Hydrophilic imide resin and preparation method thereof

Abstract

The invention provides hydrophilic imide resin and a preparation method thereof, and relates to the technical field of amino resin. The structure of the hydrophilic imide resin is YA2, Y is a divalent organic structure which is left after two primary amine terminated groups are removed from double-terminal primary amine polyether and has an inert reaction with isocyanate groups at 100 DEG C and an average molecular weight of 50-5000, the solubility of the double-terminal primary amine polyether in pure water at 25 DEG C is not less than 10g / 100g water, and the solubility of the double-terminal primary amine polyether in pure water at 25 DEG C is not less than 1g / 100g water. The structure of A is one imide structure formed by two ester groups in the aspartic acid ester resin, or two imide structures formed by four ester groups in the aspartic acid ester resin, or a combination of the two imide structures and the four ester groups in the aspartic acid ester resin. The hydrophilic imide resin disclosed by the invention has relatively good hydrophilicity, good hydrolysis resistance and high mechanical strength after curing.

Description

Technical Field

[0001] The invention belongs to the technical field of amino resins and relates to a hydrophilic imide resin and a preparation method thereof. Background Art

[0002] Asparagine is usually obtained by Michael addition reaction of dialkyl maleate (such as diethyl maleate) and polyamine compound, and cured with isocyanate curing agent to form third generation polyurea - asparagine polyurea. The ester group in dialkyl maleate plays the role of solvation and internal plasticization in polyurea. For hydrophilic asparagine, it is generally obtained by transesterification reaction of hydrophilic polyether and ester group, but due to the poor hydrolysis resistance of ester bond, the hydrophilic asparagine has insufficient hydrolysis resistance. After a long time, due to the hydrolysis of ester bond, the hydrophilic polyether segment will be separated from the asparagine, and the hydrophilic asparagine loses hydrophilicity, which affects the product performance.

[0003] Therefore, it is necessary to modify the existing technology to further improve the hydrolysis resistance of the hydrophilic asparagine resin. Summary of the invention

[0004] The imide structure has good heat resistance, hydrolysis resistance and chemical resistance. The modification method of imide is usually to graft different organic groups on N and provide different properties. For example, introducing a hydrophilic polyether structure on the N of the imide can improve its hydrophilicity, and it has good stability and is not easy to hydrolyze and cause performance deterioration or failure. However, in the prior art, maleimide or substituted maleimide is used to react with a polyamine compound to obtain an imide resin by Michael addition reaction, and polyether is used to replace maleimide, in which the activity of the carbon-carbon double bond is low. The inventors have conducted in-depth research and analysis on this. Based on this, the present invention provides a hydrophilic imide resin and a preparation method thereof.

[0005] The technical solution of the present invention is as follows:

[0006] A hydrophilic imide resin having a structure as shown in the following formula (1):

[0007] YA2(1)

[0008] Wherein, Y is a divalent organic structure with an average molecular weight of 50-5000 which is inert to isocyanate groups at 100° C. and which remains after removing two terminal primary amino groups from the double-terminal primary amino polyether. The solubility of the double-terminal primary amino polyether in pure water at 25° C. is not less than 10 g / 100 g water. The structure of A is as shown in the following formula (2) or (3), or the structure of A is a combination of the structures shown in the formula (2) and the formula (3).

[0009]

[0010] Among them, R 1 and R 2 independently selected from C1-C4 alkyl, R 3 It is selected from C1-C18 alkyl, C2-C18 substituted alkyl or polyether segment, and X is a divalent organic structure with an average molecular weight of 50-500 which is inert to the isocyanate group at 100°C and remains after the primary amino group is removed from the polyamine compound.

[0011] Preferably, the number average molecular weight of the double-terminated primary amino polyether is no more than 2500.

[0012] More preferably, in the combination of the structures represented by the formula (2) and the formula (3), the molar ratio of the formula (2) to the formula (3) is 1:4-4:1.

[0013] Preferably, the structure of the polyether segment is as shown in the following formula (4):

[0014] -(CH2CH2O) m (CH2CHCH3O) n R 4 (4)

[0015] Where m≥0, n≥0, 1≤m+n≤50, R 4 Selected from H or C1-C18 alkyl.

[0016] More preferably, m≥1.2n, R 4 Selected from C4-C18 alkyl.

[0017] More preferably, m<1.2n, R 4 Selected from H or C1-C4 alkyl.

[0018] A method for preparing a hydrophilic imide resin according to any one of the above technical solutions comprises the following steps:

[0019] The polyvalent primary amine compound and the alkyl maleate undergo Michael addition reaction to obtain the first aspartic acid resin;

[0020] The first asparagine resin and the double-terminated primary amino polyether undergo a first imide reaction to obtain the hydrophilic imide resin;

[0021] Alternatively, the first asparagine resin is reacted with the double-terminated primary amino polyether to undergo a second imide reaction, and then the R 3 The corresponding monoamine compound R 3 NH2, conduct a third imide reaction to obtain the hydrophilic imide resin; R 3 has the same meaning as above.

[0022] Preferably, the catalysts for the first imide reaction, the second imide reaction and the third imide reaction are independently selected from one or a combination of two or more of C6-C18 fatty acids, benzotriazole and substituted benzotriazole.

[0023] Preferably, the molar ratio of the first asparagine resin to the double-terminated primary amino polyether is 1.8-2.2:1.

[0024] Preferably, the molar ratio of the first asparagine resin to the monoamine compound is 1:0.2-1.

[0025] The beneficial effects of the present invention are:

[0026] (1) In the present invention, the connection between the hydrophilic polyether and the asparagine resin adopts an imide structure, which improves the hydrolysis resistance of the resin. In addition, the hydrophilic polyether is in the middle of the resin structure, and the two ends are asparagine resin structures. The obtained imide resin has good hydrophilicity and can further undergo a curing reaction with a curing agent.

[0027] (2) The ester group in the imide resin of the present invention can further undergo an imide reaction, and the ester group may be substantially absent in the imide resin. The cured product of the imide resin has significantly improved heat resistance, hydrolysis resistance, mechanical strength, etc. Moreover, the preparation process is relatively simple, the raw material source is convenient, and the resin structure design is flexible. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is further illustrated and described below through specific implementation methods.

[0029] In order to solve the shortcomings of the prior art hydrophilic asparagine resin, such as inflexible structural design, poor hydrolysis resistance, insufficient heat resistance, low mechanical strength, etc., and to avoid the problem of low reactivity caused by directly using polyether-substituted maleimide, on the one hand, the present invention provides a hydrophilic imide resin having a structure as shown in the following formula (1):

[0030] YA2(1)

[0031] Wherein, Y is a divalent organic structure with an average molecular weight of 50-5000 which is inert to isocyanate groups at 100° C. and which is left after removing two terminal primary amino groups from the double-terminal primary amino polyether. The solubility of the double-terminal primary amino polyether in pure water at 25° C. is not less than 10 g / 100 g water. The structure of A is as shown in the following formula (2) or (3), or the structure of A is a combination of the structures shown in formula (2) and formula (3).

[0032]

[0033] Among them, R 1 and R 2independently selected from C1-C4 alkyl, R 3 It is selected from C1-C18 alkyl, C2-C18 substituted alkyl or polyether segment, and X is a divalent organic structure with an average molecular weight of 50-500 which is inert to the isocyanate group at 100°C and remains after the primary amino group is removed from the polyamine compound.

[0034] In the hydrophilic imide resin structure of the present invention, the middle is a hydrophilic polyether structure, the two ends are asparagine resin structures, and the hydrophilic imide resin structure contains two secondary amine groups, which can be cured with an isocyanate curing agent. Moreover, even if the hydrophilic imide resin of the present invention has an ester group and the ester group is hydrolyzed, it will not affect the connection structure between the hydrophilic polyether and the main chain, and the stability is good. The hydrophilic imide resin of the present invention can also further imidize the ester group of the terminal group to further improve the performance of hydrolysis resistance, heat resistance, mechanical strength and the like.

[0035] Specifically, in the present invention, R 1 and R 2 Can be ethyl alone, R 3 It can be ethyl, n-butyl, n-hexyl, n-octyl, isooctyl, N,N-dimethyl-3-aminopropyl, N,N-dimethyl-4-aminobutyl, etc.; R 3 It can also be a polyether segment, which can be a monovalent polyethylene glycol polypropylene glycol structure, a monovalent polypropylene glycol structure, etc. Therefore, in the present invention, through the Y structure and R 3 By adjusting the structure of the imide resin, a variety of imide resins with different structures can be obtained, which is more flexible in structure.

[0036] Preferably, the solubility of the double-terminal primary amino polyether in pure water at 25°C is not less than 30g / 100g water. For example, the solubility can be any value of 30g / 100g water, 50g / 100g water, 80g / 100g water, 100g / 100g water, 120g / 100g water, 130g / 100g water, 150g / 100g water, 180g / 100g water, 200g / 100g water, etc., without special restrictions. The higher the solubility of the double-terminal primary amino polyether, the better its hydrophilicity. Specifically, the double-terminal primary amino polyether can be a double-terminal primary amino polyethylene glycol or a double-terminal primary amino polyethylene glycol / polypropylene glycol copolymer, which can be directly purchased from the market, such as ZED-901, ZED-601, ZED-2031, etc. of Zibo Zhengda Polyurethane Co., Ltd.

[0037] In a preferred embodiment of the present invention, the number average molecular weight of the double-terminated primary amine polyether does not exceed 2500. If the number average molecular weight of the double-terminated primary amine polyether is too large, the activity of the primary amine groups at both ends will be low, resulting in a slower rate of imide reaction or incomplete reaction. The number average molecular weight of the double-terminated primary amine polyether does not exceed 2500, and the activity of the primary amine groups at both ends is high, which can allow the imide reaction to proceed faster and more fully.

[0038] In a more preferred embodiment of the present invention, the molar ratio of the structure represented by formula (2) and formula (3) in the combination of the structure represented by formula (2) and formula (3) is 1:4-4:1. By adopting the above technical scheme, the structural design of the imide resin is more flexible. For example, the molar ratio of the structure represented by formula (2) and formula (3) can be any value of 1:4, 1:3, 1:2, 1:1, 1:2, 1:3, 1:4, etc., without special restrictions.

[0039] In a preferred embodiment of the present invention, the structure of the polyether segment is shown in the following formula (4):

[0040] -(CH2CH2O) m (CH2CHCH3O) n R 4 (4)

[0041] Where m≥0, n≥0, 1≤m+n≤50, R 4 Selected from H or C1-C18 alkyl. The molecular weight and hydrophilicity / hydrophobicity of the polyether segment can be adjusted by adjusting the values ​​of m and n. The amino polyether corresponding to the polyether segment can be directly purchased from the market, such as ZM-1100 and ZM-160 of Zibo Zhengda Polyurethane Co., Ltd.

[0042] In a more preferred embodiment of the present invention, m≥1.2n, R 4 When n≥1.2m, the hydrophilicity of the polyether segment is strong, and the hydrophilicity of the polyether segment can be increased by increasing R 4 The hydrophilicity / hydrophobicity of the polyether segment can be adjusted by the hydrophobicity of the polyether segment. For example, m = 1.2n, m = 1.5n, m = 2n, m = 2.5n, m = 3n, etc., R 4 It may be n-butyl, n-hexyl, n-octyl, lauryl, stearyl, or the like.

[0043] In a more preferred embodiment of the present invention, m<1.2n, R 4 When 0.5n≤m<1.2n, the hydrophobicity of the polyether segment is strong, and the hydrophobicity of the polyether segment can be reduced by reducing R 4 The hydrophilicity / hydrophobicity of the polyether segment can be adjusted by the hydrophobicity of the polyether segment. For example, m = 0.5n, m = 0.6n, m = 0.7n, m = 0.8n, m = 0.9n, m = n, m = 1.1n, etc., R 4It can be methyl, ethyl, isopropyl, etc.

[0044] On the other hand, the present invention provides a method for preparing the hydrophilic imide resin according to any one of the above technical solutions, comprising the following steps:

[0045] The polyamine compound and the alkyl maleate undergo Michael addition reaction to obtain the first winter resin;

[0046] The first aspartic acid resin and the double-terminated primary amino group polyether undergo a first imide reaction to obtain a hydrophilic imide resin;

[0047] Alternatively, the first aspartic acid resin is reacted with the double-terminated primary amino polyether for the second imide reaction, and then R 3 The corresponding monoamine compound R 3 NH2, undergo a third imide reaction to obtain a hydrophilic imide resin; R 3 has the same meaning as above.

[0048] The present invention adopts the above method to prepare a hydrophilic imide resin, wherein the first asparagine resin can be an existing commercially available asparagine resin, such as F420 resin, F520 resin, etc. of Shenzhen Feiyang Junyan New Materials Co., Ltd. Therefore, in the present invention, commercially available asparagine resin products can be directly used, and the hydrophilic imide resin of the present invention can be obtained through an imide reaction once, or the hydrophilic imide resin of the present invention can also be obtained through an imide reaction twice, and the reaction steps are short and the operation is simple. In the above-mentioned first imide reaction, the second imide reaction and the third imide reaction, the alcohol (such as ethanol, methanol, etc.) produced can be continuously removed by distillation, ventilation removal (such as passing into nitrogen), so as to facilitate the complete imide reaction.

[0049] In a preferred embodiment of the present invention, the catalyst for the first imide reaction, the second imide reaction and the third imide reaction is independently selected from one or a combination of two or more of C6-C18 fatty acids, benzotriazole and substituted benzotriazole. Adding a catalyst to the imide reaction can increase the reaction rate and promote a more complete reaction. For example, the catalyst can be stearic acid, lauric acid, 1-octanoic acid, 1-hydroxybenzotriazole, etc. The amount of the catalyst can be 0.1-0.5% of the weight of the first asparagine resin, for example, it can be any value of 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, etc., without special restrictions.

[0050] Specifically, in the above preparation method of the present invention, the first imide reaction can be carried out according to the following operation method: add a catalyst to the first day-old resin, heat it to 90-150°C, then add a double-terminated primary amino polyether, react until the reaction system has reflux, distill or pass nitrogen to remove the generated alcohol until no bubbles are generated in the reaction system, and obtain a hydrophilic imide resin. Alternatively, continue to add a monoamine compound to the hydrophilic imide resin prepared above to carry out a second imide reaction, still distill or pass nitrogen to remove the generated alcohol and react until no bubbles are generated in the system, and obtain a hydrophilic imide resin.

[0051] In a preferred embodiment of the present invention, the molar ratio of the first asparagine resin to the double-terminated primary amino polyether is 1.8-2.2:1. From the perspective of the reaction raw materials and products, when the molar ratio of the first asparagine resin to the double-terminated primary amino polyether is 2:1, the reaction is just carried out. When the molar ratio of the first asparagine resin to the double-terminated primary amino polyether deviates from 2:1, such as the first asparagine resin is excessive or insufficient, the two raw materials will not completely participate in the reaction. At this time, the unreacted raw materials can be removed by separation or precipitation methods, and the desired product is obtained, which is industrially feasible. However, from the perspective of industrial production, it is more preferred that the molar ratio of the first asparagine resin to the double-terminated primary amino polyether is 1.9-2.1:1, which is more suitable. At this time, the reaction product can be directly used without further separation and purification, and can also be further separated or purified when necessary. Or further, the molar ratio of the first asparagine resin to the double-terminated primary amino polyether can be 1.95-2.1:1. For example, the molar ratio can be any value of 1.95:1, 1.97:1, 1.99:1, 2:1, 2.01:1, 2.03:1, 2.05:1, 2.08:1, 2.1:1, etc., without particular limitation.

[0052] In a preferred embodiment of the present invention, the molar ratio of the first asparagine resin to the monoamine compound is 1:0.2-1. By means of the above technical scheme, the ratio of ester groups substituted in the first asparagine resin can be adjusted. For example, the molar ratio of the first asparagine resin to the monoamine compound can be any value in 1:0.2, 1:0.25, 1:0.3, 1:0.35, 1:0.4, 1:0.45, 1:0.5, 1:0.55, 1:0.6, 1:0.65, 1:0.7, 1:0.75, 1:0.8, 1:0.85, 1:0.9, 1:0.95, 1:1, etc., without any particular limitation.

[0053] The technical solution of the present invention is further described and illustrated according to various embodiments below. Unless otherwise specified, the parts described in the following embodiments are parts by weight.

[0054] Example 1

[0055] 1 mol of commercially available F420 resin (Feiyang Junyan Company) is added into a container, and 0.25% of the weight of the F420 resin as a catalyst 1-hydroxybenzotriazole is added, the temperature is raised to 120°C, and 0.5 mol of double-terminated primary amino polyethylene glycol (number average molecular weight 1100) is added, and the reaction system is stirred until reflux occurs. Nitrogen is continuously passed through to remove the generated ethanol until no bubbles are generated in the reaction system, and a hydrophilic imide resin is obtained, which is light yellow and transparent.

[0056] According to the structure of the above formula (1), the structure of the hydrophilic imide resin of this embodiment is: Y is a divalent polyether structure remaining after removing two primary amino groups from a double-terminated primary amino group polyethylene glycol, A is a structure shown in formula (2), R 1 and R 2 All are ethyl groups, and X is the divalent structure remaining after removing two primary amino groups from 4,4'-diaminodicyclohexylmethane.

[0057] Example 2

[0058] In Example 1, after no bubbles are generated in the reaction system, 0.25 mol of n-hexylamine is added, and the reaction is continued at a constant temperature of 120° C. and stirred until reflux occurs in the reaction system. Nitrogen is passed to remove the generated ethanol until no bubbles are generated in the reaction system, thereby obtaining a hydrophilic imide resin that is brown-yellow and transparent.

[0059] According to the structure of the above formula (1), the structure of the hydrophilic imide resin of this embodiment is: Y is a divalent polyether structure remaining after removing two primary amino groups from a double-terminated primary amino group polyethylene glycol, A is a combination of the structures shown in formula (2) and formula (3) in a molar ratio of 3:1, and R 1 and R 2 All are ethyl, R 3 is n-hexyl, and X is the divalent structure remaining after removing two primary amino groups from 4,4'-diaminodicyclohexylmethane.

[0060] Example 3

[0061] The difference between Example 3 and Example 2 is that in Example 2, the n-hexylamine is adjusted from 0.25 mol to 0.6 mol. The other steps remain unchanged. The product hydrophilic imide resin is brown-yellow and transparent.

[0062] Example 4

[0063] The difference between Example 4 and Example 2 is that in Example 2, the n-hexylamine is adjusted from 0.25 mol to 1 mol. The other steps remain unchanged. The product hydrophilic imide resin is brown-yellow and transparent.

[0064] Example 5

[0065] The difference between Example 5 and Example 3 is that in Example 3, n-hexylamine is replaced by an equal mole of single-terminated amino polyether ZM-160. The other steps remain unchanged. The product hydrophilic imide resin is brown-yellow and transparent.

[0066] Example 6

[0067] The difference between Example 6 and Example 4 is that in Example 4, n-hexylamine is replaced by an equal molar amount of single-terminated amino polyether ZM-160. The other steps remain unchanged. The product hydrophilic imide resin is brown-yellow and transparent.

[0068] Example 7

[0069] The difference between Example 7 and Example 5 is that in Example 5, ZM-160 is replaced by an equal molar amount of CAM-2070 (Chenhua Co., Ltd.). The other steps remain unchanged. The product hydrophilic imide resin is brown-yellow and transparent.

[0070] Example 8

[0071] 1.95 mol of commercially available F520 resin (Feiyang Junyan Company) was added into a container, and 0.3% of the weight of the F520 resin as a catalyst 1-hydroxybenzotriazole was added, the temperature was raised to 130°C, and 1 mol of ZED-901 amino-terminated polyether (Zibo Zhengda Polyurethane Company) was added, and the mixture was stirred until reflux occurred in the reaction system. Nitrogen was continuously passed through to remove the generated ethanol until no bubbles were generated in the reaction system, and a hydrophilic imide resin was obtained, which was light yellow and transparent.

[0072] Example 9

[0073] The difference between Example 9 and Example 8 is that in Example 8, the F520 resin is adjusted from 1.95 mol to 2.02 mol. The other steps remain unchanged. The product hydrophilic imide resin is brown-yellow and transparent.

[0074] Example 10

[0075] The difference between Example 10 and Example 8 is that in Example 8, the F520 resin is adjusted from 1.95 mol to 2.1 mol. The other steps remain unchanged. The product hydrophilic imide resin is brown-yellow and transparent.

[0076] Comparative Example 1

[0077] The hydrophilic polyaspartic acid ester resin was prepared according to the method of Example 1 in the prior art CN111303368A.

[0078] Test method for water solubility of the resin to be tested: Under 25°C, weigh 100 grams of the resin sample to be tested and place it in a colorless and transparent container. Slowly add an appropriate amount of pure water while stirring, stir evenly, and then measure according to the method specified in GB 1721-2008 "Test Method for Appearance and Transparency of Varnish, Clear Oil and Thinner". Record the weight of pure water added when the instrument measurement value reaches 82. The results are shown in Table 1 below. The less the weight of pure water, the worse the hydrophilicity of the resin to be tested.

[0079] The resin to be tested and the isocyanate curing agent (composed of an adduct curing agent prepared from 3% HDI trimer, 10% HMDI and 87% IPDI and polyether polyol) were mixed evenly according to the ratio of the total molar number of secondary amine and hydroxyl groups to the molar number of isocyanate of 1:1.05 to obtain a coating composition, and a film with a thickness of 0.1 mm was formed on a clean glass surface, and placed at 25°C and 55% humidity for 24 hours. The retention time of boiling in a 100°C 1wt% NaOH aqueous solution was tested, and observation was made every 0.5 hours. The time closest to the film layer showing abnormalities such as shedding, warping, bubbling, etc. was taken as the boiling time. For example, if the film layer showed abnormalities at 3.5 hours, the boiling time was 3 hours. The longer the time, the better the hydrolysis resistance.

[0080] The coating composition was formed into a film of 0.5 mm, cured at 35±2° C. for 15 days, and the tensile strength was tested.

[0081] The results are shown in Table 1 below.

[0082] Table 1

[0083]

[0084]

[0085] From the data results in Table 1 above, it can be seen that the hydrophilic imide resin of the present invention has good hydrophilicity, hydrolysis resistance and mechanical strength, and the structure and properties of the obtained imide resin can be flexibly adjusted by adjusting the double-terminated primary amino polyether and / or monoamine compound used.

[0086] As described above, the basic principles, main features and advantages of the present invention are shown and described. Those skilled in the art should understand that the present invention is not limited by the above embodiments, which are only preferred embodiments of the present invention and cannot be used to limit the scope of the present invention. That is, equivalent changes and modifications made according to the scope of the present invention and the content of the specification should still be within the scope of the present invention. The scope of protection required by the present invention is defined by the attached claims and their equivalents.

Claims

1. A hydrophilic imide resin, characterized in that: It has the structure shown in the following formula (1), YA2(1) Wherein, Y is a divalent organic structure with an average molecular weight of 50-5000 which is inert to isocyanate groups at 100° C. and which remains after removing two terminal primary amino groups from the double-terminal primary amino polyether. The solubility of the double-terminal primary amino polyether in pure water at 25° C. is not less than 10 g / 100 g water. The structure of A is as shown in the following formula (2) or (3), or the structure of A is a combination of the structures shown in the formula (2) and the formula (3). Among them, R 1 and R 2 independently selected from C1-C4 alkyl, R 3 It is selected from C1-C18 alkyl, C2-C18 substituted alkyl or polyether segment, and X is a divalent organic structure with an average molecular weight of 50-500 which is inert to the isocyanate group at 100°C and remains after the primary amino group is removed from the polyamine compound.

2. The hydrophilic imide resin according to claim 1, characterized in that The number average molecular weight of the double-terminated primary amino polyether is no more than 2500.

3. The hydrophilic imide resin according to claim 1, characterized in that In the combination of the structures represented by the formula (2) and the formula (3), the molar ratio of the formula (2) to the formula (3) is 1:4-4:

1.

4. The hydrophilic imide resin according to claim 1, characterized in that The structure of the polyether segment is shown in the following formula (4): -(CH2CH2O) m (CH2CHCH3O) n R 4 (4) Where m≥0, n≥0, 1≤m+n≤50, R 4 Selected from H or C1-C18 alkyl.

5. The hydrophilic imide resin according to claim 4, characterized in that m≥1.2n, R 4 Selected from C4-C18 alkyl.

6. The hydrophilic imide resin according to claim 4, characterized in that m<1.2n, R 4 Selected from H or C1-C4 alkyl.

7. A method for preparing a hydrophilic imide resin according to any one of claims 1 to 6, characterized in that: The following steps are involved: The polyvalent primary amine compound and the alkyl maleate undergo Michael addition reaction to obtain the first aspartic acid resin; The first asparagine resin and the double-terminated primary amino polyether undergo a first imide reaction to obtain the hydrophilic imide resin; Alternatively, the first asparagine resin is reacted with the double-terminated primary amino polyether to undergo a second imide reaction, and then the R 3 The corresponding monoamine compound R 3 NH2, conduct a third imide reaction to obtain the hydrophilic imide resin; R 3 has the same meaning as above.

8. The hydrophilic imide resin according to claim 7, characterized in that The catalysts for the first imide reaction, the second imide reaction and the third imide reaction are independently selected from one or a combination of two or more of C6-C18 fatty acids, benzotriazole and substituted benzotriazole.

9. The hydrophilic imide resin according to claim 7, characterized in that: The molar ratio of the first asparagine resin to the double-terminated primary amino polyether is 1.8-2.2:

1.

10. The hydrophilic imide resin according to claim 7, characterized in that: The molar ratio of the first asparagine resin to the monoamine compound is 1:0.2-1.

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