WO2022228449A1

WO2022228449A1 - Preparation method for polyimide resin and thin film thereof

Info

Publication number: WO2022228449A1
Application number: PCT/CN2022/089436
Authority: WO
Inventors: 程跃; 吴超; 吕凯; 刘倩倩; 庄志
Original assignee: 上海瑞暨新材料科技有限公司
Priority date: 2021-04-29
Filing date: 2022-04-27
Publication date: 2022-11-03
Also published as: CN113201136B; CN113201136A

Abstract

The present disclosure relates to the field of polyimide, and in particular to a preparation method for a polyimide resin and a thin film thereof. The method comprises the following steps: S1, upon dissolving a first batch of polydiamine in a solvent under an inert gas atmosphere, adding polydianhydride in a low-temperature environment of 30°C or below for preliminary polymerization to form a resin solution, wherein the polydianhydride is 105-110% of the total molar amount of the first batch of polydiamine and the viscosity of the resin solution is controlled to be 50,000-70,000 cps; S2, monitoring the viscosity of the resin solution and gradually raising the temperature of the resin solution within 30-80°C, and gradually adding a second batch of polyamine in batches in order of descending amounts until the viscosity of the resin solution is 180,000-200,000 cps; and S3, adding a fluorine-containing capping agent, performing uniform mixing, and performing high-vacuum defoaming to obtain a polyimide resin solution. When the polyimide resin prepared in the present disclosure is coated on a base film to prepare a thin film, a formed polyimide coating has strong thermal stability a coefficient of thermal expansion close to that of the base film, and the problem that the edge of the thin film generated in the case of a relatively large difference in coefficients of thermal expansion is prone to curl and shrink is solved.

Description

A kind of preparation method of polyimide resin and film thereof

CROSS-REFERENCE TO RELATED APPLICATIONS

This disclosure claims the priority of the Chinese patent application with the application number "CN 202110474312.6" and the title "A preparation method of polyimide resin and film thereof" filed with the China Patent Office on April 29, 2021, the entire contents of which are Incorporated in this disclosure by reference.

technical field

The present disclosure relates to the field of polyimide films, in particular to a preparation method of polyimide resin and a film thereof.

Background technique

At present, polyamic acid is synthesized by low-temperature polycondensation by first diamine and then dianhydride in an equimolar amount in a suitable organic solvent, and then by casting a film on the substrate, and finally thermal imidization to form a film. However, this preparation method makes the polymer It is difficult to control the apparent viscosity of amic acid within an ideal range of higher viscosity, the length of polymer molecular segments is not balanced, the resin viscosity is difficult to stabilize, and the amount of resin bubbles is large, and the experimental process found that when the dianhydride and diamine are close When the molar ratio is equal, the viscosity will show a similar exponential jump. Therefore, it is difficult to control the apparent viscosity of the resin by polymerization in a low temperature environment with conventional feeding methods. It is often seen that a very small amount of dianhydride is added. The viscosity surges far beyond the expected range, or the short-term viscosity at room temperature The situation of significant decline brings huge difficulties to industrial mass production. Directly adding diamine solid to control the viscosity is prone to the phenomenon of local high agglomeration and difficult polycondensation, which reduces the performance quality of polyimide resin. Not excellent.

SUMMARY OF THE INVENTION

The present disclosure provides a preparation method of polyimide with stable performance and viscosity under long-term storage, which specifically includes the following steps:

S1. After dissolving the first batch of polyvalent diamines in a solvent under an inert gas atmosphere, add 105-110% of the first batch of polyvalent diamines in a low-temperature environment of 30 ° C and below, and then polymerize to form Resin solution, control the viscosity of resin solution at 50000-70000cps;

S2. Monitor the viscosity of the resin solution and gradually increase the temperature within 30-80°C, and gradually add the second batch of polybasic diamines in batches, until the viscosity of the resin solution is 180000-200000cps;

S3, adding a fluorine-containing end-capping agent and mixing, and obtaining a polyimide resin solution after high-vacuum defoaming.

In some embodiments, the low temperature environment in step S1 is -20-30°C.

In some embodiments, the added amount of the second batch of polyvalent diamines in step S2 is 5-10% of the total molar amount of the first batch of polyvalent diamines, and the specific operation of batch addition is: adding in a temperature gradient of 30-35 °C 40% of the total molar amount of the second batch of polyvalent diamines, adding 25% of the total molar amount of the second batch of polyvalent diamines in a temperature gradient of 45-50 °C, adding the second batch of polyvalent diamines in a temperature gradient of 65-70 °C Add 20% of the total amount of polydiamine in the 75-80 °C temperature gradient, add 10% of the total molar amount of the second batch of polydiamine, continue to stir and monitor the viscosity of the resin solution, if the resin viscosity is stable at 180000-200000cps, then stop feeding, otherwise, then Continue adding the remaining second batch of polydiamine until the resin viscosity stabilizes at 50,000-70,000 cps.

In some embodiments, the total molar amount of the fluorine-containing capping agent plus the molar amount of the first batch of polybasic diamine and the second batch of polyvalent diamine is approximately equal to the molar amount of polybasic dianhydride.

In some embodiments, the polydiamines include p-phenylenediamine and its ring fluorinated compounds, benzidine and its ring fluorinated compounds, 4,4'-oxydiphenylamine, 1,3-bis( 4-Aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(2-aminophenoxy)benzene, 4,4'-bis(3-aminobenzene) oxy) biphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(5-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy) base)phenyl)sulfone, bis(4-(3-aminophenoxy)phenyl)sulfone, bis(4-(2-aminophenoxy)phenyl)sulfone, 4,4'-diaminodiphenyl Ethane, 4,4'-diaminodiphenylisopropane, 4,4'-diaminophenyl sulfide, 3,3'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 3,3'-oxydiphenylamine, 3,4'-oxydiphenylamine, 2,4'-oxydiphenylamine, 4,4'-diaminodiphenyldiethylsilane, 4,4'- Diaminodiphenylsilane, 4,4'-diaminodiphenylethylphosphine oxide, 4,4'-diaminodiphenyl N-methylamine, 4,4'-diaminodiphenyl N-aniline , 1,3-diaminobenzene, 1,2-diaminobenzene, 2,2'-bis[4-(4-aminophenoxy)phenyl]propane, 2,2'-bis[4-(4 -Aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, any two of 4,4'-diamino-2,2'-bistrifluoromethylbiphenyl or multiple ratios.

In some embodiments, the polybasic dianhydride includes pyromellitic dianhydride, 2,3,6,7-tetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride Anhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl) Propane dianhydride, 3,4,9,10-tetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)propane dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane Dianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)ethane Alkane dianhydride, hydroxydiphthalic dianhydride, bis(3,4-dicarboxyphenyl) sulfone dianhydride, ethylene bis(trimellitic acid monoester anhydride), bisphenol A bis(trimellitic acid) acid monoester anhydride), 4,4'-oxydiphthalic anhydride, 4,4'-thiodiphthalic anhydride, 3,3',4,4'-benzophenone tetraacid dianhydride, Any two or more ratios of 4,4'-oxydiphthalic anhydride and 4,4'-(hexafluoroisopropylidene)diphthalic anhydride.

In some embodiments, the fluorine-containing capping agent includes a fluorine-containing monoamine aromatic organic compound.

In some embodiments, the fluorine-containing capping agent includes m-bis(trifluoromethyl)aniline, 4-(4'-fluorophenyl)benzonitrile, p-trifluoromethylaniline, 2,6-difluoromethylaniline Fluoro-3-methylaniline, cyanoacetyl-p-trifluoromethylaniline, 4-methyl-2-(trifluoromethyl)aniline, 3-fluoro-2-(trifluoromethyl)aniline, 5-fluoro -2-trifluoromethylaniline, 4-fluoro-2-nitro-5-(trifluoromethyl)-aniline, 2,2'-bis(trifluoromethyl)diaminobiphenyl, trifluoroaniline, N-ethyl-2,3,5-trifluoroaniline, 2,2'-bis(3,4,5-trifluorophenyl)-4,4'-benzidinediamine, 2,3,4- Any of trifluorophenylacetamide and 2,3,4-trifluoro-6-nitroaniline.

In some embodiments, the solvent includes N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, cyclohexane, methylcyclohexane, tetrahydrofuran, isohexane , n-heptane, dichloromethane, trichloroethylene, carbon tetrachloride, epichlorohydrin, methyl methacrylate, dimethyl sulfoxide.

The present disclosure also provides the polyimide resin prepared by the above-mentioned preparation method.

The present disclosure also provides the use of the polyimide resin in a film.

The present disclosure also provides a film, the preparation method comprising: selecting the above-mentioned polyimide resin, sequentially adding a catalyst and a dehydrating agent to the polyimide resin, and coating the film on at least one side of the base film.

In some embodiments, the catalyst includes pyridazine, pyrimidine, pyridine, phthalazine, 1,10-phenanthroline.

In some embodiments, the mass ratio of the catalyst to the polyimide resin solution is 1:95-105.

In some embodiments, the base film includes carbon nanofiber copper foil, carbon nanofiber silver foil, carbon nanofiber aluminum foil, and carbon nanofiber gold foil.

Detailed ways

Before describing, it is to be understood that terms used in the specification and appended claims should not be construed to be limited to their ordinary dictionary meanings, but should be in accordance with principles that allow the inventor to define terms as appropriate for the best interpretation, The explanation is made based on meanings and concepts corresponding to the technical aspects of the present disclosure. Accordingly, the descriptions set forth herein are optional examples for illustrative purposes only and are not intended to limit the scope of the present disclosure, therefore, it is to be understood that other equivalents and modifications may be made without departing from the spirit and scope of the present disclosure .

Based on the problem that the properties and viscosity of the currently prepared polyimide resin cannot be stored for a long time under normal temperature and pressure, the present disclosure provides a preparation method of a polyimide resin, comprising the following steps:

S1. After dissolving the first batch of polyvalent diamines in a solvent under an inert gas atmosphere, add 105-110% of the first batch of polyvalent diamines in a low-temperature environment of 30 ° C and below, and then polymerize to form Resin solution, control the viscosity of the resin solution at 50000-70000cps; wherein, the resin solution viscosity can be in such as 55000-70000cps, 55000-65000cps or 60000-65000cps; A batch of polyvalent dianhydrides with a total molar amount of polyvalent diamines is first polymerized to form a resin solution;

S2. Monitor the viscosity of the resin solution and gradually increase the temperature at 30-80 °C, and gradually add the second batch of polybasic diamines in batches, until the viscosity of the resin solution is 180000-200000cps; Gradually increase the temperature in the range of -80°C, 40-70°C or 50-65°C;

S3, adding a fluorine-containing end-capping agent and mixing evenly, and obtaining a polyimide resin solution after high-vacuum defoaming.

The first batch of polybasic diamine and polybasic dianhydride are firstly polymerized into a low-viscosity resin solution at a low temperature, and then gradually heated at 30-80°C. Different from the conventional batch feeding of polybasic diamine, the present disclosure emphasizes the second The batch of polyvalent diamines is added to the resin solution gradually by the differential method in different temperature gradients, so that the polymer segments are continuously reformed, homogenized and then lengthened. When the lengths of all segments are kept balanced, the chain The polyimide resin solution prepared by this preparation method is homogeneous and stable, as shown in Table 1. Compared with the polyimide resin solution prepared by the current technology, it can last for a long time. Keeping the viscosity unchanged, the polyimide resin solution can be stored for a long time; at the same time, the fluorine-containing end-capping agent can effectively reduce the hydrolysis of the end chain of the polyimide resin solution, and further improve the viscosity stability of the polyimide resin solution. The structure of the film is more stable, the tensile strength of the film will be enhanced accordingly, and the fluorine-containing compound also has the effect of reducing the dielectric constant. leakage, heat generation and capacitance effects between wires.

The monitoring method of the above-mentioned monitoring resin is not limited to any method that can grasp the viscosity of the polyimide resin at any time. There are at least a viscosity testing system with a viscosity probe, multiple sub-sampling outside the bottle testing and other conventional methods in the art.

The total molar amount of the first batch of polyvalent diamines and the second batch of polyvalent diamines in the present disclosure is similar to the total molar amount of polyvalent dianhydrides. For example, when the resin viscosity reaches 185000-200000cps, 185000-195000cps or 185000-190000cps, the ratio of the total molar amount of the first batch of polyvalent diamine and the second batch of polyvalent diamine to the total molar amount of polyvalent dianhydride is 0.9-1.0:1.0 , for example, 0.92-1.0:1.0, 0.92-0.98:1.0, or 0.94-0.96:1.0.

The low temperature environment in the step S1 of the present disclosure is -20-30°C. When the polybasic diamine and polybasic dianhydride are preliminarily polymerized to form a resin solution, the reaction is a reaction that increases the exothermic entropy, so the low temperature helps the molecular chain segment The polymerization reaction promotes the reaction to proceed in the forward direction, so that the molecular segments continue to grow and the viscosity increases. Therefore, in some typical embodiments, the low temperature environment can be -20-10°C, -10-0°C, 0- 10°C, 10-30°C.

As the concrete operation method that the second batch of polyvalent diamines is added in batches in the S2 step, in the S2 step, the second batch of polyvalent diamines is added in an amount of 5-10% of the molar total amount of the first batch of polyvalent diamines, such as 6-9 %, 6-8% or 7-8%, added in batches The specific operation is: 30-35 ℃ (such as 31-35 ℃, 31-34 ℃ or 32-33 ℃) temperature gradient adding the second batch of polydiamine 40% of the total molar amount, 25% of the total molar amount of the second batch of polydiamines was added within a temperature gradient of 45-50°C (such as 46-50°C, 46-48°C or 46-47°C), 65-70°C ( Add 20% of the total molar amount of the second batch of polydiamine within a temperature gradient such as 66-69°C, 66-68°C or 66-67°C, 75-80°C (such as 76-79°C, 76-78°C or 76°C) Add 10% of the total molar amount of the second batch of polydiamines to the temperature gradient of -77°C), continue to stir and monitor the viscosity of the resin solution. If the viscosity of the resin is stable within the specified value range, stop feeding; otherwise, continue to add the remaining Two batches of the polydiamine were obtained until the resin viscosity reached the specified value.

In order to control the added amount of the fluorine-containing end-capping agent, the total molar amount of the fluorine-containing end-capping agent plus the first batch of polyvalent diamine and the second batch of polyvalent diamine can be further limited to be approximately equal to the molar amount of polyvalent dianhydride.

In the preparation method of the present disclosure, it is emphasized to use a polyvalent diamine composed of at least two kinds of diamines, and a polybasic dianhydride composed of at least two kinds of dianhydrides, and the multi-component copolymerization mode with different molar ratios of anhydrides and amines can adjust the thermal expansion coefficient, The thermal expansion coefficient of the prepared polyimide resin solution after film formation can be equal to that of the base film, so as to avoid the phenomenon of curling at the edge of the film due to a large difference in the expansion coefficient. The first diamine: ...: the nth diamine = (0.1-0.9): ...: (0.1-0.9), the first dianhydride: ...: the nth dianhydride = (0.1-0.9) :...: (0.1-0.9), n≥2; as shown in Table 1, under the same polybasic diamine and polybasic dianhydride, by changing the ratio between polybasic diamines and the ratio between polybasic dianhydrides Mixing ratios can obtain polyimide films with different thermal expansion coefficients.

Wherein, the present disclosure has no special restrictions on the diamine, which can be any well-known diamine in the art, specifically, p-phenylenediamine and its ring fluorinated compound, benzidine and its ring fluorinated compound, 4, 4'-Oxydiphenylamine, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(2-aminophenoxy) ) benzene, 4,4'-bis(3-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(5-aminophenoxy) ) biphenyl, bis(4-(4-aminophenoxy)phenyl)sulfone, bis(4-(3-aminophenoxy)phenyl)sulfone, bis(4-(2-aminophenoxy) phenyl) sulfone, 4,4'-diaminodiphenylethane, 4,4'-diaminodiphenylisopropane, 4,4'-diaminophenyl sulfide, 3,3'-diaminodiphenyl Phenylsulfone, 4,4'-diaminodiphenylsulfone, 3,3'-oxydiphenylamine, 3,4'-oxydiphenylamine, 2,4'-oxydiphenylamine, 4,4'-diphenylamine Aminodiphenyldiethylsilane, 4,4'-diaminodiphenylsilane, 4,4'-diaminodiphenylethylphosphine oxide, 4,4'-diaminodiphenyl N-methylamine , 4,4'-diaminodiphenyl N-aniline, 1,3-diaminobenzene, 1,2-diaminobenzene, 2,2'-bis[4-(4-aminophenoxy)phenyl ] propane, 2,2'-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 4,4'-diamino-2, 2'-bistrifluoromethylbiphenyl.

There is no special limitation on the dianhydride in the present disclosure, and it can be any dianhydride known in the art, and specific examples include pyromellitic dianhydride, 2,3,6,7-tetracarboxylic dianhydride, 3,3' ,4,4'-biphenyltetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,2 -Bis(3,4-dicarboxyphenyl)propane dianhydride, 3,4,9,10-tetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)propane dianhydride, 1,1-bis (2,3-Dicarboxyphenyl)ethanedianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethanedianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, Bis(3,4-dicarboxyphenyl)ethane dianhydride, hydroxydiphthalic acid dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, ethylenebis(trimellitic acid mono ester anhydride), bisphenol A bis (trimellitic acid monoester anhydride), 4,4'-oxybisphthalic anhydride, 4,4'-thiobisphthalic anhydride, 3,3',4 ,4'-benzophenone tetraacid dianhydride, 4,4'-oxydiphthalic anhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride.

The fluorine-containing end-capping agent of the present disclosure is a fluorine-containing monoamine aromatic organic compound, which reacts with the end-chain anhydride structure of the polyimide resin solution to perform end-chain end-capping, so that the end-chain structure of the polyimide resin solution is The amino structure of the fluorine-containing end-capping agent, so as to avoid the hydrolysis of the polyimide resin solution, the fluorine-containing end-capping agent can be listed as m-bis(trifluoromethyl)aniline, 4-(4'-fluorophenyl)benzyl Nitrile, p-trifluoromethylaniline, 2,6-difluoro-3-methylaniline, cyanoacetyl p-trifluoromethylaniline, 4-methyl-2-(trifluoromethyl)aniline, 3-fluoro -2-(trifluoromethyl)aniline, 5-fluoro-2-trifluoromethylaniline, 4-fluoro-2-nitro-5-(trifluoromethyl)-aniline, 2,2'-bis( Trifluoromethyl)diaminobiphenyl, trifluoroaniline, N-ethyl-2,3,5-trifluoroaniline, 2,2'-bis(3,4,5-trifluorophenyl)-4, Any of 4'-biphenylenediamine, 2,3,4-trifluorophenylacetamide, and 2,3,4-trifluoro-6-nitroaniline.

The present disclosure does not make any special limitation on solvents, which can be listed as N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, cyclohexane, methylcyclohexane, tetrahydrofuran , isohexane, n-heptane, dichloromethane, trichloroethylene, carbon tetrachloride, epichlorohydrin, methyl methacrylate, dimethyl sulfoxide.

After obtaining a polyimide resin solution with strong viscosity stability, it is more desirable to obtain a film with better performance. A catalyst and a dehydrating agent are sequentially added to the solution to rapidly dehydrate and imidize the polyimide acid to form a film, so as to improve the production efficiency. When coated on at least one side of the base film, the tensile strength of the film is increased.

On the basis of the catalyst types commonly used in the art, the present disclosure also expands the catalyst types that are not currently used in the art. The present disclosure emphasizes that the catalyst can be a monocyclic or condensed ring compound, such as pyridazine, pyrimidine, pyridine, phthalazine Also, 1,10-phenanthroline, as shown in Table 1, when the catalyst emphasized in this disclosure is selected, a polyimide film with more excellent tensile strength can be obtained. Optionally, a combination of pyridazine and pyridine can be selected. The catalytic performance is the best, and the mass ratio of the two catalysts is 1:4.

In the preparation process, the optimal ratio of the controllable catalyst and the polyimide resin solution is to control the mass ratio of the two within the range of 1:95-105.

The above-mentioned base films are not particularly limited, and can be base films commonly used in the field, such as carbon nanofiber copper foil, carbon nanofiber silver foil, carbon nanofiber aluminum foil, carbon nanofiber gold foil, but due to the excellent heat dissipation performance of carbon nanofiber copper foil , high strength, extremely stable chemical properties, low price and other characteristics can solve the problem of heat dissipation and oxidation of circuit boards, and save costs, so in some typical embodiments, the base film can be carbon nanofiber copper foil.

The preparation method provided by the present disclosure can make the polyimide stable in performance and viscosity under long-term storage.

The preparation method of the present disclosure solves the problems of viscosity control and viscosity stability. The polyimide resin obtained by the preparation method is uniform and stable, and can be stored in a natural environment at normal temperature and pressure for a long time without changing the viscosity and performance; The end agent solves the problem that the acid anhydride of the end chain is easy to be hydrolyzed. The end chain is capped by adding a suitable molar ratio of monoamine aromatic organic compounds. The end chain structure is an amino structure, which completely avoids the problem of the end group being hydrolyzed. The problem of high dielectric constant of imine resins is because fluorine-containing compounds have the effect of reducing the dielectric constant. Therefore, by adding an appropriate amount of fluorine-containing amine organic compounds, the dielectric constant can be effectively reduced, thereby reducing the leakage, heat generation of integrated circuits and between wires. capacitive effect.

When the polyimide resin prepared by the present disclosure is coated on the base film to prepare a film, the formed polyimide coating has strong thermal stability, and the thermal expansion coefficient is close to that of the base film. The film edge is prone to curling.

Example

Example 1

Weigh 245.98g N,N-dimethylformamide (analytical grade) into a flask with high-purity nitrogen atmosphere, weigh 0.09981mol p-phenylenediamine and 0.04275mol 4,4'-diphenyl ether diamine into the flask Dissolve completely; weigh 0.01500mol 3,3',4,4'-biphenyltetracarboxylic dianhydride and 0.13509mol pyromellitic dianhydride and mix them into the flask, and control the reaction temperature to be about 0°C.

After the reaction for 120min, the water bath began to heat up to 80°C, and 0.00528mol of p-phenylenediamine and 0.00225mol of 4,4'-diphenyletherdiamine were weighed and dissolved in 20g of N,N-dimethylformamide under a nitrogen atmosphere. The prepared mixed solution adopts the principle of adding more first and then less multiple times, adding 40% at 30°C-35°C, adding 25% at 45°C-50°C, adding 20% at 65°C-70°C, and adding at 75°C-80°C 10%, the remaining part is added at a temperature of 80 °C and stirred for 1 hour, depending on the viscosity. The stirring rate is 15rad/min. base) aniline end-capped, fully reacted for 60min, cooled to room temperature, weighed 86.02g N,N-dimethylformamide to gradually dilute the resin viscosity to about 50000cP, took 100g of the diluted resin, added 0.2g pyridazine and 0.8g of pyridine, stirred at a constant speed for 5 minutes, and then quickly degassed in high vacuum. The glass substrate and the carbon nanofiber copper foil were coated by casting method (the thickness of the film was controlled at about 20μm). Oxygen vacuum oven removed acetic anhydride and solvent. Test the film tensile strength, thermal expansion coefficient, water absorption, dielectric constant, edge curl. The remaining resin is sealed and stored under normal temperature and pressure, and the viscosity is tested after one month.

Example 2

Weigh 307.85g N,N-dimethylformamide (analytical grade) into a flask with high-purity nitrogen atmosphere, and weigh 0.08321mol p-phenylenediamine and 0.08321mol 4,4'-diphenylether diamine into the flask Dissolved completely; weigh 0.03502mol 3,3',4,4'-biphenyltetracarboxylic dianhydride and 0.14007mol pyromellitic dianhydride and mix them into the flask, and control the reaction temperature to be about 0°C. After the reaction for 120min, the water bath was heated to 80°C, and 0.00438mol p-phenylenediamine and 0.00438mol 4,4'-diphenyletherdiamine were weighed and dissolved in 4g N,N-dimethylformamide under nitrogen atmosphere. To configure the mixed solution, the difference method is used to add more first and then less. Add 40% at 30°C-35°C, 25% at 45°C-50°C, 20% at 65°C-70°C, and 10% at 75°C-80°C. %, the remaining part is added at a temperature of 80 °C and stirred for 1 hour depending on the viscosity. The stirring rate is 15rad/min. Fluoromethyl)aniline, fully reacted for 60min, cooled to room temperature, weighed 107.57g N,N-dimethylformamide to gradually dilute the resin viscosity to 50000cP, took 100g of the diluted resin, added 0.2g pyridazine and 0.8g g pyridine, stir at a constant speed for 5 min, and then rapidly defoam in high vacuum. Coat the glass substrate and carbon nanofiber copper foil by casting method (the thickness of the film is controlled at about 20 μm). The acetic anhydride and solvent were removed in a vacuum oven. Test the film tensile strength, thermal expansion coefficient, water absorption, dielectric constant, edge curl. The remaining resin is sealed and stored under normal temperature and pressure, and the viscosity is tested after one month.

Example 3

Weigh 291.95g of N,N-dimethylformamide (analytical grade) in a flask with a high-purity nitrogen atmosphere, weigh 0.09509mol p-phenylenediamine and 0.06332mol 4,4'-diphenyl ether diamine into the flask Dissolved completely; weigh 0.05003mol 3,3',4,4'-biphenyltetracarboxylic dianhydride and 0.11674mol pyromellitic dianhydride and mix them into the flask, and control the reaction temperature to be about 0°C. After the reaction for 120min, the water bath was heated to 80°C, and 0.00500mol p-phenylenediamine and 0.00333mol 4,4'-diphenyletherdiamine were weighed and dissolved in 4g N,N-dimethylformamide under nitrogen atmosphere. To configure the mixed solution, the difference method is used to add more first and then less. Add 40% at 30°C-35°C, 25% at 45°C-50°C, 20% at 65°C-70°C, and 10% at 75°C-80°C. %, the remaining part is added at a temperature of 80 °C and stirred for 1 hour depending on the viscosity. The stirring rate is 15rad/min. Fluoromethyl)aniline, fully reacted for 60min, cooled to room temperature, weighed 166.37g N,N-dimethylformamide to gradually dilute the resin viscosity to 50000cP, took 100g of the diluted resin, added 0.2g pyridazine and 0.8g Pyridine, stirred at a constant speed for 5 minutes, then rapidly degassed in high vacuum, and coated on glass substrate and carbon nanofiber copper foil by casting method (film thickness was controlled at about 20 μm), and after chemical imidization, oxygen-free vacuum at 250 °C was used. The oven removes acetic anhydride and solvent. Test the film tensile strength, thermal expansion coefficient, water absorption, dielectric constant, edge curl. The remaining resin is sealed and stored under normal temperature and pressure, and the viscosity is tested after one month.

Example 4

Weigh 305.89g of N,N-dimethylformamide (analytical grade) in a flask with high-purity nitrogen atmosphere, weigh 0.06342mol p-phenylenediamine and 0.09500mol 4,4'-diphenyletherdiamine into the flask Dissolved completely; weigh 0.05003mol 3,3',4,4'-biphenyltetracarboxylic dianhydride and 0.11674mol pyromellitic dianhydride and mix them into the flask, and control the reaction temperature to be about 0°C. After the reaction for 120min, the water bath was heated to 80°C, and 0.00334mol p-phenylenediamine and 0.00500mol 4,4'-diphenyletherdiamine were weighed and dissolved in 4g N,N-dimethylformamide under nitrogen atmosphere. To configure the mixed solution, the difference method is used to add more first and then less. Add 40% at 30°C-35°C, 25% at 45°C-50°C, 20% at 65°C-70°C, and 10% at 75°C-80°C. %, the remaining part is added at a temperature of 80 °C and stirred for 1 hour depending on the viscosity. The stirring rate is 15 rad/min. Fluoromethyl)aniline, fully reacted for 60min, cooled to room temperature, weighed 106.95g N,N-dimethylformamide to gradually dilute the resin viscosity to 50000cP, took 100g of the diluted resin, added 0.2g pyridazine and 0.8g Pyridine, stirred at a constant speed for 5 minutes, then rapidly degassed in high vacuum, and coated on glass substrate and carbon nanofiber copper foil by casting method (film thickness was controlled at about 20 μm), and after chemical imidization, oxygen-free vacuum at 250 °C was used. The oven removes acetic anhydride and solvent. Test the film tensile strength, thermal expansion coefficient, water absorption, dielectric constant, edge curl. The remaining resin is sealed and stored under normal temperature and pressure, and the viscosity is checked after one month.

Example 5

Weigh 223.04g of N,N-dimethylformamide (analytical grade) in a flask with a high-purity nitrogen atmosphere, weigh 0.07134mol p-phenylenediamine and 0.04750mol 4,4'-diphenylether diamine into the flask Dissolve completely; weigh 0.05003mol 3,3',4,4'-biphenyltetracarboxylic dianhydride and 0.07505mol pyromellitic dianhydride and mix them into the flask, and control the reaction temperature to be about 0°C. After the reaction for 120min, the water bath was heated to 80°C, and 0.00375mol p-phenylenediamine and 0.00250mol 4,4'-diphenyletherdiamine were weighed and dissolved in 4g N,N-dimethylformamide under nitrogen atmosphere. To configure the mixed solution, the difference method is used to add more first and then less. Add 40% at 30°C-35°C, 25% at 45°C-50°C, 20% at 65°C-70°C, and 10% at 75°C-80°C. %, the remaining part is added at a temperature of 80 °C and stirred for 1 hour, depending on the viscosity. The stirring rate is 15rad/min. Fluoromethyl)aniline, fully reacted for 60min, cooled to room temperature, weighed 127.25g N,N-dimethylformamide to gradually dilute the resin viscosity to 50000cP, took 100g of the diluted resin, added 0.2g pyridazine and 0.8g Pyridine, stirred at a constant speed for 5 minutes, then rapidly degassed in high vacuum, and coated on glass substrate and carbon nanofiber copper foil by casting method (film thickness was controlled at about 20 μm), and after chemical imidization, oxygen-free vacuum at 250 °C was used. The oven removes acetic anhydride and solvent. Test the film tensile strength, thermal expansion coefficient, water absorption, dielectric constant, edge curl. The remaining resin is sealed and stored under normal temperature and pressure, and the viscosity is tested after one month.

Comparative Example 1

Weigh 245.98g N,N-dimethylformamide (analytical grade) into a flask with high-purity nitrogen atmosphere, weigh 0.09981mol p-phenylenediamine and 0.04275mol 4,4'-diphenyl ether diamine into the flask Dissolve completely; weigh 0.01500mol 3,3',4,4'-biphenyltetracarboxylic dianhydride and 0.13509mol pyromellitic dianhydride and mix them into the flask, and control the reaction temperature to be about 0°C. After 120min of reaction, weigh 0.00528mol p-phenylenediamine and 0.00225mol 4,4'-diphenyl ether diamine and dissolve in 20g N,N-dimethylformamide under nitrogen atmosphere, add the configured mixed solution to the flask, Control the amount of addition according to experience, and control the viscosity to about 200,000cP. After 240min of reaction, weigh 86.02g of N,N-dimethylformamide to gradually dilute the resin viscosity to about 50,000cP. Take 100g of the diluted resin for rapid degassing in high vacuum and cast it. The film is coated on the glass substrate (the thickness of the film is controlled at about 20 μm), and the film is formed by imidization in an oxygen-free vacuum oven at 500 °C. Test the film tensile strength, thermal expansion coefficient, water absorption, dielectric constant, edge curl. The remaining resin is sealed and stored under normal temperature and pressure, and the viscosity is tested after one month.

Comparative Example 2

Weigh 307.85g N,N-dimethylformamide (analytical grade) into a flask with high-purity nitrogen atmosphere, and weigh 0.08321mol p-phenylenediamine and 0.08321mol 4,4'-diphenylether diamine into the flask Dissolved completely; weigh 0.03502mol 3,3',4,4'-biphenyltetracarboxylic dianhydride and 0.14007mol pyromellitic dianhydride and mix them into the flask, and control the reaction temperature to be about 0°C. After the reaction for 120min, 0.00438mol p-phenylenediamine and 0.00438mol 4,4'-diphenyl ether diamine were weighed and dissolved in 4g N,N-dimethylformamide under nitrogen atmosphere, and the configured mixed solution was added to the flask, Control the amount of addition according to experience, and control the viscosity to about 200,000cP. After 240min of reaction, weigh 86.02g of N,N-dimethylformamide to gradually dilute the resin viscosity to about 50,000cP. Take 100g of the diluted resin for rapid degassing in high vacuum and cast it. The film is coated on the glass substrate (the thickness of the film is controlled at about 20 μm), and the film is formed by imidization in an oxygen-free vacuum oven at 500 °C. Test the film tensile strength, thermal expansion coefficient, water absorption, dielectric constant, edge curl. The remaining resin is sealed and stored under normal temperature and pressure, and the viscosity is tested after one month.

Comparative Example 3

Weigh 291.95g of N,N-dimethylformamide (analytical grade) in a flask with a high-purity nitrogen atmosphere, weigh 0.09509mol p-phenylenediamine and 0.06332mol 4,4'-diphenyl ether diamine into the flask Dissolved completely; weigh 0.05003mol 3,3',4,4'-biphenyltetracarboxylic dianhydride and 0.11674mol pyromellitic dianhydride and mix them into the flask, and control the reaction temperature to be about 0°C. After 120min of reaction, weigh 0.00500mol p-phenylenediamine and 0.00333mol 4,4'-diphenyl ether diamine and dissolve in 4g N,N-dimethylformamide under nitrogen atmosphere, add the configured mixed solution to the flask, Control the amount of addition according to experience, and control the viscosity to about 200,000cP. After 240min of reaction, weigh 86.02g of N,N-dimethylformamide to gradually dilute the resin viscosity to about 50,000cP. Take 100g of the diluted resin for rapid degassing in high vacuum and cast it. The film is coated on the glass substrate (the thickness of the film is controlled at about 20 μm), and the film is formed by imidization in an oxygen-free vacuum oven at 500 °C. Test the film tensile strength, thermal expansion coefficient, water absorption, dielectric constant, edge curl. The remaining resin is sealed and stored under normal temperature and pressure, and the viscosity is tested after one month.

Comparative Example 4

Weigh 305.89g of N,N-dimethylformamide (analytical grade) in a flask with high-purity nitrogen atmosphere, weigh 0.06342mol p-phenylenediamine and 0.09500mol 4,4'-diphenyletherdiamine into the flask Dissolved completely; weigh 0.05003mol 3,3',4,4'-biphenyltetracarboxylic dianhydride and 0.11674mol pyromellitic dianhydride and mix them into the flask, and control the reaction temperature to be about 0°C. After the reaction for 120min, 0.00334mol p-phenylenediamine and 0.00500mol 4,4'-diphenyl ether diamine were weighed and dissolved in 4g N,N-dimethylformamide under nitrogen atmosphere, and the configured mixed solution was added to the flask, Control the amount of addition according to experience, and control the viscosity to be about 200000cP. After 240min of reaction, weigh 86.02g N,N-dimethylformamide to gradually dilute the resin viscosity to about 50000cP, take 100g of the diluted resin and quickly defoam under high vacuum and cast it. The film is coated on the glass substrate (the thickness of the film is controlled at about 20 μm), and the film is formed by imidization in an oxygen-free vacuum oven at 500 °C. Test the film tensile strength, thermal expansion coefficient, water absorption, dielectric constant, edge curl. The remaining resin is sealed and stored under normal temperature and pressure, and the viscosity is tested after one month.

Comparative Example 5

Weigh 223.04g of N,N-dimethylformamide (analytical grade) in a flask with a high-purity nitrogen atmosphere, weigh 0.07134mol p-phenylenediamine and 0.04750mol 4,4'-diphenylether diamine into the flask Dissolve completely; weigh 0.05003mol 3,3',4,4'-biphenyltetracarboxylic dianhydride and 0.07505mol pyromellitic dianhydride and mix them into the flask, and control the reaction temperature to be about 0°C. After 120min of reaction, weigh 0.00375mol p-phenylenediamine and 0.00250mol 4,4'-diphenyl ether diamine and dissolve in 4g N,N-dimethylformamide under nitrogen atmosphere, add the configured mixed solution to the flask, Control the amount of addition according to experience, and control the viscosity to about 200,000cP. After 240min of reaction, weigh 86.02g of N,N-dimethylformamide to gradually dilute the resin viscosity to about 50,000cP. Take 100g of the diluted resin for rapid degassing in high vacuum and cast it. The film is coated on the glass substrate (the thickness of the film is controlled at about 20 μm), and the film is formed by imidization in an oxygen-free vacuum oven at 500 °C. Test the film tensile strength, thermal expansion coefficient, water absorption, dielectric constant, edge curl. The remaining resin is sealed and stored under normal temperature and pressure, and the viscosity is tested after one month.

Table 1

It can be seen from the above table that the control of the initial apparent viscosity of Comparative Examples 1-5 is difficult without adding end-capping agent or other control conditions, the viscosity span is large, extremely unstable, and the repeatability is poor. After being stored at room temperature for one month, the viscosity of the resin decreases significantly, while the polyimide resin solution prepared in Examples 1-5 of the present disclosure is controlled at a diamine addition ratio of 98.6% to 99.3% and an end capping agent addition ratio of 1.4% to 1.4%. 0.7%, the initial apparent viscosity can be controlled at about 300,000cP, the viscosity of the resin does not change significantly after being stored at room temperature for one month, and the viscosity stability is excellent.

At the same time, the films prepared in Comparative Examples 1-5 have low tensile strength, large difference in thermal expansion coefficient and copper foil, high water absorption, high dielectric constant, and obvious curling phenomenon of the film, which cannot meet the requirements of industrial production. However, when the polyimide resin solution prepared in Examples 1-5 was used to form a film alone, the tensile strength was greater than 120MPa, the thermal expansion coefficient was close to that of copper foil (18×10-6k-1), and the water absorption rate was low, all less than 2% , the dielectric constant is less than 3, the film does not produce curling phenomenon, indicating that the performance is good, when the graphene copper foil is used as the base film, the tensile strength of the prepared film is greatly increased by more than 320MPa, and the thermal expansion coefficient is close to that of copper foil ( 18×10-6k-1), the water absorption rate is low, less than 2%, the dielectric constant is less than 3, and the outer side of the film has a very small curling phenomenon, indicating that the performance is good and meets the needs of microelectronic products.

The above are only optional embodiments of the present disclosure. It should be pointed out that for those skilled in the art, without departing from the concept of the present disclosure, several improvements and modifications can be made. It should be regarded as the protection scope of the present disclosure.

Industrial Applicability

The present disclosure provides a method for preparing polyimide resin and a film thereof. The polyimide prepared in the present disclosure has the characteristics of long-term storage performance and stable viscosity, and the polyimide resin prepared in the present disclosure is coated on When the film is prepared on the base film, the formed polyimide coating has strong thermal stability, and the thermal expansion coefficient is close to the base film, which solves the problem that the edge of the film is easily curled due to the large difference in the thermal expansion coefficient. Therefore, the polyimide prepared by the present disclosure and the film prepared therefrom have excellent industrial practical properties and good market prospects.

Claims

A preparation method of polyimide resin, comprising the following steps:

S1. After dissolving the first batch of polyvalent diamines in a solvent under an inert gas atmosphere, add 105-110% of the first batch of polyvalent diamines in a low-temperature environment of 30 ° C and below, and then polymerize to form Resin solution, control the viscosity of resin solution at 50000-70000cps;

S2. Monitor the viscosity of the resin solution and gradually increase the temperature within 30-80°C, and gradually add the second batch of polybasic diamines in batches, until the viscosity of the resin solution is 180000-200000cps;

S3, adding a fluorine-containing end-capping agent and mixing, and obtaining a polyimide resin solution after high-vacuum defoaming.
The method for preparing polyimide resin according to claim 1, wherein the low temperature environment in step S1 is -20-30°C.
The preparation method of polyimide resin according to claim 1 or 2, wherein the second batch of polyvalent diamines added in step S2 is 5-10% of the first batch of polyvalent diamines in total moles , the specific operation of adding in batches is as follows: adding 40% of the total molar amount of the second batch of polyvalent diamines in a temperature gradient of 30-35 °C, adding 25% of the total molar amount of the second batch of polyvalent diamines in a temperature gradient of 45-50 °C, Add 20% of the total molar amount of the second batch of polyvalent diamines in a temperature gradient of 65-70 °C, add 10% of the total molar amount of the second batch of polyvalent diamines in a temperature gradient of 75-80 °C, continue stirring and monitor the viscosity of the resin solution, If the resin viscosity is stable at 180000-200000cps, stop feeding, otherwise, continue to add the remaining second batch of polydiamine until the resin viscosity is stable at 50000-70000cps.
The preparation method of polyimide resin according to any one of claims 1-3, characterized in that, the molar amount of the fluorine-containing end capping agent is added to the moles of the first batch of polyvalent diamines and the second batch of polyvalent diamines. The amount is approximately equal to the molar amount of the polybasic dianhydride.
The method for preparing polyimide resin according to any one of claims 1-4, wherein the polyvalent diamine comprises p-phenylenediamine and its ring fluorinated compound, benzidine and its ring Fluorinated compounds, 4,4'-oxydiphenylamine, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene 2-Aminophenoxy)benzene, 4,4'-bis(3-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-bis( 5-Aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl)sulfone, bis(4-(3-aminophenoxy)phenyl)sulfone, bis(4-(2) -Aminophenoxy)phenyl)sulfone, 4,4'-diaminodiphenylethane, 4,4'-diaminodiphenylisopropane, 4,4'-diaminophenyl sulfide, 3, 3'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 3,3'-oxydiphenylamine, 3,4'-oxydiphenylamine, 2,4'-oxydiphenylamine, 4,4'-diaminodiphenyldiethylsilane, 4,4'-diaminodiphenylsilane, 4,4'-diaminodiphenylethylphosphine oxide, 4,4'-diaminodiphenyl Phenyl N-methylamine, 4,4'-diaminodiphenyl N-aniline, 1,3-diaminobenzene, 1,2-diaminobenzene, 2,2'-bis[4-(4-amino Phenoxy)phenyl]propane, 2,2'-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 4,4' -Any two or more ratios of diamino-2,2'-bistrifluoromethylbiphenyl.
The preparation method of polyimide resin according to any one of claims 1-5, wherein the polyvalent dianhydride comprises pyromellitic dianhydride, 2,3,6,7-tetracarboxylic acid Acid dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 1,2,5,6-naphthalene tetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic acid Carboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 3,4,9,10-tetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)propane Dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethanedianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethanedianhydride, bis(2,3-dicarboxyphenyl)ethanedianhydride Carboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)ethane dianhydride, hydroxydiphthalic dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, ethylene bis(trimellitic acid monoester anhydride), bisphenol A bis(trimellitic acid monoester anhydride), 4,4'-oxybisphthalic anhydride, 4,4'-sulfur diphthalic anhydride Acid anhydride, 3,3',4,4'-benzophenone tetraacid dianhydride, 4,4'-oxydiphthalic anhydride, 4,4'-(hexafluoroisopropylidene)diphthalic acid Any two or more ratios in formic anhydride.
The method for preparing a polyimide resin according to any one of claims 1 to 6, wherein the fluorine-containing end-capping agent comprises a fluorine-containing monoamine aromatic organic compound.
The method for preparing polyimide resin according to any one of claims 1-7, wherein the fluorine-containing end-capping agent comprises m-bis(trifluoromethyl)aniline, 4-(4'- Fluorophenyl)benzonitrile, p-trifluoromethylaniline, 2,6-difluoro-3-methylaniline, cyanoacetyl-p-trifluoromethylaniline, 4-methyl-2-(trifluoromethylaniline) ) aniline, 3-fluoro-2-(trifluoromethyl)aniline, 5-fluoro-2-trifluoromethylaniline, 4-fluoro-2-nitro-5-(trifluoromethyl)-aniline, 2 ,2'-bis(trifluoromethyl)diaminobiphenyl, trifluoroaniline, N-ethyl-2,3,5-trifluoroaniline, 2,2'-bis(3,4,5-trifluoroaniline) phenyl)-4,4'-benzidinediamine, any one of 2,3,4-trifluorophenylacetamide and 2,3,4-trifluoro-6-nitroaniline.
The method for preparing polyimide resin according to any one of claims 1-8, wherein the solvent comprises N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, cyclohexane, methylcyclohexane, tetrahydrofuran, isohexane, n-heptane, dichloromethane, trichloroethylene, carbon tetrachloride, epichlorohydrin, methyl methacrylate, dichloromethane Methyl sulfoxide.
The polyimide resin prepared by the preparation method described in any one of claims 1-9.
Use of the polyimide resin as claimed in claim 10 in a film.
A film, characterized in that the preparation method comprises: selecting the polyimide resin according to any one of claims 1-9, adding a catalyst and a dehydrating agent to the polyimide resin in sequence, and then coating the base film on the base film. on at least one side.
The film of claim 12, wherein the catalyst comprises pyridazine, pyrimidine, pyridine, phthalazine, and 1,10-phenanthroline.
The film according to claim 12, wherein the mass ratio of the catalyst to the polyimide resin solution is 1:95-105.
The film of claim 12, wherein the base film comprises carbon nanofiber copper foil, carbon nanofiber silver foil, carbon nanofiber aluminum foil, and carbon nanofiber gold foil.