Novel water-soluble polyamic acid ester, preparation method thereof and polyimide

Abstract

The invention relates to the field of polyimide materials, in particular to water-soluble polyamide acid ester, a preparation method thereof and polyimide. Compared with the prior art, the polyamic acid ester provided by the invention is excellent in water solubility, the selection of synthetic monomers is relatively flexible, corresponding water-soluble polyamic acid ester can be synthesized by utilizing a series of simple and easily available polymeric monomers, and the polyamic acid ester is not limited to monomers of water-soluble groups such as hydroxyl and carboxyl in molecules; a series of novel water-soluble polyamic acid ester with good dielectric property, heat-conducting property and the like can be synthesized, the method is simple in preparation process and low in cost, the current environmental protection requirement is met, the mechanical property of the processed, formed and imidized polyamic acid ester is not lost, polyimide with high mechanical property can be prepared, and the polyimide has good application prospects. The requirements of the fields of photosensitive polyimide photoresist, water-soluble polyimide sizing agents and the like on the application of the water-soluble polyimide are met.

Description

Technical Field

[0001] The present invention relates to the field of polyimide materials, and specifically to a water-soluble polyamic acid ester, a preparation method thereof, and a polyimide. Background Art

[0002] Polyimide resin refers to a class of high molecular polymers containing imide rings in the main chain, and has good high temperature resistance, mechanical properties, insulation properties, and electrical properties. With the rapid development of the aerospace and electronics industries, this high-performance polymer material has been rapidly developed. At present, it has been widely used in the fields of aviation, aerospace, microelectronics, nanotechnology, liquid crystals, separation membranes, lasers, etc. The application scope includes plastics, composite materials, films, adhesives, fibers, foams, liquid crystal alignment agents, separation membranes, photoresists, etc. It is considered a "problem solver", and it is considered that "there would be no current microelectronics industry without polyimide".

[0003] In some application scenarios (such as the microelectronics industry), polyimide resin must be used in a liquid form. However, the currently studied polyimide resins are basically insoluble in water and can only be dissolved in organic solvents such as dimethylacetamide and dimethylformamide to form organic solvent-based polyimide resin solutions for use. Moreover, the organic solvent-based polyimide resin solution has a very high viscosity even when the solid content of the polyimide resin is 15%, and a large amount of organic solvent is required to dilute it during use. Organic solvents are flammable, explosive, toxic, pollute the environment and endanger human health, causing many inconveniences to the storage, transportation and application of the organic solvent-based polyamide resin solution. With the continuous enhancement of people's environmental and health awareness, as well as the soaring prices of organic solvents and the strict restrictions on the use of organic solvents and waste emissions by environmental protection departments in recent years, using water-soluble resin solutions instead of organic solvent-based resin solutions has become an important direction in the current chemical industry. At present, the applications of water-soluble polyimides are mostly polyimides containing hydroxyl and carboxyl structures in the molecule, but these water-soluble polyimides are all restricted to a certain extent in the molecular skeleton.

[0004] Based on the fact that traditional polyimide resins are basically insoluble in water and can only be dissolved in organic solvents such as dimethylacetamide and dimethylformamide to form organic solvent-based polyimide resin solutions for use, at present, in order to prepare water-soluble polyimide, it is usually necessary to introduce water-soluble groups such as hydroxyl or carboxyl into the synthetic monomers to increase the water solubility of the polyimide. However, the limitations of the structural modification of the synthetic monomers are relatively large, and the types of commercial substrate monomers are few and all are relatively expensive. Summary of the Invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide a water-soluble polyamic acid ester, a preparation method thereof, and a polyimide. The water-soluble polyamic acid ester provided by the present invention has excellent water solubility. After being processed and imidized, its mechanical properties will not be lost, and a polyimide with high mechanical properties can be prepared, meeting the application requirements of water-soluble polyimide in fields such as water-developable photosensitive polyimide and water-soluble polyimide sizing agents.

[0006] The present invention provides a water-soluble polyamic acid ester having a structure shown in Formula I:

[0007]

[0008] Wherein, n is 5 - 500;

[0009] X is selected from substituted or unsubstituted C6 - C 30 aryl;

[0010] Ar1 is selected from substituted or unsubstituted C4 - C6 cycloalkyl or substituted or unsubstituted C6 - C 30 aryl;

[0011] R' and R" are independently selected from substituted or unsubstituted C1 - C 12 alkyl or substituted or unsubstituted aryl;

[0012] y is an integer from 1 to 12.

[0013] The water-soluble polyamic acid ester provided by the present invention has a -(CH2) y -NR'R" side chain group, which is derived from a fatty amine containing a hydroxyl group. Wherein, R' and R" are independently selected from substituted or unsubstituted C1 - C 12 alkyl or substituted or unsubstituted aryl. Preferably, R' and R" are independently selected from C1 - C 12 linear alkyl; More preferably, R' and R" are independently selected from C1 - C6 linear alkyl; Even more preferably, R' and R" are both selected from methyl or ethyl. y is an integer from 1 to 12, preferably, y is an integer from 1 to 8. More preferably, y is an integer from 1 to 4.

[0014] The water-soluble polyamic acid ester provided by the present invention has an X group, which is derived from the diamines commonly used in the synthesis of polyimides. The diamines for the polyamic acid ester of the present invention can be selected from the conventional diamines for synthesizing polyimides. The water solubility of the polyamic acid ester of the present invention does not cause differences in solubility in water due to different diamine structures. Therefore, the conventional diamines for synthesizing polyimides can all be used as the diamines of the present invention. However, from the perspective of dissolution rate, diamines containing a diphenyl ether group structure or a diphenyl sulfone group structure are preferred. Specifically, the X is selected from substituted or unsubstituted C6-C 30 aryl. Preferably, the X is selected from substituted or unsubstituted C 12 -C 30 aryl.

[0015] More preferably, the X is selected from the groups having the structures shown in Formula X-1 to Formula X-5;

[0016]

[0017] Even more preferably, the X is selected from the groups having the structures shown in Formula X-a to Formula X-h;

[0018]

[0019] The water-soluble polyamic acid ester provided by the present invention also has an Ar1 group, which is derived from an aliphatic dianhydride or an aromatic dianhydride. The dianhydrides for the polyamic acid ester of the present invention can be selected from the conventional dianhydrides for synthesizing polyimides. The water solubility of the polyamic acid ester of the present invention does not cause differences in solubility in water due to different dianhydride structures. Therefore, the conventional dianhydrides for synthesizing polyimides can all be used as the dianhydrides of the present invention. However, from the perspective of dissolution rate, the Ar1 is selected from a cycloaliphatic group, an aromatic group containing a carbonyl group, an aromatic group containing an ether bond, an aromatic group containing a sulfonyl group, an aromatic group containing an ester group, an aromatic group containing an alkyl group, or an aromatic group containing only a benzene ring. Preferably, the Ar1 is selected from substituted or unsubstituted C4-C6 cycloalkyl or substituted or unsubstituted C6-C 30 aryl. The water-soluble polyamic acid ester of the present invention has a soluble property in neutral water solubility, and its solubility in neutral water solubility > soluble, and its dissolution rate in neutral water solubility > 0.1 g / min.

[0020] Preferably, the Ar1 is selected from the groups having the structures shown in Formula Ar1-1 to Formula Ar1-12;

[0021]

[0022] More preferably, the Ar1 is selected from the groups having the structures shown in Formula Ar1-a to Formula Ar1-r;

[0023]

[0024] The present invention also provides a method for preparing the water-soluble polyamic acid ester described in any one of the above, comprising the following steps:

[0025] React a dianhydride having the structure of Formula 1 with an alkanolamine having the structure of Formula 2, and then react the resulting product together with a diamine having the structure of Formula 3 to obtain a water-soluble polyamic acid ester;

[0026]

[0027] Before reacting the resulting product with the diamine having the structure of Formula 3, the present invention also includes activating the resulting product. The activation described in the present invention refers to a method for activating a carboxyl group to enable the reaction between the carboxyl group and an amino group. Specifically, the activation method of the present invention refers to adding an amide condensing agent formed by a carboxylic acid and an amino group. For example, the amide condensing agent is carbodiimide, carbonyldiimidazole, carbonium salt or organophosphorus condensing agent; preferably carbodiimide or carbonyldiimidazole condensing agent. More preferably dicyclohexylcarbodiimide (DCC), diisopropylcarbodiimide (DIC) or 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI). Alternatively, the activation is to convert the carboxyl group into an acyl halide, which can then react with the amino group; for example, using a conventional acyl halide reagent to convert the carboxyl group into an acyl halide, and the acyl halide reagent can be thionyl halide, phosphoryl halide or carbonyl halide, preferably thionyl chloride (SOCl2), phosphorus oxychloride or oxalyl chloride.

[0028] Specifically, under an inert gas atmosphere, react the dianhydride having the structure of Formula 1 with the alkanolamine having the structure of Formula 2 at 0°C to 60°C for 5 h to 7 h, and then react the resulting product with an amide condensing agent, or react the resulting product with an acyl halide reagent, at -5°C to 5°C for 3 h to 7 h, and then react together with the diamine having the structure of Formula 3 at -5°C to 5°C for 11 h to 13 h to obtain a water-soluble polyamic acid ester.

[0029] More specifically, under an inert gas atmosphere, react the dianhydride having the structure of Formula 1 with the alkanolamine having the structure of Formula 2 at 0°C to 60°C for 5 h to 7 h, and then react the resulting product with dicyclohexylcarbodiimide, or react the resulting product with thionyl chloride, at -5°C to 5°C for 3 h to 7 h, and then react together with the diamine having the structure of Formula 3 at -5°C to 5°C for 11 h to 13 h to obtain a water-soluble polyamic acid ester.

[0030] In certain embodiments of the present invention, under a protective gas atmosphere, the dianhydride having the structure of Formula 1 is dissolved in an organic solvent, and an alkanolamine having the structure of Formula 2 is added thereto, and the reaction is carried out at a temperature of 0 °C to 60 °C for 5 h to 7 h. Then, the reaction product obtained is reacted with dicyclohexylcarbodiimide or thionyl chloride at -5 °C to 5 °C for 3 h to 7 h, and then reacted with a diamine having the structure of Formula 3 by stirring at -5 °C to 5 °C for 11 h to 13 h to obtain a light yellow water-soluble polyamic acid ester solution, and a light yellow water-soluble polyamic acid ester solid powder can be obtained by precipitation with ethanol.

[0031] The molar ratio of the dianhydride having the structure of Formula 1, the alkanolamine having the structure of Formula 2, and the diamine having the structure of Formula 3 in the present invention is (0.8 to 1.2):(1.6 to 2.4):1, such as 0.9:(1.6 to 2.4):1, such as 1.0:(1.6 to 2.4):1, such as 1.1:(1.6 to 2.4):1, such as 1.2:(1.6 to 2.4):1. The ratio of the amount of the amide condensing agent or acyl halide reagent used in the present invention to the amount of the diamine having the structure of Formula 3 is (1.6 to 2.4):1. The protective gas in the present invention is selected from one or more of nitrogen, helium, neon, and argon. The organic solvent in the present invention is selected from one or more of DMF, DMAc, NMP, and butyrolactone.

[0032] The dianhydride having the structure of Formula 1 in the present invention is a dibasic anhydride, which is an essential component as a polymerization monomer of polyamic acid ester, and is specifically selected from at least one of 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5-benzenetetracarboxylic dianhydride, 3,4,3',4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 2,3,2',3'-biphenyltetracarboxylic dianhydride, 3,4,3',4'-benzophenonetetracarboxylic dianhydride, 2,3,3',4'-benzophenonetetracarboxylic dianhydride, 3,4,3',4'-diphenylethertetracarboxylic dianhydride, 2,3,3',4'-diphenylethertetracarboxylic dianhydride, 3,4,3',4'-diphenylsulfonetetracarboxylic dianhydride, 2,3,3',4'-diphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)phenyl dianhydride, 1,3-bis(3,4-dicarboxyphenoxy)phenyl dianhydride, 3,4-dicarboxybenzoic acid-(3,4-dicarboxyphenol)ester dianhydride, 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride. Preferably, the dianhydride having the structure of Formula 1 is selected from benzenetetracarboxylic dianhydride, 3,4,3',4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 2,3,2',3'-biphenyltetracarboxylic dianhydride, 3,4,3',4'-diphenylethertetracarboxylic dianhydride or 2,3,3',4'-diphenylethertetracarboxylic dianhydride. More preferably, the dianhydride having the structure of Formula 1 is selected from 3,4,3',4'-diphenylethertetracarboxylic dianhydride or 2,3,3',4'-diphenylethertetracarboxylic dianhydride.

[0033] The alkanolamine having the structure of Formula 2 in the present invention, which is an essential component as an alkanolamine monomer in the esterification process, is specifically selected from at least one of dimethylaminoethanol, dimethylaminopropanol, dimethylaminopentanol, diethylaminopentanol, 4-dimethylaminophenol, 2-diphenylaminoethanol, 4-diphenylaminophenol, 2-diphenylaminomethanol.

[0034] The diamine having the structure of Formula 3 according to the present invention, as an essential component of the polymerization monomer of polyamic acid ester, is selected from diamines containing a diphenyl ether group structure or diamines containing a diphenyl sulfone group structure, specifically selected from at least one of 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 4,4'-diaminodiphenyl sulfone, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 1,3-bis(4-aminophenoxy)biphenyl or 4,4'-bis(3-aminophenoxy)biphenyl. Preferably, the selected diamine having the structure of Formula 3 is selected from 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether or 4,4'-diaminodiphenyl ether. More preferably, the diamine having the structure of Formula 3 is selected from 3,4'-diaminodiphenyl ether or 4,4'-diaminodiphenyl ether.

[0035] The present invention also provides a polyimide, which is obtained by imidizing the water-soluble polyamic acid ester described in any one of the above technical solutions or the water-soluble polyamic acid ester obtained by the preparation method described in any one of the above technical solutions. Specifically, it is processed and formed into a polyimide by the imidization curing process of the water-soluble polyamic acid ester. The imidization temperature in the present invention is a low-temperature imidization curing temperature of 200°C to 250°C. This is because the polyamic acid ester of the present invention has a tertiary amine structure, which can be used as a catalyst to achieve low-temperature imidization, which will be beneficial to the curing and forming of polyimide in temperature-sensitive scenarios.

[0036] The polyimide provided by the present invention has the structure of Formula II;

[0037]

[0038] Wherein Ar1, X and n are the same as above and will not be repeated.

[0039] Specifically, the polyimide provided by the present invention can be processed and formed into a material with a certain shape while imidizing from its aforementioned polyamic acid ester solution. This water-soluble polyamic acid ester can be used to process various materials that can usually be processed by solvent-based polyimides. Such materials can be films, coatings, paints, adhesives, foams, fibers, composite matrix resins, and bulk materials. These polyimide materials can be obtained by imidizing after the aqueous solution of the polyimide acid ester of the present invention undergoes a conventional polymer solution forming process such as casting, spin coating, dipping, spraying, etc.

[0040] The present invention provides a water-soluble polyamide acid ester, a preparation method thereof, and a polyimide. Compared with the prior art, the polyamide acid ester provided by the present invention has excellent water solubility, and the selection of synthesis monomers is relatively flexible. A series of simple and easily available polymerization monomers can be used to synthesize corresponding water-soluble polyamide acid esters, not limited to monomers with water-soluble groups such as hydroxyl groups and carboxyl groups in the molecule. A series of novel water-soluble polyamide acid esters with good properties such as dielectric properties and thermal conductivity can be synthesized. Moreover, the preparation process of this method is simple and the cost is low, meeting the requirements of current environmental protection. After processing, forming, and imidizing, the mechanical properties of the polyamide acid ester will not be lost, and a polyimide with high mechanical properties can be prepared, meeting the application requirements of water-soluble polyimides in fields such as photosensitive polyimide photoresists and water-soluble polyimide sizing agents. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a flowchart for the preparation of the water-soluble polyamide acid ester and polyimide described in the present invention;

[0042] Figure 2 It is a mechanical property test chart of the polyimide film obtained in Example 1;

[0043] Figure 3 It is a mechanical property test chart of the polyimide film obtained in Example 2;

[0044] Figure 4 It is a mechanical property test chart of the polyimide film obtained in Example 3;

[0045] Figure 5 It is a mechanical property test chart of the polyimide film obtained in Example 4;

[0046] Figure 6 It is a mechanical property test chart of the polyimide film obtained in Example 5;

[0047] Figure 7 It is a mechanical property test chart of the polyimide film obtained in Example 6;

[0048] Figure 8 It is a mechanical property test chart of the polyimide film obtained in Example 7;

[0049] Figure 9 It is a mechanical property test chart of the polyimide film obtained in Example 8;

[0050] Figure 10 It is a mechanical property test chart of the polyimide film obtained in Comparative Example 1;

[0051] Figure 11 It is a mechanical property test chart of the polyimide film obtained in Comparative Example 2;

[0052] Figure 12Mechanical property test chart of the polyimide film obtained in Comparative Example 3;

[0053] Figure 13 Mechanical property test chart of the polyimide film obtained in Comparative Example 4;

[0054] Figure 14 Mechanical property test chart of the polyimide film obtained in Comparative Example 5. Detailed implementation mode

[0055] The present invention discloses a water-soluble polyamic acid ester, its preparation method and polyimide. Those skilled in the art can draw on the content of this article and appropriately modify the process parameters to achieve. It should be particularly pointed out that all similar substitutions and modifications are obvious to those skilled in the art, and they are all regarded as included in the present invention. The method and application of the present invention have been described through preferred embodiments, and those related can obviously make changes or appropriate changes and combinations to the methods and applications in this article without departing from the content, spirit and scope of the present invention to implement and apply the technology of the present invention.

[0056] As Figure 1 shown, Figure 1 is the preparation flow chart of the water-soluble polyamic acid ester and polyimide of the present invention. The present invention prepares the water-soluble polyamic acid ester and polyimide according to the Figure 1 shown process.

[0057] The present invention will be further described below in conjunction with embodiments:

[0058] Example 1

[0059] 4,4'-oxybisphthalic anhydride ODPA (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and dimethylaminoethanol (322.2 mol, 28.7 g) were successively added to a reaction vessel and stirred at 0 °C for 6 h. Thionyl chloride SOCl2 (322.2 mmol, 38.0 g) was added to the flask, stirred at 0 °C for 3 h, and 4,4'-diaminodiphenyl ether ODA (161.1 mmol, 32.2 g) was added, stirred at 0 °C for 12 h. The obtained polyamic acid ester solution was precipitated with ethanol to obtain yellow polyamic acid ester powder.

[0060] 1. The polyamic acid ester powder was added dropwise with deionized water while stirring at a temperature of 30 °C, the stirring speed was 200 r / min, and the mass of water added to the mixed solution per minute was 3 g to investigate its solubility.

[0061] 2. A 30% by mass aqueous solution of the polyamide ester polyamic acid ester is cast on the surface of a substrate and heated to 250 °C for thermal imidization to obtain the corresponding polyimide film, and the mechanical properties of the polyimide film are investigated.

[0062] Example 2

[0063] To the reaction vessel, pyromellitic dianhydride PMDA (161.1 mol, 35.1 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and dimethylaminoethanol (322.2 mol, 28.7 g) were added in sequence, and the reaction was stirred at 0 °C for 6 h. DCC (322.2 mmol, 66.5 g) was added to the flask, and the reaction was stirred at -5 °C for 4 h. 4,4'-Diaminodiphenyl ether ODA (161.1 mmol, 32.2 g) was added, and the reaction was stirred at 0 °C for 11 h. The obtained polyamic acid ester solution was precipitated with ethanol to obtain a yellow polyamic acid ester powder.

[0064] 1. The polyamic acid ester powder was added dropwise with deionized water while stirring at a temperature of 30 °C, the stirring speed was 200 r / min, and the mass of water added to the mixed solution per minute was 3 g, and its solubility was investigated.

[0065] 2. A 30% by mass aqueous solution of the polyamide ester polyamic acid ester is cast on the surface of a substrate and heated to 220 °C for thermal imidization to obtain the corresponding polyimide film, and the mechanical properties of the polyimide film are investigated.

[0066] Example 3

[0067] To the reaction vessel, 3,3',4,4'-benzophenone tetracarboxylic dianhydride BTDA (161.1 mol, 51.9 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and dimethylaminoethanol (322.2 mol, 28.7 g) were added in sequence, and the reaction was stirred at -5 °C for 6 h. Thionyl chloride SOCl2 (322.2 mmol, 38.0 g) was added to the flask, and the reaction was stirred at 5 °C for 7 h. 4,4'-Diaminodiphenyl ether ODA (161.1 mmol, 32.2 g) was added, and the reaction was stirred at 5 °C for 13 h. The obtained polyamic acid ester solution was precipitated with ethanol to obtain a light yellow polyamic acid ester powder.

[0068] 1. The polyamic acid ester powder was added dropwise with deionized water while stirring at a temperature of 30 °C, the stirring speed was 200 r / min, and the mass of water added to the mixed solution per minute was 3 g, and its solubility was investigated.

[0069] 2. A 30% by mass aqueous solution of the polyamide ester polyamic acid ester is cast on the surface of a substrate and heated to 210 °C for thermal imidization to obtain the corresponding polyimide film, and the mechanical properties of the polyimide film are investigated.

[0070] Example 4

[0071] 4,4'-oxybisphthalic anhydride ODPA (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and dimethylaminoethanol (322.2 mol, 28.7 g) were successively added to the reaction vessel, and the mixture was stirred at 5 °C for 7 h. Thionyl chloride DCC (322.2 mmol, 66.5 g) was added to the flask, and the mixture was stirred at -5 °C for 6 h. 4,4'-Diaminodiphenyl sulfone DDS (161.1 mmol, 40.0 g) was added, and the mixture was stirred at -5 °C for 11 h. The obtained polyamic acid ester solution was precipitated with ethanol to obtain a yellow polyamic acid ester powder.

[0072] 1. Deionized water was added dropwise to the polyamic acid ester powder with stirring at a temperature of 30 °C, the stirring speed was 200 r / min, and the mass of water added to the mixture per minute was 3 g. Its solubility was investigated.

[0073] 2. An aqueous solution with a mass fraction of 30% of this polyamide ester polyamic acid ester was cast on the surface of the substrate and heated to 240 °C for thermal imidization to obtain the corresponding polyimide film. The mechanical properties of the polyimide film were investigated.

[0074] Example 5

[0075] 4,4'-oxybisphthalic anhydride ODPA (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and dimethylaminoethanol (322.2 mol, 28.7 g) were successively added to the reaction vessel, and the mixture was stirred at 3 °C for 7 h. Thionyl chloride SOCl2 (322.2 mmol, 38.0 g) was added to the flask, and the mixture was stirred at 3 °C for 5 h. 1,4-Cyclohexanediamine CHDA (161.1 mmol, 18.4 g) was added, and the mixture was stirred at 5 °C for 13 h. The obtained polyamic acid ester solution was precipitated with ethanol to obtain a yellow polyamic acid ester powder.

[0076] 1. Deionized water was added dropwise to the polyamic acid ester powder with stirring at a temperature of 30 °C, the stirring speed was 200 r / min, and the mass of water added to the mixture per minute was 3 g. Its solubility was investigated.

[0077] 2. An aqueous solution with a mass fraction of 30% of this polyamide ester polyamic acid ester was cast on the surface of the substrate and heated to 250 °C for thermal imidization to obtain the corresponding polyimide film. The mechanical properties of the polyimide film were investigated.

[0078] Example 6

[0079] 4,4'-oxydiphthalic anhydride ODPA (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and dimethylaminopropanol (322.2 mol, 33.2 g) were successively added to the reaction vessel, and the mixture was stirred at 60 °C for 7 h. DCC (322.2 mmol, 66.5 g) was added to the flask, and the mixture was stirred at 0 °C for 3 h. Then, 4,4'-diaminodiphenyl ether ODA (161.1 mmol, 32.2 g) was added, and the mixture was stirred at -5 °C for 11 h. The resulting polyamic acid ester solution was precipitated with ethanol to obtain a yellow polyamic acid ester powder.

[0080] 1. Deionized water was added dropwise to the polyamic acid ester powder with stirring at 30 °C, the stirring speed was 200 r / min, and the mass of water added to the mixture per minute was 3 g to investigate its solubility.

[0081] 2. An aqueous solution with a mass fraction of 30% of this polyamide ester polyamic acid ester was cast on the surface of the substrate and heated to 205 °C for thermal imidization to obtain the corresponding polyimide film, and the mechanical properties of the polyimide film were investigated.

[0082] Example 7

[0083] 4,4'-oxydiphthalic anhydride ODPA (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and dimethylaminopentanol (322.2 mol, 41.2 g) were successively added to the reaction vessel, and the mixture was stirred at 45 °C for 6 h. Thionyl chloride SOCl2 (322.2 mmol, 38.0 g) was added to the flask, and the mixture was stirred at 5 °C for 7 h. Then, 4,4'-diaminodiphenyl ether ODA (161.1 mmol, 32.2 g) was added, and the mixture was stirred at -5 °C for 13 h. The resulting polyamic acid ester solution was precipitated with ethanol to obtain a yellow polyamic acid ester powder.

[0084] 1. Deionized water was added dropwise to the polyamic acid ester powder with stirring at 30 °C, the stirring speed was 200 r / min, and the mass of water added to the mixture per minute was 3 g to investigate its solubility.

[0085] 2. An aqueous solution with a mass fraction of 30% of this polyamide ester polyamic acid ester was cast on the surface of the substrate and heated to 250 °C for thermal imidization to obtain the corresponding polyimide film, and the mechanical properties of the polyimide film were investigated.

[0086] Example 8

[0087] 4,4'-oxydiphthalic anhydride ODPA (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and diethylaminopentanol (322.2 mol, 49.9 g) were successively added to the reaction vessel, and the mixture was stirred at 0 °C for 6 h. DCC (322.2 mmol, 66.5 g) was added to the flask, and the mixture was stirred at 0 °C for 3 h. Then, 4,4'-diaminodiphenyl ether ODA (161.1 mmol, 32.2 g) was added, and the mixture was stirred at 0 °C for 12 h. The resulting polyamic acid ester solution was precipitated with ethanol to obtain a yellow polyamic acid ester powder.

[0088] 1. Deionized water was added dropwise with stirring to the polyamic acid ester powder at 30 °C, the stirring speed was 200 r / min, and 3 g of water was added to the mixture per minute to investigate its solubility.

[0089] 2. An aqueous solution with a mass fraction of 30% of this polyamide ester polyamic acid ester was cast on the surface of the substrate and heated to 225 °C for thermal imidization to obtain the corresponding polyimide film, and the mechanical properties of the polyimide film were investigated.

[0090] Comparative Example 1

[0091] 4,4'-oxydiphthalic anhydride ODPA (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and diisopropylaminoethanol (322.2 mol, 40.9 g) were successively added to the reaction vessel, and the mixture was stirred at 0 °C for 6 h. Dicyclohexylcarbodiimide DCC (322.2 mmol, 66.4 g) and 4,4'-diaminodiphenyl ether ODA (161.1 mmol, 32.2 g) were added to the flask, and the mixture was stirred at 0 °C for 12 h. The resulting polyamic acid ester solution was precipitated with ethanol to obtain a yellow polyamic acid ester powder.

[0092] 1. Deionized water was added dropwise with stirring to the polyamic acid ester powder at 30 °C, the stirring speed was 200 r / min, and 3 g of water was added to the mixture per minute to investigate its solubility.

[0093] 2. An aqueous solution with a mass fraction of 30% of this polyamide ester polyamic acid ester was cast on the surface of the substrate and heated to 250 °C for thermal imidization to obtain the corresponding polyimide film, and the mechanical properties of the polyimide film were investigated.

[0094] Comparative Example 2

[0095] 4,4'-oxybisphthalic anhydride ODPA (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and dimethylaminoheptanol (322.2 mol, 49.9 g) were successively added to the reaction vessel, and the mixture was stirred at 0 °C for 6 h. Dicyclohexylcarbodiimide DCC (322.2 mmol, 66.4 g) and 4,4'-diaminodiphenyl ether ODA (161.1 mmol, 32.2 g) were added to the flask, and the mixture was stirred at 0 °C for 12 h. The resulting polyamic acid ester solution was precipitated with ethanol to obtain a yellow polyamic acid ester powder.

[0096] 1. Deionized water was added dropwise with stirring to the polyamic acid ester powder at 30 °C, the stirring speed was 200 r / min, and the mass of water added to the mixture per minute was 3 g to investigate its solubility.

[0097] 2. An aqueous solution with a mass fraction of 30% of this polyamide ester polyamic acid ester was cast on the surface of the substrate and heated to 250 °C for thermal imidization to obtain the corresponding polyimide film, and the mechanical properties of the polyimide film were investigated.

[0098] Comparative Example 3

[0099] 4,4'-oxybisphthalic anhydride ODPA (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and 4-dimethylaminophenol (322.2 mol, 44.1 g) were successively added to the reaction vessel, and the mixture was stirred at 0 °C for 6 h. Dicyclohexylcarbodiimide DCC (322.2 mmol, 66.4 g) and 4,4'-diaminodiphenyl ether ODA (161.1 mmol, 32.2 g) were added to the flask, and the mixture was stirred at 0 °C for 12 h. The resulting polyamic acid ester solution was precipitated with ethanol to obtain a yellow polyamic acid ester powder.

[0100] 1. Deionized water was added dropwise with stirring to the polyamic acid ester powder at 30 °C, the stirring speed was 200 r / min, and the mass of water added to the mixture per minute was 3 g to investigate its solubility.

[0101] 2. An aqueous solution with a mass fraction of 30% of this polyamide ester polyamic acid ester was cast on the surface of the substrate and heated to 250 °C for thermal imidization to obtain the corresponding polyimide film, and the mechanical properties of the polyimide film were investigated.

[0102] Comparative Example 4

[0103] 4,4'-oxybisphthalic anhydride ODPA (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and diethanolamine (322.2 mol, 33.8 g) were successively added to the reaction vessel, and the mixture was stirred at 0 °C for 6 h. Dicyclohexylcarbodiimide DCC (322.2 mmol, 66.4 g) and 4,4'-diaminodiphenyl ether ODA (161.1 mmol, 32.2 g) were added to the flask, and the mixture was stirred at 0 °C for 12 h. The resulting polyamic acid ester solution was precipitated with ethanol to obtain a yellow polyamic acid ester powder.

[0104] 1. Deionized water was added dropwise with stirring to the polyamic acid ester powder at 30 °C, the stirring speed was 200 r / min, and the mass of water added to the mixture per minute was 3 g to investigate its solubility.

[0105] 2. An aqueous solution with a mass fraction of 30% of this polyamide ester polyamic acid ester was cast on the surface of the substrate and heated to 250 °C for thermal imidization to obtain the corresponding polyimide film, and the mechanical properties of the polyimide film were investigated.

[0106] Comparative Example 5

[0107] 4,4'-oxybisphthalic anhydride ODPA (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and triethanolamine (322.2 mol, 48.0 g) were successively added to the reaction vessel, and the mixture was stirred at 0 °C for 6 h. Dicyclohexylcarbodiimide DCC (322.2 mmol, 66.4 g) and 4,4'-diaminodiphenyl ether ODA (161.1 mmol, 32.2 g) were added to the flask, and the mixture was stirred at 0 °C for 12 h. The resulting polyamic acid ester solution was precipitated with ethanol to obtain a yellow polyamic acid ester powder.

[0108] 1. Deionized water was added dropwise with stirring to the polyamic acid ester powder at 30 °C, the stirring speed was 200 r / min, and the mass of water added to the mixture per minute was 3 g to investigate its solubility.

[0109] 2. An aqueous solution with a mass fraction of 30% of this polyamide ester polyamic acid ester was cast on the surface of the substrate and heated to 250 °C for thermal imidization to obtain the corresponding polyimide film, and the mechanical properties of the polyimide film were investigated.

[0110] Comparative Example 6

[0111] 4,4'-oxybisphthalic anhydride ODPA (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and ethanolamine (322.2 mol, 19.6 g) were successively added to a reaction vessel, and the mixture was stirred at 0 °C for 6 h. Dicyclohexylcarbodiimide DCC (322.2 mmol, 66.4 g) and 4,4'-diaminodiphenyl ether ODA (161.1 mmol, 32.2 g) were added to the flask, and the mixture was stirred at 0 °C for 12 h. The resulting poly(amic acid ester) solution could not be precipitated with ethanol to obtain a yellow poly(amic acid ester) powder, and could not be further thermally imidized to obtain the corresponding polyimide.

[0112] Comparative Example 7

[0113] 4,4'-oxybisphthalic anhydride ODPA (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and N-methyl-2-hydroxyethylamine (322.2 mol, 24.2 g) were successively added to a reaction vessel, and the mixture was stirred at 0 °C for 6 h. Dicyclohexylcarbodiimide DCC (322.2 mmol, 66.4 g) and 4,4'-diaminodiphenyl ether ODA (161.1 mmol, 32.2 g) were added to the flask, and the mixture was stirred at 0 °C for 12 h. The resulting poly(amic acid ester) solution could not be precipitated with ethanol to obtain a yellow poly(amic acid ester) powder, and could not be further thermally imidized to obtain the corresponding polyimide.

[0114] Performance test:

[0115] (1) Water was added to the poly(amic acid ester) prepared in the examples and comparative examples. Deionized water was added dropwise with stirring at 30 °C. The stirring speed was 200 r / min. The mass of water added to the mixed solution per minute was 3 g. If it was completely dissolved within 0.2 h, it was very easily soluble. If it was completely dissolved within 0.5 h, it was easily soluble. If it was completely dissolved within 1 h, it was soluble. If it was not dissolved within 1 h or precipitation or gelation was observed, it was insoluble, and the specific dissolution rate was tested.

[0116] (2) Mechanical strength: The polyimide films prepared by imidization of the examples and comparative examples were subjected to a tensile test. A universal testing machine and a 500 N pneumatic film tensile fixture were used for the tensile test at an ambient temperature of about 25 °C. The test rate was 5 mm / min. The tensile strength and elongation at break could be obtained through the test.

[0117] The test results are shown in Table 1:

[0118] Table 1

[0119]

[0120] In addition, the mechanical property test result diagrams are as follows Figures 2 to 14 shown. Among them, Figure 2 is the mechanical property test diagram of the polyimide film obtained in Example 1; Figure 3 is the mechanical property test diagram of the polyimide film obtained in Example 2; Figure 4 is the mechanical property test diagram of the polyimide film obtained in Example 3; Figure 5 is the mechanical property test diagram of the polyimide film obtained in Example 4; Figure 6 is the mechanical property test diagram of the polyimide film obtained in Example 5; Figure 7 is the mechanical property test diagram of the polyimide film obtained in Example 6; Figure 8 is the mechanical property test diagram of the polyimide film obtained in Example 7; Figure 9 is the mechanical property test diagram of the polyimide film obtained in Example 8; Figure 10 is the mechanical property test diagram of the polyimide film obtained in Comparative Example 1; Figure 11 is the mechanical property test diagram of the polyimide film obtained in Comparative Example 2; Figure 12 is the mechanical property test diagram of the polyimide film obtained in Comparative Example 3; Figure 13 is the mechanical property test diagram of the polyimide film obtained in Comparative Example 4; Figure 14 is the mechanical property test diagram of the polyimide film obtained in Comparative Example 5

[0121] According to Figures 2 to 14 and the data in Table 1, the solubility of the polyamide esters synthesized in the examples is > soluble, and the dissolution rate is > 0.1 g / min. The solubility of the polyamide esters synthesized in the comparative examples is poor. It can be seen from Examples 1 to 8 that whether the dianhydride and diamine are electron-rich or electron-deficient aromatic compounds or aliphatic compounds, the water-soluble polyamic acid esters can be obtained by reacting with this method, and the mechanical properties of the polyimide obtained by thermal imidization are not lost. However, the solubility of the polyamic acid ester powders obtained in Comparative Examples 1 to 5 is poor, and good water-soluble polyamic acid esters cannot be obtained, and the mechanical properties of the polyimide obtained after thermal imidization are reduced. In Comparative Examples 6 to 7, when the alkanolamine used is a primary amine or a secondary amine, the corresponding water-soluble polyamic acid ester powder cannot be obtained, probably because the competitive reaction brought by the amino group makes the polymerization unable to proceed normally.

[0122] As mentioned above, the above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and all should be covered within the protection scope of the present invention.

Claims

1. A water-soluble polyamic acid ester, characterized in that, It has the structure shown in Formula I: Formula I; Wherein, n is 5 to 500; The X is selected from a substituted or unsubstituted C6-C 30 aryl; Ar1 is selected from substituted or unsubstituted C4-C6 cycloalkyl or substituted or unsubstituted C6-C 30 aryl; The R' and R'' are independently selected from substituted or unsubstituted C1-C 12 alkyl or unsubstituted or substituted aryl; y is an integer from 1 to 12.

2. The water-soluble polyamic acid ester according to claim 1, wherein The R' and R'' are independently selected from C1-C 12 alkyl chains; y is an integer from 1 to 8.

3. The water-soluble polyamic acid ester according to claim 1, wherein X is selected from the groups having the structures shown in Formula X-1 to Formula X-5; 。 4. The water-soluble polyamic acid ester according to claim 1, wherein Ar1 is selected from the groups having the structures shown in Formula Ar1-1 to Formula Ar1-12; 。 5. The water-soluble polyamic acid ester according to claim 1, wherein Its solubility in neutral water solubility > soluble, and its dissolution rate in neutral water solubility > 0.1 g / min.

6. The preparation method of the water-soluble polyamic acid ester according to any one of claims 1 to 5, characterized in that, It includes the following steps: React a dianhydride having the structure of Formula 1 with an alkanolamine having the structure of Formula 2, and then react the resulting product with a diamine having the structure of Formula 3 together to obtain a water-soluble polyamic acid ester; Formula 1; Formula 2; Formula 3.

7. The preparation method according to claim 6, wherein The molar ratio of the dianhydride having the structure of Formula 1, the alkanolamine having the structure of Formula 2, and the diamine having the structure of Formula 3 is (0.8 to 1.2):(1.8 to 2.2):

1.

8. The preparation method according to claim 6, characterized in that, The dianhydride having the structure of Formula 1 is selected from at least one of 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5-benzenetetracarboxylic dianhydride, 3,4,3',4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 2,3,2',3'-biphenyltetracarboxylic dianhydride, 3,4,3',4'-benzophenonetetracarboxylic dianhydride, 2,3,3',4'-benzophenonetetracarboxylic dianhydride, 3,4,3',4'-diphenylethertetracarboxylic dianhydride, 2,3,3',4'-diphenylethertetracarboxylic dianhydride, 3,4,3',4'-diphenylsulfonetetracarboxylic dianhydride, 2,3,3',4'-diphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)phenyl dianhydride, 1,3-bis(3,4-dicarboxyphenoxy)phenyl dianhydride, 3,4-dicarboxybenzoic acid-(3,4-dicarboxyphenol)ester dianhydride, 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride; The alkanolamine having the structure of Formula 2 is selected from at least one of dimethylaminoethanol, dimethylaminopropanol, dimethylaminopentanol, diethylaminopentanol; The diamine having the structure of Formula 3 is selected from at least one of 3,4'-diaminodiphenylether, 4,4'-diaminodiphenylether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 4,4'-diaminodiphenylsulfone, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 1,3-bis(4-aminophenoxy)biphenyl or 4,4'-bis(3-aminophenoxy)biphenyl; 9. A polyimide, characterized in that, It is obtained by imidization of the water-soluble polyamic acid ester described in any one of claims 1 to 5 or the water-soluble polyamic acid ester obtained by the preparation method described in any one of claims 6 to 8.

10. The polyimide according to claim 9, wherein, The temperature of the imidization is 200°C to 250°C.

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