Abstract: A magnetic recording medium is disclosed. The medium is comprised of a non-magnetic support having coated thereon a magnetic recording layer and a backing layer on the surface opposite the magnetic recording layer. The backing layer contains carbon black and the surface treated calcium carbonate dispersed in a binder. The calcium carbonate is surface treated so as to make the particles hydrophobic. Including the carbon black and the calcium carbonate in the backing layer provides a recording medium with improved durability and a reduced amount of drop out.

Abstract: A magnetic recording medium includes a substrate, a magnetic layer and a subbing layer therebetween. The subbing layer includes tin oxide type powders having a mean particle size not higher than 0.8 micron. S/N ratio is improved.

Abstract: 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.

Abstract: 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.

Abstract: A magnetic recording medium is described comprising a magnetic layer on one surface of a non-magnetic base and a back coating on the other surface of the base, said back coating being not more than 2.mu. thick and which contains an inorganic powder and a binder, said inorganic powder consisting of fine particles of an average size of from 0.01 to 0.1.mu. and coarse particles of an average size of from 0.1 to 0.8.mu..

Abstract: A magnetic recording medium comprising a nonmagnetic flexible substrate, a magnetic layer provided on the surface of the substrate and containing ferromagnetic grains dispersed in a binder, and a back layer provided on the back surface of the substrate. The magnetic recording medium has a stiffness (S.sub.TD) of 6.0 or less. The friction coefficient (.mu..sub.B) of the back layer surface with respect to the axial direction of a loading post in a video tape recorder is controlled to satisfy the condition:0.ltoreq..mu..sub.B .ltoreq.0.1S.sub.TD -0.05so as to make the magnetic recording medium highly resistant to damage due to movement in a video tape recorder.

Abstract: A magnetic recording medium comprising a magnetic layer on one surface of a non-magnetic base and a back coating on the other surface thereof which is not thicker than 2.mu. and which contains inorganic particles and a binder is disclosed. The inorganic particles have an average size between 0.02 and 5.mu. and a Mohs hardness of 2.5 to 9.0, and the surface of the back coating has a center line average roughness (Ra) of 0.024 or less and the surface of the magnetic layer has a center line average roughness (Ra) of 0.02.

Abstract: A magnetic recording medium having a magnetic layer on one surface of a nonmagnetic base and a back coating on the opposite surface is disclosed. An undercoat is formed between the nonmagnetic base and the back coating and the back coating is not thicker than 2.mu..

Abstract: A magnetic recording medium is disclosed which is comprised of a nonmagnetic support base having a magnetic layer disposed on one surface. A back coating is disposed on the opposite surface of the support base in order to provide the magnetic recording medium with greater durability without increasing the coefficient of friction. The back coating is comprised of a binder having inorganic particles dispersed therein, the inorganic particles including SnO.sub.2 particles having an average size of about 0.01 to about 0.8.mu.. The back coating does not reduce the S/N ratio of the recording medium.

Abstract: A magnetic recording medium having a magnetic layer and a backing layer on opposite sides of a support is disclosed. The backing layer comprises an inorganic filler dispersed in a binder wherein the binder comprises one or more cellulosic resins, one or more thermoplastic polyurethane elastomers and one or more polyisocyanates.

Abstract: A process for preparing bis(hydroxyethyl)terephthalate and its low molecular weight oligomers in a reactor equipped with a rectifying column which comprises suspending or dissolving terephthalic acid in molten bis(hydroxyethyl)terephthalate and its low molecular weight oligomers at a temperature above the dew point of ethylene glycol and feeding gaseous or liquid ethylene glycol into the suspension or the solution to react it with the terephthalic acid, where the amount of ethylene glycol fed into the reactor is controlled so as to maintain the temperature inside the rectifying column at a temperature at which the ethylene glycol does not substantially distill off from the rectifying column and the partial pressure of the ethylene glycol is maximized.