Frost prevention composition, and laminate, distance measurement device, and illumination device provided with cured film using said composition

Abstract

Provided is a cured film having good frost resistance and water resistance.　A laminate 1 includes an adherend 2 and a cured film 3 formed on the adherend 2. The cured film 3 is a cured product of a resin composition containing a monofunctional monomer, a polyfunctional monomer, and a radical polymerization initiator. After the laminate 1 is taken out from -40°C to room temperature (25°C, 40% RH), the frost adhesion area on a surface of the cured film 3 is less than 30% when the thickness is 5 μm or more.

Description

Anti-frost composition, laminate with cured film using the same, distance measuring device, and lighting device

[0001] This application claims priority from Japanese Patent Application No. 2024-071435, filed on April 25, 2024, which is incorporated herein by reference.

[0002] Substrates such as glass and plastic have good visibility and are therefore used in a variety of applications. However, the surface of such substrates may freeze when exposed to sudden changes in temperature and humidity or to the outside air. Freezing of the substrate surface can cause various problems. For example, in automobiles, frost on the surface of the glass in the window can cause the glass to fog up, resulting in poor visibility. Furthermore, in sensors such as millimeter-wave radar and LiDAR (Light Detection and Ranging), which are essential for autonomous driving, frost on the cover glass can cause the cover glass to fog up, potentially resulting in sensor malfunction. Furthermore, in headlights, insufficient light output can result in poor visibility.

[0003] Methods for preventing fogging on glass surfaces include, for example, a technique of coating the adherend surface with a polymeric material made from a specific monomer (see Patent Documents 1 and 2) and a technique of blending a specific polyhydric alcohol (see Patent Document 3). The technique described in Patent Document 1 utilizes the properties of a specific acrylamide, which exhibits high water absorption at low temperatures and decreases in water absorption as the temperature rises. The technique described in Patent Document 2 utilizes the properties of a specific acrylamide derivative that is water-insoluble but hydrophilic. The technique described in Patent Document 3 utilizes specific polyhydric alcohols, since using salts to prevent freezing on metal surfaces corrodes the metal.

[0004] However, the techniques described in Patent Documents 1 to 3 do not describe or suggest how to improve both the frost resistance of the material itself used and the water resistance, which is a practical problem.

[0005] From the above viewpoints, it is desirable to have a cured film that can suppress the formation of frost on the substrate surface due to sudden changes in temperature and humidity, in other words, that has good frost resistance on the adherend surface and good water resistance.

[0006] Japanese Patent Publication No. 60-20430 Japanese Patent Publication No. 5-76511 Japanese Patent Application Laid-Open No. 2009-73877

[0007] The present technology has been proposed in view of the above-described conventional circumstances, and provides a laminate having a cured film with good frost resistance and water resistance, a distance measuring device, a lighting device, and an antifrost composition.

[0008] The laminate according to the present technology includes an adherend and a cured film formed on the adherend, the cured film being a cured product of a resin composition containing a monofunctional monomer, a polyfunctional monomer, and a radical polymerization initiator, and after the laminate is taken out from −40° C. to room temperature (25° C., 40% RH), the area of ​​frost adhesion on the surface of the cured film when the thickness is 5 μm or more is less than 30%.

[0009] The frost-proof composition according to the present technology includes (a1) more than 50 mass % and less than 94 mass % of N,N-dimethyl(meth)acrylamide, (c1) a polyfunctional (meth)acrylic monomer whose homopolymer satisfies the frost-proofing performance at −20° C., and (d) a radical polymerization initiator.

[0010] The antifrost composition according to the present technology contains (a2) 50% by mass or more and 79% by mass or less of a monofunctional (meth)acrylamide (excluding N,N-dimethyl(meth)acrylamide) whose homopolymer satisfies the frost resistance at −40° C., (c1) a polyfunctional (meth)acrylic monomer whose homopolymer satisfies the frost resistance at −20° C., and (d) a radical polymerization initiator.

[0011] The antifrost composition according to the present technology contains (b1) 79% by mass or more of a monofunctional (meth)acrylic monomer, the homopolymer of which satisfies the frost-proofing performance at −40°C, (c1) a polyfunctional (meth)acrylic monomer, the homopolymer of which satisfies the frost-proofing performance at −20°C, and (d) a radical polymerization initiator.

[0012] The antifrost composition according to the present technology comprises (a1) N,N-dimethyl(meth)acrylamide, (a2) a monofunctional (meth)acrylamide (excluding the above-mentioned component (a1)) whose homopolymer has an antifrost performance that satisfies −40°C, (c3) a polyfunctional (meth)acrylic monomer whose homopolymer does not satisfy −20°C, and (d) a radical polymerization initiator, and the total content of the components (a1) and (a2) is 90 mass% or more.

[0013] The frost-proof composition according to the present technology comprises (a1) N,N-dimethyl(meth)acrylamide, (a2) a monofunctional (meth)acrylamide (excluding the above-mentioned component (a1)) whose homopolymer has frost-proofing performance at −40° C., (c1) a polyfunctional (meth)acrylic monomer whose homopolymer has frost-proofing performance at −20° C., (c2) less than 30 mass% of a polyrotaxane di(meth)acrylate whose homopolymer does not have frost-proofing performance at −20° C., and (d) a radical polymerization initiator, and the total content of the components (a1) and (a2) is 59 mass% or more.

[0014] The frost-proof composition according to the present technology contains (a1) N,N-dimethyl(meth)acrylamide, (a2) a monofunctional (meth)acrylamide (excluding the above-mentioned component (a1)) whose homopolymer satisfies the frost-proofing performance at −40° C., (c2) less than 20 mass% of a polyrotaxane di(meth)acrylate whose homopolymer does not satisfy the frost-proofing performance at −20° C., and (d) a radical polymerization initiator, and the total content of the components (a1) and (a2) is 79 mass% or more.

[0015] The distance measuring device according to the present technology includes a light source that emits light, a light receiver that receives the emitted light, a window through which the emitted light and the received light pass, a measurement unit that measures the distance to an object by measuring the time from when the light emitted by the light source is reflected by the object until it is received by the light receiver, an adherend attached to the window, and a cured film formed on the adherend, wherein the adherend and the cured film pass through the emitted light, and the cured film is a cured product of a resin composition containing a monofunctional monomer, a polyfunctional monomer, and a radical polymerization initiator, and after the cured film is taken out from −40° C. to room temperature (25° C., 40% RH), the area of ​​frost adhesion on the surface of the cured film when it is 5 μm or thicker is less than 30%, and the measurement unit outputs information related to the distance measured.

[0016] The distance measuring device according to the present technology includes a light source that emits light, a light receiver that receives the emitted light, a window through which the emitted light and the received light pass, a measurement unit that measures the distance to an object by measuring the time from when the light emitted by the light source is reflected by the object until it is received by the light receiver, an adherend attached to the window, and a cured film formed on the adherend, and does not include a means for heating the adherend, the adherend and the cured film pass through the emitted light, and the cured film is a cured product of a resin composition containing a monofunctional monomer, a polyfunctional monomer, and a radical polymerization initiator, and after the cured film is taken out from −40° C. to room temperature (25° C., 40% RH), the area of ​​frost adhesion on the surface of the cured film when it is 5 μm or more in thickness is less than 30%, and the measurement unit outputs information related to the distance measured.

[0017] The lighting device according to the present technology includes a light source that emits light, a cover portion through which the light emitted by the light source transmits, a cured film formed on the cover portion, and a control portion that controls the light emission of the light source based on information related to ambient illuminance, wherein the cover portion and the cured film transmit the emitted light, and the cured film is a cured product of a resin composition containing a monofunctional monomer, a polyfunctional monomer, and a radical polymerization initiator, and after the cured film is taken out from −40° C. to room temperature (25° C., 40% RH), the area of ​​frost adhesion on the surface of the cured film when the film has a thickness of 5 μm or more is less than 30%.

[0018] The lighting device according to the present technology includes a light source that emits light, a cover portion through which the light emitted by the light source transmits, a cured film formed on the cover portion, and a control portion that controls light emission from the light source based on information related to ambient illuminance, and does not include a means for heating the cover member, wherein the cover portion and the cured film transmit the emitted light, and the cured film is a cured product of a resin composition containing a monofunctional monomer, a polyfunctional monomer, and a radical polymerization initiator, and after the cured film is taken out from −40° C. to room temperature (25° C., 40% RH), the area of ​​frost adhesion on the surface of the cured film when the film has a thickness of 5 μm or more is less than 30%.

[0019] This technology can provide a cured film with good frost resistance and water resistance.

[0020] Fig. 1 is a cross-sectional view for explaining frost resistance, and is a cross-sectional view for explaining an example of a frost generation mechanism in the prior art. Fig. 2 is a cross-sectional view for explaining frost resistance, and is a cross-sectional view for explaining an example of a frost generation mechanism in the present technology. Fig. 3 is a perspective view for explaining a method for evaluating the frost resistance of a cured film. Fig. 4 is a block diagram showing an example of the configuration of a LiDAR device as a distance measuring device equipped with a cured film. Fig. 5 is a block diagram showing an example of the configuration of an automotive headlight as a lighting device equipped with a cured film.

[0021] <Laminate> A laminate according to the present technology includes an adherend and a cured film formed on the adherend. The cured film in the laminate is a cured product of a resin composition containing a monofunctional monomer, a polyfunctional monomer, and a radical polymerization initiator. This cured film has good frost resistance, and after the laminate according to the present technology is removed from −40° C. to room temperature (25° C., 40% RH), the area of ​​frost adhesion on the surface of the cured film is less than 30%.

[0022] [Frost resistance of cured film] In this specification, the frost resistance of the cured film means that frost is unlikely to occur and good visibility can be maintained. For example, the frost resistance of the cured film means that the evaluation result when the frost resistance test of the examples described later is good for the cured film of the laminate according to the present technology.

[0023] Here, the types of water that hydrate on the surface of polymeric materials include, for example, three types: non-freezing water, intermediate water, and free water (see, for example, "Tanaka Masaru, Polymeric Materials and Water: Free Water, Non-freezing Water, Intermediate Water - Correlation between Biocompatibility and the Structure of Water Adsorbed on Polymeric Materials - Chemistry and Education, Vol. 60, No. 6 (2012)").

[0024] Fig. 1 is a cross-sectional view illustrating frost resistance and an example of the mechanism by which frost occurs in conventional technology. As shown in Figs. 1(A) to 1(C), for example, when a laminate 100 including an adherend 101 and a cured film 102 formed on the adherend 101 is removed from a low-temperature (e.g., -40°C) environment to a room-temperature (e.g., 25°C, 40% RH) environment, condensation 104 is generated from water vapor 103 (free water) in the atmosphere, and this condensation 104 becomes visible, causing fogging. Then, as shown in Fig. 1(C), the condensation 104 is thought to freeze to form frost 105.

[0025] 2A to 2C are cross-sectional views illustrating frost resistance and an example of the frost generation mechanism in the present technology. As shown in Figures 2A to 2C, when a laminate 1 according to the present technology, which includes an adherend 2 and a cured film 3 formed on the adherend 2, is taken out from a low-temperature environment to a room-temperature environment, similar to the frost generation mechanism in the conventional technology described above, water vapor 4 in the atmosphere is captured as non-freezing water (bound water) 5 on the surface of the cured film 3, suppressing condensation. Therefore, it is thought that frost caused by the condensation freezing is suppressed as shown in Figure 2C.

[0026] Furthermore, in the laminate 1 according to the present technology, the cured film 3 has good frost resistance, and unlike the frost generation mechanism in the conventional technology shown in FIGS. 1(A) to 1(C), condensation is prevented from freezing, and therefore the cured film 3 has good antifreeze properties.

[0027] As described above, the cured film 3 has good frost resistance after being taken out from a low-temperature (-40°C) environment to room temperature. The reason for focusing on the frost resistance of the cured film 3 when taken out from -40°C to room temperature is that, for example, the minimum operating temperature of LiDAR, which is one of the sensors essential for autonomous driving, is often set to -40°C, and the operation of the laminate 1 in such a low-temperature environment was taken into consideration.

[0028] [IR (infrared) transmittance of cured film] The laminate 1 has good frost resistance in the cured film 3, and therefore also has good IR transmittance, for example. Good IR transmittance means, for example, that the cured film of the laminate 1 has good evaluation results when subjected to an IR transmittance test in the Examples described below. The cured film 3 preferably has a transmittance of 50% or more at wavelengths of 905 nm, 1310 nm, and 1550 nm.

[0029] [Water Resistance of Cured Film] In addition to the excellent frost resistance of the cured film 3 of the laminate 1, the cured film 3 also has excellent water resistance. In this specification, water resistance means that the film is not easily dissolved in water and is not easily swollen or peeled off due to water absorption. Good water resistance means, for example, that the cured film 3 has good evaluation results when subjected to a water resistance test in the examples described below. As will be described in detail later, the cured film 3 is a cured product of a resin composition (frost-proof composition) containing a monofunctional monomer, a polyfunctional monomer, and a radical polymerization initiator, and the use of the polyfunctional monomer improves water resistance.

[0030] [Heat Resistance of Cured Film] The laminate 1 also has good heat resistance in the cured film 3. In this specification, "heat resistance" means that the film has high resistance to heat and does not flow in viscoelasticity measurement. "Good heat resistance" means, for example, that the cured film 3 has good evaluation results when subjected to the heat resistance test in the examples described below. As described above, the cured film 3 also has good heat resistance due to the use of a polyfunctional monomer.

[0031] The thickness of the cured film 3 is not particularly limited, but from the viewpoint of improving frost resistance and water resistance, it is preferably 5 μm or more, and more preferably 20 μm or more. If the thickness of the cured film 3 is less than 5 μm, the antifreeze water is likely to become saturated, which may deteriorate the frost resistance, and water may easily reach the interface of the substrate (adherend 2), which may deteriorate the water resistance. The upper limit of the thickness of the cured film 3 is not particularly limited, and can be, for example, 50 μm or less. Furthermore, the cured film 3 may be formed on only one side of the adherend 2, or on both sides of the adherend 2.

[0032] The adherend 2 can be appropriately selected depending on the application of the laminate 1 and is not particularly limited. For example, when the laminate 1 is applied to optical applications, the adherend 2 can be a material that transmits visible light, such as glass or plastic. Transmitting visible light preferably means that the visible light transmittance of the adherend 2 satisfies the standards required for the application of the laminate 1, and for example, the visible light transmittance of the adherend 2 is preferably 70% or more. Furthermore, when the laminate 1 is applied to applications other than optical applications, examples of the adherend 2 include materials that do not transmit visible light, such as metals such as aluminum, copper, SUS (Steel Use Stainless), and zinc plating that are used in the opening and closing parts of heat exchangers and freezers, and black glass or plastic that does not transmit visible light but transmits infrared light or millimeter waves.

[0033] <Anti-frost composition> Next, an example of a resin composition that can be suitably used for the cured film 3 will be described. The anti-frost composition according to the present technology contains a monofunctional monomer, a polyfunctional monomer, and a radical polymerization initiator, and has good frost resistance and water resistance after curing (cured film 3). According to studies by the present inventors, in order to improve the frost resistance of the cured film 3, it is considered preferable to select a resin composition that has a relatively large amount of antifreeze water and a relatively small amount of intermediate water and free water.

[0034] [Monofunctional Monomer] The monofunctional monomer refers to a monomer having one polymerizable group (e.g., a radically polymerizable group) having an unsaturated double bond, such as a (meth)acryloyl group or a vinyl group. Here, the (meth)acryloyl group includes both an acryloyl group and a methacryloyl group.

[0035] The antifrost composition according to the present technology preferably contains, as the monofunctional monomer, a monofunctional monomer whose homopolymer has frost-proofing properties at −40° C. (hereinafter also referred to as a “specific monofunctional monomer”). The specific monofunctional monomer is one that gives good evaluation results when the frost-proofing properties of the monofunctional monomer are tested by the method described in the Examples below. The reason for focusing on the frost-proofing properties of the homopolymer at −40° C. with respect to the monofunctional monomer is the same as the frost-proofing properties of the cured film described above.

[0036] According to the research of the present inventors, the higher the solubility of a monofunctional monomer in water, the better the frost resistance tends to be. For example, when the monofunctional monomer is an acrylic monomer having a hydroxyl group, the number of hydroxyl groups per molecular weight of the monofunctional monomer (hydroxyl group concentration) can be a factor affecting the frost resistance of the cured film 3. Even when the monofunctional monomer has multiple hydroxyl groups, if the hydroxyl group concentration in the monofunctional monomer is low, the frost resistance of the cured film 3 tends to be insufficient.

[0037] Next, when the monofunctional monomer has a hydroxyl group, the influence of the position of the hydroxyl group on the frost resistance will be examined. When the monofunctional monomer does not have a bulky group (e.g., an alicyclic structure or an aromatic ring structure) near the hydroxyl group (e.g., a site adjacent to the hydroxyl group), the hydroxyl group is more likely to appear on the surface of the cured film 3 and form hydrogen bonds with water, which tends to make the cured film 3 more frost-resistant. Furthermore, when the monofunctional monomer has a hydroxyl group, the monofunctional monomer has a hydrophobic alkyl group, which makes it easier for the hydroxyl groups to line up and form hydrogen bonds with water, which tends to make the cured film 3 more frost-resistant.

[0038] Furthermore, when the monofunctional monomer is an acrylamide-based monomer, the cured film 3 tends to have anti-frost properties, and the absence of a bulky group (for example, an alicyclic structure or an aromatic ring structure) tends to make it easier to obtain anti-frost properties for the cured film 3. This is thought to be because acrylamide-based monomers tend to easily form hydrogen bonds with water and the strength of the hydrogen bonds with water tends to be relatively high.

[0039] From the above viewpoints, in terms of the frost resistance and water resistance of the cured film 3, the specific monofunctional monomer is preferably, for example, (i) (meth)acrylic acid ester, (ii) (meth)acrylate having a polyethylene oxide skeleton, (iii) (meth)acrylate having a terminal hydroxyl group and not containing an alicyclic structure or an aromatic ring structure, (iv) acrylamide-based monomers and derivatives thereof, etc. Here, (meth)acrylic acid ester includes both acrylic acid ester and methacrylic acid ester. Furthermore, (meth)acrylate includes both acrylate and methacrylate.

[0040] The (meth)acrylic acid ester preferably does not contain an alicyclic structure or an aromatic ring structure, from the viewpoint of the frost resistance of the cured film 3. The (meth)acrylic acid ester preferably has, for example, a carbon number of 8 to 14, from the viewpoint of the frost resistance of the cured film 3. The (meth)acrylic acid ester may be linear or branched.

[0041] (Meth)acrylates having a polyethylene oxide skeleton have a "(-CH ２ CH ２ O-) ｎ１ ", and n1 is 2 or more. The (meth)acrylate having a polyethylene oxide skeleton preferably does not contain an alicyclic structure or an aromatic ring structure.

[0042] The (meth)acrylate having a hydroxyl group at its terminal and not containing an alicyclic structure or an aromatic ring structure preferably has 6 to 10 carbon atoms, from the viewpoint of the frost resistance of the cured film 3. It is preferable that the (meth)acrylate has a hydroxyl group at its terminal and not containing an alicyclic structure or an aromatic ring structure. The (meth)acrylate may be linear or branched.

[0043] Acrylamide monomers have a terminal group of "-NR １ R ２ It is preferable that R １ and R ２ are preferably each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. １ and R ２The alkyl group as R may have a substituent, and examples of the substituent include a hydroxyl group, an amino group, and an amino group substituted with a methyl group. １ and R ２ may be bonded to each other to form a ring structure. １ and R ２ The alkyl group as the alkyl group may be linear or branched. From the viewpoint of the frost resistance of the cured film 3, it is preferable that the acrylamide-based monomer and its derivatives do not contain an aromatic ring structure.

[0044] Specific examples of the specific monofunctional monomer include N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, (meth)acryloylmorpholine, N-(2-hydroxyethyl)(meth)acrylamide, N-isopropyl(meth)acrylamide, N-(3-(dimethylamino)propyl)(meth)acrylamide, 4-hydroxybutyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, ethyl carbitol(meth)acrylate, ethoxyethoxyethanol, and methoxypolyethylene glycol(meth)acrylate.

[0045] The monofunctional monomer may be used alone or in combination of two or more. For example, the antifrost composition may use a specific monofunctional monomer alone, a specific monofunctional monomer in combination of two or more specific monofunctional monomers, or a specific monofunctional monomer in combination with a monofunctional monomer that does not fall under the category of the specific monofunctional monomer.

[0046] [Polyfunctional Monomer] The polyfunctional monomer refers to a monomer having two or more polymerizable groups (for example, radically polymerizable groups) having an unsaturated double bond, such as a (meth)acryloyl group or a vinyl group.

[0047] In order to improve the frost resistance and water resistance of the cured film 3, the antifrost composition according to the present technology preferably contains, as the polyfunctional monomer, a polyfunctional monomer whose homopolymer has frost resistance at −20° C. (hereinafter also referred to as a “specific polyfunctional monomer”). A specific polyfunctional monomer is one that gives good evaluation results when the frost resistance of the polyfunctional monomer is tested by the method described in the Examples below. The reason for focusing on the frost resistance of the homopolymer at −20° C. with respect to the polyfunctional monomer is that it is within the range of commonly available polyfunctional monomers and takes into consideration practical use in cold regions.

[0048] From the viewpoint of the frost resistance of the cured film 3, the specific polyfunctional monomer is preferably, for example, a polyfunctional (meth)acrylate having a polyethylene oxide skeleton. The polyfunctional (meth)acrylate having a polyethylene oxide skeleton is, for example, a polyfunctional (meth)acrylate having a "(-CH ２ CH ２ O-) ｎ２ ". In this polyethylene oxide skeleton, n2 is preferably, for example, about 20 to 40. From the viewpoint of the frost resistance of the cured film 3, it is preferable that the specific polyfunctional monomer does not contain an alicyclic structure or an aromatic ring structure.

[0049] Specific examples of the specific polyfunctional monomer include polyethylene glycol di(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, ethoxylated glycerin tri(meth)acrylate, and ethoxylated pentaerythritol tetra(meth)acrylate.

[0050] The polyfunctional monomer may be used alone or in combination of two or more. For example, a specific polyfunctional monomer may be used alone, two or more specific polyfunctional monomers may be used in combination, or a specific polyfunctional monomer may be used in combination with a polyfunctional monomer that does not fall under the specific polyfunctional monomer.

[0051] [Polymerization initiator] The polymerization initiator is a component for polymerizing a monofunctional monomer or a polyfunctional monomer. The polymerization initiator is, for example, a radical polymerization initiator, and examples thereof include a photoradical polymerization initiator that generates radicals upon light irradiation and a thermal radical polymerization initiator that generates radicals upon heat. Examples of the photoradical polymerization initiator include a benzophenone compound, an acetophenone compound, an acylphosphine oxide compound, a titanocene compound, an oxime ester compound, a benzoin ether compound, and a thioxanthone compound. Examples of the thermal radical polymerization initiator include an azo compound and an organic peroxide. The polymerization initiator may be used alone or in combination of two or more types.

[0052] The content of the polymerization initiator can be, for example, 0.1% by mass or more, or 0.5% by mass or more, or 1.0% by mass or more, based on the total content of the monofunctional monomer and the polyfunctional monomer in the antifrost composition, and can be, for example, 3% by mass or less, or 2% by mass or less, or 1.5% by mass or less, based on the total content of the monofunctional monomer and the polyfunctional monomer in the antifrost composition.

[0053] The antifrost composition according to the present technology may further contain other components in addition to the above-mentioned components, as long as the effects of the present technology are not impaired. Examples of other components include a monofunctional monomer that does not fall under the specific monofunctional monomer and a polyfunctional monomer that does not fall under the specific polyfunctional monomer.

[0054] In order to improve the self-repairing properties of the cured film 3 in addition to the frost resistance and water resistance, the frost-resistant composition according to the present technology may contain, for example, a polyrotaxane having a radically polymerizable group in a side chain. Polyrotaxane is a supramolecule having a structure in which an axis molecule penetrates the hollow portion of a cyclic molecule such as cyclodextrin. The self-repairing properties refer to good scratch resistance, and good self-repairing properties refer to, for example, good evaluation results when the laminate 3 is subjected to a self-repairing property test in the examples described below.

[0055] From the viewpoint of improving the frost resistance and water resistance of the cured film 3, the antifrost composition according to the present technology is preferably, for example, one of the following first to sixth aspects.

[0056] [First Aspect of Frost-Proof Composition] The first aspect of the frost-proof composition (hereinafter also referred to as "first frost-proof composition") contains more than 50 mass % and less than 94 mass % of N,N-dimethyl(meth)acrylamide (hereinafter also referred to as "component (a1)"), a polyfunctional (meth)acrylic monomer (hereinafter also referred to as "component (c1)") whose homopolymer satisfies the frost-proofing performance at -20°C, and a radical polymerization initiator (hereinafter also referred to as "component (d)").

[0057] The (a1) component is the specific monofunctional monomer described above. The content of the (a1) component in the first antifrost composition may be 51% by mass or more, 55% by mass or more, 59% by mass or more, 65% by mass or more, 69% by mass or more, or 75% by mass or more. The content of the (a1) component in the first antifrost composition may be 90% by mass or less, 85% by mass or less, 83% by mass or less, 81% by mass or less, or 79% by mass or less. The (a1) component may be used alone or in combination of two or more types.

[0058] The (c1) component is the specific polyfunctional monomer described above. The content of the (c1) component in the first antifrost composition can be greater than 5% by mass, or can be 6% by mass or more, 10% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, 30% by mass or more, 35% by mass or more, or 40% by mass or more. The content of the (c1) component in the first antifrost composition can be less than 60% by mass, or can be 59% by mass or less, 55% by mass or less, 50% by mass or less, 45% by mass or less, or 40% by mass or less. The (c1) component may be used alone or in combination of two or more types.

[0059] As the component (d), the above-mentioned polymerization initiator can be used in the above-mentioned content. The component (d) may be used alone or in combination of two or more types.

[0060] As described above, the first aspect of the antifrost composition contains a specific amount of the component (a1) having antifrost properties, and also contains the component (c1) having antifrost properties, thereby enabling the cured film 3 to have good frost resistance and water resistance. Furthermore, the first aspect of the antifrost composition provides good frost resistance for the cured film 3, thereby enabling the cured film 3 to have good IR transmittance. Furthermore, the first aspect of the antifrost composition contains a specific polyfunctional monomer, thereby enabling the cured film 3 to have good heat resistance.

[0061] [Second Aspect of Antifrost Composition] A second aspect of the antifrost composition (hereinafter also referred to as "second antifrost composition") comprises 50% by mass or more and 79% by mass or less of a monofunctional (meth)acrylamide (hereinafter also referred to as "component (a2)") whose homopolymer satisfies the frost prevention performance at -40°C, excluding component (a1), component (c1), and component (d).

[0062] The component (a2) is the specific monofunctional monomer described above. As the component (a2), for example, any of the specific monofunctional monomers listed above, other than the component (a1), can be used. In the second antifrost composition, the content of the component (a2) may be 55% by mass or more, 60% by mass or more, 65% by mass or more, 70% by mass or more, or 75% by mass or more. In the second antifrost composition, the content of the component (a2) may be 75% by mass or less, 70% by mass or less, 65% by mass or less, 60% by mass or less, or 55% by mass or less. The component (a2) may be used alone or in combination of two or more types.

[0063] In the second antifrost composition, the content of component (c1) may be 20% by mass or more, 25% by mass or more, 30% by mass or more, 35% by mass or more, 40% by mass or more, or 45% by mass or more. Furthermore, in the second antifrost composition, the content of component (c1) may be 50% by mass or less, 45% by mass or less, 40% by mass or less, 35% by mass or less, or 30% by mass or less. One type of component (c1) may be used alone, or two or more types may be used in combination.

[0064] As the component (d), the above-mentioned polymerization initiator can be used in the above-mentioned content. The component (d) may be used alone or in combination of two or more types.

[0065] As described above, the second aspect of the antifrost composition contains a specific amount of the component (a2) having antifrost properties, and also contains the component (c1) having antifrost properties, thereby enabling the cured film 3 to have good frost resistance and water resistance. Furthermore, the second aspect of the antifrost composition has good frost resistance, enabling the cured film 3 to have good IR transmittance. Furthermore, the second aspect of the antifrost composition contains a specific polyfunctional monomer, enabling the cured film 3 to have good heat resistance.

[0066] [Third Aspect of Antifrost Composition] A third aspect of the antifrost composition (hereinafter also referred to as "third antifrost composition") contains 79 mass % or more of a monofunctional (meth)acrylic monomer (hereinafter also referred to as component (b1)) whose homopolymer satisfies the frost prevention performance at -40°C, component (c1), and component (d).

[0067] The (b1) component is the specific monofunctional monomer described above. As the (b1) component, for example, any of the specific monofunctional monomers listed above, other than the acrylamide-based monomer, can be used. In the third antifrost composition, the content of the (b1) component may be 82% by mass or more, 84% by mass or more, 86% by mass or more, or 88% by mass or more. In the third antifrost composition, the content of the (b1) component may be 90% by mass or less, 88% by mass or less, 86% by mass or less, or 84% by mass or less. The (b1) component may be used alone or in combination of two or more types.

[0068] In the third antifrost composition, the content of the component (c1) can be 20% by mass or less, or alternatively 19% by mass or less, or 18% by mass or less, or 16% by mass or less. In the third antifrost composition, the content of the component (c1) can be, for example, 10% by mass or more, or alternatively 15% by mass or more, or alternatively 18% by mass or more. The component (c1) may be used alone or in combination of two or more.

[0069] As the component (d), the above-mentioned polymerization initiator can be used in the above-mentioned content. The component (d) may be used alone or in combination of two or more types.

[0070] As described above, the third aspect of the antifrost composition contains a specific amount of the component (b1) having antifrost properties, and also contains the component (c1) having antifrost properties, thereby enabling the cured film 3 to have good frost resistance and water resistance. Furthermore, the third aspect of the antifrost composition has good frost resistance, enabling the cured film 3 to have good IR transmittance. Furthermore, the third aspect of the antifrost composition contains a specific polyfunctional monomer, enabling the cured film 3 to have good heat resistance.

[0071] [Fourth Aspect of Antifrost Composition] A fourth aspect of the antifrost composition (hereinafter also referred to as "fourth antifrost composition") comprises component (a1), component (a2), a polyfunctional (meth)acrylic monomer (hereinafter also referred to as component (c3)) whose homopolymer does not satisfy the frost prevention performance at -20°C, and component (d), in which the total content of component (a1) and component (a2) is 90 mass% or more.

[0072] In the fourth antifrost composition, the content of the component (a1) can be, for example, 35% by mass or more, 40% by mass or more, 42% by mass or more, 45% by mass or more, 47% by mass or more, 50% by mass or more, or 55% by mass or more. Furthermore, in the fourth antifrost composition, the content of the component (a1) can be, for example, 65% by mass or less, 60% by mass or less, 57% by mass or less, 55% by mass or less, 52% by mass or less, 50% by mass or less, or 45% by mass or less. The component (a1) may be used alone or in combination of two or more types.

[0073] In the fourth antifrost composition, the content of the component (a2) can be, for example, 30% by mass or more, 35% by mass or more, 37% by mass or more, 40% by mass or more, 42% by mass or more, 45% by mass or more, or 50% by mass or more. In the fourth antifrost composition, the content of the component (a2) can be, for example, 60% by mass or less, 55% by mass or less, 53% by mass or less, 50% by mass or less, 48% by mass or less, 45% by mass or less, or 40% by mass or less. The component (a2) may be used alone or in combination of two or more types.

[0074] In the fourth antifrost composition, the total content of the components (a1) and (a2) may be 91% by mass or more, 92% by mass or more, 93% by mass or more, or 94% by mass or more. In addition, in the fourth antifrost composition, the total content of the components (a1) and (a2) may be, for example, 99% by mass or less, 98% by mass or less, 97% by mass or less, 96% by mass or less, or 95% by mass or less.

[0075] In the fourth antifrost composition, the content of the component (c3) is preferably as low as possible from the viewpoint of the frost resistance of the cured film 3. For example, it can be less than 20% by mass, and may be 15% by mass or less, 10% by mass or less, 9% by mass or less, 8% by mass or less, 7% by mass or less, 6% by mass or less, or 5% by mass or less. Furthermore, in the fourth antifrost composition, the content of the component (c3) may be, for example, 0.5% by mass or more, 1% by mass or more, 2% by mass or more, 3% by mass or more, 4% by mass or more, or 5% by mass or more. The component (c3) may be used singly or in combination of two or more types.

[0076] As the component (d), the above-mentioned polymerization initiator can be used in the above-mentioned content. The component (d) may be used alone or in combination of two or more types.

[0077] As described above, the fourth aspect of the antifrost composition contains the frost-resistant components (a1), (a2), and (c1), and the total content of the components (a1) and (a2) is a specific amount or more, and the content of the non-frost-resistant component (c3) is a specific amount or less, thereby enabling the cured film 3 to have good frost resistance and water resistance. Furthermore, the frost-resistant properties of the cured film 3 are good in the fourth aspect of the antifrost composition, and therefore the IR transmittance of the cured film 3 can also be good. Furthermore, the frost-resistant composition of the fourth aspect contains a specific polyfunctional monomer, enabling the heat resistance of the cured film 3 to be good.

[0078] [Fifth Aspect of Antifrost Composition] A fifth aspect of the antifrost composition (hereinafter also referred to as "fifth antifrost composition") comprises the components (a1), (a2), and (c1), less than 30 mass% of a polyrotaxane di(meth)acrylate (hereinafter also referred to as the component (c2)) whose homopolymer does not satisfy the frost prevention performance at -20°C, and the component (d), in which the total content of the components (a1) and (a2) is 59 mass% or more.

[0079] In the fifth antifrost composition, the content of component (a1) can be, for example, 35% by mass or more, 40% by mass or more, 45% by mass or more, 50% by mass or more, 54% by mass or more, 59% by mass or more, or 65% by mass or more. In the fifth antifrost composition, the content of component (a1) can be, for example, 65% by mass or less, 59% by mass or less, 54% by mass or less, 50% by mass or less, 45% by mass or less, 40% by mass or less, or 35% by mass or less. The component (a1) may be used alone, or two or more types may be used in combination.

[0080] In the fifth antifrost composition, the content of component (a2) can be, for example, 5% by mass or more, 10% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, 30% by mass or more, 35% by mass or more, 40% by mass or more, or 45% by mass or more. In the fifth antifrost composition, the content of component (a2) can be, for example, 50% by mass or less, 45% by mass or less, 40% by mass or less, 35% by mass or less, 30% by mass or less, 25% by mass or less, 20% by mass or less, 15% by mass or less, 10% by mass or less, or 5% by mass or less. The component (a2) may be used alone or in combination of two or more types.

[0081] In the fifth antifrost composition, the total content of the components (a1) and (a2) may be 65% by mass or more, 69% by mass or more, 74% by mass or more, 79% by mass or more, 85% by mass or more, 89% by mass or more, or 94% by mass or more. In addition, in the fifth antifrost composition, the total content of the components (a1) and (a2) may be, for example, 98% by mass or less, 94% by mass or less, 89% by mass or less, 85% by mass or less, 79% by mass or less, 74% by mass or less, 69% by mass or less, or 65% by mass or less.

[0082] In the fifth antifrost composition, the content of the component (c1) can be, for example, 4% by mass or more, or 10% by mass or more, or 15% by mass or more, or 20% by mass or more. Furthermore, in the fifth antifrost composition, the content of the component (c1) can be, for example, 20% by mass or less, or 15% by mass or less, or 10% by mass or less, or 5% by mass or less. The component (c1) may be used singly or in combination of two or more types.

[0083] In the fifth antifrost composition, the content of component (c2) is preferably as low as possible from the viewpoint of frost resistance when formed into a cured film. For example, it can be 25% by mass or less, or may be 20% by mass or less, 15% by mass or less, 12% by mass or less, 10% by mass or less, 5% by mass or less, 3% by mass or less, 2% by mass or less, or 1% by mass or less. Furthermore, in the fifth antifrost composition, the content of component (c2) is preferably 0.5% by mass or more from the viewpoint of self-repairing properties when formed into a cured film, or may be 1% by mass or more, or may be 10% by mass or more, or 15% by mass or more, or may be 20% by mass or more. The (c2) component may be used alone or in combination of two or more types.

[0084] As the component (d), the above-mentioned polymerization initiator can be used in the above-mentioned content. The component (d) may be used alone or in combination of two or more types.

[0085] As described above, the fifth aspect of the antifrost composition contains the frost-resistant components (a1), (a2), and (c1), and the total content of the components (a1) and (a2) is a specific amount or more, and the content of the component (c2), which does not have frost resistance, is a specific amount or less. This allows the cured film 3 to have good frost resistance and water resistance. Furthermore, the fifth aspect of the antifrost composition provides good frost resistance for the cured film 3, and therefore the IR transmittance of the cured film 3 can also be improved. Furthermore, the fifth aspect of the antifrost composition contains a specific polyfunctional monomer, and therefore the heat resistance of the cured film 3 can also be improved. Furthermore, the fifth aspect of the antifrost composition contains the component (c2), and therefore the self-repairing property of the cured film 3 can also be improved.

[0086] [Sixth Aspect of the Antifrost Composition] The sixth aspect of the antifrost composition (hereinafter also referred to as "sixth antifrost composition") comprises the component (a1), the component (a2), less than 20 mass% of the component (c2), and the component (d), and the total content of the component (a1) and the component (a2) is 79 mass% or more.

[0087] In the sixth antifrost composition, the content of the component (a1) can be, for example, 40% by mass or more, or 45% by mass or more, or 50% by mass or more. Furthermore, in the sixth antifrost composition, the content of the component (a1) can be, for example, 60% by mass or less, or 55% by mass or less, or 50% by mass or less. The component (a1) may be used singly or in combination of two or more types.

[0088] In the sixth antifrost composition, the content of the component (a2) can be, for example, 35% by mass or more, or 40% by mass or more, or 45% by mass or more. Furthermore, in the sixth antifrost composition, the content of the component (a2) can be, for example, 55% by mass or less, or 50% by mass or less, or 45% by mass or less. The component (a2) may be used singly or in combination of two or more.

[0089] In the sixth antifrost composition, the total content of the components (a1) and (a2) may be 85% by mass or more, 89% by mass or more, or 94% by mass or more. In addition, in the sixth antifrost composition, the total content of the components (a1) and (a2) may be, for example, 99% by mass or less, 97% by mass or less, or 94% by mass or less.

[0090] In the sixth antifrost composition, the content of the component (c2) is, for example, preferably more than 1% by mass, and may be 3% by mass or more, 5% by mass or more, 8% by mass or more, or 10% by mass or more, from the viewpoint of the self-repairing property of the cured film 3. Furthermore, in the sixth antifrost composition, the content of the component (c2) is preferably as low as possible from the viewpoint of the frost resistance of the cured film 3, and may be, for example, 18% by mass or less, 15% by mass or less, 12% by mass or less, or 10% by mass or less. The component (c2) may be used singly or in combination of two or more types.

[0091] As the component (d), the above-mentioned polymerization initiator can be used in the above-mentioned content. The component (d) may be used alone or in combination of two or more types.

[0092] As described above, the sixth aspect of the antifrost composition contains the frost-resistant components (a1) and (a2), and the total content of the components (a1) and (a2) is a specific amount or more, and the content of the non-frost-resistant component (c2) is a specific amount or less. This allows the cured film 3 to have good frost resistance and water resistance. Furthermore, the sixth aspect of the antifrost composition provides good frost resistance for the cured film 3, and therefore the IR transmittance of the cured film 3 can also be improved. Furthermore, the sixth aspect of the antifrost composition contains a specific polyfunctional monomer, and therefore the heat resistance of the cured film 3 can also be improved. Furthermore, the sixth aspect of the antifrost composition contains the component (c2), and therefore the self-repairing property of the cured film 3 can also be improved.

[0093] <Optical Device> The above-described cured film 3 can be applied to optical devices, such as distance measuring devices and lighting devices.

[0094] <Distance Measuring Device> For example, the distance measuring device includes a light source that emits light, a light receiver that receives the emitted light, a window through which the emitted and received light pass, a measuring unit that measures the distance to an object by measuring the time it takes for the light emitted by the light source to be reflected by the object and received by the light receiver, an adherend attached to the window, and a cured film formed on the adherend, and the measuring unit outputs information about the distance measured. The adherend and the cured film transmit the emitted light. The cured film is a cured product of a resin composition containing a monofunctional monomer, a polyfunctional monomer, and a radical polymerization initiator. After the cured film is removed from -40°C to room temperature (25°C, 40% RH), the frost adhesion area on the surface of the cured film when the film is 5 μm or thick is less than 30%.

[0095] By providing the distance measuring device with a cured film having good frost resistance and water resistance on the adherend, it is possible to reduce the adhesion of frost to the adherend, thereby reducing the attenuation of the light-emitting signal and the light-receiving signal and the increase in noise in the light-receiving signal caused by the adhesion of frost on the adherend, and thus it is possible to more accurately detect the object to be measured. Specific examples of distance measuring devices are described below.

[0096] 4 is a block diagram showing an example of the configuration of a LiDAR device 41 as a distance measuring device equipped with the above-mentioned cured film 3. The LiDAR device 41 includes, for example, a laser driver 44, a laser (LD) 45, a lens 46, a cover glass 47, a cured film 48, a photodetector (PD) 49, an analog front end (AFE) 50, a digital signal processor (DSP) 51, a controller area network (CAN) communication unit 52, a power supply unit 53, a heater control unit 54, a device diagnosis and monitoring unit 55, and a beam steering control unit 56.

[0097] The cured film 48 can be the above-described cured film 3. Furthermore, the cured film 48 is not limited to a film obtained by curing any of the first to sixth aspects of the above-described antifrost composition.

[0098] An example of the operation of the LiDAR device 41 to measure the distance to the measurement object 42 will be described. First, the laser driver 44 emits a laser 45 and outputs an emission signal. The emission signal is focused by the lens 46 and passes through the cover glass 47 and the cured film 48. The emission signal that passes through the cover glass 47 and the cured film 48 reaches the measurement object 42 and is reflected by the measurement object 42. The emission signal reflected by the measurement object 42 returns to the LiDAR device 41 as a received light signal, passes through the cured film 48 and the cover glass 47, is focused by the lens 46, is received by the light receiving element 49, and is converted into an electrical signal by photoelectric conversion. The AFE 50 performs noise removal and amplitude amplification on the converted electrical signal and sends it to the DSP 51.

[0099] The DSP 51 performs digital signal processing on the electrical signal transmitted from the AFE 50. The DSP 51 also measures the elapsed time from the timing of emission of light to the laser driver 44, and calculates the distance to the measurement target 42. Information on the distance calculated by the DSP 51 is transmitted as an output signal 43 via the CAN communication unit 52 to an outside of the LiDAR device 41, for example, to a computer device inside the vehicle.

[0100] The laser 45 is a light source that emits light and is composed of, for example, a semiconductor laser (LD: Laser Diode). The laser 45 outputs an emission signal, for example, a pulsed signal or a signal with a specific waveform. The lens 46 is a window through which the emitted light and the received light pass. The cover glass 47 is an adherend that is attached to the window and has a heater function. The cured film 48 is laminated (attached) to the surface of the cover glass 47. The light-receiving element 49 is a light receiver that receives the emitted light. The DSP 51 is a measurement unit that measures the distance to the object 42 by measuring the time it takes for the light emitted by the light source to be reflected by the object and received by the light receiver.

[0101] The power supply unit 53 supplies power to each circuit. For example, the power supply unit 53 supplies power to the heater control unit 54, thereby heating the cover glass 47, which has a heater function, and enabling the frost (or snow) to be removed. For example, when frost forms on the cover glass 47, which is the light-emitting / light-receiving unit of the LiDAR device 41, the heater control unit 54 controls the heater to remove the frost. Methods for detecting frost include, for example, measuring the strength of the light-receiving signal relative to the light-emitting signal, or detecting it from the ambient temperature, humidity, or vehicle speed. When the LiDAR device 41 starts operating, the device diagnosis / monitoring unit 55 checks for any abnormalities in the light-emitting / light-receiving, checking the light-receiving level and light-emitting level, etc.

[0102] The beam steering control unit 56 controls the scanning of the laser 45 by beam steering. Beam steering methods include, for example, a mechanical scanning method using a rotating mirror, a method using a MEMS (Micro Electro Mechanical Systems) mirror, and a method using an optical phased array. There are also various other methods, such as a method in which the distance is detected by irradiating light over a wide angle at once without scanning the light emission signal, but the method is not limited thereto.

[0103] Here, if frost forms on all or part of the cover glass 47 of the LiDAR device 41, it may become impossible to emit an optical emission signal and may also become impossible to receive a received optical signal reflected by the object to be measured 42. In this case, the object to be measured 42 may not be detected correctly, which may pose a danger to the driving of a vehicle equipped with the LiDAR device. Therefore, the LiDAR device 41 prevents or reduces the formation of frost on the cover glass 47 by laminating a cured film 48 with good frost resistance and water resistance on the cover glass 47, thereby reducing the attenuation of the optical emission signal and the received optical signal and the increase in noise in the received optical signal, thereby enabling more accurate detection of the object to be measured 42.

[0104] Although the cover glass 47 is assumed to have a heater function, this is not limited to this example, and the LiDAR device 41 may not have a means for heating the cover glass 47. In other words, the LiDAR device 41, including the cover glass 47, may not have a heating means (heater function). By providing the LiDAR device 41 with the hardened film 48, even if the LiDAR device 41 does not have a heater function, it is possible to reduce frost adhesion to the cover glass 47, thereby reducing power consumption due to heater operation. Furthermore, by providing the LiDAR device 41 with the hardened film 48, it is possible to eliminate, for example, the heater function of the cover glass 47 and the heater control unit 54, thereby simplifying the configuration and reducing manufacturing costs.

[0105] <Lighting Device> The lighting device includes a light source that emits light, a cover through which the light emitted by the light source transmits, a cured film formed on the cover, and a control unit that controls the light emission of the light source based on information about the ambient illuminance. The cover and the cured film transmit the emitted light. The cured film is a cured product of a resin composition containing a monofunctional monomer, a polyfunctional monomer, and a radical polymerization initiator, and after being removed from -40°C to room temperature (25°C, 40% RH), the area of ​​frost adhesion on the surface of the cured film when it is 5 μm or thick is less than 30%.

[0106] 5 is a block diagram showing an example of the configuration of an automotive headlight as an illumination device 61 equipped with the above-described cured film 3. The illumination device 61 is, for example, an automotive headlight equipped with a variable light distribution function called ADB (Adaptive Driving Beam). The illumination device 61 includes, for example, a CAN communication unit 62, a microcomputer (MCU) 63, a matrix control unit 64, LEDs (Light Emitting Diodes) 65, a driver 66, a light guide 67, a lens 68, a cover glass 69, a cured film 70, a heater control unit 71, and a power supply unit 74.

[0107] The CAN communication unit 62 receives information necessary to control the light distribution toward the driver's seat of a preceding vehicle or an oncoming vehicle. The microcomputer 63 is a control unit that controls the light emission of the light source based on information related to the ambient illuminance. The microcomputer 63 calculates how to control the light distribution based on, for example, the ambient brightness detected by the illuminance sensor 73. The microcomputer 63 also transmits the signal received via the CAN communication unit to the matrix control unit 64. The matrix control unit 64 determines the light distribution elements based on the calculation results of the microcomputer 63.

[0108] The LED 65 is a light source that emits light. The driver 66 causes the LED 65 to emit light. The light guide 67 transmits the light from the LED 65 to the lens 68. The lens 68 outputs the light from the light guide 67 in a predetermined direction. The cover glass 69 is a cover portion through which the light emitted by the light source passes, and has a heater function. The cover glass 69 transmits the light from the lens 68 to the cured film 69.

[0109] The cured film 70 is formed on the cover portion and transmits light from the cover glass 69. The cured film 70 may be the cured film 3 described above. The cured film 70 is not limited to the cured film obtained by curing any of the first to sixth aspects of the frost-proofing composition described above.

[0110] The heater control unit 71 controls the on / off switching of the heater function of the cover glass 69 based on the temperature measured by a temperature sensor 72 that measures the temperature outside the vehicle. The power supply unit 74 supplies power to the entire lighting device 61.

[0111] In the lighting device 61, the LEDs 65 are turned on and off in the direction in which the emitted light is desired to be emitted, so if frost forms on the entire or part of the cover glass 69, the light will not be able to be emitted properly, which could pose a danger to the vehicle in which the lighting device is installed.The lighting device 61 is provided with a cured film 70 that has good frost-proofing and water-resistant properties and is formed on the cover glass 69, which can prevent or reduce the formation of frost, allowing for more appropriate light (headlight) irradiation.

[0112] Although the cover glass 69 is assumed to have a heater function, this is not limiting, and the illumination device 61 may not have a means for heating the cover glass 69. In other words, the illumination device 61, including the cover glass 69, may not be provided with a heating means (heater function). By providing the illumination device 61 with the hardened film 70, even if the illumination device 61 does not have a heater function, it is possible to reduce frost buildup on the cover glass 69, thereby reducing power consumption due to heater operation. Furthermore, by providing the illumination device 61 with the hardened film 70, it is possible to eliminate, for example, the heater function of the cover glass 69 and the heater control unit 71, thereby simplifying the configuration and reducing manufacturing costs.

[0113] Hereinafter, examples of the present technology will be described, but the present technology is not limited to these examples.

[0114] [Component (a1)] DMAA: N,N-dimethylacrylamide (manufactured by Kj Chemicals)

[0115] [Component (a2)] DEAA: N,N-diethylacrylamide (manufactured by Kj Chemicals) ACMO: acryloylmorpholine (manufactured by Kj Chemicals) HEAA: N-(2-hydroxyethyl)acrylamide (manufactured by Kj Chemicals) NIPAM: N-isopropylacrylamide (manufactured by Kj Chemicals) DMAPPA: N-(3-(dimethylamino)propyl)acrylamide (manufactured by Kj Chemicals)

[0116] [Component (a3)] HMAd: Monomer having a phenolic hydroxyl group (manufactured by Osaka Organic Chemical Industry Ltd.) DAAM: N-(1,1-dimethyl-3-oxobutyl)acrylamide (manufactured by KH Neochem Co., Ltd.)

[0117] [Component (b1)] 4HBA: 4-hydroxybutyl acrylate (manufactured by Osaka Organic Chemical Industry Ltd.) 2EHA: 2-ethylhexyl acrylate (manufactured by Mitsubishi Chemical Corporation) CBA: ethyl carbitol acrylate (manufactured by Osaka Organic Chemical Industry Ltd.)

[0118] [Component (b2)] M5700: 2-hydroxy-3-phenoxypropyl acrylate (manufactured by Toagosei Co., Ltd.) CHDMMA: 1,4-cyclohexanedimethanol monoacrylate (manufactured by Mitsubishi Chemical Corporation) HQMA: monomer having a phenolic hydroxyl group (manufactured by Osaka Organic Chemical Industry Ltd.) IBXA: isobornyl acrylate (manufactured by Osaka Organic Chemical Industry Ltd.) BA: butyl acrylate ISTA: isostearyl acrylate (manufactured by Osaka Organic Chemical Industry Ltd.)

[0119] [Component (c1)] A-1000: polyethylene glycol #1000 diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) AT-20E: ethoxylated trimethylolpropane triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) A-GLY-20E: ethoxylated glycerin triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) ATM-35E: ethoxylated pentaerythritol tetraacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)

[0120] [Component (c2)] SA3405P: CELUM Super Polymer SA3405P (manufactured by ASM Co., Ltd.)

[0121] [Component (c3)] LC3: tricyclodecane dimethanol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) PETIA: pentaerythritol (tri / tetra)acrylate (manufactured by Daicel Allnex Corporation) MBAA: N,N'-methylenebis(acrylamide) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) FOM-03006: N-[tris(3-acrylamidopropoxymethyl)methyl]acrylamide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) FOM-03007: N,N-bis(2-acrylamidoethyl)acrylamide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) FOM-03009: N,N-1,2-ethanediylbis{N-[2-(acryloylamino)ethyl]acrylamide} (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

[0122] [Component (d)] DC1173: 2-hydroxy-2-methylpropiophenone (manufactured by IGM Resins) V-501: azo polymerization initiator (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

[0123] <Frost Resistance of Monofunctional Monomers> For each monofunctional monomer (components (a1) to (a3), component (b1), and component (b2)), the frost resistance at −40° C. was evaluated when it was made into a homopolymer. A composition consisting of a monofunctional monomer and a polymerization initiator (DC1173) was coated on both sides of a glass substrate (manufactured by Matsunami Glass Co., Ltd., S923, thickness 1.3 mm), and the coated composition was cured to obtain a laminate. Specifically, the composition coated on the glass was placed in a nitrogen purge box equipped with a quartz glass window, and after purging with nitrogen at 0.3 MPa for 1 minute, the composition was exposed to an accumulated light dose of 4000 mJ / cm. ２ The composition was cured at 200°C for 30 minutes. The thickness of the cured composition was 5 to 50 μm. The untreated surface of the glass was then treated in the same manner to facilitate visual observation. This resulted in a laminate in which a cured film of a homopolymer of a monofunctional monomer was formed on both surfaces of the glass. This laminate was left in a freezer at -40°C for 30 minutes, then removed to room temperature (25°C, 40% RH), and visually observed through a light for frost formation. The frost resistance was evaluated based on the following criteria. The results are shown in Tables 1 to 8.

[0124] Good (○): No frost on the entire surface (no cloudiness, visible transmission possible) Poor (×): Frost on the entire surface (cloudiness on the entire surface, visible transmission impossible)

[0125] In the case of a poor (×) sample, for example, after being taken out from room temperature, frost formed on the entire surface 5 seconds later, making it completely white and making it difficult to visually see through. On the other hand, in the case of a good (◯) sample, for example, a clear state was maintained on the entire surface, with only a few frost particles of a few μm in size adhering to some areas.

[0126] <Frost resistance of polyfunctional monomers> For each polyfunctional monomer (components (c1) to (c3)), the frost resistance at -20°C was evaluated when it was made into a homopolymer. The frost resistance of the polyfunctional monomers was evaluated based on the following criteria in the same manner as for the frost resistance of monofunctional monomers, except that the monofunctional monomer was changed to a polyfunctional monomer to obtain a laminate in which a cured film of a homopolymer of the polyfunctional monomer was formed on both surfaces of the glass, and the evaluation temperature was changed from -40°C to -20°C. The results are shown in Tables 1 to 8.

[0127] Good (○): No frost on the entire surface (no cloudiness, visible transmission possible) Poor (×): Frost on the entire surface (cloudiness on the entire surface, visible transmission impossible)

[0128] <Preparation of Resin Composition (Anti-frost Composition)> The components shown in Table 1 were weighed out to the masses shown in Tables 1 to 8 and mixed to prepare the resin compositions of each of the Examples and Comparative Examples.

[0129] <Frost resistance of cured film> Figure 3 is a perspective view illustrating a method for evaluating frost resistance. As shown in Figure 3(A), a resin composition was coated on both sides of a glass substrate 2 (101) (manufactured by Matsunami Glass Co., Ltd., S923, thickness 1.3 mm), and the coated resin composition was cured. This resulted in a laminate 1 (100) in which a cured film 3 (102) was formed on both surfaces of the glass substrate 2 (101).

[0130] For UV-curable cured films (Examples 1 to 22, 24 to 26, Comparative Examples 1 to 26), the resin composition was applied to glass using a bar coater, placed in a nitrogen purge box with a quartz glass window, and purged with nitrogen at 0.3 MPa for 1 minute. After that, the film was exposed to an integrated light dose of 4000 mJ / cm. ２ The resin composition was cured at 5 to 50 μm in thickness. The untreated surface of the glass was then treated in the same manner to facilitate visual observation, yielding an evaluation sample (laminate 1 (100)) in which the cured resin composition was laminated on both sides of the glass.

[0131] For the thermosetting type cured film (Example 23), the resin composition was applied to glass using a bar coater and cured by heating at 80°C for 1 hour in a nitrogen atmosphere. The thickness of the cured resin composition was 5 to 50 μm. The untreated surface of the glass was then treated in the same manner to facilitate visual observation, and an evaluation sample (Laminate 1) was obtained in which the cured resin composition was laminated on both sides of the glass.

[0132] The laminate 1 (100) was cooled in a chamber (freezer) at -40°C for 30 minutes, and then removed from the -40°C chamber to room temperature (25°C, 40% RH). One minute later, the area of ​​frost on the cured film 3 (102) was visually inspected and evaluated based on the following criteria, as shown in Figures 3(B) and (C). The results are shown in Tables 1 to 8.

[0133] Good (○): The frost adhesion area is less than 30% of the application area. Poor (△): The frost adhesion area is 30% or more but less than 50% of the application area. Poor (×): The frost adhesion area is more than 50% of the application area.

[0134] <Water Resistance of Cured Film> Laminate 1 (100) shown in Figure 3(A) was prepared in the same manner as in the evaluation of the frost resistance of cured film 3 (102). This laminate 1 (100) was immersed in water at 25°C for 1 minute, and the water resistance of cured film 3 (102) was evaluated visually based on the following criteria. The results are shown in Tables 1 to 8.

[0135] Good (◯): There is no slime on the surface of the cured film 3 (102), and no lifting or peeling from the substrate, adherend 2 (101) is observed. Poor (Δ): There is no slime on the surface of the cured film 3 (102), but the film 3 swells due to water absorption, causing lifting or peeling from the substrate, adherend 2 (101). Poor (×): There is slime on the surface of the cured film 3 (102).

[0136] <Heat Resistance of Cured Film> Similar to the evaluation of the frost resistance of Cured Film 3 (102), Laminate 1 (100) shown in FIG. 3(A) was prepared, and the heat resistance of Cured Film 3 (102) for this Laminate 1 (100) was evaluated based on the following criteria. Specifically, the heat resistance of Cured Film 3 (102) was evaluated by examining whether or not a flow region occurred in dynamic viscoelasticity measurements. Specifically, using a TA Instrument RSAIII, temperature dispersion measurements were performed in tension mode at a frequency of 10 Hz, a heating rate of 10°C / min, and in the range of -20°C to 200°C, to examine whether or not a flow region (a rapid decrease in storage modulus from the rubber region) occurred. The results are shown in Tables 1 to 8.

[0137] Good (○): No flow region in dynamic viscoelasticity measurement. Bad (×): Flow region in dynamic viscoelasticity measurement.

[0138] <Self-repairing property of cured film> In the same manner as in the evaluation of the frost resistance of cured film 3 (102), laminate 1 (100) shown in FIG. 3(A) was prepared, and the self-repairing property of cured film 3 (102) of this laminate 1 (100) was evaluated based on the following criteria. Specifically, the self-repairing property of the cured film was evaluated by scratching cured film 3 (102) with a pencil having a pencil hardness of F using a pencil hardness tester specified in JIS-K5600, leaving it at room temperature for 24 hours, and confirming whether the scratch could be repaired. The results are shown in Tables 1 to 8. In Table 1, "-" indicates that self-repairing property was not evaluated.

[0139] Good (○): Self-repairing Bad (×): Not self-repairing

[0140] <IR transmittance of cured film> In the same manner as in the evaluation of the frost resistance of cured film 3 (102), laminate 1 (100) shown in Figure 3 (A) was prepared, and this laminate 1 (100) was removed from the -40°C chamber to room temperature (25°C, 40% RH). Immediately thereafter (after 5 seconds), laminate 1 (100) was returned to the -40°C chamber again, and the IR transmittance of cured film 3 (102) was measured and evaluated based on the following criteria. The results are shown in Tables 1 to 8.

[0141] Good (◯): Transmittance of all wavelengths of 905 nm, 1310 nm, and 1550 nm is 50% or more. Poor (Δ): Transmittance of at least one of wavelengths of 905 nm, 1310 nm, and 1550 nm is 10% or more and less than 50%. Poor (×): Transmittance of at least one of wavelengths of 905 nm, 1310 nm, and 1550 nm is less than 10%.

[0142]

[0143]

[0144]

[0145]

[0146]

[0147]

[0148]

[0149]

[0150] The cured films 3 using the resin compositions obtained in Examples 1 to 26 had frost adhesion areas of less than 30% after being taken out from −40° C. to room temperature, demonstrating good frost resistance and water resistance.

[0151] From the results of Examples 1 to 5, 14 to 16, and 26 shown in Table 1, it was found that the cured products (cured films) of the resin compositions containing more than 50 mass% and less than 94 mass% of the component (a1), the component (c1), and the component (d) had good frost resistance and water resistance, and also good IR transmittance and heat resistance.

[0152] The results of Examples 6 to 10 shown in Table 2 demonstrate that the cured products (cured films) of resin compositions containing 50% by mass or more and 79% by mass or less of the component (a2), the component (c1), and the component (d) have good frost resistance and water resistance, as well as good IR transmittance and heat resistance.

[0153] The results of Examples 11 to 13 shown in Table 3 demonstrate that the cured products (cured films) of resin compositions containing 79 mass% or more of the component (b1), the component (c1), and the component (d) have good frost resistance and water resistance, as well as good IR transmittance and heat resistance.

[0154] The results of Examples 17 and 18 shown in Table 4 demonstrate that a cured product (cured film) of a resin composition containing the component (a1), the component (a2), the component (c3), and the component (d), in which the total content of the component (a1) and the component (a2) was 90 mass % or more, had good frost resistance and water resistance, and also good IR transmittance and heat resistance.

[0155] From the results of Examples 20 and 22 to 25 shown in Table 5, it was found that a cured product (cured film) of a resin composition containing the components (a1), (a2), (c1), and less than 30 mass% of the component (c2), and the component (d), in which the total content of the components (a1) and (a2) was 59 mass% or more, had good frost resistance and water resistance, and also had good IR transmittance and heat resistance.

[0156] From the results of Examples 24 to 26 shown in Tables 1 and 5 and Comparative Example 26 shown in Table 8, it was found that a cured product (cured film) of a resin composition containing 5% by mass or more and less than 30% by mass of the components (a1), (a2), (c1), and (c2), and the component (d), in which the total content of the components (a1) and (a2) was 59% by mass or more, also had good self-repairing properties.

[0157] From the results of Examples 19 and 21 shown in Table 6, it was found that a cured product (cured film) of a resin composition containing the component (a1), the component (a2), less than 20 mass% of the component (c2), and the component (d), in which the total content of the component (a1) and the component (a2) was 79 mass% or more, had good frost resistance and water resistance, and also had good IR transmittance and heat resistance.

[0158] The cured films using the resin compositions obtained in Comparative Examples 1, 4 to 16, 18 to 22, 25, and 26 had frost adhesion areas of 30% or more after being removed from −40° C. to room temperature, indicating that the frost resistance was poor. Furthermore, the cured films using the resin compositions obtained in Comparative Examples 4 to 13, 18 to 22, and 26 also showed poor water resistance.

[0159] It was found that the cured film using the resin composition obtained in Comparative Example 2 did not have good water resistance. This is thought to be because the content of the polyfunctional monomer in the resin composition obtained in Comparative Example 2 was too low.

[0160] It was found that the cured film using the resin composition obtained in Comparative Example 3 did not have good water resistance and heat resistance. This is thought to be because the resin composition obtained in Comparative Example 3 did not contain a polyfunctional monomer.

[0161] In Comparative Examples 17, 23, and 24, the compatibility of the components constituting the resin composition was poor, and evaluation of frost resistance and the like was not possible.

[0162] 1 laminate, 2 adherend, 3 cured film, 4 water vapor, 5 antifreeze water, 100 laminate, 101 adherend, 102 cured film, 103 water vapor, 104 condensation, 105 frost, 41 LiDAR device, 42 measurement object, 43 output signal, 44 laser driver, 45 laser, 46 lens, 47 cover glass, 48 ​​cured film, 49 light receiving element, 50 AFE, 51 DSP, 52 CAN communication unit, 53 power supply unit, 54 heater control unit, 55 device diagnosis and monitoring unit, 56 beam steering control unit, 61 lighting device, 62 CAN communication unit, 63 microcomputer, 64 matrix control unit, 65 LED, 66 driver, 67 Light guide, 68 Lens, 69 Cover glass, 70 Protective film, 71 Heater control unit, 72 Temperature sensor, 73 Illuminance sensor, 74 Power supply unit

Claims

1. A laminate comprising: an adherend; and a cured film formed on the adherend, wherein the cured film is a cured product of a resin composition containing a monofunctional monomer, a polyfunctional monomer, and a radical polymerization initiator, and wherein, after the laminate is removed from -40°C to room temperature (25°C, 40% RH), the area of ​​frost adhesion on the surface of the cured film when the film has a thickness of 5 μm or more is less than 30%.

2. The laminate according to claim 1, wherein the monofunctional monomer contains a monofunctional monomer whose homopolymer has frost-proofing properties at -40°C.

3. The laminate according to claim 1 or 2, wherein the monofunctional monomer is at least one selected from the group consisting of (meth)acrylic acid esters, (meth)acrylates having a polyethylene oxide skeleton, (meth)acrylates having a terminal hydroxyl group and not containing an alicyclic structure or an aromatic ring structure, and acrylamide-based monomers and derivatives thereof.

4. The laminate according to claim 1 or 2, wherein the monofunctional monomer is at least one selected from the group consisting of N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, (meth)acryloylmorpholine, N-(2-hydroxyethyl)(meth)acrylamide, N-isopropyl(meth)acrylamide, N-(3-(dimethylamino)propyl)(meth)acrylamide, 4-hydroxybutyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, and ethyl carbitol(meth)acrylate.

5. The laminate according to claim 2, wherein the polyfunctional monomer contains a polyfunctional monomer whose homopolymer has frost-proofing properties at -20°C.

6. The laminate of claim 2, wherein the polyfunctional monomer is at least one selected from the group consisting of polyethylene glycol #1000 diacrylate, ethoxylated trimethylolpropane triacrylate, ethoxylated glycerin triacrylate, and ethoxylated pentaerythritol tetraacrylate.

7. The laminate according to claim 1 or 2, wherein the adherend is a member that transmits visible light.

8. The laminate according to claim 1 or 2, wherein the cured film has a transmittance of 50% or more at wavelengths of 905 nm, 1310 nm, and 1550 nm.

9. An anti-frost composition comprising: (a1) more than 50% by mass and less than 94% by mass of N,N-dimethyl(meth)acrylamide; (c1) a polyfunctional (meth)acrylic monomer whose homopolymer satisfies the anti-frost performance at -20°C; and (d) a radical polymerization initiator.

10. An anti-frost composition comprising: (a2) 50% by mass or more and 79% by mass or less of a monofunctional (meth)acrylamide (excluding N,N-dimethyl(meth)acrylamide) whose homopolymer satisfies the anti-frost performance at -40°C; (c1) a polyfunctional (meth)acrylic monomer whose homopolymer satisfies the anti-frost performance at -20°C; and (d) a radical polymerization initiator.

11. An anti-frost composition comprising: (b1) 79% by mass or more of a monofunctional (meth)acrylic monomer whose homopolymer satisfies the anti-frost performance at -40°C; (c1) a polyfunctional (meth)acrylic monomer whose homopolymer satisfies the anti-frost performance at -20°C; and (d) a radical polymerization initiator.

12. An antifrost composition comprising: (a1) N,N-dimethyl(meth)acrylamide; (a2) a monofunctional (meth)acrylamide (excluding the above-mentioned (a1) component) whose homopolymer has antifrost performance at -40°C; (c3) a polyfunctional (meth)acrylic monomer whose homopolymer has antifrost performance at -20°C; and (d) a radical polymerization initiator, wherein the total content of the above-mentioned (a1) component and the above-mentioned (a2) component is 90 mass% or more.

13. An antifrost composition comprising: (a1) N,N-dimethyl(meth)acrylamide; (a2) a monofunctional (meth)acrylamide (excluding the above component (a1)) whose homopolymer has frost resistance at -40°C; (c1) a polyfunctional (meth)acrylic monomer whose homopolymer has frost resistance at -20°C; (c2) less than 30 mass% of a polyrotaxane di(meth)acrylate whose homopolymer does not have frost resistance at -20°C; and (d) a radical polymerization initiator, wherein the total content of the above component (a1) and the above component (a2) is 59 mass% or more.

14. An antifrost composition comprising: (a1) N,N-dimethyl(meth)acrylamide; (a2) a monofunctional (meth)acrylamide (excluding the above-mentioned component (a1)) whose homopolymer has antifrost performance at -40°C; (c2) less than 20 mass% of a polyrotaxane di(meth)acrylate whose homopolymer does not have antifrost performance at -20°C; and (d) a radical polymerization initiator, wherein the total content of the above-mentioned components (a1) and (a2) is 79 mass% or more.

15. A distance measuring device comprising: a light source that emits light; a light receiver that receives the emitted light; a window through which the emitted light and the received light pass; a measuring unit that measures the distance to an object by measuring the time between the light emitted by the light source being reflected by the object and being received by the light receiver; an adherend attached to the window; and a cured film formed on the adherend, wherein the adherend and the cured film pass through the emitted light; the cured film is a cured product of a resin composition containing a monofunctional monomer, a polyfunctional monomer, and a radical polymerization initiator; after the cured film is taken out from -40°C to room temperature (25°C, 40% RH), the area of ​​frost adhesion on the surface of the cured film when it is 5 μm or thick is less than 30%; and the measuring unit outputs information related to the distance measured.

16. A lighting device comprising: a light source that emits light; a cover portion through which the light emitted by the light source transmits; a cured film formed on the cover portion; and a control portion that controls the light emission of the light source based on information related to ambient illuminance, wherein the cover portion and the cured film transmit the emitted light; the cured film is a cured product of a resin composition containing a monofunctional monomer, a polyfunctional monomer, and a radical polymerization initiator; and after the cured film is taken out from -40°C to room temperature (25°C, 40% RH), the area of ​​frost adhesion on the surface of the cured film when it is 5 μm or thick is less than 30%.

17. A distance measuring device comprising: a light source that emits light; a light receiver that receives the emitted light; a window through which the emitted light and the received light pass; a measuring unit that measures the distance to an object by measuring the time between the light emitted by the light source being reflected by the object and being received by the light receiver; an adherend attached to the window; and a cured film formed on the adherend; wherein the device does not comprise means for heating the adherend; the adherend and the cured film pass through the emitted light; the cured film is a cured product of a resin composition containing a monofunctional monomer, a polyfunctional monomer, and a radical polymerization initiator; after the cured film is taken out from -40°C to room temperature (25°C, 40% RH), the area of ​​frost on the surface of the cured film when it is 5 μm or thick is less than 30%; and the measuring unit outputs information related to the distance measured.

18. A lighting device comprising: a light source that emits light; a cover portion through which the light emitted by the light source transmits; a cured film formed on the cover portion; and a control portion that controls the light emission of the light source based on information related to ambient illuminance; wherein the lighting device does not comprise means for heating the cover member; the cover portion and the cured film transmit the emitted light; the cured film is a cured product of a resin composition containing a monofunctional monomer, a polyfunctional monomer, and a radical polymerization initiator; and when the cured film is taken out from -40°C to room temperature (25°C, 40% RH), the area of ​​frost adhesion on the surface of the cured film when it is 5 μm or thick is less than 30%.

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