A lightweight heat-preserving fiber and a preparation method thereof are provided, wherein the fiber is prepared by measuring, composite spinneret's extruding, cooling, oiling, drawing, heat setting and winding a polyester melt. The composite spinneret has a hollow spinning hole and a circular spinning hole. The ratio of the micropore length of hollow spinning hole to circular spinning hole equals to the ratio of the equivalent diameter of hollow spinning hole to circular spinning hole multiplies the coefficient K, and the equivalent diameter is the ratio of the cross-sectional area to the circumference of the cross-section, the coefficient K ranges from 0.97 to 1.03. The oil agent contains a crown ether, and the content of the crown ether ranges from 67.30 to 85.58 wt %. The thermal conductivity of a knitted fabric having a basis weight of 100 g/m.sup.2 prepared by lightweight heat-preserving fiber is no larger than 0.150 W/m.Math.K.

A description is given of continuous fibers based on cellulose and/or cellulose derivatives, more particularly for producing flame-retardant textiles or carbon fibers. The cellulose and/or the cellulose derivatives are in a dehydrated form in the continuous fibers. The oxygen content is 29 to 39 wt %, the limiting oxygen index LOI is 25 to 40 (according to DIN EN ISO 6941; 2004-05) and the density is 1.3 to 1.45 g/cm.sup.3 (according to DIN 65569-1; 1992-10). The continuous fibers may be produced advantageously by impregnating the starting fibers with a solution, more particularly an aqueous solution, of a specific salt which under thermal conditions releases a dehydrating acid which brings about the dehydration of cellulose and/or of cellulose derivatives in a subsequent thermal stage. The continuous fibers of the invention can be used in particular to produce advantageous carbon fibers.

A description is given of continuous fibers based on cellulose and/or cellulose derivatives, more particularly for producing flame-retardant textiles or carbon fibers. The cellulose and/or the cellulose derivatives are in a dehydrated form in the continuous fibers. The oxygen content is 29 to 39 wt %, the limiting oxygen index LOI is 25 to 40 (according to DIN EN ISO 6941; 2004-05) and the density is 1.3 to 1.45 g/cm.sup.3 (according to DIN 65569-1; 1992-10). The continuous fibers may be produced advantageously by impregnating the starting fibers with a solution, more particularly an aqueous solution, of a specific salt which under thermal conditions releases a dehydrating acid which brings about the dehydration of cellulose and/or of cellulose derivatives in a subsequent thermal stage. The continuous fibers of the invention can be used in particular to produce advantageous carbon fibers.

Methods for the preparation of carbon fiber from polyolefin fiber precursor, wherein the polyolefin fiber precursor is partially sulfonated and then carbonized to produce carbon fiber. Methods for producing hollow carbon fibers, wherein the hollow core is circular- or complex-shaped, are also described. Methods for producing carbon fibers possessing a circular- or complex-shaped outer surface, which may be solid or hollow, are also described.

Methods for the preparation of carbon fiber from polyolefin fiber precursor, wherein the polyolefin fiber precursor is partially sulfonated and then carbonized to produce carbon fiber. Methods for producing hollow carbon fibers, wherein the hollow core is circular- or complex-shaped, are also described. Methods for producing carbon fibers possessing a circular- or complex-shaped outer surface, which may be solid or hollow, are also described.

Disclosed is an elastic fiber treatment agent that contains a smoothing agent and an alkyl phosphate ester compound. The alkyl phosphate ester compound contains specific phosphate ester Q1 and at least one or more selected from specific phosphate esters Q2 and Q3. In a P nucleus NMR measurement of the alkyl phosphate ester compound upon an alkali over-neutralization pretreatment, a P nucleus NMR integral ratio attributed to the phosphate ester Q1 is 15% to 60% if the sum of P nucleus NMR integral ratios attributed to the phosphate esters Q1 to Q3 and phosphoric acid and its salt is taken as 100%.

The present invention is a lubricating agent containing a compound represented by the following formula 1:

##STR00001##

wherein R.sup.1 and R.sup.2 each represent a hydrocarbon group with 6 or more and 24 or less carbons; A.sup.10 and A.sup.2O each represent an alkyleneoxy group with 2 or more and 4 or less carbons; x1 and x2 are average numbers of added moles, and each represent a number of 0 or more and 10 or less; and M is a cationic ion.

The present invention is a lubricating agent containing a compound represented by the following formula 1:

##STR00001##

wherein R.sup.1 and R.sup.2 each represent a hydrocarbon group with 6 or more and 24 or less carbons; A.sup.10 and A.sup.2O each represent an alkyleneoxy group with 2 or more and 4 or less carbons; x1 and x2 are average numbers of added moles, and each represent a number of 0 or more and 10 or less; and M is a cationic ion.

The present invention provides a treatment agent composition for textile products, containing the following component (A) and the following component (B): component (A): an internal olefin sulfonate having 16 or more and 24 or less carbons; and component (B): a softening base for textile products.

An elastic fiber treatment agent that contains a smoothing agent, water and an organic phosphoric acid ester salt. The smoothing agent contains a mineral oil with an aniline point of not more than 110° C., a silicone oil, and optionally an ester oil. Assuming that the sum of the content ratios of the smoothing agent, the water, and the organic phosphoric acid ester salt in the elastic fiber treatment agent is 100 parts by mass, the elastic fiber treatment agent contains the mineral oil at a ratio of 20 to 90 parts by mass and the water at a ratio of 0.01 to 2 parts by mass.