Abstract: The present invention relates to halogen-containing aromatic compounds and methods thereof. The present invention relates a halogen-containing aromatic acid dianhydride, halogen-containing aromatic tetranitrile compound, halogen-containing m-phenylenediamine compound and fluorine compound, and a method thereof.

Abstract: A method which controls sedimentation occurring at a heat exchanger for cooling hydrodesulfurization/hydrocracking residue containing asphaltenes at a high content and thereby prevents fouling of the heat exchanger is disclosed. A method for preventing fouling of a heat exchanger for cooling hydrodesulfurization/hydrocracking residue, which injects flux oil into hydrodesulfurization/hydrocracking residue containing asphaltenes at 1% by mass or more, wherein the flux oil is at least one species of residue selected from the group consisting of crude vacuum distillation residue and fluidized catalytic cracking residue, and injected into the hydrodesulfurization/hydrocracking residue to control its actual sediment content at 0.2% by mass or less, determined in accordance with IP-375 is also disclosed.

Abstract: A polyimide excelling in heat resistance, chemical resistance, water repellency, dielectric characteristics, electrical characteristics, and optical characteristics and a polyamide acid useful as the raw material therefor are provided. Specifically, a polyamide acid containing a chlorine atom and a fluorine atom and comprising a repeating unit represented by the following formula (1): (wherein X and X? independently denote a divalent organic group; Y and Y? independently denote a chlorine, bromine, or iodine atom; p and p? denote independently denote the number of fluorine atom {F in the formula (1)} bonded to the relevant benzene ring, representing an integer of 0-3; q and q? independently denote an integer of 0-3; and p+q total 3, and p?+q? total 3).

Abstract: The present invention relates to halogen-containing aromatic compounds and methods thereof. The present invention relates a halogen-containing aromatic acid dianhydride, halogen-containing aromatic tetranitrile compound, halogen-containing m-phenylenediamine compound and fluorine compound, and a method thereof.

Abstract: The present invention relates to halogen-containing aromatic compounds and methods thereof. The present invention relates a halogen-containing aromatic acid dianhydride, halogen-containing aromatic tetranitrile compound, halogen-containing m-phenylenediamine compound and fluorine compound, and a method thereof.

Abstract: A polyimide excelling in heat resistance, chemical resistance, water repellency, dielectric characteristics, electrical characteristics, and optical characteristics and a polyamide acid useful as the raw material therefor are provided.

Abstract: The present invention relates to halogen-containing aromatic compounds and methods thereof. The present invention relates a halogen-containing aromatic acid dianhydride, halogen-containing aromatic tetranitrile compound, halogen-containing m-phenylenediamine compound and fluorine compound, and a method thereof.

Abstract: The invention provides a needle holding arrangement for only the gripping of a needle within the body cavity. There is provided a suture fixing means for gripping or fixing a suture with a needle on an outer peripheral surface of the needle-holder shaft. After piercing and passing of the needle through the tissue in the body, a knot of the suture can be made within the body cavity, and saturation and ligation of tissues in the body and end closure and ligation of blood vessel and gall duct can also be performed.