Abstract: A process for preparing a toner comprising the steps of (1) pulverizing a pulverized product of a composition comprising a resin binder and a colorant with a jet type pulverizer in the presence of fine inorganic oxide particles, to give an upper limit cut-off classification powder; and (2) classifying the upper limit cut-off classification powder with a classifier, the classifier comprising a classifying rotor comprising a driving shaft arranged in one casing as a central shaft thereof in a vertical direction, and a stationary spiral guiding vane arranged to share the same central shaft as the classifying rotor, wherein the stationary spiral guiding vane is arranged in a classification zone on an outer circumference of the classifying rotor with a given spacing to the outer circumference of the classifying rotor.

Abstract: A process for preparing a toner comprising the steps of (1) pulverizing a pulverized product of a composition comprising a resin binder and a colorant with a jet type pulverizer in the presence of fine inorganic oxide particles, to give an upper limit cut-off classification powder; and (2) classifying the upper limit cut-off classification powder with a classifier, the classifier comprising a classifying rotor comprising a driving shaft arranged in one casing as a central shaft thereof in a vertical direction, and a stationary spiral guiding vane arranged to share the same central shaft as the classifying rotor, wherein the stationary spiral guiding vane is arranged in a classification zone on an outer circumference of the classifying rotor with a given spacing to the outer circumference of the classifying rotor.

Abstract: A process for the production of dihydric phenoles by oxidizing diisopropylbenzenes, which comprises oxidizing diisopropylbenzenes with molecular oxygen to obtain a reaction product mixture (A) containing at least diisopropylbenzene dihydroperoxide (DHP) and diisopropylbenzene monocarbinol monohydroperoxide (HHP), supply said product mixture (A) in a form of oily phase as a solution in an aromatic hydrocarbon solvent to an agitation reactor, supplying thereto at the same time, as an aqueous phase, hydrogen peroxide at a feed rate of 1-5 moles per mole of HHP contained in the product mixture and an acid catalyst in an amount sufficient to reach a concentration in the aqueous phase of 10-40% by weight, the concentration of hydrogen peroxide in the aqueous phase being maintained at a value of at least 20% by weight and the weight ratio of the oily phase/aqueous phase being at least 10, causing oxidization of the HHP into DHP by hydrogen peroxide while maintaining the reaction temperature at 30.degree.-60.degree.

Abstract: An improved process for preparing an impact-resistant chemically blended propylene polymer or copolymer, which comprises the following three steps:(1) a first step of polymerizing propylene containing 0 to 1 mole% of another olefin in the presence of a catalyst composed of (a) a carrier-supported titanium catalyst component containing at least magnesium, halogen and titanium on the surface of the carrier and (b) an organo aluminum compound to form specific crystalline polypropylene;(2) a second step of copolymerizing propylene and ethylene in the presence of the reaction product of the first step and the same catalyst while maintaining the content of propylene in the gaseous phase of the polymerization zone at 65 to 90 mole% thereby to form specific low-crystalline propylene/ethylene copolymer; and(3) a third step of polymerizing ethlene, or both ethylene and propylene in the presence of the reaction product of the second step and the same catalyst while maintaining the content of propylene in the gaseous pha