摘要:
A magnetic recording medium comprising a nonmagnetic support having thereon a lower magnetic layer and a upper magnetic layer, in this order, wherein the lower magnetic layer contains as a binder a polyurethane reisn having a number average molecular weight of less than 25,000, and the upper magnetic layer contains as a binder (a) a polyurethane resin having (i) at least three organic groups having an active hydrogen per polyurethane molecule and (ii) a number average molecular weight of 25,000 or more, and (b) a polyisocyanate.
摘要:
A magnetic recording medium comprising a support having provided on one surface thereof a magnetic layer comprising a binder and ferromagnetic particles dispersed therein, and on the opposite surface thereof a backing layer comprising a binder and non-magnetic particles dispersed therein, wherein at least one of the binders comprises a vinyl chloride copolymer resin having a vinyl chloride unit content of about 70 wt % or more based on the total amount of the binder, a nitrogen content of about from 0.01 to 1 wt % based on the total amount of the binder, and a polymerization degree of about from 250 to 700; and the non-magnetic particles comprises fine carbon particles having a DBP oil absorption of about 150 ml/100 g or more.
摘要:
A magnetic recording medium comprising a nonmagnetic support having thereon a magnetic layer comprising ferromagnetic particles dispersed in a binder comprising a mixture of a polycarbonate polyurethane and a phenoxy resin in a weight ratio of from about 1.5:1 to 5:1.
摘要:
The present invention provides a magnetic recording medium having high durability and excellent electromagnetic transfer characteristics and having a lower coating layer, which contains a binder and has high dispersion property and durability. The magnetic recording medium comprises a lower coating layer where non-magnetic powder or ferromagnetic power is dispersed in a binder and an upper magnetic layer where ferromagnetic powder is dispersed in a binder, said two layers being placed on a non-magnetic support member, whereby the binder of the lower coating layer comprises polyurethane resin, which is a reaction product using diol and organic diisocyanate as major materials, the polyurethane resin contains short-chain diol having cyclic structure by 17 to 40 weight %, and the polyurethane resin contains long-chain diol, containing ether groups by 1.0 to 5.0 mmol/g to the entire polyurethane resin, by 10 to 50 weight %.
摘要:
A magnetic recording medium is described, comprising a nonmagnetic support having thereon a magnetic layer containing a binder which is cross-linkable or polymerizable by radiation irradiation and ferromagnetic particles, the ferromagnetic particles being metal or metal alloy particles mainly comprising iron having a crystal size of 300 .ANG. or less, having an atomic ratio of oxygen atoms to iron atoms of from 1.6 to 3.0 on the surface of the particles, and the magnetic layer having been irradiated with radiation, and comprising a nonmagnetic support having thereon a magnetic layer containing a binder comprising thermoplastic resins, thermosetting resins, reactive type resins and mixtures thereof and ferromagnetic particles, said ferromagnetic particles being metal or metal alloy particles mainly comprising iron having a crystal size of 250 .ANG. or less, and having an atomic ratio of oxygen atoms to iron atoms of from 1.6 to 3.0 on the surface of said particles.
摘要:
A magnetic recording medium is disclosed, which comprises a non-magnetic support having a surface roughness of not less than 0.01 .mu.m having thereon an intermediate layer and a magnetic layer, the intermediate layer comprising a polyester polyol having at least two acryloyl and/or methacryloyl groups in the molecule thereof, which has been polymerization-hardened by exposure to radiation. The magnetic recording medium has markedly improved video sensitivity, C/N ratio and adhesiveness between the support and the magnetic layer.
摘要:
A magnetic recording medium comprising a non-magnetic support having provided thereon a magnetic layer comprising a ferromagnetic powder and a binder material, wherein the magnetic layer contains at least a vinyl chloride copolymer binder having at least one polar group selected from --SO.sub.3 M and --COOM, wherein M represents a hydrogen atom, an alkali metal, or an ammonium ion, and at least one epoxy group per molecule in an amount of 1.times.10.sup.-4 to 1.times.10.sup.-2 per gram, and a fatty acid amide having from 12 to 26 atoms and present in an amount of from 0.05 to 2 wt % based on the amount of the ferromagnetic powder, and wherein the content of the polar group in the vinyl chloride copolymer binder is from about 1.times.10.sup.-7 to 1.times.10.sup.-3 equivalent per gram, and wherein the vinyl chloride copolymer binder has a weight average molecular weight of from 20,000 to 100,000 and wherein the magnetic layer further contains a polyurethane resin having a polar group.
摘要:
A magnetic recording medium comprising a non-magnetic support having provided thereon a magnetic layer comprising ferromagnetic metal particles dispersed in a binder, wherein said ferromagnetic metal particles have a crystalline size of 250 .ANG. or less, and said binder comprises(i) a polyurethane resin having an S-containing group which is at least one member selected from the group consisting of --SH, ##STR1## said polyurethane resin being one which has been synthesized by the use of a polyhydric alcohol, as a crosslinking agent, having at least three hydroxyl groups and has a branched and crosslinked structure,(ii) a vinyl chloride resin containing an --OH group and a polar group which is at least one member selected from the group consisting of --SO.sub.3 M, --SO.sub.4 M, --OPO(OM).sub.2, --PO(OM).sub.2, --COOM, --NR.sub.2 and --NR.sub.3.sup..sym. (wherein M represents a hydrogen atom or an alkali metal, and R represents an alkyl group having up to 4 carbon atoms), and(iii) a polyisocyanate compound.
摘要:
A method for preparing a magnetic recording medium is disclosed, comprising the steps of (1) surface-treating ferromagnetic particles with a glycidyl compound having a molecular weight of 1,000 or less and having an epoxy equivalent of 200 g/eq. or less, (2) dispersing the surface-treated ferromagnetic particles with a binder to prepare a magnetic coating composition, (3) coating the resulting magnetic coating composition on a nonmagnetic support, and then (4) drying the magnetic coating composition.
摘要:
A magnetic recording medium is disclosed, which comprises a non-magnetic support having provided thereon a magnetic layer mainly composed of a ferromagnetic powder and a binder resin comprising (i) a polymer having at least one polar group selected from --SO.sub.3 M.sup.1, --OSO.sub.3 M.sup.1, --COOM.sup.1, ##STR1## wherein M.sup.1 represents a hydrogen atom, Li, Na or NR.sub.4 (wherein R represents a hydrogen atom, an alkyl group, an alkenyl group, or an alkanol group), and M.sup.2 represents a hydrogen atom, Li, Na, an alkyl group, or NR.sub.4 (wherein R has the same significance as defined above); or (ii) a compound having at least one polar group selected from --SO.sub.3 M.sup.3, --COOM.sup.3, and --PO.sub.3 (M.sup.3).sub.2 (wherein M.sup.3 represents a hydrogen atom, an alkali metal, or an ammonium group) and containing at least one carbon-carbon unsaturated bond in the molecule, said magnetic layer containing at least one ester compound represented by following formula (I), (II), or (III), and when the binder resin comprises the compound (ii), the magnetic layer is irradiated by radiations: ##STR2## wherein R.sup.1 represents a straight chain or branched alkyl group having from 7 to 29 carbon atoms or a straight chain or branched alkenyl group having from 7 to 29 carbon atoms; l, k, m, and n represents an integer; l and n each is at least 2, and the sum of n and m and the sum of k and l are from 7 to 33.
摘要翻译:公开了一种磁记录介质,其包括其上设置有主要由铁磁粉末和粘合剂树脂构成的磁性层的非磁性载体,所述磁性层包含(i)具有至少一个选自-SO 3 M 1,-OSO 3 M 1, -COOM1,其中M1表示氢原子,Li,Na或NR4(其中R表示氢原子,烷基,烯基或链烷醇基),M2表示氢原子,Li,Na ,烷基或NR4(其中R具有与上述相同的含义); 或(ii)具有选自-SO 3 M 3,-COOM 3和-PO 3(M3)2中的至少一个极性基团的化合物(其中,M3表示氢原子,碱金属或铵基),并且含有至少一个碳 所述磁性层含有至少一种由下式(I),(II)或(III)表示的酯化合物,并且当粘合剂树脂包含化合物(ii)时,磁性层为 (I)其中R1表示具有7至29个碳原子的直链或支链烷基或具有7个碳原子的直链或支链烯基 至29个碳原子; l,k,m,n表示整数; l和n各自为至少2,n和m之和以及k和l之和为7至33。