Preparation method of polyamic acid solution

A polyamic acid and solution technology, which is applied in the field of polyamic acid solution preparation, can solve problems such as viscosity changes, affecting processing and molding, quality of polyimide products, and difficulty in mass transfer of dianhydride monomers.

Active Publication Date: 2021-05-11
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] 1. Due to the high viscosity of the system in the later stage of polymerization, it is very difficult for the powdery dianhydride monomer to transfer mass in the solution, and the reaction is difficult to fully proceed, which will cause more gel particles in the solution, resulting in uneven solution , which seriously affects the subsequent processing and molding and the quality of polyimide products;
[0006] 2. When the two monomers of diamine and dianhydride are close to equivalent, a small change in their molar ratio will cause a huge change in the viscosity of the solution, that is to say, when adding dianhydride monomer to the solution, a small measurement error will lead to Large viscosity changes, which brings great challenges to the control of PAA solution viscosity, especially in industrial production

Method used

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  • Preparation method of polyamic acid solution
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  • Preparation method of polyamic acid solution

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0038] Dissolve 23.38g (116.77mmol) of diphenyl ether diamine (ODA) in 273.94g of N,N-dimethylacetamide (DMAc), stir at 25°C, after complete dissolution, add 24.96g (114.43mmol) Perphthalic dianhydride (PMDA), fully reacted to obtain A solution (dianhydride, diamine molar ratio 0.98, solid content 15%, the same below). Using the same method, 19.41 g (96.92 mmol) ODA, 289.68 g DMAc, and 31.71 g (145.38 mmol) PMDA were used to prepare B solution (molar ratio 1.50, solid content 15%). Add 11.36g of solution B into solution A and stir thoroughly at 25°C to obtain a final polyamic acid solution (molar ratio 0.994, solid content 15%). The above experiment was repeated three times, and the final solution was measured at a shear rate of 1s -1 The apparent viscosities under the conditions are 288Pa·s, 293Pa·s and 290Pa·s respectively. After passing the solution through a 2 μm glass fiber filter membrane, the filter screen was irradiated by ultraviolet fluorescent lamps without any fo...

Embodiment 2

[0040]Dissolve 2002.4g (10mol) ODA in 23089.0g DMAc, stir at 25°C, after complete dissolution, add 2072.1g (9.5mol) PMDA, and obtain A solution (molar ratio 0.95, solid content 15%) after full reaction. Using the same method, 1001.2g (5mol) ODA, 14944.0g DMAc, and 1635.9g (7.5mol) PMDA were used to prepare solution B (molar ratio 1.50, solid content 15%). Add 2757.5g of solution B into solution A and stir thoroughly at 25°C to obtain a final polyamic acid solution (molar ratio 0.99, solid content 15%). The above experiment was repeated three times, and the final solution was measured at a shear rate of 1s -1 The apparent viscosities under the conditions are 248Pa·s, 244Pa·s and 252Pa·s respectively. After passing the solution through a 2 μm glass fiber filter membrane, the filter screen was irradiated by ultraviolet fluorescent lamps without any foreign matter.

Embodiment 3

[0042] Dissolve 2002.4g (10mol) ODA in 27837.0g NMP, stir at 0°C, after complete dissolution, add 1090.6g (5mol) PMDA, fully react to obtain A solution (molar ratio 0.5, solid content 10%). Using the same method, 1001.2g (5mol) ODA, 28641.6g NMP, and 2181.2g (10mol) PMDA were used to prepare solution B (molar ratio 2.0, solid content 10%). The two solutions A and B were mixed and stirred thoroughly at 0° C. to obtain the final polyamic acid solution (molar ratio 1, solid content 10%). The final solution was measured at a shear rate of 1s -1 The apparent viscosity under the condition is 168Pa·s. After passing the solution through a 2 μm glass fiber filter membrane, the filter screen was irradiated by ultraviolet fluorescent lamps without any foreign matter.

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Abstract

The invention relates to a preparation method of polyamic acid solution, which belongs to the field of preparation of polyamic acid solution, and mainly solves the problem of uncontrollable viscosity of polyamic acid solution in the preparation of polyamic acid in the prior art, easy formation of polyamic acid agglomerates or poor uniformity question. The present invention adopts a kind of preparation method of polyamic acid solution, it is characterized in that, first prepare a kind of polyamic acid solution A of amine excess and a kind of polyamic acid solution B of anhydride excess, then polyamic acid solution A, Two solutions of polyamic acid solution B are mixed to prepare the polyamic acid solution; wherein, the equivalent ratio of polyamic acid solution A and polyamic acid solution B satisfies the dianhydride and dianhydride in the prepared polyamic acid solution The technical scheme in which the molar ratio of the amine units is 0.95-1.05 solves this problem well, and can be used in the industrial application of polyamic acid preparation.

Description

technical field [0001] The invention relates to a novel method for preparing a polyamic acid solution, through which the viscosity of the polyamic acid solution can be controlled more conveniently and effectively, and the prepared polyamic acid solution has better uniformity. Background technique [0002] Polyimide (PI) refers to a class of aromatic heterocyclic polymers containing imide rings in the main chain, and is one of the highest heat-resistant polymer materials so far. In addition to outstanding thermal stability (starting decomposition temperature > 500 ° C), polyimide also has excellent low temperature resistance (not brittle under -269 ° C liquid helium), radiation resistance and good mechanical properties, Chemical corrosion resistance and dielectric properties, etc. Usually in the form of films, fibers, foams, engineering plastics or composite materials, they are widely used in aerospace, microelectronics, solar cells, high-temperature filtration, machinery...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08G73/10
CPCC08G73/1007C08G73/105C08G73/1071
Inventor 孙旭阳崔晶陈雪刘京妮陈大为
Owner CHINA PETROLEUM & CHEM CORP
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