Method for manufacturing substrate with coating film

Abstract

To provide a camera cover which can achieve sufficient resolution while facilitating manufacture.SOLUTION: A dome-shaped camera cover protects an imaging part. A coating containing an urethane acrylate resin is formed on the surface of the camera cover. An arithmetic average roughness Ra of the surface of the coating is 0.8 [μm] or less.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a camera cover, an imaging device, and a method for manufacturing a camera cover, and more particularly to a camera cover for a surveillance camera installed outdoors. [Background technology]

[0002] Surveillance cameras are widely used as security systems in residential or commercial buildings, or outdoors. Surveillance cameras are equipped with transparent camera covers to protect them from rainwater, gravel, etc. Camera covers can be scratched by blown sand or during maintenance when they become dirty with dust, etc., and scratches on the camera cover can degrade the captured image.

[0003] Therefore, there is a known technique of coating the camera cover to make it scratch-resistant. For example, Patent Document 1 discloses a hard coating made of silicone resin. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 9-255917 Summary of the Invention [Problem to be solved by the invention]

[0005] The silicone resin hard coat described in Patent Document 1 has the problem that cracks may occur after film formation and that it requires a long baking time, resulting in high costs.

[0006] An object of the present invention is to provide a camera cover that is easy to manufacture yet can achieve sufficient resolution. [Means for solving the problem]

[0007] In order to achieve the object of the present invention, a method for producing a substrate having a coating film according to one embodiment of the present invention comprises the following steps: A step of preparing a coating liquid of a urethane acrylate resin; Dome-shaped applying the coating solution containing an organic solvent to a substrate to form a coating film; curing the coating film; Including, In the step of preparing the coating solution, the viscosity of the coating solution is 1.5 [mPa·s] or more 8.4 [mPa ·s The ratio of the coating solution stock solution and organic solvent is adjusted so that it is as follows: The coating film is formed by spin-coating the coating solution onto the substrate. [Effects of the Invention]

[0008] It is possible to obtain a camera cover that is easy to manufacture and yet can achieve sufficient resolution. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of an imaging apparatus according to an embodiment. [Figure 2] FIG. 2 is an explanatory diagram of a camera cover according to an embodiment. [Figure 3] FIG. 2 is a partial cross-sectional view of a camera cover according to an embodiment. [Figure 4] FIG. 2 is a diagram illustrating a coating application method. [Figure 5] 10 is a flowchart of a method for manufacturing a camera cover according to an embodiment. [Figure 6] FIG. 2 is a diagram showing the relationship between the viscosity of a coating solution and the thickness of a coating. [Figure 7] FIG. 1 is a graph showing the relationship between coating thickness and arithmetic mean roughness Ra. [Figure 8] FIG. 13 is a diagram showing a resolution evaluation in Example 7. [Figure 9]FIG. 13 is a diagram showing a resolution evaluation in Example 8. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0011] Fig. 1 is a schematic diagram of an imaging device 10 according to an embodiment of the present invention. The imaging device 10 shown in Fig. 1 includes a camera unit 100, a data transfer unit 120, a data storage unit 121, and a controller 122. Images captured by the camera unit 100 can be transferred to a network via the controller 122 and the data transfer unit 120. In addition, images captured by the camera unit 100 can be transferred to the data storage unit 121 via the controller 122 and stored in the data storage unit 121. The data transfer unit 120, the data storage unit 121, and the controller 122 are covered by an exterior 130 to protect them from external impacts and to prevent the intrusion of moisture.

[0012] In one embodiment of the present invention, the camera unit 100 is covered with a camera cover 110. The camera cover 110 according to this embodiment is a dome-shaped camera cover that protects the imaging unit, and has a coating 1500 containing a urethane acrylate resin formed on its surface. Such a camera cover 110 can protect the camera unit 100 from external impact and moisture intrusion. The specific shape of the camera cover 110 is not particularly limited. For example, the camera cover 110 can have an outer wall and an opening, and the outer wall can define an internal space that communicates with the opening. In this case, as shown in FIG. 1 , the camera unit 100 can be protected by accommodating the camera unit 100 in the internal space of the camera cover 110 and closing the opening with a member such as an exterior casing 130. In one embodiment, the camera cover 110 has a generally hemispherical shape.

[0013] FIG. 2 is a cross-sectional view showing an example of camera cover 110. Camera cover 110 has a generally hemispherical portion 1101 in the center. In addition, a skirt portion 1102 is present near the end of generally hemispherical portion 1101, and a flange 1103 is further provided at the end. Camera cover 110 can be attached to exterior 130 by fixing flange 1103 to exterior 130 with a screw via an O-ring. In the example of FIG. 2, coating 1500 can be formed on the entire dome 140, including the outer spherical surface of generally hemispherical portion 1101.

[0014] The camera cover 110 has a dome 140, which is a dome-shaped camera cover base material, and a coating 1500 formed on the surface thereof. The dome 140 is formed of a transparent resin material to enable imaging by the camera unit 100. The type of dome 140 is not particularly limited, but it may be made of polycarbonate resin, acrylic resin, or polyester resin. In one embodiment, a dome 140 made of impact-resistant polycarbonate resin is used. For example, the material constituting the dome 140 may contain polycarbonate, or 50% or 90% (by weight) or more of the material constituting the dome 140 may be polycarbonate. Alternatively, the dome 140 may be substantially made of polycarbonate.

[0015] FIG. 3 is a partial cross-sectional view of a camera cover 110 according to one embodiment. As shown in FIG. 3, a coating 1500 is formed on the surface of the camera cover 110. In this embodiment, the coating 1500 is a coating containing a urethane acrylate resin. The coating containing a urethane acrylate resin used in this embodiment is hard and scratch-resistant, and can therefore be called a hard coat. Because the urethane acrylate resin can be photocured (ultraviolet cured), the coating 1500 can be formed at low cost. Furthermore, by using a urethane acrylate resin that has a short drying time after application, the coating 1500 can be formed at even lower cost.

[0016] The urethane acrylate resin refers to a resin having a urethane bond and an acrylic group (including a methacrylic group), or a photocured version of this resin. The urethane acrylate resin can be obtained, for example, by reacting a compound having an acrylic group (including a methacrylic group) and a hydroxyl group, a polyisocyanate compound (including a polyisocyanurate), and, if necessary, a polyol.

[0017] The type of urethane acrylate resin is not particularly limited, but in one embodiment, an aliphatic urethane acrylate resin is used. The aliphatic urethane acrylate resin refers to a urethane acrylate resin obtained by using an aliphatic diisocyanate as an isocyanate structural unit. The aliphatic urethane acrylate resin is less likely to yellow in weather resistance tests, and therefore can improve the weather resistance of the camera cover. In one embodiment, a urethane acrylate resin that does not contain a benzene ring as a structural unit is used to improve the weather resistance of the camera cover.

[0018] An example of the urethane acrylate resin is a urethane acrylate oligomer obtained by reacting a (meth)acrylate with a polyisocyanate, as described in JP-A-2009-62423, or a product obtained by curing the urethane acrylate oligomer.

[0019] To accelerate photocuring of the urethane acrylate resin, the urethane acrylate resin may contain a photoradical polymerization initiator. The type of the photoradical polymerization initiator is not particularly limited, but examples thereof include α-hydroxyalkylphenones such as 1-hydroxycyclohexyl phenyl ketone, benzophenone, and the like.

[0020] In this embodiment, the arithmetic mean roughness Ra of the surface of the coating 1500 is 0.8 μm or less. The inventors of the present application have discovered that forming the coating 1500 so that the arithmetic mean roughness Ra is 0.8 μm or less can suppress a decrease in resolution obtained when capturing an image through the camera cover 110. Using the arithmetic mean roughness Ra makes it easier to evaluate coating surface irregularities caused by film thickness variations rather than localized surface irregularities such as scratches. In this specification, the arithmetic mean roughness Ra can be measured in accordance with JIS B0601:2013.

[0021] In one embodiment, the coating 1500 has a thickness of 2 μm or more. The present inventors have found that forming the coating 1500 to a thickness of 2 μm or more allows the coating 1500 to fully function. For example, the coating 1500 may contain an ultraviolet absorber. In particular, when the dome 140 is made of polycarbonate, the weather resistance of the dome 140 can be enhanced by including an ultraviolet absorber in the coating 1500. In this case, forming the coating 1500 to a thickness of 2 μm or more allows the weather resistance of the coating 1500 to be fully exhibited. On the other hand, to reduce the arithmetic mean roughness Ra of the surface of the coating 1500, the thickness of the coating 1500 can be set to 10 μm or less. By reducing the thickness of the coating 1500, the arithmetic mean roughness Ra can be reduced, thereby reducing the optical effects of the camera cover 110.

[0022] In this specification, the arithmetic mean roughness Ra and film thickness of the coating 1500 can be measured using the arithmetic mean roughness Ra and film thickness at the peripheral portion of the camera cover 110. For example, the arithmetic mean roughness Ra and film thickness can be measured at the bottom portion 1102 of the approximately hemispherical portion 1101. If the arithmetic mean roughness Ra at the peripheral portion of the camera cover 110 is equal to or less than a predetermined value, it can be determined that the arithmetic mean roughness Ra of the camera cover 110 is equal to or less than the predetermined value. Similarly, if the film thickness at the peripheral portion of the camera cover 110 is equal to or greater than a predetermined value, it can be determined that the film thickness of the camera cover 110 is equal to or greater than a predetermined value. The arithmetic mean roughness Ra and film thickness of the peripheral portion of the camera cover 110 can be evaluated at one point or multiple points at the edge of the imaging range of the camera unit 100 on the outer surface of the camera cover 110.

[0023] In one embodiment, it can be determined that the arithmetic mean roughness Ra of camera cover 110 is equal to or less than a predetermined value when the arithmetic mean roughness Ra is equal to or less than a predetermined value at both the top and peripheral portions of camera cover 110. Similarly, it can be determined that the film thickness of camera cover 110 is equal to or greater than a predetermined value or equal to or less than a predetermined value when the film thickness is equal to or greater than a predetermined value or equal to or less than a predetermined value at both the top and peripheral portions of camera cover 110.

[0024] In one embodiment, the arithmetic mean roughness Ra is 0.8 μm or less over the entire portion of the outer surface of camera cover 110 that is included in the imaging range of camera unit 100, or over the entire outer surface of camera cover 110. Also, in one embodiment, the film thickness of coating 1500 is 2 μm or more over the entire portion of the outer surface of camera cover 110 that is included in the imaging range of camera unit 100, or over the entire outer surface of camera cover 110. Furthermore, in one embodiment, the film thickness of coating 1500 is 10 μm or less over the entire portion of the outer surface of camera cover 110 that is included in the imaging range of camera unit 100, or over the entire outer surface of camera cover 110.

[0025] Next, a method for manufacturing the camera cover 110 by forming the coating 1500 will be described with reference to FIG. 5 . In S1010, a coating solution of urethane acrylate resin is prepared. A coating solution containing a urethane acrylate oligomer can be used as the coating solution. The inventors of the present application discovered that applying a commercially available coating solution directly to a camera cover 110 having a complex three-dimensional shape reduces the uniformity of the coating, resulting in a decrease in the resolution of images captured through the camera cover 110. On the other hand, as described below, controlling the thickness of the coating 1500 can improve the uniformity of the coating 1500 while maintaining its functionality. Therefore, based on the relationship between surface tension and viscosity, the viscosity of the coating solution can be adjusted to change the thickness of the coating 1500.

[0026] Specifically, the viscosity can be adjusted by mixing and stirring an organic solvent into the coating solution. Here, the coating solution may be adjusted while measuring the viscosity. In one embodiment, in order to form a coating film with a sufficient thickness, the viscosity is adjusted to 1.5 [mPa]. ·s On the other hand, in order to reduce the unevenness of the film caused by the variation of the film thickness, the viscosity can be set to 8.2 [mPa ·s In this specification, viscosity can be measured according to ISO 2555:2018.

[0027] In S1020, the coating solution prepared in S1010 is applied to the dome 140 to form a coating film. The coating solution application device and application method are not particularly limited, but in this embodiment, spin coating is performed using a spin coater to apply the coating solution more uniformly to the dome 140, which has a three-dimensional shape. However, other methods such as dip coating or spray coating may also be used.

[0028] FIG. 4 is a partial cross-sectional view showing spin coating using a spin coater. The dome 140 can be attached to a rotating table 3001 at the top of the spin coater 3000 via an attachment jig 3002. The dome 140 and the attachment jig 3002 can be fixed together using screws. Alternatively, the attachment jig 3002 and the rotating table 3001 can be fixed together by suction using a pump (not shown). The coating liquid can be applied from the zenith 141, which is the highest point of the dome 140. As the rotating table 3001 rotates, the coating liquid is pulled in the normal direction to the rotating circumference by centrifugal force, spreading out to the skirt 1102.

[0029] On the other hand, centrifugal force is also generated in the coating solution that has flowed down to the skirt 1102, and therefore, variations in film thickness can cause unevenness in the resulting coating. As will be described later, such unevenness affects the resolution of the imaging device 10. Film unevenness is more likely to occur at the skirt 1102 than at the zenith 141 of the dome 140, and the arithmetic mean roughness Ra increases in the areas where unevenness occurs.

[0030] In this embodiment, the viscosity of the coating liquid is adjusted to suppress the occurrence of unevenness. For example, since the effect of centrifugal force increases in proportion to the weight of the liquid, the weight of the film can be reduced so that the centrifugal force is smaller than the surface tension of the coating liquid. In this embodiment, by reducing the viscosity, the film thickness can be reduced, and the weight of the film can be reduced so that the effect of centrifugal force is eliminated. On the other hand, by increasing the viscosity, the functionality of the coating 1500 can be maintained. In this way, by adjusting the viscosity of the coating liquid, it is possible to achieve both the functionality and uniformity of the coating 1500.

[0031] In S1030, the coating film applied in S1020 is cured. Because urethane acrylate resin is a photocurable resin, the coating film can be cured by irradiating it with light. In this embodiment, the organic solvent is evaporated from the coating film by heating and drying, and then ultraviolet light is irradiated to fix the coating 1500. The heating method is not particularly limited, and a method of maintaining the heating target at a specified temperature using a hot air oven, electric oven, far-infrared oven, near-infrared oven, or the like can be used. The light source is also not particularly limited, and an ultraviolet lamp such as a mercury lamp can be used. [Example]

[0032] Example 1 The coating solution was prepared by mixing the coating solution stock solution Z-700W-7 (manufactured by Aica Kogyo Co., Ltd.) with an organic solvent. The coating solution stock solution Z-700W-7 contains urethane acrylate obtained from an aliphatic diisocyanate. 1-Methoxy-2-propanol (manufactured by Kishida Chemical Co., Ltd.), one of the components of the coating solution stock solution Z-700W-7, was used as the organic solvent to adjust the viscosity. The ratio of the coating solution stock solution to the organic solvent was 1:4 by weight. In this way, the viscosity of the coating solution at room temperature of 23°C was approximately 1.0 mPa. ·s The viscosity was measured using a VISCO Package B viscometer (manufactured by Atago Co., Ltd.).

[0033] The resulting coating solution was then applied to the dome using a spin coater, dried, and cured with UV light to produce a camera cover. The spin coater used was an MS-B300 (manufactured by Mikasa Co., Ltd.). Using the method shown in Figure 4, 10 mL of coating solution was applied from the top of the dome using a nozzle. The spin coater was operated at a rotation speed of 200 rpm for 30 seconds, allowing the coating solution to wet and spread to the base, ensuring a uniform coating of the entire dome. Drying was performed by heating for 5 minutes in a circulating hot air oven at 86°C ± 5°C. UV curing was performed using an air-cooled mercury lamp H08-L41 (manufactured by Iwasaki Electric Co., Ltd.). For UV irradiation, UV light with a wavelength of 254 nm was measured, with an illuminance of 260 mW / mm. 2 ], cumulative light intensity 3500 [mJ / mm 2 ] was applied. The amount of ultraviolet light was measured using a UV integrating actinometer UIT-250 (manufactured by Ushio Inc.). The coating solution contains α-hydroxyalkylphenone, a photopolymerization initiator, so ultraviolet irradiation caused polymerization, resulting in the hardening and fixation of the coating solution. Here, the hardening of the coating solution was promoted by a photoradical polymerization reaction.

[0034] A sample cut from the resulting dome was identified using a compact, high-resolution spectrometer, Solid Lambda UV-NIR (manufactured by SpectraCorp Inc.), and the coating thickness was measured, resulting in a film thickness of 1.5 μm. A test piece was also cut from the resulting dome, and the arithmetic mean roughness Ra of the coating surface of the sample was measured using a LEXT-OLS4500 confocal laser scanning microscope (manufactured by Olympus Corporation). The arithmetic mean roughness Ra was 0.08 μm. In this and the following examples, the film thickness and arithmetic mean roughness Ra are values ​​measured at the bottom of the camera cover.

[0035] The following camera was also used to evaluate the resolution obtained by capturing an image through the resulting camera cover. Specifically, a resolution chart was captured at a distance of 30 m from the camera, using a camera with a focal length of 4.25 to 170 mm, a 40x optical zoom, and a maximum resolution of 1920 x 1080. The visual resolution of the captured resolution chart was then evaluated to determine whether or not there was any image degradation. The results showed no particular degradation.

[0036] Furthermore, the weather resistance of the coating was evaluated in accordance with JIS B7754. Specifically, a Super Xenon Weather Meter SX75 (manufactured by Suga Test Instruments Co., Ltd.) was used as a weather resistance tester. As an accelerated test, a sample cut out from the dome was subjected to a 180 [W / m 2 The sample was evaluated after irradiating it with light of an illuminance of [10 ...

[0037] Example 2 A camera cover was produced and evaluated in the same manner as in Example 1, except that the weight ratio of the coating liquid concentrate to the organic solvent was 1:3.5.

[0038] Example 3 A camera cover was produced and evaluated in the same manner as in Example 1, except that the weight ratio of the coating liquid concentrate to the organic solvent was 1:3.

[0039] Example 4 A camera cover was produced and evaluated in the same manner as in Example 1, except that the weight ratio of the coating liquid concentrate to the organic solvent was 1:2.5.

[0040] Example 5 A camera cover was produced and evaluated in the same manner as in Example 1, except that the weight ratio of the coating liquid concentrate to the organic solvent was 1:2.0.

[0041] Example 6 A camera cover was produced and evaluated in the same manner as in Example 1, except that the weight ratio of the coating liquid concentrate to the organic solvent was 1:1.5.

[0042] Example 7 Except for the weight ratio of the coating solution concentrate to the organic solvent being 1:1, a camera cover was produced and evaluated in the same manner as in Example 1. The results of the resolution evaluation in Example 7 are shown in FIG.

[0043] Example 8 Except for the weight ratio of the coating solution stock solution to the organic solvent being 1:0.8, a camera cover was produced and evaluated in the same manner as in Example 1. The results of the resolution evaluation in Example 8 are shown in FIG.

[0044] Example 9 A camera cover was produced and evaluated in the same manner as in Example 1, except that the weight ratio of the coating liquid concentrate to the organic solvent was 1:0.6.

[0045] Example 10 A camera cover was produced and evaluated in the same manner as in Example 1, except that the weight ratio of the coating liquid concentrate to the organic solvent was 1:0.5.

[0046] Example 11 A camera cover was produced and evaluated in the same manner as in Example 1, except that the weight ratio of the coating liquid concentrate to the organic solvent was 1:0.2.

[0047] Example 12 A camera cover was produced and evaluated in the same manner as in Example 1, except that the coating solution stock solution was applied to the dome using a spin coater.

[0048] The table below summarizes the evaluation results for Examples 1 to 12. In the table below, weather resistance ◯ indicates that no film peeling was observed after 600 hours of light irradiation in the weather resistance test, and no particular abnormalities occurred. Weather resistance × indicates that film peeling was observed after 600 hours of light irradiation. Furthermore, resolution ◯ indicates that no image degradation was observed in the resolution evaluation, and resolution × indicates that clear image degradation was observed in the resolution evaluation.

[0049] [Table 1]

[0050] Fig. 6 shows the relationship between the viscosity of the coating solution and the thickness of the resulting coating in Examples 1 to 12. Fig. 7 shows the relationship between the thickness of the coating and the arithmetic mean roughness Ra in Examples 1 to 12.

[0051] As shown in the table above, when the arithmetic mean roughness Ra of the coating surface was 0.8 μm or less, no degradation of the image was observed in the resolution evaluation, but when the arithmetic mean roughness Ra was 0.84 μm or more, a clear degradation of the image was observed in the resolution evaluation. Also, as shown in Figure 7, the arithmetic mean roughness Ra tended to increase as the coating film thickness increased, and by keeping the coating film thickness at 10 μm or less, the arithmetic mean roughness Ra could be kept at 0.8 μm or less. Furthermore, as shown in Figure 6, the higher the viscosity of the coating solution, the thicker the coating film tended to become, and when the viscosity of the coating solution was 8.4 mPa ·s By making the thickness less than 10 μm, the coating thickness could be reduced to 10 μm or less.

[0052] Furthermore, when the coating thickness was 2 μm or more, high weather resistance of the camera cover was confirmed, while when the coating thickness was 1.5 μm, abnormalities occurred in the camera cover during the weather resistance test. Thus, by making the coating thickness 2 μm or more, the coating function was fully demonstrated. In addition, when the viscosity of the coating application liquid was 1.0 [mPa] ·s By increasing the thickness of the coating to more than 2 μm,

[0053] According to the investigations of each example, the arithmetic mean roughness Ra was greater at the bottom of the camera cover than at the top. Therefore, the arithmetic mean roughness Ra of 0.8 μm or less at the bottom means that the arithmetic mean roughness Ra of the top is also 0.8 μm or less, and that the arithmetic mean roughness Ra of the entire outer surface of the camera cover is 0.8 μm or less.

[0054] Furthermore, according to the investigations of each example, the film thickness was thinner at the top of the camera cover than at the bottom. Furthermore, when the viscosity of the coating solution was low, there was little difference in film thickness between the bottom and top, but when the viscosity of the coating solution was high, the difference in film thickness between the bottom and top tended to increase. Therefore, a coating film thickness of 10 μm or less at the bottom means that the film thickness at the top is also 10 μm or less, and that the film thickness over the entire outer surface of the camera cover is 10 μm or less. On the other hand, in Example 2, the film thickness at the bottom and the film thickness at the top were equivalent. Therefore, a coating film thickness of 2 μm or more at the bottom means that the film thickness at the top is also 2 μm or more, and that the film thickness over the entire outer surface of the camera cover is 2 μm or more.

[0055] From the above results, by forming a coating containing urethane acrylate resin on the surface of the camera cover so that the arithmetic mean roughness Ra of the surface is 0.8 μm or less, a camera cover and an imaging device that can achieve good resolution were obtained.

[0056] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0057] 10: imaging device, 100: camera unit, 110: camera cover, 140: dome, 1500: coating

Claims

1. A step of preparing a coating liquid of a urethane acrylate resin; applying the coating solution containing an organic solvent to a dome-shaped substrate to form a coating film; curing the coating film; Including, In the step of preparing the coating liquid, a ratio of the coating liquid stock solution to the organic solvent is adjusted so that the viscosity of the coating liquid is 1.5 [mPa s] or more and 8.4 [mPa s] or less; A method for producing a substrate with a coating film, comprising spin-coating the coating solution onto the substrate to form the coating film.

2. 2. The method for producing a substrate with a coating film according to claim 1, wherein the arithmetic mean roughness Ra of the surface of the coating film is 0.8 [mu]m or less.

3. The method for producing a substrate with a coating film according to claim 1, wherein the coating film has a thickness of 2 μm or more and 10 μm or less.

4. 2. The method for producing a substrate with a coating film according to claim 1, wherein the urethane acrylate resin contains a photoradical polymerization initiator.

5. The method for producing a substrate with a coating film according to claim 4, wherein the photoradical polymerization initiator is an α-hydroxyalkylphenone.

6. The method for producing a substrate with a coating film according to claim 1, wherein the urethane acrylate resin is an aliphatic urethane acrylate resin.

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