15383-49-0Relevant articles and documents
METHOD FOR PRODUCING 1,2,4,5-CYCLOHEXANETETRACARBOXYLIC DIANHYDRIDE
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Paragraph 0103-0107; 0111-0114; 0118-0120; 0149-0151, (2020/02/15)
An object of the present invention is to provide a method for producing 1,2,4,5-cyclohexanetetracarboxylic dianhydride, which is capable of stably achieving a high dehydration rate. The method for producing 1,2,4,5-cyclohexanetetracarboxylic dianhydride of the present invention is a method for producing 1,2,4,5-cyclohexanetetracarboxylic dianhydride by subjecting 1,2,4,5-cyclohexanetetracarboxylic acid to a dehydration reaction in a slurry state in the presence of a dehydrating agent, wherein an average particle size of the 1,2,4,5-cyclohexanetetracarboxylic acid is 20 μm or more.
POLYIMIDE AND POLYIMIDE FILM
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Paragraph 0105, (2017/12/05)
PROBLEM TO BE SOLVED: To provide a polyimide that has excellent film-production process compatibility, and gives a heat-resistant film having excellent transparency, a high glass transition temperature, a relatively low linear thermal expansion coefficient, and sufficient film toughness at the same time. SOLUTION: A polyimide contains a repeating unit represented by the formula (II) (in formula (II), A is a bivalent group containing a cyclohexane ring, X is an amide group, R11-R18 independently represent a hydrogen atom, a C1-C6 alkyl group or a C1-C6 alkoxy group). SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
Electronic grade hydrogenation of pyromellitic acid dianhydride preparation method (by machine translation)
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, (2018/02/04)
The invention discloses a preparation method of electronic grade hydrogenated pyromellitic dianhydride. The method comprises the following steps: adding commercially available pyromellitic dianhydride with the purity greater than or equal to 98.0%, deionized water and a noble metal catalyst into an autoclave; feeding hydrogen into the autoclave and simultaneously carrying out a hydrolysis reaction and a catalytic hydrogenation reaction; carrying out aftertreatment after the reactions so as to obtain crude hydrogenated pyromellitic dianhydride; decoloring and refining crude hydrogenated pyromellitic dianhydride with deionized water and activated carbon so as to obtain hydrogenated pyromellitic dianhydride with the purity greater than or equal to 99.5%; finally, carrying out a dehydration reaction on hydrogenated pyromellitic dianhydride by using acetic anhydride so as to obtain electronic grade hydrogenated pyromellitic dianhydride with the purity greater than or equal to 99.85%. According to the method, the purity of prepared hydrogenated pyromellitic dianhydride can reach above 99.85%, and the content of single metal ions (such as sodium, potassium, calcium, iron, copper, aluminum and the like) in prepared hydrogenated pyromellitic dianhydride is respectively less than 1ppm. Thus, electronic grade hydrogenated pyromellitic dianhydride can be widely applied to the field of photoelectronics, micro-electronics and other high and new technologies.