WO2020029391A1

WO2020029391A1 - Method for preparing multilayer nanographite flake hybrid transparent polyimide thin film synthesis and product thereof

Info

Publication number: WO2020029391A1
Application number: PCT/CN2018/107191
Authority: WO
Inventors: 徐伟伟; 高尚林; 王勇; 祁晓东; 姜新; 陈晨
Original assignee: 江苏亚宝绝缘材料股份有限公司
Priority date: 2018-08-07
Filing date: 2018-09-25
Publication date: 2020-02-13
Also published as: CN109251529B; CN109251529A

Abstract

The present invention discloses a multilayer nanographite flake hybrid transparent polyimide thin film comprising the following substances in parts by weight: 200-500 parts of polyimide, 3-12 parts of nanographite, 3-12 parts of microcracks staining agent. According to the present multilayer nanographite flake hybrid transparent polyimide thin film, the combination of nanographite and microcracks staining agent makes the material more sensitive to tiny cracking patterns, producing alterations observable to the naked eye and easily identifiable. The color change is clearly visible within a few millimeters around the cracking. The safety conditions of the composite materials used in airplanes and automobiles can be effectively monitored, thus avoiding the occurrence of sudden accidents.

Description

Synthetic preparation method and product of multilayer nano-graphite sheet hybrid transparent polyimide film

Technical field

The invention belongs to the technical field of preparation of polyimide films, and in particular relates to a multilayer transparent graphite film hybrid nano-graphite sheet and a preparation method thereof.

Background technique

Minor damage to key components such as airplanes and automobiles can lead to serious consequences. At present, the micro fissures of components are mainly observed by human eyes and scanning instruments. Human eyes can observe large fissures, but it is difficult to effectively observe micro fissures. Equipment scanning takes a lot of time, and some parts have complex parts. Difficult to scan.

Material structural damage often starts with some small cracks and deformations. Natural materials such as colored beetles' shells can cause color changes due to distortion. Because the shell contains micro-crack color-changing substances, if polyimide film materials are prepared In the process, artificial micro-crack discoloration substance is added to prepare a “transparent polyimide film with early warning of micro-cracks”. The micro-scale cracks and defects that are difficult to detect can be used to warn of hidden damage. Damage sensitivity (Defect Sensitivity), Early Warning (Early Warning) and other fields are used to monitor the safety status of composite materials used in aircraft and automobiles, so as to avoid sudden accidents. This technology has not yet been found to have a breakthrough, and is a technology in urgent need of development and application.

Summary of the invention

The object of the present invention is to provide a multilayer nano-graphite sheet hybrid transparent polyimide film and a preparation method thereof.

A multilayer nano-graphite sheet hybrid transparent polyimide film includes the following parts by weight: 200-500 parts of polyimide, 3-12 parts of nano-graphite, and 3-12 parts of micro-crack discoloration agent.

The micro-crack discoloration agent is 1,2,3,10b-tetrahydrofluoranthene, 9-ethylfluorene or 9-benzylfluorene.

The micro-crack discoloration agent is a compound having the following molecular formula:

In the formula, X is methyl, ethyl, halogen or phenyl.

The polyimide is prepared by using a diamine and a dianhydride as raw materials and adopting a two-step solution polycondensation method.

The diamine is 2,2-bis [4- (4-aminophenoxy) phenyl] propane, α, ω-bis (methylamino) polydimethylsiloxane, 2,2'-bis (Trifluoromethyl) benzidine, 2,4-diaminofluorobenzene, 2- (trifluoromethyl) -1,4-phenylenediamine, 4-trifluoromethyl-1,2-benzenediamine Amine or 4,5-difluorobenzene-1,2-diamine.

The dianhydride is 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 4,4′-oxybisphthalic anhydride, pyromellitic dianhydride, bisphenol A dianhydride or Hexafluoroisopropylidene diphthalic dianhydride.

The method for preparing the above-mentioned multilayer nano-graphite sheet hybrid transparent polyimide film is performed according to the following steps:

(1) At room temperature, add diamine and dianhydride to the reaction kettle, add m-cresol under nitrogen protection, stir well, add isoquinoline, warm to 170-200 ° C, react for 10-14 hours, and cool Pour the reaction solution into ethanol to make a polyimide resin;

(2) The nano-graphite is placed in an organic solvent and pre-dispersed after being subjected to a high-temperature treatment by a high-shear dispersing machine, and the processing temperature is 200-800 ° C;

(3) adding the synthesized polyimide resin and the treated nano-graphite to the reaction kettle and stirring, the stirring speed is 800-1200 rpm, and the stirring time is 1-2 hours to prepare a film liquid;

(4) Add the micro-crack discoloration agent to the film liquid, continue to stir, the stirring speed is 300-500 rpm, and the stirring time is 2-5 h to make a color-changing film liquid;

(5) Hydraulically change the color-changing film into the defoaming kettle, remove the bubbles in the color-changing film liquid under vacuum conditions, put the decolorized film-changing film liquid into a casting machine and cast to form a polyimide film with uniform thickness. ;

(6) The polyimide film is placed in an imidization furnace for imidization, and processed by a winder and a slitter to produce a finished product.

The organic solvent is dimethylacetamide, dimethylsulfoxide, N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide or N-methylpyrrolidone.

Beneficial effects of the present invention: The multilayer nano-graphite sheet hybrid transparent polyimide film of the present invention adopts the technical solution of nano-graphite and micro-crack discoloration agent composite, which makes the material sensitive to minute lines of fission and presents visual observation. It is easy to identify the changes. Within a few millimeters around the crack, the color changes are clearly visible, which can effectively monitor the safety status of those composite materials used in aircraft and automobiles, thereby avoiding accidents.

detailed description

The present invention is further described below with reference to specific embodiments.

Example 1

A multilayer nano-graphite sheet hybrid transparent polyimide film includes the following parts by weight: 350 g of polyimide, 5 g of nano-graphite, and 8 g of 1,2,3,10b-tetrahydrofluoranthene.

(1) At room temperature, add 1180g of 2,2-bis [4- (4-aminophenoxy) phenyl] propane and 990g of 4,4′-oxybisphthalic anhydride to the reactor, and protect it with nitrogen. Add 15000g of m-cresol below, stir well, add 500g of isoquinoline, heat up to 190 ° C, and react for 12 hours. After cooling, pour the reaction solution into ethanol to precipitate to make a polyimide resin;

(2) 5g of nano-graphite is placed in 500g of N-methylpyrrolidone, which is pre-dispersed after being subjected to high-temperature treatment by a high-shear disperser, and the processing temperature is 500 ° C;

(3) Take 350 g of the prepared polyimide resin and add it to the nano-graphite dispersion prepared in step (2), and stir it in a reaction kettle at a stirring speed of 1000 rpm and a stirring time of 1.5 h to prepare a film liquid;

(4) Add 8 g of 1,2,3,10b-tetrahydrofluoranthene to the film liquid, continue stirring, stirring speed 400 rpm, stirring time 3 h, and make a color changing film liquid;

Example 2

A multilayer nano-graphite sheet hybrid transparent polyimide film includes the following parts by weight: 200 g of polyimide, 3 g of nano-graphite, and 3 g of 9-ethylfluorene.

(1) At room temperature, add 1108g of 2,2'-bis (trifluoromethyl) benzidine and 880g of pyromellitic dianhydride to the reaction kettle, add 13000g of m-cresol under nitrogen protection, stir well, then add 400 g of isoquinoline, heated to 170 ° C., and reacted for 10 hours. After cooling, the reaction solution was poured into ethanol to precipitate out to make a polyimide resin;

(2) Put 3g of nano-graphite in 300g of N-methylpyrrolidone, disperse it in advance after high-temperature treatment by a high-shear disperser, and the processing temperature is 300 ° C;

(3) Take 200 g of the prepared polyimide resin, add it to the nano-graphite dispersion prepared in step (2), and stir it in a reaction kettle at a stirring speed of 800 rpm and a stirring time of 1 hour to prepare a film liquid;

(4) Add 8g of 9-ethyl hydrazone to the film liquid, continue stirring, the stirring speed is 400 rpm, and the stirring time is 3 hours to prepare a color changing film liquid;

Example 3

A multilayer nano-graphite sheet hybrid transparent polyimide film includes the following parts by weight: 500 g of polyimide, 12 g of nano-graphite, and 12 g of 9-benzylfluorene.

(1) At room temperature, add 1320 g of α, ω-bis (methylamino) polydimethylsiloxane and 1010 g of bisphenol A dianhydride to the reaction kettle, add 15000 g of m-cresol under nitrogen protection, and stir well 500 g of isoquinoline was added, the temperature was raised to 200 ° C., and the reaction was carried out for 14 hours. After cooling, the reaction solution was poured into ethanol to precipitate out to make a polyimide resin;

(2) Put 12g of nano-graphite in 600g of N-methylpyrrolidone, disperse it in advance by high-temperature treatment with a high-shear disperser, and treat the temperature at 800 ° C;

(3) adding the synthesized polyimide resin and the treated nano-graphite to the reaction kettle and stirring, the stirring speed is 1200 rpm, and the stirring time is 2 hours to prepare a film liquid;

(4) Add 12 g of 9-benzylhydrazone to the film liquid, continue stirring, and stir at a speed of 500 rpm and a stirring time of 5 hours to prepare a color-changing film liquid;

Example 4

A multilayer nano-graphite sheet hybrid transparent polyimide film includes the following parts by weight: 350 g of polyimide, 5 g of nano-graphite, and (3-chloropentane-1,5-diacyl) diphenyl 8g.

(1) At room temperature, add 1180g of 2,2-bis [4- (4-aminophenoxy) phenyl] propane and 990g of 4,4′-oxybisphthalic anhydride to the reactor, and protect it with nitrogen. Add 15000g of m-cresol below, stir evenly, add 500g of isoquinoline, raise the temperature to 190 ° C, and react for 12 hours. After cooling, pour the reaction solution into ethanol to precipitate to make a polyimide resin;

(4) Add 8g of (3-chloropentane-1,5-diacyl) dibenzene to the film liquid, continue stirring, stirring speed at 400 rpm, and stirring time for 3 hours to prepare a color changing film liquid;

Example 5

A multilayer nano-graphite sheet hybrid transparent polyimide film includes the following parts by weight: 350 g of polyimide, 5 g of nano-graphite, and 8 g of pentane-1,3,5-trinitrobenzene.

(4) Add 8g of pentane-1,3,5-trinitrobenzene to the film liquid, continue stirring, stirring speed of 400 rpm, and stirring time for 3 hours to prepare a color changing film liquid;

Example 6

A multilayer nano-graphite sheet hybrid transparent polyimide film includes the following parts by weight: polyimide 350 g, nano-graphite 5 g, 1- (2-chloroethyl) -3- (4beta-chlorine Methylcyclohexane-1alpha-yl) -1-nitrosourea 8g.

(2) Put 5g of nano-graphite in 500g of N-methylpyrrolidone, and disperse it in advance by a high-shear disperser after high-temperature treatment, and the treatment temperature is 500 ° C;

(4) 8-g of 1- (2-chloroethyl) -3- (4beta-chloromethylcyclohexane-1alpha-yl) -1-nitrosourea was added to the membrane solution, and stirring was continued at a stirring speed of 400 rpm, Stirring time is 3h to make a color changing film liquid;

Example 7

A multilayer nano-graphite sheet hybrid transparent polyimide film includes the following parts by weight: 350 g of polyimide, 5 g of nano-graphite, 8 g of pentane-1,3,5-trinitrobenzene, and 3g of crustacean extract.

The extraction method of the shell artillery shell crust extract is: grinding the shell artillery shell crust, passing through a 60-mesh sieve, adding 8 times by weight of 75% ethanol aqueous solution for reflux extraction 3 times, combining the filtrates, and decolorizing the activated carbon, Made by steaming.

(4) Add 8g of pentane-1,3,5-trinitrobenzene and 3g of crustacean extract from the cannonball to the film liquid, continue stirring, stirring speed of 400 rpm, and stirring time for 3 hours to prepare a color changing film liquid;

Comparative Example 1

A multilayer nano-graphite sheet hybrid transparent polyimide film includes the following parts by weight: 350 g of polyimide and 5 g of nano-graphite.

(4) the membrane is hydraulically pressured into a defoaming kettle, and the air bubbles in the membrane liquid are removed under a vacuum condition; the defoamed membrane liquid is put into a casting machine and cast to form a polyimide film having a uniform thickness;

(5) The polyimide film is placed in an imidization furnace for imidization, and processed by a winder and a slitter to produce a finished product.

Experimental example:

Take the polyimide films prepared in Examples 1-7 and Comparative Example 1, and use a sharp knife to make a small scratch with a length of 1 cm and a width of 0.2 mm. Observe whether there is a color change around the polyimide film and calculate the color band. Width, the experimental results are shown in Table 1:

Table 1

Note: * represents P <0.05 compared with the group of Example 1.

It can be seen from Table 1 that the micro-crack discoloration agent was not added in Comparative Example 1, no ribbon was generated, the ribbon was generated in Examples 1-5, and the ribbon was generated in Examples 6-7, and the width of the ribbon was significantly higher than that of the implementation. example 1.

Claims

A multilayer nano-graphite sheet hybrid transparent polyimide film, characterized in that it includes the following materials in parts by weight: 200-500 parts of polyimide, 3-12 parts of nano-graphite, and micro-crack discoloration agent 3- 12 servings.
The hybrid nano-graphite sheet hybrid transparent polyimide film according to claim 1, wherein the micro-crack discoloration agent is 1,2,3,10b-tetrahydrofluoranthene, 9-ethylphosphonium or 9-benzylfluorene.
The hybrid nano-graphite sheet hybrid transparent polyimide film according to claim 1, wherein the micro-crack discoloration agent is a compound having the following molecular formula:

In the formula, X is methyl, ethyl, halogen or phenyl.
The hybrid nano-graphite sheet hybrid transparent polyimide film according to claim 1, wherein the polyimide is prepared by using a diamine and a dianhydride as raw materials and adopting a two-step solution polycondensation method.
The hybrid nano-graphite sheet hybrid transparent polyimide film according to claim 1, wherein the diamine is 2,2-bis [4- (4-aminophenoxy) phenyl] propane, α, ω-bis (methylamino) polydimethylsiloxane, 2,2'-bis (trifluoromethyl) benzidine, 2,4-diaminofluorobenzene, 2- (trifluoromethyl) -1,4-phenylene diamine, 4-trifluoromethyl-1,2-phenylenediamine or 4,5-difluorobenzene-1,2-diamine.
The hybrid nano-graphite sheet hybrid transparent polyimide film according to claim 1, wherein the dianhydride is 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 4,4 '-Oxybisphthalic anhydride, pyromellitic dianhydride, bisphenol A dianhydride or hexafluoroisopropylidene phthalic dianhydride.
The method of claim 1, wherein the method comprises the following steps:

(1) At room temperature, add diamine and dianhydride to the reaction kettle, add m-cresol under nitrogen protection, stir well, add isoquinoline, warm to 170-200 ° C, react for 10-14 hours, and cool Pour the reaction solution into ethanol to make a polyimide resin;

(2) The nano-graphite is placed in an organic solvent and pre-dispersed after being subjected to a high-temperature treatment by a high-shear dispersing machine, and the processing temperature is 200-800 ° C;

(3) adding the synthesized polyimide resin and the treated nano-graphite to the reaction kettle and stirring, the stirring speed is 800-1200 rpm, and the stirring time is 1-2 hours to prepare a film liquid;

(4) Add the micro-crack discoloration agent to the film liquid, continue to stir, the stirring speed is 300-500 rpm, and the stirring time is 2-5 h to make a color-changing film liquid;

(5) Hydraulically change the color-changing film into the defoaming kettle, remove the bubbles in the color-changing film liquid under vacuum conditions, put the decolorized film-changing film liquid into a casting machine and cast to form a polyimide film with uniform thickness ;

(6) The polyimide film is placed in an imidization furnace for imidization, and processed by a winder and a slitter to produce a finished product.
The method of claim 1, wherein the organic solvent is dimethylacetamide, dimethylsulfoxide, N, N-dimethyl Acetamide, N, N-dimethylformamide, dimethylsulfoxide or N-methylpyrrolidone.