Preparation method of high temperature resistant nylon resin

Abstract

The invention discloses a preparation method of high-temperature-resistant nylon resin, which comprises: making 1-hydrogen-benzimidazole-2,5-diamine, aliphatic dibasic acid or aromatic dibasic acid in the presence of a catalyst Acid and solvent are mixed and reacted under a protective atmosphere to prepare benzimidazole dicarboxylic acid; and, in the presence of a catalyst, make benzimidazole dicarboxylic acid, other binary The mixture of acid, aliphatic diamine, water and ethanol is mixed and reacted in a horizontal high-temperature and high-pressure reactor with built-in rotating stirring blades under a protective atmosphere to prepare high-temperature-resistant nylon resin. The invention truly realizes the "one-step" polymerization of high-temperature-resistant nylon resin, with simple process, mild conditions, high efficiency, environmental protection, low equipment requirements, and no agglomeration and bonding of materials during the polymerization process, which is suitable for industrialization. The high temperature resistance performance, tensile strength, bending strength and other mechanical properties of high temperature resistant nylon resin products are also significantly improved.

Description

technical field [0001] The invention specifically relates to a preparation method of high-temperature-resistant nylon resin, which belongs to the field of preparation of high-temperature, high-strength, and high-modulus nylon. Background technique [0002] With the rapid development of modern science and technology, the demand for high-performance materials, especially high-temperature-resistant engineering plastics, is increasingly urgent. Therefore, for decades, high temperature resistant engineering plastics have always been one of the hotspots of people's competing research. High temperature resistant nylon resin, as a kind of high temperature resistant engineering plastics, is prepared by polycondensation reaction of aliphatic diamine or diacid and diacid or diamine with aromatic ring. Since the main chain of nylon introduces aromatic ring structure, nylon products The heat resistance and mechanical properties of the resin have been improved, while the water absorption...

AI Technical Summary

Problems solved by technology

For example, CN1537881A, CN103360598A, and CN107383365A mentioned that the high-temperature-resistant nylon resin was prepared by melt polymerization in one step. The disadvantage of this method is that the reaction temperature is higher than the melting point of the high-temperature-resistant nylon resin, and the discharge temperature is above 300°C, which will inevitably cause material There are problems such as oxidation, carbonization and incomplete discharge

The polymerization method proposed by CN105339415A, CN104327265A and CN112321820A etc. is actually a "two-step method", that is, the first step is to synthesize the nylon salt, and the second step is to directly obtain the polymer through the nylon salt, which is not a real "one-step method"; This method has a narrow scope of application. One or two semi-aromatic nylon salts can be used to obtain homopolymerized or copolymerized semi-aromatic nylon. However, if aliphatic nylon salts, such as nylon 66 salts, are added during polymerization, this method can be used to prepare high-temperature resistant nylon. Resins, semi-aromatic nylon salts and aliphatic nylon salts have large differences in reactivity, which will inevitably cause large differences between product batches

CN104817693A adds terephthalic acid, undecyl diamine and water into a drum reactor to prepare long carbon chain semi-aromatic nylon; this method is "one-step method", but this method can only prepare homopolymer long carbon chain semi-aromatic nylon Aromatic nylon, narrow range of application

In addition, when the existing method is used to prepare high-temperature-resistant nylon resin, there are still common problems such as material agglomeration and sticking to the wall during the polymerization process.

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