Abstract: A light-resistant wholly aromatic polyamide resin composition comprises a light-resisting agent blended to a wholly aromatic polyamide resin and comprising at least one naphthalene ring structure-containing compound of the formula (I): ##STR1## wherein Ar.sub.1, Ar.sub.2, Ar.sub.3 =a divalent organic group, X=an amide bond group (--CONH), Y=an amide bond group or an imide bond group ##STR2## A and B=a monovalent organic group when Y=an amide bond group, or =a divalent organic group when Y=an imide bond group, n=1 to 10, and at least one of Ar.sub.1, Ar.sub.2, Ar.sub.3, A and B has a naphthalene ring structure.

Abstract: A wholly aromatic polyamide capable of being dissolved in organic solvents to form an isotropic dope solution and having an excellent chemical resistance, heat resistance, processability and mechanical strength and a high modulus, comprises recurring aromatic dicarbonyl units of the formulae: ##STR1## and recurring aromatic diamine units of the formulae: ##STR2## wherein R and R' are a hydrogen or halogen atom or an alkyl or alkoxyl radical, n is 1 to 3, and p and q are 1 to 4.

Abstract: A wholly aromatic copolymer and a shaped article thereof having an excellent mechanical property, high resistances to heat and chemicals, and a satisfactory processability, is composed of (1) an aromatic dicarbonyl moiety consisting of recurring dicarbonyl units (A) and (B): ##STR1## and (2) an aromatic diamine moiety consisting of recurring diamine units (C) and (D): ##STR2## and the recurring dicarbonyl units (B) being in an amount of 0.01 molar % or more but less than 20 molar % based on the total molar amount of the dicarbonyl moiety (1), and the recurring diamine units (D) being in an amount of 60 molar % or less but more than 20 molar % based on the total molar amount of the diamine moiety (2).

Abstract: A wholly aromatic polyamide copolymer having excellent heat, flame and chemical resistances, solubility in organic solvents and shaping property and useful for shaped article having a high mechanical strength and modulus of elasticity, comprising the repeating units of the formulae: ##STR1## and at least one member selected from ##STR2## wherein X=a halogen atom, n, or m=1 to 4 and n+m=1 to 8.

Abstract: A method for treating synthetic pulp particles, which includes treating a slurry of synthetic pulp particles having a Schopper-Riegler freeness of more than 30.degree.SR by a concentration provided with a rotary filter bed to lower the freeness not more than 30.degree.SR, water-washing the synthetic pulp particles in the state where the freeness is not more than 30.degree.SR, and dispersing the synthetic pulp particles in water to restore the freeness to more than 30.degree.SR.

Abstract: A biaxially oriented film of a film-forming aromatic polyester derived from an aromatic dicarboxylic acid as a main acid component and an aliphatic glycol as a main glycol component, said film having surface properties such that(1) it has a surface flatness, R.sub.CLA, of from 0.001 to 0.016 micron,(2) it has a coefficient of travelling friction, .mu.k, of from 0.01 to 0.20, and(3) the following relation is established between R.sub.CLA and .mu.k,0.10.ltoreq.10.times.R.sub.CLA +.mu.k.ltoreq.0.31.Preferably, said film has many minute protrusions on its surface which are attributed to fine particles of titanium dioxide or of both titanium dioxide and calcium carbonate, and has such further surface property that(4) a distribution curve showing the relation between the heights of said many protrusions on the film surface and the numbers of the protrusions having the respective heights does not cross a straight line represented by the following equation (1)log.sub.10 y=-8.0x+4.

Abstract: An assembly of fibers composed of at least two dissimilar fiber-forming polymers, characterized by the fact that(1) it consists of numerous fibers,(2) at least 90% of said fibers have a non-circular cross-sectional shape,(3) the cross-sections of at least 50% of said fibers differ from each other in at least one of shape and size, and(4) at least 50% of said fibers each have in their cross-section taken at right angles to the fiber axis at least two side-by-side coalesced blocks of at least two dissimilar fiber-forming polymer phases with at least a part thereof being exposed to the peripheral surface of the fiber, at least one of the number, shape and size of the blocks varying from fiber to fiber.

Abstract: A biaxially oriented film of a film-forming aromatic polyester derived from an aromatic dicarboxylic acid as a main acid component and an aliphatic glycol as a main glycol component, said film having surface properties such that(1) it has a surface flatness, R.sub.CLA, of from 0.001 to 0.016 micron,(2) it has a coefficient of travelling friction, .mu.k, of from 0.01 to 0.20, and(3) the following relation is established between R.sub.CLA and .mu.k,0.10.ltoreq.10.times.R.sub.CLA +.mu.k.ltoreq.0.31.Preferably, said film has many minute protrusions on its surface which are attributed to fine particles of titanium dioxide or of both titanium dioxide and calcium carbonate, and has such further surface property that(4) a distribution curve showing the relation between the heights of said many protrusions on the film surface and the numbers of the protrusions having the respective heights does not cross a straight line represented by the following equation (1)log.sub.10 y=-8.0.times.+4.

Abstract: A process and apparatus for producing a fibrous assembly. At least one fiber-forming polymer is extruded through a spinneret having numerous small openings. The process uses a die equipped with a spinneret having numerous closely spaced small openings and an opening ratio (.alpha.) of at least 30%. At least one fiber-forming polymer in the form of a shaped mass having a specified compression resistance is continuously stuffed into said die. Said shaped mass has a shape such that it measures more in one direction than in another. There is passed through the spinneret an electric current sufficient to give said fiber-forming polymer Joule heat required for cutting said polymer by partitioning members defining the numerous small openings of the spinneret. The cut fiber-forming polymer is taken up as fine streams.The present invention provides ultrathick aromatic polyamide fibers having an average cross-sectional area of about 0.01 mm.sup.2 to about 5 mm.sup.

Abstract: A novel filament composed of at least one thermoplastic synthetic polymer, said filament being characterized by having (1) an irregular variation in the size of its cross section along its longitudinal direction, and (2) a coefficient of intrafilament cross-sectional area variation [CV(F)] of 0.05 to 1.0; and a novel bundle of said filament.

Abstract: A novel filament composed of at least one thermoplastic synthetic polymer, said filament being characterized by having (1) an irregular variation in the size of its cross section along its longitudinal direction, and (2) a coefficient of intrafilament cross-sectional area variation [CV(F)] of 0.05 to 1.0; and a novel bundle of said filament.

Abstract: An assembly of fibers composed of at least two dissimilar fiber-forming polymers, characterized by the fact that(1) it consists of numerous fibers,(2) at least 90% of said fibers have a non-circular cross-sectional shape,(3) the cross sections of at least 50% of said fibers differ from each other in at least one of shape and size, and(4) at least 50% of said fibers each have in their cross section taken at right angles to the fiber axis at least two side-by-side coalesced blocks of at least two dissimilar fiber-forming polymer phases with at least a part thereof being exposed to the peripheral surface of the fiber, at least one of the number, shape and size of the blocks varying from fiber to fiber.

Abstract: The present invention provides a process for producing a fibrous assembly, which comprises extruding a melt of a fiber-forming polymer through a mesh spinneret, said spinneret including many closely arranged small openings and having an opening ratio (.alpha.), represented by the following formula, of at least about 10% ##EQU1## V.sub.a is the total apparent volume of the spinneret which is taken within a unit area of its mesh portion, and V.sub.

Abstract: A novel filament composed of at least one thermoplastic synthetic polymer, said filament being characterized by having (1) an irregular variation in the size of its cross section along its longitudinal direction, and (2) a coefficient of intrafilament cross-sectional area variation [CV(F)] of 0.05 to 1.0; and a novel bundle of said filament.

Abstract: A fibrous assembly of many fibers, the individual constituent fibers being interconnected at random in a spaced-apart relationship so that when spread in a direction at right angles to the longitudinal axes of the fibers, said assembly can form a continuous integral reticulated structure; said individual fibers having asymmetrical irregularly-shaped cross sections of substantially different profiles and sizes from one another when said assembly is cut at right angles to the longitudinal axes of the fibers at an arbitrary point therealong; at least 40% of the entire cross-sectional area of each fiber consisting of at least two different polymer phases which are coalesced side-by-side as at least two irregular blocks; and each of the individual fibers of said assembly having a non-uniform cross-sectional shape along its longitudinal axis; fibrous structures prepared from a plurality of such fibrous assemblies; and a process for producing such fibrous assembly.