摘要:
The perpendicular magnetic orientation of a magnetic layer containing platelet-form ferromagnetic particles coated on a web support is effectively performed by passing a web having thereon the coated magnetic layer in an undried state through a magnetic field formed by plural pairs of opposite pole type magnets disposed in the travelling direction of the web with a gap between adjacent pairs of magnets, while supplying drying air through each gap onto the surface of the travelling web to substantially complete the drying of the coated layer while the web is in the magnetic field. A partition may be inserted in each gap so that the lower end of the partition is close to the upper surface of the travelling web to divide the gap into a front section and a back section, and the drying air may be passed through these sections.
摘要:
A magnetic recording medium which comprises a non-magnetic support having thereon a magnetic layer containing plate-shaped magnetic particles which have axes of easy magnetization perpendicular to their respective plate planes dispersed in a binder, the magnetic particles each having a multiple magnetic domain structure and having a particle diameter equal to or longer than the recorded effective shortest wavelength.
摘要:
A magnetic recording medium is described having formed on a non-magnetic base at least two magnetic layers, each of the magnetic layers comprising ferromagnetic particles dispersed in a binder, wherein the ferromagnetic particles in the outermost layer have an average length of 0.3.mu. or less and a length to width ratio of greater than 1/1 but not greater than 3/1, and the ferromagnetic particles in an underlying layer have a length to width ratio of more than 3/1.
摘要:
A magnetic recording material having superior abrasion resistance and thermal stability is produced by coating a magnetic coating composition consisting essentially of aqueous emulsions of at least two resin binders capable of reacting with each other upon mixing, and being present therein in the separated state, and a ferromagnetic powder on a non-magnetic support, drying the coating, and curing the resulting magnetic recording layer where drying is insufficient to effect curing. Hazards ascribable to the use of organic solvents in conventional techniques can be obviated by this invention.
摘要:
A magnetic iron oxide having a large coercive force and an improved squareness ratio prepared by coating the surface of needle-like particles of magnetic iron oxide with a cobalt compound, placing the coated iron oxide particles in a unidirectionally oriented magnetic field thereby orienting the particles in the direction of the magnetic field, and heat-treating the needle-like particles in this state with the application of an external magnetic field, or heat-treating the needle-like particles in a magnetized state.
摘要:
In a magnetic recording medium comprising a non-magnetic support and two or more magnetic recording layers containing ferromagnetic particles dispersed in a non-magnetic binder, the ferromagnetic particles of the outermost magnetic layer are given a main magnetic anisotropy by a magnetic annealing treatment and the direction of the magnetic anisotropy is vertical to the recording surface. Thus, the vertical magnetization recording is improved.
摘要:
A magnetic recording medium which is characterized by a lubricant present in channels diagonally extending through a magnetic metal thin film having a columnar structure formed by vapor deposition; this medium possesses improved running properties and abrasion resistance which last for an extended period of time.
摘要:
A magnetic recording medium is described having formed on a non-magnetic base at least two magnetic layers, each of the magnetic layers comprising ferromagnetic particles dispersed in a binder, wherein the ferromagnetic particles in the outermost magnetic layer are substantially cubic particles and have a side length of 0.3.mu. or less, and the ferromagnetic particles in an underlying magnetic layer are acicular particles.
摘要:
A magnetic recording medium comprising a substrate, a thin magnetic metal film having spaced-apart columnar grains deposited on the substrate, and a crosslinked organic polymer formed from a polymerizable organic compound and a curing agent in the spaces between the columnar grains and integrated therewith. The medium is prepared by impregnating the spaces between the columnar grains with a polymerizable organic compound and a curing agent and curing them in the spaces by the crosslinking reaction.
摘要:
A magnetic recording medium is described comprising a first layer comprising a magnetic iron oxide powder dispersed in a binder formed on a nonmagnetic support, a second layer formed on the first layer comprising a ferromagnetic metal powder dispersed in a binder, and having a greater coercive force than the first layer, and a third layer comprising a thin ferromagnetic metal film formed on the second layer in a thickness of from 0.01.mu. to 0.5.mu..