Abstract: An apparatus for controlling a strip tension during flexible rolling of metal strip comprises a roll arrangement with at least one dancer roll, the position of said dancer roll being adjustable for controlling the strip tension of the metal strip, at least one hydraulic drive coupled to the dancer roll for adjusting the dancer roll, a hydraulic tank for hydraulic fluid, which is fluidly connected to the hydraulic drive via a hydraulic supply line, a controllable valve arrangement between the hydraulic tank and the hydraulic drive for controlling the hydraulic drive, a hydraulic pump with which the hydraulic drive is supplied with hydraulic fluid from the hydraulic tank, and at least one hydraulic pressure accumulator for temporarily storing hydraulic fluid previously delivered by the hydraulic pump, the hydraulic pressure accumulator being arranged between the hydraulic pump and the valve arrangement, wherein a pressure sensor is arranged in the hydraulic drive for determining the hydraulic pressure.

Abstract: An apparatus for controlling a strip tension during flexible rolling of metal strip comprises a roll arrangement with at least one dancer roll, the position of said dancer roll being adjustable for controlling the strip tension of the metal strip, at least one hydraulic drive coupled to the dancer roll for adjusting the dancer roll, a hydraulic tank for hydraulic fluid, which is fluidly connected to the hydraulic drive via a hydraulic supply line, a controllable valve arrangement between the hydraulic tank and the hydraulic drive for controlling the hydraulic drive, a hydraulic pump with which the hydraulic drive is supplied with hydraulic fluid from the hydraulic tank, and at least one hydraulic pressure accumulator for temporarily storing hydraulic fluid previously delivered by the hydraulic pump, the hydraulic pressure accumulator being arranged between the hydraulic pump and the valve arrangement, wherein a pressure sensor is arranged in the hydraulic drive for determining the hydraulic pressure.

Abstract: The present invention provides a process for preparing transparent perylimide pigments of the formula (I): in which u is a number from 0 to 8 and, if u>0, E is a chlorine or bromine atom and, where u>1, may be a combination thereof, which comprises wet-grinding a crude perylimide pigment in a liquid medium in a stirred ballmill operated at a power density of from 1.0 kW per liter of milling space and at a stirrer tip speed of more than 12 m/s under the action of grinding media having a diameter of less than or equal to 0.9 mm, and isolating the resulting pigment.

Abstract: The present invention provides a process for preparing transparent perylimide pigments of the formula (I) 1

Abstract: The present invention provides a process for preparing transparent perylimide pigments of the formula (I) in which u is a number from 0 to 8 and, if u>0, E is a chlorine or bromine atom and, where u>1, may be a combination thereof, which comprises wet-grinding a crude perylimide pigment in a liquid medium in a stirred ballmill operated at a power density of from 1.0 kW per liter of milling space and at a stirrer tip speed of more than 12 m/s under the action of grinding media having a diameter of less than or equal to 0.9 mm, and isolating the resulting pigment.

Abstract: The present invention provides a process for preparing transparent perylimide pigments of the formula (I) 1

Abstract: Process for the preparation of pigment preparations, which comprises wet milling the crude pigments which are present in coarsely crystalline state, or prepigments or pigments which are present in a form in which they are difficult to disperse, in a concentration of from 20 to 60% by weight based on the total weight of the pigment preparation, in a flocculation-stable liquid medium and in a stirred ball mill which is operated with a peripheral stirrer speed of more than 12 m/s, under the action of nonmetallic grinding media with a diameter of less than or equal to 1.0 mm, until the desired degree of fine division is reached, and then isolating the pigment preparation.

Abstract: A process for preparing quinacridone pigmentsA process for preparing pigments, mixed crystal pigments and pigment preparations based on linear unsubstituted or substituted quinacridones of the formula (I) ##STR1## in which the substituents R.sup.1 and R.sup.2 are identical or different and are hydrogen, chlorine, bromine or fluorine atoms or are C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy or carboxamido groups which may be substituted by C.sub.1 -C.sub.6 -alkyl groups; or are phenoxy or C.sub.6 -C.sub.10 -aryl rings onto which further aromatic, aliphatic or heterocyclic rings can be fused, which process comprises hydrolyzing the reaction mixture resulting from cyclization of the respective dianilinoterephthalic acid with polyphosphoric acid or polyphosphate at a temperature of or above 110.degree. C.