Adhesive system of PBT (polybutylene terephthalate) composite material and application of adhesive system

Abstract

The invention belongs to the technical field of high polymer materials, and particularly relates to an adhesive system of a PBT composite material and application of the adhesive system. Specifically, the adhesive system of the PBT composite material comprises the PBT composite material and a rubber type adhesive, the PBT composite material comprises the following components in parts by weight: 60-80 parts of PBT, 0-40 parts of a reinforcing filler and 0.5-5 parts of a performance additive, and the performance additive is one or more of an epoxy group, an acrylate group and a thermoplastic polyester elastomer. According to the invention, the base material PBT is modified by selecting the specific modification additive and is matched with the rubber type adhesive to form the PBT adhesive system, and when the coating material and the adhesive system are matched for use, a synergistic effect is generated; the bonding effect of the coating material is far better than that generated by single modification of a base material or a coating material, single use of an adhesive and common use of a modified material and the adhesive, and the coating material can be prevented from falling off.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and particularly relates to an adhesive system of a PBT composite material and application thereof. Background Art

[0002] Polybutylene terephthalate (PBT) boasts excellent mechanical, heat-resistant, and electrical properties, and is widely used in the electronics, electrical, and automotive industries. Based on practical application requirements, PBT materials are often coated using an encapsulation process to enhance the grip and comfort of PBT products, or to increase functionality and safety.

[0003] Overmolding involves using PBT as a base material and then coating specific areas or the entire surface of the PBT substrate with another material through secondary injection molding or other processes. Overmolding is a commonly used overmolding process that involves multiple injection molding processes using different mold cavities. The first material undergoes a typical single injection molding process, and the part is then fed into a different mold cavity for the second injection molding process. The first injected material is called the base material, and the second injected material is called the overmolding material.

[0004] Due to the high crystallinity and high melting point of PBT, the bonding strength between PBT and the coating material is low, the adhesion is poor, and it is easy to peel off, making it difficult for the coating material to truly adhere to PBT. For this reason, the above-mentioned shortcomings limit the application of PBT materials in rubber-coated products.

[0005] In the prior art, there are methods of modifying PBT materials or modifying coating materials to improve the bonding strength between PBT and the coating material. However, the improvement in bonding strength is limited and cannot meet various requirements in practical applications.

[0006] Therefore, the problem of improving the bonding strength between PBT and the coating material needs to be solved urgently. Summary of the Invention

[0007] In order to overcome the problem of poor bonding strength and easy falling off between the existing PBT as a base material and the coating material, the purpose of the present invention is to provide an adhesive system for PBT composite materials and its application, which is specifically achieved through the following technical solutions: A PBT composite adhesive system, characterized in that the adhesive system comprises a PBT composite material and a rubber adhesive, wherein the PBT composite material comprises, by weight, 60 to 80 parts of PBT, 0 to 40 parts of reinforcing filler, and 0.5 to 5 parts of a modifying agent. The modification aid is one or more of epoxy groups, acrylate groups and thermoplastic polyester elastomers.

[0008] Optionally, the rubber-type adhesive includes a base of one or both of chloroprene rubber and nitrile rubber.

[0009] Optionally, the modification aid contains one or more of epoxy resin, glycidyl methacrylate grafted polyolefin elastomer, and thermoplastic polyester elastomer.

[0010] Optionally, the PBT composite material includes, by weight, 60-80 parts of PBT, 20-40 parts of reinforcing filler, and 0.5-1 part of epoxy resin.

[0011] Optionally, the PBT composite material comprises, by weight, 60-80 parts of PBT, 20-40 parts of reinforcing filler, and 1-5 parts of glycidyl methacrylate grafted polyolefin elastomer.

[0012] Optionally, the PBT composite material includes, by weight, 60-80 parts of PBT, 20-40 parts of reinforcing filler, and 1-5 parts of thermoplastic polyester elastomer.

[0013] Optionally, the reinforcing filler is glass fiber.

[0014] The present application also provides an application of an adhesive system for a PBT composite material, including the adhesive system for a PBT composite material described in any one of the above items, wherein the PBT composite material as a substrate is bonded to a coating material through an adhesive through a coating process.

[0015] Optionally, the coating material includes one or more of thermoplastic vulcanized rubber, nitrile rubber, fluororubber, chloroprene rubber, acrylic rubber, polyurethane rubber, and fluorosilicone rubber.

[0016] Optionally, the encapsulation process includes a secondary injection molding process.

[0017] This application modifies the base material PBT by selecting a specific modifying agent and uses it in combination with a rubber-type adhesive to form a PBT adhesive system. When the coating material and the adhesive system are used in combination with each other, a synergistic effect is produced, and the bonding effect far exceeds the bonding effect produced by the single modification of the base material or the coating material, the single use of the adhesive, and the combined use of ordinary modified materials and adhesives, and is more conducive to preventing the coating material from falling off. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a picture of the test sample of the embodiment. DETAILED DESCRIPTION

[0019] The specific implementation methods of the present application are described in detail below through examples, but the specific implementation of the present application does not limit the technical solution of the present application. Any non-substantial changes such as replacing common technical solutions in the field with the technical solutions described in the examples of the present application are within the scope of protection of the present application.

[0020] It should also be noted that adhesives can be classified into organic adhesives and inorganic adhesives according to the different main materials, among which organic adhesives are further divided into natural adhesives and synthetic adhesives, and synthetic adhesives include thermosetting resin adhesives, thermoplastic resin adhesives, rubber adhesives, and mixed adhesives; in addition, nitrile rubber has excellent oil resistance, high elasticity and damping properties, and is often coated on the surface of PBT substrate as a coating layer. It is widely used in seals, electronic connector protective covers and industrial shock-absorbing components and other scenarios; finally, secondary injection molding technology is a commonly used encapsulation process in the actual production process. In actual applications, for some simple parts, of course, other methods such as manual coating can be used for encapsulation. The use of other composite materials and adhesives will no longer be listed one by one. Those skilled in the art know how to encapsulate the substrate with adhesives, and they can choose different processes according to actual needs.

[0021] 1. The raw materials used in each embodiment and comparative example are as follows PBT resin: commercially available brand MY08, purchased from Zhejiang Meiyuan New Materials Co., Ltd. Glass fiber: commercially available brand ECS10-03-534H, purchased from China Jushi Co., Ltd. Epoxy resin: commercially available brand EPON Resin 1009F, purchased from Hanson, USA; Glycidyl methacrylate grafted polyolefin elastomer (POE-g-GMA): commercially available brand SOG-03, purchased from Jiayirong Polymer (Shanghai) Co., Ltd. Thermoplastic polyester elastomer (TPEE): commercially available brand TH3040, purchased from Xinjiang Lanshan Tunhe Polyester Co., Ltd. Rubber adhesive: commercially available brand Chemlock 205, purchased from LORD Corporation, USA; Thermoplastic resin adhesive: commercially available brand SPS-2700A, purchased from Haoyi New Materials Technology Co., Ltd. Nitrile butadiene rubber (NBR): commercially available brand NBR1704, purchased from Nanjing Chunnan Rubber and Plastic Products Co., Ltd. Neoprene (CR): commercially available brand NJZY0904, purchased from Nanjing Zhengyang Rubber & Plastic Co., Ltd. Acrylonitrile-butadiene-styrene copolymer ABS: commercially available brand PA777B, purchased from Chimei Chemical; 2. Test methods and performance standards are as follows Test method: PBT, glass fiber and modifying additives weighed by weight are placed in a high-speed mixer, mixed for 2 to 5 minutes, discharged, and then extruded into granules using a twin-screw extruder.

[0022] The PBT composite material is made into a half dumbbell-shaped specimen through injection molding or molding, and the adhesive is evenly applied on one side of one end of the specimen, ensuring that the application range is greater than or equal to 30×30mm, and cured at 80℃ for 30min; at the same time, the coating material is made into a 1.5mm thick 30×30mm sample, and the two sides of the coating material are respectively in contact with the side of the PBT specimen coated with the adhesive, and cured at 200℃ for 30min under a pressure of 980N.

[0023] During the test, the upper and lower fixtures of the universal testing machine clamped the ends of the two PBT composite material specimens that were not coated with adhesive, and measured and recorded them.

[0024] Performance standard: Measure and record the tensile force during the peeling process. The maximum tensile force is recorded in the following examples and comparative examples. The greater the maximum tensile force, the better the encapsulation effect and the higher the bonding strength.

[0025] 3. The examples and comparative examples are shown in Table 1 and Table 2. Table 1: Adhesive systems of PBT composite materials of Examples 1 to 9 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 PBT 70 70 70 60 80 70 70 100 70 fiberglass 30 30 30 40 20 30 30 30 epoxy resin 0.5 3 5 3 3 3 3 POE-g-GMA 3 TPEE 3 ABS adhesive Chemlock 205 Chemlock 205 Chemlock 205 Chemlock 205 Chemlock 205 Chemlock 205 Chemlock 205 Chemlock 205 Chemlock 205 Coating material NBR NBR NBR NBR NBR NBR NBR NBR CR Maximum tensile force (N) 309.7 333.8 308.5 314.2 334.4 296.9 299.2 340.5 321.8 Table 2: Adhesive systems of PBT composite materials of Comparative Examples 1 to 7 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 PBT 70 70 70 70 70 70 70 fiberglass 30 30 30 30 30 30 30 epoxy resin 3 3 POE-g-GMA 3 TPEE 3 ABS 3 adhesive Chemlock 205 Chemlock 205 SPS-2700A Coating material NBR NBR NBR NBR NBR NBR NBR Maximum tensile force (N) 202.7 138.5 117.4 126.9 163.4 247.2 94.5 After extensive experiments, the applicant unexpectedly discovered that modifying PBT material with a specific modifying agent and then using it in combination with a rubber-type adhesive can produce a synergistic effect, which can greatly increase the maximum tensile force, that is, the bonding strength, between PBT and the coating material.

[0026] Examples 1 to 3 show that when epoxy resin is used to modify PBT, the higher the epoxy resin content, the greater the maximum tensile strength is not necessarily the case. The synergistic effect of the epoxy resin and the adhesive is better within a specific range of epoxy resin content.

[0027] Examples 4 and 8 show that although the content of the PBT substrate and glass fiber will have a certain impact on the bond strength, the main factor affecting the bond strength between the materials is the synergistic effect between the PBT modification additive and the adhesive.

[0028] Comparative Example 1 shows that if PBT is not modified and the PBT and the covering material are only bonded with an adhesive, the maximum tensile force obtained is far different from the result in the embodiment.

[0029] Comparative Examples 2 to 4 show that if the PBT material is modified only by epoxy resin, glycidyl methacrylate grafted polyolefin elastomer, or thermoplastic polyester elastomer, its bonding strength is far from reaching the level of synergistic effect with the adhesive.

[0030] Comparative Example 5 shows that if PBT is modified by ABS and then used together with an adhesive, satisfactory bonding strength results cannot be achieved.

[0031] Comparative Example 6 shows that epoxy resin and other types of adhesives do not have a synergistic effect. Although the maximum tensile force obtained is higher than that of modifying PBT alone or using only one adhesive, the value still does not reach the expected effect.

[0032] Comparative Example 7 is used to illustrate the maximum tensile force value obtained when the PBT material is not modified and no adhesive is used, which indirectly confirms that epoxy resin, glycidyl methacrylate grafted polyolefin elastomer, and thermoplastic polyester elastomer can synergize with rubber-type adhesives.

Claims

1. An adhesive system for PBT composite materials, characterized in that: The adhesive system includes a PBT composite material and a rubber adhesive. The PBT composite material includes 60 to 80 parts of PBT, 0 to 40 parts of reinforcing filler, and 0.5 to 5 parts of modifying additives, in parts by weight. The modification aid is one or more of epoxy groups, acrylate groups and thermoplastic polyester elastomers.

2. The adhesive system of the PBT composite material according to claim 1, characterized in that: The rubber-type adhesive comprises a base of one or both of chloroprene rubber and nitrile rubber.

3. The adhesive system of the PBT composite material according to claim 1, characterized in that: The modification auxiliary agent contains one or more of epoxy resin, glycidyl methacrylate grafted polyolefin elastomer, and thermoplastic polyester elastomer.

4. The adhesive system of the PBT composite material according to claim 1, characterized in that: The PBT composite material comprises, by weight, 60-80 parts of PBT, 20-40 parts of reinforcing filler, and 2-4 parts of epoxy resin.

5. The adhesive system of PBT composite material according to claim 1, characterized in that: The PBT composite material comprises, by weight, 60-80 parts of PBT, 20-40 parts of reinforcing filler, and 1-5 parts of glycidyl methacrylate grafted polyolefin elastomer.

6. The adhesive system of PBT composite material according to claim 1, characterized in that: The PBT composite material comprises, by weight, 60-80 parts of PBT, 20-40 parts of reinforcing filler, and 1-5 parts of thermoplastic polyester elastomer.

7. The adhesive system of the PBT composite material according to claim 1, characterized in that: The reinforcing filler is glass fiber.

8. Application of an adhesive system for PBT composite materials, characterized in that: An adhesive system comprising the PBT composite material according to any one of claims 1 to 7, wherein the PBT composite material as a substrate is bonded to a coating material through an adhesive through a coating process.

9. The use of the adhesive system of the PBT composite material according to claim 8, characterized in that: The coating material includes one or more of thermoplastic vulcanized rubber, nitrile rubber, fluororubber, chloroprene rubber, acrylic rubber, polyurethane rubber, and fluorosilicone rubber.

10. The use of the adhesive system of PBT composite material according to claim 8, characterized in that: The encapsulation process includes a secondary injection molding process.

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