Preparation process of high-performance phenoxy resin

Abstract

This invention discloses a preparation process for high-performance phenoxy resin, belonging to the field of phenoxy resin preparation technology. The preparation process of the phenoxy resin includes the following steps: (1) adding an epoxide compound, a chain extender, and NMP to a reaction vessel and stirring, heating, adding a catalyst under nitrogen protection, and heating to obtain a resin solution; (2) extruding the resin solution through an extruder and then pelletizing it into strips, controlling the pelletizing temperature at 50-80℃; (3) freezing the particles with liquid nitrogen and then pulverizing them to obtain a powder; (4) blowing the powder into a fluidized bed evaporator through high-pressure, high-temperature nitrogen gas, condensing and recovering NMP, collecting the high-temperature viscous material, extruding it through a twin-screw extruder, and then pelletizing it into strips to obtain phenoxy resin particles. The phenoxy resin prepared by this invention has a high molecular weight and tensile strength, has important application value, and can achieve controllable synthesis of molecular weight by changing the reaction time.

Description

Technical Field

[0001] This invention relates to the field of phenoxy resin preparation technology, and more specifically to a preparation process for high-performance phenoxy resin. Background Technology

[0002] Phenoxy resin, also known as phenolic resin or polyhydroxy ether, is a transparent or amorphous polymer material, a thermoplastic resin obtained by ring-opening polycondensation of epoxy resin and phenolic or amine compounds. The structure of phenoxy resin is basically the same as that of ordinary epoxy resin, but the degree of polymerization in phenoxy resin is particularly high, resulting in a relatively high molecular weight. Due to its excellent mechanical strength, chemical resistance, and environmental friendliness, it has important application value in electronic packaging, composite materials, and environmentally friendly coatings. Traditionally, phenoxy resin is prepared by directly reacting bisphenol compounds (such as bisphenol A and bisphenol F) with epichlorohydrin or by reacting low-functionality epoxy resins (such as bisphenol A type epoxy resin) with an excess of phenolic compounds in a solvent. However, this method results in a low molecular weight and difficult post-processing, limiting its application in high-strength and high-toughness applications.

[0003] Chinese invention patent CN104356355A discloses a high-toughness epoxy resin, its preparation method and application. The synthesis reaction is carried out in a solvent-free state, the synthesis reaction rate is fast and the reaction temperature is low. The epoxy resin of this invention has the characteristics of low viscosity, and the coating prepared has a fast curing speed, but its molecular weight is low. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a method and process for preparing phenoxy resin.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A process for preparing a high-performance phenoxy resin includes the following steps: (1) Add epoxy compound, chain extender and NMP (N-methylpyrrolidone) to the reaction vessel and stir. Heat to 120-140℃. Under nitrogen protection, add catalyst and heat to 130-150℃. React for 3-5 hours to obtain resin solution. (2) After the resin solution is extruded through an extruder, it is stretched and granulated. The granulation temperature is controlled at 50-80℃ to obtain granules with a diameter of 1-3mm. (3) After freezing the particles with liquid nitrogen (-196℃), they are ground into powder by a pulverizer, and the particle size is controlled to be 1000-3000 mesh to obtain powder. (4) The powder is blown into the fluidized bed evaporator by high pressure and high temperature nitrogen (pressure 0.5-1.0MPa, temperature 260℃). After NMP evaporates, it is condensed and recovered. The high temperature viscous material is collected, extruded by a twin-screw extruder, and then granulated to obtain phenoxy resin particles. The catalyst is prepared by reacting N-vinylimidazolium with 4-(2-aminoethoxy)phenol to generate 4-(2-{bis[2-(1H-imidazol-1-yl)ethyl]amino}ethoxy)phenol, then reacting it with 4-chlorophthalic anhydride to generate diimidazole phthalic anhydride, and finally reacting it with boron trifluoride-diethyl ether solution.

[0006] The catalyst is prepared by the following method: S1: N-vinylimidazol reacts with 4-(2-aminoethoxy)phenol to produce 4-(2-{bis[2-(1H-imidazol-1-yl)ethyl]amino}ethoxy)phenol; its reaction structure is as follows: S2: 4-(2-{bis[2-(1H-imidazol-1-yl)ethyl]amino}ethoxy)phenol reacts with 4-chlorophthalic anhydride to form a diimidazolium phthalic anhydride compound; its reaction structure is as follows: S3: The reaction of diimidazole phthalic anhydride with boron trifluoride-diethyl ether solution yields a catalyst; its reaction structure is as follows: The molar ratio of N-vinylimidazol to 4-(2-aminoethoxy)phenol in step S1 is (2-2.5):1.

[0007] In step S2, the molar ratio of 4-(2-{bis[2-(1H-imidazol-1-yl)ethyl]amino}ethoxy)phenol to 4-chlorophthalic anhydride is 1:(1-1.2).

[0008] The molar ratio of the diimidazole phthalic anhydride compound to the boron trifluoride-ethyl ether solution in step S3 is 1:(2-2.4).

[0009] The epoxy compound is an epoxy resin or a combination of epoxy resin and glycidyl ether.

[0010] The epoxy resin is one or more of bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and bisphenol H type epoxy resin; the glycidyl ether is one or more of ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, hexanediol diglycidyl ether, polypropylene glycol diglycidyl ether, and 1,4-cyclohexanediethanol diglycidyl ether.

[0011] The chain extender is one or a mixture of bisphenol A, 1,4-butanediol, ethylene glycol, piperazine, bisphenol S, bisphenol F, 4,4'-dihydroxybenzophenone, 4,4-dihydroxydiphenyl ether, and 4,4'-dihydroxydiphenyl sulfide.

[0012] The epoxy compound and chain extender are fed in a molar ratio of epoxy group to active hydrogen group of chain extender, wherein the molar ratio of epoxy group to active hydrogen group is 1:(0.95-1.05).

[0013] The NMP accounts for 15-25 wt% of the total mass of the reaction system.

[0014] The catalyst is added in an amount of 0.08-0.2 wt% of the total mass of the epoxy compound.

[0015] Due to the adoption of the above technical solutions, the beneficial effects of the present invention include: (1) The catalyst prepared in this invention activates hydroxyl groups through imidazole and acid anhydride structures, thereby improving the chain extension reaction efficiency. It achieves the controlled polymerization of phenoxy resin by neutralizing the alkalinity of imidazole. The catalyst enables the preparation of high molecular weight phenoxy resin with excellent tensile strength.

[0016] (2) The present invention uses NMP as a solvent, whose strong polarity promotes the uniform reaction between epoxy resin and chain extender; and the particle size is ensured by combining strip cutting and liquid nitrogen cryogenic grinding; the solvent is evaporated by high pressure and high temperature nitrogen purging, avoiding the problem of high residual rate in traditional vacuum distillation, and the solvent recovery rate is 95%. Attached Figure Description

[0017] Figure 1 This is a high-resolution mass spectrum of the catalyst prepared in Example 1. Detailed Implementation

[0018] The following description, in conjunction with specific embodiments, provides further details, but the present invention is not limited to these embodiments.

[0019] Example 1: Preparation of Catalyst S1: Under ice bath conditions, 1000 ml of methanol and 2 mol of N-vinylimidazole were added to the reaction vessel and stirred until well mixed. Under nitrogen protection, 500 ml of a methanol solution containing 1 mol of 4-(2-aminoethoxy)phenol was added dropwise over 2 hours. The mixture was then raised to room temperature and reacted for 10 hours. Finally, it was distilled under reduced pressure at 50 °C for 1 hour to obtain 4-(2-{bis[2-(1H-imidazol-1-yl)ethyl]amino}ethoxy)phenol. Its 1H NMR spectrum data are as follows: 1 H NMR (300 MHz, Chloroform- d)7.84 (tt, J = 1.7, 0.9 Hz, 2H), 7.38 (s,1H), 7.19 (ddt, J = 3.5, 1.7, 0.8 Hz, 2H), 7.07 (dd, J = 3.8, 1.7 Hz, 2H), 6.89 - 6.76 (m, 4H), 4.10 (t, J = 5.9 Hz, 2H), 4.01 (tt, J = 4.2, 0.9 Hz, 4H), 3.06 (t, J = 5.9 Hz, 2H), 2.84 (t, J = 4.2 Hz, 4H); S2: Under nitrogen protection, 800 ml of anhydrous THF, 0.6 mol of potassium carbonate, and 0.5 mol of 4-(2-{bis[2-(1H-imidazol-1-yl)ethyl]amino}ethoxy)phenol were added to a reaction vessel and stirred for 30 min. The mixture was then cooled to 0 °C, and 400 ml of tetrahydrofuran solution containing 0.5 mol of 4-chlorophthalic anhydride was added dropwise over 1 h. The mixture was then allowed to rise to room temperature and react for 5 h. After filtration, 1200 ml of n-hexane was added to the filtrate and stirred to precipitate a solid. The solid was then filtered and dried under vacuum at 50 °C for 8 h to obtain the diimidazole phthalic anhydride compound. Its 1H NMR data are as follows: 1 H NMR (300 MHz, Chloroform- d )8.12 (d, J = 8.1 Hz, 1H), 7.84 (tt, J = 1.7, 0.9 Hz,2H), 7.69 (d, J = 2.7 Hz, 1H), 7.41 (dd, J = 8.0, 2.7 Hz, 1H), 7.23 - 7.15(m, 2H), 7.07 (dd, J = 3.8, 1.7 Hz, 2H), 6.97 - 6.80 (m, 4H), 4.10 (t, J =5.9 Hz, 2H), 4.01 (tt, J = 4.2, 0.9 Hz, 4H), 3.06 (t, J = 5.9 Hz, 2H), 2.84(t, J = 4.2 Hz, 4H); S3: 1500 ml of anhydrous THF and 0.5 mol of diimidazole phthalic anhydride compound were added to the reaction vessel and stirred until well mixed. 145.8 g of boron trifluoride-diethyl ether solution (containing 1 mol of boron trifluoride) was added dropwise over 30 min. The reaction was carried out at room temperature for 4 h. The solid was obtained by filtration, washed twice with anhydrous THF (500 ml each time), and dried under vacuum at 60 °C for 6 h to obtain the catalyst. Its 1H NMR data are as follows: 1 HNMR (300 MHz, Chloroform- d)9.71 (th, J = 1.7, 0.9 Hz, 2H), 8.12 (d, J = 8.1Hz, 1H), 7.78 (dp, J = 5.1, 1.7 Hz, 2H), 7.69 (d, J = 2.7 Hz, 1H), 7.58 (ddt,J = 4.6, 1.8, 0.9 Hz, 2H), 7.41 (dd, J = 8.0, 2.7 Hz, 1H), 6.97 - 6.80 (m,4H), 4.18 (tt, J = 4.2, 0.8 Hz, 4H), 4.10 (t, J = 5.9 Hz, 2H), 3.06 (t, J =5.9 Hz, 2H), 2.83 (t, J = 4.2 Hz, 4H); HRMS (m / z): 623.1982.

[0020] Example 2 Preparation of Catalyst S1: Under ice bath conditions, 1000 ml of methanol and 2.4 mol of N-vinylimidazole were added to the reaction vessel and stirred until well mixed. Under nitrogen protection, 500 ml of methanol solution containing 1 mol of 4-(2-aminoethoxy)phenol was added dropwise over 2 hours. The mixture was then raised to room temperature and reacted for 12 hours. The mixture was then distilled under reduced pressure at 50 °C for 1 hour to obtain 4-(2-{bis[2-(1H-imidazol-1-yl)ethyl]amino}ethoxy)phenol. S2: Under nitrogen protection, 800 ml of anhydrous THF, 0.6 mol of potassium carbonate, and 0.5 mol of 4-(2-{bis[2-(1H-imidazol-1-yl)ethyl]amino}ethoxy)phenol were added to a reaction vessel and stirred for 30 min. The mixture was then cooled to 0 °C, and 400 ml of tetrahydrofuran solution containing 0.55 mol of 4-chlorophthalic anhydride was added dropwise over 1 h. The mixture was then heated to room temperature and reacted for 6 h. After filtration, 1200 ml of n-hexane was added to the filtrate and stirred to precipitate a solid. The solid was then filtered and dried under vacuum at 50 °C for 8 h to obtain the diimidazole phthalic anhydride compound. S3: Add 1500 ml of anhydrous THF and 0.5 mol of diimidazole phthalic anhydride compound to the reaction vessel, stir and mix well, then add 160.4 g of boron trifluoride-diethyl ether solution (containing 1.1 mol of boron trifluoride) dropwise over 30 min. React at room temperature for 5 h, filter to obtain solid, wash twice with anhydrous THF (500 ml each time), and dry under vacuum at 60 °C for 6 h to obtain catalyst.

[0021] Example 3 Preparation of Catalyst S1: Under ice bath conditions, 1000 ml of methanol and 2.5 mol of N-vinylimidazole were added to the reaction vessel and stirred until well mixed. Under nitrogen protection, 500 ml of methanol solution containing 1 mol of 4-(2-aminoethoxy)phenol was added dropwise over 2 hours. The mixture was then raised to room temperature and reacted for 15 hours. The mixture was then distilled under reduced pressure at 50 °C for 1 hour to obtain 4-(2-{bis[2-(1H-imidazol-1-yl)ethyl]amino}ethoxy)phenol. S2: Under nitrogen protection, 800 ml of anhydrous THF, 0.6 mol of potassium carbonate, and 0.5 mol of 4-(2-{bis[2-(1H-imidazol-1-yl)ethyl]amino}ethoxy)phenol were added to a reaction vessel and stirred for 30 min. The mixture was then cooled to 0 °C, and 400 ml of tetrahydrofuran solution containing 0.6 mol of 4-chlorophthalic anhydride was added dropwise over 1 h. The mixture was then heated to room temperature and reacted for 8 h. After filtration, 1200 ml of n-hexane was added to the filtrate and stirred to precipitate a solid. The solid was then filtered and dried under vacuum at 50 °C for 8 h to obtain the diimidazole phthalic anhydride compound. S3: Add 1500 ml of anhydrous THF and 0.5 mol of diimidazole phthalic anhydride compound to the reaction vessel, stir and mix well, then add 175 g of boron trifluoride-diethyl ether solution (containing 1.2 mol of boron trifluoride) dropwise over 30 min. React at room temperature for 6 h, filter to obtain solid, wash twice with anhydrous THF (500 ml each time), and dry under vacuum at 60 °C for 6 h to obtain catalyst.

[0022] Example 4: Preparation of phenoxy resin (1) 1000g of bisphenol A type epoxy resin (E-51, epoxy value 0.51eq / 100g), 500g of ethylene glycol diglycidyl ether, 1175g of bisphenol A and 472g of NMP were added to the reaction vessel and stirred. The temperature was raised to 140°C. Under nitrogen protection, 1.2g of catalyst (prepared in Example 1) was added. The temperature was raised to 150°C and reacted for 3h to obtain a resin solution. (2) The resin solution is granulated by a granulator, and the granulation temperature is controlled at 50℃ to obtain granules with a diameter of 1mm; (3) After freezing the particles with liquid nitrogen (-196℃), they are ground into powder by a pulverizer to control the particle size to 1000 mesh, thus obtaining powder. (4) The powder is injected from the bottom of the fluidized bed evaporator through high-pressure high-temperature nitrogen gas (pressure 0.5MPa, temperature 260℃) to form a fluidized boiling state. The material stays in the fluidized bed evaporator for 10 minutes. The NMP solvent evaporates in the high-temperature nitrogen gas and is discharged from the top with the airflow. The NMP is condensed and recovered (NMP 453g, recovery rate 96%). The high-temperature semi-molten viscous material (solvent residue <0.1%) collected at the bottom of the fluidized bed evaporator is directly fed into the twin-screw extruder (temperature 240℃, speed 300rpm) and extruded into strips, then air-cooled and pelletized to obtain phenoxy resin particles.

[0023] Example 5 Preparation of phenoxy resin (1) 800g of bisphenol F type epoxy resin (KF-8110, epoxy value 0.625eq / 100g), 1200g of polyethylene glycol diglycidyl ether (epoxy value 0.28eq / 100g), 377g of 1,4-butanediol and 594g of NMP were added to the reactor and stirred. The temperature was raised to 120°C. Under nitrogen protection, 3g of catalyst (prepared in Example 2) was added. The temperature was raised to 140°C and reacted for 4h to obtain a resin solution.

[0024] (2) The resin solution is granulated by a granulator, and the granulation temperature is controlled at 70℃ to obtain granules with a diameter of 2mm; (3) After freezing the particles with liquid nitrogen (-196℃), they are ground into powder by a pulverizer to control the particle size to 2000 mesh, thus obtaining powder. (4) The powder is injected from the bottom of the fluidized bed evaporator through high-pressure high-temperature nitrogen gas (pressure 0.8MPa, temperature 260℃) to form a fluidized boiling state. The material stays in the fluidized bed evaporator for 20 minutes. The NMP solvent evaporates in the high-temperature nitrogen gas and is discharged from the top with the airflow. The NMP is condensed and recovered (NMP 576g, recovery rate 97%). The high-temperature semi-molten viscous material (solvent residue <0.1%) collected at the bottom of the fluidized bed evaporator is directly fed into the twin-screw extruder (temperature 260℃, speed 200rpm) and extruded into strips, then air-cooled and pelletized to obtain phenoxy resin particles.

[0025] Example 6 (1) 800g of bisphenol S-type epoxy resin (185S, epoxy value 0.54eq / 100g), 1000g of bisphenol H-type epoxy resin (LB101, epoxy value 0.43eq / 100g), 500g of bisphenol F, 388g of 4,4'-dihydroxybenzophenone and 672g of NMP were added to a reaction vessel and stirred. The temperature was raised to 120°C. Under nitrogen protection, 3.6g of catalyst (prepared in Example 3) was added and the temperature was raised to 130°C for 5h to obtain a resin solution. (2) The resin solution is granulated by a granulator, and the granulation temperature is controlled at 80℃ to obtain granules with a diameter of 3mm; (3) After freezing the particles with liquid nitrogen (-196℃), they are ground into powder by a pulverizer to control the particle size to 3000 mesh, thus obtaining powder. (4) The powder is injected from the bottom of the fluidized bed evaporator through high pressure and high temperature nitrogen (pressure 1MPa, temperature 260℃) to form a fluidized boiling state. The material stays in the fluidized bed evaporator for 30 minutes. The NMP solvent evaporates in the high temperature nitrogen and is discharged from the top with the airflow. The NMP is condensed and recovered (652g NMPg, recovery rate 97%). The high temperature semi-molten viscous material (solvent residue <0.1%) collected at the bottom of the fluidized bed evaporator is directly fed into the twin screw extruder (temperature 280℃, speed 100rpm) and extruded into strips, then air-cooled and pelletized to obtain phenoxy resin particles.

[0026] Example 7 (1) 800g of bisphenol A type epoxy resin (E-44, epoxy value 0.44eq / 100g), 500g of polypropylene glycol diglycidyl ether (epoxy value 0.30eq / 100g), 500g of 1,4-cyclohexanediethanol diglycidyl ether, 505g of 4,4'-dihydroxydiphenyl ether, 430g of 4,4'-dihydroxydiphenyl sulfide and 684g of NMP were added to a reaction vessel and stirred. The temperature was raised to 120°C. Under nitrogen protection, 3.6g of catalyst (prepared in Example 3) was added and the temperature was raised to 140°C and reacted for 4h to obtain a resin solution. (2) The resin solution is granulated by a granulator, and the granulation temperature is controlled at 80℃ to obtain granules with a diameter of 3mm; (3) After freezing the particles with liquid nitrogen (-196℃), they are ground into powder by a pulverizer to control the particle size to 3000 mesh, thus obtaining powder. (4) The powder is injected from the bottom of the fluidized bed evaporator through high pressure and high temperature nitrogen (pressure 1MPa, temperature 260℃) to form a fluidized boiling state. The material stays in the fluidized bed evaporator for 30 minutes. The NMP solvent evaporates in the high temperature nitrogen and is discharged from the top with the air flow. The NMP is condensed and recovered (NMP 670g, recovery rate 98%). The high temperature semi-molten viscous material (solvent residue <0.1%) collected at the bottom of the fluidized bed evaporator is directly fed into the twin screw extruder (temperature 280℃, speed 100rpm) and extruded into strips, then air-cooled and pelletized to obtain phenoxy resin particles.

[0027] Example 8 Preparation of phenoxy resin (1) 1500g of bisphenol A type epoxy resin (E-44, epoxy value 0.44eq / 100g), 1500g of hexanediol diglycidyl ether, 466g of ethylene glycol, 241g of piperazine and 1236g of NMP were added to a reaction vessel and stirred. The temperature was raised to 120°C. Under nitrogen protection, 6g of catalyst (prepared in Example 3) was added and the temperature was raised to 130°C for 3h to obtain a resin solution. (2) The resin solution is granulated by a granulator, and the granulation temperature is controlled at 80℃ to obtain granules with a diameter of 3mm; (3) After freezing the particles with liquid nitrogen (-196℃), they are ground into powder by a pulverizer to control the particle size to 3000 mesh, thus obtaining powder. (4) The powder is injected from the bottom of the fluidized bed evaporator through high pressure and high temperature nitrogen gas (pressure 1MPa, temperature 260℃) to form a fluidized boiling state. The material stays in the fluidized bed evaporator for 30 minutes. The NMP solvent evaporates in the high temperature nitrogen gas and is discharged from the top with the air flow. The NMP is condensed and recovered (NMP 1211g, recovery rate 98%). The high temperature semi-molten viscous material (solvent residue <0.1%) collected at the bottom of the fluidized bed evaporator is directly fed into the twin screw extruder (temperature 280℃, speed 100rpm) and extruded into strips, then air-cooled and pelletized to obtain phenoxy resin particles.

[0028] Example 9 Preparation of phenoxy resin The raw material composition and preparation method of phenoxy resin are basically the same as those in Example 8, except that the reaction time of step (1) is 4 hours.

[0029] Example 10 Preparation of phenoxy resin The raw material composition and preparation method of phenoxy resin are basically the same as those in Example 8, except that the reaction time of step (1) is 5 hours.

[0030] Comparative Example 1 The raw material composition and preparation method of the phenoxy resin are basically the same as those in Example 9, except that the catalyst in step (1) is replaced with an equal weight of the catalyst prepared by the following method: The catalyst preparation process is basically the same as in Example 3, except that the 4-chlorophthalic anhydride in step S2 is replaced with an equimolar amount of 3-(4-chlorophenyl)glutaric anhydride.

[0031] Comparative Example 2 The raw material composition and preparation method of phenoxy resin are basically the same as those of Comparative Example 1, except that the reaction time of step (1) is 5h.

[0032] Comparative Example 3: Preparation of Phenoxy Resin The raw material composition and preparation method of phenoxy resin are basically the same as those in Example 9, except that the catalyst in step (1) is replaced with an equal weight of diimidazole phthalic anhydride compound (prepared in step S2 of Example 3).

[0033] Comparative Example 4 The raw material composition and preparation method of phenoxy resin are basically the same as those of Comparative Example 3, except that the reaction time of step (1) is 5h.

[0034] Comparative Example 5 The raw material composition and preparation method of phenoxy resin are basically the same as those in Example 9, except that the catalyst in step (1) is replaced with an equal weight of n-butyltriphenylphosphine bromide.

[0035] Comparative Example 6 The raw material composition and preparation method of phenoxy resin are basically the same as those in Example 9, except that the catalyst in step (1) is replaced with an equal weight of tetramethylammonium chloride.

[0036] Comparative Example 7 The raw material composition and preparation method of phenoxy resin are basically the same as those in Example 9, except that the catalyst in step (1) is replaced with an equal weight of 2-methylimidazole.

[0037] Comparative Example 8 The raw material composition and preparation method of phenoxy resin are basically the same as those in Example 9. The difference is that the catalyst in step (1) is replaced with an equal weight of n-butyltriphenylphosphine bromide, and the reaction time is 8h.

[0038] Comparative Example 9 The raw material composition and preparation method of phenoxy resin are basically the same as those in Example 9. The difference is that the catalyst in step (1) is replaced with an equal weight of tetramethylammonium chloride, and the reaction time is 8h.

[0039] Comparative Example 10 The raw material composition and preparation method of phenoxy resin are basically the same as those in Example 9. The difference is that the catalyst in step (1) is replaced with an equal weight of 2-methylimidazole, and the reaction time is 8h.

[0040] The concentration of the boron trifluoride-diethyl ether solution used in this application is 46.5 wt%.

[0041] The phenoxy resins prepared in Examples 4-10 and Comparative Examples 1-7 were subjected to tensile strength tests according to the 5B dumbbell type as required by GB / T 1040.1-2006. All specimens were subjected to uniaxial tension at room temperature at a tension rate of 5 mm / min. The test results are shown in Table 1.

[0042] Table 1 Performance Data Sheet project Reaction temperature ℃ reaction time h Number average molecular weight Mn Tensile strength (MPa) Example 4 150 3 25600 72.1 Example 5 140 4 35400 75.6 Example 6 130 5 34600 78.3 Example 7 140 4 31900 73.1 Example 8 130 3 15500 64.5 Example 9 130 4 23500 69.7 Example 10 130 5 36100 76.2 Comparative Example 1 130 4 18400 64.4 Comparative Example 2 130 5 26900 71.5 Comparative Example 3 130 4 27300 71.8 Comparative Example 4 130 5 28400 68.3 Comparative Example 5 130 4 9800 60.1 Comparative Example 6 130 4 12600 62.2 Comparative Example 7 130 4 18300 63.6 Comparative Example 8 130 8 10400 / Comparative Example 9 130 8 13100 / Comparative Example 10 130 8 19200 / As can be seen from the data in Examples 4-10, the phenoxy resin prepared by the present invention has a high molecular weight and excellent tensile strength, which has important application value. Furthermore, the controlled polymerization of phenoxy resin can be achieved by changing the amount of feed, reaction temperature, reaction time, etc.

[0043] The pyridine nitrogen atom on the imidazole in the catalyst prepared in this invention can first activate the anhydride and hydroxyl groups to generate oxygen anions. These oxygen anions then undergo anionic polymerization with epoxy groups, simultaneously generating hydroxyl and oxygen anions. The oxygen anions then repeatedly undergo ring-opening reactions with the epoxy groups, achieving chain growth and ultimately preparing the cured product. The nitrogen atom in the imidazole structure, acting as a Lewis base, can donate electrons, while BF3, acting as a Lewis acid, can gain electrons. The lone pair electrons on the nitrogen atom can move to the boron element in the BF3 molecule, neutralizing the basicity of imidazole and inhibiting the reaction kinetics, establishing a time-dependent molecular weight control mechanism, thereby achieving controllable polymerization of phenoxy resin molecular weight. The benzene ring conjugated system of the phthalic anhydride structure can stabilize the reaction intermediates, reduce the activation energy, and improve the reaction efficiency.

[0044] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. However, any modifications, alterations, and variations made by those skilled in the art without departing from the scope of the present invention based on the disclosed technical content are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. A process for the preparation of high performance phenoxy resin, characterized in that, Includes the following steps: (1) Add epoxy compound, chain extender and NMP to the reaction vessel and stir. Heat to 120-140℃. Under nitrogen protection, add catalyst and heat to 130-150℃. React for 3-5 hours to obtain resin solution. (2) After the resin solution is extruded through an extruder, it is stretched and granulated. The granulation temperature is controlled at 50-80℃ to obtain granules with a diameter of 1-3mm. (3) After freezing the particles with liquid nitrogen, they are ground into powder by a pulverizer, and the particle size is controlled to be 1000-3000 mesh to obtain powder. (4) The powder is blown into the fluidized bed evaporator by high pressure and high temperature nitrogen gas. After NMP evaporates, it is condensed and recovered. The high temperature and viscous material is collected, extruded by a twin-screw extruder, and then granulated to obtain phenoxy resin particles. The catalyst is prepared by reacting N-vinylimidazolium with 4-(2-aminoethoxy)phenol to generate 4-(2-{bis[2-(1H-imidazol-1-yl)ethyl]amino}ethoxy)phenol, then reacting it with 4-chlorophthalic anhydride to generate diimidazole phthalic anhydride, and finally reacting it with boron trifluoride-diethyl ether solution.

2. The preparation process of a high-performance phenoxy resin according to claim 1, characterized in that, The molar ratio of N-vinylimidazol to 4-(2-aminoethoxy)phenol is (2-2.5):

1.

3. The preparation process of a high-performance phenoxy resin according to claim 1, characterized in that, The molar ratio of 4-(2-{bis[2-(1H-imidazol-1-yl)ethyl]amino}ethoxy)phenol to 4-chlorophthalic anhydride is 1:(1-1.2).

4. The preparation process of a high-performance phenoxy resin according to claim 1, characterized in that, The molar ratio of the diimidazole phthalic anhydride compound to the boron trifluoride-diethyl ether solution is 1:(2-2.4).

5. The preparation process of a high-performance phenoxy resin according to claim 1, characterized in that, The epoxy compound is an epoxy resin or a combination of epoxy resin and glycidyl ether.

6. The preparation process of a high-performance phenoxy resin according to claim 5, characterized in that, The epoxy resin is one or more of bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and bisphenol H type epoxy resin; the glycidyl ether is one or more of ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, hexanediol diglycidyl ether, polypropylene glycol diglycidyl ether, and 1,4-cyclohexanediethanol diglycidyl ether.

7. The preparation process of a high-performance phenoxy resin according to claim 1, characterized in that, The chain extender is one or a mixture of bisphenol A, 1,4-butanediol, ethylene glycol, piperazine, bisphenol S, bisphenol F, 4,4'-dihydroxybenzophenone, 4,4-dihydroxydiphenyl ether, and 4,4'-dihydroxydiphenyl sulfide.

8. The preparation process of a high-performance phenoxy resin according to claim 1, characterized in that, The epoxy compound and chain extender are fed in a molar ratio of epoxy group to active hydrogen group of chain extender, wherein the molar ratio of epoxy group to active hydrogen group is 1:(0.95-1.05).

9. The preparation process of a high-performance phenoxy resin according to claim 1, characterized in that, The NMP accounts for 15-25 wt% of the total mass of the reaction system.

10. The preparation process of a high-performance phenoxy resin according to claim 1, characterized in that, The catalyst is added in an amount of 0.08-0.2 wt% of the total mass of the epoxy compound.

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