CN-122029246-A - Method for producing a bonded structure, bonded structure and use of said bonded structure for producing a motor vehicle component

Abstract

The present invention relates to a method for preparing a bonded structure comprising treating a surface of a polyolefin component to provide an activated polyolefin surface, applying an adhesive directly to the activated polyolefin surface and the surface of a metal component, and curing the adhesive to form a bonded joint between the polyolefin component and the metal component, wherein the adhesive comprises a polyurethane structural adhesive comprising an isocyanate component and a polyol component, wherein the isocyanate component has a density of greater than 1.2 g/ml, the polyol component has a density of greater than 1.5 g/ml, or a combination thereof.

Inventors

• J. Herahova
• H. Lindes

Assignees

• SABIC环球技术有限责任公司

Dates

Publication Date

20260512

Application Date

20241014

Priority Date

20240213

Claims (15)

1. 1. A method of making a bonded structure, the method comprising: treating the surface of the polyolefin component to provide an activated polyolefin surface; Applying an adhesive directly to the activated polyolefin surface and the surface of the metal part, and Curing the adhesive to form an adhesive joint between the polyolefin component and the metal component, Wherein the adhesive comprises a polyurethane structural adhesive comprising an isocyanate component and a polyol component, wherein The isocyanate component has a density of greater than 1.2 g/ml, The polyol component has a density of greater than 1.5 g/ml, or A combination thereof.
2. 2. The method of claim 1, wherein the isocyanate component has a density of greater than 1.2 g/ml and the polyol component has a density of greater than 1.5 g/ml.
3. 3. The method according to any of the preceding claims, wherein the polyolefin comprises polypropylene.
4. 4. The method according to any of the preceding claims, wherein the polyolefin comprises polyethylene.
5. 5. The method according to any of the preceding claims, wherein the polyolefin component further comprises glass fibers.
6. 6. The method according to any of the preceding claims, wherein the polyolefin component further comprises a flame retardant additive.
7. 7. A method according to any preceding claim, wherein the method further comprises roughening the surface of the metal part prior to applying the polyurethane structural adhesive directly to the activated polyolefin surface and the surface of the metal part.
8. 8. A method according to any preceding claim, wherein the bonded joint has a lap shear strength of greater than 8.0 mpa after conditioning for 168 hours at 23 ± 2 ℃ and 50 ± 6% relative humidity and complete immersion in ethylene glycol/water at 65 ℃ for 45 days.
9. 9. The method of any of the preceding claims, wherein treating the surface of the polyolefin component comprises treating with a flame of a propane-containing gas, the propane-containing gas being propane or a mixture comprising at least 50wt.% propane and methane, ethane, butane, pentane, hexane, or a combination thereof, based on the weight of the propane-containing gas, wherein during treating with the flame of the propane-containing gas, a flame is generated by combusting a mixture of air and the propane-containing gas, wherein the gas-to-air ratio is selected such that the volume ratio of propane gas to oxygen is equal to or less than 1:5.01.
10. 10. A bonded structure prepared by the method of claim 1.
11. 11. A battery comprising the bonded structure of claim 10.
12. 12. An electric vehicle comprising the battery of claim 11.
13. 13. An electric vehicle comprising the bonded structure of claim 10.
14. 14. Use of the bonded structure prepared by the method of claim 1 in a battery.
15. 15. Use of the bonded structure prepared by the method of claim 1 in a battery of an electric vehicle.

Description

Method for producing a bonded structure, bonded structure and use of said bonded structure for producing a motor vehicle component The present application claims the benefit of U.S. provisional application Ser. No.63/544,880, filed on day 19 at 10 in 2023, and EP application Ser. No.24157469.8, filed on day 13 at 2 in 2024, which are incorporated herein by reference in their entirety. Background The polymer and the metal material may be bonded by an adhesive applied to the bonding surface of the material to be bonded. This requires the deposition of an adhesive on the adhesive surface of the polymer and metallic material. Bonding of the adhesive to the bonding surface may be difficult to achieve due to the inherently incompatible chemistry of the material. For example, it may be difficult to adhere a surface of a polyolefin, such as polypropylene, to another surface, such as a metal surface, due to, for example, the low surface energy and low polarity of the polyolefin. There is therefore a need for an improved method for preparing bonded structures having a desired bond joint strength. Disclosure of Invention Object of the invention It is an object of the present invention to provide a method for improved bonding. It is another object of the present invention to provide a bonded structure suitable for preparing automotive parts. Summary of the invention A method for preparing a bonded structure is provided, the method comprising treating a surface of a polyolefin component to provide an activated polyolefin surface, applying an adhesive directly to the activated polyolefin surface and a surface of a metal component, and curing the adhesive to form a bonded joint (bond) between the polyolefin component and the metal component, wherein the adhesive comprises a polyurethane structural adhesive comprising an isocyanate component and a polyol component, wherein the isocyanate component has a density of greater than 1.2 g/ml, the polyol component has a density of greater than 1.5 g/ml, or a combination thereof. The isocyanate component may have a density of greater than 1.2 g/ml and the polyol component may have a density of greater than 1.5 g/ml. The polyolefin may comprise polypropylene. The polyolefin may comprise polyethylene. The polyolefin component may further comprise glass fibers. The polyolefin component may further comprise a flame retardant additive. After conditioning for 168 hours at 23±2 ℃ and 50±6% relative humidity and complete immersion in ethylene glycol/water at 65 ℃ for 45 days, the bonded joint may have a lap shear strength (LAP SHEAR STRENGTH) of greater than 8.0 MPa. Treating the surface of the polyolefin part comprises treating with a flame of a propane-containing gas, said propane-containing gas being propane or a mixture comprising at least 50 weight percent (wt.%) propane, based on the weight of the propane-containing gas, and methane, ethane, butane, pentane, hexane or a combination thereof, wherein during the treating with the flame of the propane-containing gas, a flame is generated by combusting a mixture of air and the propane-containing gas, wherein the gas-to-air ratio is selected such that the volume ratio of propane gas to oxygen is equal to or less than 1:5.01. The adhesive may comprise two components. Also provided are a bonded structure prepared by the method, a battery comprising the bonded structure, and an electric vehicle comprising the battery. An electric vehicle comprising the bonded structure is further provided. Also provided are the use of the bonded structure in a battery and the use of the bonded structure prepared by the method in a battery of an electric vehicle. Detailed description of the invention Definition of the definition The following definitions are used in this specification. As used herein, "bonding agent" refers to a material that is capable of fastening two surfaces together, typically resulting in a smooth bonded joint. Adhesives are also known as adhesives (adhesives). As used herein, "gap between the burner nozzle and the surface" refers to the distance between the burner nozzle and the surface to be treated (e.g., the surface of a polyolefin component). As used herein, "gas-to-air ratio" refers to the ratio of the gas portion to the air portion in the flame (i.e., in the total gas and air stream). Unless otherwise indicated, the ratio is a volume ratio. For example, 1:17 means that 17L of air is used as the oxidant for 1 liter (L) of gas supplied to the flame. As used herein, "treatment rate" refers to the length of the surface exposed to the flame per unit time, e.g., the length of the surface of the polyolefin component exposed to the flame per unit time. In this sense, a process speed of 300 millimeters per second (mm/s) means that a surface of, for example, a polyolefin component of 300 millimeters per second (mm) is exposed to a flame. As used herein, "total flow of gas and air mixture" refers to the number of liters per unit time of gas