Modified polyurethane master batch as well as preparation method and application thereof

Abstract

The invention discloses a modified polyurethane master batch and a preparation method and application thereof, and belongs to the technical field of polymer composites.The modified polyurethane master batch is prepared from polyethersulfone resin, thermoplastic polyurethane particles, a compatibilizer and nano mica sheets through the steps that the raw materials are subjected to drying treatment and then subjected to segmented co-extrusion through a double-screw extruder, underwater pelletizing and hot air drying, and the modified polyurethane master batch is obtained; the modified polyurethane master batch successfully solves the key problems that in an existing PC / PET bonding technology, heat resistance and flowability of a hot melt adhesive are difficult to achieve at the same time, interfacial compatibility is insufficient, solvent pollution is caused and the like, breaks through the bottlenecks that a traditional adhesive is insufficient in heat resistance, poor in interfacial compatibility and the like, achieves reliable bonding which is free of solvent, resistant to high temperature and high in interface combination, and has a good application prospect. The composite material has excellent high temperature resistance and strong interface bonding force, the preparation process is simple, the energy consumption is low, the environmental pollution is avoided, the mechanical stability and aging resistance of the composite material are remarkably improved, the operation is simple and convenient, and the composite material is suitable for large-scale industrial application.

Description

Technical Field

[0001] This invention relates to a modified polyurethane masterbatch, its preparation method, and its application, belonging to the field of polymer composite materials technology. Background Technology

[0002] In modern industrial production, polycarbonate (PC) and polyethylene terephthalate (PET) are widely used in various fields such as automobiles, electronics, and packaging due to their unique performance advantages. For example, in the manufacture of automotive interiors, PC is often used as the skeleton material and PET as the skin material; in the production of electronic devices, PC is used for the casing, while PET is used as the insulating film.

[0003] However, achieving efficient and reliable bonding between these two materials with significantly different chemical structures has always been a challenging problem for the industry. Currently, hot melt adhesive technology is the main method for bonding PC and PET. While hot melt adhesives based on polyethersulfone (PES) have excellent high-temperature resistance and can meet the needs of automobiles and electronic devices in complex working environments, their excessively rigid molecular chains result in poor melt flow. During the bonding process, it is difficult to fully fill the tiny gaps at the substrate interface, affecting the bonding effect. To improve flow, the industry has tried adding viscosity-reducing agents, but this has caused new problems. The agents are prone to migrating to the bonding interface, weakening the adhesive force. On the other hand, hot melt adhesives based on thermoplastic polyurethane (TPU) have good melt flow and excellent toughness, which can ensure the bonding strength to a certain extent. However, their soft segment thermal stability is poor. Under high-temperature environments, the chain segments are prone to relaxation, leading to softening and failure of the adhesive layer, which cannot meet the requirements for long-term heat resistance.

[0004] To overcome these shortcomings, existing technologies have proposed improvement schemes such as blending modification and the addition of nanofillers. Although blending modification can combine the performance of PES and TPU to a certain extent, due to the large differences in their molecular structures and poor compatibility, phase separation is likely to occur after simple blending, which greatly reduces the bonding strength. The addition of nanofillers faces the problems of uneven dispersion and easy agglomeration, which not only fails to improve the bonding performance, but also aggravates the interface defects.

[0005] In addition, traditional solvent-based adhesives cause environmental pollution due to the volatilization of organic solvents, and residual solvents are prone to migration in humid and hot environments, forming weak boundary layers and causing interfacial delamination risks. These factors severely restrict the development of PC and PET bonding technology, making it difficult to find ideal bonding solutions in fields such as automobiles and electronics where bonding quality and durability are extremely important. Summary of the Invention

[0006] To address the issues of heat resistance versus flowability, insufficient interfacial compatibility, and solvent contamination in existing PC / PET bonding technologies, this invention provides a modified polyurethane masterbatch, its preparation method, and its application. This masterbatch achieves reliable bonding with solvent-free, high-temperature resistance, and strong interfacial adhesion through a blend of polyethersulfone (PES) and thermoplastic polyurethane (TPU).

[0007] To achieve the above objectives, one of the technical solutions of the present invention is as follows: A modified polyurethane masterbatch comprises the following raw materials in parts by weight: 30-40 parts of polyethersulfone resin, 50-60 parts of thermoplastic polyurethane particles, 8-10 parts of compatibilizer, and 3-4 parts of nano-mica sheets.

[0008] The compatibilizer is PES-g-MAH.

[0009] The present invention also provides a method for preparing the above-mentioned modified polyurethane masterbatch, the steps of which are as follows: S1. The raw materials are dried so that the moisture content of the polyethersulfone resin is <0.05% and the moisture content of the thermoplastic polyurethane particles is ≤0.1%; S2. The dried raw materials are mixed and then co-extruded in stages using a twin-screw extruder and then pelletized underwater. S3. After centrifuging and dehydrating the cut particles, dry them with hot air until the moisture content is <0.05%.

[0010] Based on the above technical solution, the present invention further limits the solution as follows: Furthermore, the drying process involves vacuum drying the polyethersulfone resin at 120°C for 4 hours, and / or drying the thermoplastic polyurethane particles at 80°C with forced air for 2 hours, and / or drying the compatibilizer and nano-mica sheets at 60°C for 1 hour.

[0011] Furthermore, the mixing speed was 50 rpm, and the mixing time was 8 minutes; Furthermore, the twin-screw extruder has a screw speed of 250 rpm, a vacuum degree of -0.08 MPa, removes volatiles, and has a zone temperature of 260°C (completely melts the rigid PES chain), a zone temperature of 240°C (triggers the reaction between MAH and the carboxyl group at the end of PET), and a zone temperature of 190°C (protects the active groups of TPU-NCO).

[0012] Furthermore, the underwater pelleting temperature is 40℃.

[0013] Furthermore, the temperature for hot air drying is 60°C.

[0014] The present invention also provides the application of the above-mentioned modified polyurethane masterbatch in the preparation of hot melt materials for bonding polycarbonate (PC) and polyethylene terephthalate (PET), especially in the fields of automotive interior (such as bonding PC skeleton to PET skin), electronic packaging (such as bonding PC shell to PET insulating film) and environmentally friendly packaging. Preferably, the hot melt material is a hot melt adhesive film.

[0015] The beneficial effects of this invention are as follows: The modified polyurethane masterbatch of this invention successfully solves the key problems in existing PC / PET bonding technology, such as the difficulty in achieving both heat resistance and flowability of hot melt adhesives, insufficient interfacial compatibility, and solvent pollution. It breaks through the bottlenecks of traditional adhesives, such as insufficient heat resistance (<120℃) and poor interfacial compatibility, and achieves reliable bonding with solvent-free, high-temperature resistance and strong interfacial bonding. It has both excellent high-temperature resistance and strong interfacial bonding force, and the preparation process is simple, energy consumption is low, environmental pollution is avoided, and the mechanical stability and aging resistance of composite materials are significantly improved. It is easy to operate and suitable for large-scale industrial applications. Attached Figure Description

[0016] Figure 1 This is a flowchart of the preparation process of the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] In the following examples, the polyethersulfone resin was purchased from Shanghai Qianli New Materials Co., Ltd.; the thermoplastic polyurethane granules were purchased from Dongguan Jixin Polymer Technology Co., Ltd.; and the compatibilizer was PES-g-MAH, purchased from Dongguan Anchen Plastics Technology Co., Ltd. The polyethersulfone (PES), maleic anhydride, acetone and initiator dicumyl peroxide (DCP) were mixed and then extruded into granules.

[0019] Example 1 Modified polyurethane masterbatch comprises the following raw materials in parts by weight: 35 parts polyethersulfone resin, 55 parts thermoplastic polyurethane granules, 8 parts compatibilizer, and 3 parts nano mica sheets.

[0020] The preparation method steps are as follows: S1. The raw materials are dried. The drying process is as follows: the polyethersulfone resin is vacuum dried at 120°C for 4 hours with a moisture content of <0.05%; the thermoplastic polyurethane particles are dried by forced air drying at 80°C for 2 hours with a moisture content of ≤0.1%; and the compatibilizer and nano mica sheets are dried at 60°C for 1 hour. S2. After mixing the dried raw materials at 50 rpm for 8 min, the mixture is co-extruded in stages using a twin-screw extruder. The screw speed is 250 rpm, the vacuum degree is -0.08 MPa, the temperature of zone 1 is 260℃, the temperature of zone 2 is 240℃, and the temperature of zone 3 is 190℃. The mixture is then placed in a 40℃ warm water bath and granulated underwater by rotating blades (particle size 3×3 mm). S3. After centrifuging and dehydrating the cut particles, dry them with hot air at 60°C until the moisture content is <0.05%.

[0021] Example 2 Modified polyurethane masterbatch comprises the following raw materials in parts by weight: 30 parts polyethersulfone resin, 60 parts thermoplastic polyurethane granules, 8 parts compatibilizer, and 4 parts nano mica sheets.

[0022] The preparation method steps are as follows: S1. The raw materials are dried. The drying process is as follows: the polyethersulfone resin is vacuum dried at 120°C for 4 hours with a moisture content of <0.05%; the thermoplastic polyurethane particles are dried by forced air drying at 80°C for 2 hours with a moisture content of ≤0.1%; and the compatibilizer and nano mica sheets are dried at 60°C for 1 hour. S2. After mixing the dried raw materials at 50 rpm for 8 min, the mixture is co-extruded in stages using a twin-screw extruder. The screw speed is 250 rpm, the vacuum degree is -0.08 MPa, the temperature of zone 1 is 260℃, the temperature of zone 2 is 240℃, and the temperature of zone 3 is 190℃. The mixture is then placed in a 40℃ warm water bath and granulated underwater by rotating blades (particle size 3×3 mm). S3. After centrifuging and dehydrating the cut particles, dry them with hot air at 60°C until the moisture content is <0.05%.

[0023] Example 3 Modified polyurethane masterbatch comprises the following raw materials in parts by weight: 40 parts polyethersulfone resin, 50 parts thermoplastic polyurethane granules, 10 parts compatibilizer, and 4 parts nano mica sheets.

[0024] The preparation method steps are as follows: S1. The raw materials are dried. The drying process is as follows: the polyethersulfone resin is vacuum dried at 120°C for 4 hours with a moisture content of <0.05%; the thermoplastic polyurethane particles are dried by forced air drying at 80°C for 2 hours with a moisture content of ≤0.1%; and the compatibilizer and nano mica sheets are dried at 60°C for 1 hour. S2. After mixing the dried raw materials at 50 rpm for 8 min, the mixture is co-extruded in stages using a twin-screw extruder. The screw speed is 250 rpm, the vacuum degree is -0.08 MPa, the temperature of zone 1 is 260℃, the temperature of zone 2 is 240℃, and the temperature of zone 3 is 190℃. The mixture is then placed in a 40℃ warm water bath and granulated underwater by rotating blades (particle size 3×3 mm). S3. After centrifuging and dehydrating the cut particles, dry them with hot air at 60°C until the moisture content is <0.05%.

[0025] Test case The modified polyurethane masterbatches prepared in Examples 1-3 above were subjected to performance testing. The testing items, methods, and results are shown in the table below:

Claims

1. A modified polyurethane masterbatch, characterized in that, The raw materials include the following parts by weight: 30-40 parts of polyethersulfone resin, 50-60 parts of thermoplastic polyurethane granules, 8-10 parts of compatibilizer, and 3-4 parts of nano mica sheets.

2. The modified polyurethane masterbatch according to claim 1, characterized in that, The compatibilizer is PES-g-MAH.

3. A method for preparing a modified polyurethane masterbatch, characterized in that, The steps are as follows: S1. The raw materials are dried so that the moisture content of the polyethersulfone resin is <0.05% and the moisture content of the thermoplastic polyurethane particles is ≤0.1%; S2. The dried raw materials are mixed and then co-extruded in stages using a twin-screw extruder and then pelletized underwater. S3. After centrifuging and dehydrating the cut particles, dry them with hot air until the moisture content is <0.05%.

4. The method for preparing the modified polyurethane masterbatch according to claim 3, characterized in that, The drying process involves vacuum drying of polyethersulfone resin at 120°C for 4 hours, and / or forced-air drying of thermoplastic polyurethane particles at 80°C for 2 hours, and / or drying of compatibilizer and nano-mica sheets at 60°C for 1 hour.

5. The method for preparing the modified polyurethane masterbatch according to claim 3, characterized in that, The mixing speed is 50 rpm and the mixing time is 8 min.

6. The method for preparing the modified polyurethane masterbatch according to claim 3, characterized in that, The twin-screw extruder has a screw speed of 250 rpm, a vacuum degree of -0.08 MPa, a zone 1 temperature of 260℃, a zone 2 temperature of 240℃, and a zone 3 temperature of 190℃.

7. The method for preparing the modified polyurethane masterbatch according to claim 3, characterized in that, The underwater pelleting temperature is 40°C.

8. The method for preparing the modified polyurethane masterbatch according to claim 3, characterized in that, The temperature for hot air drying is 60°C.

9. The application of a modified polyurethane masterbatch in the preparation of a hot melt material for bonding polycarbonate and polyethylene terephthalate.

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