Abstract: A process is provided for preparing specific polycarboxylic acids by oxidative cleavage of double-bond compounds with hydrogen peroxide or hydrogen peroxide donors. The polycarboxylic acids thus obtained are notable for excellent acid stability, and consequently ease of handling in aqueous solution and are useful for treating cellulosic fibers or textile or paper materials produced therefrom.

Abstract: The invention relates to substrates bearing visible information that is secure against unauthorized copying obtained by applying information in the form of combinations of at least one emitting colorant and at least one reflecting colorant that are selected to exhibit similar or identical hues when viewed, with no cognizance being taken of fluorescence, and are applied in such a manner that their color fields touch, wherein the color loci of the two colorants correspond to one of the trichromatic colors yellow, magenta, or cyan and the reflecting colorant is an organic or inorganic pigment.

Abstract: A pressure roller for textile machines, in particular for a texturing machine, is provided. A covering (3) is preferably arranged over an intermediate sheath (4) on a support sheath (5). The support sheath (5) is rotatably supported via a deep groove ball bearing (1) on a carrying axle (2). For cost-effective manufacturing of a pressure roller, a standardized deep groove ball bearing (1) that has at least an outer bearing race (6, 7) and balls (9) that roll on the ball grooves (10, 11) of the bearing race (6, 7) is proposed; the outer bearing race (6) of which carries the support sheath. The structural height of the standardized deep groove ball bearing amounts to at maximum 80 percent of the axial extension of the support sheath (5).

Abstract: This invention relates to quinacridone pigments of formula (I) ##STR1## wherein X is O, S, or NR;R is hydrogen, C.sub.1 -C.sub.6 alkyl, C.sub.5 -C.sub.7 cycloalkyl, or C.sub.7 -C.sub.16 aralkyl;Y is C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.6 alkoxy, or halogen;the dashed line represents an optional double bond;R.sup.1 and R.sup.2 are independently hydrogen, C.sub.1 -C.sub.6 alkyl, C.sub.5 -C.sub.7 cycloalkyl, C.sub.6 -C.sub.10 aryl, C.sub.7 -C.sub.16 aralkyl, nitrile, or carboxyl or an ester or an amide thereof, or R.sup.1 and R.sup.2 together form a C.sub.5 -C.sub.8 cycloaliphatic ring or a fused-on aromatic or heteroaromatic ring;R.sup.3 is hydrogen or C.sub.1 -C.sub.6 alkyl; andm is 0, 1, or 2.This invention further relates to the preparation and use of such quinacridone pigments.

Abstract: This invention relates to a process for the preparation of quinacridone pigments comprising(a) heating, at a temperature of about 80.degree. C. to about 145.degree. C., a reaction mixture comprising(i) 2,5-dianilinoterephthalic acid or a 2,5-dianilinoterephthalic acid derivative having one or more substituents in at least one aniline ring,(ii) about 2 to about 10 parts by weight, relative to component (a)(i), of a dehydrating agent, and(iii) about 0.01 to about 10 percent by weight, relative to component (a)(i), of a salt other than an iron salt;(b) drowning the reaction mixture from step (a) by adding said reaction mixture to about 3 to about 15 parts by weight, relative to component (a)(i), of a liquid in which the pigment is substantially insoluble;(c) isolating the quinacridone pigment; and(d) optionally, conditioning the quinacridone pigment.

Abstract: This invention relates to a process for the preparation of quinacridone pigments comprising(a) heating, at a temperature of about 80.degree. C. to about 145.degree. C., a reaction mixture comprising(i) 2,5-dianilinoterephthalic acid or a 2,5-dianilinoterephthalic acid derivative having one or more substituents in at least one aniline ring,(ii) about 2 to about 10 parts by weight, relative to component (i), of a strong acid, and(iii) at least about 0.4 mole percent, relative to component (i), of iron in the form of an iron salt;(b) drowning the reaction mixture from step (a) by adding said reaction mixture to about 3 to about 15 pads by weight, relative to component (i), of a liquid in which the pigment is substantially insoluble;(c) isolating the quinacridone pigment; and(d) optionally, conditioning the quinacridone pigment.