Abstract:
PROBLEM TO BE SOLVED: To provide a wholly aromatic polyester having excellent heat resistance and toughness and showing optical anisotropy in a molten state, and a composition of the polyester.SOLUTION: The polyester resin composition is obtained by compounding 100 parts by mass of the following wholly aromatic polyester showing optical anisotropy and 120 parts by mass of an inorganic or organic filler. The wholly aromatic polyester comprises five structural units as essential components derived from: para-aromatic hydroxybenzoic acid; 2,6-hydroxy carboxyl group-substituted naphthalene; terephthalic acid; meta-dihydroxy benzene; and para-dihydroxybiphenyl.
Abstract:
Excellent tracking index as well as flame-resistant properties are achieved with other desirable characteristics of LCPs in a resin composition consisting essentially of: a) a wholly aromatic polyester which is melt processible and which displays anisotropy in the molten state; b) a non-conductive filler material having a diameter of less than about 3 ñm, with said non-conductive filler material being present in an amount sufficient to increase the comparative tracking index (CTI) rating of said composition to above 220 volts and render the composition non-burning. Optionally, an extraordinarily small amount of non-volatile fluorescent brightener can be added to the resin composition. In combination with the non-conductive filler, the fluorescent brightener is found to surprisingly and significantly improve the flame-retardant property of the resin.
Abstract:
A low dielectric constant, a low dielectric loss tangent, and heat resistance are achieved. An active ester resin that has a resin structure produced by reacting a polyfunctional phenolic compound (a1) with a monofunctional aromatic carboxylic acid or its chloride (a2) and an aromatic dicarboxylic acid or its chloride (a3) in such a manner that the amount of the component (a2) is 0.4 to 0.95 moles and the amount of the component (a3) is 0.3 to 0.025 moles per mole of phenolic hydroxyl groups of the component (a1) is used as a curing agent for epoxy resin. The polyfunctional phenolic compound (a1) is represented by structural formula (1) below: (where Ar represents a benzene ring, a naphthalene ring, a benzene ring nuclear-substituted by an alkyl group having 1 to 4 carbon atoms, or a naphthalene ring nuclear-substituted by an alkyl group having 1 to 4 carbon atoms, X represents a methylene group, a divalent cyclic aliphatic hydrocarbon group, a phenylene dimethylene group, or a biphenylene-dimethylene group, and n represents the number of repeating units and the average thereof is in a range of 0.5 to 10).