Highly adhesive polyester compositions, process for their preparation and use
By adding components such as TPU, epoxy resin, and EVOH to a polyester composition, and combining them with a specific polyester-based elastomer copolymer, the problem of insufficient adhesion between polyester plastic products and polyurethane adhesives is solved, achieving efficient bonding and simplifying the process, reducing production costs and improving production efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BENSONG ENG PLASTICS HANGZHOU
- Filing Date
- 2026-03-27
- Publication Date
- 2026-06-09
AI Technical Summary
Existing technologies for improving the adhesion between polyester plastic products and polyurethane adhesives suffer from high costs and low production efficiency. Furthermore, conventional methods may increase the costs of plasma equipment and labor, and their effectiveness is limited.
By adding thermoplastic polyurethane (TPU), epoxy resin, ethylene-vinyl alcohol copolymer (EVOH) and other components to polyester compositions, the bonding effect between polyester plastic products and polyurethane adhesives is improved, the process is simplified, direct bonding is possible without a base coat, and specific polyester-based elastomer copolymers are combined to improve adhesion and toughening properties.
It significantly improves the adhesion between polyester plastic products and polyurethane adhesives without increasing costs or impacting production efficiency, simplifies the process, reduces production costs, and increases production efficiency.
Smart Images
Figure CN122167961A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of polymer compositions, specifically relating to high-adhesion polyester compositions, preparation methods, and applications. Background Technology
[0002] When bonding plastic products to automotive glass, polyurethane adhesive is often used as an bonding layer to achieve adhesion between the glass and the plastic. However, due to insufficient adhesion between conventional polyester-based plastics and polyurethane adhesive, a primer is usually applied to the surface of the plastic product. This primer typically includes polyurethane prepolymer, silane coupling agent solvent, solvent, curing agent, and plasticizer. The solvent evaporates and adheres to the polyester plastic product to improve the adhesion between the plastic and the glass. However, this process has several drawbacks: firstly, the primer solvent has a long evaporation time, which significantly impacts the construction environment and the health of operators; secondly, it increases costs, and the primer application process reduces overall production efficiency.
[0003] Existing technologies include plasma treatment of plastic product surfaces to improve the adhesion between the plastic product surface and polyurethane adhesive. However, while the plasma treatment process on the plastic product surface avoids the need for a primer, it also increases the costs of plasma equipment, energy, and labor, resulting in limited improvement in production efficiency.
[0004] There is currently no good solution that can improve the adhesion between polyester plastic products and polyurethane adhesives under the conditions of limited cost and minimal impact on production efficiency. Summary of the Invention
[0005] To overcome the aforementioned technical problems, the present invention aims to provide a high-adhesion polyester composition, its preparation method, and its application that can improve the bonding effect of polyurethane adhesives. This is achieved through the following technical solution: A high-adhesion polyester composition, comprising, by weight, the following components: 60-100 parts of polyester resin, 0-40 parts of reinforcing filler Adhesive additives 0.1-3 parts, Other auxiliary agents: 0-10 parts The adhesive additives include one or more of thermoplastic polyurethane, epoxy resin, and ethylene-vinyl alcohol copolymer.
[0006] Optionally, it also includes polyester-based elastomer copolymers, in amounts of 1 to 10 parts by weight.
[0007] Optionally, the polyester-based elastomer copolymer includes one or more of polyether ester elastomers (TPEE), polyesteramide elastomers, and polyester-type polyurethane elastomers.
[0008] Optionally, the polyesteramide elastomer includes one or more of polyester block amide (PEA) and polyester block amide (PEEA).
[0009] Optionally, the polyether ester elastomer is a polyester polyether copolymer (TPEE).
[0010] Optionally, the polyester resin includes one or more of PBT (polybutylene terephthalate), PET (polyethylene terephthalate), PTT (polypropylene terephthalate), and PCT (poly(1,4-cyclohexanediol terephthalate)).
[0011] Optionally, the reinforcing filler includes one or more of glass fiber, carbon fiber, and powder reinforcing filler.
[0012] Optionally, the powder reinforcing filler is selected from one or more of the following: wollastonite, zeolite, kaolin, mica, talc, clay, pyrophyllite, bentonite, montmorillonite, asbestos, aluminosilicate, alumina, silicon dioxide, magnesium oxide, zirconium oxide, titanium dioxide, iron oxide, calcium carbonate, magnesium carbonate, dolomite, calcium sulfate, barium sulfate, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, glass microspheres, glass powder, ceramic beads, ground glass fiber, boron nitride, or silicon carbide.
[0013] Optionally, the other additives include one or more of the following: color powder, coupling agent, antioxidant, lubricant, flow modifier, and plasticizer.
[0014] The present invention also provides a method for preparing a polyester composition according to any of the above embodiments, characterized in that it includes the following steps: adding each component into a screw extruder for melt extrusion granulation to obtain the polyester composition.
[0015] The present invention also provides an application of articles formed by processing the polyester composition described in any of the above embodiments to improve the adhesion when bonded with polyurethane adhesive.
[0016] Compared with the prior art, the present invention improves the bonding effect between polyester plastic products and polyurethane adhesive by modifying the polyester formulation of plastic products. Polyester plastic products can be directly bonded to polyurethane adhesive without the need for pre-coating a primer layer, simplifying the process, reducing production costs, and improving production efficiency.
[0017] Adding components such as thermoplastic polyurethane elastomer (TPU), epoxy resin, and ethylene-vinyl alcohol copolymer (EVOH) to polyester compositions carries a certain risk of degradation during high-temperature processing. Therefore, those skilled in the art generally do not recommend adding such substances to polyester compositions. This solution overcomes this technical bias by adding thermoplastic polyurethane (TPU), epoxy resin, and ethylene-vinyl alcohol copolymer (EVOH) components, achieving a significant improvement in adhesion even with small dosages. Simultaneously, due to the low dosage, the risk of degradation during high-temperature processing is also very low, resulting in excellent overall performance.
[0018] Furthermore, due to the notch sensitivity of polyester products, thin wall thickness, insufficient reinforcement from ribs, and the need for toughening modification in assembly processes such as snap-fit connections and interference fits, toughening modification is often required. The applicant has found that toughening agents commonly used in polyester compositions, such as POE, SEBS, and EBA-co-GMA, significantly reduce the adhesion between polyester products and polyurethane adhesives. The applicant believes the possible mechanism is that the aforementioned toughening agents may affect the adhesive effect due to their low surface energy, low molecular weight, or limited compatibility with polyester resins. The polyester-based elastomer copolymer specifically selected in this invention has good compatibility with the resin matrix and high surface energy. Even if it migrates to the surface, it has little impact on the adhesive strength, thus improving toughness while maintaining high adhesive performance. Attached Figure Description
[0019] Figure 1 Example photograph showing an adhesion performance test grade of 1; Figure 2 Example photo showing an adhesion performance test level of 2; Figure 3 Example photo showing an adhesion performance test level of 3; Figure 4 Example photo showing an adhesion performance test level of 4; Figure 5 Example photos showing that the thermal degradation performance test was OK; Figure 6 Example photo showing a thermal degradation performance test result of NG. Detailed Implementation
[0020] The specific implementation of the present invention is described in detail below through examples. However, the specific implementation of the present invention is not intended to limit the technical solution of the present invention. Any non-substantial changes, such as replacing common technical solutions in the field, using the technical solutions described in the embodiments of the present invention are within the protection scope of the present invention.
[0021] Unless otherwise specified, the experimental methods used in the following examples and comparative examples are conventional methods, and the materials and reagents used are commercially available unless otherwise specified.
[0022] The sources of some of the raw materials in the examples and comparative examples are as follows, but they should not be construed as limiting the scope of the present invention: PBT resin: Zhejiang Meiyuan New Material Co., Ltd., MY10; PET resin: Zhejiang Wankai New Material Co., Ltd., WK-631; TPU (Thermoplastic Polyurethane): Wanhua Chemical, 4055ic; Epoxy resin: Guodu Chemical, KD-213; EVOH (ethylene-vinyl alcohol copolymer): Sinopec Sichuan Vinylon Plant, EW-3201S; Fiberglass: Chongqing International Composite, ECS303-3-H; Glass microspheres: Sofitel, France, MicroPerl 050-20-216; TPEE-1 (polyether ester elastomer): Xinjiang Tunhe, TH3040; TPEE-2 (polyether ester elastomer): Shanghai Yitan, HP2511; Polyolefin elastomers (POE): Dow Chemical, ENGAGE 8150; SEBS: Baling Petrochemical, YH-503T; Glycidyl methacrylate copolyethylene-butyl acrylate (EBA-co-GMA): DuPont, Elvaloy PTW; Silane coupling agent, commercially available, KH-560; Black masterbatch, commercially available; Polyurethane adhesive: Sikaflex-255FC Among them, TPEE-1 and TPEE-2 are two different types of PTEE.
[0023] The preparation method of the compositions described in the various embodiments and comparative examples is as follows: each component is added to a screw extruder for melt extrusion and granulation to obtain the polyester composition. Specific steps are well known to those skilled in the art and will not be repeated here. The processing temperature of the twin-screw extruder is 230–260°C, the screw speed is 300–450 r / min, the melt pressure is 1.5–2.5 MPa, and the vacuum degree is -0.1–-0.04 MPa.
[0024] Adhesion strength test: The composition was injection molded into 60 x 60 mm square sheet samples. One side of the sample was coated with polyurethane adhesive. After 5 days, the polyurethane adhesive and sample were separated by hand, and the residual amount of polyurethane adhesive on the sample surface was visually evaluated (also known as CF value). Based on the amount of residual adhesive, it was divided into four levels: 1, 2, 3, and 4, as shown below. Figure 1 , 2For levels 1, 3, and 4 examples, they can be clearly distinguished by the naked eye. Among them: Level 1 indicates that the residual amount of polyurethane glue accounts for about 75% - 100% of the sample surface, excluding the lower limit endpoint of 75%; Level 2 indicates that the residual amount of polyurethane glue accounts for about 50% - 75% of the sample surface, excluding the lower limit endpoint of 50%; Level 3 indicates that the residual amount of polyurethane glue accounts for about 25% - 50% of the sample surface, excluding the lower limit endpoint of 25%; Level 4 indicates that the residual amount of polyurethane glue accounts for about 0 - 25% of the sample surface. Level 1 has high bonding strength (or good bonding performance), and the bonding strength decreases sequentially to Level 4 (or the bonding performance is the worst), and Level 2 generally can meet the actual use requirements. It should be noted that the placement time of the sample can be reasonably selected according to the specific curing requirements of the polyurethane glue. Those skilled in the art can set the parameters of injection molding and its process according to actual needs.
[0025] Thermal degradation performance test: Keep the composition in the injection molding machine for 5 minutes, and the barrel temperature of the injection molding machine is 255°C. Observe the state of the injected melt after cooling, and evaluate the degradation situation. Among them, the smoother the surface is as Figure 5 shown, the less the composition degrades, which will not affect the appearance of the product, and it is represented by qualified OK; the rougher the surface is as Figure 6 shown, the more the composition degrades, which will affect the appearance of the product, and it is represented by unqualified NG.
[0026] It should be noted that this test scheme is more in line with the actual use conditions of users compared to the reaction heat degradation performance such as the fluidity of the composition. It can be used by injection molding machine operators during actual injection molding, and the evaluation is more flexible.
[0027] It should be noted that it is common knowledge in the art that elastomers such as TPEE, POE, SEBS, and EBA - co - GMA have a toughening effect, and their relationship with the core index of bonding strength in this scheme is not significant, so the specific toughening performance data are not listed in the table.
[0028] Table 1 and Table 2 show the component and performance test data of the examples and comparative examples. The content in the components is in parts by weight. It should be noted that the number of parts of the black masterbatch remains the same at 1.6 parts in both the examples and comparative examples, and it is not shown in the table.
[0029] Table 1 Component and Performance Test Data of Examples 1 - 7
[0030] Table 2 Component and Performance Test Data of Comparative Examples 1 - 8
[0031] The data in the table show that, compared to Comparative Examples 1-3, adding a small amount of TPU to the polyester composition in Examples 1-3 significantly improves the adhesive properties. Too little TPU results in poor performance, while too much reduces the composition's thermal degradation properties, leading to poor injection molding appearance and making it unusable in practice. In Example 4, the addition of TPU to the composition formulation without reinforcing fillers also significantly improves the adhesive properties. Compared to Comparative Examples 4-6, in Examples 5-7, conventional toughening agents such as POE, EBA-co-GMA, and SEBS cause a decrease in the adhesive strength of the composition when toughening is required. The applicant believes the possible mechanism is that the aforementioned toughening agents may affect the adhesive effect due to their low surface energy, low molecular weight, or limited compatibility with polyester resin. The addition of toughening agents can be considered a detrimental factor to the adhesive properties of the material. The TPEE specifically selected in this invention has good compatibility with the resin matrix and high surface energy; even if it migrates to the surface, it has little impact on the adhesive strength, thus improving toughness while maintaining high polyurethane adhesive strength. In Comparative Example 2, the addition of 5 parts of TPU resulted in excellent adhesive properties, but it also led to thermal degradation of the material. In Comparative Example 7, the addition of 15 parts of TPEE-1, while increasing the TPU content, still caused the adhesive strength grade to drop to level 3, rendering it practically unusable. In Comparative Example 8, even with the addition of a small amount of the conventional toughening agent EBA-co-GMA, the adhesive properties of the polyester composition were significantly reduced, rendering it practically unusable.
Claims
1. A high-adhesion polyester composition, characterized in that, By weight, it includes the following components: 60-100 parts of polyester resin, 0-40 parts of reinforcing filler Adhesive additives 0.1-3 parts, Other auxiliary agents: 0-10 parts The adhesive additives include one or more of thermoplastic polyurethane, epoxy resin, and ethylene-vinyl alcohol copolymer.
2. The polyester composition according to claim 1, characterized in that, It also includes polyester-based elastomer copolymers, in amounts of 1 to 10 parts by weight.
3. The polyester composition according to claim 2, characterized in that, The polyester-based elastomer copolymer includes one or more of polyester-type polyurethane elastomers, polyesteramide elastomers, and polyether ester elastomers.
4. The polyester composition according to claim 3, characterized in that, The polyether ester elastomer is a polyester polyether copolymer.
5. The polyester composition according to claim 1, characterized in that, The polyester resin includes one or more of PBT (polybutylene terephthalate), PET (polyethylene terephthalate), PTT (polypropylene terephthalate), and PCT (poly(1,4-cyclohexanediol terephthalate)).
6. The polyester composition according to claim 1, characterized in that, The reinforcing filler includes one or more of glass fiber, carbon fiber, and powder reinforcing filler.
7. The polyester composition according to claim 1, characterized in that, The powder reinforcing filler is selected from one or more of the following: wollastonite, zeolite, kaolin, mica, talc, clay, pyrophyllite, bentonite, montmorillonite, asbestos, aluminosilicates, alumina, silicon dioxide, magnesium oxide, zirconium oxide, titanium dioxide, iron oxide, calcium carbonate, magnesium carbonate, dolomite, calcium sulfate, barium sulfate, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, glass microspheres, glass powder, ceramic beads, ground glass fibers, boron nitride, or silicon carbide.
8. The polyester composition according to claim 1, characterized in that, The other additives include one or more of the following: colorant, coupling agent, antioxidant, lubricant, flow modifier, and plasticizer.
9. The method for preparing the polyester composition according to any one of claims 1 to 8, characterized in that, The process includes the following steps: adding each component into a screw extruder for melt extrusion granulation to obtain the polyester composition.
10. An application of an article formed from the polyester composition according to any one of claims 1 to 8 to improve adhesion when bonded to a polyurethane adhesive.