Kawamata, Toshio; Hayakawa, Satoru; Endo, Yasushi;

Magnetic recording disk

A magnetic recording disk having a good overwriting characteristic and an excellent electromagnetic characteristic, as well as superior running durability. The magnetic recording disk comprises a non-magnetic support having coated thereon, in the order, a non-magnetic layer comprising mainly a non-magnetic powder and a binder resin and a magnetic layer comprising mainly a ferromagnetic powder and a binder resin, wherein the magnetic layer is formed by applying a magnetic layer coating solution onto the coated non-magnetic layer while the non-magnetic layer remains in a wet condition, the average thickness of the magnetic layer is 0.5 .mu.m or less, and the maximum thickness and the minimum thickness thereof fall within the range of .+-.15% of the average thickness of the magnetic layer.

• 5,6-dihydro-4H-imidazo[4,5,1-ij]quinolines Safety suction valve
• Collets Paint box and easel combination
• Focus condition detecting device Cephalosporin antibiotics
• Jack assembly & panel system Shampoo compositions containing beer solids
• Interfacially synthesized reverse osmosis membrane Pilfer-resistant peg hook assembly
• Closure device in motor vehicles Evaporator coil heat exchanger assembly
• Riser buoyancy system Additive product dispensing apparatus
• Conveying apparatus Disc brakes for vehicles
• Stretching device for furniture Transmission shifter with park lock
• Pallet container Silyl-linked polyamidoamines and their preparation
• Post mount Composite-to-metal shaft joint
• Electrophotographic image forming apparatus Aminoacyllabdanes
• Vehicle suspension assembly Millimeter wave multilayer assembly
• Kinetic treatment platform Medical lithotripsy work station
• Beverage dispenser Rotary press
• Pneumatically-operated liquid slug projector apparatus Process for preparing ester plasticizers
• Deburring tool with cutting blade Automobile body structure
• Therapeutic nucleosides Torque measurement apparatus
• Heat exchanger assembly Corynebacterial stress proteins
• Packaging machine Aminoplast-anchored ultraviolet light stabilizers
• Vehicle article carrier Hydraulic brake booster
• Force and torque converter Shaft seal
• Low-force transducer Fluorescent display apparatus
• Portable cement mixer

What is claimed is:

1. A magnetic recording disk comprising a non-magnetic support having coated thereon, in the following order, a non-magnetic layer comprising mainly a non-magnetic powder and a binder resin and a magnetic layer comprising mainly a ferromagnetic powder and a binder resin, wherein the non-magnetic layer is formed by applying a non-magnetic coating solution containing a first solvent onto the non-magnetic support, the magnetic layer is formed by applying a magnetic layer coating solution containing a second solvent onto the coated non-magnetic layer while the non-magnetic layer remains in a wet condition, the first solvent for the non-magnetic coating solution has a boiling point higher than that of the second solvent for the magnetic layer is 0.01 to 0.5 .mu.m, and the maximum thickness and the minimum thickness of the magnetic layer fall within the range of .+-.15% of the average thickness of the magnetic layer.

2. The magnetic recording disk as in claim 1, wherein at least a part of the non-magnetic powder is an electroconductive powder.

3. The magnetic recording disk as in claim 1, wherein the ferromagnetic powder is a ferromagnetic metal powder or a hexagonal series ferrite powder.

4. The magnetic recording disk as in claim 1, wherein the magnetic recording disk has a surface electric resistance of 5.times.10.sup.9 .OMEGA./sq or less.

5. The magnetic recording disk as in claim 1, wherein the first solvent has a boiling point of 90.degree. C. or more, the second solvent has a boiling point 100.degree. C. or less, and the difference in boiling point between the first solvent and the second solvent is 40.degree. C. or more.

6. The magnetic recording disk as in claim 2, wherein the electroconductive powder is carbon black.