Dyed polyester fiber composite structure

Claim 1

A dyed polyester fiber composite structure having an enhanced brilliance and color, produced by the process comprising: (A) (1) forming a polyester resin by reacting a dicarboxylic acid component comprising at least one member selected from the group consisting of terephthalic acid and ester-forming derivative thereof as a principal ingredient thereof, with a glycol component comprising at least one alkylene glycol having 2 to 6 carbon atoms as a principal ingredient thereof to form a primary reaction mixture, and polycondensing the primary reaction mixture, in at least one stage of the polyester resin-forming procedure, admixing with the mixture at least one precursory pore-forming agent selected from the group consisting of: (a) a mixture of at least one pentavalent phosphorus compound in an amount of 0.3 to 3 molar % based on the molar amount of said dicarboxylic acid component and at least one calcium compound which is in an amount of 1 mole to 1.7 moles per mole of said pentavalent phosphorus compound and which has not been preliminarily reacted with said pentavalent phosphorus compound; (b) a mixture of at least one trivalent phosphorus compound in an amount of 0.3 to 3 mole % based on the molar amount of said dicarboxylic acid component, and at least one alkaline earth metal compound which is in an amount of 1 mole to 1.7 moles per mole of said trivalent phosphorus compound and which has not been preliminarily reacted with said trivalent phosphorus compound; (c) a mixture of 0.3 to 3 molar % based on the molar amount of said dicarboxylic acid component, of at least one phophorus compound of the formula (I): ##STR10## wherein R 1 and R 2 represent, independently from each other, a member selected from the group consisting of hydrogen and monovalent organic radicals, M represents a member selected from the group consisting of alkali metals and alkaline earth metals, and m represents 1 when M represents an alkali metal and 1/2 when M represents an alkaline earth metal, and at least one alkaline earth metal compound in an amount of 0.5 to 1.2 moles per mole of said phosphorus compound of the formula (I) and which has not been preliminarily reacted with said phosphorus compound of the formula (I); (d) a mixture of ingredients comprising (i) at least one member selected from the group consisting of isophthalic acid compounds having an alkali metal sulfonate radical and ester-forming derivatives thereof in an amount 0.5 to 10 molar % based on the molar amount of said dicarboxylic acid component, (ii) at least one phosphorus compound of the formula (II): ##STR11## wherein R 1 and R 2 represent, independently from each other, a member selected from the group consisting of hydrogen and monovalent organic radicals, X represents a member selected from the group consisting of hydrogen, monovalent organic radicals and monovalent metal atoms, and n represents 0 or 1, in an amount of 0.3 to 3 molar % based on the molar amount of said dicarboxylic acid component, and (iii) at least one lithium compound in an amount such that the sum of the equivalent numbers of the metals contained in said ingredients (ii) and (iii) is in the range of from 2.0 times to 3.2 times the molar amount of the phosphorus compound in ingredient (ii), said ingredients (i), (ii), and (iii) not having been preliminarily reacted with each other; and (e) a mixture of 0.5 to 3 molar % based on the molar amount of said dicarboxylic acid component, of at least one phosphorus compound of the formula (III): ##STR12## wherein R 1 and R 2 represent, independently from each other, a member selected from the group consisting of hydrogen and monovalent organic radicals, M represents a member selected from the group consisting of alkali metals and alkaline earth metals, and m represents 1 when M represents an alkali metal and 1/2 when M represents an alkaline earth metal, and at least one alkaline earth metal compound in an amount of from 0.5 to 1.2 moles per mole of said phosphorus compound of the formula (III) and which has not been preliminarily reacted with said phosphorus compound of the formula (III); whereby said precursory pore-forming agent is converted into a pore-forming agent dispersed in fine particle form in the resultant polyester resin, (2) melting spinning said resultant pore-forming agent-containing polyester resin to provide a polyester fiber in which fine particles of said pore-forming agent are dispersed, (3) treating said polyester fiber with an aqueous alkali solution to an extent that at least 2% of the weight of said polyester fiber is dissolved in said aqueous alkali solution, whereby a number of pores are formed in said polyester fiber, and (4) dying said resultant porous polyester fiber; and (B) coating said dyed porous polyester fiber with a composition comprising a polymeric material having a smaller refractive index than that of said porous polyester fiber.