1. Field of the Invention
This invention relates to magnetic recording media and more particularly, to an improvement in magnetic recording layer media such as used for video tape recorders.
2. Description of the Prior Art
In recent years, there have been introduced onto the market video tape recorders of the long-time picture recording type. The recorders of this type are characterized by a magnetic head of narrow width which provide high recording density of the magnetic recording tape, thus imposing a great load on the magnetic tape.
Also, home video tape recorders have now come into wide use, and small-size, portable video tape recorders are increasing in number. The recording and reproducing system of these apparatus is a so-called helical capstan system using rotary magnetic heads by which a still picture can be reproduced. In the helical capstan system, when a pause mechanism is operated on recording or a still picture is reproduced, the magnetic head alone is allowed to rotate without feeding the magnetic tape, so that the magnetic tape is repeatedly scanned on the same portion. The portable video tape recorder of the just-mentioned type is often used under high temperature and high humidity conditions or at very low temperature in the open. Known magnetic recording tapes are rather unsatisfactory for use under these environmental or climatic conditions for still picture-reproducing or long-time reproducing purposes. Typical known magnetic recording tapes for the video tape recorder are obtained by applying onto a support such as polyester film or the like, magnetic paints which comprise magnetic powders, binders, carbon black and lubricants such as choresterin butyrate, silicone, graphite and molybdenum disulfide. When these tapes are subjected to long-time reproduction or still picture reproduction under high or low temperature conditions, there are encountered problems such as blooming and exudation of the lubricant used, head clogging, and abrasions produced on the tape coupled with rather poor magnetic characteristics.