Optical product

Abstract

To provide an optical product capable of having various optical characteristics in addition to antifogging properties while suppressing the occurrence of cracks.SOLUTION: The optical product 1 includes a base material 2, a water absorbing layer 4 directly or indirectly arranged on a film arrangement surface M of the base material 2, and a multilayer film 6 arranged on an anti-base material side of the water absorbing layer 4. The multilayer film 6 includes one or more low refractive index layers 10 and one or more high refractive index layers 12. The water-absorbing layer 4 and the high refractive index layer 12 are obtained from a composition containing a (meth) acrylic resin (A) having specific proportions of structural units derived from specific monomers (a- 1) to (a- 4), a polyfunctional isocyanate compound (B), and an epoxide (C) that is an organic compound having a plurality of epoxy groups.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an optical product with anti-fogging properties. [Background technology]

[0002] A known coating composition capable of forming an anti-fogging cured film, which has the property of suppressing fogging, on the surface of an article is described in Japanese Patent No. 6340539 (Patent Document 1). This coating composition contains a (meth)acrylic resin (A) having structural units (a-1) to (a-4) derived from four types of monomers, a polyol compound (B), and a polyfunctional isocyanate compound (C), each in a specified range of mass %. This coating composition is constructed as follows: The structural unit (a-1) of (A) has an amide group, which allows it to easily hold and absorb moisture. (C) crosslinks with (A) to form a cured film. However, if the crosslink density of (a-1) after curing is too high, the gaps through which moisture can penetrate become small, making it difficult for moisture to be absorbed. Therefore, by incorporating (B) as a crosslinking aid, gaps for moisture absorption are created while maintaining the required crosslink density. The structural unit (a-2) of (A) has a polycaprolactone structure, and its flexible chemical skeleton improves the flexibility and elasticity of the cured film, thereby improving the scratch resistance of the cured film. The structural unit (a-4) of (A) has a polydimethylsiloxane chain, which improves the slipperiness of the cured film, improving the scratch resistance of the cured film. The structural unit (a-3) of (A) is a hydroxyalkyl (meth)acrylate, which is harder than (a-2) in the cured film, and adjusts the flexibility provided mainly by (a-2) to achieve a good balance with elasticity. Although the cured film formed from this coating composition has anti-fogging properties due to moisture absorption, it does not also have optical properties such as anti-reflection properties.

[0003] A known coating having an anti-fogging layer as a bottom coating and an anti-reflection layer as a top coating is described in US Pat. No. 10,520,647 (Patent Document 2). The undercoating contains a hydrophilic resin binder and forms an anti-fogging layer. The undercoating swells upon absorbing moisture. Therefore, even if a typical anti-reflection coating using an inorganic layer is formed on the undercoating, cracks will occur due to at least one of film stress caused by the swelling of the undercoating and breath whitening. Therefore, in the above-mentioned coating, a nanoporous coating is used as the upper coating, and an example of the upper coating is a single-layer film made of a cross-linked porous organic material containing silica nanoparticles, which is dip-coated with a mixed suspension of silica nanoparticles dispersed in isopropyl alcohol (IPA) diluted with propylene glycol methyl ether. If the upper coating is a single-layer porous organic film, the moisture absorbed in the lower coating can escape through the pores, thereby suppressing the occurrence of cracks. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6340539 [Patent Document 2] U.S. Patent No. 10,520,647 Summary of the Invention [Problem to be solved by the invention]

[0005] The coating having the above-described upper and lower coatings exhibits anti-fog and anti-reflective properties with reduced cracking. However, since the top coating is a single layer, there is a limit to how much anti-reflection performance can be improved, and the film does not exhibit any other properties besides anti-reflection.

[0006] A primary object of the present invention is to provide an optical product that is capable of being provided with a variety of optical properties in addition to anti-fogging properties while suppressing the occurrence of cracks. [Means for solving the problem]

[0007] The present specification discloses an optical product. The optical product may include a substrate. The optical product may include a water-absorbing layer disposed directly or indirectly on the film-mounting surface of the substrate. The optical product may include a multilayer film disposed on the opposite side of the water-absorbing layer to the substrate. The multilayer film may include one or more low-refractive-index layers. The multilayer film may include one or more high-refractive-index layers. [Effects of the Invention]

[0008] The main effect of the present invention is to provide an optical product that can have a variety of optical properties in addition to anti-fogging properties while suppressing the occurrence of cracks. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic cross-sectional view of an optical product according to an embodiment of the present invention. [Figure 2] 1 is a graph showing the spectral reflectance distributions of Example 1 and Comparative Example 1 in the visible range. [Figure 3] 10 is a graph showing a spectral reflectance distribution in the visible range in a computer simulation. [Figure 4] 1 is a graph showing the spectral reflectance distribution in the visible range according to Examples 1 to 4. [Figure 5] 1 is a graph showing the spectral reflectance distribution in the visible range according to Comparative Examples 1 and 2. [Figure 6] 1 is a graph showing the color of reflected light according to Examples 1 to 4 and Comparative Examples 1 and 2. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, examples of embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to these examples. Furthermore, when a group (atomic group) is represented in a chemical formula or the like without specifying whether it is substituted or unsubstituted, it encompasses both unsubstituted and substituted groups. For example, an alkyl group encompasses not only an alkyl group without a substituent (an unsubstituted alkyl group) but also an alkyl group with a substituent (a substituted alkyl group). Furthermore, (meth)acrylic includes both acrylic and methacrylic. The same applies to similar expressions such as (meth)acrylate. In addition, a structural unit derived from the monomer (a-1) may be referred to as the structural unit (a-1). The same applies to similar notations such as a structural unit derived from the monomer (a-2). Furthermore, the explanations of various physical properties in the embodiments of the present invention include properties that have actually been confirmed as well as properties that can be reasonably inferred from chemical structures and the like.

[0011] [Overall configuration] As shown in FIG. 1, the optical product 1 according to this embodiment includes a substrate 2, a water-absorbing layer 4, a multilayer film 6, and a water-repellent layer 8.

[0012] The substrate 2 is a target to which anti-fogging properties and one or more optical properties are imparted, and is, for example, a plastic substrate made of plastic. The plastic substrate is, for example, a plastic eyeglass lens substrate for eyeglass lenses. The eyeglass lenses may include those with prescription lenses, those without prescription lenses, and sunglasses. The material of the substrate 2 is, for example, at least one of an allyl-based resin such as polydiethylene glycol bisallyl carbonate (CR-39), a thiourethane-based resin, an episulfide-based resin, polymethyl methacrylate, a copolymer of polymethyl methacrylate, polycarbonate, cellulose acetate, polyethylene terephthalate, polyvinyl chloride, an acrylic resin, and a polyurethane resin. The shape of the substrate may be any shape, such as a plate or a block, and may be, for example, a shape corresponding to that of a spectacle lens substrate.

[0013] The water-absorbing layer 4 is a water-absorbing resin layer. The water-absorbing layer 4 may be a water-absorbing multilayer film having a plurality of layers. The water-absorbing layer 4 is formed on a membrane placement surface M (air side) that is disposed on one or both surfaces of the substrate 2 . The water-absorbing layer 4 is formed from a composition containing the following components. That is, the composition contains a (meth)acrylic resin (A), a polyfunctional isocyanate compound (B), and an epoxide (C).

[0014] The (meth)acrylic resin (A) has a structural unit derived from a monomer (a-1) represented by the following general formula (1), a structural unit derived from a monomer (a-2) represented by the following general formula (2), a structural unit derived from a hydroxyalkyl (meth)acrylate (a-3), and a structural unit derived from a monomer (a-4) represented by the following general formula (3).

[0015] [ka] In general formula (1), R1 is a hydrogen atom or a methyl group, R2 and R3 are hydrogen atoms or linear or branched alkyl groups having 1 to 3 carbon atoms, and R2 and R3 may be the same or different.

[0016] [ka] In the general formula (2), R4 is a hydrogen atom or a methyl group, and n1 is an integer of 1 or more and 5 or less.

[0017] [ka] In general formula (3), R5 is a hydrogen atom or a methyl group, R6 is a divalent organic group, and n2 is an integer of 0 or 1 or more.

[0018] In the (meth)acrylic resin (A), the constituent units derived from monomer (a-1) account for 20% by mass or more and 65% by mass or less, the constituent units derived from monomer (a-2) account for 10% by mass or more and 40% by mass or less, and the constituent units derived from monomer (a-4) account for 1% by mass or more and 10% by mass or less, based on 100% by mass of all constituent units constituting the resin.

[0019] The polyfunctional isocyanate compound (B) is a compound having two or more isocyanate groups in one molecule, including isocyanate groups protected with a leaving group. The number of functional groups in the polyfunctional isocyanate compound (B) is preferably 2 or more and 6 or less per molecule, and more preferably 2 or more and 4 or less per molecule.

[0020] The epoxide (C) is an organic compound having multiple epoxy groups. The epoxide (C) preferably has two epoxy groups, and more preferably has a straight chain of carbon atoms with an epoxy group at each end. The epoxide (C) preferably has one or more hydroxyl groups to inhibit liberation from other components.

[0021] The composition may further contain other components, such as additives used in preparing the composition (paint). For example, at least one of a curing catalyst, an ultraviolet absorber, a light stabilizer, a surfactant, a leveling agent, and an antifoaming agent may be used.

[0022] The water-absorbing layer 4 is formed by applying such a composition to the membrane placement surface M and polymerizing it. The configuration of the water-absorbing layer 4 may be considered to be specified by the manufacturing method of applying the composition, and even if this is the case, it is considered that such specification is permissible due to the existence of so-called impossible or impractical circumstances. In other words, there are a wide variety of polymers of this composition combining various monomers, and it is not practical to directly identify the water-absorbing layer 4 by its structure or properties by listing specific examples in order to distinguish it from other polymers. Furthermore, the specific structure and properties of the polymer of such a composition are currently unknown, and even if such a structure and properties exist, it is considered impossible or impractical to explore such structure and properties, as it would require a great deal of equipment and time. Therefore, even if the water-absorbing layer 4 is considered to be specified by the manufacturing method of applying the above-mentioned composition, such specification should be permitted. In addition, the above-mentioned Patent Document 1 patents an invention relating to a cured film formed from a specific composition (see claim 7 of the patent).

[0023] The multilayer film 6 is disposed on the water absorbing layer 4 (on the air side, opposite the substrate side). The physical thickness of the multilayer film 6 is preferably equal to or less than the physical thickness of the water absorbing layer 4 . The multilayer film 6 has two or more layers. The multilayer film 6 has a plurality of layers. A portion of each layer has a refractive index different from that of the other portions. The number of types of refractive index in the layers belonging to the multilayer film 6 may be two, three, or four or more. When the number of refractive index types is two, the multilayer film 6 is an alternating film of low-refractive-index layers 10, which are layers with a relatively low refractive index, and high-refractive-index layers 12, which are layers with a relatively high refractive index. In this case, the layer closest to the substrate 2 and the water-absorbing layer 4 may be the low-refractive-index layer 10 or the high-refractive-index layer 12. Hereinafter, the layer closest to the substrate 2 will be referred to as the first layer, the layer adjacent to it on the air side as the second layer, and so on for the third layer and beyond from the substrate 2 side. Each layer of the multilayer film 6 is a porous layer having a plurality of pores, from the viewpoint of enabling the release of moisture from the water absorbing layer 4 and suppressing cracks. Each layer of the multilayer film 6 is preferably a porous layer. The size of the pores in each layer of the multilayer film 6 is preferably about 1 nm or more and 1000 nm or less, i.e., on the order of nanometers, from the viewpoint of obtaining apparent uniformity and non-uniform distribution of functional portions. The material of each layer in the multilayer film 6 may be any material as long as it has the refractive index and holes described above. The properties exhibited by the multilayer film 6, in other words, the functions provided by the multilayer film 6 may be any, and may be, for example, at least one of anti-reflection properties, low-pass filter properties, high-pass filter properties, band-pass filter properties, and mirror properties. At least one of the high-pass filter properties and band-pass filter properties may include blue light blocking properties.

[0024] The water-repellent layer 8 is a layer that exhibits water-repellent properties and is formed on the multilayer film 6 . The water-repellent layer 8 may be omitted. Alternatively, one or more additional layers may be disposed on the multilayer film 6 instead of or in addition to the water-repellent layer 8. The additional layer may be an oil-repellent layer or a stain-resistant layer exhibiting water and oil repellency. One or more additional layers may be disposed between the water-absorbing layer 4 and the multilayer film 6. One or more additional layers may be disposed between the substrate 2 and the water-absorbing layer 4. The layer between the substrate 2 and the water-absorbing layer 4 may be a primer layer (undercoat layer). If a primer layer or the like is formed on the surface of the substrate 2, the surface of the primer layer or the like may be treated as the surface of the substrate 2. The primer layer may also be a connecting layer disposed to improve adhesion between the water-absorbing layer 4 and the substrate 2. Examples of primer layers include urethane resins, acrylic resins, methacrylic resins, and organosilicon resins. The primer layer is formed, for example, by immersing the substrate 2 in a primer liquid (dip method). The primer layer may be formed by any of a spray method, a roll coating method, and a spin coating method.

[0025] The water-repellent layer 8 is preferably formed from a water-repellent agent containing at least one of amino-modified silicone and mercapto-modified silicone as a main component, where the main component means that it accounts for the majority in terms of mass %. The amount of the water repellent agent is set so that the multilayer film 6 exhibits water repellency while suppressing the obstruction of the passage of moisture into the water absorption layer 4. The water-repellent layer 8 is preferably formed by drying the substrate 2 with the water-absorbing layer 4 to which the water-repellent agent has been attached, and more preferably by heating and drying the substrate 2 with the water-absorbing layer 4 to which the water-repellent agent has been attached. Furthermore, when the water-repellent layer 8 is formed, preferably before the water-repellent agent is attached, the substrate 2 with the water-absorbing layer 4 is subjected to a cleaning treatment (pretreatment). The cleaning treatment is, for example, at least one of cleaning with an ultrasonic cleaner, cleaning with a plasma cleaner, and degreasing with an acid or alkali. Ultrasonic waves are applied to the substrate 2 with the water-absorbing layer 4 with the ultrasonic cleaner (ultrasonic treatment). Plasma is applied to the substrate 2 with the water-absorbing layer 4 with the plasma cleaner (plasma treatment). Such cleaning treatment improves the adhesion of the water-repellent layer 8. Note that a similar pretreatment may be performed before forming at least one of the water-absorbing layer 4 and other layers. The configuration of the water-repellent layer 8 may be considered to be specified by the manufacturing method of forming it from the water-repellent agent, and even if this is the case, it is considered that such specification is permissible due to the existence of so-called impossible or impractical circumstances. In other words, there are a wide variety of molecular structures of the water-repellent layer 8 derived from the water-repellent agent, and it is not practical to directly identify the water-repellent layer 8 by its structure or properties by listing specific examples in order to distinguish it from other structures. Furthermore, there are currently no known unified structures and properties derived from water repellents, and even if such structures and properties existed, it would be considered impossible or impractical to seek such unified structures and properties, as it would require a great deal of equipment and time. Therefore, even if the water-repellent layer 8 is considered to be specified by the manufacturing method of forming it from the water-repellent agent, such specification should be permitted.

[0026] [(Meth)acrylic resin (A) of water absorption layer 4 composition] The (meth)acrylic resin (A), which is one of the components of the composition for the water absorbing layer 4, will be described in further detail.

[0027] The structural unit (a-1) has an amide group, is highly hydrophilic, and easily holds moisture. Therefore, moisture adhering to the upper part of the water-absorbing layer 4 is absorbed into the water-absorbing layer 4, suppressing the occurrence of fogging in the optical product 1. In other words, the inclusion of the structural unit (a-1) imparts anti-fogging properties to the optical product 1.

[0028] The structural unit (a-2) has a so-called polycaprolactone structure, which contributes to improving the flexibility and elasticity of the water-absorbing layer 4 due to its flexible chemical skeleton. The structural unit (a-4) has a polydimethylsiloxane chain, which contributes to improving the slipperiness of the water absorption layer 4. The structural units (a-2) and (a-4) of the water absorbent layer 4 provide flexibility and elasticity to absorb external forces applied to the water absorbent layer 4, while providing slipperiness to release the forces, thereby preventing scratches from forming. In other words, the water absorbent layer 4 is provided with tear resistance.

[0029] Furthermore, the structural unit (a-2) has a terminal hydroxyl group, which causes a crosslinking reaction with the polyfunctional isocyanate compound (B), contributing to the formation of the water-absorbing layer 4. If the crosslinking reaction between the (meth)acrylic resin (A) and the polyfunctional isocyanate compound (B) occurs only in the structural unit (a-2), the water absorption layer 4 will be too soft and will lack elasticity while exhibiting sufficient flexibility. Therefore, by including the structural unit (a-3), which is harder than the structural unit (a-2), as a component of the (meth)acrylic resin (A), a water-absorbing layer 4 with a good balance of flexibility and elasticity can be obtained. The structural unit (a-3) contains a hydroxyl group.

[0030] Furthermore, due to its polycaprolactone structure, the structural unit (a-2) increases the flexibility and elasticity of the water absorbent layer 4 while also increasing the frictional resistance of the water absorbent layer 4. Therefore, when the water absorbent layer 4 in which the structural unit (a-2) is predominant is stroked with a finger, the finger is likely to catch and feel resistance. On the other hand, the structural unit (a-4) imparts slipperiness to the water absorbent layer 4 through the polydimethylsiloxane chain and reduces the frictional resistance of the water absorbent layer 4, but because the abundance ratio of the structural unit (a-4) is smaller than the abundance ratio of the structural unit (a-2), it is difficult to obtain sufficiently low frictional resistance even if sufficient tear resistance is obtained. In order to reduce the resistance in the water absorbent layer 4, in addition to slipperiness, a certain level of hardness or more is required. Therefore, by setting the equivalent ratio (NCO / OH), which is the ratio of isocyanate groups (numerators) to hydroxyl groups (denominators), within a specific range of less than 1 while maintaining a balanced ratio between the hydroxyl group-containing structural units (a-2) and (a-3), the hardness of the water absorbent layer 4 is improved to the extent that frictional resistance is sufficiently reduced. If the equivalent ratio (NCO / OH) is less than 1, the number of isocyanate groups will be fewer than the hydroxyl groups. If the number of isocyanate groups is fewer than the hydroxyl groups, the number of isocyanate groups not involved in crosslinking will decrease. In other words, the crosslink density of the water absorbent layer 4 will increase, the hardness of the water absorbent layer 4 will improve, and frictional resistance will decrease. However, if the equivalent ratio (NCO / OH) is too small, the number of crosslinking points that form the basis of the water absorption layer 4 will be too few, resulting in insufficient strength of the water absorption layer 4. Therefore, there is a lower limit to the equivalent ratio (NCO / OH).

[0031] The (meth)acrylic resin (A) is typically obtained by polymerization of the monomer (a-1), the monomer (a-2), the monomer (a-3) and the monomer (a-4). It is not necessary for all of the constituent units of the (meth)acrylic resin (A) to be derived from a (meth)acrylic monomer. That is, the (meth)acrylic resin (A) may contain some constituent units derived from a non-(meth)acrylic monomer. However, in order to fully obtain the effects derived from the (meth)acrylic structure, it is preferable that 50% by mass or more of the constituent units of the (meth)acrylic resin (A) are constituent units derived from a (meth)acrylic monomer. It is more preferable that 80% by mass or more of the constituent units of the (meth)acrylic resin (A) are constituent units derived from a (meth)acrylic monomer, and even more preferable that 100% by mass of the constituent units of the (meth)acrylic resin (A) are constituent units derived from a (meth)acrylic monomer.

[0032] Monomer (a-1) is not particularly limited as long as it has the structure of the above general formula (1). Examples of monomer (a-1) include at least one of (meth)acrylamide, N-methylacrylamide, N,N-dimethyl(meth)acrylamide, N-ethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, Nn-propyl(meth)acrylamide, and N-isopropyl(meth)acrylamide. The monomer (a-1) may be at least one kind, or may be a combination of two or more kinds. For example, the (meth)acrylic resin (A) may be obtained by carrying out a polymerization reaction using two or more kinds of the above-mentioned monomers.

[0033] From the viewpoint of improving the anti-fogging performance of the water absorbing layer 4, it is particularly preferable that the monomer (a-1) contains N,N-dimethyl(meth)acrylamide or N,N-diethyl(meth)acrylamide. The content of the structural units derived from the monomer (a-1) in the (meth)acrylic resin (A) is 20% by mass or more and 65% by mass or less, more preferably 35% by mass or more and 60% by mass or less, and even more preferably 40% by mass or more and 55% by mass or less, based on the total structural units of the resin. If the content of the structural units derived from the monomer (a-1) is less than 20% by mass, it is difficult to form a water-absorbing layer 4 that exhibits anti-fogging properties suitable for practical use. On the other hand, if the content of the structural units derived from the monomer (a-1) exceeds 65% by mass, the proportion of structural units derived from other monomers decreases relatively, resulting in a relatively poor balance of the composition as a whole.

[0034] Monomer (a-2) is not particularly limited as long as it has the structure of the above general formula (2). Monomer (a-2) is, for example, the "Placcel F" series manufactured by Daicel Corporation. The content of the structural units derived from the monomer (a-2) in the (meth)acrylic resin (A) is 10% by mass or more and 40% by mass or less, more preferably 20% by mass or more and 38% by mass or less, and even more preferably 25% by mass or more and 35% by mass or less, based on the total structural units of the resin. If the content of the structural units derived from the monomer (a-2) is less than 10% by mass, the flexibility of the water absorbent layer 4 will be insufficient. On the other hand, if the content of the structural units derived from the monomer (a-2) is more than 40% by mass, the elasticity of the water absorbent layer 4 will be insufficient. The (meth)acrylic resin (A) may contain multiple repeating units derived from the monomer (a-2). For example, the (meth)acrylic resin (A) may be obtained by polymerization containing two or more compounds belonging to the "PLACCEL F" series.

[0035] The monomer (a-3) is a hydroxyalkyl (meth)acrylate. Examples of the monomer (a-3) include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate. Among these, hydroxyethyl (meth)acrylate is preferred. The (meth)acrylic resin (A) preferably contains 1% by mass or more and 30% by mass or less of the structural units derived from the monomer (a-3) relative to all structural units of the (meth)acrylic resin (A), more preferably 2% by mass or more and 20% by mass or less, and even more preferably 3% by mass or more and 15% by mass or less.

[0036] The monomer (a-3), like the monomer (a-2), has a hydroxyl group and undergoes a crosslinking reaction with the polyfunctional isocyanate compound (B) to form the water absorption layer 4. The water absorption layer 4 is not formed by the crosslinking reaction of the monomer (a-2) alone, but by the crosslinking reaction of the monomer (a-3) with the polyfunctional isocyanate compound (B) together with the monomer (a-3), thereby forming the water absorption layer 4, which has a variety of physical properties. Since the (meth)acrylic resin (A) contains structural units derived from the monomers (a-2) and (a-3), it has hydroxyl groups as a whole, i.e., it is a resin having a hydroxyl value, and therefore the (meth)acrylic resin (A) can react with the polyfunctional isocyanate compound (B) to form a crosslinked structure. The hydroxyl value of the (meth)acrylic resin (A) is preferably 40 mgKOH / g or more and 150 mgKOH / g or less, more preferably 70 mgKOH / g or more and 140 mgKOH / g or less, and even more preferably 90 mgKOH / g or more and 130 mgKOH / g or less. Here, the hydroxyl value refers to the number of milligrams (mg) of potassium hydroxide required to neutralize acetic acid bonded to hydroxyl groups when 1 g of a sample is acetylated. By setting the hydroxyl value within this range, the reaction with the polyfunctional isocyanate compound (B) is facilitated, and the crosslinked structure is appropriately controlled. As a result, the water absorption layer 4 becomes hard while maintaining its flexibility and elasticity. This allows the water absorption layer 4 to achieve both high abrasion resistance and reduced frictional resistance at a higher level.

[0037] Monomer (a-4) is not particularly limited as long as it has the structure of the above general formula (3). Examples of monomer (a-4) include Silaplane "FM-0711", "FM-0721", and "FM-0725" manufactured by JNC Corporation, "X-22-174DX" and "X-22-2426" manufactured by Shin-Etsu Chemical Co., Ltd., and "AK-5" and "AK-32" manufactured by Toagosei Co., Ltd. The (meth)acrylic resin (A) may contain multiple repeating units derived from the monomer (a-4). For example, the (meth)acrylic resin (A) may be obtained by carrying out a polymerization reaction using two or more of the above-mentioned monomers. The content of the structural units derived from the monomer (a-4) in the (meth)acrylic resin (A) is 1% by mass or more and 10% by mass or less, more preferably 2% by mass or more and 8% by mass or less, and even more preferably 3% by mass or more and 7% by mass or less, based on the total structural units of the resin. If the content of the structural units derived from the monomer (a-4) is less than 1 mass %, it is difficult to obtain a water absorbing layer 4 with sufficient scratch resistance. On the other hand, if the content of the structural units derived from the monomer (a-4) is more than 10 mass %, it is difficult to synthesize a homogeneous (meth)acrylic resin (A). This is because the monomer (a-1) has an amide group and is extremely hydrophilic, meaning it easily blends with water, while the monomer (a-4) is relatively hydrophobic, meaning that they are difficult to mix with each other.

[0038] The (meth)acrylic resin (A) may or may not contain an optional structural unit (a-5) other than the structural units (a-1), (a-2), (a-3), and (a-4). Examples of the structural unit (a-5) include structural units derived from the monomers shown below. By including such a structural unit (a-5), the glass transition temperature of the (meth)acrylic resin (A) and the physical properties (hardness, softness, etc.) of the water absorption layer 4 can be adjusted. That is, the structural unit (a-5) is, for example, a structural unit derived from a monomer represented by the general formula CH═CR-COO-R′. Here, R is a hydrogen atom or a methyl group, and R′ is an alkyl group, a monocyclic or polycyclic cycloalkyl group, an aryl group, or an aralkyl group. Examples of such monomers include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, n-lauryl (meth)acrylate, n-stearyl (meth)acrylate, phenyl (meth)acrylate, and benzyl (meth)acrylate. Among these, those in which R′ is an alkyl group having 1 to 8 carbon atoms are preferred, those in which R′ is an alkyl group having 1 to 6 carbon atoms are more preferred, and those in which R′ is an alkyl group having 1 to 4 carbon atoms are even more preferred. The (meth)acrylic resin (A) may contain multiple repeating units corresponding to the structural unit (a-5). For example, the (meth)acrylic resin (A) may be obtained by carrying out a polymerization reaction using two or more of the above monomers. When the (meth)acrylic resin (A) contains the structural unit (a-5), the content thereof is preferably from 1 to 40% by mass, more preferably from 3 to 30% by mass, and even more preferably from 5 to 20% by mass, based on all structural units of the (meth)acrylic resin (A).

[0039] The weight average molecular weight (Mw) of the (meth)acrylic resin (A) is not particularly limited, but is preferably from 10,000 to 100,000, more preferably from 20,000 to 70,000, and even more preferably from 30,000 to 60,000. If the weight average molecular weight is 10,000 or more, anti-fogging properties are likely to be imparted, and if the weight average molecular weight is 100,000 or less, paintability is likely to be imparted. The weight average molecular weight can be determined by gel permeation chromatography (GPC) using polystyrene as a standard substance.

[0040] The glass transition temperature of the (meth)acrylic resin (A) is not particularly limited, but is preferably 20°C or higher and 120°C or lower, more preferably 30°C or higher and 110°C or lower, and even more preferably 35°C or higher and 100°C or lower. The glass transition temperature of the (meth)acrylic resin (A) can be determined by various methods. For example, the glass transition temperature can be determined based on the Fox equation. For monomers whose glass transition temperatures are unknown, such as special monomers and polyfunctional monomers, the glass transition temperature can be determined using only monomers whose glass transition temperatures are known.

[0041] The (meth)acrylic resin (A) is typically obtained by a polymerization reaction. The polymerization reaction may be any of various methods such as radical polymerization, cationic polymerization, and anionic polymerization, and among these, radical polymerization is preferred. The polymerization may be any of solution polymerization, suspension polymerization, and emulsion polymerization. Of these, solution polymerization is preferred from the viewpoint of precise control of the polymerization.

[0042] Known polymerization initiators for radical polymerization can be used. Examples of such initiators include azo initiators such as azobisisobutyronitrile, 2,2-azobis(2-methylbutyronitrile), 2,2-azobis(2-methylpropionitrile), and 2,2-azobis(2,4-dimethylvaleronitrile); peroxide initiators such as benzoyl peroxide, t-butyl peroxyoctanoate, diisobutyl peroxide, di(2-ethylhexyl)peroxypivalate, decanoyl peroxide, t-butylperoxy-2-ethylhexanoate, and t-butyl peroxybenzoate; and redox initiators combining an oxidizing agent and a reducing agent, such as hydrogen peroxide and an iron(II) salt, or a persulfate and sodium hydrogen sulfite. These initiators may be used alone or in combination. The amount of the polymerization initiator to be added is not particularly limited, but is preferably 0.001 parts by mass or more and 10 parts by mass or less when the total mixed solution of the monomers to be polymerized is 100 parts by mass.

[0043] In addition, during the polymerization reaction, known chain transfer agents, polymerization inhibitors, molecular weight modifiers, etc. may be used as appropriate. Furthermore, the polymerization reaction may be carried out in one stage or in two or more stages. The temperature of the polymerization reaction is not particularly limited, but is typically 50°C or higher and 200°C or lower, and preferably 80°C or higher and 150°C or lower.

[0044] [Polyfunctional Isocyanate Compound (B) of Water Absorbing Layer 4 Composition] The polyfunctional isocyanate compound (B), which is one of the components of the composition for the water absorbing layer 4, will be described in further detail.

[0045] The polyfunctional isocyanate compound (B) undergoes a crosslinking reaction with the hydroxyl groups of the structural units (a-2) and (a-3) contained in the (meth)acrylic resin (A). The polyfunctional isocyanate compound (B) is a compound having two or more isocyanate groups (including isocyanate groups protected with a leaving group) in one molecule. The number of functional groups in the polyfunctional isocyanate compound (B) is preferably 2 to 6 per molecule, more preferably 2 to 4 per molecule.

[0046] Examples of the polyfunctional isocyanate compound (B) include aliphatic diisocyanates such as lysine isocyanate, hexamethylene diisocyanate, and trimethylhexane diisocyanate; alicyclic diisocyanates such as hydrogenated xylylene diisocyanate, isophorone diisocyanate, methylcyclohexane-2,4-(or 2,6)-diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), and 1,3-(isocyanatomethyl)cyclohexane; and tri- or higher functional isocyanates such as lysine triisocyanate. In addition to the above-listed polyfunctional isocyanate compounds (B), known polymers include biuret, isocyanurate, and adduct types. While any of these can be used in the composition, it is particularly preferable to use biuret polyfunctional isocyanate compounds. This is because the biuret type has a structure that is softer than the isocyanurate type and harder than the adduct type, providing a more appropriate hardness.

[0047] The polyfunctional isocyanate compound (B) may be a so-called blocked isocyanate. That is, some or all of the isocyanate groups of the polyfunctional isocyanate compound (B) may be in the form of blocked isocyanate groups blocked with protecting groups. The blocked isocyanate groups are formed by blocking the isocyanate groups with active hydrogen compounds such as alcohols, phenols, lactams, oximes, and active methylene compounds. In particular, when the composition is of a one-component type, a polyfunctional isocyanate compound (B) having a blocked isocyanate group is preferred from the viewpoint of storage stability (stability over time).

[0048] Examples of the polyfunctional isocyanate compound (B) that can be used include the "Duranate" series manufactured by Asahi Kasei Corporation, the "Sumidur" series manufactured by Sumika Bayer Urethane Co., Ltd., and the "Coronate" series manufactured by Tosoh Corporation.

[0049] The content of the polyfunctional isocyanate compound (B) in the composition is not particularly limited, but is preferably blended according to an equivalent ratio (NCO) / (OH), specifically, preferably 5 to 100 parts by mass, more preferably 7 to 75 parts by mass, and even more preferably 10 to 70 parts by mass, per 100 parts by mass of the (meth)acrylic resin (A). When the content of the polyfunctional isocyanate compound (B) is within this range, sufficient crosslinking is achieved within the water absorption layer 4.

[0050] [Epoxide (C) of Water Absorbing Layer 4 Composition] As described above, the epoxide (C) is an organic compound having multiple epoxy groups. The epoxide (C) is, for example, at least one of ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol #200 diglycidyl ether, polyethylene glycol #400 diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol #400 diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, hydrogenated bisphenol A diglycidyl ether, and bisphenol A PO 2mol adduct diglycidyl ether. Among these, the epoxide (C) having a hydroxyl group is, for example, glycerin diglycidyl ether. As the epoxide (C), for example, the "Epolite" series manufactured by Kyoeisha Chemical Co., Ltd. Among these, the epoxide (C) having a hydroxyl group is "Epolite 80MF."

[0051] The content of the epoxide (C) in the composition is not particularly limited, but is preferably determined so that sufficient adhesion of the water absorbing layer 4 is obtained without excessively impairing the water absorbing properties, etc., of the water absorbing layer 4. Specifically, the content is preferably 1 part by mass or more and 10 parts by mass or less, more preferably 3 parts by mass or more and 8 parts by mass or less, and even more preferably 5 parts by mass or more and 7 parts by mass or less, relative to 100 parts by mass of the (meth)acrylic resin (A) and the polyfunctional isocyanate compound (B) combined. When the content of the epoxide (C) falls within this range, the water absorbing layer 4 has sufficient adhesion without excessively impairing other performances.

[0052] [Solvent for Water Absorbing Layer 4 Composition] The composition is typically used in a state where each component is dissolved or dispersed in a solvent. In one embodiment, the solvent is an organic solvent, and examples of the organic solvent include aromatic hydrocarbon solvents such as toluene and xylene, alcohol solvents such as methanol, ethanol, isopropyl alcohol, n-butanol, and isobutanol, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, ester solvents such as ethyl acetate, propyl acetate, butyl acetate, and isobutyl acetate, and glycol ether solvents such as propylene glycol monomethyl acetate, propylene glycol monomethyl ether, and propylene glycol monomethyl ether acetate. The amount of solvent used is not particularly limited, but is preferably an amount such that the concentration of solids (non-volatile components) is 5% by mass or more and 60% by mass or less, more preferably 10% by mass or more and 50% by mass or less.

[0053] [Ratio of Components in Water Absorbent Layer 4 Composition] By appropriately adjusting the quantitative ratio of the components of the (meth)acrylic resin (A), the polyfunctional isocyanate compound (B), and the epoxide (C), the composition can further improve the flexibility and elasticity of the cured film, thereby forming a cured film with excellent physical properties. In particular, if the ratio of the amount of isocyanate groups to the amount of hydroxyl groups in the composition is appropriately adjusted, the physical properties of the water absorbing layer 4 that is finally obtained will be better.

[0054] That is, the molar amount (equivalent ratio (NCO) / (OH)) of the isocyanate groups (including blocked isocyanate groups) contained in the polyfunctional isocyanate compound (B) relative to the hydroxyl groups contained in the (meth)acrylic resin (A) is preferably in the range of 0.15 or more and 0.55 or less. The reason for this is that, first, when the equivalent ratio (NCO) / (OH) is less than 0.15, even if all the isocyanate groups (NCO) contained in the composition undergo a crosslinking reaction, the crosslink density is insufficient and it is difficult to reach the level required for the water absorption layer 4. On the other hand, even if the equivalent ratio (NCO) / (OH) exceeds 0.55, the number of isocyanate groups (NCO) relative to the hydroxyl groups (OH) becomes too high, making it difficult to obtain the required crosslink density for the entire water absorbent layer 4. The reason for this is that if the number of isocyanate groups (NCO) relative to the hydroxyl groups (OH) is relatively high, for example, in the case of one molecule of a polyfunctional isocyanate compound, it is likely that some isocyanate groups will participate in the reaction and others will not participate in the reaction, and as a result, the crosslink density will be relatively low, making it difficult for the water absorbent layer 4 to have sufficient functions such as anti-fogging property and solvent resistance. The equivalent ratio (NCO) / (OH) is more preferably 0.25 or more and 0.50 or less, and even more preferably 0.35 or more and 0.45 or less.

[0055] In the composition, the hydroxyl value of the (meth)acrylic resin (A) is preferably in the range of 80 mgKOH / g to 190 mgKOH / g, more preferably 100 mgKOH / g to 150 mgKOH / g, and even more preferably 110 mgKOH / g to 140 mgKOH / g. By setting the hydroxyl value in this range, the flexibility and elasticity of the water absorbent layer 4 are further improved, and a water absorbent layer 4 having various more excellent physical properties is formed.

[0056] [Form of composition of water-absorbing layer 4, etc.] The composition may be of one-component type, that is, in a state in which all components other than the solvent are substantially uniformly mixed (dissolved or dispersed) in the solvent. When the polyfunctional isocyanate compound (B) is a blocked isocyanate, a one-component type is preferred.

[0057] The composition may also be a two-component type. If the composition is a two-component type, the storage stability of the composition can be further improved. For example, the composition may be composed of (1) a first component containing a (meth)acrylic resin (A) but not containing a polyfunctional isocyanate compound (B), and (2) a second component containing a polyfunctional isocyanate compound (B) but not containing a (meth)acrylic resin (A), the first component and the second component being stored in separate containers, and the first component and the second component being mixed immediately before use (coating). Components other than the (meth)acrylic resin (A) and the polyfunctional isocyanate compound (B) may be contained in the first liquid, the second liquid, or prepared in other containers. In particular, when the polyfunctional isocyanate compound (B) is not a blocked isocyanate (when the isocyanate group is present in the form of -NCO in the system), the composition is preferably a two-component type.

[0058] The physical thickness of the water absorbing layer 4 is preferably 1 μm (micrometer) or more and 50 μm or less, and more preferably 5 μm or more and 30 μm or less. By keeping the physical film thickness within this range, a good appearance (suppression of deterioration in optical performance compared to the case of the substrate 2 alone) and various properties of the water absorbing layer 4 can be achieved at a higher level.

[0059] [Multilayer film 6] Subsequently, the multilayer film 6 will be described in more detail.

[0060] From the viewpoint of obtaining at least one of affinity with the water absorption layer 4 and ease of production, the layers in the multilayer film 6 are preferably formed in the same manner as the water absorption layer 4 or by adding a filler to the water absorption layer 4. In other words, the material of each layer in the multilayer film 6 is preferably the same as the material of the water absorption layer 4 or a combination of the same material as the water absorption layer 4 and the material of the filler. Hereinafter, a layer in the multilayer film 6 that is formed in the same manner as the water absorption layer 4 and has the same material as the water absorption layer 4 may be referred to as a "same-material layer." Furthermore, a layer in the multilayer film 6 that is formed by adding a filler to the water absorption layer 4 and has a material that is a combination of the water absorption layer 4 and the filler may be referred to as a "filler-added layer." The filler-added layer may contain the same material as the water-absorbing layer 4, and may act as a binder to fix the filler in a dispersed state. The binder may also be called a matrix. The filler may be any material that changes the refractive index of the layer after addition, compared to the refractive index before addition, such as hollow particles including hollow silica particles.

[0061] Hollow particle fillers are further described below. The hollow particles are preferably sealed, i.e., the ingress of fluid 26 into the interior space or cavity of the hollow particles is preferably inhibited. The size of the hollow portion in the hollow particle may be any size. The porosity (%) of a hollow particle is the percentage of the volume of the hollow portion relative to the total volume of the particle 28, and is calculated as (volume of hollow portion / total volume) × 100. Therefore, the porosity of a hollow particle may be any size. Hollow particles with diameters on the nano-size order may be called hollow nanoparticles.Hollow particles made of silica with diameters on the nano-size order may be called hollow silica nanoparticles.

[0062] When the water absorption layer 4 is formed from a composition containing a (meth)acrylic resin (A), a polyfunctional isocyanate compound (B), and an epoxide (C), the identical material layer is formed from the composition. In this case, the binder of the filler-added layer is formed from the composition. In this case, the identical material layer and the filler-added layer are organic layers made of organic materials. The layer made of the same material is an independent layer and is not adjacent to the water-absorbing layer 4. For example, if a layer made of a different material from the water-absorbing layer 4, such as a filler-added layer, is placed between the layer made of the same material and the water-absorbing layer 4, the layer made of the same material can exist as an independent layer. Similarly, there can be alternating layers made of layers made of the same material as the water-absorbing layer 4 and layers made of a different material from the water-absorbing layer 4.

[0063] When the binder of the filler-added layer is formed from the above-described composition and the filler is hollow particles, the refractive index of the filler-added layer changes according to the ratio (F / M) of the mass (F) of the filler to the mass (M) of the binder. As the mass of the filler increases with respect to the same mass of the binder, that is, as F / M increases, the refractive index decreases. For example, when the binder is a specific example of the following composition and the filler is hollow silica nanoparticles with a diameter of 20 nm or less, the refractive index n0 for light with a wavelength of 500 nm in the layer in the state of only the binder (without filler), that is, the layer of the same material, is n0 = 1.523. Unless otherwise specified, the refractive indices in this specific example and the examples and comparative examples described later are for light with a wavelength of 500 nm. Here, F / M in the layer of the same material is F / M = 0. Also, in this case, the refractive index n1 in the filler-added layer where a filler having the same mass as the binder, that is, F / M = 50 / 50 = 1, is added is n1 = 1.359. And in the filler-added layer, by adjusting the mass of the filler added in the range of 0 < F / M < 1, the refractive index n f of the filler-added layer f can be changed within the range of 1.359 < n < 1.523. If F / M is too large, there will be too much filler relative to the binder, and the retention of the filler from a long-term perspective will be insufficient, resulting in insufficient durability of the filler-added layer. In the case of this specific example, for example, when F / M > 1.2, the durability of the filler-added layer becomes insufficient. The polyfunctional isocyanate compound (B) in this composition is a biuret type of hexamethylene diisocyanate ("24A-100" manufactured by Asahi Kasei Corporation), and is contained in an amount of 18 parts by mass per 100 parts by mass of the (meth)acrylic resin (A). Furthermore, the epoxide (C) in the composition here is glycerin diglycidyl ether ("Epolite 80M" manufactured by Kyoeisha Chemical Co., Ltd.), and is 6 parts by mass (approximately 6% by mass of the solid content of the composition) per 100 parts by mass of the (meth)acrylic resin (A) and the polyfunctional isocyanate compound (B). In this specific example, the amount of residual hydroxyl groups (residual OH Vol.) is 20% or more but less than 30% (20-30%), and the amount of hydroxyl groups in the resin (resin OH Vol.) is medium (medium). Because the applicant is not a material manufacturer, only information on a wide range of residual OH Vol. can be obtained (requiring a great deal of time and cost for analysis), and because analyzing the elements of the resin requires a great deal of time and cost for resin OH Vol., the relative magnitude can be grasped.

[0064] The properties of Example 1, which was actually produced, and the results of various computer simulations relating to the multilayer film 6 according to this specific example of composition will be described below.

[0065] First, Example 1 is prepared as follows. That is, the above-mentioned composition is applied by dipping to a substrate 2 made of thiourethane ("MR-8" manufactured by Mitsui Chemicals, Inc.) with a refractive index of 1.60, which is a spectacle lens substrate with a diopter of S-2.00. In the dipping method, the substrate 2 is immersed for 10 seconds and pulled up at a speed of 200 mm / min. The applied composition is then cured by heating at 130°C for 1.5 hours, thereby forming a water-absorbing layer 4. The physical film thickness of the water-absorbing layer 4 is 10,000 nm, i.e., 10 μm. In Example 1, propylene glycol monomethyl ether (PGM) is used as the solvent. Then, a multilayer film 6 consisting of five layers is formed on the water absorbing layer 4. The high refractive index layers 12 in this multilayer film 6 are made of the same material as in the above specific example. The low refractive index layers 10 are filler-added layers in the above specific example, and have a refractive index of 1.359. The multilayer film 6 is an alternating film of low refractive index layers 10 and high refractive index layers 12. The low refractive index layers 10 are arranged in odd-numbered layers, and the high refractive index layers 12 are arranged in even-numbered layers. The physical film thickness of each layer in the multilayer film 6 is shown in Table 1 below. The first low-refractive index layer 10 is formed by spin-coating an additive liquid obtained by adding hollow silica nanoparticles to the specific example of the composition at an F / M ratio of 1, and then curing the resulting solution by heating at 100°C for 10 minutes. The physical thickness of the first low-refractive index layer 10 can be adjusted by the spin rotation speed, since the additive liquid has a fixed non-volatile content of 2.0% by mass in the spin-coating process. The physical thickness of the first low-refractive index layer 10 may also be adjusted by changing the non-volatile content of the additive liquid while the spin rotation speed is fixed at a predetermined value. The second high refractive index layer 12 is formed in the same manner as the first low refractive index layer 10, except that hollow silica nanoparticles are not added. The third and subsequent layers are formed in the same manner as the first or second layer, except that the fifth layer is heated for hardening at 130°C for 90 minutes in order to provide a final hardening for the entire multilayer film 6. After the multilayer film 6 is formed in this manner, a water-repellent layer 8 is formed on the multilayer film 6. The water-repellent layer 8 is formed by applying amino-modified silicone ("KF-869" manufactured by Shin-Etsu Chemical Co., Ltd.) by dipping, followed by drying at 100°C for 10 minutes.

[0066] [Table 1]

[0067] Comparative Example 1, which consists of only the substrate 2 and water-absorbing layer 4 in Example 1 and does not include the multilayer film 6 and water-repellent layer 8, was produced by the same method as in Example 1 up to the production of the water-absorbing layer 4.

[0068] FIG. 2 is a graph showing the spectral reflectance distributions of Example 1 and Comparative Example 1 in the visible range. The visible range here is 380 nm or more and 780 nm or less. However, the visible range may be other wavelength ranges. For example, the lower limit of the visible range may be any of 360, 370, 390, 400, 410, 420, 430, and 440 nm. Furthermore, the lower limit of the visible range may be any of 650, 680, 700, 720, 740, 760, and 800 nm.

[0069] The reflectance distribution of Comparative Example 1 oscillates with an amplitude of about 1 point around a virtual center line corresponding to about 4.2%, and from a bird's-eye view, it is a flat distribution of about 4.2% in the visible range. In contrast, the reflectance distribution of Example 1 oscillates with an amplitude of approximately 0.4 points around a "W"-shaped imaginary center line, which corresponds to the reflectance distribution of a typical eyeglass lens with anti-reflection properties. The two minimum values ​​on this imaginary center line are approximately 0.5% and 0.2%. The maximum value between the two minimum values ​​on this imaginary center line is approximately 1.5%. The reflectance distribution of Example 1 exhibits anti-reflection properties that suppress reflectance in the visible range. In Example 1, the anti-reflection function is imparted by adding a multilayer film 6 to Comparative Example 1. In the spectral reflectance distributions of Example 1 and Comparative Example 1, the wavelength of vibration centered on a virtual center line is approximately 10 nm or more and 15 nm or less.

[0070] Next, computer simulations for low refractive index layers 10 having various refractive indices will be described. In the multilayer film 6 consisting of alternating low refractive index layers 10 and high refractive index layers 12, the larger the refractive index difference between the refractive index of the low refractive index layers 10 and the refractive index of the high refractive index layers 12, the easier it is to design the film to have functions such as anti-reflection properties. In Example 1, when the amount of filler added to the low refractive index layer 10 decreases, the refractive index of the low refractive index layer 10 increases and approaches the refractive index of the high refractive index layer 12, thereby reducing the refractive index difference.

[0071] Therefore, computer simulations were performed on the same multilayer film 6 as in Example 1, and on various modified examples in which the refractive index of the low refractive index layer 10 of the multilayer film 6 was changed to various values ​​by reducing the mass of the filler. In this computer simulation, the refractive index of the low refractive index layer 10 is 1.3590 (same as in Example 1), 1.3652, 1.3800, 1.3920, and 1.4005. In addition, the refractive index of the high refractive index layer 12 is 1.523 (same as in Example 1). In this computer simulation, the water absorbing layer 4 is omitted. The physical thicknesses of the low refractive index layer 10 and the high refractive index layer 12 in each of the modified examples are optimized to make the reflectance distribution as low as possible over the entire visible range, and are not significantly different from the physical thicknesses of the multilayer film 6 in Example 1.

[0072] FIG. 3 is a graph showing the spectral reflectance distribution in the visible range in a computer simulation. As the refractive index of low refractive index layer 10 increases and the refractive index difference decreases, the spectral reflectance distribution in the visible range of multilayer film 6 increases. At a wavelength of 530 nm, when the refractive index of low refractive index layer 10 is 1.3590, the reflectance is about 2%, while when the refractive index of low refractive index layer 10 is 1.4005, the reflectance is about 2.8%. In view of the results of such computer simulations, and from the viewpoint of sufficiently and simply obtaining the functions of the multilayer film 6, the refractive index difference is preferably 0.13 or more, which exceeds 1.523-1.4005=0.123, and more preferably 0.158 or more, which exceeds 1.523-1.3652=0.1578. The refractive index of the low refractive index layer 10 is preferably 1.4 or less, and more preferably 1.365 or less.

[0073] [Water-repellent layer 8] The main component of the water-repellent layer 8 is preferably reactive silicone. The reactive silicone is a polydimethylsiloxane (silicone) obtained by polycondensing an organosilicon compound, to which a reactive functional group has been introduced, and is preferably at least one of an amino-modified silicone or a mercapto-modified silicone. When reactive silicone contains an amino group and a mercapto group, it has good reactivity with the water absorption layer 4 having an ester bond. On the other hand, silicones having a silanol group and fluoroalkylsilanes have relatively poor reactivity with the water absorption layer 4 and are inferior in water repellency. The functional group equivalent weight of the amino-modified silicone and mercapto-modified silicone is preferably 5,000 or more and 100,000 or less, and more preferably 10,000 or more and 60,000 or less. The amino-modified silicone is, for example, at least one of "KF-869" and "KF-8021" manufactured by Shin-Etsu Chemical Co., Ltd. These are side-chain amino-modified silicones and diamine-modified types. Among these, "KF-8021" (viscosity (at 25°C) 15,000 mm 2 per second, functional group equivalent 55,000 g / mol) is "KF-869" (viscosity 1,500 mm 2 per second, functional group equivalent of 3800 g / mol), and is therefore preferable in terms of contributing to improving the slipperiness of the water-repellent layer 8.

[0074] The water-repellent layer 8 can be formed by applying a solution prepared by mixing the above components in a non-reactive solvent to the surface of the water-absorbing layer 4 by a wet method such as dipping, spraying, roll coating, or spin coating. Examples of the non-reactive solvent include aliphatic hydrocarbon solvents such as hexane, heptane, and cyclohexane, and ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone. These solvents may be used alone or in combination. The physical thickness of the water-repellent layer 8 is preferably 0.5 nm or more and 20 nm or less, and more preferably 10 nm or less in order to suppress the influence on the water absorption properties of the water-absorbing layer 4.

[0075] The contact angle of the surface of the water-repellent layer 8 with water is preferably 100 degrees or more. The magnitude of the contact angle depends on the degree to which water-soluble components, such as surfactants, contained in the water-absorbing layer 4 remain, and the degree to which the modified silicone adheres to the surface of the water-absorbing layer 4. To increase the contact angle, the substrate 2 with the water-absorbing layer 4 may be treated with at least one of water and alcohol during the formation of the water-repellent layer 8 to remove the water-soluble components, or may be subjected to a surface activation treatment to increase the reactivity. Such treatment is preferably a physical treatment, such as at least one of plasma treatment and ultraviolet treatment, with plasma treatment being more preferred. [Example]

[0076] Examples belonging to the present invention and comparative examples not belonging to the present invention are shown below. However, the examples do not limit the scope of the present invention. Depending on how the present invention is interpreted, some of the following examples may essentially be comparative examples, and some of the following comparative examples may essentially be examples.

[0077] [Preparation of Examples 1 to 4] Example 1 is prepared as described above. Examples 2 and 3 are each fabricated in the same manner as Example 1, except for the physical film thickness of each layer in the multilayer film 6, which has a total of five layers. Example 4 is fabricated in the same manner as Example 1, except that the multilayer film 6 is made up of two layers in total, and the physical film thickness of each layer is 90 nm. The physical film thickness of each layer in Examples 1 to 4 is shown in Table 2 below.

[0078] [Table 2]

[0079] [Preparation of Comparative Examples 1 and 2] As described above, Comparative Example 1 is equivalent to Example 1 except that the multilayer film 6 is removed, and is formed by forming the water absorbing layer 4 of Example 1 on the substrate 2 of Example 1. Comparative Example 2 is obtained by adding a single optical film layer to Comparative Example 1. The optical film of Comparative Example 2 is formed in the same manner as the first layer in the multilayer film 6 of Example 1. The physical film thickness of the optical film of Comparative Example 2 is 92 nm. The physical film thickness of each layer in Comparative Examples 1 and 2 is shown in Table 3 below.

[0080] [Table 3]

[0081] [Reflectivity] For Examples 1 to 4 and Comparative Examples 1 and 2, the spectral reflectance distribution in the visible range and the color of reflected light were measured. Furthermore, for Examples 1 to 4 and Comparative Examples 1 and 2, the luminous reflectance was measured at a 2° field of view using a D65 light source, and the average reflectance of visible light was calculated. The luminous reflectance is specified in JIS T 7334:2011. JIS T 7334:2011 is based on ISO 8980-4:2006. Fig. 4 is a graph showing the spectral reflectance distribution in the visible range for Examples 1 to 4. Fig. 5 is a graph showing the spectral reflectance distribution in the visible range for Comparative Examples 1 and 2. Fig. 6 is a graph showing the color of reflected light for Examples 1 to 4 and Comparative Examples 1 and 2. In FIG. 6, the color of the reflected light is expressed in an xy chromaticity diagram in the CIE1931XYZ color system. The color of reflected light, luminous reflectance in a 2° field of view with a D65 light source, and average reflectance of visible light for Examples 1 to 4 and Comparative Examples 1 and 2 are shown in Table 4 below.

[0082] [Table 4]

[0083] As described above and shown in Figures 2 and 4, the spectral reflectance distribution in the visible range of Example 1 is centered on a virtual center line of a "W" shape, which corresponds to the reflectance distribution of a general eyeglass lens with anti-reflection performance. The color of the reflected light that exists at a slight intensity in Example 1 is green. The x of the color of the reflected light in Example 1 is x = 0.25. The y of the color of the reflected light in Example 1 is y = 0.39. The luminous reflectance in Example 1 is 1.01%. The average reflectance in the visible range in Example 1 is 1.29%. As shown in FIG. 4, the spectral reflectance distribution in the visible range of Example 2 is centered on a virtual center line corresponding to the reflectance distribution of a spectacle lens with a blue light blocking function, in which the reflectance of blue light is higher than that of other colors of visible light. The color of reflected light in Example 2 is blue. In Example 2, blue light is blocked by reflection. The x of the color of reflected light in Example 2 is x=0.19. The y of the color of reflected light in Example 2 is y=0.18. The luminous reflectance in Example 2 is 1.01%. The average reflectance in the visible range in Example 2 is 1.88%. As shown in FIG. 4, the spectral reflectance distribution in the visible range of Example 3 is centered on a virtual center line that corresponds to the reflectance distribution of a spectacle lens that has a characteristic in which the reflectance of visible light on the long wavelength side is higher than that of visible light on the short wavelength side. The color of reflected light in Example 3 is orange. In Example 3, visible light on the long wavelength side is cut by reflection. The x of the color of reflected light in Example 3 is x=0.41. The y of the color of reflected light in Example 3 is y=0.38. The luminous reflectance in Example 3 is 1.78%. The average reflectance in the visible range in Example 3 is 2.59%. As shown in FIG. 4, the spectral reflectance distribution in the visible range of Example 4 is centered on a virtual center line corresponding to the reflectance distribution of a reflective enhancer, i.e., a mirror, in which the reflected light has greater characteristics than when there is no multilayer film 6, i.e., Comparative Example 1. The color of the reflected light in Example 4 is white. Example 4 can be used for mirror coatings on eyeglass lenses. The color x of the reflected light in Example 4 is x=0.35. The color y of the reflected light in Example 4 is y=0.36. The luminous reflectance in Example 4 is 9.35%. The average reflectance in the visible range of Example 4 is 7.84%.

[0084] As described above and shown in Figures 2 and 5, the spectral reflectance distribution in the visible range of Comparative Example 1 is, from a bird's eye view, a flat distribution of about 4.2% in the visible range. The color of reflected light in Comparative Example 1 is white. The x of the color of reflected light in Comparative Example 1 is x = 0.35. The y of the color of reflected light in Comparative Example 1 is y = 0.35. The luminous reflectance in Comparative Example 1 is 4.32%. The average reflectance in the visible range of Comparative Example 1 is 4.32%. As shown in FIG. 5, the spectral reflectance distribution in the visible range of Comparative Example 2 is, from a bird's eye view, a gentle "U"-shaped distribution of around 2% in the visible range. The color of reflected light in Comparative Example 2 is light pink. The x of the color of reflected light in Comparative Example 2 is x=0.36. The y of the color of reflected light in Comparative Example 2 is y=0.34. The luminous reflectance in Comparative Example 2 is 1.09%. The average reflectance in the visible range of Comparative Example 2 is 1.34%.

[0085] In Examples 1 to 4, the number of layers in the multilayer film 6 is increased compared to Comparative Examples 1 and 2, making it possible to impart a variety of functions. Furthermore, in Examples 1 to 4, compared to Comparative Examples 1 and 2, the number of layers in the multilayer film 6 is increased, making it possible to realize a wider variety of reflected light colors.

[0086] [Anti-fogging properties] Three types of anti-fogging tests were conducted to evaluate the anti-fogging properties of Examples 1 to 4 and Comparative Examples 1 and 2. The three types of anti-fogging tests were a breath whitening test, an anti-fogging performance duration 40°C steam test, and an anti-fogging performance duration 50°C steam test. In the breath whitening test, the tester breathes out onto the water-absorbent layer 4 side of the test object from a distance of approximately 10 mm for 2 seconds, and immediately thereafter checks for the occurrence of fogging. If the test object does not fogging up, the test object is evaluated as "Positive" in terms of anti-fogging properties. If the test object fogging up, the test object is evaluated as "Negative" in terms of anti-fogging properties. In the 40°C steam anti-fogging performance duration test, a tester tests the anti-fogging performance using a lidded bottle filled with water. First, the tester places the lidded bottle filled with water in a thermostatic chamber. The diameter of the bottle's opening, where the lid fits, is 30 mm. The bottle's capacity is 120 ml. The volume of water is 100 ml. The temperature inside the thermostatic chamber is maintained at 40°C. After a specified time, the bottle, including the water, is heated to 40°C and removed from the thermostatic chamber. The tester promptly removes the lid from the removed bottle and places the test object, with the water-absorbing layer 4 facing downward, in the opening of the bottle. The tester then measures the time from when the test object is placed in the opening of the bottle to when fogging begins to occur on the test object. This time can be considered the duration of anti-fogging performance; a shorter time indicates better anti-fogging performance. The Anti-Fog Performance Duration 50°C Steam Test is conducted in the same manner as the Anti-Fog Performance Duration 40°C Steam Test, except that the temperature chamber is maintained at 50°C instead of 40°C and the bottle is heated to 50°C. The results of various tests for Examples 1 to 4 and Comparative Examples 1 and 2 are shown in Table 5 below.

[0087] [Table 5]

[0088] The results of the breath whitening test for Examples 1 to 4 and Comparative Examples 1 and 2 were all "Positive," indicating good anti-fogging properties. Furthermore, the anti-fogging performance duration 40°C steam test and the anti-fogging performance duration 50°C steam test for Examples 1 to 4 showed better results than the test results for Comparative Examples 1 and 2, despite the addition of a more complex multilayer film 6 in Examples 1 to 4 compared to Comparative Examples 1 and 2. In Examples 1 to 4, the material of the high refractive index layer 12 is the same as the material of the water absorption layer 4, and is believed to have water absorbency and contribute to anti-fogging properties. Furthermore, in Examples 1 to 4, the material of the low refractive index layer 10 is a mixture of hollow silica nanoparticles with a binder made of the same material as the water absorption layer 4, and is believed to have water absorbency in the binder and contribute to anti-fogging properties. Therefore, even if the water absorption layer 4 is made of a different material from Examples 1 to 4, as long as at least one of the material of the high refractive index layer 12 and the material of the binder of the low refractive index layer 10 is the material used in Examples 1 to 4, improved anti-fogging properties can be achieved. Of course, when the material of the water absorption layer 4, the material of the high refractive index layer 12, and the material of the binder of the low refractive index layer 10 are as described above, as in Examples 1 to 4, the anti-fogging performance is sufficiently high, as shown in Examples 1 to 4.

[0089] [summary] Unlike Comparative Examples 1 and 2, Examples 1 to 4 include a substrate 2, a water-absorbing layer 4 disposed directly or indirectly on the film-mounting surface M of the substrate 2, and a multilayer film 6 disposed on the opposite side of the water-absorbing layer 4 to the substrate. The multilayer film 6 of Examples 1 to 4 includes one or more low-refractive index layers 10 and one or more high-refractive index layers 12. Therefore, the optical product 1 is provided that has anti-fogging properties and can have a variety of optical properties.

[0090] In Examples 1 to 4, the water-absorbing layer 4 and the high-refractive-index layer 12 are obtained from a composition containing a (meth)acrylic resin (A) having a structural unit derived from a monomer (a-1) represented by the general formula (1), a structural unit derived from a monomer (a-2) represented by the general formula (2), a structural unit derived from a hydroxyalkyl (meth)acrylate (a-3), and a structural unit derived from a monomer (a-4) represented by the general formula (3), a polyfunctional isocyanate compound (B), and an epoxide (C), which is an organic compound having multiple epoxy groups. The (meth)acrylic resin (A) contains, relative to 100% by mass of all structural units, 20% to 65% by mass of structural units derived from monomer (a-1), 10% to 40% by mass of structural units derived from monomer (a-2), and 1% to 10% by mass of structural units derived from monomer (a-4). This improves the anti-fogging properties of the optical product 1. Furthermore, the water absorbing layer 4 and the high refractive index layer 12 are formed by the same forming method, making the optical product 1 easier to form.

[0091] Furthermore, in Examples 1 to 4, the low refractive index layer 10 contains a filler and a binder. The filler is hollow particles. The binder is obtained from a composition containing a (meth)acrylic resin (A) having a structural unit derived from a monomer (a-1) represented by the above general formula (1), a structural unit derived from a monomer (a-2) represented by the above general formula (2), a structural unit derived from a hydroxyalkyl (meth)acrylate (a-3), and a structural unit derived from a monomer (a-4) represented by the above general formula (3), a polyfunctional isocyanate compound (B), and an epoxide (C), which is an organic compound having multiple epoxy groups. This improves the anti-fogging properties of the optical product 1. Furthermore, the binders of the water absorbing layer 4, the high refractive index layer 12, and the low refractive index layer 10 are made of the same material, making the optical product 1 easier to form.

[0092] In addition to Examples 1 to 4, various modified examples were prepared in which the amount of the polyfunctional isocyanate compound (B) of Examples 1 to 4 was varied, and it was confirmed that, from the viewpoint of maintaining various performances at a higher level, the preferable ratio of the polyfunctional isocyanate compound (B) is 5 parts by mass or more and 100 parts by mass or less per 100 parts by mass of the (meth)acrylic resin (A). Furthermore, apart from Examples 1 to 4, various modified examples were prepared in which the amount of epoxide (C) of Example 1 was varied, and it was confirmed that, from the viewpoint of maintaining various performances (particularly adhesion) at a higher level, the preferable ratio of the epoxide (C) is 1 part by mass or more and 10 parts by mass or less per 100 parts by mass of the (meth)acrylic resin (A) and the polyfunctional isocyanate compound (B) combined. In addition, apart from Examples 1 to 4, various modified examples were created in which the type (functional group equivalent) of the water repellent agent of Examples 1 to 4 was varied, and it was confirmed that the preferred range of the functional group equivalent of the water repellent agent is 5000 or more from the viewpoint of maintaining a higher level of various performances (especially slipperiness). [Explanation of symbols]

[0093] 1.Optical products 2...Base material 4...Water absorption layer 6...Multilayer film 8. Water-repellent layer 10. Low refractive index layer 12. High refractive index layer M··Membrane placement surface.

Claims

1. A substrate; a water-absorbing layer disposed directly or indirectly on the membrane-arranged surface of the substrate; a multilayer film disposed on the opposite side of the water absorption layer to the substrate; It is equipped with The multilayer film includes one or more low refractive index layers and one or more high refractive index layers. An optical product characterized by:

2. At least one of the water absorbing layer and the high refractive index layer is a (meth)acrylic resin (A) having a structural unit derived from a monomer (a-1) represented by the following general formula (1), a structural unit derived from a monomer (a-2) represented by the following general formula (2), a structural unit derived from a hydroxyalkyl (meth)acrylate (a-3), and a structural unit derived from a monomer (a-4) represented by the following general formula (3); A polyfunctional isocyanate compound (B), an epoxide (C) which is an organic compound having a plurality of epoxy groups; obtained from a composition comprising In the (meth)acrylic resin (A), the proportion of the structural units derived from the monomer (a-1) is 20% by mass or more and 65% by mass or less, the proportion of the structural units derived from the monomer (a-2) is 10% by mass or more and 40% by mass or less, and the proportion of the structural units derived from the monomer (a-4) is 1% by mass or more and 10% by mass or less, relative to 100% by mass of all structural units.

2. The optical product according to claim 1. 【Chemistry 1】 In general formula (1), R １ is a hydrogen atom or a methyl group, and R ２ and R ３ is a hydrogen atom or a linear or branched alkyl group having 1 to 3 carbon atoms, and R ２ and R ３ may be the same as each other or may be different from each other. 【Chemistry 2】 In general formula (2), R ４ is a hydrogen atom or a methyl group, and n １ is an integer between 1 and 5 inclusive. 【Transformation 3】 In general formula (3), R ５ is a hydrogen atom or a methyl group, and R ６ is a divalent organic group, and n ２ is an integer of 0 or 1 or more.

3. the low refractive index layer includes a filler and a binder, The filler is a hollow particle, The binder is a (meth)acrylic resin (A) having a structural unit derived from a monomer (a-1) represented by the following general formula (1), a structural unit derived from a monomer (a-2) represented by the following general formula (2), a structural unit derived from a hydroxyalkyl (meth)acrylate (a-3), and a structural unit derived from a monomer (a-4) represented by the following general formula (3); A polyfunctional isocyanate compound (B), an epoxide (C) which is an organic compound having a plurality of epoxy groups; obtained from a composition comprising In the (meth)acrylic resin (A), the proportion of the structural units derived from the monomer (a-1) is 20% by mass or more and 65% by mass or less, the proportion of the structural units derived from the monomer (a-2) is 10% by mass or more and 40% by mass or less, and the proportion of the structural units derived from the monomer (a-4) is 1% by mass or more and 10% by mass or less, relative to 100% by mass of all structural units.

2. The optical product according to claim 1. 【Chemistry 4】 In general formula (1), R １ is a hydrogen atom or a methyl group, and R ２ and R ３ is a hydrogen atom or a linear or branched alkyl group having 1 to 3 carbon atoms, and R ２ and R ３ may be the same as each other or may be different from each other. 【Transformation 5】 In general formula (2), R ４ is a hydrogen atom or a methyl group, and n １ is an integer between 1 and 5 inclusive. 【Transformation 6】 In general formula (3), R ５ is a hydrogen atom or a methyl group, and R ６ is a divalent organic group, and n ２ is an integer of 0 or 1 or more.

4. The proportion of the polyfunctional isocyanate compound (B) is 5 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the (meth)acrylic resin (A).

4. The optical product according to claim 2 or 3.

5. The epoxide (C) is 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the (meth)acrylic resin (A) and the polyfunctional isocyanate compound (B) combined.

4. The optical product according to claim 2 or 3.

6. The epoxide (C) has one or more hydroxyl groups.

4. The optical product according to claim 2 or 3.

7. The refractive index of the low refractive index layer for light with a wavelength of 500 nm is 1.4 or less.

2. The optical product according to claim 1.

8. Furthermore, a water-repellent layer containing at least one of amino-modified silicone and mercapto-modified silicone as a main component is provided on the multilayer film.

2. The optical product according to claim 1.

9. The water-repellent layer is mainly composed of at least one of the amino-modified silicone and the mercapto-modified silicone, each having a functional group equivalent of 5000 or more.

9. The optical product according to claim 8.

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