peeling off the coating with a cutter after the light-shielding film has cured, and pressing the back side of the peeled film against the sample mounting surface of the spectrometer. The second surface 18 is measured by peeling off the light-shielding film 1 and pressing the surface of the peeled film against the sample mounting surface of the spectrometer. The ratio of the curing reaction rates is calculated from the obtained results using the above equation (2).

[0171] <Method for measuring the ratio of elastic modulus>

[0172] For the measurement of the ratio of elastic modulus, it is used in the same manner as the measurement of the ratio of curing reaction rate. Figure 9The test piece shown is an example. Furthermore, the elastic modulus was measured using a nanoindenter. The test piece, comprising the light-shielding film 1 formed on the glass component, was naturally dried for 1 hour in the same manner as the ratio used to measure the curing reaction rate, and then cured under the corresponding conditions described in Examples 1 to 18. The sample produced for the ratio of elastic modulus measurement was placed in a nanoindenter (Nano Indenter G200, manufactured by Toyo Corporation), and the elastic modulus of the first surface 17 and the second surface 18 of the light-shielding film 1 accumulated in the groove formed by the end faces of the chamfered portion 15 and the adhesive 53 was measured. The elastic modulus of the first surface 17 was evaluated by grinding and shaving the coating to a thickness of 0.5 μm, and measuring the elastic modulus from the coating surface adjusted to a thickness of 0.5 μm to a depth of 50 nm. Furthermore, the elastic modulus of the second surface 18 was evaluated by measuring the elastic modulus from the coating surface to a depth of 50 nm.

[0173] <Methods for measuring internal surface reflectivity>

[0174] Figure 8 This is a schematic diagram illustrating the method for measuring the reflectivity of an inner surface. For example... Figure 8 As shown, the internal surface reflectance was measured using a spectrophotometer (U-4100, manufactured by Hitachi High-Tech Corporation). A triangular prism 50 was used as the measurement sample. The triangular prism 50 has a shape comprising two sides forming a right angle, each with a length of 30 mm, a thickness of 10 mm, and is made of S-LAH53 (n d =1.8 (manufactured by Ohara Inc.)

[0175] Figure 8 The method for measuring the internal surface reflectance of a triangular prism 50 at an incident angle “b” of 90° relative to the prism 50 is shown. Light emitted from a spectrophotometer enters the triangular prism 50 at an incident angle “b” of 90°. In this case, refraction of light occurs based on the difference between the refractive index of air and the refractive index of the triangular prism 50. The incident angle “c” after refraction is 68.13°. The angle “e” after refraction relative to the incident angle “d” is calculated using the following formula (4). Furthermore, the incident angle “c” is calculated from the angle “e” after refraction.

[0176] n = sin d / sin e (4)

[0177] Next, the light refracted by the triangular prism 50 strikes the bottom surface of the triangular prism 50, is reflected from it, and exits the triangular prism 50. The intensity of this reflected light in the visible light region with wavelengths from 400 nm to 700 nm is detected using a detector. The background is measured using a triangular prism 50 with three mirror-finished surfaces—a bottom surface, an incident surface, and a reflecting surface—and with nothing coated on the bottom surface as a sample. The internal surface reflectivity is measured using a triangular prism 50 with three mirror-finished surfaces—a bottom surface, an incident surface, and a reflecting surface—and with a film formed on the bottom surface.

[0178] Furthermore, internal reflectivity was obtained by measuring the internal reflection of visible light at wavelengths from 400 nm to 700 nm at 1 nm intervals, and the average value of the results was determined. Internal reflectivity was evaluated based on the following criteria: "A" indicates an extremely excellent film with an internal reflectivity of less than 40%. "B" indicates an excellent film with an internal reflectivity of 40% or more but less than 50%. "C" indicates a film with an internal reflectivity of 50% or more but less than 60%, slightly worse in internal reflectivity, but without practical problems. "D" indicates a film with an internal reflectivity of 60% or more and poor optical properties.

[0179] A: The internal surface reflectivity is less than 40%.

[0180] B: The internal surface reflectivity is above 40% and below 50%.

[0181] C: The internal surface reflectivity is greater than 50% and less than 60%.

[0182] D: The internal surface reflectivity is over 60%.

[0183] <Evaluation Methods for Thermal Shock Resistance>

[0184] For the evaluation of thermal shock resistance, the method used is the same as that used to measure the curing reaction rate. Figure 9The test piece shown is an optical device. A light-shielding coating is applied to the outer peripheral surface of the glass component using a dispenser, such that the maximum thickness 54 of the light-shielding film 1 in the groove is 40 μm (5 μm in Example 11), and the average thickness of the light-shielding film 1 in each flat portion 55 is 5 μm. Furthermore, the test piece with the light-shielding film 1 formed on it is allowed to air dry for 1 hour, and then cured under the corresponding conditions described in Examples 1 to 18. The produced test piece is placed at -50°C for 30 minutes, and then at 60°C for 30 minutes. This operation is defined as one cycle, and 10 cycles are repeated to apply thermal shock. Thermal shock resistance is evaluated based on the following criteria: "A" indicates an optical device with no practical problems in terms of thermal shock resistance. "B" indicates an optical device in which a white line less than 0.5 mm in length is observed on the boundary surface between the light-shielding film and the chamfer, and slight changes are observed in appearance, within the range that do not cause practical problems. "C" indicates an optical device with a white line longer than 0.5 mm but shorter than 1 mm observed on the boundary surface between the light-shielding film and the chamfer, and a change observed in appearance, within the range that does not cause practical problems. "D" indicates an optical device with an appearance defect longer than 1 mm observed on the boundary surface between the light-shielding film and the chamfer, and glass cracking observed, meaning that the optical device has problems with thermal shock resistance.

[0185] A: No changes were observed in the light-shielding film and glass.

[0186] B: Slight changes were observed in the light-shielding film, within a range that would not cause problems.

[0187] C: Changes were observed in the light-shielding film, within a range that did not cause problems.

[0188] D: Appearance defects were observed in the light-shielding film, and glass cracks were also observed.

[0189] (Evaluation method for cleaning resistance)

[0190] For the evaluation of cleaning resistance, in the same manner as the evaluation of the curing reaction rate, it was performed by applying adhesive 53. Figure 9 The test piece is formed by bonding the first monitoring glass 51 and the second monitoring glass 52 together and forming a light-shielding film 1 on their outer peripheral surface under the corresponding conditions of Examples 1 to 18.

[0191] The produced test pieces were placed in water and subjected to ultrasonic cleaning for 5 minutes, then dried. Ultrasonic cleaning was performed 5 times. Cleaning resistance was evaluated based on the following criteria: "A" indicates that no peeling was observed and no color change was observed within the lens, indicating a light-shielding film with no practical problems. "B" indicates that no peeling was observed and a slight color change was observed within the lens, within the range that does not cause practical problems. "C" indicates that slight peeling was observed and a slight color change was observed within the lens, within the range that does not cause practical problems. "D" indicates that peeling was observed in the light-shielding film.

[0192] A: No peeling was observed and no color change was observed within the lens.

[0193] B: No peeling was observed and a slight change in color was observed within the lens, which is within the range that does not cause practical problems.

[0194] C: Slight peeling was observed and a slight change in color was observed within the lens, within the range that does not cause practical problems.

[0195] D: Delamination was observed.

[0196] <Thickness Measurement Methods>

[0197] The thickness of the optical device was measured by grinding the cut cross-section of the sample and measuring the cut cross-section using a field emission scanning electron microscope (ULTRA 55, manufactured by Carl Zeiss AG).

[0198] (Example 1)

[0199] <Preparation of Opacifying Coatings>

[0200] In Example 1, the light-blocking coating was produced by the following method.

[0201] Weigh 600g of photosensitive resin material A, 30g of colorant A, 200g of inorganic particles A, 5g of coupling agent A, 30g of dispersant A, and 600g of solvent A. Place all weighed raw materials in a container and stir with a stirring blade for 20 minutes to provide a pre-dispersion. Stir the pre-dispersion using a bead mill for 180 minutes to provide the base of the light-blocking coating of Example 1.

[0202] Toluene was used as solvent A. Rutile titanium dioxide was used as inorganic particles A with an d-line refractive index of 2.0 or higher and an average particle size of 200 nm or less. Carbon black was used as colorant A. DISPERBYK-2155 (manufactured by BYK JapanKK) was used as dispersant A. Acrylic resin was used as photosensitive resin material A.

[0203] An epoxy silane coupling agent (KBM-403, manufactured by Shin-Etsu Silicones) was used as coupling agent A.

[0204] Next, 12g of photopolymerization initiator A and 20g of compound A with thiol groups were added to 180g of the light-blocking coating main agent of Example 1 to provide the light-blocking coating of Example 1.

[0205] <Production of Light-Shielding Film>

[0206] In Example 1, the light-shielding film was produced by the following method.

[0207] The obtained light-shielding coating was applied to glass or a lens to a predetermined thickness and dried at room temperature for 10 minutes. After the film dried, it was irradiated with a UV irradiator EXECURE 4000-D (manufactured by HOYA Corporation) at 200 mW / cm². 2 Irradiate with UV light at a certain intensity for 5 minutes to provide the membrane of Example 1.

[0208] S-FPL53 (manufactured by Ohara Inc., linear expansion coefficient: 14.5ppm) was used as the first monitoring glass.

[0209] Quartz S-FPL53 (manufactured by Ohara Inc., linear expansion coefficient: 0.5ppm) was used as the second monitoring glass.

[0210] Production of samples used to evaluate the ratio of curing reaction rate, elastic modulus ratio, thermal shock resistance, and cleanability.

[0211] For the production of samples used to evaluate the curing reaction rate ratio, elastic modulus ratio, thermal shock resistance, and cleanability, S-FPL55 (manufactured by Ohara Inc., linear expansion coefficient: 13.6 ppm) was used as the first monitoring glass. The first monitoring glass was processed such that the diameter of the optics was 65 mm, the chamfer length of the first optical element was 0.3 mm, and the radius of curvature of the rounded corners was 0.3 mm. Furthermore, quartz S-FPL53 (manufactured by Ohara Inc., linear expansion coefficient: 0.5 ppm) was used as the second monitoring glass. The second monitoring glass was processed such that the diameter of the optics was 65 mm, the chamfer length of the second optical element was 0.3 mm, and the radius of curvature of the rounded corners was 0.3 mm. OP-1030M (manufactured by Denka Company Limited) was used as adhesive A, and curing was performed using UV light.

[0212] (Examples 2 to 18)

[0213] In each of Examples 2 to 18, the light-shielding film is produced in the same manner as in Example 1, except that the materials and conditions in Tables 1-1, 1-2, 2-1, 2-2, 3-1, 3-2 and 4 are used.

[0214] The same colorant, inorganic particles, coupling agent, dispersant, and solvent were used in all examples and comparative examples.

[0215] M-240 (manufactured by Toagosei Co., Ltd.) was used as photosensitive resin material B. CELLOXIDE2021P (manufactured by Daicel Chemical Industries, Ltd.) was used as photosensitive resin material C. WPI-113 (manufactured by FUJIFILM Corporation) was used as photopolymerization initiator B. 1-Eocenediol (manufactured by Tokyo Chemical Industry Co., Ltd.) was used as compound B containing a thiol group. Karenz MT PE1 (manufactured by Resonac Corporation) was used as compound C containing a thiol group. Nikkacure TG-10 (manufactured by Nippon Chemical Industrial Co., Ltd.) was used as curing accelerator A.

[0216] A mixture of 100g of OP-1505 (manufactured by Denka Company Limited), 150g of xylene resin Y-50 (manufactured by Fudow Co., Ltd.), and 1g of photopolymerization initiator A is used as adhesive B. A mixture of 10g of AEROSIL R972 (manufactured by Nippon Aerosil Co., Ltd.) and 100g of OP-3010P (manufactured by Denka Company Limited) is used as adhesive C. A mixture of 1g of photopolymerization initiator A and 100g of ACRYDIC WFU-580 (manufactured by DICCorporation) is used as adhesive D. A mixture of 30g of AEROSIL R972 (manufactured by Nippon Aerosil Co., Ltd.) and 1g of photopolymerization initiator A with 100g of ACRYDIC WFU-580 is used as adhesive E.

[0217] Table 1-1

[0218]

[0219] Table 1-2

[0220]

[0221] Table 2-1

[0222]

[0223] Table 2-2

[0224]

[0225] Table 3-1

[0226]

[0227] Table 3-2

[0228]

[0229] Table 4

[0230]

[0231] <Evaluation Results>

[0232] The results obtained by evaluating the thermal shock resistance, cleaning resistance, inner surface reflectivity, and curing time of each light-shielding film of Examples 1 to 18 using the methods described above are shown in Tables 5 to 8.

[0233] As an evaluation result, in the thermal shock resistance test, it is preferable that no change or slight change is observed in the light-shielding film of the optics, and that the change falls within a range that does not cause problems. Furthermore, in the cleanliness resistance test, it is preferable that there is no peeling or slight peeling of the light-shielding film on the optics, and that no change or slight change in color is observed inside the lens, and that the result falls within a range that does not cause problems. Furthermore, it is preferable that the internal surface reflectivity is less than 60%. Furthermore, it is preferable that the curing time using UV light is less than 10 minutes.

[0234] In Example 1, the main component of the light-blocking coating was produced using photosensitive resin material A, colorant A, inorganic particles A, coupling agent A, dispersant A, and solvent. Furthermore, the light-blocking coating was produced by mixing the produced main component, photopolymerization initiator A, and compound A containing thiol groups. The light-blocking coating was applied to each evaluation test piece to form a light-blocking film, and the thermal shock resistance, cleaning resistance, and internal reflectivity of the film were evaluated. As shown in Table 5, no change in thermal shock resistance was observed, therefore the results are satisfactory. Furthermore, regarding cleaning resistance, no film peeling and no color change within the lens were observed. Additionally, the internal reflectivity was less than 40%, therefore the results are satisfactory. Furthermore, the curing time was 5 minutes, which is short and satisfactory.

[0235] In Example 2, the light-shielding film was produced in the same manner as in Example 1, except that a light-shielding coating containing 12g of curing accelerator A was used. As shown in Table 5, no change in thermal shock resistance was observed, therefore the results are satisfactory. Furthermore, regarding cleanability, no film peeling and no color change within the lens were observed. Additionally, the internal surface reflectivity was less than 40%, therefore the results are satisfactory. Furthermore, the curing time was 5 minutes, which is short and satisfactory.

[0236] In Example 3, the light-shielding film was produced in the same manner as in Example 1, except that a material providing a third optical element with an elastic modulus of 0.1 MPa was used. As shown in Table 5, no change in thermal shock resistance was observed, so the results are satisfactory. Furthermore, regarding cleanability, no film peeling and no color change within the lens were observed. Additionally, the internal surface reflectivity was less than 40%, so the results are satisfactory. Furthermore, the curing time was 5 minutes, which is short and satisfactory.

[0237] In Example 4, the light-shielding film was produced in the same manner as in Example 1, except that a material providing a third optical element with an elastic modulus of 700 MPa was used. As shown in Table 5, a slight change in thermal shock resistance was observed in the light-shielding film, which fell within a range that did not cause problems. Furthermore, regarding cleanability, no peeling of the film and no color change within the lens were observed. Additionally, the internal surface reflectivity was less than 40%, thus the results were satisfactory. Furthermore, the curing time was 5 minutes, which was short and satisfactory.

[0238] In Example 5, the light-shielding film was produced in the same manner as in Example 1, except that a third optical element with an elastic modulus of 2,500 MPa was used. As shown in Table 5, changes in thermal shock resistance were observed in the light-shielding film, which fell within a range that did not cause problems. Furthermore, regarding cleanability, no peeling of the film and no color change within the lens were observed. Additionally, the internal surface reflectivity was less than 40%, thus the results were satisfactory. Furthermore, the curing time was 5 minutes, which was short and satisfactory.

[0239] In Example 6, the light-shielding film was produced in the same manner as in Example 1, except that a third optical element with an elastic modulus of 3,000 MPa was used. As shown in Table 6, changes in thermal shock resistance were observed in the light-shielding film, which fell within a range that did not cause problems. Furthermore, regarding cleanability, no peeling of the film and no color change within the lens were observed. Additionally, the internal surface reflectivity was less than 40%, thus the results were satisfactory. Furthermore, the curing time was 5 minutes, which was short and satisfactory.

[0240] In Example 7, the light-shielding film was produced in the same manner as in Example 1, except that a light-shielding coating comprising a non-hydroxyl-containing photosensitive resin material B was used as the photosensitive resin material. As shown in Table 6, no change in thermal shock resistance was observed, therefore the results are satisfactory. Furthermore, regarding cleanability, no peeling of the film was observed, but a slight change in color within the lens was observed, which was within a range that did not cause problems. Additionally, the internal surface reflectivity was less than 40%, therefore the results are satisfactory. Furthermore, the curing time was 5 minutes, which is short and satisfactory.

[0241] In Example 8, the light-shielding film was produced in the same manner as in Example 1, except that a light-shielding coating comprising photosensitive resin material C having epoxy groups as the photosensitive resin material and photopolymerization initiator B as the photopolymerization initiator was used. As shown in Table 6, a slight change in thermal shock resistance was observed in the light-shielding film, which fell within a range that did not cause problems. Furthermore, regarding cleanability, no peeling of the film was observed and no color change was observed within the lens. In addition, the internal surface reflectivity was less than 40%, so the results were satisfactory. Furthermore, the curing time was 5 minutes, which was short and satisfactory.

[0242] In Example 9, the light-shielding film was produced in the same manner as in Example 1, except that a light-shielding coating containing compound B (a monofunctional thiol) with a thiol group was used as the compound with the thiol group. As shown in Table 6, no change in thermal shock resistance was observed, so the results are satisfactory. Furthermore, regarding cleanability, no peeling of the film was observed, but a slight change in color within the lens was observed, which was within a range that did not cause problems. Additionally, the internal surface reflectivity was less than 40%, so the results are satisfactory. Furthermore, the curing time was 5 minutes, which is short and satisfactory.

[0243] In Example 10, the light-shielding film was produced in the same manner as in Example 1, except that compound C, which contains an ester bond and has a thiol group, was used as the compound with the thiol group. As shown in Table 6, no change in thermal shock resistance was observed, so the results are satisfactory. Furthermore, regarding cleanability, slight peeling of the film and slight color change within the lens were observed, but these results are within a non-problematic range. Additionally, the internal surface reflectivity is less than 40%, so the results are satisfactory. Furthermore, the curing time is 5 minutes, which is short and satisfactory.

[0244] In Example 11, the light-shielding film was produced in the same manner as in Example 1, except that the difference between the maximum and minimum thickness was adjusted to less than 1 μm. As shown in Table 7, no change in thermal shock resistance was observed, so the results are satisfactory. Furthermore, regarding cleanability, no film peeling and no color change within the lens were observed. Additionally, the internal surface reflectivity was less than 40%, so the results are satisfactory. Furthermore, the curing time was 5 minutes, which is short and satisfactory.

[0245] In Example 12, the light-shielding film was produced in the same manner as in Example 1, except that a light-shielding film was used that employed a curing process of 2 minutes to adjust the curing reaction rate to 0.6. As shown in Table 7, no change in thermal shock resistance was observed, therefore the results are satisfactory. Furthermore, regarding cleanability, no film peeling and no color change within the lens were observed. Additionally, the internal surface reflectivity was less than 40%, therefore the results are satisfactory. Furthermore, the curing time of 2 minutes is short and satisfactory.

[0246] In Example 13, the light-shielding film was produced in the same manner as in Example 1, except that a light-shielding film was used that employed a curing time of 0.5 minutes to adjust the curing reaction rate to 0.31. As shown in Table 7, no change in thermal shock resistance was observed, therefore the results were satisfactory. Furthermore, regarding cleanability, no film peeling was observed, but a slight change in color within the lens was observed, which was within a non-problematic range. Additionally, the internal surface reflectivity was less than 40%, therefore the results were satisfactory. Furthermore, the curing time of 0.5 minutes was short and satisfactory.

[0247] In Example 14, the light-shielding film was produced in the same manner as in Example 1, except that a light-shielding film was used that employed a curing time of 20 seconds to adjust the curing reaction rate to 0.29. As shown in Table 7, no change in thermal shock resistance was observed, therefore the results are satisfactory. Furthermore, regarding cleanability, no film peeling was observed, but a slight change in color within the lens was observed, which was within a non-problematic range. Additionally, the internal surface reflectivity was less than 40%, therefore the results are satisfactory. Furthermore, the curing time of 20 seconds is short and satisfactory.

[0248] In Example 15, in addition to using optical density (ODt) / μm -1Except for the light-shielding coating adjusted to 0.14, the light-shielding film was produced in the same manner as in Example 1. As shown in Table 7, no change in thermal shock resistance was observed, so the results are satisfactory. Furthermore, regarding cleanability, no film peeling and no color change within the lens were observed. Additionally, the internal surface reflectance was above 40% and below 50%, a result that falls within a non-problematic range. Moreover, the curing time was 5 minutes, which is short and satisfactory.

[0249] In Example 16, in addition to using optical density (ODt) / μm -1 Except for the light-shielding coating adjusted to 0.53, the light-shielding film was produced in the same manner as in Example 1. As shown in Table 8, no change in thermal shock resistance was observed, so the results are satisfactory. Furthermore, regarding cleanability, slight peeling of the film and slight color change within the lens were observed, but these results are within a non-problematic range. Additionally, the internal surface reflectivity is less than 40%, so the results are satisfactory. Moreover, the curing time is 5 minutes, which is short and satisfactory.

[0250] In Example 17, in addition to using optical density (ODt) / μm -1 Except for the light-shielding coating adjusted to 0.12, the light-shielding film was produced in the same manner as in Example 1. As shown in Table 8, no change in thermal shock resistance was observed, so the results are satisfactory. Furthermore, regarding cleanability, no film peeling and no color change within the lens were observed. Additionally, the internal surface reflectance was greater than 50% and less than 60%, a result that falls within a non-problematic range. Moreover, the curing time was 5 minutes, which is short and satisfactory.

[0251] In Example 18, in addition to using optical density (ODt) / μm -1 Except for the light-shielding coating adjusted to 0.55, the light-shielding film was produced in the same manner as in Example 1. As shown in Table 8, no change in thermal shock resistance was observed, so the results are satisfactory. Furthermore, regarding cleanability, slight peeling of the film and slight color change within the lens were observed, but these results are within a non-problematic range. Additionally, the internal surface reflectivity is less than 40%, so the results are satisfactory. Moreover, the curing time is 5 minutes, which is short and satisfactory.

[0252] Table 5

[0253]

[0254] Table 6

[0255]

[0256] Table 7

[0257]

[0258] Table 8

[0259]

[0260] (Comparative Examples 1 to 3)

[0261] In each of Comparative Examples 1 to 3, the light-shielding film was produced in the same manner as in Example 1, except that the materials and conditions in Table 9 were used.

[0262] The materials and mixing ratios of the coatings and hardeners for each of Comparative Examples 1 to 3 are shown in Table 9.

[0263] Table 10 shows the evaluation results of Comparative Examples 1 to 3, each using the coatings and hardeners listed in Table 9.

[0264] In Comparative Example 1, the light-shielding film was produced in the same manner as in Example 1, except that a light-shielding coating without the addition of compounds containing thiol groups was used. As shown in Table 10, no change in thermal shock resistance was observed, so the results were satisfactory. However, regarding cleanability, significant peeling of the light-shielding film was observed. The inner surface reflectivity was less than 40%, so the results were satisfactory. Furthermore, the curing time was 5 minutes, which was short and satisfactory.

[0265] In Comparative Example 2, the light-shielding film was produced in the same manner as in Example 1, except that a light-shielding coating without thiol groups was used and curing accelerator A was added. As shown in Table 10, no change in thermal shock resistance was observed, so the results are satisfactory. However, regarding cleaning resistance, slight peeling of the film was observed. Furthermore, the internal reflectivity was less than 40%, so the results are satisfactory. In addition, the curing time was 5 minutes, which is short and satisfactory.

[0266] In Comparative Example 3, the light-shielding film was produced in the same manner as in Example 1, except that it was cured using UV light applied from the back of the film with a curing reaction rate ratio of 1.02. As shown in Table 10, appearance defects and glass cracking were observed in the thermal shock resistance test. However, no change was observed in the cleaning resistance. The internal surface reflectivity was less than 40%, so the results were satisfactory. Furthermore, the curing time was 5 minutes, which was short and satisfactory.

[0267] Table 9

[0268]

[0269] Table 10

[0270]

[0271] According to this disclosure, optical devices with excellent manufacturability and environmental resistance can be provided, as well as light-shielding films that contribute to the optical devices.

[0272] The optical devices and light-shielding films disclosed herein can each be used in the lens barrels of, for example, cameras, video cameras, or broadcasting equipment, or in camera bodies, video recorder bodies, surveillance cameras, vehicle cameras, or weather cameras that can be used outdoors.

[0273] Although this disclosure has been described with reference to embodiments, it should be understood that this disclosure is not limited to the disclosed embodiments. The scope of the appended claims should be given the broadest interpretation to cover all such modifications and equivalent structures and functions.

Claims

1. An optical device comprising: First optical element; Second optical element; A third optical element is configured to join the first optical element and the second optical element together; as well as A light-shielding film continuously formed in contact with the end faces of the first optical element, the second optical element, and the third optical element. The light-shielding film mentioned above is a cured film of a photosensitive resin composition. The end face of the first optical element and / or the end face of the second optical element includes a chamfered portion formed by contacting the outer periphery of the mating surface of the first optical element and / or the second optical element. The curing rate of the photosensitive resin composition on the first surface of the light-shielding film that contacts the end faces of the first and second optical elements is lower than the curing rate of the photosensitive resin composition on the second surface opposite to the first surface. The light-shielding film contains a compound having a thiol group.

2. The optical device according to claim 1, wherein the elastic modulus of the light-shielding film is equal to or greater than the elastic modulus of the third optical element.

3. The optical device according to claim 1, wherein the photosensitive resin composition comprises a polymeric compound having an acryloyl group and a hydroxyl group.

4. The optical device according to any one of claims 1 to 3, wherein the compound having a thiol group is a polyfunctional thiol.

5. The optical device according to any one of claims 1 to 3, wherein the compound having a thiol group does not contain an ester bond.

6. The optical device according to any one of claims 1 to 3, wherein the thickness of the light-shielding film formed in contact with the end face of the third optical element is at least 1 μm greater than the thickness of the light-shielding film formed in contact with the surface of the end face of the first optical element and / or the end face of the second optical element, excluding the chamfered portion.

7. The optical device according to any one of claims 1 to 3, wherein the optical density ODt of the light-shielding film is 0.14 μm. -1 Above and 0.53μm -1 the following.

8. The optical device according to any one of claims 1 to 3, wherein, When the first surface, measured by Fourier transform infrared spectroscopy, is at 1,407 cm⁻¹ -1 The absorbance at 700 cm⁻¹ is denoted by A1, and its absorbance at 700 cm⁻¹ is... -1 Up to 4,000cm -1 The average absorbance within the range is determined by A. avg 1 indicates that, and when the second surface is measured by Fourier transform infrared spectroscopy at 1,407 cm⁻¹ -1 The absorbance at 700 cm⁻¹ is denoted by A², and its absorbance at 700 cm⁻¹ is... -1 Up to 4,000cm -1 The average absorbance within the range is determined by A. avg When represented by 2, the value of R determined by the following formula (2) is greater than or equal to 0.1 and less than or equal to 0.99: R=(A2 / A avg 2) / (A1 / A avg 1) (2)。 9. The optical device according to claim 8, wherein the value of R is 0.3 or more and 0.99 or less.

10. The optical device according to claim 8, wherein the value of R is 0.6 or more and 0.99 or less.

11. An optical instrument comprising: case; and An optical system, configured inside the housing, includes at least one lens. The at least one lens is an optical device according to any one of claims 1 to 10.

12. A camera device, comprising: case; An optical system, configured inside the housing and comprising at least one lens; and A camera device configured to receive light passing through the optical system. The at least one lens is an optical device according to any one of claims 1 to 10.

13. A light-shielding film for use by forming on an optical device, said optical device including a first optical element, a second optical element, and a third optical element configured to join the first optical element and the second optical element together, wherein the end face of the first optical element and / or the end face of the second optical element includes a chamfered portion formed in contact with the outer periphery of the joining surface of the first optical element and / or the second optical element, and the light-shielding film contacts the end face of the first optical element, the end face of the second optical element, and the end face of the third optical element. The light-shielding film mentioned above is a cured film of a photosensitive resin composition. The light-shielding film has a first surface that contacts the end faces of the first optical element and the second optical element, and a second surface on the opposite side of the first surface. The curing rate of the photosensitive resin composition on the first surface is lower than that on the second surface, and The light-shielding film contains a compound having a thiol group.

14. The light-shielding film of claim 13, wherein the photosensitive resin composition comprises a polymeric compound having an acryloyl group and a hydroxyl group.

15. The light-shielding film according to claim 13 or 14, wherein the compound having a thiol group is a polyfunctional thiol.

16. The light-shielding film according to claim 13 or 14, wherein the compound having a thiol group does not contain an ester bond.

17. The light-shielding film according to claim 13 or 14, wherein the thickness of the portion of the light-shielding film formed in contact with the end face of the third optical element is at least 1 μm greater than the thickness of the portion of the light-shielding film formed in contact with the surface of the portion other than the chamfered portion of the end face of the first optical element and / or the end face of the second optical element.

18. The light-shielding film according to claim 13 or 14, wherein the optical density ODt of the light-shielding film is 0.14 μm. -1 Above and 0.53μm -1 the following.

19. The light-shielding film according to claim 13 or 14, wherein, When the first surface, measured by Fourier transform infrared spectroscopy, is at 1,407 cm⁻¹ -1 The absorbance at 700 cm⁻¹ is denoted by A1, and its absorbance at 700 cm⁻¹ is... -1 Up to 4,000cm -1 The average absorbance within the range is determined by A. avg 1 indicates that, and when the second surface is measured by Fourier transform infrared spectroscopy at 1,407 cm⁻¹ -1 The absorbance at 700 cm⁻¹ is denoted by A², and its absorbance at 700 cm⁻¹ is... -1 Up to 4,000cm -1 The average absorbance within the range is determined by A. avg When represented by 2, the value of R determined by the following formula (2) is greater than or equal to 0.1 and less than or equal to 0.

99. R=(A2 / A avg 2) / (A1 / A avg 1) (2)。 20. The light-shielding film according to claim 19, wherein the value of R is 0.3 or more and 0.99 or less.

21. The light-shielding film according to claim 19, wherein the value of R is 0.6 or more and 0.99 or less.

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