The present invention relates to a method for preparing an ester-based composition, the method configured to sequentially operate a plurality of batch reactors and control pressure in each reactor, and the ester-based composition is semi-continuously prepared to have high productivity as well as stability of the batch reactors.

The present disclosure relates to a manufacturing system and a manufacturing method which are capable of continuously manufacturing an ester-based composition, and has a technical feature of being capable of manufacturing an ether-based composition continuously, economically, and efficiently.

The present disclosure relates to a manufacturing system and a manufacturing method which are capable of continuously manufacturing an ester-based composition, and has a technical feature of being capable of manufacturing an ether-based composition continuously, economically, and efficiently.

The present disclosure relates to a method and a system for manufacturing an ester-based composition which are characterized in sequentially operating a plurality of batch reactors, and since an ester-based composition is semi-continuously manufactured, the productivity is high and the stability of a batch reactor is secured.

The present disclosure relates to a method and a system for manufacturing an ester-based composition which are characterized in sequentially operating a plurality of batch reactors, and since an ester-based composition is semi-continuously manufactured, the productivity is high and the stability of a batch reactor is secured.

An object of the present invention is to provide a novel compound that provides a curing agent that is less likely to volatilize during curing reaction and is excellent in various properties such as heat resistance. As a solution, an aromatic tetracarboxylic acid compound represented by formula (I) below is provided.

##STR00001##

(In the formula, each R independently represents an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and each n independently represents 0 or an integer of 1 to 4.)

An object of the present invention is to provide a novel compound that provides a curing agent that is less likely to volatilize during curing reaction and is excellent in various properties such as heat resistance. As a solution, an aromatic tetracarboxylic acid compound represented by formula (I) below is provided.

##STR00001##

(In the formula, each R independently represents an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and each n independently represents 0 or an integer of 1 to 4.)

An internal electron donor compound for preparing α-olefin polymerization catalyst component, including two kinds of electron donors; the proportion of the two kinds of electron donors in the compounding preparation of the catalyst is determined via designed experiments so as to obtain a catalyst component having good comprehensive performance or a particular performance. The electron donor compound of the present invention can be used in the preparation of α-olefin polymerization and co-polymerization catalyst component, particular the preparation of propylene polymerization catalyst component, and is applicable to prepare the propylene polymerization catalyst component by reacting magnesium chloride-ethanolscomlex compound carrier with titanium tetrachloride and electron donors, or to directly prepare the propylene polymerization catalyst component by reacting magnesium chloride, alcohols, titanium tetrachloride, and internal electron donor. In addition, also provided is a theoretical basis for selecting a proper electron donor combination from a plurality of electron donors.

An internal electron donor compound for preparing α-olefin polymerization catalyst component, including two kinds of electron donors; the proportion of the two kinds of electron donors in the compounding preparation of the catalyst is determined via designed experiments so as to obtain a catalyst component having good comprehensive performance or a particular performance. The electron donor compound of the present invention can be used in the preparation of α-olefin polymerization and co-polymerization catalyst component, particular the preparation of propylene polymerization catalyst component, and is applicable to prepare the propylene polymerization catalyst component by reacting magnesium chloride-ethanolscomlex compound carrier with titanium tetrachloride and electron donors, or to directly prepare the propylene polymerization catalyst component by reacting magnesium chloride, alcohols, titanium tetrachloride, and internal electron donor. In addition, also provided is a theoretical basis for selecting a proper electron donor combination from a plurality of electron donors.

The present invention aims to provide a means by which a cured product to be obtained has a low dielectric loss tangent and higher heat resistance. Specifically, provided are an active ester compound represented by chemical formula (1): ##STR00001## (where in chemical formula (1), Ar.sup.1 is a substituted or unsubstituted first aromatic ring group, and each Ar.sup.2 is independently a substituted or unsubstituted second aromatic ring group, in which at least one of Ar.sup.1 and Ar.sup.2 has an unsaturated bond-containing substituent, and n is an integer of 2 or 3), a curable composition containing the active ester compound, and a cured product thereof.