Polyuria Anti-cracking coating and automobile having same

Abstract

A polyurea anti-cracking coating, comprising: a metal layer; a polyurea layer comprising a first polyurea layer and a second polyurea layer, the first polyurea layer is located on a pressure side of the metal layer, the second polyurea layer is located on a tension side of the metal layer, and the thickness of the first polyurea layer is less than that of the second polyurea layer; and a bonding layer sandwiched between the polyurea layer and the metal layer and bonded to the polyurea layer and the metal layer respectively.

Description

Polyurea anti-cracking coating and automobile having the same

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims priority to the Chinese patent application filed on August 25, 2023, with application number 202311085810.7 and invention name “A polyurea anti-cracking coating and an automobile having the same”, the full text of which is incorporated herein by reference. Technical Field

[0003] The present application relates to the field of coating technology, and in particular to a polyurea anti-cracking coating and a car having the same. Background Art

[0004] Today, more and more automakers are using lightweight metal materials for their vehicle bodies. These materials offer the advantage of low weight. However, due to their low ductility, they are more susceptible to cracking in a collision, leading to structural failure and significantly reducing the energy absorbed by the vehicle during a collision. Consequently, lightweight metal bodies have a low safety factor.

[0005] Polyurea coating is a polymer coating with strong anti-corrosion and waterproof properties, and is widely used in large-scale infrastructure projects and construction engineering fields.

[0006] Summary of the Invention

[0007] The present application provides a polyurea anti-cracking coating for preventing vehicle body structure fracture, comprising: a metal layer, a polyurea layer, the polyurea layer comprising a first polyurea layer and a second polyurea layer, the first polyurea layer being located on a compression side of the metal layer, the second polyurea layer being located on a tension side of the metal layer, the thickness of the first polyurea layer being less than the thickness of the second polyurea layer; and an adhesive layer, the adhesive layer being sandwiched between the polyurea layer and the metal layer and bonded to the polyurea layer and the metal layer, respectively.

[0008] Furthermore, the adhesive layer includes epoxy resin glue.

[0009] Furthermore, the metal layer includes any one of cast aluminum and boron steel.

[0010] Furthermore, the adhesive layer includes: a first adhesive layer, the first adhesive layer is located between the metal layer and the first polyurea layer and is used to bond the first polyurea layer to the metal layer; and a second adhesive layer, the second adhesive layer is located between the metal layer and the second polyurea layer and is used to bond the second polyurea layer to the metal layer.

[0011] Furthermore, the thickness ratio of the first polyurea layer to the second polyurea layer is 1:2.

[0012] Furthermore, the thickness of the metal layer is smaller than the thickness of the first polyurea layer.

[0013] Furthermore, the thickness ratio of the first polyurea layer, the second polyurea layer and the metal layer is 1:2:1.

[0014] Furthermore, the polyurea anti-cracking coating is made by a spraying process, and the adhesive layer and the polyurea layer are sprayed on the outer side of the metal layer.

[0015] Furthermore, the first adhesive layer is sprayed between the metal layer and the first polyurea layer, and the second adhesive layer is sprayed between the metal layer and the second polyurea layer.

[0016] Furthermore, the thickness of the first polyurea layer is 3 mm, and the thickness of the second polyurea layer is 6 mm.

[0017] Furthermore, the thickness of the first polyurea layer is 1 mm, the thickness of the second polyurea layer is 2 mm, and the thickness of the metal layer is 1 mm.

[0018] Furthermore, the thickness of the metal layer is less than or equal to the thickness of the first polyurea layer.

[0019] Furthermore, the present application also provides an automobile, which includes the aforementioned polyurea anti-cracking coating, and the polyurea anti-cracking coating is arranged on the structure of the vehicle body that is prone to collision and impact.

[0020] Furthermore, the polyurea anti-cracking coating is provided in a center channel area of ​​the front panel.

[0021] Furthermore, the first polyurea layer is provided on the compression side of the dash panel facing the front of the vehicle body, and the second polyurea layer is provided on the tension side of the dash panel facing the rear of the vehicle body. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG1 is a schematic diagram of a polyurea anti-cracking coating provided by an exemplary embodiment of the present application.

[0023] FIG. 2 is a perspective view of a dash panel in an exemplary embodiment of the present application.

[0024] FIG. 3 is a rear view of a dash panel in an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0025] In order to further explain the technical means and effects adopted by this application to achieve the predetermined invention purpose, the application is described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0026] The terms "first," "second," "third," "fourth," etc. in the description and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0027] It should be noted that the directional terms "X-direction," "Y-direction," and "Z-direction" in this specification refer to the commonly used "body X-direction," "body Y-direction," and "body Z-direction," respectively, in the automotive field. The "body X-direction" refers to the length of the body, which also refers to the front-to-back direction, with the vehicle's front end as the positive direction. The "body Y-direction" refers to the width of the body, with the direction from the cab side to the door side as the positive direction. The "body Z-direction" refers to the height of the body, which also refers to the direction of gravity and the up-down direction, with the direction opposite to the direction of gravity as the positive direction. Furthermore, the terms "outside" and "inside" in this specification refer to the relative directions of the interior and exterior of the polyurea anti-cracking coating structure itself.

[0028] Referring to Figure 1 , the polyurea anti-cracking coating of the present application is a coating produced using a spraying process and is particularly suitable for vehicle bodies made of lightweight metal materials. The polyurea anti-cracking coating of the present application comprises a polyurea layer, a metal layer 4, and an adhesive layer 3. The adhesive layer 3 and the polyurea layer are sprayed onto the exterior of the metal layer 4. The adhesive layer 3 is sandwiched between the polyurea layer and the metal layer 4 and adheres to both layers, respectively. For example, the polyurea anti-cracking coating of the present application comprises a composite sandwich structure with the metal layer 4 positioned innermost and the polyurea layer positioned outermost. The metal layer 4 and the polyurea layer are bonded together via the adhesive layer 3 located between them. In actual production, the adhesive layer 3 is first sprayed onto the exterior of the metal layer 4, followed by the polyurea layer sprayed onto the exterior of the adhesive layer 3. This polyurea anti-cracking coating has the advantages of a simple structure, light weight, and a large number of compatible components. It can improve the vehicle body's energy absorption performance while maintaining the weight advantage of using lightweight metal materials, thereby enhancing the collision safety of the vehicle body. In an embodiment of the present application, the metal layer 4 includes any one of cast aluminum and boron steel, and lightweight cast aluminum is the best because it is lighter and has worse ductility than boron steel. When combined with the polyurea anti-cracking coating in the present application, it has better economic benefits and high efficiency in improving ductility; the adhesive layer 3 includes an epoxy resin glue with high adhesion.

[0029] Furthermore, the polyurea layer of the present application includes a first polyurea layer 1 and a second polyurea layer 2, each located on opposite sides of a metal layer 4. In some embodiments, the first and second polyurea layers 1 and 2 are spray-coated on opposite sides of the metal layer 4. The polyurea anti-cracking coating of the present application also includes a first adhesive layer 31 for bonding the metal layer 4 to the first polyurea layer 1, and a second adhesive layer 32 for bonding the metal layer 4 to the second polyurea layer 2. As will be readily understood, the first and second polyurea layers 1 and 2 are located on opposite sides of the metal layer 4. This design of the polyurea anti-cracking coating protects the metal layer 4 from two opposing directions, absorbing some of the impact energy from either direction to mitigate the impact. Furthermore, it improves the overall ductility of the polyurea anti-cracking coating, slowing the initiation and expansion of metal fractures caused by collisions and impacts. In the embodiments of the present application, the first polyurea layer 1 is spray-coated on the side of the metal layer 4 that directly faces the impact, i.e., the compressive side, while the second polyurea layer 2 is spray-coated on the back side of the metal layer 4, i.e., the tensile side. The compressive side is opposite the tensile side. When a collision occurs, the first polyurea layer 1 on the pressure side directly faces the impact, first absorbing and reducing part of the impact force, and the second polyurea layer 2 on the opposite back side of the metal layer 4 delays the impact on the metal layer 4, reducing the overall bending deformation amplitude of the metal layer 4 and preventing it from breaking.

[0030] Referring to Figure 1 , the thickness of the first polyurea layer 1 in this application is less than that of the second polyurea layer 2 , meaning the coating thickness on the compressive side is less than that on the tensile side, and the thickness of the metal layer 4 is less than or equal to the thickness of the first polyurea layer 1 . Currently, conventional applications of polyurea coatings primarily utilize their waterproof, corrosion-resistant, salt-resistant, and high-temperature-resistant properties. By applying or spraying them on the exterior surfaces of designated equipment or materials, they aim to increase their lifespan and durability, thereby protecting the structures coated with the polyurea coating. While applying or spraying a polyurea coating on the exterior or a single surface of lightweight metal materials, particularly cast aluminum used in the automotive industry for vehicle bodies, can improve their corrosion resistance, salt resistance, and high-temperature resistance, the improvement in their fracture and impact resistance is relatively limited.

[0031] The first polyurea layer 1 and the second polyurea layer 2 in the present application are respectively bonded to the metal layer 4 from two directions by epoxy resin glue and protect the metal layer 4, providing the metal layer 4 with improved impact resistance and fracture resistance from the compression side and the tension side respectively. Since the coating thickness on the compression side is less than the coating thickness on the tension side, the compression side is further prevented from bending and deforming toward the tension side when impacted, causing structural fracture. While improving the life and durability of the metal layer 4, within the limited cost and weight adjustment space, its impact resistance when facing collision impact is greatly enhanced. Compared with other solutions such as replacing the body material, it has certain advantages in cost and weight. If the coating thickness on the compression side of the metal layer 4 is greater than the coating thickness on the tension side, then this impact resistance and fracture resistance effect cannot be achieved. However, since it is a coating rather than a structural change, the polyurea anti-cracking coating of the present application has good overall economic benefits when used on the production line and has a wide range of applications.

[0032] In one embodiment of the present application, the metal layer 4 is made of 2mm thick cast aluminum, and the adhesive layer 3 is made of epoxy resin adhesive. A first adhesive layer 31 and a first polyurea layer 1 are spray-coated on the first surface of the metal layer 4, while a second adhesive layer 32 and a second polyurea layer 2 are spray-coated on the second surface of the metal layer 4, opposite the first surface. The first and second polyurea layers 1 and 2 are located on the outermost sides of the polyurea anti-cracking coating, while the metal layer 4 is located on the innermost side. The thickness ratio of the first and second polyurea layers 1 and 2 is 1:2, with thicknesses of 3mm and 6mm, respectively. The first polyurea layer 1 is located on the compressive side of the metal layer 4, while the second polyurea layer 2 is located on the tensile side of the metal layer 4. The polyurea anti-cracking coating in this embodiment is suitable for sheet metal structures at the front of a vehicle body, particularly those with large surface areas, such as the dash panel 5, which often collides with the motor in a head-on collision.

[0033] In another embodiment of the present application, the metal layer 4 is made of 1mm thick boron steel, and the adhesive layer 3 is made of epoxy resin adhesive. A first adhesive layer 31 and a first polyurea layer 1 are spray-coated on the first surface of the metal layer 4, and a second adhesive layer 32 and a second polyurea layer 2 are spray-coated on the second surface of the metal layer 4, opposite the first surface. The first and second polyurea layers 1 and 2 are located on the outermost sides of the polyurea anti-cracking coating, while the metal layer 4 is located on the innermost side. The thickness ratio of the first, second, and metal layers is 1:2:1, meaning that the metal layer 4 is the same thickness as the first polyurea layer 1. The first and second polyurea layers 1 and 2 are 1mm and 2mm thick, respectively. The first polyurea layer 1 is located on the compressive side of the metal layer 4, while the second polyurea layer 2 is located on the tensile side. The polyurea anti-cracking coating in this embodiment is suitable for sheet metal structures at the front of a vehicle body, particularly for components with large surface areas, such as the dash panel 5, which often collides with the motor in a head-on collision.

[0034] Referring to Figures 2 and 3 , the present application also includes an automobile comprising the aforementioned polyurea anti-cracking coating. The polyurea anti-cracking coating is primarily applied to structures on the vehicle body that are susceptible to collision impact, such as the central channel in the center of the dash panel 5. For example, the dash panel 5 is one of the vehicle body components most susceptible to structural fracture in a frontal collision, and its center portion has a large, flat area, making it suitable for the polyurea anti-cracking coating of the present application. As will be readily understood, other vehicle body components, such as the side panels, are susceptible to deformation and fracture in collisions and require energy absorption. As long as these components can be designed with a large, flat area as much as possible, they can also be adapted for the polyurea anti-cracking coating of the present application to enhance their impact and fracture resistance.

[0035] Referring to Figures 2 and 3, in one embodiment of the present application, a polyurea anti-cracking coating is applied to the center channel area of ​​the dash panel 5, near the firewall. The vehicle's motor is located in front of the dash panel 5, i.e., the front portion in the X-direction. The passenger compartment, which also serves as the driver's footrest, is located in the rear of the dash panel 5, i.e., the rear portion in the X-direction. The polyurea anti-cracking coating in this embodiment comprises a metal layer 4 made of 2mm thick cast aluminum, and an adhesive layer 3 made of epoxy resin adhesive. A first adhesive layer 31 and a first polyurea layer 1 are spray-coated on the first surface of the metal layer 4. A second adhesive layer 32 and a second polyurea layer 2 are spray-coated on the second surface of the metal layer 4, opposite the first surface. The first and second polyurea layers 1 and 2 are located on the outermost sides of the polyurea anti-cracking coating in this embodiment, while the metal layer 4 is located on the innermost side. The first polyurea layer 1 is located on the compression side of the metal layer 4, which also corresponds to the front side of the dash panel 5 in the X-direction, facing the front of the vehicle. The second polyurea layer 2 is located on the tension side of the metal layer 4, which also corresponds to the rear side of the dash panel 5 in the X-direction, facing the rear of the vehicle. The thickness ratio of the first and second polyurea layers 1 and 2 is 1:2, with thicknesses of 3 mm and 6 mm, respectively. When a collision occurs, the motor located in front of the dash panel 5 strikes the dash panel 5. The first polyurea layer 1 withstands and absorbs this force, while the second polyurea layer 2, on the opposite rear side of the dash panel 5, slows the impact on the metal layer 4, reducing the overall bending deformation of the metal layer 4 and delaying the onset and propagation of cracks, thereby preventing the dash panel 5 from breaking and maximizing protection for the passenger compartment.

[0036] In summary, the polyurea anti-cracking coating of the present application is achieved by spraying a polyurea coating onto opposing surfaces of a lightweight metal material. The first and second polyurea layers are bonded to and protected by epoxy resin adhesive from two directions, respectively. This improves the impact resistance and fracture resistance of the metal layer on both the compression and tension sides. Because the coating thickness on the compression side is thinner than that on the tension side, this further prevents structural fracture caused by bending and deformation of the compression side toward the tension side during impact. Within limited cost and weight adjustment margins, the coating significantly enhances its impact resistance during collisions, improving the collision safety of the vehicle body without compromising the weight advantage of a vehicle body made of lightweight metal materials. The polyurea anti-cracking coating of the present application offers the advantages of a simple structure, light weight, and highly efficient ductility enhancement, making it particularly suitable for large flat vehicle body parts.

[0037] The above are only specific embodiments of the present application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A polyurea anti-cracking coating, comprising: Metal layer (4), a polyurea layer, the polyurea layer comprising a first polyurea layer (1) and a second polyurea layer (2), the first polyurea layer (1) being located on the compression side of the metal layer (4), the second polyurea layer (2) being located on the tension side of the metal layer (4), the thickness of the first polyurea layer (1) being smaller than the thickness of the second polyurea layer (2); and An adhesive layer (3), wherein the adhesive layer (3) is sandwiched between the polyurea layer and the metal layer (4) and is respectively bonded to the polyurea layer and the metal layer (4).

2. The polyurea anti-cracking coating according to claim 1, characterized in that: The adhesive layer (3) comprises epoxy resin glue.

3. The polyurea anti-cracking coating according to claim 1, characterized in that: The metal layer (4) comprises any one of cast aluminum and boron steel.

4. The polyurea anti-cracking coating according to claim 1, characterized in that: The adhesive layer (3) comprises: a first adhesive layer (31), the first adhesive layer (31) being located between the metal layer (4) and the first polyurea layer (1) and used for bonding the first polyurea layer (1) and the metal layer (4), and A second adhesive layer (32), the second adhesive layer (32) is located between the metal layer (4) and the second polyurea layer (2) and is used to bond the second polyurea layer (2) and the metal layer (4).

5. The polyurea anti-cracking coating according to any one of claims 1 to 4, characterized in that: The thickness ratio of the first polyurea layer (1) to the second polyurea layer (2) is 1:

2.

6. The polyurea anti-cracking coating according to claim 5, characterized in that: The thickness of the metal layer (4) is smaller than the thickness of the first polyurea layer (1).

7. The polyurea anti-cracking coating according to any one of claims 1 to 4, characterized in that: The thickness ratio of the first polyurea layer (1), the second polyurea layer (2) and the metal layer (4) is 1:2:

1.

8. The polyurea anti-cracking coating according to claim 1, characterized in that: The polyurea anti-cracking coating is made by a spraying process, and the adhesive layer (3) and the polyurea layer are sprayed on the outer side of the metal layer (4).

9. The polyurea anti-cracking coating according to claim 4, characterized in that: The first adhesive layer (31) is sprayed between the metal layer (4) and the first polyurea layer (1). The second adhesive layer (32) is sprayed between the metal layer (4) and the second polyurea layer (2).

10. The polyurea anti-cracking coating according to claim 5, characterized in that: The thickness of the first polyurea layer (1) is 3 mm, and the thickness of the second polyurea layer (2) is 6 mm.

11. The polyurea anti-cracking coating according to claim 7, characterized in that: The thickness of the first polyurea layer (1) is 1 mm, the thickness of the second polyurea layer (2) is 2 mm, and the thickness of the metal layer (4) is 1 mm.

12. The polyurea anti-cracking coating according to claim 1, characterized in that: The thickness of the metal layer (4) is less than or equal to the thickness of the first polyurea layer (1).

13. A car, characterized in that: It comprises the polyurea anti-cracking coating according to any one of claims 1 to 12, wherein the polyurea anti-cracking coating is arranged on a structure of a vehicle body that is prone to collision and impact.

14. The automobile according to claim 13, characterized in that The polyurea anti-cracking coating is arranged in the middle channel area of ​​the front panel (5).

15. The automobile according to claim 14, characterized in that The first polyurea layer (1) is arranged on the compression side of the front panel (5) facing the front of the vehicle body, and the second polyurea layer (2) is arranged on the tension side of the front panel (5) facing the rear of the vehicle body.

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