摘要:
A method for preparing a magnetic recording medium is described, comprising (1) pre-dispersing ferromagnetic particles having an S.sub.BET specific surface area of 35 m.sup.2 /g or more and having an adjusted water content of 0.8 wt % or more with a binder, (2) adding an additional binder and a lubricating agent thereinto, mixing and dispersing them to prepare a diserpsion of a magnetic coating composition, and (3) coating the resulting dispersion of a magnetic coating composition on a non-magnetic support.
摘要:
A magnetic recording medium is described, comprising a non-magnetic support having coated thereon on opposite surfaces a magnetic layer containing a magnetic substance and a binder-containing backing layer, wherein the magnetic layer has a light transmittance of 2% or more for light having a wavelength of 900 nm, the backing layer has a transmittance of from 1 to 10% for light having a wavelength of 900 nm, the magnetic recording medium as a whole has a transmittance of 1% or less for light having a wavelength of 900 nm, and the backing layer has a center line average roughness (Ra) of 0.05 .mu.m or less at a cut-off value of 0.08 mm.
摘要:
A magnetic recording medium which comprises a non-magnetic support having on the surface side thereof a magnetic recording layer and on the opposite side thereof a backing layer having a thickness of 2 .mu.m or less, which contains carbon black and a binder and optionally, an inorganic powder, in which the backing layer contains at least two kinds of carbon black, one being fine-grained carbon black having a mean grain size of 10 to 30 m.mu. and the other being coarse-grained carbon black having a mean grain size of 150 to 500 m.mu. such that the weight ratio (P/B) of the total amount of carbon black and inorganic powder (P) to binder (B) is from about 1/0.5 to 1/3.5. The recording medium described provided smooth and stable tape-running for an extended period and a high S/N ratio.
摘要:
A magnetic coating composition comprising a binder dissolved in a solvent and magnetic grains dispersed therein is applied onto a surface of a non-magnetic substrate continuously moved. The coating film thus overlaid on the non-magnetic substrate is subjected to a preliminary orientation step for orientating the magnetic grains in the coating film, and then to a preliminary drying step. A final orientation step is then conducted while intermediate drying is carried out. Thereafter, final drying is effected.
摘要:
A magnetic recording medium which comprises a non-magnetic support having on the surface side thereof a magnetic recording layer and on the opposite side thereof a backing layer is disclosed. The backing layer contains carbon black and a binder and has a thickness of 2 .mu.m or less. The carbon black is composed of fine-grained carbon black having a mean grain size of 10 to 30 m.mu. and coarse-grained carbon black having a mean grain size of 100 to 150 m.mu.. In the backing layer the ratio of the content of carbon black to the binder ranges from 1:0.5 to 1:3.5 by weight.
摘要:
A magnetic recording medium is disclosed. The medium comprises a non-magnetic support having provided on opposite surfaces a magnetic recording layer and a backing layer containing two types of carbon black and a binder and having a thickness of 2 .mu.m or less, one of said carbon black being fine carbon black having an average particle size of 30 to 100 m.mu. and the other of said carbon black being coarse carbon black having an average particle size of 150 to 500 m.mu., and the mixing weight ratio of said carbon black and the binder being 1:1.5 to 1:3.5.
摘要:
A magnetic recording medium including a nonmagnetic support having a magnetic layer on one side thereof and a backing layer on the opposite side thereof, said backing layer comprising a fatty acid having 12 or more carbon atoms and copper or copper ions. Fatty acid is saturated or unsaturated, and copper is 0.2 micron or less in size.
摘要:
A magnetic recording medium comprising a non-magnetic support having coated thereon a magnetic layer, the magnetic layer containing (i) ferromagnetic alloy particles having an average length in the long axis of 0.25 .mu.m or less and (ii) fatty acid components comprising behenic acid in an amount of 20 to 75 wt%, stearic acid in an amount of 10 to 45 wt% and oleic acid in an amount of 10 to 45 wt% based on the total weight of the three fatty acids.
摘要:
A magnetic recording medium is disclosed. The medium is comprised of a non-magnetic flexible support having a subbing layer coated thereon with a magnetic layer coated on the subbing layer. The subbing layer is comprised of a copolymer of a diolefin and a vinyl monomer. The subbing layer provides excellent adhesiveness between the support and the magnetic layer and can be produced without the use of organic solvents. Accordingly, the subbing layer can be economically produced without environmental pollution.
摘要:
A magnetic recording medium is disclosed. The medium is comprised of a support base having position thereon a subbing layer and a magnetic layer. The subbing layer is comprised of an amorphous saturated polyester having a glass transition temperature of 10.degree. C. to 60.degree. C. The recording medium provided has excellent adhesiveness between the magnetic layer and the support due to the presence of the subbing layer. Furthermore, the resulting magnetic recording medium provides excellent electromagnetic characteristics such as a desirable video S/N ratio.