Antistatic material for wafer loader and preparation method thereof

Abstract

The invention discloses an antistatic material for a wafer loader and a preparation method of the antistatic material, and belongs to the technical field of semiconductor equipment materials. The antistatic material for the wafer loader is prepared from the following components in parts by weight: 100 to 120 parts of polyether-ether-ketone, 10 to 15 parts of polysulfonic acid modified poly (3, 4-ethylenedioxythiophene), 6 to 10 parts of polyether ester amide, 3 to 5 parts of lubricant, 2 to 3 parts of modifier and 0.5 to 1 part of conductive filler. By limiting the components of the antistatic material, the obtained material has low resistivity, can prevent electrostatic damage and ensure that the performance of the antistatic material is not influenced by acid-base and high-temperature conditions, and is suitable for various working environments in a semiconductor manufacturing process.

Description

Technical Field

[0001] This application relates to an antistatic material for wafer carriers and its preparation method, belonging to the field of semiconductor equipment materials technology. Background Technology

[0002] In the context of the rapid development of integrated circuits, as wafer feature sizes continue to shrink, wafer cleaning standards are also gradually improving. Single-wafer cleaning machines are being used more widely due to their high precision and low contamination characteristics. Single-wafer cleaning machines are crucial equipment in semiconductor wet processes, involving the use of chemical solutions, including strong acids, strong alkalis, and organic solvents. Therefore, the wafer clamping device must have excellent corrosion resistance. Polyetheretherketone (PEEK), as a high-performance engineering plastic, is widely used in aerospace, automotive manufacturing, and electronics industries due to its excellent mechanical properties, chemical resistance, heat resistance, and abrasion resistance.

[0003] However, polyetheretherketone (PEEK) itself has a high surface resistivity. During the cleaning process, due to the high-speed rotation of the wafer, various surface charges can be generated between the equipment and the wafer. These charges can damage the physical structure and cause surface defects on the wafer through electrostatic discharge. Therefore, the wafer support structure not only needs to have good corrosion resistance but also a certain degree of conductivity.

[0004] In the prior art, conductive fillers are used to improve the conductivity of polyetheretherketone (PEEK). However, conductive fillers usually have problems such as uneven distribution, easy precipitation, and poor color, which result in limited antistatic properties. They also have problems with poor interfacial bonding with PEEK materials, which leads to a decline in the performance of the material. Summary of the Invention

[0005] To address the aforementioned issues, this application proposes an antistatic material for wafer carriers and its preparation method. By defining the material composition of the wafer carrier, the resulting wafer carrier material possesses excellent electrical conductivity, can prevent electrostatic damage, and ensures the corrosion resistance and mechanical properties of the wafer carrier.

[0006] According to one aspect of this application, an antistatic material for a wafer carrier is provided, comprising, by weight, the following components: 100-120 parts of polyetheretherketone, 10-15 parts of polysulfonic acid-modified poly3,4-ethylenedioxythiophene, 6-10 parts of polyether ester amide, 3-5 parts of lubricant, 2-3 parts of modifier, and 0.5-1 parts of conductive filler.

[0007] This solution improves the conductivity of polyetheretherketone (PEEK) by adding two flexible conductive agents to the antistatic material, avoiding interfacial separation issues caused by excessive particulate conductive filler while maintaining the mechanical properties of PEEK. The addition of polysulfonic acid-modified poly3,4-ethylenedioxythiophene (PED-3,4-ethylenedioxythiophene) enhances its conductivity by forming a conductive cross-linked network and provides better thermal stability, making it suitable for semiconductor wet process manufacturing. Polyether ester amide is also a conductive polymer; its addition utilizes the polyamide segments as hard segments. It acts as a physical cross-linking point, preventing polymer molecular chain slippage and viscous flow, and imparting thermoplasticity and elasticity to the polymer; the polyether segment, as a soft segment, gives the polymer softness and extensibility. The abundant polar ether and amide bonds in its molecule can bind water molecules present in the air or during the cleaning process, accelerate charge dissipation, and improve the antistatic ability of the material. Moreover, due to the similarity of its own functional groups with polyether ether ketone, the two polymers have good compatibility; in addition, the ether bonds in polyether ester amide have good compatibility with polyether ether ketone, while its amide groups are electrostatically bound to poly3,4-ethylenedioxythiophene, acting as a bridge between poly3,4-ethylenedioxythiophene and polyether ether ketone to achieve good bonding between the two.

[0008] Optionally, the polysulfonic acid includes one or more of polyaniline sulfonic acid, pyrene tetrasulfonic acid, pyrene disulfonic acid, and pyrene trisulfonic acid.

[0009] The poly(3,4-ethylenedioxythiophene) can electrostatically combine with polysulfonic acids to form a conductive network, thus exhibiting better charge conduction capabilities.

[0010] Specifically, the preparation method of the polysulfonic acid-modified poly3,4-ethylenedioxythiophene is as follows: 1a. After fully dissolving polysulfonic acid in an aqueous ethanol solution, add 3,4-ethylenedioxythiophene monomer to obtain a mixed solution, wherein the molar ratio of polysulfonic acid to 3,4-ethylenedioxythiophene monomer is (0.3-0.5):1; 1b. Ferric p-toluenesulfonate solution was added dropwise to the mixed solution, and the reaction was carried out at 10-15℃ for 20-24 h. After purification, polysulfonic acid-modified poly(3,4-ethylenedioxythiophene) was obtained.

[0011] Optionally, the modifier is a sulfonated aromatic polymer, which is one of sulfonated polyether ether ketone, sulfonated polystyrene, and sulfonated polybenzimidazole.

[0012] Aromatic polymers can improve the overall mechanical properties and thermal stability of antistatic materials, making them suitable for high-temperature environments. Due to their phenyl groups, they have good compatibility with polyether ether ketone (PEEK). After sulfonation, aromatic polymers can achieve good bonding with PEEK through hydrogen bonding and dipole moment. The presence of sulfonic acid groups can form ion-conducting channels in the substrate, further improving the conductivity of the material.

[0013] Specifically, the sulfonation process of the aromatic polymer is as follows: 2a. Halogenation: At 0-5℃, the aromatic polymer is dissolved in dichloroethane and Br2 is added, such that the molar ratio of Br2 to the aromatic ring in the aromatic polymer is (0.3-0.5):1. After reacting for 0.5-1h, the halogenated aromatic polymer is obtained by separation. 2b. Sulfonation: Under nitrogen protection at 80-90℃, the halogenated aromatic polymer is dissolved in DMF, and sodium sulfite and TBAB are added to make the molar ratio of sodium sulfite to the aromatic ring in the aromatic polymer (0.4-0.7):1. After the reaction is completed for 6-8 hours, the system is rapidly cooled and the reaction system is neutralized to pH 6-7. The system is then dialyzed and dried to obtain the sulfonated aromatic polymer.

[0014] Optionally, the polyether ester amide is obtained by reacting polyether segments and polyamide prepolymer, wherein the molar ratio of polyether segments to polyamide prepolymer in the polyether ester amide is (1.2-2):1.

[0015] Optionally, the polyether segment is a polymer of 1,2-epoxybutane and ethylene glycol, with a ratio of 1:(1-4).

[0016] The polyether segment in polyether ester amide is a polymer of 1,2-epoxybutane and ethylene glycol in a certain proportion, which can balance the antistatic properties and hydrophobicity of polyether ester amide and inhibit problems such as swelling caused by excessive moisture absorption of the material.

[0017] Specifically, the preparation method of the 1,2-epoxybutyl polyether and ethylene glycol block copolyether is as follows: 3a. DMC, acetic acid, and Beta molecular sieve were added to deionized water and stirred and heated to 80°C. Potassium cobalt cyanide solution was slowly added, and the mixture was cooled, centrifuged, and pulverized to obtain the molecular sieve-supported DCM catalyst. 3b. The DCM catalyst, chain transfer agent, ethylene glycol and 1,2-epoxybutane supported on molecular sieve are heated to 110-120°C, sealed and stirred at 500 rpm for 4-6 hours. The product is then separated to obtain the copolyether.

[0018] Optionally, the polyether segment is 1,2-epoxybutyl polyether, and the polyamide prepolymer is diacid-terminated PA6; the molecular weight of the polyether segment is 1200-1400.

[0019] The higher the weight-average molecular weight of the polyether segment, the more conducive it is to the formation of conductive networks or channels, thereby accelerating the leakage of static charge and increasing conductivity. However, the higher the weight-average molecular weight of the flexible polyether segment, the lower the overall mechanical strength of the material. Therefore, the weight-average molecular weight of the polyether segment needs to be limited by the conditions for its preparation.

[0020] Specifically, the method for preparing the polyamide prepolymer is as follows: caprolactam is reacted with dicarboxylic acid and deionized water at 240-260℃ in an inert gas atmosphere of 0.5-0.7MPa for 2-4 hours to remove impurities and obtain the polyamide prepolymer.

[0021] Specifically, the dicarboxylic acid includes one or more of oxalic acid, adipic acid, sebacic acid, and octanoic acid.

[0022] Optionally, the conductive filler is one or more selected from carbon black, carbon nanotubes, black phosphorus, acetylene black, and graphene. The lubricant is polytetrafluoroethylene.

[0023] The lubricating effect of polytetrafluoroethylene (PTFE) effectively reduces wear in stress concentration areas, delays the propagation of fatigue cracks, and improves the durability of the material. In addition, the fluorine atoms in PTFE have high electronegativity or strong electron-withdrawing ability, which can attract electrons and increase the charge density on the material surface, thereby further improving conductivity.

[0024] Optionally, the conductive filler is modified by maleic anhydride grafting.

[0025] After the conductive filler is grafted with maleic anhydride, the strong interaction between the anhydride groups in the maleic anhydride and the ketone and ether bonds in polyether ether ketone (PEEK) enables it to bond well with the PEEK substrate, thereby improving the distribution of the conductive filler in PEEK.

[0026] Specifically, the process of modifying the maleic anhydride conductive filler is as follows: 4a. The conductive filler, maleic anhydride, DCP and polyolefin carrier are melt-blended in a twin-screw extruder at 180-200℃ and 200 rpm and held for 3-5 minutes. Nitrogen protection is used during the reaction. 4b. Dissolve the extrudate in xylene at 130°C and centrifuge to obtain maleic anhydride-grafted conductive filler.

[0027] According to another aspect of this application, a method for preparing an antistatic material for a wafer carrier is provided, comprising the following steps: S1. Polysulfonic acid-modified poly(3,4-ethylenedioxythiophene) and polyether ester amide were prepared; S2. Thoroughly mix the obtained polyether ester amide, polyether ether ketone and lubricant to obtain a mixture; S3. Add polysulfonic acid-modified poly3,4-ethylenedioxythiophene, a modifier, and a conductive filler to the mixture described in step S2, mix well, and then perform melt extrusion granulation to obtain antistatic material particles for wafer carriers.

[0028] Specifically, in step S3, the melting temperature is 350~400℃.

[0029] The beneficial effects that this application may produce include, but are not limited to: 1. The antistatic material for wafer carriers provided in this application, by setting the types and components of the antistatic material, consists of polysulfonic acid-modified poly(3,4-ethylenedioxythiophene) and polyether ester amide forming a conductive network, combined with conductive fillers, so that the material has good conductivity. At the same time, it also takes into account the overall mechanical properties, heat resistance, and corrosion resistance of the material, and can meet the production requirements of the semiconductor manufacturing industry, especially in the wafer carrier process.

[0030] 2. The antistatic material for wafer carriers provided in this application improves the conductivity of the material by modifying poly(3,4-ethylenedioxythiophene) with polysulfonic acid, transforming the linear conductive polymer into a conductive network. Furthermore, the intertwining of poly(3,4-ethylenedioxythiophene) with conductive polyether ester amide to form a three-dimensional conductive structure further enhances the overall conductivity of the antistatic material. Additionally, the conductive materials used in this solution exhibit excellent bonding properties, ensuring the mechanical properties of the wafer carrier.

[0031] 3. The antistatic material for wafer carriers provided in this application, by limiting the ratio of polyether segments and polyamide prepolymer, the ratio of flexible segments and rigid segments, and the ratio of hydrophilic segments and hydrophobic segments in the polyether ester amide, enables the material to balance the relationship between conductivity and mechanical properties, thereby improving the practicality of the material in production. Detailed Implementation

[0032] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of skill in the art. The reagents and raw materials used in this invention are readily available through conventional means, and unless otherwise specified, they shall be used in accordance with conventional methods in the art or as per the product instructions. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to the methods of this invention. The preferred embodiments and materials described in this patent are for illustrative purposes only.

[0034] The preparation method of polysulfonic acid modified poly3,4-ethylenedioxythiophene in the following examples is as follows: 1a. After fully dissolving polysulfonic acid in an aqueous ethanol solution, 3,4-ethylenedioxythiophene monomer is added to obtain a mixed solution, wherein the molar ratio of polysulfonic acid to 3,4-ethylenedioxythiophene monomer is 0.4:1; 1b. Ferric p-toluenesulfonate solution was added dropwise to the mixed solution, and after reacting at 10°C for 22 h, the polysulfonic acid-modified poly(3,4-ethylenedioxythiophene) was purified.

[0035] The preparation method of sulfonated aromatic polymers is as follows: 2a. Halogenation: At 0°C, the aromatic polymer is dissolved in dichloroethane and Br2 is added, such that the molar ratio of Br2 to the aromatic ring in the aromatic polymer is 0.3:1. After reacting for 0.5 h, the halogenated aromatic polymer is obtained by separation. 2b. Sulfonation: Under nitrogen protection at 80°C, the halogenated aromatic polymer is dissolved in DMF, sodium sulfite and TBAB are added, and the molar ratio of sodium sulfite to aromatic rings in the aromatic polymer is 0.4:1. After reacting for 6-8 hours, the reaction is rapidly cooled and the reaction system is neutralized to pH 6-7. The reaction is then dialyzed and dried to obtain the sulfonated aromatic polymer.

[0036] The preparation method of 1,2-epoxybutyl polyether and ethylene glycol block copolyether is as follows: 3a. DMC, acetic acid, and Beta molecular sieve were added to deionized water and stirred and heated to 80°C. Potassium cobalt cyanide solution was slowly added, and the mixture was cooled, centrifuged, and pulverized to obtain the molecular sieve-supported DCM catalyst. 3b. The DCM catalyst, chain transfer agent, ethylene glycol and 1,2-epoxybutane supported on the molecular sieve were heated to 110°C, sealed and stirred at 500 rpm for 5 h, and the product was separated to obtain the copolyether.

[0037] The preparation method of polyamide prepolymer is as follows: Caprolactam was reacted with dicarboxylic acid and deionized water at 250°C in an inert gas atmosphere of 0.6 MPa for 3 hours to remove impurities and obtain a polyamide prepolymer.

[0038] The process of modifying conductive fillers with maleic anhydride is as follows: 4a. The conductive filler, maleic anhydride, DCP and polyolefin carrier are melt-blended in a twin-screw extruder at 180-200℃ and 200 rpm and held for 3-5 minutes. The reaction process is protected by nitrogen. 4b. Dissolve the extrudate in xylene at 130°C and centrifuge to obtain maleic anhydride-grafted conductive filler.

[0039] Example 1 The preparation method of the antistatic material for wafer carriers includes the following steps: S1. The synthesized polyamide prepolymer and polyether melt were first reacted at 260℃ under inert gas protection for 1.5h, then heated to 300℃ and vacuumed at 1000Pa for 2h. After the reaction was completed, the product was cooled and collected to obtain polyether ester amide. S2. Thoroughly mix the obtained polyether ester amide, polyether ether ketone and lubricant to obtain a mixture; S3. Add polysulfonic acid-modified poly3,4-ethylenedioxythiophene, a modifier, and a conductive filler to the mixture described in step S2, mix well, and then perform melt extrusion granulation to obtain antistatic material particles for wafer carriers.

[0040] S3. Add polysulfonic acid-modified poly3,4-ethylenedioxythiophene, modifier and conductive filler to the mixture described in step S2, mix well and then melt extrude and granulate at 400°C to obtain antistatic material particles 1# for wafer carriers. 120 parts of polyetheretherketone, 15 parts of poly(3,4-ethylenedioxythiophene) modified with polyaniline sulfonic acid, 10 parts of polyether ester amide, 5 parts of polytetrafluoroethylene, 3 parts of polystyrene, and 1 part of acetylene black. In the copolyether segment of the polyether ester amide, the ratio of 1,2-epoxybutane to ethylene glycol is 1:1; The molar ratio of the coether segment to the polyamide prepolymer is 2:1.

[0041] Example 2 The preparation method of the antistatic material for wafer carriers includes the following steps: S1. The synthesized polyamide prepolymer and polyether melt were first reacted at 240℃ under inert gas protection for 2h, then heated to 280℃ and vacuumed at 500Pa for 1.5h. After the reaction was completed, the product was collected by cooling to obtain polyether ester amide. S2. Thoroughly mix the obtained polyether ester amide, polyether ether ketone and lubricant to obtain a mixture; S3. Add polysulfonic acid-modified poly3,4-ethylenedioxythiophene, a modifier, and a conductive filler to the mixture described in step S2, mix well, and then perform melt extrusion granulation to obtain antistatic material particles for wafer carriers.

[0042] S3. Add polysulfonic acid-modified poly3,4-ethylenedioxythiophene, modifier and conductive filler to the mixture described in step S2, mix well and then melt extrude and granulate at 350°C to obtain antistatic material particles 2# for wafer carriers. 100 parts of polyetheretherketone, 10 parts of pyrene disulfonic acid modified poly3,4-ethylenedioxythiophene, 6 parts of polyether ester amide, 3 parts of polytetrafluoroethylene, 2 parts of polybenzimidazole, and 0.5 parts of carbon nanotubes. In the copolyether segment of the polyether ester amide, the ratio of 1,2-epoxybutane to ethylene glycol is 1:4; The molar ratio of the coether segment to the polyamide prepolymer is 1.2:1.

[0043] Example 3 The preparation method of the antistatic material for wafer carriers includes the following steps: S1. The synthesized polyamide prepolymer and polyether melt were first reacted at 250°C under inert gas protection for 1.8 h, then heated to 290°C and vacuumed at 750 Pa for 1.5 h. After the reaction was completed, the product was collected by cooling to obtain polyether ester amide. S2. Thoroughly mix the obtained polyether ester amide, polyether ether ketone and lubricant to obtain a mixture; S3. Add polysulfonic acid-modified poly3,4-ethylenedioxythiophene, a modifier, and a conductive filler to the mixture described in step S2. After mixing, perform melt extrusion granulation at 390°C to obtain antistatic material particles for wafer carriers.

[0044] S3. Add polysulfonic acid-modified poly3,4-ethylenedioxythiophene, modifier and conductive filler to the mixture described in step S2, mix well and then melt extrude and granulate to obtain antistatic material particles 3# for wafer carriers. 110 parts of polyetheretherketone, 12 parts of poly(3,4-ethylenedioxythiophene) modified with pyrenetetroxide, 8 parts of polyether ester amide, 4 parts of polytetrafluoroethylene, 3 parts of sulfonated polystyrene, and 1 part of black phosphorus. In the copolyether segment of the polyether ester amide, the ratio of 1,2-epoxybutane to ethylene glycol is 1:2; The molar ratio of the coether segment to the polyamide prepolymer is 1.6:1.

[0045] Example 4 The difference from Example 3 is that the ratio of the copolyether to the amide segment of the polyether ester amide is 2:1, and antistatic material 4# for wafer carrier is prepared.

[0046] Example 5 The difference from Example 3 is that the weight-average molecular weight of the polyether segment is 2000, and an antistatic material 5# for wafer carrier is prepared.

[0047] Example 6 The difference from Example 3 is that in the copolyether segment of the polyether ester amide, the ratio of 1,2-epoxybutane to ethylene glycol is 2:1, thus preparing antistatic material 6# for wafer carriers.

[0048] Example 7 The difference from Example 3 is that the conductive filler is maleic anhydride-grafted carbon nanotubes, and antistatic material 7# for wafer carrier is prepared.

[0049] Comparative Example 1 The difference from Example 3 is that no modifier is added to the copolyether segment of the polyether ester amide, and an antistatic material D1# for wafer carrier is prepared.

[0050] Comparative Example 2 The difference from Example 3 is that no polyether ester amide was added and the number of carbon nanotubes was increased to 6 parts to prepare an antistatic material D2# for wafer carriers.

[0051] Comparative Example 3 The difference from Example 3 is that the poly(3,4-ethylenedioxythiophene) was not modified with pyrene tetrasulfonic acid, and the resulting material was an antistatic material D3# for wafer carriers.

[0052] Experimental Example Test specimens were prepared from the materials provided in the application examples and comparative examples according to the standards and their performance was tested. The tensile strength was tested according to the standard GB-T1040-1992, the flexural strength was tested according to the standard ASTM D790, and the volume resistivity was tested according to GBT-1410-2006. The test results are shown in Table 1.

[0053] Table 1

[0054] The test pieces were immersed in 18% hydrochloric acid solution at 80℃ for 25 minutes, cleaned, and then tested according to the above standards. The test results are shown in Table 2.

[0055] Table 2

[0056] As can be seen from the above data, the polyetheretherketone material obtained by this method has high mechanical properties, low resistivity and excellent temperature and corrosion resistance, which can avoid electrostatic damage to the wafer placement device made of polyetheretherketone material during operation.

[0057] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0058] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. An antistatic material for wafer carriers, characterized in that, The antistatic material for the wafer carrier, by weight, comprises the following components: 100-120 parts of polyetheretherketone, 10-15 parts of polysulfonic acid-modified poly3,4-ethylenedioxythiophene, 6-10 parts of polyether ester amide, 3-5 parts of lubricant, 2-3 parts of modifier, and 0.5-1 parts of conductive filler.

2. The antistatic material for wafer carriers according to claim 1, characterized in that, The polysulfonic acid includes one or more of polyaniline sulfonic acid, pyrene tetrasulfonic acid, pyrene disulfonic acid, and pyrene trisulfonic acid.

3. The antistatic material for wafer carriers according to claim 1, characterized in that, The modifier is a sulfonated aromatic polymer, which is one of sulfonated polyether ether ketone, sulfonated polystyrene, and sulfonated polybenzimidazole.

4. The antistatic material for wafer carriers according to claim 1, characterized in that, The polyether ester amide is obtained by reacting polyether segments and polyamide prepolymer, and the molar ratio of polyether segments to polyamide prepolymer in the polyether ester amide is (1.2-2):

1.

5. The antistatic material for wafer carriers according to claim 1, characterized in that, The polyether segment is a polymer of 1,2-epoxybutane and ethylene glycol, with a ratio of 1:(1-4).

6. The antistatic material for wafer carriers according to claim 1, characterized in that, The polyether segment is 1,2-epoxybutyl polyether, and the polyamide prepolymer is diacid-terminated PA6; the molecular weight of the polyether segment is 1200-1400.

7. The antistatic material for wafer carriers according to claim 1, characterized in that, The conductive filler is one or more of carbon black, carbon nanotubes, black phosphorus, acetylene black, and graphene. The lubricant is polytetrafluoroethylene.

8. The antistatic material for wafer carriers according to claim 1, characterized in that, The conductive filler is modified by maleic anhydride grafting.

9. The method for preparing the antistatic material for wafer carriers according to claims 1-8, characterized in that, Includes the following steps: S1. Polysulfonic acid-modified poly(3,4-ethylenedioxythiophene) and polyether ester amide were prepared; S2. Thoroughly mix the obtained polyether ester amide, polyether ether ketone and lubricant to obtain a mixture; S3. Add polysulfonic acid-modified poly3,4-ethylenedioxythiophene, a modifier, and a conductive filler to the mixture described in step S2, mix well, and then perform melt extrusion granulation to obtain antistatic material particles for wafer carriers.

10. The method for preparing the antistatic material for a wafer carrier according to claim 9, characterized in that, The preparation process of the polyether ester amide is as follows: the synthesized polyamide prepolymer and polyether melt are reacted at 240-260℃ under inert gas protection for 1.5-2h, then the temperature is raised to 280-300℃ and a vacuum of 500-1000Pa is applied for 1.5-2h. After the reaction is completed, the product is cooled and collected to obtain the polyether ester amide.

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