Micro-prism structured license plate reflective film

Abstract

The application relates to the technical field of reflective film, in particular to a micro-prism structure type license plate reflective film which comprises a substrate layer, a micro-prism array layer and a protective coating. The micro-prism array layer is composed of three-prism pyramid micro-prism units, the top angle is 80-100 DEG, the surface is coated with an antireflection film, and the interval groove is filled with high-refractive-index optical glue. The substrate layer is provided with a sticking layer and a release film, the protective coating is externally provided with an anti-fouling layer, and a reflection layer is additionally arranged at the bottom. The micro-prism design and material selection are optimized, the reflective performance under complex light conditions is significantly improved, the production cost is reduced, the process flow is simplified, and large-scale production is facilitated. The reflective film has excellent weather resistance and anti-pollution capacity and is suitable for the license plate identification field.

Description

Technical Field

[0001] This utility model belongs to the field of traffic safety and optical materials technology, specifically a microprism structure license plate reflective film. Background Technology

[0002] With the continuous development of reflective film technology, various types of reflective films have been widely used in the license plate manufacturing industry. However, existing reflective films still have some problems in practical use. For example, most license plate reflective films on the market currently use glass microsphere structures or simple heat transfer processes. Although their reflective performance and weather resistance have been improved to some extent, their reflective effect under complex lighting conditions (such as strong light, weak light, or large-angle incident light) is still insufficient. In addition, the production process of some reflective films is complex, making it difficult to meet the needs of efficient, low-cost large-scale production.

[0003] A search revealed a high-brightness black glass microsphere-type license plate reflective film and its preparation method, with publication number CN112051632B, published on April 11, 2025. This design employs a structure where glass microspheres are embedded in a black color layer. By optimizing the contact method between the glass microspheres and the surface layer, it overcomes the problem of the black color layer affecting light propagation in traditional reflective films, thereby improving reflective brightness performance. However, the reflectivity of this glass microsphere-type reflective film remains limited under complex lighting conditions, especially under large-angle incident light, where the light reflectivity decreases significantly. Furthermore, the glass microsphere-type reflective film requires high material precision and has a relatively complex manufacturing process, resulting in high production costs and making it difficult to fully meet the demands of modern license plate manufacturing for high efficiency and low cost.

[0004] A search revealed a heat transfer film for vehicle license plates and its preparation method, with publication number CN112976840B, published on December 2, 2022. This design consists of two parts: a carbon ribbon and a reflective film, achieving one-time forming of the license plate through a heat transfer process. This design offers good visibility, durability, and weather resistance. However, the reflective film primarily relies on the color and adhesive layers of the heat transfer layer for its function; its reflective structure itself has not undergone innovative improvements, resulting in room for improvement in its reflective performance at night or under low light conditions. Furthermore, the heat transfer process requires sophisticated equipment and precise temperature and pressure control, increasing production difficulty and cost.

[0005] The aforementioned problems indicate that traditional reflective films currently on the market are insufficient to effectively meet the new demands for high reflectivity and low-cost production under complex lighting conditions. Therefore, this invention provides a microprism structure license plate reflective film to overcome these shortcomings and offer a more efficient, durable, and adaptable solution for changing environments. Utility Model Content

[0006] The purpose of this invention is to provide a microprism structure license plate reflective film to solve the problem of insufficient reflective effect of existing reflective films under complex lighting conditions (such as strong light, weak light or large angle incident light) mentioned in the background art, while overcoming the defects of complex production process and high cost.

[0007] To achieve the above objectives, this utility model provides the following technical solution: a microprism structure license plate reflective film, comprising a base layer, a microprism array layer, and a protective coating. The upper surface of the base layer is provided with a microprism array layer, which is composed of multiple regularly arranged microprism units. Each microprism unit has a triangular pyramidal structure, and its apex angle ranges from 80° to 100°. The bottom surface of each microprism unit is fixedly connected to the upper surface of the base layer by an adhesive, which is a transparent epoxy resin material with a thickness of 0.05 mm to 0.1 mm. The protective coating covers the outer surface of the microprism array layer and is made of polyurethane material with a thickness of 0.1 mm to 0.2 mm.

[0008] Preferably, an adhesive layer is provided on the lower surface of the base layer. The adhesive layer is made of hot melt adhesive material and has a thickness of 0.15 mm to 0.25 mm. A release film is covered on the lower surface of the adhesive layer. The release film is silicone-coated paper with a thickness of 0.08 mm to 0.12 mm. The release film is bonded to the adhesive layer by electrostatic adsorption, facilitating quick peeling during use.

[0009] Preferably, spacer slots are provided between the microprism units in the microprism array layer. The width of the spacer slots is 0.02 mm to 0.05 mm, and the depth is 0.1 mm to 0.15 mm. The spacer slots are filled with high-refractive-index optical adhesive with a refractive index of 1.5 to 1.6 to reduce light scattering loss between the microprism units.

[0010] Preferably, the surface of the microprism unit is coated with an antireflection film made of silicon dioxide with a thickness of 0.01 mm to 0.03 mm. The antireflection film is attached to the surface of the microprism unit by a vacuum deposition process to improve light transmittance and reduce reflection loss.

[0011] Preferably, the outer surface of the protective coating is provided with an anti-fouling layer, which is made of a fluoride material and has a thickness of 0.02 mm to 0.05 mm. The anti-fouling layer is uniformly applied to the outer surface of the protective coating by a spraying process to enhance the weather resistance and anti-fouling ability of the reflective film.

[0012] Preferably, the base layer is made of polyethylene terephthalate (PET) with a thickness of 0.2 mm to 0.3 mm. Positioning marks are provided on both sides of the base layer. These positioning marks are grooves with a width of 1 mm to 2 mm and a depth of 0.1 mm to 0.2 mm. The positioning marks are used to assist in alignment and cutting operations during the production process.

[0013] Preferably, the arrangement direction of the microprism array layer is parallel to the length direction of the substrate layer, and the arrangement density of the microprism units is 1000 to 1500 per square centimeter. The arrangement density of the microprism units is achieved through a precision mold pressing process to ensure the consistency of shape and size of each microprism unit.

[0014] Preferably, the microprism unit has a rounded transition structure at its apex, the radius of which is 0.01 mm to 0.03 mm. This rounded transition structure is formed through a polishing process to reduce light scattering at the apex, thereby improving reflectivity.

[0015] Preferably, a reflective layer is disposed at the bottom of the microprism array layer. The reflective layer is made of aluminum foil and has a thickness of 0.02 mm to 0.05 mm. The reflective layer is bonded to the upper surface of the substrate layer by a hot-pressing process to enhance the light reflection effect.

[0016] Preferably, the side surface of the microprism unit forms an angle with the upper surface of the substrate layer, the angle ranging from 40° to 50°. This angle is designed by adjusting the tilt angle of the mold to optimize the incident and reflection paths of light, thereby improving reflectivity.

[0017] This invention solves the problem of insufficient reflectivity of existing reflective films under complex lighting conditions through the above-described technical solution. The microprism array layer design utilizes the optical properties of a triangular pyramid structure to effectively capture and reflect large-angle incident light, significantly improving reflectivity. The high-refractive-index optical adhesive within the spacers reduces light scattering loss, further enhancing reflectivity. The application of an anti-reflective film increases light transmittance and reduces reflection loss, resulting in superior performance of the reflective film under low-light conditions. Furthermore, the combination of a protective coating and an anti-fouling layer improves the reflective film's weather resistance and anti-fouling capabilities, extending its service life.

[0018] The manufacturing process of this invention is relatively simple, and large-scale production can be achieved through mature technologies such as precision mold pressing and vacuum coating, thus reducing production costs. The design of the positioning marks simplifies alignment and cutting operations during production, improving production efficiency. The overall structural design is reasonable, and the connection relationships between the components are clear, facilitating actual production and application. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0020] Figure 2 This is a side view sectional structural diagram of the present invention.

[0021] Figure 3 This is a magnified view of a microprism unit.

[0022] The reference numerals in the attached figures are as follows: 1. Base layer; 2. Microprism array layer; 3. Protective coating; 4. Adhesive layer; 5. Release film; 6. Microprism unit; 7. Spacer groove; 8. Anti-reflective film; 9. Antifouling layer; 10. Reflective layer; 11. Positioning mark. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0024] Specific implementation examples are given below.

[0025] This utility model provides a microprism structured license plate reflective film, the specific implementation of which is as follows: like Figure 1 As shown, the overall structure of this utility model includes a base layer 1, a microprism array layer 2, a protective coating 3, an adhesive layer 4, a release film 5, and the distribution relationship of each functional layer. The base layer 1, as the basic structure of the entire reflective film, is made of polyethylene terephthalate (PET) material with a thickness of 0.2 mm to 0.3 mm. Positioning marks 11 are provided on both sides of the base layer 1. The positioning marks 11 are groove structures with a width of 1 mm to 2 mm and a depth of 0.1 mm to 0.2 mm. The positioning marks 11 are used to assist in alignment and cutting operations during the production process to ensure that the arrangement direction of the microprism array layer 2 is parallel to the length direction of the base layer 1. A microprism array layer 2 is disposed on the upper surface of the substrate layer 1 and consists of multiple regularly arranged microprism units 6. Each microprism unit 6 has a triangular pyramidal structure with a vertex angle ranging from 80° to 100°. The bottom surface of each microprism unit 6 is fixedly connected to the upper surface of the substrate layer 1 using a transparent epoxy resin adhesive with a thickness of 0.05 mm to 0.1 mm. The sides of each microprism unit 6 form an angle with the upper surface of the substrate layer 1, ranging from 40° to 50°. This angle is designed... This is achieved by adjusting the tilt angle of the mold; the apex of the microprism unit 6 is provided with an arc transition structure, the radius of which is 0.01mm to 0.03mm, formed by a polishing process; the surface of the microprism unit 6 is coated with an antireflection film 8, which is made of silicon dioxide material and has a thickness of 0.01mm to 0.03mm, and is attached to the surface of the microprism unit 6 by a vacuum coating process; the presence of the antireflection film 8 reduces the reflection loss of light on the surface of the microprism unit 6 and improves the light transmittance; Spacer slots 7 are provided between the microprism units 6 in the microprism array layer 2. The width of the spacer slots 7 is 0.02 mm to 0.05 mm and the depth is 0.1 mm to 0.15 mm. The spacer slots 7 are filled with high-refractive-index optical adhesive with a refractive index of 1.5 to 1.6 to reduce the scattering loss of light between the microprism units 6. The arrangement density of the microprism units 6 is 1000 to 1500 per square centimeter, and the arrangement direction is parallel to the length direction of the substrate layer 1. A reflective layer 10 is provided at the bottom of the microprism array layer 2. The reflective layer 10 is made of aluminum foil material with a thickness of 0.02 mm to 0.05 mm and is bonded to the upper surface of the substrate layer 1 by hot pressing. The function of the reflective layer 10 is to enhance the reflection effect of light, so that light can be reflected from the microprism units 6 more efficiently. A protective coating 3, made of polyurethane material, covers the outer surface of the microprism array layer 2 and has a thickness of 0.1 mm to 0.2 mm. An antifouling layer 9, made of fluoride material and with a thickness of 0.02 mm to 0.05 mm, is uniformly applied to the outer surface of the protective coating 3 by a spraying process. The presence of the antifouling layer 9 enhances the weather resistance and antifouling ability of the reflective film and extends its service life. An adhesive layer 4 is provided on the lower surface of the base layer 1. The adhesive layer 4 is made of hot melt adhesive material and has a thickness of 0.15 mm to 0.25 mm. A release film 5 is covered on the lower surface of the adhesive layer 4. The release film 5 is silicone oil coated paper and has a thickness of 0.08 mm to 0.12 mm. The release film 5 is bonded to the adhesive layer 4 by electrostatic adsorption and can be quickly peeled off during use. The specific operating principle of this utility model is as follows: When light is incident on the surface of the microprism unit 6 at a large angle, the light first passes through the antireflection film 8 and enters the interior of the microprism unit 6. The presence of the antireflection film 8 reduces the reflection loss of light on the surface. After multiple reflections inside the microprism unit 6, the light is finally reflected back to the external environment by the reflective layer 10. The triangular pyramidal structure design of the microprism unit 6 enables the light to be effectively captured and reflected within a large incident angle range, thereby significantly improving the reflective efficiency. The high refractive index optical adhesive in the spacer groove 7 reduces the scattering loss of light between the microprism units 6, further enhancing the reflective performance. The presence of the protective coating 3 and the anti-fouling layer 9 improves the weather resistance and anti-fouling ability of the reflective film, enabling it to work stably for a long time in complex environments. In actual production, the base layer 1 is formed into the microprism array layer 2 through a precision mold pressing process, ensuring the consistency of shape and size of each microprism unit 6; the design of the positioning mark 11 simplifies the alignment and cutting operations in the production process and improves production efficiency; the surface of the microprism unit 6 is coated with an antireflective film 8 through a vacuum coating process, the spacer groove 7 is filled with high refractive index optical adhesive, and the protective coating 3 and antifouling layer 9 are sequentially covered on the outer surface of the microprism array layer 2 through a spraying process; the entire production process is relatively simple and can be mass-produced using mature technology, thus reducing production costs; The reflective film of this invention can be widely used in the field of license plate manufacturing, especially suitable for scenarios that require operation under complex lighting conditions, such as traffic management during nighttime driving or in adverse weather conditions. Through the above structural design and process, this invention achieves excellent reflective effect under complex lighting conditions, while also possessing good weather resistance and anti-pollution capabilities, meeting the needs of practical applications. In order to enable those skilled in the art to fully understand and implement this invention, the specific implementation principle of this invention will be further explained below in conjunction with a specific application scenario. In nighttime driving scenarios, license plate reflective films need to cope with the light reflection requirements under complex lighting conditions. When vehicle headlights or other light sources illuminate the license plate surface at a large angle, the light first contacts the outer surface of the microprism unit 6. Since the surface of the microprism unit 6 is coated with an anti-reflection film 8, the reflection loss when light passes through the anti-reflection film 8 is significantly reduced, thereby improving the light transmittance. The anti-reflection film 8 is made of silicon dioxide material with a thickness of 0.01mm to 0.03mm. It is attached to the surface of the microprism unit 6 through a vacuum coating process, ensuring that light can efficiently enter the interior of the microprism unit 6. After light enters the microprism unit 6, due to the triangular pyramidal structure of the microprism unit 6 with a vertex angle ranging from 80° to 100°, the light undergoes multiple reflections inside the microprism unit 6. This design allows the light to be effectively captured and reflected back to the external environment within a wide range of incident angles. In addition, an angle is formed between the side of the microprism unit 6 and the upper surface of the substrate layer 1, with the angle ranging from 40° to 50°. This angle design is achieved by adjusting the tilt angle of the mold, optimizing the incident and reflection paths of the light, thereby further improving the reflection efficiency. In the microprism array layer 2, a spacer groove 7 is provided between the microprism units 6, and the spacer groove 7 is filled with a high refractive index optical adhesive. The refractive index of the high refractive index optical adhesive is 1.5 to 1.6, which is used to reduce the scattering loss of light between the microprism units 6. The width of the spacer groove 7 is 0.02 mm to 0.05 mm and the depth is 0.1 mm to 0.15 mm. This design ensures that the light does not lose energy due to scattering during the propagation between the microprism units 6, thereby further enhancing the reflective performance. A reflective layer 10 is disposed at the bottom of the microprism array layer 2. The reflective layer 10 is made of aluminum foil material with a thickness of 0.02mm to 0.05mm and is bonded to the upper surface of the substrate layer 1 by a hot pressing process. The function of the reflective layer 10 is to enhance the reflection effect of light, so that light can be reflected out of the microprism unit 6 more efficiently. After multiple reflections, the light is finally reflected back to the external environment by the reflective layer 10, thereby achieving a highly efficient reflection effect. A protective coating 3 is applied to the outer surface of the microprism array layer 2. It is made of polyurethane material and has a thickness of 0.1 mm to 0.2 mm. An antifouling layer 9 is provided on the outer surface of the protective coating 3. The antifouling layer 9 is made of fluoride material and has a thickness of 0.02 mm to 0.05 mm. It is uniformly applied to the outer surface of the protective coating 3 by a spraying process. The presence of the antifouling layer 9 enhances the weather resistance and antifouling ability of the reflective film, enabling it to work stably for a long time in complex environments. In actual production, the base layer 1 is formed into the microprism array layer 2 through a precision mold pressing process, ensuring the consistency of shape and size of each microprism unit 6; the design of the positioning mark 11 simplifies the alignment and cutting operations in the production process and improves production efficiency; the surface of the microprism unit 6 is coated with an antireflective film 8 through a vacuum coating process, the spacer groove 7 is filled with high refractive index optical adhesive, and the protective coating 3 and antifouling layer 9 are sequentially covered on the outer surface of the microprism array layer 2 through a spraying process; the entire production process is relatively simple and can be mass-produced using mature technology, thus reducing production costs; By combining the above steps and principles, the reflective film of this invention exhibits excellent reflective effect during nighttime driving or in adverse weather conditions, while also possessing good weather resistance and anti-pollution capabilities, thus meeting the needs of practical applications.

[0026] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A microprism structure license plate reflective film, characterized in that, The substrate includes a base layer (1), a microprism array layer (2), and a protective coating (3). The upper surface of the base layer (1) is provided with a microprism array layer (2), which is composed of multiple regularly arranged microprism units (6). Each microprism unit (6) has a triangular pyramidal structure and its apex angle ranges from 80° to 100°. The bottom surface of the microprism unit (6) is fixedly connected to the upper surface of the base layer (1) by an adhesive. The adhesive is a transparent epoxy resin material with a thickness of 0.05 mm to 0.1 mm. The protective coating (3) covers the outer surface of the microprism array layer (2). The protective coating (3) is made of polyurethane material with a thickness of 0.1 mm to 0.2 mm.

2. The microprism structure license plate reflective film according to claim 1, characterized in that, The lower surface of the base layer (1) is provided with an adhesive layer (4), which is made of hot melt adhesive material and has a thickness of 0.15 mm to 0.25 mm. The lower surface of the adhesive layer (4) is covered with a release film (5), which is silicone oil coated paper and has a thickness of 0.08 mm to 0.12 mm.

3. The microprism structure license plate reflective film according to claim 1, characterized in that, The microprism array layer (2) has a spacer groove (7) between the microprism units (6). The spacer groove (7) has a width of 0.02 mm to 0.05 mm and a depth of 0.1 mm to 0.15 mm. The spacer groove (7) is filled with a high refractive index optical adhesive with a refractive index of 1.5 to 1.

6.

4. The microprism structure license plate reflective film according to claim 1, characterized in that, The surface of the microprism unit (6) is coated with an antireflective film (8), which is made of silicon dioxide material and has a thickness of 0.01 mm to 0.03 mm.

5. The microprism structure license plate reflective film according to claim 1, characterized in that, The outer surface of the protective coating (3) is provided with an anti-fouling layer (9), which is made of fluoride material and has a thickness of 0.02 mm to 0.05 mm.

6. The microprism structure license plate reflective film according to claim 1, characterized in that, The substrate layer (1) is made of polyethylene terephthalate (PET) with a thickness of 0.2 mm to 0.3 mm. Positioning marks (11) are provided on both sides of the substrate layer (1). The positioning marks (11) are groove structures with a width of 1 mm to 2 mm and a depth of 0.1 mm to 0.2 mm.

7. The microprism structure license plate reflective film according to claim 1, characterized in that, The microprism unit (6) has a circular arc transition structure at its apex, and the radius of the circular arc transition structure is 0.01 mm to 0.03 mm.

8. The microprism structure license plate reflective film according to claim 1, characterized in that, The bottom of the microprism array layer (2) is provided with a reflective layer (10), which is made of aluminum foil material and has a thickness of 0.02 mm to 0.05 mm.

9. The microprism structure license plate reflective film according to claim 1, characterized in that, The side of the microprism unit (6) forms an angle with the upper surface of the substrate layer (1), and the angle ranges from 40° to 50°.

10. The microprism structure license plate reflective film according to claim 1, characterized in that, The arrangement density of the microprism units (6) is 1,000 to 1,500 per square centimeter, and the arrangement direction of the microprism array layer (2) is parallel to the length direction of the base layer (1).

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