摘要:
A process for the preparation of finely divided acicular hexagonal ferrites which have a high coercive force and are of the general formula MFe.sub.12 O.sub.19, where M is barium or strontium, and their use for the production of magnetic recording media and plastoferrites.
摘要:
A method of obtaining crystals of a solute in which the fresh solution is initially cooled by contacting with a mother liquor containing crystals below the desired grain size to produce a mother phase in a state of incipient crystallization. The latter is crystallized with or without further cooling by passing it through an elongated crystallizer body with angularly adjoining portions swung around an offset axis and having cooled walls. The resulting slurry is then continuously filtered to separate out the crystals of the required size and form the mother liquor containing particles below the required size.
摘要:
An apparatus for crystallization which utilizes a treating device for the formation of a crystal slurry having a prismatic drum at the inlet end of the device and a zigzag body eccentrically connected to the wide end of the drum and formed by ducts which have their axes intersecting the axis of the drum, the final duct section terminating at a ring which is coaxial with the drum. The duct walls are planar as well. The entire system is closed and includes a filter having a prismatic drum and duct arrangement but with walls which are perforated.
摘要:
A hand-guided apparatus may include an operating lever, a switch, and an intermediate lever. The operating lever may actuate a function of the hand-guided apparatus, be constructed in an elongated manner and be pivotably attached to a housing of the apparatus. The switch actuates the function and is arranged in the housing. The intermediate lever mechanically actuates the switch. The operating lever includes a safety element enabled to be pretensioned and shifted along a longitudinal axis of the operating lever. The operating lever and the intermediate lever are enabled to be mechanically coupled by shifting the safety element into a pretensioned state to enable actuation of the switch by pivoting of the operating lever. The operating lever and the intermediate lever are enabled to be mechanically decoupled by shifting the safety element into a relaxed state to prevent actuation of the switch by pivoting of the operating lever.
摘要:
A multilayered composite material comprises as components: (A) a sheet material, (B) a material capable of absorbing water or aqueous fluids, (C) at least one bonding layer and (D) a polyurethane layer with capillaries passing through the entire thickness of the polyurethane layer, wherein the polyurethane layer (D) comes into direct contact with sheet material (A) or absorption-capable material (B) in one or more places.
摘要:
Process for the continuously operated purification by distillation of the methanol used as solvent in the synthesis of propylene oxide by reaction of a hydroperoxide with propylene, with the methoxypropanols being separated off simultaneously, wherein the solvent mixture obtained in the synthesis is separated in a dividing wall column into a low-boiling fraction including methanol, an intermediate-boiling fraction containing the methoxypropanols as azeotrope with water and a high-boiling fraction including water and propylene glycol.
摘要:
An organic compound having at least one C—C double bond is epoxidized by means of hydrogen peroxide in the presence of at least one catalytically active compound and at least one solvent, wherein a product mixture comprising α-hydroperoxyalcohols is reduced using at least one reducing agent. The process advantageously comprises at least the following steps: (i) reacting an organic compound having at least one C—C double bond with hydrogen peroxide in the presence of at least one catalytically active compound and at least one solvent to give a product mixture P1 comprising α-hydroperoxyalcohols; (ii) separating an epoxide formed in the reaction in step (i) and the unreacted organic compound having at least one C—C double bond from P1 or P1′ to give a product mixture P2 or P2′, where P2 comprises the α-hydroperoxyalcohols formed as by-product in the reaction in step (i) and P2′ is largely free of α-hydroperoxyalcohols; (iii) treating P1 and/or P2 with at least one reducing agent so that the α-hydroperoxyalcohols are converted into corresponding glycols to give a product mixture P1′ or P3.
摘要:
Magnetic recording media consist of a nonmagnetic substrate and at least one magnetizable layer bonded thereon and based on a magnetic material dispersed in at least one polyurethane and one polyurethaneurea (meth)acrylate, the polyurethaneurea (meth)acrylate being obtained by reacting a hydroxyl-containing poly(meth)acrylate with a mixture of di- and polyisocyanates and converting the remaining NCO groups with ammonia or primary or secondary amines into urea groups.
摘要:
According to the process the sludge is homogenized and heated to 30.degree.-60.degree. C. temperature. The heated sludge is circulated under 2-4 bar overpressure, and its temperature is raised to about 130.degree.-150.degree. C. in 1-2 sec by conducting steam of 130.degree.-151.degree. C. and 2-4 bar pressure directly into the sludge, thus granulation is brought about in the sludge. The sludge of increased temperature--while its temperature and pressure maintained--is further circulated for about 60-300 sec. Then, the sludge is adiabatically expanded in 1-2 sec by reducing the pressure to about 0.01-0.02 bar. The expanded sludge is separated to water, fat containing water and solid impurity and wet solid phase containing protein.It is characteristic to the apparatus that it is provided with device for heating the sludge, and pipe (18) for passing on the heated sludge connected with the heating unit (5) where an expansion valve is built in. Pipe (22) joining the separating tank (7) is connected with the expansion valve (6). The apparatus is provided with separator for separation of the sludge leaving the tank (7) to water, fat and solid phase.